JP2562877B2 - Flame retardant composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flame-retardant composition having low pollution and excellent mechanical strength and electrical properties.

[Problems requiring conventional technology and solutions]

As an insulating coating material for electric wires that are wired inside electronic devices such as personal computers, electronic musical instruments, and microwave ovens, electric wires for vehicles, or electric wires for ships, it withstands wiring work and normal operation under severe conditions Thus, a flame-retardant electrically insulating composition having high mechanical strength and good electrical properties at high temperatures is required.

In addition, conventional compositions flame-retarded by using a halogen-based flame retardant have a problem that a large amount of harmful halogen-containing gas is generated by combustion, and thus they are halogen-free, in other words, low-pollution. There is a strong demand for a flame-retardant composition that is volatile.

On the other hand, recently, aluminum hydroxide was used as a flame retardant, and it was used as a copolymer of ethylene and an α-olefin having 4 to 8 carbon atoms (hereinafter, the polymer is poly-α.
-A flame-retardant composition prepared by adding a large amount of olefin). However, the composition of such a proposal has a problem that it is inferior in electrical properties, particularly electrical properties and mechanical properties at high temperature, and flame retardancy is not always sufficient due to a large amount of aluminum hydroxide compounded.

[Means for Solving Problems] By the way, in the course of the basic research on the flame retardance of the composition of the present inventors, magnesium hydroxide instead of aluminum hydroxide as a flame retardant, red phosphorus, carbon It was found that the use of black unexpectedly yields a flame-retardant electrically insulating composition having excellent mechanical strength and electrical properties at high temperatures. Thus, the present invention provides a co-aggregate of ethylene having a density of 0.85 to 0.89 and a melt index (MI) of 1 to 10 and an α-olefin having 4 to 8 carbon atoms, magnesium hydroxide, red phosphorus and carbon. It relates to a flame-retardant composition comprising black.

[Action]

As described above, a flame retardant electrical insulating material having high mechanical strength and good electrical properties is obtained by using the above-mentioned one instead of aluminum hydroxide as a flame retardant and mixing it with poly-α-olefin. A composition is obtained. Further, among various poly-α-olefins, those having the above-mentioned density and melt index provide a composition having particularly excellent mechanical strength and electrical properties even when a large amount of magnesium hydroxide is compounded. .

Moreover, since the composition of the present invention employs a non-halogen type flame retardant, it is halogen-free unless other chemicals containing halogen are compounded, and therefore, even if it burns, it does not contain halogen-containing gas. It does not cause any pollution.

The poly-α-olefin used in the present invention is a copolymer of ethylene and an α-olefin having 4 to 8 carbon atoms, and particularly has a density of 0.85 to 0.89 and a melt index of 1 to 10. Is used. The poly-α-olefin can be produced by polymerizing at least one α-olefin having 4 to 8 carbon atoms and ethylene in the presence of a Ziegler catalyst. Examples of commercially available products include Tuffmer A-4090 and Tuffmer A-4085 (both manufactured by Mitsui Petrochemical Co., Ltd.). When the density is out of the range of 0.85 to 0.89, it is difficult to obtain a composition having a satisfactory mechanical strength, and when the melt index is less than 1, the extrudability is high and the melt index is low.
Those having a value of more than 10 have a problem in use in the present invention because they have a reduced mechanical strength. Therefore, the density as a poly-α-olefin is 0.85-0.89, the melt index is 1-10, especially the density is 0.88-0.89.
And those having a melt index of 2 to 5 are preferred.

A commercially available product may be used as the magnesium hydroxide used as a flame retardant for poly-α-olefins instead of the conventionally used aluminum hydroxide, but the average particle size is 5 μm.
Those having an average particle diameter of 2 μm or less, particularly those having an average particle diameter of 2 μm or less are preferable.

Among commercially available products, Kisuma 5B manufactured by Kyowa Chemical Industry Co., Ltd. and the like are preferable.

As the red phosphorus used in the present invention, those commercially available in the past can be widely used. For example, the red phosphorus component is 80% by weight or more, the loss on drying is 0.8% by weight or less and the 74 mesh sieve residue. Those having a content of 7% by weight or less are preferable. It is also preferable that the surface of the above red phosphorus is coated with a thermosetting resin such as phenol-formalin resin. Specific examples thereof include Novarred # 120 and Novared # 120UF (both manufactured by Rin Kagaku Kogyo Co., Ltd.).

In the present invention, metal oxides such as antimony trioxide, antimony pentoxide, antimony dioxide, zinc oxide, magnesium oxide and aluminum oxide, or other inorganic flame retardants such as zinc borate and magnesium carbonate are used. You may use together with magnesium hydroxide in the range which is not a large amount.

The amount of magnesium hydroxide used is 50 to 200 parts by weight per 100 parts by weight of poly-α-olefin. When the amount of magnesium hydroxide used is less than 50 parts by weight, a composition having both good mechanical strength and flame retardancy cannot be obtained, while when the amount of magnesium hydroxide used is more than 200 parts by weight, the composition is The mechanical properties and workability of the product deteriorate. Therefore, the preferred amount of magnesium hydroxide is 50 to 180 parts by weight, particularly 80 to 150 parts by weight, per 100 parts by weight of poly-α-olefin.
Parts by weight.

The composition of the present invention may be used without being crosslinked or after being crosslinked. The cross-linking is t-butyl cumyl peroxide,
Di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy)
Cross-linking using an organic peroxide cross-linking agent such as hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,3-bis (t-butylperoxy-isopropyl) benzene It can be crosslinked by a method, irradiation crosslinking method or the like. At that time, in order to increase the processing efficiency, it is preferable to use an appropriate crosslinking aid depending on the crosslinking method. Preferred cross-linking aids in the cross-linking method using an organic peroxide cross-linking agent and the irradiation cross-linking method include aliphatic or aromatic polyfunctional compounds, aliphatic polyfunctional cyclic compounds, and nitrogen-containing polyfunctional cyclic compounds. , Metal-containing polyfunctional compounds, especially nitrogen-containing polyfunctional cyclic compounds, especially triallyl isocyanurate (TAIC), trimetaallyl isocyanurate (TMAI)
C), triallyl cyanurate (TAC), triacroylhexahydro-1,3,5-triazine (TAF) and the like.

The amount of the crosslinking aid used is 0.1 to 5 parts by weight, particularly 0.5 to 2 parts by weight, per 100 parts by weight of the poly-α-olefin.

In the composition of the present invention, carbon black is further added, and if necessary, ordinary fillers such as inorganic fillers such as clay, talc and calcium carbonate, antioxidants, coupling agents, processing aids and pigments are added. It does not matter even if the usual amount is blended.

[Effects] Electric wires, electric wires for vehicles, or electric wires for ships, which are wired inside electronic devices such as personal computers, electronic musical instruments, and microwave ovens, are narrowly wired and used in parts inside the device such as mazes. In many cases, it is subject to strong ironing, and after wiring, there is a danger of fire due to the high temperature conditions. On the other hand, since the composition of the present invention has excellent electrical characteristics, mechanical strength, and flame retardancy, it is an insulating coating material for electric wires such as mechanical wiring, electric wires for vehicles, or electric wires for ships. It is very useful as

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Examples 1 and 2 and Comparative Examples 1 to 6 The compositions (composition ratio are parts by weight) of various Examples and Comparative Examples shown in Table 1 were kneaded with two rolls, and then press molded at 150 ° C. for 10 minutes. Was processed into a sheet with a thickness of 1 mm or 3 mm. The following tests were performed on each sheet.

Flame retardance: Oxygen index is measured by the method specified in JIS K7201.

Mechanical strength: Measured by the method specified in JIS K6723.

 The above test results are shown in Table 1.

Examples 3 to 4 and Comparative Examples 7 to 12 The compositions of various Examples and Comparative Examples shown in Table 2 were kneaded by a two-roll mill, and then press-crosslinked at 180 ° C. for 30 minutes to give a thickness of 1 mm or 3 mm. Processed into a cross-linked sheet. The same test as described above was performed for each crosslinked sheet.

The above test results are shown in Table 2. The contents of the notes in Tables 1 and 2 are as follows.

Note 1: Mitsui Petrochemical Co., Tuffmer A-4090 Density: 0.89 g / cm ² , MI: 3.6 Note 2: Mitsui Petrochemical Co., Tuffmer A-4085 Density: 0.88 g / cm ² , MI: 3.6 Note 3 : Showa Light Metal Co., Ltd., Heidilite H42M Note 4: Kyowa Chemical Industry Co., Kisuma 5B Note 5: Phosphorus Chemical Co., No Barred # 120 Note 6: Ouchi Shinko Chemical Industry Co., Nocrac 300 Note 7: Mitsubishi Kasei Kogyo Co., Ltd., Diamond Black H Note 8: Kayaku Nouri Co., Kayabutyl C Note 9: TAIC

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Fuchimoto 8 Nishino-cho, Higashimukaijima, Amagasaki City Tomoki Nagasaka, Judge Chief of the Board of Directors, Dainichi Nippon Electric Co. References JP-A-61-34036 (JP, A) JP-A-62-199638 (JP, A) JP-A-61-254647 (JP, A) JP-B 1-229502 (JP, B2) JP-B 5- 17934 (JP, B2)

Claims (1)

(57) [Claims] 1. A density of 0.85 to 0.89 and a melt index of 1
A flame-retardant composition comprising a copolymer of ethylene of 10 to 10 and an α-olefin having 4 to 8 carbon atoms, magnesium hydroxide, red phosphorus and carbon black.