JP3210411B2 - Flame retardant resin composition - Google Patents

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 having excellent scratch resistance and abrasion resistance, and more particularly to a flame-retardant resin composition useful as a wire covering material.

[0002]

2. Description of the Related Art Heretofore, as a flame-retardant resin composition having the advantage of not generating a toxic gas during combustion like a halogen-containing composition, a hydrated metal oxide as a flame-retardant filler has been added to a polyolefin base polymer. A so-called non-halogen resin composition mixed in an appropriate amount is used. However, in order to make the composition flame-retardant to such an extent that the composition has self-extinguishing properties, it is necessary to incorporate a large amount of hydrated metal oxide, and such a composition requires mechanical resistance such as trauma resistance and abrasion resistance. There was a problem that the strength was brittle and it was unsuitable for applications such as wire covering materials.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a non-halogen non-halogen which has excellent flame retardancy and excellent mechanical strength such as trauma resistance and abrasion resistance, and is suitable for use in wire coating materials and the like. It is an object to provide a flame-retardant resin composition.

[0004]

The flame-retardant resin composition of the present invention comprises an ethylene-methyl acrylate copolymer or an ethylene-ethyl acrylate copolymer having a density of 0.85 to 0.94 g / cm3, The density is 0.94 g / cm3
The hydrated metal oxide was added in an amount of 50 to 30 with respect to 100 parts by weight of a polymer obtained by blending the above high-density polyethylene with the former and the latter at a weight ratio of 95 to 65: 5 to 35.
It is characterized in that 0 parts by weight are blended.

[0005]

DISCLOSURE OF THE INVENTION The high crystallinity of high-density polyethylene acts on the base polymer of the present invention in which a predetermined amount of high-density polyethylene is blended with ethylene / methyl acrylate copolymer or ethylene / ethyl acrylate copolymer. It was found that even if a large amount of hydrated metal oxide was added to improve the flame retardancy, the flame retardant resin composition could maintain a high level of mechanical properties such as trauma resistance and abrasion resistance. Then, the present invention has been proposed.

[0006] The density used in the present invention is 0.85-0.
Examples of the 94 g / cm ³ polyolefin include α-olefins such as polyethylene, polypropylene, polybutene and poly-4-methylpentene-1, and α-olefins such as ethylene-propylene copolymer and ethylene-butene copolymer.
Copolymers of olefins, ethylene / vinyl acetate copolymers, ethylene / methyl acrylate copolymers, copolymers of α-olefins and other monomers such as ethylene / ethyl acrylate copolymer, etc. can give. Among them, poly-α-olefins such as polyethylene, ethylene / α-olefin copolymers, ethylene / vinyl acetate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer and the like can be preferably used. .

The high-density polyethylene has a density of 0.94 g / cm ³ or more, preferably 0.95 g / cm ^3.
cm ³ or more ones can be used, specifically Yukaron EX4
0 (Mitsubishi Yuka Corporation trade name; density 0.96g / c
m ³ ), HIZEX 5305 (trade name of Mitsui Petrochemical Co., Ltd .; density 0.954 g / cm ³ ), Shorex C
4502 (trade name of Showa Denko KK; density 0.943g
/ Cm ³ ), Stacrene E802 (trade name of Nippon Petrochemical Co .; density: 0.967 g / cm ³ ), Nipolon Hard 6
200 (trade name of Tosoh Corporation; density 0.957 g / cm
³ ) and the like.

In the present invention, the above-mentioned polyolefin and high-density polyethylene are mixed to form a base polymer. The mixing ratio of the two is in the range of 95 to 65: 5 to 35, preferably 90 to 70:10 to 30 by weight of the polyolefin and the high-density polyethylene. If the blending amount of the high-density polyethylene is too small, the effect of improving the scratch resistance and abrasion resistance tends to decrease. It is not preferable because mixing becomes impossible and the flame retardancy tends to decrease.

Examples of the hydrated metal oxide mixed with the composition of the present invention as a flame retardant include aluminum hydroxide, magnesium hydroxide, and huntite (Mg ₃ Ca (C
Hydrotalcites such as a mixture of O ₃ ) ₄ ) and hydromagnesite;

The amount of the hydrated metal oxide is 50 to 300 parts by weight, preferably 70 to 200 parts by weight, particularly preferably 80 to 1 part by weight, per 100 parts by weight of the base polymer.
50 parts by weight. If the amount is less than 50 parts by weight, satisfactory flame retardancy cannot be realized, and if it exceeds 300 parts by weight, the mechanical strength tends to decrease even when the base polymer of the present invention is used.

The flame-retardant resin composition of the present invention may contain various additives as necessary. For example, maleic acid-modified polyethylene, polypropylene, polymer blend compatibilizers such as ethylene propylene rubber, talc, clay, calcium carbonate, magnesium carbonate, fillers such as silica, carbon black, titanium oxide, phthalocyanine blue, and bengalara Colorants, antioxidants such as binderd phenols and aromatic amines, flame retardant aids such as red phosphorus, zinc borate, zinc hydroxystannate, zinc stannate, antimony oxide, stearic acid, olein Lubricants such as acids and metal salts of higher fatty acids, processing aids, and coupling agents such as titanates and silanes can be added.

If necessary, dicumyl peroxide, 1,1-bis (t-butylperoxy) -3,
Peroxides such as 3,5-trimethylcyclohexane, P-quinonedioxime, PP'-dibenzoyl,
One or two or more of bifunctional crosslinking assistants such as oximes such as quinone dioxime, N-N'-metaphenylenedimaleimide, trimethylpropanetrimethacrylate, polybutadiene oligomer and diallyl phthalate are used in a small amount (for example, 0. (1 to 3 parts by weight).

The composition of the present invention is applicable to various uses, and is particularly suitable as a covering material for insulators of electric wires and cables, outer sheaths and the like. Above all, electric wires for automobiles,
It is especially useful for wiring cables in buildings. That is, the composition of the present invention is particularly advantageous in that it is halogen-free and thus is harmless, and has excellent mechanical strength, so that it has good resistance to external forces and can be made thin. In addition, the composition of the present invention can be suitably used for, for example, pipes, hoses, various sheets, and building materials.

[0014]

EXAMPLES With the formulations shown in Table 1, eight samples of the flame-retardant resin compositions (Examples 1 to 8) according to the present invention were prepared.
The sample was a 1 mm thick sheet-like sample formed by kneading each composition with a mixing roll at 130 ° C. and then performing hot press molding at 170 ° C. × 10 minutes. For comparison with the example products, sheet-like samples comprising three types of flame-retardant resin compositions (Comparative Examples 1 to 3) having the formulations shown in Table 1 were prepared in the same manner as described above. The characteristics of these samples were evaluated by the following methods. Table 1 shows the results.

Tensile strength and elongation test Each of the above sheet samples was subjected to JIS K672.
Tensile strength and elongation were tested according to the tensile test method No. 3. The tensile strength was 1.3 kg / mm ² or more, and the elongation was 150% or more.

Taber abrasion test For each of the above sheet-shaped samples, ASTM-D10
44-56 "Wear resistance of the surface of transparent plastic" Based on the measuring method, the wear amount in 1000 times using an H-18 wear wheel was shown in mg.

Flame retardancy test JIS K720 was applied to each of the above sheet samples.
The oxygen index was determined according to 1 (oxygen index method), and the flame retardancy was evaluated.

[0018]

[Table 1]

[0019]

According to the flame-retardant resin composition of the present invention as described above, the flame-retardant resin composition of the present invention has sufficient flame retardancy as well as excellent trauma resistance and abrasion resistance. When applied to, it can be made highly durable. In addition, since it has excellent mechanical properties as described above, even if it is thinner than conventional products, it is possible to sufficiently satisfy strength properties.For example, when used as a wire covering material, it is necessary to reduce the outer diameter of the wire. Becomes possible. Further, the present invention has excellent effects such as being pollution-free because it is halogen-free.

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 3/00-3/40

Claims (1)

(57) [Claims] An ethylene / methyl acrylate copolymer having a density of 0.85 to 0.94 g / cm3 and an ethylene / ethyl acrylate copolymer having a density of 0.94 g / cm3.
hydrated metal oxide was added to 100 parts by weight of a polymer obtained by blending a high-density polyethylene having a molecular weight of 3 cm 3 or more in a mixing ratio of 95 to 65: 5 to 35 by weight of the former and the latter.
A flame-retardant resin composition characterized by being mixed in an amount of 300 parts by weight.