JP2001151949A - Flame-retardant resin composition and molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel resin composition which does not contain a halogen compound and has a high flame retardance. SOLUTION: The composition is obtained by compounding a polyolefin resin with (A) 10-60 wt.% hydrated metal oxide, (B) 1-36 wt.% melamine salt of at least one inorganic acid selected from among nitric, sulfuric, polyphosphoric, boric, phosphorous, and sulfurous acids, and (C) 0.5-50 wt.% silicone compound.

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 containing no halogen compound, and to a molded article such as an electric wire, an automobile interior material, a building material film, an electric component, and daily necessities using the same.

[0002]

2. Description of the Related Art Conventionally, thermoplastic resins have been used in a wide range of fields because of their excellent moldability, lightness, durability, and electrical insulation. However, since it is an organic material unlike an inorganic material represented by a metal, it has a drawback that it is inherently flammable. Since flame retardancy is indispensable from the viewpoint of fire prevention, a flame retardant resin composition in which various flame retardants are blended with a thermoplastic resin has been proposed and disclosed.

In order to impart flame retardancy to a thermoplastic resin,
It has been common practice to mix an organic halogen compound and antimony trioxide and utilize the chemical and physical synergistic effects of both. However, a resin composition containing an organic halogen-based compound is regarded as a problem due to hydrogen halide gas generated during combustion or molding processing or when a molded article is incinerated, or corrosiveness of an organic halogen-based compound. Was.

[0004] In order to eliminate such disadvantages, a method of adding a hydrated metal oxide has been used, but it has been necessary to add a large amount due to insufficient flame retardancy. For example, "Polymer Digest", Volume 51, 1 , pages 61, 199
As described in No. 9, it was used in combination with various flame retardant aids such as red phosphorus, metal compounds, and nitrogen compounds.

[0005]

The use of a melamine salt as a flame retardant is described in Japanese Patent Publication No. 61-44095, and melamine phosphate is mentioned as an example of an organic phosphate. JP-A-7-330980 discloses a flame-retardant resin composition containing melamine or melamine cyanurate, a hydrated metal oxide and talc as flame retardants for nitrogen compounds. However, further improvement has been desired in order to demand higher flame retardancy.

[0006]

Means for Solving the Problems A first invention of the present invention is:
(A) hydrated metal oxide 10 to polyolefin resin
60% by weight, (B) nitric acid, sulfuric acid, polyphosphoric acid, boric acid,
A flame-retardant resin composition comprising 1 to 36% by weight of a salt of melamine and one or more inorganic acids selected from phosphorous acid and sulfurous acid, and 0.5 to 50% by weight of a silicone compound (C). is there.

A second invention is the flame-retardant resin composition according to the first invention, wherein at least a part of the polyolefin resin is an ethylene-vinyl acetate copolymer.

A third aspect of the present invention is that (B) the melamine salt with at least one inorganic acid selected from nitric acid, sulfuric acid, polyphosphoric acid, boric acid, phosphorous acid and sulfurous acid is melamine sulfate or melamine borate. And 2 to 20% by weight of the flame-retardant resin composition according to the first or second invention.

A fourth invention is the flame-retardant resin composition according to any one of the first to third inventions, wherein the (C) silicone compound is a silicone resin.

A fifth aspect of the present invention is the flame retardant according to any one of the first to third aspects, wherein the (C) silicone compound is a copolymer of silicone rubber and ethylene-propylene rubber. It is a conductive resin composition.

A sixth invention is a molded article using the flame-retardant resin composition according to any one of the first to fifth inventions.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The polyolefin resin used in the present invention,
Ethylene, propylene, 1-butene, or other α
-Polymers such as olefins, these copolymers,
Also includes blends. Further, a copolymer with another α-olefin, vinyl acetate, styrene, vinyl ether, maleic anhydride, carbon monoxide, N-vinyl carbazole, or the like may be used. Specific examples include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer, polyketone, and copolymers produced with metallocene catalyst. Further, those obtained by chemically reacting and modifying these polymers, specifically, ionomer resins, E
A saponified product of VA, an olefin-based elastomer produced using dynamic vulcanization in an extruder, and the like are also included, and a mixture of these resins may be used.

Of these, polyethylene, polypropylene and EVA have a good balance between mechanical strength and flame retardancy.
It is preferable because it can be applied to various uses, and it is preferable that at least a part of the polyolefin resin is any of these resins.

EVA in the present invention is obtained by copolymerizing ethylene and vinyl acetate. If the vinyl acetate content is less than 15% by weight, the hardness of the molded product tends to increase, and the balance between flame retardancy, mechanical properties and flexibility is increased.
If it is more than 0% by weight, the mechanical properties tend to decrease. Therefore, the vinyl acetate content is preferably 15 to 30% by weight.

The hydrated metal oxide (A) used in the present invention is dehydrated by dehydration of adsorbed water or a chemical reaction in a combustion test or in a fire, and the combustible gas generated from the resin composition is diluted with water vapor. The endothermic reaction lowers the combustion temperature.

Specific examples include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, tin hydroxide and the like. Among them, magnesium hydroxide has a dehydration temperature of 3
The temperature is 40 to 350 ° C., which is preferable because dehydration and endothermic reaction occur during combustion without dehydration due to heat during resin processing.

The hydrated metal oxide (A) is usually used as a powder having a particle diameter of 0.1 to 10 μm. Particle size 0.1
If it is smaller than μm, poor dispersion is likely to occur during melting and kneading with the resin, and it is difficult to obtain a flame retardant effect. On the other hand, when it is larger than 10 μm, the particles are easily conspicuous in the resin composition, and significantly impair the appearance. In addition, these materials improve the dispersibility in the resin, in order to easily exhibit an excellent flame retardant effect,
Surface treatment with a fatty acid, a fatty acid metal soap, a silane coupling agent, or the like, a metal soap such as magnesium stearate, or a dispersant such as polyethylene wax may be used in advance.

The amount of the hydrated metal oxide (A) to be added to the flame-retardant resin composition is preferably from 10 to 60% by weight. If it is less than 10% by weight, the flame retardant effect cannot be obtained, and if it exceeds 60% by weight, the mechanical properties deteriorate.

The (B) melamine salt with one or more inorganic acids selected from nitric acid, sulfuric acid, polyphosphoric acid, boric acid, phosphorous acid, and sulfurous acid used in the present invention is obtained by converting melamine having basicity to the above inorganic acid. It is a melamine salt neutralized with an acid, and one or two or more salts may be used in combination. (B) is obtained by introducing melamine into water, adding a calculated amount of an inorganic acid, heating and reacting, filtering, drying and pulverizing.

(B) shows that the solubility in water is smaller, the flame retardancy and the appearance are smaller, in view of the actual use situation, for example, the problem of dew condensation on wallpaper, and the application to weather resistance when the electric wire is used outdoors. Is good. Melamine sulfate and melamine borate are preferred from the standpoint of improving flame retardancy. Melamine sulfate is particularly preferred because of its excellent flame retardancy and low solubility in water.

The compounding amount of (B) to the flame-retardant resin composition is 1
It is preferably from 36 to 36% by weight, particularly preferably from 2 to 20% by weight. If it is less than 1% by weight, the flame retardant effect cannot be obtained, and 36% by weight.
If it exceeds, mechanical properties will be reduced.

The (C) silicone compound used in the present invention includes, for example, silicone resin, silicone oil,
Silane coupling agents, copolymers of silicone rubber and ethylene-propylene rubber, polyolefins in the continuous phase, silicone-based network structures in the non-continuous phase, silicone elastomers made from compatibilizers, among which silicone resins and Preferably, a copolymer of silicone rubber and ethylene-propylene rubber is used. Further, the above compounds may be used in combination.

By adding the silicone compound (C) as a flame retardant aid, the flame retardant effect is superior to using the components (A) and (B) alone or in combination. Because of its excellent holding effect, it can be used for electric wires and electric parts that require strict flame retardant standards.

The amount of the silicone compound (C) to be added to the flame-retardant resin composition is preferably 0.5 to 50% by weight, more preferably 0.7 to 30% by weight. If it is less than 0.5% by weight, the flame retardant effect cannot be obtained, and if it is more than 50% by weight, mechanical properties are impaired.

The flame-retardant resin composition of the present invention may contain, in addition to the above-mentioned components, various commonly used additives such as an antioxidant, an ultraviolet absorber, various dyes and pigments for coloring, a crosslinking agent, a crosslinking assistant, A foaming agent, a lubricant and the like can be contained, but in order to eliminate the generation of halogen gas, these additives must not contain a halogen element.
Also, other halogen-free flame retardants, such as red phosphorus,
Various metal salts and the like can be contained.

The flame-retardant resin composition of the present invention can be easily produced by melt-kneading the above components. Specific examples include a two-roll, a Banbury mixer, a kneader, and a twin-screw kneader. In addition, if the flame-retardant resin composition is a compound as it is, in the case of a master batch, it is appropriately diluted with a polyolefin-based resin to obtain a desired flame-retardant concentration, and the molding is performed using an extruder, an injection molding machine, or the like. , And molded products. Examples of molded articles include electric wires, automotive interior materials, films for building materials, and electric components.

[0027]

The present invention will be described below with reference to examples. Examples 1 to 6, Comparative Examples 1 to 4 EVA: Evaflex 360 (manufactured by Du Pont-Mitsui Polychemicals) Low-density polyethylene (LDPE): Mirason 11P (manufactured by Mitsui Petrochemical Co., Ltd.) Mg (OH) ₂ : Kisuma 5B (manufactured by Kyowa Chemical Industry Co., Ltd.) Melamine sulfate: Avinone 901 (manufactured by Sanwa Chemical Co., Ltd.) Silicone resin: SH410GUM (manufactured by Toray Silicone Co., Ltd.) Silicone-modified ethylene-propylene rubber: SEP1
721U (manufactured by Shin-Etsu Silicone Co., Ltd.) Magnesium stearate: NP-1500 (manufactured by Tannan Chemical Co., Ltd.) The above components were mixed at the compounding amounts (% by weight) shown in Table 1 and mixed.
The mixture was melt-kneaded with two rolls set at 40 ° C. for 5 minutes, and a plate-like sample was prepared from the obtained flame-retardant resin composition by hot pressing at 180 ° C. According to JIS K 7201
The oxygen index of this plate-like sample was measured. In addition, a fire resistance test including shape retention was performed in accordance with the UL94 vertical combustion test method (specimen: 13 mm x 127 mm, thickness 3 mm). The evaluation was を for V0, dripping (drip property) and surface cracking. Was not observed, and x was observed when dripping (drip property) and surface cracking were observed. The results are shown in Table 1.

[0028]

[Table 1]

From the results of Examples 1 to 6, it was confirmed that the flame retardant effect and the shape retention by adding the silicone compound were confirmed. In particular, in Examples 4 to 6, flame retardancy and shape retention were further improved, and it was confirmed that UL94 was equivalent to V0. On the other hand, the comparative example was poor in both the flame retardant effect and the shape retention.

[0030]

Industrial Applicability The flame-retardant resin composition containing no halogen element of the present invention has excellent flame retardancy due to a synergistic effect with (A), (B) and (C). It is effective as molded products such as company interior materials, building material films, and electrical components.

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Claims (6)

[Claims] 1. A polyolefin resin comprising (A) 10 to 60% by weight of a hydrated metal oxide and (B) at least one inorganic material selected from nitric acid, sulfuric acid, polyphosphoric acid, boric acid, phosphorous acid and sulfurous acid. A flame-retardant resin composition characterized by adding 1 to 36% by weight of a salt of an acid and melamine and (C) 0.5 to 50% by weight of a silicone compound. 2. The flame-retardant resin composition according to claim 1, wherein at least a part of the polyolefin resin is an ethylene-vinyl acetate copolymer. (B) nitric acid, sulfuric acid, polyphosphoric acid, boric acid,
The salt of melamine with one or more inorganic acids selected from phosphorous acid and sulfurous acid is melamine sulfate or melamine borate, and is added in an amount of 2 to 20% by weight. The flame-retardant resin composition according to the above. 4. The flame-retardant resin composition according to claim 1, wherein the silicone compound (C) is a silicone resin. 5. The flame-retardant resin composition according to claim 1, wherein the silicone compound (C) is a copolymer of silicone rubber and ethylene-propylene rubber. 6. A molded article using the flame-retardant resin composition according to any one of claims 1 to 5.