JPH0593111A - Flame retardant resin composition - Google Patents

Abstract

(57) [Summary] [Object] To provide a resin composition having flame retardancy and high thermal stability. [Structure] Polypropylene 100 parts by weight Vinyl chloride resin 30 to 200 parts by weight Antimony trioxide 5 to 30 parts by weight Ethylene-vinyl acetate copolymer 5 to 100 parts by weight Magnesium hydroxide 20 to 150 parts by weight Resin composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition having both flame retardancy and high thermal stability.

[0002]

2. Description of the Related Art Polypropylene has various disadvantages because it has the drawbacks of being easily ignited and combustible. In particular, polypropylene used in electric products and building materials tends to be required to have higher flame retardancy. For example, in the UL standard of the United States, a high flame retardancy of V-1 to V-0 is required for parts of home electric appliances such as a TV outer frame. Therefore, for products exported to the United States such as home appliances, V-1 to V-
A flame retardancy of 0 must be given. Also, in recent years, in Japan, too, there have been many cases of TV burning, and as a voluntary regulation by home electric appliance manufacturers, it has been decided to make the TV back cover highly flame-retardant (V-0). Therefore,
Combining organic and inorganic flame retardants, it is designed to be flame retardant.

On the other hand, vinyl chloride resin as a flame retardant is
It itself has high flame retardancy. However, it is unsuitable to simply add a vinyl chloride resin to polypropylene to impart flame retardancy, because the two are incompatible. However, recently, various compatibilizers have been proposed, and it has become possible to form a composite of polypropylene and vinyl chloride resin.

[0004]

As described above, the compounding of polypropylene and vinyl chloride resin has been made possible by using a compatibilizing agent in combination, but the vinyl chloride resin is compounded up to a compounding amount for exhibiting flame retardant performance. As a result, decomposition occurs in the molding machine, and discoloration easily occurs. That is, there is a disadvantage that the heat resistance originally possessed by polypropylene is lost.

Therefore, it has been a problem to maintain a high flame retardancy and a high heat resistance stability in a resin composition obtained by compounding polypropylene and vinyl chloride resin.

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above problems, and as a result, polypropylene, vinyl chloride resin, antimony trioxide, and ethylene-
The inventors have found that the combined use of magnesium hydroxide in addition to the vinyl acetate copolymer improves both flame retardancy and heat stability, and have completed the present invention.

That is, the present invention is based on 100 parts by weight of polypropylene, 30 to 200 parts by weight of vinyl chloride resin, 5 to 30 parts by weight of antimony trioxide, 5 to 100 parts by weight of ethylene-vinyl acetate copolymer, and magnesium hydroxide. 20
The resin composition is characterized by containing ˜150 parts by weight.

In the resin composition of the present invention, polypropylene is combined with vinyl chloride resin, antimony trioxide, ethylene-vinyl acetate copolymer, and magnesium hydroxide in combination to obtain both flame retardancy and heat stability. Is improved. Magnesium hydroxide generally exhibits flame retardancy even if it is mixed alone with polypropylene, but a large amount of filling is required to exhibit the required flame retardancy. For this reason, it may be used in combination with other flame retardants, but depending on the type of flame retardant, the flame retardancy may decrease. Therefore, careful consideration is required for the combination.

Examples of the polypropylene used in the present invention include homopolymers of propylene, random and block copolymers of propylene with α-olefins such as ethylene and butylene, and mixtures thereof.

As the vinyl chloride resin, a general vinyl chloride resin can be used without limitation. The compounding amount of vinyl chloride resin is 30 to 200 with respect to 100 parts by weight of polypropylene.
Parts by weight, preferably 50 to 160 parts by weight. When the blending amount of the vinyl chloride resin is less than the above lower limit value, sufficient flame retardancy cannot be obtained, and when it is more than the above upper limit value, the heat stability is deteriorated, which is not preferable.

As the antimony trioxide, commercially available general ones can be used. The compounding amount of antimony trioxide is 5 to 3 with respect to 100 parts by weight of polypropylene.
It is 0 part by weight, preferably 7 to 25 parts by weight. That is, when the compounding amount of antimony trioxide in the resin composition is less than the above lower limit, sufficient flame retardancy cannot be obtained, and when it is more than the above upper limit, flame retardance is not improved. In addition, the specific gravity increases and the impact resistance decreases, which is not preferable.

As the ethylene-vinyl acetate copolymer, a commercially available general copolymer having a vinyl acetate content of 5 to 30 wt% can be used. The blending amount of the ethylene-vinyl acetate copolymer is 5 to 100 parts by weight, preferably 10 to 80 parts by weight, based on 100 parts by weight of polypropylene. When the blending amount of the ethylene-vinyl acetate copolymer is less than the above lower limit value, sufficient compatibilizing effect is not exhibited, polypropylene and vinyl chloride resin are not sufficiently mixed, and heat deterioration resistance is also sufficiently exhibited. Not done. On the other hand, if it is more than the above upper limit, the compatibility is not further improved and the flexural modulus, hardness and rigidity are lowered, which is not preferable.

The magnesium hydroxide is not particularly limited and any one can be used, but the particle size is 0.1 to 0.1.
When a product having a particle size of 50 μ, particularly 0.1 to 20 μ, and a BET specific surface area of 20 m ² / g or less is used, a molded product having improved impact resistance and a good surface condition (no silver streak is generated) is obtained. It is preferable because it is possible. Furthermore, magnesium hydroxide, which has been surface-treated with a surfactant such as sodium stearate or sodium lauryl sulfonate beforehand, has the advantage of improving dispersibility and fluidity, and is therefore preferably used. The compounding amount of such magnesium hydroxide is 20 to 150 parts by weight, preferably 25 to 130 parts by weight, based on 100 parts by weight of polypropylene. That is, when the content of magnesium hydroxide in the resin composition is less than the lower limit value described above, not only sufficient flame retardancy is not obtained, but also heat resistance stability is not sufficient. On the other hand, if the amount is more than the above upper limit, not only is the impact resistance lowered, but also it becomes difficult to knead and pelletize with an extruder when producing a molded product, which is not industrially preferable.

The resin composition of the present invention contains, in addition to the above-mentioned components, if necessary, conventionally known stabilizers, colorants, antistatic agents, lubricants, nucleating agents, flame retardants, anti-blooming properties and spinnability. Various fillers and the like may be added within a range that does not adversely affect the above.

The mixing order and mixing method of the respective components for preparing the resin composition of the present invention are not particularly limited, and it is generally carried out by a conventional method using a tumbler type blender, a V type blender, a Henschel mixer, a ribbon mixer and the like. ..

[0016]

[Effect] The resin composition of the present invention has a high flame resistance of V-2, V-1 to V-0 and a high heat stability in accordance with UL94 standard (combustion test standard for plastic materials). .. Although the reason why such characteristics are obtained is not clear, polypropylene and vinyl chloride resin are dispersed with each other by the ethylene-vinyl acetate copolymer, and the dispersibility of magnesium hydroxide is further improved by the ethylene-vinyl acetate copolymer. It is estimated that it will also improve.
It is also presumed that the heat resistance stability is improved by preventing the chloride radicals generated at the initial stage of decomposition of the vinyl chloride resin from being trapped by magnesium hydroxide and expanding the decomposition radical chain reaction. Also, due to the synergistic action of the vinyl chloride resin, antimony trioxide and magnesium hydroxide,
The flame retardancy is also improved as compared to when used alone.

That is, it is presumed that the resin composition of the present invention interacted with each other to obtain high flame retardancy and high heat stability.

[0018]

EXAMPLES In order to more specifically describe the present invention, examples and comparative examples will be described below, but the present invention is not limited to these examples. The symbols shown in Examples and Comparative Examples are as follows.

1. Polypropylene (manufactured by Tokuyama Soda Co., Ltd .: powder) A: ethylene-propylene block copolymer (melt flow rate 23 g / 10 min, ethylene content 2.0 wt%) B: propylene homopolymer (melt flow rate 9
g / 10 min) 2. Vinyl chloride resin (manufactured by Sunarrow Chemical Co., Ltd.) C: Polyvinyl chloride (average degree of polymerization 400, SA400
L) D: Polyvinyl chloride (average degree of polymerization 680, SA600
R) 3. Compounding material E: Ethylene-vinyl acetate copolymer (Sumitomo Chemical Co., Ltd., Evatate K2010, vinyl acetate content 25%) F: Antimony trioxide G: Magnesium hydroxide (Kyowa Chemical Co., Kisuma 5A) Examples 1 to 1 4 and Comparative Examples 1 to 6 The method for preparing and testing the polypropylene resin composition is
The procedure was as follows.

(1) Premixing With respect to 100 parts by weight of polypropylene, the vinyl chloride resin, the compounding material and 2,6-di-t-butyl-in the compounding amounts shown in Table 1 are used.
4-methylphenol (Sumitomo Chemical Co., Ltd., Stabilizer BHT): 0.1%, dilauryl thiodipropionate (Sumitomo Chemical Co., Ltd., Sumilizer TPL-R): 0.2
%, Calcium stearate (Dainippon Ink and Chemicals):
0.1% was blended and premixed with a Henschel mixer.

(2) Pelletization The above mixture was pelletized using a 50 mmφ extruder equipped with a kneader.

(3) Preparation of test piece A combustion test piece was prepared from the above pellets using a 2oz injection molding machine. Further, for heat resistance deterioration test, color plates were prepared at the molding temperature of 200 ° C. and at the time of standing for 15 minutes.

(4) Effect test (a) Combustion test A combustibility category was determined by a combustion test according to UL standard 94.

(A) Heat deterioration resistance test In accordance with JIS-K7103, the yellowness (yellow index = Y.I.) Was measured for the color plate that was normally molded and the color plate that had been retained for 15 minutes. ..

The results are shown in Table 1.

[0026]

[Table 1]

Claims (1)

[Claims] 1. A vinyl chloride resin of 30 to 200 parts by weight and an antimony trioxide of 5 to 100 parts by weight of polypropylene.
30 parts by weight, ethylene-vinyl acetate copolymer 5-100
A flame-retardant resin composition comprising 20 parts by weight and 20 to 150 parts by weight of magnesium hydroxide.