JP3040217B2 - Polypropylene 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 polypropylene resin composition having improved heat deterioration resistance.

[0002]

2. Description of the Related Art Polypropylene is used in a wide variety of fields, but has a drawback that it is easily ignited and flammable. Therefore, various uses of flame retardancy are applied to flame retardants.

In general, organic and / or inorganic flame retardants are used as flame retardants for combustible plastic materials. However, organic flame retardants tend to cause sagging during combustion, and inorganic flame retardants do not easily cause sagging, but have the problem of requiring a large amount of addition for flame retardancy.

[0004] On the other hand, polypropylene used in electric appliances may be required to have a high degree of flame retardancy (U.S. UL standards V-2 to V-0) and a high degree of heat deterioration resistance. Conventionally, various heat stabilizers have been added to improve heat deterioration resistance. However, depending on the type of flame retardant used, even if the amount of the heat stabilizer added is increased, the type and combination of the heat stabilizers may be increased. Even if it changes, the effect hardly changes, and conversely, it becomes easy to burn by increasing the addition amount of the heat stabilizer, and the flame retardancy of a high level (V-2 to V-0) may not be satisfied. is there. In order to improve such disadvantages, various proposals have been made in which an organic flame retardant is combined with an inorganic flame retardant. Examples of the organic flame retardant having the above include polybromodiphenyl ether represented by decabromodiphenyl ether.

However, recently, the use of polybromodiphenyl ether has been restricted mainly in Europe. Therefore, it has been an issue to find a good formulation of a flame retardant which can be used instead. The present inventors have already identified a specific ethylene bisbrominated phthalimide to polypropylene,
By using antimony trioxide and magnesium hydroxide in combination, it has a high (V-2 to V-0) flame retardancy,
In addition, a polypropylene resin composition having improved impact resistance was found and proposed (Japanese Patent Application No. 2-222496).

[0006]

The above-mentioned improved polypropylene-based resin composition has high flame retardancy, but is slightly inferior in heat deterioration, so that very high heat deterioration is required. Use in certain fields is restricted. Therefore,
An object of the present invention is to obtain a polypropylene-based resin composition which maintains high (V-2 to V-0) flame retardancy and further has high heat deterioration resistance.

[0007]

Means for Solving the Problems The present inventors have intensively studied to solve the above problems. As a result, a propylene composition obtained by using a combination of ethylene bisbrominated phthalimide as an organic flame retardant, antimony trioxide and magnesium hydroxide as an inorganic flame retardant, and further adding epoxidized soybean oil to polypropylene is obtained. The present inventors have found that the heat deterioration resistance is remarkably improved without impairing the high flame retardancy, and the present invention has been completed.

That is, the present invention relates to polypropylene 100
15 parts by weight of ethylene bis brominated phthalimide
-100 parts by weight, antimony trioxide 3-50 parts by weight ,
Particle size 0.1-50 μm treated with surfactant, BET method
Magnesium Water oxide 30 below a specific surface area of 20 m ² / g
A polypropylene-based resin composition comprising 150 parts by weight and 0.1 to 5 parts by weight of epoxidized soybean oil.

As the polypropylene used in the present invention, a homopolymer of propylene, a random copolymer of α-olefin such as ethylene and butene and propylene, a block copolymer or a mixture thereof is not particularly limited. Can be

The ethylene bisbrominated phthalimide used in the present invention is represented by the following formula:

[0011]

Embedded image

The known brominated flame retardant represented by the formula (1) can be used without particular limitation. To illustrate the typical example,
For example, ethylene bistetrabromophthalimide, ethylenebistribromophthalimide, ethylenebisdibromophthalimide, etc., and particularly, ethylenebistetrabromophthalimide having a high bromine content is the most effective and preferable. The amount of such ethylene bisbrominated phthalimide is 1 to 100 parts by weight of polypropylene.
It is 5 to 100 parts by weight, preferably 20 to 50 parts by weight. When the amount of ethylenebisbrominated phthalimide is less than the above lower limit, sufficient flame retardancy cannot be obtained, and when it is more than the above upper limit, moldability and various physical properties are deteriorated.

As the antimony trioxide used in the present invention, commercially available general ones can be used without particular limitation. The blending amount of antimony trioxide is polypropylene 10
3 to 30 parts by weight, preferably 5 to 30 parts by weight per 0 parts by weight
Parts by weight. If the amount of antimony trioxide is less than the above lower limit, sufficient flame retardancy cannot be obtained, and if it is more than the above upper limit, no improvement in flame retardancy is observed and the specific gravity increases. And various physical properties are undesirably reduced.

The magnesium hydroxide used in the present invention has a particle size of 0.1 to 50 μm, especially 0.1 to 20 μm,
ET method specific surface area of 20 m ² / g or less
Improved and good surface condition (no silver streaks)
It is preferable because a molded article can be obtained. In addition,
Gnesium in sodium stearate, lauryl sulfonic acid
Surface treatment with a surfactant, such as soda, results in dispersibility and flow.
This is preferable because there is an advantage that mobility can be improved. The amount of such magnesium hydroxide is 30 to 150 parts by weight, preferably 50 to 130 parts by weight, per 100 parts by weight of polypropylene. If the amount of magnesium hydroxide is less than the above lower limit, a sufficient flame retardant effect is not exhibited, and if it is more than the above upper limit, not only the physical properties are reduced, but also when manufacturing a molded article. It is not industrially suitable because kneading pelletizing in an extruder becomes difficult.

The epoxidized soybean oil used in the present invention is not particularly limited, and known oils can be used. Generally, those having an iodine value of 3.0 or less and oxirane oxygen of 6.8% or more can be suitably used. The amount of the epoxidized soybean oil is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the polypropylene. When the amount of the epoxidized soybean oil is less than the above lower limit, a sufficient improvement in heat deterioration resistance is not exhibited, and when it is more than the above upper limit, the flame retardancy decreases, which is not preferable.

The polypropylene resin composition of the present invention comprises:
In addition to the above components, if necessary, conventionally known stabilizers, coloring agents, antistatic agents, lubricants, nucleating agents and various fillers within a range not adversely affecting the flame retardancy, anti-blooming properties, and spinning properties. May be added.

There are no particular restrictions on the order in which the components are mixed or the mixing method used when preparing the polypropylene resin composition of the present invention. Generally, a tumbler type blender, a V-type blender, a Henschel mixer, a ribbon mixer or the like is used. It is done by law.

[0018]

The polypropylene resin composition of the present invention has a high flame resistance of V-2, V-1, or V-0 and a high heat resistance in accordance with UL94 standard (flammability test method for plastic materials). It has degradability. It is not clear why the blending of epoxidized soybean oil is particularly effective compared to other epoxy compounds in order to improve heat deterioration resistance, but the epoxy group captures bromine liberated by heating, and the soybean oil part further It is presumed that by improving compatibility and dispersibility with polypropylene, improvement in heat deterioration resistance is exhibited.

[0019]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The symbols used in the examples and comparative examples are as follows.

1. Polypropylene (manufactured by Tokuyama Soda Co., Ltd.):
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 / 10min) 2. Flame retardant C: ethylenebistetrabromophthalimide (Saytex BT-93, manufactured by Ethyl Corporation) D: antimony trioxide E: surface-treated magnesium hydroxide (Kyowa Chemical Co., Ltd., Kisuma 5A: average particle size 0.8 μm, BET ratio) 5.5m surface area
² / g) 3. Stabilizer F: tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (Irganox 1010, manufactured by Ciba Geigy) G: tris (3,5-di-t-) Butyl-4-hydroxybenzyl) isocyanurate (Irganox 3114, Ciba-Geigy) H: Tris (2,4-di-t-butylphenyl) phosphite (Irgafos 168, Ciba-Geigy) I: Tetrakis (2,4) -Di-t-butylphenyl)-
4,4-biphenylenediphosphonite (manufactured by Sando,
Sandstub P-EPQ) J: 3,9-bis [2- {3- (3-t-butyl-4-)
[Hydroxy-5-methylphenyl) propionyloxy {-1,1-dimethylethyl] -2,4,8,10-
Tetrakis-spiro [5,5] undecane (Sumitomo Chemical Co., Ltd., Sumilizer GA80) K: dilauryl thiodipropionate (Sumitomo Chemical Co., Ltd.)
Sumilizer TPL-R) L: Dimyristyl thiodipropionate (Sumitomo Chemical Co., Ltd., Sumilizer TPM) M: Epoxidized soybean oil (Daichika Chemical Co., SO) Examples 1-7 and Comparative Examples 1-21 Polypropylene Preparation and test methods of the resin composition were performed as follows.

(1) Preliminary mixing Flame retardants, stabilizers and calcium stearate (manufactured by Dainippon Ink): 0.1% in the amounts shown in Table 1 were blended with 100 parts by weight of polypropylene, and the mixture was preliminarily mixed with a Henschel mixer. Mixed.

(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 2 oz injection molding machine. In addition, the test piece (50 mm × 3
5 mm x 0.5 mmt).

(4) Effect test (a) Combustion test The flammability classification was determined by a combustion test based on UL standard sb94.

(A) Heat resistance deterioration test According to JIS-K7212, the number of heating days until surface deterioration of a molded article heated in an oven at 150 ° C. was measured.

Table 1 shows the results.

[0027]

[Table 1]

────────────────────────────────────────────────── (5) Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08K 9:04) (56) References JP-A-3-231946 (JP, A) JP-A-4-106139 (JP, A) JP-A-63-146949 (JP, A) "Kisma" catalog (Kyowa Chemical Industry Co., Ltd.) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16

Claims (1)

(57) [Claims] (1) 100 parts by weight of polypropylene, 15 to 100 parts by weight of ethylene bis brominated phthalimide of the following formula:
Antimony trioxide 3-50 parts by weight , treated with surfactant
Particle size 0.1-50 μm, BET specific surface area 20 m ²
/ G or less of magnesium water oxidation 30 to 150 parts by weight of the polypropylene resin composition obtained by blending the epoxidized soybean oil 0.1 to 5 parts by weight. Embedded image