JPH06184375A - Flame-retardant polypropylene resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition having high flame retardancy and suppressed in the formation of corrosive gases and noxious gases by mixing a polypropylene resin with a phenyl phosphorothioate compound and an antimony compound. CONSTITUTION:This resin composition is prepared by mixing a polypropylene resin with 1-30wt.% phenyl phosphorothioate compound of formula I and 0.5-15wt.% antimony compound. Examples of the polypropylene resins used include a polypropylene homopolymer, block and random copolymers of ethylene with butene-1, pentene-1, hexene-1, 4-methyl-pentene-1 and mixture thereof. Examples of the phenyl phosphorothioate compounds used include S,S,S-triphenyl phosphorotrithioate, O-phenyl S,S-diphenyl phosphorodithioate and O,O-diphenyl phosphorothioate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant polypropylene resin composition. More specifically, the present invention relates to a flame-retardant polypropylene resin composition having a high degree of flame-retardant property with less generation of corrosive gas and harmful gas.

[0002]

2. Description of the Related Art Polypropylene resins are excellent in their properties and can be used in the form of injection molded products, films and blow molded products.
Widely used in the fields of automobiles, building materials, electric parts, etc. However, polypropylene-based resins have a drawback that they are extremely flammable, and as their applications are widespread, there are many demands for flame retardancy, and the flame retardancy level is increasing. Generally, the flame retardation of organic polymers is performed by (1) adding a flame retardant to the resin, (2) blending the flame retardant resin, (3) making a flame retardant polymer by reaction with a flame retardant monomer, etc. Has been done. The most commonly used method among these methods is to add a flame retardant to the resin, and this method is usually used for polyolefin resins. Flame retardants used for these include organic chlorides, halides such as bromides, phosphoric acid esters, phosphorous acid esters, phosphorus,
Phosphorus-containing compounds such as ammonium phosphate, water-containing inorganic compounds such as aluminum hydroxide and magnesium hydroxide, and antimony trioxide are usually used as a flame retardant aid.

Among them, in order to make a polypropylene resin flame-retardant, a method in which a halogen-based flame retardant and antimony trioxide are added together is most effective and is generally used. However, a resin composition containing a halogen-based flame retardant has the drawback that it generates a corrosive gas during processing and combustion, causing equipment troubles, and generating a harmful gas such as hydrogen halide. .

Therefore, it has been proposed to add magnesium hydroxide or ammonium polyphosphate as a flame-retardant polypropylene resin composition to which such a halogen-based flame retardant is not added. However, in order to obtain sufficient flame retardancy by adding magnesium hydroxide, it is necessary to add a large amount of magnesium hydroxide, resulting in deterioration of physical properties and processability of the resin composition. Further, in the composition using ammonium polyphosphate, not only the poor dispersion of ammonium polyphosphate and the generation of ammonia gas due to thermal decomposition but also the poor dispersibility of nitrogen compound and pentaerythritol used as a co-reactant, water absorption, and Due to the sublimation property, bleeding and deterioration of water resistance are observed. Further, it is known that it is almost impossible to make a polypropylene resin flame-retardant by adding a phosphoric acid ester compound and a phosphorous acid ester compound.

[0005]

The object of the present invention is to have a high degree of flame retardancy, generate very little corrosive gas and harmful gas, and be excellent in workability, physical properties, water resistance and bleeding resistance. Another object of the present invention is to provide a flame-retardant polypropylene resin composition.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventor has found that by adding a specific phenylphosphorothioate compound and an antimony compound to a polypropylene resin, a high degree of difficulty can be obtained. It has been found that it is possible to obtain a flame-retardant polypropylene resin composition which is flammable and in which generation of corrosive gas and harmful gas is extremely small.

That is, the present invention provides a phenylphosphorothioate compound represented by the following general formula (1) in an amount of 1 to 3
It is a polypropylene resin composition in which 0% by weight and an antimony compound are blended in an amount of 0.5 to 15% by weight.

[0008]

[Chemical 2]

(In the formula, X ^{1 to} X ⁵ each independently represent a hydrogen atom, an alkyl group, an NH ₂ group, a NO ₂ group or a SO ₃ H group, R represents an alkyl group, and n represents 0 to 0. It is an integer of 2.) The resin composition of the present invention is a flame-retardant polypropylene-based resin composition having a high degree of flame retardancy and generating very little corrosive gas or harmful gas.

The polypropylene resin used in the present invention includes polypropylene homopolymer and propylene, ethylene, butene-1, pentene-1 or hexene-1,4-.
A block copolymer with methylpentene-1, a random copolymer and a mixture thereof can be used.

Examples of the phenylphosphorothioate compound represented by the general formula (1) used in the present invention include S, S,
Mention may be made of S-triphenylphosphorotrithioate, O-phenyl-S, S-diphenylphosphorodithioate and O, O-diphenyl-S-phenylphosphorothioate. The addition amount of these is 1 to
It is preferably 30% by weight, more preferably 2 to 20% by weight. If the amount added is less than 1% by weight, a sufficient flame retardant effect cannot be obtained, whereas if the amount added exceeds 30% by weight, thermal stability and heat resistance are impaired.

The phenylphosphorothioate compound may be microencapsulated by a usual method using a thermosetting resin or the like.

As the antimony compound used in the present invention, antimony trioxide and antimony pentoxide can be used. This addition amount varies depending on the addition amount of the phenylphosphorothioate compound, but is 0.5 to 1
The range is preferably 5% by weight, more preferably 1 to 10% by weight. If it is less or more than this, a sufficient flame retardant effect cannot be obtained.

Further, the resin composition of the present invention may be blended with those which are usually used as a flame retardant aid, for example, an inorganic tin salt and zinc borate in a range which is usually used. By adding these, the flame retardancy can be further improved.

Further, the resin composition of the present invention can be used in combination with an inorganic filler within the range usually used to improve the physical properties. For these purposes, talc, mica, silica, calcium silicate, glass fiber, carbon fiber, calcium carbonate and the like are usually used.

Further, the modified polypropylene resin, which is usually added to improve the physical properties when an inorganic filler or the like is added, can be added to the resin composition of the present invention within the range usually used.

Further, a small amount of rubber may be added to the resin composition of the present invention in order to improve impact strength, but the addition amount is preferably 10% by weight or less. If the addition amount is larger than this, a sufficient flame retarding effect may not be obtained.

In addition to the above, the resin composition of the present invention may contain additives that are usually used as polyolefin resin additives, antioxidants, light stabilizers, ultraviolet absorbers and stabilizers.

The polypropylene resin composition of the present invention thus obtained can be molded into a molded product by a usual processing method such as injection molding, extrusion molding and blow molding.

[0020]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. still,
Various test methods carried out in Examples and Comparative Examples are as follows.

Flame retardance test Oxygen index: According to JIS K7201 "Combustion test method for polymer materials by oxygen index method".

UL94: According to the UL94 vertical burning test.

The test pieces were prepared using an injection molding machine.

Evaluation of Bleedability A flat plate of 100 × 65 × 3 mm was prepared using an injection molding machine. 1 in a thermo-hygrostat at a temperature of 70 ° C and a humidity of 90%
After the treatment for 68 hours, it was taken out and the bleeding state was visually evaluated.

Example 1 Polypropylene resin (manufactured by Tosoh Corporation: J5100)
A, MFR 10, homopolymer) 96 wt% S,
3% by weight of S, S-triphenylphosphorotrithioate, 1% by weight of antimony trioxide (manufactured by Nippon Seiko Co., Ltd .: Atox S) and an antioxidant were added in the composition shown in Table 1, and a Henschel mixer was used. The mixture was mixed with an ar and was extruded at 220 ° C. with a twin-screw kneading extruder having a diameter of 30 mm to produce pellets. Then, a test piece was prepared from the pellet with a 150 t injection molding machine at a resin temperature of 230 ° C. and evaluated. The results are shown in Table 1, and the resin composition obtained is UL94 / V-2.
It had flame retardancy and good bleed resistance.

Example 2 A test piece was prepared in the same manner as in Example 1 except that 86% by weight of polypropylene resin was replaced with 10% by weight of S, S, S-triphenylphosphorotrithioate and 4% by weight of antimony trioxide. Created and evaluated. The results are shown in Table 1. The resin composition obtained was good in both flame retardancy and bleed resistance.

Example 3 73% by weight of polypropylene resin, 12% by weight of S, S, S-triphenylphosphorotrithioate, 5% by weight of antimony trioxide, talc (Micro White 5000A manufactured by Hayashi Kasei Co., Ltd.) Test pieces were prepared and evaluated in the same manner as in Example 1 except that the amount was 10% by weight. The results are shown in Table 1. The resin composition obtained was good in both flame retardancy and bleed resistance.

Example 4 Polypropylene resin 95% by weight O-phenyl-S, S-
Test pieces were prepared and evaluated in the same manner as in Example 1 except that 4% by weight of diphenylphosphorodithioate and 1% by weight of antimony trioxide were used. The results are shown in Table 1. The resin composition obtained was good in both flame retardancy and bleed resistance.

Example 5 84 wt% polypropylene resin O-phenyl-S, S-
Test pieces were prepared and evaluated in the same manner as in Example 1 except that 12% by weight of diphenylphosphorodithioate and 4% by weight of antimony trioxide were used. The results are shown in Table 1.
As shown in Table 1, the obtained resin composition had good flame retardancy and bleed resistance.

Comparative Example 1 A test piece was prepared and evaluated in the same manner as in Example 1 except that triphenylphosphite was used instead of the phenylphosphorothioate compound. The results are shown in Table 1.
However, the obtained resin composition did not show sufficient flame retardancy and bleeding was observed.

Comparative Example 2 A test piece was prepared and evaluated in the same manner as in Example 2 except that triphenylphosphite was used instead of the phenylphosphorothioate compound. The results are shown in Table 1.
However, the obtained resin composition did not show sufficient flame retardancy and bleeding was observed.

[0032]

[Table 1]

[0033]

As is clear from the above description, the composition of the present invention has a high degree of flame retardancy, has extremely little generation of corrosive gas and harmful gas, and has good processability, physical properties, water resistance, A composition with excellent bleed resistance.

Claims (1)

[Claims] 1. A polypropylene resin composition comprising 1 to 30% by weight of a phenylphosphorothioate compound represented by the following general formula (1) and 0.5 to 15% by weight of an antimony compound. [Chemical 1] (X ^{1 to} X ⁵ in the formula each independently represent a hydrogen atom, an alkyl group, an NH ₂ group, a NO ₂ group, or a SO ₃ H group, R represents an alkyl group, and n represents 0 to 2 It is an integer.)