JPH06128430A - Flame-retardant polypropylene resin composition - Google Patents

Abstract

PURPOSE:To provide a composition excellent in moldability and capable of producing a molding excellent in impact strength and free from generation of a corrosive or harmful gas in molding or combustion without generating a corrosive or harmful gas. CONSTITUTION:With polypropylene resin, ammonium polyphosphate and/or melamine-modified ammonium polyphosphate, one or more kinds of polyvalent alcohols selected from pentaerythritol, dipentaerythritol, tripentaerythritol, a pentitol, a hexitol and a saccharide and an ethylene-vinyl acetate resin are blended in an amount of 10 to 30wt.% based on the whole flame-retardant polypropylene resin composition.

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 excellent moldability, high strength as a molded product, and a high degree of flame resistance without generating corrosive or toxic gas.

[0002]

2. Description of the Related Art Polypropylene resin is excellent in processability, chemical resistance, weather resistance, electrical properties and mechanical properties, so that it is used in the field of household electrical appliances, buildings, upholstery, automobile parts, etc. It is widely used in various fields. This polypropylene resin is a resin that is naturally easy to burn because it is a polyolefin resin consisting only of carbon atoms and hydrogen atoms, but flame retardancy is required as the field of use expands, and the required flame retardant properties are also required. It is getting tougher year by year.

In response to such circumstances, various flame-retardant polypropylene resin compositions have hitherto been proposed.
For example, JP-A-53-92855, JP-A-54-29350, JP-A-54-77658, JP-A-56-26954, JP-A-57-87462,
As disclosed in JP-A-60-110738 and the like, resin compositions in which a hydrous inorganic compound (for example, magnesium hydroxide, aluminum hydroxide, hydrotalcite, etc.) is mixed with polypropylene resin, and JP-B-55-30739 are disclosed. From the halogen compounds of polyethylene and decabromodiphenyl ether (or dodecachlorododecahydromethanodibenzocyclooctene) with a melt index of 0.01 to 2.0 as disclosed and from powdered talc, kaolinite, sericite, silica, diatomaceous earth. Chosen one
A resin composition prepared by blending one or more kinds of inorganic fillers with a polypropylene resin, or as disclosed in JP-A-52-146452, JP-A-59-147050, etc., is inserted in an ammonium (or amine phosphate) and cyclic structure. A reaction product of a nitrogen-containing organic compound containing> C = O (or> C = S,> NH) with an aldehyde or an oligomer (or polymer) of a 1,3,5-triazine derivative was blended with a polypropylene resin. Resin compositions and the like have been proposed.

Further, Japanese Patent Laid-Open Nos. 64-14277 and 3-565.
47, etc., discloses a flame-retardant polypropylene resin composition containing ammonium polyphosphate or melamine-modified ammonium polyphosphate and polyhydric alcohols such as pentaerythritol, dipentaerythritol, and tripentaerythritol.

[0005]

However, the above-mentioned conventionally proposed flame-retardant polypropylene resin composition has the following problems.

A polypropylene resin composition containing a water-containing inorganic compound is required to have a high degree of flame retardancy.
It is necessary to mix a large amount of hydrous inorganic compound. As a result, there are problems that this flame-retardant polypropylene resin composition is inferior in moldability and the impact strength of the molded product is significantly reduced.

A flame-retardant polypropylene resin composition containing a halogen-based compound and an inorganic filler has relatively good molding processability and a high degree of flame-retardancy, but it is corroded during molding or burning of a molded product. There is a problem that it emits toxic and toxic gas.

The flame-retardant polypropylene resin compositions disclosed in JP-A-52-146452 and JP-A-59-147050 are
Moldability is relatively good, and neither corrosive nor toxic gas is generated during molding or burning of molded products, but it is necessary to add a large amount of flame retardant in order to impart high flame retardancy. .
As a result, this flame-retardant polypropylene resin composition has a problem that the impact strength of the molded product is significantly reduced.

Further, JP-A-64-14277 and JP-A-3-565
The flame-retardant polypropylene resin composition disclosed in 47 and the like also needs to contain a large amount of a flame retardant or a flame retardant auxiliary in order to impart a high degree of flame retardancy. In addition, since the polyhydric alcohols that are blended as flame retardant aids are relatively low molecular weight components, the melt viscosity during kneading is significantly lower than other blending components. There is a problem that it is difficult to do. As a result, this flame-retardant polypropylene resin composition also has a problem that the impact strength and flame retardancy of the molded product are reduced.

The present invention has been made in consideration of the above problems and is excellent in molding processability, and does not generate corrosive or toxic gas at the time of molding or burning of a molded product, and is a molded product. An object of the present invention is to provide a flame-retardant polypropylene resin composition having excellent impact strength.

[0011]

The flame-retardant polypropylene resin composition of the present invention comprises a polypropylene resin, the polypropylene resin, ammonium polyphosphate and / or melamine-modified ammonium polyphosphate, pentaerythritol, dipentaerythritol, At least one polyhydric alcohol selected from the group consisting of tripentaerythritol, pentitols, hexitols and saccharides, and 10 wt% to 30 wt% of the whole flame-retardant polypropylene resin composition. It is characterized by being mixed with a ratio of ethylene vinyl acetate resin.

The polypropylene resin which can be used in the flame-retardant polypropylene resin composition of the present invention includes, in addition to crystalline polypropylene homopolymer, propylene and ethylene, butene-1, pentene-1, hexene-1, which contain propylene as a main component. A crystalline polypropylene copolymer with one or more selected from the group of 4-methylpentene-1, heptene-1, octene-1, and decene-1, or a mixture of two or more thereof can be used. An ethylene-propylene block copolymer is particularly preferable.

The ammonium polyphosphate or the melamine-modified ammonium polyphosphate as the flame retardant used in the flame-retardant polypropylene resin composition of the present invention may be a commercially available product as it is. For example, as ammonium polyphosphate, Sumisafe P (Sumitomo Chemical Co., Ltd. product name) and Exolit 422 (Hoechst product name) are available. As melamine-modified ammonium polyphosphate, Sumisafe PM (Sumitomo Chemical Co., Ltd. product) and Exolit
Examples of commercial products include 462 (trade name of Hoechst Co.). Ammonium polyphosphate or melamine-modified ammonium polyphosphate can be used alone or in combination.

Further, a polyhydric alcohol selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, pentitols, hexitols and saccharides is used in combination.
This polyhydric alcohol is ammonium polyphosphate and / or
Or, ammonium polyphosphate and / or melamine-modified ammonium polyphosphate required to act as an additional carbon source for melamine-modified ammonium polyphosphate, thereby increasing the amount of carbon formed and exhibiting useful flame retardant properties. This is because it is effective as a flame retardant aid for reducing the amount of addition of The pentitols include adonitol, arabinitol, etc., the hexitols include dulcitol, sorbitol, etc., and the saccharides include amylose, xylan, etc.

The ethylene vinyl acetate resin which can be used in the flame-retardant polypropylene resin composition of the present invention is a copolymer of ethylene and vinyl acetate and has a vinyl acetate ratio of 2%.
It is preferably from 0% to 60% by weight.

In the present invention, the proportion of vinyl acetate is 2
Ethylene vinyl acetate resin in the range of 0 wt% to 60 wt% is added to the flame-retardant polypropylene resin composition as a whole.
It is blended in a proportion of 0 to 30% by weight. By setting the above ethylene vinyl acetate resin in this range, the dispersion of the flame retardant and the flame retardant aid in the polypropylene resin becomes good, and as a result of the effect of the ethylene vinyl acetate resin as an elastic body, resistance to molding is improved. This is because the impact strength is most improved. Also, as a result of good dispersion of the flame retardant,
The amount of the flame retardant and the flame retardant auxiliary compounded can be reduced, and a molded product having excellent flame retardant properties can be obtained. In the present invention,
Ammonium polyphosphate as a flame retardant and / or melamine-modified ammonium polyphosphate is 10% by weight to 4% by weight.
0% by weight, 2% by weight of polyhydric alcohol as flame retardant aid
It is preferably about 10 to 10% by weight.

In the flame-retardant polypropylene resin composition of the present invention, various additives usually added to polypropylene resin, such as an antioxidant, an antistatic agent, a lubricant, a neutralizing agent (metal stearate salt, Hydrotalcite, etc.) and pigments can be used in combination.

[0018]

[Function] At least one polyvalent ammonium selected from the group consisting of ammonium polyphosphate and / or melamine-modified ammonium polyphosphate and pentaerythritol, dipentaerythritol, tripentaerythritol, pentitols, hexitols and saccharides. By using an ethylene vinyl acetate resin in combination with a flame-retardant polypropylene resin composition prepared by blending alcohols, a high degree of flame retardancy can be imparted.

Further, due to the action of the ethylene vinyl acetate resin as an elastic body, the blending amount of the ethylene vinyl acetate resin with respect to the whole flame-retardant polypropylene resin composition is 10
If the proportion is from 30% by weight to 30% by weight, the impact strength of the molded product can be increased. Further, it does not deteriorate the moldability.

[0020]

EXAMPLES Details of the present invention will be described below with reference to examples. Examples 1 to 3 Ethylene-propylene block copolymers having a melt index (MI) of 8 g / 10 mi, which is an index of moldability.
BJHH-G (trade name of Mitsui Toatsu Chemicals, Inc.) as polypropylene resin of n., Sumisafe P (trade name of Sumitomo Chemical Co., Ltd.) as ammonium polyphosphate, pentaerythritol of polyhydric alcohol Pentol (trade name, manufactured by Mitsui Toatsu Chemicals, Inc.) and Evertate K3010 (trade name, manufactured by Sumitomo Chemical Co., Ltd.) containing 28% by weight of vinyl acetate as an ethylene vinyl acetate resin should have the composition shown in Table 1. Weighed, put into a Henschel mixer, and mixed by stirring at 800 rpm for 2 minutes. The obtained mixture was kneaded at a melt-kneading temperature of 180 ° C. with an extruder having a diameter of 40 mm to form pellets.

The obtained pellets were injection-molded at a temperature of 190 ° C. and subjected to physical property tests of IZOD impact strength, flame retardancy and melt index (MI). The flame retardance test is based on the vertical combustion test based on UL (Underwriter Laboratories, Inc.) Subject 94 “Combustion test of plastic materials for parts of equipment”, and the thickness of the sample piece is measured at 1/16 inch. did. The melt index (MI) was measured in pellet form at 230 ° C and 2.16 kg.

Table 1 shows the composition (% by weight) of the flame-retardant polypropylene resin compositions of Examples 1 to 3 and the results of physical property tests. Further, the relationship between the blending amount of the ethylene vinyl acetate resin obtained from Table 1 and the IZOD impact strength is shown in FIG.

[0023]

[Table 1] Comparative Example 1 to Comparative Example 4 Excluding the silicone oil used in Comparative Example 4, Example 1
To IZOD impact strength and flame retardancy by using the same materials as in Example 3 to be weighed so as to have the composition shown in Table 2, pelletizing and injection molding in the same manner as in Examples 1 to 3. A physical property test of melt index (MI) was performed. The silicone oil used in Comparative Example 4 was a polydimethylsiloxane polymer having a viscosity of 10,000 cp which was terminated with silanol.

The results of the physical property tests are shown in Table 2.

In Comparative Example 1, since no ethylene vinyl acetate resin was blended, the IZOD impact strength was low and a practical flame-retardant polypropylene resin composition could not be obtained. In addition, Comparative Example 2 was a very brittle material, and the test piece was destroyed at the time of mold release after injection molding, and the physical property test could not be performed. In Comparative Example 3, the IZOD impact strength was lower than that of Comparative Example 1 because the blending amount of pentaerythritol as the flame retardant aid was too large. In Comparative Example 4, the IZOD impact strength is relatively good, but the flame retardancy is as low as rank V-2.
D Impact strength and flame retardancy were not well balanced.

[0026]

[Table 2]

[0027]

The flame-retardant polypropylene resin composition of the present invention comprises ammonium polyphosphate and / or melamine-modified ammonium polyphosphate, pentaerythritol, dipentaerythritol, tripentaerythritol, pentitols, hexitols and saccharides. Ethylene vinyl acetate resin in addition to at least one polyhydric alcohol selected from the group consisting of 10 wt.
Since it is compounded in a proportion of 0% by weight, it has a high flame retardant property without deteriorating the molding processability. Moreover, the impact strength of the molded product can be increased by the action of the ethylene vinyl acetate resin as an elastic body.

Further, since it does not generate a corrosive or toxic gas at the time of combustion, it is useful in various fields such as household electric appliances, buildings, upholstery and automobile parts.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the blending amount of ethylene vinyl acetate resin and IZOD impact strength in Examples 1 to 3.

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Claims (1)

[Claims] 1. A group consisting of a polypropylene resin, an ammonium polyphosphate and / or a melamine-modified ammonium polyphosphate in the polypropylene resin, pentaerythritol, dipentaerythritol, tripentaerythritol, pentitols, hexitols and saccharides. A flame-retardant polypropylene resin composition prepared by blending with at least one polyhydric alcohol selected from the group consisting of: a flame-retardant polypropylene resin composition and an ethylene vinyl acetate resin; A flame-retardant polypropylene resin composition, which is compounded in a proportion of 10% by weight to 30% by weight with respect to the entire product.