JPH0662818B2 - Flame-retardant polypropylene resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flame-retardant polypropylene resin composition. More specifically, a polypropylene resin as a main component, no corrosive gas or toxic gas is generated, deterioration of molding processability and deterioration of mechanical strength of the molded product when formed are small, and The present invention relates to a flame-retardant polypropylene resin composition from which a molded article having flame-retardant performance can be obtained.

Conventionally, polypropylene resin has been used for processability, chemical resistance,
Due to its weather resistance, electrical characteristics and mechanical strength, it is widely used not only in the field of household electric appliances but also in various fields such as buildings, upholstery and automobile parts.

(Prior art) Originally, polypropylene resin is a resin that is easy to burn, but with the expansion of the applications in which it is used, polypropylene resin is required to have performance as a flame-retardant material, and moreover, the performance required every year becomes severe. There is. Various flame-retardant polypropylene resin compositions have been proposed to meet these demands.

For example, JP-A-53-92855, JP-A-54-29350, JP-A-54-77658, JP-A-56-26954,
As disclosed in JP-A-57-87462 and JP-A-60-110738, hydrous inorganic compounds (for example, magnesium hydroxide, aluminum hydroxide, barium sulfate, magnesium antimony oxide, hydrotalcite) Etc.) to a polypropylene resin, for example, melt index, 0.01 to 2.0 polyethylene and decabromo diphenyl ether (or dodecachloro odecahydromethanodibenzo as disclosed in JP-B-55-30739). Cyclooctene) and powdered talc, kaolinite, sericite, silica, a composition obtained by adding one or more inorganic fillers selected from diatomaceous earth to a polypropylene resin, as disclosed in JP-A-59-147050. And ammonium phosphate (or amine phosphate) and 1,3,5-triazine derivatives Such compositions oligomer (or polymer) was added to a polypropylene resin has been proposed.

However, in order to impart a high degree of flame retardancy to a composition obtained by adding a water-containing inorganic compound to a polypropylene resin, for example, a composition containing magnesium hydroxide, it is necessary to add a large amount of the water-containing inorganic compound. As a result, the composition causes deterioration of molding processability and mechanical strength of the molded product when it is formed into a molded product.

Further, a composition containing a halogen-based compound has relatively little deterioration in molding processability and mechanical strength of the molded product when formed into a molded product, and a molded product having a high degree of flame retardancy can be obtained. When processing or burning, a corrosive gas or a toxic gas is generated, which is a drawback.

Further, the flame-retardant polypropylene resin composition disclosed in JP-A-59-147050 has relatively little deterioration in molding processability and mechanical strength of the molded product when formed into a molded product. Corrosive gas and toxic gas are rarely generated at the time of combustion.

However, the composition is flammable in a test (hereinafter referred to as UL94 flammability test) based on the vertical flammability test of "Combustion test of plastic material for parts of equipment" of UL Subject 94 (Underwriter Laboratories, Inc.). Although the rank is VO at a thickness of ⅛ inch, in the 5V test that requires higher flame retardancy, dropping of droplets and dropping of burned pieces due to melting (hereinafter, these droplets and drops It is difficult to achieve a flame retardancy of 5V with a 1/8 inch wall thickness, which is a highly flame retardant property, because the thing called a drip and the property of causing a drip is called the drip property.). Further, even if an ethylene-based synthetic rubber or elastomer, which is generally used for improving the impact strength of polypropylene, is added to the composition, the effect of improving the impact resistance such as Izod impact strength is hardly seen.

(Problems to be Solved by the Invention) The present inventors have found that high flame retardancy, that is, 1 in UL94 combustion test.
/ 8 inch thick, 5V flame retardant, does not generate corrosive gas or toxic gas at the time of processing or burning, and has lower molding processability or molding product In order to obtain a flame-retardant polypropylene resin composition capable of obtaining a molded article having excellent impact resistance with little decrease in the mechanical strength, the above-mentioned studies were conducted earnestly. As a result, a polypropylene resin, a polyethylene resin or a polyethylene resin and an ethylene-based synthetic rubber or elastomer, ammonium polyphosphate, a 1,3,5-triazine derivative having a structure represented by the following general formula [I], [In the formula, X is a morpholino group or a piperidino group, Y is a divalent group of piperazine, and n is an integer of 2 to 50. A composition containing a crosslinking aid and one or more specific amounts of thiophosphite selected from those represented by the general formulas [II], [III], [IV] and [V] solves the above-mentioned problems. Based on this finding, the present invention has been completed.

[In the formula, R ₁ represents an alkyl group having 6 or more carbon atoms, a cycloalkyl group, or an aryl group. R ₂ is -SR
A ₂ 'or -R _{2', R 3} is -SR ₃ 'or -R
₃ ′ and —R ₂ ′ and —R ₃ ′ represent the same or different alkyl group, cycloalkyl group or aryl group having 6 or more carbon atoms.

X is _{- (CH 2) n -,} - (CH 2) n-O- (CH 2) m-
It is represented by or.

Here, n, m, and l represent the same or different integers of 2 to 6. As is clear from the above description, an object of the present invention is to provide a flame-retardant polypropylene resin composition which can solve the above-mentioned problems and can obtain a molded article having a high degree of flame retardancy.

(Means for Solving the Problems) The present invention has the following configurations.

(1) 100% by weight of the total of (A) to (F) below
As (A) polyethylene resin 5 to 30% by weight (B) ammonium polyphosphate 12 to 25% by weight (C) having a structure represented by the following general formula [I] 1,3,
5-triazine derivative 5-10% by weight [In the formula, X is a morpholino group or a piperidino group, Y is a divalent group of piperazine, and n is an integer of 2 to 50. (D) Crosslinking aid 1 to 15% by weight (E) Thiophosphite 0.05 to 5% by weight selected from those represented by the following general formulas [II], [III], [IV] and [V] [In the formula, R ₁ represents an alkyl group having 6 or more carbon atoms, a cycloalkyl group, or an aryl group. R ₂ is-
SR ₂ ′ or —R ₂ ′, R ₃ is —SR ₃ ′ or —
R ₃ ′, and —R ₂ ′ and —R ₃ ′ represent the same or different alkyl group, cycloalkyl group or aryl group having 6 or more carbon atoms. X is _{- (CH 2) n -,} -
_{(CH 2) n-O- (} CH 2) represented m- or at.
Here, n, m, and l represent the same or different integers of 2 to 6. ] (F) Flame-retardant polypropylene resin composition which is the remaining polypropylene resin.

(2) The total of the following (A) to (G) is 100% by weight.
As (A) polyethylene resin 5 to 30% by weight (B) ammonia polyphosphate 12 to 25% by weight (C) having a structure represented by the following general formula [I] 1,
3,5-triazine derivative 5-10% by weight [In the formula, X is a morpholino group or a piperidino group, Y is a divalent group of piperazine, and n is an integer of 2 to 50. (D) Crosslinking aid 1 to 15% by weight (E) Thiophosphite 0.05 to 5% by weight selected from the compounds represented by the following general formulas [II], [III], [IV] and [V] [In the formula, R ₁ represents an alkyl group having 6 or more carbon atoms, a cycloalkyl group, or an aryl group. R ₂ is-
SR ₂ ′ or —R ₂ ′, R ₃ is —SR ₃ ′ or —
R ₃ ′, and —R ₂ ′ and —R ₃ ′ represent the same or different alkyl group, cycloalkyl group or aryl group having 6 or more carbon atoms. X is _{- (CH 2) n -,} -
_{(CH 2) n-O- (} CH 2) represented m- or at.
Here, n, m, and l represent the same or different integers of 2 to 6. ] (G) Ethylene Synthetic Rubber or Elastomer 5
30% by weight (F) Flame-retardant polypropylene resin composition containing the remaining polypropylene resin.

As the polypropylene resin used in the present invention, a crystalline propylene homopolymer, a crystalline copolymer containing a propylene component 70% by weight or more, propylene and ethylene, butene-1, pentene-1, hexene-1, A crystalline copolymer with one or more selected from 4-methylpentene-1, heptene-1, octene-1, and decene-1, or a mixture of two or more thereof can be mentioned.
A crystalline ethylene-propylene block copolymer is particularly preferable.

The polyethylene resin used in the present invention may be any of high-density polyethylene, medium-density polyethylene, and low-density polyethylene, but it is preferable to use high-density polyethylene in order to prevent a decrease in the rigidity of the molded product.

The mixing ratio of the polyethylene resin is 5 to 30 relative to the composition.
% By weight, preferably 7 to 20% by weight, particularly preferably 10 to
20% by weight. If the blending ratio is less than 5% by weight, the flame retardancy of 5V at 1/8 inch wall thickness cannot be achieved in the UL94 combustion test, and if it exceeds 30% by weight, it becomes 5V at 1/8 inch wall thickness again. It is not preferable because the flame retardancy of 1 cannot be achieved.

Examples of the ethylene-based synthetic rubber or elastomer used in the present invention include ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-1-butene rubber, ethylene-vinyl acetate copolymer, and polyolefin-based thermoplastic elastomer. Among them, ethylene-propylene rubber and ethylene-propylene-diene rubber are preferably used from the viewpoint of improving impact strength.

The blending ratio of the ethylene-based synthetic rubber or elastomer is 5 to 30% by weight, preferably 7 to 20% by weight, particularly preferably 10 to 20% by weight, based on the composition. If the blending ratio is less than 5% by weight, the effect of improving the impact strength is poor, and 30
If it exceeds 5% by weight, good mechanical strength and heat resistance inherent to polypropylene are lost, which is not preferable.

As the ammonium polyphosphate used in the present invention, a commercially available product may be used as it is, and as the commercially available product, for example, ammonium polyphosphate such as Sumisafe P (trade name, manufactured by Sumitomo Chemical Co., Ltd.) can be mentioned.

The compounding ratio of the ammonium polyphosphate is 12 with respect to the composition.
~ 25% by weight. If the compounding ratio is less than 12% by weight, UL94
A composition that achieves a flame retardancy of 5V with a 1/8 inch wall thickness in a combustion test cannot be obtained, and even if the composition exceeds 25% by weight, no further improvement effect of flame retardancy can be obtained. In addition, hygroscopicity is increased due to the ammonium polyphosphate, which is not preferable.

The 1,3,5-triazine derivative used in the present invention includes 2
Examples thereof include an oligomer or polymer of piperazinylene-4-morpholino-1,3,5-triazine and an oligomer or polymer of 2-piperazinylene-4-piperidino-1,3,5-triazine.

The content of the 1,3,5-triazine derivative is 5 to 10% by weight based on the composition. If the blending ratio is less than 5% by weight, it is highly flame-retardant.
The flame retardancy of 5V cannot be achieved, and even if it exceeds 10% by weight, the flame retardancy cannot be further improved. Also,
The above-mentioned 2-piperazinylene-4-morpholino-1,3,5-triazine oligomer or polymer, which is one of the 1,3,5-triazine derivatives, can be obtained, for example, by the following method. That is, equimolar amounts of 2,6-dihalo-4-morpholino-1,3,5-triazine (e.g. 2,6-dichloro-4-morpholino-1,3,5-triazine or
2,6-Dibromo-4-morpholino-1,3,5-triazine)
And piperazine in the presence of an organic or inorganic base (eg triethylamine, tributylamine, sodium hydroxide, potassium hydroxide, sodium carbonate, etc.) in an inert solvent such as xylene under heating, preferably under the boiling point of the inert solvent. After the completion of the reaction, the reaction mixture is passed to separate and remove the by-product salt, which is washed with boiling water and dried.

Further, the above-mentioned 2-piperazinylene-4-piperidino-1,
The 3,5-triazine oligomer or polymer can also be obtained, for example, by the following method. That is, equimolar amounts of 2,6-dihalo-4-piperidino-1,3,5-triazine (e.g. 2,6-dichloro-4-piperidino-1,3,5-triazine or 2,6-dibromo-4- Piperidino-1,
3,5-triazine) and piperazine in the presence of an organic or inorganic base (eg triethylamine, tributylamine, sodium hydroxide, potassium hydroxide, sodium carbonate) using an inert solvent such as triisopropylbenzene. Preferably, the reaction is carried out at the boiling point of the inert solvent, and after the reaction is completed, the reaction mixture is passed to separate and remove salts of by-products, followed by washing with boiling water and drying. You can

Examples of the crosslinking aid used in the present invention include polyfunctional monomers, oxime nitroso compounds, maleimide compounds and the like. As specific examples, for example, triallyl isocyanurate, (di) ethylene glycol di (meth) acrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,
Trimethylol ethylene triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, divinylbenzene, diallylphthalate, divinylpyridine, quinonedioxime, benzoquinonedioxime, p-nitrosophenol, N, N'-m
Examples thereof include phenylene bismaleimide. Preferred are polyfunctional (meth) acrylic acid esters such as trimethylolpropane tri (meth) acrylate and pentaerythritol triacrylate.

The blending ratio of the crosslinking aid is 1 to 15% by weight, more preferably 1 to 7% by weight. If it is less than 1% by weight, there is almost no effect of preventing dripping during combustion, and if it is added in excess of 15% by weight, it is meaningless because further improvement of the effect of preventing dripping is lost.

The above-mentioned general formulas [II], [III], and [I] used in the present invention
Examples of the thiophosphite represented by V] and [V] include trilauryltrithiophosphite, tridecyltrithiophosphite, tribenzyltrithiophosphite, tricyclohexyltrithiophosphite, tri (2-ethylhexyl) trithiophosphite, trinaphthyltrithiate. Ofosphite, diphenyldecyltrithiophosphite, diphenyllauryltrithiophosphite, tetralauryl-4-oxabutylene, -1,7-
Tetrathiophosphite, tetrakis (mercaptolauryl) -1,6-dimercaptohexylene diphosphite, pentakis (mercaptolauryl) bis (1,6-hexylene-dimercapto) trithiophosphite, tetrakis (mercaptolauryl) -2, 9-dimercapto-
Para-methylene diphosphite, bis (mercaptolauryl) -1,6-dimercaptohexylene-bis (benzenephosphonite), tetrakis (mercaptolauryl)
-2,9-dimercapto-para-methylene diphosphite, dioctyl dithiopentaerythritol diphosphite, dilauryl dithiopentaerythritol diphosphite, phenyl lauryl dithiopentaerythritol diphosphite and mixtures of two or more thereof. be able to.

The compounding ratio of the thiophosphite is 0.05 to 5% by weight, more preferably 0.1 to 2% by weight. If the blending ratio is less than 0.05% by weight, the anti-dripping effect is poor, and it is 5% by weight.
It is meaningless to add more than 5% since the improvement of the anti-dripping effect is lost.

In the composition of the present invention, various additives which are usually added to polypropylene resin, such as an antioxidant, an antistatic agent, a lubricant and a pigment, can be used in combination.

The flame-retardant polypropylene resin composition of the present invention can be produced, for example, by the following method.

That is, the above-mentioned polyethylene resin or the polyethylene resin and the ethylene-based synthetic rubber or elastomer in polypropylene resin, ammonium polyphosphate, the 1,3,5-triazine derivative having the structure represented by the general formula [I], the crosslinking aid and the general formula [II], [III], [IV]
And thiophosphite selected from among those represented by [V] and predetermined amounts of the above-mentioned various additives are put into a stirrer / mixer such as a hexel mixer (trade name), a super mixer or a tumbler mixer, and stirred for 1 to 10 minutes. After mixing, the obtained mixture can be obtained by melt-kneading at a melt-kneading temperature of 170 to 220 ° C. with a roll, an extruder or the like and pelletizing.

(Examples) Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation methods used in Examples and Comparative Examples were as follows.

1) Flame-retardant UL Subject 94 (Underwriter Laboratories, Inc.) 'S "Combustion test of plastic materials for equipment parts" conforms to the A method of 5V combustion test, the thickness of the test piece is 1/8 inch.

2) Flexural modulus Complies with JIS K 7203.

3) Izod impact strength Complies with JIS K 7110.

Example 1, Comparative Examples 1-2 As polypropylene resin, ethylene content 8.5% by weight, melt flow rate (temperature 230 ° C., discharge amount of molten resin for 10 minutes when load 2.16 kg) 20 g / 10 minutes 51% by weight of a crystalline ethylene-propylene block copolymer,
As the polyethylene resin as the component (A), a melt index (a temperature of 190 ° C., a discharge amount of the molten resin for 10 minutes when a load of 2.16 kg is added) 6.5 g / 10 minutes of an ethylene homopolymer (Chisso Polyethylene (trademark) M680) , Chisso Co., Ltd.) 15% by weight, component (B) ammonium polyphosphate (Sumisafe P (trademark) Sumitomo Chemical Co., Ltd.) 21% by weight, component (C) 1,3,5- As a triazine derivative, 2-piperazinylene-4-morpholino-1,3,5-triazine polymer (n = 11, molecular weight about 2770) 8% by weight, component (D)
3% by weight of trimethylolpropane triacrylate as a crosslinking aid, 0.5% by weight of trilauryltrithiophosphite as a thiophosphite as the component (E), and 2,6-di-t-butyl-p
-0.15% by weight of cresol, 0.2% by weight of di-myristyl-β, β-thiodipropionate and 0.1% by weight of calcium stearate were placed in a Hensell mixer (trade name) and mixed with stirring for 3 minutes. The obtained mixture was melt-kneaded and extruded at a melt-kneading temperature of 200 ° C. with an extruder having a diameter of 45 mm to form a pellet.

Further, as Comparative Examples 1 and 2, Comparative Example 1 does not contain the polyethylene resin which is the component (A), and Comparative Example 2 does the component (D).
And (E) except that trimethylolpropane triacrylate and trilauryltrithiophosphite are not blended, each blending component was put in a Henschel mixer (trade name) at a blending ratio according to Example 1, and according to Example 1. Then, the mixture was stirred and mixed, melt-kneaded, extruded, and pelletized.

The pellets obtained in Examples and Comparative Examples were mixed at a temperature of 100 ° C for 3 days.
After drying for an hour, predetermined pellets for flame retardancy, flexural modulus, and Izod impact strength measurement were molded using an injection molding machine in which the maximum cylinder temperature was set to 220 ° C. using the pellet. Flame resistance, flexural modulus,
The Izod impact strength was measured. The results are shown in Table 1.

Examples 2 to 5 and Comparative Examples 3 to 4 According to Example 1 except that the polypropylene resin, polyethylene resin, trimethylolpropane triacrylate and trilauryltrithiophosphite were changed to the compounding ratios shown in Table 1. The respective components were put in a hexel mixer (trade name), and stirred and mixed, melt-kneaded and extruded according to Example 1, and pelletized.

Using the pellets obtained in each of Examples and Comparative Examples, a test piece for flame retardancy evaluation was prepared according to Example 1 and flame retardancy was evaluated. The results are shown in Table 1.

Example 6 As the 1,3,5-triazine derivative which is the component (C), 2-
According to the same manner as in Example 1 except that a polymer of piperazinylene-4-piperidino-1,3,5-triazine (n = 11, molecular weight of about 2800) was used, each compounding component was put into a Hensell mixer (trade name), and execution was performed. According to Example 1, the mixture was stirred, melt-kneaded, extruded, and pelletized. Using the pellet obtained, a flame-retardant evaluation test piece was prepared according to Example 1, and the flame-retardant property was evaluated. The results are shown in Table 1.

Examples 7 to 9 and Comparative Examples 5 to 13 As the component (F) polypropylene resin, a crystalline ethylene-propylene block copolymer having an ethylene content of 8.5% by weight and a melt flow rate of 20 g / 10 min, component (A).
6.5 g of melt index as polyethylene resin which is
/ 10 min ethylene homopolymer (Chisopolyethm)
M680, manufactured by Chisso Corp., ethylene-propylene rubber (JSR EP (trademark) 02P, Japan Synthetic Rubber Co., Ltd.) as an ethylene-based synthetic rubber or elastomer as component (G)
), Component (D) trimethylolpropane triacrylate and component (E) trilauryltrithiophosphite at the compounding ratios shown in Table 2, and component (B) ammonium polyphosphate ( 21% by weight of Sumisafe P (trademark) manufactured by Sumitomo Chemical Co., Ltd., a polymer of 2-piperazinylene-4-morpholino-1,3,5-triazine (1,3,5-triazine derivative as component (C) ( n = 11, molecular weight about 2770) 8% by weight, and as various additives 2,6-di-t-butyl-p-cresol, 0.1
5% by weight, di-myristyl-β, β-thiodipropionate 0.2% by weight and calcium stearate 0.1% by weight
Was placed in a Henschel mixer (trade name) and mixed by stirring for 3 minutes. The obtained mixture was melt-kneaded and extruded at a melt-kneading temperature of 200 ° C. with an extruder having a diameter of 45 mm to form a pellet.

After drying the pellets obtained in each Example and Comparative Example for 3 hours at a temperature of 100 ° C, the pellets were used for flame retardancy and Izod impact strength with an injection molding machine in which the maximum temperature of the cylinder was set to 220 ° C. Each predetermined test piece for measurement was molded. Using the test piece, flame retardancy and Izod impact strength were measured. The results are shown in Table 2.

(Effects of the Invention) The composition of the present invention has a high degree of flame retardancy, that is, a flame resistance of 5 V at a thickness of ⅛ inch in UL94 combustion test, corrosive gas and toxicity during processing and combustion. A flame-retardant polypropylene resin composition capable of producing a molded product having excellent impact resistance, which is free from the generation of gas, and has little deterioration in molding processability and mechanical strength of the molded product when formed into a molded product. Is. Therefore, it can be suitably used for manufacturing buildings, upholstery, household electric appliances, automobile parts and the like.

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Claims (3)

[Claims] 1. A total of (A) to (F) below is 100% by weight, (A) polyethylene resin 5 to 30% by weight (B) ammonium polyphosphate 12 to 25% by weight (C) the following general formula [ I]] 1,3,5-triazine derivative having a structure represented by 5-10% by weight [Wherein, X is a morpholino group or a piperidino group, Y is a divalent group of piperazine, and n is an integer of 2 to 50] (D) Crosslinking aid 1 to 15% by weight (E) The following general formula [II ], [III], [IV] and [V] selected from thiophosphite 0.05
~ 5% by weight [In the formula, R ₁ represents an alkyl group having 6 or more carbon atoms, a cycloalkyl group or an aryl group. R ₂ is -SR ₂ 'or -R _{2', R 3} is -SR ₃ 'or _{-R 3', -R 2 ',} -R 3' are the same or different than 6 carbon atoms It represents an alkyl group, a cycloalkyl group or an aryl group. X is - (CH ₂₎ n-, or - (CH ₂₎
n-O- (CH ₂₎ represented by the m-. Where n and m are 2
Representing the same or different integer of 6] (F) Flame-retardant polypropylene resin composition which is the remaining polypropylene resin. 2. The total of (A) to (G) below is 100% by weight, (A) polyethylene resin 5 to 30% by weight (B) ammonium polyphosphate 12 to 25% by weight (C) the following general formula [ I]] 1,3,5-triazine derivative having a structure represented by 5-10% by weight [Wherein, X is a morpholino group or a piperidino group, Y is a divalent group of piperazine, and n is an integer of 2 to 50] (D) Crosslinking aid 1 to 15% by weight (E) The following general formula [II ], [III], [IV] and [V] selected from thiophosphite 0.05
~ 5% by weight [In the formula, R ₁ represents an alkyl group having 6 or more carbon atoms, a cycloalkyl group or an aryl group. R ₂ is -SR ₂ 'or -R _{2', R 3} is -SR ₃ 'or _{-R 3', -R 2 ',} -R 3' are the same or different than 6 carbon atoms It represents an alkyl group, a cycloalkyl group or an aryl group. X is - (CH ₂₎ n-, or - (CH ₂₎
n-O- (CH ₂₎ represented by the m-. Where n and m are 2
Representing the same or different integer of 6] (G) Ethylene synthetic rubber or elastomer 5 to 30 wt% (F) Remaining polypropylene resin Flame-retardant polypropylene resin composition. 3. A polypropylene resin, which is a crystalline propylene homopolymer or a crystalline copolymer containing 70% by weight or more of a propylene component, wherein propylene and ethylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, decene-1
The flame-retardant polypropylene resin composition according to claim 1 or 2, wherein a crystalline copolymer with one or more selected from the above and a mixture of two or more thereof are used.