JPH07330969A - Flame-retardant polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyolefin composition which can exhibit excellent flame retardancy without using any halogenous compound and is so excellent in fabricability that it can provide a fabricated article with excellent qualities. CONSTITUTION:This composition comprises a polyolefin resin, a phosphorus compound represented by the formula, and a metal oxide, the content of the metal oxide being 0.5-10wt.% based on the phosphorus compound. In the formula, R1 and R3 are each hydrogen, a 1-16 C linear or branched alkyl or aryl; and R2 is hydrogen, hydroxyl, a 1-16 C linear or branched alkyl, a 1-16 C linear or branched alkoxyl, aryl or aryloxy.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant polyolefin resin composition.

[0002]

2. Description of the Related Art Polyolefin resins are appropriately crosslinked by a method such as electron beam irradiation or addition of peroxide,
Since it exhibits excellent mechanical strength and heat resistance,
Widely used as a wire covering material, heat shrinkable tube, etc.

Such a polyolefin resin is originally a resin that easily burns (flammability), but with the recent expansion of its applications, the demand for flame retardancy has increased, making it difficult to use polyolefin resins by various methods. Burning is being considered. As described above, cross-linking the polyolefin-based resin improves mechanical strength, heat resistance and the like, and some flame retardancy is recognized, but it is still flammable.

As a general method for making a polyolefin resin flame-retardant, a method of adding a halogen-containing compound is performed. The method of adding the halogen-containing compound, it is possible to impart a high degree of flame retardancy to the polyolefin resin, a large amount of corrosive gas due to the halogen-containing compound is generated during secondary processing and combustion, Toxicity to the human body and corrosiveness to equipment have become problems. In order to address the above problems, a safe flame-retardant method for polyolefin-based resins that does not use halogen-containing compounds has been strongly demanded.

Various methods for flame-retarding a polyolefin resin without using the above halogen-containing compound have been studied, for example, 100 parts by weight of an olefin resin, 50 to 300 parts by weight of hydrated alumina and / or hydrated magnesia, and red. phosphorus,
A flame-retardant resin composition containing 3 to 50 parts by weight of at least one selected from zinc borate and titanium dioxide and 0.1 to 5 parts by weight of a coupling agent (JP-A-61-21323).
No. 4), 100 parts by weight of polyolefin,
50 to 300 parts by weight of an inorganic flame retardant such as aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, calcium hydroxide, and hydrotalcite, and an inorganic powder 1 having an average particle size of 50 μm or less that becomes glass at 800 ° C. or less
Flame-retardant compositions (JP-A-4-253745) containing 0 to 100 parts by weight, respectively, have been proposed.

However, in the case of the above-mentioned method or the method proposed above, in order to impart sufficient flame retardancy to the polyolefin resin, it is necessary to add a large amount of a hydrated metal oxide or an inorganic flame retardant. As a result, there are problems that the secondary processability of the polyolefin-based resin composition becomes difficult, and the quality of the secondary processed product such as mechanical strength is remarkably deteriorated and it cannot be practically used. That is, the fact is that a method for sufficiently flame-retarding a polyolefin resin has not yet been established without using a halogen-containing compound and without lowering the secondary processability or the quality of the secondary processed product. is there.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention exhibits excellent flame retardancy without using a halogen-containing compound, as well as secondary processability and secondary processed products. It is an object of the present invention to provide a flame-retardant polyolefin resin composition having excellent quality.

[0008]

A flame-retardant polyolefin resin composition according to the present invention comprises a polyolefin resin containing a phosphorus-containing compound represented by the following general formula (1) and a metal oxide. The content of the metal oxide is 0.5 to 10% by weight of the phosphorus-containing compound,
Thereby, the above object is achieved.

[Chemical 2] (In the formula, R ₁ and R ₃ represent a hydrogen atom, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group,
R ₂ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 16 carbon atoms, a linear or branched alkoxyl group having 1 to 16 carbon atoms, an aryl group, or an aryloxyl group)

The type of polyolefin resin used in the flame-retardant polyolefin resin composition according to the present invention is not particularly limited, but polypropylene resin, polyethylene resin, poly (1-butene) resin is used. , Polypentene resins, etc., and one or more of these are preferably used.

The polypropylene resin may be not only a polypropylene homopolymer but also a copolymer containing propylene as a main component and a mixture thereof. The copolymer containing propylene as a main component is not particularly limited, but propylene and ethylene, 1-
Hexene, 4-methyl-1-pentene, 1-octene,
Examples thereof include copolymers with 1-butene, 1-pentene, and other α-olefins, and one or more of these are preferably used.

The polyethylene resin may be not only a polyethylene homopolymer but also a copolymer containing ethylene as a main component and a mixture thereof. The copolymer containing ethylene as a main component is not particularly limited, but ethylene and propylene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-
Examples thereof include copolymers with α-olefins such as butene and 1-pentene, copolymers with ethylene and vinyl acetate, and copolymers with ethylene and ethyl acrylate. One or more of these are preferred. Used for.

The type of the phosphorus-containing compound represented by the above general formula (1) used in the flame-retardant polyolefin resin composition according to the present invention is not particularly limited, but methylphosphonic acid, methyl Dimethyl phosphonate, Diethyl methylphosphonate, Ethylphosphonic acid, Propylphosphonic acid, Butylphosphonic acid, 2-
Methyl-propylphosphonic acid, tert-butylphosphonic acid, 2,3-dimethyl-butylphosphonic acid,
Octylphosphonic acid, phenylphosphonic acid, dioctylphenylphosphonate, dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, diethylphosphinic acid, dioctylphosphinic acid, phenylphosphinic acid, diethylphenyl Examples thereof include phosphinic acid, diphenylphosphinic acid and bis (4-methoxyphenyl) phosphinic acid, and one or more of these are preferably used.

The content of the phosphorus-containing compound in the polyolefin resin is not particularly limited, but is preferably 5 to 200 parts by weight with respect to 100 parts by weight of the polyolefin resin.

When the content of the phosphorus-containing compound is less than 5 parts by weight based on 100 parts by weight of the polyolefin resin, the flame retardancy of the polyolefin resin composition becomes insufficient, and when it exceeds 200 parts by weight, the polyolefin resin is contained. The secondary processability of the resin composition and the mechanical strength of the secondary processed product are deteriorated, resulting in poor practicability.

The type of metal oxide used in the flame-retardant polyolefin resin composition according to the present invention is not particularly limited, but transition metal oxides excluding alkali metals are preferable. Alkali metal oxides are not easily used in the present invention because they are easily decomposed and unstable.

The types of transition metal oxides other than the above alkali metals are not particularly limited, but magnesium oxide, aluminum oxide, titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide. , Nickel oxide, zinc oxide and the like, and one or more of these are preferably used. Also, the metal oxides may be in different oxidation states.

The metal oxide functions as a flame retardant aid, and the addition of a relatively small amount of the metal oxide remarkably improves the flame retardant effect of the phosphorus-containing compound as a flame retardant.

In the flame-retardant polyolefin resin composition according to the present invention, the content of the metal oxide is 0.5 to 10% by weight of the phosphorus-containing compound represented by the general formula (1).
It is necessary to be.

When the content of the above metal oxide is less than 0.5% by weight of the above phosphorus-containing compound, the flame retardancy-improving effect cannot be sufficiently obtained. Although it is no longer improved, the quality such as the mechanical strength of the secondary processed product deteriorates.

The flame-retardant polyolefin resin composition according to the present invention may contain a nitrogen-containing compound.

The kind of the above-mentioned nitrogen-containing compound is not particularly limited, but urea, uric acid, thiourea, biuret, adenine, guanine, 2,6-diaminopurine, 2,4,6-triaminopyrimidine. , Melamine, cyanuric acid and their derivatives, and one or more of these are preferably used.

The nitrogen-containing compound is represented by the general formula (1) above.
The flame retardancy of the polyolefin resin composition is further improved by a synergistic effect with the phosphorus-containing compound represented by

The content of the nitrogen-containing compound in the polyolefin resin is not particularly limited,
The amount of the nitrogen-containing compound is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the polyolefin resin.

If the content of the nitrogen-containing compound is less than 1 part by weight based on 100 parts by weight of the polyolefin resin, the flame retardancy-improving effect cannot be sufficiently obtained. On the contrary, if it exceeds 50 parts by weight, the flame retardancy is no longer exhibited. Although not improved, the quality of the secondary processed product such as mechanical strength is deteriorated.

Further, in the flame-retardant polyolefin resin composition according to the present invention, a phenol-based antioxidant, an amine-based antioxidant, a sulfur-based antioxidant or the like, and a metal damage inhibitor may be added, if necessary, within a range that does not impair the object of the present invention. , One or more kinds of various additives such as a stabilizer, an ultraviolet absorber, an antistatic agent, a crosslinking initiator, a lubricant, a softening agent, a filler and a coloring agent may be contained in an appropriate amount.

The method for producing the flame-retardant polyolefin resin composition according to the present invention is not particularly limited,
For example, a method of melt-kneading a predetermined amount of each component constituting the flame-retardant polyolefin-based resin composition using a general-purpose kneading device such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, or a roll is used. Can be mentioned.

[0027]

The flame-retardant polyolefin resin composition according to the present invention has the same general formula (1) as the polyolefin resin.
Since a phosphorus-containing compound represented by and a specific amount of a metal oxide are contained, excellent flame retardancy is exhibited, and secondary processability and quality of the secondary processed product are also excellent.

Further, since it does not contain a halogen-containing compound, there are almost no safety-related problems such as toxicity to human bodies and corrosiveness to equipment.

[0029]

EXAMPLES In order to explain the present invention in more detail, examples will be given below. In addition, "part" in an Example means a "weight part."

(Example 1)

( 1) Polyolefin resin composition and composition
Preparation of shaped sheet For 100 parts of polypropylene resin (density = 0.90, melt index = 1.5), 8 parts of phenylphosphinic acid (made by Wako Pure Chemical Industries, Ltd.) as a phosphorus-containing compound and oxidation as a metal oxide. Magnesium (made by Wako Pure Chemical Industries, Ltd.)
0.6 part, and 2 parts of biuret (manufactured by Wako Pure Chemical Industries, Ltd.) as a nitrogen-containing compound, and melt-kneaded at 170 ° C. for 5 minutes at 60 rpm with a Labo Plastomill. Thus, a polyolefin resin composition was obtained. Then, the above composition was press-molded at 170 ° C. to give a thickness of 3 mm.
A molded sheet of was prepared.

( 2) Evaluation The flame retardancy of the molded sheet obtained above was evaluated by the following method, and the results are shown in Table 1.

In accordance with JIS K-7201 "Combustion test method for polymer materials by oxygen index method", combustion of No. A-1 test piece (length 150 mm, width 6.5 mm, thickness 3 mm) of the above-mentioned molded sheet. A test was conducted, the oxygen index was calculated, and the flame retardancy was judged according to the following evaluation criteria. [Evaluation Criteria] O The degree of improvement of the oxygen index of the sample containing the metal oxide is 2 or more with respect to the oxygen index of the sample containing the same metal oxide but not containing the metal oxide. In the above case, the degree of improvement in the oxygen index of the sample containing the metal oxide was less than 2 with respect to the oxygen index of the sample containing no metal oxide.

(Examples 2 to 4)

Three kinds of polyolefin resin compositions and molded sheets were prepared in the same manner as in Example 1 with three kinds of compounding compositions as shown in Table 1.

The flame retardancy of the obtained three types of molded sheets was evaluated in the same manner as in Example 1 and the results are shown in Table 1.

(Comparative Examples 1 and 2)

Two kinds of polyolefin resin compositions and molded sheets were prepared in the same manner as in Example 1 with the two kinds of composition as shown in Table 1.

The results of evaluating the flame retardancy of the obtained two types of molded sheets in the same manner as in Example 1 are shown in Table 1.

[0040]

[Table 1]

[0041]

As described above, the flame-retardant polyolefin resin composition according to the present invention has excellent flame retardancy, secondary processability and secondary processed product quality. Further, since it does not contain a halogen-containing compound, there is almost no safety problem.

Claims (1)

[Claims] 1. A polyolefin resin containing a phosphorus-containing compound represented by the following general formula (1) and a metal oxide, wherein the content of the metal oxide is 0.5 to 0.5% of that of the phosphorus-containing compound. A flame-retardant polyolefin resin composition, which is 10% by weight. [Chemical 1] (In the formula, R ₁ and R ₃ represent a hydrogen atom, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group,
R ₂ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 16 carbon atoms, a linear or branched alkoxyl group having 1 to 16 carbon atoms, an aryl group, or an aryloxyl group)