JPH07330970A - Flame-retardant crosslinkable polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition to which excellent flame retardancy, excellent fabricability, etc., are imparted without using any halogenous compound by mixing a polyolefin resin with a nitrogenous compound and a specified phosphorus compound. CONSTITUTION:This resin composition is obtained by mixing 100 pts.wt. polyolefin resin (A) (e.g. polyprolylene resin) with 0.5-30 pts.wt. nitrogenous compound (B) (e.g. triallyl isocyanurate) and 1-15 pts.wt. phosphorus compound (C) represented by formula I (wherein at least two of R1, R2 and R3 are groups of formula II and III, the rest are H, hydroxyl, a 20 C or lower linear or branched alkyl, a 20 C or lower linear or branched alkoxyl, aryl or aryloxy; R4 and R5 are H or methyl; and R5 is a 30 C or lower linear or branched alkyl) (e.g. dimethacryloyl phosphate) in such amounts that the total content of components B and C is 5 pts.wt. or above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant crosslinkable polyolefin resin composition.

[0002]

2. Description of the Related Art Polyolefin resins are crosslinked by adding peroxide to impart mechanical strength and heat resistance and by electron beam irradiation and the like to obtain foams, electric wire covering materials, heat shrinkable tubes, etc. Widely used.

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 which does not use the halogen-containing compound have been investigated, for example, a low crystalline ethylene copolymer treated with a titanate coupling agent and hydrated alumina. Flame-retardant polyolefin composition with low smoke pollution obtained by adding a hydrated metal oxide such as basic magnesium carbonate, zinc borate, zinc carbonate (JP-A-57-165437), polyethylene or ethylene vinyl acetate copolymer and ethylene 50 to 50 parts by weight of an inorganic flame retardant such as aluminum hydroxide, basic magnesium carbonate, magnesium hydroxide, hydrotalcite, etc., relative to 100 parts by weight of the blend of α-polyolefin.
Flame-retardant electrical insulating composition containing 300 parts by weight
1-36343), high-impact thermoplastic base polymers free of halogens and substances that form cyanides on combustion, are provided with flame-retardant additives such as ammonium polyphosphate and chopped reinforcing fibers. A flame-retardant and high-impact polyethylene molding composition (Japanese Patent Laid-Open No. 3-217456) containing a predetermined amount has 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 resin composition is difficult and the quality of the secondary processed product is deteriorated. Further, in the case of the method proposed above, there is a problem that a flame-retardant effect which is practically effective cannot be obtained by adding only a flame-retardant additive such as ammonium polyphosphate. As described above, a method for sufficiently flame-retarding a polyolefin-based resin without using a halogen-containing compound and without lowering the secondary processability or the quality of the secondary processed product has not yet been established. It is the reality.

[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 polyolefin-based flame-retardant crosslinkable resin composition having excellent quality.

[0008]

A polyolefin-based flame-retardant crosslinkable resin composition according to the present invention comprises 0.5 to 30 parts by weight of a nitrogen-containing compound and 100 parts by weight of a polyolefin-based resin and the following general formula (1). Phosphorus-containing compounds 1-5 represented
It is characterized by containing 0 parts by weight, and the total amount of the nitrogen-containing compound and the phosphorus-containing compound is 5 parts by weight or more, which achieves the above object.

[Chemical 3] (In the formula, two or more of R ₁ , R ₂ and R ₃ represent the following general formula (a) or (b), and the others represent a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 20 or less carbon atoms. Represents a linear or branched alkoxyl group having 20 or less carbon atoms, an aryl group, or an aryloxyl group)

[Chemical 4] [In the formulas (a) and (b), R ₄ and R ₆ represent a hydrogen atom or a methyl group, and R ₅ represents a linear or alkyl group having 30 or less carbon atoms)

The type of polyolefin resin used in the polyolefin flame-retardant crosslinkable resin composition of the present invention (hereinafter referred to as "polyolefin resin composition") is not particularly limited, but polypropylene type Examples thereof include resins, polyethylene-based resins, poly (1-butene) -based resins, polypentene-based resins and the like, 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 kind of the nitrogen-containing compound used in the polyolefin resin composition according to the present invention is not particularly limited, but it is preferable that the decomposition temperature thereof is close to the melting point of the polyolefin resin, for example, urea. , Biuret, thiourea, thiouric acid, melamine, melamine cyanurate, isocyanurate, mono (hydroxymethyl) isocyanurate, bis (hydroxymethyl) isocyanurate, tris (hydroxymethyl) isocyanurate, mono (dihydroxymethyl) isocyanurate, Bis (dihydroxymethyl) isocyanurate, tris (dihydroxymethyl) isocyanurate,
Mono (2-hydroxyethyl) isocyanurate, bis (2-hydroxyethyl) isocyanurate, tris (1,2-dihydroxyethyl) isocyanurate, tris (3-hydroxypropyl) isocyanurate, tris (2,3-dihydroxypropyl) ) Isocyanurate, tris (4-hydroxypropyl) isocyanurate, tris (3,4-dihydroxybutyl) isocyanurate, tris (8-hydroxyoctyl) isocyanurate, tris (4-hydroxyphenyl) isocyanurate, tris (2,2) 4-dihydroxyphenyl) isocyanurate, 1,3,5-tris (2-hydroxyethyl) cyanurate, isocyanuric acid triallyl ester, isocyanuric acid (N-propyl) diallyl ester, isocyanuric acid ( - ethyl) diallyl ester,
Isocyanuric acid (N-ethyl) allyl vinyl ester,
Isocyanuric acid (tri) homoallyl ester, cyanuric acid triallyl ester, isocyanuric acid triacryloyl ester, cyanuric acid diallyl monopropyl ester, cyanuric acid (tri) homoallyl ester, cyanuric acid triacryloyl ester, etc.
One kind or two or more kinds are preferably used.

The type of the phosphorus-containing compound represented by the general formula (1) used in the polyolefin resin composition according to the present invention is not particularly limited, but includes dimethacryloyl phosphate and di (methacryloyloxy). Methyl) phosphate, di (2-methacryloyloxyethyl) phosphate, di (3-methacryloyloxypropyl) phosphate, diacryloylphosphate, di (acryloyloxymethyl) phosphate, di (2-acryloyloxyethyl) phosphate Fate, di (3-acryloyloxypropyl) phosphate, trimethacryloyl phosphate, triacryloyl phosphate, trimethacryloyloxymethyl phosphate, trimethacryloyl (2-oxyethyl) phosphate Eto, tri methacryloyl (3-
(Oxypropyl) phosphate, triacryloyl phosphate, triacryloyloxymethyl phosphate, triacryloyl (2-oxyethyl) phosphate, triacryloyl (3-oxypropyl) phosphate, dimethacryloylphosphonic acid, di (methacryloyloxymethyl) ) Phosphonic acid, di (2-methacryloyloxyethyl) phosphonic acid, di (3-methacryloyloxypropyl) phosphonic acid, diacryloylphosphonic acid, di (acryloyloxymethyl)
Phosphonic acid, di (2-acryloyloxyethyl) phosphonic acid, di (3-acryloyloxypropyl) phosphonic acid, dimethacryloylphosphinic acid, di (methacryloyloxymethyl) phosphinic acid, di (2-
Methacryloyloxyethyl) phosphinic acid, di (3
-Methacryloyloxypropyl) phosphinic acid, diacryloylphosphinic acid, di (acryloyloxymethyl) phosphinic acid, di (2-acryloyloxyethyl) phosphinic acid, di (3-acryloyloxypropyl) phosphinic acid, and the like. 1 type or 2 types or more of these are used suitably.

Further, in the present invention, the above-mentioned phosphorus-containing compound, methacryloyl phosphate, methacryloyloxymethyl phosphate, (2-methacryloyloxyethyl) phosphate, (3-methacryloyloxypropyl) phosphate, acryloyl phosphate, Acryloyloxymethyl phosphate, (2
-Acryloyloxyethyl) phosphate, (3-
Acryloyloxypropyl) phosphate, methacryloylphosphonic acid, methacryloyloxymethylphosphonic acid, (2-methacryloyloxyethyl) phosphonic acid, (3-methacryloyloxypropyl) phosphonic acid, acryloylphosphonic acid, acryloyloxymethylphosphonic acid , (2-acryloyloxyethyl) phosphonic acid, (3-acryloyloxypropyl) phosphonic acid, methacryloylphosphinic acid, methacryloyloxymethylphosphinic acid, (2-methacryloyloxyethyl) phosphinic acid, (3-methacryloyloxypropyl) Phosphinic acid, acryloylphosphinic acid, acryloyloxymethylphosphinic acid, (2-acryloyloxyethyl) phosphinic acid, (3-a Leroy oxy propyl) monofunctional monomers such as phosphine acid may be used in combination.

In the polyolefin resin composition according to the present invention, the nitrogen-containing compound is contained in an amount of 0.5 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the polyolefin resin. is necessary.

When the content of the nitrogen-containing compound is less than 0.5 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 30 parts by weight, The mechanical properties and the like of the secondary processed product are deteriorated, resulting in poor practicability.

In the polyolefin resin composition according to the present invention, 1 to 1 part by weight of the phosphorus-containing compound represented by the general formula (1) is used with respect to 100 parts by weight of the polyolefin resin.
It is necessary to contain 50 parts by weight, more preferably 2 to 40 parts by weight.

When the content of the phosphorus-containing compound is less than 1 part by weight based on 100 parts by weight of the polyolefin resin, the crosslinkability and flame retardancy of the polyolefin resin composition become insufficient, and when it exceeds 50 parts by weight. However, the mechanical properties and the like of the secondary processed product are deteriorated, resulting in poor practicability.

Further, in the polyolefin resin composition according to the present invention, the total amount of the nitrogen-containing compound and the phosphorus-containing compound is 5 parts by weight or more, more preferably 10 parts by weight, based on 100 parts by weight of the polyolefin resin. As mentioned above, it is necessary to contain.

When the total amount of the nitrogen-containing compound and the phosphorus-containing compound is less than 5 parts by weight with respect to 100 parts by weight of the polyolefin resin, the flame retardancy of the polyolefin resin composition becomes insufficient.

In the polyolefin resin composition according to the present invention, in addition to the polyolefin resin, the nitrogen-containing compound and the phosphorus-containing compound represented by the general formula (1), which are essential components, red phosphorus and the particle surface are coated with a resin. Surface-treated red phosphorus, phosphorus-containing compounds such as polyphosphoric acid esters such as red phosphorus, ammonium polyphosphate, ammonium carbamyl polyphosphate, polyphosphoric acid amide, hydrated metal hydroxides, basic magnesium carbonate, etc. One kind or two or more kinds of the combustion auxiliary agent may be contained.

The content of the flame retardant aid is not particularly limited, but is preferably 100 parts by weight or less with respect to 100 parts by weight of the polyolefin resin. When the content of the flame retardant aid with respect to 100 parts by weight of the polyolefin-based resin exceeds 100 parts by weight, the mechanical strength and the like of the secondary processed product deteriorates, resulting in poor practicability.

Further, in the polyolefin resin composition according to the present invention, divinylbenzene, diallylbenzene, trimethylolpropane trimethacrylate, ethylvinylbenzene, 1,9-nonanediol dimethacrylate and trimellitate are added in order to enhance the crosslinking efficiency. Acid triallyl ester, isophthalic acid diallyl ester, isobutyl methacrylate, isodecyl methacrylate, tridecyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, lauryl acrylate, stearyl acrylate, 2-hydroxyethyl acrylate, etc. Two or more kinds may be contained in appropriate amounts.

Furthermore, in the polyolefin resin composition according to the present invention, a crosslinking initiator such as a peroxide, a phenolic resin,
One or more kinds of various additives such as amine-based and sulfur-based antioxidants, metal damage inhibitors, stabilizers, ultraviolet absorbers, antistatic agents, fillers, colorants, etc. are contained in appropriate amounts. May be.

The method for producing the polyolefin-based resin composition according to the present invention is not particularly limited. For example, a predetermined amount of each component constituting the polyolefin-based resin composition is added to a single-screw extruder or a twin-screw extruder. A kneading machine, a Banbury mixer, a kneader, a roll, or other general-purpose kneading device is used for melt-kneading and molding into a sheet to form a molded sheet of the polyolefin resin composition. Next, the molded sheet of the polyolefin resin composition is irradiated with radiation such as an electron beam to be crosslinked, or a crosslinking initiator such as a peroxide is contained in the polyolefin resin composition in advance, The crosslinking initiator may be decomposed by heating above the decomposition temperature of the crosslinking initiator to be crosslinked.

The cross-linking by the radiation such as the electron beam and the cross-linking by the cross-linking initiator may be carried out individually or in combination. The degree of crosslinking of the obtained crosslinked product is not particularly limited, but is preferably 5 to 90% by weight, and more preferably 10 to 70% by weight.

When crosslinking is carried out by radiation such as the electron beam, the irradiation dose of radiation is not particularly limited, but is preferably 0.5 to 20 Mrad, and particularly 1 to 8 Mrad. More preferable.

If the irradiation dose of radiation is less than 0.5 Mrad, a sufficient degree of crosslinking cannot be obtained, while if it exceeds 20 Mrad, the degree of crosslinking becomes too high and the workability and the quality of processed products deteriorate.

In the case of carrying out the cross-linking with the above-mentioned cross-linking initiator, the kind of the cross-linking initiator is not particularly limited, but benzoyl peroxide, octanoyl peroxide, decanoyl peroxide, acetyl peroxide, tertiary butyl peroxide. Isobutyrate,
Examples include peroxides such as cumene hydroperoxide,
These 1 type (s) or 2 or more types are used suitably.

The content of the above-mentioned crosslinking initiator in the polyolefin resin composition according to the present invention is not particularly limited, but 0.05 to 5 parts by weight of the crosslinking initiator relative to 100 parts by weight of the polyolefin resin. Is preferred, and more preferably 0.5 to 1 part by weight.

When the content of the cross-linking initiator is less than 0.05 parts by weight based on 100 parts by weight of the polyolefin resin,
If a sufficient degree of cross-linking cannot be obtained and conversely exceeds 5 parts by weight, the degree of cross-linking becomes too high and the secondary processability and the quality of the secondary processed product deteriorate.

[0032]

The polyolefin-based flame-retardant crosslinkable resin composition according to the present invention is excellent because it contains a specific amount of the nitrogen-containing compound and the phosphorus-containing compound represented by the general formula (1) in the polyolefin-based resin. In addition to exhibiting flame retardancy, it is also excellent in secondary processability and the quality of secondary processed products.

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.

[0034]

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, molding
Preparation of sheets and crosslinked sheets Polypropylene resin (melt index 0.5) 10
To 0 parts, 2.5 parts of 1,3,5-tris (2-hydroxyethyl) cyanurate as a nitrogen-containing compound, 6 parts of di (2-methacryloyloxyethyl) phosphate as a phosphorus-containing compound, and difficult 10 parts of ammonium polyphosphate (trade name “Sumisafe P”, manufactured by Sumitomo Chemical Co., Ltd.) was added as a combustion aid, and the mixture was kneaded at 170 ° C. for 5 minutes at 60 rpm with a Labo Plastomill. Thus, a polyolefin resin composition was obtained. Then, the composition was press-molded at 170 ° C. to form a molded sheet having a thickness of 0.4 mm. The obtained formed sheet was irradiated with an electron beam at an accelerating voltage of 700 kV for 4 Mrad to be crosslinked, to prepare a crosslinked sheet.

( 2) Evaluation The results of evaluating the degree of crosslinking, flammability, and secondary workability of the crosslinked sheet obtained above by the following methods are shown in Table 1.

Degree of crosslinking : The crosslinked sheet cut to a weight of A (g) was immersed in xylene at 120 ° C. for 24 hours, and then 2
The mixture was filtered through a 00 mesh wire net, the dry weight B (g) of the residue remaining on the wire net was measured, and the degree of crosslinking (% by weight) was calculated by the following formula. Crosslinking degree (% by weight) = [B (g) / A (g)] × 100

Flammability : The flammability of the crosslinked sheet was tested according to JIS D-1201 "Method for testing flammability of organic materials for automobiles", and the flammability was determined according to the following evaluation criteria. [Evaluation Criteria] Self-extinguishing property: When a crosslinked sheet that has once ignited in a windless atmosphere extinguishes spontaneously after removing the ignition source. Flame retardant property: A bridge that has ignited once in a windless atmosphere. When the sheet continues to burn slowly even after removing the ignition source Flammability: A crosslinked sheet that has ignited once in a windless atmosphere continued to burn easily even after removing the ignition source. If

Secondary workability : In accordance with JIS K-7113 "Plastic tensile test method", the tensile test (elongation rate) of the crosslinked sheet was performed at 23 ° C and 170 ° C, and the secondary workability was evaluated according to the following evaluation criteria. Was judged. [Evaluation Criteria] ∙ The elongation at 23 ° C is 200% or more and the elongation at 170 ° C is 500% or more. ∙ The elongation at 23 ° C is 200%. Less than or
Or, the elongation rate at 170 ° C is less than 500% × ... The elongation rate at 23 ° C is less than 200%, and the elongation rate at 170 ° C is less than 500%.

(Examples 2 to 6)

Five kinds of polyolefin resin compositions and molded sheets were prepared in the same manner as in Example 1 with five kinds of compounded compositions as shown in Table 1, and the obtained five kinds of molded sheets are shown in Table 1. Five types of crosslinked sheets were prepared by crosslinking under the conditions shown below.

Table 5 shows the results of evaluations of the obtained 5 kinds of crosslinked sheets in the same manner as in Example 1.

(Comparative Example 1)

With respect to 100 parts of the same polypropylene resin as used in Example 1, 3.5 parts of melamine was used as a nitrogen-containing compound without adding a phosphorus-containing compound, and
Mixing 4 parts of divinylbenzene as a polyfunctional monomer,
A polyolefin resin composition was prepared in the same manner as in Example 1. Then, a molded sheet and a crosslinked sheet were prepared in the same manner as in Example 1.

The results of evaluation of the crosslinked sheet obtained above in the same manner as in Example 1 are as shown in Table 2.

(Comparative Examples 2 to 7)

Six kinds of polyolefin resin compositions and molded sheets were prepared in the same manner as in Example 1 with six kinds of compounded compositions as shown in Table 2, and the obtained six kinds of molded sheets are shown in Table 2. Six types of crosslinked sheets were prepared by crosslinking under the conditions shown below.

The results of evaluating the six types of crosslinked sheets obtained in the same manner as in Example 1 are shown in Table 2.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

As described above, the polyolefin flame-retardant crosslinkable 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 composition comprising 0.5 to 30 parts by weight of a nitrogen-containing compound and 1 to 50 parts by weight of a phosphorus-containing compound represented by the following general formula (1) per 100 parts by weight of a polyolefin resin. A polyolefin-based flame-retardant crosslinkable resin composition, wherein the total amount of the nitrogen-containing compound and the phosphorus-containing compound is 5 parts by weight or more. [Chemical 1] (In the formula, two or more of R ₁ , R ₂ and R ₃ represent the following general formula (a) or (b), and the others represent a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 20 or less carbon atoms. Represents a linear or branched alkoxyl group having 20 or less carbon atoms, an aryl group, or an aryloxyl group) [In the formulas (a) and (b), R ₄ and R ₆ represent a hydrogen atom or a methyl group, and R ₅ represents a linear or branched alkyl group having 30 or less carbon atoms]