JPH0995563A - Flame-retardant heat-resistant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame-retardant heat-resistant polyolefin resin compsn. which is excellent in early-stage mechanical strengths, flame retardance, and resistances to heat and heat aging and is free from bleeding. SOLUTION: This compsn. resin comprises 100 pts.wt. polyolefin, 5-50 pts.wt. ethylenebistetrabromophthalimide, up to 15 pts.wt. hindered phenol antioxidant, up to 5 pts.wt. bis [2-methyl-4- 3-n-alkyl(12-14C)thiopropionloxy}-5-tert- butylphenyl] sulfide, and up to 5 pts.wt. decamethylenedicarboxylic acid disalicyloylhydrazide. The compsn. pref. further contains 1-15 pts.wt. zinc oxide and still pref. further contains an effective amt. of talc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant heat-resistant resin composition useful as an electrical insulating material, and more particularly to a flame-retardant heat-resistant resin composition mainly composed of polyolefin, which is excellent in flame retardancy and heat resistance.

[0002]

2. Description of the Related Art Polyolefin resins have excellent electrical characteristics and are widely used as insulating materials. For example, polyethylene is an indispensable insulating material because it has excellent electrical insulation, water resistance, and chemical resistance. However, the heat resistance of polyolefin resins is generally insufficient. Therefore, when a polyolefin resin is used as an insulating material, in order to improve thermal deformability, it is usually crosslinked with electromagnetic radiation, an organic peroxide or a silane compound described in Japanese Patent Publication No. 48-1711 to give a solid line. It has an eye-shaped structure. However,
Even if cross-linked, there is a problem that it is flammable and that it cannot be used at high temperature for a long time unless heat aging resistance is improved.

As a method for eliminating the drawback of flammability, a combined use system of a halogen compound as a flame retardant and a heavy metal compound such as antimony trioxide which is a synergist thereof has been mainly adopted. However, the flame-retardant ethylene-based polymer composition containing a halogen compound has a problem that the heat aging resistance and the like are reduced as compared with the non-flame-retarded ethylene-based polymer composition due to the high thermal decomposability of the halogen compound. there were. In recent years, in particular, in the fields of electric equipment, vehicles, automobiles and nuclear power plants, it is required to pass the advanced flame retardant test such as UL-94 VO and UL-62 VW-1 for insulated wires. However, in order to impart such high flame retardancy, a large amount of a halogen compound must be blended, and in that case, the heat aging resistance of the resulting composition is significantly reduced.

As a method for improving the heat aging resistance, Japanese Patent Publication No. 56-34174 proposes to add a high molecular weight hindered phenolic antioxidant and a zinc compound. According to this conventional technique, UL (Un
derwriters Lacola-tories.
Inc. ) It is said that a resin material that passes the standard aging test can be obtained.

[0005]

However, in recent years, insulating materials such as insulated wires and automobile electrical equipment used in electronic and electric equipment have long been exposed to high-temperature atmospheric conditions that have not been predicted in the past. There is an increasing demand for normal functioning over time. As described above, the heat aging resistance to polyolefin resin materials is becoming more and more severe, and it is not enough to simply pass the UL standard, and further excellent heat aging resistance is required. . In addition, Tokkyo 1-16
No. 263, Japanese Patent Publication No. 48884, Japanese Patent Publication No. 4-2522
The respective publications of No. 46 also describe techniques for overcoming the above-mentioned drawbacks, but they were not sufficient. The present invention
To provide a polyolefin-based flame-retardant heat-resistant resin composition that overcomes the above-mentioned drawbacks of the prior art, is excellent in both initial mechanical strength, flame retardancy, heat resistance and heat aging resistance, and that also suppresses the bleeding phenomenon. With the goal.

[0006]

Means for Solving the Problems As a result of earnest research to achieve the object of the present invention, a polyolefin composition obtained by adding ethylenebistetrabromophthalimide to a flame retardant was added to a hindered phenolic antioxidant and bisphenol used in combination with [2-methyl-4-{3-n-alkyl (C ₁₂ ~C ₁₄₎ thio propionyloxy} -5-tert-butyl phenyl] specific amount of sulfide and decamethylene dicarboxylic acid disalicyloylhydrazide As a result, a flame-retardant heat-resistant resin composition (hereinafter, also simply referred to as a resin composition) having significantly improved flame retardancy and heat resistance was obtained.

The polyolefin used in the resin composition of the present invention includes ethylene, propylene, butene-1,
Homopolymers of olefinic hydrocarbon monomers such as bentene-1, hexene-1, heptene-1, 3-methylbutene-1, 4-methylpentene-1, copolymers of these two or more monomers (eg, Ethylene / propylene copolymers, ethylene / butene-1 copolymers, etc.), and copolymers of these olefinic hydrocarbon monomers with a small amount of vinyl ester monomers or (meth) acrylate monomers (for example, ethylene. Vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl methacrylate copolymer and the like).
These various polymers can be used alone or as a mixture of two or more kinds.

The number average molecular weight of the polyolefin used in the present invention is not particularly limited. Among the above polyolefins, polyethylene is preferable, and low density polyethylene is particularly preferable.

Ethylene bis tetrabromophthalimide used as a flame retardant in the resin composition of the present invention is
It is used in a proportion of 5 to 50 parts by weight with respect to 100 parts by weight of polyolefin. If it is less than 5 parts by weight, the flame retardant properties of the composition are remarkably deteriorated, and if it exceeds 50 parts by weight, the flame retardant properties are saturated and mechanical strength such as tensile strength and elongation is remarkably deteriorated. Therefore, it is not preferable. As the hindered phenolic antioxidant used in the present invention, any known compound can be used, and specifically preferred compounds are 1,3,5-trimethyl-2,4,6. -Tris (3,5-di-tert-butyl-
4-hydroxybenzyl) benzene etc. are illustrated.

In the resin composition of the present invention, the hindered phenolic antioxidant is 15 parts by weight or less, preferably 0.1 to 10 parts by weight, and bis [2-methyl-4-amino acid] based on 100 parts by weight of the polyolefin. {3-n-alkyl (C ₁₂
Up to 5 parts by weight of C ₁₄ ) thiopropionyloxy} -5-tert-butylphenyl] sulfide, preferably 0.1
~ 3 parts by weight, 5 parts by weight or less of decamethylenedicarboxylic acid disalicyloyl hydrazide, preferably 0.1 to 3 parts by weight, but when these three compounds are used outside the specified amount range However, the synergistic effect of these three types of compounds cannot be sufficiently obtained, and excellent heat aging resistance cannot be obtained. The sulfide acts as a peroxide decomposing agent and decomposes peroxide into an inactive compound to prevent oxidative deterioration of the resin. Further, the hydrazide is generally a copper damage inhibitor, but when used in combination with the antioxidant and sulfide, the heat resistance is remarkably improved.

In the present invention, the polyolefin 100 is further included.
By adding 1 to 15 parts by weight, preferably 2 to 10 parts by weight of zinc oxide to parts by weight, the hindered phenol-based antioxidant, bis [2-methyl-4- {3
-N- alkyl (C ₁₂ ~C ₁₄₎ synergy thio propionyloxy} -5-tert-butyl phenyl] sulfide and decamethylene dicarboxylic acid disalicyloylhydrazide is better exhibited, prevent particularly excellent heat aging The function is demonstrated. Here, if the content of zinc oxide exceeds 15 parts by weight, the heat aging prevention performance reaches saturation and the characteristics such as mechanical characteristics are deteriorated, which is not preferable.

Further, bis [2-methyl-
4- {3-n-alkyl (C₁₂~ C ₁₄) Thiopropioni
Luoxy} -5-tert-butylphenyl] sulfide is
Due to its readability, an effective amount of talc should be
By using it, it is effective as a filler of talc.
In addition, bis [2-methyl-4- {3-n-alkyl (C
₁₂~ C₁₄) Thiopropionyloxy} -5-tert-butyl
Suppresses the bleeding phenomenon due to the use of [phenyl] sulfide
It was possible and was found to be preferable. Talc is hydrous silicic acid
It is crushed magnesium, and it is also burned
Is also included. The addition amount of talc is 10
It is preferably 50 parts by weight or less with respect to 0 parts by weight,
Bis [2-methyl-4- {3-n-alkyl (C₁₂~ C
₁₄) Thiopropionyloxy} -5-tert-butylpheny
Of the composition while suppressing the bleeding phenomenon of sulfide.
The addition amount can be arbitrarily determined within the range that satisfies various characteristics.
it can. If the added amount exceeds 50 parts by weight, mechanical properties and
Mold workability is significantly reduced.

The resin composition of the present invention may contain an inorganic flame retardant such as antimony trioxide and zirconium oxide as a flame retardant synergist, and further, another halogen compound flame retardant can be obtained. It can be used in combination within a range where the deterioration of heat aging resistance of the product is not remarkable. Inorganic flame retardants are
Preferably 5 to 5 relative to 100 parts by weight of polyolefin
It is 0, more preferably 10 to 30. Further, the resin composition of the present invention can appropriately contain a known inorganic filler other than talc as a filler, such as zinc borate, magnesium carbonate, calcium carbonate, clay and silica.

Further, a crosslinking aid usually used in this field,
Other antioxidants, lubricants, UV absorbers, metal deactivators,
Colorants, stabilizers, rubbers, reinforcing agents for plastics, flame retardants and the like can be added. As the cross-linking aid, known compounds, for example, triazine compounds, diacrylate compounds, and the like, specifically, trimethylolpropane trimethacrylate, 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, etc. Is mentioned. Examples of other antioxidants include phosphite-based, thioether-based, and phenol-based agents, and lubricants include fatty acids such as stearic acid, hydroxystearic acid, fatty acid amides such as oleylamide.

The flame-retardant heat-resistant resin composition of the present invention is prepared by blending the above-mentioned respective components. When crosslinking, a method of heating in the presence of an organic peroxide and an ionizing property of an electron beam or the like are used. Cross-linking methods known in the art such as a method of irradiating with radiation can be appropriately used. Examples of the organic peroxide include dicumyl peroxide and the like. In the method of irradiating ionizing radiation such as electron beam, for example, the electron beam irradiation amount is suitably 10 to 20 Mrad.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto. In addition, "part" refers to "part by weight". The composition having the composition ratio shown in Table 1 is uniformly kneaded with an open roll at 150 ° C. to form a sheet. This was pelletized with a pelletizer. Using a small extruder, the above pellets were extrusion-coated to a thickness of 0.5 mm on a copper conductor with a calculated cross-sectional area of 0.5 cm ² (0.18 sq / 20 core, outer diameter 1.0 mm) to obtain an insulated wire (material extrusion temperature : 160-170 ° C.) and 1 electron beam
It was cross-linked by irradiation with 4 Mrad.

The materials used will be described below. LDPE low density polyethylene (density: 0.924, MI: 0.25) HDPE high density polyethylene (density: 0.949, MI: 0.30) EEA ethylene ethyl acrylate copolymer (EA content: 15 wt%, MI: 0. 75) The flame retardant 1 ethylene bistetrabromophthalimide flame retardant 2 trioxide antimony compound A hindered phenolic antioxidant compound B bis [2-methyl-4-{3-n-alkyl (C ₁₂ -C ₁₄₎ thio propionyl [Oxy} -5-tert-butylphenyl] sulfide Compound C Decamethylenedicarboxylic acid disalicyloyl hydrazide Inorganic filler Talc lubricant Stearic acid Cross-linking aid Trimethylolpropane trimethacrylate Evaluate the properties of each obtained insulated wire, The results are shown in Table-1.
It was also described in.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

By using the compounds A, B and C together in an addition amount within the specific amount range of the present invention (Examples 1 to 5), an insulated wire excellent in both flame retardancy and heat resistance can be obtained. Furthermore, by using zinc oxide together (Examples 2 to 5),
Heat resistance while maintaining sufficient flame retardancy, especially 200 ° C x 96
Hr. The heat resistance is greatly improved. In addition, compounds A and B
Even when C and C were used together in an amount exceeding the range specified in the present invention (Comparative Example 1), the heat aging resistance of the composition was not improved so much by increasing the amounts of these compounds, and the flame retardancy was rather lowered. Resulting in. Furthermore, when the three compounds of Compounds A, B and C are not used together (Comparative Examples 2 to 7), the initial elongation is low and the heat aging resistance is low. In particular, as compared with these comparative examples, the composition of the present invention (Example 3) had a temperature of 200 ° C. × 96 hr. It can be seen that the heat resistance at is significantly improved.

Further, in Comparative Example 8 in which the added amount of the flame retardant 1 was less than the amount specified in the present invention, the flame retardancy was remarkably lowered,
In Comparative Example 9 in which the addition amount is large, the flame retardancy can be maintained, but the initial elongation and heat resistance are reduced. In addition, Comparative Example 3
From the results of 10 and 10, even if the addition amount of the compound B is increased,
It can be seen that the addition of talc suppresses the bleeding phenomenon and does not impair the appearance of the composition. Like this
Examples 1 to 5 obtained within the compounding amount range of each compound that constitutes the resin composition of the present invention are compared with Comparative Examples 1 to 10,
Excellent heat aging resistance and flame retardancy.

[0023]

EFFECTS OF THE INVENTION By using the resin composition of the present invention, it is possible to obtain a crosslinked polyolefin resin composition which is extremely excellent in flame retardancy, heat resistance and heat aging resistance, and particularly electric insulation such as electric wire coating. When used as a material, it is possible to obtain a flame-retardant crosslinked polyolefin-coated electric wire that can be continuously used for a long period of time at a high temperature of about 130 to 170 ° C.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08K 5/3415 C08K 5/3415 5/45 KFJ 5/45 KFJ H01B 3/30 H01B 3/30 N 7/34 7/34 B

Claims (3)

[Claims] 1. With respect to 100 parts by weight of polyolefin,
5 to 50 parts by weight of ethylene bis tetrabromophthalimide is contained, and further 15 parts by weight or less of a hindered phenolic antioxidant and 5 parts by weight or less of bis [2-methyl-4
-{3-n-alkyl (C ₁₂ -C ₁₄ ) thiopropionyloxy} -5-tert-butylphenyl] sulfide and 5 parts by weight or less of decamethylenedicarboxylic acid disalicyloyl hydrazide. Flame-retardant heat-resistant resin composition. 2. The flame-retardant heat-resistant resin composition according to claim 1, which further contains 1 to 15 parts by weight of zinc oxide. 3. The flame-retardant heat-resistant resin composition according to claim 1, further comprising an effective amount of talc.