JPH0830130B2 - Flame-retardant polyolefin composition - Google Patents

Description

TECHNICAL FIELD The present invention generally uses a flame retardant material in combination with a linear ethylene-α-olefin copolymer produced using an organometallic catalyst by a gas phase / low pressure method. A flame-retardant polyolefin composition and a molded article produced therefrom.

Conventional technology and its problems Conventionally, flame-retardant polyolefin compositions have been used as a base material in a branched and low-density polyethylene (HPLDPE), an ethylene vinyl acetate copolymer (EVA) and an ethylene ethyl acrylate copolymer manufactured by a high pressure method. Polymer (EEA) is used. Flame-retardant polyolefin composition by combining these with a flame-retardant material mainly composed of an organic chlorine or bromine compound and antimony trioxide, or with a flame-retardant material such as aluminum hydroxide or magnesium hydroxide. However, in order to exert practical flame retardancy, it is necessary to use a large amount of flame retardant material, and then tensile strength, elongation, low temperature characteristics,
The environmental stress cracking property is deteriorated, and these properties are deteriorated so that it cannot be used. Therefore, it has been desired to develop a flame-retardant polyolefin composition having sufficient flame retardancy and having the above-mentioned properties at a level at which it can withstand practical use.

In recent years, linear ethylene-α-olefin copolymers with a density of 0.910 g / ml or less produced by the gas phase / low pressure method instead of the high pressure method have been produced. Since it contains almost no polar groups, it has poor affinity with flame-retardant materials having many polar groups, it is difficult to mix both, and a flame-retardant composition having sufficient properties is obtained. Was considered difficult.

As a result of diligent research, the present inventors have found that an unexpectedly large amount of flame-retardant material has a density of 0.910 g / ml by the vapor phase / low pressure method
Flame retardant that can be practically dispersed by being homogeneously dispersed in the following ethylene-α-olefin copolymer and has sufficient physical properties such as tensile strength, elongation, low temperature characteristics, and environmental stress cracking resistance. It has been found to obtain an active polyolefin composition.

OBJECT OF THE INVENTION The object of the present invention is to provide a flame-retardant polyolefin composition having both practical flame retardancy and sufficient physical properties.

Detailed Description of the Invention That is, the present invention has a density of 0.
The present invention relates to a flame-retardant polyolefin composition comprising 100 parts by weight of a linear ethylene-α-olefin copolymer of 910 g / ml or less and 70 to 190 parts by weight of a flame-retardant material.

In the present invention, various additives such as an antioxidant, a colorant, an organic peroxide, and a crosslinking accelerator are blended in the above composition, if necessary.

In the present invention, the ethylene-α-olefin copolymer means that ethylene accounts for 50% or more, preferably 70% or more, and α-olefin has 3 to 10 carbon atoms. Preferred α-olefins may be linear or branched and include, for example, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1,4-methylenepentene-1,4-methylhexene- 1,4-4-dimethylpentene-1 and the like.

The linear ethylene-α-olefin copolymers of the present invention comprise ethylene (A) (1) at a temperature of about 10 ° C. to about 115 ° C. in the gas phase with at least one C ₃ -C ₁₀ α-olefin. A) a vanadium compound which is a reaction product of palladium (3) halide with chlorine, bromine or iodine and an electron donor (b) which is a liquid organic Lewis base in which the vanadium trihalide is soluble; 2) The following formula MX _a (where M is either boron or AlR _(3-a) ,
Each R is each alkyl, provided that the total number of aliphatic carbon atoms in any R group does not exceed 14, X is chlorine, bromine or iodine, and a is 0, 1 or 2, A when M is boron
Is a supported precursor consisting essentially of a silica or alumina supported on a solid inert carrier, and (B) the following formula AlR ₃ (where R is Is as defined above), and (C) is of the formula _R'b CX ' _(4-b) where R'is hydrogen or unsubstituted or halogen-substituted lower alkyl. , X ′ is a halogen, and b is 0, 1 or 2), and a catalyst composition comprising a promoter is added to produce a polyethylene. And is described in detail in JP-A-59-230006.

In the present invention, the flame-retardant material that can be used is aluminum hydroxide, magnesium hydroxide, potassium hydroxide,
Zircon oxide, barium metaborate, zinc metaborate, calcium hydroxide, kaolinite, montmorillonite, talc, clay, red phosphorus, barium borate, silica, white carbon, diatomaceous earth, barium sulfate, celite, anhydrous alumina, titanium oxide, There are inorganic flame-retardant materials such as zinc oxide, molybdenum disulfide, calcium phosphate, asbestos, and lithobon. These may be used alone or in combination of two or more kinds, and hexabrombenzene, tris ( 2,3-
Dibromopropyl) isocyanate, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxyethoxy-3,5-dibromophenyl) propane, decabromodiphenyl oxide, pentab Bromine-based, chlorinated, such as romdiphenyl ether, hexabromobihienyl, chlorinated paraffin, brominated epoxy resin, halogenated phosphoric acid ester, trischloroethyl phosphate, halogenated condensed phosphoric acid ester, diphenyl cresyl phosphate, etc. , And a phosphorus-containing flame retardant may be used in combination.

Flame retardant material is ethylene-α-olefin copolymer 10
It is blended in an amount of 70 to 190 parts by weight per 0 parts by weight.

In addition, the flame-retardant polyolefin composition of the present invention may be mixed with various additives such as usual antioxidants, colorants, organic peroxides and crosslinking accelerators, if necessary.

The flame-retardant polyolefin composition of the present invention can be produced by mixing various components by a well-known means such as a Banbury kneader.

Examples Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these embodiments.

The various samples in Examples 1 to 7 and Comparative Examples 1 to 5 were all prepared by a Banbury kneader, and test pieces were prepared for these samples to evaluate various performances.

The details of the composition are shown in Table 1, and the evaluation results of each composition are shown in Table 2.

Aluminum hydroxide is added to 100 parts by weight of high-pressure low density polyethylene, EVA (ethylene-vinyl acetate copolymer), EEA (ethylene-ethyl acrylate copolymer).
The composition containing 20 parts by weight has an oxygen index of 29 to 30, which is an index of flame retardancy defined by JIS K 7201, as shown in Comparative Examples 1 to 3 of Table 2, and has practically sufficient flame retardancy. However, in all cases, remarkable dripping of the melt was observed during combustion, and there is a risk of burning in the vicinity of combustible substances. Furthermore, Comparative Examples 1 to 3
In the heat deformation test according to JIS K 6723, remarkable deformation was observed at 90 ° C, and it was completely deformed at 100 ° C.

As can be seen from Example 1, vapor phase / low pressure linear ethylene-α with a density of 0.903 g / ml melt index 1.2 g / 10 min
-Aluminum hydroxide in 100 parts by weight of olefin copolymer
The blend of 20 parts by weight has an oxygen index of 32, no melt dripping was observed, and the thermal deformation rate was small at the measurement temperature of 70 ° C to 110 ° C, and even at 110 ° C, the deformation was limited to 20.5%. In addition, the tensile strength and elongation measured according to JIS K 6730 are 118 kg / cm ² and 620%, respectively, which are sufficiently large for practical use, and are extremely effective as a halogen-free, pollution-free flame-retardant cable jacket material. It is useful.

As can be seen from Examples 2 to 5, even if the base polymer is changed, aluminum hydroxide is changed to magnesium hydroxide, or a mixture of aluminum hydroxide and antimony trioxide is used, the flame-retardant material is not changed. Practical performance does not change.

As shown in Comparative Example 4, when the blending amount of aluminum hydroxide was 50 parts by weight, the oxygen index was as small as 23, flame retardancy was insufficient, and some molten drip was observed, and Comparative Example 5 As you can see, the compounding amount of aluminum hydroxide is 23
When the amount is 0 parts by weight, the tensile strength is as small as 20 kg / cm ^2, and in any case, the practical properties as a flame retardant material are insufficient. As can be seen from Examples 6 to 7, when the blending amount of aluminum hydroxide is in the range of 70 to 190 parts by weight with respect to 100 parts by weight of the base polymer, suitable performance as a jacket material for flame retardant cables is provided.

As described above, the flame-retardant polyolefin composition of the present invention has a density of 0.910 g / ml or less and a linear ethylene-α-olefin copolymer produced by a gas-phase / low-pressure method and aluminum hydroxide or the like. It has been found that the combination of flammable materials has sufficient flame retardancy, no melt dripping, small thermal deformation and large tensile strength and elongation.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyomine Taniguchi 2-55-2, Migaoka, Midori-ku, Yokohama-shi, Kanagawa (56) References JP 63-8445 (JP, A) JP 62-280243 ( JP, A) JP 62-199638 (JP, A) JP 62-22839 (JP, A)

Claims (1)

[Claims] 1. A linear ethylene-α-olefin copolymer produced by a gas phase / low pressure method having a density of 0.910 g / ml or less.
A flame-retardant polyolefin composition comprising 100 parts by weight and 70 to 190 parts by weight of a flame-retardant material, wherein the linear ethylene-α
The olefin copolymer contains ethylene and at least one C ₃
~ C ₁₀ α-olefin in the gas phase about 10 ℃ ~ 115 ℃
(A) (1) Palladium trihalide (a) with chlorine, bromine or iodine and an electron donor (b) which is a liquid organic Lewis base in which the vanadium trihalide is soluble. A vanadium compound which is a reaction product and (2) the following formula MXa (where M is either boron or AlR _(3-a) ,
Each R is each alkyl, provided that the total number of aliphatic carbon atoms in any R group does not exceed 14, X is chlorine, bromine or iodine, and a is 0, 1 or 2, A when M is boron
Is a supported precursor consisting essentially of a silica or alumina supported on a solid inert carrier, and (B) the following formula AlR ₃ (where R is Is as defined above), and (C) is of the formula _R'b CX ' _(4-b) where R'is hydrogen or unsubstituted or halogen-substituted lower alkyl. , X'is a halogen, and b is 0, 1 or 2) and is prepared by a process comprising polymerizing the monomer by contacting it with a catalyst composition containing a promoter having A flame-retardant polyolefin composition characterized by the following.