JP2006283001A - Flame-retardant resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant resin composition capable of being suitably used for various purposes, such as an electric wire coating and a construction material, for which flame retardance is required, by furnishing them with the flame retardance, mechanical properties, and processability, while maintaining desirable physical properties inherent in an ethylene-based resin. <P>SOLUTION: This flame-retardant resin composition is given by mixing 0.01-10 pts.wt. of olefin-based wax which has a viscosity-average molecular weight of ≤30,000, a density of 880-980 kg/m<SP>3</SP>, and a melting point of 60-160°C and 50-300 pts.wt. of an inorganic flame retardant into 100 pts.wt. of the ethylene-based resin. A preferable embodiment comprises using ethylene-based wax which is obtained by using a metallocene-based catalyst as the olefin-based wax. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flame retardant ethylene resin composition. More specifically, the present invention relates to a flame retardant ethylene resin composition that improves flame retardancy while maintaining preferable physical properties of the ethylene resin and imparts mechanical properties and processability.

  Olefin resins are widely used as electrical insulating materials because they are generally excellent in electrical characteristics, mechanical properties, processability, and the like. Particularly for applications such as electric wires and cables, ethylene / unsaturated ester random copolymers are widely used because of a good balance of strength, low temperature characteristics, scratch resistance, hardness and the like.

  Such an ethylene copolymer needs to be flame retardant because it requires flame retardancy in applications such as a covering material for electric wires and communication wires, and building materials. Among ethylene resins, ethylene polymers such as ethylene / vinyl acetate copolymers and ethylene / unsaturated carboxylic acid ester copolymers have good filler filling properties. Has been used for applications where flame retardancy is required. In the past, flame retardants have been dealt with by incorporating halogen-based flame retardants. However, such a compound has a problem of generating a harmful gas during combustion. Therefore, in recent years, a formulation in which a metal hydroxide flame retardant such as magnesium hydroxide or aluminum hydroxide is blended as a non-halogen flame retardant is used. Has been adopted.

  In a system in which an inorganic hydroxide flame retardant is blended with the olefin resin as described above, an attempt has been made to blend various polymers or additives to improve physical properties (for example, Japanese Patent Publication No. 63-225641). JP-A-5-117452). However, metal hydroxide flame retardants need to be added in a considerable amount in order to exert a sufficient flame retardant effect, so at the expense of processability, scratch resistance and other mechanical properties of the ethylene copolymer. There was something to do. Particularly in applications such as thin-walled wires, thin-wall building material sheets, and thin-walled vehicle seats, high-level flame retardancy, good moldability, and mechanical properties are required for thin-walled materials. It was not.

Japanese Examined Patent Publication No. 63-225641 Japanese Patent Laid-Open No. 5-117252

In view of the above situation, the inventors of the present invention provide flame retardancy, mechanical properties, and workability while maintaining preferable physical properties that are inherent characteristics of an ethylene-based resin, and provide flame retardancy such as wire coating and building materials. As a result of diligent efforts to develop a flame retardant resin composition that can be suitably used in applications where the demand is high, the present invention has been achieved.
The present invention provides a flame retardant ethylene resin composition having improved flame retardancy while maintaining preferable physical properties of the ethylene resin.
The present invention further provides a flame retardant ethylene resin composition having improved mechanical properties and fluid processability while maintaining the flame retardancy of the ethylene resin.

In the present invention, an olefin wax having a viscosity average molecular weight of 30,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 160 ° C. is 0.01 to 100 parts by weight of an ethylene resin. The present invention provides a flame retardant resin composition comprising 10 parts by weight and 50 to 300 parts by weight of an inorganic flame retardant.

The olefin wax is a flame retardant resin composition having a viscosity average molecular weight of 8,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 160 ° C., produced by a metallocene catalyst. This is a preferred embodiment of the invention.

The above-mentioned flame-retardant resin composition, in which the olefin wax is an ethylene wax having a viscosity average molecular weight of 8,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 130 ° C., This is a preferred embodiment of the invention.

  The above-mentioned flame retardant resin composition in which the olefin wax is an ethylene wax is a preferred embodiment of the present invention.

  The above-mentioned difficulty that the ethylene-based resin is at least one selected from an ethylene / vinyl ester copolymer, an ethylene / unsaturated carboxylic acid ester copolymer, and an ethylene / unsaturated carboxylic acid copolymer and an ionomer thereof. A flammable resin composition is a preferred embodiment of the present invention.

  The said flame retardant resin composition whose said inorganic flame retardant is a metal hydrate is a preferable aspect of this invention.

  The above-mentioned flame retardant resin composition in which the olefin wax is a modified wax is a preferred embodiment of the present invention.

  The present invention also provides the flame retardant resin composition according to any one of the above, wherein the flame retardancy is V-0 as measured with a test piece having a thickness of 3 mm according to the UL94 flame resistance test.

The present invention provides a flame retardant resin composition having improved flame retardancy while maintaining preferable physical properties of the ethylene-based resin.
The ethylene-based resin composition provided by the present invention is a flame retardant resin composition having improved mechanical properties and fluid workability while maintaining flame retardancy.
According to the present invention, while maintaining the preferable physical properties of ethylene-based resin, it provides flame retardancy, mechanical properties and processability, and is suitable for applications that require flame retardancy such as wire coating and building materials. A flame retardant resin composition that can be used is provided.

In the present invention, an olefin wax having a viscosity average molecular weight of 30,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 160 ° C. is 0.01 to 100 parts by weight of an ethylene resin. A flame retardant resin composition comprising 10 parts by weight and 50 to 300 parts by weight of an inorganic flame retardant is provided.

Ethylene-based resin The ethylene-based resin (A) used in the present invention includes an ethylene homopolymer, a copolymer of ethylene and another α-olefin, a copolymer of ethylene and a polar monomer, or a mixture thereof. Can be mentioned.

Preferred examples of ethylene homopolymers and copolymers of ethylene and other α-olefins include various catalyst systems such as radical polymerization catalysts, Ziegler catalysts composed of highly active titanium catalyst components and organoaluminum compound catalyst components. A homopolymer of ethylene produced by various methods using a multi-site catalyst, a single site catalyst such as a metallocene catalyst composed of a metallocene catalyst component, typically a zirconium compound and a catalyst component such as aluminoxane, or the like Mention may be made of a copolymer of ethylene and an α-olefin having 3 or more carbon atoms. More specifically, a polymer obtained by the above method and usually called polyethylene is preferable. For example, high-pressure polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ultra-low-density linear polyethylene, ethylene series An elastomer etc. can be mentioned.
The α-olefin is preferably an α-olefin having 3 or more carbon atoms, preferably 3 to 20, more preferably 3 to 8, and specifically, propylene, 1-butene, 1-hexene, 4-methyl-1 -Pentene, 1-octene, etc. can be mentioned.

As a copolymer of ethylene and a polar monomer, a copolymer of ethylene and one or more polar monomers selected from unsaturated esters, unsaturated carboxylic acids and salts thereof, carbon monoxide, vinylsilane compounds, and the like is used. A polymer can be mentioned.
Preferred examples of the unsaturated ester include vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, methyl methacrylate, glycidyl methacrylate, and dimethyl maleate. And unsaturated carboxylic acid esters.

Preferable examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, monoethyl maleate, maleic anhydride and the like.
Preferable examples of the unsaturated carboxylic acid salt include salts of the unsaturated carboxylic acid such as Na, Li, K, Zn, Mg, and Ca.

  There are no particular restrictions on the method for producing these ethylene and polar monomer copolymers, and conventionally known methods can be selected as appropriate. For example, radical copolymerization, solution polymerization, emulsion polymerization, etc. under high temperature and high pressure can be used. Obtainable.

  As ethylene-based resins, unsaturated carboxylic acids, their anhydrides, vinyl silane compounds, etc. can be grafted to the above ethylene homopolymers, copolymers of ethylene and α-olefins, copolymers of ethylene and polar monomers, etc. A polymerized product may be used.

  Among these ethylene resins, a copolymer of ethylene and a polar monomer is particularly preferable. Of these, ethylene / unsaturated ester copolymers such as ethylene / vinyl acetate copolymers, and ethylene / saturated carboxylic acid copolymers or salts thereof (ionomers) are preferred. Among these, ethylene / vinyl acetate copolymer and ethylene / ethyl acrylate copolymer are particularly preferable from the viewpoint of filler loading.

  In the ethylene / vinyl acetate copolymer and the ethylene / ethyl acrylate copolymer, the amount of the comonomer is not limited, but in the case of the ethylene / vinyl acetate copolymer, the vinyl acetate content is 15 to 47% by weight. It is preferable that the content is 21 to 47% by weight, more preferably 27 to 47% by weight. In the case of an ethylene / ethyl acrylate copolymer, the ethyl acrylate content is preferably 10 to 35% by weight, more preferably 13 to 30% by weight, and still more preferably 14 to 26% by weight. desirable.

  The ethylene-based resin of the present invention may be used alone or in combination of two or more. Moreover, it can also be used as a mixture with resin other than ethylene-type resin. Other resins that can be used in combination with ethylene resins include polyolefins such as polypropylene and polybutene, styrene-isoprene-styrene block copolymers, styrene-butadiene-styrene block copolymers, and hydrogenated products thereof. Examples thereof include SEBS, SEPS, and styrene-based thermoplastic elastomers such as carboxyl-modified products. As the polypropylene, it is possible to select and use from a homopolymer of propylene, a random copolymer or block copolymer with ethylene, a multi-component PP resin alloy, and the like. These other resins can be used as long as the object of the present invention is not impaired.

  Examples of mixing and using other resins in this manner with ethylene-based resins include melting and mixing polypropylene with ethylene / vinyl acetate copolymer, and heat such as SEBS with ethylene / vinyl acetate copolymer and polypropylene. The aspect which melt-mixes a plastic elastomer can be mentioned. Further, a multi-component PP resin can be melt-kneaded in the presence of an organic peroxide in an ethylene / vinyl acetate copolymer to obtain a dynamically crosslinked resin. Even in such a case, it is preferable to blend so that the main proportion of the ethylene-based resin does not impair the object of the present invention.

  From the viewpoint of various physical properties, the melt flow rate (JIS K 7210-1999, 190 ° C., 2,160 g load) of the ethylene-based resin of the present invention is preferably 5 or less, more preferably 0.01 to 1.2, Preferably it is 0.01-0.5.

As for the density of the ethylene-based resin of the present invention, the polyethylene has a density of 870 to 970 kg / m ³ , preferably 890 to 960 kg / m ³ , more preferably 900 to 950 kg / m ³ , and ethylene and a polar monomer as copolymers of a density of 920 kg / ^{m 3} or more, preferably it is preferable that the 930~970kg / ^{m 3.}

Examples of olefin waxes include waxes obtained by thermal decomposition of high molecular weight polyolefins, waxes obtained by homopolymerization of olefins or copolymerization with other olefins, and the like, which can be appropriately selected and used. From the viewpoint of compatibility, ethylene wax is preferred for the purpose of the present invention.

  Examples of the ethylene wax include polyethylene wax obtained by thermal decomposition of high molecular weight polyethylene, polyethylene wax obtained by free radical polymerization of ethylene in a high pressure method, or ethylene is homopolymerized in the presence of a metal catalyst, or ethylene and α -Polyethylene waxes obtained by copolymerizing olefins in the presence of metal catalysts. Among these, ethylene / α-olefin copolymer wax is more preferably used from the viewpoint of compatibility. As the α-olefin, those exemplified above can be mentioned as preferred examples. The content of α-olefin in the ethylene / α-olefin copolymer wax is preferably 15 mol% or less, more preferably 10 mol% or less.

  Examples of the metal catalyst suitably used for the production of such an ethylene wax include a multi-site catalyst such as a Ziegler catalyst and a single site catalyst such as a metallocene catalyst. When an ethylene-based wax is used with a metallocene-based catalyst, favorable results can be obtained from the viewpoint of improving mechanical properties, and therefore, a single-site catalyst, particularly an ethylene-based wax produced with a metallocene-based catalyst is preferable.

  The metallocene catalyst is a catalyst component comprising a metallocene compound having a ligand having at least one cyclopentadienyl skeleton in a transition metal such as titanium, zirconium, hafnium, an organoaluminum compound such as alumoxane, alkylaluminum, A catalyst composed of cocatalyst components such as an organoaluminum oxy compound and an ionized ionic compound. It is sometimes called a single-site catalyst because of its characteristics as a catalyst.

  Examples of the ligand having a cyclopentadienyl skeleton include a cyclopentadienyl ring indenyl ring, a fluorenyl ring, etc., and these ligands may have a substituent. They may be bonded to each other via a hydrocarbon group, a silyl group, or the like.

  Specific examples of the metallocene catalyst include, for example, JP-A-58-19309, JP-A-59-96292, JP-A-60-35005, JP-A-61-130314, JP-A-3-163808, and European patents. Although what is described in the publication 420,436, US Patent 5,055,438, etc. can be mentioned, it is not limited to these.

  Examples of metallocene compounds include cyclopentacyenyl titanium (dimethylamide), dimethylsilyltetramethylcyclopentadienyl-t-butylamide zirconium dichloride, indenyl titanium (diethylamide), bis (cyclopentadienyl) zirconium dichloride, bis (Indenyl) zirconium bis (methylphosphonate) and the like can be mentioned.

  The ethylene-based wax obtained by the metallocene-based catalyst can be produced with reference to, for example, the methods described in JP-A-8-231640 and JP-A-2004-59869. Moreover, you may select and use from what is marketed as polyethylene wax.

The viscosity average molecular weight of the olefin wax used in the present invention is 30,000 or less, preferably 8000 or less, more preferably 1,000 to 8,000, and the density is 880 to 980 kg / m ³ , preferably 900 to It is 980 kg / m ³ and the melting point is 60 to 160 ° C., preferably 60 to 130 ° C.

A more preferred olefin wax of the present invention is a wax having a viscosity average molecular weight of 8,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 160 ° C.

An ethylene wax having a viscosity average molecular weight of 8,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 130 ° C. is a more preferable olefin wax of the olefin wax of the present invention.

  The olefin wax of the present invention may contain a reactive group such as a hydroxyl group, a carboxylic acid group, or an epoxy group in the molecule. These reactive groups can be introduced by copolymerizing an unsaturated compound containing a reactive group at the time of wax production, or by graft reaction to an olefinic wax. Inclusion of a reactive group in the molecule of the olefin wax is called modification of the olefin wax. Moreover, the olefin oxide wax obtained by the oxidation reaction of an olefin wax can also be used as the modified olefin wax. The modified olefin wax is preferably an olefin wax obtained by graft reaction of an unsaturated compound. As an unsaturated compound, unsaturated carboxylic acid, its anhydride, or a derivative can be mentioned, Among these, maleic anhydride can be mentioned as a particularly preferable thing.

  The blending amount of the olefin-based wax of the present invention is 0.01 to 10 parts by weight, preferably 0.5 to 100 parts by weight of the ethylene-based resin, from the viewpoint of the intended effect of the present invention and the kneadability during molding. It is desirable that the content be ˜5 wt%, more preferably 0.5 to 3 wt%.

Inorganic flame retardant Examples of the inorganic flame retardant used in the present invention include aluminum hydroxide, magnesium hydroxide, hydrotalcite, basic magnesium carbonate, calcium carbonate, silica, talc, clay, and zeolite. Of these, metal hydrates such as aluminum hydroxide, magnesium hydroxide and hydrotalcite are preferred.

  For the purpose of improving the dispersibility and miscibility of the inorganic flame retardant of the present invention, fatty acids, fatty acid amides, fatty acid salts, fatty acid esters, aliphatic alcohols, silane coupling agents, titanium coupling agents, silicone oils, silicone polymers, phosphorus An inorganic flame retardant surface-treated with an acid ester or the like can be used. In this case, a plurality of different types of inorganic flame retardants treated with different surface treatment agents can also be used.

  The blending amount of the inorganic flame retardant is desirably 50 to 300 parts by weight, preferably 80 to 250 parts by weight, and more preferably 100 to 200 parts by weight with respect to 100 parts by weight of the resin component.

  In the flame-retardant resin composition of the present invention, additives such as an antioxidant, a light-resistant stabilizer, an ultraviolet absorber, a pigment, and carbon black are used as necessary within a range not impairing the object of the present invention. May be.

  There is no restriction | limiting in particular in the method of manufacturing the flame-retardant resin composition of this invention, It manufactures by knead | mixing the component which comprises it, and other resin and additive mix | blended as needed by a conventionally well-known method. be able to. There is no particular limitation on the mixing order. For example, ordinary kneading of ethylene resins, olefin waxes, inorganic flame retardants, and other additives blended as necessary, such as a single screw extruder, twin screw extruder, Banbury mixer, pressure kneader, roll, etc. And a method of kneading at a temperature equal to or higher than the melting point of the ethylene resin. Moreover, what is necessary is just to knead | mix at the temperature below the melting | fusing point, when mix | blending an organic peroxide. Such blending may be performed all at once or in stages.

  The flame retardant resin composition provided by the present invention is a composition imparted with flame retardancy, mechanical properties and processability while maintaining preferable physical properties which are inherent characteristics, and therefore has good flame retardancy. In addition, since it exhibits excellent mechanical properties and fluidity, it is a flame retardant resin composition that can be suitably used for coatings for electric wires and communication lines, building materials, and other uses that require flame resistance.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited at all by these examples.
The raw materials used in the examples and comparative examples are as follows.

(1) Ethylene / vinyl acetate copolymer (EVA): vinyl acetate unit content 33 wt%, MFR (JIS K7210-1999, 190 ° C., 2160 g load): 0.15 g / 10 min.
(2) Olefin wax 1 (WAX-1)
Viscosity average molecular weight: 4000, density: 980 kg / m ³ , melting point: 128 ° C.
(Mitsui Chemicals trade name EXEXEX HW40800)
(3) Olefin wax 2 (WAX-2)
Viscosity average molecular weight: 4100, density: 942 kg / m ³ , melting point: 113 ° C.
(Brand name Excellex HW41420P manufactured by Mitsui Chemicals)
(4) Olefin wax 3 (WAX-3)
Viscosity average molecular weight: 4600, density: 902 kg / m ³ , melting point: 90 ° C.
(Brand name Excellex HW48070B made by Mitsui Chemicals)
(5) Olefin wax 4 (WAX-4)
Viscosity average molecular weight: 2600, density: 947 kg / m ³ , melting point: 85 ° C., acid value 19
(Mitsui Chemicals trade name EXEXEX HW26502PE)
(6) Flame retardant: Brand name Kisuma 5A (magnesium hydroxide manufactured by Kyowa Chemical Industry Co., Ltd.)
(7) Antioxidant: Irganox 1010 (manufactured by Ciba Specialty Chemicals)

In the present invention, the following physical properties were measured by the following measuring methods.
(I) Strand appearance According to JIS K 7210, a strand was extruded at 190 ° C. under a load of 10 kg, the surface state was observed, and evaluation was performed according to the following criteria.
○: No rough skin was observed.
Δ: Some rough skin was observed.
X: The rough skin was remarkable.

(Ii) Tensile test Measured according to JIS K6760 method (however, the test piece was measured using a JIS K6301 No. 3 dumbbell and a sample thickness of 1 mm at a tensile speed of 200 mm / min).

(Iii) Flame Retardancy Test UL94 Flame Resistance Test: A flame retardant evaluation by UL94 vertical test was performed on a 3.0 mm thick press sheet using a UL94 combustion tester (manufactured by Suga Test Instruments Co., Ltd.).

(Iv) Viscosity average molecular weight (Mv)
Measurement was performed using a cross-fractionation chromatograph using o-dichlorobenzene as a solvent.
(V) Density (Unit: kg / m ³ )
Measured using JIS K7112-1999 method.
(Vi) Melting point (unit: ° C)
It measured using melting | fusing point by a differential scanning calorimeter (DSC).

(Examples 1-4)
Preparation of Sample Using a 6-inch roll set at 150 ° C., 100 parts by weight of EVA, 2 parts by weight of WAX-1, 150 parts by weight of flame retardant, and 0.2 parts by weight of antioxidant were melt-blended in advance. Furthermore, it melt-kneaded for 20 minutes using the pressurization kneader set to 160 degreeC.
Next, the obtained compound was press-molded for 10 minutes under the condition of a pressure of 100 kg / cm ² (gauge pressure) using a press molding machine set at a hot plate of 160 ° C., and a predetermined press sheet was produced.
The physical properties of the obtained press sheet were measured according to the previous method. The result of the measurement is shown in the review.

(Comparative Example 1)
In Example 1, a sample was prepared in the same manner except that the use of the olefin wax was omitted, and the obtained press sheet was evaluated. The results are shown in Table 1.

The present invention provides a flame retardant resin composition having improved flame retardancy while maintaining preferable physical properties of the ethylene-based resin.
The ethylene-based resin composition provided by the present invention is a flame retardant resin composition having improved mechanical properties and fluid workability while maintaining flame retardancy.
According to the present invention, it is a composition to which flame retardancy, mechanical properties and processability are imparted while maintaining preferable physical properties which are inherent characteristics, and has excellent mechanical properties and fluidity along with good flame retardancy. Since it shows, the flame-retardant resin composition suitable for the use as which the flame retardant of a coating | covering material, building materials, etc. of an electric wire or a communication line is calculated | required is provided.

Claims (9)

0.01 to 10 parts by weight of an olefin wax having a viscosity average molecular weight of 30,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 160 ° C. with respect to 100 parts by weight of the ethylene resin. And a flame retardant resin composition comprising 50 to 300 parts by weight of an inorganic flame retardant. 2. The olefin wax according to claim 1, wherein the olefin wax has a viscosity average molecular weight of 8,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 160 ° C. produced by a metallocene catalyst. The flame-retardant resin composition as described. ^3. The flame retardant according to claim 1, wherein the olefin wax has a viscosity average molecular weight of 8,000 or less, a density of 880 to 980 kg / m ³ , and a melting point of 60 to 130 ° C. ^3. Resin composition.   The flame retardant resin composition according to claim 1, wherein the olefin wax is an ethylene wax.   The ethylene resin is at least one selected from an ethylene / vinyl ester copolymer, an ethylene / unsaturated carboxylic acid ester copolymer, and an ethylene / unsaturated carboxylic acid copolymer and an ionomer thereof. The flame-retardant resin composition according to any one of claims 1 to 4.   The flame retardant resin composition according to claim 1, wherein the inorganic flame retardant is a metal hydrate.   The flame retardant resin composition according to claim 6, wherein the metal hydrate is at least one selected from aluminum hydroxide, magnesium hydroxide, and hydrotalcite.   The flame retardant resin composition according to claim 1, wherein the olefin wax is a modified wax.   The flame retardant resin composition according to any one of claims 1 to 8, wherein the flame retardancy measured by a test piece having a thickness of 3 mm according to UL94 flame resistance test is V-0.