JPH06248130A - Crosslinkable flame-retardant composition - Google Patents

Abstract

PURPOSE:To obtain a flame retardant compsn. which has a high crosslinkability and excellent resistances to abrasion and heat while retaining flexibility, mechanical characteristics, and chemical resistance by compounding an ethylene copolymer having carbon-carbon unsatd. bonds with a flame retardant. CONSTITUTION:This flame retardant compsn. is prepd. by compounding 100 pts.wt. ethylene copolymer having carbon-carbon unsatd. bonds (e.g. a copolymer obtd. from 70-99. 99wt.% ethylene, 0.01-30wt.% monomer having at least two carbon-carbon unsatd. bonds [e.g. allyl (meth)acrylate], and 0-29.99wt.% another unsatd. monomer (e.g. propylene)} with 3-200 pts.wt. flame retardant. Since the compsn. has a high crosslinkability (degree of crosslinking) and such well- balanced properties that it has improved resistances to abrasion and heat while retaining mechanical strengths, flexibility, processibility, and a high flame retardancy, it is useful as a molding material for producing a film, a sheet, a container, an electric wire, a packing, a sealant. a hose, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinkable flame-retardant composition containing a crosslinkable carbon-carbon unsaturated bond-containing ethylene copolymer (hereinafter abbreviated as ethylene copolymer) and a flame retardant. More specifically, it relates to a flame-retardant composition having high crosslinkability (crosslinking rate), maintaining flexibility, mechanical properties and chemical resistance, and particularly excellent in abrasion resistance and heat resistance.

[0002]

2. Description of the Related Art Polyolefin resins are excellent in physical properties and chemical properties, and are therefore formed into films, sheets, pipes, containers, electric wires, cables, etc. by various molding methods such as extrusion molding and injection molding. It is the most popular general-purpose resin used in many applications for household and industrial applications. Since the above polyolefin-based resin is easily flammable, various methods for making it flame-retardant have been conventionally proposed. The most common method is to add a halogen- or phosphorus-based organic flame retardant to the polyolefin resin to make it flame-retardant. Further, recently, various methods have been studied for adding a hydrate of an inorganic metal compound such as aluminum hydroxide and magnesium hydroxide as a non-pollution-type flame retardant that does not generate a harmful gas during combustion, has a low smoke property, and is a pollution-free type. (Japanese Patent Application Laid-Open No. 2-353845,
JP-A-2-145632). However, in the flame-retardant composition using the inorganic flame retardant, it is necessary to highly fill the inorganic flame retardant in order to enhance the flame retardancy,
When the filling amount is increased, not only the mechanical strength, flexibility and workability are deteriorated, but also the wear resistance is significantly impaired.Therefore, during manufacturing, wiring / assembling, transportation or normal use, Electrical insulating materials such as electric wires and cables that are easily damaged by vibration and friction under high temperature and severe conditions, and require abrasion resistance, as well as electrical materials such as protective tubes and joint covers, There is a problem that it cannot be applied to interior materials such as sheets and floor materials, and molded products such as cabinets and boxes. However, these flame-retardant compositions have the drawbacks of poor crosslinkability and poor wear resistance and heat resistance.

[0003]

The crosslinkable flame-retardant composition of the present invention has a high crosslinkability (crosslinking ratio) and is resistant to mechanical strength, flexibility, processability and high flame retardancy. Wear resistance,
Provided is a flame-retardant composition having improved heat resistance and well-balanced physical properties, wherein the composition is a film, a sheet, a container, an electric wire, a cable, a packing, a sealant, a hose, an injection product, or the like. It is used as a molding application.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a cross-link comprising a composition containing (I) 100 parts by weight of an ethylene copolymer having a carbon-carbon unsaturated bond, and (II) a flame retardant of 3 to 200 parts by weight. Flame-retardant composition.

The present invention will be described in detail below. The ethylene copolymer of the component (I) in the present invention is a copolymer comprising ethylene, a monomer having two or more carbon-carbon unsaturated bonds and, if desired, another unsaturated monomer, or Ethylene homopolymer, linear low density polyethylene (LLDPE), ultra low density polyethylene (VLDP)
E), ethylene-propylene copolymer rubber (EPM),
Ethylene-propylene-diene copolymer rubber (EPD
M), copolymers of ethylene with other α-olefins, ethylene-vinyl acetate copolymers (EVA), ethylene- (meth) acrylic acid or its alkyl ester copolymers, etc. It includes those obtained by addition-polymerizing a monomer having two or more bonds.

The above-mentioned monomer having two or more carbon-carbon unsaturated bonds means allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, divinyltoluene, 1,5-hexadiene-3-yne. , Divinyl compounds such as hexatriene, divinyl ether and divinyl sulfone, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, polyfunctional methacrylate monomers represented by diethylene glycol dimethacrylate, triallyl isocyanurate, diallyl phthalate, vinyl butyrate And other polyfunctional vinyl monomers, allyl phthalate, diallyl compounds such as 2,6-diacrylphenol and diallyl carbinol, allyl styrene, divinyl styrene, 5-vinyl-2-norbo Nen (VBH), 5-ethylidene-2-norbornene (EBH), vinylcyclohexene (VCH), allyl (meth) acrylate, and vinyl (meth) acrylate.

The other unsaturated monomers copolymerizable with the above-mentioned monomer having two or more carbon-carbon unsaturated bonds include α-olefins such as propylene and 1-butene, styrene and its derivatives, and acryl. Unsaturated carboxylic acids such as acid, methacrylic acid, maleic acid, fumaric acid, maleic anhydride, and itaconic anhydride, -methyl of (meth) acrylic acid,-
Ethyl, -propyl, -isopyropyr, -n-butyl,
-Alkyl ester of cyclohexyl, -lauryl, -stearyl, etc., maleic acid monomethyl ester, maleic acid dimethyl ester, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, unsaturated carboxylic acid (meth) acrylic acid glycidyl, etc. Examples thereof include acid esters, vinyl propionate, vinyl acetate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl stearate, vinyl trifluorate, and other vinyl esters. Among these, (meth) acrylic acid alkyl ester and vinyl ester are particularly preferable. More specifically, ethyl acrylate, methyl methacrylate and vinyl acetate can be mentioned.

Specific examples of the ethylene copolymer having a carbon-carbon unsaturated bond, which is the component (I), include ethylene-
Allyl (meth) acrylate copolymer, ethylene-vinyl (meth) acrylate copolymer, ethylene-allyl (meth) acrylate-vinyl acetate copolymer, ethylene-allyl (meth) acrylate-vinyl acetate copolymer Combined, ethylene-allyl (meth) acrylate- (meth) acrylic acid ester copolymer, ethylene-vinyl vinyl (meth) acrylate-
Examples thereof include vinyl acetate copolymers and ethylene- (meth) acrylic acid vinyl- (meth) acrylic acid ester copolymers. It is preferable that these copolymers are produced by a high-pressure radical polymerization method, and it is desirable that they have a proper balance of crystallinity and non-crystallinity.

The ethylene copolymer as the component (I) of the present invention includes 70 to 99.99% by weight of ethylene and 0.01 to 30% by weight of a monomer having two or more carbon-carbon unsaturated bonds. A copolymer composed of 0 to 29.99% by weight of another unsaturated monomer is preferable. When the amount of the monomer having two or more carbon-carbon unsaturated bonds is less than 0.01, the degree of crosslinking due to irradiation with ionizing radiation is low, and when it exceeds 30% by weight, a gel due to thermal crosslinking is generated in the processing step. May cause harmful effects. The type and amount of the other unsaturated monomer are appropriately selected in order to impart other properties such as flexibility of the copolymer.

As the flame retardant which is the component (II) of the present invention, addition type flame retardants such as halogen flame retardants, phosphorus flame retardants and inorganic flame retardants can be used. As a halogen-based flame retardant, tetrabromobisphenol A (TB
A), hexabromobenzene, decabromodiphenyl ether, tetrabromoethane (TBE), tetrabromobutane (TBB), hexabromocyclodecane (HBC
D) and other bromine and chlorinated paraffin, chlorinated polyphenyl, chlorinated diphenyl, perchloropentacyclodecane, chlorinated naphthalene and other chlorinated compounds are listed, and more effective when used in combination with antimony trioxide. To do.

As the phosphorus-based flame retardant, tricresyl phosphate, tri (β-chloroethyl) phosphate, tri (dichloropropyl) phosphate, tri (dibromopropyl) phosphate, 2,3-dibromopropyl-2,3 A phosphoric acid ester such as chloropropyl phosphate or a halogenated phosphoric acid ester is mainly mentioned.

As the inorganic flame retardant, aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, basic magnesium carbonate, dolomite, hydrotalcite,
Calcium hydroxide, barium hydroxide, tin oxide hydrate, hydrates of inorganic metal compounds such as borax, zinc borate, zinc metaborate, barium metaborate, zinc carbonate, magnesium carbonate-calcium carbonate, calcium carbonate, barium carbonate ,
Examples thereof include magnesium oxide, molybdenum oxide, zirconium oxide, tin oxide and red phosphorus. These may be used alone or in combination of two or more. Among these, hydrates of at least one metal compound selected from the group consisting of aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, basic magnesium carbonate, dolomite, and hydrotalcite, especially aluminum hydroxide and water. Magnesium oxide has a good flame retardant effect and is economically advantageous. The particle size of these inorganic flame retardants varies depending on the type, but in the above aluminum hydroxide and magnesium hydroxide, the average particle size is 20 μm or less, preferably 1 μm or less.
It is preferably 0 μm or less.

The composition of the present invention contains 3 to 200 parts by weight of the flame retardant as the component (II) per 100 parts by weight of the component (I). When a halogen-based flame retardant or a phosphorus-based flame retardant is selected as the flame retardant, these flame retardants are 3 to 50 parts by weight, preferably 5 to 40 parts by weight, relative to 100 parts by weight of the component (I). If the blending amount of these flame retardants is less than 3 parts by weight, it is difficult to make the flame retardant to a high degree. On the other hand, if the blending amount exceeds 50 parts by weight, the flame retarding is not improved so much and it becomes uneconomical. On the other hand, when an inorganic flame retardant is selected as the flame retardant,
30 parts by weight of the inorganic flame retardant is added to 100 parts by weight of the component (I).
200 parts by weight, preferably 40 to 150 parts by weight.
When the content of the inorganic flame retardant is less than 30 parts by weight, it is difficult to achieve sufficient flame retardancy by using the inorganic flame retardant alone, and therefore it is necessary to use the organic flame retardant together. On the other hand, when the amount is more than 200 parts by weight, the abrasion resistance is poor, the mechanical strength is lowered such as the impact strength is lowered, the flexibility is lost, and the low temperature characteristics are poor. When an inorganic flame retardant is selected as the flame retardant, there is an advantage that no toxic gas such as halogen gas is generated when burning.

In the present invention, the amount of the flame retardant compounded can be reduced or other characteristics can be imparted by using the composition and the inorganic filler in combination. Examples of the inorganic filler include calcium sulfate, calcium silicate, clay, diatomaceous earth, talc, alumina, silica sand, glass powder, iron oxide, metal powder, graphite, silicon carbide, silicon nitride, silica, boron nitride, aluminum nitride, carbon black. , Mica, glass plate, sericite, pyrophyllite, aluminum flake, graphite, silas paloon, metal paloon, glass paloon, pumice stone, glass fiber, carbon fiber, whiskers, metal fiber, graphite fiber, silicon carbide fiber, asbestos, Wollastonite and the like. These ingredients are compositions 100 of the present invention.
It is applied up to about 100 parts by weight with respect to parts by weight. If the blending amount exceeds 100 parts by weight, mechanical properties such as impact strength of the molded product deteriorate, which is not preferable.

In the present invention, when the flame retardant or the inorganic filler is used, the surface of the flame retardant or the filler is treated with a fatty acid such as stearic acid, oleic acid or palmitic acid or a metal salt thereof, or paraffin. ,
It is preferable to apply a surface treatment such as coating with wax, polyethylene wax or a modified product thereof, organic silane, organic borane, organic titanate and the like.

In the present invention, mineral oils, waxes and paraffins are used as long as they do not impair the physical properties of the composition comprising the ethylene copolymer having a carbon-carbon unsaturated bond as the component (I) and the flame retardant as the component (II). Scratch-whitening agents such as higher fatty acids and their esters, amides or metal salts, silicones, partial fatty acid esters of polyhydric alcohols or fatty acid alcohols, fatty acids, fatty acid amides, alkylphenols or alkylnaphthol alkylene oxide adducts may be added. .

The method of crosslinking the composition of the present invention is not particularly limited, and a crosslinking method using an organic peroxide, a method of irradiating with high-energy radiation such as electron beam, β ray, γ ray and the like. Any method such as a water crosslinking method using a silane compound may be used. The gel fraction of the flame-retardant composition after crosslinking is preferably 50% or more. If it is 50% or less, the effect of improving heat resistance and flame retardancy becomes insufficient. The larger the gel fraction, the larger the effect of improving wear resistance, heat resistance, flame retardancy, etc., and therefore it is preferable.

As the cross-linking agent used in the present invention, organic peroxides, dihydro compounds, dicumyl compounds and the like can be used. Examples of the organic peroxide include hydroperoxide, dicumyl peroxide, t-butylcumyl peroxide, dialkyl (allyl) peroxide, diisopropylbenzene hydroperoxide, dipropionyl peroxide, dioctanoyl peroxide, Benzoyl peroxide, peroxysuccinic acid, peroxyketal, 2,5-dimethyl-2,
5 Di (t-butylperoxy) hexane, t-butyloxyacetate, t-butylperoxyisobutyrate and the like are preferably used.

As the dihydroaromatic compound, dihydroquinoline or its derivative, dihydrofuran, 1,2-
Dihydrobenzene, 1,2-dihydronaphthalene, 9,
10-dihydrophenanthrene and the like can be mentioned.

Specific examples of the dicumyl compound include 2,
3-dimethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-di (p-methylphenyl) butane, 2,3-diethyl-2,3-di (p-bromo Examples thereof include phenyl) butane, and particularly 2,3-diethyl-2,3-diphenylbutane is preferably used.

The amount of these crosslinking agents added is such that the gel fraction is 50.
% Or more. Generally, composition 1
It is used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 00 parts by weight.

The method for producing the crosslinkable flame-retardant composition of the present invention is not particularly limited, and it can be produced by a known method. For example, an ethylene copolymer as the component (I), a flame retardant as the component (II) and, if necessary, a cross-linking agent, a cross-linking auxiliary agent, an inorganic filler, an additive, etc. are blended, and these are dried with an ordinary tumbler. Blended or melt-kneaded with a usual kneading machine such as a Banbury mixer, a pressure kneader, a kneading extruder, a twin-screw extruder, a roll, etc., and uniformly dispersed to obtain a mixture of resin compositions, or a molded product thereof. May be crosslinked by heating, water crosslinking in warm water, or irradiation with an electron beam or high-energy radiation for crosslinking. The crosslinked product may be obtained at the same time as producing a mixture of resin compositions or a molded product made of them by melt-kneading and uniformly dispersing with a usual kneader.

[0023]

The composition of the present invention comprises a component (I), an ethylene copolymer having a carbon-carbon unsaturated bond, a component (II), a flame retardant and, if necessary, a crosslinking agent or a crosslinking aid.
A cross-linkable flame-retardant composition composed of an additive such as an inorganic filler, wherein the ethylene copolymer having a carbon-carbon unsaturated bond as the component (I) increases the acceptance of the flame-retardant, and
Crosslinking efficiency is good, and it has a role of enhancing the flame retardant effect without lowering the mechanical strength. The flame retardant of the component (II) is
It has a role of achieving a high degree of flame retardancy, and particularly has a role of achieving a halogen-free high degree of flame retardation when an inorganic flame retardant is selected.

Further, within the scope of the present invention,
Organic fillers, antioxidants, lubricants, organic or inorganic pigments, UV inhibitors, dispersants, copper damage inhibitors, neutralizing agents, plasticizers, nucleating agents and the like may be added.

The present invention includes the following embodiments. (1) The crosslinkable flame retardant composition according to claim 1, wherein the flame retardant as the component (II) is an inorganic flame retardant. (2) The crosslinkable flame retardant composition according to claim 1, wherein the inorganic flame retardant as the component (II) is a hydrate of an inorganic metal compound. (3) The crosslinkable flame retardant composition according to claim 1, wherein the inorganic flame retardant as the component (II) is magnesium hydroxide.

[0026]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited thereto. [Resin and materials used] (I) Component 1: Ethylene-allyl methacrylate copolymer (hereinafter referred to as EA
MA) [AMA content = 1.0 wt%, MFR = 1.0 g / 10 min.] 2: ethylene-vinyl methacrylic acid copolymer (hereinafter referred to as E-
VMA content) [VMA content = 1.0 wt%, MFR = 1.0 g / 10 min.] 3: ethylene-allyl methacrylate-ethyl acrylate copolymer (hereinafter referred to as E-EA-AMA) [AMA content = 1.0 wt%, EA content = 10 wt%, MF
R = 0.4 g / 10 min.] 4: Ethylene-vinyl methacrylate-ethyl acrylate copolymer (hereinafter referred to as E-EA-VMA) [VMA content = 1.0 wt%, EA content = 10 wt%, MF
R = 0.4g / 10min.] (II) Component 1: Magnesium hydroxide [Brand name: Kisuma 5J Kyowa Chemical Co., Ltd.] 2: Aluminum oxide [Brand name: Heidilite 42M, manufactured by Nippon Light Metal Co., Ltd.] 3: Decabromodiphenyl ether 4: Antimony trioxide

(Test method) (1) Tensile test (YTS), (UTS) and elongation (UE
L) (%) A test piece punched with a No. 3 dumbbell from a sheet having a thickness of 1 mm was measured with a Tensilon at a tensile speed of 200 mm / min. (2) Oxygen index (OI) The oxygen index was measured according to JIS K7201. (3) Wear resistance test Using a Taber type wear tester, wear wheels H-22, load 1
Weight loss was measured after testing at Kg, 1000 revolutions. (4) Gel Fraction Dicumyl peroxide [trade name: Park Mill D, manufactured by NOF CORPORATION] 2.0w%, Thiobis [trade name: Nocrac 300, manufactured by Ouchi Shinko Co., Ltd.] 0.2w% (I), (I
The component I) was kneaded with a roll at 120 ° C., and thermally crosslinked for 30 minutes by a press molding machine at 160 ° C., the sample was crushed to within 35 to 20 mesh, and the residual rate after extraction with xylene at 120 ° C. for 10 hours was obtained. . (5) Heat resistance (heat deformation rate) The heat resistance was measured according to JIS C3005. Temperature 120 ℃,
It was measured with a load of 1 kg.

(Examples 1 to 6) The compositions having the formulations shown in Table 1 were dry blended, and then melt-kneaded at a resin temperature of 200 ° C. using a 50 mmφ extruder to pelletize. 1 more
A sample was prepared by press molding at 80 ° C., a pressure of 100 kg / cm ² , and a time of 5 minutes, and used for the test. The test results are shown in Table 1. In the same manner as in Example 2 and the following, a sample was prepared with the composition shown in Table 1 and subjected to the test. The test items were MFR, tensile strength, elongation, oxygen index, wear resistance, gel fraction, heat resistance (heat deformation rate), etc. (however, the gel fraction was measured without adding a flame retardant). The results are shown in Table 1.

(Comparative Example 1) As the component (I), low density polyethylene [density = 0.92]
2 g / cm ³ , MFR = 1.0 g / 10 min. Manufactured by Nippon Petrochemical Co., Ltd.] was used. The results are also shown in Table 1.

Comparative Example 2 Example 3 was repeated except that 100 parts by weight of E-EA-AMA was used as the component (I) and 20 parts by weight of magnesium hydroxide was used as the component (II). The results are also shown in Table 1.

Comparative Example 3 Example 3 was repeated, except that 100 parts by weight of E-EA-AMA was used as the component (I) and 250 parts by weight of magnesium hydroxide was used as the component (II). The results are shown in Table 1.
Are shown together with.

[0032]

[Table 1]

[0033]

INDUSTRIAL APPLICABILITY As described above, the present invention provides the component (I), an ethylene copolymer having a carbon-carbon unsaturated bond, (I).
The present invention provides a cross-linkable flame-retardant composition obtained by blending a flame retardant of component (I) or, if necessary, various additives, wherein an ethylene copolymer having a carbon-carbon unsaturated bond of component (I) is used. The polymer has a role of increasing the acceptance of the inorganic flame retardant, having a good crosslinking efficiency, and enhancing the flame retardant effect without lowering the mechanical strength. The flame retardant as the component (II) has a role of achieving a high degree of flame retardancy, and particularly when an inorganic flame retardant is selected as the flame retardant, a role of achieving a halogen-free high degree of flame retardant. Have. Thus, the crosslinkable flame-retardant resin composition of the present invention,
In addition to having a high level of flame retardancy, especially when an inorganic flame retardant is selected as the flame retardant, there is no generation of toxic gas such as halogen gas during combustion, it has excellent wear resistance and heat resistance, and it is safe and easy to use. It has excellent flexibility, mechanical properties, chemical resistance, and electrical properties, so it can be used as a film, sheet,
It is used for molding applications such as extrusion molded products such as pipes or injection molded products, and for electric wires and cables.
It is used in various fields such as electricity, electronics, automobiles, ships, aircraft, construction, and civil engineering, and has a great industrial utility value.

Claims (2)

[Claims] 1. A crosslinkable flame-retardant composition comprising a composition containing (I) 100 parts by weight of an ethylene copolymer having a carbon-carbon unsaturated bond, and (II) 3 to 200 parts by weight of a flame retardant. 2. An ethylene copolymer having a carbon-carbon unsaturated bond has an ethylene content of 70 to 99.99% by weight, and a monomer 0.01 to 3 having at least two carbon-carbon unsaturated bonds.
The crosslinkable flame-retardant composition according to claim 1, which is a copolymer composed of 0% by weight and 0 to 29.99% by weight of another unsaturated monomer.