DESCRIPTION FLAME RETARDANT ETHYLENE RESIN COMPOSITION AND USE THEREOF
Technical Field
The present invention relates to a thermoplastic resin composition and a molded product comprising the same, and in particular to a thermoplastic resin composition suitable as an insulating material or sheath material for electric wires, a polymer composition having high flame retardancy, and a molded product comprising the same.
Background Art
Conventionally, a sheath material and a partially insulating material for electric wires often make use of polyvinyl chloride (PVC), and its flexibility, flame retardancy and insulating properties have been appraised. Generally, PVC contains a large amount of plasticizer so that when the plasticizer is lost by heating, and the like, the PVC is easily hardened and generates a chlorine-based gas upon combustion, and thus development for electric wires which can be substituted for PVC has been desired in recent years.
Under these circumstances, various flame retardant resin compositions based on ethylene polymers such as

polyethylene have been proposed.
U.S. Patent No. 6,232,377 describes a flame retardant resin composition which comprises a specific ethylene copolymer selected from an ethylene/vinyl ester copolymer, an ethylene/a,(3-unsaturated carboxylic acid copolymer and low-density polyethylene, and further comprises a metal hydroxide, a triazine compound and a specific flame retardant compound. However, these ethylene polymers have a problem that pliability and flexibility are easily lowered when the amount of inorganic compounds such as metal hydroxides is increased in order to increase the flam retardant effect (Patent Document 1).
Accordingly, it is a first object of the present invention to provide a resin composition excellent in flame retardant effect, and also excellent in pliability and flexibility and superior in tensile physical properties, and a molded product comprising the same, particularly an insulating material and/or sheath for electric wires.
On the other hand, many kinds of thermoplastic polymers and thermosetting polymers have been used in internal wiring for home electronic appliances, buildings, interior decorations, automobile parts, and electronic instruments. A majority of these polymers (particularly olefin polymers) are easily flammable.

From the viewpoint of protection against disasters, there is increasing demand for incombustibility and flame retardancy of various facilities and structures, and particularly high flame retardancy is required for home electronic appliances that can be the origin of a fire. Criteria for flame retardancy of internal wiring materials are stipulated by, for example, UL standards in the US (Underwriters Laboratories Inc.), and the like, and evaluated by a vertical flame test called VW-1 test. Accordingly, materials usable for a long time exposure to high temperatures and fires are desired, and a method of conferring high flame retardancy on many thermoplastic polymers and thermosetting polymers by adding a flame retardant in the preparation of the polymers or in the preparation of molded products is widely employed.
As the flame retardant, many compounds such as metal hydroxides, borates, organic halogenated compounds, phosphorus compounds such as phosphates, red phosphorus and organic phosphorus compounds; and organic nitrogen compounds are used. Among these, organic halogenated compounds, organic phosphorus compounds, and the like exhibit an excellent flame retardant effect.
However, these halogen-containing compounds have a problem that they are heat-decomposed at the time of molding

resin to generate hydrogen halide and deteriorate the resin itself thus causing coloration, or to generate hydrogen halide on the occasion of a fire.
As a halogen-free flame retardant, an inorganic flame retardant such as aluminum hydroxide and magnesium hydroxide is conventionally used. When only the inorganic compound is used, however, the flame retardant effect is low, and a large amount of the inorganic compound is required to exhibit a sufficient effect, but when it is added in a large amount, physical properties inherent in the resin may be deteriorated, and thus its application is limited.
As halogen-free flame retardants exhibiting a relatively excellent flame retardant effect, there are specific organic phosphorus compounds and specific organic nitrogen compounds, and these are also often practically used.
The conventional organic phosphate ester flame retardant is represented by triphenyl phosphate (hereinafter referred to as "TPP"), but this compound is poor in heat resistance and highly volatile, and is thus not suitable for resin to be molded at high temperatures, and particularly because of contamination of a molding die, its application is limited.
As the compounds used as flame retardants which are

lowered in volatilization of organic phosphorus, there described phosphates ester condensate in JP-B-51-19858, JP-A-59-202240, and the like. These compounds are superior to TPP with respect to heat resistance and low volatilization, but do not surpass TPP in flame retardant effect per unit weight of phosphorus, and therefore there is a problem that these should be added in a large amount, and thus the temperature of thermal deformation is significantly lowered due to the effect of the plasticizer for resin. (Patent Documents 2 and 3) .
A large number of formulations of flame retardants using polyphosphates such as ammonium polyphosphate, and phosphate condensates such as polyphosphoric amides are also proposed (JP-A-54-22450, JP-A-9-316250, etc.). However, polyphosphoric acid absorbs water to reduce electrical resistance gradually due to water absorption and is thus not suitable as an insulating coating material for an electric wire/cable, and the like, and therefore its application is limited. (Patent Documents 4 and 5). To prevent entrophication in closed water systems such as lakes and marshes, formulations substituted for phosphorus flame retardants are also required in recent years.
Organic nitrogen compounds such as melamine also exhibit a relatively high flame retardant effect (JP-A-8-

176343, etc.). However, conventionally these compounds have been often used in combination with the phosphorus flame retardant in order to achieve higher flame retardant effect. (Patent Document 6).
Therefore, it is a second object of the present invention to provide a polymer composition having high flame retardancy without containing halogen-containing retardants or phosphorous flame retardants, in particular, a flame retardant polymer composition suitable for a coating material or a sheath for electric wires.
Recently, a resin composition comprising an ethylene/a-olefin copolymer, a graft modified ethylene polymer and a metal hydroxide (WO 03/10654), and a resin composition comprising an ethylene/cc-olefin copolymer, a graft modified ethylene polymer, an ethylene/vinyl ester copolymer, and a metal hydroxide (Patent Documents 7 and 8) are also disclosed.
[Patent Document 1] U.S. Patent No. 6,232,377
[Patent Document 2] JP-B-51-19858
[Patent Document 3] JP-A-59-202240
[Patent Document 4] JP-A-54-22450
[Patent Document 5] JP-A-9-316250
[Patent Document 6] JP-A-8-176343
[Patent Document 7] International Publication of WO 03-

[Patent Document 8] JP-A-2000-239459
Disclosure of the Invention Problems to be Solved by the Invention
The present invention is to solve the problem of the related art technology as mentioned above, and thus to provide a resin composition having good pliability and flexibility as well as excellent flame retardant effect, and a molded product comprising the same.
Means for Solving the Problems
The present invention provides a flame retardant ethylene resin composition, comprising
51 to 95 parts by weight of an ethylene/a-olefin copolymer (A) comprising ethylene and C3 to CIO a-olefin, and
5 to 49 parts by weight of a copolymer (B) of ethylene and a vinyl ester,
and further comprising
0.1 to 50 parts by weight of a graft modified ethylene polymer (C),
50 to 250 parts by weight of a metal hydroxide (D),
0.1 to 50 parts by weight of a triazine compound (E),

and
0.1 to 40 parts by weight of a powdered silicone (F), relative to 100 parts by weight of the total (A) and (B),
wherein the weight ratio of (E) to (F) ((E)/(F)) is 1.2 or more.
The present invention also provides an electric wire/cable coated with the flame retardant ethylene resin composition as described above.
Effect of -the Invention
The resin composition of the present invention has good pliability and flexibility, as well as excellent flame retardant effect.
Best Mode for Carrying Out the Invention
Ethylene/g-Olefin copolymer (A)
The ethylene/a-olefin copolymer (A) used in the present invention is a copolymer of ethylene and a C3-C10 a-olefin. Specific examples of the C3-C10 a-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-l-butene, 3-methyl-1-pentene, 3-ethyl-l-pentene, 4-methyl-l-pentene, 4-methyl-1-hexene, 4,4-dimethyl-l-pentene, 4-ethyl-l-hexene, 3-ethyl-l-hexene, 1-octene, 1-decene, and the like. The copolymer is composed of ethylene and one or more of these

olefins. Among these olefins, at least one of propylene, 1-butene, 1-hexene, and 1-octene is preferably used.
Above all, an ethylene/1-butene copolymer has particularly excellent balance between the pliability and the tensile property at the same density, thus it being more preferable.
With respect to the content of each structural unit in the ethylene/a-olefin copolymer, it is preferable that the content of the structural units derived from ethylene is usually 75 to 95 mol%, preferably 80 to 95 mol%, and the content of the structural units derived from at least one
compound selected from C3 to CIO a-olefins is usually 5 to 25 mol%, preferably 5 to 20 mol%.
The ethylene/a-olefin copolymer (A) used in the present invention preferably has the following properties:
§51
(i) the density is 855 to 900 kg/m3, preferably OiO&-7 to
S-qo
6r^9t) kg/m3,
(ii) the melt flow rate (MFR2) under a load of 2.16 kg at 190°C is in the range of 0.1 to 100 g/10 min, preferably 0.1 to 20 g/10 min, more preferably 0.1 to 0.9 g/10 min,
(iii) the index (Mw/Mn) of molecular-weight
distribution evaluated by GPC is in the range of 1.5 to 3.5, preferably 1.5 to 3.0, more preferably 1.8 to 2.5,
(iv) the B value determined from 13C-NMR spectrum and

the following equation is 0.9 to 1.5, preferably 0.9 to 1.2:
B value = [POE]/(2-[PE][PO])
wherein [PE] is a molar fraction of structural unit derived from ethylene in the copolymer, and [PO] is a molar fraction of structural unit derived from a-olefin in the copolymer, and [POE] is a ratio of the number of ethylene • a-olefin dyad to the number of the total dyad in the copolymer.
This B value is an index indicating the distribution state of the ethylene and C3 to CIO a-olefin in the ethylene/a-olefin copolymer, and can be determined on the basis of reports of J. C. Randall (Macromolecules, 15, 353 (1982)) and J. Ray (Macromolecules, 10, 773 (1977)), etc.
A higher B value indicates that a block chain of the ethylene or a-olefin .Gopolyme-r is shorter, and it means that the distribution of ethylene and a-olefin is more uniform and the composition distribution of the copolymer rubber is narrower. Further, as the B value becomes lower than 1.0, the composition distribution of the ethylene/a-olefin copolymer tends to be broader and there may occur problems such as deterioration of handling properties.
Even more preferably, (v) the intensity ratio of Tap to Taa (Tap/Taa) in 13C-NMR spectrum is 0.5 or less, preferably 0.4 or less, more preferably 0.3 or less. Here, Taa and Tap in 13C-NMR spectrum represent respective peak intensities of

two kinds of CH2's at different positions relative to the tertiary carbon atom in the structural unit derived from a-olefin having 3 or more carbon atoms as described below.
R R R R
II II
-C-CH2-CH2-C- -CH2-C-CH2-C-
H H H H
T a & T a a
The intensity ratio of Tap/Tact may be determined in the following manner: 13C-NMR spectrum of the ethylene/a-olefin copolymer is measured, for example, by using JEOL-GX270 NMR spectrometer manufactured by JEOL Ltd. Measurement is made at 67.8 MHz using d6-benzene (128 ppm) standard in a mixed solution containing 5% by weight of a sample in hexachlorobutadiene/d6-benzene (2/1, by volume) at 25°C. The 13C-NMR spectrum was analyzed according to the proposal by Lindemann Adams (Analysis Chemistry, 43, p. 1245 (1971)) and J. C. Randall (Review Macromolecular Chemistry Physics, C29, 201 (1989)) to determine the intensity ratio of Tap/Taa.
The ethylene/a-olefin copolymer of the present invention having not only the above properties but also the following property is also preferably used.
(vi) The ratio [MFRi0/MFR2] of the melt flow rate (MFRio)

at 190°C under a load of 10 kg to the melt flow rate (MFR2) at 190°C under a load of 2.16 kg satisfies the following relationship:
Mw/Mn + 4.7 < MFRio/MFR2
wherein when MFRio, MFR2, and Mw/Mn do not satisfy the above relationship, moldability and/or material strength may be deteriorated. [Method of Producing Ethylene/oc-olefin Copolymer (A) ]
The ethylene/a-olefin copolymer (A) can be produced by copolymerizing ethylene with at least one C3 to CIO ct-olefin in the presence of a metallocene catalyst or a Ziegler catalyst comprising a V compound and an organoaluminum compound, and the metallocene catalyst is preferably used.
The metallocene catalyst may be composed of a metallocene compound (a) , an organoaluminum oxy compound (b) and/or a compound (c) capable of forming an ion pair by reacting with the metallocene compound (a), or may be composed of (a), (b) and/or (c) and an organoaluminum compound (d). Copolymerization of ethylene/a-olefin can be carried out in the presence of the above catalyst, usually in a liquid phase using a hydrocarbon solvent by batch, semi-continuous or continuous method. When the metallocene catalyst comprising the metallocene compound (a) and the organoaluminum oxy compound (b) or the ionized ionic

compound (c) is used, the concentration of the metallocene compound (a) in the polymerization system is usually 0.00005 to 0.1 mmol/L (polymerization volume), preferably 0.0001 to 0.05 mmol/L. The organoaluminum oxy compound (b) is supplied in an amount of 1 to 10000, preferably 10 to 5000, in terms of the molar ratio (Al/transition metal) of aluminum atom to the transition metal in the metallocene compound in the polymerization system. The ionized ionic compound (c) is supplied in an amount of 0.5 to 20, preferably 1 to 10, in terms of the molar ratio (ionized ionic compound (c)/metallocene compound (a)) of the ionized ionic compound (c) to the metallocene compound (a) in the polymerization system. When the organoaluminum compound is used, it is used in an amount of usually 0 to 5 mmol/L (polymerization volume), preferably about 0 to 2 mmol/L.
The copolymerization reaction is carried out usually at a reaction temperature of -20°C to +150°C, preferably 0 to 120°C, more preferably 0 to 100°C and at a pressure of 0 to 7.8 MPa (80 kgf/cm2, gauge pressure), preferably 0 to 4.9 MPa (50 kgf/cm2, gauge pressure).
Ethylene and a-olefin are supplied in such an amount that the ethylene/a-olefin copolymer (A) having the above specific composition is obtained. In copolymerization, a molecular weight modifier such as hydrogen can also be used.

Copolymer (B) of Ethylene and Vinyl Ester
The copolymer of ethylene and vinyl ester used in the present invention is conventionally produced by a high pressure radical polymerization process.
Examples of the vinyl ester monomer to be copolymerized with ethylene include vinyl propionate, vinyl acetate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl trifluoroacetate, and the like, and among them, vinyl acetate is preferably used. Further, it is desirable that the copolymer of ethylene and vinyl ester has a melt flow rate of 0.5 to 50 g/10 min, preferably 0.5 to 10 g/10 min, and a vinyl monomer content of 5 to 40 % by weight, preferably 10 to 35% by weight. If the melt flow rate is less than 0.5 g/10 min, processibility is deteriorated, while if the melt flow rate is more than 50 g/10 min, the mechanical characteristics of the resulting resin composition, such as tensile strength, elongation, hardness and impact strength are deteriorated, thus it being not preferable. If the content of the vinyl monomer is less than 5% by weight, processibility is deteriorated as well as the flame retardant added as a filler is hardly uniformly distributed, while if the content of the vinyl monomer is more than 40% by weight, the mechanical characteristics of the resulting resin composition are deteriorated, thus it

being not preferable.
Graft Modified Ethylene Polymer (C)
The ethylene polymer used as the material of the graft modified ethylene polymer in the present invention is preferably an ethylene/a-olefin copolymer. The ethylene/a-olefin copolymer used as the material of the graft modified ethylene polymer is preferably an ethylene/C3 to CIO cc-olefin copolymer. Specific examples of the C3 to CIO cc-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-l-pentene, 3-ethyl-l-pentene, 4-methyl-1-pentene, 4-methyl-l-hexene, 4,4-dimethyl-l-pentene 4-ethyl-l-hexene, 1 octane, 3-ethyl-l-hexene, 1-octene, 1-decene, and the like. These may be used alone or in combination of two or more kinds. Among these olefins, at least one of propylene, 1-butene, 1-hexene, and 1-octene is particularly preferable.
With respect to the content of each structural unit in the ethylene copolymer, it is preferable that the content of a structural unit derived from ethylene is usually 75 to 95 mol%, preferably 80 to 95 mol%, and the content of a structural unit derived from at least one compound selected
from C3 to CIO a-olefins is usually 5 to 25 mol%, preferably 5 to 20 mol%.
The ethylene/a-olefin copolymer used for graft

modification preferably has the following properties:
(i) the density is 855 to 910 kg/ra3, preferably 857 to
890 kg/m3,
(ii) the melt flow rate (MFR2) under a load of 2.16 kg
;»
at 190°C is in the range of 0.1 to 100 g/10 min, preferably 0.1 to 20 g/10 min,
(iii) the index (Mw/Mn) of molecular-weight
distribution evaluated by GPC is in the range of 1.5 to 3.5, preferably 1.5 to 3.0, more preferably 1.8 to 2.5,
(iv) the B value determined from 13C-NMR spectrum and the following equation is 0.9 to 1.5, preferably 1.0 to 1.2:
B value = [POE]/(2• [PE] [PO] )
wherein [PE] is a molar fraction of structural unit derived from ethylene in the copolymer, and [PO] is a molar fraction of structural unit derived from a-olefin in the copolymer, and [POE] is a ratio of the chain number of ethylene/a-olefin to the chain number of the total dyad in the copolymer.
Other characteristics of ethylene/cc-olefin copolymer used as the material of the graft-modified ethylene polymer are preferably the same as those described in the ethylene/a-olefin copolymer used in (A), but the comonomer species, density, molecular weight, and the like of the copolymer may be the same as or different from those of (A).

The graft-modified ethylene polymer according to the present invention is obtained by graft-modification of the ethylene copolymer with a vinyl compound having at least one kind of polar group. The vinyl compound having a polar group includes vinyl compounds having oxygen-containing groups such as acid, acid anhydride, ester, alcohol, epoxy and ether as polar groups, vinyl compounds having nitrogen-containing groups such as isocyanate and amide, and vinyl compounds having silicon-containing groups such as vinyl silane.
Among these compounds, vinyl compounds having oxygen-containing groups are preferable, and unsaturated epoxy monomers, unsaturated carboxylic acids and derivatives thereof are preferable.
The unsaturated epoxy monomers include unsaturated glycidyl ethers, unsaturated glycidyl esters (for example glycidyl methacrylate) , and the like.
Examples of the unsaturated carboxylic acids include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid and nadic acid™(endo-cis-bicyclo[2,2,1]hept-5-ene-2, 3-dicarboxylic acid), and the like.
Derivatives of the unsaturated carboxylic acids include,

for example, acid halide compounds, amide compounds, imide compounds, acid anhydrides, and ester compounds of the unsaturated carboxylic acids. Specific examples include malenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate, and the like.
Among these compounds, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, and particularly maleic acid, nadic acid™ or acid anhydrides thereof are preferable. The graft position of the unsaturated carboxylic acid or its derivative onto the unmodified ethylene copolymer is not particularly limited, and the unsaturated carboxylic acid or its derivative may be bonded to an arbitrary carbon atom of the ethylene polymer constituting the graft-modified ethylene polymer.
The graft-modified ethylene polymer (C) can be prepared by conventionally known methods, for example by the following methods.
(1) A method of graft copolymerization by melting the
unmodified ethylene polymer in an extruder, etc., and then
adding unsaturated carboxylic acid, etc.,
(2) A method of graft copolymerization by dissolving
the unmodified ethylene polymer in a solvent and adding
unsaturated carboxylic acid, etc.

In both methods, the graft reaction is conducted preferably in the presence of a radical initiator for efficient graft copolymerization of graft monomers such as the unsaturated carboxylic acid.
An organic peroxide, an azo compound, or the like is used as the radical initiator. Examples of the radical initiator include organic peroxides such as benzoyl peroxide, dichlorobenzoyl peroxide and dicumyl peroxide, and azo compounds such as azobisisobutyronitrile and dimethyl azoisobutyrate. Preferably used among these are dialkyl peroxides such as dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butyl peroxy)hexyn-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 1,4-bis(tert-butylperoxyisopropyl)benzene.
The radical initiator is used in an amount of usually 0.001 to 1 part by weight, preferably 0.003 to 0.5 part by weight, more preferably 0.05 to 0.3 part by weight, relative to 100 parts by weight of the unmodified ethylene polymer.
The reaction temperature in the graft reaction using the radical initiator or in the graft reaction without using the radical initiator is set up in the range of usually 60 to 350°C, preferably 150 to 300°C. Metal Hydroxide (D)
Examples of the metal hydroxide in the present

invention include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, manganese hydroxide, zinc hydroxide, hydrotalcite, and the like. These metal hydroxides may be used alone or as a mixture thereof, and magnesium hydroxide alone or a magnesium hydroxide-containing mixture, or aluminum hydroxide alone or an aluminum hydroxide-containing mixture is particularly preferable. Triazine Compound (E)
The triazine ring containing compound (E) in the present invention may be any one generally known as a flame retardant, and includes melamine, ammeline, melam, benzoguanamine, acetoguanamine, phthalodiguanamine, melamine cyanurate, pyrophosphoric melamine, butylene diguanamine, norbornene diguanamine, methylene dimelamine, ethylene dimelamine, trimethylene dimelamine, tetramethylene dimelamine, hexamethylene dimelamine, 1,3-hexylene dimelamine, and the like, among which melamine cyanurate is particularly preferable. The amount of the triazine ring containing compound to be blended is 0.1 to 50 parts by weight, preferably 5 to 40 parts by weight, relative to 100 parts by weight of the total of the ethylene/ct-olefin
copolymer (A) and the copolymer (B) of ethylene and a vinyl
0-1
ester. If the amount to be blended is less than-*- part by

weight, the generation of combustion inert gas (nitrogen gas) is not significant, and also there is no exhibition of a synergistic effect with other flame retardants. On the other hand, if the amount to be blended is more than 50 parts by weight, the flame retardant effect is not so increased, and rather the molding processibility or mechanical properties of the molded article may be deteriorated, thus it being unfavorable. Powdered Silicone
Examples of the powdered silicone (also referred to as silicone power) of the present invention include an organic organopolysiloxane powder, such as dimethyl polysiloxane powder. The powdered silicone of the present invention has a molecular weight (Mn), as measured by GPC, of 100000 to 10000000, preferably 500000 to 5000000. Other Additives
The polymer composition according to the present invention can be blended, if necessary, with additives such as an antioxidant, a UV absorber, a weatherability stabilizer, a heat stabilizer, an antistatic, a flame retardant, a pigment, a dye, a lubricant, and the like in addition to those described above. It is more preferable that the polymer composition of the present invention contains a boric acid compound, preferably zinc borate, as a

flame retardant aid. Polymer Composition
The polymer composition according to the present invention is characterized in that it comprises 51 to 95 parts by weight of an ethylene/a-olefin copolymer (A) and 5 to 49 parts by weight of a copolymer (B) of ethylene and a vinyl ester, and further comprises 0.1 to 50 parts by weight of a graft modified ethylene polymer (C) , 50 to 250 parts by weight of a metal hydroxide (D), 0.1 to 50 parts by weight of a triazine compound (E), and 0.1 to 40 parts by weight of a powdered silicone (F), relative to 100 parts by weight of the total (A) and (B), wherein the weight ratio of (E) to (F) ((E)/(F) ) is 1.2 or more.
More preferably, the polymer composition comprises 51 to 85 parts by weight of an ethylene/a-olefin copolymer (A) and 15 to 49 parts by weight of a copolymer (B) of ethylene and a vinyl ester, and further comprises 0.1 to 40 parts by weight of a graft modified ethylene polymer (C), 50 to 250 parts by weight of a metal hydroxide (D), 1 to 40 parts by weight of a triazine compound (E), and 0.1 to 26 parts by weight of a powdered silicone (F), relative to 100 parts by weight of the total (A) and (B), wherein the weight ratio of (E) to (F) ((E)/(F)) is 1.5 or more.
Even more preferably, the polymer composition comprises

55 to 85 parts by weight of an ethylene/a-olefin copolymer (A) and 15 to 45 parts by weight of a copolymer (B) of ethylene and a vinyl ester, and further comprises 0.1 to 30 parts by weight of a graft modified ethylene polymer (C), 50 to 250 parts by weight of a metal hydroxide (D), 5 to 40 parts by weight of a triazine compound (E), and 0.1 to 26 parts by weight of a powdered silicone (F), relative to 100 parts by weight of the total (A) and (B), wherein the weight ratio of (E) to (F) ((E)/(F)) is 1.5 or more.
Most preferably, the polymer composition comprises 55 to 75 parts by weight of an ethylene/a-olefin copolymer (A) and 25 to 45 parts by weight of a copolymer (B) of ethylene and a vinyl ester, and further comprises 0.1 to 30 parts by weight of a graft modified ethylene polymer (C), 50 to 250 parts by weight of a metal hydroxide (D), 5 to 40 parts by weight of a triazine compound (E), and 0.1 to 26 parts by weight of a powdered silicone (F), relative to 100 parts by weight of the total (A) and (B), wherein the weight ratio of (E) to (F) ((E)/(F)) is 2.0 or more.
Preferably, the polymer composition contains 0.1 to 30 parts by weight, preferably 0.1 to 20 parts by weight of a boric acid compound as a flame retardant aid, relative to 100 parts by weight of the total of the ethylene/a-olefin copolymer (A) and the copolymer (B) of ethylene and a vinyl

ester.
The polymer composition according to the present invention is prepared in various known methods by melt-mixing the above components (A), (B), (C), (D), (E) and (F), and additives blended if necessary.
The polymer composition according to the present invention is obtained, for example, by mixing the above components simultaneously or successively in a Henschel mixer, a V-type blender, a tumbler mixer, a ribbon blender, and the like and then melt-kneading the mixture by a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer, and the like.
Among them, when the multi-screw extruder, the kneader or the Banbury mixer, which is particularly excellent in kneading performance, is used, a high-quality polymer composition wherein the respective components are dispersed more uniformly can be obtained.
Further, the additives, for example, an antioxidant, and the like can be added if necessary in an arbitrary stage. Molded Product Comprising Flame retardant Ethylene Resin Composition
The molded product according to the present invention can be produced by molding the flame retardant ethylene resin composition according to the present invention in

various shapes by conventionally known melt-molding methods such as extrusion molding, rotational molding, calender molding, injection molding, compression molding, transfer molding, powder molding, blow molding and vacuum molding.
The flame retardant ethylene resin composition according to the present invention is preferably used in applications, for example, for coating of electric wires, such as a sheath or an insulating material for electric wires. The molded product of the present invention is a coating layer such as a sheath or an insulating material for electric wires, and this coating layer such as a sheath or an insulating material for electric wires is formed around an electric wire by a conventionally known method such as extrusion molding.
Examples
Hereinafter, the present invention is described in more detail by reference to the Examples, but the present invention is not limited to the Examples.
Physical properties of the ethylene/a-olefin copolymer were evaluated in the following manner.
(1) Density
A strand after measurement of MFR at 190°C under a load of 2.16 kg was heat-treated at 120°C for 1 hour, then cooled

over 1 hour to room temperature and measured by a density gradient tube method.
(2) a-Olefin Content, TafJ/Taa, and B value
Determined by 13C-NMR spectrum.
(3) Mw/Mn
Determined at 140°C in an o-dichlorobenzene solvent by using GPC (gel permeation chromatography).
(4) MFR10/MFR2
MFRio at 190°C under a load of 10 kg and MFR2 at 190°C under a load of 2.16 kg were measured in accordance with ASTMD-1238, and the MFRi0/MFR2 ratio was calculated. A higher ratio indicates higher fluidity of the polymer upon melting, that is, higher processability.
The ethylene/a-olefin copolymers, the copolymers of ethylene and a vinyl ester, the graft modified ethylene polymers, metal hydroxides, triazine compounds, powdered silicone and silicon resins which were used in Examples are the followings:
Ethylene/a-Olefin Copolymer (A):
The ethylene/a-olefin copolymer is the ethylene/1-butene copolymer A-l which was prepared in the following Preparation Example 1.
[Preparation Example 1]

(Preparation of ethylene/1-butene copolymer A-l)
18.4 mg of triphenyl
carbenium(tetrakispentafluorophenyl)borate was dissolved in 5 ml of toluene to prepare a toluene solution at a concentration of 0.004 mM/ml. 1.8 mg of [dimethyl(t-butylamide) (tetramethyl-ri5-cyclopentadienyl) silane] titanium dichloride was dissolved in 5 ml of toluene to prepare a toluene solution at a concentration of 0.001 mM/ml. At the initiation of polymerization, 0.38 ml of toluene solution of triphenyl carbonium (tetrakispentafluorophenyl) borate and 0.38 ml of toluene solution of [dimethyl(t-butylamide) (tetramethyl-r|5-cyclopentadienyl) silane] titanium dichloride, were mixed with 4.24 ml of diluting toluene, to prepare 5 ml of toluene solution of triphenyl carbenium(tetrakispentafluorophenyl)borate at a concentration of 0.002 mM/L in terms of B and [dimethyl(t-butylamide) (tetramethyl-ri5-cyclopentadienyl) silane] titanium dichloride at 0.0005 mM/L in terms of Ti.
750 ml of heptane was introduced at 23°C into a 1.5-L SUS autoclave equipped with a stirring blade and purged sufficiently with nitrogen. This autoclave was charged under cooling in ice with 10 g of 1-butene and 100 ml of hydrogen with stirring. Then, the autoclave was heated to 100°C, and further pressurized with ethylene such that the

total pressure was increased to 6 KG. When the internal pressure of the autoclave reached 6 KG, 1.0 ml of 1.0 mM/ml triisobutyl aluminum (TIBA) in hexane was injected with nitrogen. Subsequently, 5 ml of the catalyst solution prepared as above was injected with nitrogen into the autoclave to initiate polymerization. Thereafter, the temperature was regulated for 5 minutes such that the inner temperature of the autoclave was 100°C, while ethylene was directly fed to attain a pressure of 6 kg. Five minutes after the polymerization was initiated, 5 ml of methanol was introduced by a pump into the autoclave to terminate the polymerization, and the autoclave was depressurized to the atmospheric pressure. 3 L of methanol was poured into the reaction solution under stirring. The resulting polymer containing the solvent was dried at 130°C for 13 hours at 600 torr, to give 10 g of an ethylene/butene copolymer A-l. The properties of the resulting ethylene/1-butene copolymer are shown in Table 1. [Table 1]



Properties of Polymer
Density (kg/m ) MFR-190°C (g/10 rain) Mw/Mn
B Value TapXTaa

A-l
885
0.5
2.1
10.0
1.05
0.3

Copolymer (B) of ethylene and vinyl ester: Ethylene/vinyl acetate copolymer Trade name EVAFLEX
EV360 (manufactured by Du Pont-Mitsui Polychemicals Co.,
Ltd.) (hereinafter abbreviated as EVA). Graft modified ethylene polymer (C): Maleic anhydride graft modified ethylene/1-butene
copolymer which was prepared in the following Preparation
Example 2.
[Preparation Example 2]
(Preparation of Maleic Anhydride Graft Modified Ethylene/1-Butene Copolymer)
10 kg of the ethylene/1-butene copolymer A-l, and a solution of 50 g of maleic anhydride and 3 g of di-tert-butyl peroxide dissolved in 50 g of acetone, were blended in a Henschel mixer.
Then, the blend thus obtained was introduced via a hopper into a single-screw extruder having a screw diameter of 40 mm and a L/D ratio of 26, extruded into a strand at a resin temperature of 260°C and at an extrusion output of 6 kg/hr, then cooled with water, and pelletized to give a maleic anhydride graft modified ethylene/1-butene copolymer C-l.

From the resultant graft modified ethylene/1-butene copolymer C-l, the unreacted maleic anhydride was extracted with acetone, and the measurement of the graft amount of the maleic anhydride in this graft modified ethylene/1-butene copolymer proved to be 0.43% by weight.
Metal Hydroxide (D):
Magnesium hydroxide, trade name: KISUMA 5B (manufactured by Kyowa Chemical Industry Co., Ltd.)
Triazine Compound (E):
Melamine cyanurate, trade name: MC-440 (manufactured by Nissan Chemical Industries , Ltd.)
Powdered silicone (F):
Polyorganosiloxane, trade name: DC4-7081 (manufactured by Dow Corning Toray Co., Ltd.)
Number average molecular weight (Mn) as measured by a GPC method: 1000000
Preparation of an insulated wire sample and evaluation thereof were conducted by the following methods.
(Preparation of Insulated Wire Sample)
The polymer composition with composition as shown in Table 2 was applied to a thickness of 0.8 mm around a conductor (outer diameter: about 1.35 mm) of 7 twisted soft copper wires having a wire diameter of 0.45 mm, at a dice temperature of 190°C, a screw revolution of 30 rpm and at an

extrusion output of 1.6 to 1.8 kg/hr in a melt-extruder (trade name: Laboplast Mill, manufactured by Toyo Seiki Seisaku-sho, Ltd.) having an electric wire coating dice arranged therein, whereby an insulated wire sample having a diameter of 3.0 mm was obtained.
(5) Tensile Strength and Elongation at Break
In accordance with JIS K6301, a tensile test was conducted with a span of 20 mm at a stress rate of 200 mm/min to determine tensile strength and elongation at break.
(6) Torsional Rigidity
In accordance with JIS K6745, torsional rigidity at a temperature of 23°C was measured by using a Clash-Berg testing machine manufactured by Toyo Seiki Seisaku-sho, Ltd.
(7) Flame retardancy (Combustion Test)
The flame retardancy was evaluated by the VW-1 vertical flame test stipulated in the above-mentioned UL standards, using the above prepared insulated wire sample.
The results of the above evaluation are shown in Table 2.

[Table 2]

Example 1 Comp. Ex. 1 Comp. Ex. 2 Comp. Ex. 3 Comp. Ex. 4
Composition A-l 60 60 60 60 60

EV360 40 40 40 40 40

C*-l 3 3 3 3 3

Kisuma 5B 180 180 180 180 180

MC-440 20 20 40

DC4-7081 10 10 30
Tensile Strength MPa 11 12 8 12 9
Elongation at Break % 600 600 500 620 520
Torsional Rigidity MPa 30 27 34 25 31
Combustion Test VW-1 Passed Failed Failed Failed Failed
Industrial Applicability
The resin composition of the present invention has good pliability and flexibility, as well as excellent flame retardant effect, and thus it can be preferably used in applications, for example, for coating of electric wires, such as a sheath or an insulating material for electric wires.

CLAIMS
1. A flame retardant ethylene resin composition,
comprising 51 to 95 parts by weight of an ethylene/a-olefin
copolymer (A) and 5 to 49 parts by weight of a copolymer (B)
of ethylene and a vinyl ester, and further comprising 0.1 to
50 parts by weight of a graft modified ethylene polymer (C),
50 to 250 parts by weight of a metal hydroxide (D), 0.1 to
50 parts by weight of a triazine compound (E), and 0.1 to 40
parts by weight of a powdered silicone (F), relative to 100
parts by weight of the total (A) and (B) , wherein the weight
ratio of (E) to (F) ((E)/(F)) is 1.2 or more.
2. An electric wire or cable coated with the flame
retardant ethylene resin composition according to claim 1.