KR20000061604A - Flame retarding silane crosslinkable polyethylene composition and method of preparing flame retarding cable by the same - Google Patents

Abstract

PURPOSE: A water-bridged nonflammable resin composition for insulating a power line which shows uniform and excellent mechanical properties and a method for preparing a nonflammable insulating cable, which has a scorch-resistant property, crack-resistant property and shows an excellent electrical property, nonflammability and extrusion-processing property and high early bridging stability, are provided. CONSTITUTION: The water-bridged nonflammable resin composition for insulating a power line comprises: (i) 20-80 parts by weight of a silane graft polyethylene; (ii) not more than 30 parts by weight of an ethylene copolymer; (iii) 0.1-1 parts by weight of a catalyst for water-bridging; (iv) not more than 1 parts by weight of a metal stabilizer; (v) not more than 1 parts by weight of an antioxidant; (vi) 10-40 parts by weight of a halogenic non-flaming agent; and (vii) 1-40 parts by weight of an inorganic non-flaming agent. The method comprises steps of: (i) throwing a polyethylene, silane and antioxidant in a two-axis extruder and then extruding them to prepare a silane graft polyethylene; (ii) mixing an olefinic resin, catalyst for water-bridging and antioxidant in a banbury mixer to prepare a catalyst master batch; (iii) mixing a halogenic non-flaming agent, inorganic non-flaming agent, antioxidant, activator and olefinic resin in a banbury mixer to prepare a nonflammable master batch; and (iv) mixing the silane graft polyethylene of step (i), catalyst master batch of step (ii) and nonflammable master batch of step (iii) to prepare a mixture and then extruding the mixture in an extruder to prepare a cable.

Description

Water-retardant crosslinked flame retardant resin composition for power line insulation and flame retardant insulated cable manufacturing method {FLAME RETARDING SILANE CROSSLINKABLE POLYETHYLENE COMPOSITION AND METHOD OF PREPARING FLAME RETARDING CABLE BY THE SAME}

[Industrial use]

The present invention relates to a water crosslinked flame retardant resin composition for power line insulation. In particular, a composition comprising polyethylene, a polyethylene copolymer, an antioxidant, a halogen-based flame retardant, and an inorganic substance grafted with a silane monomer, relates to a composition crosslinked by moisture and having an excellent flame retardant effect.

[Prior art]

In general, the power line includes a conductor part made of metal such as aluminum or copper, an insulating layer which insulates the conductor from the outside, an inner semiconducting layer of the conductor part which protects the conductor and the insulating layer from electric shock, an outer semiconducting layer outside the insulating layer, and a cable. It consists of a coating layer for protecting itself, and the structure may change as needed.

In the conventional power line having such a structure, a high voltage current flows, which may cause a fire due to a short circuit or an electric shock. Once a fire occurs, a coating layer, an insulating layer, and a semiconducting layer protecting the conductor are burned. Easy to destroy Because of this, the conductors are often short-circuited, and an outer coating layer made of a vinyl-based flame retardant resin composition has been used in order to protect the power line from the risk of such a fire.

However, if the flame retardant is imposed only on the outer coating layer, the performance of the insulating layer is reduced due to the fire of the insulating layer. In order to maintain perfect flame retardancy, it is important to flame retardant both the insulating layer and the covering layer, but the insulating layer is the most important part of the structure of the power line, and the insulating performance should be excellent. Foreign matter should not be mixed as it is destroyed. In addition, it is necessary to maintain excellent mechanical strength, and because the power line is maintained at a high temperature due to conductor heating during energization, stability at a high temperature is required to crosslink the insulating layer.

As such, it is very difficult to have high crosslinking efficiency while simultaneously maintaining excellent electrical properties and excellent flame retardancy. Until now, in order to obtain a resin composition having the above properties, a resin composition in which a halogen-based flame retardant and an inorganic substance, an antioxidant, a crosslinking agent such as a peroxide, etc. are mixed has been used.

However, in order to process the resin composition, an additional device called a vulcanization tube must be passed. This device has a high equipment cost and a large amount of discarded due to the basic length of the vulcanizing tube when the processing conditions are changed. There is this.

In order to solve this problem, a water-crosslinked resin composition in which a halogen-based flame retardant, an inorganic substance, and an antioxidant is mixed with an ethylene-modified ethylene alkylene alkyl copolymer has been introduced (US Pat. No. 4,353,997). In order to reinforce mechanical properties, a copolymer must be obtained by reacting an alpha olefin with an alkylene alkyl acrylate organometallic catalyst, an organosilane, etc. in a reactor, so that a process is complicated and a relatively large reactor is required. The inorganic crosslinking is relatively easy to absorb moisture, and thus has a disadvantage in that early crosslinking can easily occur.

The present invention has all the properties to be provided as an insulating layer in consideration of the problems of the prior art, has excellent flame retardancy, applying a cross-linking method using water and separately preparing a cross-linkable copolymer with an inorganic material, input when processing the cable This greatly reduces the equipment cost and operation cost, and allows the user to easily control the degree of flame retardancy, and has excellent flame retardancy so as to effectively block the short circuit of electricity in the event of a fire. It is an object of the present invention to provide a composition and a method for producing a flame retardant insulated cable using the same.

[Means for solving the problem]

The present invention to achieve the above object

a) 20 to 80 parts by weight of silane graft polyethylene;

b) 30 parts by weight or less of an ethylene copolymer;

c) 0.1 to 1 parts by weight of the crosslinking catalyst;

d) 1 part by weight or less of a metal stabilizer;

e) 1 part by weight or less of antioxidant;

f) 10 to 40 parts by weight of halogen-based flame retardant; And

g) 1 to 40 parts by weight of inorganic flame retardant

It provides a water-crosslinked flame retardant resin composition for power line insulation.

The composition is prepared by master batching a halogen-based flame retardant and an inorganic flame retardant based on an olefin resin, and adding the composition having the same composition as above, and master-batching 0.1 to 1 parts by weight of a crosslinking catalyst using an olefin resin as a base resin. It is a water-crosslinked flame retardant resin composition for power line insulation added afterward to have the same composition as above.

In addition, 0.5-10 weight part of pigment | dye masterbatches may be added to the said composition, and the division | segmentation of a cable may be easy.

In addition, the present invention is a method of manufacturing a flame retardant insulated cable,

a) polyethylene, silane, crosslinking aid and antioxidant

Silane graft chemically bonded to polyethylene by reaction extrusion

Preparing polyethylene;

b) the olefin resin, the crosslinking catalyst and the antioxidant are kneaded in a Banbury mixer

Preparing a catalyst master batch;

c) halogen flame retardants, inorganic flame retardants, antioxidants, lubricants, olefin resins

Kneading in a Banbury mixer to produce a flame retardant master batch; And

d) silane graft polyethylene of step a), catalyst masterbatch of step b)

And c) mixing the flame retardant masterbatch of step to prepare a mixture, and then extruder

Manufacturing a cable by extruding the mixture into a furnace

It provides a method comprising a.

The mixture composition of d) uses the composition of the water-crosslinked flame retardant resin composition for power line insulation.

The present invention is described in detail below.

As the base resin of the water-crosslinked flame retardant resin composition for power line insulation of the present invention, a polyethylene resin, for example, a melt index polymerized from ethylene and an α-olefin having 3 or more carbon atoms of 0.5 to 6.0 g / 10 minutes, and a density of 0.910 to 0.960 g / cm 3 of ultra low density polyethylene, low density polyethylene, medium density polyethylene, linear low density polyethylene, high density polyethylene alone, or a blend of two or more components may be used.

The olefin resin used in the present invention is an ethylene and an alpha olefin having at least trivalent carbon atoms, that is, propylene, 1-butene, 1-pentene, 1-hexene, and 1-hexene. ), Ethylene alphaolefin copolymers alone or copolymerized from 1-octene and the like and ethylene and polar copolymers, i.e., organic or anhydrous organic acids such as acrylic acid, maleic acid, methacrylic acid, etaacrylic acid or dehydrating compounds thereof A single or a mixture of two or more kinds of polar ethylene copolymers alone or copolymerized with acrylic anhydride, maleic anhydride, methacrylic anhydride, eta acrylic anhydride or vinyl ester, vinyl acetate and the like.

The alpha olefin copolymer used in the present invention has an alpha olefin content of 1 to 80% of the alpha olefin copolymer, a melt index of 0.1 to 20 g / min at a load of 2.16 kg at 190 ° C, and a density of 0.860 to 0.960 g. Low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ultra low density polyethylene, etc., characterized in that it is characterized in that / 3 cm3, wherein the polar polyethylene copolymer has a content of 1 to 50% by weight of the polar copolymer in the total weight of the polar polyethylene copolymer And a melt index of 0.1 to 20 g / min and a density of 0.860 to 0.960 g / cm 3 under a load of 2.16 kg at 190 ° C.

The silanes used in the present invention are chemically bonded to polyethylene and act as functional groups for crosslinking of flame retardant insulated cables, such as vinyl trimethoxy silane and vinyl triethoxy silane. , Vinyl dichlorosilane (vinyl dichloro silane), vinyl trichlorosilane (vinyl trichloro silane), divinyl dichloro silane (divinyl dichloro silane), vinyl dibromo silane (vinyl dibromo silane), vinyl tri- normal butoxy silane (vinyl tri- n-butoxy silane) or the like is used, and the amount finally contained in the water-crosslinked flame retardant resin composition for power line insulation is 0.5 to 5.0 parts by weight based on 100 parts by weight of the base resin.

The crosslinking aid used in the present invention is added as an intermediate medium that chemically grafts polyethylene and silane, and includes t-butyl cumyl peroxide, dicumyl peroxide, Methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di (t-butyl peroxy) hexane (2,5-dimethyl-2,5-di (t-butyl peroxy) hexane ), Di-t-butyl peroxide, t-butyl peroxy benzoate, α, α-bis (t-butyl peroxy isopropyl) benzene (α and α-bis (t-butyl peroxy isopropyl) benzene and the like are used, and the amount finally added to the water-crosslinked flame retardant resin composition for power line insulation is 0.01 to 1.0 part by weight based on 100 parts by weight of the base resin.

The catalyst used in the present invention is added for the economic benefit of shortening the crosslinking time when crosslinking by exposure to moisture after preparing the power line, dibutyltin dilaulate, dibutyltin maleate, di Dibutyltin diacetate, dibutyltin dioctoate, tetrabutyl titanate, hexylamine, dibutylamine, etc. are used. The amount finally contained in the flame retardant resin composition is 0.01 to 0.1 parts by weight based on 100 parts by weight of the base resin, and is used in a master batch to add a fixed ratio in the production of flame retardant insulated cables. It is 0.1-2.0 weight% of the batch total weight.

Antioxidants used in the present invention not only inhibit the oxidation of insulators that are directly or indirectly received during power line processing or after installation, but also inhibit the premature crosslinking that may occur during chemical reactions of silanes, crosslinking aids and polyethylene. As an additive having a phenolic antioxidant, for example, pentaerythryl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate] (pentaaerythrityl-tetrakis [ 3-3,5-di-t-butyl-4-hydoxy phenyl) -propionate], 2,2'-thio diethyl bis- [3- (3,5-di-t-4-hydroxy phenyl)- Propionate] (2,2'-thiodiethyl bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate], octadecyl 3- (3,5-di-t-4- Hydroxydecyl) -propionate (octadecyl 3- (3,5-di-t-butyl-4-hydroxy phenyl) propionate), 4,4'-thiobis (6-t-butyl-m-cresol) ( 4,4'-thio bis (6-t-butyl-m-cresol), triethylene glycol-bis-3 (3-t-butyl-4-hydroxy-5 methyl Phenyl) propionate (triethylene glycol-bis-3 (3-t-butyl-4-hydroxy-5-methyl phenyl) propionate and the like, and ester-based antioxidants such as dilauryl thiodipropionate Used alone or in combination, the amount finally added to the water-crosslinked flame retardant resin composition for power line insulation is 0.1 to 0.6 parts by weight based on 100 parts by weight of the base resin.

The halogen-based flame retardant used in the present invention plays a role of imparting flame retardancy of the water-crosslinked flame retardant resin composition for power line insulation through reactions such as heat source removal by endothermic reaction during combustion and deodorization of combustion materials such as hydrogen atom removal from combustion materials. It is an additive characterized by a form in which a relatively reactive and transitionable halogen group element, ie chlorine, bromine, iodine, etc. is combined with an organic compound among the elements of Group 7 on the periodic table of the elements, among which bromine element Examples of halogen-based flame retardants include decabromodiphenyl ether, decabromodiphenyl ethane, decabromodiphenyl oxide in the form of having two benzene rings in the compound. , Octabromodiphenyl ether, pentabromodiphenyl ether enyl ether), hexabromodiphenoxy ethane, and the like; Tetrabromo phthalic anhydride and its derivatives as tetrabromophalic anhydride, tetrabromo phthalate diols and polyethers, ethylene bis tetrabromo phthalamide, ethylene bis (tetrabromopthalamide) Tetrabromo bisphenol A and the like; polypentabromobenzyl acrylate (poly (pentabromobenzyl arylate), brominated polystyrene, etc. as a flame retarded polymer; or hexabromododecane, dibromoneophene as an aliphatic compound It is used alone or in combination of two or more thereof, such as methyl glycol (dibromoneopentyl glycol), vinyl bromide (vinylbromide), and the amount finally used in the water-crosslinked flame retardant resin composition for power line insulation is 10 to 40 parts by weight of the total resin composition.

Inorganic flame retardant used in the present invention is used simultaneously with the halogen-based flame retardant and acts as a flame retardant synergistic effect alone or halogen-based flame retardant to add the flame retardancy of the water-crosslinked flame retardant resin composition for power line insulation, decomposes at high temperature to dissociate moisture Hydrated forms of metal hydroxides or metal oxides, such as hydrates of aluminum hydroxide or aluminum trioxide (Al ₂ O ₃ · 2H ₂ O), hydrates of magnesium hydroxide or magnesium oxide (MgO · H ₂ O), hydroxides Hydrates of calcium or calcium oxide (CaO.H ₂ O) and calcium carbonate may be used. As a material having a form of metal oxide, that is, X _n O _m , for example, antimony trioxide is used, and the like for power line insulation The amount finally used in the crosslinked flame retardant resin composition is 1 to 40 parts by weight of the total resin composition.

In the present invention, a method for producing a crosslinkable flame retardant resin composition for power line insulation using an additive such as silane graft polyethylene, a catalyst, and a halogen-based flame retardant and an inorganic flame retardant includes the following three steps.

The first process

As a process for producing silane graft polyethylene (compound in which silane is chemically bonded to polyethylene), a mixture of polyethylene, silane, crosslinking aid, and antioxidant is introduced into a twin screw extruder to chemically bond silane to polyethylene. The extruder operation temperature at this time is set so that the temperature of the silane graft polyethylene in a molten state may be 180-280 degreeC.

2nd process

As a process for preparing a catalyst master batch, the final catalyst master batch is prepared by kneading the polyethylene, the catalyst and the antioxidant as a carrier in a batch type kneader in which the heating medium is maintained at a temperature of 110 to 130 ° C. for 30 minutes.

The third process

The process for producing a halogen-based flame retardant master batch consists of the following two steps. In the first step, the Henschel mixer is filled with an olefin resin, a halogen flame retardant, an inorganic flame retardant, an appropriate amount of antioxidant, and a lubricant at room temperature, followed by high speed stirring for 20 to 30 minutes. In step 2, the kneaded material prepared in step 1 is added to a batch kneader in which the heating medium is maintained at a temperature of 110 to 130 ° C., and then kneaded at a temperature of 140 to 180 ° C. for 30 minutes.

The present invention will be described in detail with reference to the following Examples and Comparative Examples, but these Examples are for illustrating the present invention, and the present invention is not limited thereto.

EXAMPLE

Example 1

As a first step of the above three processes, 2.0 parts by weight of vinyltrimethoxysilane as silane and 100 parts by weight of low density polyethylene (density 0.920, melt index 2.0; LG Chemical Co., Ltd. Lutene) in a twin screw extruder, as a crosslinking aid, 0.05 parts by weight of Milperoxide and 0.1 parts by weight of an antioxidant (Irganox 1076, manufactured by Shiva-Geigy Co., Ltd.) were added thereto, followed by reaction extrusion to prepare silane graft polyethylene.

The operating conditions at this time were set so that the silane graft polyethylene temperature in the molten state was set to 220 to 240 ° C, and the graft ratio (a measure of the amount of silane chemically bonded to polyethylene) was 8 to 12%.

Dibutyltindiaulate 0.5 to 2.0 as a catalyst based on 100 parts by weight of low density polyethylene (density 0.920, melt index 2.0; LG Chemicals Lutene) in a Banbury mixer maintained at a temperature of 110 to 130 ° C as the second step. A catalyst masterbatch was prepared by kneading for 30 minutes by weight (preferably 1.5 parts by weight) and 0.1 to 0.15 parts by weight of an antioxidant (Irganox 1076, manufactured by Shivagaigi Co., Ltd.).

As a third step, 52.5% by weight of decabromo diphenyl ethylene (manufactured by Albemarle) having an bromine content of 82%, 17.5% by weight of antimony trioxide, and an ethylene anthacrylic anhydride copolymer (melt) in a Henschel mixer maintained at room temperature in the first step. Index 2.0, 15% eta acrylic acid anhydride; 25% by weight Mitsui Duton Petrochemical Evalflex) and ultra-low density polyethylene (melt index 2.0, density 0.885, Exact manufactured by Exxon) prepared using a single-site catalyst Thereafter, 1 part by weight of polyethylene wax (LC102N manufactured by Lion Chemical Co., Ltd.) and 0.5 part by weight of an antioxidant (Irganox 1076, manufactured by Shiva-Geigy Co., Ltd.) were kneaded with respect to 100 parts by weight of the total mixture.

In the second step as the third step, the kneaded material of the first step kneaded well is kneaded for 30 minutes in a batch banbury mixer maintained at a temperature of 120 to 160 ° C., and finally a halogen-based flame retardant, an inorganic flame retardant, an antioxidant, and a polyethylene wax Halogen-based flame retardant master batches were prepared comprising polyethylene, polyethylene, and ethylene anthacrylic anhydride copolymers.

The product of each process was added to a tumbler mixer by mixing 55% by weight of silane graft polyethylene, 5% by weight of catalyst masterbatch, 40% by weight of halogen-based flame retardant masterbatch for 5 minutes, and then mixing the mixture by a single screw extruder. A flame retardant insulated cable for 1 kW was manufactured under the conditions indicated by 1, and the resulting cable was soaked in water at 90 ° C. for 3 hours to undergo cross-linking, followed by characteristic evaluation, and the results are shown in Table 3.

[Table 1] Fire Retardant Insulation Cable Manufacturing Condition

device 90 ψ, L / D = 24 Wire ash 1㎸, 38SQMM Extruder temperature (℃) C1 = 160, C2 = 170, C3 = 180, C4 = 180, C5 = 190, neck = 200, head = 200, die = 200 Line speed (m / min) 40

Example 2

When preparing the halogen-based flame retardant masterbatch of Example 1, a flame retardant insulated cable for 1 kW was manufactured using a single screw extruder under the same conditions as in Example 1 except that polyethylene wax was not added. Table 3 shows the results of evaluating the characteristics of this cable.

Example 3

A flame retardant insulated cable for 1 kW was prepared using a single screw extruder under the same conditions as in Example 1 except that 2.5 parts by weight of vinyltrimethoxysilane was added as the silane to produce silane graft polyethylene having a graft ratio of 12 to 13%. . Table 3 shows the results of evaluating the characteristics of this cable.

Comparative Example 1

Instead of preparing silane graft polyethylene using the twin-screw extruder of Example 1, the mixture and water crosslinking of the same composition as when the silane graft polyethyl of Example 1 was prepared in a Henschel mixer maintained at a temperature of 80 ° C. After adding the catalyst to 0.1% by weight of the total composition, the mixture was stirred for 30 minutes to impregnate the silane, the crosslinking aid, the catalyst, and the antioxidant with the low density polyethylene, and then the halogen-based flame retardant master batch prepared in the same manner as in Example 1 was carried out. After mixing to the same content as in Example 1, using a single screw extruder under the same conditions to prepare a flame-retardant insulation cable for 1 kW. Table 3 shows the results of evaluating the characteristics of this cable.

Comparative Example 2

Ethylene acrylate anhydride copolymer (melt index) in 100 parts by weight of low density polyethylene (density 0.920, melt index 2.0; LG Chemicals Lutene) in a twin-screw extruder in the same manner as in the process for producing the silane graft polyethylene of Example 1 2.0, 15% by weight of eta acrylic acid anhydride; 15 parts by weight of Mitsui DuPont Petrochemicals Evaflex), 2.0 parts by weight of vinyltrimethoxysilane as a silane, 0.05 parts by weight of dicumyl peroxide as a crosslinking aid, and an antioxidant (Ilganox from Ciba-Geigy Co., Ltd.) 1076) 0.1 part by weight of the reaction was extruded to prepare a silane graft ethylene anhydrous acrylate acrylic copolymer.

The operating conditions at this time were set so that the silane graft polyethylene temperature in the molten state was set to 220 to 240 ° C, and the graft ratio (a measure of the amount of silane chemically bonded to polyethylene) was 8 to 12%.

Decabromo diphenyl ethylene (manufactured by Albemarle) having a bromine content of 82% in a Henschel mixer maintained at room temperature in one step so as to have the same composition as in Example 1 in the silane graft ethylene anhydrous acrylate acrylic acid polyethylene copolymer thus prepared; Antimony trioxide, polyethylene wax, and antioxidant were added and kneaded well at room temperature for 10 minutes.

The mixture kneaded well in two stages was kneaded for 30 minutes in a batch banbury mixer maintained at a temperature of 120 to 160 ° C. and finally based on a silane graft ethylene anhydride polyethylene acrylate copolymer and a halogen-based flame retardant and an inorganic flame retardant. To prepare a primary composition containing an antioxidant, polyethylene wax and the like.

Finally, the primary composition prepared above and the catalyst master batch prepared by the method of Example 1 were mixed to prepare a flame-retardant insulated cable for 1 kW using a single screw extruder under the same conditions. Table 3 shows the results of evaluating the characteristics of this cable.

Comparative Example 3

Decabromo diphenyl ethylene (saytex 8010 from Albemarle), antimony trioxide, and oxides with a bromine content of 82% per 100 parts by weight of low density polyethylene (density 0.920, melt index 2.0; LG Chemicals Lutene) in one step After adding the inhibitor and the polyethylene wax to the same composition as in Example 1, and sufficiently kneading in a Henschel mixer maintained at room temperature, melt kneading using a twin screw extruder so that the melt temperature is maintained at 220 ~ 240 ℃ Halogen-based flame retardant compounds were prepared.

100 parts by weight of the total halogen-based flame retardant compound was added to the Henschel mixer maintained at a temperature of 80 ° C. in the flame retardant compound prepared above in two steps, and then 2 parts by weight of dicumyl peroxide (100 parts by weight of the halogen-based flame retardant) DCP) was impregnated.

Using the halogen-based crosslinkable flame retardant compound prepared in three steps using a single screw extruder and a vulcanization tube, a flame retardant insulated cable for 1 kW was manufactured under the processing conditions of Table 2 below. Table 3 shows the results of evaluating the characteristics of this cable.

[Table 2] Flame Retardant Insulation Cable Manufacturing Conditions

device 90 ψ, L / D = 24 Wire ash 1㎸, 38SQMM Extruder temperature (℃) C1 = 120, C2 = 125, C3 = 125, C4 = 125, C5 = 125, neck = 125, head = 125, die = 125 Line speed (m / min) 20

TABLE 3

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile Strength (kg / ㎠) 150-170 150-170 155-175 110 to 150 150-170 140-170 Elongation (%) 350-380 350-380 300-330 310 to 360 350-380 380-420 Tensile Strength Residual Rate after Heating (%) 96 94 98 80 95 98 Elongation at rest after heating (%) 92 91 96 78 92 96 hot elongation (%) 70-80 70-80 60-70 90 to 150 60-70 30-50 set elongation (%) 0 to 5 0 to 5 0 to 5 0 to 5 0 to 5 0 to 5 Extrusion load (A) 75 93 78 87 77 125 Extrusion appearance Very good Great Very good Bad usually Great Withstand voltage characteristic (㎸ / mm) 38 34 39 28 38 36 Crack resistance (time) More than 1500 More than 1200 More than 1500 500 or more More than 1200 More than 1500 Scotch stability (minutes) 60 50 55 25 40 - purging weight (kg) 20 20 20 20 20 100 waste cablelength (m) 25 25 25 25 25 100

In Table 3 above

Hot elongation and set elongation were measured by the method of IEC 840 (hot elongation is 200 ° C, 20 N / cm 2 load, 15 minutes, and set elongation is 5 minutes without load).

Tensile strength after heating and elongation after heating are measured as tensile strength and elongation after aging the specimen in an oven at 135 ° C. for 7 days, and displayed as a residual compared to room temperature characteristics. The higher the value, the better the heat resistance.

Withstand voltage characteristics were measured according to the ASTM D149 method after producing a 1 mm specimen by extrusion molding.

Crack resistance is evaluated as the environmental stress cracking resistance measured according to the method of ASTM D1693, which means the time elapsed from the first soaking of 10 specimens in 10% solution of Igepal to the occurrence of cracking. It means good crackability.

Scorch stability means the time when the crosslinking degree reaches 5% by measuring the crosslinking degree with time while mixing each species at 180 ° C and 30rpm using a haake mixer. The higher the value, the better the scorch stability.

The purging weight (kg) is the total amount of resin required to clean the extruder before entering the cable continuous process in the cable manufacturing process. The larger the value, the more waste and the higher the manufacturing cost.

The waste cable length means the minimum cable length that is wasted by pulling and cutting when the same length of cable is manufactured in the cable manufacturing process. The larger the value, the more waste and the higher the manufacturing cost.

The composition of the present invention exhibits uniform and excellent mechanical properties, flame-retardant insulated cable using the same has excellent scorch resistance, crack resistance, electrical properties and flame retardancy, and excellent extrusion processing characteristics during extrusion compared to chemical crosslinking, vulcanization Waste elements due to tube retention can be reduced, and early crosslinking stability is high as compared with the integral water crosslinking resin composition.

Claims (20)

In the water crosslinked flame retardant resin composition for power line insulation a) 20 to 80 parts by weight of silane graft polyethylene; b) 30 parts by weight or less of an ethylene copolymer; c) 0.1 to 1 parts by weight of the crosslinking catalyst; d) 1 part by weight or less of a metal stabilizer; e) 1 part by weight or less of antioxidant; f) 10 to 40 parts by weight of halogen-based flame retardant; And g) 1 to 40 parts by weight of inorganic flame retardant Composition comprising a. The method of claim 1, Wherein the silane graft polyethylene of a) is produced by reaction extrusion of a polyethylene resin, a silane, a crosslinking aid and an antioxidant in a twin screw extruder in a twin screw extruder. The method of claim 2, The polyethylene resin is ultra low density polyethylene, low density polyethylene, medium density polyethylene, linear low density polyethylene having a melt index of 0.5 to 6.0 g / 10 minutes and a density of 0.0910 to 0.960 g / cm 2 polymerized from ethylene and an α-olefin having 3 or more carbon atoms. And a blend of polyethylene selected from the group consisting of high density polyethylene. The method of claim 2, Wherein said silane is selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinyldichlorosilane, vinyltrichlorosilane, divinyldichlorosilane, vinyldibromosilane, and vinyltrinomalbutoxysilane. The method of claim 2, The crosslinking aid is t-butyl cumyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di (t-butyl peroxy) hexane, di-t-butyl peroxide, t-butyl peroxy benzoate, α, α-bis (t-butyl peroxy isopropyl) benzene. The method of claim 1, Wherein the water crosslinking catalyst of c) is selected from the group consisting of dibutyl dilaurate, dibutyl dimaleate, dibutyl tin diacetate, dibutyl tin dioctoate, tetrabutyl titanate, hexylamine, dibutylamine. The method of claim 1, The antioxidant of e) is pentaerythryl-tetrakis [3-3,5-di-t-butyl-4-hydroxy phenyl) -propionate], 2,2'thio diethyl bis- [3 -(3,5-di-t-butyl-4-hydroxy phenyl) -propionate], octadecyl 3- (3,5-di-t-butyl-4-hydroxy phenyl) -propionate, 4,4'-thiobis (6-t-butyl-m-cresol), triethylene glycol-bis-3 (3-t-butyl-4-hydroxy-5 methyl phenyl) propionate, dilauryl thiodi A composition selected from the group consisting of propionate. The method of claim 1, The halogen-based flame retardant of f) is decabromo diphenyl ether, decabromo diphenyl ethane, decabromo diphenyl oxide, octabromo diphenyl ether, pentabromo diphenyl ether, hexabromo diphenoxy ethane, Tetrabromo phthalic anhydride, tetrabromo phthalate diol polyether, ethylene bis tetrabromo phthalamide, tetrabromo bisphenol A, poly pentabromobenzyl acrylate, brominated polystyrene, hexabromo dodecane, dibromine At least one composition selected from the group consisting of opentyl glycol and vinyl bromide. The method of claim 1, The inorganic flame retardant of g) is at least one selected from the group consisting of aluminum hydroxide, aluminum trioxide, magnesium hydroxide, magnesium oxide hydrate, calcium hydroxide, calcium oxide hydrate, calcium carbonate, antimony trioxide. The method of claim 1, The composition which adds 0.5-10 weight part of pigment master batches further. The method of claim 1, Wherein the water crosslinking catalyst of c) is added to the catalyst master batch prepared by kneading the olefinic resin, the water crosslinking catalyst and the antioxidant in a Banbury mixer. The method of claim 1, The halogen-based flame retardant of f) and the inorganic flame retardant of g) is included in the flame retardant masterbatch prepared by kneading a halogen-based flame retardant, an antioxidant, a lubricant, and an olefin resin in a Banbury mixer. The method according to claim 11 or 12, The olefin resin is Ethylene alpha olefin copolymers obtained by copolymerizing ethylene and propylene, 1-butene, 1-pentene, 1-octene and at least one alpha olefin having 3 or more carbon atoms selected from the group consisting of; And Polar ethylene copolymers obtained by copolymerizing ethylene with at least one polar copolymer selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, eta acrylic acid, acrylic anhydride, maleic anhydride, methacrylic anhydride, eta acrylic anhydride, vinyl ester, and vinyl acetate A composition which is a mixture selected from at least one member from the group consisting of. The method of claim 13, The ethylene alphaolefin polymer has an alpha olefin content of 1 to 80% by weight, a melt index of 0.1 to 20 g / min and a density of 0.860 to 0.960 g / cm 3 at a temperature of 190 ° C. and a load of 2.16 kg. The method of claim 13, The ethylene alpha olefin polymer is at least one selected from the group consisting of ultra low density polyethylene, low density polyethylene, linear low density polyethylene, high density polyethylene. The method of claim 13, The polar polyethylene copolymer has a content of 1 to 50% by weight of a polar copolymer, a melt index of 0.1 to 20 g / min and a density of 0.860 to 0.960 g / cm 3 at a temperature of 190 ° C. and a load of 2.16 kg. . The method of claim 13, The said olefin resin is an ultra-low density polyethylene using the single site catalyst. In the manufacturing method of a flame-retardant insulated cable, a) polyethylene, silane, crosslinking aid and antioxidant Silane graft chemically bonded to polyethylene by reaction extrusion Preparing polyethylene; b) the olefin resin, the crosslinking catalyst and the antioxidant are kneaded in a Banbury mixer Preparing a catalyst master batch; c) halogen flame retardants, inorganic flame retardants, antioxidants, lubricants, olefin resins Kneading in a Banbury mixer to produce a flame retardant master batch; And d) silane graft polyethylene of step a), catalyst masterbatch of step b) And c) mixing the flame retardant masterbatch of step to prepare a mixture, and then extruder Manufacturing a cable by extruding the mixture into a furnace How to include. The method of claim 18, 20 to 80 parts by weight of the silane graft polyethylene composition of step d); 30 parts by weight or less of an olefin resin; 0.1 to 1 parts by weight of the crosslinking catalyst; 1 part by weight or less of a metal stabilizer; 1 part by weight or less of antioxidant; 10 to 40 parts by weight of a halogen flame retardant; And 1 to 40 parts by weight of inorganic flame retardant. The method of claim 17 or 18, Further adding a pigment master batch to the mixture of step d).