KR20150085544A - Extra high voltage cable - Google Patents

Abstract

The present invention relates to an extra high voltage cable. More particularly, the present invention relates to an extra high voltage cable which is lighter than an existing extra high voltage cable and has a watertight layer which has superior corrosion resistance, maintains interlayer adhesion even though external physical impact and temperature change and effectively prevents delamination.

Description

Extra high voltage cable

The present invention relates to an ultra high voltage cable. More particularly, the present invention relates to an ultra-high voltage cable having a watertight layer that is light in weight compared to conventional high-voltage cables, has excellent corrosion resistance, and is effectively prevented from peeling by maintaining an interlaminar adhesive strength even under external physical impact and temperature changes.

Ultra-high voltage cables such as submarine cables generally include a watertight layer that suppresses the penetration of moisture from the outside.

1 schematically shows a cross-sectional structure of a power cable disclosed in U.S. Patent No. 4,472,597. 1, the conventional power cable includes a conductor 1, an inner semiconductive layer 2, an insulating layer 3, an outer semiconductive layer 4, a metal shielding layer 5, a conductive tape layer 8, The watertight layer 7, and the outer jacket 6 in this order.

When aluminum laminated tape coated with polyethylene on both sides of an aluminum foil is used as the watertight layer 7, the aluminum foil is vulnerable to corrosion, Damage can shorten the life of the cable.

2 schematically shows a cross-sectional structure of a power cable disclosed in U.S. Patent No. 4,501,928. As shown in FIG. 2, the conventional power cable includes a conductor 1 ', an inner semiconductive layer 2', an insulating layer 3 ', an outer semiconductive layer 4', a metal shielding layer 5 ' The conductive tape 6 ', the watertight layer 7', and the outer jacket 8 'in this order.

When a lead laminate tape coated with polyethylene or polyvinyl chloride on both surfaces of a lead foil is used as the watertight layer 7 ', the weight of the lead foil is low and the lightness of the cable is deteriorated .

In addition, the watertight layer 7, 7 'applied to the conventional power cable is insufficiently adhered to the outer jacket 6, 8' so that the watertight layer 7, 7 ' And the outer jacket 6 and 8 'are peeled from each other.

Accordingly, there is a demand for an ultra-high voltage cable having a watertight layer which is lighter in weight than conventional ultra-high voltage cables, has improved corrosion resistance, and is effectively prevented from peeling by maintaining interlayer adhesion even under external physical impact and temperature changes.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultra high voltage cable which is light in weight compared with the conventional super high voltage cable.

It is another object of the present invention to provide an ultra high voltage cable having a watertight layer in which the corrosion resistance is improved and the interlaminar adhesive force is maintained even when the external physical impact and the temperature are changed.

In order to solve the above problems,

A semiconductor device comprising: a core conductor; an inner semiconductive layer surrounding the central conductor; an insulating layer surrounding the inner semiconductive layer; an outer semiconductive layer surrounding the insulating layer; a metal shielding layer surrounding the outer semiconductive layer; Wherein the watertight layer comprises a copper tape and an adhesion-promoting layer formed on the copper tape and comprising a random copolymer resin of an olefin and a polar monomer, wherein the waterproof layer comprises an adhesive layer Voltage cable.

Herein, the polar monomer may be a vinyl ester monomer of vinyl acetate or vinyl versatate, a vinyl-unsaturated carboxylic acid monomer of methacrylic acid, acrylic acid, maleic acid or itaconic acid, an acrylic monomer of (meth) acrylate or alkyl (meth) Wherein the cable is an ultra high voltage cable.

The present invention also provides an ultra high voltage cable characterized in that the random copolymer resin of the olefin and the polar monomer is ethylene acrylic acid (EAA), ethylene vinyl acetate (EVA), or ethylene butyl acrylate (EBA).

Here, the content of the polar monomer is 5 to 20% by weight based on the total weight of the random copolymer resin.

Further, the thickness of the copper tape is 0.1 to 0.2 mm, and the thickness of the adhesion-assisting layer is 0.05 to 0.09 mm.

On the other hand, the outer jacket is made of high density polyethylene (HDPE) and has a thickness of 6.5 to 7.5 mm.

The metal shield layer may include a first semi-conductive tape transversely disposed on the outer semiconductive layer, a metal layer disposed on the first semi-conductive tape and including a plurality of copper neutral lines, and a second semi- Voltage cable.

Further, there is provided an ultra-high voltage cable, wherein the insulating layer is made of crosslinked polyethylene (XLPE).

Further, the watertight layer has both ends superimposed on each other, and the lower surface and the upper surface of the watertight layer in the overlap region are bonded by a hot-melt adhesive.

Here, the ultra-high voltage cable is characterized in that the hot melt adhesive is made of a polyamide resin.

Also, the hot-melt adhesive has a creep resistance temperature and a softening temperature of 90 ° C or higher.

On the other hand, an ultra-high voltage cable is provided, wherein the inner semiconductive layer, the insulating layer and the outer semiconductive layer are made of the same base resin.

The ultra-high voltage cable according to the present invention includes a water-tight layer made of a lightweight material, so that it has an excellent effect in that it is light in weight compared with a conventional high-voltage cable.

The ultra-high voltage cable according to the present invention includes a water-tight layer made of a material excellent in corrosion resistance, so that corrosion of the water-tight layer is suppressed.

The ultra-high voltage cable according to the present invention can improve the adhesion between the watertight layer and the outer jacket, thereby effectively suppressing the peeling of the watertight layer against external physical impact and temperature change. As a result, .

1 schematically shows a cross-sectional structure of a conventional power cable.
2 schematically shows a cross-sectional structure of another conventional power cable.
3 is a cross-sectional view schematically showing a cross-sectional structure of an embodiment of an ultra-high voltage cable according to the present invention.
4 is a longitudinal sectional view schematically showing a cross-sectional structure of an embodiment of an ultra-high voltage cable according to the present invention.
5 schematically shows a cross-sectional structure of the watertight layer 80 in the ultra-high voltage cable according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Like reference numerals designate like elements throughout the specification.

FIGS. 3 and 4 schematically show cross-sectional structures of an embodiment of an ultra-high voltage cable according to the present invention. 3 and 4, the ultra-high voltage cable according to the present invention includes a center conductor 10, an inner semiconductive layer 20 surrounding the central conductor 10, an insulating layer (not shown) surrounding the inner semiconductive layer 20 A first semi-conductive tape 50, a metal layer 60, and a second semi-conductive tape 70 surrounding the outer semiconductive layer 40. The first semi- A waterproof layer 80 surrounding the metal shielding layer 80, an adhesive layer 90 for bonding the waterproof layer 80 to the outer jacket 100, and an outer jacket 100.

The center conductor 10 may be formed of a single wire made of copper, aluminum, preferably copper, or a twisted wire associated with a plurality of wires. The diameter of the center conductor 10, the diameter of the wire constituting the twisted wire, The standard to be included may vary depending on the transmission voltage of the power cable, the use thereof, etc., and may be appropriately selected by a person skilled in the art. For example, when the ultra-high voltage cable according to the present invention is used as a submarine cable for installation, flexibility, etc., it is preferable that the center conductor 10 is made of twisted wire excellent in flexibility than broken wire.

The inner semiconductive layer 20 is disposed between the central conductor 10 and the insulating layer 30 to remove an air layer inducing interlayer delamination between the center conductor 10 and the insulating layer 30, And relaxes the electric field concentration. On the other hand, the outer semiconductive layer 40 functions to uniformly apply an electric field to the insulating layer 30, to alleviate local field concentration, and to protect the cable insulation layer from the outside.

Typically, the inner semiconductive layer 20 and the outer semiconductive layer 40 are formed by extrusion of a semi-conductive composition in which conductive particles such as carbon black, carbon nanotube, carbon nanoplate, and graphite are dispersed in a base resin, The base resin may be an olefin resin of the same series as the base resin of the insulating composition forming the insulating layer 30 for the interlayer adhesion between the semiconductive layer 20, 40 and the insulating layer 30, for example, (EBA), ethylene ethyl acrylate (EEA), and the like are preferably used as the copolymer resin of the acrylic monomer and the acrylic monomer, particularly, ethylene butyl acrylate (EBA) and ethylene ethyl acrylate (EEA).

The thickness of the inner and outer semiconductive layers 20 and 40 may differ depending on the transmission voltage of the cable. For example, in the case of a 345 kV super high voltage cable, the thickness of the inner semiconductive layer 20 is 1.6 to 1.8 mm And the thickness of the outer semiconductive layer 40 may be 1.02 to 2.54 mm.

The insulating layer 30 may be, for example, a polyolefin resin such as polyethylene, polypropylene or the like as a base resin, and may preferably be formed by extrusion of an insulating composition comprising a polyethylene resin.

The polyethylene resin may be ultra low density polyethylene (ULDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), or a combination thereof. The polyethylene resin may be a homopolymer, a random or block copolymer of ethylene and an? -Olefin such as propylene, 1-butene, 1-pentene, 1-hexene or 1-octene, or a combination thereof.

The insulating layer 30 may include a crosslinking agent. The insulating layer 30 may be formed of a crosslinked polyolefin (XLPO), preferably a crosslinked polyethylene (XLPE) ). The insulating composition may further include other additives such as an antioxidant, an extrusion-promoting agent, and a crosslinking assistant.

The crosslinking agent may be a silane crosslinking agent or a crosslinking agent such as dicumylperoxide, benzoylperoxide, laurylperoxide, t-butylcumylperoxide, di (t-butylperoxyisopropyl) benzene, -Dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butyl peroxide and the like. The crosslinking agent may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the base resin.

The thickness of the insulating layer 30 may vary depending on the transmission voltage of the power cable. For example, in the case of a 345 kV super high voltage cable, the thickness of the insulating layer 30 may be 27.45 to 34.55 mm.

The metal shielding layer is made of a first semi-conductive tape 40 which is rolled up under a metal layer 50 formed by a plurality of neutral lines made of metal, preferably copper, and on which the second semi- And performs the function of protecting the cable under severe environmental conditions such as seabed.

The first semi-conductive tape 40 performs buffering to suppress the deformation of the insulating layer 30 due to the load of the metal layer 50 and the second semi-conductive tape 60 contacts the metal layer 50 ). ≪ / RTI > The first and second semi-conductive tapes 40 and 60 may be a wet-swellable tape, and in this case, a water-shielding function for blocking moisture may be performed in parallel. The thickness of the first and second semi-conductive tapes 40 may be, for example, about 200 to 1,000 μm.

The thickness of the metal layer 50 forming the metal shielding layer may be, for example, about 2.2 to 2.4 mm, and the thickness of the first and second semiconductive tapes 40 and 60 may be, for example, about 0.85 to 0.95 mm.

5 schematically shows a cross-sectional structure of the watertight layer 80 in the ultra-high voltage cable according to the present invention. As shown in FIG. 5, the watertight layer 80 may comprise a metal, preferably a copper tape 81 and an adhesion-promoting layer 82. The watertight layer 80 functions to prevent moisture penetrated through the outer jacket 100 from penetrating into the insulating layer 30. [

The thickness of the copper tape 81 may be, for example, about 0.1 to 0.25 mm, and the thickness of the adhesion-promoting layer 82 may be, for example, about 0.05 to 0.09 mm. The adhesion-promoting layer 82 should be as thin as possible to avoid adverse effects on the electrical properties of the cable.

In the watertight layer, the copper tape 81 is superior in corrosion resistance to the conventional aluminum foil layer, and is advantageous in that it is lighter in weight than the conventional lead foil layer. On the copper tape 81, an adhesion-assisting layer 82 is formed. It is not easy to adhere the copper tape 81 and the adhesive layer 90 to each other so that the adhesive auxiliary layer 82 made of a resin that is easily adhered to the adhesive layer 90 is laminated on the copper tape 81 lamination.

The method of laminating the adhesion-assisting layer 82 is not particularly limited, and for example, deposition, electro deposition, extrusion, or the like can be used. The adhesive auxiliary layer 82 has a function of maintaining close adhesion between the watertight layer 80 and the outer jacket 100 under a severe condition in which an impact is applied from the outside of the cable or a temperature is rapidly changed, 81).

The adhesion-assisting layer 82 may be formed of an acrylic resin, an olefin resin, preferably an adhesive containing a random copolymer resin of an olefin and a polar monomer as a base resin. The adhesion-promoting layer 82 may be formed by a general coating process such as spraying, impregnating, or extruding.

Here, the polar monomers include vinyl ester monomers such as vinyl acetate and vinyl versatate; Vinyl-unsaturated carboxylic acid monomers such as methacrylic acid, acrylic acid, maleic acid and itaconic acid; (Meth) acrylate, alkyl (meth) acrylate and the like, or a combination thereof, and the content of the polar monomer is 5 to 20% by weight, preferably 5 to 20% by weight, To 15% by weight.

Preferably, the base resin of the adhesive forming the adhesion-assisting layer 82 may be ethylene acrylic acid (EAA), ethylene vinyl acetate (EVA), ethylene butyl acrylate (EBA), or the like.

As shown in FIG. 4, the watertight layer 80 may be overlapped at both ends to realize better watertightness, and the lower and upper surfaces of the watertight layer 80 in the overlapping area may be hot melt hot melt adhesive. The hot-melt adhesive is a hot-melt adhesive which does not use water or a solvent at all but uses a 100% thermoplastic resin and is applied in a liquid state at a high temperature in a liquid form,

The hot-melt adhesive does not require a drying process, such as other solvent-based adhesives, water-dispersed adhesives, and the like, and has a low work space and fast bonding speed. The material of the hot melt adhesive may be, for example, a polyurethane, a polyamide, a polyester, an ethylene vinyl acetate, a rubber, and the like, and may generally further include wax, a pressure-sensitive adhesive, a plasticizer, a filler and an antioxidant.

The hotmelt is preferably made of a polyamide series having a creep resistance temperature and a softening temperature of 90 DEG C or higher for use in a power cable. For example, Quot; Q8740 " or " Q6239 "

The adhesive layer 90 functions to bond the water-tight layer 80 to the outer jacket 100. The adhesive layer 90 may be made of the same series resin as the resin forming the watertight layer 80 and the outer jacket 100 to closely adhere the watertight layer 80 and the outer jacket 100, For example, a copolymer resin of an? -Olefin resin, preferably an? -Olefin and an acrylic monomer, more preferably a random copolymer resin of ethylene and acrylic acid, a polyethylene copolymer resin in which ethylene, acrylic acid and butyl acrylate are randomly copolymerized, . The thickness of the adhesive layer 90 may be, for example, 0.5 to 2 mm.

The outer jacket 100 may include polyethylene, polyvinyl chloride, polyurethane, and the like. In order to maintain a close adhesive force with the adhesive layer 90, the outer jacket 100 may be made of the same resin as the resin constituting the adhesive layer 90, For example, it is preferable that it is made of a polyethylene resin, and since it is disposed at the outermost portion of the cable, it is more preferable that it is made of a high-density polyethylene resin in consideration of mechanical strength.

The external jacket 100 preferably has a thickness of, for example, 6 to 8 mm in order to absorb the shock when the external impact is applied to the cable from the outside to maintain close adhesion with the adhesive layer 90.

As described above, the ultra-high voltage cable according to the present invention is lightweight and has excellent corrosion resistance compared with the conventional high-voltage cable by forming the base layer of the watertight layer with a copper tape which is lighter in weight than conventional lead and superior in corrosion resistance compared to conventional aluminum, An adhesive layer for bonding the watertight layer and the outer jacket, a thickness of the outer jacket and a specific resin constituting the outer jacket, And exhibits an excellent effect that the adhesion can be maintained tightly.

[Example]

1. Manufacturing Example

A sample sheet of Examples and Comparative Examples made of layers and thicknesses as shown in Table 1 below under the conditions of a press temperature of 160 占 폚 (10 minutes), a cooling temperature of 40 占 폚 (10 minutes) and a pressure of 4,800 kg / Respectively. The thickness of the layer shown in Table 1 below is in mm.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Cu
tape 0.215 0.16 0.127 0.127 0.127 0.132 0.132 0.132 adhesion
Auxiliary layer 0.055 - - - - - - - Adhesive layer 0.5 0.5 2 0.5 2 2 0.5 2 Out
jacket 6 3 6 6 3 6 6 3

- Cu tape (manufacturer: Korea Ilrecom)

- Adhesion-assisting layer: Ethylene / acrylic acid random copolymer resin (EAA)

Adhesive layer: Ethylene / acrylic acid random copolymer resin adhesive (manufactured by Bassell; product name: Lucalen A2920M)

- Outer jacket: High density polyethylene

2. Evaluation of stripping

The interlayer delamination was evaluated for impact or impact + high temperature corrosion according to the IEC 61901 standard specified in AEIC CG-13. Specifically, sample sheets according to each of the examples and comparative examples prepared in the above-mentioned Production Example were subjected to impacts corresponding to a weight of 5 kg at a height of 1 m from the sample sheets, And some samples were subjected to high temperature erosion conditions in an oven at 80 캜 for one week after the impact was applied as described above, and it was confirmed whether or not they were delaminated. The results are shown in Table 2 below.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Rating 1 Good Bad Bad Bad Bad Bad Bad Bad Rating 2 Good Bad Bad Bad Bad Bad Bad Bad

- Evaluation 1: Assessment of whether or not to peel off after impact

- Evaluation 2: Assessment of detachment after application of impact and high temperature corrosion

As shown in Table 2 above, the sample sheet of the example according to the present invention maintains the interlaminar adhesion even under external physical impact and rapid temperature change by the appropriate thickness of the constituent layers and the adhesion promoting layer laminated on the copper (cu) tape And no interlayer peeling was observed. On the other hand, interlaminar peeling was observed in all of the sample sheets according to the comparative example due to interlayer adhesion failure.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. . It is therefore to be understood that the modified embodiments are included in the technical scope of the present invention if they basically include elements of the claims of the present invention.

10: conductor 20: inner semiconductive layer
30: insulating layer 40: outer semiconductive layer
50, 70: semi-conductive tape 60: metal layer
80: watertight layer 90: adhesive layer
100: Outer jacket

Claims (12)

A semiconductor device comprising: a core conductor; an inner semiconductive layer surrounding the central conductor; an insulating layer surrounding the inner semiconductive layer; an outer semiconductive layer surrounding the insulating layer; a metal shielding layer surrounding the outer semiconductive layer; An ultra-high voltage cable comprising an adhesive layer surrounding a watertight layer and an outer jacket surrounding the adhesive layer,
Wherein said watertight layer comprises a copper tape and an adhesion-promoting layer formed on said copper tape and comprising a random copolymer resin of an olefin and a polar monomer. The method according to claim 1,
The polar monomer may be a vinyl ester monomer of vinyl acetate or vinyl versatate, a vinyl-unsaturated carboxylic acid monomer of methacrylic acid, acrylic acid, maleic acid or itaconic acid, or an acrylic monomer of (meth) acrylate or alkyl (meth) acrylate Features, ultra-high voltage cable. 3. The method of claim 2,
Wherein the random copolymer resin of the olefin and the polar monomer is ethylene acrylic acid (EAA), ethylene vinyl acetate (EVA), or ethylene butyl acrylate (EBA). The method of claim 3,
Wherein the content of the polar monomer is 5 to 20% by weight based on the total weight of the random copolymer resin. 5. The method according to any one of claims 1 to 4,
Wherein the thickness of the copper tape is 0.1 to 0.2 mm, and the thickness of the adhesion-assisting layer is 0.05 to 0.09 mm. 5. The method according to any one of claims 1 to 4,
Wherein the outer jacket is made of high density polyethylene (HDPE) and has a thickness of 6.5 to 7.5 mm. 5. The method according to any one of claims 1 to 4,
Wherein the metal shielding layer comprises a first semi-conductive tape transversely disposed on the outer semiconductive layer, a metal layer disposed on the first semi-conductive tape and including a plurality of copper neutral lines, and a second semi- Lt; / RTI > cable. 5. The method according to any one of claims 1 to 4,
Wherein the insulating layer is made of crosslinked polyethylene (XLPE). 5. The method according to any one of claims 1 to 4,
Wherein the watertight layer has both ends superimposed on each other and the lower surface and the upper surface of the watertight layer in the overlap region are bonded by hot melt adhesive. 10. The method of claim 9,
Wherein the hot melt adhesive is made of a polyamide resin. 10. The method of claim 9,
Wherein the hot melt adhesive has a creep resistance temperature and a softening temperature of at least < RTI ID = 0.0 > 90 C. < / RTI > 5. The method according to any one of claims 1 to 4,
Wherein the inner semiconductive layer, the insulating layer, and the outer semiconductive layer are made of the same series of base resins.

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