KR20170064245A - High fire-resistant mica tape and high fire-resistant cable having fire-resistant layer formed from the same - Google Patents

Abstract

The present invention relates to a high refractory cable having a refractory layer formed therefrom and a mica tape excellent in refractory performance. More specifically, the present invention relates to a high-refractory mica tape and a refractory layer formed therefrom, which can realize a high fire resistance characteristic of 830 DEG C or higher, and can reduce the manufacturing cost of the cable without lowering the flexibility of the cable Refractory cable.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-fire-resistant mica tape having a high-fire mica tape and a refractory layer formed therefrom,

The present invention relates to a high refractory cable having a refractory layer formed therefrom and a mica tape excellent in refractory performance. More specifically, the present invention relates to a high-refractory mica tape and a refractory layer formed therefrom, which can realize a high fire resistance characteristic of 830 DEG C or higher, and can reduce the manufacturing cost of the cable without lowering the flexibility of the cable Refractory cable.

In recent years, a major issue in the cable manufacturing industry is maintaining cable behavior and performance in extreme temperature conditions, particularly in the face of fire. For safety, it is essential to delay the spread of flames and to maximize the fire-resistance of the cables that can withstand flames.

Fig. 1 schematically shows a cross-sectional structure of a conventional refractory cable.

1, a conventional refractory cable is made of a conductive material such as copper (Cu) or aluminum (Al), and includes a conductor 11 for providing a current flow path, an insulation layer 13, A refractory layer 12 surrounding the conductor 11 so that the behavior and performance of the cable can be maintained by performing the insulation function of the conductor 11 instead of the insulation layer 13, One or more cores 10 including an insulating layer 13 surrounding the layer 12, a sheath layer 20 that entirely covers the at least one core 10, and the like.

The refractory layer 12 may be formed by a horizontal portion of a refractory tape such as a mica tape. Conventional mica tapes include mica of 140 to 170 g / m < 2 > per unit area, so that the standard of IEC 60331-1, IEC 60331-2, BS6387, BS EN 50200, BS 8481 and the like.

However, as the content of mica contained in the mica tape increases, the thickness of the refractory layer 12 is increased. As a result, the insulation layer thickness of the cable and the outer diameter of the cable are increased, And the manufacturing cost of the cable can be greatly increased.

Therefore, there is a serious demand for a high-refractory mica tape capable of realizing a high fire-resisting property of 830 DEG C or higher, and capable of reducing the manufacturing cost of the cable without lowering the flexibility of the cable.

It is an object of the present invention to provide a high-refractory cable having a refractory layer formed from the high-resistance mica tape capable of realizing a high fire resistance characteristic of 830 DEG C or higher.

It is still another object of the present invention to provide a high refractory cable having a refractory mica tape and a refractory layer formed therefrom that does not deteriorate the flexibility of the cable.

It is still another object of the present invention to provide a high refractory cable having a refractory mica tape and a refractory layer formed therefrom that can reduce the manufacturing cost of the cable.

In order to solve the above problems,

A mica layer having a mica density of 80 to 120 g / m 2, the weight per unit area of the mica powder; A glass yarn layer laminated on the lower side of the mica layer by an adhesive and formed by a weave of glass yarn; And a reinforcing layer laminated below the glass cloth layer and formed by a mica powder or a metal hydroxide coating.

Here, the glass cloth layer is formed by weaving a glass yarn having a thickness (D) of 80 to 120 탆 at a horizontal gap (A) of 200 to 500 탆 and a vertical gap (B) of 100 to 300 탆, Characterized in that the density of the glass yarn weave density is 35 to 70%.

[Equation 1]

Glass woven density (%) = 100 x {(A x B) - (A-D) x (B-D)} / A x B

Further, the present invention provides a mica tape characterized in that the glass yarn density (%) is 45 to 65%.

The present invention also provides a mica tape characterized in that the content of the adhesive is 14 to 16 wt% based on the total weight of the mica tape.

On the other hand, the mica powder contained in the mica layer includes a soft mica powder, a hard mica powder, or both of them.

Here, the mica powder contained in the mica layer includes a soft mica powder having a heat-resistant temperature of 900 to 1,000 ° C.

Also, the adhesive includes a silicone-based resin and is preferably a resin having a weight-average molecular weight of about 5,000 to about 20,000, such as benzyl alcohol, ethane, hexachloro, 7,9-di-tert- butyl-1-oxaspiro (4,5) deca- 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-28-done or a combination thereof.

And, the metal hydroxide coating is characterized in that it comprises aluminum hydroxide (Al (OH) ₃ ), magnesium hydroxide (Mg (OH) ₂ ), or both.

A step of firing the mica mineral at 900 DEG C, a step of pulverizing the mica mineral calcined at high pressure water pressure with the mica powder, the step of mixing the obtained mica powder and water to form a pulp-shaped mica thin film, A step of thinly spreading a thin film of the mica film to remove moisture and drying, a step of bonding the dried mica thin film to the glass cloth layer by using an adhesive for application including silicone, epoxy and organic solvent, Coating a soft or hard mica powder or a metal hydroxide powder to form a reinforcing layer thereon.

At least one core including a conductor, a first refractory layer formed by winding one of the first through third resistors with a mica tape, and an insulating layer surrounding the first refractory layer; A second refractory layer formed entirely of the one or more cores and formed of a glass tape, a urethane glass tape, a polyethylene tape or a polypropylene tape; An interstice filling the void space between the at least one core and the second refractory layer; And a sheath layer surrounding the second refractory layer.

Here, the first refractory layer is formed by winding one piece of the mica tape.

The insulating layer may be formed of at least one selected from the group consisting of silicone rubber, cross-linked polyolefin (XLPO), ethylene-propylene rubber (EPR), high-strength ethylene-propylene rubber ), Polyvinylchloride (PVC) or a combination thereof, said intervening material comprising polyethylene, polypropylene, ethylene-propylene-diene rubber, glass yarn or a combination thereof, said sheath layer Polyvinylchloride (PVC), polychloroprene rubber (CR), chlorosulfonated polyethylene (CSPE), chlorinated polyethylene (CPE), ethylene vinyl acetate EVA), ethylene-propylene-diene rubber (EPDM), or a combination thereof.

The mica tape for refractory according to the present invention exhibits an excellent effect of realizing a high fire resistance characteristic of a cable by controlling a specific single layer structure and a mica content and at the same time reducing the manufacturing cost of a cable without lowering the flexibility.

Fig. 1 schematically shows a cross-sectional structure of a conventional refractory cable.
2 schematically shows a cross-sectional structure of a high-refractory mica tape according to the present invention.
Fig. 3 schematically shows the structure of a glass cloth forming a reinforcing layer in the high-refractory mica tape shown in Fig. 2. Fig.
4 schematically shows a cross-sectional structure of a high-refractory 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.

2 schematically shows a cross-sectional structure of a high-refractory mica tape according to the present invention.

2, the high-refractory mica tape 120 according to the present invention comprises a mica layer 121 formed by agglomeration of a mica powder, an adhesive layer (not shown) for reinforcing the strength of the mica layer 121, A reinforcing layer 123 laminated below the glass cloth layer 122 for further improving the insulation characteristics and strength of the glass fiber cloth layer 122 laminated on the lower side of the mica layer 121 and furthermore the mica tape 123, ).

Here, the mica powder constituting the mica layer 121 is not particularly limited, but it may be a soft mica powder, a hard mica powder, or a mixture thereof. Preferably, the soft mica powder having a heat-resistant temperature of 900 to 1,000 ° C As shown in FIG. Preferably, the mica layer 121 has a mica density of 80 to 120 g / m 2, which represents the weight of the mica powder per unit area of the mica tape 120.

The weight of the mica powder is reduced by 27% or more in terms of the mica density included in the conventional mica tape, thereby reducing the total thickness of the mica tape 120 to reduce the insulation layer and outer diameter of the cable, The manufacturing cost of the cable can be reduced.

When the above-mentioned mica density is less than 80 g / m 2, the flame resistance characteristic is insufficient, and the flame resistance test of IEC 60331-21 (750 ° C, 90 minutes) can be passed. However, IEC 60331-1,2, BS 6387 , BS 8491, etc. can not be passed.

On the other hand, when the mica density is more than 120 g / m 2, the thickness of the mica tape 120 increases, thereby increasing the insulation layer and outer diameter of the high-refractory cable, resulting in reduced flexibility of the cable, The adhesive force between the mica powder constituting the mica layer 121 is relatively lowered and cracking and breakage may occur during taping operation of the mica tape 120 on the conductor of the high refractory cable.

The mica layer 121 and the glass cloth layer 122 may be adhered to each other with an adhesive. The adhesive is not particularly limited and may be, for example, an adhesive containing a silicone resin. The adhesive may be selected from the group consisting of benzyl alcohol, ethane, hexachloro, 7,9-di-tert- 1-oxaspiro (4,5) deca-6,9-diene-28-done < / RTI > ) May be added.

The amount of the adhesive may be 14 to 16% by weight based on the total weight of the mica tape 120. If the content of the adhesive is less than 14% by weight, adhesion between the mica layer 121 and the glass cloth layer 122 may be insufficient to cause cracking during taping of the mica tape 120 on the conductor of the high- The mica layer 121 may be peeled off from the glass cloth layer 122.

On the other hand, when the content of the adhesive exceeds 16% by weight, the thickness of the mica tape 120 is unnecessarily increased, thereby increasing the insulation layer and outer diameter of the high-refractory cable, Can be increased.

The glass cloth layer 122 functions to reinforce the strength of the mica layer 121. As shown in FIG. 3, a glass fiber having a thickness D of 80 to 120 占 퐉 has a width A, 200 to 500 占 퐉, and a vertical interval (B) of 100 to 300 占 퐉.

Preferably, the glass fiber cloth layer 122 has a glass fiber weight density of 20 to 26 g / m < 2 >, which means the glass cloth weight per unit area, and the glass cloth layer 122 As a percentage of the area occupied by the glass cloth weave density defined by the following equation (1) may be 35 to 70%, preferably 45 to 65%.

[Equation 1]

Glass woven density (%) = 100 x {(A x B) - (A-D) x (B-D)} / A x B

In the above equation (1), A is the horizontal gap shown in Fig. 3, B is the vertical gap shown in Fig. 3, and D is the glass fiber thickness shown in Fig.

If the density of the glass yarn is less than 35%, the entire contact area between the mica layer 121 and the glass cloth layer 122 is insufficient, and the mica tape 120 is wound on a conductor having a small outer diameter of less than 16 SQ There may be a problem that the mica layer 121 is partially separated from the glass cloth layer 122 or the glass cloth forming the glass cloth layer 122 is loosened.

As shown in FIG. 2, the mica tape 120 according to the present invention may have a reinforcing layer 123 formed below the glass cloth layer 122. The reinforcing layer 123 functions to further improve the insulation property and strength of the mica tape 120. The stiffening layer 123 may be formed by a soft or hard mica powder or a metal hydroxide coating, and may preferably be formed by a metal hydroxide coating. The metal hydroxide coating for forming the reinforcing layer 123 is not particularly limited and may include, for example, aluminum hydroxide (Al (OH) ₃ ), magnesium hydroxide (Mg (OH) ₂ ) and the like.

The metal hydroxide coating layer reinforces the refractory characteristics of the mica tape 120 with excellent heat resistance that can withstand a high temperature of 1,100 ° C or more, and at the same time, aluminum oxide (Al (OH) ₃ ) (Mg (OH) ₂ ) causes the endothermic reaction decomposed into metal oxide (metal oxide) which is an inorganic material capable of blocking water, that is, ceramic and water (H ₂ O) The mica tape 120 can maintain the refractory characteristics even under harsh conditions such as spraying and striking by the ceramic not only lowering the temperature but also improving the strength and water resistance.

_{2Al (OH) 3 → Al 2} O 3 + 3H 2 O - 298kJ / mol at ≥200 ℃

Mg (OH) ₂ - > MgO + H ₂ O - 330 kJ / mol at >

Preferably, the thickness of the reinforcing layer 123 may be greater than the thickness of the glass cloth layer 122, based on the surface of the mica layer 121. When the thickness of the reinforcing layer 123 is thinner than the thickness of the glass cloth layer 122, the side surface of the glass cloth constituting the glass cloth layer 122 is partially covered with metal hydroxide or the like forming the reinforcing layer 123 The mica tape 120 may have insufficient fire resistance, structural stability, and water resistance.

The manufacturing method of the mica tape 120 according to the present invention is not particularly limited, but it can be manufactured by a process including the following steps a) to f).

a) firing at 900 ° C in order to improve the mechanical and electrical properties by burning and removing foreign substances and organic matters of mica mineral;

b) crushing the mica mineral into thin and small pieces at high pressure water pressure;

c) mixing the obtained mica powder with water to form a pulp-shaped mica thin film having a desired thickness;

d) an aging process in which a thin film of mica is spread to remove moisture and dry;

e) bonding and drying the mica thin film with the glass cloth layer using an adhesive for application comprising silicone, epoxy, organic solvent and the like; And

f) coating soft or hard mica powder or metal hydroxide powder to form a reinforcing layer on the glass fiber fabric layer

The mica tape 120 according to the present invention has a high fire resistance characteristic of 830 占 폚 or more in a high-refractory cable due to the specific lamination structure described above, the content of the controlled mica powder and adhesive, and the weaving density of the regulated glass fiber cloth layer And at the same time, it is possible to prevent an increase in the insulation layer and the outer diameter of the cable, thereby reducing the flexibility of the cable and reducing the manufacturing cost of the cable.

4 schematically shows a cross-sectional structure of a high-refractory cable according to the present invention.

4, the high-refractory cable according to the present invention is made of a conductive material such as copper (Cu) or aluminum (Al) to provide a current path for current flow, and Class 2 or 5 A first refractory layer formed from the conductor 110, the above-described high-refractory mica tape 120, and a second refractory layer surrounding the first refractory layer and being made of a silicone rubber, a cross-linked polyethylene (XLPE) Polymers such as cross-linked polyolefin (XLPO), ethylene-propylene rubber (EPR), high-strength ethylene-propylene rubber (HEPR), and polyvinylchloride And a second refractory layer 200 surrounding the at least one core 100. The core 100 and the second refractory layer 100 may be formed of a single layer or a multi- 200) An intervening space 300, a sheath layer 400, and the like.

In the high-refractory cable according to the present invention, the first refractory layer can be formed by a single sheet of the high-refractory mica tape (120) according to the present invention, and compared with the case of two conventional mica tapes , The insulating layer and the outer diameter of the cable are reduced, thereby reducing the flexibility of the cable and reducing the manufacturing cost of the cable. The second refractory layer for replenishing the refractory characteristics by the first refractory layer may be formed by a glass tape, a urethane glass tape, a polyolefin tape such as a polyethylene tape or a polypropylene tape, or the like.

The intervening material 300 filling the void space between the at least one core 100 and the second refractory layer 200 may include a polyolefin resin such as polyethylene or polypropylene or a polymer resin such as ethylene-propylene-diene rubber Or a glass yarn or the like may be applied as the case may be.

The sheath layer 400 may be formed of polyvinylchloride (PVC), polychloroprene rubber (CR), chlorosulfonated polyethylene (CSPE), chlorinated polyethylene (CPE) ), Ethylene vinyl acetate (EVA), ethylene-propylene-diene rubber (EPDM) resin, and the like.

[Example]

1. Manufacturing Example

Highly refractory cable specimens according to Examples and Comparative Examples were produced with the specifications shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Conductor 4 x 10 SQ
Mica
tape Buying One One One One One One 2 Thickness / Thickness (mm) 0.13 0.13 0.11 0.16 0.15 0.15 0.15 Mica density (g / m 2) 120 120 80 180 180 160 160 Glass Resin Density (%) 53 53 55 25 55 40 40 Adhesive content (% by weight) 15 15 15 13 15 13 13 Reinforced layer Al (OH) ₃ powder coating Insulating layer Crosslinked polyethylene (XLPE) interposition Flame Retardant Polypropylene (FRPP) The second refractory layer - urethane
Glass tape - - - - Sheath layer Polyvinyl chloride (PVC)

2. Property evaluation

1) Mica taping workability evaluation

Examples and Comparative Examples [0053] When a mica tape was wound on a conductor during the manufacture of each of the cable specimens, whether the mica layer was peeled off or whether the glass fiber was peeled off was evaluated.

2) Cable flexibility evaluation

EXAMPLES AND COMPARATIVE EXAMPLES The outer diameter of each of the cable specimens was measured and the degree of stiffness at the time of bending was evaluated.

3) Fire resistance evaluation

The flame is applied for 90 minutes at 750 ℃ according to the standard IEC-60331-11, 21, and the general fire resistance is evaluated. The flame is applied at 830 ℃ for 2 hours according to IEC-60331-1,2, The fire resistance characteristics were evaluated.

The evaluation results of the physical properties are shown in Table 2 below.

Evaluation items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4
Taping
Workability Mica floor
Whether or not peeling Good Good Good Bad Bad Bad Bad Glassware
Loose Good Good Good Bad Good Good Good flexibility Flexibility Good Good Good Stiffness Stiffness Stiffness Stiffness Diameter (mm) 22.12 22.58 22.43 22.52 22.5 22.5 23 Fireproof
characteristic 750 ℃ pass pass pass pass pass pass pass 830 ° C fail pass pass fail fail fail pass

As shown in Table 2, the mica tape according to the present invention did not cause problems such as peeling of the mica layer and loosening of the glass yarn upon winding the conductor, and the cable having the refractory layer by the mica tape had excellent flexibility It was confirmed that the second refractory layer made of urethane glass tape was also excellent in high fire resistance characteristic at 830 캜.

On the other hand, in the cables of Comparative Examples 1 to 3, since the mica density of the mica tape was excessive and the adhesive content was insufficient, the mica layer was peeled off when the mica tape was wound around the conductor and the flexibility was insufficient. It was confirmed that the problem of loosening of the glass yarn was caused by the low density of glass weaving. Also, it was confirmed that the high fire resistance characteristic at 830 캜 was not satisfied.

Further, in the cable of Comparative Example 4, since the mica tape of the mica tape is excessively insufficient and the adhesive content is insufficient, the mica layer is peeled off when the mica tape is wound on the conductor and the flexibility is large Respectively.

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.

100: core 200: second refractory layer
300: interposed 400: sheath layer

Claims (13)

A mica layer having a mica density of 80 to 120 g / m 2, the weight per unit area of the mica powder;
A glass yarn layer laminated on the lower side of the mica layer by an adhesive and formed by a weave of glass yarn; And
And a reinforcing layer laminated below the glass cloth layer and formed by a mica powder or a metal hydroxide coating. The method according to claim 1,
The glass fiber fabric layer is formed by weaving a glass yarn having a thickness (D) of 80 to 120 탆 at a width (A) of 200 to 500 탆 and a length (B) of 100 to 300 탆, Wherein the weft density is 35 to 70%.
[Equation 1]
Glass yarn density (%) = 100 x {(A x B) - (AD) x (BD)} / A x B 3. The method of claim 2,
Wherein the glass yarn weaving density (%) is 45 to 65%. 4. The method according to any one of claims 1 to 3,
Characterized in that the content of the adhesive is from 14 to 16% by weight, based on the total weight of the mica tape. 4. The method according to any one of claims 1 to 3,
Wherein the mica powder contained in the mica layer comprises a soft mica powder, a hard mica powder, or both. 6. The method of claim 5,
Wherein the mica powder contained in the mica layer comprises soft mica powder having a heat-resistant temperature of 900 to 1,000 ° C. 4. The method according to any one of claims 1 to 3,
The adhesive comprises a silicone resin and is selected from the group consisting of benzyl alcohol, ethane, hexachloro, 7,9-di-tert-butyl-1-oxaspiro (4,5) deca- 9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-28-done or a combination thereof. 4. The method according to any one of claims 1 to 3,
Wherein the metal hydroxide coating comprises aluminum hydroxide (Al (OH) ₃ ), magnesium hydroxide (Mg (OH) ₂ ), or both. Calcining the mica mineral at 900 DEG C,
Pulverizing the mica mineral calcined at a high pressure water pressure with a mica powder,
Mixing the obtained mica powder and water to form a pulp-shaped mica thin film,
A step of thinly spreading the obtained mica thin film to remove moisture and drying,
A step of bonding the dried mica thin film with a glass cloth layer using an adhesive for application including silicon, epoxy and organic solvent, followed by drying, and
The method for producing a mica tape according to any one of claims 1 to 3, comprising coating a soft or hard mica powder or a metal hydroxide powder to form a reinforcing layer on the glass cloth layer. At least one core including a conductor, a first refractory layer formed by winding the conductor with the mica tape according to any one of claims 1 to 3, and an insulating layer surrounding the first refractory layer;
A second refractory layer formed entirely of the one or more cores and formed of a glass tape, a urethane glass tape, a polyethylene tape or a polypropylene tape;
An interstice filling the void space between the at least one core and the second refractory layer; And
And a sheath layer surrounding the second refractory layer. 11. The method of claim 10,
Wherein the mica tape has a content of the adhesive of 14 to 16 wt% based on the total weight of the mica tape. 12. The method of claim 11,
Wherein the first refractory layer is formed by winding one piece of the mica tape. 12. The method of claim 11,
The insulating layer may include at least one of silicone rubber, cross-linked polyolefin (XLPO), ethylene-propylene rubber (EPR), high-strength ethylene- Polyvinylchloride (PVC), or a combination thereof,
The interstices include polyethylene, polypropylene, ethylene-propylene-diene rubber, glass yarn or a combination thereof,
The sheath layer may be formed of at least one selected from the group consisting of polyvinylchloride (PVC), polychloroprene rubber (CR), chlorosulfonated polyethylene (CSPE), chlorinated polyethylene (CPE), ethylene vinyl acetate vinyl acetate (EVA), ethylene-propylene-diene rubber (EPDM), or a combination thereof.

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