KR102516310B1 - Insulating composition for joint box for electric cable having excellent self healing property and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an insulating composition for a power cable junction box having excellent self-restoration properties and a manufacturing method thereof. In one embodiment, the insulation composition for the power cable junction box includes 97 to 99.5% by weight of a resin matrix; and 0.5 to 3% by weight of a self-healing capsule dispersed in the resin matrix, wherein the resin matrix includes a silicone-based resin and an amine-based curing agent, and the self-healing capsule has a restoring agent and an outer wall supporting the restoring agent. The restoring agent includes an epoxy-based resin, and the outer wall of the self-healing capsule is destroyed by an electrical tree generated when the resin matrix is damaged, so that the restoring agent is released and contacted with the curing agent, Restore damage to the resin matrix.

Description

Insulation composition for power cable junction box with excellent self-healing properties and manufacturing method thereof

The present invention relates to an insulating composition for a power cable junction box having excellent self-restoration properties and a manufacturing method thereof.

The power cable is a wire for supplying power to a desired place through the ground and the ground. In recent years, the use of extra-high voltage power cables has increased due to an increase in power demand and an increase in transmission capacity, and these extra-high voltage power cables are mainly installed underground.

In addition, these extra-high-voltage power cables are divided into appropriate lengths according to the total installation length, and are installed by connecting power cables of each section. At this time, a power line connection box is used to connect each power cable. The power cable junction box can be classified into a joint box for mutual connection of power cables and a terminal/end box for connecting an end of a power cable and an overhead line.

The power cable is connected by exposing the conductors embedded in the center of both power cables and electrically connecting the conductors of both exposed power cables through a connection member such as a sleeve. An insulating member is inserted to prevent

On the other hand, electrical insulating materials applied to junction boxes of extra-high voltage power cables must have comprehensively excellent dielectric strength, dielectric properties (dielectric constant ε and dielectric loss tangent tanδ), heat resistance, water resistance, weather resistance, mechanical properties and oil resistance, and conventionally satisfies these requirements. Silicone and EPR (ethylene-propylene rubber) were being applied to the terminal junction box and the intermediate junction box as the materials used.

In recent years, insulation breakdown failures have increased in intermediate junction boxes of extra-high voltage underground cables of 154 kV or higher to which silicon and EPR are applied as insulating materials, which has become a problem. It is pointed out that the failure of the ultra-high voltage power-cutting cable and the insulator is caused by the progress of an electric tree starting from a crack or a void inside and outside the insulator.

In addition, it is difficult to identify the point where the failure occurred due to the large explosion energy at the time of insulation breakdown, and for this reason, the electric tree that occurs under high voltage conditions including self-recovery/healing functions without degrading the performance of the insulator. There is a demand for an insulating member to alleviate the.

Background art related to the present invention is disclosed in Republic of Korea Patent Publication No. 1992-7001993 (published on August 12, 1992, title of the invention: Apparatus and method for reducing cracks in polyolefin insulation in cables).

One object of the present invention is to provide an insulation composition for a power cable junction box, which has excellent insulation resistance and mechanical properties, and excellent self-restoration property when insulation damage of a member occurs.

Another object of the present invention is to provide an insulation composition for a power cable junction box having excellent mixing and dispersibility.

Another object of the present invention is to provide an insulation composition for a power cable junction box that has excellent reliability and can minimize maintenance and repair costs.

Another object of the present invention is to provide a method for manufacturing the insulation composition for the power cable junction box.

One aspect of the present invention relates to an insulating composition for a power cable junction box. In one embodiment, the insulation composition for the power cable junction box includes 97 to 99.5% by weight of a resin matrix; and 0.5 to 3% by weight of a self-healing capsule dispersed in the resin matrix, wherein the resin matrix includes a silicone-based resin and an amine-based curing agent, and the self-healing capsule has a restoring agent and an outer wall supporting the restoring agent. The restoring agent includes an epoxy-based resin, and the outer wall of the self-healing capsule is destroyed by an electrical tree generated when the resin matrix is damaged, so that the restoring agent is released and contacted with the curing agent, Damage to the resin matrix can be restored.

In one embodiment, the epoxy-based resin may have a permittivity of 2 to 5 at 60 Hz.

In one embodiment, the self-healing capsules may have an average size of 50 to 300 μm.

In one embodiment, the self-healing capsule may include the restoring agent and the outer wall in a weight ratio of 2:1 to 5:1.

In one embodiment, the outer wall may include one or more of MUF (melamine-urea-formaldehyde), UF (urea-formaldehyde), epoxy, polyurethane and silica coated MUF (melamine-urea-formaldehyde). .

In one embodiment, the insulation composition may have a rate of change in dielectric strength of 15% or less by Equation 1 below:

[Equation 1]

Dielectric strength change rate (%) = |((A2-A1)/A1)| X 100

(In Equation 1, A1 is the dielectric strength (kV/mm) of the insulating composition when the self-healing capsule and the amine-based curing agent are not included, measured in accordance with the IEC 60243 standard, and A2 is the self measured in accordance with the IEC 60243 standard It is the dielectric strength (kV/mm) of the insulating composition including the recovery capsule and the amine-based curing agent)

Another aspect of the present invention relates to a method for manufacturing an insulation composition for a power cable junction box. In one embodiment, the method for manufacturing an insulation composition for a power cable junction box includes mixing a first mixture including a silicone-based resin and a self-healing capsule with a second mixture including an amine-based curing agent and a self-healing capsule; A method of manufacturing an insulating composition for a cable junction box, wherein the insulating composition comprises 97 to 99.5% by weight of a resin matrix; and 0.5 to 3% by weight of a self-healing capsule dispersed in the resin matrix, wherein the resin matrix includes a silicone-based resin and an amine-based curing agent, and the self-healing capsule includes a restoring agent and an outer wall on which the restoring agent is supported. The restoring agent includes an epoxy-based resin, and the outer wall of the self-healing capsule is destroyed by an electrical tree generated when the resin matrix is damaged, so that the restoring agent is released, and in contact with the curing agent, the resin Restore matrix damage.

In one embodiment, the first mixture and the second mixture may be included in a weight ratio of 1:0.5 to 1:2.

In one embodiment, the epoxy-based resin has a dielectric constant at 60 Hz It can be 2-5 days.

In one embodiment, the self-healing capsules may have an average size of 50 to 300 μm.

In one embodiment, the self-healing capsule may include the restoring agent and the outer wall in a weight ratio of 2:1 to 5:1.

In one embodiment, the outer wall may include one or more of MUF (melamine-urea-formaldehyde), UF (urea-formaldehyde), epoxy, polyurethane and silica coated MUF (melamine-urea-formaldehyde). .

The insulation composition for a power cable junction box according to the present invention has excellent insulation resistance and mechanical properties, excellent self-recovery property when insulation damage occurs, excellent mixing and dispersibility when manufacturing the insulation composition for a junction box, and Reliability is excellent, and maintenance and repair costs can be minimized.

FIG. 1(a) is a schematic diagram showing an electrical tree generated when the resin matrix of the present invention is damaged, and FIG. 1(b) is a schematic diagram showing self-restoration of damage to the resin matrix.
Figure 2 (a) shows the insulation of the power cable junction box according to one embodiment of the present invention, Figure 2 (b) shows the insulation of the power cable junction box according to another embodiment of the present invention, Figure 2 (c ) represents the insulation of the power cable junction box according to another embodiment of the present invention.
Figure 3 (a) shows the insulation of the power cable junction box according to one embodiment of the present invention, Figure 3 (b) shows the insulation of the power cable junction box according to another embodiment of the present invention.
Figure 4 (a) shows the electric tree immediately after generation of the insulating composition of the embodiment, Figure 4 (b) is a photograph showing the self-restoration of the electric tree generated in the insulating composition of the embodiment.

In describing the present invention, if it is determined that a detailed description of a related known technology or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

In addition, the terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator, so the definitions should be made based on the content throughout this specification describing the present invention.

Insulation composition for power cable junction box

One aspect of the present invention relates to an insulating composition for a power cable junction box. In one embodiment, the insulation composition for the power cable junction box includes 97 to 99.5% by weight of a resin matrix; and 0.5 to 3% by weight of a self-healing capsule dispersed in the resin matrix, wherein the resin matrix includes a silicone-based resin and an amine-based curing agent, and the self-healing capsule has a restoring agent and an outer wall supporting the restoring agent. Including, the restoration agent includes an epoxy-based resin.

FIG. 1(a) is a schematic diagram showing an electrical tree generated when the resin matrix of the present invention is damaged, and FIG. 1(b) is a schematic diagram showing self-restoration of damage to the resin matrix.

The electric tree (T) generated in the resin matrix of the insulating composition grows in various forms depending on the shape and size of the defect and the applied voltage, and the insulating composition is decomposed due to high electric energy to form a fine space (crack), After that, a localized discharge occurs in the space and the tree advances. That is, by controlling the initially generated electric tree space, local discharge can be reduced, and the progress of the electric tree can be hindered or stopped.

Referring to FIGS. 1(a) and 1(b), the outer wall of the self-healing capsule 10 is destroyed by the electrical tree T generated when the resin matrix 20 is damaged, and the restoring agent is released, In contact with the curing agent, damage caused by the electrical tree of the resin matrix 20 is self-repaired. That is, when the electric tree generated in the resin matrix of the insulating composition comes into contact with the self-healing capsule, the outer wall is destroyed by electric energy, and the restoring agent containing the epoxy-based resin inside the capsule is introduced into the electric tree by the capillary effect. It moves and fills the space. The resin matrix of the insulating composition includes an amine-based curing agent capable of curing the epoxy-based resin, so that the restoring agent can be cured in chain.

In one embodiment, the resin matrix is included in an amount of 97 to 99.5% by weight based on the total weight of the insulating composition. When the resin matrix is included in an amount of less than 97% by weight, the insulation strength of the insulation composition is reduced, and when it is included in an amount exceeding 99.5% by weight, the self-healing effect of the insulation composition when electrically damaged may be deteriorated.

In one embodiment, the self-healing capsule is included in an amount of 0.5 to 3% by weight based on the total weight of the insulating composition. When the self-healing capsule is contained in an amount of less than 0.5% by weight, the propagation of the electric tree cannot be effectively prevented when the insulating composition is electrically damaged, and the self-healing effect is reduced. And dispersibility is lowered, and the insulating strength of the insulating composition may be lowered.

In one embodiment, the silicone-based resin may include at least one of a silicone resin and a silicone elastomer. When the silicone-based resin is included, insulation performance and mechanical strength may be excellent.

The amine-based curing agent cures the epoxy-based resin by a cross-linking reaction with the restoring agent containing the epoxy-based resin. Epoxy is hardened by a crosslinking structure generated by the reaction between an amine-based curing agent and an epoxy-based resin, and the structure becomes dense due to the crosslinking reaction, so that the insulating composition may have an excellent effect of improving the insulating strength.

In one embodiment, the silicone-based resin and the amine-based curing agent may be included in a weight ratio of 1:0.5 to 1:2. When included in the above weight ratio, the insulation performance and mechanical strength of the present invention are excellent, and the self-restoration efficiency of electrical damage may be excellent by easily curing the restoration agent containing the epoxy resin. For example, it may be included in a weight ratio of 1:1 to 1:1.5.

The self-healing capsule may be spherical, ellipsoidal, polyhedral or irregular.

In one embodiment, the self-healing capsules may have an average size of 50 to 300 μm. Mixability and moldability of the insulating composition may be excellent within the average size range. In the present specification, the size may be the maximum length or diameter of the self-recovering capsule.

In one embodiment, the epoxy-based resin may have a permittivity of 2 to 5 at 60 Hz. In the above conditions, the effect of restoring electrical damage while maintaining insulation performance may be excellent. For example, the epoxy-based resin may have a permittivity of 2 to 5 at 60 Hz.

In one embodiment, the outer wall may include one or more of MUF (melamine-urea-formaldehyde), UF (urea-formaldehyde), epoxy, polyurethane and silica coated MUF (melamine-urea-formaldehyde). . When the outer wall is included, the durability of the self-healing capsule is excellent, and when electrically damaged, it is easily destroyed by an electric tree and the restoring agent inside can be easily released.

In one embodiment, the self-healing capsule may include the restoring agent and the outer wall in a weight ratio of 2:1 to 5:1. When included in the weight ratio, the self-healing capsule can be easily molded, and has excellent structural stability and durability.

In one embodiment, the insulation composition may have a rate of change in dielectric strength of 15% or less by Equation 1 below:

[Equation 1]

Dielectric strength change rate (%) = |((A2-A1)/A1)| X 100

(In Equation 1, A1 is the dielectric strength (kV/mm) of the insulating composition when the self-healing capsule and the amine-based curing agent are not included, measured in accordance with the IEC 60243 standard, and A2 is the self measured in accordance with the IEC 60243 standard It is the dielectric strength (kV/mm) of the insulating composition including the recovery capsule and the amine-based curing agent)

Under the above conditions, it is possible to secure insulation strength suitable for use in the insulation composition for the power cable junction box while being excellent in self-restoration property. For example, the dielectric strength change rate may be 0.01 to 5%.

In one embodiment, the power cable junction box surrounds the ends of a pair of power cable conductors and includes a connection portion electrically connecting the conductors; and at least one semi-conductive rubber unit contacting the conductor and insulating layer of the pair of power cables and the connection part.

The semi-conductive rubber unit may serve as a high-voltage electrode electrically connected to the connection part and the conductor of the power cable or to disperse the electric field without local concentration.

In one embodiment, an insulating rubber unit formed on an outer circumferential surface of the semiconductive rubber unit may be further included.

The insulating composition of the present invention may be applied to the surface of the semiconductive rubber unit and to the space between the spaced apart semiconductive rubber units to form an insulating layer.

Figure 2 (a) shows the insulation of the power cable junction box according to one embodiment of the present invention, Figure 2 (b) shows the insulation of the power cable junction box according to another embodiment of the present invention, Figure 2 (c ) represents the insulation of the power cable junction box according to another embodiment of the present invention.

Referring to FIG. 2(a), the insulating unit 200 includes a semiconductive rubber unit 100, an insulating layer 110 formed by applying an insulating composition on the surface of the semiconductive rubber unit 100, and an insulating layer ( 110) may include an insulating rubber unit 120 formed on an outer circumferential surface thereof. When applying the insulating composition as described above, the amount of use can be minimized.

Referring to FIG. 2(b), in the insulating part 201, an insulating layer 110 is formed by applying an insulating composition to an electric field concentration region E, which is a space between semiconducting rubber units 100 spaced apart from each other. In addition, the insulating rubber unit 120 may be formed on the outer circumferential surfaces of the insulating layer 110 and the semiconductive rubber unit 110 . The electric field concentration region is a region with a high possibility of occurrence of failure.

Referring to FIG. 2(c), the insulation unit 202 may include a semiconductive rubber unit 100 and an insulation layer 110 formed by applying an insulation composition to surround the semiconductive rubber unit. Molding convenience may be excellent when formed as described above.

In addition, FIG. 3 (a) shows an insulation portion of a power cable junction box according to one embodiment of the present invention, and FIG. 3 (b) shows an insulation portion of a power cable junction box according to another embodiment of the present invention.

Referring to FIG. 3(a), the insulator 300 of the power cable junction box of the present invention includes a semiconductive rubber unit 102, an insulating rubber unit formed on the surface of the semiconductive rubber unit 102; and an insulating layer 112 formed by applying an insulating composition to a surface of the insulating rubber unit.

Referring to FIG. 3(b), the insulator 301 of the power cable termination box of the present invention includes a semiconductive rubber unit 102, an insulating rubber unit formed on the surface of the semiconductive rubber unit 102; and an insulating layer 112 formed by applying an insulating composition to a surface of the insulating rubber unit.

In one specific embodiment, the insulating composition of the present invention can be applied to the insulation portion of the unit of junction box and the stress stress cone of termination box.

Manufacturing method of insulation composition for power cable junction box

Another aspect of the present invention relates to a method for manufacturing the insulating composition for the power cable junction box. In one embodiment, a method of manufacturing an insulation composition for a power cable junction box includes mixing a first mixture including a silicone-based resin and a self-healing capsule with a second mixture including an amine-based curing agent and a self-healing capsule.

The insulating composition comprises 97 to 99.5% by weight of a resin matrix; and 0.5 to 3% by weight of a self-healing capsule dispersed in the resin matrix, wherein the resin matrix includes a silicone-based resin and an amine-based curing agent, and the self-healing capsule includes a restoring agent and an outer wall on which the restoring agent is supported. And, the restoration agent includes an epoxy resin.

Since the components of the insulating composition may be the same as those described above, a detailed description thereof will be omitted.

The outer wall of the self-healing capsule is destroyed by an electrical tree generated when the resin matrix is damaged, and the restoring agent is released to contact the curing agent to restore damage to the resin matrix.

In one embodiment, the first mixture and the second mixture may be included in a weight ratio of 1:0.5 to 1:2. When included in the above weight ratio, the insulation performance and mechanical strength of the present invention are excellent, and the self-restoration efficiency of electrical damage may be excellent by easily curing the restoration agent containing the epoxy resin. For example, the first mixture and the second mixture may be included in a weight ratio of 1:1 to 1:1.5.

In one embodiment, the epoxy-based resin may have a permittivity of 2 to 5 at 60 Hz.

The self-healing capsule can be prepared using a conventional method. For example, the self-healing capsule forms an outer wall by adjusting the pH of a mixture containing water, urea, an outer wall reinforcing agent, ammonium and ethyl methacrylate (EMA); preparing a first stirring product by adding and stirring a restoring agent containing an epoxy resin to the mixture; adding formaldehyde to the agitated product and stirring to prepare a secondary agitated product; And obtaining a self-restoring capsule precipitated in the secondary agitation; can be prepared including.

The self-healing capsule may be spherical, ellipsoidal, polyhedral or irregular.

In one embodiment, the self-healing capsules may have an average size of 50 to 300 μm. Mixability and moldability of the insulating composition may be excellent within the average size range. In the present specification, the size may be the maximum length or diameter of the self-recovering capsule.

In one embodiment, the epoxy-based resin may have a permittivity of 2 to 5 at 60 Hz. In the above conditions, the effect of restoring electrical damage while maintaining insulation performance may be excellent. For example, the epoxy-based resin may have a permittivity of 2 to 5 at 60 Hz.

In one embodiment, the outer wall may include one or more of MUF (melamine-urea-formaldehyde), UF (urea-formaldehyde), epoxy, polyurethane and silica coated MUF (melamine-urea-formaldehyde). . When the outer wall is included, the durability of the self-healing capsule is excellent, and when electrically damaged, it is easily destroyed by an electric tree and the restoring agent inside can be easily released.

In one embodiment, the self-healing capsule may include the restoring agent and the outer wall in a weight ratio of 2:1 to 5:1. When included in the weight ratio, the self-healing capsule can be easily molded, and has excellent structural stability and durability.

The insulation composition for a power cable junction box according to the present invention has excellent insulation resistance and mechanical properties, excellent self-recovery property when insulation damage occurs, excellent mixing and dispersibility when manufacturing the insulation composition for a junction box, and Reliability is excellent, and maintenance and repair costs can be minimized.

It is possible to secure technology for countermeasures against human errors such as internal and external scratches that may occur during the manufacture of power cable junction boxes, and by including self-healing capsules with excellent self-healing properties that can minimize the electric tree phenomenon in the resin matrix, high functionality, A cable system of a high-stability transmission system can be constructed. In particular, when the insulation composition of the present invention is applied to the technology of a new type of junction box that can be easily assembled on site after evaluating the quality reliability in advance at the factory, such as PMJ (Premolded Joint), the quality reliability and maintenance aspects of the transmission network is also expected to benefit from

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention by this in any sense. Contents not described herein can be technically inferred by those skilled in the art, so descriptions thereof will be omitted.

Examples and Comparative Examples

Example

A spherical shape having an average particle diameter of 300 μm, including a restoring agent containing an epoxy-based resin (Epon826, Hexion) having a permittivity of 2 to 5 at 60 Hz, and an outer wall (including urea-formaldehyde) supporting the restoring agent. Self-healing capsules (restoring agent: outer wall = 2: 1 to 5: 1 weight ratio) were prepared by a known method.

Then, a first mixture prepared by mixing a silicone-based resin (liquid silicone elastomer) (SL8640, KCC) and the self-healing capsules with a mixer, an amine-based curing agent (Jeffamine, HUNTSMAN) and the self-healing capsules in a mixer The insulating composition was prepared by mixing the second mixture prepared by mixing with a static mixer in a weight ratio of 1: 1 using a static mixer. The prepared insulating composition includes 97 to 99.5% by weight of a resin matrix; and 0.5 to 3% by weight of self-healing capsules dispersed in the resin matrix, wherein the resin matrix includes the silicone-based resin and the amine-based curing agent in a weight ratio of 1:1.

Comparative Example 1

An insulating composition was prepared in the same manner as in the above example, except that the self-healing capsule and the amine-based curing agent were not included.

Comparative Example 2

An insulating composition was prepared in the same manner as in the above example, except that 5.0% by weight of the self-healing capsule was applied to the total weight of the insulating composition.

Comparative Example 3

An insulating composition was prepared in the same manner as in the above example, except that 10.0% by weight of the self-healing capsule was applied to the total weight of the insulating composition.

The physical properties of the Examples and Comparative Examples 1 to 3 were measured in the following manner.

(1) Dielectric strength (dielectric breakdown strength) (kV/mm) and dielectric strength change rate (%): Measured in accordance with IEC 60243 standards, and calculated the dielectric strength change rate according to Equation 1 below, and the results are shown in Table 1 below showed:

[Equation 1]

Dielectric strength change rate (%) = |((A2-A1)/A1)| X 100

(A1 is the dielectric strength (kV/mm) of the insulating composition when the self-healing capsule and amine-based curing agent are not included, and A2 is the dielectric strength (kV/mm) of the insulating composition including the self-healing capsule and the amine-based curing agent. ).

(2) Average propagation speed of electric tree (mm/min): When an electric tree is generated in the insulating compositions of Examples and Comparative Examples 1 to 3, the average propagation speed of the electric tree is measured and shown in Table 1 below.

FIG. 4(a) is a picture immediately after the electric tree is generated in the insulating composition of the example, and FIG. 4(b) is a photograph showing the self-restoration of the electric tree generated in the insulating composition of the example. Referring to Table 1 and FIG. 4, the insulating composition of the embodiment of the present invention has dielectric strength performance and electrical strength compared to Comparative Example 1 using only a silicone-based resin and Comparative Examples 2 to 3 outside the self-healing capsule content condition of the present invention. It was found that the delay effect of the tree propagation speed was excellent.

So far, the present invention has been looked at mainly through embodiments. Those skilled in the art to which the present invention pertains will be able to understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent scope will be construed as being included in the present invention.

10: self-healing capsule 20: resin matrix
100, 102: semi-conductive rubber unit 110, 112: insulating layer
120: insulating rubber unit 200, 201, 202: insulator
300, 301: insulator

Claims (12)

97-99.5% by weight of a resin matrix; And 0.5 to 3% by weight of self-healing capsules dispersed in the resin matrix;
The resin matrix includes a silicone-based resin and an amine-based curing agent in a weight ratio of 1:1 to 1:1.5,
The self-healing capsule includes a restoring agent and an outer wall supporting the restoring agent,
The restoring agent includes an epoxy-based resin,
The self-healing capsule is an insulating composition for a power cable junction box in which the outer wall is destroyed by an electrical tree caused by damage to the resin matrix, the restoring agent is released, and it contacts the curing agent to restore damage to the resin matrix. ,
The insulation composition for a power cable junction box, characterized in that the change rate of the insulation strength by the following formula 1 is 5% or less:
[Equation 1]
Dielectric strength change rate (%) = |((A2-A1)/A1)| X 100
(In Equation 1, A1 is the dielectric strength (kV/mm) of the insulating composition when the self-healing capsule and the amine-based curing agent are not included, measured in accordance with the IEC 60243 standard, and A2 is the self measured in accordance with the IEC 60243 standard It is the dielectric strength (kV/mm) of the insulating composition including the recovery capsule and the amine-based curing agent).
The method of claim 1, wherein the epoxy-based resin has a dielectric constant at 60Hz Insulation composition for power cable junction box, characterized in that 2 to 5.
The insulation composition for a power cable junction box according to claim 1, wherein the self-healing capsule has an average particle diameter of 50 to 300 μm.
The insulation composition for a power cable junction box according to claim 1, wherein the self-healing capsule contains the restoring agent and the outer wall in a weight ratio of 2:1 to 5:1.
The method of claim 1, wherein the outer wall comprises at least one of MUF (melamine-urea-formaldehyde), UF (urea-formaldehyde), epoxy, polyurethane, and silica-coated MUF (melamine-urea-formaldehyde). Insulation composition for power cable junction box, characterized in that.
delete Mixing a first mixture containing a silicone-based resin and a self-healing capsule with a second mixture containing an amine-based curing agent and a self-healing capsule; A method for manufacturing an insulation composition for a power cable junction box,
The insulating composition comprises 97 to 99.5% by weight of a resin matrix; And 0.5 to 3% by weight of self-healing capsules dispersed in the resin matrix;
The resin matrix includes a silicone-based resin and an amine-based curing agent in a weight ratio of 1:1 to 1:1.5,
The self-healing capsule includes a restoring agent and an outer wall on which the restoring agent is supported,
The restoring agent includes an epoxy resin,
The outer wall of the self-healing capsule is destroyed by an electrical tree generated when the resin matrix is damaged, and the restoring agent is released to contact the curing agent to restore damage to the resin matrix,
The method of manufacturing an insulating composition for a power cable junction box, characterized in that the insulating composition has a change rate of 5% or less in insulation strength according to the following formula 1:
[Equation 1]
Dielectric strength change rate (%) = |((A2-A1)/A1)| X 100
(In Equation 1, A1 is the dielectric strength (kV/mm) of the insulating composition when the self-healing capsule and the amine-based curing agent are not included, measured according to the IEC 60243 standard, and A2 is the self measured according to the IEC 60243 standard. It is the dielectric strength (kV/mm) of the insulating composition including the recovery capsule and the amine-based curing agent).
The method of claim 7, wherein the first mixture and the second mixture are included in a weight ratio of 1:0.5 to 1:2.
The method of claim 7, wherein the epoxy-based resin has a permittivity of 2 to 5 at 60 Hz.
The method of claim 7, wherein the self-healing capsule has an average particle diameter of 50 to 300 μm.
The method of claim 7, wherein the self-healing capsule contains the restoring agent and the outer wall in a weight ratio of 2:1 to 5:1.
The method of claim 7, wherein the outer wall is MUF (melamine-urea-formaldehyde), UF (urea-formaldehyde), epoxy, polyurethane and silica coated MUF (melamine-urea-formaldehyde) comprising one or more of Method for manufacturing an insulating composition for a power cable junction box, characterized in that.

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