JPH04171615A - Insulator - Google Patents

Abstract

PURPOSE:To improve water repellent and electrical insulating properties and maintain characteristics for a long period by forming a coat including a film made of ceramic material with a repellent property on its surface or the ceramic material. CONSTITUTION:A coat including a film made of ceramic material with a water repellent property on its surface or the ceramic material is formed. As the repellent coat, a coat with eveness and strong binding property is used, which is formed of a ceramic material excellent in its weather resistance and having an electrical insulating property, such as BN, Si3N4, SiC, SiO2, TiO2, Al2O4, AIN, amorphous diamond which is used as a mono-layer or with an intermediate layer, by the physical vapor deposition method(PVD) or chemical vapor deposition(CVD). It is thus possible to prevent decrease of the electrical property of an insulator produced by the above-mentioned method owing to the repelling property of the coat.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an insulator with excellent weather resistance and water repellency.

(Prior Art) Insulators for power transmission equipment are made of insulating materials such as porcelain and glass, and when the surface of the insulator becomes soiled and wet, the insulation resistance of the insulator surface decreases and the insulation strength is impaired. At this time, if a leakage current flows on the surface of the insulator, this leakage current causes a dry zone on the surface of the insulator, and a local discharge occurs in the dry zone, resulting in the generation of a fouling corona. This causes noise to be generated in radio waves such as TVs. Conventionally, the solution to this problem has been to coat the insulator surface with silicone grease so that the surface becomes difficult to wet.

(Problem to be solved by the invention) However, due to storms and the progress of air pollution in recent years, insulators are exposed to salt damage, dirt from dust, acid rain, etc. In order to maintain the weather resistance and tracking resistance of the insulator due to the loss of water repellency, it is often necessary to repaint or replace the insulator, resulting in the problem of requiring time, effort, and cost for maintenance.

(Means for Solving the Problems) In view of the above points, the present invention aims to provide an insulator having a coating formed on its surface that has excellent water repellency and electrical insulation properties and maintains the above characteristics for a long period of time. This insulator is characterized in that a coating made of a water-repellent ceramic material or a coating containing the ceramic material is formed on the surface.

(Example) The water-repellent coating formed on the insulator of the present invention is made of a ceramic material that is electrically insulating and has excellent weather resistance, such as BN, Si3
N+, SiC, 5in2, TiO2, Al2O,, A
IN.

A uniform and strong bonding film can be formed by physical vapor deposition (PVD) or chemical vapor deposition (CVD) using a material such as amorphous diamond in a single layer or by interposing an intermediate layer.

In order to maintain the water-repellent properties of this water-repellent coating for a long period of time, it is necessary that the coating surface does not deteriorate even when exposed to harsh conditions and has a high degree of weather resistance. It is preferable to keep the vapor deposition temperature sufficiently high. If the deposition temperature is low, the water repellency of the coating will be stable; conversely, if the deposition temperature is higher than the melting point of the insulator constituting the insulator body, the bonding force of the coating will be weak and it will easily peel off. Increasing the thickness of the coating does not contribute to long-term maintenance of water repellency. It goes without saying that the present invention can be widely applied to various types of porcelain insulators such as pin insulators, insulator tubes, support 6rl insulators, and glass insulators in addition to suspension insulators, and the insulators on which the coating is formed can also be coated with glaze or coated in advance. Next, specific examples of manufacturing methods will be described, which may or may not be treated.

Manufacturing Example By applying a coating forming method such as physical vapor deposition (PVD) or chemical vapor deposition (CVD), ceramic materials are applied to the surface of an insulator made of porcelain or glass (the thermal expansion coefficient is different from that of the insulator surface). If the amount is large, it is formed as a stable and dense ceramic material coating (with an intermediate layer interposed).

(Functions and Effects) The surface of such an insulator is covered with a coating made of a water-repellent ceramic/yx material or a coating containing a water-repellent ceramic material, so the insulator body can absorb electricity due to the water repellency of this coating. It has excellent weather resistance and tracking resistance, that is, long-term reliability, without deteriorating its physical properties and compared to conventional silicone grease applied to the surface of the insulator. Below, test methods for confirming the effects of the insulators of the present invention manufactured by various methods and the data of the results are shown. Regarding the insulator made according to the above manufacturing example (A-1)
Preparation of soiled corona characteristic test sample BN, S+aN4, S+C, Si02, TlO2,
One type of water-repellent ceramic coating selected from A1□03, AIN, and amorphous diamond is formed using conventional coating forming methods such as physical vapor deposition (PVD) and chemical vapor deposition (C:VD). Each sample was created by applying

Test method: The staining corona test confirms the water repellency effect, that is, the staining corona suppressing effect, for the initial state of the insulator with a water-repellent ceramic material coating formed on the surface and the state after the 12-month outdoor exposure test.

The soiling corona test was conducted using a measuring method based on the fixed mark fog method specified as a reference test of JEC201.

Test results: The occurrence of fouling corona shown in Table A-1 indicates the degree of fouling at 0.12 mg/cn.
f, if the leakage current exceeds 10 mA when applying electricity to three series of insulators under the condition of 8.4 KV, it is considered that a fouling corona has occurred, and if it is less than 10 mA, it is considered that a fouling corona has not occurred. I judged it.

Table A-1 [○: None, △: Slightly present, ×, Present] Conventional porcelain suspension insulators without a water-repellent coating on the surface both in the initial state and after the 12-month outdoor exposure test. Contamination corona has occurred. In addition, the insulator whose surface was coated with silicone grease developed fouling corona after a 12-month outdoor exposure test. - The insulators on which the water-repellent ceramic material coating of Rikiki's invention was formed showed good results, with no fouling corona occurring not only in the initial state but also in the wet state after 12 months of outdoor exposure.

(A-2) Preparation of water repellency and weather resistance test sample
A test method in which each sample was created by forming a water-repellent ceramic coating on the surface of a 0x 20x 5 mm plate in the same manner as in the preparation of the sample for the (A-1) soiling corona characteristic test.

The water repellency weather resistance test was conducted using an accelerated weather resistance tester (Sunshine Carbon Weather Meter) under conditions based on JISD2025.

Test results: Shown in Table A-2.

In this table, ○ indicates the contact angle of the sample with distilled water or 40°.
This shows the above.

Table A-2 Samples coated with the water-repellent ceramic material of the present invention show good results and exhibit water-repellency over a long period of time. On the other hand, a sample coated with silicone grease may initially have good water repellency, but after 1000 hours of accelerated deterioration test, the contact angle becomes less than 30°, resulting in poor long-term durability.

(A-3) Preparation of tracking resistance test sample ・Prepare the above (8-1) on the surface of a porcelain bar 26 mmφ x 280 mmL of the same quality as porcelain for insulators with a glassy glaze applied to the surface.
Each sample was prepared by forming a water-repellent ceramic coating in the same manner as the sample preparation for the staining corona test.

Test method.

The tracking resistance test was carried out using a merry-go-round tester, in which a sample with an interelectrode distance of 120 strokes was immersed in salt water for 18 seconds at an angle of 15 degrees from the horizontal (1.3 ms/cm), and then electrical current was applied for 42 seconds (ACIOKV). ), immersion and electrification were repeated, and the surface condition, that is, tracking, which indicates a phenomenon in which a conductive path is formed, and the occurrence of erosion, which indicates a phenomenon in which electrical erosion occurs, were visually confirmed and the leakage current was measured and evaluated.

Test results: Shown in Table 113.

O indicates that the leakage current is 100 mA or less, × indicates 1
00 mA is shown.

Table A-3 Samples coated with the water-repellent ceramic material coating of the present invention and samples of the same quality as insulator porcelain coated with a conventional glassy glaze had a leakage current of approximately 4 after a 1500 hour test.
It is 0mA or less and has not deteriorated. On the other hand, the sample coated with silicone grease had a leakage current of 50m at the start of the test.
100 m after 800 hours.
A, and after another 1250 hours, it reached 230 mA and deteriorated significantly.

(Effects of the Invention) As explained above, the present invention is an insulator that has excellent water repellency and electrical properties and maintains these properties for a long period of time, eliminating the problems of the conventional ones and greatly contributing to the development of industry. Large patent applicants Chubu Electric Power Co., Ltd. Nippon Insulators Co., Ltd.

Claims (1)

[Scope of Claims] 1. An insulator characterized in that a coating made of a water-repellent ceramic material or a coating containing the ceramic material is formed on the surface. 2. Ceramic materials with water repellency are BN and Si_3
N_4, SiC, SiO_2, TiO_2, Al_2O
The insulator according to claim 1, wherein the insulator is selected from among __3, AlN, and amorphous diamond. 3. Claim 1, wherein the water-repellent ceramic material is formed by physical vapor deposition (PVD) or chemical vapor deposition (CVD) in a temperature range lower than the melting point of the insulator constituting the insulator body. The insulator mentioned.