JPS5815581A - Sealant for repairing transformer - Google Patents

Abstract

PURPOSE:To obtain a paste sealant having a high sealing effect, consisting of liquid A containing as a main constituent a liquid epoxy compound and having a specified viscosity and liquid B comprising a liquid polysulfide rubber, a cold curing secondary or tertiary amine and others. CONSTITUTION:Liquid A comprising 40-70 parts liquid epoxy compound (e.g., a bisphenol A type epoxy), 30-50 parts inorganic filler and 0-3 parts aluminosilicate and having a viscosity adjusted to 300,000-1,000,000cps, and liquid B comprising 40-60 parts liquid polysulfide rubber, 3-10 cold curing secondary or tertiary amine, 30-50 parts inorganic filler and 0-3 parts aluminosilicate and having a viscosity adjusted to 300,000-1,000,000cps are blended. The obtained liquid sealant exhibits a powerful adhesive force to an oil leaking part, is excellent in the resistance to oil and high temperature, flexible and hardly cracked.

Description

[Detailed Description of the Invention] The present invention relates to a sealant for completely repairing oil leaks in transformers.
In particular, it is a paste-like sealing agent containing liquid epoxy and polysulfur rubber as the main ingredients, and is applied to oil leaking parts of a transformer to completely seal it.

The transformer is roughly as shown in the figure, and consists of a main body 1, a canopy 2, a conservator 3, a bushing 4, and a heat sink (not shown). It contains a magnetic core and coil, and is filled with insulating oil. A backing 5 is installed between the main body 1 and the canopy 2, and between the canopy 2 and the conservator 3 or the bushing 4, and is tightly secured to prevent the insulating oil inside the container from leaking. It is sealed.

Incidentally, the puffing that has been used in the past is mainly made of nitrile rubber, and usually a vulcanized product of nitrile rubber or a mixture of nitrile rubber with cork and vulcanization is used. However, although nitrile rubber is somewhat satisfactory in terms of oil resistance and vibration resistance, it has low high temperature resistance, so it does not meet the heat generation conditions of the transformer, and it deteriorates and causes oil leakage. Of course, in this case,
Deteriorated backing? Although it is possible to replace it with a new one, for example, a large transformer with a rated capacity of 3600 KVA and a rated voltage of 33,000 V requires a heavy load of 1 s.
It weighs several tens of tons, making it extremely difficult to lift the canopy 2, and it takes a lot of time and money to replace the bolts and tow the canopy. It is necessary. Moreover, when the transformer is installed indoors, it is often impossible to lift the canopy 2 because it is stuck to the ceiling. Therefore, it is necessary to apply a sealant to the oil leaking part of the transformer and repair it. You can't get it.

For this reason, in the past, methods of applying sealants to oil leaking areas using sealants mainly composed of oxime-free silicone resins or sealing side pipes containing amine- or polyamide-cured epoxy resins as the main component have been considered. Ta.
However, the former does not harden unless exposed to air, so is it necessary to recoat it? On the other hand, the latter is difficult because it is hard and has poor flexibility, and cracks will occur if it is applied thickly on a vibrating transformer while the current is flowing. It cannot be applied thickly and a complete sealing effect cannot be obtained.

The present invention improves the above-mentioned conventional drawbacks, and
Liquid polysulfide rubber and epoxy? The main component is a sealing agent that has strong adhesion to oil leaking areas, has poor oil resistance and high temperature resistance, and is flexible and resistant to cracking due to vibration.

The present invention will be explained in detail below.

The sealant of the present invention is a two-component sealant, consisting of a liquid A containing liquid epoxy gold as a main component and a B liquid containing polysulfide rubber as a main component and an epoxy curing agent. Epoxy, which is the main component of liquid A, is not particularly limited in its molecular structure, but it may be in a liquid state as a monomer, or it may be dissolved in a small amount of an organic solvent to improve its fluidity.
In addition, since the sealant hardens and it becomes a problem to apply the flexible material after eating, for example, bisphenol A
Relatively long molecules such as type epoxies are suitable. Also, polysulfide rubber, which is the main component of liquid B, is liquid and has moderate fluidity. On the other hand, the hardening agent has a hardening agent, taking into consideration the fact that the transformer is installed outdoors.
It is appropriate to use a curing agent tube of room temperature curing type such as secondary amine or tertiary amine. Inorganic fillers, thixotropic additives, etc. are all added to these depending on the usage conditions and coating conditions. Next, embodiments of the present invention will be described.

Blend example ■ (Blend example that does not run out even on vertical surfaces) Ai
Bisphenol A type epoxy 60 parts Light calcium carbonate 6 parts Anatase titanium oxide 13 parts Aluminate silicate 2 parts B solution Polysulfide rubber 50 parts Secondary amine 8 parts Light calcium carbonate (I, Heavy calcium carbonate
20＠Aluminate silicate 2 parts Mixing example ■ (Suitable fluidity for pouring? Mixing example) 8g, Bisphenol A type epoxy resin 60 parts 1 Light calcium carbonate, 25 parts Anatase type titanium oxide 14 parts Aluminum silicate Nato 1 part B liquid Polysulfide rubber 50 parts Tertiary amine 5 parts Light calcium carbonate 22 parts Heavy calcium carbonate 22 parts Aluminate silicate
1 part Each of the above liquids is added to liquid epoxy and liquid polysulfide rubber in order of the total amount of other additives, and mixed in a niegu, and then 3 parts for paint, this roll? I passed it twice. There is no particular restriction on the order in which the additive 1 is added, and the smallest amount is added at the end. The second light shows the tensile shear strength of the sealant, and the third light shows the 180 degree peel strength. In the table, "blank" indicates the adhesive pressure. "Okg/txt?" is a mild steel plate bonded to a mild steel plate. "Oil" is a mild steel plate that is bonded after being coated with an insulating oil. "Silicone sealant" is a product that uses an oxime-free silicone sealant. is.

Table - General properties of the compounded liquid Poured all over the shim type silicone and leaked oil? prevent 'f
C started leaking oil again in a week. Although it depends on the construction, the first factor was that the work was not compatible with the number of days, procedures, etc. The sealant shown in Formulation Example 2 of the present invention? Oil leakage was stopped by injecting oil between the terminal board and the main body flange. Also, the adapter was coated on a bake plate and attached to the terminal board, which stopped oil leakage.
- This is an example of a work that was completely completed by leaving it alone overnight, was done reliably with a small amount of materials, and achieved its purpose cleanly and quickly.

Construction example 2 In a large indoor transformer, there was oil leakage from the terminal board and main body flange, but the transformer manufacturer used oxime-free silicone sealing to solve this problem, which was a reliable construction method. was carried out, but oil leakage occurred again in 2010. Since silicone cannot be overcoated, the sealant shown in Formulation Example 1 of the present invention is used. Oil leak location? I sealed it.

Construction Example 3 Again, this is an example of an indoor transformer, but seven frames are made of baked boards around the terminal board, and the sealant shown in Formulation Example 2 is used. When I poured it in, the oil leakage between the terminal board and the main body flange, and between the terminal board and the adapter had stopped.

I asked, after wiping up all the oil leaks, did you apply toluene diisocyanate here? Coated with Bi as shown in Formulation Example 1
? Apply it appropriately with a spatula and cure with toluene diisocyanate to quickly stop oil leakage, then wipe off excess liquid A, and add sealant to this? Another method is to apply it.

In this method, the toluene diisocyanate hardens immediately, so the equipment is completely stopped and the oil is removed. It has the advantage of being able to be installed without removing it.

As detailed above, the present invention is based on a paste-like epoxy compound liquid and a paste-like polysulfide rubber compound liquid. It is mixed. What are the characteristics of the mixture of epoxy resin and polysulfide rubber? It has strong adhesive strength, excellent oil resistance and high temperature resistance, and is flexible and does not crack due to vibration, making it suitable as a sealant for engines and transformers.

[Brief explanation of drawings]

Is the diagram a transformer? This is a schematic front view. l; Book body 2; Top lid 3; Conservator 4; Bushing 5; Backing 573-

Claims (1)

[Claims] By blending 40 to 70 parts of liquid epoxy, 30 to 50 parts of inorganic filler, and 0 to 3 parts of aluminate silicate, the viscosity is rr30.
Q, 000-1000000 cps K adjustment t, *Liquid A, 40-60 parts of liquid polysulfide rubber, 3-10 parts of room temperature curable secondary or tertiary amine, 30 parts of inorganic filler
~50 parts, 0 to 3 parts of aluminate sulfate and viscosity? 300,000 = 1,000,000 cpa and is a transformer repair sealant consisting of fcB liquid.