JPS61218003A - Insulation oil for electric equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to insulating oil used in electrical equipment, and particularly to an additive that plays a suitable role in preventing deterioration of the insulating oil and does not adversely affect coexisting materials. Concerning insulating oil for electrical equipment.

[Background of the invention]

Conventionally, antioxidants and the like have been added to lubricating oils and the like to prevent deterioration, but additives are not usually added to insulated hydraulic oils for electrical equipment. For example, as shown on page 390 of 8 Stone Review (VOL25/l'&6.1988), insulating oil used in electrical equipment is manufactured without additives, and antioxidants are added only if requested by the customer. DBPC(Di-tart-Butyl-
Para Cresol) is added. .

However, this DBPC may have adverse effects if the conditions of use of subsidiary materials such as festivals differ (edited by Yamada and Kawamura).
(Refer to "New Electrical Insulating Oil" (1968) p. 67).

In addition, FEW in which DBPC-added insulating oil is a coexisting material
According to research results on the effect on wire (enamel wire with acrylonitrile coating), DBPCF in insulating oil
It tends to blacken the iFEW film and slightly reduce the number of torsional flakes. As shown in the cyst vomiting shown below, it affects the PVF wire (polyvinyl formal coated enamel wire). That is, DBPC paint oil discolors and alters the coating of the coexisting PVF wire, causing it to deteriorate.

This indicates that the use of DBPC-added oil can cause the coating to flake and the resulting copper substrate to accelerate deterioration of the insulation oil.

As mentioned above, conventionally no additives are added to insulating oil for electrical equipment, but sometimes DBPC is added.
In this case, no consideration was given to the effect on coexistence materials, and there remained a risk of deterioration of the materials and insulating oil.

[Purpose of the invention]

An object of the present invention is to provide an advantageous long-life insulating oil for electrical equipment that can prevent the deterioration of insulating oil used in electrical equipment due to isobaric oxidation and that can achieve its effects without adversely affecting coexisting materials. Our goal is to provide the following.

[Summary of the invention]

The insulating oil for electrical equipment of the present invention is 2% 2' in mineral oil-based insulating oil.
-methylenebis(4-methyl-6-tert-butylphenol) is n-octadecyl-8-(4-hydroxy-
3,5-butylphenyl)globionate 0.0
It is added in an amount of 5 to 1.0%.

In the present invention, when a phenolic substance is added to free radicals that are decomposition products such as hydroperoxides generated in the process of oxidative deterioration of insulating oil, etc., the diphenolic substance itself is easily oxidized, that is, dehydrated. It was developed as a result of focusing on its ability to stop oxidative chain reactions by reacting with free radicals.

That is, the present invention provides P3 oil with 2, whose structural formula is shown in FIG.
．． By adding 2'-methylenebis(4-methyl-6-8th-butylphenol) or n-octadecyl-8-(4-hydroxy-3,5-8th-butylphenyl)globionate whose structural formula is shown in FIG. , which prevents deterioration of insulating oil. This effect is probably due to the fact that the compound functions as the dehydrogenated phenolic substance mentioned above. However, according to the inventor's experiments,
Among various phenols, the above-mentioned compounds are excellent in that they can prevent deterioration without any adverse effects.

In the present invention, the concentration of the above compound added is from 0.05 to
It is set to 1.0 wt%. This is because a concentration within this range provides good stability against oxidation. Any of the above compounds may be added alone to the above concentration range, or may be used in combination with a single compound.

[Embodiments of the invention]

Examples of the present invention will be described below. As shown in Figure 1 below, 2,2'-methylenebis(4-methyl-8-butylphenol) or n-octadecyl-
8-(4-hydroxy-3,5-8th-butylphenyl)
Zurobionate is added to P3 edge oil used in electrical equipment.
05 to 1.0% was added. Specifically, in this example, mineral oil-based transformer oil was used as the insulating oil, and 0.5 wt % of each of the above compounds was added to the sample 1 of this example.
and sample 2 of this example.

Figure 1 shows DBPC-added oil (comparative sample 1) for comparison.
and additive-free insulating oil (comparative sample 2) are also shown, and the initial characteristics of each are shown. As shown in the same figure.

The electrical properties of the insulating oil of sample 1.2 of this example are the same as those of the additive-free insulating oil of comparative sample 2, and there is no effect on the insulation performance.

FIG. 5 shows the results of an oxidation stability test conducted on each of the above samples in accordance with JISC2101. The sample according to this example is
Compared to additive-free oil without additives, the sludge value and total acid value are lower, indicating that deterioration is prevented.

Note that the total acid value is the amount of potassium hydroxide consumed to neutralize the acid in the insulating oil. Insulating oil produces fatty acids, oxyacids, etc. due to deterioration such as oxidation, and the degree of deterioration can be determined by neutralizing these at with potassium hydroxide. The lower the total acid value, the less deterioration occurs, and this example sample shows good results in this respect.

Furthermore, sludge is a metal-insoluble substance produced by the combination of oxidized and deteriorated oil and metal, and its amount is measured by a filtration gravimetric method to determine deterioration. In this respect as well, the sample of this example shows good results.

Figure 6 shows 2,2'-methylenebis(4-methyl-6-
This shows the oxidation stability test results of insulating oil to which tertiary butylphenol (tertiary butyl phenol) has been added, and shows the relationship between the addition concentration, sludge, and total acid value in graphs. Figure 7 also shows n-octadecyl-3-(4-hydroxy-3,5
The case of addition of -fluorophenyl)cropionate is shown. From Fig. 6 and Fig. 7, each compound is 0.0
It can be seen that the addition of 5 to 1.0 wt% gives good results.

As described above, according to this embodiment, adding 0.05 to 1.0% of the above additive to the insulating oil has the effect of preventing deterioration of the insulating oil.

Next, the influence on coexisting materials will be explained.

Figure 8 shows the same <2.2'-methylenebis(4
-Methyl-6 type 3-butylphenol added oil (sample 1 of this example), n-octadecyl-8-(4-hydroxy-3,
5 set 8 butylphenyl) propionate 1f & oil added (
Example sample 2), and DBPC-added oil (comparative sample 1),
The tests shown in FIG. 8 were conducted on the additive-free insulating oil (comparative sample 2) and, in FIG. 8, the BTA-added oil (comparative sample 3), and the results are shown.

As shown in Fig. 8, sample 1.2 of this example showed no color loss in the twist peeling test results of aluminum wire coated with PVF (polyvinyl formal), compared to comparative sample 1.8 containing other additives. , it can be seen that the influence on coexisting materials is small.

Incidentally, BTA (benzotriazole) is generally used as a copper corrosion inhibitor, but there is a problem that it is difficult to soak in insulating oil.

The above-mentioned twist peeling test is a test in which PVFIIIJi is placed in insulating oil and subjected to a deterioration test to see the effect of the insulating oil on polyvinyl formal nuclides. PVF line l on one side Km
and apply rotation 2 from the other side.

This test measures the number of times until delamination occurs, and the higher the number of times, the better. According to FIG. 8, sample 1 of this example.
2 is almost the same as the additive-free oil of Comparative Sample 2, and also shows superior values to Comparative Sample 1 with L)RPC added.

The results are almost the same as those of Comparative Sample 3 in which BTA, which is a copper corrosion inhibitor, is added to prevent deterioration of the wire itself.

As mentioned above, 2,2'-methylenebis(4-methyl-8th-butylphenol) is added to the insulating oil used in electrical equipment.
．． By adding 5%, compared to insulating oil without additives, as is clear from the data of sample 1 of this example in Figure 5,
An insulating oil with a sludge and total acid value 50 degrees lower can be obtained, and therefore can be said to have a deterioration inhibiting effect of 50%.

Also, n-octadecyl-8-(4-hydroxy-3,
By adding 0.5% of 5-tert-butylphenyl) propionate, the sludge and total acid value are 10% lower than the oil without additives, as is clear from the data of Sample 2 of this example in Figure 5. Insulating oil is obtained, and therefore it can be said that there is an effect of suppressing deterioration by 10%.

Moreover, from the results shown in FIG. 8, no matter which additive is added, it does not have a negative effect on the coexisting materials in the insulating oil.

It should be noted that, as a matter of course, the present invention is not limited only to the above embodiments.

〔Effect of the invention〕

As described above, the excellent oil for gaseous equipment of the present invention has the advantage of being able to prevent deterioration due to oxidation, etc., and exhibiting this effect without adversely affecting coexisting substances.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the properties of lll5-rimmed oil in an example of the present invention, Figs. 2 and 8 are 4-methyl-6-tert-butylphenol and n-octadecyl, respectively, which are mixed with additives. -8-(4-Hydroxy-3,5-tert-butylphenyl)propionate diagram showing the chemical structure, 4th
The figure is a front view of the twist peeling test device, and Figure 5 is sample 1 of this example.
．． Figures 6 and 7 show the deterioration suppressing effect of 4-methyl-6-tert-butylphenol and !2, respectively. 1-
octadenru 8-(4-hydroxyne-3,5-tertiary)
FIG. 8 is a diagram showing the correlation between the degree of sulfurization and the deterioration suppressing effect of butyl phenyl) propionate, and FIG. 8 is a diagram showing the results of the coexisting substance deterioration test and the twist peeling test. 1:)'VF line, 2: Rotation.弗 1 Kunihan 2 Seki:! P-3 Figure CCHs) 3C Early 4 Concave

Claims (1)

[Claims] 1. An insulating oil used in electrical equipment, in which 2,2'-methylenebis(4-methyl-6-tert-butylphenol) or n-octadecyl-3-(4-hydroxy-3,5 - An additive-containing insulating oil for electrical equipment, characterized in that 0.05 to 1.0 wt% of tert-butylphenyl) propionate is added.