JPS6018588A - New electrical insulating oil - Google Patents

Abstract

PURPOSE:A novel electrical insulating oil consisting of a diolefin having two aromatic rings, having good impregnation into an electrical insulating material of plastic, improved hydrogn gas absorption properties and corona discharge resistance, a long life, capable of attaining high voltage. CONSTITUTION:The desired electrical insulating oil containing one or more of diolefin having two (non)condensed type aromatic rings[e.g., diarylalkane derivative shown by the formula I (R1-R3 are hydrocarbon; m+n >=0), diaryl derivative shown by the formula II (m+n) >=1), alkylnaphthalene derivative shown by the formula III (m+n) >=1), etc.]. A ratio of the diolefin blended is usually 0.5- 40wt%(preferably 1-20wt%). USE:For impregnation of electric devices impregnated with oil, such as condenser, cable, transformer, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new electrical insulating oil consisting of diolefins containing aromatic rings.

Unsaturated compounds are generally considered to be undesirable compounds for use as electrical insulating oils because they cause polymerization, and thus they have been given little attention to date.

On the other hand, with the demand for higher voltage and smaller size in oil-impregnated electrical equipment such as power capacitors and power cables, some or all of the conventional insulating paper is replaced with plastic as a dielectric or insulator. Improvements are being made with the use of film instead.

Furthermore, various improvements have been made regarding the electrical insulating oil that is impregnated into such oil-impregnated electrical equipment, but a fully satisfactory electrical insulating oil has not yet been developed.

The present inventors have completed the present invention by discovering that certain kinds of diolefins, which have not been considered in the past, are excellent as electrical insulating oils.

That is, the present invention relates to an electrical insulating oil containing a diolefin having two fused or non-fused aromatic rings.

The diolefins having two fused or non-fused aromatic rings according to the present application include the following compounds.

That is, a compound represented by the following general formula (i) which is a diaryl alkane derivative, (m+n≧0) a compound represented by the following general formula (IT) which is a diaryl derivative, (m+n≧1), and the following general Examples include alkylnaphthalene derivatives represented by formula (llI).

(m-1-n≧1), and in the general formulas (I) to (1■), R
1 to R5 are hydrocarbon residues, and m and n are 0 or positive integers. Further, m R, , R, and n R3 are each the same or different groups, and the total number of double bonds of all groups in each formula is 2.

Specific examples of the general formulas (I) to (III) include the following compounds.

Compounds of general formula (I): 1-phenyl-1-(4'-vinylphenyl)ethylene, 1,1-diphenylbutadiene, 2,4-diphenyl-1,3-pentadiene, bis(4
Tisopropenylphenyl)methane, 1,2- or 1
, 1-bis(4-isopropenylphenyl)ethane, 1.1-bis(vinylphenyl)ethane, compound of general formula OD: 2.27-divinylbiphenyl, 4.4'-diisofurobenylbiphenyl, general formula (II
I) Compounds Nidivinylnaphthalene, Diisopropenylnaphthalene.

Among the methods for producing the diolefin of the present invention, the easiest method is to produce it by dehydrogenation.

That is, when producing the diolefin by dehydrogenation, the raw material has two or three fused or non-fused aromatic rings, and has two or more carbon atoms, and is capable of producing olefinic properties by dehydrogenation. Any hydrocarbon compound may be used as long as it has a hydrocarbon residue that produces two double bonds, or has a plurality of hydrocarbon residues that form one olefinic double bond. Examples of such raw material hydrocarbons include diarylalkane, alkyl biphenyl, alkyl or dialkylnaphthalene, and triarylalkane.

A catalyst is used for dehydrogenation reaction, but as a dehydrogenation catalyst,
Any conventionally known catalyst can be used. For example, Cr, Fe, Cu, K, Mg
, a catalyst such as a metal oxide such as Ca, a noble metal such as PT or PD, or a combination of these metal oxides or a noble metal with alumina or the like is used.

The reaction temperature for dehydrogenation is 350 to 650C1, preferably 40C.
It is 0-600C. When using a fixed bed flow system,
LH8V is 0.2-10, preferably 05-3.

During dehydrogenation, an inert gas such as water vapor can also be present. In addition, an appropriate diluent may be used if necessary. However, it is usually advantageous to carry out the reaction without increasing the dehydrogenation rate so high, since the raw material hydrocarbon itself can be used as a diluent.

As a method for producing diolefins other than the above method, a synthetic chemical method can be used. For example, it can be obtained by obtaining a Grignard reagent having a vinyl group and an aromatic ring from bromostyrene or the like, then reacting it with an aromatic ketone such as acetophenone, and dehydrogenating it.

As described later, the diolefin of the present invention can be used in combination with other electrical insulating oils, so it may be solid at room temperature as long as it is a compound that dissolves in other electrical insulating oils. However, even if it is soluble in other electrical insulating oils, it is not preferable to use one with too high a molecular weight because the solution viscosity will become too high. Usually, the molecular weight is about 500 or less,
A better case is about 300 yen or less.

The diolefin of the present invention can be used alone or as a mixture of multiple components, and can also be mixed with other electrical insulating oils in any proportion.

However, the mixing ratio is usually 0.5 to 40% by weight of the diolefin of the present invention in the mixed insulating oil.
Preferably, the amount is 1 to 20% by weight.

Other electrical insulating oils to be mixed include conventionally known electrical insulating oils, such as mineral oil, olefin oligomers such as polybutene, alkyl or cycloalkyl benzenes such as dodecylbenzene and synchrohexylbenzene, triglycerides, animal and vegetable oils such as castor oil, and dioctyl phthalate. phthalate esters, silicone oil, etc.

Other examples include saturated compounds having at least two fused or non-fused aromatic rings, and aromatic monoolefins having at least two fused or non-fused aromatic rings.

The above-mentioned saturated compounds having at least two fused or non-fused aromatic rings include diphenylbutane, lower alkyl group substituted products of unaciphenylmethane such as benzyltoluene, -phenyl-1-1-norylethane, 1-phenyl- 1-ethylphenylethane, 1-phenyl~1-
1) ethane, ■-phenyl-1-1-sopropylphenylethane, 1-phenyl-1-) IJ methylphenylethane, 1, 1-cy(ethylphenyl)ethane,
■-Fue, =-Lou 2- Ethyl phenylethane, ■
-Phenyl-2-inglobylphenylethane, 1.2
- More 1,1-diphenylethane or 1,2-diphenylethane such as diphenylethane or lower alkyl group substituted products thereof, 1,3-diphenylbutane, 2
．． Diarylalkane or diarylcycloalkane such as 4-synyl-2-methylpentane, diphenylcyclohexane, alkylarylindane such as methylphenylindane, biphenyl, alkyl or cycloalkylbiphenyl such as mono- or diisopropylbiphenyl, cyclohexylbiphenyl, mono- or Alkylnaphthalenes such as diimpropylnaphthalene, ethers such as ditolyl ether ether, dibenzyl ether, and cyanol thioether are 75'-, dibenzyltoluene, distyrenated xylene, bisphenethyltoluene, terphenyl, styrenated naphculene, and Examples include tri-noaryl alkanes such as triphenylhexane.

In addition, the aromatic monoolefins having at least two fused or non-fused aromatic rings include 1, t-diphenylethylene, stilbe/styrene, α-methylstyrene, and impropenyltoluene in an amount of 3. i.e. 1,3-diphenylethane/-1
, 2,4-diphenyl-4-methylpentene-1, etc.
and 1-vinylphenyl-1-phenylethane, 1
-Impropenylphenyl--Phenylethane, vinylphenylphenyl alkane modules of vinylphenyl phenylmethanato, lower alkyl group-substituted products thereof, and aromatic monoolefins such as impropenylphenyl and impropenylnaphthalene.

Any of the above insulating oils can be mixed with the diolefin of the present invention singly or as a mixture of two or more.

By the way, as mentioned above, with the demand for miniaturization of oil-impregnated electrical equipment, it is becoming increasingly important to use it as an insulating material or dielectric material in oil-impregnated electrical equipment instead of conventional insulating paper or in combination with insulating paper. Plastics are starting to be used. Specifically, in capacitors, stretched or unstretched polypropylene, polymethylpentene,
Those that use a combination of a polyester film and insulating paper, or those that use only these plastic films, and those that use fine embossing on the surface to make it easier to impregnate, and those that use a surface metal layer as an electrode. Some use metallized plastic films. In addition, as an insulator for oil-impregnated power cables (OF cables), plastic films such as crosslinked or uncrosslinked polyethylene, stretched or unstretched polypropylene, and polyolefins such as polymethylpentene are used instead of insulating paper. , films made by laminating insulating paper and these plastics by melt extrusion, composite films made by crosslinking insulating paper and silane-crafted polyethylene in the presence of a silanol condensation catalyst, or paper pulp and polyolefin fibers. There are also papers mixed with

The electrical insulating oil of the present invention can be suitably used in oil-impregnated electrical equipment having the structure described above, but among the other electrical insulating oils mentioned above, it is preferable to use electrical insulating oils having at least two fused or non-fused aromatic rings. When used in combination with one or more types of aromatic monoolefins, such as saturated compounds and aromatic monoolefins having at least two fused or non-fused aromatic rings, a synergistic effect with the characteristics of those components. This is preferable because it produces the following effect. The mixing ratio at which such a synergistic effect can be expected may be the same as the mixing ratio with other electrical insulating oils described above.

In addition, antioxidants known for use in electrical insulating oils, such as 2,6-di-tert-butyl-p-cresol (trade name BHT) and 2.2' as phenol-based antioxidants.

-methylenebis(4-methyl-6-tert-butylpht/-
), 4,4'-butylidene bis(3-J thyl-6
-tert-butylphenol), 4.4'=f obis(3-
methyl-6-tert-butylphenol), stearyl-β
-(3,5-di-tert-butyl-4-hydroxyphenol)gropionate (trade name Irganox 1076
), tetrakis[methylene-3(315'-di-tert-butyl-4'-hydroxyphenyl)gropionate]methane (trade name ■rganox 1010), 1', 3
．． 5-) Re-mailing 2. 4. 6-)
Lis (3,5-tert-butyl-4-hydroxybenzyl)benzene (trade name Ionox 330), 1
,1.3-)lis(2-methyl-4-hydroxy-5-
tert-butylphenol) butane (trade name: Topanol)
CA), etc. Sulfur-based compounds include dilaurylthiodiglobionate, distearylthiodiglobionate, laurylstearylthiodiglobionate, dimyristylthiodiglopionate, and phosphorus-based compounds include triisodecyl phosphite and diphenyl isopropionate. Decyl phosphite, triphenyl phosphite, and trinonylphenyl phosphite can be added to the electrical insulating oil of the present invention. These antioxidants can be used alone or in combination of two or more, and the amount added is 0.001 to 5% by weight based on the insulating oil, more preferably,
The content is 0.01 to 2.0% by weight.

Further, for the purpose of imparting flame retardance or other purposes, a well-known phosphoric acid ester compound or other epoxy compound may be used in combination as an additive for electrical insulating oil.

The electrical insulating oil of the present invention is suitable as a general electrical insulating oil, and is particularly suitable for impregnating oil-impregnated electrical equipment such as capacitors, cables, and transformers. As mentioned above, it is suitable for impregnating oil-impregnated electric equipment such as capacitors and cables, which use plastic as part or all of its insulator or dielectric.

That is, when a capacitor that uses plastic, particularly polyolefin, as part or all of the insulator (dielectric) is impregnated with the electrical insulating oil of the present invention, the plastic insulator does not swell much. is sufficiently impregnated, and no voids (unimpregnated areas) occur. Therefore, there is no fear that corona discharge due to electric field concentration in the void will occur and lead to dielectric breakdown. Furthermore, the electrical insulating oil of the present invention has excellent hydrogen gas absorption properties and corona discharge resistance under high voltage, has a long life, and can achieve high pressure.

Similarly, in the case of cables, the dimensional change of the insulation due to swelling is small, so the oil flow resistance of the insulating oil is extremely low.
When impregnating the cable with oil, the impregnation time for insulating oil is shortened. Of course, since impregnation is easily performed, voids are less likely to occur, resulting in a higher dielectric breakdown voltage. In addition, cables using an insulator made of a laminated film of plastic film and insulating paper or a composite film may suffer from delamination, peeling due to bending, wrinkles, and buckling even if they come into contact with the insulating oil of the present invention for a long period of time. There is little risk that such things will occur. Furthermore, since insulating oil has excellent hydrogen gas absorption properties, it is possible to obtain a cable with excellent corona discharge resistance, similar to a capacitor. Therefore, a cable with a long life and high voltage can be obtained like a capacitor.

Furthermore, by impregnating an insulating oil consisting of multiple components, the synergistic effect of component 1 improves the above-mentioned properties, and each component itself has excellent electrical properties, biodegradability, heat resistance, and oxidation stability. Oil-impregnated electrical equipment can be manufactured efficiently and easily, as oil-impregnated electrical equipment can be manufactured efficiently and easily, and exhibits high performance without restrictions due to usage conditions. type electrical equipment can be obtained.

Next, the present invention will be further explained with reference to Examples and Comparative Examples.

Magnesium 14 in 250ml dry tetrahydrofuran
．． 6 g (0,601 mol) is added, heated to 65 U, and 100 g (0,546 mol) of p-bromstyrene is added dropwise to prepare a Grignard reagent. Add this to 2O
Cool to r and add 765.5 g of acetophenol (0,54
6 mol) was added dropwise. 500g of ice crushed reaction solution, 5g of water
00g and 15 mt of 98-thiosulfuric acid. The reaction product alcohol was obtained by ether extraction. This alcohol is then dehydrated with potassium hydrogen sulfate,
62.8 g of the target product, 1-phenyl-1-(4'-vinylphenyl)ethylene, which is liquid at room temperature (yield: 56%)
) I got it.

This product has a boiling point of 151 C (10+nmHg), 1
The temperature was 14°C (2 mwHg), and its structure was confirmed by NMR spectrum and IR spectrum.

The oil obtained by mixing this oil 't, i-phenyl-1-xylylethane to a weight of 10 was designated as Insulating Oil 1, and the electrical properties described below were investigated.

Example 2 An oil having the following composition was obtained by dehydrogenating 1-phenyl-1-(4'-ethylphenyl)ethane in the presence of steam under the following conditions. This oil was then added to 1-phenyl-1-xylylethane so that the amount of diolefin compound was 5% by weight. This oil was used as insulating oil 2 and the tests described below were conducted.

Dehydrogenation conditions Catalyst: Nissan Girdler Catalyst Co., Ltd., G64A, iron oxide catalyst with potassium carbonate and chromium oxide as promoters, particle size 14-28 meso/yu Temperature: 550C LH8V: 1. O H, O/raw material (weight ratio): 3.0 pressure Composition type of crab atmospheric dehydrogenation product Weight % 1-phenyl-1-(4'-ethylphenyl)ethane
23.81-phenyl-1-(4'-ethylphenyl)
Ethylene 39.91-Phenyl-1-(4'-vinylphenyl)ethane 5.01-Phenyl-1-(4'-
Vinylphenyl) ethylene 28.1 Others 32 Total 1000 A capacitor was impregnated with insulating oil 1 obtained in Test Example 1, insulating oil 2 obtained in Example 2, and 1-phenyl-1-quinrylethane as a comparative example, and the performance was evaluated.

The capacitor was made by using two layers of polypropylene easily impregnated film on polypropylene with a thickness of 14 μm as a dielectric material, and aluminum foil as an electrode, respectively, and the capacitance after impregnation was about 0.4 μF.

Capacitor performance test is corona starting voltage (C8V)
, the corona extinction voltage (CEv), and the breakdown time until the capacitor was destroyed under constant voltage application were measured.

The results are shown in Table 1. In addition, regarding the capacitor breakdown time, each capacitor impregnated with the same oil was
Each capacitor was produced individually, and the capacitor was destroyed by being charged with a constant voltage.The samples showing the maximum and minimum breakdown times were excluded, and the average value of the remaining five samples was taken as the breakdown time of the capacitor. Moreover, the breakdown time was expressed as a relative value to the measured value of a capacitor made of 1-phenyl-1=xylylethane alone as a comparative example.

In addition, the insulating oil used in the capacitor test was used with 0.2% by weight of 100 flT added thereto as an antioxidant.

Table 1 Patent Applicant Japan Petrochemical Co., Ltd. Agent Patent Attorney Hajime Maejima

Claims (1)

[Claims] (1) An electrical insulating oil characterized by containing one or more diolefins having two fused or non-fused aromatic rings.