JPS5947403B2 - Insulating material for high voltage - Google Patents

Description

[Detailed Description of the Invention] This invention relates to high voltage insulating materials, specifically for transformers,
This relates to insulating materials with improved dielectric breakdown resistance used in high-voltage electrical equipment such as insulators.

Conventionally, various techniques have been proposed for improving the dielectric breakdown resistance of this type of insulating material. For example (1)
) Improving casting and impregnation techniques when applying insulating materials to high voltage equipment; (2) Methods for removing mechanical stress, thermal stress, etc. from insulating materials after casting and impregnating high voltage equipment; (3) 2.) Methods of forming conductive layers and semiconductive layers in high voltage equipment in addition to insulating materials are known. However, methods 1) to (3) above cannot always sufficiently improve the dielectric breakdown resistance of the insulating material, and are not a fundamental solution. For this reason, high-voltage insulation materials have been proposed in which the various voltage stabilizers shown below are added to thermoplastic and thermosetting resin insulation materials to improve dielectric breakdown resistance. There is.

Examples of the voltage stabilizer include a mixture of a substituted aromatic hydrocarbon compound having an electron-accepting group and an electron-donating group and a naphthenic hydrocarbon, or polyethylene,
There are polymers and copolymers such as polyether and polyepoxy mixed with aromatic and alicyclic organometallic compounds. However, the voltage stabilizer described above is effective because it is stably dispersed and mixed into thermoplastic resins that can be used for electrical equipment such as power cables and electric wires. When blended with thermosetting resins that can be used for, it hardens with the resin and significantly accelerates the resin's original hardening reaction, so it hardens in a short period of time and does not function as a voltage stabilizer. As a result, the original casting and impregnating properties of the resin cannot be obtained, and the electrical and mechanical properties deteriorate.

Furthermore, the dielectric breakdown resistance was not improved. This invention was made to solve the above problems, and it is possible to obtain the casting and impregnating properties inherent to thermosetting resins, without deteriorating the electrical or mechanical properties, and with significantly improved dielectric breakdown resistance. The present invention aims to provide an improved high voltage insulating material. The present invention will be explained in detail below.

Examples of the voltage stabilizer used in the present invention include bioanthrone, iso-bioanthrone, flavanthrone, mesonaphthodianthrone, pyrantrone, and piperidine, which have 6 or more benzene rings and have 2 or more carbonyl groups. or porphyrins (POrphy) such as chlorophyll, phthalocyanine, phthalocyanine blue, and phthalocyanine green.
rin) nucleus or a compound having a phthalocyanine nucleus, or a general formula consisting of a higher alkyl quaternary ammonium ion containing a hydroxyalkyl group and vitaltrexacide, dihydrogen cytotrexacide, etc. [
However, R1, R2 and R3 represent a methyl group, ethyl group, propyl group, butyl group, X1, X2, X3 and X4 represent a hydrogen atom, hydroxyl group, carboxyl group, and carboxymethyl group, and n is an integer of 1 to 5 ]
It consists of one or more types of class ammonium salts.

Therefore, the high voltage insulating material of the present invention is made by uniformly mixing 0.1 to 30% by weight, preferably 0.5 to 10% by weight, of the voltage stabilizer described above to a thermosetting resin. It is something.

In this case, it is also possible to use a plasticizer, a heat and weather resistance imparting agent, or a deterioration inhibitor in combination with the voltage stabilizer, if necessary. The reason for limiting the amount of voltage stabilizer in the thermosetting resin is that the voltage stabilizer is 0.1% by weight.
If it is less than 3, the dielectric breakdown resistance cannot be improved;
If it exceeds 0% by weight, the effect of accelerating the hardening of the thermosetting resin tends to occur significantly (this is because the casting and impregnating properties inherent to the thermosetting resin cannot be obtained, and the dielectric breakdown resistance cannot be improved). . Examples of the thermosetting resin used in the present invention include condensation polymerization thermosetting resins such as phenol resins, alkyd resins, and silicone resins, and addition polymerization type thermosetting resins such as diallyl phthalate resins, polyimide resins, unsaturated polyester resins, and epoxy resins. One or two thermosetting resins
It is more than a species.

Further, examples of the curing agent that may be added to the thermosetting resin if necessary include phthalic anhydride, hexahydrophthalic anhydride, methylendumethylenetetrahydrophthalic anhydride, and pyromellitic anhydride.
The blending ratio of the thermosetting resin and curing agent may be appropriately selected depending on the type of resin and curing agent used.
For example, when an epoxy resin is used as the thermosetting resin, it is blended so that one mole of the curing agent is bonded to two epoxy groups. Therefore, in the high voltage insulating material of the present invention, the voltage stabilizer in the material is a fused polycyclic aromatic compound having six or more benzene rings and two or more carbonyl groups, a porphyrin nucleus, or a phthalocyanine nucleus. or one or more of the quaternary ammonium salts represented by the above general formula, these voltage stabilizers are added to the thermosetting resin in a predetermined amount (0.1 to 30% by weight). ), it has little curing reaction accelerating effect on the thermosetting resin, so it improves the resin's inherent casting and impregnating properties.
Other electrical properties and mechanical properties can be maintained, and the voltage stabilizer can be extremely stably mixed and dispersed as it is without any modification of the crosslinked structure of the thermosetting resin.

Therefore, according to the present invention, casting and impregnating operations when forming a mold resin layer on an electrical device are facilitated, and furthermore,
The original properties of the thermosetting resin can be maintained, and the dielectric breakdown resistance can be significantly improved. In addition to using the high voltage insulation composition of the present invention in the form of a resin mold as described above, it can also be used in the form of a laminate, paint, or adhesive. When used in electrical equipment in such a form, corona discharge characteristics, tree characteristics, and tracking characteristics can be improved, and precursor phenomena of dielectric breakdown can be suppressed.

Examples of the present invention will be described below.

Examples 1 to 5 For a thermosetting resin obtained by mixing 100 parts by weight of a bisphenol type epoxy resin and 30 parts by weight of phthalic anhydride,
5 parts by weight each of bioanthrone (Example 1), flavanthrone (Example 2), chlorophyll (Example 3), phthalocyanine green (Example 4), and choline bitartrate (Example 5) were blended, and the mixture was heated at 100°C. Five types of high voltage insulating materials were obtained by stirring and mixing at a temperature.

In contrast, as comparative examples, ferrocene (comparative example 1), tetraphenyltin (comparative example 2)
, benzquinone (comparative example 3), chloranil (comparative example 4)
, hexamethylbenzene (Comparative Example 5), and phenyltrimethylammonium chloride (Comparative Example 6).
Parts by weight were blended and stirred and mixed at a temperature of 100°C to produce six types of high voltage insulating materials.

Furthermore, as Comparative Example 7, a high voltage insulating material made only of a thermosetting resin was produced. After the insulating materials of Examples 1 to 5 and Comparative Examples 1 to 7 were vacuum degassed in a vacuum tank, they were transferred to a hot air dryer and 100°C hot air was sent to reduce the viscosity of the insulating materials. The time required for the value to reach 30 poise or more was measured. In addition, after vacuum degassing the insulating materials of the above-mentioned Examples and Comparative Examples except Comparative Example 6, each insulating material was cast into the electrode plate 1 of the withstand voltage measuring device shown in the figure to form a resin mold 2. , force the electrode rod 3 into each mold 2 to form air bubbles 4
Insert so that it forms.

Subsequently, hot air at 100° C. was sent to each mold 2 to cure it, and then the voltage was sequentially increased through the discharge detector 5 to measure the corona start voltage and the corona end voltage within the board. Furthermore, the above Examples 1 to 5, Comparative Examples 1 to 5 and 6
After vacuum degassing the insulating material, it was heated to 100 mW
It was poured into a flat plate with a size of 0 mL x 1 WUfLt, and then this flat plate was stored dry in a desiccator, and the humidity was 6.
The volume resistivity value was measured by applying a DC current of 1000 at 0% room temperature.

The above-mentioned measurement results are shown in Table 1 below.

As is clear from Table 1 above, the high voltage insulating material containing the voltage stabilizer according to the present invention has significantly less curing reaction promoting effect than the insulating material containing the conventional voltage stabilizer. The curing time was approximately the same as that of the thermosetting resin (Comparative Example 7), and it was extremely easy to cast and impregnate electrical equipment.

Furthermore, the starting voltage and ending voltage of corona discharge in a board in a resin mold cast with the high-voltage insulating material of the present invention were higher than those of conventional insulating materials, and an improvement in dielectric breakdown resistance was observed. Furthermore, the volume resistivity of the high voltage insulating material of the present invention is lower than that of conventional insulating materials, making it possible to alleviate localized high electric fields and further improving the dielectric breakdown resistance of the insulating material. Ta. Example 6
~8 Except for using the voltage stabilizer shown in Table 2 below,
i! by the same method as in Example 1. ) Three types of high voltage insulating materials were obtained.

For each of the obtained insulating materials, the time required for the viscosity to reach 30 poise or higher, the corona start voltage, the corona end voltage, and the volume resistivity were examined in the same manner as in Example 1.

The results are also listed in Table 2. As detailed above,
According to the present invention, it is possible to facilitate the casting and impregnating operations into electrical equipment, significantly improving workability, and furthermore, it is possible to significantly improve dielectric breakdown resistance without impairing the electrical and mechanical properties inherent to the thermosetting resin. It is possible to provide an insulating material for high voltage that has remarkable effects such as improved performance.

[Brief explanation of drawings]

The figure is a schematic cross-sectional view of a discharge voltage measuring device used in an embodiment of the present invention. 1...Electrode plate, 2...Resin mold, 4...Bubble.

Claims (1)

[Claims] 1 A thermosetting resin having 6 or more benzene rings,
and a fused polycyclic aromatic compound having two or more carbonyl groups, a compound having a porphyrin nucleus or a phthalocyanine nucleus, or a general formula ▲ Numerical formula, chemical formula, table, etc. ▼ [However, R_1, R_2 and R_3 in the formula are methyl group, ethyl group, propyl group, butyl group, X_1, X_2
, X_3 and X_4 represent a hydrogen atom, a hydroxyl group, a carboxyl group, or a carboxymethyl group, and n represents an integer of 1 to 5. ] A voltage stabilizer consisting of one or more quaternary ammonium salts selected from the following:
High voltage insulating material containing 30% by weight.