METHOD OF PRODUCTION OF THE ELECTRICAL INSULATING OIL Russian patent published in 2006 - IPC C10G53/04 C10M129/10 C10M133/44 C10N40/14 

FIELD: petroleum refining industry; methods of production of the electrical insulating oil.

SUBSTANCE: the invention is pertaining to the field of petroleum refining industry, in particular, to the method of production of the electrical insulating oil intended for usage as the heat-removing and electrical insulating medium in oil-filled equipment: the oil-filled transformers, capacitors, cables, etc. Substance: the petroleum fraction with bubble point of no less than 270°C at the temperature difference of the beginning of the boiling and the end of the boiling nearby 65-70°C is subjected to the selective refining by N-methyl- pyrrolidone at the following multiplicity of the raw: the dissolvent = 1: no less than 3.7 with the subsequent dewaxing of the produced refined oil and with the adsorption afterpurification of the dewaxed oil. Into the prepared basis introduce the dopes in the following amounts in terms of the oil (in mass %): 2.6-ditret-butyl-4-methylphenol - 0.2-0.7 and 1-(diethylaminomethyl)benzotriazole 0.003-0.1. The adsorption afterpurification of the oil fraction is preferentially exercised by the ground up to achievement of the value of the tangent of the dielectric losses at the temperature of 90°C of no more than 0.5 %. The technical result of the invention is the increase of stability of the electric characteristics of the oil.

EFFECT: the invention ensures the increased stability of the electric characteristics of the oil.

2 cl, 1 tbl, 3 ex