Dielectric impregnant contg. phthalate di:ester - bisphenol=A di:glycidyl ether and oxidn. inhibitor, with low vapour pressure

摘要

A compsn. (I) with dielectric properties contains (A) 90-110 (95-100) pts. wt. of a phthalic acid ester of formula where R1 and R2 are 6-12C branched alkyl gps., (b) 0.05-2 0.1-1)pts of bisphenol A diglycidyl ether, and (c) 0.05-2(0.1-1) pts. of an oxidn. inhibitor. The dielectric constant of (I) at 20 degrees C is generally 4.7-5.5 (4.8-5.3). (I) has a lower vapour pressure than known dielectrics, and does not alter in compsn. on heating. No acid decompsn. prods. are formed on heating; corrosion is thus avoided.