Mixture containing calixarenes, process for the production thereof and use thereof for preparing detergent compositions for lubricants

The present invention relates to mixtures containing calixarenes of formula (I) with a reduced alkyl phenol and linear oligomer content and the preparation process thereof, wherein: a. R is selected between a linear or branched alkyl having a number of carbon atoms comprised between 4 and 40, more preferably between 4 and 24, even more preferably comprised between 8 and 18; b. n is the number of units of the calixarene cycle and is comprised in the range from 4 to 16, preferably between 4 and 12. Furthermore, the present invention relates to detergent compositions containing overbased metal salts of calixarenes, the preparation process thereof and the use thereof in lubricant compositions.