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

Detergent compositions, comprising:

• overbased metal salts of calixarenes not containing sulphur and soluble in lubricant base oil having the following general formula (I):
• wherein:
• a. R is selected from a linear or branched alkyl having a number of carbon atoms ranging from 4 to 40;
• b. n is the number of units of the calixarene cycle and is comprised in the range between 4 and 16;
• said detergent compositions having:
• a content of overbased metallic salts of calixarenes of formula (I), expressed as a percentage by weight with respect to the detergent composition, ranging from 10% to 90%;
• an alkylphenol content of formula (II) and its corresponding metal salt, expressed as the sum of the weight percentages of the alkylphenol and its metal salt with respect to the weight of the detergent composition, less than or equal to 0.29%, wherein the alkylphenol of formula (II) is the following:
• wherein R is as described for formula (I);
• a content of overbased metal salts of linear oligomers of formula (III), expressed as a percentage by weight with respect to the weight of the detergent composition, less than or equal to 15%, wherein such linear oligomers of formula (III) are the following:
• wherein R is as defined in formula (I), R1 and R1 are hydrogen, or the hydroxymethylene group (—CH2OH), and p is comprised between 0 and 6;
• a Total Base Number (TBN) value, expressed in mg KOH/g, between 120 and 550;
• and
• a kinematic viscosity value at 100° C. less than or equal to 600 mm2/s.