Study Of Synthesis Calcium-magnesium Salicylate Composite Detergent

Salicylate is an important class of lubricant detergents. With higher total base number,low ash, stronger neutralization capability，magnesium salt detergents have been developingquickly in recent years. Because these two kinds of detergents have good synergistic effect，they are usually taken in a compound form in practical application. Compared to other metaldetergents (sulfonate, alkylphenol), salicylate have the excellent acid neutralization capacity,high temperature detergency, anti-oxidaation stability and hydrolysis stability. Presently，themost widely used lubricant detergents are sulfonate.Although these two koinds of detergentsare also takin in a compounde form in practice, the sedimentation phenomena sometimesoccur when detergents compounded with each other.In view of the above circumstance,usingthe salicylic acid from Lanzhou petrochemical company and the ammonium sulfonate fromYumen petrochemical factory as raw materials，studies on the synthesis process conditions ofcalcium-magnesium salicylate composite detergents and calcium-magnesiumsalicylate/sulfonate composite detergents are optimized by single factor and orthogonalexperiments. The main contents and conclusions are summarized as follow:(1) The optimum conditions of synthesis calcium-magnesium salicylate compositedetergents is determined as follow:under the conditions of salicylic acid80g, calcium oxide5g,xylene160mL, magnesium oxide20g, water10mL, ammonia water6mL, methanol20mL, carbonation temperature45～50℃, carbonation times3hours,carbon dioxide120mL min-1，salt reaction time1hour. The base number of product synthesized by the optimumconditions is higher than350mgKOH g-1. The distribution of colloidal particles in product ishomogeneous. The average diameter of colloidal particles is about40nm. The properties ofthe lubricating oil can be improved after adding the product.(2) The optimal dosage of main materials in synthesis calcium-magnesiumsalicylate/sulfonate composite detergents is determined as follow: under the condition of thetotal dosage of salicylic acid and ammonium heavy sulfonate is80g, ammonium heavysulfonate8g, magnesium oxide22g, water10mL, ammonia water6mL, methanol20mL. Thebase number of product synthesized by the optimum conditions is higher than400mgKOH g-1.The properties of the lubricating oil can be improved after adding the product. (3)The comprehensive property of calcium-magnesium salicylate/sulfonate compositedetergents is superior to that of calcium-magnesium salicylate composite detergents.