摘要 |
<p>A detergent composition comprises a Mannich reaction product of a hydrocarbyl-substituted ortho-alkyl substituted phenol (1) or a mixture of the phenol (1) and a hydrocarbyl-substituted phenol (2), an aldehyde, and an amine where the phenol (1) is present in the mixture at about 50 mole % or higher. Concentrate and fuel compositions include the detergent composition. A method of controlling deposits in an internal combustion engine comprises operating the engine with the fuel composition which results in unexpectedly superior detergent performance.</p> |