Succinic acid semi-amides as anti-corrosive agents

Abstract

The invention relates to improved compositions based on lubricants and comprising succinic acid semi-amides and to the use of those lubricant compositions in improving the use properties of lubricants, such as hydraulic or metal-working fluids, greases, gear oils or engine oils.

1 . A composition comprising
 a) At least one compound of formula   
     
       
         
         
             
             
         
       
       
         Wherein 
         R 1  is a substituent selected from the group consisting of C 1 -C 22 alkyl, C 2 -C 22 alkyl substituted by hydroxy, C 2 -C 22 alkyl interrupted by —C(═O)—, —O—C(═O)— or by —NR a —C(═O)—, C 3 -C 22 alkyl interrupted by —O—, —S—, —NR a —, —C(═O)—O— or by —C(═O)—NR a —, wherein R a  denotes hydrogen or C 1 -C 22 alkyl, phenyl, benzyl, 1- or 2-phenylethyl, 2-phenoxyethyl, furfuryl, 1-naphthyl, 1-naphthylmethyl, cyclohexyl, cyclohexylmethyl and isobornyl; 
         R 2  and R 3  are hydrogen, or one of R 2  and R 3  is hydrogen and the other is methyl; and 
         X is carboxy or carboxylate and Y +  is a salt-forming cation suitable for lubricant compositions; or 
         X is derivatised carboxy selected from the group consisting of cyano, carboxy esterified by C 1 -C 22 alkyl, carboxy esterified by hydroxy-C 2 -C 22 alkyl, carboxy esterified by C 2 -C 22 alkyl interrupted by —C(═O)—, —C(═O)—O— or by —C(═O)—NR a —, carboxy esterified by C 3 -C 22 alkyl interrupted by —O—, —S—, —NR a —, —O—C(═O)— or by —NR a —(C═O)—, wherein R a  denotes hydrogen or C 1 -C 22 alkyl, carboxy esterified by phenyl, benzyl, 1- or 2-phenylethyl, 2-phenoxyethyl, furfuryl, 1-naphthyl, 1-naphthylmethyl, cyclohexyl, cyclohexylmethyl, isobornyl, and carbamoyl of the partial formula 
       
     
     
       
         
         
             
             
         
       
       
          Wherein R b  and R c  are each independently of the other hydrogen, C 1 -C 22 alkyl or 2-hydroxyethyl, or R b  and R c  together are C 2 -C 8 alkylene, C 2 -C 8 alkenylene, C 2 -C 8 alkadienylene or C 2 -C 8 alkylene, C 2 -C 8 alkenylene or C 2 -C 8 alkadienylene interrupted by —O— or by —NR a —, with R a  being as defined; and 
         Y +  is a hydrogen ion or is a salt-forming cation suitable for lubricant compositions; and 
       
       b) A base oil of lubricating viscosity. 
     
   
   
       2 . A composition according to  claim 1 , comprising
 a) At least one compound (I), wherein
 R 1  is a substituent selected from the group consisting of C 1 -C 22 alkyl, C 2 -C 22 alkyl substituted by hydroxy, C 2 -C 22 alkyl interrupted by —C(═O)—, —O—C(═O)— or by —NR a —C(═O)—, C 3 -C 22 alkyl interrupted by —O—, —S—, —NR a —, —C(═O)—O— or by —C(═O)—NR a —, wherein R a  denotes hydrogen or C 1 -C 22 alkyl, phenyl, benzyl, 1- or 2-phenylethyl, 2-phenoxyethyl, furfuryl, 1-naphthyl, 1-naphthylmethyl, cyclohexyl, cyclohexylmethyl, and isobornyl; 
 R 2  and R 3  are hydrogen, or one of R 2  and R 3  is hydrogen and the other is methyl; 
 X is derivatised carboxy selected from the group consisting of cyano, carboxy esterified by C 1 -C 22 alkyl, carboxy esterified by hydroxy-C 2 -C 22 alkyl, carboxy esterified by C 2 -C 22 alkyl interrupted by —C(═O)—, —C(═O)—O— or by —C(═O)—NR a —, carboxy esterified by C 3 -C 22 alkyl interrupted by —O—, —S—, —NR a —, —O—C(═O)— or by —NR a —(C═O)—, wherein R a  denotes hydrogen or C 1 -C 22 alkyl, carboxy esterified by phenyl, benzyl, 1- or 2-phenylethyl, 2-phenoxyethyl, furfuryl, 1-naphthyl, 1-naphthylmethyl, cyclohexyl, cyclohexylmethyl, isobornyl, and carbamoyl of the partial formula (A), wherein R b  and R c  are each independently of the other hydrogen, C 1 -C 22 alkyl, or 2-hydroxyethyl, or R b  and R c  together are C 2 -C 8 alkylene, C 2 -C 8 alkenylene, C 2 -C 8 alkadienylene or C 2 -C 8 alkylene, C 2 -C 8 alkenylene or C 2 -C 8 alkadienylene interrupted by —O— or by —NR a —, with R a  being as defined; and 
 Y +  is a hydrogen ion or is a salt-forming cation suitable for lubricant compositions; and 
   b) A base oil of lubricating viscosity.   
   
   
       3 . A composition according to  claim 1 , comprising
 a) At least one compound (I), wherein
 R 1  is a substituent selected from the group consisting of C 1 -C 22 alkyl, C 2 -C 22 alkyl interrupted by —C(═O)— or by —O—C(═O)—, C 3 -C 22 alkyl interrupted by —O—, —S— or by —C(═O)—O—, phenyl and benzyl; 
 R 2  and R 3  are hydrogen; 
 X is derivatised carboxy selected from the group consisting of cyano, carboxy esterified by C 1 -C 22 alkyl, carboxy esterified by hydroxy-C 2 -C 22 alkyl, carboxy esterified by C 2 -C 22 alkyl interrupted by —C(═O)— or by —C(═O)—O—, carboxy esterified by C 3 -C 22 alkyl interrupted by —O—, —S— or by —O—C(═O)—, and carbamoyl of the partial formula (A) defined as heterocyclylcarbonyl; and 
 Y +  is a hydrogen ion, ammonium, (C 1 -C 4 alkyl) 1-4 ammonium or (2-hydroxyethyl) 1-4 ammonium; and 
   b) A base oil of lubricating viscosity.