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The C2-4 -alkanolamine salts of alkenyl succinic acid(cas:110-15-6) dialkyl semiamides are used as corrosion inhibitors in aqueous systems.
EXAMPLE 1
Production Method
852 g (8.7 mols) of maleic acid anhydride and 1830 g (10.9 mols) of 1-dodecene are first heated to reflux temperature and thereafter to a temperature of approximately 230° C. in the presence of 9.1 g of 2,6-di-tert.-butyl-4-methylphenol. After stirring for approximately 2 hours at 230° C., the reaction mixture is cooled, the excess olefin is distilled off in vacuo and the dodecenyl succinic acid(cas:110-15-6) anhydride left as residue is freed from polymeric particles by filtration. Yield: 1829 g (70% of theoretical), saponification number 430.
236 g (0.9 mol based on the saponification number) of dodecenyl succinic acid(cas:110-15-6) anhydride are heated under nitrogen to 50° C., followed by the addition of 116 g (0.9 mol) of dibutylamine, during which the temperature may rise to around 90° C. On completion of the addition, the mixture is stirred for about another hour at 100° C. After cooling, dodecenyl succinic acid(cas:110-15-6) mono-dibutylamide is obtained in the form of a clear, highly viscous substance.
Yield: 352 g (quantitative), acid number: 148 (theoretical: 143).
The semiamide is converted into the alkanolamine salts by gentle heating with excess mono-, di- or tri-ethanolamine in the presence of a little water.
EXAMPLE 2
The following succinic acid(cas:110-15-6) semiamides and their alkanolamine salts were produced by the method described in Example 1.
1. Decenyl succinic acid(cas:110-15-6) mono-diisopropyl amide
2. Dodecenyl succinic acid mono-dibutylamide
3. C14/16 -alkenyl succinic acid mono-dibutylamide*
4. C14/16 -alkenyl succinic acid mono-dipropylamide*
5. C14/16 -alkenyl succinic acid mono-di(2-ethylhexyl)-amide*
6. Hexadecenyl succinic acid mono-dibutylamide
7. Isomer-C15/18 -alkenyl succinic acid(cas:110-15-6) mono-dibutylamide** FNT *Starting material α-C14/16 -olefins containing approximately 19% of vinylidene olefins FNT **Olefin (mixture) containing a internal double bond
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