Selective alkylation method for producing p, p′-di-alkylated diphenylamine antioxidants
US9890346B2 · kind B2 · utility
1Cited by
6References
11Claims
0Family size
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Key dates
| Filing date | Jun 29, 2015 |
| Grant date | Feb 13, 2018 |
| Priority date | — |
| Expiry date | Jun 29, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2030/10
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Liquid diphenylamine compositions comprising predominately p,p′-di-alkylated diphenylamines and low amounts of mono-alkylated diphenylamines are prepared by adding an olefin to a mixture comprising mono-alkylated diphenylamines, di-alkylated diphenylamines, Lewis acid catalyst and an amount of another olefin sufficient to suppress dealkylation of the alkylated diphenylamines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.