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US 6,761,832 B1Granted
Process for the production of dithiophosphoric acid polysulfide mixtures
AssigneeRhein Chemie Rheinau GmbH
InventorsLudger Heiliger, Alfred Pauli, Joachim Hegmann, Clemens Schudok, Thomas Früh
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Abstract
This invention relates to a process for the production of dithiophosphoric acid poly-sulfide mixtures, which is characterized in that dithiophosphoric acid disulfides are reacted with sulfur at elevated temperatures. The dithiophosphoric acid polysulfide mixtures produced using the process according to the present invention are used as sulfur donors for the vulcanization of natural and synthetic rubbers and in the latex vulcanization of natural and synthetic rubber latex.
Claims1
A process for the production of dithiophosphoric acid polysulfide mixtures of the formula
- in which
- R1 to R4 are identical or different and denote a linear or branched C1-C18 alkyl residue, C1-C18 alkenyl residue, C5-C28 cycloalkyl residue, C5-C28 cycloalkenyl residue as well as a C6-C28 aryl residue or C7-C28 aralkyl residue and
- n denotes a number from 2.5 to 3.5,
- comprising the step of reacting dithiophosphoric acid disulfides of the formula
- in which
- R1 to R4 have the above-stated meaning,
- with 0.5 to 1.5 mol of sulfur, optionally in the presence of a solvent, at temperatures of 100 to 140° C.
4 more elements
Dependencies are inferred from the claim text.