Organic compounds -- part of the class 532-570 series – Organic compounds – Sulfur containing
Reexamination Certificate
2005-05-17
2005-05-17
Price, Elvis O. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Sulfur containing
C568S018000, C568S020000, C568S021000, C568S061000, C568S062000, C568S063000
Reexamination Certificate
active
06894194
ABSTRACT:
In a process to make dithiodiglycol by oxidation of β-mercaptoethanol with sulfur, an improved product is recovered when a 1-10 mol % excess of β-mercaptoethanol is used and hydrogen sulfide is removed by vacuum or nitrogen sparge. A typical product contains 88.1 mol % (92.0 wt %) dithiodiglycol, 2.3 mol % (2.9 wt %) trithiodiglycol and 9.6 mol % (5.1 wt %) unreacted β-mercaptoethanol. Reaction of this product with 35 to 50 wt % solution hydrogen peroxide reduces residual β-mercaptoethanol to less than 0.02 wt % mercaptan. Residual water of about 3.6 wt % after hydrogen peroxide treatment is reduced to less than 1 wt % by vacuum stripping and/or nitrogen sparge or with a wiped film evaporator.
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Inkrott Kenneth E.
Matson Michael S.
Pauwels Alex
Chevron Phillips Chemical Company
Price Elvis O.
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