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US 2003/0165420 A1Published application
Method for the purification of hydrogen peroxide solutions
AssigneeMerck Patent GmbH
InventorsDietmar Oeter, Claus Dusemund, Ewald Neumann, Klaus Freissler, Martin Hostalek
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Abstract
The invention relates to a novel chromatographic process for the further purification of hydrogen peroxide solutions, giving high-purity solutions which can be employed in semiconductor technology under today's high purity requirements.
Claims9
Process for the further purification of hydrogen peroxide solutions, characterized in that the hydrogen peroxide solutions to be purified, which have concentrations in the range 5-59%, are treated
- a) with an anion exchanger resin,
- b) with a nonionic adsorber resin in the form of a hydrophobic aromatic, crosslinked polymer having a macroporous structure, and
- c) with a neutral adsorber resin from the group consisting of styrene-divinylbenzene resins having a highly macroporous structure, the latter having been formed by pyrolysis treatment of the resin,
- with the proviso that the treatment with the adsorber or exchanger resins can be carried out in any desired sequence, but with the condition that the treatment with the neutral adsorber resin takes place in the final step.
1 more element
Dependencies are inferred from the claim text.