Process for preparing high purity epichlorohydrin
First Claim
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1. A process for preparing high-purity epichlorohydrin from epichlorohydrin containing technical impurities, which comprises the steps of:
- preheating technical epichlorohydrin to a temperature below its boiling point; and
fractionally distilling said preheated technical epichlorohydrin at a pressure of 0.2 to 1.05 bar in a column having at least 15 theoretical plates and which is provided with heating or evaporating means located at or near the sump of the column, inlet means for introducing technical epichlorohydrin at an intermediate point in said column, and outlet means for withdrawing high-purity epichlorohydrin at a point above said inlet means,wherein said preheated technical epichlorohydrin is introduced into said column at a distance from said evaporation or heating means which is greater than one-tenth of the total length of the column, and the high-purity epichlorohydrin is withdrawn at a distance from said evaporation or heating means which is greater than one-third of the total length of the column,and wherein the temperature difference between said preheated technical epichlorohydrin introduced into the column and the operational epichlorohydrin introduced into the column and the operational temperature in the column is 50°
C. or less.
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Abstract
The present invention relates to a process for preparing ultrapure epichlorohydrin from epichlorohydrin containing technical impurities, by fractional distillation under particular conditions, preferably with continuous operation, that yield a product of very high purity and very low content of halogenated hydrocarbons. Epoxy resins made with such ultrapure epichlorohydrin are especially well suited for use in fabricating electrical components and microchips.
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14 Claims
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1. A process for preparing high-purity epichlorohydrin from epichlorohydrin containing technical impurities, which comprises the steps of:
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preheating technical epichlorohydrin to a temperature below its boiling point; and fractionally distilling said preheated technical epichlorohydrin at a pressure of 0.2 to 1.05 bar in a column having at least 15 theoretical plates and which is provided with heating or evaporating means located at or near the sump of the column, inlet means for introducing technical epichlorohydrin at an intermediate point in said column, and outlet means for withdrawing high-purity epichlorohydrin at a point above said inlet means, wherein said preheated technical epichlorohydrin is introduced into said column at a distance from said evaporation or heating means which is greater than one-tenth of the total length of the column, and the high-purity epichlorohydrin is withdrawn at a distance from said evaporation or heating means which is greater than one-third of the total length of the column, and wherein the temperature difference between said preheated technical epichlorohydrin introduced into the column and the operational epichlorohydrin introduced into the column and the operational temperature in the column is 50°
C. or less. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification