Columbian Chemicals Company

Cities Service Company

Saytech, Inc.

Francis T Wadsworth

Anderson O Dotson, Jr

Lionel T Wolford

(Cyclo)alkylenediammonium compounds corresponding to the formula: ##STR1## wherein X is halogen, R is an alkylene or cycloalkylene group containing 2-15 carbon atoms, each R' alone is an alkyl, cycloalkyl, or aralkyl group, and R'-R' together represent an alkylene, cycloalkylene, or aralkylene group are prepared by esterifying a tetrahalophthalic anhydride with a mono- or dihydroxyalkane, -cycloalkane, or -aralkane having a boiling point below 250.degree. C. to form a half-ester and then reacting the half-ester with a stoichiometric amount of a diaminoalkane or diaminocycloalkane containing 2-15 carbon atoms. The (cyclo)alkylenediammonium compounds of the invention are useful as flame retardants for normally flammable organic polymers and also have utility as intermediates for the preparation of N,N'-(cyclo)alkylene-bis-tetrahalophthalimides, which are also useful as flame retardants. The imides are prepared simply by heating the diammonium compounds.

Process for preparing nitrogen compounds

An alkyl t-alkyl ether corresponding to the formula R--O--R', wherein R is a methyl or ethyl group and R' is a t-butyl or t-amyl group, is separated from the alkanol in a reactor effluent comprising a mixture of the ether, unreacted C.sub.1 -C.sub.2 alkanol, and unreacted hydrocarbon by (1) alternately passing effluent from the reactor through first and second absorption vessels containing fixed beds of solid calcium chloride to complex the unreacted alkanol with the calcium chloride while the ether and unreacted hydrocarbon pass through the vessel, (2) while one absorption vessel is being used to complex unreacted alkanol, regenerating the other absorption vessel by passing a liquid C.sub.4 or C.sub.5 hydrocarbon feed comprising an isoolefin therethrough at a temperature of about 80.degree.-120.degree. C. to desorb the alkanol and provide a desorption effluent of liquid C.sub.4 or C.sub.5 hydrocarbon feed and alkanol, and (3) feeding the desorption effluent to the reactor.

Process for purifying ethers

A C.sub.1 -C.sub.2 alkanol is separated from aqueous calcium chloride by adding a C.sub.4 or C.sub.5 hydrocarbon feed comprising an isoolefin to an aqueous solution of a calcium chloride-alkanol complex wherein the alkanol is methanol or ethanol at a temperature of about 80.degree.-120.degree. C. and a pressure of about 20-180 psig to provide an upper phase comprising the hydrocarbon feed and alkanol and a lower phase comprising aqueous calcium chloride. The invention is particularly useful as a step in a process for preparing and purifying methyl t-butyl ether by (1) reacting an excess of methanol with isobutylene or a C.sub.4 hydrocarbon stream containing isobutylene to form a crude reaction product comprising methyl t-butyl ether and excess methanol, (2) intimately mixing the crude reaction product with aqueous calcium chloride to complex the methanol and separate it from the ether, and (3) adding the hydrocarbon stream to extract the methanol from the aqueous calcium chloride-methanol complex solution.

Process for separating alkanols from aqueous calcium chloride

(Cyclo)alkylenediammonium compounds corresponding to the formula: ##STR1## wherein X is halogen, R is an alkylene or cycloalkylene group containing 2-15 carbon atoms, each R' alone is an alkyl, cycloalkyl, or aralkyl group, and R'---R' together represent an alkylene, cycloalkylene, or aralkylene group are prepared by esterifying a tetrahalophthalic anhydride with a mono- or dihydroxyalkane, -cycloalkane, or -aralkane having a boiling point below 250.degree. C. to form a half-ester and then reacting the half-ester with a stoichiometric amount of a diaminoalkane or diaminocycloalkane containing 2-15 carbon atoms. The (cyclo)alkylenediammonium compounds of the invention are useful as flame retardants for normally flammable organic polymers and also have utility as intermediates for the preparation of N,N'-(cyclo)alkylene-bis-tetrahalophthalimides, which are also useful as flame retardants. The imides are prepared simply by heating the diammonium compounds.

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Trenton, NJ, United States of America

Francis T Wadsworth