Production of peroxydicarbonates

In a process for preparing peroxydicarbonate represented by the formula R--OCO--OO--OCO--R wherein R is an alkyl or cycloalkyl radical derived from a monohydric alcohol and containing up to 18 carbon atoms by reacting, at a temperature of from -10.degree. C. to 30.degree. C., a chloroformate of the formula R--OCO--Cl, wherein R is as defined above, with hydrogen peroxide and alkali metal hydroxide and recovering undiluted peroxydicarbonate from the reaction mixture, wherein the improvement resides in adding aqueous alkali metal hydroxide solution, containing from 20 percent to 40 percent by weight alkali metal hydroxide, to a continuously stirred batch of an aqueous unemulsified, non-colloidal mixture consisting essentially of chloroformate and hydrogen peroxide the mixture containing from 4 to 12 percent stoichiometric excess of hydrogen peroxide based on the quantity of chloroformate and having a hydrogen peroxide content of from about 10 percent to about 35 percent by weight based on the quantity of water in the mixture, sufficient alkali metal hydroxide solution being added to the mixture so as to provide from 1 to 10 percent stoichiometric excess of alkali metal hydroxide based on the quantity of chloroformate in the mixture.