Patent GB-688937-A (GB)
Title: A process for producing tertiary alkyl peroxides and the tertiary alkyl peroxides so produced
IPC: C25B3/23
Filed: 1950-09-25
Abstract: <PICT:0688937/IV (b)/1> <PICT:0688937/IV (b)/2> A process for the production of tertiary alkyl peroxides comprises in combination the steps of continuously passing an aqueous solution of a strong non-reducing mineral oxy-acid or a salt thereof through an anodizing zone wherein the solution is electrolysed to produce an aqueous solution comprising the corresponding peroxy acid or salt thereof, and continuously heating the effluent from the anodizing zone with a tertiary alkylating agent in the presence of an acidic catalyst.  The tertiary alkylating agent is defined as a tertiary alcohol, a tertiary alkyl ester of a mineral acid, or a mixture of a tertiary olefin and a mineral acid.  The mineral oxy-acid present in the effluent from the anodizing zone may act as the acidic catalyst. The treatment of the effluent may be carried out in contact with the effluent in contact with an inert water-immiscible organic solvent, for example, a halogen-substituted lower aliphatic hydrocarbon, the tertiary alkyl peroxide being recovered from the organic solvent phase of the reaction mixture.  In the flow diagram shown in Fig. 1, a mineral oxy-acid or salt thereof is conveyed from a storage vessel to the anode compartment of an electrolytic cell 2 (see Group XXXVI). The oxy-acid may be, for example, phosphoric acid or sulphuric acid the latter preferably containing a trace of concentrated hydrochloric or hydrofluoric acid, or potassium cyanide and/or potassium dichromate.  The solution after electrolysis is withdrawn through an outlet 14 and is preferably heated in a preheater 18, though part or all of the liquid may be passed through conduit 19, the solution being led through a conduit 20 to a reactor into which the tertiary alkylating agent is fed in several streams by way of a manifold 22 and valved inlets 23.  The tertiary alkylating agent may be tertiary-butyl alcohol, tertiary-amyl alcohol, or a higher tertiary-aliphatic alcohol, such as the tertiary alcohols obtained by substituting hydroxyl for one or more of the hydrogen atoms which are directly linked to a tertiary carbon atom in aliphatic hydrocarbons and their homologues, as well as their halogenated derivatives in which the halogen atoms are attached to primary or secondary carbon atoms so that the tertiary carbon atoms contain an unsubstituted hydrogen atom.  There may also be used tertiary aliphatic alcohols wherein one or more of the hydrogen atoms of the alkyl radical have been substituted by organic radicals such as aryl, cycloalkyl, alkoxy or ester groups.  The reaction is conducted in the presence of an acid catalyst which may be acid contained in the effluent from the anode compartment of the cell or may be acid from a storage tank connected to the reactor by way of conduits 26, 28 and 25, or by way of conduits 27 and 20.  The effluent from the reactor flows to a settling tank 30 where the organic product phase is separated from the aqueous phase, the organic product phase being withdrawn to storage tanks 32 and the aqueous solution being concentrated in apparatus 34 and recirculated through the process.  In the arrangement shown in Fig. 2, the reactor 37 is supplied, in addition to the effluent from the anode compartment of the cell and the tertiary alkylating agent, with an inert, preferably low-boiling, water-immiscible organic solvent from a vessel 40, the reaction mixture being vigorously agitated.  The mixture is continuously withdrawn by way of conduit 42 and taken to a phase separator wherein the organic solvent phase and the aqueous phase are separated.  The aqueous phase may be in part returned to the reactor through conduits 43, 44, or may be wholly or partly withdrawn through conduit 45, reconcentrated and purified, and returned to the electrolytic cell. The organic solvent phase is passed to an evaporator or stripping column 47 wherein the solvent is flushed overhead, leaving the alkyl peroxide, which is withdrawn through conduit 48 to storage.