Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C407/00—Preparation of peroxy compounds
  • C07C407/003—Separation; Purification; Stabilisation; Use of additives

Definitions

• the present invention is concerned with a process for the production of water free solutions of percarboxylic acids having two to four carbon atoms.
• organic percarboxylic acid solutions can be produced safely if aqueous solutions of percarboxylic acids having two to four carbon atoms, specifically the peralkanoic acids, 'peracetic acids, perpropionic acid, perisobutyric acid and perbutyric acid, are extracted with organic phosphates having three to 30 carbon atoms whereupon the extract is desorbed with an organic solvent, preferably an ester of a carboxylic acid having four to carbon atoms, e.g., an alkyl alkanoate, and the desorbate of percarboxylic acid and solvent dehydrated, in a given case by azeotropic distillation, if necessary after addition of a carboxylic acid ester boiling below the percarboxylic acid.
• an organic solvent preferably an ester of a carboxylic acid having four to carbon atoms, e.g., an alkyl alkanoate, and the desorbate of percarboxylic acid and solvent dehydrated, in a given case by
• aqueous solutions of percarboxylic acids there are preferably employed those prepared by German Pat. Nos. 1,165,576 and 1,170,926. The entire disclosure of these two German patents is hereby incorporated by reference.
• the concentration of the aqueous percarboxylic acid can be between 10 and percent, preferably 20 to 60 percent.
• phosphate esters there can be employed tertiary phosphates of the formula where R R and R are the same or different and are alkyl, aryl or aralkyl and have a total of three to 30 carbon atoms.
• Suitable extraction agents are trimethyl phosphate, tributyl phosphate, trioctyl phosphates, dioctylphenyl phosphate, triethyl phosphate, tripropyl phosphate, triisobutyl phosphate, triamyl phosphate,
• esters employed to aid in the dehydration can be the same as those set forth above so long as they boil below the percarboxylic acid.
• the extraction is preferably carried out continuously, best by countercurrent operation, namely in conventional extraction apparatus such as for example extraction columns with plates or packing with or without pulsation.
• conventional extraction apparatus such as for example extraction columns with plates or packing with or without pulsation.
• packing there can suitably be added rings, saddles or helices.
• plates there can be used perforated plates, tunnel plates or bubble trays.
• the aqueous percarboxylic acid is fed below the top of the column and the phosphate ester at the lower end of the column.
• a largely water free solution of percarboxylic acid is drawn off at the top of the column while the raffinate which contains negligibly small amounts of active oxygen is withdrawn from the lower end.
• the amount of ester used is determined by special solvent loading curve and by the required coucentration of percarboxylic acid.
• the extract is fed to a thin film evaporator, preferably with moving inner zene, toluene, xylene, and ethyl benzene or mixtures of such solvents.
• a thin film evaporator preferably with moving inner zene, toluene, xylene, and ethyl benzene or mixtures of such solvents.
• carboxylic acid esters containing four to 10 carbon atoms or mixtures containing them.
• ylic acid solution on the lower side is determined by mwherein a portion of the solvent is fed to the lower end dustrial considerations and on the upper side by the of the evaporator in vapor form.
• the solutions therefore can contain a is determined likewise by the required concentration of concentration of to 60 percent, preferably to 50 percarboxylic acid. 10 percent of the percarboxylic acid.
• condensation of the desorbate water containing The extraction can be operated at normal pressure at percarboxylic acid solutions in organic solvents are obtemperatures of 5 to 50C., preferably at 10 to C. tained.
• the water content of the so- The azeotropic dehydration and desorption are carried lution, e.g., does not play a disturbing role so that the Out n a Vacuum a! 20 I0 400 TOIT, p a y 5010 250 organic percarboxylic acid solution is usable directly 15 To he sump temperature is to 100C, preferawithout a previous azeotropic distillation. bly to C.
• the invention is further eXPlaihed y the following the desorbate is preferably fed to a continuously operexamples.
• W ating distillation plant which is provided at the top with V EXAMPLES a separator for the water taken off while the percarbox- 20
• a Apparatus Employed The extraction unit wit the y acid Solution is drawn f l he 59mg necessary equipment consisted of a tube 2 meters long If a carboxylic acid ester having ahigher boiling point d having a diameter of 2.8 cm in which the e Were than the percarboxylic acid is used for the desorption located 40 screens having a hole diamete o 1 then there must be added to the desorbate a carboxylic: The column was pulsated with a pulsation pump and acid ester having a lower boiling point than the percar- 25 operated in countercurrent manner.
• the amount of lower boiling ester can be determined by one skilled in the art by a simple preliminary test.
• organic solvents which are lower boiling than the phosphate esters for example carboxylic acid esters such as those set forth above, chlorinated hydrocarbons, e.g., carbon tetrachloride, chloroform, ethylene dichloride, acety-
• chlorinated hydrocarbons e.g., carbon tetrachloride, chloroform, ethylene dichloride, acety-
• peracids e.g., perpropionic acid and perisobutyric acid can be extracted with equally good success.
• the yield of active oxygen and the purity of the product in such cases corresponds to that with peracetic acid.
• Example C Pressure 250 Torr; Head Temperature: about 42C.
• a process forv the production of water free solutions of percarboxylic acids having two to four carbon atoms comprising extracting the aqueous solution of the percarboxylic acid with a tertiary phosphate ester having three to carbon atoms and desorbing the extract with a solvent for said percarboxylic acid selected from the group consisting of hydrocarbyl alkanoates having four to 10 carbon atoms, chlorinated aliphatic hydrocarbons and aromatic hydrocarbons, said solvent boiling lower than said phosphate ester.
• R R and R are alkyl, aryl or aralkyl.
• a process according to claim 2 including the additional step of removing the final amount of water from the desorbate by azeotropic distillation with a hydro- 4.
• phosphate ester is trimethyl phosphate, tributyl phosphate or trioctyl phosphate.
• hydrocarbyl alkanoate is an alkyl alkanoate.
• hydrocarbyl alkanoate is an alkyl alkanoate or cyclohexyl alkanoate.
• a process according to claim 2 including the ad- 14.
• a process according to claim 13 wherein the alkyl acetate is ethyl acetate.
• the solvent is selected from the group consisting of ethyl acetate, propyl acetate, butyl acetate, amyl acetate, 2- ethyl-hexyl acetate, cyclohexyl acetate, t-butyl acetate, isoamyl acetate, propyl formate, butyl formate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl valerate, sec.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (2)

• 1971
  • 1971-09-13 DE DE2145604A patent/DE2145604A1/de active Pending
• 1972
  • 1972-06-23 NL NL7208670A patent/NL7208670A/xx not_active Application Discontinuation
  • 1972-07-25 US US00274965A patent/US3839216A/en not_active Expired - Lifetime
  • 1972-09-07 GB GB4155072A patent/GB1358333A/en not_active Expired
  • 1972-09-08 SU SU721827028A patent/SU593661A3/ru active
  • 1972-09-12 BE BE788729D patent/BE788729A/xx unknown
  • 1972-09-13 CA CA151,625A patent/CA966857A/en not_active Expired
  • 1972-09-13 FR FR7232464A patent/FR2152923B1/fr not_active Expired
  • 1972-09-13 JP JP9220472A patent/JPS5317576B2/ja not_active Expired

Patent Citations (2)

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