Abstract: The present invention provides a process of preparing terephthalic acid of high quality which is characterized by:oxidizing p-xylene with molecular oxygen in an acetic acid solvent in the presence of a catalyst comprised of at least one heavy metal and bromine at a temperature of from 180.degree. to 230.degree. C. to convert at least 95 wt % of the p-xylene into terephthalic acid and, optionally, subjecting the resultant reaction mixture to low temperature post-oxidation with molecular oxygen at temperatures lower than the temperature of the first oxidation reaction, thereby obtaining a slurry containing terephthalic acid particles whose spectral reflectance defined below is not less than 70% and whose reflectance ratio (400/500) defined below is not less than 0.92;subjecting the slurry to high temperature post-oxidation with molecular oxygen at a temperature of from 235.degree. to 290.degree. C. and then to crystallization; andcollecting the resultant terephthalic acid from the reaction mixture.

Abstract: A method is disclosed for preparing a substituted cyclic carboxylic acid from a corresponding substituted cyclic hydrocarbon. The hydrocarbon is oxidized in oxygen or air in a liquid phase in an organic solvent under alkaline conditions, in the presence of a catalyst selected from the group consisting of metal tetraphenylporphins, metal acetylacetonates, metal phthalocyanines and mixtures thereof. The oxidation is capable of proceeding generally at room temperature and atmospheric pressure.

Abstract: The preparation, structure, and properties of solid inorganic materials containing cobalt, boron, oxygen and, optionally, aluminum, is described. Also described is the use of such materials in catalytic compositions for the conversion of organic compounds. In particular, the new material Co(BO.sub.2)OH is described as well as the use of such material in various catalyzed processes including oxidation of organic compound processes. A particularly useful process is a heterogeneous catalyzed partial oxidation of an alkylaromatic followed by complete oxidation to an aromatic polycarboxlic acid in a water phase.

Abstract: A method for the continuous, catalytic production of an aromatic carboxylic acid product by liquid-phase, exothermic oxidaion of an aromatic alkyl with an oxygen-containing gas and a solvent medium in an oxidation reactor and utilizing reverse osmosis is disclosed. In particular, a multiple ingredient or component-containing slurry product stream is withdrawn from the reactor, the slurry product stream is then separated to produce a product-containing stream and at least one mother liquor stream which contains, in addition to a number of desirable process stream components, such as oxidation reaction catalysts, a number of undesirable process stream impurities. The impurities are selectively removed from the mother liquor stream by passing at least a portion of the mother liquor stream through a reverse osmosis separation device to produce a catalyst-bearing stream having a relatively lesser impurities-to-catalyst weight ratio and a purge stream having a relatively greater impurities-to-catalyst weight ratio.

Abstract: The present invention provides a process for producing aromatic ether bismaleimides of the Formula (II) ##STR1## wherein A is a divalent mononuclear or polynuclear aromatic linking group. The process provides good yields and can be scaled up readily to commercial size runs.The present invention also provides compositions containing at least about 80 weight % of the bismaleimide of Formula (II) above.

Abstract: The yield of dimethyl terephthalate obtained by the oxidation of a mixture of p-xylene and methyl p-toluate, preferably with air, and esterification of the thus-produced acids is increased by utilizing a mixture of cobalt and manganese compounds as the oxidation catalyst.

Abstract: Disclosed herein is a process for producing a highly pure produce of 2,6-naphthalenedicarboxylic acid in a large quantity at a moderate price by oxidizing 2,6-diisopropylnaphthalene while using a water-soluble salt of cobalt, a water-soluble salt of maganese or a mixture thereof, a water-soluble salt of cerium and a bromine compound as the catalyst of the oxidation.

Abstract: A catalyst, a process for preparing said catalyst, and a process for producing purified terephthalic acid, wherein 4-carboxybenzaldehyde is reduced to very low levels, wherein said catalyst is prepared by contacting a solution of a suitable palladium salt in an organic solvent with a suitable activated carbon support, wherein said palladium salt is reduced to palladium metal crystallites by said activated carbon support. Purified terephthalic acid is prepared by hydrogenating crude terephthalic acid in the presence of said catalyst.

Abstract: A novel method of oxidizing di- and trimethylbenzenes with molecular oxygen to the corresponding di- or tricarboxylic acid under liquid-phase conditions is disclosed. The process is conducted at a temperature of about 100.degree. C. to 260.degree. C. This process comprises conducting the oxidation in the presence of a catalyst system comprising a source of bromine with nickel, manganese and zirconium. The benzene di- and tricarboxylic acids have wide industrial application, including the manufacture of polyesters, polyamides, and fibers and films.

Abstract: A process is disclosed for recovery of cobalt and manganese, and other metals, in the form of their acetate salts, directly from mixed metal oxides present in oxidation residue incinerator ash comprising fly ash and clinkers from incineration of a residue from manufacture of benzene di- and tricarboxylic acids by catalytic means. These acetate salts are recycled directly for manufacture of benzene di- and tricarboxylic acids after recovery.

Abstract: A process for producing fiber grade terephthalic acid is disclosed. In this process impurities having high molecular weight are eliminated by hydrogenation comprising the following steps: (a) treating an aqueous solution containing at least about 1 percent of said impure terephthalic acid with hydrogen at a temperature in the range of about 300.degree. F. to about 450.degree. F. and at a pressure sufficient to maintain the solution in the liquid phase in the presence of a supported or unsupported metallic Group VIII noble metal catalyst wherein both the metal and support components are insoluble in the solution at the temperature and at a hydrogen partial pressure of from about 30 to about 300 pounds per square inch; (b) separating the treated solution from the catalyst; (c) crystallizing terephthalic acid from the separated solution while retaining impurities and the reduced aromatic compounds dissolved in the resulting mother liquor at a temperature in the range of about 100.degree. F. to about 450.degree.

Abstract: A method of recovering useful components at least containing dimethyl terephthalate from high-boiling byproducts occurring in the production of dimethyl terephthalate, which comprises oxidizing p-xylene and/or methyl p-toluate with a molecular oxygen-containing gas in the presence of a heavy metal oxidation catalyst, subjecting the resulting oxidation product to esterification with methanol, separating dimethyl terephthalate and esters having lower boiling points than dimethyl terephthalate from the esterification reaction product by distillation, and thereafter treating the distillation residue containing byproducts having higher boiling points than dimethyl terephthalate with methanol to recover at least dimethyl terephthalate from the treated product; wherein the treatment of the distillation residue with methanol is carried out at a temperature of 110.degree. to 240.degree. C. under a pressure sufficient to maintain methanol in the liquid phase.

Abstract: A novel process for producing oxygen-containing organic compounds with high selectivity and good yield by oxidizing organic compounds under mild conditions is provided, which process comprises using as a catalyst for the oxidation, a complex (M.sub.m X.sub.n.L.sub.l) consisting of a transition metal compound (M.sub.m X.sub.n) and an organic phosphorous compound (L) as a ligand, wherein M represents a transition metal belonging to group I, group IV.about.VII or iron group in group VIII of the periodic table; X represents an anion such as a halogen; ligand L represents an organic phosphorous compound; and m and n mean a number of the atomic valence of said transition metal (ion) M and said anion X, respectively, and l means a number of said ligand.

Abstract: The invention relates to a process for preparing purified, virtually odorless, solid benzoic acid obtained from toluene by oxidation with a gas containing molecular oxygen, by means of a treatment using an inert gas or gas mixture, wherein the benzoic acid to be purified is supplied in a liquid state to a fluid or spouted bed granulator in which the prevailing temperature is below the solidification temperature of the benzoic acid and in which the benzoic acid is treated, during and possibly after the granulating process, with the said gas or gas mixture, the impurities present being taken up in whole or in part in the gas or gas mixture, upon which the benzoic acid thus purified is removed from the fluid or spouted bed device.

Abstract: The temperature of the exit gas from the gas washer in the preparation of phthalic anhydride by catalytic oxidation of naphthalene or o-xylene with air is increased by a method in which flue gas from the combustion furnace for residues is mixed with the exit gas before the latter emerges into the atmosphere.

Abstract: A process for the production of terephthalic acid from p-xylene and methanol by way of the dimethyl terephthalate obtained by oxidation, in the liquid phase with atmospheric oxygen in the presence of dissolved heavy metal compounds as the catalyst, of a mixture of p-xylene and a fraction containing predominantly methyl p-toluate, which fraction is recycled into the oxidation, to obtain an oxidation product containing primarily p-toluic acid and monomethyl terephthalate at a temperature of 140.degree.-170.degree. C. and under a pressure of 4-8 bar; by esterification of the oxidation product in a reactor with liquid and subsequently vaporized methanol brought to an elevated pressure, at a temperature of 220.degree.-280.degree. C.

Abstract: A process for the production of dimethyl terephthalate from p-xylene and methanol by oxidation in a reactor, in the liquid phase with atmospheric oxygen in the presence of dissolved heavy metal compounds as a catalyst, of a mixture of p-xylene and a fraction containing predominantly methyl p-toluate, which fraction is recycled into the oxidation, to obtain an oxidation product containing primarily p-toluic acid and monomethyl terephthalate, at a temperature of 140.degree.-170.degree. C. and under a pressure of 4-8 bar; by esterification of the oxidation product with liquid and subsequently vaporized methanol brought to an elevated pressure, at a temperature of 220.degree.-280.degree. C.

Abstract: The present invention provides an improved process for the purification of crude terephthalic acid which has been produced by the oxidation of para-xylene. The process comprises contacting the crude terephthalic acid with oxygen-containing gas at a temperature of about 190.degree. to 230.degree. C. and a pressure of about 1500 to 3600 kPa in the presence of a solvent comprising an alkanoic acid which is preferably acetic acid. The process further comprises the use of a novel and surprisingly effective catalyst system. The catalyst system comprises cobalt, a bromine source, and pyridine.

Abstract: 2,2',6,6'-Tetramethyl-4,4'-dicarboxylic acid is prepared by the oxidation of bimesityl and derivatives of the dicarboxylic acid are used in the preparation of polyesters of high molecular weight.

Abstract: The invention is concerned with a method of purifying benzoic acid, as obtained by catalytic oxidation of toluene and purification by rectification with the secondary streams being cycled back into the oxidation reactor, characterized in that the secondary streams flowing out of the stripping column undergo the following sequential steps: (a) at least one distillation and at least one crystallization in an organic solvent; (b) scrubbing of the crystals obtained from (a) with the same solvent as in (a); (c) cycling of the mother liquors from crystallization in (a) plus the scrubbing liquors as in (b) back into the dissolver; (d) further scrubbing of the crystals from (b) with the same solvent as in (a) and cycling back of the scrubbing liquors, the crystals scrubbed as in (d) being optionally (d1) further scrubbed with water.

Abstract: Pharmaceutical benzoic acid is prepared from raw benzoic acid made of oxidation of toluene with an oxygen containing gas, the process is characterized in that the oxidation reaction product is contacted with at least 1 m.sup.3 per kg of benzoic acid of a gas with a critical temperature lower than 435 K by passing this gas through the oxidation reaction product at a flow rate of at least 1 m.sup.3 per hour per kg of benzoic acid at a temperature of 340-600 K. and a pressure of at least 3 MPa. The pharmaceutical benzoic acid is separated from the mixture by cooling it to 315-370 K. at a pressure of 3-300 MPa.

Abstract: Benzoic acid is prepared by oxidation of toluene with an oxygen containing gas, the process is characterized in that the oxidation reaction product is subjected to an extraction with a gas of which the critical temperature is lower than 435 K, this being effected by passing it during at least 1 minute over or through the oxidation reaction product at a flow rate of at least 1 m.sup.3 gas per hour per kg of benzoic acid at a temperature of 285-340 K and at a pressure of at least 3 MPa.

Abstract: A process for the removal of para-toluic acid from purified terephthalic acid is disclosed. This process comprises extracting the para-toluic acid with paraxylene from the aqueous terephthalic acid-water phase and recycling the para-toluic acid and paraxylene to the paraxylene oxidation reactor. The process improves the overall yield of purified terephthalic acid recovered. Purified terephthalic acid is used as a basic raw material in the manufacture of polyester fibers and films.

Abstract: A process is provided for the recovery and recycling of spent cobalt and/or manganese catalysts used in the air oxidation of alkyl aromatics in acetic acid. The catalysts are isolated in the form of oxalates of extremely low solubility from the acetic acid mother liquors and the cobalt oxalate dihydrate and/or manganese oxalate dihydrate catalysts are restored by the joint action of hydrogen bromide and acetic anhydride, acetyl bromide, or a mixture thereof, to a form in which they are soluble in acetic acid and can be used, again, as oxidation catalysts.

Abstract: In a process for the isolation of cobalt and/or manganese in the form of precipitated, easily filtrable cobalt and/or manganese oxalates from acetic acid solutions or extracts, the solutions in question are treated with oxalic acid dimethyl or diethyl ester at temperatures of 50.degree. to 250.degree. C.

Abstract: In a process for the recovery of cobalt oxalate and/or manganese oxalate, the solutions or extracts containing cobalt and/or manganese are treated with sodium, potassium or ammonium oxalate. To obtain an easily filtrable cobalt and/or manganese oxalate precipitate, the precipitation is performed at temperatures of 50.degree. to 160.degree. C. with 1 to 2 moles of solid alkali oxalate or ammonium oxalate. When sodium oxalate is used, the water content of the solutions or extracts is from 5 to 90% by weight, when potassium oxalate is used it is from 2 to 15% by weight, and when ammonium oxalate is used it is from 1 to 12% by weight.

Abstract: An improved process for the catalytic oxidation of propylene to acrylic acid the improvement comprising conducting the process in the presence of an effective amount of hydroquinone. The improved process is particularly applicable to the aqueous liquid phase reaction of propylene with molecular oxygen using a supported palladium catalyst.

Abstract: A process for purifying aromatic polycarboxylic acid produced by liquid phase catalytic oxidation of polyalkyl aromatic hydrocarbon to remove undesirable aldehyde aromatic carboxylic acid and other impurities including the step of contacting an aqueous solution of said impure acid and hydrogen with a noble metal-containing catalyst, our improvement comprising eliminating any gas phase during the contacting step and conducting said contacting step with said aqueous solution by maintaining hydrogen at about 10 to about 75 percent of saturation in the liquid reaction medium to produce purified aromatic polycarboxylic acid having delta Y values below ten.

Abstract: A stabilized heteropoly molybdate catalyst precursor in calcined form and containing anionic molybdenum in defect state is surface impregnated with certain metal cations. The stabilized precursor is one obtained by incorporating into the reaction product of a molybdate and a soluble phosphate, silicate or arsenate, an aqueous chloride ion and a compound of phosphotungstate, silicotungstate, vanadium arsenate, silico-arsenate, phosphovanadate, or silicovanadate, followed by drying and calcining. During the chloride ion stabilization step other metals may be optionally incorporated in forming the stabilized precursor.The obtained precursor is catalytically active in the conversion of the unsaturated aldehydes to the corresponding unsaturated carboxylic acids with or without incorporation of the metal cation during the chloride ion stabilization step.

Abstract: A process for continuously producing high purity terephthalic acid, in particular, useful for direct polymerization, which comprises continuously introducing p-dialkylbenzene as a feed material together with a solvent and an oxidation catalyst into a reactor, subjecting the p-dialkylbenzene to a liquid phase oxidation with oxygen in the reactor to produce terephthalic acid, continuously or intermittently introducing the reaction mixture containing terephthalic acid thus produced into a stabilizer, and oxidizing the reaction mixture in the stabilizer for an extended period of time with a molecular oxygen containing gas of a low oxygen concentration at a temperature and pressure the same as or lower than those in the oxidation reaction while keeping the volume change of the contents in the stabilizer below about 30% by volume of the contents of the stabilizer.

Abstract: The reaction mixture obtained by oxidizing p-xylene in the presence of water as diluent, at a temperature comprised between 140.degree. and 220.degree. C., and consisting of terephthalic acid crystals in suspension in an aqueous solution comprising unreacted p-xylene, intermediate oxidation products thereof, the heavy-metal catalyst and water is introduced in the upper part of a sedimentation column wherein the acid is separated by gravity and is washed with a counter current of water introduced near the bottom of said column, the temperature of the washing zone being higher than the minimum value T.sub.w given by the equation T.sub.w =144+0.225 T.sub.R, wherein T.sub.R is the oxidation temperature.

Abstract: A filter cake of crude isophthalic acid is dispersed as a slurry in acetic acid, and thereafter heated to a temperature bringing about the dissolving of the isophthalic acid. Such hot solution is subjected to very rapid evaporative crystallization in a single crystallization zone maintained at a pressure at which volatilization of the acetic acid occurs and at a temperature within the range of 180.degree.-250.degree. F., the heat input being controlled to promote such very rapid volatilization that more than half of the solvent quickly is volatilized. Moreover, more than half of the isophthalic acid content of the effluent is in the solids suspended in the slurry of such effluent. Because the volatilization is so rapid, only a relatively short residence time in the single crystallization zone is required for obtaining an effluent suitable for transfer to a separation zone. Isophthalic acid crystals are separated from the mother liquor in such separation zone.

Abstract: A process for the preparation of dimethyl terephthalate by the oxidation of p-xylene/methyl p-toluate mixtures, preferably with air, esterification of the resulting acid products, and recycling of the methyl p-toluate to the oxidation stage, employs an oxidation catalyst consisting of a combination of cobalt and manganese compounds. The concentration of manganese (Mn.sup.++) ranges between about 0.0001% and about 0.005% by weight.

Abstract: A novel vertical induced circulation reactor is utilized to carry out the oxidation of p-xylene and p-methyltoluate with air in the presence of a catalyst to produce p-toluic acid and monomethylterephthalate (MMT). A novel method for preparation of dimethylterephthalate (DMT) is provided wherein the p-toluic acid and MMT formed according to the invention are esterified by conventional means in the presence of methanol to produce p-methyl toluate and dimethylterephthalate (DMT), respectively, the p-methyl toluate being recycled to the reactor as a reactant stream.

Abstract: A process for the preparing of a benzene-monocarboxylic acid by oxidation of a monoalkyl-benzene compound in the liquid phase with the aid of a gas containing molecular oxygen in the presence of a catalyst composed of a cobalt and a manganese compound, both of which are soluble in the reaction mixture, with a manganese-cobalt atomic ratio between 1:500 and 1:100,000, thus improving the selectivity of the reaction to form the desired benzene-monocarboxylic acid.

Abstract: A process and an apparatus for producing an aromatic dicarboxylic acid by oxidizing a benzene derivative with molecular oxygen in the liquid phase in a lower aliphatic carboxylic acid as a solvent in the presence of an oxidation catalyst, wherein a starting material liquid e.g., a benzene derivative or a solution thereof in the lower aliphatic carboxylic acid, is fed into the liquid-phase reaction system in a uniformly dispersed state by being passed through a porous material causing the pressure of the starting material liquid just after passing through said porous material to drop more than about 1 kg/m.sup.2 in relation to the pressure of the starting material liquid just before passing through said porous material. The resultant aromatic dicarboxylic acid has high purity and has good color.

Abstract: A substituted aromatic compound e.g. p-xylene is oxidized to an aromatic dicarboxylic acid e.g. terephthalic acid using a Co/Mn/Br catalyst in acetic acid and the slurry product is purified by treating with molecular oxygen and diluting with fresh acetic acid before separation of the terephthalic acid and mother liquor.

Abstract: This invention relates to the preparation of o-phthalic acid by the oxidation of liquid o-xylene with a source of molecular oxygen at a temperature in the range of from 150.degree. C. up to 235.degree. C. in the presence of catalysis provided by the combination of components which include a source of bromine and at least cobalt as metal oxidation catalyst, in the presence of liquid water in an amount to activate said catalysis and solubilize a catalytically effective amount of metal oxidation catalyst in liquid phthalic acid and under conditions which retain substantially all the o-phthalic acid in the free acid form but in the absence of any material extraneous to the oxidation reaction or its products as solvent.Such preparative process results in yields of 85 to 92 mole percent and higher to o-phthalic acid in but a single oxidation step with recycle thereto of only o-xylene vaporized from the reaction zone and recovered.

Abstract: Methyl-substituted polyphenylacyl compounds are prepared by selective oxidation of oligomers of mesitylene. These methyl-substituted polyphenylacyl compounds are useful as intermediates for polyamides and polyesters. The esters are useful as plasticizers for polyvinylchloride.

Abstract: Benzoic acid is produced from process residues resulting from the liquid phase air oxidation of toluene by a process in which(a) a benzyl benzoate-rich fraction is separated from the spent catalyst and high-boiling reaction by-products in the process residue;(b) the benzyl benzoate-rich fraction is contacted with an oxygen-containing gas in the presence of an oxidation catalyst at 130.degree.-200.degree. C./1-10 atmospheres until 25% to 60% of the benzyl benzoate has been oxidized to benzoic acid, and(c) benzoic acid is recovered from the oxidation product mixture.

Abstract: There is disclosed a process for preparing terephthalic acid by oxidizing p-xylene which comprises contacting a substantially liquid mixture of p-xylene with p-toluic acid and water wherein the molar ratio of p-toluic acid to p-xylene is between about 0.01 and about 100 and the molar ratio of water to p-toluic acid is between about 0.4 and about 60, with a molecular oxygen-containing gas in the presence of an oxidation catalyst.

Abstract: An oxidizable hydrocarbon is oxidized in a reaction zone at elevated temperature in the presence of a liquid reaction medium by introducing the hydrocarbon and a feed stream containing molecular oxygen to the reaction zone under conditions sufficient to oxidize at least a portion of the hydrocarbon; withdrawing at least a portion of the liquid reaction medium from the reaction zone; passing at least a portion of the withdrawn liquid reaction medium to an oxygen injection zone located external to the reaction zone; contacting the liquid in said oxygen-injection zone with a gas stream containing molecular oxygen under conditions sufficient to form a two-phase gas/liquid mixture; and passing said two-phase gas/liquid mixture to the reaction zone as the feed of molecular oxygen thereto.

Abstract: Process for producing isophthalic acid by direct oxidation of m-toluic acid or a mixture of m-toluic acid with m-xylene and partially oxidized intermediates under mild conditions without the presence of consumable organic solvents or corrosive bromine promoters comprising forming a homogeneous, aqueous mixture of said substrate containing from 10 to 80 weight percent water and an active catalyst comprising a manganese compound or a mixture of a maganese compound and a cobalt compound, the minimum concentration (M) of catalyst in said mixture in millimoles per kilogram of mixture being given by the equation ##EQU1## wherein x is the mole fraction of maganese in the catalyst, y is the mole ratio of water to m-toluic acid and z is the ratio of dissolved isophthalic acid to m-toluic acid, the maximum concentration of catalyst being not more than about 40 millimoles catalyst per kilogram of mixture and reacting said substrate with a molecular oxygen-containing gas at a temperature from about 140.degree. to 220.

Abstract: A process for preparing terephthalic acid is disclosed which comprises the steps of oxidizing a substantially homogenous liquid reaction mixture, comprising p-toluic acid, optionally in admixture with p-xylene and partially oxidized p-cylene derivatives, an amount of between 5% and 80% by weight of water, and an oxidation catalyst comprising a catalytically-active metal compound such as manganese compounds, cobalt compounds or mixtures thereof, with an oxygen-containing gas. At least a minimum amount of M millimoles of the catalytically-active metal compound per kg of the liquid reaction mixture is used, wherein M is defined by the following equation (1) ##EQU1## wherein y represents the molar ratio of water/p-toluic acid in the reaction mixture,x represents the molar ratio of manganese/total amount of manganese + cobalt in the catalyst composition Mn/(Mn+Co),A equals about 0.200,B equals about 10.9,C equals about 4.35; andD equals about 0.0724.

Abstract: Terephthalic acid having a purity of 99% or more can be produced in a yield of 95% by mole or more by oxidizing p-tolualdehyde or a mixture of p-tolualdehyde and p-toluic acid with molecular oxygen in a solvent in the presence of a cobalt salt catalyst under the conditions that (1) a Co/solvent ratio is 0.05 to 0.70% by weight and (2) a toluic acid/Co ratio is 0.1 to 3.0 moles/gram atom, without using either a promoter or an oxidation accelerator.

Abstract: N,N-difluoroamines are prepared by fluorination of compounds containing a >C.dbd.N-- bond using molecular fluorine or a hypofluorite in which the fluoroxy group is bonded to an inert electron attracting group, such hypofluorites including fluoroalkyl hypofluorites such as trifluoromethyl hypofluorite. The fluorination is advantageously conducted in the presence of an alkanol or other nucleophilic compound. Suitable starting materials include imino ethers and esters and aliphatic and aromatic Schiff's bases, use of the latter being particularly convenient.

Abstract: Process for manufacturing a benzene carboxylic acid by oxidation of an alkyl substituted benzene, and in particular for manufacturing terephthalic acid by oxidation of paraxylene, in which said benzene carboxylic acid, in solution in an aliphatic monocarboxylic acid, such as acetic acid, is oxidized by means of a gas containing molecular oxygen at a temperature T from 80.degree. to 260.degree. C. under a pressure from 2 to 30 kg/cm.sup.2, in the presence of a transition metal compound, in at least one reactor whose internal wall is maintained during the whole reaction time at a temperature, in .degree.C., from T - 10 to T + 100.

Abstract: This invention relates to the preparation of the subject aqueous solution from a non-bromine manganous salt. More specifically this invention pertains to a critical order of dissolving such salt and elemental bromine and to the use of an anti-oxidant for the manganous ion to prevent its conversion to hydrated manganous dioxide: MnO(OH).sub.2. According to "A Comprehensive Treatise On Inorganic And Theoretical Chemistry", J. W. Mellor, Vol. XII at pages 189 and 259 (published by Longmans, Green and Co., 1947) hydrated manganous dioxide results from the oxidation of a solution of manganous salt with chlorine, bromine, hypochlorous acid, hydrogen peroxide, etc. Such oxidation of a solution of manganous acetate was specifically mentioned. Such hydrated manganous dioxide is described as a white solid product which upon standing in contact with air becomes a dark brown to black product identified as MnO.sub.2.