Abstract: Purification of aqueous hydrogen peroxide solutions using conventional ion-exchange techniques can result in the hydrogen peroxide decomposing explosively. Much safer processes are obtained by restricting the contact between the resin bed and the hydrogen peroxide solution to a very short contact time, by employing a treatment chamber that is vented to the atmosphere and also by slurrying the resin bed. The bed is conveniently retained on a mesh that acts as a filter (13) preferably conical having an aperture (17) at its apex through which is introduced a small fraction of the solution countercurrent (10) to the main solution flow (9) in order to slurry the bed (19). The solution can be recycled through the same bed or a plurality of beds. Very high purification can be achieved and combined with improved safety of operation.

Abstract: It would be desirable to replace nitric acid based solutions for surface treating steels and like materials with a sulphuric acid based solution containing hydrogen peroxide, but such replacement solutions lose hydrogen peroxide rapidly through mainly iron-induced decomposition.A surface treatment solution that is based on sulphuric acid and hydrogen peroxide, but has improved stability, contains an effective amount in combination of hydrofluoric acid, are hydroxybenzoic acid and an N-alkoxyphenyl-acetamide. Preferably, the hydroxybenzoic acid is para-hydroxybenzoic acid and the N-alkoxyphenyl-acetamide is N-(4-ethoxyphenyl)-acetamide. It is preferable to employ a saturated solution of each of the two latter components, and this can achieved practically and simply by adding the solid components in the shape of a block or blocks which maintain the saturated solution over an extended period of time.

Abstract: Conventional plant to produce peroxomonosulphuric acid (Caro's acid) is large and emphasises extensive cooling, so that it is awkward to transport, can be cumbersome to install beside existing plant and can suffer from relatively expensive capital and/or running costs.In the present invention, Caro's acid is generated continuously in relatively small plant adiabatically, by introducing concentrated hydrogen peroxide into a stream of concentrated sulphuric acid in a reaction chamber dimensioned so that the throughput is very fast. In particularly suitable embodiments, the reaction chamber is annular at the points of introduction of the reagents, its width being greater in the vicinity of the hydrogen peroxide inlet than in the vicinity of the sulphuric acid inlet. The hydrogen peroxide inlet is preferably angled backwardly so that its encounter angle with the sulphuric acid stream is over 90.degree. to about 165.degree..

Abstract: The invention provides a new sub-class or organic peroxyacids comprising N-alkyl substituted peroxytrimellitimide of formula (I) in which R=hydrogen or linear or branched alkyl, which demonstrates an excellent combination of safe-handling and bleach performance rendering the sub-class particularly suitable for use as bleach and/or disinfectant in various bleach, bleach additive or washing compositions. Effective bleaching peroxyacids include those in which R=n propyl, iso-propyl, n butyl, sec-butyl, n pentyl and n heptyl. The invention also comprises processes for making the peroxyacids, compositions containing them and processes for washing and/or bleaching and/or disinfecting employing the invention peroxyacids or compositions containing them.

Abstract: The electronics industry demands that hydrogen peroxide for use therein be purified to very low levels of impurities, currently at the level of a few ppb for some impurities, or even lower. However, existing methods are either inherently unsafe because they bring concentrated hydrogen peroxide into contact with a concentrate of transition metal decomposition agents for peroxide and a purification resin which acts as a source of carbon, or are unable to attain the desired impurity level. The instant purification process first makes a concentrated suspension of stannic oxide particles in an aqueous medium, which can include aqueous hydrogen peroxide, by subjecting the mixture to high shear mixing, introducing an effective amount of the dispersion into the peroxide solution and filtering the mixture so as to remove the stannic oxide particles that now are loaded with ionic impurities, and particularly with transition metal ions.

Abstract: In one class of processes for making poorly soluble organic peroxyacids the corresponding carboxylic acid is reacted with hydrogen peroxide in a reaction medium containing a high concentration of sulphuric acid. The presence of such constituents in the reaction mixture and the manner of the reactants and the way in which they are brought into contact, can result in the processes being hazardous. In the present invention, hazard problems are reduced or eliminated by first dissolving the carboxylic acid in concentrated sulphuric acid, secondly forming a Caro's acid solution containing a complementary amount of sulphuric acid and hydrogen peroxide within a predetermined range, and then introducing the carboxylic acid solution at a controlled rate in the Caro's acid solution, often over a period of from about 30 to 90 minutes, with agitation and temperature control.

Abstract: The electronics industry demands that hydrogen peroxide for use therein be purified to very low levels of impurities, currently at the level of a few ppb for some impurities, or even lower. However, existing methods are either inherently unsafe because they bring concentrated hydrogen peroxide into contact with a concentrate of transition metal decomposition agents for peroxide and a purification resin which acts as a source of carbon, or are unable to attain the desired impurity level. In the instant purification process, the hydrogen peroxide solution is passed through a membrane having a very small pore size which contains an ion exchange resin that is capable of removing alkali and alkaline earth metal ions from solution. The feed solution in characterized in that it contains no more than a small proportion by weight of transition metals that catalyse hydrogen peroxide decomposition compared with the total metals content.

Abstract: Diacetoxyatene compounds are obtained by reacting a perborate such as sodium perborate monohydrate or tetrahydrate and acetic acid with an iodoarene compound under mild conditions, such as 40 to 50.degree. C. The iodoarene can be further substituted by a wide range of substituents, such as halo, nitro, alkyl, alkoxy or carbosylic acid, in any position around the nucleus, except that electron withdrawing substituents occupy meta positions only. The invention process thus enables a wide range of substituted diacetoxyarene compounds to be produced using widely available and easily handled materials under mild operating conditions.

Abstract: A multi stage process for the conversion of 2-chloro-4-sulphotoluene (SCT) to 2-chloro-4-sulphobenzoic acid (SCUBA). Stage (a) comprises a process S1 for the selective side chain bromination of SCT to 2-chloro-4-sulpho-dibromotoluene (SCDBT) or 2-chloro-4-sulpho-bromotoluene (SCMBT) by contacting the starting material with bromine in chloroform or trichloroethane and irradiating the mixture with light that dissociates bromine. Subsequently, in stage (b), process S2, the product of S1 can be hydrolysed at elevated temperature after separation from the organic solvent to the corresponding alcohol (SCOL) or aldehyde (SCAB). In stage (c), the product of S2 can be oxidized to SCUBA either by oxidation with a peroxyacid, optionally generated in situ, provided that the aqueous solution has previously been stripped of bromide/bromine in process S3.

Abstract: Concentrated solutions of hydrogen peroxide tend to decompose on storage, thereby losing their effectiveness, amongst other reasons by virtue of interaction with contaminating transition metals.Peroxygen compounds are stabilized by contact with a stabilizing amount of compound of general formula: ##STR1## in which X represents a methylene phosphonic acid group of formula --CH.sub.2 --(--PO.sub.3 H.sub.2) or salt thereof, R represents a tetra methylene diradical, optionally alkyl-substituted, that completes a cyclo-aliphatic ring and thereby establishes the two NX.sub.2 groups in a substantially fixed configuration and Y represents a hydrogen or lower alkyl group.Preferably, the solutions contain additionally one or more co-stabilizers, including stannate, phosphates, hydroxybenzoic acid, citric acid and nitrate.The stabilizer system can enable the solution to be diluted, even with municipal water.

Abstract: The incorporation of many percarboxylic acids in household formulations is precluded from by adverse physicochemical properties, such as a propensity to decompose too quickly during storage or explode on impact or when subjected to pressure, though otherwise they would be effective disinfectants and bleaching agents, especially at hand-hot temperatures.The invention provides a stable and effective selection of organic percarboxylic acids which satisfy one or other of the general formulae (1) or (2):R.sup.a --CO--NH--C.sub.6 H.sub.4 --CO--OOH (1)orHOO--CO--R.sup.b --CO--NH--C.sub.6 H.sub.4 X (2)in which in formula (1) the amido substituent is meta or para to the percarboxylic acid group and R.sup.a represents an alkyl group containing from 1 to 5 carbons in formula (1) and in formula (2) R.sup.b represents a branched or preferably linear alkylene group containing from 4 to 7 carbon atoms of which at least 4 are linear and X represents hydrogen or a substituent like chloride.

Abstract: Selective bromination of alkylarenes to the alpha monobrominated derivative is desirable as a precursor for the selective production of, for example, the corresponding alcohols. The product can be obtained by a photolytic reaction between the substrate, hydrogen peroxide and hydrogen bromide in approximately equimolar ratios in an organic solvent, but improvement in the yield of the product coupled with similar or improved selectivity in its production was either not achieved or was actually impaired by a range of variations in the ratios and by omitting the solvent.The invention employs mole ratios of H.sub.2 O.sub.2 :substrate of 0.1:1 to 0.4:1, preferably 0.2:1 to 0.33:1 and of H.sub.2 O.sub.2 :bromide of 1:1.2 to 1:2, preferably about 1:1.3 to 1:1.8 and progressive introduction of the H.sub.2 O.sub.

Abstract: Alkyl phosphates, undiluted or dissolved in hydrophobic solvents can be destroyed in situ by reaction with hydrogen peroxide in the presence of certain transition metal catalyst systems. The invention catalyst system comprises a chromium compound, which dissolves in the aqueous phase, typically an alkali metal chromate, which is employed in conjunction with introduction of an alkali, preferably sodium hydroxide, or in the presence of an alkali buffer to keep the pH of the aqueous phase within a window spanning mildly acidic to mildly alkaline pH during the course of progressive introduction of the hydrogen peroxide, which often lasts from 3 to 10 hours, thereby enabling the oxidation of the alkyl phosphate to continue. The reaction is preferably carried out at a temperature of at least 60.degree. C., and particularly at about 65.degree. to 75.degree. C., or at about the boiling point of the aqueous phase.

Abstract: It is desired to find an alternative way to produce benzophenones or substituted benzophenones which does so selectively and avoids the problems of previous methods that use, for example, large amounts of an aluminium chloride catalyst or nitric acid.In the invention process, a diphenyl methane starting material (DPM) in a hydrophobic phase is oxidized in a photolytic process by contact with an aqueous phase containing greater than 1 mole of HBr and at least 1.5 moles of H.sub.2 O.sub.2, both per mole of DPM, the radiation being capable of dissociating bromine to its radicals, and especially using light of wavelength 600 to 250 nm. Preferably, a reaction temperature of around 50.degree. to 65.degree. C., is used, the organic solvent comprising a suitably boiling chlorinated carbon or hydrocarbon. The H.sub.2 O.sub.2 is introduced progressively into the reaction mixture.

Abstract: Selective bromination of alkylarenes to the alpha dibrominated derivative is desirable as a precursor for the selective production of, for example, the corresponding aromatic aldehyde.Improvements in the extent of selectivity of the product and/or its rate of production can be obtained by employing a photolytic reaction between the substrate, hydrogen peroxide and hydrogen bromide using mole ratios of H.sub.2 O.sub.2 : substrate of about 2.8:1 or higher, preferably 3,2: to 3.5:1 and of bromide:substrate of over 2.5:1, preferably about 2.8:1 to 3.2:1 and progressive controlled introduction of the H.sub.2 O.sub.2, the reaction being carried out in the presence of a substantial amount of an organic solvent, and preferably more than 5.5 volumes per volume of substrate, whilst irradiating with light preferably having principal emissions in the range of 250 to 600 nm. The reaction mixture is preferably maintained at 50.degree. to 60.degree. C.

Abstract: Hitherto processes proposed in recent years for preparing esters of phenol sulphonate salts by reaction between a carboxylic acid chloride and a phenol sulphonate salt place considerable emphasis upon dehydrating the reactants before they are brought into contact in an organic solvent reaction medium.The present invention avoids the problems of employing non-aqueous solvents by carrying out the reaction under aqueous conditions but with controlled alkalinity and water content, especially at a base to phenol sulphonate mole ratio of from 1.3:1 to 1.6:1 and a total water to phenol sulphonate (as the anhydrous material) of not more than 4.5:1. The reaction advantageously employs in preference only a small molar excess of carboxylic acid chloride over the phenol sulphonate and preferably has a reaction temperature controlled to below 30.degree. C., expecially 5.degree. to 20.degree. C.

Abstract: Under conditions of misuse, water-soluble peroxyacids when they are left in direct contact with dyed fabrics can cause spotting and dye damage. The problem can be ameliorated by surface-treating the peroxyacid with an effective amount, preferably selected in the range of 8 to 25% w/w based on the peroxyacid, of aliphatic amines which melt or soften at about 30.degree. to 70.degree. C. Preferred agents include hydrogenated tallow amine dicocoamine and methyl dihydrogenated tallow amine. The agent can be applied in molten fashion or in inert solvent such as a chlorinated aliphatic hydrocarbon onto agitated particles of the peroxyacid.

Abstract: Phenol sulphonate esters can be made in a known process by reacting an alkali metal phenol sulphonate salt with an acyl halide in a hydrocarbon solvent at elevated temperatures, but the use of anhydrous materials were strongly advocated because any residual water hydrolyses the acyl chloride in a competitive reaction. However, it becomes particularly difficult and expensive to dehydrate phenol sulphonate salts below about 2% w/w water on a commercial scale and the product obtained by reaction from such partly dehydrated salts can be comparatively impure or reduced in yield. Consequently, changes to the process such as omitting the solvent or using a different acylating agent have been proposed, but these alternatives introduce their own respective manufacturing problems such as entrainment of viscous acyl chloride and anhydride in the product or introduction of a cumbersome and hence expensive recovery process involving an extra distillation step amongst others.

Abstract: Oxidation of alcohols to ketones using bromine suffers from a side reaction of comparable speed in which a bromide substituted product is formed. Additionally, the use of bromine as reagent is relatively unpleasant and it creates a major waste disposal problem.The latter problem can be solved by generating bromine in situ by reaction between hydrogen peroxide and bromide ions or hydrogen bromide, but this inevitably increases the exposure of the alcohol to HBr/Br.sup.-. The selectivity of the process towards non-substituted oxidation depending upon the inherent deactivation or reactivity of the alcohol can be improved by irradiating the reactants with light of suitable frequency to generate bromine radicals in the mixture, and/or by controlling the rate of introduction of the hydrogen peroxide and controlling the extent to which mole ratio of HBr:alcohol is substoichiometric.

Abstract: It is desired to enhance the ability of hydrogen peroxide and persalts at wash temperatures of around 30.degree. to 70.degree. C., in order to use less energy and to minimize damage to various fabric finishes. It has been proposed in the past to use transition metal compounds, including cobaltous compounds for this purpose, but the literature is self-conflicting in the way to do this. In repeat trials the simple cobaltous salts did not show much activation.The invention provides a class of activators for persalts and hydrogen peroxide comprising cobalt III ammine complexes, preferably containing 4 or 5 ammine ligands obeying the formula:Co[(NH.sub.3).sub.n M.sub.m B.sub.b T.sub.t Q.sub.q ] Y.sub.yPreferred complexes contain a chloride, bromide, hydroxyl or water ligand.Such complexes can activate particularly well at above about pH10.2, which can vary from complex to complex, and retain activity in the presence of normal concentrations of many heavy duty washing compositions.