Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N37/00—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having three bonds to hetero atoms with at the most two bonds to halogen, e.g. carboxylic acids
  • A01N37/16—Biocides, pest repellants or attractants, or plant growth regulators containing organic compounds containing a carbon atom having three bonds to hetero atoms with at the most two bonds to halogen, e.g. carboxylic acids containing the group; Thio analogues thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L12/00—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor
  • A61L12/08—Methods or apparatus for disinfecting or sterilising contact lenses; Accessories therefor using chemical substances
  • A61L12/12—Non-macromolecular oxygen-containing compounds, e.g. hydrogen peroxide or ozone
  • A61L12/124—Hydrogen peroxide; Peroxy compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3902—Organic or inorganic per-compounds combined with specific additives
  • C11D3/3905—Bleach activators or bleach catalysts
  • C11D3/3907—Organic compounds
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06L—DRY-CLEANING, WASHING OR BLEACHING FIBRES, FILAMENTS, THREADS, YARNS, FABRICS, FEATHERS OR MADE-UP FIBROUS GOODS; BLEACHING LEATHER OR FURS
  • D06L4/00—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs
  • D06L4/10—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which develop oxygen
  • D06L4/12—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which develop oxygen combined with specific additives
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/16—Bleaching ; Apparatus therefor with per compounds

Definitions

• the present invention relates to the in situ production of peroxygen-based oxidising species from a peroxygen source and an activator followed by the use of the product as an oxidising agent, for instance as a bleach or a biocide.
• peroxygen bleach precursor or peroxygen source
• bleach activator are acyl- donors.
• the bleach precursor and activator when added to the aqueous laundry liquor react together in a reaction involving attack by peroxide anion on the activator to form a peroxygen bleaching species usually the peroxy acid anion.
• the conditions of laundry liquors are invariably alkaline, usually having a pH of at least 9.
• the activator and peroxygen source do not react together during storage and are themselves stable under storage conditions. It is known to coat or agglomerate bleach activators to increase their stability on storage in a laundry detergent composition and/or to affect their dissolution characteristics in the wash liquor.
• Fatty acids have been used and in WO-A-9213798 solid organic acids such as monomeric aliphatic hydroxy carboxylic acids including citric, lactic and glycolic acids, are incorporated into activator particles.
• solid organic acids such as monomeric aliphatic hydroxy carboxylic acids including citric, lactic and glycolic acids
• bleach particles are stabilised for storage by incorporating acidic components. The particles are incorporated into conventional alkaline laundry detergents.
• acylated citrate esters are used to increase the bleaching effect of hydrogen peroxide.
• the esters are incorporated into bleach booster compositions which then appear to be used in conjunction with normal laundry detergents.
• the bleach booster composition may be acidic or alkaline.
• liquid laundry bleaching compositions are described which contain a dispersion of a solid particulate bleach activator in acidic aqueous hydrogen peroxide.
• the preferred activators are substituted phenyl esters of alkanoic acids.
• the compositions are used in conjunction with conventional laundry detergents so that the detersive solution produced is alkaline.
• the perborate is used normally at alkaline pH since acidification (using acetic acid) to neutral or acidic (pH 4.5) is said to cause a loss of effectiveness as the oxidising species is not formed.
• the perborate is, in some instances, activated by the addition of tetraacetyl ethylenediamine.
• Organic peroxy acids are well known as useful oxidising agents for a wide range of specific oxidation reactions that they perform in high-to-quantitative yield.
• a review of the various methods known for the preparation of peroxy acids is available in "Organic Peroxides 1 ' , volume l, D. Swern Ed, Wiley Interscience (1970) 313-335.
• Most of the reactions described use the corresponding carboxylic acid, the acid anhydride, the acid chloride or the aldehyde as the starting materials for instance for a perhydrolysis reaction using hydrogen peroxide.
• One of the reactions uses the alkaline perhydrolysis of imidazolides of carboxylic acids to form the peroxy carboxylic acids (Folli, U et al (1968) Bollettino, 26, 61-69).
• GB-A-931,119 a process for producing carboxylic peroxy acids by reacting hydrogen peroxide with an ester of the organic carboxylic acid in the absence of water and in the presence of a catalytic quantity of an acid catalyst.
• the process is used to make peracetic, perbenzoic, peradipic, perpropionic and peroxalic acids.
• the process requires hydrogen peroxide to be dissolved into the liquid ester, water to be removed and then acid catalyst to be added only after complete removal of the water.
• the product solution was subsequently used to oxidise cyclohexene to form cyclohexene oxide.
• GB-A-930,056 describes a process for the reaction of an aromatic carboxylic acid ester with hydrogen peroxide in an alkane sulphonic acid to form the aromatic peroxy acid. Hydrogen peroxide was added to the reaction mixture as an aqueous solution having a concentration of at least 70%.
• GB-A-l,363,916 describes anhydrous processes for producing percarboxylic acids which are aromatic or aliphatic in nature by carrying out the reaction in the presence of organic phosphorous compounds. The citation contemplates the use of acid derivatives, including esters, although anhydrides or the acids themselves are preferred and there are no worked examples using other derivatives. There may be some water left in the reaction mixture.
• peracetic acid a strong oxidising agent
• peracids are however unstable and can be dangerous to transport in bulk.
• the problem with the in situ reaction of acetic acid and hydrogen peroxide is that water must be removed to drive the reaction or else a large excess of one of the reactants must be used which necessitates complex separation and recycling steps.
• Acetic anhydride has also been used in place of acetic acid as starting material for this in situ reaction. The conditions during the in situ reaction step and subsequent oxidation reaction will be acidic.
• Acetic acid and acetic anhydrides as starting materials for an in situ reaction require special precautions on handling and so are not suitable for use in a domestic environment.
• Acetic anhydride is water sensitive and so requires special storage conditions.
• FR-A-1176059 bleaching solutions for textiles are made by adding acetic anhydride to oxygenated water at pH 3 to 6.
• the solutions are used to bleach textiles at temperatures in the range 50 to 104°C.
• the production of oxygenated water requires special apparatus.
• FR-A-1187519 the bleaching properties of hydrogen peroxide solution at acidic pH is increased by the addition of anhydrides of organic carboxylic acids such as acetic anhydride.
• the resultant solution is used at high temperatures, from 70 Q C up to over 100 ⁇ C.
• the utility appears to be in the industrial bleaching of fabrics.
• GB-A-901687 and US-A-3227655 constitute similar disclosures and describe the incorporation of heavy metal sequesterants into the bleaching solution and the use of ammonia or ethanolamine to regulate the pH.
• the solutions are used at temperatures of more than 60°C to bleach fabrics.
• the anhydride is incorporated in stoichiometric or higher amounts as compared to the amount of peroxide.
• Acetic anhydride is a liquid and reacts with water and other ingredients on storage and is difficult to formulate into a storage stable composition.
• tooth whitening compositions which contain peroxy acetic acid as the bleaching agent.
• Compositions into which peroxy acetic acid itself is incorporated are acidic. It is suggested that the peroxy acetic acid can be generated in situ by the reaction in aqueous solution of tetraacetyl ethylene diamine and sodium perborate. In the specific examples of that embodiment of the invention the aqueous solution formed when the perborate and activator are dissolved is alkaline.
• a peroxygen source is reacted with an activator compound which is a C 2 or higher acyl donor in a first step in aqueous solution under acidic conditions, the peroxygen source being present in the reaction mixture at a concentration of less than 20M to form a product solution containing an oxidising product which is a stronger oxidising agent than the peroxygen source itself and the product solution is subsequently used as a bleach under acidic conditions.
• L is a leaving group and R is an alkyl, aralkyl, alkaryl, or aryl group, any of which groups has up to 24 carbon atoms and may be substituted or unsubstituted, in a first "perhydrolysis step in aqueous solution under acidic conditions the peroxygen source being present at a concentration of less than 10M in the perhydrolysis reaction mixture, to form a product solution containing an oxidising species which is a stronger oxidising agent than the peroxygen source, itself and the solution containing the oxidising species is used as a bleach under acidic conditions.
• the present inventors believe that the mechanism of reaction is that the activator is perhydrolysed to form the percarboxylic acid of the acyl group.
• the oxidising product, the percarboxylic acid is found to be a stronger oxidising agent that than the peroxygen source. It is believed that the activator of the formula I forms a percarboxylic acid of the formula II
• the first step is consequently sometimes referred to as the perhydrolysis step.
• the leaving group L is preferably a compound the conjugate acid of which has a pKa in the range 4 to 13, preferably 7 to 11, most preferably 8 to 11.
• R is an aliphatic group preferably a C t . 18 alkyl group, or an aryl group.
• alkyl includes alkenyl and alkyl groups may be straight, branched or cyclic.
• L and R may be joined to form a cyclic compound, usually a lactone or a lactam.
• cyclic groups may include heteroatoms, for instance oxygen or optionally substituted nitrogen atoms, carboxy1 groups as well as -CH 2 - groups or substituted derivatives thereof. They may be saturated or unsaturated.
• the compound of the formula I can be any acyl-donor compound, usually an N-acyl or O-acyl compound, which has been described as a bleach activator for use in laundry detergents.
• the compound of the formula I may be an anhydride, but is preferably an ester or, even more preferably, an amide derivative.
• Amide derivatives include acyl imidazolides as described by Folli et al (op. cit.) and N,N-di acylamides.
• Other examples of N-acyl derivatives are: a) 1,5-diacetyl-2,4-dioxohexahydro-l,3,5-triazine (DADHT) ; b) N-alkyl-N-suphonyl carbonamides, for example the compounds N-methyl-N-mesyl acetamide, N-methyl-N-mesyl benzamide, N-methyl-N-mesyl-p-nitrobenzamide, andN-methyl- N-mesyl-p-methoxybenzamide; c) N-acylated cyclic hydrazides, acylated triazoles or urazoles, for example monoacetyl maleic acid hydrazide; d) o,N,N-trisubstituted hydroxylamines, such as O
• the compound may be an ester, for instance
• N-acyl lactams such as N-benzoyl-caprolactam
• N-acetyl caprolactam the analogous compounds formed from c _,- ⁇ o lactams.
• sugar esters such as pentaacetylglucose
• esters of imidic acids such as ethyl benzimidate
• triacylcyanurates such as triacetylcyanurate and tribenzoylcyanurate
• L comprises an aryl group having a sulphonic acid group (optionally salified) substituted in the ring to confer water solubility on a benzyl group, especially nonanoyloxy- benzenesulphonate sodium salt (NOBS) , isononanoyloxy- benzenesulphonate sodium salt (ISONOBS) and benzoyloxy- benzenesulphonate sodium salt (BOBS) r) phenyl esters of C u .
• NOBS nonanoyloxy- benzenesulphonate sodium salt
• ISONOBS isononanoyloxy- benzenesulphonate sodium salt
• BOBS benzoyloxy- benzenesulphonate sodium salt
• the activator is an anhydride it is preferably a solid material, and is preferably an intra-molecular anhydride, or a polyacid polyanhydride.
• Such anhydride compounds are more storage stable than liquid anhydrides, such as acetic anhydride.
• Anhydride derivatives which may be used as activator include v) intramolecular anhydrides of dibasic carboxylic acids, for instance succinic, maleic, adipic, phthalic or 5- norbornene-2,3-dicarboxylic anhydride, w) intermolecular anhydrides, including mixed anhydrides, of mono- poly-basic carboxylic acids, such as diacetic anhydride of isophthalic or perphthalic acid x) isatoic anhydride or related compounds such as described in WO-A-8907639, for instance 2-methyl-(4H)3,l- benzoxazin-4-one (2MB4) or 2-phenyl-(4H)3,l-benzoxazin-4- one (2PB4) and y) polymeric anhydrides such as poly(adipic) anhydride or other compounds described in our co-pending application W0- A-9306203.
• dibasic carboxylic acids for instance succinic, maleic, adipic, phthalic or 5-
• the precursor peroxygen source may be hydrogen peroxide itself, but is alternatively an inorganic persalt, for instance a percarbonate or, a perborate, for instance sodium perborate, or an organic peroxide such as benzoyl peroxide or urea peroxide.
• the pH in the perhydrolysis step is preferably less than 6.5, more preferably about 6.0.
• the pH in the hydrolysis step is usually more than 2.0, preferably more than 5.0.
• the amount of water present is preferably at least as much (in terms of moles) as the peroxygen source.
• the concentration of hydrogen peroxide is preferably less than 70% weight/volume (that is weight of hydrogen peroxide based on volume of water plus hydrogen peroxide plus other components in the mixture concerted) .
• the concentration is less than 60% weight by volume and more preferably less than 30% w/v.
• the concentration is preferred for the concentration to be less than 15% or even 10% w/v or less than 5% w/v.
• the concentration is usually at least 0.2%, preferably at least 1% w/v, more preferably at least 2% w/v. Where the peroxygen source is other than hydrogen peroxide then the concentration is preferably such as to give the equivalent available oxygen as the quoted concentrations of hydrogen peroxide.
• the concentration of peroxygen source in the aqueous liquid is for instance less than 10M, preferably less than 5M or sometimes even less than 3M down to 0.01M.
• the concentration is at least 0.05M, more preferably 0.1M, even more preferably at least 0.2M.
• the pH in the bleaching step is usually less than 6.5, preferably less than 6.0.
• the pH is usually more than 2.0, for instance more than 3.0, most preferably more than 5.0.
• the temperature is preferably in the range 0 to 95 ⁇ C, more preferably in the range 10 to 80 ⁇ C.
• the invention is most useful when the temperature is less than 60°C, or even less than 50°C, for instance less than 40 ⁇ C or even around room temperature.
• the temperature is often above 20°C.
• the temperature in any subsequent oxidising step is preferably in the same ranges as the temperature during the perhydrolysis step and is preferably substantially the same temperature especially where the product solution is immediately used for instance as a bleach or disinfectant.
• a particular advantage of using activators for the peroxygen source is that the oxidising product tends to be formed at a relatively low temperature, for instance less than hand hot which.is advantageous from a safety point of view.
• the present invention provides also a new use of a composite product comprising starting materials for the perhydrolysis reaction.
• the product can simply be added to water to provide the entire reaction mixture.
• the product therefore comprises a peroxygen source, an activator compound as well, if necessary, as components for rendering the pH of an aqueous solution to which the components of the product are added acidic. Acidifying components may not be necessary where the peroxygen source itself is sufficiently acidic to achieve the desired pH.
• the activator is a solid anhydride compound.
• the peroxygen source may be hydrogen peroxide or a solid peroxygen compound.
• the activator is other than an anhydride.
• the peroxygen source is a solid, preferably an inorganic persalt.
• An acidifying component may comprise an acid and/or buffering material.
• the component may comprise a polybasic organic acid, such as a polybasic carboxylic acid such as citric, succinic, or adipic acid or sulphamic acid.
• the component may react with a by-product of the perhydrolysis reaction to make an acid.
• perborate is used, borate is a by-product and so any component known to react with borate to drop the pH, eg cis-l,2-diols, such as glycols and polyols, boric acid, or sodium dihydrogen phosphate can be used.
• Such acidifying components are also suitable for use where percarbonate is the peroxygen source.
• the composite product may contain the individual components each in separate compositions, for instance one of which contains the peroxygen source, another of which contains the activator and another of which contains an acidifying component, it is preferred to provide at least the activator and acidifying component as a mixture in a single composition in a form in which they are stable.
• a product which does not contain peroxygen source may, for instance, be added to an aqueous solution of peroxgyen source such as aqueous hydrogen peroxide, which is readily commercially available, in the form of, for instance 60%, 20%, 10% or, preferably, 5% w/v or less solution. It is most preferred for all of the components to be provided in a single composition, in which the components do not react, and which is preferably therefore substantially waterfree.
• the product(s) may be in liquid form, for instance in a non-aqueous liquid medium, in which the components may be dissolved or dispersed.
• particles of activator with protective coatings for instance produced by microencapsulation techniques or spray coating of solid activator, may be suspended in an aqueous, or non aqueous, solution of peroxygen source.
• particles of solid peroxygen source optionally being coated with a protective coating. Coated particles of either peroxygen source or activator may be disrupted or diluted in to water or with abrasion.
• the or each composition of the composite product is in solid form, for instance as a mixture of particles of the individual components or, more preferably, comprising particles each of which comprise all of the components.
• Such particles may be provided by techniques similar to those used in the laundry detergent industry, for instance including particles produced by spray drying liquid slurries, by granulation techniques using binders (for instance synthetic or natural polymers or derivatives) or by melt blending followed by extrusion or other techniques.
• the product contains the active ingredients in appropriate relative quantities so that when the composition is diluted (or the compositions are mixed) with water the first step of the reaction proceeds at the optimal rate and at the desired pH.
• the activator and peroxygen source are for instance present in relative amounts such that up to 500%, preferably 5% to 150% of the stoichiometric amount of activator (for complete reaction with the peroxygen source) is provided.
• the amount of activator is 10 to 100%, more preferably 20 to 80% of the stoichiometric amount.
• the composite product may include other additives, for instance stabilisers which stabilise the product before use, as well as stabilisers for the peroxy acid oxidising species formed in the reaction, especially heavy metal sequestrants.
• the new product may also include surfactants to act as wetting agents and inorganic salts, for instance which affect the physical properties of the solid form or act as diluent.
• Other ingredients may be included depending on the mode of use of the composition on the final application of the reaction product, for instance perfumes, or agents to assist dissolution or dispersion of the product into water.
• a preferred embodiment of the composite product for use in the present invention comprises a peroxygen source, an activator compound, a surfactant and, if necessary, an acidifying component.
• the reaction product of the perhydrolysis reaction is preferably used immediately, without removal of any by ⁇ products or addition of other materials, in the second step in which it is used as a bleaching (including disinfecting) agent.
• ком ⁇ онентs for the second step such as pH-adjusters, surfactants/wetting agents which may be cationic, anionic, amphoteric or non-ionic, or other additives to improve the second step of the process for instance co-disinfectants, biocides, slimicides, enzymes, enzyme inhibitors or radical scavengers, abrasives etc.
• Cobiocides are particularly valuable where the primary objective of the second step is disinfection/sterilisation.
• the second step of the process of the present invention may be used as a bleaching/disinfection process, by which we mean any process in which unwanted colour is reduced or removed, non-coloured stains are reduced or removed and/or a substrate is disinfected.
• the second step may include processes in which hard surfaces eg floors, food preparation surfaces, utensils, toilets, washing facilities in domestic, industrial or institutional applications are cleansed, and bleaching processes for fabrics (for instance during fabric manufacture and dyeing) .
• the second step may comprise water, effluent or sewage treatment as a biocide, pulp and paper bleaching, paper deinking, wood bleaching, fibre and fabric manufacture, use as an biocide, fungicide, bacteriocide, sporicide and/or viricide, as a contact lens disinfectant or general disinfectant for use inter alia in general environmental clean up.
• the second step may be used in food production for instance to bleach flour, beverages, or edible oils in the food and brewing industries, for instance to clean pipes used for beverages, or, in cosmetic uses such as hair bleaching or tooth or denture whitening and/or disinfecting.
• reaction can be carried out at a relatively low concentration it can be carried out without special precautions, for instance in a domestic or institutional environment.
• compositions which are suitable to be diluted direct into water to allow the first and second steps of the reaction to proceed without further additions may be categorised in four convenient categories.
• the first category comprises liquid formulations which include a surfactant.
• surfactant for use as hard surface cleaners and other uses where surface active disinfection and/or bleaching is required, for instance floor cleaning compositions, domestic and institutional hard surface cleaners, toilet disinfectants, general toiletries disinfectant, sanitising bottles, including glass and plastic bottles, and pipe cleaning compositions.
• floor cleaning compositions for instance floor cleaning compositions, domestic and institutional hard surface cleaners, toilet disinfectants, general toiletries disinfectant, sanitising bottles, including glass and plastic bottles, and pipe cleaning compositions.
• the composition will be relatively low foaming, although for some, for instance toilet disinfecting and general toiletries disinfectant, it may be desirable for the composition to have a relatively high foam.
• suitable surfactants which will foam is well known in the art.
• anti-foaming agents for instance soap or silicone anti-foams.
• Liquid formulations including surfactants may be useful in other applications such as for use to bleach fibres or fabrics, such as nappies or in fabric production, cellulose fibres, especially in paper de-inking operations, and in general environmental clean-up operations.
• A. second category of composition comprises liquid formulations but which contain no surfactants. These may be useful where no surface activity is necessary, for instance in effluent and water treatment, in toilet disinfectants, for use as a swimming pool treatment, for colour removal from chemicals, from pulp during paper making or recycling, in general industrial sterilisation and in some domestic sterilisation situations, for instance as a general toiletry disinfectant, in denture cleaning compositions, in sanitising glass and plastic bottles or other containers, as well as in certain environmental clean-up operations.
• compositions may be pourable liquids, which are aqueous or non-aqueous, or may be in gel or paste form.
• compositions may be two-phase, for instance a cream form.
• the compositions could be in the form of a mousse (where the composition contains surfactant) by the injection of a gas, especially for domestic hard surface cleaning operations.
• a further category of composition is in solid form and includes a surfactant.
• the general uses of these compositions are similar to those for which the liquid formulations including a surfactant are useful, as mentioned above.
• a further category of formulation comprises a solid composition but without surfactant. These compositions are useful in the same categories of uses as the liquid formulations without surfactant.
• the compositions may, in solid form, be more storage stable, since it is in general easier to keep the bleach activator and peroxygen donor compound in separate particles and prevent them coming into contact with one another during storage. It is furthermore easier to isolate other components of the composition from one another and from the bleach components, especially where storage sensitive compounds such as enzymes, other biocides or perfumes are present.
• Solid compositions may be in the form of particulate mixtures or may be tabletted.
• Tabletted formulations, or even granular formulations may include agents to increase the dissolution rate of the compositions upon addition to water.
• suitable components incorporating into tablets aid disintegration of the tablet.
• Such ingredients may create effervescence, for instance; a suitable component is sodium bicarbonate, or other alkali metal bicarbonate.
• compositions may also contain ingredients to assist in their application or stability or which improve their appearance, for instance thickeners, dispersants, opacifiers, hydrotropes, dyes, perfumes etc.
• the activator/peroxygen source combination used was 60% hydrogen peroxide in a 10:1 ratio with the activator.
• Small swatches of cloth (20-25cm ) were used and the stain was chlorophyll.
• the bleaching experiments were run using lOmls hydrogen peroxide (60%) which was adjusted to the required pH using sodium hydroxide solution.
• a weighed quantity of the activator (sufficient to produce 33mmol of peracid) was then added and the mixture stirred for 2 minutes to dissolve the activator. The swatch of cloth was then added and left for 30 minutes with occasional stirring.
• Timed bleaching experiments were carried out using the same technique and quantities as in 2.1.1 above with different dwell times of the swatch in the bleach solution. Six separate solutions were prepared and a swatch added to each at the same time. The swatches were removed and rinsed in deionised water after set time periods. The times used were 5mins, lO ins, 20mins, 30mins, lhr and 2hrs. The final brightness after drying by the usual technique was determined using the Hunterlab. The results are shown in Table 5. 2.1.4 Time/pH bleaching profile
• the solutions and swatches used were prepared as in the above experiments. Four solutions were prepared and a swatch added to each after a set period of time. The cloth was left in the bleach solution for 5mins and then removed and rinsed thoroughly with deionised water. The times at which the swatches were added were after lmin, 15mins, 30mins and lhr. A different solution was used for each swatch.
• the activators used were TAED and DADHT. The final brightness after drying of the cloth was measured using the Hunterlab. The results are shown in Table 7.
• SNOBS sodium nonanoyloxybenzene sulphonate
• BOBS benzoyloxybenzoic acid sodium salt
• DADHT 1,5-diacetyl-2,4-dioxohexahydro-l,3,5-triazine
• 2MB4 2-methyl-(4H)3,l-benzoxazin-4-one
• ISONOBS Sodium isononanoyl oxybenzene sulphonate
• Biocidal activity of activator/hydrogen peroxide mixtures 3.1 The assessments were performed in a test tube situation following the principles of BS 6471:1984. 3.2 100ml volumes of Nutrient Broth were inoculated with Escherichia coli. Staphylococcus aureus and Streptococcus faecalis.
• PAA peracetic acid
• test solutions of the formulations were prepared using TAED, SNOBS or acetic anhydride in the amount noted in the respective table below in 100ml of 1% hydrogen peroxide solution.
• the test solution was left to age for 24 hours before use. Other test solutions were used immediately after make up.
• test bacterial culture 3.5 1ml was added to 9ml of the appropriate formulation, mixed and left for a period of time at a given temperature. (The conditions are noted in the respective table below.)
• Chlorophyll stained swatches were used as the substrate. Reflectance was measured using an ICS Texicon Spectraflash 500 (a colorimeter using the CIE Lab system) using software version 4.70.
• Acetic anhydride is a widely used source of peracids under laboratory conditions. This material is however water sensitive, corrosive and therefore not easy to handle. The following experiments were designed to see how effective acetic anhydride was as a peracid generator under dilute aqueous conditions.
• Chlorophyll stained swatches were added to the solutions used above and left to bleach overnight for 17 hours. The swatches were rinsed. The pH of the bleaching solution was measured after the cloths had been removed.
• the TAED activated solution gives a lower initial concentration of peracetic acid.
• the TAED solution increases in strong oxidising agent concentration while the acetic anhydride solution loses oxidising agent.
• the levels of strong oxidising agent are higher in the TAED containing solution.
• PAG penta-acetylglucose
• the bleaching performance of some of the solutions was determined on un-glazed, tea-stained tiles.
• the bleaching solution is applied to one half of the tile and the difference in whiteness, as determined using a hunter Lab apparatus between the two halves is determined. The value is given as ⁇ W.
• the Hunter-Lab apparatus is set to CIE tristimulus XYZ scale.
• the W reading is the Z% brightness.
• Granule 1 is Mykon ATC (available from the applicant company) formed from 90-94% TAED carboxymethyl cellulose binder and no more than 2% water and has particle size 95% in the range 0.2 to 1.6 mm.
• Granule 2 is Mykon ASD formed from 83 TO 87% TAED, CMC binder and 2.5 to 3.5% methylene phosphonic acid sequestrant and no more than 2.5% water having particle size 95% in the range 0.2 to 1.6 mm.
• compositions were formulated by blending the ingredients in particulate form and storing them in a closed container at ambient temperature.
• the amount of available oxygen after 12 weeks of storage was determined by a standard Avox titration.
• the percentage loss of available oxygen is reported in the following table.
• the solutions were applied with a brush to half a tile and then either dipped in water or wiped with a cloth to remove the liquid. The whiteness was then recorded as described above.
• the ⁇ W values for Flash alone, removed by wiping and dipping, were 4.0 and 9.7, respectively.
• the ⁇ W values for the boosted Flash were 4.8 and 13.5 respectively.

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• 1993
  • 1993-02-08 GB GB939302441A patent/GB9302441D0/en active Pending
• 1994
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  • 1994-02-07 WO PCT/GB1994/000228 patent/WO1994018297A1/en not_active Application Discontinuation
  • 1994-02-07 CA CA002155636A patent/CA2155636A1/en not_active Abandoned
  • 1994-02-07 EP EP94905801A patent/EP0682694A1/de not_active Ceased
  • 1994-02-08 IN IN79CA1994 patent/IN180820B/en unknown
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