Classifications

• • 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
  • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
  • A61L2/16—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using chemical substances
  • A61L2/18—Liquid substances or solutions comprising solids or dissolved gases
• • 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
  • 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
  • A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds

Definitions

• Thickened Compositions The present invention relates to thickened compositions and particularly to thickened peroxygen compositions. '
• An alternative class of compounds comprises peroxygen compounds, of which one sub-class of especial interest comprises peracids which contain the moiety -CO-OOH.
• Peracids like hydrogen peroxide enjoy the substantial advantage of generating oxygen, either as such or in an active form during its deployment rather than chlorine or active chlorine species upon which environmentalists currently cast doubts.
• peracids are more effective in general than hydrogen peroxide.
• a number of the peracids are either liquid themselves or are produced conveniently in aqueous solution. Although such compositions are particularly appropriate for the treatment of or incorporation in liquid media, they are less appropriate for the treatment of solid surfaces, and particularly non-horizontal surfaces on account of the ability of liquid compositions to flow away from the point of contact. In consequence, and in order to extend the range of applications for peracids, it would be desirable to devise peracid-containing compositions that flowed less freely.
• liquid compositions can be rendered less free-flowing by the incorporation of materials which thicken the liquid or introduce structure into the liquid.
• substances which have hitherto been effective thickeners for other liquids would automatically to be suitable for thickening liquid peracids or peracid solutions.
• This difficulty derives from the very same properties of the peracids that make them effective oxidising agents and bleaches. Interaction with thickeners during storage can result in the mutual decomposition of the peracid and the thickener, which in turn not only negates the beneficial effects of thickening, but also progressively removes the capability of the peracid to perform its desired task.
• aqueous compositions comprising a peroxygen compound at least partly in solution together with a thickener characterised in that the thickener comprises an alkali metal silicate in an amount sufficient to increase the viscosity to at least lOOcPs.
• the invention thickening system is intended particularly for thickening soluble peracids.
• the thickening system may alternatively be employed to thicken alternative peroxygen compositions, including compositions which are easier to thicken than soluble peracid compositions.
• the peroxygen compound is organic.
• the system is applicable to organic peroxides, ie organic compounds containing a -C-O-O-H or C-O-O-C- moiety, 5 including alkyl, cycloalkyl or aryl peroxides, acyl peroxides, peroxycarbonates, and organic hydroperoxides and to compositions containing less or even poorly soluble peroxyacids such as those containing at least 8 carbons.
• the system is applied to compositions containing soluble peracids, which may include low molecular weight aliphatic peroxyacids, for example containing up to 6 carbon atoms, of which especially preferred examples comprise peracetic acid and perpropionic acid.
• compositions may alternatively include soluble aromatic peroxyacids, such monoperphthalic acid, or sulphoperbenzoic acid. A mixture of peracids may be employed, if desired.
• the peroxygen compound such as the peracid
• % herein is by weight based on the total weight of the composition, unless specifically stated otherwise.
• the lower limit is at the discretion of the user, but is normally not below about 0.1%.
• the invention is particularly applicable to ready to use compositions containing a low concentration of active peroxygen compound, and for example compositions intended for application for cleansing and/or disinfecting purposes to hard surfaces and particularly to non-horizontal surfaces.
• Such dilute compositions typically contain from 0.25 to about 5% by weight of an organic peroxygen compound, preferably a peracid, for example peracetic acid and in a number of practical embodiments the peroxygen compound content will be from about 0.5 to 2%. It will be recognised that such compositions may contain a significant concentration of hydrogen peroxide, which may, for example, ⁇ comprise from about 1 to 12% of the composition, and in a number of embodiments from 3 to 10%.
• the peracid compositions, and particularly those containing aliphatic peracids are often conveniently derived by oxidation of the corresponding aliphatic carboxylic acid with aqueous hydrogen peroxide, and will often contain residual amounts of both the carboxylic acid and hydrogen peroxide.
• the compositions may contain up to 40% of the corresponding carboxylic acid and up to 40 % hydrogen peroxide, with a minimum water content usually of 20%.
• concentration of the carboxylic acid and of hydrogen peroxide each tend to be selected in the range from about 1 to 12%.
• the total concentration of carboxylic acid plus percarboxylic acid is often from 3 to 20% and in many instances from 3 to 15%. It is often convenient to restrict the concentration of hydrogen peroxide to no greater than 7%.
• equilibrium amounts of carboxylic acid, percarboxylic acid and hydrogen peroxide are present.
• the thickening system of the present invention comprises an alkali metal silicate.
• the amount of silicate to employ depends on how thick a composition is desired. By appropriate adjustment of the silicate concentration, it is possible to o ⁇ tain a wide range of compositions. At one extreme, the compositions remain easily pourable, but distinctly more viscous than the corresponding composition without added silicate. At the other extreme, the compositions are gelled, forming as product that is in effect a solid.
• the silicate concentrations tend to be selected in the region of at least 2% by weight in order to obtain compositions having viscosities of about 300cPs or higher and in many embodiments the concentration is not greater than 6% by weight.
• the silicate is usually sodium silicate, on account of its widespread availability at a reasonable cost, but other silicates such as potassium or lithium may be employed instead of all or part of the sodium silicate.
• the silicates are conveniently introduced into the composition in the form of an aqueous solution, preferably concentrated and for example containing between about 30 and 50% by weight alkali metal silicate, in order to assist even distribution and mixing of the silicate with the peroxygen compound solution. Direct introduction of solid silicate is not recommended.
• the physical state of the composition may also be modified by the presence of one or more viscosity modifiers. By so doing, it is possible to fine tune, to at least some extent, the ability of the composition to be poured.
• the pH of the composition is a further factor affecting the viscosity attained by a thickened composition during storage and the rate at which thickening occurs in the present invention.
• a pH of at least 1, approximately so as to encourage thickening to occur and in practice the pH is normally not higher than about 4.5.
• a preferred pH range for the compositions comprise from about pH 3 to 4.5.
• many compositions such as dilute peracetic acid compositions attain that range without any further adjustment.
• compositions of the present invention tend to thicken over a period of time, rather than attain the maximum thickness quickly.
• compositions may include one or more stabilisers for peracids and/or hydrogen peroxide so as to encourage the chemical stability of the " thickened products.
• Known stabilisers for peroxy compounds include aminopolycarboxylic acids, such as EDTA and DTPA, or N-heterocyclic aromatic carboxylic acids such as quinolinic acid, picolinic acid and dipicolinic acid.
• Particularly effective stabilisers comprise organic polyphosphonic acids, including hydroxyethylidene-diphosphonic acid and aminopolymethylene phosphonic acids. The latter often satisfy the general formula: X2N-(-CHR-CHR-NX-) n -NX 2 in which X represents -CH2-PO3H2
• R represents H or the two R substituents combine to complete a cyclohexane ring, and n is an integer from 1 to 3.
• Examples of the formula include ethylenediaminetetra- (methylene phosphonic acid), diethylenetriaminepenta- (methylene phosphonic acid) and cyclohexanediaminetetra- (methylene phosphonic acid) .
• composition may also contain one or more surfactants, for example amine oxides, and additionally or alternatively, one or more perfumes and/or dyes, preferably selected at least partly on the basis of resistance to oxidation.
• surfactants for example amine oxides
• perfumes and/or dyes preferably selected at least partly on the basis of resistance to oxidation.
• compositions of the present invention can be made by introducing the selected amount of the alkali metal silicate, preferably in concentrated aqueous solution, into an aqueous precursor composition containing essentially water and the peroxygen compound, such as an aqueous solution of peracid, which solution can optionally contain any residual amounts of the corresponding carboxylic acid and hydrogen peroxide, and agitating the resultant mixture to distribute the thickener substantially evenly through the mixture.
• the silicate solution introduced preferably has a concentration of at least 30% w/w up to a saturated solution.
• the pH of the solution is measured and adjusted, if necessary, by introduction of the appropriate choice from a mineral acid if the solution is insufficiently acid or an alkali if the solution is too acid.
• the process can be conducted at any convenient temperature, for example at the prevailing ambient temperature which is typically in the range of from 10 to 35°C.
• the mixture may be gently heated to not higher than about 50°C so as to encourage rapid distribution of the thickener and the mixture thereafter permitted to cool to ambient.
• compositions of the present invention and particularly those having a viscosity in the region of about 200 to 600cPs are intended for application domestically to surfaces, such as non-horizontal surfaces, which it is desired to disinfect and clean, thereby taking advantage of the disinfectant properties of the peroxygen compound, especially the peracid and the cleansing properties of the detergents.
• the peroxygen compositions in solid form may be incorporated in particulate or granular washing or disinfecting compositions or dispersed in blocks or bars.
• a second aspect of the present invention comprises the use the aforementioned invention compositions for disinfecting and cleansing by applying the composition to a hard surface and permitting contact to be maintained until at least some disinfection has occurred.
• compositions may be applied using conventional means and will also take into account the physical state of the composition, particularly whether it is a viscous pourable liquid or a gel.
• the compositions may be poured or smeared onto a distributor such as a cloth or sponge and applied to a receiving surface by passage of distributor across the surface.
• the compositions which have a sufficiently low viscosity for them to be pourable may be forced through a distributing nozzle directly onto the receiving surface, for example by squeezing a resilient deformable storage container.
• Compositions in gel form may be applied by a spatula or like article or as indicated previously by incorporation in a host composition or block.
• the surfaces onto which the compositions may be applied are often domestic and especially in the kitchen and other locations in which micro-organisms may be found.
• Suitable receptive surfaces are usually made from wood, glass, ceramics, plastic laminates and metal, and include work surfaces, sinks, pipework, walls, floors, and especially toilet bowls. It will be recognised, though, that similar potentially infected surfaces may be found in non-domestic situations, such as in commercial kitchens, food processing apparatus or containers or brewery or distillery vessels or hospitals or in animal or poultry-rearing establishments or in glass houses or other areas where the maintenance of hygienic conditions is important.
• the present invention includes the use of invention compositions in such non- domestic situations.
• compositions may subsequently be removed from the surfaces by water washing, possibly applied using a cloth, sponge or like article.
• a further use for a gelled composition is to form it into a block and suspend it, either as such or within a permeable container, within a liquid medium that it is desired to disinfect, such as process water, industrial circulating water or domestically the water supply to a toilet.
• a thickened peracid composition was made by stirring at laboratory ambient temperature (about 22°C), the aforementioned silicate solution (5g) and hydroxyethylidene-diphosphonic acid available under the Trademark DEQUEST grade 2010 (lOOpp ) into a solution of peracetic acid available from Interox Chemicals (lOOg) which analysed as peracetic acid (1%) acetic acid (9%) hydrogen peroxide (6%) and the balance water.
• the resultant composition had a pH of about 3.5, which fell to about pH 3.3 during storage. After 16 weeks, the composition had a viscosity measured using a Brookfield synchroelectric viscometer of 400cPs.
• Example 1 Example 1 was repeated, but employing 7g of the sodium silicate solution.
• the resultant composition had a pH of 3.5 rising to pH 4 after storage for 20 days and a viscosity of about 1500 cPs after 12 days.
• the composition had become solidified during storage for 20 weeks at 22°C, by which time it had retained 86% of its Avox.
• Example 4 Example 1 was repeated, but employing 5 13g of the sodium silicate solution.
• the resultant composition had a pH of 3.9 rising to pH 4.0 after storage for 20 days and a viscosity of over 80,000cPs after 16 weeks.
• the composition retained 47% of its Avox after 16 weeks storage at 22°C. 10
• Example 4 Example 4
• Example 4 Example 4 was repeated, but employing in addition concentrated sulphuric acid, 1.2ml.
• the resultant composition had a pH of 1.2, and a viscosity of about 1400 cPs after 16 weeks.
• the composition retained 74% 15 of its Avox after 16 weeks storage at 22°C.
• Example 5 Example 5
• Example 3 was repeated, additionally incorporating an alkylammonium methosulphate (2g) available from Stepan under their trademark STEPANQUAT F.
• the 20. resultant composition had a viscosity of 22,000 cPs after 16 weeks storage at 22°C and had retained 99% of its Avox.
• Example 6
• Example 3 was repeated, additionally incorporating an amine oxide (2g). After 16 weeks storage 25 at 22°C, the composition had a viscosity of 3000 cPs and had retained 72% of its Avox.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Wood Science & Technology (AREA)
• Environmental Sciences (AREA)
• Plant Pathology (AREA)
• Pest Control & Pesticides (AREA)
• Engineering & Computer Science (AREA)
• Dentistry (AREA)
• Agronomy & Crop Science (AREA)
• Chemical & Material Sciences (AREA)
• Zoology (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Epidemiology (AREA)
• Animal Behavior & Ethology (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Detergent Compositions (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

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Cited By (18)

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• 1991
  • 1991-05-08 GB GB919109928A patent/GB9109928D0/en active Pending
• 1992
  • 1992-04-17 AR AR32221892A patent/AR245208A1/es active
  • 1992-05-06 CA CA002102597A patent/CA2102597A1/en not_active Abandoned
  • 1992-05-06 BR BR9205982A patent/BR9205982A/pt not_active Application Discontinuation
  • 1992-05-06 WO PCT/GB1992/000820 patent/WO1992019287A1/en not_active Application Discontinuation
  • 1992-05-06 JP JP50866892A patent/JP3163500B2/ja not_active Expired - Fee Related
  • 1992-05-06 AU AU16655/92A patent/AU664548B2/en not_active Ceased
  • 1992-05-06 EP EP19920909325 patent/EP0583293A1/en not_active Withdrawn
• 1996
  • 1996-02-22 AU AU45689/96A patent/AU692667B2/en not_active Ceased

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