RU2387705C2 - Aqueous liquid bleaching compositions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: described is an aqueous liquid bleaching composition which contains a hypochlorite salt in amount sufficient for providing 0.0014-1.4 mol/l of hypochlorite ions, and an N-chloro-compound with pH higher than 7, which is selected from N-chloroarylsulfonamides and N-chlorimidodisulphate salt, where the composition contains at least one surfactant. Also described is a container which contains the said composition and a method of treating a solid surface using the said composition.

EFFECT: prolonged antibacterial activity on a solid surface.

11 cl, 3 tbl, 5 ex

Description

FIELD OF THE INVENTION

The present invention relates to aqueous liquid whitening compositions and to a method for disinfecting hard surfaces using liquid whitening compositions.

State of the art

Aqueous liquid hypochlorite whitening compositions are well known in the art. On the one hand, they are used for bleaching and stain removal in laundries, on the other hand, they are used for cleaning and disinfecting hard surfaces such as kitchen surfaces, floors, bathrooms, and especially in toilets. To increase the duration of contact of the bleaching agent with the surface, in particular with an inclined or vertical surface, the whitening compositions often have a relatively high viscosity and such compositions are commonly known as “thick bleaches”.

Hypochlorite bleaching compositions are in most cases highly alkaline and usually have a pH of 10 or higher. The pH in the acid region decomposes the bleaching agent with hypochlorite to form chlorine gas. In some applications, this was considered an undesirable limitation, and therefore, alternative bleaching agents with “active chlorine” have been used for these purposes. In most cases, they belong to the group of N-chloro compounds, such as mono-, di- and trichloroisocyanurate, mono- and dichlorosulfamic acid, N-chlorohydantoins, N-chlorosuccinimide, N-chlorophthalimide, N-chloro-r. Toluenesulfonamide (chloramine T), N-chlorimidodisulfate, N-chloromelamine, N-chloroglycoluracil and others. The starting NH-compounds usually react with gaseous chlorine to form an N-chloro-compound and thus are said to stabilize hypochlorite at low pH by utilizing the chlorine generated with decomposition of hypochlorite. In fact, no stabilization occurs, because although one compound with active chlorine (hypochlorite) is replaced by another (N-chloro compound), the whitening power of the N-chloro compound is in most cases weaker than the bleaching power of hypochlorite, and therefore the bleaching power of the total mixture weaker than the bleaching power of an equivalent amount of only one freshly prepared hypochlorite.

US 3,749,672 describes the stabilization of hypochlorite solutions at pH 4 to 11 by the addition of an NH compound suitable for conversion to the corresponding NCl derivative. A list of all possible and a large number of less suitable NH candidate compounds is provided, but all examples focus on the use of sulfamic acid.

EP 119560 describes hypochlorite solutions with a pH> 11 stabilized by the addition of an NH compound in a molar ratio ClO ^- : NH of ≤1. Again, a large number of NH compounds are listed as potential candidates, but only sulfamic acid is mentioned in the examples.

US 3054753 describes detergents in the form of powders containing solid inorganic sources of active chlorine, such as chlorinated sodium phosphate or lithium hypochlorite, and organic sulfonamide as a stabilizing agent for compounds with active chlorine. Similarly, EP 165676 describes solid detergents containing hypochlorite in the form of powders, which are stabilized and solidified by the addition of anhydrous additives, in particular sodium phosphates, and r. Toluenesulfonamide. N-chloro-r. Toluenesulfonamide itself is described as an ineffective source of active chlorine with a low whitening activity. The detergent powders described in these two documents are typical laundry detergents in which additives based on sodium phosphate and sodium carbonate are the predominant materials in the composition.

WO 9821308 describes acid whitening compositions obtained by mixing an acidic solution of a compound with deactivated chlorine (NH compounds) with an alkaline solution of hypochlorite immediately before use. It is further specified that the compound with deactivated chlorine is sulfamic acid.

WO 0100029 describes antibacterial solutions, which are called “stabilized hypochlorite” solutions, but which are essentially solutions of N-chloro and N-dichlorosulfamate and the so-called “dopant” (additive) selected from dialkyl hydantoin, arylsulfonamide, succinimide and glycoluracil.

WO 9627651 and 9627652 describe whitening compositions that reduce the unpleasant odor of the skin of the hands and contain a bleach with active chlorine such as hypochlorite and an NH compound. It is said that the compositions are useful, in particular, for protecting the hands of the user during prolonged contact with the composition from the skin acquiring a well-known unpleasant odor of bleach.

Although it is known that compounds of active chlorine and, in particular, hypochlorite are powerful disinfectants, after treatment of the substrate with a chloride compound, disinfecting activity usually does not last long. So, after surface treatment with hypochlorite, it can quickly be re-seeded with microorganisms. This, in particular, takes place if the surface is washed with water after treatment, since traces of hypochlorite remaining on the surface are washed off.

There is a need for oxidative cleaning / surface whitening methods that provide powerful initial disinfection and also create sufficient residual antibacterial activity on the surface that prevents the growth of bacteria over long periods of time. Therefore, compositions suitable for use in such methods should be sufficiently stable in the production, transportation and storage without significant loss of active chlorine.

SUMMARY OF THE INVENTION

The inventors unexpectedly found that treating hard surfaces with a liquid composition, including a combination of hypochlorite with one or more specific N-chloro compounds, provides thorough oxidative cleaning and stain removal while ensuring not only initial surface disinfection, but also antibacterial activity on the cleaned surface. surfaces for a long period of time, even after repeated flushing. The selected N-chloro compounds provide compositions that are stable and can be stored for extended periods of time without significant loss of active chlorine.

Thus, the invention provides a method for providing antibacterial activity on hard surfaces, comprising surface treatment with a liquid whitening composition containing hypochlorite and one or more specific N-chloro compounds.

In addition, the invention provides, in particular, a method for cleaning and disinfecting surfaces of toilets, in particular toilets, comprising applying to the surface a liquid whitening composition containing hypochlorite and one or more specific N-chloro compounds.

Therefore, the invention provides stable liquid whitening compositions suitable for use in the methods described above.

DETAILED DESCRIPTION OF THE INVENTION

All percentages indicated in the description are given in wt.%, If there is no reference to another dimension.

The present invention provides a method for providing long-term antibacterial activity on a substrate, as well as an aqueous liquid whitening composition suitable for use in this method. The method includes treating the substrate with a composition comprising a hypochlorite salt and an N-chloro compound selected from N-chloroarylsulfonamides and an N-chlorimidodisulfate salt, the composition having a pH above 7. The method can be applied to any substrate, including textiles, but is most useful for use on hard surfaces.

The hypochlorite salt is usually an alkali metal or alkaline earth metal salt, although other salts may be used. Salts of K, Na and Ca are preferred, and the latter two are particularly preferred. Compositions used to achieve the objectives of the invention, in most cases, contain from 0.01 to 10% NaClO or an equivalent amount of another hypochlorite salt, which is equivalent to from 0.0014 to 1.4 mol / L of hypochlorite ions. The preferred content of hypochlorite ions is from 0.005 to 1.0 mol / L, more preferably at least 0.01 mol / L.

Compositions according to the invention and used to achieve the objectives of the invention usually contain from 0.00001 to 0.5 mol / L N-chloro compounds, preferably at least 0.00002 mol / L or even 0.00005 mol / L, more preferably 0.0001 to 0.2 mol / L, most preferably a maximum of 0.1 mol / L. The molar ratio between hypochlorite ions and the N-chloro compound is useful to maintain at a level of from 15,000: 1 to 1: 1, preferably at a maximum of 5000: 1. Ratios from 200: 1 to 1: 1 are even more useful, more preferably a maximum of 100: 1, even more preferably from 100: 1 to 2: 1, most preferably from 50: 1 to 5: 1.

Of the N-chloro-arylsulfonamides, benzene and r. Toluene sulfonamide and N-chloro-saccharin (or the N-chloro compound obtained therefrom) are preferred, with N-chlorobenzenesulfonamide and r-toluene sulfonamide being most preferred. R. toluene sulfonamide is especially preferred and is marketed as a Na salt like chloramine T. N-chloro compounds can be added to the composition in their native form or they can be prepared in situ by adding the corresponding NH compound to the hypochlorite solution. To achieve complete control over the amount of N-chloro compound present in the composition, and not part of hypochlorite, it is preferable to add the N-chloro compound in its native form.

In order to ensure long-term stability of the compositions according to the invention, they must be alkaline, i.e. have a pH above 7. Preferably, the pH is maintained at 8 or higher, or even 9. At the pH of the compositions of the invention, N-chloro compounds can be present predominantly in the form of their salts, preferably in the form of alkali metal or alkaline earth metal salts.

The method according to the invention includes surface treatment or a composition diluted in the above ratio, i.e. a composition in which hypochlorite and an N-chloro compound are present at lower concentrations of the above ranges, or a concentrated composition, i.e. a composition in which the components are present in concentrations of the upper limits of the above concentration ranges. Diluted compositions can be easily prepared by the consumer by appropriate dilution of the concentrated composition. Such concentrated compositions preferably have a concentration of hypochlorite from 0.1 to 1.0 mol / L, a concentration of N-Cl compound from 0.01 to 0.5 mol / L (more preferably from 0.02 to 0.2 mol / L) and a pH of at least 9; they can be conveniently diluted 10-100 times.

The concentrated compositions according to the invention in most cases are not suitable for contact with the skin of the hands and therefore must be diluted before application by hand on the treated surface (for example, using a brush or rag, or other device). Alternatively, and in preferred embodiments of the invention, the compositions of the invention (either diluted or concentrated) are applied to the surface to be treated so that they do not come into contact with the skin of the user's hands, but remain in contact with the surface for a long period of time sufficient for oxidative cleaning and disinfecting this surface, after which the surface can, if necessary, be washed with water. In most cases, a contact time of 1 minute is sufficient for initial disinfection, and a contact time of at least 5 minutes is maintained to achieve long-term disinfection, preferably at least 15 minutes, more preferably at least 30 minutes. One example of such an option involves applying the composition according to the invention using a spray device, such as a trigger spray or the like, also well known in the art of cleaning hard surfaces. Another embodiment of the invention includes applying a thin stream of concentrated solution directly to the container into which this solution is packaged onto a surface to be treated.

The invention, in particular, provides a method for cleaning and disinfecting toilet surfaces, comprising applying to the surface the composition described above. In a preferred embodiment, in which the surface of the toilet to be treated is the surface of the toilet, the concentrated composition described above is applied directly from the container to the toilet — either on the surface of the toilet above the water surface, for example, under the upper rim of the toilet, or into the water in the toilet — without contact with the skin user’s hands. In particular, containers suitable for this purpose are well known in the art. In typical cases in such containers, the longitudinal axis of the outlet in the cap forms an angle typically less than 90 ° (preferably 10-80 °) with the longitudinal axis of the container, which makes it easy to apply the composition under the upper edge of the toilet bowl. An example of such a container is described in UK Industrial design registration no. 1057823. The addition of a concentrated composition to water in a toilet bowl results in a dilute solution according to the invention.

As emphasized above, the surface treatment with the whitening composition according to the invention not only oxidizes and cleanses and disinfects this surface, but also provides long-term antibacterial activity on this surface, which prevents the growth of microorganisms for many hours after treatment, in particular, in the case if the composition remains on the surface until completely dry. This antibacterial activity persists even after repeated washing of the surface, despite the fact that the active chlorine compounds in the composition are water-soluble and could be expected to be completely removed by washing.

The compositions of the invention may optionally contain other components known in the art as useful for whitening compositions. Particularly useful among these optional components are those which impart increased viscosity to aqueous solutions. Viscous whitening compositions known in the art as “thick bleaches” are particularly suitable for treating inclined and vertical surfaces, such as the surface of the toilet, since they can easily be applied to and left on such surfaces. High viscosity is the reason that the composition slowly drains from the surface, thereby providing a longer contact time of the composition with the surface, which leads to improved cleaning and disinfection without manual intervention. Typically, such whitening compositions have a viscosity of from 50 to 5000 MPa · s, preferably from 100 to 2000 MPa · s, more preferably from 200 to 1000 MPa · s (which is measured by a Haake RT20 Rotovisco rheometer equipped with a DIN 53018 sensor (rotor Z41 and measuring cylinder Z43), located on the same axis as the cylinder with a gap of 3 mm, Flow curves are obtained at 25 ° C in the range of shear force from 0.1 to 1000 s ^-1 ).

Components that increase the viscosity of whitening compositions are well known in the art. They can be selected from polymer thickeners containing natural or synthetic polymers, provided that the polymers must be stable surrounded by active chlorine in the whitening composition. Such polymers are described, for example, in EP 636689. They can also be selected from viscous clays or viscous silicas known in the art. Especially suitable for increasing viscosity systems are provided with appropriate structuring surfactants. It is known from the prior art that many organic sulfates or sulfonates can be suitable as surfactants, in particular in combination with nonionic surfactants or amine oxide-based surfactants. A system especially suitable for increasing viscosity is formed by combining amine oxide-based surfactants with fatty acids. Amino oxides are preferably selected from C8-C20 alkyl dimethyl amine oxide, preferably in an amount of from 0.1 to 5%, and fatty acids from C8-C20 fatty acids, preferably in an amount of from 0.1 to 3%.

Other optional components include antioxidants; substances trapping free radicals; metal chelating agents that tend to induce or accelerate the decomposition of hypochlorite (such as silicates or periodates), hydrotropes, and anticorrosion agents. Hard abrasives may also be added. On the other hand, additives such as inorganic phosphates may not play a useful role in the compositions according to the invention. Thus, they are preferably present only in minor amounts (less than 0.1%, preferably less than 0.01%), if at all. Most preferably, they are completely absent. Likewise, additives such as carbonates are preferably not used in large quantities, although small amounts of alkali metal carbonate (≤5%, preferably ≤1%) can be used as an alkalizing / buffering agent to establish the desired pH.

Other hypochlorite-resistant surfactants, mainly anionic, nonionic, amphoteric and zwitterionic surfactants, can be added to improve cleaning properties. Examples of suitable surfactants are given in well-known textbooks: “Surface Active Agents”, Vol.1 by Schwartz & Perry, Interscience 1949; "Surface Active Agents", Vol. 2 by Schwartz & Perry, Interscience 1958; the latest edition of McCutcheon's Emulsifiers and Detergents, published by Manufacturing Confectioners Company; "Tenside-Taschenbuch", H. Stache, 2 ^nd Edn., Carl Hauser Verlag. 1981. The total surfactant content in the compositions is usually at most 10%, preferably at most 5%.

Thus, the aqueous liquid whitening compositions according to the invention preferably contain at least one surfactant added either only to improve cleaning or as part of a viscosity increasing system that also provides improved cleaning.

Coloring agents, dyes and pigments can be added in order to give the desired color to the compositions, and perfumes can be added to give the compositions the desired odor, mainly to mask the smell of hypochlorite, which many people do not like. Components that are stable to bleaches should be selected; they are also well known in the art.

As emphasized above, the compositions according to the invention are alkaline and in order to ensure this, they must contain a sufficient amount of alkali, preferably alkali metal hydroxide. It is useful that the compositions also contain a buffer to ensure long-term pH stability. Carbonates / bicarbonates and alkali metal silicates are particularly suitable for this purpose.

The compositions are preferably clear aqueous liquids.

In a particularly useful and preferred embodiment, the invention provides toilet cleaning products comprising an elongated container having an outlet, the longitudinal axis of which forms an angle of at least 5 ° but less than 90 ° (preferably 10-80 °), with a longitudinal axis container, the container contains the above-described concentrated aqueous liquid whitening composition having a viscosity of from 50 to 5000 MPa · s.

Information confirming the possibility of carrying out the invention

Aqueous liquid whitening compositions were prepared according to formulations 1-3 (the amount is given in%):

one 2 3 Hypochlorite Na 4.80 4.80 4.80 Chloramine T, trihydrate 1.00 0.75 1.00 Empigen OD *) 1.75 2.10 1.16 Lauric acid 0.30 0.35 0.60 Perfume 0.06 0.06 0.06 Alkaline Silicate Na 0.05 0.05 0.05

All examples contain enough NaOH to bring the pH to 12.5.

All examples contain demineralized water to bring the volume of the mixture to 100%.

*) C ₁₀ -C ₁₈ alkyl dimethyl amine oxide marketed by Huntsman.

alignment tests

The stability of composition 3 (see above) and compositions containing hypochlorite and various other N-chloro compounds were investigated. In the case of other N-chloro compounds or their NH precursors, 1% of each compound was added instead of chloramine T to the formulation according to formulation 3. Some of the test materials immediately reacted with hypochlorite to give off heat, and in some cases to give off gas bubbles or discoloration, or the formation of sediment. In the case of these unstable mixtures, analysis for the presence of chlorine was not carried out. In samples with higher stability, the residual content of available chlorine, expressed in% of the initial content of available chlorine, was evaluated after 7 days of storage in the dark at ambient temperature.

The results are given in table. 1. From the data of Table 1 it can be seen that only the first three N-chloro compounds, which are compounds according to the invention, were quite stable and therefore had a slight or weakly pronounced effect on the amount of chlorine available, while the other N-chloro-compounds the compounds were cleaved and, thereby, a significant amount of hypochlorite was utilized.

Table 1
(X = not analyzed for the above reasons) N-chloro compound or its precursor % residual available CL ₂ Absent one hundred N-chloro-p-toluenesulfonamide, Na-salt (chloramine T) one hundred Trisodium imidodisulfate 99 N-chloro-saccharin 92 Sulfamic acid X (exothermic reaction; with the release of gas bubbles) Methylsulfamic Acid 51 Cyclohexylsulfamic Acid, Na Salt 41 Dichloroisocyanuronic Acid, Na Salt (NaDCCA) X (exothermic reaction; with the release of gas bubbles) N-chlorosuccinamide X (exothermic reaction; with the release of gas bubbles; with the formation of a white precipitate) Indoline-2-carboxylic acid X (dark brown precipitate) 1,3-dichloro-5,5-dimethylhydantoin X (exothermic reaction; with the release of gas bubbles) Sarkozin X (exothermic reaction; with the release of gas bubbles) Iminodiacetic acid, Na-salt X (exothermic reaction; with the release of gas bubbles; with the formation of a white precipitate) Melamine 3 Glycoluracil four

The residual amount of available chlorine present was determined by iodometric analysis according to the following procedure:

a known sample of the test solution (w) was placed in a flask with iodine. The sample was diluted with approximately 20 ml of distilled water. Added 10 g of a 5% solution of potassium iodide, and then 10 ml of 0.5 M sulfuric acid. The flask was closed with a ground stopper and intensively rotated to mix the contents before subsequent storage in the dark for 5 minutes until the color of the mixture became completely brown due to the released iodine. The released iodine was titrated against a 0.1 M sodium thiosulfate solution until the solution became colorless, followed by the addition of a soluble starch indicator near the end of the titration to increase the accuracy of the analysis.

The following series of N-chloro compounds or their precursors was evaluated in the presence of a sufficient amount of hypochlorite so as to have 5% of available Cl ₂ and 0.9% sodium hydroxide, giving a solution with a pH> 13, but without surfactants or other components composition. Acidic materials, for example, sulfamic acid, were first neutralized by mixing with sodium hydroxide solution before the subsequent addition of sodium hypochlorite. The residual chlorine present in these samples was checked after different periods of storage in the dark; the results of these stability tests, expressed as% of the initial available chlorine content, are given in table. 2. Most of these materials (sulfamic acid, NaDCCA, TCCA, uracil, taurine) were immediately involved in the reaction with hypochlorite with the release of heat and gas bubbles.

The residual chlorine present in some of these samples was determined within 30 minutes; it was found to be low (> 55% of the initial content).

table 2
(X = not analyzed) N-chloro compound or its precursor % residual available Cl ₂ 30 minutes. 3 days 9 days 35 days Not used one hundred one hundred 99 98 Sulfamic acid 53 26 24 eighteen Di-Cl-isocyanuronic acid, Na-salt (NaDCCA) (2%) 40 four four 3 Tri-Cl-isocyanuronic acid (TCCA) (1%) 26 5 2 X Uracil (1%) 40 5 X X Taurine (1%) 22 8 X X Chloramine-T (1%) one hundred one hundred one hundred 98 Tri-Na-imidodisulfate (1%) one hundred 99 99 99

These estimates show that of the pre-formed N-chloro compounds, only chloramine-T remained highly stable in the presence of high levels of sodium hypochlorite, giving more than 90% of the remaining available chlorine after 1 month of storage at ambient temperature. Of the precursors of N-chloro compounds, only imidodisulfate also met the specified criterion.

Hygiene Test

This test measures the ability of a composition to provide long-lasting and wash-resistant surface disinfection. The test uses a highly productive screening method to assess the hygienic properties of standard samples of 10 μl of the composition, which were metered into wells on a microtiter plate and allowed to dry (at 30 ° C. overnight), after which they were subjected to a series of automatic washes. Each test was repeated 8 times. Washings were performed with standard hardness sterile water using a hole washer on an Ascent Wellwash ™ plate. After a series of washes, the plates were dried at 30 ° C for 45 minutes and left to cool at 20 ° C for 15 minutes. After this, each well was incubated with 50 μl of an aqueous suspension of E. coli (0.5 × 10 ⁸ CFU (= colony forming units)) in 0.3% protein (BSA = bovine serum albumin) soil and left in contact for 1 h at 20 ° C. Then the wells were washed by adding 100 μl of water of standard hardness and shaking for 10 seconds, after which the washing liquid and non-fixed cells were removed by aspiration (suction).

After that, 270 μl of tryptone-soy broth nutrient medium was placed in each well and incubated for 24 hours at 37 ° C in order to control the re-growth of the remaining bacteria. The test was classified as successful after a series of washes if at least 90% of the samples did not show re-growth. The maximum number of flushes that led to such a successful test was taken as a “hygienic assessment”.

Tab. 3 shows a comparative analysis of hygiene estimates obtained with a simple 1% aqueous solution of chloramine-T and two viscosity-compatible compositions: composition 4, which corresponds to the invention and contains 1% chloramine-T, and composition 5, which does not contain 1% chloramine -T. The table shows that the introduction of chloramine-T into the hypochlorite base significantly increases its rinsing-resistant, long-term hygienic level.

four 5 Hypochlorite Na 4.80 4.80 Chloramine-T, trihydrate 1.00 0 Empigen OD *) 2.00 2.00 Lauric acid 0.2 0.5 Perfume 0.06 0.06 Alkaline Silicate Na 0.05 0.05

Both compositions contain enough NaOH to bring the pH to 12.5. Both compositions contain demineralized water to bring up to 100% volume. Viscosity (1-3 s ^-1 ): 450 mPa · s (both compositions).

Table 3 Composition Hygienic assessment * 1% chloramine-T one Composition 4 6 Composition 5 3

Hygienic assessment is expressed as the number of washes, which ensures the complete sterility of the microtiter plate.

The table clearly shows that chloramine-T alone is not able to provide a disinfecting effect that can withstand a single wash cycle. The disinfecting effect of hypochlorite persists for 3 washes, and a combination of both of these substances is effective after 6 washes.

Claims (11)

1. An aqueous liquid whitening composition containing a hypochlorite salt in an amount sufficient to provide from 0.0014 to 1.4 mol / L of hypochlorite ions, and an N-chloro compound and having a pH above 7, characterized in that N-chloro the compound is selected from N-chloroarylsulfonamides and N-chlorimidodisulfate salt, and the composition contains at least one surfactant. 2. The composition according to claim 1, characterized in that it contains from 0.00001 to 0.5 mol / l N-chloro compounds. 3. The composition according to claim 2, characterized in that it contains at least 0.0001 mol / L N-chloro compounds. 4. The composition according to claim 2, characterized in that the molar ratio of hypochlorite ions to the N-chlorine compound is from 15000: 1 to 1: 1. 5. The composition according to claim 4, characterized in that the molar ratio of hypochlorite ions to the N-chloro compound is a maximum of 200: 1. 6. The composition according to claim 1, characterized in that the N-chloro compound is N-chlorobenzenesulfonamide, or N-chloro-p-toluenesulfonamide, or a salt of any of these compounds. 7. The composition according to any one of claims 1 to 6, characterized in that it has a viscosity of from 50 to 5000 MPa · s. 8. The composition according to claim 7, characterized in that it includes a viscosity-increasing system containing C ₈ -C ₂₀ alkyldimethylamine oxide and C ₈ -C ₂₀ fatty acid. 9. The product for cleaning the toilet, which is an elongated container having an outlet, the longitudinal axis of which forms an angle of at least 5 °, but not more than 90 ° with the longitudinal axis of the container, containing the concentrated aqueous liquid composition according to claim 6. 10. A method of disinfecting a hard surface, comprising the step of treating said surface with a composition according to any one of claims 1 to 8. 11. The method according to claim 10, in which the surface is the surface of the toilet.