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(11) | EP 0 867 503 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Perfumed hypochlorite bleaching compositions |
(57) Liquid aqueous bleaching compositions are disclosed which are suitable for use in
diluted form. The compositions comprise an akali metal hypochlorite and a bleach stable
perfume. The compositions have a pH as is of from 11.5 to 14, and comprise a buffering
means, i.e., a carbonate salt and/or a silicate salt. A method of bleaching fabrics
with such a composition is also disclosed.
Technical field
[0001] The present invention relates to a liquid bleaching composition which is suitable both for laundry and household applications. Compositions herein are particularly suitable in laundry applications, as a pre-wash bleaching composition.
Background of the invention
[0002] Liquid bleaching compositions are well known in the art. Amongst the different bleaching compositions available, those relying on bleaching by hypochlorite are often preferred, mainly for performance reasons. These hypochlorite-based compositions are typically used in dilute form and are suitable both for laundry and household applications. However a major drawback associated with chlorine-based compositions is the malodor they generate during and after use. Indeed, not only does the composition itself smell chlorine bleach, but the malodor remains noticeable on fabrics or surfaces which have been treated with said compositions, as well as on the skin of the user of the composition, even after the bleaching composition has been thoroughly rinsed away. Formulators have tried to solve that problem by designing perfumed chlorine-based bleaching compositions. However, this has proved difficult mainly for two reasons. Firstly, only a few perfume components are available which are stable in a strong oxidative environment such as a chlorine-based bleaching composition, resulting in limited flexibility in designing perfumes for such compositions. Secondly, chlorine bleach odor is strong and therefore difficult to mask even when perfumes are present.
[0003] It is thus an object of the present invention to provide a chlorine bleaching composition wherein the chlorine odor is reduced during and after use.
[0004] Various solutions to this problem have been discussed in the art. See for instance JP 63108099, where sulphamates were proposed to diminish chlorine odor. See also ES 8800652 which proposes a process for packaging chlorine bleach where perfume is injected into the container just before the container is closed. See also JP62205200 which proposes certain perfume ingredients in combination with certain surfactants.
[0005] Our invention proposes a simple solution to this problem. We have now found that a chlorine-based bleaching composition suitable for use in diluted form could be formulated, which exhibits a reduced chlorine odor upon use, by adding a buffering means, i.e., a carbonate salt at a level of 0.2% to 5% by weight of a total composition and/or a silicate salt at a level of 0.02% to 3% by weight to an aqueous bleaching composition comprising an alkali metal hypochlorite (2%-10%) and a bleach stable perfume and being formulated at a pH of from 11.5 to 14.
[0006] WO 88/05461, discloses a bleaching composition comprising sodium hypochlorite, sodium carbonate and sodium hydroxide
[0007] US 4 287 079 discloses aqueous cleaning compositions to be applied from squirt bottle comprising a particulate abrasive, a two part thickener consisting essentially of a mixture of fumed silicon dioxide and smectite clay, an aqueous hypohalite bleach solution, an alkaline builder and perfume like isobornylacetate. Said compositions are suitable for cleaning hard surfaces, no laundry application is disclosed.
[0008] GB-A-2 076 010 discloses thickened aqueous bleach compositions comprising an alkali metal hypochlorite, one or more carboxylated surfactants, metal hydroxide, electrolytes such as calcium carbonate and perfume. Said compositions are suitable for cleaning vertical and inclined surfaces, no laundry application is disclosed.
[0009] EP-A-30 401 discloses liquid thickened chlorine bleaching compositions having a pH of from 10 to 12.5 and comprising hypochlorite, a buffering means like alkali metal salts of carbonic acid and of silicilic acid, perfume and a thickening system, i.e. a mixture of two different detergent active compounds. Said compositions are useful for bleaching hard surfaces, no laundry application is disclosed.
[0010] EP-A-204 472 discloses a thickened aqueous cleaning composition comprising a specific tertiary amino oxide and an alkali metal or alkaline earth metal mono-or polyalkylated benzene or naphthalene sulphonate in which the alkyl groups contain from 1 to 4 carbon atoms. Said compositions may further comprise hypochlorite, metal hydroxide, alkali metal carbonate and perfume like isobornylacetate dihydroter pincol, dihydroterpinyl acetate and isoborneol. Alkali metal carbonate may be present as a contaminant of commercially available hypochlorite solution at a level of from 0.01% to 0.1% by weight of the hypochlorite solution. Said compositions are suitable for cleaning non-horizontal structural surfaces, no laundry application is disclosed.
[0011] US 4 235 732 discloses alkaline aqueous hypochlorite cleaning compositions containing paraffin sulphonate surfactant, an inorganic colloid-forming clay, insoluble particulate abrasive, an inorganic alkaline salt capable of maintaining the composition pH within the range of from about 10 to 14 and perfume. Different bleaching applications are disclosed including bleaching of textiles.
[0012] US 3 876 551 discloses aqueous perfumed compositions (pH 12 to 13.5) containing an alkali metal hypochlorite, a stable perfume oil and a surface active agent consisting solely of an amine oxide composition which consists essentially of one or more morpholine and/or dimethyl C11-C13 straight chain alkyl amine oxides. No pH buffering means are disclosed. Said compositions are suitable for laundry and domestic bleaching.
[0013] EP-A-186 386 discloses an aqueous composition and having a pH above 12, comprising sodium hypochlorite, perfume, optical brighteners and amine oxides. No pH buffering means are disclosed. Said compositions are suitable for laundry applications.
Summary of the invention
[0014] The present invention encompasses an aqueous liquid bleaching composition suitable for use in diluted form, said composition having a pH as is of from 11.5 to 14 and comprising:
- a bleach stable perfume, whereby said perfume causes no more than 10 % AvCl2 loss in 5 days at 50°c,
- from 2% to 10% by weight of the total composition of an alkali metal hypochlorite,
- from 0.2% to 5% by weight of the total composition of a carbonate salt and/or from 0.02% to 3% by weight of a silicate salt,
[0015] The present invention further encompasses a method of bleaching and washing fabrics or surfaces, when said fabrics or surfaces are contacted with a composition according to the present invention.
Detailed Description of the invention
[0016] The compositions according to the present invention are aqueous bleaching compositions. Thus they comprise hypochlorite in an aqueous matrix. Various forms of alkali metal hypochlorite are commercially available and, although this is not critical for the present invention, it is preferred herein to use sodium hypochlorite. Compositions according to the present invention comprise a bleaching amount of alkali metal hypochlorite, which represents from 2% to 10% by weight of the total composition, based on active chlorine, of alkali metal hypochlorite. Preferred compositions herein comprise from 3% to 6% of alkali metal hypochlorite.
[0017] As a second essential feature, the compositions according to the present invention have a pH as is of from 11.5 to 14, preferably from 12.5 to 14. Suitable means to achieve such a pH value include potassium and sodium hydroxide.
[0018] The compositions according to the present invention are suitable for use in diluted form. The expression "use in diluted form" herein includes dilution by the user, which occurs for instance in household application or hand laundry applications, as well as dilution by other means, such as in a washing machine. Typical dilution levels are of from 0.5% to 20% for hand laundry application, 0.1% to 10% in a washing machine, and 0.5 to 20% for household application. As the composition according to the present invention is diluted, the pH of the composition as is changes, i.e. decreases, to a certain pH value which is hereinafter referred to as the pH of the diluted composition. For the purpose of the present invention, it is essential that the pH of the diluted composition is buffered to a substantially constant value throughout use, i.e. from the moment the dilution is completed and until the hypochlorite bleaching composition is started to be rinsed away.
[0019] Therefore, as a third essential feature, the composition according to the present invention comprise pH buffering means whereby the pH of the diluted composition remains constant throughout use.
[0020] In order to achieve a proper buffering of the pH within the present invention, the pH buffering mean used herein is silicate salt at a level of from 0.02% to 3% and/or carbonate salt at a level of from 0.2% to 5% by weight of the total composition. Particularly useful are alkali metal salts of silicate and carbonate, preferably sodium silicate and sodium carbonate, both of which are commercially available, or mixtures thereof. Preferred compositions herein use a mixture of sodium carbonate and sodium silicate. Preferred composition herein comprise from 0.2% to 5% by weight of the total composition of sodium carbonate, preferably from 0.5% to 3%, and from 0.02% to 3% by weight of the total composition of sodium silicate, preferably from 0.04% to 3%.
[0021] As a fourth essential ingredient, the compositions according to the present invention comprise a bleach stable perfume, whereby said perfume causes no more than 10% loss of available chlorine in 5 days at 50°c, preferably not more than 8% loss of available chlorine. Indeed, it is well known that most perfume ingredients are incompatible for use in a strong oxidizing environment such as hypochlorite bleaching compositions. In such compositions, the hypochlorite attacks the perfume, resulting not only in the degradation of the perfume but also in the loss of available chlorine, thus bleaching power. Perfumes useful for use herein do not cause loss of available chlorine outside the limits described hereinabove. The capacity of a perfume to meet this criteria is evaluated by comparing a composition with the perfume to a composition without, to account for the loss of available chlorine which is not due to the perfume.
[0022] In both, the available chlorine is measured in the fresh compositions, i.e. just after they are made, and in the same compositions after 5 days storage at 50 °c, using the method described for instance in "Analyses des Eaux et Extraits de Javel" by La chambre syndicale nationale de L'eau de Javel et des produits connexes, Pages 9-10 (1984). The % loss of available chlorine is then calculated.
[0023] By perfume, it is meant herein individual perfume components as well as mixtures thereof. Bleach stable perfumes for use herein are components in the class of acetals, aldehydes, esters, alcohols, ketones, ethers, nitriles, terpenes, as well as miscellaneous materials, including materials of natural origin. More specifically, suitable acetals components include 1,2,3,4,6,7,8-octahydro 2,3,8,8- tetramethyl -2 acetal naphtalene, available from IFF under the trade name Iso E Super®, octane 1,1-dimethoxy acetal, commercially available from Dragoco under the trade name Resedyl Acetal®, 1,3-dioxane 2,4,6-trimethyl 4-phenyl acetal, commercially available from Dragoco under the trade name Vertacetal®, 1,3-dioxolane 2-hexyl acetal, commercially available from Dragoco under the trade name Ylamone®, phenylacetaldehyde dimethyl acetal, aldehyde dimethyl acetal, citral diethyl acetal, and acetaldehyde phenyl ethyl propyl acetal. Suitable perfume components within the class of esters include dihydro terpinyl acetate, tetrahydro linalyl acetate, benzene propanoltrimethyl acetate, commercially available from Dragoco under the trade name Vetikol Acetate®, ortho tertiary butyl cyclohexanol acetate, ortho tertiary amyl cyclohexanyl acetate, Fenchyl acetate, Iso bomyl acetate, styrallyl acetate. Suitable perfume components within the class of alcohols are 4-tert-butylcyclohexanol, dihydro terpineol, tetrahydro geraniol, tetrahydro myrcenol, tetrahydro linaleol, fenchyl alcohol, dimethyl octanol, 2,5-dimethyl heptan-2-ol, commercially available from IFF under the trade name Dimetol®, phenyl methyl ethyl carbinol, dimethyl benzyl carbinol, dimethyl phenyl ethyl carbinol. Suitable perfume components from the class of ketones are Menthone, Iso menthone racemic, dimethyl octanone, Fenchone-1,1,3-trimethyl bicyclo-1,2,2-heptanone 2, benzophenone. Suitable perfume components from the class of ehters include monoterpenes and cyclic monoterpenes ethers, commercially available from Givaudan Roure under the trade name Lime Oxide®, diphenyl oxide, iso amyl phenyl ethyl ether, paracrasyl methyl ether, phenyl ethyl methyl ether, beta naphtol methyl ether, methyl diphenyl ether.
[0024] Suitable perfume components in the class of nitriles are 3-cyclopentane 2,2,3-trimethyl 1-acetonitrile, commercially available from Dragoco under the trade name Cantryl®, bicyclo [2.2.1] heptane-2 carbonitrile, commercially available from Dragoco under the trade name Romaryl®, 5-phenyl-3-methyl-pentaneacid nitrile, dodecanenitrile, tetrahydro geranyl nitrile. Suitable terpenes as perfume components herein are para cymene and terpinolene. Suitable materials of natural origin include essential oils and resins such as eucalyptus oil, cistus oil, patchouli oil. Finally, suitable miscellaneous materials are eucalyptol and 2,4,6-trinitro-3,5-dimethyl-tert-butyl benzene. The compositions according to the present invention typically comprise from 0.000002% to 2% by weight of the total composition of said perfume, preferably from 0.000005% to 0.5 %.
[0025] As a highly preferred ingredient, the compositions according to the present invention further comprise a bleach-stable perfume solubilizer, i.e. a surface active ingredient which helps the homogeneization or solubilization of the perfume in the composition. Suitable bleach-stable perfume solubilizers include amine oxides, alkyl ethoxy methyl carboxylates, alkyl phenyl ethoxy methyl carboxylates, diphenyl oxide sulphonates, sarcosinates, taurates, betaines, quaternary ammonium salts, sulphates, sulphonates, and mixtures thereof. Preferred for use herein are amine oxides, alkyl ethoxy methyl carboxylates, alkyl phenyl ehtoxy methyl carboxylates, diphenyl oxides and mixtures thereof. The compositions according to the present invention typically comprise from 0.000001% to 20% by weight of the total composition of a perfume solubilizer, preferably from 0.000002% to 5%.
[0026] The present invention further encompasses a method of bleaching fabrics which comprises the steps of first contacting said fabrics with an aqueous liquid bleaching composition suitable for use in diluted form, having a pH as is of from 11.5 to 14 and comprising:
- a bleach stable perfume, whereby said perfume causes no more than 10 % AvCl2 loss in 5 days at 50°c,
- from 2% to 10% by weight of the total composition of an alkali metal hypochlorite,
- from 0.2% to 5% by weight of the total composition of a carbonate salt and/or from 0.02% to 3% by weight of a silicate salt,
Example 1
[0028] A composition of pH 13.1 is prepared which contains 5% available chlorine, 0.7% sodium hydroxide, 1% sodium carbonate, 0.02% benzophenone, 0.02% nonyl phenyl ethoxy(7) methyl carboxylate and water up to 100%. In said composition, the loss of available chlorine is the same with and without benzophenone and amounts to about 14% loss of available chlorine in 5 days at 50°c.
Example 2
[0029] A composition of pH 13.2 is prepared which contains 5% available chlorine, 0.7% sodium hydroxide, 1% sodium carbonate, 1.0% sodium silicate, 0.03% tetrahydromyrcenol, 0.04% nonyl phenyl ethoxy(7) methyl carboxylate, and water up to 100%. In said composition, the loss of available chlorine is the same with and without tetrahydromercenol and amounts to about 14% loss of available chlorine in 5 days at 50°c.
Example 3
[0030] A composition of pH 13.2 is prepared which contains 5% available chlorine, 0.8% sodium hydroxide, 1% sodium carbonate, 0.03% tetrahydrolynalool, 0.07% nonyl ethoxy(5) methyl carboxylate and water up to 100%. In said composition, the loss of available chlorine is the same with and without tetrahydrolynalool and amounts to about 16% loss of available chlorine in 5 days at 50°c.
Example 4
[0031] A composition of pH 13.0 is prepared which contains 5% available chlorine, 0.7% sodium hydroxide, 1% sodium silicate, 0.03% fenchylacetate, 0.08% nonyl ethoxy(5) methyl carboxylate, and water up to 100%. In said composition, the loss of available chlorine is the same with and without fenchylacetate and amounts to about 16% loss of available chlorine in 5 days at 50°c.
Example 5
[0032] A composition of pH 13.2 is prepared which contains 5% available chlorine, 0.8% sodium hydroxide, 1% sodium carbonate, 0.03% ortho tertiary amyl cyclohexanyl acetate, 0.1% diphenyl oxide, and water up to 100%. In said composition, the loss of available chlorine is the same with and without fenchylacetate and amounts to about 16% loss of available chlorine in 5 days at 50°c.
Example 6
[0033] A composition of pH 13.0 is prepared which contains 5% available chlorine, 0.7% sodium hydroxide, 1% sodium silicate, 0.03% eucaliptol, 0.04% nonyl phenyl ethoxy(7) methyl carboxylate, and water up to 100%. In said composition, the loss of available chlorine is the same with and without fenchylacetate and amounts to about 16% loss of available chlorine in 5 days at 50°c.
1. An aqueous liquid bleaching composition suitable for use in diluted form, said composition
having a pH as is of from 11.5 to 14 and comprising:
- a bleach stable perfume, whereby said perfume causes no more than 10 % AvCl2 loss in 5 days at 50°c,
- from 2% to 10% by weight of the total composition of an alkali metal hypochlorite,
- from 0.2% to 5% by weight of the total composition of a carbonate salt and/or from 0.02% to 3% by weight of a silicate salt,
and wherein said bleach stable perfume is selected from the group consisting of 1,2,3,4,6,7,8-octahydro 2,3,8,8- tetramethyl -2 acetal naphtalene, octane 1,1-dimethoxy acetal, 1,3-dioxane 2,4,6-trimethyl 4-phenyl acetal, 1,3-dioxolane 2-hexyl acetal, phenylacetaldehyde dimethyl acetal, aldehyde dimethyl acetal, citral diethyl acetal, acetaldehyde phenyl ethyl propyl acetal, dihydro terpinyl acetate, iso bornyl acetate, tetrahydro linalyl acetate, benzene propanoltrimethyl acetate, ortho tertiary butyl cyclohexanol acetate, ortho tertiary amyl cyclohexanyl acetate, Fenchyl acetate, styrallyl acetate, 4-tert-butylcyclohexanol, dihydro terpineol, tetrahydro geraniol, tetrahydro myrcenol, tetrahydro linaleol, Fenchyl alcohol, dimethyl octanol, 2,5-dimethyl heptan-2-ol, phenyl methyl ethyl carbinol, dimethyl benzyl carbinol, dimethyl phenyl ethyl carbinol, Menthone, Iso menthone racemic, dimethyl octanone, Fenchone-1,1,3-trimethyl bicyclo-1,2,2-heptanone 2, benzophenone, monoterpenes and cyclic monoterpenes ethers, diphenyl oxide, iso amyl phenyl ethyl ether, paracrasyl methyl ether, phenyl ethyl methyl ether, beta naphtol methyl ether, methyl diphenyl ether, 3-cyclopentane 2,2,3-trimethyl 1-acetonitrile, bicyclo [2.2.1] heptane-2 carbonitrile, 5-phenyl-3-methyl-pentaneacid nitrile, dodecanenitrile, tetrahydro geranyl nitrile, para cymene and terpinolene, eucalyptol, 2,4,6-trinitro-3,5-dimethyl-tert-butyl benzene, essential oils and resins including eucalyptus oil, cistus oil and patchouli oil, and mixtures thereof.2. A composition according to claim 1 which comprises from 3% to 6% by weight of the
total composition, based on active chlorine, of hypochlorite.
3. A composition according to claims 1 and 2 wherein said perfume causes no more than
8% loss of available chlorine in 5 days at 50 °c.
4. A composition according to the preceding claims wherein said pH is of from 12.5 to
14.
5. A composition according to the preceding claims which comprises from 0.000002% to
2%, preferably from 0.000005% to 0.5% by weight of the total composition of said bleach
stable perfume.
6. A composition according to the preceding claims which further comprises from 0.000001%
to 20% by weight of the total composition of a perfume solubilizer, preferably 0.000002%
to 5%.
7. A method of bleaching fabrics which comprises the steps of:
- first contacting said fabrics with an aqueous liquid bleaching composition according to any of the preceding claims,
- then allowing said fabrics to remain in contact with said composition for a period of time sufficient to bleach said fabrics,
- then rinsing said fabrics in water to remove said composition.
8. A method according to claim 7 which further comprises a subsequent step where said
fabrics are washed with a detergent composition comprising at least one surface active
agent.