POURABLE DETERGENT AND BLEACH COMPOSITIONS

Abstract: The present invention provides pourable, aqueous detergent and bleach compositions containing a linear alkyl benzene sulphonate, an ethoxylated fatty alcohol and a suspended peroxydicarboxylic acid, e.g. diperoxydodecanedioic acid, the pH of the compositions being set to 3,5 to 4,1.

Description: The invention relates to a pourable, aqueous detergent and bleach composition containing an anionic surfactant, a non-ionic surfactant and a suspended organic per compound. A composition of the above type is disclosed in Netherlands Patent Specification No. 276 283. Over the detergent and bleach compositions which are in a form varying from powdered to granular as widely used in actual practice a liquid composition of the type indicated above has great advantages as regards preparation and use. Its preparation does not require cost increasing shaping steps and its liquid form contributes to ease of handling and dispensing and does away with dusting problems. The above-mentioned Netherlands Patent Specification proposes as bleaching component suspended organic per compounds of the general formula R - O - O - R¹, where R and R¹ represent organic radicals; moreover, the pH of the compositions described should be at least 7 and preference is given to alkaline reacting compositions. To these compositions, however, there is the disadvantage that they are not stable under storage conditions prevailing in actual practice, i.e. there occurs an unacceptable loss of active oxygen. Therefore, these compositions have not found acceptance in actual practice. The invention envisages eliminating this drawback. The composition according to the invention is characterized in that the anionic surfactant is a linear alkyl benzene sulphonate, the non-ionic surfactant an ethoxylated fatty alcohol and the organic per compound an aliphatic peroxydicarboxylic acid containing 8 to 13 carbon atoms, the pH of the composition being set to 3,5 to 4,1. The earlier, non-prepublished European Patent Application No. 0 160 342 discloses liquid, aqueous bleaching compositions having a pH in the range of from 2 to 5 and containing an alkyl benzene sulphonate, an ethoxylated fatty alcohol, a suspended peroxy acid and an electrolyte; Examples IV and V in it disclose compositions having a pH of 4,5. Aside from the fact that the compositions according to the present invention are not disclosed in said European Patent Application, the present compositions display better storage stability as compared with the compositions according to said Application. This is demonstrated in the Examples below. The present composition is storage stable, i.e. after 2 weeks' storage at 40°C it has entirely or practically entirely retained its active oxygen content. The pourability of the present composition may be set in accordance with any particular need. For practical purposes the viscosity of the composition, measured with a Brookfield rotational viscometer (RV type; 20 rpm) at 20°C, is between 1 and 1200 m Pa.s and preferably between 50 and 500 m Pa.s. The linear alkyl benzene sulphonate and the ethoxylated fatty alcohol to be contained in the present composition are the substances that are also normally used in detergent compositions. Preferred linear alkyl benzene sulphonates are those having 11 to 14 carbon atoms in the alkyl chain. As suitable ethoxylated fatty alcohols there are mentioned ethoxylated C₉-C₁₈ alcohols having an average degree of ethoxylation from 3 to 15. The amounts of the surfactants to be used may vary with the desired pourability. The composition according to the invention generally contains 2 to 20% by weight of the linear alkyl benzene sulphonate and 5 to 30% by weight of the ethoxylated fatty alcohol, calculated on the weight of the composition. The bleaching agent to be used according to the invention is an aliphatic peroxydicarboxylic acid containing 8 to 13 carbon atoms. The term peroxydicarboxylic acid as used here refers to both a monoperoxydicarboxylic acid and a diperoxydicarboxylic acid. Use also may be made of mixtures of these peracids or combinations of peracids of different chain lengths. It is preferred that the peroxydicarboxylic acid to be used should substantially consist of a diperoxydicarboxylic acid. As examples of the diperoxydicarboxylic acids according to the invention may be mentioned 1,12-diperoxydodecanedioic acid and 1,13-diperoxytridecanedioic acid. Particularly preferred is 1,12-diperoxydodecanedioic acid (referred to hereinafter as DPDA). The amount of peroxydicarboxylic acid to be used in the composition according to the invention is generally such that the composition, calculated on the weight thereof, contains active oxygen in an amount ranging between 0,1 and 4% by weight, preferably between 0,1 and 3% by weight. To prevent sedimentation of the suspended peroxydicarboxylic acid particles their average size is advantageously chosen between 1 and 100 microns. The peroxydicarboxylic acids are compounds that are known in themselves and may be prepared by reacting a dicarboxylic acid with hydrogen peroxide under the influence of sulphuric acid. Of importance is the quality of the water to be used in the present composition in order to obtain satisfactory storage stability. Favourable results may be obtained with bidistilled water or with deionized water. It will be of advantage also to incorporate a sequestering agent in the composition for the purpose of complexing metal ions, the presence of which may cause decomposition of the peroxydicarboxylic acid. As examples of these sequestering agents, which must not be sensitive to the oxidative action of the peracid, may be mentioned dipicolinic acid, hydroxyethylidene diphosphonic acid, alkali metal pyrophosphate and phosphonic acid. The amount of sequestering agent that may be used in the present composition is generally in the range of 0 to 1% by weight, preferably 0,01 to 1% by weight, calculated on the weight of the composition. The pH of the composition is of great importance. It should be set to 3,5 to 4,1. At a pH higher than 4,1 the storage stability of the composition obtained will diminish; at a pH lower than 3,5 the composition obtained will be less suitable for washing and bleaching purposes because of a too low pH of the wash liquor upon dilution with water in, for instance, a washing machine. It has been found that the present composition, in spite of its displaying a slightly acidic reaction upon dilution with water, can be very effectively used in the treatment of dirty washing. This is surprising in that it had up to now been generally assumed that for this purpose neutral to alkaline conditions are required. The present composition may still contain various commonly applied additives. Examples of such additives include dirt suspending agents, fluorescent and optical brighteners or whitening agents, perfumes and hydrotopic substances. The choice thereof is, of course, dependent on the desired properties of the composition and on the compatibility with the other constituents. In this connection it should be noted that because of the oxidative action of the peroxydicarboxylic acid some additives, such as enzymes and particular oxidation sensitive brighteners or whitening agents cannot be incorporated as such in the present composition. However, such substances may previously be provided with a suitable coating, which may be in the form of, for instance, a solid detergent-active material which dissolves during the washing stage, after which its incorporation in the composition is no longer objectionable. The present composition can be prepared in a simple manner by adding finely divided peroxydicarboxylic acid, with stirring, to an acidified (pH about 2) mixture in water of the anionic and the non-ionic surfactant and any other constituents, after which the pH of the resulting composition is set to the desired value with, say, sodium hydroxide. The following examples serve to illustrate the invention. All percentages therein are by weight. Example 1 Three compositions according to the invention were tested for loss of active oxygen during storage. The table below gives the constituents in percentages and the relevant properties of the compositions and the test results. In addition the table gives the test results of a comparative test conducted on a composition according to Example 4 of Netherlands Patent Specification No. 276 283 (Composition A). The test results show that the compositions according to the invention display satisfactory storage stability at 40°C. At this temperature prior art composition A was subject to total decomposition, which was moreover attended with severe froth forming. It appears from the test results that also at 32°C composition A shows poor storage stability. Into several compositions corresponding to composition 3 a number of additives were incorporated after which the storage stability was determined in the same way as described above. Use was made of the following additives in amounts given in brackets: - methylhydroxypropyl cellulose (1%) - optical brightener ATS-X, a commercial product of Ciba Geigy (0,15%) - perfumes Turbo, Lanea and Kalifa, Commercial products of Naarden Chemie Int. Holland B.V. (0,3%). After 1 month's storage at 40°C all these compositions showed a loss of active oxygen of only a few per cent. Example 2 Of the Composition 3 described in Example 1 an amount of 120 ml was tested under practical conditions for its capability of removing stains and dirty spots from domestic laundry. Comparative tests were carried out on recommended portions of two commercially available compositions, which are referred to hereinafter as Composition B and Composition C. Composition B was a liquid detergent concentrate containing about 37% of water, about 40% of surfactants and also enzymes and other substances, such as optical whitener; of this composition 120 ml were used. Composition C was a powdered detergent and bleach agent containing about 14% of surfactants, about 19% of polyphosphate, about 15% of sodium aluminium silicate, about 23% of sodium sulphate, about 9% of sodium perborate.₄H₂O, about 4% of tetraacetyl ethylene diamine and also enzymes and other additives; of this composition 131 g were used. In each test in all 216 articles, including tea towels, sheets, pillow cases and underwear, were washed in an AEG-Turnamat washer with tap water of 9° GH. The maximum washing temperature was 62°C, the total washing time, including heating up, was 59 minutes and the amount of water admitted 19 litres. Following the washing process the washing was rinsed with 5 × 17 litres of cold water and dried. Subsequently, the washing was rated by a panel by counting the number of clean fourth parts of the tea towels, sheets and pillow cases. Both sides were rated, so that the rating of a perfectly clean article was 8 points. The underwear was compared with totally clean underwear , the rating for totally clean underwear being 8 points and for less clean underwear between 0 and 8. For each of the three compositions tested the ratings of 12 tests were averaged. For the composition according to the invention the rating was 6,8, for Composition B it was 6,5 and for Composition C 6,9. These results show that the effectiveness of the composition according to the invention is excellent. Repeating the above tests at a maximum washing temperature of 40°C resulted in similar ratings. Example 3 In this Example compositions according to the invention are compared with compositions according to European Patent Application No. 0 160 342 as regards storage stability. A composition was prepared containing 100 g of sodium dodecyl benzene sulphonate (85%, the remainder substantially consisting of sodium sulphate and some sodium chloride), 100 g of ethoxylated (7,5 EO) C₁₂-C₁₄ fatty alcohol, 5 g of Dequest 2010, 243 g of DPDA (aqueous paste with an active oxygen content of 5,1%), 557 g of water. This composition was divided into several portions which were each set to a different pH. Of the resulting compositions the storage stability was determined by measuring the percentage of active oxygen remaining after storage at 40°C during 1, 3 and 4 weeks. The results are tabulated below. The results in the table clearly demonstrate the good storage stability of the compositions according to the invention as compared with that of the compositions according to EP 0 160 342.

Claims: 1. A pourable, aqueous detergent and bleach composition containing an anionic surfactant, a non-ionic surfactant and a suspended organic per compound, characterized in that the anionic surfactant is a linear alkyl benzene sulphonate, the non-ionic surfactant an ethoxylated fatty alcohol and the organic per compound an aliphatic peroxydicarboxylic acid containing 8 to 13 carbon atoms, the pH of the composition being set to 3,5 to 4.1. 2. A composition according to claim 1, characterized in that, calculated on the weight of the composition, the amount of linear alkyl benzene sulphonate is 2 to 20% by weight and the amount of ethoxylated fatty alcohol 5 to 30% by weight, and the amount of peroxydicarboxylic acid is such that the composition contains 0,1 to 4% by weight of active oxygen. 3. A composition according to claim 1 or 2, characterized in that the peroxydicarboxylic acid is 1,12-diperoxydodecanedioic acid.

Inventors: DE JONG, AALDERT, JOHANNES, MEIJER, JOHN, VAN GENDT, JOACHIM WILLEM JOSEPH
Applicants: AKZO N.V.
Application year: 1986
Main classification: C11D3
IPC codes: C11D3, C11D1, C11D10