CZ385398A3 - Concentrated alkaline isotropic liquid detergent with a bleaching agent - Google Patents

Abstract

A concentrated alkaline isotropic fabric washing liquid detergent composition comprising at least 23 % of surfactants and further comprising at least 0.2 % hydrogen peroxide bleach, the composition is substantially free from hydrotropes which cause the pH to reduce and impair the effectiveness of the composition. Also a concentrated alkaline isotropic fabric washing liquid detergent composition comprising at least 15 % by weight of surfactant further comprises at least 0.2 % by weight hydrogen peroxide bleach and an optical brightener and is also substantially free from hydrotropes. The compositions may be used as a main wash bleaching liquid or a pretreatment liquid and may be activated with a bleach activator.

Description

Concentrated alkaline isotropic detergent liquid with bleach

Technical field

The present invention relates to concentrated alkaline isotropic liquid detergents which are intended for textile washing and which contain a hydrogen peroxide bleach.

BACKGROUND OF THE INVENTION

Concentrated alkaline isotropic liquid detergents used for fabric washing typically contain a hydrotrope that allows the use of a high level of surfactant without increasing viscosity too much. Typical hydrotropes are sodium xylene sulfonate, ethanol and propylene glycol. International Application WO96 / 30483 discloses such compositions comprising a mixture of a nonionic surfactant and anionic surfactant together with a hydrotrope and hydrogen peroxide, and characterized in that, for the predominant nonionic surfactant, the proportion of all surfactants in the composition is greater than 40% and for predominant anionic surfactant the proportion of all surfactants in the composition greater than 20%. To reduce shipping and storage costs, it is desirable for the liquid to contain concentrated peroxide. The solution to the problem of constructing stable, concentrated, alkaline isotropic liquid detergents for washing textiles and containing peroxide has been unattainable for many years in the art.

Although many publications on concentrated alkaline isotropic liquid detergent compositions for textile washing and containing a hydrotrope can be found, there are indeed very few papers describing hydrotrope-free materials. Closest to this is probably a composition comprising 15% anionic surfactant (secondary alkyl sulfonate) and 3.75% nonionic surfactant [primary alcohol ethoxylate (7EO)] and described in WO 96/01311. This recipe has a total surfactant level below 20%. In addition, the composition does not contain additional ingredients such as an optical brightener, an anti-redeposition agent, or a dye transfer inhibiting agent, making the composition unsuitable for use as a practical concentrated alkaline isotropic liquid laundry detergent, containing hydrogen peroxide bleach .

Thickened peroxide compositions are also known. These include a thickening system to increase the viscosity when the surfactant is only present at a low concentration. A typical example is GB 2255507, which discloses a concentrated, peroxide-containing composition with less than 10% surfactant. Such compositions are not suitable for use as laundry detergents. They are thickened, CHANGED USP ·· fcfcfcfc fcfc · * • · fc · · · · fcfc · fcfcfcfc · fc fcfc · fcfcfc · · · fc fcfc · · · fcfc · • fcfcfc • fcfc · in order to achieve the desired result, namely a sticky agent that does not flow when applied to a vertical surface. The skilled artisan would not use these thickened hydrotrope-free compositions as a basis for the formulation of new concentrated laundry detergents.

SUMMARY OF THE INVENTION

We have now found that the presence of a hydrotrope has a considerable and very undesirable negative effect on the storage stability of concentrated alkaline isotropic liquid laundry detergents. In particular, we have found that this is a problem with compositions containing high surfactant concentrations. This is a problem with formulations for concentrated liquid detergents, since hydrotropes are commonly present in such detergents. In the present description, the word concentrated means that the liquid in its undiluted state contains more than 15%, preferably at least 20% and preferably at least 23% surfactants. Unless otherwise indicated, all percentages are by weight.

The present invention describes a concentrated alkaline isotropic liquid laundry detergent composition comprising at least 15% total surfactant, at least 0.2% hydrogen peroxide bleach, and finally an optical brightener in a total surfactant concentration. The composition is characterized in that it is substantially free of hydrotropes. It is preferred that no hydrotropes are added to the composition. It is possible that a substance that can act as a hydrotrope will be present in small amounts (i.e. up to 2.5%, preferably less than 1.5% and preferably less than 0.5%), possibly due to the fact that some of the ingredients of the composition contain the substance in the form of a minor component or an impurity. However, it is preferable to avoid such additives since they probably require a compromise on the shelf life of the composition, which is otherwise very stable, the loss of efficiency due to the fact that the amount of hydrotrope material is very small can be compensated by acceptable shelf life. In this specification, the term "substantially free of hydrotropes" means that materials that can act as hydrotropes are present in concentrations up to 2.5%, preferably less than 1.5% and preferably less than 0.5%.

The total surfactant concentration is preferably at least 20%, preferably at least 23%. Preferably, the composition comprises both anionic and nonionic surfactants.

Any peroxide-compatible optical brightener can be used. Good compatibility with peroxide bleach has the optical brightener Tinopal CBS-X (a derivative of distyryl biphenyl) from Ciba Geigy. Stilbene-based fluorescent agents can also be used as optical brighteners.

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · A second aspect of the present invention is a concentrated alkaline isotropic liquid laundry detergent composition comprising, in total surfactant concentration, at least 23% of a surfactant selected from the group consisting of anionic and nonionic surfactants, and furthermore at least 0, 2% hydrogen peroxide bleach. The composition is characterized in that it is substantially free of hydrotropes. The composition may also comprise an optical brightener as described above.

The nonionic surfactant, if present, preferably constitutes more than 5% by weight of the total composition. It is preferred that the composition does not contain more than 5% of surfactants that do not meet the pH criteria when tested according to Test A as described below. Most preferably, it does not contain more than 5% surfactants that do not meet the criteria for residual peroxides when tested according to Test A, as described below.

Preferably, the surfactant system is a mixture of anionic and nonionic surfactants, although purely nonionic or purely anionic systems may also be used. The compositions may contain or be free of a suitable adjuvant (builder).

Preferred anionic surfactants include:

(a) secondary alkanesulfonates such as Hostapur SAS 93 (93% active flakes) from Hoechst or Marlon PS 65 [low sodium sulphate n-alkanesulfonate (C13-17)] from Huls;

b) Linear alkyl (C _{0 3} .i) benzenesulfonic acids such as Marlon AS3 ex Huls

c) alkyl ether sulfonates such as Neopon LOS 70 (70% active sodium salt) from Witco; and

d) olefin sulfonates such as Hostapur OS, supplied by Hoechst as a formulation with 40% active ingredients.

Preferred nonionic surfactants include:

e) primary alcohol ethoxylates (C ₁₃ -i _5), ethoxylated five to nine moles of ethylene oxide, preferably seven moles such as Synperonic A7 ex ICI / Cargo Fleet.

The pH of the composition may range from 7 to 12, preferably about 9.5.

The peroxide is preferably present as dissolved hydrogen peroxide in a weight concentration in the range of from 0.2 to 15%, preferably from 1 to 8%, preferably about 5%.

The composition may also contain minor components which are commonly added to liquid detergent compositions intended for demanding applications. These ingredients include perfumes, suitably protected enzymes, surfactant preservatives, thickeners, colorants, adjuvants, antiredeposition agents, dye transfer inhibiting agents (preferably, dye transfer agents may be used). Polyvinylpyrrolidone, PVP, which simultaneously acts as an anti-redeposition agent as a dye transfer inhibiting polymer) and other conventional additives.

Preferably, the composition may contain chelating agents (sequestrants). The preferred chelating agents are diethylenetriaminepentamethylene phosphate sodium, sold as Dequest 2066 by Monsanto, either alone or together with 2,2-dipyridylamine (DPA), optionally with 1,2'-diaminocyclohexyl- (ε-methylenephosphorous acid). . Other chelating agents for transition metal ions may be used in place of, or in addition to, these sequestrants.

In a preferred embodiment of the present invention, the composition is activated by a bleach activator such as TAED, which can be contacted with the composition at the time of use using a two-chamber (two-dose) dosing system.

According to a third aspect of the invention, the concentrated alkaline isotropic liquid detergent composition for fabric washing can also be used to pre-clean stains or other specific areas on the fabric before the fabric is subjected to washing. In this process, stain removal is superior to known peroxyacid formulations and overall efficiency is enhanced by the high concentration of surfactants that can be achieved with the compositions of the present invention. The use of a concentrated formulation also has the advantage of lower transport and packaging costs, which is desirable from an environmental point of view. The pretreatment method consists in applying the composition of any one of claims 1 to 11 to a selected area of the fabric, leaving the composition in contact with the fabric for a short period of time and then washing. The pretreatment time is typically 1 to 5 minutes, preferably 2 minutes.

Compatibility of surfactants with peroxide

The following procedure, referred to as Test A, is used to identify suitable surfactants based on pH and peroxide stability data. The test composition is prepared with 20 wt% surfactants to be tested, except for Marlinat CM20, which was tested at a concentration of 15 wt%. After chelation with Dequest 2066, hydrogen peroxide is added in an amount sufficient to achieve a concentration of 5% by weight and the pH is adjusted to 9.5 by the addition of a pre-chelated (presekvestrated) caustic solution. Details of the surfactants tested are given in Table 1.

Based on our experience, we have deduced the target pH values and peroxide stability. The residual peroxide is determined by titration with a permanganate solution. The surfactant should satisfy both

Table 1 - Surfactants tested

Code Surfactant Source Type Active Substances % by weight A n ionic Al Marlon AS3 Huls alkylbenzenesulfonic acid (linear alkyl, C 10 -b) 97 A2 Marlon AS350 Huls alkylbenzenesulfonic acid sodium salt (linear alkyl, C10-13) 50 A3 Marlon PS65 Huls secondary alkanesulfonate sodium (C13-17) 65 A4 Hostapur SAS93 Hoechst secondary alkanesulfonate (Cn-is) 93 A5 Empicol 0045 Albright alkyl sulfate, sodium lauryl sulfate 95 A6 Neopon LOS70 Witco alkyl ether sulfate, sodium lauryl ether sulfate 70 A7 Marlinat CM20 Huls alkyl ether carboxylic acid, C12 / C14 fatty alcohol polyglycol ether (2EO) carboxylic acid 90 A8 Crodasinic LS30 Croda sarcosinate - RCONCH ₂ (CH ₃ ) COOH, R = alkyl, sodium lauroylsarcosine 30 A9 Adinol CT95 Croda taurate - RCON (CH ₃ ) CH ₂ CH ₂ SO ₃ Na, R = alkyl, sodium methyl cocoyl taurate 95 A10 Hostapur OS Hoechst olefin sulfonate 40 No ionic NI Synperonic ICI primary alcohol ethoxylate, C13 / C15 primary alcohol ethoxylate (7EO) 90 N2 Genaminox LA Hoechst amine oxide, lauryldimethylamine oxide 30 A m f 0 t e r η í PI Dehyton AB30 Henkel betaine - RN (CH ₃ ) ₂ CH ₂ COO, R = alkyl, cocobetaine 30

the target pH as well as the target peroxide stability. Small amounts (preferably <5%) of surfactant can be used, which does not meet all target requirements, but this is practical only when most surfactants exceed the target values with good margin. As will be apparent from the results in Table 2, it is possible to achieve satisfactory room temperature stability, although stability at elevated temperature is reduced. Such surfactants would not be suitable for compositions intended to be stored at temperatures above 30 ° C, as is often the case in warm areas.

PH targets: pH ²⁵ j2 9.0 after 12 weeks at 25 ° C pH ³⁷ i2> 7.5 after 12 weeks at 37 ° C pH ⁴⁵ 4> 8.0 after 4 weeks at 45 ° C

Target values of residual peroxide:

Per ²⁵ i2> 85% after 12 weeks at 25 ° C Per ³⁷ i2> 50% after 12 weeks at 37 ° C Per ⁴⁵ 4> 55% after 4 weeks at 45 ° C

Surfactants that passed the pH and peroxide stability tests are listed below (this combination eliminates surfactants whose good peroxide stability is mainly due to a decrease in the pH of the composition). Samples A3 and A4 are worse in terms of pH stability because their pH has increased. In practice, this increase should not be a problem since the benefits of the alkaline composition are maintained.

Surfactants sorted by decreasing pH stability:

A1> A4 / A3> N1 / A6

Surfactants sorted by decreasing peroxide stability:

NI> A6> A3> A4> Al

A list of surfactants preferred for both pH and peroxide stability is given above. Secondary alkane sulfonates A3 and A4 are particularly suitable for their combination of pH and epoxide stability. In addition to pH and peroxide stability, appropriate phase behavior is also required. In this regard, we have examined surfactants that meet the stability criteria of pH and peroxides, and using the procedure described in this specification as Test B, we have obtained the results below. Test B consists of measuring the viscosity of a series of surfactant solutions whose concentration increases by 5% each. The concentration above which the viscosity exceeds 1.2 kg / cm @ ² is referred to as a threshold concentration in this specification. For the purposes of this test, a value of 1.2 kg.nf.s ^{-1 is} considered as an upper limit in terms of consumer acceptance. The level at which the surfactant is used in the liquid detergent should be below a threshold concentration, preferably at least about 0.10%.

Table 2 - Test results

Surfactant pH ²⁵ 12 tt37 pH ₁₂ pH ⁴⁵ 4 Pe? ⁵ n Per ³⁷ I2 Per ⁴⁵ 4 Target values > 9.0 > 7.5 > 8.0 > 85.0 > 50.0 > 55.0 Al 9.7 9.4 9.5 85.0 53.8 56.4 A2 9.3 6.9 6.7 69.2 34.8 43.2 A3 9.9 10.0 9.9 99.2 58.0 55.6 A4 9.9 * 10.1 * 9.6 84,8 * 51,8 * 64.0 A5 9 7 ** 9 2 ** 8.4 70.4 ** 25.6 ** 22.2 A6 9.4 7.5 8.2 85.4 56.8 62.2 A7 9 4 ** - - ** 7.7 7.3 97,6 ** 82,4 ** 83.8 A8 7.7 7.2 7.0 75.2 37.4 52.5 A9 6.9 5.7 6.1 84.7 70.2 71.1 A10 9.6 *** 9.5 *** 9.5 96,5 *** 88,2 *** 76.5 Nl 9.1 8.2 8.8 90.0 79.6 82.2 N2 8.2 7.5 7.5 90.0 59.0 64.6 Pl 9 3 ** 8.1 ** 7.5 84,2 ** 0 ** 0.2

* Data for 16 weeks ** Data for 8 weeks *** Data for 4 weeks%, preferably at least 9%. This is to provide a margin for inaccurate dosing in commercial production and / or evaporation during storage. Results of the determination of threshold concentrations for the preferred surfactants are shown in Table 3. The numbers in brackets are the viscosity of the aqueous surfactant solution in kg.mÁs ^-1 at 25 ° C and 21 to ¹ at the indicated concentration (Ed. Translator's vs .: figure ¹ is likely to involve rotational viscometer per second).

• · · · · · · · · · · · · · · · · · · · ·

Table 3 - Test results

Surfaktan t Concentration (w / w) below which the viscosity is <1,2 kg / m ² at 25 ° C and 21 s ¹ anionic Al 25 (1,165) A3 35 (0.925) A4 40 (0.755) A6 25 (0.014) nonionic NI 25 (0.675)

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described in more detail based on the following non-limiting examples:

Table 4 details the recipe examples. All composition data are percent by weight. The compositions contained PVP (polyvinylpyrrolidone) as an anti-redeposition and dye-retardant and TINOPAL CBS-X, an optical brightener from Ciba Geigy. The effect of storage on the compositions under various types of isothermal storage conditions is shown in Tables 5 to 9 in the form of pH data and residual peroxide concentration. Since peroxide is more stable under more acidic conditions, a favorable peroxide stability is often achieved when the pH of the composition decreases. However, a decrease in pH is undesirable as it reduces the detergency effect and makes it difficult to activate peroxide with a bleach activator such as TAED.

«· · ··············································

Table 4

Ingredient Ex i k 1 and d 1 2 3 4 5 NI 14.0 17.5 7.5 7.5 15.4 Al 6.0 - - - 5.6 A3 - 7.5 17.5 - 7.0 A4 - - - 17.5 - NaOH * 0.77 - - - 0.71 Dequest 2066 0.5 DPA 0.06 PVP 0.5 Tinopal CBS-X 0.2 peroxide 5.0 water up to 100% initial pH 9.50 9.48 9.50 9.51 9.45 Viscosity (21 s ^-1, 25 ° C) kg.níVs ^-1 0.840 0.280 0,115 0,070 0.370

Additional NaOH is added to reach the final pH

Table 5 - Example 1

Time in weeks PH Residual peroxide (%) Low: 14 ° C Deň: 22 ° C Deň: 32 ° C High: 32 ° C Low: 14 ° C Deň: 22 ° C Deň: 32 ° C Noc: 2 ° C 0 9.50 9.50 9.50 9.50 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 1 9.39 9.25 9.22 9.16 - - - - 2 9.63 9.37 9.37 9.24 100 ALIGN! 99.59 96.69 96.48 4 9.34 9.22 9.19 8.98 - - - - 8 9.37 9.07 8.92 7.21 100 ALIGN! 97.52 88.61 82.61 12 9.43 9.13 8.73 7.0 100 ALIGN! 94.21 84.89 77.64 16 9,30 9.13 7.77 6.50 100 ALIGN! 94.20 84.88 81.98 24 9.47 9.03 7.47 6.05 100 ALIGN! 92.55 78.70 75.80

·······················

Table 6 - Example 2

Doba v weeks PH Residual peroxide (%) Low: 14 ° C Deň: 22 ° C Deň: 32 ° C Deň: 32 ° C Low: 14 ° C Deň: 22 ° C Deň: 32 ° C High: 32 ° C 0 9.48 9.48 9.48 9.48 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 1 9.36 9.44 9.32 9.42 100 ALIGN! 100 ALIGN! 99.60 98.60 2 9.54 9.16 9.14 9.14 100 ALIGN! 100 ALIGN! 97.60 95.19 4 9.44 9.08 9.03 7.35 100 ALIGN! 100 ALIGN! 95.79 89.38 8 9.35 8.87 8.14 6.86 97 100 ALIGN! 92.86 88.17 12 9.52 9.03 7.52 6.50 100 ALIGN! 100 ALIGN! 90.60 92.60

Table 7 - Example 3

Doba v weeks pH Residual peroxide (%) Low: 14 ° C Deň: 22 ° C Deň: 32 ° C Deň: 32 ° C Low: 14 ° C Deň: 22 ° C Deň: 32 ° C High: 32 ° C 0 9.50 9.50 9.50 9.50 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 1 9.40 9.65 9.32 9,30 98.80 99.60 98.60 100 ALIGN! 2 9.61 9.47 9.51 9.38 100 ALIGN! 98.00 96.60 91.38 4 9.46 9.37 9.38 8.88 100 ALIGN! 99.00 87.20 79.36 8 9.31 9.15 9.05 6.99 100 ALIGN! 95 82.17 70.94 12 9.55 9.35 9.15 6.85 100 ALIGN! 96.2 80.6 71.70

Table 8 - Example 4

Doba v weeks PH Residual peroxide (%) Low: 14 ° C Deň: 22 ° C Deň: 32 ° C Deň: 32 ° C Low: 14 ° C Deň: 22 ° C Deň: 32 ° C High: 32 ° C 0 9.51 9.51 9.51 9.51 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 1 9.57 9.55 9.56 9.62 100 ALIGN! 100 ALIGN! 98.97 92.61 2 9.86 9.67 9.74 9.78 100 ALIGN! 100 ALIGN! 96.72 85.42 4 9.61 9.55 9.47 9.35 100 ALIGN! 98.56 78.03 73.10 8 9.68 9.57 9.44 7.80 98.15 96.72 75.16 59.10 12 9.88 9.59 9.37 7.00 100 ALIGN! 98.15 73.70 55.10

Table 9 - Example 5

Doba v weeks PH Residual peroxide (%) Low: 14 ° C Deň: 22 ° C Deň: 32 ° C Deň: 32 ° C Low: 14 ° C Deň: 22 ° C Deň: 32 ° C High: 32 ° C 0 9.45 9.45 9.45 9.45 100 ALIGN! 100 ALIGN! 100 ALIGN! 100 ALIGN! 1 9.53 9.49 9.42 9.39 100 ALIGN! 100 ALIGN! 95.42 92.03 2 9.58 9.50 9.40 9.31 99.4 98.41 95.62 91.44 4 9.62 9.46 9.32 8.16 100 ALIGN! 99.0 91.24 81.08 8 9.80 9.63 9.05 6.99 100 ALIGN! 100 ALIGN! 86.70 78.50

Claims (13)

PATENT CLAIMS A concentrated alkaline isotropic liquid laundry detergent composition comprising at least 15 wt% surfactant, at least 0.2 wt% hydrogen peroxide bleach, and an optical brightener, characterized in that the composition is substantially free of hydrotropes as found in the composition. text defined. A concentrated alkaline isotropic liquid laundry detergent composition according to claim 1 comprising at least 20% by weight surfactant. 3. A concentrated alkaline isotropic liquid laundry detergent composition comprising at least 23% by weight surfactant and at least 0.2% by weight hydrogen peroxide bleach, wherein the composition is substantially free of hydrotropes as defined herein. . Concentrated alkaline isotropic liquid laundry detergent composition according to any one of the preceding claims, characterized in that the surfactant comprises anionic and nonionic surfactant. A concentrated alkaline isotropic liquid laundry detergent composition according to any one of the preceding claims, further comprising an anti-redeposition agent. A concentrated alkaline isotropic liquid laundry detergent composition according to any one of the preceding claims, further comprising a dye transfer agent. Concentrated alkaline isotropic liquid laundry detergent composition according to any one of claims 4 to 6, characterized in that the nonionic surfactant constitutes more than 5% by weight of the total composition. A concentrated alkaline isotropic liquid laundry detergent composition according to claim 7 comprising at most 5% by weight of surfactant not reaching the target pH value in Test A described herein. A concentrated alkaline isotropic liquid laundry detergent composition according to claim 8 comprising at most 5 wt% surfactant not reaching the residual peroxide concentration value in Test A described herein. A concentrated alkaline isotropic liquid laundry detergent composition according to claim 6 wherein at least 95% by weight of the surfactant comprises surfactants which are used at concentrations below the concentration threshold determined by Test B described herein. ·· Concentrated alkaline isotropic liquid laundry detergent composition according to claim 3, characterized in that all surfactants used therein meet the pH target and preferably also the peroxide stability target values according to Test A and are used at concentrations below the concentration threshold determined by testem B. A method of washing laundry with a washing liquid, characterized in that a composition according to any one of the preceding claims is added to the washing liquid together with a bleach activator, preferably TAED. A method of pretreating an article of laundry, wherein the selected portion of said article applies a concentrated alkaline isotropic liquid laundry detergent composition according to any one of claims 1 to 11, leaving it in contact for a short period of time, and then contacting said article. piece washes.