EP0863199A2 - Acidic pH detergent composition - Google Patents

Abstract

Particulate laundry agent composition for washing textiles comprises: (i) 5-70 wt.% anionic, non-ionic, cationic, amphoteric and/or zwitterionic surfactants; (ii) 5-50 wt.% NaHCO3 and/or Na2CO3; and (iii) 20-50 wt.% solid citric acid and/or another (in)organic acidifying agent, such that a 1 wt.% aqueous solution has a pH of less than 7.

Description

The present invention relates to a detergent, the 1 wt .-% solution has acidic pH, that is, the pH of the solution is below 7. In In a further embodiment, the invention relates to a special detergent for wool, whose 1% by weight solution has a pH between 5.5 and 6.0. This Detergent compositions combine high cleaning performance with optimal Gentle on the fibers. In addition to an acidifying agent, they contain tensides, builders and optionally other ingredients common in textile detergents.

The builder properties of organic oligo- and polycarboxylates have been known for a long time, and the use of citric acid and citrates in textile detergents is also a state of the art. Free-flowing powder detergents are generally formulated in such a way that a pH of the solution between 9.8 and 10.5 results, so that preference is given to the salts of citric acid when used in detergents. In particular with regard to the performance of bleaching agents, care is taken to ensure that not only universal but also special and mild detergents deliver a washing liquor which has a pH above 8. Sensitive textiles such as wool tend to become matted in an alkaline environment and the use of commercially available powder detergents in hand washing can cause skin irritation in sensitive people.
As a rule, the negative charge on fibers and pigment components of soiling, which can be measured via the zeta potential, increases with the pH value. This increase in the zeta potential is particularly drastic for wool (see Ullmanns Encyklopadie der Technische Chemie, 4th edition 1983, volume 24, Verlag Chemie, Weinheim, page 74). This negative charge and the consequent rejection of dirt pigment and fiber is one of the reasons for the alkaline setting of detergents and the derived prejudice that acid detergents have poorer washing performance.

The use of citric acid is also broadly stated in the prior art. The European patent application EP-A-0 110 588 (Unilever) describes free-flowing Detergent compositions containing a polycarboxylate builder in amounts of 0.2 up to 50% by weight, an alkali or alkaline earth metal carbonate in amounts of 1 to 80% by weight and 1 to 50 wt .-% of a nonionic surfactant, wherein citric acid or citrate in Amounts between 5 and 40, preferably 5 to 15 wt .-% are used. In the The compositions described in this application exhibit in aqueous solution due to their components pH values above 8.

Textile detergent made from surfactant (s) and a builder system made from aluminosilicates and citric acid / citrate, as well as optional bleaches and Bleach precursors are disclosed in EP-A-0 448 298 (Unilever). This can Citric acid is used in amounts between 3 and 18 wt .-%, the pH of the funds disclosed, given the remaining components, again above 8 lies.

EP-A-0 534 525 (Unilever) also describes free-flowing detergent compositions which have a bulk density between 650 and 1100 g / l and in addition to anionic and nonionic surfactants 5 to 30% by weight sodium carbonate or hydrogen carbonate and 1 to 15 wt .-% of a citric acid with a defined Particle size included. These detergent compositions have improved Washability and solubility, which is not affected even during storage.

Detergent compositions with subsequently mixed citric acid Solubility improvements are known from EP-A-0 581 857 (Procter & Gamble). The disclosed granular detergents or detergent additives contain in addition 5 to 70 % By weight of surfactant (s) 5 to 75% by weight of admixed sodium carbonate and additionally to 15% by weight of citric acid, which improves the solubility of the detergent. Also at The detergent compositions disclosed in this document have a pH of Solution due to the components above 8.

Finally, international patent application WO91 / 17232 (Procter & Gamble) describes granular laundry detergents with low pH and bulk densities between 500 and 600 g / l, the aluminosilicate (s), citric acid and carbonate builders contain. Citric acid is used here in amounts between 4 and 10% by weight, wherein the pH of the 1 wt .-% solution is between 7 and 9.3.

Brausezusätze" werden sowohl die Citronensäure als auch das Hydrogencarbonat als feinteilige Feststoffe eingesetzt. Aus diesem Stand der Technik resultiert auch die Verwendung eines Kohlendioxid entwickelnden Systems in granularen Waschmittelzusammensetzungen, die in der US-A-4,414,130 (Colgate) beschrieben ist.The use of mixtures of citric acid and sodium hydrogen carbonate to improve the solubility of pharmaceutical formulations is also generally known. With the aim of a uniform distribution of these

Both citric acid and bicarbonate are used as finely divided solids. This prior art also results in the use of a system which produces carbon dioxide in granular detergent compositions, which is described in US Pat. No. 4,414,130 (Colgate).

The invention was based on the object, a particulate detergent composition To provide the conventional results in the washing result Powder detergents equals or surpasses them, but by lowering them to values 7 acidic pH value of the wash liquor is optimal fiber protection for wool and enables optimal skin protection in hand washing.

a) 5 bis 70 Gew.-% eines oder mehrerer Tenside, ausgewählt aus der Gruppe der anionischen, nichtionischen, kationischen, amphoteren und zwitterionischen Tenside sowie Mischungen hieraus,

b) 5 bis 50 Gew.-% Natriumhydrogencarbonat und/oder -carbonat,

c) 20 bis 50 Gew.-% fester Citronensäure oder eines anderen organischen oder anorganischen Acidifierungsmittels sowie Mischungen hieraus,

wobei der pH-Wert der 1 Gew.-%-igen Lösung in Wasser unterhalb von 7 liegt.The invention relates to a particulate detergent composition for washing textile fabrics, containing, in addition to other optional components

a) 5 to 70% by weight of one or more surfactants selected from the group of anionic, nonionic, cationic, amphoteric and zwitterionic surfactants and mixtures thereof,

b) 5 to 50% by weight of sodium hydrogen carbonate and / or carbonate,

c) 20 to 50% by weight of solid citric acid or another organic or inorganic acidifying agent and mixtures thereof,

wherein the pH of the 1 wt .-% solution in water is below 7.

The measuring temperature of the pH values specified in the context of this application is 20 ° C. To keep the pH of the wash liquor below 7 in the acidic range lower, the detergent compositions according to the invention one or several acidifiers added. This component c) is dosed in Orders of magnitude that ensure that the pH of the wash liquor is well below Contamination level falls below 7. Depending on the other components of the detergent composition, which may change the pH, is the Component c) in amounts between 20 to 50 wt .-%, preferably between 20 and 40 wt .-% and in particular between 25 and 35 wt .-% in the inventive Contain detergent compositions.

As component c), in addition to or in addition to, are preferably used Citric acid, in particular the solid mono-, oligo- and polycarboxylic acids. From this group, tartaric acid, succinic acid, malonic acid, Adipic acid, maleic acid, fumaric acid, oxalic acid and polyacrylic acid. Organic Sulfonic acids such as amidosulfonic acid can also be used. Also inorganic acids or acidic salts can in the detergent compositions according to the invention as Component c) or used as a component of component c). Below are especially preferred the boric acid and alkali hydrogen sulfates, with the Alkali salts in addition to the sodium salts, the potassium salts can also be used.

The detergent compositions according to the invention particularly preferably contain as component c) citric acid, Sokalan DCS® (BASF) or sodium hydrogen sulfate or mixtures of these.

From an application technology point of view, the requirement for the acidifying agent (s) is to make sure that they are not volatile. From this point of view are fixed Acidifiers that have a low tendency to sublimation and a high one Agree melting point with a good water solubility, clearly preferred. Liquid or pasty acidifying agents can only be used in minor amounts below 5 wt .-% of the total composition are used and in their Assembly measures must be taken to ensure storage stability To ensure even with increased humidity. Liquid and volatile or in Powder detergents such as salt, saltpetre or unmanageable acids Therefore, sulfuric acid is automatically forbidden the acidifying agent (s) also ensure that the resulting wash liquor does not harm textiles or human skin.

The detergent compositions according to the invention contain the second essential component b) Sodium bicarbonate and / or sodium carbonate, where Sodium bicarbonate with regard to the acidic wash liquor to be adjusted with pH values is preferred under 7. Component b) serves as a builder and carries to adjust the pH at. Both the bicarbonate and the carbonate react with the acidifying agent and release carbon dioxide. Hereby becomes the dissolution of the detergent composition in the hand wash basin and also the washability in the washing machine is improved, on the other hand by the mixing of the fleet quickly a solution without concentration differences receive.

Component b) is in the detergent compositions according to the invention in Amounts from 5 to 50% by weight, preferably from 10 to 40% by weight and in particular from Contain 20 to 35 wt .-%. Agents which are particularly preferred as component b) only sodium bicarbonate in amounts of 10 to 40 wt .-% and contain in particular from 20 to 35 wt .-%.

The third component a), which contain the agents according to the invention, is derived from the Group of anionic, nonionic, cationic, amphoteric and zwitterionic Surfactants and mixtures selected from them.

As anionic surfactants come in the invention Detergent compositions mainly alkyl sulfates and sulfonates, Alkylbenzenesulfonates (ABS), α-sulfofatty acid esters (ester sulfonates), short and long chain Glycerol esters, fatty alcohol sulfates (FAS), alkyl sulfosuccinic acid (ASB) and soaps in Consideration. Examples of anionic surfactants from the above groups are those on the market available Eltesol® SX30 (sodium xylene sulfonate, commercial product from Albright & Wilson), Triton® H55 (potassium phosphate ester, commercial product from Union Carbide), Marlinat® DF8 (sodium sulfosuccinate, commercial product from Hüls), Hostapur® SAS 30X (sodium alkane sulfonate, commercial product from Hoechst), Hostapur® 0S (Sodium olefin sulfonate, commercial product from Hoechst), Petronat® S (Sodium petroleum sulfonate, commercial product from Witco), Hamposyl® L 30 (Sodium lauroyl sarcosinate, commercial product from Hampshire); Fenopon® T33 (Sodium-N-methyl-N-oleyl taurate, commercial product from GAS) and Fenopon® AC 78 (Sodium coconut isethionate, commercial product from GAS).

Cationic surfactants used in the detergent compositions according to the invention can be included, come from the group of quaternary ammonium salts, the primary, secondary and tertiary amines and their salts and the polyamines. Examples of such cationic surfactants are Empigen® BAC (Alkyldimethylbenzalkonium chloride, commercial product from Albright & Wilson), Armac® 1 (tallow amine acetate amine salts, commercial product from Akzo), Synprolan® 35N3 (N-alkyl propanediamine, commercial product from ICI), Stepantex® VA and VS (Methyl-N (2-hydroxyethyl) -N, N-di (tallow acyloxyethyl) ammonium methosulfate, Commercial product from Stepan) and Symprolan® 35 X10 (ethoxylated primary Amine with 10 EO, commercial product from ICI).

The nonionic surfactants used in the detergent compositions according to the invention originate primarily from the group of the amine oxides, the glucosides and alkyl polyglucosides (APG), the alkoxylated fatty alcohols and their esters, the alkoxylated fatty acids and alkylphenols, the alkanolamides and their alkoxylation products, the sucrose and sugar esters, the fatty acid esters and the alkylamine. Examples include Synperonic® A (alcohol ethoxylates, commercial product from ICI), Dehydol® LT 7 (ethoxylated C _12-18 fatty alcohol, commercial product from Henkel), Crodet® L24 (polyoxyethylene-24-lauric acid, commercial product from Croda), Synperonic® NP nonylphenol ethoxylates, commercial product from ICI), Empilan® CME (coconut monoethynolamide, commercial product from Albright & Wilson), Triton® CG110 (alkyl glucoside, commercial product from Union Carbide), Glucam® E10 (methylglucoside with 10 EO , Amerchol commercial product), Crodesta® SL 40 (sucrose cocoate, commercial product from Croda), Empilan® MAA (ethoxylated coconut monoethanolamide, commercial product from Albright & Wilson), Ethomeen® C12 (ethoxylated coconut amine, commercial product from Akzo) and Tegosoft® 16 B (cetyl isooctanoate, commercial product from Goldschmidt).

Possibly used amphoteric surfactants, mostly only in combination with Anionic surfactants are selected from the group of alkyl betaines, Alkylaminopropionates, alkyliminodipropionates, alkylglycinates, carboxyglycinates, Alkylimidazolines, sulfobetaines, alkylpolyaminocarboxylates and Polyamphocarboxyglycinates. Examples of these types of surfactants are Tegobetain® A4080 (Alkyldimethylbetaine, commercial product from Goldschmidt), Ampholak® XCU (Coconut amphoglycolate, commercial product from Bero Nobel), Amphotensid CT® (Alkylimidazoline based amphoteric surfactant, commercial product from Zschimmer and Black), Ampholak® XCO 30 (coconut amphocarboxyglycinate, commercial product of Bero Nobel) and Sandobet® SC (coconut amide sulfobetaine, commercial product of Sandoz).

The surfactants or surfactant mixtures of component a) are used in amounts between 5 and 70 wt .-%, based on the total detergent composition. Preferred agents contain 20 to 50, preferably 25 to 40 wt .-% of the component a).

In special embodiments of the invention, component a) consists exclusively of nonionic surfactants from the group of the ethoxylated alcohols, the alkyl polyglycosides and the glucamides. These surfactants or mixtures of them have clear advantages with regard to the preparation of the agents according to the invention and with regard to their primary and secondary washing power. Glucamides also have the advantage that they are solid, that is, in the simplest case, the agents can be prepared by mixing different solids. In addition, glucamides have the advantage that protonation of the nitrogen atom can take place in the acidic pH range and, as a result, there is a change in charge. This quasi-cationic character can be pulled up on suitable textile surfaces and connected to one soft grip ".

Mixtures of nonionic and cationic surfactants can also be used as a component a) are used. This can be the benefits of using cationic surfactants with regard to static charge and soft care offers, directly in the wash liquor be used. Special embodiments of the detergent compositions according to the invention advantageously contain in addition to nonionic surfactants such as Alcohol ethoxylates cationic compounds from the group of the alkyl-N (2-hydroxyethyl) -N, N-di (acyloxyethyl) ammonium salts.

When the agents according to the invention are dissolved in water, an acidic wash liquor, the means a wash liquor with a pH below 7, measured on a 1 wt .-% aqueous solution. The pH value is adjusted by the Ingredients adjusted so that an increase to values above even when contaminated 7 not done. The inventive compositions contain with particular advantage Detergent compositions the individual components a) to c) in such Amounts that the pH of the 1 wt .-% aqueous solution between 5.5 and 6.5 lies.

In the simplest case, the agents according to the invention are produced by simple means Mixing solid components. When using liquid or pasty surfactants can be placed in the mixer or on a solid mixture in the mixer is submitted to be given up. All known granulation processes of the State of the art can be used. Also spraying the surfactants on one or several fixed components are possible, possibly followed by one Surface treatment like powdering. Different surfactants of component a) can be applied to different solids or granulated together with them in order to increase storage stability even with increased humidity ensure, where compounds are also conceivable in which the component b) Surfactant sprayed and then powdered with the acidifying agent.

There is also the option of acidic and alkaline or neutral To subject the component to an extrusion process. Through this embodiment are obtained means with high bulk density (so-called extrudates), which as Compact detergents can be used.

In addition to the ingredients a), b) and c) mentioned, the agents according to the invention can contain other common ingredients of detergents. These include in particular other builders, foam inhibitors, salts of polyphosphonic acids, optical Brighteners, enzymes, enzyme stabilizers, small amounts of neutral filling salts as well Dyes and fragrances, opacifiers or pearlescent agents.

The agents according to the invention are suitable for both machine and Hand wash all textiles. The funds for Washing wool used in a washing machine or hand wash since the acid wash liquor significantly minimizes the tendency of the wool textiles to felt. In the Hand washing protects the pH of the wash liquor from the natural acid mantle Skin and thus prevents skin irritation.

Examples:

Agents E1 to E5 according to the invention were prepared by mixing the following starting materials: Composition [% by weight]: E1 E2 E3 E4 E5 Na-C _12-18 fatty alcohol sulfate 33.3 - - - - C _12-18 fatty alcohol with 7 EO - 33.3 - - 23.3 Cocoamidopropyl betaine - - 33.3 - - Plantacare® 1200 - - - 33.3 - Stepantex® VS 90 - - - - 10.0 Sodium bicarbonate 33.3 33.3 33.3 33.3 33.3 Citric acid 33.3 33.3 33.3 33.3 33.3 Foam inhibitor (silicone) 0.1 0.1 0.1 0.1 0.1 pH of the 1% by weight solution in water (20 ° C) 5.6 5.6 5.6 6.0 5.2 Stepantex® VS 90: methyl-N (2-hydroxyethyl) -N, N-di (tallow acyloxyethyl) ammonium methosulfate, from Stepan
Plantacare®1200: C ₁₂ -C ₁₆ alkyl oligo- (1.4) glucoside, 50% in water, from Henkel

Agents E1 to E5 according to the invention were used in comparison to a commercially available powder detergent for wool (V1) for washing textiles soiled with test soils. The cleaning performance was determined via the reflectance, the mean values of which are listed in Table 2. Cleaning performance [% remission], mean values for all textiles E1 E2 E3 E4 E5 V1 Initial value 82.4 82.4 82.4 82.4 82.4 82.4 Dust / grease pollution 55.9 62.4 58.1 59.7 61.3 52.1 Soot / grease pollution 54.7 61.4 57.6 53.6 60.1 52.1 Cosmetic pollution 46.3 57.3 48.5 55.8 57.6 51.5 Ø over all soiling 52.3 60.4 54.7 56.4 59.7 51.9 Ranking 5 1 4th 3rd 2nd 6

Claims (10)

Particulate detergent composition for washing textile fabrics, containing, in addition to other optional components a) 5 to 70% by weight of one or more surfactants selected from the group of anionic, nonionic, cationic, amphoteric and zwitterionic surfactants and mixtures thereof, b) 5 to 50% by weight of sodium hydrogen carbonate and / or carbonate, c) 20 to 50% by weight of solid citric acid or another organic or inorganic acidifying agent and mixtures thereof, wherein the pH of the 1 wt .-% solution in water is below 7. Detergent composition according to claim 1, characterized in that it component a) in amounts of 20 to 50, preferably 25 to 40,% by weight, based on the total composition. Detergent composition according to one of claims 1 to 2, characterized characterized in that component c) in amounts of 20 to 40, preferably from 25 to 35% by weight, based on the total composition, is contained. Detergent composition according to one of claims 1 to 3, characterized characterized in that one or more surfactants from the Group of ethoxylated alcohols, alkyl polyglycosides and glucamides in the funds are included. Detergent composition according to one of claims 1 to 4, characterized characterized in that component a) in addition to nonionic surfactants cationic surfactants, especially alkyl-N (2-hydroxyethyl) -N, N-di (acyloxyethyl) ammonium salts, contains. Detergent composition according to any one of claims 1 to 5, characterized characterized in that as component b) 10 to 40, preferably 20 to 35 wt .-% Sodium bicarbonate can be used. Detergent composition according to any one of claims 1 to 6, characterized characterized in that component c) is selected from the group of solid mono-, oligo- and polycarboxylic acids and the inorganic acid salts. Detergent composition according to any one of claims 1 to 7, characterized characterized in that as component c) citric acid or Sodium hydrogen sulfate or mixtures of these can be used. Detergent composition according to one of claims 1 to 8, characterized characterized in that the pH of the 1 wt .-% aqueous solution between 5.5 and 6.5 lies. Use of an agent according to one of claims 1 to 9 for washing Wool in a washing machine or hand wash.