WO1993001270A1

WO1993001270A1 - Liquid washing agent

Info

Publication number: WO1993001270A1
Application number: PCT/EP1992/001508
Authority: WO
Inventors: Hans-Jürgen Riebe; Walter Parchatka; Reiner Schackmann
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1991-07-12
Filing date: 1992-07-03
Publication date: 1993-01-21
Also published as: DE4123142A1

Abstract

The invention concerns an aqueous liquid washing agent containing surfactant, hydrogen peroxide and a water-soluble borate in amounts such that the molar ratio of H2?O2? to boron is at least 1.5 : 1. When in concentrated form, the washing agent has a pH of less than 8.5. When diluted to the concentration at which it is used, however, its pH increases to significantly higher values, thus giving the dissolved agent good bleaching and cleaning characteristics.

Description

"Liquid detergent"

The present invention is in the field of textile detergents and relates to a liquid textile detergent containing bleach.

In the field of textile laundry, powdery agents have been known for a long time, which contain all the active ingredients that are necessary for the laundry and at the same time have an adequate storage stability in the solid state. Liquid textile detergents, on the other hand, which have recently been increasingly developed, often have only very limited storage stability due to interactions between individual ingredients. The incorporation of bleaching agents into liquid systems is particularly problematic. In the case of liquid detergents which contain inorganic peroxy compounds as bleaching agents, a distinction is made today between several development directions: one relates to low-water or water-free systems in which solid detergent active ingredients are suspended in liquid nonionic surfactants or other organic liquids. Solid inorganic peroxo compounds, such as sodium perborate, are primarily used as bleaching agents (see, for example, DE 37 04 874). A disadvantage of these agents is the need to use disproportionately large amounts of nonionic surfactants or organic solvents which, in addition to high costs, also cause unnecessary pollution of the waste water. In addition, liquid detergents are known, for example from patent applications WO 90/15857 and WO 91/902, in which the bleaching agent is suspended in a predominantly aqueous phase. Here too, large amounts of auxiliary substances are required in order to achieve sufficient results with regard to stability and washing effectiveness. Finally, a third direction of development relates to liquid detergents in a homogeneous, mostly predominantly aqueous phase, in which hydrogen peroxide in the form of a solution is primarily used as the bleaching agent (see for example EP 86511 and US 4430236). Because of the low stability of hydrogen peroxide in the alkaline range, it is necessary to make these detergents largely pH neutral or slightly acidic. However, this results in a loss of washing effectiveness, since the dirt removal is generally quicker and more thorough at alkaline pH values. Work is therefore still ongoing to improve these liquid detergents containing bleach.

The present invention offers a solution to these problems in the form of an aqueous liquid detergent with a pH of not more than 8.5, which contains surfactant, hydrogen peroxide and, if appropriate, other active substances which are customary in detergents and which is distinguished in that it additionally contains 1 to Contains 20 percent by weight of water-soluble borate and the molar ratio of hydrogen peroxide to boron is at least 1.5: 1.

In its undiluted state, the new detergent has a pH value near the neutral point and thus ensures a high stability of the hydrogen peroxide it contains during storage. When the agent is diluted to the concentrations customary for the washing process, the pH value rises to alkaline ranges, so that not only good bleaching effects but also excellent washing performance are achieved with the washing liquors. In addition, the new detergents are distinguished by the fact that they can be formulated as homogeneous, single-phase systems, so that sedimentation problems during storage are also eliminated.

Suitable surfactants for the new detergents are all surfactants from the classes of the nonionic surfactants, the anionic surfactants, the surfactants with betaine structure and the cationic surfactants which are usually used in liquid detergents, provided that they are combined with the other constituents of the detergent, in particular with the hydrogen peroxide are tolerated. Synthetic anionic surfactants, nonionic surfactants and mixtures of these types of surfactants and mixtures of these surfactants with soaps are particularly preferred. Suitable synthetic anionic surfactants are in particular those of the sulfonate and sulfate type. The surfactants of the sulfonate type are alkylbenzenesulfonates with a Cg_i5-alkyl radical, olefin sulfonates, ie mixtures of alkene and hydroxyalkanesulfonates and disulfonates, such as are obtained, for example, from C12-Ci8 ~ monoolefins with terminal or internal double bond by sulfonating with gaseous Sulfur trioxide and subsequent alkaline or acidic hydrolysis of the sulfonation products are considered. Also suitable are the alkanesulfonates which are obtainable from (2- Cjg-alkanes by sulfochlorination or sulfoxidation and subsequent hydrolysis or neutralization or by bisulfite addition to olefins, as well as the esters of alpha-sulfo fatty acids, e.g. the alpha-sulfonated methyl Suitable surfactants of the sulfate type are the sulfuric acid monoesters from primary alcohols of natural or synthetic origin, ie from fatty alcohols, such as, for example, coconut fatty alcohols, tallow fatty alcohols, lauryl, myristyl alcohols. , Palmityl or stearyl alcohol, or the Cιo-C2θ ^_ 0xoalkoholen, and those secondary alcohols of this chain length, including the sulfuric acid monoesters of the aliphatic primary alcohols or ethoxylated secondary alcohols ethoxylated with 1 to 6 mol ethylene oxide (EO), the so-called ether sulfates, Sulfated fatty acid alkanolamides and sulfated fatty acid are also suitable re-monoglycerides.

Suitable anionic surfactants based on natural raw materials are primarily the wash-active soaps, i.e. H. the salts of the fatty acids with preferably 12 to 18 carbon atoms. Longer-chain soaps can be present as foam inhibitors. All anionic surfactants are preferably used as alkali salts, in particular as sodium salts. Particularly preferred anionic surfactants are the alkylbenzenesulfonates and the soaps.

Nonionic surfactants are the addition products of 3 to 20 moles of ethylene oxide (EO) with primary Cιo-C2θ- ^A lkohole ^wιe _f ^z ^"B" are ^on coconut or tallow fatty, oxoalcohols or secondary alcohols with the same Ket¬ tenlänge particularly important. In addition to the water-soluble compounds included here, the water-insoluble or not completely water-soluble compounds low ethoxylated fatty alcohol polyglycol ethers with 3 to 7 ethylene glycol ether residues in the molecule can be of importance if they are used together with water-soluble nonionic or anionic surfactants. In combination with the low ethoxylated fatty alcohol polyglycol ethers, the non-ionic surfactants are also the water-soluble addition products containing 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups of ethylene oxide on polypropylene glycol, alkylene diamine polypropylene glycol and on alkyl polypropylene glycols with 1 to 10 carbon atoms in the Alkyl chain in which the polypropylene glycol chain acts as a hydrophobic residue.

Nonionic surfactants of the amine oxide or sulfoxide type can also be used, for example the compound N-cocoalkyl-N, N-dimethylamine oxide. Also suitable as nonionic surfactants are the addition products of ethylene oxide and long-chain fatty acids and fatty acid amides with 12-18 C atoms, and the water-soluble alkylglucosides, the hydrophobic Cg-C20-alkyl radical of which is linked to a mostly oligomeric, hydrophilic glucoside radical. However, the preferred nonionic surfactants are the addition products of ethylene oxide and long-chain alkanols, especially fatty alcohols.

The surfactants with betaine structure primarily include the quaternary ammonium compounds which, in addition to a longer alkyl chain with about 12 to 18 carbon atoms on nitrogen, carry a substituent with carboxyl or sulfonate groups. In particular, these substituents are the carboxymethyl or the omega-sulfopropyl group. Quaternary ammonium compounds which carry a long-chain alkyl group with preferably 12 to 18 carbon atoms in addition to three short-chain alkyl groups which are optionally substituted by hydroxyl groups are particularly important as cationic surfactants.

The agents according to the invention preferably contain not only one surfactant, but a mixture of several surfactants. Mixtures of alkylbenzenesulfonates and water-soluble additive products of ethylene oxide with long-chain alcohols and mixtures which contain these two types of surfactant together with soap are particularly preferred. The total amount of surfactants is 1 to 60 percent by weight, preferably 10 to 40 percent by weight, in the agents according to the invention.

The agents contain hydrogen peroxide as a further essential component, which is responsible for the bleaching performance of the agents. The amount of hydrogen peroxide in the compositions is preferably 2 to 30 percent by weight and in particular 5 to 10 percent by weight. Preparations with up to 10 percent by weight of H2O2 are generally not considered to be corrosive, so that these preparations are also suitable for manual handling. To produce the agents according to the invention, it is of course also possible to start from more highly concentrated hydrogen peroxide or from hydrogen peroxide addition compounds, for example on urea.

The third essential component of the new agents are the water-soluble borates. These are alkali salts, preferably sodium salts, of the most diverse boric acids, for example sodium methaborate (NaBÜ2) and borax (Na2B4Ü7.10 H2O). The amount of borates is 1 to 20 percent by weight, preferably 3 to 15 percent by weight of the finished agent, the amount of borate being calculated as if all of the boron were present as sodium metaborate tetrahydrate. This also applies if, due to the pH value, there is actually a mixture of boric acids and borates. The decisive factor for the properties of the new agents is the molar ratio of hydrogen peroxide to boron, which should be at least 1.5: 1, preferably at least 2: 1 and in particular at least 4: 1. The upper limit of this ratio is about 150: 1, preferably not more than 50: 1. Sodium perborate, in particular the readily water-soluble sodium perborate monohydrate, and additional hydrogen peroxide can also be used to produce this ratio. It is noteworthy that when these molar ratios are selected, a fully sufficient pH jump is achieved without the addition of cis-diols which form complexes with boron. The content of fiber which is not actually washing-active can thus be kept low.

In addition to the mandatory ingredients of surfactant, hydrogen peroxide, borate and water, the new agents can also add other components such as: are known in liquid detergents. When selecting these ingredients, care must also be taken to ensure that there are no incompatibilities with other components, in particular with hydrogen peroxide. Examples of such optional components are water-miscible organic solvents, hydrotropes, complexing agents for heavy metals and / or for the ions of water hardness, pH regulators, perfume, optical brighteners, dispersants, bleach activators, foam inhibitors, enzymes, and graying inhibitors. With these additional active ingredients, the agents can be improved in individual directions of action without impairing the basic properties of the agents. Substances which can be mixed with the other constituents of the compositions to form single-phase systems are preferably used, but it is also possible to incorporate insoluble components if the measures are taken to ensure adequate stability of the dispersion.

The amounts of the optional components mainly depend on the purpose that is to be achieved with them. Water-miscible organic solvents, preferably lower alcohols with 2 to 3 carbon atoms or ether alcohols with up to 6 carbon atoms, are generally incorporated in amounts not exceeding 40 percent by weight, preferably in amounts between 5 and 20 percent by weight. Like the hydro trope, the organic solvents serve primarily to combine the various constituents of the compositions into a homogeneous solution. Examples of suitable hydrotropes are the non-surface-active sulfonic acids, carboxylic acids and sulfocarboxylic acids containing 2 to 9 carbon atoms, in particular sodium cumene sulfonate and sodium xylene sulfonate, but also sodium acetate and urea. The amount of hydrotropes is usually not more than 10 percent by weight, preferably between 1 and 8 percent by weight. The main task of complexing agents for heavy metals is to ensure the stability of the hydrogen peroxide in the liquid agents and to prevent fiber damage due to traces of heavy metals when the agents are used. Conventional aminopolycarboxylic acids and polyphosphonic acids and their alkali metal salts, for example ethylenediamine tetraacetate and hydroxyethane diphosphonic acid, which generally do not exceed 2% by weight, preferably between 0.01 and 1% by weight, are highly suitable for the new agents. Percent can be used. Low-molecular or high-molecular polycarboxylic acids, for example citric acid, carboxymethyloxysuccinic acid and homo- or copolymers of acrylic acid, methacrylic acid and maleic acid as such or in the form of their water-soluble salts are usually used for sequestering the water hardness. The amount of sequestering agent is usually not more than 10 percent by weight, preferably between 0.5 and 3 percent by weight, based on the total agent. The amount of the other optional components is generally not more than 10 percent by weight, preferably between 0.1 and 10 percent by weight, based on the total agent.

In order to achieve the highest possible stability of the hydrogen peroxide during the storage of the agents, the agents should not have a pH in the undiluted state above 8.5 and preferably between 6 and 8. If this pH value does not automatically result from the choice of suitable starting materials, suitable pH regulators are added. As a rule, these are strong acids or bases, for example sulfuric acid, alkylbenzenesulfonic acid and sodium hydroxide solution. Salts with an acidic or alkaline reaction can also be suitable. Larger proportions of components which have a buffer range in the range between the pH value of the undiluted agent and a pH value of about 10 generally have an unfavorable effect, since this can impair the pH jump inherent in the agents when diluted.

The preparation of the agents according to the invention presents no problems. In general, the components are put together in simple mixing apparatus without having to follow a particular order. In individual cases, however, it can also be expedient to start from premixes of individual components or from stock solutions. Of course, when dealing with highly concentrated hydrogen peroxide, the respective safety regulations must be observed. Examples 1. Liquid detergent

By mixing the individual components together, several liquid detergents according to the invention (a - f) and, for comparison, some corresponding detergents without borate content (g - 1) were produced. The composition of the compositions is given in Table 1, the percentages by weight in each case referring to pure components, while hydrogen peroxide, for example, was used as a 35% strength aqueous solution and alkylbenzenesulfonate as a 55% strength suspension. To prepare the agents, water was initially introduced, then sodium hydroxide solution and organic solvents were added, and the remaining components were then stirred in in the order given. If necessary, the sodium salts formed from acids. If cloudiness occurred in between, this was dissolved again at the latest when the hydrogen peroxide was added, so that all agents were finally available as water-clear liquids which were viscous at room temperature.

The components listed in short form in Table 1 are the following compounds:

Dequest ( ^R ) 2066: pentasodium salt of ethylenediaminetetramethylenephosphonic acid turpinal ( ^R ) SL: hydroxyethane diphosphonic acid dehydol ( ^R ) LT 7: Ci2 / i8 coconut alcohol + 7 ethylene oxide (EO) dehydol ( ^R ) LST: mixture of Ci2 / i8 ^coconut alcohol + 5 EO and

Ci2 / 14 coconut alcohol + 3 EO Lutensol ( ^R ) A 07: Ci3 / i5-0xo alcohol + 7 EO

Table le 1 c d e

Water fully salted, to 100

NaOH

Ethanol

Propylene glycol

Technical oleic acid

Technical lauric acid

citric acid

Dequest 00 2066

Turpinal (O SL

Na-Dodecy 1 benzo 1 su 1 f oπat

Dehydol W LT 7

Dehydol 00 LST 80/20 opt. Raiser (Tinopal 00 BS-x)

Lutensol 00 A 07

NaBθ x 4 H ₂ 0

Boric acid

H ₂ 0 ₂

Triacetin (bleach activator)

pH undiluted pH at 9.25 g / 1 water

/ «

The detergents listed in Table 1 did not separate out any precipitate or showed phase separation even after prolonged storage. The active oxygen content also proved to be stable. The increase in alkalinity caused by the borate content when diluting the compositions to the use concentration can be seen from the pH values listed in Table 1.

2. Washing attempts

Washing tests were carried out with the detergents in a drum washing machine of the Miele W 722 type under the following conditions:

Program: One-eye process Temperature: 60 ° C Water hardness: 17 ° dH Volume of the washing liquor 20 1 Load: 3.5 kg laundry load Soiling: Several per wash cycle in the form of artificially soiled cloths of about 12 x 12 cm

Detergent: 185 g / wash

The evaluation was carried out by measuring the light remission at 465 nm on the dried lobules with the aid of a Zeiss RFC 24 measuring device. The results on various wash- and bleach-sensitive soiling are given in Table 2 as a percent light remission by way of example for some of the agents. They clearly demonstrate the excellent effectiveness of the agents according to the invention.

//

Table 2: Results of the washing tests

(Mean values of remission measurements on 3 lobes)

Claims

lPatent claims

1. Aqueous liquid detergent with a pH of not more than 8.5, which contains surfactant, hydrogen peroxide and, if appropriate, other active substances customary in detergents, characterized in that it additionally contains 1 to 20% by weight of water-soluble borate, calculated as NaBÜ2 x 4H20, and the molar ratio of H2O2 to boron is at least 1.5: 1.

2. Detergent according to claim 1, in which the molar ratio of H2O2 to boron is at least 2: 1 and preferably at least 4: 1.

3. Detergent according to one of claims 1 or 2, containing 2 to 30, preferably 5 to 10 wt .-% of H2O2 and preferably 3 to 15 wt .-% of borate.

4. Detergent according to one of claims 1 or 2, containing 1 to 60 wt .-%, preferably 10 to 40 wt .-% of surfactant.

5. Detergent according to one of claims 1 or 2, which is free of dispersed portions.

6. Detergent according to claim 1, containing

1 to 60 wt .-%, preferably 10 to 40 wt .-% of surfactant from the

Group of synthetic anionic surfactants, nonionic surfactants, soaps and mixtures thereof,

2 to 30% by weight, preferably 5 to 10% by weight of hydrogen peroxide, 1 to 20% by weight, preferably 3 to 15% by weight of water-soluble

Borate, 0 to 40% by weight, preferably 5 to 20% by weight of water-miscible organic solvent, 0 to 10% by weight, preferably 1 to 8% by weight of hydrotrope, 0 to 2% by weight, preferably 0.01 to 1% by weight of heavy metal complexing agent, 12

0 to 10% by weight, preferably 0.5 to 3% by weight of sequestering agent, 0 to 10% by weight, preferably 0.1 to 10% by weight of other constituents customary in detergents,

ad 100 wt .-% water.