EP0486786A1 - Liquid, foaming detergent - Google Patents

Abstract

Conventional liquid dishwashing agents are predominantly produced from surfactants with a petrochemical basis and which additionally have the disadvantage of incomplete biodegradability. A liquid, foaming detergent which has all the beneficial properties of conventional dishwashing agents while, at the same time, being well tolerated by skin and very environmentally compatible is now proposed. The surfactant ingredients are predominantly composed of alkyl polyglycosides and anionic surfactant as well as other surfactants.

Description

The invention relates to an environmentally friendly, foaming, liquid cleaning agent.

Liquid, foaming cleaning agents aim at the manual cleaning of hard surfaces, especially in the household, such as. B. ceramics, porcelain, glass, metal and plastic. The most important area of application are manual dishwashing detergents for cleaning dishes.

Modern products here consist of neutral aqueous formulations based on highly foaming surfactants. The main components are sulfonates, such as. B. alkylbenzenesulfonates or sec-alkanesulfonates, both combined with fatty alcohol ether sulfates or fatty alcohol sulfates (EP-A-0 112 047). Small amounts of fatty acid alkanolamides and, more rarely, oxyethylates are added. Other common ingredients are solubilizers, colors and fragrances, preservatives etc.

The criteria for the quality of the detergent are primarily the rinsing effect and the skin and environmental compatibility. Other characteristics include the foaming power and finally the viscosity of the detergent concentrate.

Generally recognized methods for determining the cleaning effect are a) the plate test with foaming detergents, the end point of which is determined by the foam disintegration, and b) the fat titration, as a measure of the cleaning power, both of which have very similar results (see G. Jakobi in H. Stache, Tensid Taschenbuch, 2nd edition, Munich 1981, pp. 252 ff.

The importance of the skin compatibility of the detergent is immediately apparent when you consider the duration of skin contact during manual rinsing. When the consumer assesses the cleaning power, the foaming power of the solution plays a significant role, for example in the sense that the longer the cleaning solution foams during the rinsing process, the greater its cleaning power.

Another important consumer property of the cleaning liquid is the flow behavior. Too high and too low viscosities make manual dosing of the cleaning concentrate difficult. Very low viscosities also lead to the impression of a low active substance content. Average viscosities between 150 and 300 mPa · s at shear rates of approx. 10 sec⁻¹ are ideal for household products.

The currently customary cleaning agents usually have a good cleaning effect, degrading flow behavior and a pronounced, possibly excessive foaming power. In contrast, these mixtures have a low skin-friendliness, since their essential components - namely the anionic surfactants of the sulfonate or sulfate type - are highly irritating to the skin. Another disadvantage with regard to the scarcity of raw material reserves is the predominantly petrochemical basis of the anionic surfactants mentioned, combined with incomplete biodegradability.

The object of the invention was therefore to provide a cleaning agent which implies all the advantages mentioned, but at the same time offers high skin compatibility and excellent environmental compatibility.

The object was achieved by a liquid cleaning agent, the surfactant combination of which contains highly environmentally compatible alkyl polyglycosides. Other constituents are alternatively fatty alcohol ether sulfates, fatty alcohol sulfates and alkylbenzenesulfonates.

The invention relates to a liquid, foaming cleaning agent whose surfactant content
a% by weight alkyl polyglycoside,
b% by weight of anionic surfactant and
c% by weight of other surfactants
, which is characterized in that a complements b + c to 100 parts, where b = 10 to 59 parts and c = 0 to 5 parts if the anionic surfactant is fatty alcohol ether sulfate or fatty alcohol ether sulfate / fatty alcohol sulfate mixtures, or b = 10 to 49 parts and c = 0 to 5 parts when the anionic surfactant is alkylbenzenesulfonate.

The other constituents of these cleaning concentrates are conventional solubilizers, hydrotropics, complexing agents, dyes, perfume oils, etc. The surfactant content in the cleaning agent in aqueous solution is 3 to 40%.

The use of alkyl polyglycosides in detergents and cleaning agents is known in combination with other surfactants. For example, AT-PS 135 333 already describes the effect of lauryl glycoside combined with the sodium salt of ricinol sulfuric acid ester as a wool detergent. In US Pat. No. 3,721,633, alkyl polyglycosides in combination with builder substances, such as nitrilotriacetic acid or sodium tripolyphosphate, are described as detergents. EP-A-0 105 556 claims the combination of alkypolyglycosides with fatty alcohol oxyethylates as the liquid detergent. Manual detergents using alkyl polyglycosides are described in EP-A-0 070 074, EP-A-0 070 075 and EP-A-0 070 076, where u. a. anionic surfactants can be used as cosurfactants. DE-OS 35 34 082 and EP-A-0 199 765 also have analogous content.

All of these combinations, with a comparatively more or less good cleaning effect, imply the disadvantage of a relatively high content of non-purely native cosurfactants and thus that of limited environmental compatibility and skin friendliness. So calls for. B. EP-A-0 070 074 a minimum cosurfactant content of alkylbenzenesulfonate of 50% or for sulfates of 60% based on total surfactant.

This characteristic selection criterion of EP-A-0 070 074 now suggests that some important product properties speak against a desirable high content of alkyl polyglycoside.

It was surprisingly observed that detergent formulations with higher levels of alkyl polyglycosides and reduced levels of anionic surfactants compared to EP-A-0 070 074 lead to significantly more favorable cleaning values.

The cleaning agent formulations according to the invention therefore not only mean less environmentally harmful surfactants due to the recipe, but also lower use concentrations.

Alkyl polyglycosides

Alkyl polyglycosides used according to the invention satisfy formula I.



RON _n I,



in which R represents a linear or branched, saturated or unsaturated aliphatic alkyl radical having 10 to 18 carbon atoms or mixtures thereof and Z _{n represents} a polyglycosyl radical with n = 1.5 to 3 hexose or pentose units or mixtures thereof.

Alkyl polyglycosides with fatty alkyl radicals having 12 to 16 carbon atoms and a polyglycosyl radical of n = 1.5 to 2.5 are preferred. Alkyl polyglycosides are particularly preferred.

The alkyl polyglycosides used according to the invention can be produced by known processes based on renewable raw materials. For example, dextrose is reacted with n-butanol to give butylpolyglycoside mixtures in the presence of an acidic catalyst, which are re-glycosidated with long-chain alcohols in the presence of an acidic catalyst to give the desired alkylpolyglycoside mixtures.

The structure of the products can be varied within certain limits. The alkyl radical R is determined by the choice of the long-chain alcohol. Favorable for economic reasons are the industrially accessible surfactant alcohols with 10 to 18 carbon atoms, in particular native fatty alcohols from the hydrogenation of fatty acids or fatty acid derivatives. Ziegler alcohols or oxo alcohols can also be used.

The polyglycosyl radical Z _n is determined, on the one hand, by the selection of the carbohydrate and, on the other hand, by setting the average degree of polymerization n. B. according to DE-OS 19 43 689. In principle, it is known that polysaccharides, e.g. B. starch, maltodextrins, dextrose, galactose, mannose, xylose etc. can be used. The industrially available carbohydrates starch, maltodextrins and especially dextrose are preferred. Since the economically interesting alkyl polyglycoside syntheses are not regio- and stereoselective, the alkyl polyglycosides are always mixtures of oligomers, which in turn represent mixtures of different isomeric forms. They exist side by side with α- and β-glycosidic bonds in pyranose and furanose form. The links between two saccharide residues are also different.

Alkyl polyglycosides used according to the invention can also be prepared by mixing alkyl polyglycosides with alkyl monoglycosides. The latter can e.g. B according to EP-A-0 092 355 by means of polar solvents, such as acetone, from alkylpolyglycosides.

The degree of glycosidation is advantageously determined by means of 1 H-NMR.

The cleaning agents according to the invention contain 3 to 30%, preferably 5 to 20%, of alkyl polyglycoside in aqueous solution.

Compared to all other surfactants used in cleaning agents, the alkyl polyglycosides are considered to be extremely environmentally compatible. The degree of biodegradation for the alkyl polyglycosides according to the invention, determined by means of a sewage treatment plant simulation model / DOC analysis, is 96 ± 3%. This number can be seen against the background that with this test method (total degradation) a degree of degradation> 70% already indicates that the substance is readily degradable.

The acute oral toxicity LD 50 (rat) as well as the aquatic toxicity LC 50 (gold orfe) and EC 50 (daphnia) and values of> 10,000 mg / kg, 12 or 30 mg / l are three to five times cheaper as the corresponding values of the most important surfactants today. The same applies to the skin and mucous membrane compatibility, which is particularly important for flushing agents.

The alkyl polyglycosides according to the invention are obtained as an approximately 50% aqueous solution due to the synthesis.

Anionic surfactant

Suitable anionic surfactants are fatty alcohol ether sulfates - alone and as a mixture with fatty alcohol sulfates - and alkylbenzenesulfonates. Anionic surfactants with alkyl radicals of 10 to 20 carbon atoms in the hydrophobic part of the molecule are preferred. Preferred fatty alcohol ether sulfates contain 1 to 4 mol ethylene oxide / mol.

The cleaning agents according to the invention contain 3 to 25%, preferably 5 to 20%, of anionic surfactant in aqueous solution.

Other components

By adding solvents such as low-molecular, mono- and polyhydric alcohols and glycol ethers, the solubility can be increased significantly, especially at low temperatures. Particularly suitable solvents are ethanol, isopropanol, propylene glycol-1.2 etc. Typical concentrations in the cleaning agent are 3 to 12% in the aqueous solution.

In combination of the solvent with electrolytes, the solubility can be achieved especially at low temperatures, e.g. T. increase significantly. Alkali and alkaline earth metal halides have proven to be suitable electrolytes. The ratio of solvent / electrolyte can be 1: 1 to 8: 1.

Other additives are nonionic, ampholytic and / or zwitterionic surfactants with total concentrations between 0 and 5% in the aqueous solution.

Finally, the cleaning liquid according to the invention can contain small amounts (0.1 to 5 percent by weight) of conventional dyes and Perfume oils and alkanolamines or hydrotropes, such as non-surfactant alkylbenzenesulfonates with 1 to 3 carbon atoms in the alkyl radical - usually in the form of sodium salts - and urea.

Water-soluble polymers, such as carboxymethyl cellulose, hydroxyethyl cellulose, xanthans, polyethylene oxide, polyacrylate, etc., can optionally be added to adjust the viscosity.

Citric acid EDTA, NTA and other complexing agents have proven to be further suitable additives.

Examples

The following examples are intended to illustrate the invention.

The mini-plate test (cf. RM Anstett and EJ Schuck JAOCS 43, 576 (1966) was carried out to test the detergent effect. In this case, watch glasses loaded with fat are cleaned manually with a brush in the surfactant solution at elevated temperature. The test conditions (preparations, geometries, Quantities and concentrations of substances, temperatures, temperature gradients, times) are precisely defined. The test is carried out by several people and provides reproducible results. Vanishing foam shows the number of cleaned plates (watch glasses). Pork lard, which at 50, 0 ° C. was applied to the glasses, which are then subjected to a defined cooling process to 23 ° C. (room temperature), and the initial rinse temperature is also 50 ° C.

The foaming power of the cleaning agent was determined in accordance with DIN 53 902, Part 1. The concentration of detergent substance was 1 g / l in each case. The foam volume was registered after 5 minutes.

The viscosity of the cleaning liquid was measured in a rotary viscometer (Haake RV 20) at 25 ° C under defined shear rates (D approx. 10 sec⁻¹).

To determine the clear point, 10 g of cleaning agent were cooled to -20 ° C. in a Shukoff flask and then heated. The temperature of the product is measured with complete clarification.

The examples (cf. Table) show that the formulations according to the invention (Examples 5 to 9) have a significantly better cleaning power than the comparative tests according to EP-A-0 070 074.

Another advantage is the more favorable flow behavior of the formulations according to the invention, which is particularly noticeable when ether sulfates are used as anionic surfactants. For example, significantly higher amounts of electrolyte (Examples 1, 2 and 3 compared to Examples 5 and 6) have to be added to the formulation according to EP-A-0 070 074 in order to set a similarly favorable flow behavior.

The following abbreviations were used in the table: APG 1 ≙ alkyl polyglycoside, alkyl chain C _12/13 and G = 1.7 APG 2 ≙ alkyl polyglycoside, alkyl chain C _12/14 and G = 1.5 SECTION ≙ alkylbenzenesulfonate, alkyl chain = C _10/13 Alkyl ether sulfate ≙ alkyl chain = C _12/14 , 2 mol ethylene oxide / mol, Na salt Alkyl sulfate ≙ alkyl chain = C _12/14 , Na salt

The examples according to the invention lead to a lower consumption of environmentally harmful surfactants compared to the prior art.

Claims (8)

Liquid, foaming cleaning agent, the surfactant content of

a% by weight alkyl polyglycoside,
b% by weight of anionic surfactant and
c% by weight of other surfactants

consists,
characterized,
that a complements 100 parts with b + c, where b = 10 to 59 parts and c = 0 to 5 parts if the anionic surfactant is fatty alcohol ether sulfate or fatty alcohol ether sulfate / fatty alcohol sulfate mixtures, or b = 10 to 49 parts and c = 0 to 5 parts are when the anionic surfactant is alkyl benzene sulfonate. Liquid, foaming cleaning agent according to claim 1,
characterized,
that the alkyl polyglycoside of formula I



RON _n I



corresponds, where R is a saturated or unsaturated, branched or unbranched alkyl radical having 10 to 18 carbon atoms, Z _{n is} a polyglycosyl radical with n = 1.5 to 3 hexose or pentose units or mixtures thereof. Liquid, foaming cleaning agent according to claim 1,
characterized,
that the alkyl polyglycoside of the formula I is an alkyl polyglycoside with n = 1.5 to 2.5 hexose or pentose units. Liquid, foaming cleaning agent according to claims 1 to 3,
characterized,
that the anionic surfactant is alkylbenzenesulfonate, the alkyl radical of which contains 10 to 18 carbon atoms. Liquid, foaming cleaning agent according to claims 1 to 3,
characterized,
that a fatty alcohol ether sulfate whose hydrophobic radical contains C₁₀ to C₁ bis carbon atoms and which comprises 1 to 4 ethylene oxide groups is used as the anionic surfactant. Liquid, foaming cleaning agent according to claims 1 to 3,
characterized,
that the anionic surfactant is a mixture of fatty alcohol ether sulfate and fatty alcohol sulfate, the ratio of which can be 1: 5 to 5: 1. Liquid, foaming cleaning agent according to claims 1 to 6,
characterized,
that solvents such as mono- and polyhydric alcohols, alkyl ethers, polyhydric alcohols, electrolytes, complexing agents, hydrotropics, polymers, dyes, fragrances etc. are used as further additives. Use of the liquid, foaming cleaning agent according to claims 1 to 7 as a manual detergent.