NO178267B - Liquid detergent with a high proportion of surfactants based on recyclable raw materials - Google Patents

Abstract

Liquid detergents consist nowadays in the surfactant component mainly of petrochemical-based surfactants; the biodegradability and the ecotoxicity usually do not correspond to those of surfactants based on natural raw materials. A mixture is therefore proposed for liquid detergents, which contains a very high proportion of surfactants from renewable raw materials; the washing results and biodegradability are outstanding. The mixtures according to the invention consist of fatty alcohol ethoxylate, soap and anionic surfactant, plus alkyl polyglycoside.

Description

The present invention relates to liquid textile detergents.

Today, liquid detergents mainly consist of anionic surfactants, especially alkylbenzene sulphonate, fatty alcohol oxyethylate and soap. These surfactants, which are common in detergent formulations, are mainly petrochemical based. With regard to the future raw material situation (petroleum scarcity), this petrochemical base is a significant disadvantage. A further disadvantage is that the biodegradability and ecotoxicity of these surfactants is often not as great as that of surfactants on a native basis.

The invention is therefore based on the task of obtaining surfactants

liquid detergent compositions containing a high proportion of surfactants, derived from raw materials that can be recycled; in addition to having outstanding washing results and promoting biodegradability.

This task is solved with a mixture, which next to fatty alcohol

oxyethylate and soap, contain only low amounts of anionic surfactant such as 3-30% alkyl polyglycoside.

The object of the invention is thus a liquid detergent containing 3-30% by weight alkyl polyglycoside according to formula I

where R denotes a linear or branched, saturated or unsaturated aliphatic alkyl residue with 8-18 carbon atoms, or mixtures thereof, and Zn denotes a polyglycosyl residue with n = 1.0 to 1.4 hexose or pentose units, or mixtures thereof,

0-7% by weight of anionic surfactant,

11-30 weight percent fatty alcohol oxyethylate and

5-30 weight percent soap, and

to 100% by weight of water, builders (Builder), play material, product auxiliary substance (Stellmittel), enzyme, stabilizers, graying inhibitors, corrosion inhibitors, optical brightener, dye, perfume oil and further additives, in which the added concentration of surfactants amounts to 0.3 to 20 g/l.

In EP-0 075 994, EP-0 075 995 and EP-0 075 996 claims are made for surfactant mixtures which, in addition to APG, contain anionic and non-ionic surfactants, although the degree of glycosidation of APG is > 1.5. DE-37 02 286 requires alkyl polyglycoside alongside anionic and nonionic surfactants as a detergent, with the restriction that the anionic proportion must be < 50% of the oxyethylates. In EP-0 199 765, alkyl polyglycoside mixtures with anionic and nonionic surfactants are described, where the content of nonionic surfactants must amount to < 10% and the degree of glycosidation of the alkylpolyglycosides < 1.4. The brochure "Henkel APG, alkyl polyglycoside" (1990) recommends recipes for liquid detergent which, in accordance with EP-0 199 765, contain amounts for oxyethylate < 10%, whereas the amount of alkylbenzene sulphonate in each case amounts to 13% by weight.

It is now surprisingly established that the formulation according to the invention gives excellent washing results with a low anionic surfactant content.

Alkyl polyglycoside

Alkypolyglycosides used according to the invention preferably have the formula I,

where R denotes a linear or branched, saturated or unsaturated aliphatic alkyl residue with 8-18 carbon atoms, or a mixture of such alkyl residues, and Zn denotes a polyglycosyl residue with

n = 1.0 to 1.4 hexose or pentose units, or mixtures of such residues.

Alkyl polyglycoside with alkyl residues with 9-16 carbon atoms and a polyglycosyl residue with n = 1.1 to 1.4 is preferred. Particularly preferred is alkyl polyglucoside.

The alkyl polyglycosides used according to the invention can be produced using a known method on the basis of renewable raw materials.

E.g. dextrose in the presence of an acidic catalyst is reacted with n-butanol to butyl polyglycoside mixtures, which with long-chain alcohols, also in the presence of an acidic catalyst, are reglycosidated to the desired alkyl polyglycoside mixture. Alternatively, dextrose is directly reacted with the desired long-chain alcohol.

The structure of the products can be varied within certain limits. The alkyl radical R is determined by the choice of long-chain alcohols. For economic reasons, the industrially available alcohols with 8-18 C atoms are favorable, especially native alcohols from the hydration of carbonic acid or carbonic acid derivatives. Ziegler alcohols or oxo alcohols can also be used.

The polyglycosyl residue Zn is determined on the one hand through the choice of carbohydrates and on the other hand through setting the average degree of polymerization n, e.g. according to DE-OS 19 43 689. In principle, as is known, polysaccharides, e.g. starch, maltodextrin, dextrose, galactose, mannose, xylose, etc. are used. The industrially available carbohydrates starch, maltodextrin and especially dextrose are preferred. As the economically interesting alkyl polyglycoside syntheses do not proceed regio- and stereoselectively, the alkyl polyglycosides are always mixtures of oligomers, which in turn constitute mixtures of different isomeric forms. They exist next to each other with 6- and 1-glycosidic bonds in pyranose and furanose form. The binding sites between two saccharide residues are also different.

The alkyl polyglycosides, which are used according to the invention, can also be prepared by mixing alkyl polyglycosides with alkyl monoglycosides. The latter can be obtained or enriched from alkyl polyglycosides by means of polar solvents, such as acetone, e.g. according to EP-A 0 092 355. The degree of glycosidation is conveniently determined by means of 1 H-NMR.

The detergents according to the invention contain 3-30% alkylpolyglycoside, preferably 5-20%.

Compared to almost all other surfactants used in detergents, alkyl polyglycosides are considered very environmentally friendly. Thus, the degree of biological degradation for the alkyl polyglycosides according to the invention, determined by treatment plant simulation model/DOC analysis, is 96 ± 3%. This number must be assessed on the basis of the fact that there is already a degradation rate of

> 70% by this test method (total degradation), indicates that the substance is easily degradable.

Also the acute oral toxicity LD 50 (rats) on

> 10,000 mg/kg as well as the aquatic toxicity LC 50 (golden carp) of approx. 12 mg/l and EC 50 (water fleas (Daphnia)) of 30 mg/l are 3-5 times more favorable than the corresponding values for the surfactants that today are the most important. Similar conditions apply to skin and mucous membrane compatibility.

Anionic surfactants

Alkyl benzene sulfate, alkanesulfonate, olefin sulfonate, fatty alcohol sulfate and fatty alcohol ether sulfate with 9-18 C atoms in the alkyl or alkylene group are used as anionic surfactants. Na, K, NH4, Mg and mixtures make up the counterions. Among these anionic surfactants, which can be present in amounts from 0-7% by weight in mixtures according to the invention, soap is not counted. Amounts from 0-5 percent by weight are preferred.

Fatty alcohol oxyethylate

Fatty alcohol oxyethylate, used in the invention, corresponds to the compound of formula II

where R" denotes a linear or branched, saturated or unsaturated alkyl radical with 8-22, preferably 10-20 carbon atoms and x is 2-20, preferably 3-15.

The compounds are usually prepared by deposition of ethylene oxide on long-chain alcohols in the presence of basic or acidic catalysts. For economic reasons, it is advantageous to use industrially available alcohol with 8-22 C atoms, from the hydration of carboxylic acids, respectively carboxylic acid derivatives. Ziegler alcohol or oxo alcohols are also applicable.

The alcohol oxyethylates are known to be biodegradable, and they also show favorable results with regard to water toxicity, skin and mucus compatibility.

The liquid detergent according to the invention contains 11-30% fatty alcohol oxyethylate, which can also occur as a mixture. Concentrations of 12-25 percent by weight are preferred.

Soap

Fatty acid salts, respectively their acids, according to the invention correspond to formula III

where R"<1> is a saturated or unsaturated alkyl radical with 8-22

C atoms, and P denotes hydrogen, alkali, ammonium or alkanolammonium.

The detergent according to the invention contains 5-30% soap, which is mostly a mixture of different components. A concentration of 7-25% is preferred.

Additional non-surfactant components

As non-surfactant ingredients, builders can primarily be mentioned. According to the invention, water-soluble builders are used, such as various polyphosphates, phosphonates, carbonates, polycarboxylates, citrates, polyacetates, e.g. NTA and EDTA, etc. or mixtures thereof. These compounds are usually used as alkali salts, preferably sodium salts. Although it does not act as a complexing agent, sodium sulphate should also be mentioned in this connection. It is also within the scope of the invention to use water-insoluble builders, such as aluminosilicates with a suitable particle size (see EP-A 0 075 994). The concentration of builders in the detergent amounts to 0-70%, preferably 0-50%.

According to the invention, further bleaching agents are used, such as sodium perborate, possibly in combination with bleaching activators, such as tetraacetylenediamine, etc. or percarbonate. Other bleaching agents are naturally also suitable (see K. Engel, Tenside Surfactants 25, p. 21 (1988)). The concentration of the bleaching agents is 0-40%, preferably 0-30%.

, According to the invention, it is also possible to use product auxiliaries (Stellmittel), such as low molecular weight 1- or 2-hydric alcohols, alkyl ethers of polyhydric alcohols, hydrotropic compounds, such as alkylbenzenesulfonates with 1-3 C atoms in the alkyl residue, alkanolamines or urea, enzymes such as

special proteases, as well as enzyme stabilizers, corrosion inhibitors, such as alkali silicates, optical brighteners, especially on a stilbene and pyrazoline basis, foam regulators, graying inhibitors, such as e.g. carboxymethyl cellulose, perfume oils, dyes and additional additives for liquid or powder detergent.

The total concentration of the surfactant components in the liquid detergents according to the invention amounts to 0.3-20 g/l. 0.5-10 g/l is preferred.

Examples

The invention is explained in more detail using the following examples. The liquid detergent formulations listed in Table 1 contain, in addition to the aforementioned surfactant components according to the invention, respectively 6% triethanolamine, 12% ethanol, 6% 1,2-propylene glycol and 100% water.

To characterize the cleaning bag, the clearing point and viscosity were determined.

When determining the clearing point, 10 g of cleaning liquid was cooled to -20 °C in a Shukoff flask and then heated. The temperature at complete clarification was measured.

The viscosity of the cleaning liquid was measured in a rotary viscometer (Haake RV 20) at 25 °C under shear rates (Scherraten) of approximately 10 s-<1>.

The washing ability was determined in a normal household machine where the foam development was also determined.

11 x 18 cm cloths of WFK test fabric, soiled by skin fat and pigment: polyester (PE), mixed fabric (MG) and cotton (BW), sewn onto cotton towels, served as model fabric. At the same time, the washing machine was filled with 4 kg of ballast material. Drinking water (13 °dH) was used as water, where the concentration of active substance is 5 g/l, pH value 8, the ratio between textiles and washing liquid is 1 : 4, and the washing time approx. 80 min. The washing value after drying the fabric was - as usual - measured spectrophotometrically in relation to a white standard (Datacolor, 560 nm).

The table shows a comparison between the properties of the detergent i

according to the invention, as a liquid formulation, and the properties of other known combinations, as well as the properties of a commercial liquid detergent, where one can assume that the recipe was optimized. Clearing point, viscosity and foaming action fully corresponded to the standard common in the market for liquid detergents.

In comparison with the commercial detergent (ex. 9 (V) and even also with alkylpolyglycoside-containing formulation (ex. 1 (V) to 3 (V), the detergent according to the present invention is clearly superior in washing activity. The results are even outstanding at low temperatures and with problem substances, such as PE and MG: The experiments show the superiority, with regard to the cost of oxyethylate, of the formulation according to the invention in relation to the use of alkyl polyglycosides with an excessively high degree of glycosidation, respectively in relation to an excessively high content of anionic surfactants The following abbreviations are used in the table:

Claims (4)

1. Liquid detergent characterized in that it contains 3-30 percent by weight alkyl polyglycoside according to formula I in which R denotes a linear or branched, saturated or unsaturated aliphatic alkyl residue with 8-18 carbon atoms, or a mixture thereof, and Zn denotes a polyglycosyl residue with n = 1.0 to 1.4 hexose or pentose units, or mixtures thereof, 0-7% by weight of anionic surfactant, 11-30% by weight of fatty alcohol oxyacetylate and 5-30 weight percent soap, and to 100% by weight of water, builders (Builder), bleaching agent, product auxiliary agent (Stellmittel), enzyme, stabilizers, graying inhibitors, corrosion inhibitors, optical brightener, dye, perfume oil and further additives, in which the added concentration of surfactants amounts to 0.3 to 20 g /l. 2. Liquid detergent according to claim 1, characterized in that the anionic surfactant means alkylbenzenesulfonate, alkanesulfonate, olefinsulfonate, fatty alcoholsulfonate and/or fatty alcohol ether sulfate, whereby the respective alkyl or alkylene group contains 9-18 C atoms and Na, K, NH4, Mg, as well as a mixture of these, constitute the counterions. 3. Liquid detergent according to claims 1 and 2, characterized in that the fatty alcohol oxyethylate corresponds to formula II in which R" denotes a linear or branched, saturated or unsaturated alkyl radical of 8-22 carbon atoms and x = 2 to 20. 4. Liquid detergent according to claims 1-3, characterized in that the soap corresponds to formula III in which R'" denotes a saturated or unsaturated alkyl residue with 8-22 carbon atoms and P denotes hydrogen, alkali, ammonium or alkanolammonium.