EP0457965A1 - Low foaming washing-machine detergents - Google Patents

Abstract

The invention relates to low foaming, liquid or powder washing machine detergents whose surfactant content is very substantially synthesised from renewable raw materials and which displays very good washing results associated with excellent biodegradability. Currently used in known washing machine detergents are mainly petrochemically produced surfactants which in most cases are not completely biodegradable and represent a potential problem because of the raw materials situation expected in the future (petroleum shortage). For these reasons, washing machine detergents which contain as surfactant component 5 - 30 % alkyl polyglycoside, 5 - 30 % alkenol ether carboxylates, 5 - 30 % soap and 0 - 3 % other surfactants are proposed.

Description

The present invention relates to low-foaming liquid or powdery preparations for washing textiles, the surfactants of which are largely made from renewable raw materials.

Liquid detergents today mainly consist of anionic surfactants, especially alkylbenzenesulfonate, fatty alcohol oxyethylate and soap, whereas washing powders contain not only the surfactants alkylbenzenesulfonate and fatty alcohol oxyethylate, but also builder substances, bleaching agents and other electrolytes as essential active ingredients. Common to liquid and powder detergent formulations is that surfactants, in particular those based on petrochemicals, are used.

In view of the future raw material situation (oil shortage), this petrochemical basis is a considerable disadvantage. Another disadvantage is that the biodegradability of these surfactants does not reach the corresponding level of surfactants on a native basis.

The object of the invention was therefore to find a surfactant combination for low-foaming detergents, which are largely made from renewable raw materials, which are extremely biodegradable and achieve very good washing results.

This object was achieved by a combination of surfactants, which essentially consists of alkyl polyglycosides, ether carboxylates and soap.

The invention therefore relates to a low-foaming, liquid or powdered machine detergent, which is characterized in that the surfactant component consists of
5 to 30% alkyl polyglycoside,
5 to 30% alkanol ether carboxylate,
5 to 30% soap and
0 to 3% other surfactants
consists.

Surprisingly, it was found that very good washing results are achieved with the combinations according to the invention.

The use of alkyl polyglycoside in combination with anionic surfactants is known. DE-OS 593 422 already mentions the washing effect-enhancing effect of alkyl glycoside in soaps. Later documents such as EP-A 0 075 994, 0 105 556, 0 199 765 or DE-OS 37 02 286 describe the use of alkyl polyglycosides in combination with a number of known anionic surfactants in detergents. The most important in terms of quantity is the most important surfactant, alkylbenzenesulfonate.

The use in detergents of carboxymethylated fatty alcohol oxyethylates, which are a subset of the ether carboxylates, is known from DE-OSS 23 27 234 and 33 20 340; however, the use of bisalkanol alkoxylate acetates, which are also a subset of ether carboxylates, is new. The use of the ether carboxylates in connection with alkyl polyglycosides in detergents is also unknown.

Other components depending on the state of aggregation (liquid or powder formulations) are other surfactants in small quantities, complexing agents, bleaching agents, optical brighteners, graying inhibitors, corrosion inhibitors, foam regulators, stabilizers, enzymes, enzyme stabilizers, electrolytes, hydrotropic substances, solubilizers, etc.

Alkyl polyglycosides

Alkyl polyglycosides used according to the invention satisfy formula I.



RO-Zn 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 = 1.0 to 3 hexose or pentose units or mixtures thereof.

Alkyl polyglycosides with fatty alkyl radicals having 10 to 16 carbon atoms and a polyglycosyl radical of n = 1.1 to 2 are preferred. Alkyl polyglucosides 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 transglycosidated with long-chain alcohols in the presence of an acidic catalyst to give the desired alkylpolyglycoside mixtures. Or dextrose is immediately 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 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 z. 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. are used will. 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 junctions between two Saccachrid 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 using polar solvents, such as acetone, from alkyl polyglycosides.

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

The detergents according to the invention contain 5 to 30% alkyl polyglycoside, preferably 7 to 20%.

Compared to almost all other surfactants used in detergents, 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) with> 10,000 mg / kg as well as the aquatic toxicity LC 50 (gold orfe) with approx. 12 mg / l and EC 50 (daphnia) with 30 mg / l are by a factor of 3 to 5 cheaper than the corresponding values of today's most important surfactants. The same applies to skin and mucous membrane compatibility.

Fatty alcohol ether carboxylates

Fatty alcohol ether carboxylates are compounds of either formula II or III,



(R'-O (CH₂-CH₂-O) _x CH₂COO) _m M ^{m +} II,



in which R 'is a linear or branched, saturated or unsaturated alkyl radical having 8 to 22 preferably 10 to 18 carbon atoms, x 1 to 40, preferably 3 to 30, m 1 or 2 and M is hydrogen, alkali, alkaline earth metal, ammonium or alkanolammonium or



([R '' - O (CH₂-CH₂-O) _y ] ₂CHCOO) _z N ^{z +} III



in which R '' is a linear or branched, saturated or unsaturated alkyl radical having 8 to 22, preferably 10 to 18 carbon atoms, y 1 to 4, preferably 3 to 30, z 1 or 2 and NH, alkali, alkaline earth metal, ammonium, alkanolammonium.

Compounds corresponding to formula II are called carboxymethylated oxethylates, those corresponding to formula III are bisalkanol ethoxylate acetates.

The carboxymethylated oxethylates can be according to DE-OS 24 18 444 or EP-A 0 106 018 by reacting oxethylates of the formula R'-O (CH₂-CH₂-O) _n H with chloroacetic acid or a salt of chloroacetic acid in the presence of alkali metal hydroxide or other bases. But other manufacturing processes such. B. by means of catalytic oxidation according to EP-A 0 018 681 or 0 039 111 are suitable.

Bisalkanol ethoxylate acetates can be e.g. B. according to DE-OS 39 02 663 from oxyethylates and dichloroacetic acid.

Corresponding alcohols for the production of the fatty alcohol ether carboxylates are preferably fatty alcohols or Ziegler alcohols, in exceptional cases also oxo alcohols. The carboxymethylation following the oxethylation can be carried out with the appropriate driving style be complete so that the fatty alcohol ether carboxylates are purely anionic surfactants. Alternatively, if the carboxymethylation is incomplete, the products contain certain amounts of unreacted oxyethylate. The formulas II and III therefore usually mean a mixture with different amounts of unreacted oxethylates. Accordingly, a degree of implementation can be defined. A degree of conversion between 70 and 100% is preferred.

The fatty alcohol ether carboxylates are also very environmentally friendly surfactants. Biodegradation rates above 90% were determined using a sewage plant simulation model / DOC analysis. The acute oral toxicity LD 50 (rat) and the aquatic toxicity LC 50 (gold orfe) are about as favorable as that of the alkyl polyglucosides. The same applies to skin and mucous membrane compatibility.

The detergents according to the invention contain 5 to 30% fatty alcohol ether carboxylates, which can also be mixtures. A content of 7 to 20% fatty alcohol ether carboxylate is preferred.

Soap

Fatty acid salts or their acids according to the invention correspond to formula IV



R '''COOP IV,



in which R '''is a saturated or unsaturated alkyl radical having 8 to 22 carbon atoms and P is hydrogen, alkali, ammonium or alkanolammonium.

The detergents according to the invention contain 5 to 30%, preferably 7 to 20% soap, which will usually be a mixture of different components.

Other surfactant components

Up to 3% of further anionic, nonionic, zwitterionic and ampholytic surfactants are to be used according to the invention. In particular, these are alkanesulfonates, olefinsulfonates, alkylbenzenesulfonates, α-sulfo fatty acid esters, fatty alcohol sulfates, fatty alcohol ether sulfates, sulfosuccinic acid esters, alkanoloxethylates, fatty acid alkanolamides, amine oxides, betaines, sulfobetaines, etc.

Other non-surfactant components

First of all, builders should be mentioned as non-surfactant components. According to the invention, water-soluble builders such as different polyphosphates, phosphonates, carbonates, polycarboxylates, citronates, polyacetates such as NTA and DETA, etc. or mixtures thereof are used. These compounds are usually used as alkali salts, preferably as sodium salts. Although not complexing, sodium sulfate should also be mentioned here. The use of water-insoluble builders, such as aluminosilicates of suitable particle size, is also according to the invention (cf. EP-A 0 075 994). The concentration of the builders in the detergent is 0 to 70%, preferably 0 to 50%.

Bleaching agents such as sodium perborate, optionally combined with bleach activators such as tetraacetylethylene diamine etc. or percarbonate, are also used according to the invention; Other bleaching agents are of course also possible (cf. K. Engel, Tenside Surfactants 25, p. 21 (1988). The concentration of the bleaching agents is 0 to 40%, preferably 0 to 30%.

Adjusting agents such as low molecular weight mono- or dihydric alcohols, alkyl ethers of polyhydric alcohols, hydrotropics such as alkylbenzenesulfonates with 1 to 3C atoms in the alkyl radical, alkanolamines or urea, enzymes such as in particular proteases and enzyme stabilizers, corrosion inhibitors such as alkali silicates, optical brighteners may be used according to the invention especially based on and stilbene and pyrazoline, foam regulators, graying inhibitors such. B. carboxymethyl cellulose, perfume oils, dyes and other ingredients customary for liquid or powder detergents.

The total use concentration in the machine detergents according to the invention is 0.3-20 g / l for the surfactant fraction. 0.5-10 g / l are preferred.

Examples

The invention is illustrated by the following examples. The liquid detergent formulations listed in Tables 1 and 2 each contain 6% triethanolamine, 12% ethanol, 6% 1,2-propylene glycol and water ad 100% in addition to the surfactant components mentioned according to the invention.

The foaming power was determined in accordance with DIN 53 902, Part 1. The concentration of detergent substance was 1 g / l, the foam volume was registered after 5 minutes. The washability was measured both in the Linitest laboratory washing machine (i.e. with moderate mechanical stress) and in a normal household machine. 11 x 18 cm rags made of WFK test fabric with skin fat pigment soiling served as model fabric: polyester (PE), mixed fabric (MG) and cotton (BW), and drinking water (13 ° dH) as water. Polyester was washed at 30 ° C, blended fabrics and cotton at 60 ° C. In the Linitest laboratory washing machine, the active ingredient concentration was 1 g / l, in the household washing machine 5 g / l, the pH in each case about 7, the liquor ratio in about 1: 60 and 1: 4, the washing times in both cases were about 30 minutes .

In the Linitest machine, the washing process was repeated twice after each rinse. The washing values after drying the fabrics were - as usual - measured spectrophotometrically relative to a white standard (Datacolor, 560 nm).

Liquid formulations:

Tables 1 and 2 show the comparison of the properties of the detergents according to the invention as a liquid formulation with those of other known combinations and of a liquid branded detergent, in which one can assume that the formulation has been optimized.

The clear point and viscosity fully correspond to the standard customary for liquid detergents. The foaming power of the formulations according to the invention shows - without further regulating additives - very favorable values. This applies in particular to the washing ability. The formulations according to the invention behave far more effectively here than other known combinations, the surfactant content of which also consists of anionic surfactant, alkyl polyglucoside and soap (comparative examples 1 and 2).

Powder formulations :

Tab. 3 shows the comparison of the properties of powdery detergent formulations according to the invention with those of a known combination or a branded detergent. Bulk density, angle of repose and foaming power were determined according to DIN methods. The solubility can be estimated by plotting the electrical conductivity over time, 80% of an average final conductivity being taken as the measured value when 1 g of powder is dissolved in 800 ml of drinking water (13 ° dH). The measured values contain an error of ± 5%.

Apart from a much higher bulk density, typical of agglomerated washing powders compared to the spray-dried brand product (example 20), the powders according to the invention behave very similarly and better in their washing values. Again, the washing effects, which are greatly improved in contrast to known formulations of Example 15 with anionic surfactants, are clear.

Claims (8)

Low-foaming, liquid or powdered machine detergent characterized in that
that the surfactant portion

5 to 30% alkyl polyglycoside,
5 to 30% alkanol ether carboxylate,
5 to 30% soap and
0 to 3% other surfactants

consists. Low-foaming, liquid or powdered machine detergent according to claim 1,
characterized,
that the alkyl polyglycoside of formula I



RON _n I



corresponds, where R is a linear or branched, saturated or unsaturated alkyl radical having 10 to 18 carbon atoms or mixtures thereof and Z _{n is} a polyglycosyl radical with n = 1 to 3 hexose or pentose units or mixtures thereof. Low-foaming, liquid or powdered machine detergent according to claims 1 and 2,
characterized,
that the alkyl polyglycoside is a fatty alcohol polyglucoside with n = 1.1 to 2. Low-foaming, liquid or powdered machine detergent according to claims 1 to 3,
characterized,
that the alkanol ether carboxylate of the formula II or III



[R'-O (CH₂-CH₂-O) _x CH₂COO] _m M ^{m +} II




([R '' - O (CH₂-CH₂-O) _y ] ₂CHCOO) _z N ^{z +} III



corresponds in which R 'and R''are saturated or unsaturated, linear or branched alkyl radicals having 8 to 22 carbon atoms, x and y 1 to 40, m and z 1 or 2 and M and N being hydrogen, alkali, alkaline earth metal, ammonium or alkanolammonium mean. Low-foaming, liquid or powdery
Machine detergent according to claim 4,
characterized,
that the alkanol ether carboxylate is a carboxymethylated fatty alcohol oxyethylate corresponding to formula II, in which R'10 to 18 carbon atoms, x = 3 - 20, m = 1 and M mean sodium, potassium, ammonium or alkanolammonium. Low-foaming, liquid or powdered machine detergent according to claims 1 to 5,
characterized,
that the soap of formula IV



R '''COOP IV



in which R '''is a saturated and / or unsaturated alkyl radical having 8 to 22 carbon atoms and P is hydrogen, alkali, ammonium or alkanolammonium. Low-foaming, liquid or powdered machine
Detergent according to claims 1 to 6,
characterized,
that builders, bleaching agents, adjusting agents, enzymes, stabilizers, graying inhibitors, corrosion inhibitors, optical brighteners, dyes, perfume oils and possibly other additives are contained as non-surfactant constituents. Low-foaming, liquid or powdered machine wash
agent according to claims 1 to 7,
characterized,
that the concentration of the surfactant portion is 0.3-2O g / l.