Detergents for household laundry and industrial washing generally comprise anionic surfactants, nonionic surfactants, builders and numerous organic and inorganic additives. The anionic surfactants used for cleaning the laundry usually have a tendency toward foam development during the washing cycle, which firstly has a negative effect on the washing result and secondly can lead to the washing machine overflowing. There is therefore a practical need to control, and in particular to minimize, the development of foam during the washing operation. Antifoams are used for this purpose; these firstly are intended to reduce the development of foam and secondly to reduce foam which has already formed. The anionic surfactants, such as alkylbenzenesulfonates (also known in abbreviated form as ABS or LAS) or fatty alcohol sulfates (also known in abbreviated form as FAS) can be defoamed relatively readily and reliably using customary antifoams, for example those based on paraffins. Suitable paraffin wax mixtures as antifoams are described, for example, in European patent application EP 0309931 A1.
The defoaming or foam control in the case of surfactant mixtures with high contents of nonionic surfactants and in particular above all if the nonionic surfactants used are alkyl oligoglucosides based on linear fatty alcohols or branched oxo alcohols has proven more problematical. Such surfactant mixtures, which are characterized by particularly advantageous dissolution properties and are therefore of particular interest for the consumer, have hitherto only been reliably defoamed if silicones are used as antifoams, which are generally applied to carrier materials and optionally coated with other substances which have an antifoam action.
Thus, for example, European patent application EP 0496510 A1 discloses silicone-containing antifoams, a mixture of silicones and fatty alcohols, fatty acids or glycerol monoesters with specific melting points being applied to starch as carrier material. However, because of their sticky, oily consistency, silicones firstly have a tendency to stick together, as a result of which undesired silicone flecks may arise as residue on the washed laundry and, secondly, the silicones are relatively expensive antifoams.
Accordingly, there is a need for surfactant mixtures with high contents of nonionic surfactants which comprise alkyl oligoglycosides which can be defoamed more readily, it being possible to dispense with silicones and antifoams at least partially, preferably completely.
The object of the present invention was accordingly to provide surfactant mixtures for the preparation of solid detergents with high contents of nonionic surfactants which, despite the alkyl oligoglycosides present, are foam-controlled even with small amounts of antifoams. Furthermore, it was the intention for good foam control to be possible as far as possible with small amounts or even without silicones and antifoams. The surfactants or the, solid laundry detergents based thereon should of course satisfy the requirements for laundry detergents with regard to primary detergency.
The present invention relates, in general, to surfactant mixtures for the preparation of solid, foam-controlled laundry detergents, and more particularly, to surfactant mixtures with high contents of specifically selected nonionic surfactants and no or only low contents of anionic surfactants. Further subject-matter of the present invention relates to solid foam-controlled laundry detergents comprising such surfactant mixtures, and the use of such surfactant mixtures for the preparation of solid, foam-controlled detergents.
One subject-matter of the present invention thus relates to surfactant mixtures for the preparation of solid laundry detergents, comprising
A) anionic surfactants in amounts of from 0 to 6% by weight and
B) a nonionic surfactant mixture in amounts greater than 60% by weightxe2x80x94in each case based on the total surfactant mixturexe2x80x94, where the nonionic surfactant mixture comprises
a) at least one alkyl and/or alkenyl oligoglycoside of the formula (I),
R1Oxe2x80x94[G]pxe2x80x83xe2x80x83(I)
xe2x80x83in which R1 is a linear and/or branched alkyl and/or alkenyl radical having 4 to 22 carbon atoms, G is a sugar radical having 5 or 6 carbon atoms and p is a number from 1 to 10, and
b) at least one nonionic surfactant of the formula (II)
R2O(CH2CHRO)xHxe2x80x83xe2x80x83(II)
xe2x80x83in which x is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R2 is alkyl radicals derived from an alcohol mixture of: 80 to 100% by weight of linear saturated and/or unsaturated alcohols having 16 to 22 carbon atoms and 0 to 20% by weight of linear saturated and/or unsaturated alcohols having 6 to 14 carbon atoms, and optionally
c) at least one further nonionic surfactant chosen from the group formed by
c1) alcohol ethoxylates of the formula (III)
R3O(CH2CHRO)yHxe2x80x83xe2x80x83(III)
xe2x80x83in which y is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R3 is alkyl radicals derived from an alcohol mixture of: 70 to 95% by weight of linear saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and 5 to 30% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with methyl groups, and 0 to 10% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with alkyl groups having at least 2 carbon atoms
c2) alcohol ethoxylates of the formula (IV)
R4O(CH2CHRO)xHxe2x80x83xe2x80x83(IV)
xe2x80x83in which z is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R4 is alkyl radicals derived from an alcohol mixture of: 35 to 55% by weight of linear saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and 10 to 20% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with methyl groups, and 35 to 45% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with alkyl groups having at least 2 carbon atoms
c3) alcohol ethoxylates of the formula (V)
R5O(CH2CHRO)qHxe2x80x83xe2x80x83(V)
xe2x80x83in which q is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R5 is alkyl radicals derived from an alcohol mixture of: 0 to 10% by weight of linear saturated and/or unsaturated alcohols having 6 to 10 carbon atoms and 40 to 90% by weight of linear saturated and/or unsaturated alcohols having 12 to 14 carbon atoms and 0 to 30% by weight of linear saturated and/or unsaturated alcohols having 16 to 22 carbon atoms
c4) fatty acid polyglycol esters of the formula (VI)
R6COO(CH2CHRO)sR7xe2x80x83xe2x80x83(VI)
xe2x80x83in which s is a number from 1 to 30, R6CO is linear or branched saturated or unsaturated acyl radicals having 6 to 22 carbon atoms, R7 is linear or branched alkyl radicals having 1 to 4 carbon atoms and R is hydrogen, methyl and/or ethyl.
A further subject-matter of the present invention relates to solid foam-controlled laundry detergents comprising, in amounts of from 5 to 30% by weight, a surfactant mixture comprising
A) anionic surfactants in amounts of from 0 to 6% by weight and
B) a nonionic surfactant mixture in amounts greater than 60% by weightxe2x80x94in each case based on the total surfactant mixturexe2x80x94, where the nonionic surfactant mixture comprises
a) at least one alkyl and/or alkenyl oligoglycoside of the formula (I),
R1Oxe2x80x94[G]pxe2x80x83xe2x80x83(I)
xe2x80x83in which R1 is a linear and/or branched alkyl and/or alkenyl radical having 4 to 22 carbon atoms, G is a sugar radical having 5 or 6 carbon atoms and p is a number from 1 to 10, and
b) at least one nonionic surfactant of the formula (II)
R2O(CH2CHRO)xHxe2x80x83xe2x80x83(II)
xe2x80x83in which x is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R2 is alkyl radicals derived from an alcohol mixture of: 80 to 100% by weight of linear saturated and/or unsaturated alcohols having 16 to 22 carbon atoms and 0 to 20% by weight of linear saturated and/or unsaturated alcohols having 6 to 14 carbon atoms, and optionally
c) at least one further nonionic surfactant chosen from the group formed by
c1) alcohol ethoxylates of the formula (III)
R3O(CH2CHRO)yHxe2x80x83xe2x80x83(III)
xe2x80x83in which y is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R3 is alkyl radicals derived from an alcohol mixture of: 70 to 95% by weight of linear saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and 5 to 30% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with methyl groups, and 0 to 10% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with alkyl groups having at least 2 carbon atoms
c2) alcohol ethoxylates of the formula (IV)
R4O(CH2CHRO)zHxe2x80x83xe2x80x83(IV)
xe2x80x83in which z is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R4 is alkyl radicals derived from an alcohol mixture of: 35 to 55% by weight of linear saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and 10 to 20% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with methyl groups, and 35 to 45% by weight of saturated and/or unsaturated alcohols having 8 to 22 carbon atoms and branched with alkyl groups having at least 2 carbon atoms
c3) alcohol ethoxylates of the formula (V)
R5O(CH2CHRO)qHxe2x80x83xe2x80x83(V)
xe2x80x83in which q is a number from 1 to 30, R is hydrogen, methyl and/or ethyl and R5 is alkyl radicals derived from an alcohol mixture of: 0 to 10% by weight of linear saturated and/or unsaturated alcohols having 6 to 10 carbon atoms and 40 to 90% by weight of linear saturated and/or unsaturated alcohols having 12 to 14 carbon atoms and 0 to 30% by weight of linear saturated and/or unsaturated alcohols having 16 to 22 carbon atoms
c4) fatty acid polyglycol esters of the formula (VI)
R6COO(CH2CHRO)sR7xe2x80x83xe2x80x83(VI)
xe2x80x83in which s is a number from 1 to 30, R6CO is linear or branched saturated or unsaturated acyl radicals having 6 to 22 carbon atoms, R7 is linear or branched alkyl radicals having 1 to 4 carbon atoms and R is hydrogen, methyl and/or ethyl.
The present application further relates to the use of the surfactant mixture of the type described for the preparation of solid, foam-controlled laundry detergents.
Surprisingly, it has been found that a very good foam control, especially of the difficult-to-defoam alkyl glycosides, is achieved in the presence of nonionic surfactants of the formula (II), which in simplified terms are alkoxylates of long-chain alcohols having 16 to 18 carbon atoms. Particularly good results are achieved with regard to detergency and foam control if further nonionic surfactants are additionally used, such as shorter-chain alcohol alkoxylates and branched alcohol alkoxylates and/or fatty acid polyglycol esters.