Bleaching and dyeing; fluid treatment and chemical modification – Cleaning or laundering
Reexamination Certificate
1998-06-26
2001-02-13
Kopec, Mark (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Cleaning or laundering
C510S302000, C510S305000, C510S367000, C510S374000, C510S375000, C510S470000, C510S471000
Reexamination Certificate
active
06187055
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to detergents which contain as their builder or co-builder component an oligosaccharide which has been modified at its reducing end in such a way, instead of a hydroxymethylene aldehyde unit, a carboxyl unit is present at that end.
2. Discussion of Related Art
In addition to surfactants essential to their cleaning performance, detergents normally contain so-called builders of which the function is to support the work of the surfactants by eliminating hardness salts, i.e. essentially calcium and magnesium ions, from the wash liquor so that they do not negatively interact with the surfactants. One well-known example of builders which improve single wash cycle performance is zeolite Na-A which is known to be capable of forming such stable complexes, particularly with calcium ions, that their reaction with anions responsible for water hardness, particularly carbonate, to form insoluble compounds is suppressed. Another function of builders, particularly in laundry detergents, is to prevent redeposition of the soil detached from the fibers or generally from the surface to be cleaned and also insoluble compounds formed by the reaction of hardness-forming cations with hardness-forming anions onto the cleaned textile or rather onto the surface. So-called co-builders, generally polymeric polycarboxylates, are normally used for this purpose. In addition to the contribution they make towards multiple wash cycle performance, co-builders advantageously have a complexing effect on the cations responsible for water hardness.
The present invention seeks to make a contribution towards the use of so-called biologically degradable builders, i.e. naturally occurring substances or minimally modified derivatives thereof which are assumed to have better degradabiltiy than synthetic polymers of unsaturated mono- and dicarboxylic acids.
DESCRIPTION OF THE INVENTION
The present invention relates to a detergent containing surfactant, inorganic builder, oxygen-based bleaching agent, bleach activator and/or enzyme, characterized in that it contains an oligosaccharide containing a —COOH group instead of a —CH(OH)—CHO group at its originally reducing end as the builder or co-builder component.
It is particularly surprising that an oxidatively modified oligosaccharide of the type in question should have a distinctly better redeposition-inhibiting effect under washing conditions than conventional acrylic acid/maleic acid copolymers for at least the same ash values and at least the same incrustation-inhibiting effect. Accordingly, the present invention also relates to the use of oligosaccharides containing a —COOH group instead of a —CH(OH)—CHO group at their originally reducing end as redeposition inhibitors in detergents and water-containing wash liquors for washing fabrics. The present invention also relates to a process for washing textiles in water-containing and, in particular, surfactant-containing liquors using the modified oligosaccharides mentioned as redeposition inhibitors.
The preferred monomer in the builder or co-builder to be used in accordance with the invention after oxidative modification is glucose. The average degree of oligomerization n, which—as an analytically determined quantity—may even be a broken number, is preferably in the range from 2 to 20 and more preferably in the range from 2 to 10.
The oligosaccharide used as builder or co-builder in accordance with the invention has been oxidatively modified with the loss of a carbon atom at its originally reducing end. If the originally reducing end of the oligosaccharide was an anhydroglucose unit, an arabonic acid unit is present after the modification:
(glucose)
n
→(glucose)
n−1
-arabonic acid.
This oxidative modification may be carried out, for example, with Fe, Cu, Ag, Co or Ni catalysts, as described in International patent application WO 92/18542, with Pd, Pt, Rh or Os catalysts, as described in EP 0 232 202, or with a quinone/hydroquinone system in alkaline medium in the presence of oxygen, optionally followed by aftertreatment with hydrogen peroxide.
The oligosaccharide starting material modifiable by such oxidation processes is preferably an oligosaccharide with a dextrose equivalent (DE) of 20 to 50, the DE being a standard measure of the reducing effect of a polysaccharide by comparison with dextrose which has a DE of 100. Suitable polysaccharides are, in particular, so-called glucose sirups (DE 20-37) and dextrins which are both obtainable by partial hydrolysis of starch by conventional methods, for example by acid- or enzyme-catalyzed methods, and which may be used in the above-mentioned oxidation processes as such or in the form of higher polymers, for example in the form of starch, providing the polymer chain structure of the starch also undergoes corresponding degradation under the oxidation conditions.
The detergents according to the invention preferably contain 0.5% by weight to 10% by weight and more preferably 2% by weight to 7% by weight of the oxidatively modified oligosaccharide which is normally used in the form of its alkali metal salt. Concentrations of oxidatively modified oligosaccharide in the wash liquor of 0.001% by weight to 0.05% by weight are preferred both for the use according to the invention and for the washing process according to the invention.
In addition to the active substance used in accordance with the invention, the detergents according to the invention, which may be present in particular as particulate solids, pastes, homogeneous solutions or suspensions, may basically contain any known ingredients typically encountered in detergents. The detergents according to the invention may contain in particular surfactants, bleaching agents, bleach activators, water-miscible organic solvents, enzymes, additional builders, sequestering agents, electrolytes, pH regulators and other auxiliaries, such as optical brighteners, dye transfer inhibitors, foam regulators, abrasives and dyes and perfumes.
In one preferred embodiment, a detergent according to the invention contains a water-soluble and/or water-insoluble organic and/or inorganic (main) builder in addition to the oxidatively modified oligosaccharide. Builders are present in the detergents according to the invention in total quantities of preferably up to 60% by weight and, more preferably, from 5% by weight to 40% by weight.
Particularly suitable water-soluble inorganic builders are polyphosphates, preferably sodium triphosphate. Particularly suitable water-insoluble, water-dispersible inorganic builders are crystalline or amorphous alkali metal alumosilicates which are used in quantities of up to 50% by weight, preferably in quantities of not more than 40% by weight and—in liquid detergents in particular—in quantities of 1% by weight to 5% by weight. Of these crystalline or amorphous alkali metal alumosilicates, detergent-quality crystalline sodium alumosilicates, more particularly zeolite A, zeolite P and optionally zeolite X, are preferred. Quantities near the upper limit mentioned are preferably used in solid particulate detergents. Suitable alumosilicates in particular contain no particles larger than 30 &mgr;m in size, preferably at least 80% by weight consisting of particles less than 10 &mgr;m in size. Their calcium binding power, which may be determined in accordance with DE 24 12 837, is generally in the range from 100 to 200 mg CaO per gram.
Suitable substitutes or partial substitutes for the alumosilicate mentioned are crystalline alkali metal silicates which may be present either on their own or in admixture with amorphous silicates. The alkali metal silicates suitable for use as builders in the detergents according to the invention preferably have a molar ratio of alkali metal oxide to SiO
2
of less than 0.95:1 and, more particularly, from 1:1.1 to 1:12 and may be present in amorphous or crystalline form. Preferred alkali metal silicates are the sodium silicates, more particularly the amorphous sodium silicates, with a molar ratio of Na
2
O to SiO
2
Kottwitz Beatrix
Poethkow Joerg
Upadek Horst
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Kopec Mark
Mruk Brian P.
Murphy Glenn E. J.
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