NL8501031A - LIQUID BLEACH CONTAINING DETERGENT COMPOSITION. - Google Patents

Description

* * «V VO 7130

Liquid bleach-containing detergent composition.

The invention relates to non-aqueous liquid detergent for heavy washing tasks.

According to an aspect of the invention, a highly effective and stable non-aqueous liquid detergent for heavy washing tasks is prepared by dispersing a solid builder salt, sodium perborate monohydrate and a solid activator for the perborate in a substantially water-free liquid nonionic surfactant and grind the dispersion to reduce the particle size of the solids to less than about 10 µm, for example, to an average particle size of 2-10 µm, or even lower, for example, 1 µm. Preferably, in the milled product, less than about 20 wt% (more preferably less than about 10 wt%) of the suspended particles have diameters above 10 µm.

It will be appreciated that as the particle size is reduced by 15 times, fresh reactive surfaces become exposed and the surface available for reaction increases. Also, the energy involved in the fine grinding necessarily causes local temperature increases within the mixture being ground (even though the grinder is cooled, for example, by cold water running through a jacket of the mill during the grinding). Despite this, the compositions of the invention are very stable, show little or no loss of bleaching activity during grinding or storage.

In the grinding operation, it is preferred that the amount of solid ingredients be large enough (for example, about 40% such as about 50%) for the solids to contact and not to be highly shielded from each other by the liquid nonionic surfactant. Grinders using grinding balls (ball mills) or using similar mobile grinding elements have given very good results. For example, one can use a laboratory batch attritor with 8 mm diameter steatite grinding balls. For larger scale work, a continuously operating mill can be used in which 1mm or 1.5mm diameter grinding balls operate in a very small gap between a stator and a rotor operating at a relatively high speed (eg a CoBall mill) ; when such a grinder is used, it is desirable to first pass the mixture of nonionic surfactant and solids through a mill that does not process such fine grinding (e.g., a colloid mill) to reduce the particle size to below 5 100 µm (for example, to about 40 µm) before milling to an average particle diameter below about 10 µm in the continuous ball mill.

It is preferred that the builder solid salt be an alkali metal polyphosphate such as sodium tripolyphosphate ("TPP"). Other suitable polyphosphates include the pyrophosphates such as tetrasodium pyrophosphate and metaphosphates. Instead of the polyphosphate or part thereof, one or more other detergent builder salts, such as alkali metal carbonates or bicarbonates, silicates, or organic builders such as polycarboxylates, may be used. Typical suitable builders are those described in U.S. Patents 4,316,812; 4,264,466 and 3,630,929.

The preferred activator is tetraacetylethylenediamine ("TAED"). Another suitable activator is glucose pentaacetate. Other suitable activators are those described in U.S. Patent No. 4,264,466 or in Column 1 of U.S. Patent No. 4,430,244. Polyacyl compounds are preferred activators.

The following examples are provided to further illustrate the invention. All amounts in this application are by weight unless otherwise indicated.

Example I

The following compositions A and B were each ground for 30 minutes at room temperature in a Wieneroto Wl.S attritor with 8 mm diameter steatite balls, producing a liquid suspension in which the average particle size of the ground material was below about 10 in both cases .

850 1 0 3 1 -3- \ "r

Quantities A B

Nonionic surfactant 35 32.57

Acid-reacted noniogenic surfactant 16 16 active agent TPP 30 '30 5 Sodium salt of ethylenediaminetetramethylene phosphonic acid (EDITEMPA) 1.5 1.5

Copolymer of methacrylic acid and maleic anhydride, completely converted into the sodium salt form (Sokalan CP5) 4 4 10 Sodium carphonate 2.5 2.5

Sodium Perborate Monohydrate (NaBO- ^ O) 4.5

Sodium perborate tetrahydrate - 6.93 TAED 5 5 15 Stilbene optical brighteners 4 type 0.5 0.5

Enzyme suspension (Protease suspended in nonionic surfactant) 1 1 20 Each composition contained 0.72% active Oj and the unbound water content of the ingredients is less than 1%. After aging at 35 ° C for 48 hours, composition A was still liquid while composition B had become substantially solid (its weight stress had increased to a value greater than 20 Pascal). After aging for 5 days at 35 ° C, analysis for the available peracetic acid showed that the effective loss of TAED on milling and aging was 7% for Composition A and 45% for Composition B.

The nonionic surfactant used in this example comprised a mixture of equal amounts of: a) a relatively water-soluble nonionic surfactant which forms a gel when mixed with water at 25 ° C, more specifically a C13 to C15 alkanol which is alkoxylated is to introduce 10 ethylene oxide and 5 propylene oxide units per alkanol unit; 8501031-4- (b) a less water-soluble nonionic surfactant, more specifically one to C15 alkanol which is alkoxylated to introduce 4-ethylene oxide and 7 propylene oxide units per alkanol unit.

The acid-reacted nonoionic surfactant is a half-ester of succinic acid and a nonionic surfactant (especially ethoxylated C 2 to alkanol with about 5 ethylene oxide units per alkanol molecule). This semester can be prepared by the reaction of tartaric anhydride and the nonionic surfactant at elevated temperature (eg 60 ° C), preferably in the presence of a small amount of catalyst such as pyridine. The resulting terminal acid product acts as an anti-gelling agent in the compositions. It lowers the temperature at which the nonionic surfactant forms a gel with cold water and thus contributes to the release of the compositions while operating automatic home washers at winter temperatures. Other carboxylic acid materials that are soluble in the nonionic surfactant can be used for this purpose.

The TPP is a mixture of anhydrous TPP and a small amount of TPP hexahydrate, such that the chemically bound water content is about 3%, which corresponds to about one H 2 O per pentasodium tripolyphosphate molecule. Such TPP can be prepared by treating anhydrous TPP with a limited amount of water. The presence of the hexahydrate slows down the rapid dissolution rate of the TPP in the wash bath and inhibits caking. A suitable TPP is marketed under the name Thermphos NW? the particle size of this TPP as supplied is in the region of 400 µm? its phase X content is about 60%.

In the preparation of the mixture prior to grinding, it is preferred that the solid ingredients are added to the nonionic surfactant, with the TPP being added last.

The mixture is easily dispensed with cold water in the automatic washing machine. Its specific gravity is about 1.25.

It gives excellent washing results when used in a dosage of about 100 g per load of laundry (compared to 8501031 -5-170 g per load of laundry for the usual detergent washing powders for heavy washing tasks) in conventional European home washing machines, which contains about 20 liters of water for the washing bath) in which the water is heated to about 60 ° C during washing.

Example II

A ground composition is prepared in the manner described in Example I from the following ingredients in the amounts indicated: nonionic surfactant 40.8 10 TPP 49.8 ethylenediamine tetraacetic acid 1.2 TSED 4.5 sodium perborate monohydrate 3.6 hydroxylamine sulfate 0 The hydroxylamine sulfate acts as an inhibitor for the undesired bleach-reducing effect of the enzyme catalase, which is present in soiled clothing.

As is known, the nonionic synthetic surfactants are characterized by the presence of an organic hydrophobic group and an organic hydrophilic group and are typically prepared by the condensation of an organic aliphatic or alkyl aromatic hydrophobic compound with ethylene. oxide (hydrophilic in nature). Practically any hydrophobic compound having a carboxy, hydroxy, amido or amino group with a free hydrogen atom bonded to the nitrogen atom can be condensed with ethylene oxide or with its polyhydration product, polyethylene glycol, to form a nonionic detergent. the hydrophilic or polyoxyethylene chain can be easily adjusted to achieve the desired balance between the hydrophobic and hydrophilic groups. Examples of suitable liquid nonionic surfactants are those described in U.S. Patents 4,316,812 and 3,630,929, as well as those described in the discussion of nonionic surfactants in the Kirk-Othmer "Encyclopedia of Chemical Technology", 3rd Edition, 35 Vol. 22 (1983) pp 360-379.

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The activator usually interacts with the peroxygen fat bond to form a peroxyacid bleach in the wash water. It is preferred that a high complexing power sequestrant be included to inhibit any undesired reactions between such peroxyacid and hydrogen peroxide in the wash solution in the presence of metal ions. Such a sequestrant is an organic compound capable of 2+ complexing with Cu ions such that the stability constant (pK) of the complexation is equal to or greater than 6 at 25 ° C, in water with an ionic strength of 0.1 mol / liter, pK is conventionally defined by the formula: pK = -log K where K represents the equilibrium constant. The pK values for complexing copper ions with ΝΤΆ and EDTA under the stated conditions were resp. 12.7 and 18.8. Suitable sequestrants include the sodium 15 salts of nitrilotriacetic acid (NTA); ethylenedlamine tetraacetic acid (EDTA); diethylene triamine pentaacetic acid (DETPA) diethylene triamine pentaethylene phosphoric acid (DTPMP); and ethylenediaminetetramethylene phosphonic acid (EDITEMPA).

Other ingredients that can be included in the composition are enzymes (eg proteases, amylases or lipases or mixtures thereof); optical brighteners, anti-redeposition agents (e.g. sodium carboxymethyl cellulose), colorants (e.g. pigments or dyes), etc.

The composition may also contain a very high surface inorganic insoluble thickener or dispersant such as finely divided silica of extremely fine particle size (eg, a diameter of 5-100 nm as commercially sold under the name Aerosil) or the other very bulky inorganic carrier materials described in U.S. Pat. No. 3,630,929, in amounts of 0.1-10%, for example, 1-5%. However, it is preferred that the compositions be substantially free of such compounds and of other silicates, for example, it has been found that silica and silicates promote undesirable decomposition of the peroxyacid formed in the wash bath. In the compositions of the invention, typical amounts of ingredients are as follows:

Suspended detergent builder, in the range of about 10-60%, such as about 20-50%, for example about 25-40%; 8501031

a

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Liquid phase comprising nonionic surfactant (and, optionally dissolved carboxylic acid material), in the range of about 30-70%, such as about 40-60%; this phase may also include a binder such as a glycol, for example, polyethylene glycol (e.g., "PEG 400") or hexylene glycol? Carbon acidic anti-gelling agent, in the range of about 0.01 to 1 part per partionic surfactant such as about 0.05-0.6 dl, e.g., about 0.2-0.5 dl?

Sodium perborate monohydrate, in the range of about 10 2-15%, such as about 4-10%?

Activator in the range of about 1-8%, such as about 3-6%.

The unbound moisture content of the composition preferably has less than about 2%, preferably less than about 1%, such as about £% or less.

While it is most convenient and effective to grind all solid ingredients together, it is within the broader scope of the invention to grind separate suspensions of individual ingredients or groups of ingredients and combine them after such grinding operation.

In this application, all amounts are by weight unless otherwise indicated. Atmospheric pressures are used in the examples unless otherwise indicated.

It should be noted that the above detailed description is given for illustration later and that variations are possible without leaving the idea of the invention.

8501031

Claims (7)

1. Mainly anhydrous, liquid detergent composition for heavy duty washing, comprising solid sodium perborate monohydrate particles, solid activator particles for the perborate and solid builder salt particles, all dispersed in a liquid nonionic surfactant, the dimensions of the particles being smaller than about 10 yum. . The composition of claim 1, wherein the activator comprises tetraacetylethylenediamine and the builder salt comprises pentasodium tripolyphosphate. The composition of claim 1 prepared by grinding a slurry of said solids in said liquid, said solids having particle sizes of at least 40 µm before the grinding operation is performed. The composition of claim 1 comprising about 10-60% of said builder salt, about 2-15% sodium perborate monohydrate and about 1-8% activator. The composition of claim 4, wherein the amount of the builder salt is about 25-40%. The composition of claim 5, wherein the activator comprises 20 tetraacetylethylenediamine, the builder salt comprises pentasodium tri-polyphosphate, and said composition is prepared by milling a suspension of said solids in said liquid, which solids particles prior to milling have particle sizes of at least 40 possess. The composition of claim 6, which is substantially free of silica or silicates. 8501031