NL8501032A - LIQUID DETERGENT COMPOSITION. - Google Patents

Description

VO 7129

Liquid detergent composition.

The invention relates to liquid detergent compositions.

Non-aqueous liquid detergent compositions for heavy washing tasks are known. For example, compositions of this type may contain a liquid nonionic surfactant in which particles of a builder are dispersed, as shown, for example, in U.S. Patents 4,316,812; 3,630,929; 4,264,466, and British Patents 1,205,711 and 1,270,040.

In normal use of automatic washing machines in European households, the user puts the detergent composition into a dispensing unit (e.g. a dispensing loader) of the machine.

During the operation of the machine, the detergent in the dispenser is subjected to a stream of cold water, thereby transferring it into the main mass of washing solutions. In winter, when the detergent composition and the water supplied to the dispenser are cold, problems can arise because some of the composition is not completely rinsed out of the dispenser during machine operation, and deposits are deposited with repeated wash cycles. composition so that it may become necessary for the user to rinse the dispenser with hot water.

One reason for this problem has to do with the behavior of the nonionic surfactant when mixed with cold water. Its viscosity increases significantly and a gel is formed. As a result, the detergent composition does not flow out of the dispenser as easily or completely.

It has now been found that the flow from the dispenser can be greatly improved by including in the liquid detergent composition a nonionic surfactant which has been modified by converting a free hydroxyl group thereof into a free carboxyl group moiety. For example, such a compound can be formed by reacting a nonionic surfactant with a polycarboxylic anhydride, such as succinic anhydride, to form a partial ester of the polycarboxylic acid. The resulting acidic compound will react in the wash bath with the alkaline elements of the detergent composition and acts as an 8501032 -2-J. * effective- anionic surfactant.

The invention is further illustrated by the following examples.

Example I

400 g of nonionic surfactant / which is one to alkanol which has been alkoxylated to introduce 6-ethylene oxide and 3-propylene oxide units per alkanol unit, with 32 g of succinic anhydride and heated at 100 ° C for 7 hours. The mixture was then cooled and filtered to remove unreacted succinic acid material. Infrared analysis showed that about half of the nonionic surfactant had been converted to its acidic half-ester. Viscosities and gel temperatures of the product compared to the unmodified nonionic surfactant are shown below 15 Product Unmodified nonionic surfactant

Viscosity at 20 ° C 138 cps 60 cps *

Gel temperature of a 40/60 mixture 20 with water (i.e. a mixture containing 60%

water) 7 ° C 20 ° C

Viscosity of the 40/60 mixture with water at 25 ° C. Q_ J 60 cps 189 cps

25 at 20 ° C "AAC

J 100 cps 445 cps

It is understood that while the product (which as mentioned previously is a mixture of approximately equal amounts of unmodified nonionic surfactant and its acidic semester) had a higher viscosity than the unmodified surfactant, its viscosity when diluted with water is significantly lower, as is its gelation temperature.

Example II

It was mixed. 522 g of the nonionic surfactant, known as Dobanol, 25-7 (the product of ethoxylation of an alkanol, which product contains about 7 ethylene oxide units per alkanol molecule) with 100 g of amber anhydride and 0.1 g of pyridine (which here worked as an esterification catalyst) and heated at 60 ° C for 2 hours at 8501032-3, cooled and filtered to remove unreacted tartaric acid material. Infrared analysis showed that almost all free hydroxyl groups of the surfactant had reacted.

Other esterification catalysts such as an alkali metal alkoxide (e.g. sodium methoxide) could be used in place of or mixed with pyridine.

Example III ............

Example II was repeated, using 1000 g Dobanol 10 91-5 (the product of ethoxylation of a C 6 alkanol, which product contained about 5 ethylene oxide units per alkanol molecule) and 265 g succinic anhydride.

Example IV

A non-aqueous liquid detergent for heavy duty washing was formulated from the following ingredients in the amounts indicated.

35% nonionic surfactant, comprising 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 ~ alkanol which was alkoxylated to introduce 10 ethylene oxide and 5 propylene oxide units per alkanol unit; and (b) a less water-soluble nonionic surfactant, more specifically a (^3 - alkanol which was alkoxylated to introduce 4 ethylene oxide and 7 propylene oxide units per alkanol unit.

12% of the product of Example III; 31.2% sodium tripolyphosphate; 30 9% sodium perborate monohydrate; 4.5% tetracetylethylenediamine; this is an activator for the sodium perborate; 4% copolymer of about an equal number of moles of methacrylic acid and maleic anhydride, completely neutralized to its sodium salt (Sokalan CP5); this acts as an inhibitor for crust deposits (such as by the formation of Vein dicalcium phosphate); 850 1 0 32 '"4" 1% sodium salt of diethylene triamine pentamethylene phosphonic acid (DTPMP); 1% proteolytic enzyme suspension (in nonionic surfactant) (Esperase); 5 1% mixture of sodium carboxymethyl cellulose and hydroxymethyl cellulose (an anti-renewal agent) deposition) (Relatin DM 4096); 0.5% perfume; 0.5% optical brightener (of the stilene 4 type); 0.3% partial ester of phosphoric acid and a C 1 / C 2 / g alkanol (Empiphos 5632, in which about 1/3 monoester and 2/3 diester).

The ingredients were mixed together with the phosphoric acid ester and then the sodium tripolyphosphate preferably being added last, and passed through a colloid mill to reduce the particle size of the solids below 100 µm (e.g., to about 40 µm um). The mixture was then milled to reduce the sizes of the suspended solids to below 10 µm (for example, in the range of about 2-10 µm with less than about 10% of the solids with particle sizes above about 10 µm).

The ingredients and conditions were chosen such that the total unbound water content of the composition is less than 2%, preferably less than 1%, such as about 1% or less.

The mixture had a high viscosity, but was easily dispensed with cold water in an automatic washing machine. Its specific gravity was about 1.25. It gave excellent washing results when used at a dosage of about 100 g per load of laundry (compared to 170 g per load of laundry for the usual heavy duty detergent powders) in conventional European-home washing machines (containing about 20 liters of water for the wash bath use) .

In the above examples, a carboxylic acid piece was attached to the residue of the nonionic surfactant through a carboxylic acid ester bridge. Instead of barasthenic acid, other polycarboxylic acid pieces can be used, for example maleic, glutaric, malonic, phthalic, citric, etc. In broader aspects of the invention, other bridges such as ether, thioether or urethane bridges formed by conventional reactions can be used. For example, to form an ether bridge, 8501032 Λ -5- the nonionic surfactant can be treated with a strong base (to convert its OH group to, for example, an ONa group) and then reacted with a halo no carboxylic acid such as chloroacetic acid or chlooopropionic acid or the corresponding bromo compound. Thus, the resulting carboxylic acid can have the formula RY-ZCOOH, where R is the residue of a nonionic surfactant (after removal of OH terminal group), Y represents oxygen or sulfur, and Z represents an organic bridge such as a hydrocarbon group of sedge 1-10 carbon atoms, which may be attached to the oxygen (or sulfur) of the formula directly or through an intermediate bridge, such as an oxygen-containing bridge, for example a -CO- or -CONH- ( ie carbonyl or carboxymido bridge, respectively.

In another aspect of the invention, the carboxylic acid 15 may be prepared from a polyether which is not a nonionic surfactant, for example it may be prepared by a reaction with a polyalkoxy compound such as polyethylene glycol or a monoester or monoether thereof, which is not has the long alkyl chain properties of the nonionic surfactants.

1 9 .2

Thus, R can satisfy the formula R (O-CH (R 2) -CH) -, wherein R

δ n is hydrogen or methyl, R 1 is alkylphenyl or alkyl or another chain-terminating group and n is at least 3, e.g. 5-25,

When alkyl is a higher alkyl group in the meanings of R *, R is a residue of a nonionic surfactant. As mentioned above, R 1 may instead be hydrogen or lower alkyl (eg methyl, ethyl, propyl, butyl) or lower acyl (eg acetyl, etc.). The acidic polyether compound is preferably present in the detergent composition as a solution in the nonionic surfactant.

The carboxylic acid compound used may also be a polyalkoxy carboxylate or N-acyl sarcosinate, as described in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd edition, volume 22 (1983), pp. 348-349.

As is known, the nonionic synthetic organic detergents are characterized by the presence of an organic 8501032-6 hydrophobic group and an organic hydrophilic groups, they 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 on the nitrogen atom can be condensed with ethylene oxide or with its polyhydration product, polyethylene glycol, to form a nonionic detergent. The length of the hydrophilic or polyoxyethylene chain can be easily adjusted to achieve the correct balance between the hydrophobic and the hydrophilic groups. Examples of suitable nonionic surfactants are those described in U.S. Patents 4,316,812 and 3,630,929, as well as those described in discussing nonionic surfactants in the Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Edition, volume 22, (1983), 360-379.

The compositions preferably contain fine particles of a detergent builder dispersed in the non-ionic surfactant. Examples of suitable builders are described in U.S. Patents 4,316,812, 4,264,466, and 3,630,929.

Since the compositions of the invention, as indicated in Example IV, can be used in relatively low dosages, it is desirable to supplement an optional phosphate builder (such as sodium tri-polyphosphate) with an auxiliary builder such as a polymeric carboxylic acid with a high calcium-binding capacity. ability in an amount in the range of, for example, about 1-10% of the composition, to inhibit crust deposits that might otherwise be caused by the formation of an insoluble calcium phosphate. Such help builders are well known.

The composition preferably includes a peroxygen bleach. This can be a peroxygen compound such as an alkali metal perborate, percarbonate or perphosphate; a particularly suitable material is sodium perborate monohydrate. The peroxygen compound is preferably used in admixture with an activator. Suitable 8501032 -7 activators are those described in U.S. Patent 4,264,466 or in column 1 U.S. Patent 4,430,244. Polyacyl compounds are preferred activators; of these, compounds such as tetraacetyl ethylenediamine ("TAED") and penta-5 acetyl glucose are particularly preferred.

The activator usually interacts with the peroxygen compound 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 sequencing agent is an organic compound which can complex 2 with Cu + + ions so that the stability constant (pK) of the complex ring is equal to or greater than 6 at 25 ° C in water with an ionic strength of 0 , 1 mol / liter, where pK is conventionally defined by the formula pK = -log K where K represents the equilibrium constant. Thus, for example, the pK values for complexing copper ions with NTA and EDTA at the stated conditions are respectively. 12.7 and 18.8. Suitable sequestrants include the sodium salts of nitrilotriacetic acid (NTA); ethylenediamine tetraacetic acid (EDTA) diethylene triamine pentaacetic acid (DETPA); diethylene triamine pentamethylene phosphonic acid (DTPMP); and ethylenediaminetetramethylene phosphonic acid (EDITEMPA).

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

The composition may also contain an inorganic insoluble thickener or dispersant with a very large surface area such as finely divided silica. with extremely fine particle size (eg, 5-100 nm diameter as sold under the name Aerosil) or the other highly bulky inorganic support materials described in U.S. Pat. No. 3,630,929, in amounts of 0.1-10%, e.g. 1 -5%. However, it is preferred that compositions that form peroxyacids in the wash bath (eg, compositions containing a peroxygen compound and activator therefor) are substantially free of such compounds and other silicates; For example, it has been found that silica and silicates promote the undesirable decomposition of 8501032 J the peroxyacid.

In a preferred embodiment of the invention, the mixture of liquid nonionic surfactant and solid ingredients is subjected to an abrasion-type milling operation in which the particle sizes of the solid ingredients are reduced to below about 10 µm, for example to an average particle size of 2-10 ^ um or or even smaller (eg 1 ^ um). Compositions whose dispersed particles have such small dimensions have better stability against separation or deposition upon storage. It has been found that the acidic polyether compound can reduce the yield stress of such dispersions, which contributes to the releasability, without accompanying a corresponding decrease in their stability against deposition.

The mixture may contain anti-deposit ingredients, such as a partial ester of phosphoric acid and a higher alkanol, present in small amounts such as less than 1%, for example below 1%, during grinding. Other phosphate ester surfactants can be used in places, for example, those described in the Kirk-Othmer Encyclopedia of Chemical Technology, "3 edition, voltime 20 22 (1983), pp. 359-361.

In the grinding operation, it is preferred that the amount of solid ingredients is large enough (eg, at least about 40%, such as, about 50%), so that the solids are in contact with each other and are not largely shielded from each other by liquid non ionic surfactant. Grinders using grinding balls (ball mills) or similar mobile grinding elements have given very good results. For example, one may use a laboratory batch attritor with 8 mm diameter spheroidal grinding balls. For larger scale work, use can be made of a continuously operating mill in which 1mm or 1.5mm diameter grinding balls operate in a very small gap between stator and a rotor operating at a relatively high speed (eg, a CoBall mill); when such a mill 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 (eg, a colloid mill) to reduce particle size to below 100 µm (eg to 8501032 m -9- about 40 µm) before mowing to an average particle diameter below about 10 µm in the continuous ball mill.

In the composition of the invention, typical amounts of the ingredients are as follows: S Suspended detergent builder in the range of about 10-60%, for example about 20-50%, most preferably about 25-40%;

Liquid phase comprising nonionic surfactant and dissolved carboxylic acid gel inhibitor compound, in the range of about 30-70%, for example about 40-60%, this phase may also include a diluent, such as a glycol, for example polyethylene glycol (for example, "PEG 400") or hexylene glycol 1.

Carboxylic acid gel inhibition compound, an amount of in the range of about 0.5 to 10 parts (eg 1 to 6 parts, preferably about 2-5 parts) of -C00H (molecular weight 45) per 100 parts mixture of this acidic compound and a non-ionic surfactant is provided. (In Example IV, there are about 3 parts COQH per 100 parts of such a mixture). The amount of the carboxylic acid compound is typically in the range of about 0.01 to 1 dl per dl nonionic surfactant, such as about 0.05-0.6 dl, for example about 0.2-0.5 dl;

Peroxygen compound (such as sodium perborate monohydrate) in the range of about 2-15%, such as about 4-10%;

Activator in the range of about 1-8%, such as about 3-6%; A high complexing power sequestrant in the range of about a quarter to 3%, for example, one to 2%.

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 illustrative only and that variations are possible without departing from the idea of the invention.

8501032

Claims (15)

A liquid detergent composition for heavy duty washing tasks, comprising a suspension of builder salt in a liquid nonionic surfactant, which composition contains a polyether carboxylic acid to lower the temperature wafer the surfactant forms a gel with water. The composition of claim 1, wherein the polyether carboxylic acid is soluble in the nonionic surfactant and the composition is substantially non-aqueous. 3. A composition according to claim 1, wherein the polyether carboxylic acid 2 2 10 contains a group of the formula -O-CH (R) -CH 1) -YZ-COOH, where R 1 is hydrogen or methyl, Y is oxygen or sulfur and Z is an organic bridge. The composition of claim 1, wherein the polyether carboxylic acid is a half ester of a dicarboxylic acid and a nonionic surfactant. The composition of claim 1, wherein the amount of the polyether carboxylic acid is such that about 0.05-10 parts of -COOH per 100 parts of the mixture of the polyether carboxylic acid and the nonionic surfactant is provided. A heavy duty laundry detergent composition comprising a suspension of a builder salt in a liquid non-ionic surfactant, which composition also contains a compound comprising a nonionic surfactant in which a hydrogen atom is replaced by a group with a free COOH. A composition according to claim 6, wherein the compound is a partial ester of a non-anionic surfactant and a polycarboxylic acid. The composition of claim 7, wherein the polycarboxylic acid is succinic acid. The composition of claim 7, wherein the compound is a partial ester of a polycarboxylic acid and a polyethoxy higher alkanol. The composition of claim 6, wherein the builder salt is an alkali metal polyphosphate. 35 ii. The composition of claim 6, which also contains a suspended peroxygen bleach. 8501032 It ^ τ -11- The composition of claim 11, wherein the bleaching agent comprises sodium perborate monohydrate and an activator therefor. The composition of claim 11, wherein the activator comprises tetraacetyl ethylenediamine. The composition of claim 1, wherein the particle size of the suspended builder salt is below about 10 µm. A semester of (a) a nonionic surfactant which is a polyoxyethylated higher alkanol and (b) a dicarboxylic acid. The semester according to claim 15, wherein the dicarboxylic acid is 10 succinic acid. 850 1 0 32