FI80290C - Liquid detergent composition - Google Patents

Description

1 80290

This invention relates to liquid detergent compositions.

Liquid anhydrous detergent compositions for laundry facilities are well known in the art. For example, compositions of this type may comprise a liquid nonionic surfactant dispersed with enhancer particles, as disclosed in, e.g., U.S. Patents 4,316,812, 3,630,929, 4,264,466, and GB Patents 1,205,711 and 1,270,040.

In the normal use of European household automatic washing machines, the user places the detergent composition in the machine's dispensing unit under a cold water jet to transport it to the main body washing solutions. In winter, when the detergent composition and the water fed to the dispensing unit are cold, there may be problems with the detergent composition not being completely flushed out of the dispensing unit while the machine is running, thus forming a detergent composition reservoir with repeated wash cycles.

One reason for this problem is related to 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 easily or completely from the dispensing unit.

It has now been found that the flow from the dispensing unit can be greatly improved by adding to the liquid detergent composition a nonionic surfactant modified by converting its free hydroxyl group to a moiety having a free carboxyl group. Such a compound can be formed, for example, by a reaction between a nonionic surfactant and a polycarboxylic acid anhydride, such as succinic anhydride, to form a polycarboxylic acid partial ester. The resulting acidic compound reacts in the wash bath with the alkalinity of the detergent composition and acts as an effective anionic surfactant.

The invention therefore relates to a substantially anhydrous liquid detergent composition for laundries comprising a suspension of a structural salt in a liquid nonionic surfactant, characterized in that the composition further comprises a) a polyether group having a polyether carboxylic acid of the formula R 1 - (OCH-CH 2) n -R 2 wherein R 2 is hydrogen or methyl, R 1 is alkylphenyl or alkyl and n is at least 3, or b) a compound which is a nonionic surfactant in which one hydrogen atom is replaced by free -COOH and that the composition contains an amount of component a) or b) capable of lowering the temperature at which said liquid nonionic surfactant forms a gel with water, and that the proportion of component a) or b) is about 0, 5-10 parts by weight of -C00H per 100 parts by weight of component a) i b) and a mixture of a liquid nonionic surfactant.

The invention is further illustrated by the following examples. Example 1 400 g of a nonionic surfactant which is a C13-C15 alkanol alkoxylated to give 6-ethylene oxide and 3-propylene oxide units per alkanol unit are mixed with 32 g of succinic anhydride and heated

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3,80290 for 7 hours at 100 ° C. The mixture is cooled and filtered to remove unreacted succinic anhydride material.

Based on infrared analysis, about half of the nonionic surfactant has been converted to its acidic half ester. The viscosities and gel temperatures of the product compared to the unmodified nonionic surfactant are given below:

Product Non-modified non-ionic surfactant _ substance_

Viscosity at 20 ° C 138 cps 60 cps

Gel temperature (40/60 mixture with water, ie the mixture contains

60% water) 7 ° C to 20 ° C

40/60 mixture with water viscosity at 25 ° C 60 cps 189 cps at 20 ° C 100 cps 445 cps

It can be seen that although the product (which, as previously stated, has a mixture of equal parts of the unmodified nonionic surfactant and its acidic half-ester) has a higher viscosity than the unmodified surfactant, its viscosity when dissolved in water is considerably lower, as is its gel temperature.

4,80290

Example 2 522 g of a nonionic surfactant (Dobanol 25-7, which is the product of the ethoxylation of a C 1 -C 4 alkanol having about 7 ethylene units of an ethylene oxide unit per alkanol molecule) are mixed with 100 g of succinic anhydride and With 0.1 g of pyridine (which here acts as an esterification catalyst) and heated for 2 hours at 60 ° C, cooled and filtered to remove unreacted succinic material. Based on infrared analysis, virtually all of the free surfactant hydroxyls have reacted.

Other esterification catalysts, such as an alkali metal alkoxide (e.g., sodium methoxide), may be used with or instead of a mixture with pyridine.

Example 3

According to Example 2, using 1000 g of Dobanol 9165 (the product of the ethoxylation of C 6 -C 4 alkanol having about 5 ethylene oxide units per alkanol molecule) and 265 g of succinic anhydride.

Example 4

Liquid anhydrous laundry detergent for laundries is composed of the following ingredients, in specified proportions.

35% nonionic surfactant comprising a mixture of equal parts of: (a) a relatively water-soluble nonionic surfactant which forms a gel when mixed with water at 25 ° C, in particular a C 2-2 5 alkane which is alkoxylated to give 10- ethylene oxide and 5-propylene oxide units per alkanol unit; and (b) a less water-soluble nonionic surfactant, especially a C 1 -C 4 alkanol alkoxylated to give 4-ethylene oxide and 7-propylene oxide units per alkanol unit.

Il 5 80290 12% of the product of Example 3.

31.2% sodium tripolyphosphate.

9% sodium perborate monohydrate.

4.5% tetraacetylethylenediamine; which is an activator for sodium perborate.

4% of a copolymer of about the same number of moles of methacrylic acid and maleic anhydride, completely neutralized to form its sodium salt (Sokala CP5); this acts as an inhibitor of deposition (dicalcium phosphate formation).

1% sodium salt of diethylenetriamine pentamethylene phosphoric acid (DTPMP).

1% proteolytic enzyme slurry (in non-ionic surfactant) (Esperase).

A mixture of 1% sodium carboxymethylcellulose and hydroxymethylcellulose (anti-redeposition agent) (Fear DM 4096).

0.5% perfume.

0.5% optical brightener (stilbene type 4).

0.3% partial ester between phosphoric acid and C16-C18 alkanol (Empiphos 5632 with about 1/3 monoester and 2/3 diester).

The ingredients are mixed together, the phosphoric ester and then sodium tripolyphosphate, preferably added last, and fed through a colloid mill to reduce the particle size of the solids to less than 100 microns (e.g., about 40 microns). The mixture is then ground to reduce the size of the suspended solid particles to less than 10 microns (e.g., in the range of 2-10 microns and less than 10% solids are greater than about 10 microns in particle size).

The ingredients and conditions are selected so that the total amount of unbound water in the composition is less than 2%, preferably less than 1%, such as about 1/2% or less.

The mixture has a high viscosity, but it disperses easily in cold water in automatic washing machines. Its specific gravity is about 1.25. It provides excellent washing results when using 6,80290 dosages of about 100 grams per wash (compared to 170 grams per wash with standard laundry detergent powders) in conventional European household washing machines (using about 20 liters of water for a wash bath).

In the above examples, the carboxylic acid moiety is attached to the residue of the nonionic surfactant by a carboxylic ester bond. Instead of the succinic acid moiety, other polycarboxylic acid moieties can be used, e.g., maleic, glutarine, malonic, phthalic, lemon, etc. Thus, the carboxylic acid may have the formula RO-ZCOOH, wherein R is a nonionic surfactant residue (by removal of terminal OH) and Z is a hydrocarbon group having 1 to 10 carbon atoms attached to the oxygen 0 in the formula

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via the -C-carbonyl group.

In another embodiment of the invention, the carboxylic acid may be prepared from a polyether which is not a nonionic surfactant, e.g. it may be prepared by reaction with a polyalkoxy compound such as polyethylene glycol or a monoester or monoether thereof which is not typical of nonionic surfactants. long alkyl chain. Thus, a polyethercarboxylic acid may have the formula R 1 - (OCH-CH 2) r L-O-Z-C 10 H, wherein R 2 R 2 is hydrogen or methyl, R 1 is alkylphenyl or alkyl, n is at least 3, such as 5-25, and Z is same as above.

R 1 may be higher alkyl or lower alkyl (e.g. methyl, ethyl, propyl, butyl). The detergent composition preferably contains the acidic polyether compound as a solution in a nonionic surfactant.

The carboxyl used may also be a polyalkoxycarboxylate or N-acyl sarcosinate, as disclosed and listed in 7,80290 in Kirk-Othmer, "Encyclopedia of Chemical Technology", 3rd Edition, Vol. 22 (1983), pages 348-349.

As is known, nonionic synthetic organic detergents are identifiable from an organic hydrophobic and an organic hydrophilic group, and are typically prepared by condensation between an organic aliphatic or aromatic hydrophobic alkyl compound and ethylene oxide (hydrophilic in nature). Virtually any hydrophobic compound having a carboxy, hydroxy, amido, or amino group with free hydrogen attached to the nitrogen can be condensed with ethylene oxide or 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 desired balance between hydrophobic and hydrophilic groups. Typical suitable nonionic surfactants are mentioned in U.S. Patents 4,316,812 and 3,630,929, as well as those disclosed and listed in the review of nonionic surfactants in Kirk-Othmer's "Encyclopedia of Chemical Technology" 3rd Edition. Butter. 22 (1983), pages 360-379.

The compositions preferably contain fine detergent builder particles dispersed in a nonionic surfactant. Useful bases include inorganic and organic base salts such as phosphates, carbonates, silicates, phosphonates, polyhydroxysulfonates, polycarboxylates and the like. Typical suitable bases are mentioned in U.S. Patents 4,316,812, 4,264,466 and 3,630,929.

Since, as mentioned in Example 4, the compositions of this invention can be used in relatively low doses, it is desirable to provide any phosphate base (such as sodium tripolyphosphate) with an additional base such as a polymeric carboxylic acid having high calcium binding capacity, for example, about 1 to 80290. 10% of the amount of the composition, to prevent deposition, which could otherwise be caused by the formation of insoluble calcium phosphate. Such additional bases are well known in the art.

The composition preferably contains a peroxide bleach. This may be a peroxide compound such as an alkali metal perborate, percarbonate or perphosphate; a particularly suitable substance is sodium perborate monohydrate. The peroxide compound is preferably used in admixture with its activator. Suitable activators are mentioned in U.S. Patent 4,264,466 or paragraph 1 of U.S. Patent 4,430,244. Polyacylated compounds are preferred activators; among these, compounds such as tetraacetylethylenediamine ("TAED") and pentaacetylglucose are particularly preferred.

In general, the activator works with the peroxide compound to form a peroxyacid bleach in the wash water. It is desirable to add a sequestering agent having a high complexing ability to prevent any undesired reaction between such peroxyacid and hydrogen peroxide in the washing solution in the presence of metal ions. Such a sequestering agent is an organic compound capable of forming a complex with CU4 ions such that the stability constant (pK) for the complexation is 6 or more at 25 ° C in water with an ionic strength of 0.1 mol / liter, pK as determined by the conventional formula: pK = -log K, where K is the equilibrium constant. Thus, for example, the pK values for copper ion complexation with NTA and EDTA under said conditions are 12.7 and 18.8, respectively. Suitable sequestering agents include nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DETPA), diethylenetriamine pentamethylenephosphoric acid (DTPMP), and ethylenediaminetetramethylenediamine (DTPMP).

Other ingredients that may be included in the composition include enzymes (e.g., proteases, amylases, or lipases).

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9 80290 or mixtures thereof), optical brighteners, antireposants, dyes (e.g. pigments and dyes), etc.

The composition may also contain an inorganic insoluble thickener or a very large surface area dispersant such as finely divided silica having an extremely small particle size (e.g., 5-100 millimicrons in diameter; sold as Aerosil) or other high pore volume inorganic carriers. mentioned in U.S. Patent 3,630,929 in 0.1-10% proportions, e.g. 1-5%. However, it is desirable that compositions that form peroxyacids in a wash bath (e.g., compositions containing a peroxide compound and its activator) be substantially free of such compounds and other silicates; it has been found, for example, that silica and silicates participate in the undesired decomposition of peroxyacid.

In a preferred embodiment of the invention, the mixture of liquid nonionic surfactant and solids is finely ground in a mill where the particle size of the solids is reduced to less than about 10 microns, e.g., on average 2-10 microns or even smaller (e.g., 1 micron). Compositions with such a small size of dispersed particles have better stability against separation or precipitation during storage. It has been found that an acidic polyether compound can reduce the yield stress of such dispersions, helping them to disperse without a corresponding deterioration in precipitation stability.

, 0 80290

The mixture may contain anti-precipitating ingredients such as a partial ester of a higher alcohol and phosphoric acid in small amounts such as less than 1%, e.g. less than 1/2%, during grinding. Other phosphate ester surfactants may be used, such as those set forth and listed in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Edition, Vol. 22 (1983) on pages 359-361.

During the grinding process, it is desirable that the proportion of solid ingredients be high enough (e.g., at least about 40% such as about 50%) for the solid particles to be in contact with each other and not more so to be protected from each other by the liquid nonionic surfactant. Mills using powder grinding balls (ball mills) or similar movable grinding elements have given good results. Thus, a laboratory batch chopper equipped with 8 mm diameter steatite grinding balls can be used. For larger scale work, a continuous mill with 1 mm or 1.5 mm diameter grinding balls operating in a very small gap between the body and a relatively high speed rotor (e.g. a CoBall mill) can be used; when using such a mill, it is desirable to first feed the mixture of nonionic surfactant and solids through a mill that does not grind so finely (e.g., a colloid mill) but reduces the particle size to less than 100 microns (e.g., about 40 microns) before grinding in a continuous ball mill below average 10 microns in particle size.

Typical proportions of ingredients in the compositions of the invention are as follows: a suspended detergent base, in the range of about 10-60% such as about 20-50%, e.g. about 25-40%.

A liquid phase comprising a nonionic surfactant and a dissolved carboxylic acid anti-gelling compound, in the range of about 11,80290 30-70%, such as about 40-60%, this phase may also contain a solvent such as glycol, e.g. polyethylene glycol (e.g. "PEG 400") or hexylene glycol.

The carboxylic acid anti-gelling compound in an amount ranging from about 0.5 to 10 parts (e.g., about 1 to 6 parts, such as about 2 to 5 parts) of -C00H per 100 parts of a mixture of such an acid compound and a nonionic surfactant. (Example 4 contains about 3 parts COOH per 100 parts of such a mixture.) Typically, the amount of carboxylic acid compound is in the range of about 0.01 to 1 part per part of nonionic surfactant, such as about 0.05 to 0.6 parts, e.g. , 2-0.5 parts.

The peroxide compound (such as sodium perborate monohydrate) ranges from about 2-15%, such as about 4-10%.

The activator ranges from 1-8%, such as about 3-6%.

A sequestering agent with high complexing ability is in the range of about 1 / 4-3%, such as about 1 / 2-2%.

In this specification, all proportions are by weight unless otherwise indicated. Atmospheric pressure is used in the examples unless otherwise stated.

It is to be understood that the detailed descriptions set forth above are provided for clarity only and that variations may be made therein without departing from the scope of the invention.

Claims (12)

80290 A substantially anhydrous liquid detergent composition for laundries comprising a suspension of a structural salt in a liquid nonionic surfactant, characterized in that the composition further comprises a) a polyethercarboxylic acid having a polyether group attached via an ester bond to a carboxyl group - (OCH-CH 2) n -R 2 wherein R 1 is hydrogen or methyl, R 1 · is alkylphenyl or alkyl and n is at least 3, or b) a compound which is a nonionic surfactant in which one hydrogen atom is replaced by a free - COOH-containing group, and that the composition contains an amount of component a) or b) capable of lowering the temperature at which said liquid nonionic surfactant forms a gel with water, and that the proportion of component a) or b) is about 0 , 5-10 parts by weight of -COOH per 100 parts by weight of component a) or b) and liquid nonionic surfactant a mixture of that substance. Composition according to Claim 1, characterized in that the polyether carboxylic acid is soluble in said nonionic surfactant. Composition according to Claim 1, characterized in that the polyethercarboxylic acid contains a group of the formula - (OCH-CH 0) n O 2 -COOH, R 2 and II 13 80290 having hydrogen or methyl, Z being a hydrocarbon group having 1 to 10 carbon atoms attached to to the oxygen in the formula via a carbonyl group, and n is at least 3. Composition according to Claim 1, characterized in that the polyether carboxylic acid is a half ester of a dicarboxylic acid and a nonionic surfactant. A composition according to claim 1, characterized in that said compound is a partial ester of a nonionic surfactant and a polycarboxylic acid. Composition according to Claim 5, characterized in that the polycarboxylic acid is succinic acid. Composition according to Claim 5, characterized in that said compound is a partial ester of a polycarboxylic acid and a polyethoxylated higher alkanol. Composition according to Claim 1, characterized in that the structural salt is an alkali metal polyphosphate. Composition according to Claim 1, characterized in that it also contains a suspended peroxide bleach. Composition according to Claim 9, characterized in that the bleaching agent comprises sodium perborate monohydrate and its activator. Composition according to Claim 10, characterized in that the activator is tetraacetylethylenediamine. The composition of claim 1, characterized in that the particle size of the suspended structural salt is less than about 10 μm. l4 80290