DK162658B - LIQUID DETERGENTS CONTAINING POLYPHOSPHATE - Google Patents

Description

DK 162658 B

This invention relates to a liquid detergent.

Liquid, non-aqueous, powerful detergents are well known. Funds of this type can e.g. comprise a liquid, nonionic surfactant containing dispersed particles of a builder such as a polyphosphate builder, as shown in e.g. U.S. Patent Nos. 4,316,812, 3,630,929, 4,264,466 and British Patent Nos. 1,205,711 and 1,270,040.

It is known that such suspensions can be stabilized against precipitation by the addition of an inorganic, insoluble thickener or dispersant having a very large surface area, such as finely divided particle size silica (e.g., 5-100 millimicron diameter, 15 such as that sold under the name Aerosil®) or the other highly bulky inorganic carriers disclosed in U.S. Patent No. 3,630,929 or by inclusion of various clays, such as attapulgite, as disclosed in U.S. Patent No. 4,264,466. . Grinding to very small particle sizes also increases stability.

The present invention relates to liquid, non-aqueous, powerful laundry detergent laundry detergents having a float value of 2-8 Pa, and the detergent is characterized in that it comprises a suspension of an alkali metal polyphosphate builder salt having a particle size below 10 microns. 30 to 70% by weight based on the detergent, of a liquid nonionic surfactant prepared by condensing an alkoxylable organic hydrophobic compound with alkylene oxide, and 0.01-30% by weight of an organic phosphorous compound, which has an acidic POH group and is a partial ester of phosphoric acid or phosphoric acid with a mono- or polyhydric alcohol.

According to the present invention, the stability of the suspension is increased by including an acidic organic phosphorus compound with an acidic -POH group. This is a partial ester of phosphoric or phosphoric acid and a mono- or poly-2

DK 162658 B

lent alcohol, such as an alkanol having a lipophilic character, and with e.g. more than 5 carbon atoms, e.g. 8 to 20 carbon atoms. It has been found that, as a result of the inclusion of very small amounts of the acidic organic phosphorus compound, the suspension becomes considerably more stable against precipitation upon standing, but remains pourable. Thus, as shown below, the inclusion of the acidic phosphorus compound increases the flow value of the suspension but reduces its plastic viscosity.

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It is believed that the use of the acidic phosphorus compound may result in the formation of high energy physical bond between the molecule-POH moiety and the surface of the inorganic polyphosphate builder, so that this surface assumes an organic character and becomes more compatible with the -ionogenic surfactant.

The suspensions of the alkali metal polyphosphate exchanger such as sodium tripolyphosphate ("TPP") in the nonionic surfactant are found to behave rheologically substantially according to the Casson equation: 1/2 1/2 1/2 1/2 σ = σ0 + ne. y 25 γ is the shear rate, σ is the shear stress, σ0 is the yield stress (or yield value), and i) »is the plastic viscosity at infinite shear rate (which can be measured by determining the slope of the graph over the square root of the shear stress (as ordinate) toward square root of displacement

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flow rate). The float value is the minimum shear stress below which no flow occurs (i.e., it corresponds to the cut-off on the ordinate at a shear rate of zero, on the graph mentioned above). As a result, it is a criterion of stability. The plastic viscosity 3 o is a measure of flowability once the float value has been exceeded.

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The FT performance value in one (measured at 25 ° C) must be at least 2 Pascal and (in order to be able to pour and distribute the material) not more than 8 Pascal, such as 3 to 7 Pascal, and more preferably approx. 4 Pascal.

5 For the study of rheological behavior, a uniform, well-defined shear velocity viscometer (with either coaxial cylinders or cone geometry) such as Rheometrics rheometer should be used.

The suspensions are preferably prepared by grinding a mixture of nonionic surfactant, particles of polyphosphate builder salt and the acidic organic phosphorus compound in a mill which will decompose the builder particles to diameters below approx. 10 microns. The builder salt will usually be added as much larger particles of over approx. 40 microns in diameter, such as 100, 200 or 400 microns. If desired, the builder salt can be premixed with the acidic organic phosphorus compound (for example, by spraying the acidic compound dispersed or dissolved in water or a volatile organic solvent on the builder salt).

During grinding, it is preferred that the amount of solid constituents be large enough (e.g., at least about 40%, such as about 50%) for the solid particles to be in contact with each other and not substantially shielded from each other of the liquid, nonionic, surfactant. Mills using grinding balls (ball mills) or similar mobile grinding elements have produced good results. Thus, a laboratory charge attribute with steatite grinding balls having a diameter of 8 mm can be used. For larger-scale work, a continuously operating mill may be used in which there are 1 mm or 1.5 mm diameter grinding balls operating in a very small aperture between a stator and a rotor operating at a relatively high speed (eg a CoBall mill 1e). When such a mill is used, it is desirable to first pass the mixture of nonionic, surfactant and solid through a mill which does not cause such fine milling (e.g.

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colloid mill) to reduce the particle size to less than 100 microns (e.g., to about 40 microns) before milling to an average particle diameter below 10 microns in the continuous ball mill.

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The following examples further illustrate the invention.

Example 10 A non-aqueous, high-performance builder-containing liquid detergent is prepared by mixing nonionic surfactant and sodium tripolyphosphate ("TPP") with other ingredients with and without acidic organic phosphorus compound as described below, and then grinding the mixture in an attractor-15 mill (to reduce the particle size of the suspended components to less than 10 microns). The grinding conditions are identical in each case: grinding for a 1/2 hour in an attriter mill containing steatite grinding balls with a diameter of 8 mm. (Wieneroto W-l.S attritor, loaded with 2.5 kg 20 mixture).

A BCD

Relative amount of acidic organic phosphorus compound (%) 0 0.1 0.2 0.3 Liquid stress (Pascal) 0.3 1.6 3.2 5.6

Plastic viscosity (Pascal »second) 1.1 1.0 1.0 0.9

The apparent viscosity at any shear rate can be calculated using the Casson equation and relationship: apparent viscosity is equal to shear stress divided by shear rate.

The acidic organic phosphorus compound in this example is a partial ester of phosphoric acid and a C16 "c18" a3 cannula (Empiphos 35 5632 from Marchon) and is constituted by about 35% monoester and 65% diester.

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The material contains the following constituents in the stated proportions: 35% nonionic surfactant comprising a mixture of equal parts: (a) a relatively water soluble nonionic surfactant which forms a gel when mixed with water at 25 ° C, especially an alkanol which has been alkoxylated to introduce 10 ethylene oxide and 5 propylene oxide units per liter. and (b) a less water-soluble, nonionic, surfactant, especially an alkanol which has been alkoxylated to introduce 4 ethylene oxide and 7 propylene oxide units per liter. alkanol unit, 12% of a reaction product prepared by mixing 2Q of 100 g of succinic anhydride with 522 g of the nonionic surfactant known as Dobanol 25-7 (the product of ethoxylation of an alkanol, which product has approx. 7 ethylene oxide units per alkanol molecule) and 0.1 g of pyridine (acting here as an esterification catalyst), heating 25 to 60 ° C for 2 hours, cooling and filtering to remove unreacted succinic material (infrared analysis indicates that substantially all of the free hydroxyl groups on the surfactant have reacted to form an acidic half-ester in which the non-ionic, surfactant OH group has been esterified with bark a carboxyl group on the succinic anhydride), 31.5% TPP in Formulation A; 31.4% in formulation Bf 31.3% in C and 31.2% in D, 3g 9% sodium perborate monohydrate, NaBO ^ i ^, 4.5% tetraacetylethylenediamine, which is an activator of the sodium perborate, 6

DK 162658 B

4% copolymer of approximately equal moles of methacrylic acid and maleic anhydride, completely neutralized to form its sodium salt (Sokalan CP5), which serves to prevent deposits (as from dicalcium phosphate formation), 5% diethylenediamine pentamethylene phosphonic acid sodium, sequestering agent with a high stability constant for complexation, 1% slurry of proteolytic enzyme (in nonionic, surfactant) (Esperase), 1% mixture of Na-carboxymethylcellulose and hydroxymethylcellulose (an antigen scavenger) (Relatin DM 4050), 15 0.5 % perfume, and 0.5% optical brightener (of the 4-leg type).

Preferably, the 2 0 TPP is an anhydrous material containing a small amount of TPP hexahydrate (for example, an amount such that the chemically bound water content is about 3%, which corresponds to about one molecule of E 2 O per pentane sodium tripolyphos -phatmolekyle). Such a TPP can be prepared by treating 25 anhydrous TPP with a limited amount of water. The presence of the hexahydrate decreases the rapid dissolution rate of TPP in the wash bath and prevents baking, of suitable quality TPP is sold under the name Thermphos NW, and the particle size of this TPP is approximately 400 microns and its 30 phase I content is approx. 60%.

The mixture dissolves easily in cold water in an automatic washing machine. Its density is approx. 1.25, and this provides a prominent wash when used with an amount of approx. 100 g 35 per washing volume (compared with 170 per wash volume for the usual, powerful detergent powders) in conventional European home washing machines (using about 20 liters of water for the wash bath).

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The partial esters of the phosphoric acid are known to act as antifoam agents and are mentioned for this purpose in U.S. Patent No. 4,264,466 (column 33, lines 34-45). However, the agents of this example are of the low-foaming type and when used for the washing of conventional washing volumes in typical European, e.g. German, front-loading washing machines make only a little foam even in the absence of the phosphoric acid partial ester, and therefore do not require any antifoaming agent.

The acidic organic phosphorus compound can be selected from a wide variety of materials in addition to the aforementioned partial esters of phosphoric acid and alkanols. Thus, a partial ester of phosphoric acid or phosphoric acid may be used with a mono- or polyhydric alcohol such as hexylene glycol, ethylene glycol, di- or triethylene glycol or higher polyethylene glycol, polypropylene glycol, glycerol, sorbitol, mono- or diglycerides of fatty acids. etc, in which one, two or more of the alcoholic OH groups of the molecule may be esterified with the phosphorus acid. The alcohol may be a nonionic surfactant such as an ethoxylated or ethoxylated propoxylated higher alkanol, higher alkylphenol or higher alkylamide. The carbon: phosphorus atom ratio of the organic phosphorus compound is preferably at least 3: 1, such as 5: 1, 10: 1, 20: 1, 30: 1 or 40: 1. Among the suitable compounds are the 25 surfactant phosphate ester substances described and listed in Kirk-Othmer "Encyclopedia of Chemical Technology", 3rd edition, Vol. 22 (1983), pages 359 to 361.

The particular partial alkyl ester of phosphoric acid and the C ^ g-C ^ g-30 alkanol described in the previous example is a solid which usually swells but does not dissolve in the nonionic surfactant. It is applied as a powder. According to a preferred method described in this example, TPP is added last (after the other solid ingredients have been added to the liquid mixture of nonionic surfactant and the reaction product of succinic anhydride and nonionic surfactant) and the powder d <>

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of the partial alkyl ester of phosphoric acid is added just before TPP. Acidic organic phosphorus compounds soluble in the nonionic surfactant can also be used.

As is well known, nonionic surfactants are characterized by the presence of an organic hydrophobic group and an organic hydrophilic group and are typically prepared by condensation of an organic aliphatic or alkyl aromatic hydrophobic compound with ethylene oxide (which is hydrophilic in nature ). Practically any hydrophobic compound having a carboxy, hydroxy, amido or amino group having a free hydrogen atom attached to 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 desired balance between the hydrophobic and the hydrophilic groups. Typical, convenient, nonionic surfactants are those described in U.S. Patent Nos. 4,316,812 and 3,630,929, as well as those described and disclosed in the discussion of nonionic, surfactants in Kirk-Othmer "Encyclopedia of Chemical Technology", 3rd edition, Vol. 22 (1983), pages 360 to 379.

Nonionic surfactants often tend to form gels with limited amounts of cold water. This container sometimes interferes with the complete dispensing of the material from the usual dispensing container found in the conventional automatic home washing machines used in

Europe. In order to lower the gelation temperature and thus facilitate easier dispensing of the detergent, a carboxylic acid antifreeze may be included. A preferred type of agent of this type is a compound having a carboxylic moiety attached to the molecular residue of a nonionic surfactant, e.g. a half-ester of succinic acid or another dicarboxylic acid in which the OH group of the nonionic surfactant has been esterified with a carboxylic group from the acid. This material is preferably dissolved in the nonionic surfactant.

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The polyphosphate builder salt is preferably an alkali metal (eg Na or K) tripolyphosphate, pyrophosphate (eg tetra sodium pyrophosphate) or hexamethaphosphate. It is preferred that these are mainly in anhydrous form. Mixtures of two or more different polyphosphates may be used. The polyphosphate can also be used in admixture with one or more other water-soluble detergent builders.

Among the suitable builders are inorganic and organic builder salts such as phosphates, carbonates, silicates, phosphonates, polyhydroxy sulfonates, polycarboxylates and the like. Typical suitable builders are those disclosed in U.S. Patent Nos. 4,316,812, 4,264,466, and 3,630,929.

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Since the agents of this invention, as set forth in the example, can be used in relatively low doses, it is desirable to supplement any phosphate or phophate-forming builder (such as sodium tripolyphosphate) with an auxiliary builder, such as a polymeric carboxylic acid with high calcium binding capacity in an amount in the range of , eg. from approx. 1 to 10% of the agent to prevent deposits that could otherwise be caused by the formation of an insoluble calcium phosphate. Such auxiliary builders are well known in the art.

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The agent preferably comprises a peroxygen bleach. This may be a peroxygen compound such as an alkali metal perborate, percarbonate or perphosphate, and a particularly suitable material is sodium perborate monohydrate. The peroxygen compound is preferably used in admixture with an activator therefor. Suitable 30 activators are those described in U.S. Patent No. 4,264,466 or in column 1 of U.S. Patent No. 4,430,244. Polyacylated compounds are preferred activators. Among these, compounds such as tetraacetylethylenediamine ("TAED") and glucose pentaacetate are particularly preferred.

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The activator usually acts on the peroxygen compound to form a peroxyacid bleach in the wash water. It 10

DK 162658 B

It is preferred to include a sequestering agent with a high ability of complex bonding to prevent any undesired reaction between such peroxyacid and hydrogen peroxide in the wash solution in the presence of metal ions. Such a sequestering agent is an organic compound capable of forming 2+ a complex with Cu ions such that the stability constant (pK) of complex formation is equal to or greater than 6 at 25 ° C in water with a ionic strength of 0.1 mol / liter, where pK is usually defined by the formula: pK = -log K, where K represents 10 the equilibrium constant. Thus, for example, the pK values for the complexation of copper ion with NTA and EDTA under the mentioned conditions are 12.7 and 18.8, respectively. Suitable sequestrants include the sodium salts of nitrilotriacetic acid (NTA), ethylene diamine tetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DETPA), diethylenetriamine pentamethylene phosphonic acid (DTPMP) and ethylenediaminetetramethylene phosphonic acid (EDTP).

Other constituents which may be included in midlet enzymes (e.g., proteases, amylases or lipases or mixtures thereof), optical brighteners, antigenic depositors, dyes (e.g., pigments or dyes), etc.

The agent may also contain an inorganic, insoluble thickener or dispersant having a very large surface area, such as finely divided particle size silica (e.g., 5-100 millimeters in diameter, such as sold under the name Aerosii) or the other highly voluminous, inorganic carriers described in U.S. Patent No. 3,630,929, in a ratio of 0.1 to 10%, e.g. 1-5%.

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However, to obtain the best results, it is preferred that agents which form peroxyacids in the wash water (e.g. agents containing peroxygen compound and activator therefor) substantially contain no such compounds and other silicates. It has e.g. It has been found that silica and silicates promote the undesired degradation of the peroxyacid. In addition, the use of these water-insoluble or inorganic materials can cause other problems in the system. No bulky silica or clay

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The chain structure type is required in the practice of this invention, and the agent is preferably substantially free of such materials.

5 Although the average particle size of the solids in the preferred agents has been reduced to less than ca. 10 microns (for example, typically only about 5-10% of the solids content has a particle size above 10 microns) the invention can also be applied to agents which have not been so finely milled. It is to be understood that finer milling increases the stability of the agent against settling upon standing, as according to Stoke's law, the smaller the particle size, the lower the sedimentation rate. By increasing the flow value obtained at a given degree of grinding, the use of the acidic phosphorus compound can enable the stability of agents in which the average particle diameter is e.g. 15, 20 or 25 microns, e.g. by using increased amounts of the acidic phosphorus compound to obtain the desired flow value of at least approx. 2 Pascal.

The compositions of the invention are typical proportions of the ingredients as follows:

Suspended detergent builder in the range of approx. 10 to 25%, such as 20 to 50%, e.g. ca. 25 to 40%, a liquid phase comprising nonionic surfactant (and optionally a dissolved carboxylic acid inhibitor) in the range of about 30 to 70%, such as approx. 40 to 60%, where this 3 ° phase may also comprise a diluent such as a glycol, e.g. polyethylene glycol (e.g., "PEG 400") or hexylene glycol, carboxylic acid antifreeze in an amount in the range of about 35 0.5 to 10 parts (e.g., about 1 to 6 parts, such as approx.

2 to 5 parts) -COOH (molecular weight 45) per 100 parts of the mixture of such a compound and the ionic surfactant.

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Typically, the amount of this anti-gelling agent is in the range of about 0.01 to 1 part per part of nonionic surfactant such as ca. 0.05 to 0.6 parts, e.g. ca. 0.2 to 0.5 parts, 5 peroxygen compound (such as sodium peroborate monohydrate) in the range of about 2 to 15%, such as approx. 4 to 10%, activator in the range of approx. 1 to 8%, such as approx. 3 to 6%, 10 sequestering agent with high complexity capability in the range of approx. 1/4 to 3%, such as approx. 1/2 to 2%, acidic organic-POH compound in the range of 0.01 to 5%, such as approx. 0.05 to 2%, e.g. ca. 0.1 to 1%.

In this application all weight ratios are by weight, unless otherwise stated. In the examples, atmospheric pressure is used unless otherwise indicated.

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Claims (4)

1. Liquid, non-aqueous, powerful detergent for 5 clothes washing and having a float value of 2 to 8 Pa, characterized in that it comprises a suspension of an alkali metal polyphosphate builder salt having a particle size of less than 10 μι »in 30 to 70 weight %, based on the detergent, of a liquid nonionic surfactant prepared by condensing an alkoxylatable organic hydrophobic compound with alkylene oxide, and 0.01-5% by weight of an organic phosphorus compound having an acidic POH group and is a partial ester of phosphoric acid or phosphoric acid with a mono- or polyhydric alcohol. 15 Agent according to claim 1, characterized in that the organic phosphorus compound is a partial ester of a higher alkanol and phosphoric acid. Agent according to claim 1 or 2, characterized in that the C: P atomic ratio of the phosphorus compound is at least 3: 1. Detergent according to claims 1-3, characterized in that the nonionic surfactant is prepared by alkoxylation of a higher alkanol and contains ethylene oxide units and propylene oxide units. 1 35