FI80292C - VAETSKEFORMIG BYKTVAETTMEDELSKOMPOSITION INNEHAOLLANDE POLYFOSFAT. - Google Patents

Description

χ 80292

This invention relates to a composition for a liquid laundry detergent.

Compositions of liquid, heavy-duty, anhydrous laundry detergents are well known in the art. Such compositions may, for example, contain a liquid nonionic surfactant in which a basic ingredient such as polyphosphate is dispersed; disclosed, for example, in U.S. Patents 4,316,812, 3,630,929, 4,264,466 and GB Patents 1,205,711 and 1,270,15,040.

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 silicate having an extremely small particle size (e.g. 5-100 millimicrons in diameter, such as Aerosil), or other very high pore volume inorganic carriers disclosed in U.S. Patent 25,330,929, or by incorporating various clays, such as attapulgite, as disclosed in U.S. Patent 4,264,466. Grinding to Very Small Grain Size also increases stability.

According to one aspect of the invention, the stability of the suspension is improved by adding an acidic organophosphorus compound having an acidic -POH group. This may be, for example, a partial ester of phosphoric acid and an alcohol, in which case the alcohol may be an alkanol having a lipophilic nature, for example having more than 5 carbon atoms, e.g. 8-20 carbon atoms. It has been found that with the addition of even small amounts of acidic organophosphorus compound, the suspension becomes significantly more stable against precipitation while still remaining flowing. Thus, as shown below, the addition of an acidic phosphorus compound raises the yield point of the suspension but lowers its plastic viscosity.

It is believed that the use of an acidic phosphorus compound can lead to the formation of a high energy physical bond between the -POH moiety of the molecule and the surfaces of the inorganic polyphosphate structure so that these surfaces become organic in nature and more miscible with the non-ionic surfactant.

The invention is very useful in suspensions with a particle size of the polyphosphate builder reduced to less than 10 microns.

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Suspensions of a polyphosphate structuring agent such as sodium tripolyphosphate ("TPP") and a nonionic surfactant have been found to behave theologically according to the Casson equation: 20 σ '* = σ0 ** + η * "® * · γ ** γ is the shear rate, σ is the shear rate , σ0 is the yield stress (or yield strength) and n ~ is the plastic viscosity of an infinite shear-speed {which can be measured by determining the slope of a line obtained by plotting the square root of the shear stress (ordinate) as a function of the square root of the shear rate}. no flow occurs (i.e., it 30 corresponds to the point of intersection of the ordinate when the shear rate is zero, in the above graph.) It is a corresponding criterion for stability.Plastic viscosity is a measure of fluidity when the fluidity limit is exceeded.

It is desirable that the yield strength (measured at 25 ° C) be at least about 2 Pascals (due to cellularity and dispensability) and no more than about 8 Pascals, such as about 3-7 Pascals, more preferably about 4 Pascals.

il 3 80292 A uniformly defined shear rate viscometer (either coaxial or conical plate geometry), such as a Rheometric-5 rheometer, should be used to study this Theological behavior.

The suspensions are preferably prepared by grinding a mixture of a nonionic surfactant, a polyphosphate structural salt and an acidic organophosphorus compound in a mill 10 which breaks down the components to less than 10 microns in diameter. The structural salt generally has much larger granules, more than about 40 microns in diameter, such as 100, 200, or 400 microns. If desired, the structural salt may be premixed with the acidic organophosphorus compound (e.g., by spraying the acidic compound, dispersed or dissolved in water or a volatile organic solvent, over the structural salt).

During grinding, it is desirable that the proportion of solids 20 be high enough (e.g., at least 40% to 50%) for the solids to be in contact with each other, and not more so to be protected from each other by the nonionic surfactant solution. Mills with grinding balls (ball mills) or similar mobile grinding elements have given good results. Thus, a laboratory batch grinder with 8 mm diameter steatite grinding balls can be used.

For larger-scale work, 30 mills with 1 mm or 1.5 mm diameter grinding balls can be used, operating in a very small gap between the body and the rotor at a relatively high rotational speed (e.g. a CoBall mill); when using such a mill, it is desirable to first feed a mixture of nonionic surfactant and solids to 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., 40 microns). The next step is grinding to an average particle size of 4,80292 less than 10 microns in a continuous ball mill.

The following example further illustrates this invention; 5

Example

The anhydrous heavy duty liquid detergent composition is prepared by mixing a nonionic surfactant and sodium tripolyphosphate ("TPP") 10 with other ingredients and with and without an acidic organophosphorus compound, as described below, after which the mixture is ground in a grinder. (to make the particle size of the components of the suspension less than 10 microns). The grinding conditions are the same in each of the 15 cases: grind for ¼ hours in a grinder with 8 mm diameter steatite grinding balls. (Wieneroto W-1.S chopper, charge 2.5 kg mixture).

A B C D

20 Proportion (%) of acidic organophosphorus compound 0 0.1 0.2 0.3

Flow stress (Pascal) 0.3 1.6 3.2 5.6 25 Plastic viscosity (Pascal s) 1.1 1.0 1.0 0.9 The apparent viscosity can be calculated at any shear rate using the Casson equation: apparent vis-30 cosity = shear stress / shear rate.

In this example, a partial ester of phosphoric acid and a C 1 -C 6 alkanol (Marchon Empiphos 5632) is used as the acidic organophosphorus compound; with approximately 35% 35 monoesters and 65% diesters.

The composition contains the following ingredients in certain proportions.

80292 35% nonionic surfactant consisting of equal parts of: (a) a relatively water-soluble nonionic surfactant which forms a gel when mixed with water at 25 ° C, in particular Ca 3 -C 18 alkanol, which is etherified to give 10 ethylene oxide and 5 propylene oxide units per alkanol unit and 10 (b) less water-soluble nonionic surfactants, in particular C 13 -C 18 alkanol etherified to give 4 ethylene oxide and 7 propylene oxide units per alkanol unit.

12% of the reaction product obtained by mixing 100 g of succinic anhydride with 522 g of a nonionic surfactant known as Dobanol 25-7 (a C12-Cis-alkanol ethoxylation product with about 7 molecules of ethylene oxide per alkanol molecule), and 0, With 1 g of pyridine 20 (which acts as an esterification catalyst); heating at 60 ° C for 2 hours; cooling and filtering off unreacted succinic material; (Based on infrared analysis, virtually all of the surfactant hydroxyls have reacted to acidic half-esters in which the -OH group of the nonionic surfactant is esterified with one carboxyl group of the succinic anhydride).

31.5% TPP in Formulation A, 31.4% in Formulation B, 31.3% in Formulation C and 31.2% TPP in Formulation D.

9% sodium perborate monohydrate, NaBO 3 · H 2 O.

4.5% tetraacetylethylenediamine, an activator of sodium per-35 borate.

4% of a copolymer containing approximately equal moles of methacrylic acid and maleic anhydride and completely neutralized to 6,80292 sodium salt (Sokala CP5); it acts as an inhibitor of calcification (dicalcium phosphate formation).

1% sodium salt of diethylenediamine pentamethylenephosphonic acid; this is a sequestering agent with a high stability constant for complexation.

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

10% mixture of Na-carboxymethylcellulose and hydroxymethylcellulose (antiredeposition agent) (Relatin DM 4050).

0.5% perfume.

15 0.5% optical brightener (silbene type 4).

It is desirable that the TPP is mostly an anhydrous material with a small amount of TPP hexahydrate (e.g., an amount such that the amount of chemically bound water is about 3%, which corresponds to about one HaOita per pentasodium tripolyphosphate molecule). Such TPP can be prepared by treating anhydrous TPP for rapid dissolution in a wash bath and preventing sintering. One suitable TPP is sold under the name Thermphos NW; this TPP has a particle size of about 400 microns and a phase I concentration of about 60%.

The mixture easily dispenses into cold water in an automatic washing machine. It has a specific gravity of about 1.25 and gives parasitic washing results at a dosage of about 100 g per load (compared to 170 g per load of standard heavy-duty laundry detergents) in European conventional household washing machines (which use about 20 liters of water per load). .

35

Partial esters of phosphoric acid are known to act as defoamers and are mentioned for this purpose in U.S. Patent 4,264,466 (paragraph 33, lines 34-45). This

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However, the compositions of the 7 80292 mark are of the low-foam type; when washing conventional detergents in typical European (e.g. German) front-loading washing machines. They form a small foam even in the absence of the partial ester of phosphoric acid 5 and thus do not require any antifoams.

The acidic phosphorus compound can be selected from a wide variety of substances in addition to the aforementioned phosphoric acid moieties and alkanols. Thus, a partial ester of phosphoric acid or acid can be used with a mono- or polyhydric alcohol such as hexylene glycol, ethylene glycol, di- or triethylene glycol or higher polyethylene glycols, polypropylene glycol, glycerol, sorbitol, etc., fatty acids, mono-fatty acids, fatty acids, fatty acids. , wherein one, two or more alcoholic OH groups of the molecule can be esterified with phosphoric acid. The alcohol may be a nonionic surfactant such as ethoxylated or ethoxylated-propoxylated higher alkanol, higher alkylphenol or higher alkylamide. -T The POH group need not be attached by an ester bond to an organic part of the molecule; instead, it may be directly attached to carbon (such as in phosphoric acid, such as polystyrene, where some aromatic rings have phosphoric acid-25 or phosphinic acid groups; or in an alkyl phosphoric acid, such as propyl or lauryl phosphoric acid), or it may be attached to carbon by other intermediates such as By coupling of S or N atoms). The carbon phosphorus atomic ratio in the organophosphorus compound is preferably at least 3: 1, 30 such as 5: 1, 10: 1, 20: 1, 30: 1 or 40: 1. Useful compounds include the phosphate ester surfactants listed in Kirk-Othmer's "Encyclopedia of Chemical Technology", 3rd Edition, Vol. 22 (1983) on pages 359-361.

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The partial alkyl ester of phosphoric acid and C 1 -C 6 alkanol as described in the previous example is a solid that generally swells but is insoluble in the nonionic surfactant. It is obtained as a powder. In the preferred manner in the example, TPP is added last (after the other solids are added to the liquid mixture between the nonionic surfactant and the reaction product between succinic anhydride and nonionic surfactant) and the powdered partial alkyl ester of phosphoric acid is added just before the TPP. Acidic organophosphorus compounds that are soluble in the nonionic surfactant can also be used.

10

As is well known, nonionic surfactants are recognizable in that they have an organic hydrophobic group and an organic hydrophilic group, and that they are typically prepared by condensation between an organic aliphatic or alkyl aromatic hydrophobic compound and ethylene oxide (hydrophilic in nature). Virtually any hydrophobic compound having a carboxy, hydroxy, amido or amino group and free hydrogen bound to 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 ion-25 surfactants are disclosed in U.S. Patents 4,316,812 and 3,630,929, as well as those disclosed and described in the review of nonionic surfactants in the Kirk-Othmer Encyclopedia of Chemical Technology. 3-rd Edition, Vol. 22 (1983), pages 360-379.

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Nonionic surfactants tend to form gels with a limited amount of cold water; this can sometimes interfere with the complete distribution of the compound when using compounds commonly used in conventional automatic home washing machines in Europe. To lower the gelation temperature, resulting in easier distribution, a carboxylic acid antigelizing agent can be added to the compound. It is desirable that this type

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9,80292 is a compound having a carboxyl moiety combined with a residue of a nonionic surfactant, e.g., a half ester of a succinic acid or other dicarboxylic acid in which the OH group of the nonionic surfactant is esterified with one carboxyl group of the acid. This material is preferably in solution of a nonionic surfactant.

It is desirable that the polyphosphate structural salt be an alkali metal (e.g. Na or K) tripolyphosphate, pyrophosphate (e.g. tetrasodium pyrophosphate) or hexametaphosphate. These should preferably be in their mostly anhydrous form. A mixture of two or more different polyphosphates may be used. Polyphosphate can also be used in blends. . with one or more water-soluble detergent builders.

Useful building materials include inorganic and organic structural salts such as phosphates, carbonates, silicates, phosphonates, polyhydroxysulfonates, polycarboxylates, and the like. Typical useful building materials are disclosed in U.S. Patents 4,316,812; 4,264,466; and 3,630,929.

Since, as shown in the example, the compounds of this invention can be used in relatively small doses, it is desirable to provide any phosphate or phosphate-forming builder (such as sodium tripolyphosphate) with an auxiliary builder such as a high calcium calcium carboxylic acid polymer, e.g. -10% of the compound. This prevents deposition that could otherwise occur with the formation of insoluble calcium phosphate. Such auxiliary structural materials are well known in the art.

The compound should preferably contain a peroxide bleach.

This may be a peroxide compound such as alkali metal perborate, percarbonate or perphosphate; a particularly suitable substance is sodium perborate monohydrate. The peroxide compounds are preferably used in a mixture with an activator. Suitable activators are disclosed 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 glucose pentaacetate are particularly preferred.

The activator generally acts with the peroxide compound to form the peroxyacid bleach in the wash water. It is desirable to add an insulating agent having a high complexing ability to prevent any undesired reaction between peroxyacid and hydrogen peroxide in a washing solution containing metal ions. Such an insulating agent is an organic compound having the ability to form a complex with Cu 2 - * ions such that the stability constant (pK) of the complexation is 6 or more at 25 ° C in water with an ionic strength of 0.1 mol / liter. pK is conventionally defined by the equation: pK = -log K, where K is the equilibrium -20 kio. Thus, for example, copper ion complexation with NTAs and EDTA under the conditions described gives pK values of 12.7 and 18.8, respectively. Suitable insulating agents include nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetate-25-diacid (DETPA), diethylenetriaminepentamethylenephosphoric acid (DTPMP), and ethylenediaminapethylenediamine (DTPMP).

Other ingredients to be added to the compound may be enzymes (e.g., proteases, amylases, or lipases, or mixtures thereof), optical brighteners, antireposants, dyes (e.g., pigments or dyes), and the like.

The compound may also include an inorganic insoluble precipitant or dispersant having a very high surface area, such as finely divided silica having a very small particle size (e.g., 5 to 100 millimicrons in diameter sold as Aerosil) or other large

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n 80292 pore volume inorganic carrier materials disclosed in U.S. Patent 3,630,929 in dosages of 0.1-10%, e.g. 1-5%. However, in order to obtain the best results, it is desirable that the compounds which form peroxyacids in the wash solution (e.g., compounds having a peroxide compound and an activator) be fairly pure of such compounds and other silicates; it has been found that e.g. silica and silicates cause the degradation of unwanted peroxyacid. In addition, the use of these inorganic substances in water-soluble mats can cause other problems in the system. No porous silica or chain clay is required within the scope of this invention, and the compound is preferably quite free of these materials.

Although the preferred compounds have reduced the average particle size of the solids to less than 10 microns (e.g., usually only about 5-10% of the solids content exceeds the particle size of 10 microns), the invention is also applicable to compounds that are not so finely divided. It will be appreciated that fine grinding increases the stability of the compound against precipitation while standing in solution; According to Stoke's law, the smaller the particle size, the slower the precipitation rate. By raising the yield strength obtained with a given degree of grinding, the use of an acidic phosphorus compound may make it possible to increase stability in compounds having an average particle size of, for example, 15, 20 or 25 microns, such as using increased amounts of an acidic phosphorus compound to achieve the desired at least about 2 Pascals. 30 limit.

Typical ratios of the compounds of the invention are as follows: Suspended detergent base, in the range of 10-60%, such as 20-50%, e.g. about 25-40%; 12 80292

A liquid phase containing a nonionic surfactant (and, optionally, a dissolved carboxylic acid gel inhibitor) in the range of about 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;

A carboxylic acid antigenizing agent, an amount to give 0.5 to 10 parts (e.g., about 1 to 6 parts, such as about 2 to 5 parts) of 10 -C 10 H per 100 parts of a mixture of such a compound and a nonionic surfactant; usually the amount of this antigen binding agent 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. about 0.2 to 0.5 parts.

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A peroxide 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%; 20

A sequestering agent having a high complexing ability in the range of about k-3%, such as about% -2%;

Acidic organic POH compound, in the range of 0.01-5%, such as about 0.05-2%, e.g. about 0.1-1%.

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

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It is to be understood that the foregoing detailed description is merely a way of describing the invention, and that modifications may be made without departing from the scope of the invention.

il

Claims (15)

A liquid heavy duty laundry detergent composition comprising an alkali metal polyphosphate builder salt suspension in a liquid nonionic surfactant, characterized in that said composition contains an organophosphorus compound having an acidic -POH group and sufficient to elevate said compound. Composition according to Claim 1, characterized in that it is practically anhydrous and has a flow limit in the range of about 2 to 8 Pa. Composition according to Claim 1, characterized in that it is of the low-foam type, even in the absence of an organic phosphorus compound. Composition according to Claim 1, characterized in that the polyphosphate salt is sodium tripolyphosphate. 20 The composition of claim 1, characterized in that the suspended base salt has a particle size of less than about 10 microns. The composition of claim 1, wherein the C: P atomic ratio in the phosphorus compound is at least about 3: 1. Composition according to Claim 1, characterized in that the organophosphorus compound is a partial ester of an alkanol and phosphoric acid. Composition according to Claim 6, characterized in that the alkanol is a higher alkanol. 35 The composition of claim 1, characterized in that it is prepared by grinding the suspension until the particle size of the suspended base salt is less than about 10 microns. Composition according to Claim 1, characterized in that the compound is practically anhydrous and contains a peroxide bleach. Composition according to Claim 10, characterized in that the peroxide bleach comprises sodium perborate and its activator. Composition according to Claim 11, characterized in that the activator is tetraacetylethylenediamine. Composition according to Claim 1, characterized in that it is practically free of silica and silicate precipitant. 13 80292 Composition according to Claim 1, characterized in that it is practically free of chain-like clay. Composition according to Claim 1, characterized in that it comprises a carboxylic acid antigenizing agent. is 80292