NL8800351A - AQUEOUS LIQUID THIXOTROPE COMPOSITION FOR USE IN AUTOMATIC WASHERS. - Google Patents

Description

a

VO 1035

Aqueous liquid thixotropic composition for use in automatic washing machines.

The invention relates to an aqueous thixotropic clay suspension with improved physical stability. The invention particularly relates to the use of potassium polyphosphates and long chain fatty acid metal salts as physical stabilizers for aqueous thixotropic clay suspensions.

The addition of low effective amounts of potassium polyphosphates and low effective amounts of long chain polyhydric metal salts of fatty acids improves physical stability and variations in theological properties over time of aqueous thixotropic clay suspensions containing detergent compositions. The thixotropic properties can be maintained or improved using smaller amounts, such as 0.25-0.50%, of the thixotropic clay thickener than in the absence of the potassium polyphosphate stabilizer.

The invention particularly relates to detergent compositions intended for use in automatic dishwashers having thixotropic properties, improved chemical and physical stability, improved stability against variations in theological properties with time and with improved apparent viscosity, which are readily dispersible in the washing medium to provide effective cleaning of dishes, glassware, porcelain and the like.

Commercially available powder detergents intended for use in household dishwashers have various drawbacks, such as a non-uniform composition; expensive preparation methods; tendency to coagulate on storage, at high humidity, resulting in the formation of lumps difficult to disperse; dusting, a source of particular irritation for users suffering from allergies; and tendency to bake together in the dishwasher dispenser.

Recent research and development activity has focused on the gel or "thixotropic" form of such compositions, for example, abrasive cleaners and thixotropic pastes characterized products for automatic dishwashers. Such dishwashing products are primarily disadvantageous in that they are insufficiently viscous to remain "anchored" in the dishwasher's dispenser. Ideally, thixotropic cleaning compositions in the resting state are a high fish choice, Bingham plastic in nature 5 and have relatively high yield values. However, when they are exposed to shear stresses, for example before being shaken in a vessel, or squeezed through a nozzle, they should liquefy quickly and then quickly return to the high viscosity when the applied shear stress is removed. Bingham 10 plastic condition. Stability is also of primary importance, i.e. that after long standing there should be no significant phase separation or leakage.

United States Patent Application 744,754, filed June 14, 1985, relates to aqueous thixotropic clay suspensions containing detergent compositions for dishwashers containing aluminum stearate as a physical stabilizing agent. The compositions of the aforementioned U.S. Patent Application 744,754 show improvement in the physical stability of the detergent composition and improvement against phase separation over clay-containing compositions that do not contain aluminum stearate. However, these previously proposed compositions, in some instances, exhibit difficulties in achieving stability against variations in theological properties over time and over wide temperature variations and generally require a relatively large clay content, such as 0.25-2.0%.

The provision of gel form compositions intended for use in automatic dishwashing machines with the aforementioned properties, other than the improvements described in the above-mentioned US patent application, has hitherto proved problematic, especially as regards compositions for use in household dishwashing machines. . For effective use, it is generally recommended that the automatic dishwashing detergent, also referred to herein as AVD, contain (1) sodium tripolyphosfeat (NaTPP) for mineral bonding in hard water and for emulsification and / or peptization of soil; (2) sodium silicate to provide the alkalinity necessary for effective detergent and to protect the enamel and fine porcelain cartridge; (3) sodium carbonate, which is generally considered optional to enhance alkalinity; (4) a chlorine-providing agent to promote the elimination of splashes of dirt leading to water stains; and (5) anti-foaming agent / capillary-5 active compound to reduce foaming and thereby improve machine efficiency and provide the required detergent. For example, reference is made to SDA Detergents in Depth, "Formulations Aspect of Machine Dishwashing," Thomas Oberle (1974). Detergents approximating the 10 compositions described above are usually liquids or powders. Combination of such ingredients in the form of a gel, which is effective for a household dishwasher, has proved difficult. Generally, hypochlorite bleach is omitted in such compositions where it tends to react with other chemically active ingredients, especially surfactant. For example, thixotropic pastes intended for use in automatic dishwashers are known from United States Patent Specification 4,115,308 which contain a suspending agent, for example CMC, synthetic clay or the like; inorganic salts; including silicates, phosphates and polyphosphates; contains a small amount of surfactant and a foam suppressant.

A bleaching agent is not mentioned. US 4,147,650 discloses a similar composition, optionally containing chlorine (hypochlorite) bleach, but no organic surfactant or foam suppressant. The product is additionally described as a detergent suspension, apparently without thixotropic properties.

US Patent 3,985,668 describes abrasive abrasive cleaners of gel-like consistency containing (1) suspending agent, preferably the Smectite and attapulgite types of clay; (2) abrasive, for example silica sand or perlite; and (3) fillers, such as low density powdered polymers, expanded perlite or the like, which have a buoyancy and thereby exhibit a stabilizing effect on the composition and additionally act as a mass-delivering agent, thereby replacing water otherwise 880035 «-4- f would be available to form an unwanted supernatant layer due to leakage and phase destabilization. The ingredients listed are essential. Optional ingredients are hypochlorite bleach, bleach stable capillary-5 active material and buffer, for example, silicates, carbonates and monophosphates. As further optional ingredients, builder salts, such as sodium tripolyphosphate, may be included to provide or supplement builder function, which is not provided by the buffer, the amount of such builder salt not appearing to exceed 5% of the patent. the total composition. Maintaining the desired pH of 10 or more is achieved by the buffer / build-up salt components. Higher pH decomposition of the chlorine bleach * is said to reduce undesirable interaction between surfactant and bleach to a minimum. If present, sodium tripolyphosphate, as mentioned, is limited to 5%. An anti-foaming agent is not mentioned.

In the U.K. patent applications GB 2,116,199A and GB 2,140,450A disclose liquid AVD compositions which have desirable properties, which characterize a thixotropic, gel-like structure, and which contain each of the various ingredients necessary for effective detergent with an automatic Dishwasher. The normally gel-like aqueous detergent composition for use in automatic dishwashers: having thixotropic properties contains the following ingredients: 25 (a) 5-35 wt% alkali metal tripolyphosphate; (b) 2.5-20 wt% sodium silicate; (c) 0-9 wt% alkali metal carbonate; (d) 0.1-5 wt% water-dispersible organic detergent active material resistant to chlorine bleach; (e) 0-5% by weight of a foam suppressant, which is resistant to chlorine bleaching agents (f) chlorine bleaching agent in an amount to provide 0.2-4% by weight of available chlorine; (G) thixotropic thickener in an amount sufficient to impart a thixotropy index of 2.5-10.

8800351 -5- (h) sodium hydroxide as necessary for pH adjustment; and (i) water.

AVD compositions thus formulated form little foam, are easily soluble in the wash medium and are most effective at pH values best suited for improved cleaning performance, i.e., a pH of 10.5-14.0. The compositions are normally of gel consistency, especially a highly viscous opaque jelly-like material with Bingham plastic character and thus relatively high yield values. Under such conditions, the composition is quickly liquefied and easily dispersed.

When the shear is removed, the liquid composition quickly returns to a highly viscous, Bingham plastic state, which closely approximates the earlier consistency.

15 In. U.S. Patent 4,511,487 describes a low foaming detergent paste for dishwashers. The patented thixotropic detergent has a viscosity of at least 30 Pa.s at 20 ° C determined with a rotary viscometer at an axis speed of 5 rpm. The composition is based on a mixture of finely divided hydrated. sodium metasilicate, an active chlorine compound and a thickener which is a hectorite-type leaf silicate. The composition may contain a minor amount of nonionic surfactant and alkali metal carbonates and / or hydroxides.

From JAOCS, 61 (1984) 382 the formation of organoclay materials is known due to the interaction of clay materials (such as bentonite and hectorite) with organic compounds, such as quaternary ammonium salts.

While these previously described liquid AVD compositions do not exhibit, or to a lesser extent, the defects described above, it has been found that further improvements in physical stability and stability against variations in theological properties over time are desired, to improve product shelf life and increase the acceptability for the user.

It would also be highly desirable to have physical stability and stability against variations in the theological properties. 8 ε o e; · m -6- * improve the time of other thixotropic liquid clay-based preparations, such as abrasive cleaners, toothpastes, "liquid" soaps and the like.

An object of the invention is to provide anti-settling additives for aqueous thixotropic clay suspensions.

Another object of the invention is to provide liquid AVD compositions, which have thixotropic properties, with improved physical stability and improved stability against variations in rheological properties with time.

A further object of the invention is to provide liquid thixotropic AVD compositions with a reduced thixotropic thickener content without the generally high viscosity at low shear value and lower viscosity at high shear value characteristic of the desired thixotropic proprietary -15 shelves, are adversely affected.

Yet another object of the invention is to improve the stability of aqueous clay-based thixotropic compositions, in particular liquid detergent pastes or gels for automatic dishwashers, by incorporating in the aqueous clay suspension a minor amount of potassium polyphosphates and a minor amount of a metal salt of a fatty acid, effective to inhibit settling of the suspended particles and to prevent phase separation.

Yet a further object of the invention is to improve stability against variations in rheological properties over time of aqueous clay thixotropic compositions, in particular liquid detergent pastes or gels for automatic dishwashers, by incorporation into the aqueous clay suspension of a low effective amount of potassium polyphosphates and low effective amount of a metal salt of a fatty acid as stabilizers.

These and other objects of the invention, which may be understood from the following detailed description of the invention and the preferred embodiments thereof, are prepared by incorporation into a normally gel-like aqueous liquid composition, 8 8 0 03 5 1 -7- a small but effective amount of physical stabilizers. being potassium phosphates and a long chain fatty acid metal salt. According to a preferred embodiment of the invention, there is provided a normally gel-like detergent composition intended for use in automatic dishwashing machines containing an amount of potassium polyphosphates and an amount of a metal salt of a long chain fatty acid effective to vary the rheological properties inhibit over time and are effective to inhibit settling of the suspended particles, such as thixotropic agent and sodium tripolyphosphate boob salt.

In accordance with these particular aspects, the invention provides a normally gel-like aqueous detergent composition for use in automatic dishwashers with thixotropic properties, comprising: 15 (a) 5-35 wt% sodium tripolyphosphate; (b) 2.5-20 wt% sodium silicate; (c) 0-9 wt% alkali metal carbonate; (d) 0.1-5% by weight water-dispersible organic detergent active material resistant to chlorine bleaches; (e) 0-5% by weight of a foam suppressant, which is resistant to chlorine bleaches; (f) chlorine bleach in an amount to provide 0.2-4% by weight of available chlorine; (G) thixotropic thickener in an amount sufficient to impart a thixotropy index of 2.5-10, (h) 0-8 wt% sodium hydroxide; (i) potassium polyphosphates and a long chain fatty acid polyvalent metal salt in amounts effective to increase the physical stability of the composition and the physical stability of the composition against variations of rheological properties with time; and 35 (j) water.

. 8 8 0 0 3 S 1 -8-

Related to this particular aspect, the invention provides a method of cleaning dishes in an automatic dishwashing machine with an aqueous washing bath containing an effective amount of the liquid automatic dishwashing detergent (VAVD) composition described above. According to this aspect of the invention, the VAVD composition can be easily poured into the dispenser of the automatic dishwashing machine, where the composition compacts to normal gel or pasty state within seconds.

10 In general, the effectiveness of a VAVD

directly related to (a) available chlorine content, (b) alkalinity; (c) solubility in the wash medium and (d) foam inhibition. Preferably, the pH of the VAVD composition is at least 9.5, 1 especially 10.5-14.0 and most preferably at least 11.5. The presence of carbonate is often necessary as it acts as a buffer to help maintain the desired pH level. However, an excess of carbonate should be avoided as this can cause the formation of needle-like carbonate crystals, thereby reducing stability, thixotropy and / or detergent of the VAVD product can be adversely affected, as can the dosability of the product from, for example, squeeze bottles. NaOH carries on production until it neutralizes the phosphorus or phosphonic acid ester suds suppressor, if any. Typically 0.5-6 wt% NaOH and 2-9 wt% sodium carbonate in the VAVD composition, although it should be noted that sufficient alkalinity can be provided by the sodium tripolyphosphate and sodium silicate.

The sodium tripolyphosphate, which is used in the VAVD in an amount of 8-35 wt.%, Preferably of 20-3.0 wt.%, Is preferably free of heavy metals, which can decompose or deactivate chlorine bleaches, preferably sodium hypochlorite . The sodium tripolyphosphate can be anhydrous or hydrated, including the stable hexahydrate with a degree of hydration of 6, corresponding to about 18% by weight of water or more. Particularly preferred VAVD compositions are obtained, for example, by using a weight ratio of anhydrous sodium tripolyphosphate to the hexa-8800551-9 hydrate of 0.5: 1 to 2: 1, with the value of about 1: 1 being particularly preferred.

Foam inhibition is important to increase the effectiveness of the dishwasher and minimize the stabilizing effects that may occur due to the presence of excess foam within the washing machine during use. Foaming can be sufficiently reduced by an appropriate choice of the type and / or amount of detergent active material, the major foaming component. The degree of foaming is also somewhat dependent on the hardness of the washing water in the machine, whereby a suitable addition of the amount of sodium tripolyphosphate, which has a water-softening effect, can help to provide the desired degree of foam inhibition. Generally, however, it is preferable to use an antifouling or inhibiting agent which is resistant to chlorine bleaches. The alkylphosphonic acid esters of the formula O are particularly effective

HO- P- R

OR

available from, for example, BASF-Wyandotte (PCUK-PAE) and in particular the alkyl acid phosphate esters of the formula O

B

HO - P - OR

OR

available from, for example, Hooker (SAP) and Knapsack (LPKn-158), in which a group R or both groups R in each type of ester can independently represent a {{2-20 alkyl group. Mixtures of the two types or any other type which is resistant to chlorine bleaches or mixtures of mono- and diesters of the same type can be used. Particular preference is given to a mixture of mono and di-16-18 alkyl acid phosphate esters, such as monostearyl / distearyl acid phosphates 1.2 / 1 (Knapsack) or (UGINE KUHLMAN). When used, amounts are from 0.1-5 wt%, preferably 0.1-0.5 wt%, of a foam suppressant. 88 0 058 1 -10- * in the composition, wherein the weight ratio of the detergent active component (d) to suds suppressant (e) is generally between about 10: 1 and 1: 1, preferably between about 5: 1 and 1: 1. Other anti-foaming agents which can be used are, for example, the known silicone. Furthermore, an advantageous aspect of the invention is that many of the stabilizing salts, such as the stearate salts, for example, aluminum stearate, are also effective as anti-foaming agents.

Although any chlorine bleaching compound such as dichloroisocyanurate, dichlorodimethylhydantoin or chlorinated TSP can be used in the composition of the invention, alkali metal hypochlorite, for example potassium, lithium, magnesium and especially sodium hypochlorite, is preferred. The composition containing sufficient chlorine bleaching compound to provide 0.2-4.0 wt% available chlorine, for example, determined by acidifying 100 parts of the composition with an excess of hydrochloric acid. A solution containing 0.2-4.0 wt% sodium hypochlorite provides approximately the same percentage of available chlorine. About 0.8-1.6% by weight of available chlorine is particularly preferred. For example, a solution of sodium hypochlorite (NaOCl) with about 11 to about 13% available chlorine in amounts of about 3-20%, preferably about 7 to 12%, can be used advantageously.

The sodium silicate, which provides alkalinity and hard surface protection, such as the glaze and fine porcelain pattern, is used in the composition in an amount of 2.5-20 wt%, preferably 5-15 wt%. The sodium silicate is generally added in the form of an aqueous solution, preferably with a Na 2 O: SiO 2 ratio of about 1: 2 to 1 * 2.8.

The detergent active material to be used according to the invention must be stable in the presence of chlorine bleaches, in particular hypochlorite bleaches. Detergent-active materials of the organic anionic, amine oxide, phosphine oxide, sulfoxide or betaine water-dispersible surfactants are preferred, with the former anionic materials being most preferred. They are used in amounts of 0.1-5%, preferably 0.3-2.0%. Particularly preferred surfactants are the linear or branched alkali metal mono- and / or di- (C8-4) alkyl diphenyl oxide mono- and / or di-sulfates or disulfonates, commercially available under, for example, the trade names DOWFAX 3B- 2 and DOWFAX 2A-1. Furthermore, the surfactant material must be compatible with the other ingredients of the composition. Other suitable surfactants are the primary alkyl sulfates, alkyl sulfonates, alkyl aryl sulfonates and secondary alkyl sulfates. Examples are sodium GL 1 -C 2 g alkyl sulfates such as sodium dodecyl sulfate and sodium tallo alcohol sulfate; sodium C 1 -C 4 g alkane sulfonates such as sodium hexadecyl-1-sulfonate and sodium C 1 -C 4 g alkylbenzene sulfonates, such as sodium dodecylbenzene sulfonates. The corresponding potassium salts can also be used.

As for other suitable surfactants or detergents, the amine oxide surfactants typically have the structure R_R ^ N-O, wherein each R represents a lower alkyl group, eg Z 1 methyl, and R is a long chain alkyl group of 8-22 carbon atoms, for example, a lauryl, myristyl, palmityl-20 or cetyl group. Instead of an amine oxide, a corresponding surfactant phosphine oxide R 1 R 2 PO or sulfoxide R 1 SO 2 can be used. Surfactants typically have the structure R 1, R 1, N-R'COO, wherein each R represents a lower alkylene group with 1 to 5 carbon atoms. Specific examples of these compounds are lauryl dimethylamine oxide, myristyl dimethylamine oxide, the corresponding phosphine oxides and sulf oxides, and the corresponding betaines, including dodecyl dimethyl ammonium acetate, tetradecyldiethyl ammonium pentanoate, hexadecyldimethyl ammonium hexanoate and the like. For biodegradability, the alkyl groups in these surfactants should be linear, and such compounds are preferred.

Surfactants of the type mentioned are known and described, for example, in U.S. Patents 3,985,668 and 4,271,030.

Thixotropic thickeners, in particular thickeners or. 68003-1-12 suspending agents which impart thixotropic properties to an aqueous medium are known and may be organic or inorganic water-soluble, water-dispersible or colloid-forming monomeric or polymeric materials and, of course, should be stable in the compositions ie resistant to high alkalinity and chlorine bleaching compounds such as sodium hypochlorite. Particularly preferred materials are generally the inorganic colloid-forming clays of smectite and / or attapulgite type. These materials are used in the VAVD compositions according to the above-mentioned U.K. patent applications 2,116,199A and GB 2,140,450A used in amounts of 1.5-10% by weight, preferably 2-5% by weight, to impart the desired thixotropic properties and Bingham plastic character to the compositions. One of the advantages of the VAVD compositions of the invention is that the desired thixotropic properties and Bingham plastic character can be obtained with smaller amounts of the thixotropic thickeners in the presence of the potassium polyphosphates and the metal salt of a fatty acid, which be used as a stabilizer.

For example, amounts of the inorganic colloid-20 forming clays of the smectite and / or attapulgite type are from 0.1-0.5%, preferably 0.2-0.4%, especially 0.25-0, 30% is generally sufficient to achieve the desired thixotropic properties and Bingham plastic character when used in combination with the potassium polyphosphates and fatty acid metal salts used as physical stabilizers according to the invention.

Examples of smectite clay materials are montmorillonite (bentonite), hectorite, attapulgite, smectite, saponite and the like. Montmorillonite clay materials are preferred and are available under brand names such as Thixogel no.1 and Gelwhite 30 GP, H, etc., from Georgia Kaolin Company, and under the brand name ECCAGUM GP, H, etc., from Luthern Clay Products. Examples of attapulgite clay materials are those commercially available under the brand name Attagel, especially Attagel 40, Attagel 50 and Attagel 150 from Engelhard Minerals and Chemicals Corporation.

Mixtures of smectite and attapulgite in weight ratios of 4: 1 to 1: 5 can also be used. Thickeners or suspensions-8800351; 13. Means of said types are well known and are described, for example, in the aforementioned U.S. Pat. No. 3,985,668. In the VAVD compositions, abrasive materials or polishes should be avoided, as they can damage the surface of fine dishes, crystal and the like.

The amount of water in the compositions should of course not be so large as to obtain an undesirably low viscosity and high fluidity, nor so small that the viscosity is undesirably high and the fluidity low, since in either case the thixotropic properties are impaired or A suitable amount is readily determined for routine testing and is generally 30-75 wt%, preferably 30-65 wt%. The water is preferably deionized or softened.

So far, the description of the VAVD product 15, unless otherwise stated, corresponds to the compositions described in the aforementioned U.K. patent applications GB 2.Ï16.199A and GB 2.140.450.

The VAVD products according to the aforementioned U.K. Patent applications show improved rheological properties, as can be seen by measuring the product viscosity as a function of the shear.

The compositions exhibit higher viscosity at low shear and lower viscosity at high shear, and the measurement data shows efficient fluidity and gel formation within the shear values prevailing in the standard dishwasher. In practical terms, this means improved casting and operating properties, as well as less leakage in the dispenser of the machine compared to earlier liquid or gel AVD products. For shear values, corresponding to 3-30 revolutions per minute, the viscosities (Brookfield) range from about 10,000 to 30,000 cps to about 2,000-6000 cps, 30 measured at room temperature using an LVT Brookfield viscometer after 3 minutes using shaft number 4 one day after preparation. A 7.4 sec shear corresponds to a shaft revolution speed of about 3 rpm. An approximately 10-fold increase in shear value yields an approximately 35 3-9-fold decrease in viscosity. In prior AVD gels, the corresponding viscosity decrease was only about two-fold.

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In addition, in such compositions, the initial viscosity at about 3 rpm was only about 2500-2700 cps. Thus, the compositions of said U.K. patent applications exhibit threshold fluxes at lower shear rates and to a significantly greater degree in terms of incremental shear increases versus incremental viscosity drops. This property of the VAVD products according to the aforementioned U.K. patent application is summarized in terms of a thixotropy index (TI), which is the ratio of the apparent viscosities at 3 rpm and 30 rpm. The earlier 10 compositions have a TI of 2-10. The proven VAVD compositions showed a marked and rapid return to the previous resting state consistency, when the shear force was removed.

The invention is based on the discovery that the physical stability, ie the resistance to phase separation, settling and the like, of the liquid aqueous AVD compositions of UK patent application GB 2,116,199A and GB 2,140,450 and US patent application 744,754 can be marked be improved or not adversely affected, while at the same time significantly improving stability against variations in rheological properties with time and temperature by adding to the composition a small but effective amount of potassium polyphosphates and small but effective amounts of a long chain fatty acid metal salt.

As an example of the improvement in rheological properties, it can be mentioned that the viscosities at low shear values, for example at an axis speed of about 3 rev / min, the apparent viscosities can often be up to two or three fold. are increased by adding as little as 1-2% or less of the potassium polyphosphate and as little as 0.25-0.50% of the metal salt of the fatty acid. At the same time, the physical stability can be improved such that even after 12 weeks or more over temperature ranges, extending from near freezing point to 40 ° C and above, the compositions containing the potassium polyphosphates and the metal salt stabilizers are stable against variation in the rheological properties with time and temperature and no visible phase separation.

.8800351 -j-5 "

The potassium polyphosphates which can be used are generally commercially available. Specific examples of potassium polyphosphates are potassium tripolyphosphate, potassium pyrophosphate and potassium hexametaphosphate. Potassium tripolyphosphate (TPP) is preferred.

The amount of the potassium polyphosphates required to achieve the desired improvement in physical stability depends on various factors, such as the nature of the fatty acid salt, the nature and amount of the thixotropic agent, the detergent active compound , inorganic salts, sodium (TPP), other VAVD ingredients, as well as the intended storage and transportation conditions.

The amounts of the potassium polyphosphates (50% Al) to be used are 0.5-3.0%, preferably 0.80-2.0%, most preferably 1.0-1.8%.

The preferred long chain fatty acids are the higher aliphatic fatty acids having 8-22 carbon atoms, preferably 10-20 carbon atoms, most preferably 12-18 carbon atoms, including the carbon atom of the carboxyl group of the fatty acid. The aliphatic group may be saturated or unsaturated and linear or branched.

Linear saturated fatty acids are preferred. Mixtures of fatty acids, such as the acids from natural sources, such as tallow fatty acid, coco fatty acid, soy fatty acid and the like, or from synthetic sources available from industrial processing processes can also be used.

Examples of the fatty acids with which the polyvalent metal salt stabilizer can be formed are decanoic acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, oleic acid, eicosanoic acid, tallow fatty acid, coco fatty acid, soy fatty acid and mixtures of two or more such acids. Stearic acid and mixed fatty acids are preferred.

The preferred metals are the polyvalent metals from groups IIA, IIB and IIIB, such as magnesium, calcium, aluminum and zinc, although other polyvalent metals can also be used, including those from the groups UIA »IVA, VA, VIA, VIIA, IB , IVB, VB} 35 SDS, VUB and VIII of the periodic table. Specific examples of such other polyvalent metals are titanium, zirconium, vanadium,. 8 8 β C 7-h 1 -16-niobium, manganese, iron, cobalt, nickel, cadmium, tin, antimony, bismuth and the like. Generally, the metals can be present in the divalent to pentavalent state. Preferably, the metal salts are used in their higher oxidation states. Obviously 5 serves for VAVD compositions, as well as for other applications in which the composition according to the invention could or may come into contact with objects that are used for the handling, storage or serving of food products or that can otherwise come into contact with or can be consumed by humans or animals to take into account the toxicity of the metal when choosing the metal salt. For this reason, the calcium and magnesium salts are particularly preferred as generally safe food additives.

Many of these metal salts are commercially available.

For example, the aluminum salts are available in the triacid form, for example, aluminum stearate such as aluminum tristearate, AICC-H-COO). The monoacid salts, for example, aluminum monostate, Al (OH) ((0 ^ 11 ^ 000) and diacid salts, for example, aluminum distearate, Al (OH) (C ^ H ^ COO ^), and mixtures of two or three of the mono-, di- and triacid salts can be used for metals with valences of +3, for example aluminum, while mixtures of the mono and diacid salts can be used for the metals with valences of +2, for example zinc.

It is particularly preferred that the diacids of the + 2 -value metals, and the triacids of the + 3 -value metals, the tetraacids of the + 4 -value metals and the pentacids of the + 5 -value metals, be used in predominant amounts used. For example, at least 30%, preferably at least 50% and most preferably 80-100% of the total amount of metal salt is used in the highest possible oxidation state, i.e. all possible valence sites are occupied by a fatty acid residue.

As mentioned, the metal salts are widely available commercially, but they can also be readily prepared, for example, by saponification of a fatty acid, such as animal fat, stearic acid and the like, or the corresponding fatty acid ester, followed by treatment with a hydroxide or oxide of the . 8 £ G 8 5 R 1 4 -17- polyvalent metal, for example with alum, alumina and the like in the case of the aluminum salt.

Calcium stearate, especially calcium distearate, magnesium stearate, especially magnesium distearate, aluminum stearate, especially aluminum tristearate, and zinc stearate, especially zinc distearate, are the preferred fatty acid salt stabilizers. Also, metal salts of mixed fatty acids, such as the naturally occurring acids, for example, cocoic acid, as well as the mixed fatty acids from industrial manufacturing processes, can advantageously be used as an inexpensive but effective source of the long chain fatty acid.

The amount of potassium polyphosphates and fatty acid salt stabilizers to be used to achieve the desired improvement in physical stability also depends on various factors, such as the nature of the fatty acid salt, the nature and amount of the thixotropic agent, the detergent active compound, the inorganic salts, sodium tripolyphosphate, other VAVD ingredients, as well as the intended storage and transportation conditions.

Generally, however, the amounts of the fatty acid salt stabilizer are 0.10-0.5%, preferably 0.2-0.4%, most preferably 0.25-0.30%. The use of the potassium polyphosphates with the fatty acid metal salt stabilizers provides the long-term physical stability, stability against variations of theological properties with time and temperature, and the absence of phase separation in cataracts, or during transport at both low and high temperatures, such as required for a commercially acceptable product.

In another embodiment of the invention, the fatty acids themselves can be used as a stabilizer in place of the above-described fatty acid metal salts.

Long chain useful fatty acids are, for example, the 30 aliphatic fatty acids having 8-22 carbon atoms, preferably 10-20 carbon atoms, and most preferably 12-18 carbon atoms, including the carbon atom of the carboxyl group of the fatty acid. The aliphatic group can be saturated or unsaturated and linear or branched. Linear saturated fatty acids are preferred. Mixtures of fatty acids can also be used, such as fatty acids from natural sources, such as tallow fatty acid, coco fatty acid, soy fatty acid and the like, 8800351-1S or fatty acids from synthetic sources, which are available from individual preparation processes.

Examples of the fatty acids which can be used as a stabilizer are decanoic acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, behenic acid, oleic acid, eicosanic acid, tallow fatty acid, coco fatty acid, soy fatty acid, or mixtures of two or more such acids. Beenoic acid, stearic acid and mixed fatty acids can be used.

Many of the fatty acids are commercially available. For example, stearic acid and behenic acid are easy to obtain. Mixed fatty acids, such as the naturally occurring acids, for example cocoic acid, as well as mixed fatty acids from the commercial preparation process, can advantageously be used as an inexpensive but efficient source of long chain fatty acids. Also, the sodium and potassium salts of the fatty acids can be used as stabilizers.

The fatty acid stabilizers and / or the sodium or potassium salts thereof can be used in the same amounts as the above fatty acid metal salts.

The examples will show that depending on the amounts, ratios and types of physical stabilizers and thixotropic agents, the addition of potassium polyphosphates and of the fatty acid salt not only increases physical stability, but in some cases also a simultaneous increase in apparent viscosity and provides stability against variations in rheological properties with time and / or temperature. The physical stabilizers are added just before the addition of the clay thickener. Apart from the chlorine bleach compound, the total salt concentration (Sodium tripolyphosphate, sodium silicate and sodium carbonate) is generally about 20-50 wt%, preferably 30-40 wt% of the composition.

As for the mixing of the ingredients of the VAVD composition, preferably a mixture is first formed of the water, the suds suppressor, detergent, physical stabilizer (potassium tri-35 polyphosphate and fatty acid salt) and thixotropic agent, for example clay.

, 8800351 -19--

These ingredients are mixed under high shear conditions, preferably starting at room temperature, to form a uniform dispersion. In this premixed portion, the remaining ingredients are incorporated under low shear mixing conditions. For example, the required amount of the premix can be placed in a low shear mixer and then the remaining ingredients can be added simultaneously or sequentially with mixing. Preferably, the ingredients are added sequentially, although it is not necessary to complete the addition of the entire amount of an ingredient before starting the next ingredient. Furthermore, one or more of the ingredients can be divided into portions and the portions can be added at different times. Good results were prepared by adding the remaining ingredients in the following order: sodium hydroxide, alkali metal carbonate, sodium silicate, sodium tripolyphosphate (hydrated), sodium tripolyphosphate (anhydrous or with up to 5% water), bleach (preferably sodium hypochlorite) and sodium hydroxide.

Other compositions may also be included in the compositions in minor amounts, generally less than about 3% by weight, such as perfume, hydrotropic agents such as the sodium benzene, toluene, xylene and cumene sulfonates, preservatives, dyes and pigments and the like, all of which must of course be resistant to chlorine bleaches and high alkalinity (properties of all components). For coloring, particular preference is given to the chlorinated phthalocyanines and polysulfides of aluminosilicate, which yield pleasant shades of green and blue, respectively. TiC ^ can be used to whiten or neutralize off-tones.

The liquid AVD compositions according to the invention are readily used in known manner for washing dishes, other kitchen utensils and the like in an automatic dishwasher, which is provided with a suitable detergent dosing device in an aqueous washing bath, which has an effective amount of 35 composition.

Although the invention has been particularly described in connection with its application to liquid automatic detergents. 88 0 From 1 to 20 dishwashers, it will be appreciated that the benefits obtained by the addition of potassium tripolyphosphate and the metal salt of a long chain fatty acid, in particular, the increased physical stability of the clay-based thixotropic suspension and the stability against Variations of rheological properties over time apply equally to other clay-based thixotropic suspensions, such as the scouring pastes described in the aforementioned U.S. Pat. No. 3,985,668.

The invention is further illustrated by the following examples, in which all amounts and proportions relate to the weight of the composition, unless otherwise stated.

, Example I

I -

To demonstrate the effect of the potassium tripolyphosphate and metal salt stabilizers, liquid AVD mixtures are prepared as follows with varying amounts of potassium tripolyphosphate and fatty acid salt stabilizers and thixotropic clay thickener:

THIXOTROPE CLAY CONTAINING MIXTURES

_%

Deionized water (up to 100%) 33.06-42.55 20 Monostearyl Phosphate 0.16

Dowfax 3B2 (45% Na-monodecyl / didecyldiphenyloxide disulfonate - aqueous solution 0.8

Potassium TPP (50% AI) 0-1.6

Aluminum stearate 0-0.4 25 Pharmagel H 0.25-2.0

These ingredients are mixed under high shear at room temperature and the following ingredients are added at room temperature.

2 2-10.2 50% NaOH solution 30 Sodium carbonate, anhydrous 5.00

Sodium silicate, 47.5% solution with a 15.74

Na £ 0: SiO2 ratio of 1: 2.4

Sodium TPP hexahydrate (Thermphos N hexa) 12.00

Sodium TPP (0.5-3% moisture) (Thermphos NW) 12.00 35 Sodium hypochlorite solution (11% available chlorine) 9.00. 0 6 0 D 3 b 1 -21-

Liquid AVD mixtures 1-9 are prepared and measured for density, apparent viscosity at 3 and 30 rpm and physical stability (phase separation) on standing and in a transport test. The results obtained are shown in Table A.

5 From the data listed in Table A, the following conclusions can be drawn:

The incorporation of 0.1Z aluminum stearate in a 1.25% Pharmagel H-containing mixture. Test 2 (control) results in an increase in physical stability without altering the apparent viscosity compared to test 1 (control).

The inclusion of 0.4% aluminum stearate in a 0.25% Pharmagel H-containing mixture, test 3 (control), compared to tests 1 (control) and 3 (control), leads to an increase in physical stability and apparent viscosity.

The use of the larger amount of 0.4% aluminum stearate, Run 3 (Control), also allows the clay content of 1.25%, Run 2 (Control) to be reduced to 0.25%, Run 3 ( control) while maintaining the physical stability of the mixture.

The data in Table A also show that the simultaneous use of 1.6% potassium TPP in a mixture containing 0.5% or 0.3% Pharmagel H, Runs 4 and 6, has no adverse effect on the physical stability of the mixture and stabilizes the variations of Theological properties over time.

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Example II

To determine variations of theological properties with time, the apparent viscosities of Runs 2-7 of Example 1 were measured at 3 rpm and at 30 rpm after 1 day, 2 weeks, 4 weeks , 6 weeks and 12 weeks. The results are shown in Table B.

The data in Table B show that the addition of 1.6% potassium tripolyphosphate (Runs 4, 6 and 7) results in a strong stabilization of variations of Theological properties over time, without affecting the physical stabilities of the mixtures at a Pharmagel H clay contents of 0.3% and 0.5% are changed compared to Runs 3 (control) and 5 (control), which show significant variations of the apparent viscosity over time.

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Example III

Analogously as described in Example I, the following gel-like thixotropic liquid AVD is prepared:

Ingredient Quantity% 5 Sodium Silicate (47.5% * s solution with a

Na2O: SiO2 ratio of 1: 2.4) 7.48

Monostearyl Phosphate 0.16

Dowfax 3B-2 0.36

Thermphos NW 12.0 10 Thermphos N hexa 12.0 'Potassium TPP (50% AI) 1.6

Aluminum stearate 0.25

Sodium carbonate, anhydrous 4.9 50% * s NaOH solution 6.2 15 Pharmagel H 1.25

Sodium hypochlorite 1.0 (11% available chlorine)

Water rag pH = 13-13.4. Minor amounts of perfume, colorant, and the like can be added to the mixture.

The composition has been found to have good thixotropic properties, good phase separation stability, and good stability against variations of rheological properties over time.

Example IV

In the manner described in Example III, a gel-like thixotropic liquid AVD becomes bare, however, the potassium TPP is replaced by 1.6% (50% Al) potassium pyrophosphate. Analogous results as in Example III are obtained.

Example V

In an analogous manner as described in Example I, the following gel-like thixotropic liquid AVD is prepared: C C (P r P t F * *. G w v W v w * c -27—

Ingredient Quantity%

Sodium Silicate (47.5% solution with a

Na2O: SiO2 ratio of 1: 2.4 7.48

Monostearyl Phosphate 0.16 5 Dowfax 3B-2 0.36

Thermphos NW 12.0

Thermphos N hexa 12.0

Potassium TPP (50% AI) 1.6

Stearic Acid 0.4 10 Sodium Carbonate, Anhydrous 5.0 50% NaOH Solution 3.1

Pharmagel H 0.5

Sodium hypochlorite solution (11%) 1 »0

Water residue 15 Minor amounts of perfume, colorant and the like can be added to the mixture.

Example VI

Analogously as described in Example I, the following gel-like thixotropic liquid AVD is prepared: 20 Ingredient Amount%

Sodium Silicate (47.5% solution with a

Na2O: SiO2 ratio of 1: 2.4) 7.48

Monostearyl Phosphate 0.16

Dowfax 3B-2 0.36 25 Thermphos NW 12.0

Thermphos N hexa 12.0

Potassium TPP (50% AI) 1.6

Addic acid 0.2

Sodium carbonate, anhydrous 5.0 30 50% NaOH solution 5.2

Pharmagel H 0.5

Sodium hypochlorite solution (11%) 1> 0

Water rest

Minor amounts of perfume, colorant and the like can be added to the mixture.

8800351

Claims (27)

An aqueous liquid thixotropic composition containing a clay as a thixotropic agent, water and at least one ingredient selected from organic detergents, pH modifiers, chlorine bleaches, detergent build-up salts, sequestering agents, foam inhibitors, abrasive particles and mixtures of two or more such materials characterized by potassium polyphosphate and at least one long chain fatty acid or a metal salt of a long chain fatty acid, which potassium polyphosphate and fatty acid or fatty acid metal salt are present in amounts effective to increase physical stability and stability against variations of the rheological properties of the composition with time. Composition according to claim 1, characterized by potassium tripolyphosphate, potassium pyrophosphate and / or potassium hexametaphosphate. Composition according to claims 1-2, characterized by potassium tripolyphosphate. 4 B (a) 5-35 wt% tripolyphosphate, (b) 2.5-20 wt% sodium silicate, (c) 0-9 wt% alkali metal carbonate, (d) 0.1-5 wt% in water dispersible organic detergent-5 active material which is resistant to chlorine bleaches, (e) 0-5 wt% of a foam suppressant which is resistant to chlorine bleaches, (f) chlorine bleach compound in an amount of 0.2-4 wt% available. chlorine. (G) thixotropic thickener in an amount sufficient to impart a thixotropy index of 2-10; (h) 0-8 wt% sodium hydroxide, (i) a physical and rheological properties stabilizing agent, comprising potassium polyphosphate and a polyvalent metal salt and an aliphatic fatty acid of 12-18 carbon atoms, and (j) the balance water. Composition according to claims 1-3, characterized in that the metal salt is a salt of a polyvalent metal of group II, III or IV of the periodic table and a fatty acid with 8-22 carbon atoms or a mixture of two or more of such fatty acids. Composition according to claims 1-4, characterized in that the polyvalent metal is aluminum, zinc, calcium or magnesium. 6. A composition according to claims 1-5, characterized in that the metal salt is aluminum stearate, calcium stearate or magnesium stearate. Aqueous thixotropic composition intended for use in an automatic dishwasher, characterized by (a) 5-35 wt% sodium tripolyphosphate, (b) 2.5-20 wt% sodium silicate, 30 (c) 0-9 wt% alkali metal carbonate , (d) 0.1-5 wt% water-dispersible organic detergent active material resistant to chlorine bleaches, (e) 0-5 wt% foam suppressant resistant to chlorine bleaches, 8600351 s -29 - (f) chlorine bleaching compound in an amount to provide 0.2-4% by weight of available chlorine; (g) thixotropic thickener in an amount sufficient to impart a thixotropy index of 2-10, 5 (h) 0-8 wt% sodium hydroxide, (i) a physical and theological properties stabilizing agent, including potassium tripolyphosphate, potassium pyrophosphate and / or potassium hexametaphosphate, as well as a polyvalent metal salt and long chain fatty acid, and the remainder water. Composition according to claim 7, characterized in that the stabilizer comprises potassium tripolyphosphate. Composition according to claim 7, characterized in that the stabilizer comprises potassium pyrophosphate. Composition according to claim 7, characterized in that the stabilizer comprises potassium hexametaphosphate. Composition according to claims 7-10, characterized in that the metal salt stabilizer is a salt of a polyvalent metal and an aliphatic fatty acid with 8-22 carbon atoms. Composition according to claim 11, characterized in that the acid has 12-18 carbon atoms. Composition according to claims 7-12, characterized in that the metal salt stabilizer is an aluminum or zinc salt of the fatty acid. Composition according to claim 13, characterized in that the metal salt stabilizer is aluminum stearate. Composition according to claim 13, characterized in that the metal salt stabilizer is zinc stearate. 16. A composition according to claims 7-15, characterized by 0.1-0.5 wt% clay, 0.5-3.0 wt% potassium polyphosphate and 0.1-0.5 wt% fatty acid metal salt. The composition according to claims 7-16, characterized in that the thixotropic thickener (g) is an inorganic eollid forming clay. Aqueous thixotropic composition intended for use in an automatic dishwasher, characterized by .8600351 -30- Composition according to claim 18, characterized by potassium tripolyphosphate. Composition according to claim 18, characterized by potassium pyro-20 phosphate. A composition according to claims 18-20, characterized in that the metal salt stabilizer is the aluminum or zinc salt of the fatty acid. 22. A composition according to claim 21, characterized in that the metal salt stabilizer is aluminum stearate. Composition according to claim 21, characterized in that the metal salt stabilizer is zinc stearate. A composition according to claims 18-23, characterized by 0.2-0.4 wt% clay, 0.8-2.0 wt% potassium polyphosphate and 0.2-0.4 wt% fatty acid metal salt. Composition according to claims 18-24, characterized in that the thixotropic thickener (e) is an inorganic colloid-forming clay. 26. A method for cleaning dirty dishes in an automatic dishwasher, characterized in that the dirty dishes are brought into contact with an automatic dishwasher. E 0 C ": i 1 -31- V τ an aqueous wash bath in which an effective amount of the composition according to claim 7 is dispersed. 27. A method of cleaning dirty dishes in an automatic dishwasher, characterized in that the dirty dishes 5 in an automatic dishwasher are contacted with an aqueous washing bath, in which an effective amount of the composition according to claim 18 is dispersed. β p f f * 1 * I? v> '* * t