CH669393A5 - - Google Patents

Description

DESCRIPTION The invention relates to a liquid, gel-like, thixotropic cleaning agent which is suitable as a cleaning agent in automatic dishwashers.

In particular, the invention relates to cleaning agents for dishwashers which have thixotropic properties and improved chemical and physical resistance, have an increased apparent viscosity, are easily dispersible in the washing medium and ensure the effective cleaning of dishes, glass, porcelain and the like.

The commercially available powder detergents for household dishwashers have various disadvantages: for example, they are not of a uniform composition; they require expensive processes to manufacture them; they tend to cake when stored in a humid environment and thereby form lumps that are difficult to disperse; they dust and are therefore a source of special irritation for allergy-sensitive consumers; and finally they tend to cake in the dishwasher dispenser. Liquid forms of such compositions, in turn, cannot generally be used in automatic dishwashers because of their strong foaming, unacceptably low viscosities and excessively high alkalinity.

Recent research and development efforts have focused on the gel or "thixotropic" form of such compositions which are not viscous enough to be "held" in the dishwasher dispenser and also leave stained residue on dishes, glass, porcelain and the like . Ideally, thixotropic cleaning agents should be highly viscous at rest, correspond in nature to Bingham plastic media and show relatively high Hiess limits. If they are subjected to shear stresses (for example, if they are shaken into a container or squeezed through an opening), they should fluidize quickly and quickly return to the high viscosity / Bingham plastic state after the applied shear stress has ended. Stability is also of primary importance, i.e. phase separation or leakage should not occur significantly after standing for a long time.

So far, however, there have been problems when trying to produce gel-form detergents for dishwashers with the above properties, especially detergents for household dishwashers. In general, it is recommended that a dishwasher-grade detergent, also referred to herein as ADD, contains the following: (1) sodium tripolyphosphate (NaTPP) to soften or bind the hard water minerals and emulsify dirt, and / or peptize; (2) sodium silicate to complement the alkalinity required for effective cleaning and to protect the pattern and glaze of fine porcelain; (3) sodium carbonate, which is mostly an optional ingredient to increase alkalinity; (4) a chlorine-releasing substance for easier removal of dirt stains that lead to water stains; and (5) foam damper / surfactant to reduce foam formation, thereby increasing the efficiency of the machine and supplementing the required washing power (see, for example, SDA Detergents in Dephth, “Formulations Aspects of Machine Dishwashing” by Thomas Oberle, 1974) . Detergents that roughly correspond to the above compositions are mostly liquids or powders. Combining such ingredients in a gel form suitable for household machines is difficult. The chlorine bleach is usually omitted from these compositions because it tends to react with other chemically active ingredients, especially surfactants, degrading the suspending or thixotropic agent and reducing its effectiveness. For example, U.S. Patent 4,115,308 discloses thixotropic pastes for automatic dishwashers containing suspending agents, e.g. CMC, synthetic clays or the like; inorganic salts including silicates, phosphates and poly-phosphates; a small amount of surfactant and a foam suppressor. A bleaching substance is not disclosed. U.S. Patent No. 4,147,650 is quite similar, may contain a chlorine (hypochlorite) bleach, but has no organic surfactant or foam suppressor. The product is also described as a mushy detergent with no visible thixotropic properties.

U.S. Patent 3,985,668 describes a scouring agent having a gel-like consistency, comprising: (1) a suspending agent, preferably smectite and attapulgite type clay; (2) abrasives, e.g. Silica sand or pearlite; and (3) powdered filler

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

3rd

669 393

Low density polymers, expanded perlite and the like, which have buoyancy and thereby have a stabilizing effect on the composition, in addition to imparting quantity or volume and thereby replacing water, which is otherwise available due to leakage and phase destabilization and an undesirable protruding Layer forms. The components mentioned are the essential ones. Optional ingredients include hypochlorite bleach, bleach resistant surfactants and buffers e.g. Silicates, carbonates and monophosphates. As additional optional components, builders such as NaTPP can be incorporated in order to supplement the builder action not performed by the buffer or for additional builder action, the amount of this builder not exceeding 5% of the total composition of this patent specification. The buffer / builder components maintain the pH values (desirably higher than pH 10). A high pH is said to minimize the decomposition of the chlorine bleach and the undesirable interaction between the surfactant and bleach. As mentioned, NaTPP, if present, does not make up more than 5%. Foam preventing substances are not disclosed.

British patent applications 2116 199A and 2 140 450A have disclosed liquid ADD compositions which have a desired thixotropic gel structure and all contain the various ingredients necessary for effective dishwashing. These normally gel-like, aqueous detergents for dishwashers with thixotropic properties contain the following components on a weight basis:

(a) 5 to 35% alkali tripolyphosphate;

(b) 2.5 to 20% sodium silicate;

(c) 0 to 9% alkali carbonate;

(d) 0.1 to 5% chlorine bleach resistant, water dispersible organic surfactant material;

(e) 0 to 5% chlorine bleach resistant foam damper;

(f) chlorine bleach in an amount that provides about 0.2 to 4% chlorine;

(g) thixotropic thickener in an amount sufficient to impart a thixotropy index of about 2.5 to 10 to the composition;

(h) Sodium hydroxide as needed to adjust the pH.

ADD compositions formulated in this way are low-foaming, readily soluble in the washing medium and most effective at pH values which are most useful for improved cleaning action, namely pH values from 10.5 to 13.5. The compositions are usually of a gel-like consistency, i.e. a highly viscous, opaque, gelatinous material with a Bingham-plastic character and with relatively high flow limits. As a result, a defined shear force is required in order to start or increase the flow, e.g. receives in the moving dispenser of a switched on dishwasher. Under such conditions, the composition is quickly fluidized and easily dispersed. If the shear force is removed or interrupted, the fluid composition quickly returns to its high viscosity or Bingham plastic state, corresponding approximately to its previous consistency.

US Pat. No. 4,511,487 describes a low-foaming cleaning paste for dishwashers. This thixotropic cleaning agent has a viscosity of at least 30 Pa • s at 20 0 C, which is determined with a rotary viscometer at a spindle speed of 5 rpm. The composition is a mixture based on finely divided hydrated sodium metasilicate, an active chlorine compound and a thickener, which is a leafy silicate of the hectorite type. If necessary, small amounts of nonionic surfactants and alkali carbonates and / or hydroxides are used.

Also described (W.S. Mardis, JAOCS, Volume 61, No. 2, page 382 [1984]) is the formation of organoclay by the interaction of clays such as bentonite and hectorite with organic compounds such as quaternary ammonium salts.

Although these known liquid ADD formulations do not have, or to a lesser extent, one or some of the disadvantages described above, it has been found that in practice further improvements in physical stability are required in order to increase the shelf life of the product and thus increase consumer acceptance.

In (the mentioned) US-Ser.-No. 744 754 and its continuation-in-part it is proposed to improve the physical stability of thixotropic liquid formulations based on clay by adding small amounts, e.g. adds about 0.02 to 1% by weight of a polyvalent metal salt of a long chain fatty acid such as aluminum stearate.

The combination of clay thickeners and fatty acid salt as a stabilizer gave satisfactory long-term stability, i.e. there was no phase separation for up to 12 weeks or longer, but the addition of clay to these formulations has various disadvantages.

For example, when clay thickeners are used, the order of addition of the various ingredients and the regulation of process conditions during formulation of the compositions become critical if the desired thixotropic and low-foaming properties are to be achieved. In addition, the clay thickeners are expensive and can contribute significantly to the end product costs borne by the consumer. In some cases, the clay thickeners can even affect the overall cleaning effect.

In general terms, the object of the invention is to produce stable, aqueous, thixotropic, non-clay-based compositions, in particular liquid cleaning pastes or gels for dishwashing machines, by incorporating a small amount of a fatty acid into the clay-free aqueous suspension, which settles the suspended particles and phase separation prevented.

The invention is characterized by the features in independent claim 1.

To achieve these and other objects, which also appear from the following description, it is proposed according to the invention to incorporate a small but effective amount of a thixotropic agent, which is not polymeric and not clay, but a long-chain one, into an aqueous, liquid detergent composition Fatty acid. In particular and in accordance with a preferred embodiment of the invention, a normally gel-like composition for automatic dishwashers is proposed which contains about 0.03 to 0.5% by weight, based on the composition, of a long-chain fatty acid which settles the suspended particles such as the builder salts effectively prevented by alkali metals, etc. without the need for clay, polymers or other thickeners.

Accordingly, a normally gel-like, aqueous detergent composition, in particular for automatic dishwashers, with thixotropic properties is preferably proposed, which contains the following constituents on a weight basis:

(a) 5 to 35% alkali tripolyphosphate;

(b) 2.5 to 40% sodium silicate;

(c) 0 to 9% alkali carbonate;

(d) 0.1 to 5% chlorine bleach-resistant, water-dispersible, organic, cleaning-active material;

(e) 0 to 5% chlorine bleach resistant foam presser;

(f) chlorine bleach in an amount that provides about 0.2 to 4% chlorine;

(g) 0.03 to 0.5% of a long chain fatty acid;

(h) 0 to 8% sodium hydroxide and

(i) water as rest.

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

669 393

4th

A method of cleaning dishes in an automatic dishwasher with an aqueous washing bath containing an effective amount of this liquid detergent composition (LADD) for automatic dishwashers is also proposed. This LADD composition can be easily poured into the dispenser of the dishwasher and will immediately thicken to its normal gel-like or pasty state in just a few seconds, in which it remains safely in the dispenser until shear forces are applied again, for example from spray water the dishwasher.

In the following, special embodiments of the invention are described with reference to the attached drawing, which shows a graphical representation of the thixotropy index of two different formulations of the invention and a clay-thickened liquid detergent for dishwashers according to GB 2 140 450A.

The known LADD products according to GB 2 116 199A, GB 2 140 450A and US Ser.-No. 744 754, including their continuation-in-part, show improved rheological behavior, which was determined by examining the product viscosity as a function of the shear rate. The compositions had a higher viscosity at a low shear rate and a lower viscosity at a high shear rate, the data showing effective hydration and gelling well within the shear rates that exist in standard dishwashers. In practice, this means improved pouring and processing behavior and less leakage from the machine's dispenser compared to previous liquid or gel ADD products. At shear speeds corresponding to 3 to 30 rpm, the viscosities (Brookfield) were accordingly in the range from about 10 to 30 Pa s (10,000 to 30,000 cps) to about 3 to 7 Pa s (3000 to 7,000 cps), which at room temperature using an LVT Brookfield viscometer after 3 minutes using a # 4 spindle. A shear rate of 7.4 seconds-1 corresponds to approximately 3 spindles * revolutions per minute. An approximately 10-fold increase in the shear rate results in an approximately 3 to 9-fold reduction in viscosity. These known compositions (by the applicant) thus showed threshold fluidizations at lower shear rates and to a significantly greater extent, expressed as a proportional increase in the shear rate against a proportional decrease in the viscosity. This property of the applicant's known LADD products was summarized with the term thixotropy index (IT), which represents the ratio of the apparent viscosity at 3 rpm and at 30 rpm. The known compositions have a TT of 2 to 10. The LADD compositions should clearly and quickly return to the consistency of the previous state of rest when the shear force is interrupted.

Although determining the thixotropy index TT as the ratio of the apparent viscosity at 3 and at 30 rpm provides a satisfactory measure of the usability of the product, further research and experience have shown that a more reliable measure of the thixotropy index and the usability of the product as a liquid ADD is obtained if the thixotropy is determined as the size of the area in the hysteresis loop. The latter is obtained by plotting the shear stress, S, as a function of the shear rate, T |, under the conditions described below, increasing the shear rate from 0 to a maximum value and then returning to 0. The larger the area in the hysteresis loop, the larger the thixotropy index. Expressed in terms of the apparent viscosity: It was also found that as long as the viscosity measured at room temperature (22 ° ± 1 ° C) in a Brookfield viscometer HAID with a No. 4 spindle at 20 rpm was less than about 20 Pa - see

(20,000 cps), the composition can be easily shaken so that a thixotropic composition can easily be "fluidized" or "liquefied" and the product can be dispensed using a conventional squeeze tube or bottle or other conventional dispenser.

The invention is based on the surprising finding that the same or improved rheological properties and physical stability, i.e. Resistance to phase separation, settling, etc., as in these known liquid ADD compositions, can be achieved at significantly lower cost and with no particular process requirements by adding a small but effective amount of a long chain fatty acid to the composition instead of the thixotropic clay thickener -kers admits, the metal salt of the fatty acid can also be used. At the same time, improvements in stain removal, namely fewer stains, and film formation, namely lower film formation, can be achieved.

The improvement in the theological properties compared to a thixotropic liquid ADD based on clay can be seen, for example, from the attached drawing, in which the shear stress, S, as a function of the shear rate, T], for a clay-based LADD (3% by weight clay) ( Curve 1) and for two similar LADD compositions, in which the clay is by 0.06% by weight stearic acid + 25% silicate (curve 2) or 25 by 0.08% by weight stearic acid + 25% silicate (Curve 3) is replaced. The shear stress, S, was measured in a static test using a Haake RV-3 machine equipped with a coaxial cup device. The sample was placed in the outer cup and the inner cup was rotated 30 at progressively higher shear rates to a maximum of 113 s-1, after which the shear rate was progressively reduced to zero. The response was automatically plotted as a shear stress. These tests were carried out with the help of an MV II sensor system (constant values A = 3.76 Pa, M = 0.9 s-1). The area between the curve lines obtained - each sample is a measure of the thixotropy, with larger areas indicating greater thixotropy. The flow limit of each sample can also be taken from the curves shown in the figure; the yield point is the maximum stress in the shear stress versus shear rate curve. At the same time, the physical resistance is such that the compositions containing fatty acid thickeners are not subject to any visible phase separation after 6 weeks or more, 45 with the temperature ranges from freezing point to 40 ° C and above.

The long-chain fatty acids used are the higher aliphatic monocarboxylic acids with about 8 to 22, especially about 10 to 20 and particularly preferably about 12 to 18 carbon atoms, the carbon atom of the carboxyl group of the fatty acid being included. Polycarboxylic acids can also be used. The aliphatic radical can be saturated or unsaturated, straight-chain or branched. Straight chain, saturated fatty acids are preferred. Mixtures of fatty acids can be used which are, for example, of natural origin, such as tallow fatty acid, coconut fatty acid, soybean fatty acid, etc., or which are industrially produced synthetically.

Examples of fatty acids that can be used as thickeners instead of clay or polymeric thickeners 60 include decanoic acid, lauric acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, oleic acid, eicosanoic acid, tallow fatty acid, coconut fatty acid, soybean fatty acid and mixtures of these acids . The dimers or trimers of these acids can also be used. Stearic acid 65 and mixed fatty acids, e.g. Coconut fatty acid is preferred.

Within the ranges specified here for the carbon chain lengths of the fatty monocarboxylic acids, the viscosity of the product tends to vary with the number of carbon atoms in the

5

669 393

Lose fat monocarboxylic acid. No systematic limits were observed for the dimers or trimers or polybasic carboxylic acids.

The amount of fatty acid thickener required to achieve the desired values of thixotropy and physical stability depends on such factors as the type of fatty acid, the detergent-active compound or the surfactant, inorganic salts, especially TPP, other LADD components and the intended storage and Shipping conditions.

In general, however, amounts of the fatty acid used as the thixotropic agent in the range of about 0.03 to 0.5, preferably about 0.03 to 0.2, particularly preferably from about 0.03 to 0.08% ensure long-term stability and lack of Phase separation when standing and during transport at both low and elevated temperatures, as required for a product to be accepted commercially.

In general, LADD activity is directly related to (a) the amounts of chlorine available; (b) alkalinity; (c) the solubility in the washing medium and (d) the foam inhibition. Preferably, the pH of the LADD composition is at least about 9.5, especially about 10.5 to 13.5 and especially at least about 11.5. At the relatively lower pH values, the LADD product is too viscous, i.e. too similar to a solid, and is therefore not easily fluidized at the level of shear force generated within the dispenser during normal machine operation. In essence, the composition loses a large part, if not all, of the thixotropic character. The addition of NaOH is often necessary in order to raise the pH to the above ranges and to increase the flowability. The presence of carbonate is also often required as it acts as a buffer and helps maintain the desired pH level. Excess carbonate should, however, be avoided since it can cause the formation of needle-like carbonate crystals, which affects the stability, thixotropy and / or cleaning power of the LADD product, as well as the dispensability of the product from e.g. Squeeze tubes or bottles. Caustic soda (NaOH) has the further function of neutralizing any phosphoric acid or phosphonic acid esters present as foam inhibitors. Usually about 0.5 to 3% by weight of NaOH and about 2 to 9% by weight of sodium carbonate are present in the LADD composition, although it should be noted that sufficient alkalinity can be ensured by the NaTPP and sodium silicate.

The NaTPP can be present in the LADD composition in an amount of about 8 to 35, preferably about 20 to 30% by weight and should preferably be free of heavy metal which tends to decompose or inactivate the preferred sodium hypochlorite and other chlorine bleach . The NaTPP can be anhydrous or hydrated, for example the stable hexahydrate with a degree of hydration of 6, corresponding to approximately 18% by weight of water or more. In fact, the presence of some water of hydration is highly effective in view of the resistance of the hexahydrate, which is believed to serve to nucleate the stable hexahydrate, which requires hydration and solubilization of the remaining NaTPP particles. If only hexahydrate is used, the detergent may be too liquid and too little, if any, thixotropic. On the other hand, if only the anhydrous NaTPP is used, the product can be too thick in some cases and therefore unsuitable. Particularly preferred LADD compositions are obtained if, for example, a weight ratio of anhydrous to hexahydrated NaTPP of 0.5: 1 to 2: 1 is used, values of about 1: 1 being particularly preferred. -

Foam inhibition is important to increase the efficiency of the dishwasher and to minimize the destabilizing effects that can occur when using excessive foam when using the machine. The foam can be sufficiently reduced by appropriately selecting the type and / or amount of the surfactant, which is the main component for foam formation. The extent of foam formation also depends somewhat on the hardness of the washing water in the machine. Proper adjustment of the amounts of water softening NaTPP can help ensure the level of foam inhibition desired. In general, however, it is preferred to incorporate a chlorine bleach resistant foam damper or inhibitor. The alkylphosphonic acid esters of the formula are particularly effective

0

ho p r

OR

which are available, for example, from BASF-Wyandotte (PCUK-PAE), especially the acidic alkyl phosphate esters of the formula

0

HO- P OR

Or available from Hooker (SAP) and Knapsack (LPKn-158), for example, in which one or both R groups in each ester type can independently be a Cn to C2o alkyl group. Mixtures of the two types or any other chlorine bleach-resistant types or mixtures of mono- and diesters of the same types can be used. A mixture of acidic mono- and di-C16 to Cjg alkyl phosphate esters, e.g. acidic monosteaiyl / disteaiyl phosphates 1.2 / 1 (Knapsack). If used, amounts of 0.01 to 5, preferably 0.1 to 5, particularly about 0.1 to 0.5% by weight of the foam suppressant in the composition are typical, the weight ratio of detergent active compound or surfactant ( d): Foam damper (s) is generally in the range from about 10: 1 to 1: 1 and preferably from about 4: 1 to 1: 1. Other known defoaming agents are, for example, the known silicones.

Although any chlorine bleach can be used in the compositions of the invention, e.g. Dichloroisocyanurate, dichlorodimethylhydantoin or chlorinated TSP, alkali (potassium, lithium), magnesium and especially sodium hypochlorite is preferred. The composition is said to contain sufficient chlorine bleach to provide about 0.2 to 4.0 weight percent chlorine, which is determined, for example, by acidifying 100 parts of the composition with excess hydrochloric acid. A solution containing 0.2 to 4.0% by weight sodium hypochlorite contains or provides approximately the same percentage of available chlorine. About 0.8 to 1.6% by weight of available chlorine is particularly preferred. For example, sodium hypochlorite (NaOCl) solution with about 11 to about 13% available chlorine can be used advantageously in amounts of about 3 to 20%, preferably about 7 to 12%.

The sodium silicate, which ensures alkalinity and protection of hard surfaces such as fine glaze and porcelain patterns, is used in the composition in amounts of about 2.5 to 40, preferably about 10 to 35% by weight. At the higher amounts specified here, for example at amounts above about 10% by weight, the silicate also ensures an increased stain-preventing effect. The sodium silicate is generally in the form of an aqueous solution, for example with a Na20: SiO2 ratio of about 1: 2.2 to 1: 2.8, e.g. 1: 2.4 added. Most of the other components of the composition, especially NaOH, sodium hypochlorite and the foam suppressants, can also be added in the form of an aqueous dispersion or solution.

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

669 393

6

The cleaning-active material (surfactant) used according to the invention must be stable in the presence of chlorine bleach, especially hypochlorite, water-dispersible types of surfactants such as the organic anionic, amine oxide, phosphine oxide, sulphoxide or betaine surfactants being preferred and the anionic surfactants mentioned first are most preferred. They are used in amounts of about 0.1 to 5%, preferably about 0.3 to 2.0%. Particularly preferred surfactants of the invention are the linear or branched alkali mono- and / or -di (Cg to -Ci4) alkyldiphenyloxide mono- and / or disulfates, which are commercially available, for example, as DOWFAX 3B-2 and DOWFAX 2A-1.

The paraffin sulfonates generally tend to interfere with, if not destroy, the thixotropy and cause an unacceptable increase in viscosity, which creates severe shear problems. The surfactant is also said to be compatible with the other components of the composition. Other suitable surfactants include the primary alkyl sulfates , Alkyl sulfonates, alkyl aryl sulfonates and secondary alkyl sulfates, examples being the Ci0 to CI8 alkyl sulfates such as sodium dodecyl sulfate and sodium tallow alcohol sulfate, the sodium cio to Ci8 alkane sulfonates such as sodium hexadecyl l sulfonate and sodium Ci2 to Ci8 Alkylbenzenesulfonates such as sodium dodecylbenzenesulfonates, and the corresponding potassium salts can also be used.

As further suitable surface-active substances or surfactants, the amine oxide surfactants of the structure R2R'NO are typical, in which each R has a lower alkyl group, e.g. Is methyl and R1 is a long alkyl radical of 8 to 22 carbon atoms, e.g. is a lauiyl, myristyl, palmityl or cetyl group. Instead of an amine oxide surfactant, a corresponding phosphine oxide R2R'PO or sulfooxide RR1 SO can be used. Betaine surfactants usually have the structure R2R'N - R "COO ~, where each denotes pure lower alkylene group having 1 to 5 carbon atoms. Specific examples of these surfactants are lauiyldimethylamine oxide, myristyldimethylamine oxide, the corresponding phosphine oxides and sulfoxides and the corresponding betaines including dodecyldimethylammonium acetate, Tetra-decyldiethylammonium pentanoate, hexadecyldimethylammonium hexanoate, etc. For reasons of biodegradability, the alkyl groups in these surfactants are said to be linear, and these compounds are preferred.

Surfactants of this type are known and are described, for example, in US Pat. No. 3,985,668 and 4,271,030.

The amount of water contained in these compositions should of course not be so great that an unacceptably low viscosity and great fluidity is produced, nor so small that

Dishes, other kitchen utensils and the like are produced in an aqueous, an effective amount of the composition-an unacceptably high viscosity and low flowability, the thixotropic properties being reduced or destroyed in any case. This amount is easily determined by routine experimentation in each individual case and is generally about 25 to 75, preferably about 55 to 65% by weight. The water should also preferably be demineralized or softened.

io In these compositions, other usual ones

Components are incorporated in small amounts, which are generally less than about 3 wt .-%, such as perfume, hydrotropes such as sodium benzene, toluene, xylene and cumene sulfonates, protective substances, dyes and pigments and the like, that's natural all have to be resistant to chlorine bleach and high alkalinity (properties of all components). The chlorinated phthalocyanines and polysulfides of aluminum silicate, which in each case produce pleasant green and blue tonings, are particularly preferred as the coloring substance. H02 20 can be used to whiten or neutralize false tints.

The liquid ADD compositions of the invention are used in a simple manner known per se for washing the trend washing bath in an automatic dishwasher which is equipped with a suitable dispenser for the detergent.

Although the invention has been described in particular in relation to liquid detergents for dishwashers, the advantageous results in terms of thixotropy and physical stability can also be achieved by adding the fatty acid if it is used in place of clay or polymeric thickeners in other thixotropic suspensions, such as in the abrasive pastes described in the aforementioned U.S. Patent 3,985,668, pasty dentifrices and the like. 35 The following examples are intended to illustrate the invention. All amounts and ratios are by weight unless otherwise stated.

example 1

40 In order to show the effect of the fatty acid used as a thickener, liquid ADD formulations with varying amounts of fatty acid were prepared as a thixotropic thickener as shown in Table 1 (batches 1, 2 and 3). For comparison, a similar composition (batch 4) corresponding to the composition of Example 1 according to GB 2 140 450A was prepared according to the method disclosed in this example.

7,669,393

Table 1

Ingredient Approach No. 1 Approach No. 2 Approach No. 3 Approach No. 4

water

32.99

32.96

32.94

41.92

Stearic acid

0.03

0.06

0.08

-

Clay (Gelweiss GP)

-

-

-

3.00

Sodium silicate (47.5% solution

of Na2: Si02 in a ratio

from 1: 2.4)

25.00

25.00

25.00

13.73

Sodium tripolyphosphate (im

essentially anhydrous, i.e. approximately

3% moisture)

12.00

12.00

12.00

12.00

Sodium tripolyphosphate hexahydrate

12.00

12.00

12.00

12.00

Sodium carbonate (soda ash)

7.00

7.00

7.00

7.00

Sodium hypochlorite

(13% available chlorine)

7.61

7.61

7.61

7.61

Surfactant (Dowfax 3B-2.45%

aqueous solution of

Sodium mono- and

-di-decyldiphenyloxide disulfonate)

0.80

0.80

0.80

0.80

Anti-foaming agent

(Knapsack LPKn 158, mixture of

Mono- and disteaiyl- (C16- bis

-C18) alkyl esters of phosphoric acid,

Molar ratio about 1: 1.3

0.16

0.16

0.16

0.16

Caustic soda solution

(50% NaOH)

2.40

2.40

2.40

2.40

Dye (graphite green)

0.01

0.01

0.01

0.01

100.00

100.00

100.00

100.00

A sample of the formulations of batches 2 and 3 and the comparison formulation based on clay (batch 4) was subjected to a measurement of the shear stress with the aid of the Haake RV-3 apparatus described above in order to determine the thixotropy index and the yield point. The results are recorded in the attached figure, with curve 1 based on the sample from batch 4, curve 2 based on the sample from batch 2 and curve 3 based on the sample from batch 3. The value of the yield point (the maximum value of the shear stress), S, is given in Table 2.

Table 2 also lists other properties, namely the apparent viscosity (T), on a 24 hour sample using a Brookfield HATD viscometer using a # 4 spindle at 20 rpm (T = 22 ° C ± 1 ° C) was measured; the concentration; the capillary running speed, stability and centrifugation. The capillary drainage rate (CDR) is a measure of stability, with higher values indicating greater stability. The CDR measurements are carried out as follows: A Whatman No. 1 filter paper with a 6.4 cm diameter circle is placed on a flat glass plate, 10 cm × 10 cm. A plastic tube, length 6.4 cm, diameter 3.4 cm, is placed standing and concentrically on the circle. The tube is filled with the liquid ADD composition to be tested (after standing for one day). The time it takes for the solvent to seep out of the pipe and reach the circle shown is determined. You measure the time in three places and determine the average. Faster or shorter times mean that the gel does not successfully hold the solvent (water), which can therefore seep into the filter paper. Times over about 7 minutes (all samples) are acceptable. To measure stability, the sample is placed in a glass bottle, left at room temperature and the percentage separation is determined at the end of 4 weeks. The centrifugation test is also a measure of stability. Glass centrifuge tubes are filled with equal volumes of each sample and vertical, i.e. Centrifuged in a plane parallel to the ground in a Sorwall centrifuge for 25 minutes at 500 rpm. Then you measure the volume of the clear liquid. The results are reported as the ratio of the height of the clear liquid to the total height of the sample multiplied by 100, i.e.

Level of clear liquid _ ^

Total height of the liquid

Lower numbers indicate greater durability.

Table 2

property

approach

approach

approach

approach

number 1

No. 2

No. 3

No. 4

Viscosity, Pa-s

11.460

10.660

11.260

5,100

(cps)

(11460)

(10 660)

(11,260)

(5100)

Yield point,

Dynes / cm2

-

372

720

392

Density, g / ml

1.35

1.36

1.34

1.37

CDR (minutes)

-

8.5

10.0

7.0

Resistance,

% Separation

after 4 weeks

1.0

0.0

0.0

5.0

Centrifugation

1.0

0.0

0.0

5.0

The data in Table 2 clearly shows the superior resistance to phase separation of the formulations based on stearic acid in comparison with the formulation based on clay. These results, together with the thixotropy properties corresponding to the graphic representation in the figure, also show the superiority of the formulations according to the invention in terms of leakage from the dishwasher dispenser.

40

45

50

55

60

669 393

8th

Each of the formulations of runs 1 to 4 of Example 1 was tested to compare the cleaning effect (thawing of Rekken and films on glass) using a Kenmore dishwasher and tap water at a temperature of 54.44 ° C. (130 ° F.) and a hardness of 120 ppm was used. The test procedure is described in ASTM D3566-79, with the exception that only four cleaning cycles were performed. The film and staining behavior was evaluated according to the following scales:

Film rating scale

1. Best, no visible film

2. low film formation, becoming visible

3rd noticeable film, increasing

4. Continued increase in significant film

5. The film formation becomes excessive

6. strong sludge formation, excessive build-up

7. Continued increase in excessive filming.

Hedge rating scale

A. best, no warriors

B. very few visible hedges

C. single, clear hedges

D. Significant coverage of approximately 50%.

The results are summarized in Table 3.

Table 3

Approach no.

Performance stains

Movie

5

1

B

1.2

2nd

B, C

1.2

3rd

B, C

2.3

4th

C.

2.3

10th

Example 3

Results similar to those described above are obtained if, instead of stearic acid, isostearic acid, myristic acid, palmitic acid, lauric acid, emphol dimer acid, emphol-15 trimer acid or Emphol 1052 polybasic acid is used.

In addition to superior physical durability, thixotropy, and cleaning performance, the compositions of the invention have the additional significant advantage that a particular order of addition of the individual components is not necessary. You can add all the ingredients in any order or at the same time in a single pot, mixer etc. and stir until you get a homogeneous mixture. Mixing can be done at room temperature or at elevated temperature. It is not necessary to premix any 25 ingredients or apply different shear mixing conditions.

G

1 sheet of drawings

Claims (11)

669393 2nd PATENT CLAIMS 1. Liquid, gel-like, thixotropic cleaning agent based on water and at least one component from the group consisting of organic surfactant, chlorine bleach, builder, sequestering agent, foam inhibitors, scouring particles and mixtures thereof, characterized by a content of 0.03 to 0.5% by weight. %, based on the total composition, of a mono- or polycarboxylic acid having 8 to 22 carbon atoms or the dimers or trimers thereof. 2. Detergent according to claim 1 for an automatic dishwasher, characterized in that it, based on the weight, approximately (a) 5 to 35% alkali tripolyphosphate, (b) 2.5 to 40% sodium silicate; (c) 0 to 9% alkali carbonate; (d) 0.1 to 5% chlorine bleach resistant, water dispersible organic surfactant; (e) 0 to 5% chlorine bleach resistant foam damper; (f) chlorine bleach in an amount sufficient to provide about 0.2 to 4% chlorine; (g) 0.03 to 0.5% of an aliphatic fatty acid having 8 to 22 carbon atoms, their dimers or trimers; (h) 0 to 8% sodium hydroxide; (i) contains water as the remainder. 3. Cleaning agent according to claim 2, characterized in that the aliphatic fatty acid (g) has 10 to 20 carbon atoms. 4. Cleaning agent according to claim 3, characterized in that the fatty acid has 12 to 18 carbon atoms. 5. Cleaning agent according to claim 2, characterized in that the fatty acid is stearic acid. 6. Cleaning agent according to claim 2, characterized in that the fatty acid (g) is present in an amount of about 0.03 to 0.2%. 7. Cleaning agent according to claim 5, characterized in that the fatty acid (g) is present in an amount of about 0.03 to 0.08%. 8. Cleaning agent according to claim 2, characterized in that the chlorine bleach (f) is sodium hypochlorite. 9. Cleaning agent according to claim 2, characterized in that it contains at least about 0.1% of the foam damper (s). 10. Cleaning agent according to claim 9, characterized in that the foam damper is an acidic alkyl phosphate ester or an alkyl phosphonic acid ester with one or two Ci2- to C2o-alkyl groups or a mixture thereof. 11. Cleaning agent according to claim 2, characterized by a pH of about 10.5 to about 13.5.