PT100549A - Linear viscoelastic aqueous liquid detergent composition for automatic dishwashers containing a thickener of the cross-linked polyacrylic acid type - Google Patents

Abstract

This invention relates to a detergent composition for automatic dishwashers which is formulated as a linear viscoelastic pseudoplastic aqueous product of the gel type having exceptionally good physical stability when exposed to daylight, with little residue in the bottle, little loss in glasses and better cleaning performance without substantially adhering to or moistening the inner surface of a polyolefin bottle. Linear viscosity and pseudoplastic behaviour are obtained by incorporating at least one thickener of the cross-linked polyacrylic acid type having a high molecular weight. Potassium to sodium ratios by weight of at least 1/1 reduce the quantity of undissolved solid particles to a minimum in order the better to contribute to the stability and pourability characteristics of the composition. Control of the incorporated air bubbles has the function of giving the product a bulk density of between 1.32 g/cm3 and 1.40 g/cm3 which approximately corresponds to the density of the liquid phase. The presence of a stearic acid or other fatty acid or salt in the composition further improves its physical stability. The said composition comprises 10 to 60% by weight of a compound containing alkali metal, 0 to 1.5% by weight of a foam suppressing agent, 0 to 5% by weight of a counter- dispersible organic active detergent material which is stable in the presence of a chlorine-based bleaching agent, 0.02 to 2.0% by weight of a long chain fatty acid or its metal salt, water and means to substantially prevent moistening of the composition and sticking to the inside vertical surface of a polyolefin bottle.

Description

BACKGROUND OF THE INVENTION

Automatic liquid detergent compositions for automatic dishwashers, both aqueous and non-aqueous, have recently been the subject of much attention, and aqueous products have attained commercial popularity. The acceptance and popularity of liquid formulations as compared to the more conventional powder products comes from the convenience and yield of liquid products. However, even the best of the normally marketed liquid formulations still suffer from two major problems, namely product phase instability and bottle residue and somehow loss of dispensing cup from the automatic dishwasher. As representative of important patents in this technical area, U.S. Patent 4,556,504 to Rek; U.S. Patent 4,226,736 to Bush, et al., U.S. Patent 4,431,559 to Ulrich; U.S. Patent 4,147,650 to Sabatelli; U.S. Patent 4,079,015 to Paucot; U.S. Patent 4,116,849 to Leikhem; U.S. Patent 4,521,332 to Milora; U.S. Patent 4 597 889 to Jones; U.S. Patent 4 512 908 to Heile; U.S. Patent 4,753,748 to Laitem; U.S. Patent 3,569,455 to Sabatelli; U.S. Patent 3,684,722 to Hynam. Other patents relating to thick detergent compositions include U.S. Patent 3,985,668; GB 2 116 199A and GB 240 450A; U.S. Patent 4 511 487; U.S. Patent 4,752,409 (Drapier, et al.); U.S. Patent 4,801,395 (Drapier, et al.). Co-pending, co-pending patents include, for example, N®. No. 204,476, filed June 9, 1988; No. 924,385, filed October 29, 1986; N® 323 series 138, 3

1A

application dated 13 March 1989; No. 087 836, filed Aug. 21, 1987; No 328 716, filed on 27 March 1989; NS Serial No. 323,137, filed March 13, 1989; No. 323,134, filed March 13, 1989. The present invention provides a solution to the above problems.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1-13 are rheograms, which represent elastic moduli G 'and modulus of viscosity G " as a function of the applied force, for the compositions of Example 1, Formulations A, C, D, G, J. Η, I and K, Example 2, A and B, Example 3, L and M and Comparative Example 1, respectively.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a new automatic liquid dishwashing liquid detergent composition. The composition is characterized by its linear viscoelastic behavior, substantially indefinite stability against phase separation or sedimentation of dissolved or suspended particles, low levels of residue in the bottle, relatively high density, substantial absence of unbound or free water, and composition does not adhere to the inner surface of a polyolefin bottle. This unique combination of properties is achieved by incorporating in the aqueous mixture of dishwashing detergent surfactant, salt or alkali metal builder salts for detergents and chlorine bleaching compound and a small but effective amount of a polymeric thickening agent, such as a thick crosslinking polyacrylic acid type thickening agent, a physical stabilizing amount of a long chain fatty acid or its salt, and a source of potassium ions to provide a weight ratio of potassium / sodium in the range of 1: 1 to 45: 1, such that practically all of the builder salts for detergents and other normally solid detergent additives present in the composition are dissolved in the aqueous phase. The compositions further comprise a density of at least 1.18 g / cm, so that the density of the polymer phase and the density of the (continuous) aqueous phase are approximately equal.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The compositions of this invention are aqueous liquids containing various active cleansing ingredients, detergent adjuvants, builders and thickeners and stabilizing components, although some ingredients may serve more than one of these functions.

Advantageous features of the compositions of this invention, including physical stability, small bottle residue, high cleaning yield, for example, poor stain and film formation, soil debris removal, etc., and higher aesthetic characteristics are believed to be attributed to various interconnected factors such as low solids, i.e. undissolved particulate content, product density and linear viscoelastic rheology, as well as to a method of preventing the composition from wetting and adhering to the inner surface of a polyolefin bottle . These factors are, in turn, dependent on several critical composition components of the formulations, namely, (1) inclusion of a thickening effective amount of polymeric thickening agent having high water absorption capacity, exemplified by acid

(2) inclusion of a physical stabilizing amount of a long chain fatty acid or salt thereof, (3) weight ratio of potassium ions to sodium ions (K / Na) in the range (1) to 45: 1, in particular from 1: 1 to 3: 1, and (4) a density of the hair product 3 at least 1.28 g / cm, such that the density and liquid phase are the same.

Polymeric thickening agents contribute to the linear viscoelastic rheology of the compositions of the invention. As used herein, the term " linear viscoelastic " or " linear viscoelastici-dade " means that the modulus of elasticity (storage) (G ') and the modulus of viscosity (loss) (G') are both substantially independent of the force at least in an applied force range of 0 - 50%, preferably in a range of forces applied from 0 - 80%. More specifically, a composition is considered to be linear viscoelastic for the purposes of this invention if, in a 0-50% strength range, the modulus of. . 2 elasticity G 'have a minimum value of 10 N / m (100 dimentions / cm 2), preferably at least 25 N / m 2 (250 dynes / cm 2) and has a variation of less than 50 N / cm), preferably less than 30 N / m (300 dynes / cm), most preferably. . 2 . 2 to less than 10 N / m (100 dms / cm). Preferably, the minimum value of G 'and maximum variation of G / apply in the force range of 0 to 80%. Typically, the variation in loss modules G " will be lower than G '. A further feature of the preferred linear viscoelastic compositions is that the G " / G '(tg δ) ratio is less than 1, preferably less than 0.8, although greater than 0.05, preferably greater than 0, 2, at least in a range of 0 to 50%, and preferably in a range of 0 to 80%. In this respect it should be noted that the force in% is the shear force x 100.

For better explanation, the modulus of elasticity (storage) G 'is a measure of energy stored and recovered when a force is applied to the composition, while the modulus of viscosity (loss) G &quot; is a measure of the amount of energy dissipated in the form of heat when the force is applied. Therefore, a value of tg 5, 0.05 < tg δ < 1 preferably 0.2 &lt; tg &lt; 0.8 means that the compositions will retain sufficient energy, when a force or tension is applied, at least to the extent expected to be encountered for products of this type, for example, when poured or stirred in a bottle, or stored in a dispenser cup of detergent. automatic dishwasher to return to its previous state when the voltage or force is interrupted. Compositions with tangential values in these ranges will therefore have a high cohesive characteristic, namely, when a cut or force is applied to a portion of the composition in order to cause it to flow, the surrounding portions will follow. As a result of this cohesion of the linear viscoelastic compositions in question, the compositions will flow uniformly and homogeneously from a bottle when it is inclined, thus contributing to the physical (phase) stability of the formulation and small residue in the bottle (poor product loss in the bottle) which characterizes the compositions of the invention. The linear viscoelastic feature also contributes to improved physical stability against phase separation of any undissolved particles in suspension, providing a

resistance to particle motion due to the stress exerted by a particle in the surrounding fluid medium.

Also contributing to the physical stability and small residue in the bottle of the compositions of the invention are the potassium to sodium ion ratios in the range of 1: 1 to 45: 1, preferably 1: 1 to 4: 1, very preferably from 1.05: 1 to 3: 1, for example 1.1: 1, 1.2: 1, 1.5: 1, 2: 1 or 2.5: 1. In these relationships, the solubility of the solid salt components, such as builder salts for detergents, bleaching agent, alkali metal silicates and the like, is substantially increased since the presence of the potassium (K +) ions requires less water of hydration than the ions of sodium (Na +), so that more water is available to dissolve these saline compounds. Accordingly, all or nearly all of the normally solid components are present dissolved in the aqueous phase. Since there is no or only a very small percentage, i.e., less than 5%, preferably less than 3% by weight solids present in the formulation, there is no tendency or there is only a reduced tendency, so that undissolved particles form sediments of the compositions, causing, for example, formation of hard particle masses, which could result in high bottle residues (i.e. loss of product). Furthermore, any undissolved solids tend to be present in extremely small particle size, usually colloidal or sub-colloidal, such as 1 micron or less, thereby further reducing the tendency for sedimentation of the undissolved particles.

Another attribute of the compositions of this invention which contributes to the overall stability of the product and small bottle residue is the high water absorption capacity of the crosslinked polyacrylic acid type thickening agent. Like 8

As a result of this high water absorption capacity, the entire aqueous vehicle component is kept closely connected to the polymer matrix. Therefore, there is no or virtually no free water present in the compositions of the invention. This absence of free water (as well as the cohesive capacity of the composition) is manifested by the observation that, when the composition is poured from a bottle to a piece of water absorbent filter paper, no water is virtually absorbed by the filter paper and in addition, the mass of the linear viscoelastic material poured into the filter paper will retain its shape and structure until it is again subjected to a tension or force. As a result of the absence of unbound or free water, there is virtually no phase separation between the aqueous phase and the polymer matrix or dissolved solids. This feature is manifested by the fact that when the compositions in question are subjected to centrifugation, for example at 1000 rpm for 30 minutes, there is no phase separation and the composition remains homogeneous.

However, it has also been found that the linear viscosity and K / Na ratios in the above-mentioned range do not in themselves ensure long-lasting physical stability (as determined by phase separation). To maximize the physical (phase) stability, the density of the composition should be controlled such that the density of the liquid phase is approximately equal to the density of the complete composition, including the polymeric thickening agent. This control and equalization of densities are achieved according to the invention by providing the composition with a density of at least 1.28 g / cm 2, preferably at least 1.32 g / cm2, to 1.42 g / cm, preferably up to 1.40 g / cm. Furthermore, in order to obtain these relatively high mass densities, it is important to minimize the amount of air incorporated in the composition (density of 1.42 g / cm2 is essentially equivalent to an air content of zero).

It has previously been found in connection with other types of aqueous liquid detergent compositions thickened for automatic dishwashers that the incorporation of finely divided air bubbles in amounts of up to 8 to 10% by volume can function effectively to stabilize the composition against phase separation but that in order to avoid agglomeration or leakage of the air bubbles it is important to incorporate certain surface active ingredients, especially higher fatty acids and their salts, namely stearic acid, behenic acid, palmitic acid, sodium stearate, aluminum stearate, and the like. These surfactants have apparently had the function of forming an interfacial film on the surface of the bubbles, while also forming hydrogen bonds or contributing to electrostatic attraction with the particles in suspension, so that the air bubbles and the attracted particles form agglomerates of density approximately equal to the density of the continuous liquid phase.

Therefore, in a preferred embodiment of the present invention, stabilization of air bubbles which may be incorporated into the compositions during normal processing, in particular during the various mixing steps, is avoided by the subsequent addition of the surfactants, including fatty acid stabilizer or fatty acid salt, to the remainder of the composition under low shear conditions using blending devices designed to reduce cavitation and vortex formation to a minimum.

As will be described in more detail below, the surface active ingredients present in the composition will include the 10-

the main detergent surfactant, and will also preferably include antifoaming agent and higher fatty acid or salt thereof as a physical stabilizer. Crosslinked polyacrylic acid type thickening agents are those sold by BFGoodrich under the tradename Carbopol, namely Carbopol 941, which is the most insensitive to ions of this class of polymers, and Carbopol 940 and Carbopol 934. Carbopol resins, also known as &quot; Carbomer &quot;, are hydrophilic, high molecular weight crosslinked acrylic acid polymers having an average equivalent weight of 76, and the general structure shown by the following formula:

Η H H 0 Jn has a molecular weight of 1 250 000,

Carbopol 941

Carbopol 940 has a molecular weight of 4,000,000 and carbopol 934 has a molecular weight of 3,000,000. Carbopol resins form crosslinking with polyalkenyl polyether, for example, 1% of a sucralose polyallyl ether having a mean of 5.8 allyl groups for each sucrose molecule. There is more detailed information on Carbopol resins supplied by B.F. Goodrich, see, for example, the catalog of B.F. Goodrich GC-67, Carbopol Water Soluble Resins.

While the most favorable results were obtained with Carbopol 941 polyacrylic resin, other thickening agents may also be used in the compositions of this invention.

crosslinked polyacrylic acid type. As used herein, the term &quot; polyacrylic acid type &quot; refers to water-soluble homopolymers of acrylic acid or methacrylic acid, or the water-soluble or water-dispersible salts or esters thereof, or water-soluble copolymers thereof, or water-soluble copolymers thereof, salts, esters or amides thereof, other or with one or more other ethylenically unsaturated monomers such as, for example, styrene, maleic acid, maleic anhydride, 2-hydroxyethyl acrylate, acrylonitrile, vinyl acetate, ethylene, propylene and the like.

These homopolymers or copolymers are characterized by their high molecular weight, in the range of 500,000 to 10,000,000, preferably 500,000 to 5,000,000, especially 1,000,000 to 4,000,000, and by their solubility in water, generally at least in an extent up to 5% by weight or more in water at 25 ° C.

These thickening agents are used in their slightly cross-linked form, in which cross-linking can be achieved by means known in the art of polymeric techniques, in particular by irradiation, or preferably by incorporation into the monomer mixture, to be polymerised monomers of known cross-linking chemical monomers, typically polyunsaturated (e.g., diethylenically unsaturated) monomers, such as, for example, divinylbenzene, diethylene glycol divinyl ether, Ν ', Ν'-methylene polyalkylene polyethers (such as those described above), and the like. Typically, amounts of cross-linking agent to be incorporated into the final polymer may range from 0.01 to 1.5%, preferably from 0.05 to 1.2%, and especially preferably from 0.1 to 0, 9% by weight of crosslinking agent relative to the weight of the total polymer. In general, those skilled in the art will recognize that the degrees of attachment 12

crosslinking agents should be sufficient to impart some winding to the otherwise generally linear polymer compound, the crosslinking polymer further remaining at least water dispersible and highly swellable in water in an aqueous aqueous medium. It is also evident that the water swellability of the polymer which provides the desired thickening and viscous properties depends on one or two mechanisms, namely conversion of the acid group containing polymers to the corresponding salts, for example sodium, generating negative charges along the spine dorsal portion of the polymer, thereby causing the expansion of the coiled molecules and the thickening of the aqueous solution; or by the formation of hydrogen bonds, for example between the carboxyl groups of the polymer and hydroxyl donor. The first mechanism is especially important in the present invention, and therefore the polyacrylic acid type thickening agents will contain free carboxylic acid (COOH) groups along the polymer backbone. It will also be apparent that the degree of crosslinking should not be so high that the crosslinking polymer is completely insoluble or non-dispersible in water or that inhibits or prevents the unwinding of the polymer molecules in the presence of the aqueous ionic system. The amount of at least one high molecular weight crosslinking polyacrylic acid or other high molecular weight hydrophilic crosslinking polyacrylic acid thickening agent to provide the desired rheological property of linear viscoelasticity, will generally be in the range of 0.1 to 2%, preferably 0.2 to 1.4%, by weight, based on the weight of the composition, although the amount depends on the specific cross-linking agent, strength composition, hydroxyl donors and the like. A mixture of the polymeric polyacrylic thickening agents may also be used. 13

The compositions of this invention should include a quantity of potassium ions and sufficient sodium ions to provide a K / Na weight ratio of at least 1: 1, preferably 1: 1 to 45: 1, especially 1: 1 to 3: 1, more preferably from 1.05: 1 to 3: 1, such as 1.5: 1, or 2: 1. When the K / Na ratio is less than 1, there is insufficient solubility of the normally solid ingredients, whereas when the K / Na ratio is greater than 45, especially when it is greater than 3, the product becomes too liquid and phase separation begins to occur. When K / Na ratios become much higher than 45, as in a single or almost only potassium formulation, the polymeric thickener loses its absorption capacity and begins to separate from the aqueous phase as the salt.

Potassium and sodium ions may be present in the compositions in the form of the alkali metal cation of the detergent builder salts or alkali metal silicate or alkali metal hydroxide components of the compositions. The alkali metal cation may also be present in the compositions as a component of ionic detergent, bleaching agent or other ionizable salt compound additive, for example, alkali metal carbonate. In determining the weight ratios of K / Na, all these sources must be taken into account.

Specific examples of builder salts for detergents include polyphosphates, namely alkali metal pyrophosphate, alkali metal tripolyphosphate, alkali metal metaphosphate, and the like, for example sodium or potassium (hydrated or anhydrous) tripolyphosphate, tetrasodium or tetrapotassium pyrophosphate, hexa sodium or potassium metaphosphate, orthophosphate-trisodium or tripotassium and the like, sodium or potassium carbonate, sodium or potassium citrate, nitrilotriacetate of 14

sodium or potassium, and the like. Phosphate based builders, if not excluded due to local regulations, are preferred, and mixtures of tetrapotassium pyrophosphate (TKPF) 'and sodium tripolyphosphate (NaTPF) (especially hexahydrate) are especially preferred. Typical NaTPF ratios for TKPF are from 2: 1 to 1: 8, especially 1: 1.1 to 1: 6. The total amount of builder salts for detergents is preferably 5 to 35% by weight, more preferably 15 to 35%, especially 18 to 30% by weight, of the composition.

In connection with the structuring salts, non-crosslinking polyacrylates of low molecular weight having a molecular weight of from 1 000 to 100 000, more preferably 2000 to 80 000, are optionally used. A preferred low molecular weight polyacrylate is Norasol LMW45ND, manufactured by Norso-shaas and having a molecular weight of 4,500. These low molecular weight polyacrylates are used in a concentration of 0.1 to 15% by weight, more preferably 0.25 to 10% by weight.

Other low molecular weight polymers, which do not crosslink, are Acusol 640D supplied by Rohm &amp;

Haas; Norasol QR1014 from Norsoshaas having a GPC molecular weight of 10,000.

The linear viscoelastic compositions of this invention may contain, and preferably contain, a small but stabilizing effective amount of a long chain fatty acid or its monovalent or polyvalent salt. While the manner in which the fatty acid or the salt contributes to the rheology and stability of the composition has not been fully elucidated, it is hypothesized that it may function as a hydrogen bonding agent or crosslinking agent for the polymeric thickener. 15

Preferred long chain fatty acids are the higher aliphatic fatty acids having 8 to 22 carbon atoms, more preferably 10 to 20 carbon atoms, and most preferably 12 to 18 carbon atoms, including carbon atoms of the carboxyl group of the fatty acid. The aliphatic radical may be saturated or unsaturated and may be linear or branched. The saturated straight chain fatty acids are preferred. Mixtures of fatty acids, such as those derived from natural sources, such as tallow fatty acid, coconut fatty acid, soy fatty acid, mixtures of these acids, etc. may be used. Stearic acid and mixed fatty acids, for example, stearic acid / palmitic acid, are preferred.

The most preferred long chain fatty acids are the higher aliphatic fatty acids having 10 to 50 carbon atoms, more preferably 12 to 40 carbon atoms, and most preferably 14 to 40 carbon atoms, and most preferably 20 to 40 carbon atoms, inclusive of the carbon atom of the carboxyl group of the fatty acid. The aliphatic radical may be saturated or unsaturated and may be linear or branched. The saturated straight chain fatty acids are preferred. Mixtures of fatty acids, such as those derived from natural sources, such as tallow fatty acid, coconut fatty acid, soy fatty acid, etc., or from synthetic sources resulting from industrial manufacturing processes may be used.

Thus examples of the fatty acids include, for example, decanoic acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, behenic acid, oleic acid, eicosanoic acid, tallow fatty acid, coconut fatty acid, , mixtures of these acids, etc. Stearic acid and mixtures of mixed fatty acids, for example, stearic acid / palmitic acid, are preferred. 16

It has, however, recently been discovered by some of us and others that further improvements in phase stability, in particular under high temperature storage conditions, and maintenance of product viscosity levels can be obtained by using fatty acids with a longer chain length, particularly in the range of C4 to C4q. Although both the higher single chain length fatty acids and mixtures of these acids may be used, the average chain length should be in the range of 20 to 32 carbon atoms, especially 24 to 30 carbon atoms, and mixtures of fatty acids included in this range are preferred. Suitable mixed fatty acids, for example those sold under the trade name Syncrowax by Croda, are commercially available.

When the free acid form of the fatty acid is used directly, it will generally be associated with the potassium and sodium ions in the aqueous phase to form the corresponding alkali metal fatty acid soap. However, the fatty acid salts can be directly added to the composition in the form of the sodium salt or potassium salt, or as a polyvalent metal salt, although the alkali metal salts of the fatty acids are the preferred fatty acid salts.

Preferred polyvalent metals are the bi- and trivalent metals of Groups IIA, IIB and IIIB, namely magnesium, calcium, aluminum and zinc, although other polyvalent metals may also be used, including those of Groups IIIA, IVA, VA, IB, IVB , VB, VIB, VIIB and VIII of the Periodic Table of the Elements. Specific examples of these other polyvalent metals include Ti, Zr, V, Nb, Mn, Fe, Co, Ni, Cd, Sn, Sb, Bi, etc. Generally, metals may be present in the bivalent to pentavalent state. Preferably, the metal salts are used in their higher oxidation states. Naturally, for use in automatic dishwashers as well as in any other applications where the composition of the invention is or may come into contact with articles used for the handling, storage or service of food, or otherwise contact or be consumed by humans or animals, the metal salt should be selected taking into account the toxicity of the metal. To this end, the magnesium and calcium and alkali metal salts are especially preferred as generally safe food additives. The amount of the fatty acid stabilizer or fatty acid salt required to achieve the desired increase in physical stability will depend on factors such as the nature of the fatty acid or salt thereof, the nature and amount of the thickening agent, detergent active compound, salts inorganic, other ingredients, as well as conditions of anticipated storage and transportation.

Generally, however, amounts of fatty acid stabilizing agents or fatty acid salt in the range of 0.02 to 2%, preferably 0.04%, more preferably of 0.06 to 0.8%, most preferably from 0.08 to 0.4% provide a long lasting stability and absence of phase separation at rest or during transport at both high and low temperatures as required for a commercially acceptable product.

Depending on the amounts, proportions and types of fatty acid physical stabilizers and polyacrylic acid type thickening agents, the addition of the fatty acid or salt does not only increase the physical stability, but also provides a simultaneous increase in apparent viscosity. Amounts of fatty acid or salt relative to polymeric thickening agent in the range of 0.08-0.4% by weight of fatty acid salt and 0.4-1.5% by weight, 18

of polymeric thickening agent are usually sufficient to provide these simultaneous benefits, and therefore the use of these ingredients in these amounts is more preferred.

In order to achieve the desired benefit of the fatty acid stabilizer or fatty acid salt without stabilizing excess air bubbles and consequently excessive reduction of the density of the product, the fatty acid or salt should be added to the formulation thereafter, preferably together with the other surface-active ingredients, including detergent active compound and antifoaming agent, when present. These surfactant ingredients are preferably added in the form of an emulsion in water, wherein the oily or oily emulsified materials are thin and homogeneously dispersed throughout the aqueous phase. To achieve the desired fine emulsification of the fatty acid or fatty acid salt and other surface active ingredients, it is generally necessary to heat the emulsion (or preheat the water) to an elevated temperature close to the melting temperature of the fatty acid or its salt . For example, for stearic acid having a melting point of 68 ° -69 ° C, a temperature in the range of 50 ° C to 70 ° C will be used. For lauric acid (mp = 47 ° C), a high temperature of 35 ° to 50 ° C may be used. Apparently, at these elevated temperatures, the fatty acid or salt and other surface active ingredients may be more easily and evenly dispersed (emulsified) in the form of fine droplets throughout the composition.

In contrast, as will be seen in the examples which will follow, if the fatty acid is simply added thereafter at room temperature, the composition is not linear viscoelastic as defined above and the stability of the composition is clearly lower. 19 -

Foam inhibition is important to increase the efficiency of the washer and to minimize the destabilizing effects that could occur as a result of the presence of too much foam inside the machine during use. The foam may be reduced by appropriate selection of the type and / or amount of detergent active material, the main foam generating component. The degree of foam is also somewhat dependent on the hardness of the washing water in the machine, and a suitable adjustment of the proportions of the structuring salts, namely NaTPF, which has a water softening effect, can contribute to provide a degree of foam inhibition. However, it is generally preferred to include a stable foam inhibitor or suppressant in the presence of the bleach based on chlorine. Particularly effective are the alkyl esters of phosphoric acid of formula 0

II

HO-P-R

I

OR and in particular the alkyl acid phosphate esters of the formula 0

II

HO-P-OR

I

OR

In the above formulas, one or both R groups in each ester type may independently represent a C 1 -C 4 alkyl group. Ethoxylated derivatives of each type of ester may also be used, for example the condensation products of one mole of ester with 1 to 10 mol, preferably 2 to 6 mol, more preferably 3 or 4 mol of ethylene oxide . Some examples of the foregoing are commercially available, 1 * 1 20

namely SAP's Hooker and LPKN-158 products from Knapsack. Mixtures of both types, or any other stable types in the presence of chlorine bleaching agent, or mixtures of mono- and di-esters of the same type may be used. Particularly preferred is a mixture of mono- and di-C1-C10-alkyl esters of acid phosphate, such as monostearyl / di-stearyl acid phosphates, 1.2 / 1, and condensed with 3 to 4 mol of ethylene oxide. When used, proportions of 0.05 to 1.5% by weight, preferably 0.1 to 0.5% by weight, of suds suppressor in the composition, typically varying the ratio by weight of component active detergent (d) for foam suppressant (e) from 10: 1 to 1: 1, and preferably 5: 1 to 1: 1. Other foam suppressors which may be used include, for example, the known silicones, such as those sold by Dow Chemicals. Furthermore, it is an advantageous aspect of this invention that many of the stabilizing salts, namely the stearate salts, for example, aluminum stearate, when included, are also effective as foam suppressants.

Although any chlorine bleaching compound, namely dichloro-isocyanurate, dichloro-dimethylhydantoin, or chlorinated TSF, may be used in the compositions of this invention, alkali metal or alkaline earth metal hypochlorite, for example, potassium, lithium, magnesium and especially sodium. The composition should contain sufficient amount of chlorine bleaching compound to provide 0.2 to 4.0% by weight of available chlorine as determined, for example, by acidifying 100 parts of the composition with excess hydrochloric acid . A solution containing 0.2 to 4.0% by weight of sodium hypochlorite contains or provides almost the same percentage of available chlorine. Particularly preferred is a proportion of 0.8 to 1.6% by weight available chlorine. For example, sodium hypochlorite (NaOCl) solution of 11 to 13% available chlorine may be used in amounts of 3 to 20%, preferably 7 to 12%. The detergent active material useful in this specification should be stable in the presence of chlorine bleaching agent, especially hypochlorite bleaching agent and to this end the types of surfactants dispersible in organic anionic water are preferred, amine oxide, phosphine oxide, sulfoxide or betaine, the most preferred being the anionic ones mentioned first. Particularly preferred surfactants are the commercially available branched or linear alkali metal di- (C--C)) -alkyl-diphenyl-oxide-mono- and / or disulfates, for example as DOWFAX (trade mark) 3B- 2 and DOWFAX 2A-1. In addition, the sur-facto must be compatible with the other ingredients of the composition. Other suitable organic anionic nonionic surfactants include alkyl sulphates, alkyl sulphonates, primary alkyl aryl sulphonates and sec-alkyl sulphates. Examples include sodium C1 -C18 alkylsulfates, such as sodium dodecyl sulfate and sodium tallow sulfate alcohol; c10-c8 alkane sulfonates, such as sodium hexadecyl-1-sulfonate and sodium C12 -C18 alkyl benzene sulfonates, such as sodium dodecyl benzene sulfonates. The corresponding salts may also be used. of potassium.

Like other suitable surfactants or detergents, the amine oxide surfactants are typically of structure 1 ... RR NO, wherein each R represents a lower alkyl group, e.g. 1 . . for example, methyl, and R represents a long chain alkyl group having 8 to 22 carbon atoms, for example a lauryl, myristyl, palmityl or cetyl group. Instead of an amine oxide, a corresponding surfactant of phosphine oxide R2R1P0 or sulfoxide RR1S0 may be used. Betaine surfactants are

. . 1 + typically of the structure R2RNR &quot; COO-, wherein each R represents a lower alkylene group having 1 to 5 carbon atoms. Specific examples of such surfactants include lauryl dimethyl amine oxide, myristyl dimethyl amine oxide, the corresponding phosphine oxides and sulphoxides, and the corresponding betaine, including dodecyl dimethyl ammonium acetate, tetradecyl- diethyl ammonium hexadecyl dimethyl ammonium hexanoate and the like. For reasons of biodegradability, the alkyl groups in these surfactants should be linear, such compounds being preferred.

Surfactants of the foregoing type, all well known in the art, are described, for example, in U.S. Patents 3,985,668 and 4,271,030. If no chlorine bleach compound is used, then any of the well-known non-ionic surfactants with poor foaming, in particular alkoxylated fatty alcohols, for example mixed ethylene oxide-propylene oxide condensates of C 1 -C 3 fatty alcohols. The water dispersible organic detergent (surfactant) active material stable in the presence of the chlorine bleaching agent will normally be present in the composition in small amounts, generally 1% by weight of the composition, although smaller or larger amounts may be used , in particular up to 5%, for example 0 to 5%, preferably 0.1 or 0.24 to 3%, by weight of the composition. Generally alkali metal silicate (for example potassium or sodium), which provides alkalinity and protection of hard surfaces, such as gloss and fine porcelain pattern, is used in an amount ranging from 5 to 20% by weight, preferably 5 to 15% by weight, more preferably 8 to 12% by weight,

composition. The sodium or potassium silicate is generally added in the form of an aqueous solution, preferably having a ratio of 1: 1.3 to 1: 2.8, most preferably 1: 2 Na 2: SiC 2 or K 2 O 2 Si 2: 0 to 1: 2.6. It should now be noted that many of the other components of this composition, in particular alkali metal hydroxide and bleaching agent, are also often added in the form of a preliminarily prepared aqueous solution or dispersion.

In addition to detergent active surfactant, foam inhibitor, alkali metal silicate corrosion inhibitor, and builder salts for detergents, which all contribute to cleaning performance, it is also known that the effectiveness of the machine liquid detergent compositions Automatic dishwasher is related to alkalinity, and particularly with moderate to high alkalinity levels. Accordingly, the compositions of this invention will have pH values of at least 9.5, preferably at least 11 at values as high as 14, generally up to 13 or more, and, when added to the aqueous washing lavage at one level of a typical concentration of 10 grams per liter, will provide a pH in the wash bath of at least 9, preferably at least 10, in particular 10.5, 11, 11.5 or 12 or more. The alkalinity will be partly absorbed through the alkali metal ions provided by the alkali metal structuring salts for detergents, for example sodium tripolyphosphate, tetrapotassium pyrophosphate and alkali metal silicate; however, it is usually necessary to include alkali metal hydroxide, for example NaOH or KOH, to obtain the desired high alkalinity. Amounts of alkali metal hydroxide in the range (on an active basis) of 0.5 to 8%, preferably 1 to 6%, more preferably 1.2 to 4% by weight of the composition, will be 24

sufficient to achieve the desired pH level and / or to adjust the K / Na weight ratio.

Other alkali metal salts, in particular alkali metal carbonates, may also be present in the compositions in minor amounts, for example 0 to 4%, preferably 0 to 2%, by weight of the composition.

Other conventional ingredients may be included in these compositions in small amounts, generally less than 3% by weight, namely perfume, hydrotropic agents such as benzene, toluene, xylene and sodium cumene sulfonates, preservatives, dyes and pigments and the like, all of which evidently stable in the presence of chlorine bleaching compound and under high alkalinity. Particularly preferred are chlorinated phthalocyanines and aluminosilicate polysulfides, which respectively provide pleasant shades of green and blue. Ti02 can be used to bleach or neutralize discolorations. Still further preferred dyes used in a concentration of 0.01 to 1.0% by weight are Cl Direct Yellow # 28 and Graphtol Green pigments, both made by Sandoz Chemical Corp.

Although, for the reasons given above, an excess of air bubbles in the compositions of the invention, depending on the amounts of dissolved solids and densities of the liquid phase, the incorporation of small amounts of finely divided air bubbles, generally up to 10%, is not desirable, by volume, preferably up to 4% by volume, more preferably up to 2% by volume, may occur to adjust the bulk density to a density close to the liquid phase. The built-up air bubbles should be finely divided, such as up to 100 microns in diameter, preferably 20 to 40 microns in diameter, to ensure 25 - 4 i

stability. Although air is the preferred gaseous medium for adjusting densities to improve the physical stability of the composition, other inert gases, such as nitrogen, carbon dioxide, helium, oxygen, etc. may also be used. The amount of water contained in such compositions should obviously not be so high that it produces undesirably low viscosity and fluidity, or so low that it produces unduly high viscosity and poor fluidity, both of which are reduced or destroyed by linear viscoelastic properties, This amount is readily determined by routine experimentation in each specific case, generally ranging from 30 to 75% by weight, preferably 35 to 65% by weight. The water should preferably be deionized or softened. The manner of formulating the compositions of the invention is also important. As noted above, the mixing order of the ingredients as well as the manner in which the blending is performed will generally have a significant effect on the properties of the composition, and in particular on product density (by incorporation and stabilization of more or less air) and physical stability (for example phase separation). Thus, according to the preferred practice of this invention, the compositions are prepared by first forming a dispersion of the polyacrylic acid thickener in water under moderate to high shear conditions, neutralizing the dissolved polymer to cause gelation, the detergent builder salts, alkali metal silicates, chlorine bleaching compound and other detergent additives, including any previously unused alkali metal hydroxide, if present, in addition to of the surfactants. All supplemental ingredients 26 may be added simultaneously or sequentially. Preferably, the ingredients are added sequentially, although it is not necessary to complete the addition of one ingredient before starting the addition of the next ingredient. In addition, one or more of these ingredients may be divided into portions and added several times. These mixing steps should also be performed under moderate to high shear conditions to obtain a complete and uniform blend. These mixing steps may be performed at room temperature, although neutralization with polymeric thickener (gelling) is usually exothermic. The composition may be allowed to age, if necessary, to cause dissolved or dispersed air to dissipate from the composition.

The remaining surfactant ingredients, including the antifoam agent, organic detergent compound and fatty acid stabilizer or fatty acid salt are subsequently added to the pre-formed mixture as an aqueous emulsion (using 10% , preferably from 2 to 4% of the total water added to the composition in addition to the water added as vehicle for other ingredients or water of hydration), which is preheated to a temperature in the range of Tf + 5 to Tf-20, preferably from Tf to Tf-10, where Tf is the melting point temperature of the fatty acid or the fatty acid salt. For the preferred stearic acid stabilizer, the heating temperature is in the range of 50 ° C to 70 ° C. However, if care is taken to avoid excessive entrapping of air bubbles during the gelling step or during mixing of the structural salts for detergents and other additives, for example by operating under vacuum, or by using conditions of low cut, or special mixing apparatus, etc., the order of addition of the surfactants should be less important. 27

According to a particularly preferred embodiment of the invention, the automatic dishwasher-type linear viscoelastic automatic dishwashing detergent composition of this invention comprises, on a weight basis: (a) 10 to 35%, preferably 15 to 30% %, from builder for detergents based on alkali metal polyphosphate; (b) 5 to 15%, preferably 8 to 12%, of alkali metal silicate; (c) 1 to 6%, preferably 1.2 to 4%, of alkali metal hydroxide; (d) from 0 to 5%, preferably from 0.1 to 3%, of poor detergent organic detergent active material, water dispersible, stable in the presence of the chlorine bleaching agent, preferably anionic detergent not soap; (e) 0 to 1.5%, preferably 0.1 to 0.5%, of chlorine bleach stable suds suppressor; (f) chlorine bleaching compound in an amount sufficient to provide 0.2 to 4%, preferably 0.8 to 1.6% available chlorine; (g) at least one polymeric thickening agent, such as a high molecular weight hydrophilic crosslinking polyacrylic acid thickening agent, in an amount sufficient to provide a linear viscoelasticity to the formulation, preferably 0.1 to 2% , more preferably from 0.2 to 1.0%; X ί. X ί.

(h) a long chain fatty acid or a metal salt of a long chain fatty acid in an amount effective to increase the physical stability of the compositions, preferably from 0.02 to 2.0%, more preferably from 0.2 to 1.0%; (i) water to be present, preferably from 30 to 75%, more preferably from 35 to 65%; and wherein in (a) the alkali metal polyphosphate comprises a mixture of 5 to 30%, preferably 12 to 22% potassium tetrapotassium pyrophosphate or potassium tripolyphosphate, and 0 to 20%, preferably 3 to 18% % of sodium tripolyphosphate, and wherein, throughout the composition, the weight ratio of potassium ions to sodium ions is from 1.05 / 1 to 3/1, preferably from 1.1 / 1 to 2, 5/1, the compositions having an amount of air incorporated such that the density of the composition is 3. 3.28 to 1.42 g / cm, preferably 1.32 to 1.40 g / cm2. The improved gel-type viscoelastic automatic dishwashing composition is further described as containing 10 to 60% by weight of an alkali metal containing compound which is selected from the group consisting essentially of alkali metal hydroxides, alkali metal tripolyphosphates, alkali metal carbonates, alkali metal carbonates and alkali metal silicates, in which both potassium and sodium ions are present in the composition in a weight ratio of 1/1 to 45/1, 0 to 1,5%, in weight ratio of foam suppressant 0 to 5% by weight of a water dispersible organic detergent active stable in the presence of bleach based on chlorine 0.02 to 2.0% by weight , a long chain fatty acid or a metal salt thereof, and a method for substantially preventing wetting of the composition and its adhesion to an inner vertical surface of a polyolefin bottle; wherein the process comprises the addition of a polymeric thickening agent, namely a high molecular weight polyacrylic thickening agent, to the composition, wherein almost all of the normally solid components of the composition

are present dissolved in the aqueous phase, and almost all of the water is intimately bound to the polymeric thickening agent and the composition has a density of 1.28 g / cm @ -1 at 1.42 g / cm3 and the composition does not exhibit phase separation and remains homogenous, when the composition is centrifuged at 1000 rpm for three minutes. The composition may further comprise 0.1 to 10.0% by weight of a polyacrylate having a molecular weight of 1,000 to 100,000 and a chlorine-containing compound to provide 0.2 to 4.0% by weight of available chlorine.

According to another especially preferred embodiment of the invention, the automatic dishwashable linear viscoelastic automatic dishwashing detergent composition of this invention comprises, on a weight basis: (a) (i) 8 to 25%, preferably to 20%, of a builder for detergents based on potassium tripolyphosphate; (ii) 2 to 10%, preferably 4 to 8%, of sodium tripolyphosphate detergent builder in a weight ratio of (i) / (ii) of 1.4 / 1 to 10% / 1, preferably 2/1 to 6/1; (b) 5 to 15%, preferably 8 to 12%, of alkali metal silicate; (c) 1 to 6%, preferably 1.2 to 4%, of alkali metal hydroxide; (d) 0.1 to 3%, preferably 0.5 to 2%, of a low foaming, water-dispersible, organic detergent active detergent active material stable in the presence of the chlorine bleaching agent, preferably nonionic soap detergent; 30 (e) 0 to 1.5%, preferably 0.1 to 0.5%, of stable suds suppressor in the presence of chlorine bleaching agent; (f) chlorine bleaching compound in an amount sufficient to provide 0.2 to 4%, preferably 0.8 to 1.6% available chlorine; (g) at least one non-linear water dispersible polyacrylic acid thickening agent comprising at least one high molecular weight hydrophilic polycarboxylate having a molecular weight of 750,000 to 4,000,000, preferably 800,000 to 3,000,000. 000 000 in an amount sufficient to provide a linear viscoelasticity to the formulation, preferably from 0.2 to 2%, most preferably from 0.4 to 1.5%, more preferably from 0.4 to 1.0%; (h) a long chain fatty acid or a metal salt of a long chain fatty acid in an amount effective to increase the physical stability of the compositions, preferably from 0.02 to 0.4%, more preferably from 0.1 to 0.3%; and (i) 0 to 10%, preferably 1 to 8%, especially 2 to 6% of non-crosslinked polyacrylic acid having a molecular weight in the range of 800 to 200,000, preferably 1 000 to 150,000, in particular 2 000 to 100 000; and (j) water to be present, preferably 30 to 75%, more preferably 35 to 65%; and wherein, throughout the composition, the weight ratio of potassium ions to sodium ions is from 1.05 / 1 to 3/1, or 4/1, preferably from 1.1 / 1 to 2.5 /1. The compositions may also have an amount of incorporated air such that a. 3 vol% of the composition and 1.28 to 1.42 g / cm 3 of 31 - X> 31-X &gt;

Preferably from 1.32 to 1.42 g / cm2, more preferably from 1.35 to 3 1.40 g / cm2.

According to another especially preferred embodiment of the invention, the automatic dishwasher-type linear viscoelastic detergent composition of this invention comprises, on a weight basis: (a) 10 to 35%, preferably 15 to 30%, of at least one alkali metal detergent builder salt; (b) 0 to 15%, preferably 8 to 12%, of alkali metal silicate; (c) 1 to 6%, preferably 1.2 to 4%, of alkali metal hydroxide; (d) 0 to 3%, preferably 0.1 to 2%, of poor detergent organic detergent active material, water-dispersible, stable in the presence of the chlorine bleaching agent, preferably anionic detergent not soap; (e) 0 to 1.5%, preferably 0.1 to 0.5%, of chlorine bleach stable suds suppressor; (f) chlorine bleaching compound in an amount sufficient to provide 0.2 to 4%, preferably 0.8 to 1.6% available chlorine; (g) high molecular weight hydrophilic crosslinking polyacrylic acid thickening agent in an amount sufficient to provide a linear viscoelasticity 32 Λ, t

to the formulation, preferably 0.1 to 2.0%, more preferably 0.4 to 1.5%; (h) a long chain fatty acid or a metal salt of a long chain fatty acid in an amount effective to increase the physical stability of the compositions, preferably from 0.08 to 2.0%, more preferably from 0.04 to 0.5%; and (i) water to be made, preferably from 30 to 75%, more preferably from 35 to 65%; and wherein in (a) the alkali metal polyphosphate comprises a mixture of 5 to 30%, preferably 12 to 22%, of tetrapotassium pyrophosphate, and 0 to 20%, preferably 3 to 18% of tripolyphosphate of sodium, and wherein, throughout the composition, the weight ratio of potassium ions to sodium ions is from 1.05 / 1 to 3/1, preferably from 1.1 / 1 to 2.5 / 1, the compositions having such an amount of air such that the density of the composition is 1.32 to 1.42 g / cm 3, preferably 3 1.35 to 1.40 g / cm 2. (j) 0.01 to 1.09%, of a stable dye in presence of chlorine or stable pigment in the presence of chlorine.

The compositions will be provided to the consumer in suitable dispensing containers, preferably formed of molded plastic, in particular polyolefin plastic, and more preferably polyethylene, in which the compositions of the invention have particularly favorable sliding characteristics. The sliding characteristic of the composition is manifested by the fact that the present compositions do not substantially adhere to the inner vertical surface of a polyolefin bottle, namely a high density, blow molded polyethylene bottle or a bottle of polyethylene terephthalate . This sliding characteristic of the composition is directly linked to the addition of polymeric thickening agent to the composition, which is the cause thereof to obtain its gel-like viscoelastic characteristic. In addition to their linear viscoelastic nature, the compositions of this invention may also be characterized as being pseudoplastic (non-thixotropic) gels, which are typically close to the boundary between solid viscoelastic gel and liquid, depending, for example, on the amount of polymeric thickener. The compositions of the invention can be easily poured from their containers without any agitation or compression, although the containers of compression are often convenient and accepted by the consumer for gel-like products.

The liquid aqueous linear dishwashing machine compositions of this invention are easy to use, in the known manner for washing dishes, other kitchenware and the like, in an automatic dishwasher equipped with a suitable detergent dispensing container in a bath of aqueous washing containing an effective amount of the composition, generally sufficient to fill or partially fill the automatic dispensing cup of the specific machine to be used. The invention also provides a method for dishwashing in an automatic dishwashing machine with an aqueous washing bath containing an effective amount of the liquid linear viscoelastic automatic dishwashing detergent composition as previously described. The composition can be easily poured from the polyethylene container with little or no tightening or shaking into the dispensing cup of the automatic dishwasher and will be sufficiently viscous and cohesive to remain secured within the dispensing cup until it is again applied the shear forces, * * * *

such as those caused by the water jet from the dishwasher. The invention may be practiced in various ways and a number of specific embodiments will be described to illustrate the invention in connection with the accompanying examples.

All amounts and proportions referred to herein are based on the weight of the composition, unless otherwise indicated. EXAMPLE 1 Formulations A-K, as the following are prepared as follows: Ingredient / 1 I Formulation 1 B c D E F G H I J η Deionized water The perf. The perf. The perf. The perf. The perf. The perf. The perf. The perf. The perf. The perf. The perf. Carbopol 941 0.9 0.9 0.9 0.9 1 ... 0.9 0.9 ... 1.5 0.91 NaOH (50%) 2.4 2.4 2.4 2.4 3.5 3.5 2.4 - 2.4 2.4 2.4 KOH (50%) - - - - - - - 2.4 ... - TKPF TPF Hexahydrate, Na 13 13 12 7.5 7.5 7.5 13 7.5 Na silicate (47.5%) (1: 2.3) 21 21 21 21 17 17 21 21 21 21 K Silicate (29.1% ) (1: 2.3) 34 LPKN (5%) 3.2 3.2 3.2 3.2 - - 3.2 3.2 3.2 3.2 3.2 DOWFAX 3B2 1 1 1 1 1 1 1 1 1 1 1 2 Fatty acid 0.1 0.1 0.1 0.1 ... 0.1 0.1 1 0.1 0.1 Bleaching agent (13.0% Cl) 7.5 7.5 7.5 7.5 9.1 9.1 7.5 7.5 7.5 7.5 9 Ar (% vol) <2.0 <2.0 <2.0 <lt 2.0 &gt; 2.0 &lt; 2.0 &lt; 2.0 Fragrance - 0.17 - - - - - - - - K / Na ratio 1.12 1.12 1.16 1.89 1.95 1.95 4.16 45.15 - 1.89 - 3 Density (g / cm) 1.37 1.37 1.35 1.37 1.36 - 1.37. .. ... 1.37 1.37 Ratio Fig. 1 Fig.2 Fig.3 Fig.4 Fig.6 Fig.7 Fig.5 Fig.8 Stability Results à tem (%) 0.0 0.0 oo 0.0 &gt; 10.0 &gt; 10.0 &gt; 20.0 &gt; 5.0 0.0 Stability Results at 38 ° C (100 ° F ) 6 weeks (%) 0.0 0.0 oo oo &gt; 10.0 &gt; 10.0 &gt; 20.0 &gt; 5.0 oo

Carbopol 940

Emersol 132 (Mixture of stearic acid and palmitic acid in a ratio of 1: 1)

All formulations are aerated to a certain degree, depending on the cutting conditions used for the preparation; typically the air volume does not exceed 7-8% by volume, the preferred degree of aeration (2%, by volume) resulting in the stated densities; the air bubbles have on average between 20 and 60 micron in diameter. 36 -

Formulations A, B, C, D, E / G / JeK are prepared by first forming a uniform dispersion of Carbopol 941 or Carbopol 940 thickener in 97% water (used to make). The Carbopol is slowly added to the deionized water at room temperature using a master blade mixer with agitation set at a medium shear rate as recommended by the manufacturer. The dispersion is then neutralized by the addition, with mixing, of the caustic soda component (50% NaOH or KOH) to form a thick gel-like thickening product. To the resulting gelled dispersion, silicate, tetrapotassium pyrophosphate (TKPF), sodium tripolyphosphate (TP) (TPF, Na) and bleaching agent are sequentially added sequentially in the order indicated, continuing the blending with medium cut.

Separately, an emulsion of the phosphate-based antifoam agent (LPKN), a mixture of stearic acid / palmitic acid and detergent (Dowfax 3B2) is added, these ingredients being added to the remaining 3% of the water (used to make ) and the resulting mixture is warmed to a temperature in the range of 50 ° C to 70 ° C. The heated emulsion is then added to the gelled dispersion previously prepared under low shear conditions so that a vortex does not form.

The remaining formulations F, HeI are prepared in essentially the same manner as described above, except that the heated emulsion of LPKN, stearic acid and Dowfax 3B2 is directly added to the neutralized Carbopol dispersion prior to the addition of the remaining ingredients. In 37 - χ *

As a result, the formulations F, Hei have higher levels of incorporated air and densities below 1.30 g / cm.

The rheograms for formulations A, C, D, G and J are shown in figures 1-5, respectively, and the rheograms for the formulations Η, I and K are indicated in figures 6, 7 and 8, respectively.

These rheograms are obtained with System Rheometer 4 from Rheometrics equipped with a Fluid Servo with a torque torser transducer of 100 grams-centimeter and a geometry of parallel plates of 50 millimeters, having a 0.8 millimeter interval between plates . All measurements are made at room temperature (25 ° C ± 1 ° C) in a humidity chamber after a storage period of 5 minutes or 10 minutes of the sample in the aperture. Measurements are made by applying a frequency of 10 radians per second.

All formulations of compositions A, B, C, D, G and J according to the preferred embodiment of the invention, which include Carbopol 941 and stearic acid exhibit linear viscoelasticities, as evident from the graphs of Figure 1 -5. Formulation E, which includes Carbopol 941, but not stearic acid, showed no phase separation at either room temperature or at 38øC (100øF) after 3 weeks, but showed 10% phase separation after 8 weeks at at room temperature and after only 6 weeks at 38øC (100øF). Formulation K, containing Carbopol 940 instead of Carbopol 941, as disclosed in the diagram of Figure 8, exhibits substantial linearity over a 2 to 50% strength range (G 'at 1% 2 G-force at 50% of force &gt; 500 dynes / cm) although tg 5 &gt; 1 at a force above 50%. EXAMPLE 2

This example demonstrates the importance of the order of adding the premixture of the surfactant components to the remaining part of the composition relative to the density and stability of the product.

The following formulations are prepared by methods A and B:

Ingredient Water, deionized to be made

Carbopol 941 0.5

NaOH (50%) 2.4

Na Silicate (47.5%) 21 TKPF 15 TPF, Na 13

Bleaching agent (1%) 7.5 LPKN 0.16 Stearic acid 0.1

Dowfax 3B2 1 Method A: Carbopol 941 is dispersed at a medium shear rate using a master blade blender in deionized water at room temperature. NaOH is added with blending to neutralize and gel the Carbopol 941 dispersion. To the thickened blend the following ingredients are added sequentially while stirring: sodium silicate, TKPF, TPF and bleaching agent.

39 - j t Λ V

An emulsion is prepared separately by adding Dowfax 3B2, stearic acid and LPKN to water, while mixing at moderate shear rate and heating the mixture to 65 ° C to finely disperse the surfactant ingredients emulsified in the water phase. This emulsion premix is then slowly added to the Carbopol dispersion while blending under low shear conditions without vortexing. The results are presented below. Method B:

Method A is repeated except that the heated emulsion premix is added to the neutralized Carbopol 941 dispersion prior to sodium stearate, TKPF, TPF and bleaching agent. The results are also presented below.

Method A Method B 1.38 1.30 0.00% 7.00% Fig.9 Fig.10 3

Density (g / cm)

Stability (TA-8 weeks)

From the graphs of Figures 9 and 10 it is seen that both products are linear viscoelastic, although the elastic and viscous modules G 'and G &quot; are higher for Method A than for Method B.

It will be appreciated from the results that the anticipated addition of the surfactants to the Carbopol gel significantly increases the degree of aeration and reduces the bulk density of the final product. Since the density is lower than the density of the continuous liquid phase, the liquid phase undergoes an inverse separation (a clear liquid phase forms at 40 -

composition background). This reverse separation process appears to be kinetically controlled and will occur much more rapidly as the product density becomes lower. EXAMPLE 3

This example shows the importance of the temperature at which the pre-mixed surfactant emulsion is prepared.

Two formulations, L and M, having the same composition as in Example 2, were prepared except that the amount of stearic acid was increased from 0.1% to 0.2% as revealed in Method A for formulation L and by the following Method C for formulation M. Method C:

The process of Method A is repeated in all its details, except that the emulsion premixture of the surfactants is prepared at ambient temperature and not heated before being added subsequently to the thickened dispersion of Carbopol containing silicate , builders and bleaching agent. The rheograms for the formulations L and M are shown in Figures 11 and 12, respectively. From these rheograms it is seen that the formulation L is linear viscoelastic in both G 'and G', whereas the formulation M is not linear viscoelastic, in particular for the elastic modulus G '(G' at 1% strength- G 'at 30% strength &gt; 500 dynes / cm) and also for G &quot; (G &quot; at 21% G-force at 30% strength = 300 dms / cm). Formulation L remains stable after storage at RT and 38øC (100øF) for at least 6 weeks, while formulation M undergoes phase separation. COMPARATIVE EXAMPLE 1

The following formulation is prepared without any potassium salts: wt%

Water Carbopol 941 NaOH (50%) TPF, Na (50%) Na Silicate (47.5%) Whitening Agent Stearic Acid LPKN (5%) Dowfax 3B2 Sodium Carbonate Acrysol LMW 45- 4 21.0 17.24 (1%) 7,130.1 3,20.8 5.02.0 The procedure used is analogous to that of Method A of Example 2 with sodium carbonate and Acrysol LMW 45-N (polymer of low molecular weight polyacrylate) before and after, respectively, the silicate, TPF and bleaching agent, to the thickened dispersion of Carbopol 941, followed by the addition of the heated surfactant emulsion premix. The rheogram is shown in figure 13 and is nonlinear with G "/ G '(tg δ) &gt; 1 in the force range of 5% to 80%. EXAMPLE 4

The formulations A, B, C, D and K prepared according to this invention and the comparative formulations F and a commercial dishwashing liquid detergent product, 42

X

as shown in Table 1 above, were subjected to a bottle residue test using a standard polyethylene bottle of 28 ounces (794 g), which corresponds to a bottle normally used for commercial dishwashing liquid detergents.

Six bottles were filled with respective samples and the product was distributed, with a minimum of force, in dosages of 80 grams, with a 2 minute rest period between dosages, until the flow stops. At this point, the bottle was vigorously stirred in an attempt to expel the additional product. The amount of product remaining in the bottle was measured, representing a percentage of the total product originally introduced into the bottle. The results are shown below.

Waste in the bottle

Formulation Residue A 8 B 10 C 6 D 5 K 7 * * F 4 Commercial Product 20 The sample separates with aging. * *

The following formulations A-F were prepared as described below: FORMULATION INGREDIENT A B C D E F Water Q.A. Q.A. Q.A. Q.A Q.A. Q.A. Carbopol 941 0.9 - - - - - Carbopol 940. - 0.9 Carbopol 614 - - 0.9 0.9 0.9 0.9 NaOH (50%) 2.4 4.5 4.5 4.0. 4,5 4.5 Na Silicate (47.5%) (1: 2.4) 21 21 20.83 20.83 20.83 20.83 TKPF 15 15 - - - - KTPF - - 20.35 20.35 13 20.35 NaTPF (anhydrous) 13 13 5.26 5.26 3 5.26 DOUFAX3B2 1 0.8 0.8 0.8 0.8 0.8 LPKN (antifoaming agent) 0.160, 16 0.16 0.16 0.16 0.16 Fatty acid 2 0.10 1 0.20 3 0.15 2 0.15 0.152 0.152 Whitening agent (13.1%) 8.1 11.1 10.13 10.13 10.13 10.13 Green Grapthol 0.0025 0.003 0.003 0.003 0.003 - Cl Direct Yellow 28 - - - - - 0.003 Ar (Vol.%) Approx. Acrysol LMW 45-N (45.0%) - - - - 4.4 - Highlights (fragrance) - - 0,05 0,05 0,05 0,05 K / Na 0,98 0,98 1.61 1.61 1.17 1.17 Density 1.35 1.37 1.37 1.37 1.28 1.37 Stability at room temperature. environment 8 without 8 without 24 without 24 without 12 without. 4 without Stability at 38 ° C (100 ° F) 2 without 2 without - 20 without 8 without 4 without Stability at 49 ° C (120 ° F) - - - 8 without 8 without 4 without Stability at 60 ° C (140 ° F F) - - - 2 without 2 without 2 without crystals at 38 ° C (100 ° F) Yes Yes No No No No Régram Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Acid stearic Syncrowax C24_26 Syncrowax c18_36 a.jt a.jt

Formulations A, B, C, D, E and F are prepared by first forming a uniform dispersion of Carbopol 614 or 940 thickening agent in 97% water of the total water of the formulation. The Carbopol is added slowly by vortexing pre-heated deionized water, preheated to a temperature of 41øC (105øF) using a blender equipped with a main blade, with stirring set to a speed of as recommended by the manufacturer. After mixing for about 15 minutes, the dispersion is then neutralized by the addition, under the same mixing action, of the caustic soda component (50% NaOH) to form a thick gel-like thickening product (10 minutes). To the resulting gelled dispersion are added sequentially, in the order indicated, silicate, sodium tripolyphosphate (NaTPF), tetrapotassium pyrophosphate (TKPF), or potassium tripolyphosphate (KTPF), the surfactant emulsion (described below), and the agent bleaching agent and the dye, with the act of mixing with medium cut for several minutes prior to the addition of the next ingredient. After addition of the surfactant emulsion [at 71øC (160øF)], the mixture is cooled to 90ø-95øF (32ø-35øC) before the bleaching agent is added.

Separately, the surfactant emulsion of the phosphate antifoaming agent (LPKN), stearic acid or fatty acid mixture and detergent (Dowfax 3B2) are prepared by adding these ingredients to the remaining 3% water and heating the mixture resulting at a temperature in the range of 71øC (160øF). In formulation E, Acrysol LMW 45-N can be added at this stage. - 45 - - 45 -

The rheograms for formulations A, B, C, D, E and F are shown in Figures 1-6, respectively.

These rheograms are obtained with the System 4 Rheometer from the Rheometrics equipped with a Fluid Servo with a 100 gram-centimeter torsion transducer and a 50 millimeter parallel plate geometry having a 0.8 millimeter gap between the plates. All measurements are made at room temperature (25 ° ± 1 ° C) in a humidity chamber after a holding period of 5 minutes or 10 minutes of the sample in the range. The measurements are made applying a frequency of 10 radians per second.

All formulations C, D and F of the composition exhibit linear viscoelasticity as can be seen from the graphs of Figures 2-6. No separation of phases was observed from room temperature to 140 ° F for any of the formulations for at least the minimum number of weeks required to meet the stability criteria as indicated in Table A above. Formulations E and F were still being tested when this patent application was filed. t

However, in control formulations A and B maintained at 38Â ° C (100Â ° F), TKPF crystallized on the aqueous phase and eventually formed crystals of sufficiently large size that separated towards the bottom of the composition. Also, as seen in Figures 1 and 2, the formulations A and B do not have linear viscosity, at least within the limits of the preferred criteria as previously described. The formulations C, D, E and F according to the invention did not undergo any crystal growth. 46

For bottle residue testing, each formulation is allowed to stand for about 1 week at room temperature in a standard 907 g (32 ounce) small neck polyethylene bottle. A quantity of product is poured from the bottle to fill a standard sized dispensing cup of an automatic dishwasher. The bottle is then replaced in an upright position and held upright for at least 15 minutes. This process of filling the dispensing cup by placing the container upright and waiting for at least 15 minutes is repeated until no more products flow from the bottle. At this time, the weight of the bottle is measured, the residue of the bottle is calculated as W x 100

Wo

Io is the starting weight of the full bottle and Wf is the final weight of the full bottle. The residue of the bottle for each formulation A-F is about 4 to 5%. The C-F formulations have viscosities which. -2 range from 10 to 20 N * s * m (10,000 and 20,000 cps) measured with a Brookfield LVT viscometer, spindle # 4 at 20 rpm measured at 26øC (80øF). All these products are easily poured from the polyethylene bottle. EXAMPLE 6

A slurry of Carbopol 614 is formed as described in Example 1 except that the coloring agent is first added to the deionized water (about 92% of the total added water) and the amounts of the ingredients are changed as indicated forward. The premix (surfactant emulsion) of the surfactant ingredients is also formed as in Example 1 using stearic acid as the fatty acid stabilizer and the remaining 8% of the total added water.

The ingredients are then mixed together with the Carbopol 614 slurry in the following order: alkali metal silicate, NaTPF (powder), KTPF (powder), surfactant emulsion, bleaching agent and perfume. The resulting composition is obtained with the following ingredients in the following amounts:

Ingredient

Quantity (% by weight) s. 100.00 1.00 6.38 20.83 20.35 5.26 0.80 0.16 0.15 9.23 0.0024 0.05 Deionized water q.

Carbopol 614 NaOH (38% Na2 O)

Na Silicate (1:24) (47.5%) KTPF powder (anhydrous)

NaTPF (H 2 O 3%)

Dowfax 3B2 LPKN Stearic acid

Bleaching agent (Na-13% hypochlorite) Cl Pigment Green 7 (Cl 74260)

Highlights The composition has a pH of 11.3 ± 0.1 and density (specific gravity) of 1.39 ± 0.03. Viscosity at 27øC (80øF) measured with a Brookfield LVT viscometer at 20 rpm with a # 4 spindle is 12 ± 2 N-m-2 (12,000 ± 2,000 cps).

All preferred criteria as indicated in Table A above are satisfied. EXAMPLE 7

The following formulas were prepared according to the procedure of Example 1 and were tested. 1 2 3 4 Water q.a. q.a. qa qa Carbopol 941 0.9 - - - Carbopol 940 0.9 - - Carbopol 614 0.9 0.9 NaOH (50%) 4.5 4.5 4.5 4.5 Na silicate 21 21 21 21 TKPF 15 15 15 15 Na-TPF Anhydrous 13 13 13 13 NaOCl (1.0 Chlorine available) 7.5 11.1 11 11 LPKN 158 0.16 0.16 0.16 0.16 DOWFAX 3B-2 10, 8 0.8 0.8 Sa (Emery 132) 0.2 - - - Syncro Wax Acid (cig_3gj - - 0.2 - Syncro Wax Acid (^ 4-35) - 0.1 - 0.2 Ar (% v / v) &lt; 2.0 &lt; 2.0 &lt; 2.0 &lt; 2.0 Vise 0.8 TA 8.600 7.020 8.000 8.000 Vise 6 wk TA 4,200 6,000 7,100 8,000 Vise 6 wk 38 ° (100 ° F) 4,200 6,000 7,100 8,000 Phase Separation TA Sep.Light Stable Stable Stable Stability 38 ° C (100 ° F) Unstable Stable Stable Stable 49 -

1 1 * BCDEFGH Carbopol 941 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 Acrysol LMW45N 0 0.5 1.0 2.0 2.0 0.5 1.0 2.0 2.0 NaOH (50%) 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 LPKN (5%) 3.2 2.4 2.4 3.2 3.2 2.4 2.4 3.2 3.2 Stearic Acid 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 DOWFAX 3B-2 0.8 0.8 0.8 0.8 1.0 0.8 0.8 0.8 0.8 Sodium Silicate (47.5%) 21 , 0 21.0 21.0 21.0 21.0 21.0 21.0 21.0 21.0 Potassium Pyrophosphate 15.0 15.0 15.0 20.0 20.0 15.0 15.0 20.0 20.0 Sodium Tripolyphosphate 12.0 12.0 12.0 7.0 7.5 12.0 12.0 7.0 7.0 Sodium hypochlorite (13%) 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 Water 37.25 37.55 37.05 35.25 34.55 37.50 37.0 37.20 35.1976 Highlight # 3 0.05 0.05 0.05 0, 05 Cl Green Pigment # 7 0.0024 Density 1.30 1.30 1.37 1.37 1.37 1 n 11,100 12,100 12,000 11,600 10,000 12,800 16,000 8,800 Brookfield viscosity measured at room temperature, spindle # 4, at 20 rpm (in Nsm) EXAMPLE 8

The following formulas A-B were prepared according to the procedure of Example 1.

Carbopol 614 1.0 1.0 NaOH (50%) 4.5 4.5 LPKN 158 3.2 3.2 Stearic Acid 0.06 0.06 Dowfax 3B-2 0.8 0.8 Sodium Silicate (47 , 5%) 20.83 20.83 Potassium tripolyphosphate 20.35 20.35 Sodium tripolyphosphate H20 (3%) 5.26 5.26 Sodium hypochlorite (13%) 10.13 10.13 Water 36.877 36.877 Cl Direct Yellow 28 0.003 - Perfume Highlight III 0.05 0.03 Density 1.30 Viscosity 12,100

Brookfield viscosity measured at room temperature at spindle # 4 at 20 rpm

J. PEREIRA DA CRUZ Legal Agent of Industrial Property RUA VICTOR CORDON, 10-A 3.® 1200 USBOA

Lisbon, May 29, 1992

Claims (5)

I. A gel-like viscoelastic automatic dishwashing composition comprising 10 to 60% by weight of an alkali metal-containing compound selected from the group consisting essentially of alkali metal hydroxides, alkali metal tripolyphosphates, metal pyrophosphates alkali metal carbonates, and alkali metal silicates, and in that said composition comprises both potassium ions and sodium ions in a ratio of 1/1 to 45/1, 0 to 1,5% by weight of a foam; 0 to 5% by weight of a stable, water-dispersible organic detergent active material in the presence of a bleach based on chlorine, 0.02 to 2.0% by weight of a fatty acid chain or a metal salt thereof, water, and a means for substantially preventing the wetting of the composition and its adhesion to an inner vertical surface of a polyolefin bottle. Composition according to Claim 1, characterized in that said means consists in adding to the composition 0.1 to 2.0% by weight of at least one polyacrylic acid thickening agent selected from the group consisting essentially by acrylic acid or methacrylic acid, water-dispersible or water-soluble salts or esters or amides thereof, and copolymers of these acids or their water-soluble salts, esters or amides in combination with one another or with one or more other ethylenically unsaturated fatty acids, in which almost all the normally solid components of the composition are present dissolved in the aqueous phase, and almost all the water in the composition is firmly attached to the thickening agent of acid 2 polyacrylic acid composition in that said composition has a density of 1.28 g / cm @ -1 at 1.42 g / cm2 and said composition has no phase separation and remains homogeneous when it is centrifuged at 1000 rpm for 30 minutes. 3a. The composition of claim 2, further comprising a chlorine bleach compound in an amount sufficient to provide 0.2 to 4.0% by weight of available chlorine. 4a. Composition according to Claim 3, characterized in that it further comprises 0.1 to 10.0% by weight of a polyacrylate having a molecular weight of 1 000 to 100 000. 53. A linear, viscoelastic, aqueous liquid detergent composition for automatic dishwashing machine, characterized in that it comprises water, 0.01 to 2% by weight of a long chain fatty acid or its salt having 20 to 50 carbon atoms, 0 to 5% by weight of a non-saponified organic detergent, for automatic, dishwashing, water-dispersible, stable in the presence of the chlorine bleaching agent and poor foaming; to 40% by weight of at least one alkali metal detergent builder salt, an amount of a chlorine bleach compound sufficient to provide 0.2 to 4.0% by weight of available chlorine, and 0.1 to 2% by weight of at least one crosslinking polycarboxylate thickening agent having a molecular weight of at least 800,000, wherein the aqueous phase comprises both sodium ions and potassium ions in a ratio, by weight K / Na ratio of 1/1 to 45/1. Composition according to Claim 5, characterized in that the polycarboxylate type thickening agent is a crosslinked polyacrylic acid having a molecular weight in the range of 1,000,000 to 4,000,000. 7a. A linear, viscoelastic, aqueous liquid detergent composition for automatic dishwashers, characterized in that it comprises in approximate values and by weight: (a) from 10 to 35% of at least one alkali metal builder salt for detergents, said alkali metal detergent builder salt being selected from the group consisting essentially of alkali metal tripolyphosphate, alkali metal pyrophosphate, alkali metal metaphosphate, alkali metal carbonate, alkali metal citrate, and alkali metal nitrile triacetate and their salts. mixtures; (b) 5 to 15% alkali metal silicate; (c) 1 to 6% alkali metal hydroxide; (d) 0 to 3.0% of water-dispersible organic detergent active material stable in the presence of chlorine bleaching agent; (e) 0 to 1.5% of chlorine bleach stable suds suppressor; (f) chlorine bleaching compound in an amount sufficient to provide 0.2 to 4% available chlorine; (g) 0.1 to 2.0% of a cross-linking polyacrylic acid thickening agent having a molecular weight of from 1% to 4%; 4 (h) 0.02 to 2% of a long chain fatty acid or a metal salt of a fatty acid; (i) 0.01 to 1.0% by weight of a pigment and / or colorant; (j) water, and in that said polyacrylic acid thickening agent is selected from the group consisting essentially of acrylic acid or methacrylic acid, water-soluble or water-soluble salts or esters or their amides and copolymers of these acids or their salts , water soluble esters or amides in combination with one another or with one or more other ethylenically unsaturated monomers and in that the aqueous phase includes both sodium ions and potassium ions in a weight ratio of K / Na of 1 / 1 to 45/1, for almost all of the normally solid components of the composition are present dissolved in the aqueous phase, and almost all the water in the composition is firmly attached to the cross-linking polyacrylic acid thickening agent, in that said composition has a density from 1.32 g / cm to 1.42 g / cm and in that said composition has no phase separation and remains homogeneous when it is centrifuged at 1000 rpm and 30 minutes. ga. Composition according to Claim 8, characterized in that the chlorine bleaching compound is sodium hypochlorite. 5 Composition according to Claim 8, characterized in that it further comprises a fragrance. Lisbon, May 29, 1992 J. PEREIRA DA CRUZ Official Agent for Industrial Property RUA VtCTOR CORDON, 10-A 3 "1200 LISBOA