PT88929B - A process for the preparation of a detergent composition comprising a disintegrating agent and a disintegrating agent for the preparation of a disintegrating agent. - Google Patents

Abstract

Thixotropic aqueous liquid automatic dishwashing detergent composition with improved anti-filming and anti-spotting properties and method of using the detergent composition. The detergent composition comprises alumina or titanium dioxide anti-filming agent, polyacrylate polymer anti-spotting agent, inorganic builder salts, chlorine bleach, bleach-stable detergent and a thixotropic thickener. The compositions provide reduced filming and spotting on dishware, glassware, china and the like, particularly in hard water, and remain stable against phase separation.

Description

FIELD OF THE INVENTION

The present invention relates to a process for the preparation of a thixotropic aqueous liquid detergent composition for automatic dishwashing with better anti-film and stain-forming properties, as well as a method of using the detergent composition for washing dishes, glasses, porcelain and the like.

The dishwashing composition contains alumina or titanium dioxide as an anti-film agent, inorganic structuring salts for polyacrylic acid polymer structuring, chlorine-based bleaching agent, stable detergent in the presence of the bleaching agent and a thixotropic thickener.

The dishwashing detergent composition of the present invention reduces the formation of film and stains on dishes, glass, porcelain and the like, particularly in hard water and remains stable against phase separation.

More specifically, the invention relates to the use of alumina or titanium dioxide, as an anti-film agent, and polyacrylic acid polder builder in thixotropic aqueous liquid dishwashing compositions to reduce the formation of film and stains.

Detergent compositions do not require additional rinsing, are stable in storage, do not settle and are easily redispersible and spillable.

the present invention also relates to an aqueous thixotropic suspension with better physical stability. The invention concerns the use of acids

-4 long chain fatty acids, metal salts of fatty acids and clay, as thixotropic agents, to form stable liquid gel-like suspensions suitable for use as liquid detergent compositions for automatic dishwashers.

The present invention relates specifically to aqueous liquid detergent compositions for automatic dishwashing having thixotropic properties, better anti-film and stain properties and better physical stability, which are readily dispersible in the washing medium, providing effective cleaning of dishes , glasses, porcelain and the like.

PREVIOUS TECHNIQUE GIVES SPECIALTY

The commercially available detergents for domestic dishwashers presented in powder form have several disadvantages, namely non-uniform composition; expensive operations necessary for its manufacture; tendency to fill in a warehouse at high humidity, resulting in the formation of clumps that are difficult to disperse; dust, a source of irritating particles for consumers suffering from allergies, and a tendency to stick to the dishwasher's dispensing device. However, the liquid forms of such compositions cannot generally be used in automatic dishwashers due to their high foam levels, unacceptably low viscosity and excessively high alkalinity.

In addition, the powder detergents presently used require a separate hand-wiping step and drying of plates, cups, porcelain and the like, to avoid undesirable traces or film of precipitated calcium and magnesium salts. The use of liquid detergent compositions presents other problems

^{: f =} n

-5 but. The structuring salts sediment in the warehouse and are not easily redispersed. Compositions also often become thicker in storage and are not easily spilled

Recent research and development activity has focused on the gel or xotropic form of such compositions, however these compositions have proven to be insufficiently viscous to remain anchored in the dishwasher dispensing cup and, furthermore, , produce residues in the form of stains on plates, glass, porcelain and the like. Ideally, the compositions. Thixotropic cleaning applications must be highly viscous at rest, of a Bingham plastic nature and have relatively high yield values. However, when subjected to shear stresses, such as when they are agitated in a container or squeezed through an orifice, they must fluidize quickly and, after cessation of the applied shear stress, they must revert quickly to the state of high viscosity / plastic toughness of Bingham. Stability is also of primary importance, that is, there should be no significant evidence of phase separation or absence of tightness after a long rest.

For effective use, it is generally recommended that the detergent for automatic washing. crockery, hereinafter also referred to as DLA, contains (1) sodium tripolyphosphate (NaTPF) to soften or bind minerals in hard water and to emulsify and / or peptize dirt; (2) sodium silicate to provide the necessary alkalinity for effective detergency and to protect enamel and fine porcelain contour; (3) sodium carbonate, generally considered to be optional, to increase alkalinity; (4) a chlorine releasing agent for contri. contribute to the elimination of dirt stains that lead to water staining; and (5) foam suppressant / surfactant to reduce foam, thus increasing the effectiveness of

-6machine and providing the necessary detergency. See, for example, SDA Detergents in Depth, Formulations Aspects of Machine Dishwashing ¹ , ¹ Thomas Oberle (19 74). The cleaning products that most closely match the compositions described above are mainly liquids or powders. In general, such compositions omit the hypochlorite bleaching agent, as it has a tendency to react with other chemically active ingredients. especially with the surfactant, thus degrading the suspending or thixotropic agent and impairing its effectiveness.

Thus, U.S. Patent No. 2.

3,985,668 describes abrasive degreasing cleaners with a gel-like consistency, containing (1) suspending agent, preferably attapulgite and smectite clay; (2) abrasive agent, for example, silica or pearlite sand; and (3) filler, consisting of pulverized polymers of light density, expanded perlite and the like, which has a buoyant power and, therefore, a stabilizing effect on the composition in addition to serving as a swelling agent, thereby replacing the otherwise available water for the undesirable formation of a supernatant layer due to the absence of tightness and destabilization of phases. The above ingredients are the essentials. Optional ingredients include hypochlorite-based bleaching agent, stable surfactant stable in the presence of bleaching agent and buffer solution, for example, silicates, carbonates and monophosphates. The structuring agents, namely NaTPF, can be included as other optional ingredients to provide or complete the structuring function not ensured by the buffer solution, not exceeding the amount of that structurer. 5% of the total composition, according to the patent. The maintenance of desirable pH levels, equal to or greater than 10, is achieved by the solution / buffer / structuring components. A high pH is said to reduce the decomposition of the chlorine bleaching agent to a minimum and undesirable interaction between the

-Ί-

surfactant and the bleaching agent. When present, NaTPF is limited to 5%, as stated. No disclosure is made regarding a foam suppressor.

English Patent Applications GB 2,116,199 A and GB 2,140,450 A, both assigned to ColgatePalmolive, reveal liquid DLA compositions, which desirably have thixotropic properties, gel-like structures and which include each of the various ingredients necessary for an effective detergent with an automatic dishwasher.

The aqueous detergent composition, usually of gel type, for automatic dishwasher, having tropic properties includes the following ingredients, on a weight basis:

(a) 5 to 35% alkali metal tripolyphosphate;

(b) 2.5 to 20% sodium silicate;

(c) 0 to 9% alkali metal carbonate;

(d) 0.1 to 5% of water-dispersible organic detergent active material, stable in the presence of chlorine-based bleaching agent;

(e) 0 to 5% stable foam suppressant in the presence of the chlorine-based bleaching agent;

(f) chlorine bleaching compound, in a quantity. enough to provide about 0.2 to 4% of available heat;

(g) thixotropic thickener in an amount sufficient to provide the composition with a thixotropy index of about 2.5 to 10; and (h) sodium hydroxide, when necessary, to adjust the

-8 The DLA compositions thus formulated are of low foaming; they are quickly soluble in the washing medium and very effective at pH values that better lead to better cleaning performance, viz. pH 10.5-13.5. The compositions usually have the consistency of a gel, that is, a highly viscous, opaque material, of a ge Latin type and having a Bingham plastic nature and, therefore, relatively high yield values. Accordingly, a defined cutting force is required to initiate or increase the flow, just as would be obtained within a stirring dispensing device of an automatic dishwasher in operation, or by a jet of water.

Under these conditions, the composition fluidizes rapidly and is easily dispersed. When the cutting force is interrupted, the fluid composition easily reverts to a state of high viscosity, Bingham's plastic nature very close to its previous consistency.

U.S. Patent 4,511,487 of April 16, 1985 discloses a low foaming detergent paste for dishwashers. The composition is based on a mixture of finely divided hydrated sodium metasilicate, which is a flashy silica of the hectonte type. A small amount of nonionic surfactant derivatives and alkali metal carbonates and / or hydroxides can be used.

A related order that is also pending and has a common assignment is Series no. 816,535, filed on January 7, 1987, which is incorporated herein by reference.

The equally pending application discloses a thixotropic aqueous detergent composition for automatic dishwashing, which contains a long-chain fatty acid as a tropic thickener. Another related order that is also pending is also of common attribution is the Series 924.385 deposited on October 29, 1986, which is incorporated herein by reference. This application for a common allocation reveals a liquid detergent composition

-9 thixotropic clay-based water for dishwashing containing a metal salt of a long chain fatty acid and or a polyacrylic acid polymer or a salt thereof, as a stable agent. lizing.

ADVANTAGES OVER THE PREVIOUS TECHNIQUE OF SPECIALTY

The liquid detergent compositions of the thixotropic aqueous solutions of the present invention overcome many of the problems of the prior art in the art related to liquid and powder detergents. Due to the addition of a small effective amount of a film-forming agent based on alumina or titanium dioxide and a polyacrylic acid polymer builder or a salt thereof, an additional rinse is not necessary and is not necessary. wipe with a cloth and dry to obtain dry, shiny dishes, glasses, bowls and kitchen utensils. The thixotropic aqueous liquid detergent composition has the additional advantages of being stable, non-sedimentary in the warehouse and quickly redispersible. The liquid compositions of the present invention are easily pourable, easy to measure and to be placed in dishwashers.

An additional and unexpected advantage of adding alumina or titanium dioxide-based anti-film agent to the detergent formulation is that titanium or aluminum dioxide inhibits the formation of brown spots in the dishwasher. The brown stain is formed by depositing iron oxides and / or manganese in the dishwasher.

Brown spotting is a particularly serious problem in areas with hard water. THE

-10alumina or titanium dioxide in the formulation acts on the iron and manganese of the washing water, preventing its deposition in the dishwasher, in the form of iron oxides and / or manganese

OBJECTIVES OF THE PRESENT INVENTION

It is an object of the present invention to provide a thixotropic aqueous liquid detergent composition for an automatic dishwasher that has better anti-film and stain properties.

It is another object of the invention to provide a thixotropic aqueous liquid detergent composition that is stable in the warehouse, easily pourable and readily dispersible in the dishwashing water.

Another object of the invention is to present a method for washing dishes, glasses, porcelain and the like, in an automatic dishwasher, using a thixotropic aqueous liquid detergent composition, in which no additional rinsing is necessary.

It is yet another object of the invention to present a method for washing dishes, glasses, porcelain and the like in an automatic washing machine, using an aqueous liquid detergent composition, whereby the plates, glasses, porcelain and the like are machine-dried without leave traces or a film.

It is yet another object of this invention to provide stable aqueous thixotropic liquid compositions, in particular automatic machine detergent compositions. dishwashing, incorporating in the aqueous suspension a small effective amount of a film-forming agent based on alumina or titanium dioxide and polyacrylic acid polymeric builder or a salt thereof.

A smaller amount of fatty acid, metal salt of a fatty acid and / or clay is also added as a thixotropic thickener, effective to inhibit the sedimentation of suspended particles and to prevent phase separation.

DESCRIBED MEMORY OF THE INVENTION

These and other objectives of the invention, which will be more easily understood from the following specification of the invention and its preferred embodiments, are achieved by incorporating in a water-based liquid detergent composition a small effective amount of an anti-film formation agent. based on alumina or tetanium dioxide and structuring of polyacrylic acid polymers or a salt thereof. The physical stability of the composition is improved by the addition of fatty acid, metal salt of a fatty acid and / or clay, as a thixotropic thickener. More particularly, in accordance with a preferred and specific embodiment of the invention, a detergent composition, usually gel type, for automatic dishwasher, in which about 0.5 to 5% of an agent is incorporated, is provided. anti-film formation based on alumina or titanium dioxide and about 2 to 14% of a polyacrylic acid polymer builder or a water-soluble salt thereof. The anti-film-forming agent based on alumina or titanium dioxide has a particle size of about 0.1 to 10 microns. Polyacrylic acid or its water-soluble salt has a molecular weight of about 500 ε 1000 000. In a preferred embodiment of the invention, an amount of a long-chain fatty acid or a metal salt of a long-chain fatty acid is added to the composition, or

any of them in admixture with an air-based thickener, sufficient to provide a thixotropic index of about 2.5 to 10 and to inhibit sedimentation of suspended particles, namely alkali metal structuring salts, etc.

In accordance with this aspect, the present invention provides an aqueous liquid detergent composition, usually of a gel type, for an automatic wool machine. tableware, having thixotropic properties, which includes, on a weight basis:

(a) 5 to 35% alkali metal tripolyphosphate;

(b) 2.5 to 40% sodium silicate;

(c) 0.5 to 5% of an anti-film forming agent based on alumina or titanium dioxide;

(d) 2 to 14% polyacrylic acid polymer builder or a salt thereof;

(e) 0 to 9% alkali metal carbonate;

(f) 0.1 to 5% of active water-dispersible organic detergent material, stable in the presence of chlorine-based bleaching agent;

(g) 0 to 5% stable foam suppressant in the presence of the chlorine-based bleaching agent;

(h) chlorine bleach compound in an amount sufficient to provide about 0.2 to 4% of available chlorine;

(i) thixotropic thickener in an amount sufficient to provide a thixotropic index of about 2.5 to 10.

(j) 2 to 8% sodium hydroxide; and (1) water to be made up.

Also related to this specific aspect, the invention features a method for washing dishes in an automatic dishwasher with an aqueous washing bath containing an effective amount of the liquid dishwasher detergent (DLAL) composition, as previously described. In accordance with this aspect of the invention, the DLAL composition can be easily poured into the dispensing cup of the automatic dishwasher, and in just a few seconds it will become thick, returning to its normal pasty state or gel-type, to stay safe inside the dispensing cup, until cutting forces such as those caused by the water jet from the dishwasher are applied again.

The invention will now be described in more detail, by means of its specific embodiments.

DLAL products, for example, from the previous disclosure but mentioned above GB 2,116,199 A and GB 2,140,450 A have rheological properties, as assessed by testing the product viscosity as a function of cutting speed.

The compositions present a higher viscosity at a low cutting speed and a lower viscosity at a high cutting viscosity, indicating the data an efficient fluidization and gelation, well within the cutting speeds existing inside the standard dishwasher. In practical terms, this means better pouring and processing characteristics, as well as less lack of tightness to the machine's dispensing cup, compared to previous liquid or gel DLA products. For applied cutting speeds corresponding to 3 to 30 rpm, the viscosities ('Brookfield') correspondingly varied from about 10,000 to 30,000 cps to about 3,000 to 7,000 cps as measured at room temperature, using a viscosi

meter LVT Brookfield after 3 minutes, using a n24 spindle. A cutting speed of 7.4 sec ^_d corresponds to about 3 rpm of the spindle. An approximate 10-fold increase in cutting speed produces a viscosity reduction of about 3 to 9 times

The compositions of the applicant's previous invention thus exhibit step fluidizations at slower and significantly significant cutting speeds. significantly higher in terms of increasing increases in cutting speed versus decreasing- increasing viscosity. This property of the DLAL products of the previous invention is summarized in terms of a thixotropic index (IT), which is the ratio of the apparent viscosity at 3 rpm and 30 rpm. The previous compositions have an IT of 2 to 10. DLAL compositions must show a quick and substantial return to the previous consistency in a resting state, when the cutting force is interrupted.

In terms of apparent viscosity, it was found that, since the viscosity at room temperature (22 ° + 1 ° C) measured on a Brookfield HATD viscometer using a No. 4 spindle at 20 rpm is less than about 20,000 cps, the The composition can be easily agitated so that a thixotropic composition can be quickly fluidized or liquefied to allow the product to be delivered via a compressible tube-shaped bottle or other convenient dispensing device.

The present invention is based on the surprising discovery that anti-film and anti-stain properties can be obtained when a small effective amount of an anti-film agent based on alumina or dioxide is added to the thixotropic aqueous liquid detergent composition. titanium and polyacrylic acid polymer builder or a salt thereof. Physical stability, that is, resistance to phase separation, sedimentation, etc., can be achieved by adding to the composition a small and effective amount of a thixotropic thickener and stabilizing agent.

X

-15 ANTI-FILM FORMING AGENTS

The materials for the film-forming agent based on alumina or titanium dioxide that can be used are easily commercialized. The alumina material that can be used as an anti-film agent is insoluble in water and has the formula A1 ₂ O ₃ . Suitable materials are sold under the trade names of Alumina Oxide C, Degussa and Catapal D, Vista. A preferred alumina material is __.

The particle size of the alumina and titanium dioxide material that is used is important to achieve the desired anti-film properties.

The alumina or titanium dioxide particles that are used are finely divided and can have a size of about 0.10 to 10 microns, preferably 0.50 to 8 microns and more preferably about 1.0 to 5.0 microns . Alumina and titanium dioxide particles of this size and in the amount used here are not abrasive.

The finely divided particles of the alumina or titanium dioxide material in the dishwashing bath have the action of coagulating protein particles in the form of particles and keeping them in suspension, and the polyacrylic acid polymer or its salt acts as an agerite. anti-formation, to prevent them from settling on the washed glasses and dishes.

Without wishing to limit the invention in any way, there is a theory that anti-film forming agents based on alumina and titanium dioxide work as follows.

-16The glass surface of the cups contains negative charges on their surface through the Si-O connections. Normally, oxygen atoms carry these charges. These negatively charged ions are intended to be attracted to the positively charged particles, thus forming an artificial layer of dust. This protective layer will repel normal food soiling and increase the anti-fedeposition property of the automatic dishwashing detergent. The alumina and titanium dioxide particles, respectively, will generate positively charged particles that will bond to the surface of the cups to form the layer of artificial dirt that will prevent the formation of a film.

The amount of film-forming agent based on alumina or titanium dioxide that can be used to achieve the desired improvement in the formation of film and stains will depend on the hardness of the water, the active detergent compound of the inorganic salts and other DLA ingredients. The anti-film-forming agent based on aluminum or titanium dioxide is particularly effective in hard washing water of, for example, 300 ppm hardness or more. The amount of alumina or titanium dioxide-based anti-film agent used can be about 0.5 to 5%, preferably about 1 to 4%, and more preferably about 1.5 to 3%, by weight, based on the weight of the total composition. Alumina and titanium dioxide can each be used alone or can be used mixed together and / or mixed with a silica-based film-forming agent. When anti-film agents are used mixed together, the weight percent amounts previously mentioned are the total for the ingredients in the mixture.

-V ..

-17POLYMERIC POLYACRYLIC ACID AND ITS SALTS

Polyacrylic acid polymers and their salts, which can be used, are generally available and are briefly described below.

Polymers of polyacrylic acid and their salts, which can be used, consist of water-soluble polymers of low molecular weight having the formula ^R 1 ^R 2 —C —CR _o COOM 3 n where R ^, R ₂ and Rg can be the same or different and can be hydrogen, lower C ^-C ^ alkyl, or combinations thereof. The value of n is 5 to 1000, preferably 10 to 500, and more preferably 20 to 100. M represents hydrogen or an alkali metal such as sodium or potassium. The preferred substituent for M is sodium.

Preferred R ^, R ₂ and Rg groups are hydrogen, methyl, ethyl and propyl. The preferred acrylic acid monomer is one in which R ^ to Rg are hydrogen, e.g., acrylic acid, or where R ^ and Rg are hydrogen and ^R 2 is methyl, e.g., acrylic acid methyl monomer.

The degree of polymerization, that is, the value of n, is generally determined by the limit compatible with the polymer's solubility in water. The terminal or end groups of the polymer are not critical and can be H, OH, CH ₃ or a low molecular weight hydrocarbon.

Polyacrylic acid polymers and their salts can have a molecular weight of 500 or 1000 to 100,000, preferably 1,500 to 50,000 and most preferably 2,000 to 10,000.

The specific polyacrylic acid polymers that can be used include Acrysol LMW acrylic acid polymers from Rohn and Haas, namely Acrysol LMW-45NX, a neutralized sodium salt, which has a molecular weight of about 4500 and Acrysol LMW-20NX, a neutralized sodium salt, which has a molecular weight of about 2,000.

Low molecular weight acrylic acid polymers can, for example, have a molecular weight of about 1000 to 10,000. Another polyacrylic acid polymer that can be used is Alcosperse 110 (from Alco), which is a sodium salt. of an organic polycarboxylate and which has a molecular weight of about 100000.

The foregoing polyacrylic acid polymers and their salts can be made by processes known in the art, see, for example, U.S. Patent 4.20 3,858.

The amount of polyacrylic acid polymer builder or a salt thereof, which can be used to achieve the desired improvement in anti-film and anti-stain properties, will depend on the hardness of the water, active detergent compound, inorganic salts and other DLA ingredients.

The polyester acid builder

-X

-19 acrylic or a salt thereof is particularly effective in reducing the formation of stains in hard water of at least 300 ppm hardness or more.

In general, the amounts of the polyacrylic acid limer powder or a salt thereof, which can be used, are in the range of about 2.0 to 14%, preferably of about 3.0 to 12%, preferably needed about 4 to 10%.

THIXOTROPIC THICKENERS

Thixotropic thickeners or suspending agents, which can be used according to the present invention to provide the aqueous medium with thixotropic properties, can be organic, for example, fatty acids or polyvalent metal salts of fatty acids or inorganic clay materials that forms colloids. Thixotropic thickeners must be stable at high alkalinity and stable in the presence of chlorine-based bleaching compounds, such as sodium hypochlorite. Preferred thixotropic thickeners consist of fatty acids, polyvalent metal salts of fatty acids and inorganic clays, which form colloids of the types smithite and / or atapulgite. The amount of thixotropic thickener used will depend on the specific thickener used, but enough thickener is added to the formulation to provide the composition with a thixotropic index of about 2.5 to 10.

The preferred thixotropic thickeners of fatty acids are aliphatic-superior-fatty-mono-carboxylic acids, having from about 8 to about 22 carbon atoms, more preferably from about 10 to 20 atoms of

-20 carbon, and most preferably about 12 to 18 carbon atoms, including the carbon atom of the fatty acid carboxyl group. The aliphatic radical can be saturated or unsaturated and can be linear or branched. Straight chain saturated fatty acids are preferred. Mixtures of fatty acids can be used, such as those derived from natural sources, namely coconut fatty acid, tallow fatty acid, soy fatty acid, etc., or from synthetic sources, resulting from industrial manufacturing processes.

Thus, examples of fatty acids that can be used as thickeners include, for example, decanoic acid, lauric acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, oleic acid, licosanoic acid, tallow fatty acid, fatty acid coconut oil, soy fatty acid and mixtures of these acids are preferred stearic acid and mixed fatty acids, e.g. , coconut fatty acid.

The amount of fatty acid thickener required to achieve the desired values of thixotropy and physical stability will depend on factors such as the nature of the fatty acid, active detergent compound, inorganic i .. salts, in particular TPF, other DLAL ingredients, as well as conditions advance storage and transportation.

In general, however, the amount of the fatty acid thixotropic agent that can be used is in the range of about 0.03 to 0.5%, preferably about 0.02 to 0, 2%, most preferably from about 0.05 to 0.15%, providing the desired properties of long-term stability and absence of phase separation.

The polyvalent metal salts of the above fatty acids can also be used in the present invention as thixotropic thickening agents. The thixotropic thickeners of suitable metal salts are disclosed

-21in the previous order Series n2. 903,924, deposited on September 5, 1986, in the name of Drapier et al., Which is incorporated herein by reference.

Preferred metals are polyvalent metals such as magnesium, calcium, aluminum and zinc.

In general, metals can be present in the bivalent to pentavalent state. Preferably, the metal salts are used in their higher oxidation states. It is evident that, for DLAL compositions, as well as any other applications in which the composition of the invention is or may come into contact with articles used for the handling, storage or service of food products or that may otherwise be used. be in contact with or consumed by people or animals, the metal salt should be selected taking into account the toxicity of the metal. For this purpose, calcium and magnesium salts are particularly preferred, as especially safe food additives.

Many of these metal salts are marketed. For example, aluminum salts are in the triacid form, for example, aluminum stearate such as aluminum tristearate, Al (C ^ -H ^^ COOJ ^ · Monoacid salts, for example, aluminum monostearate, Al (OH) ₂ (C ^ H ^^ COO) and diacid salts, eg aluminum di-stearte, Al (OHjC- ^ H ^ j-COO ^ and mixtures of two or three of the salts may be used of mono-, di- and tri-acids for those metals, eg Al, with valences of +3, and mixtures of the mono- and di-acid salts for those metals, eg Zn, can be used , with valences of -1- 2. It is more preferable that the diacids of metals with valences of +2 and the triacids of metals with valences of +3, the tetraacids of metals with valence of +4 and the metal pentaacids with valences of + 5, are used in predominant amounts, for example at least 30%, preferably at least

-22>. \ '

50%, most preferably 80 to 100% of the total metal salt should be in its highest possible oxidation state, that is, each of the possible valence sites is occupied by a fatty acid residue.

Metal salts, as mentioned above, are generally marketed, but can be produced by, for example, saponification of a fatty acid, eg, animal fat, stearic acid, etc., or corresponding fatty acid ester followed treatment with a polyvalent metal hydroxide or oxide, for example, in the case of aluminum salt, with alum, alumina, etc.

Calcium stearate, that is, calcium distearate, magnesium stearate, that is, magnesium distearate, aluminum stearate, that is, aluminum tristearate and zinc stearate, that is, zinc distearate, are the preferred stabilizers polyvalent salts of fatty acids. Metal salts of mixed fatty acids, in particular those of natural derivation, eg coconut acid, as well as mixed fatty acids resulting from the commercial manufacturing process, are also advantageously used as an inexpensive but effective source of long chain fatty acid.

The amount of fatty acid salt stabilizers needed to achieve the desired increase in physical stability will depend on factors such as the nature of the fatty acid salt, the nature and quantity of the thixotropic agent, active detergent compound, inorganic salts, in particular TPF, other DLAL ingredients, as well as advance storage and transport conditions.

In general, however, amounts of the polyvalent fatty acid metal salt stabilizing agents in the range of about 0.02 to 1%, preferably about 0.06 to 0.8%, most preferably about 0 , 0 8

23 to 0.4%, provide long-term stability and absence of phase separation at rest or during transport at both low and high temperatures, as required for a commercially acceptable product.

Conventional clay-based inorganic thixotropic thickeners can also be used in the present invention. Clay thickeners can be used in small amounts in combination with fatty acid thickeners or in combination with polyvalent fatty acid metal salt thickeners. Clay-based thickeners, however, can be used on their own, as thixotropic thickeners.

Preferred clay thickeners are inorganic clays that form colloids, of the types smithite and / or atapulgite.

Esmectid clays include montmorillonite (bentonite), hectorite, atapulgite, emmetite, saponite and the like. Montmorillonite clays are preferred and are marketed under names such as -Thixogel (Trademark) nQ.l and Gelwhite (Trademark) GP, H, etc., by the Georgia Kaolin Company; and Eccagum (Trademark) GP, H, etc., by Luthern Clay Products. Atapulgite clays include materials marketed under the name of Attgel (Trademark), that is, Attgel 40, Attgel 50 and Attgel 150 from Engelhard Minerals and Chemicals Corporation. Mixtures of the smectite and atapulgite types in weight ratios, from 4: 1 to 1: 5, are also useful for this purpose. Thickening or suspending agents of the above types are well known in the art and are described, for example, in U.S. Patent No. 3,985,668 above. Polishing or abrasive agents should be avoided in DLAL compositions, as they can damage the surface of fine china, crystals and the like.

V ·

-24When used in combination with fatty acids or polyvalent metal salts of fatty acids, thixotropic thickeners based on clay are used in quantities of 0.1 to 3%, preferably 0.1 to 2.5% and more preferably in amounts of 0.1 to 2%.

When using only thixotropic thickeners based on clay with the thixotropic thickener, they can be used in amounts of about 1.5 to 8%, preferably 2 to 5%, by weight, of the formulation.

In general, the effectiveness of DLAL is directly related to (a) levels of available chlorine;

(b) alkalinity;

(c) washing name solubility; and (d) foam inhibition. It is preferred, for this purpose, that the pH of the DLAL composition is at least about 9.5, more preferably about 10.5 to 13.5 and, in the most preferred form, of all, at least about 11, 5. At relatively lower pH values. The DLAL product is too viscous, that is, similar to a solid, and does not easily fluidize to the levels of cutting forces created inside the dispensing cup, under normal machine operating conditions. The addition of NaOH is thus often necessary to increase the pH to the levels of the above forms and to increase the flow properties. The presence of carbonate is also often necessary as it acts as a buffer solution, helping to maintain the desired pH level. However, excess carbonate should be avoided, as it can cause the formation of needle-like carbonate crystals, thereby impairing the stability, thixotropic and / or detergency of the DLAL product, as well as the dispersibility of the product, for example , bottles in the shape of a compressible tube. Caustic soda (NaOH) still has the

ν

-25 function to neutralize the foam suppressor of phosphoric or phosphonic acid ester, when present. Typical amounts of about 0.5 to 3% by weight of NaOH and about 2 to 9% by weight of sodium carbonate in the DLAL composition are typical, although it should be noted that sufficient alkalinity can be provided by NaTPF and preferred sodium silicate.

NaTPF can be used in the DLAL composition in a range of about 8 to 35% by weight, preferably about 20 to 30% by weight, and should preferably be free of heavy metal, which tends to decompose or inactivate sodium hypochlorite and other chlorine-based bleaching compounds. NaTPF can be anhydrous or hydrated including the stable hexahydrate with a hydration degree of 6 corresponding to about 18% by weight of water or more. In reality, given the stability of the hexahydrate, the presence of some hydration water is highly effective, serving, as is thought, to form seeds of the stable hexahydrate that speed up the hydration and solubilization of the remaining NaTPF particles. If only hexahydrate is used, the detergent product may be too liquid. Conversely, if only anhydrous NaTPF is used, the product may, in some cases, be too thick and therefore unsuitable. Especially preferred DLAL compositions are obtained, for example, when using a weight ratio of 0.5: 1 to 2: 1 of anhydrous NaTPF to hexahydrate, with values of about 1: 1 being particularly preferred.

Foam inhibition is important to increase the efficiency of the dishwasher and to reduce to a minimum the destabilizing effects that can occur due to the presence of excess foam inside the machine during use.

-26 The foam can be sufficiently reduced by proper selection of the type and / or amount of active detergent material, the main foam-producing component. The degree of foam is also somewhat dependent on the hardness of the washing water in the machine, and an appropriate adjustment of the proportions of NaTPF, which has a water softening effect, can contribute to providing the desired degree of foam inhibition. However, it is generally preferable to include a stable foam suppressant or inhibitor in the presence of the chlorine-based bleaching agent. The phosphonic acid alkyl esters of the formula are particularly effective

HO — P --- R

OR marketed, for example, by BASF-Wyandotte (PCUK-PAE) and, in particular, the acidic phosphate esters of the formula

HO — P --- OR

OR marketed, for example, by Hooker (SAP) and Knapsack (LPK _No. -158), where one or both R groups in each type of ester can independently represent an alkyl group ^^ 2-20 '

Mixtures of the two types, or of any other types stable in the presence of the chlorine-based bleaching agent, or mixtures of mono and diesters of the same type, may be used. Especially preferred is a mixture of mono esters and dialkyl lytic ^c qg_qg particular acid monostearyl phosphate / distearyl acid phosphates 1.2 / 1 (Knapsack). When used in the foam suppressor position, proportions of 0.01 to 5% by weight, preferably 0.1 to 5% by weight, especially about 0.1 to 0.5% by weight, are typical, the weight ratio of active detergent component (d) to foam suppressor (e) generally varies from about 10: 1 to 1: 1 and preferably about 4: 1 to 1: 1. Other foam suppressors that can be used include, for example, the known silicones.

Although any chlorine-based bleaching compound can be used in the compositions of this invention such as dichloroisocyanurate, dichloro-dimethylhydantoin, or chlorinated TSF, alkali metal, eg potassium, lithium, magnesium and in special sodium hypochlorite. The composition should contain enough chlorine bleaching compound to provide about 0.2 to 4.0% by weight of available chlorine, as determined, for example, by acidifying 100 parts of the composition with excess acid hydrochloric. A solution containing about 0.2 to 4.0% by weight of sodium hypochlorite contains or provides almost the same percentage of available chlorine. A solution containing about 0.8 to 1.6% by weight of sodium hypochlorite contains about 1.6% by weight of available chlorine and is especially preferred. For example, a solution of about 11 to about 13% sodium chlorite (NaOCl) of advantageously available in quantities of about 3 to 20%, preferably about 7 to 12%.

Sodium silicate, which gives hardness and protection to hard surfaces, such as contorin and fine porcelain enamel, is used in an amount

-28 which ranges from about 2.5 to 40% by weight, preferably about 10 to 35% by weight, in the composition. At the highest levels indicated here, for example, at levels above about 10% by weight, the silicate also provides a greater anti-staining action. Sodium silicate is generally added in the form of an aqueous solution, preferably having a Na ₂ ©: SiO ₂ ratio of about 1: 2.2 to 1: 2.8, for example, 1: 2, 4. Most of the other components of the composition, in particular NaOH, sodium hypochlorite and foam suppressant can also be added in the form of an aqueous dispersion or solution.

The detergent active material useful for this purpose must be stable in the presence of chlorine-based bleaching agent, in particular hypochlorite-based bleaching agent, and those of organic, aionic water-dispersible surfactants are preferred. , amine oxide, phosphine oxide, sulfoxide or betaine, with the anionics mentioned first being most preferred. They are used in amounts ranging from about 0.1 to 5%. preferably, about 0.3 to 2.0%. Particularly preferred surfactants for this purpose are the mono- and / or di- (Οθ - ^) alkyl-diphenyl-oxide-mono and / or straight or branched alkali metal disulfates, marketed, for example, with DOWFAX (Trademark) 3B2 and DOWFAX 2A.1.

In addition, the surfactant must be compatible with the other ingredients of the composition. Other suitable surfactants include primary alkyl sulfates, alkyl sulfonates, alkyl aryl sulfonates and sec-alkyl sulfates. Examples include alkyl Cio_i8 ° ^ io ~ ^s sulfates such as sodium dodecyl sulfate and sodium sulphate and sodium tallow alcohol; alkaneC. _The lu - x sulfonates

Sodium -29de such as hexadecyl-l-sulphonate and sodium ^C 12 alkyl ig ^- ^ ^{'enzeno su} ~ -'- sodium ^sulfonates such as sodium dodecyl benzene sulfonates. The corresponding potassium salts can also be used.

Like other suitable surfactants or detergents, amine oxide surfactants are typically of the structure R ₂ R ¹ NO, where each R represents a lower alkyl group, for example, methyl, and R ¹ represents a long-chain alkyl group having from 22 carbon atoms, for example a lauryl, myristyl, palmityl or cetyl group. Instead of an amine oxide, a corresponding surfactant of 1 i phosphine R ₂ R PO or RR SO sulfoxide can be used. Betaine surfactants are typically of the structure R ₂ R N-RCOO, where each R represents a lower alkylene group, having 1 to 5 carbon atoms. Specific examples of these surfactants are lauryl dimethyl amine oxide, myristyl dimethylamine oxide, the corresponding phosphine oxides and sulfoxides and the corresponding betaines, including dodecyl dimethylammonium acetate, tetradecyldiethyl ammonium pentanoate, hexaneate hexadecyl-dimethyl-ammonium and the like. For biodepradability effects, the alkyl groups in these surfactants must be linear and these compounds are preferred. Surfactants of the above type, all well known in the art, are described, for example, in US Patents 3,985,668 and 4,271,030.

The amount of water contained in these compositions must, of course, neither be so high as to produce an undesirably low and fluid viscosity nor so low as to produce an unduly high viscosity and poor fluidity, in both cases the thixotropic properties being reduced or destroyed. Such an amount is easily determined by routine experiments in any

-30 ^? · Σ-_

specific case, generally ranging from about 25 to 75% by weight, preferably about 50 to 65% by weight. The water should preferably be deionized or soft. These amounts of water in the composition include water added as parts of the liquid solutions of other ingredients, but do not include bound water, for example that contained in NaTPF hexahydrate.

Other conventional ingredients, generally less than about 3% by weight, namely perfume, hydrotropic agents such as benzene, toluene, xylene and sodium cumene sulfonates, preservatives, dyes and pigments and the like, can be included in these heading items. evidently stable in the presence of the chlorine-based bleaching compound and high alkalinity (properties of all components). Chlorinated phthalocyanines and aluminosilicate polysulphides which provide pleasant green and blue colors, respectively, are especially preferred as coloring agents.

The liquid DLA compositions of this invention are easily used in a known manner to wash dishes, glasses, cups, other kitchen utensils and the like - in an automatic dishwasher, equipped with a suitable detergent dispensing device, in an aqueous washing bath containing an effective amount of with position.

In a preferred embodiment of the invention, the liquid dishwashing liquid detergent composition is formulated using the ingredients mentioned below.

Percentage

-31Components by weight

Alkali metal tripolyphosphate 10-25

Sodium silicate (47.5%) 15-40

Anti-film-forming agent based on alumina or titanium dioxide 1-4

Polyacrylic acid polymer or salt 3-12

Alkali metal carbonate (anhydrous) 2-8

Active Material Organic detergent

Water-dispersible, stable in the presence of chlorine-based bleaching agent 0.5-3

Stable foam suppressor in the presence of chlorine bleaching agent 0.10-3

0.2-4 Chlorine Bleaching Compound

Thixotropic Fatty Acid Thickener 0.0 3-o, 5

Sodium Hydroxide (50%) 2-6

Water to Make Up

The thixotropic aqueous automatic dishwashing detergent compositions of the present invention may contain conventional additives. The formulations can be prepared with commercially available powdered solid builders and / or the ingredients can be mixed and the formulations ground to a size

\, desired particle.

The invention can be practiced in several ways and a series of specific embodiments will be described to illustrate the invention with reference to the accompanying examples.

All amounts and proportions referred to herein are percentages by weight of the composition, unless otherwise specified.

the present invention is further illustrated by the following examples:

-32EXAMPLE 1

A thixotropic aqueous liquid detergent composition for automatic dishwashing is formulated from the following ingredients in the amounts indicated.

Percentage

Component by weight Deionized water 31.04 Foam suppressor (1) Knapsack LPKN-158 ^k ' 0.16 Sodium hydroxide (50%) 2.34 Sodium carbonate (anhydrous) 4.88

-33 Sodium tripolyphosphate (anhydrous) 11.70

Sodium tripolyphosphate (hexahydrate) 11.70

Anti-film-forming agent (2) based on alumina '2.5

Structuring of sodium polyacrylate polymers ³ ) (IA) 8.00

Clay Gel White H 1.22

0.09 Aluminum stearate thixotropic thickener

Surfactant

Dowfax 3B-2 ⁽⁴⁾ 0.78

Sodium hypochlorite (11%) 8.78

Sodium silicate (1 / 2.23-43.5%) 16.81

Graphtol Green Color 0,00 2

100, 00 2 (1) Mixture of mono and distearyl (C ^ gc ^ _g ) alkyl phosphonic acid esters, molar ratio 1: 1.3 (2) Aluminumoxid C (Degussa), having a particle size of about 4 micron (3) Alcosperse 149, about 2000 mw, marketed as a 40% solution (4) mono and didecyl-diphenyl-ether-disulfonate / 45% solution).

The ingredients are mixed following the same pending and commonly assigned order process, Series No. 903,924, filed on September 5, 1986, which is incorporated herein by reference.

(The ingredients are added to the water generally in the order indicated under gentle stirring until a homogeneous mixture is obtained). The formulation is tested by washing glasses and plates at a temperature of approx.

50 ° C (120 ° F) in hard water (300 ppm hardness) in an automatic dishwasher and it was found that the clean, dry dishes had no apparent film and only very few evident stains.

EXAMPLE 2

To demonstrate the effect of adding the film-forming agent based on alumina or titanium dioxide, formulations are prepared with and without film-forming agent based on alumina or titanium dioxide, which are compared with a commercially available detergent powder composition.

- 'Ο - -35- containing the following The compositions are formulated Ingredients. THE B Ç D AND Dioxide Without anti- Alumina/ Alumina/ Dioxide Titanium/ formation without Titanium/ without of film Polyacrylate Components Polyacrylate Polyacrylate Polyacrylate Polyacrylat3 Deionized water 31.04 Suppressor foam Knapsack 39.04 31.04 39, 04 33.54 LPKN-158 0.16 Sodium hydroxide 0.16 0.16 0.16 0.16 (50%) 2.34 Sodium carbonate 2.34 2.34 2.34 2.34 (anhydrous) 4.88 Sodium tripolyphosphate 4.88 4.88 4.88 4.88 (anhydrous) 11.70 Sodium tripolyphosphate 11.70 11.70 11.70 11.70 (hexahydrate) 11.70 Anti- 11.70 11.70 11.70 11.70 -formation 2.50 of film Sodium Polyacrylate Polymer 2.50 2.50 2.50 2.50 (I.A.) 8.00 Clay - - - 8.00 8.00 White H Gel 1.22 Stearate thixotropic thickener 1.22 1.22 1.22 1.22 aluminum 0, 0 9 0, 0 9 0, 0 9 0.09 0.09

-36Surfactant

Dowfax 3B-2 0.78 0.78 0.78 0.78 0.78 Sodium hypochlorite (11%) 8.78 8.78 8.78 8.78 8.78 Sodium silicate (1 / 2.23-43.5%) 16, 81 16.81 16, 81 16.81 16, 81 100.00 100.00 100.00 100.00 100.00

(1)

Alcosperse 149.

The ingredients are mixed in a conventional manner or can be mixed according to the equally pending and common assignment process, Series No. 2,903,924, filed on September 5, 1986, which is incorporated herein by reference. (The ingredients are added to the water generally in the order indicated and stirred gently until a homogeneous mixture is obtained). The formulation is tested by washing glass cups at approximately 50 ° C (120 ° F) in hard water (300 ppm hardness).

The previous five formulations res (A), (B), (C), (D) and (E) have been tested and compared with a commercially available powder detergent formulation for the automatic dishwasher (F). The formulations were tested in a Kenmore automatic dishwasher using the process described in ASTMD 3566-79, with the exception of only four washing cycles. The evaluation of the formation of films and stains is done according to the following scales:

-37 Film rating scale

1. Great, no apparent film

2. Slight film formation, becoming apparent

3. Visible film, increasing

4. Continuous increase of significant film

5. Film formation becoming excessive

6. High and excessive film formation

7. Continuous increase of excessive film

Scale of stain formation

A - great- without stains

B - Very few apparent stains

C - Distinct

D - Significant coverage, approximately 50% the results obtained are shown in Table 1 below.

i

-38Formulation

TABLE 1

Evaluation

Stain Film (A) Alumina / Polyacrylate B (B) Alumina / Without Polyacrylate BC (C) Titanium Dioxide / Polyacrylate B (D) Titanium Dioxide / Without Polyacrylate BC (E) Without Anti-film-forming Agent / Polyacrylate BC ( F) Commercial powder detergent BC

1-2

2-3

2-3

3-4

3-4

Products (A) and (C) left no stains on the glasses, with the exception of one or two brands and were classified with (Β). The product (E) without film antiforming agent left a significant uniform film B-C, 3-4 in the cups. However, a significant improvement in the formation of stains and film has been obtained with formulations containing both anti-film agent and polyacrylate.

ι

EXAMPLE 3

-39A thixotropic aqueous liquid detergent composition for automatic dishwashing is formulated from the following ingredients in the amounts indicated.

Component

Percentage by weight

Deionized water

Foam suppressor

LPKN-158 Knapsack

Sodium hydroxide (50%)

Sodium carbonate (anhydrous)

Sodium tripolyphosphate (anhydrous)

Sodium tripolyphosphate (hexahydrate)

Alumina-based anti-film agent

Thixotropic thickener of stearic acid

Sodium polyacrylate (MW 2000), 8, 16

2.34

4.88

11.70

11.70

2.50

Dowfax surfactant 3B-2, 10

6.00, 60

-40Sodium hypochlorite (11%)

Sodium silicate (1 / 2.4-47.5%)

Graphitol Green

7.61

25.60, 01 10 0; 00

The ingredients are added to the water generally in the order indicated and stirred gently until a homogeneous mixture is obtained. The formulation is tested by washing glasses at approx. 55 ° C (130 ° F) in hard water (300 ppm hard) in an automatic dishwasher. It was found that the washed and dried glasses had no apparent film and only very few evident stains.

The thixotropic aqueous liquid detergent compositions of the present invention have the best anti-film properties. The invention is not limited to the previous disclosure and Examples which are given for illustration only. The invention must be interpreted in accordance with the appended claims.

Claims (14)

CLAIMS wool. - Process for the preparation of a thixotropic aqueous liquid detergent composition, of a gel type, for automatic dishwashing, characterized in that water is included in the said composition; at least one ingredient selected from the group consisting of organic detergent, chlorine bleaching agent, detergent builder, sequestering agent, foam inhibitors and mixtures thereof; from about 0.5 to 5% of an alumina or titanium dioxide or a mixture thereof, as an anti-film agent; and an amount of a thixotropic thickening agent sufficient to provide a thixotropic index of about 2.5 to 10. 2nd. Process according to claim 1, characterized in that the amount of anti-film forming agent based on alumina or titanium dioxide is in the range of about 1 to 4%. 3rd. - Process for the preparation of an aqueous liquid thixotropic composition for an automatic dishwasher, characterized in that it is included in the said composition, by weight, in approximate values: (a) 5 to 35% of detergent builder; (b) 2.5 to 40% sodium silicate; (c) 0.5 to 5% of an anti-film forming agent based on alumina or titanium dioxide, having a particle size of about 0.1 to 10 microns; -42 (d) 0 to 9%. alkanyl metal carbonate; (e) 0.1 to 5% active water-dispersible organic detergent material, stable in the presence of chlorine-based bleaching agent; (f) 0 to 5% stable foam suppressant in the presence of the chlorine-based bleaching agent; (g) chlorine bleaching compound, in a quanti. enough to provide about 0.2 to 4% of available cl <3 ro; (h) thixotropic thickener in an amount sufficient to provide a thixotropic index of about 2.5 to 10; (i) 0 to 8% sodium hydroxide; (j) water to be made up. 4th. Process according to claim 3, characterized in that the thixotropic thickener consists of a long chain fatty acid, in an amount of about 0, 0 to 0, 5%. 52. The method of claim 3, wherein the thixotropic thickener consists of a polyvalent metal salt of a long chain fatty acid in an amount of about 0.02 to 1.0%. -43.X χ ’ 6th. Process according to claim 4, characterized in that a thixotropic thickener based on clay is also included in said composition, in an amount of about 0.1 to 3.0%. 7§. Process according to claim 5, characterized in that a thixotropic thickener based on clay is also included in said composition, in an amount of about 0.1 to 3.0%. 8th. Process according to claim 3, characterized in that the anti-film forming agent based on alumina or titanium dioxide has a particle size of about 0.5 to 8.0 microns. 9 and. - Process for the preparation of an aqueous liquid thixotropic composition for automatic dishwashing machines, characterized in that it is included in the said composition, by weight, in approximate values: (a) 5 to 35% alkali metal tripolyphosphate; (b) 2.5 to 40% sodium silicate; (c) 1 to 4% of an anti-film forming agent based on alumina or titanium dioxide, having a particle size of about 0.5 to 8.0 microns; (d) 0 to 9% alkali metal carbonate; (e) 0.1 to 5% of active water-dispersible organic detergent material, stable in the presence of chlorine bleaching agent; (f) 0 to 5% stable foam suppressant in the presence of the chlorine-based bleaching agent; (g) chlorine bleach compound in an amount | enough to supply about 0.2 to 4% of available chlorine; (h) a thixotropic thickener in an amount sufficient to provide a thixotropic index of about 2.5 a) ¹⁰ '(i) 0 to 8% sodium hydroxide; and (j) water to be made up. 10th. Process according to claim 8, characterized in that the silica-based film-forming agent contains about 0.1 to 5% alumina, based on the weight of the silica. llã. Process according to claim 8, characterized in that the alumina-based anti-film agent has a particle size of about 1 to 5 microns. 12th. Process according to claim 8, characterized in that the anti-film forming agent based on titanium dioxide has a particle size of about 1 to 5 microns. -4513. Process according to claim 8, characterized in that the thixotropic thickener consists of a long-chain fatty acid, with the C ₂ q carbon atoms, in an amount of about 0.03 to 0.20%. 14th. - Process according to claim 8, wherein the thixotropic thickener consist of a salt of polyvalent metal fatty acid ca hate long, and C _lg C _2Q carbon atoms, in an amount from about 0 06 to 0, 8%. 15th. Process according to claim 14, characterized in that the polyvalent metal is aluminum, calcium, zinc or magnesium. 16 ^. Process according to claim 13, characterized in that a thixotropic thickener based on clay is also included in said composition, in an amount of about 0.1 to 2.5%. -4617ã. Process according to claim 14, characterized in that a thixotropic thickener in an amount of about 0.1 to 2.5% is further included in said composition.