LU87356A1 - THIXOTROPIC LIQUID COMPOSITIONS FOR AUTOMATIC DISHWASHING AND METHODS OF USE THEREOF - Google Patents

Description

88 / B 52 781 Q7 7 R ß GRAND-DUCHY OF LUXEMBOURG *

Patent No ..... Q ...... / .......... M .......... U. , ^, ψ & ψ & ζ, Minister of ...... 39 ssoteis-a 1988 SBg d = rÉ = onomi = et des Classes Moyennes t-v j, Kœ Intellectual Property Service _Z_ 0¾¾) LUXEMBOURG '

Patent Application -------------------------------- (1) I. Request

The so-called company: COLGATE-PALMOLIVE COMPANY, 300 Park Avenue. * ------------------------------------------------- ---------------------------------------------------------- ------------------------------------- “------------ ---------------------------- \ 2) ........ NEW YORK. NY ..... 10022 ________ (United States of America), represented _______________ ....... p.ax ...... MQn.s.ieur ...... Jacque.s .... jde. „Mu.y.ser ...... ag ± s.eant .._ eu _ .. qual.ité __... d.e _______________________________________ ........ agent___________________________________________________________________________________________________________________________________________________ (3) deposit) ce .. .... Y.ing ± -neuf ...... sep.t..e.mh.r.e _..... 19..Q..Û ........ q. uat.re = vin.gt ...... eight .................................... .......... (4) at .......... 1.5 ..................... hours, at the Ministry of Economy and the Middle Classes, in Luxembourg: 1. the present request for obtaining a patent for invention concerning: "Compositionsliquidesthixotropes ...... pour le lavage __ ^ (5) .... ........... automatic ...... from ....... the ...... dishes ...... and ...... their .. .... procedures ....... of use ........

2. description in language ............................................ ........................ of the invention in triplicate; 3. ................. /, ............................. ..................... drawing boards, in triplicate; 4. the receipt of the taxes paid to the Luxembourg Registration Office on ....?. § ...... September ..... 1988 ..........

5. the delegation of power, dated ......................................... .................................................. ..................... the............................ .................................................. ...........................; 6. the successor document (authorization); declares (s) assuming responsibility for this declaration, that the inventor (s) is (are): (6) ......... r ....... Fahim .. .... (J .......... AHMED, ......... 46 ....... Wetherhill Way, DAYTON r ...... New Jersey .. ............._..........

.......................(.United States of America.)..... .................................................. .................................................. .............................................

........-...... Charles E. BUCK, 3 Lockward Road. CALDWELL, New Jersey__________ _______________________ (United States of America) ___________________________________________________________________________________________________________________________________ claims (s) for the above patent application the priority of one (s) application (s) of (7) ......... patent ___________________________________________________________________________________________ filed ( s) in (8) in the United States ....... of America on (9) September 29, 1987___________________________________________________________________________________________________________________________ under N ° (10) ______ 1.Q..2 ....... 205 ._______________________________________________________________________________________________________________________ „ in the name of (he) s ...... inve.ntsnr.s ___________________________________________________________________________________________________________________________________________________ elect (elect) domicile for him / her and, if designated, for his / her representative, in Luxembourg________________ ________________________________________________ ......... 3 5, Boulevard Royal___________________________________________________________________________________________________________________________________ (12) seeks (s) the grant of a patent for the invention for the subject described and represented in the abovementioned appendices, with deferment of this grant to § .________________________________________________________________________________________________________________________month. (13) ^ HE ^^ pu & dut / agent: _____________________________________________________________________________________________________________________________________________________________________________________________________________________________ (14) -verbal de Dépôt

The above-mentioned application for avenon patent was filed with the Ministry of the Economy and the Middle Classes, Department of Intellectual Property in Luxembourg, dated: September 29, 1988 ^ j. fi V \ Pr. the Minister of the Economy and the Middle Classes, 1 ^ Le chef du serv ^ l Intellectual property, A 68007_ NSW. _ /] / _ (1) if applicable "Request for certificate of addition to the main patent, at the main patent application Nodu ............” - (2) enter last name, first name, profession.

address of the applicant, when the applicant is an individual or corporate name, legal form, address of the head office, when the applicant is a legal person - (3) enter (AAT \ last name, first name, address of professional representative, counsel in industrial property, with special powers, if applicable: "represented by ........... acting as an agent" J, S - (4) date of filing in all letters - (5) title of invention - (6) enter the names, first names, addresses of the inventors or the indication "(see) separate designation (will follow)", when the desl · 88 / B-52 781

CLAIM OF PRIORITY

of the BK patent application / utility model IN THE UNITED STATES OF AMERICA_

SEPTEMBER 29, 1987 (No. 102 205) Brief Description filed in support of a request for

PATENT

at

Luxembourg

in the name of: COLGATE-PALMOLIVE COMPANY

NEW YORK, N.Y. 10022 (United States of America)

For: "Thixotropic liquid compositions for automatic dishwashing and methods of using them."

Thixotropic liquid compositions for automatic dishwashing and methods of using them.

The present invention relates to a thixotropic aqueous liquid detergent composition for automatic dishwashing, which has improved anti-veiling properties, and to a method of using the detergent composition for cleaning plates, glasses, porcelain, etc. The dishwashing composition contains silica, as an anti-veil agent, adjuvant mineral detergents, a chlorine bleach, a detergent stable to the bleach and a thickener thixotropic.

The dishwashing detergent composition according to the present invention reduces the formation of haze on plates, glasses, wool, etc., especially in hard water, and remains stable against phase separation.

More particularly, the invention relates to the use of silica as an anti-veil agent in aqueous thixotropic liquid detergent compositions for washing dishes in order to reduce the formation of haze.

Detergent compositions do not require added rinse aid and are storage stable, do not settle, are

, I

2 lashes to redisperse and are easy to pour.

The present invention also relates to a thixotropic aqueous suspension providing improved physical stability. The invention relates to the use of long chain fatty acids / metal salts of fatty acids and clay as thixotropic agents to form stable liquid gel-like suspensions which are suitable for use as liquid detergent compositions for auto-XO matt dishwasher.

The present invention relates in particular to aqueous liquid detergent compositions for automatic dishwashing which are endowed with thixotropic / properties as well as better anti-veil properties and physical stability and which are easily dispersible in the washing medium to ensure efficient cleaning of plates / glasses / porcelain / etc.

Commercial detergents for household automatic dishwashers which are supplied in powder form have several disadvantages / eg non-uniform composition; the costly operations which are necessary for their manufacture; a tendency to solidify when stored under high humidity / which results in the formation of large pieces which are difficult to disperse; a dusty character which is a particular source of irritation for users suffering from allergies; and a tendency to agglomerate in the dispenser of the dishwasher.

Liquid forms of dishwashing compositions, however, generally cannot be used in automatic dishwashers due to unacceptably low levels of foam / viscosity and alkalinity. excessively strong.

In addition, the powder formulated detergent products currently used often require a separate step of manual wiping and drying with a cloth of plates, glasses, porcelain, etc., to prevent any haze or traces remaining. undesirable precipitated calcium and magnesium salts. The use of liquid detergent compositions presents other problems. The detergency builder salts settle out during storage and are not readily redispersed. It also often happens that the compositions thicken during storage and are not easy to pour.

Recent research and development activity has focused on the "gel" or "thixo trope" form of such compositions; however, these compositions have generally been shown to be insufficiently viscous to remain "anchored" in the dispenser compartment of the dishwasher, and they also leave small residual stains on plates, glasses, porcelain, etc. Ideally, the thixotropic cleaning compositions should be very viscous at rest, have a plasticity according to Bingham, and have relatively high flow limits. However, when subjected to shear stresses, for example by being shaken in a container or expressed by an orifice, these compositions should fluidize quickly and, when the shear stress ceases to be applied, quickly return to the state of strong viscosity / plasticity Bingham. Stability is also of prime importance, that is, there should be no overt signs of phase separation or oozing after a long rest.

35 For effective use, it is generally recommended that the automatic dishwasher detergent / also referred to below as DLVA / contains (1) sodium tripolyphosphate (NaTPP) to soften water or retain mineral substances in hard water and for emulsifying and / or peptizing soiling; (2) sodium silicate to provide the alkalinity necessary for a good detergent action and to provide protection to the varnishes and patterns of fine porcelain. (3) sodium carbonate / generally considered as optional / to reinforce the alkalinity; (4) a chlorine-releasing agent to help remove small soils that lead to the formation of water spots; and (5) a combination of anti-foam agent / surfactant to reduce foam / thereby improving the efficiency of the machine / and providing the required detergent power. See / for example / SDA Detergents in Depth / "Formulations Aspects of Machine Dishwashing" / Thomas Oberle (1974). The cleaning products which approach the compositions described above are essentially liquids or powders. In general / these compositions do not contain a bleaching agent of the hypochlorite type / because this tends to react with other chemically active ingredients / in particular the surfactant / which degrades the suspending or thixotropic agent and alters its effectiveness.

Thus / the US patent No. 3,985,668 describes abrasive scouring cleaners having a gel consistency / which contain (1) a suspending agent / preferably clays of the smectite and attapulgite types; (2) an abrasive, for example silica sand or perlite; and (3) a filler made of powdered low density polymers, expanded perlite or the like, which exhibits 55 buoyancy and thus exerts a stabilizing effect on the composition / in addition to the fact that it serves as bulking agent thereby replacing water which would otherwise be available to form an undesirable supernatant layer as a result of seepage and phase destabilization. The above ingredients are essential. Optional ingredients include hypochlorite as a bleaching agent, a surfactant stable to bleaching agent and a buffer, for example silicates, carbonates and monophosphates. Detergency builders, such as NaTPP, may be included as additional optional ingredients to assume or supplement the adjuvant function not provided by the buffer, the proportion of such detergency builders not exceeding 5% of the composition total, according to this patent. Maintaining the desired pH values (higher than pH 10) is achieved by the buffer / detergency builder components. It is said that a high pH minimizes the decomposition of the chlorine bleach and an undesirable interaction between the surfactant and the bleach. If present, NaTPP is limited to 5%, as stated. No foam suppressant is mentioned.

In the patent applications of the United Kingdom 25 GB-2 116 199A and GB-2 120 450A, both ceded to the company Colgate-Palmolive, there are described liquid DLVA compositions which have properties advantageously characterizing a thixotropic structure of the type gel and which each comprise the various ingredients necessary for effective detergent action in an automatic dishwasher. The aqueous detergent composition for an automatic dishwasher, normally in the gel state, endowed with thixotropic properties, comprises the following ingredients, on a weighted basis: 35 line 6 (a) 5 to 35% · of alkali metal tripolyphosphate ; (b) 2/5 to 20% sodium silicate; (c) 0 to 9% alkali metal carbonate; 5 (d) 0/1 to 5% organic detersive substance dispersible in water / stable vis-à-vis the chlorine bleach; (e) 0 to 5% of foam inhibitor stable towards the bleaching agent; (f) a chlorine bleach in a proportion capable of providing about 0/2 to 4% of active chlorine; (g) a thixotropic thickener in an amount sufficient to impart to the composition a thixotropy index of about 2/5 to 10; and (h) sodium hydroxide / as needed / to adjust the pH.

The DLVA compositions thus formulated are not very foaming and easily soluble in the washing medium / and their effectiveness is greatest at the pH most favorable to the best cleaning performance, that is to say at pH 10 / 5-13 / 5. These compositions normally have the consistency of a gel / that is to say that they are opaque / very viscous gelatinous products / having a plastic character according to Bingham and their flow limits are therefore relatively high. Consequently / in order to initiate or increase their flow, a determined shear force such as may be generated in the dispenser compartment with stirring of an automatic dishwasher in operation. Under these conditions / the composition fluidizes quickly and disperses easily. When the shear force ceases to be applied / the fluid composition quickly returns to 55 a state of high viscosity and Bingham plasticity very close to its former consistency.

The U.S. Patent No. 4,511,487 describes a low foaming detergent paste for dishwashers. The composition is based on a mixture of finely divided hydrated sodium metasilicate, a compound containing active chlorine and a thickening agent which is a laminated silicate of the hectorite type. · It is possible to use small amounts of nonionic surfactants and alkali metal carbonates and / or hydroxides.

A U.S. patent application simultaneously pending related, which is assigned to the Applicant, is Application No. 816,535 filed January 7, 1987. This patent application describes a thixotropic aqueous deter-15ente composition for automatic washing of dishes, which contains a fatty acid long chain as a thixotropic thickening agent.

The aqueous thixotropic liquid compositions of the present invention overcome many of the problems associated with liquid and powdered detergents. Thanks to the addition of a small effective proportion of silica as an anti-veil agent to the composition, a rinsing aid is not necessary and wiping with the cloth and drying are not necessary to obtain plates, sparkling dry glasses, cups and cutlery. The thixotropic aqueous liquid detergent composition offers the additional advantages of being stable, of not settling during storage and of being easily redispersible. The liquid compositions of the present invention are easy to pour, dose and introduce into automatic dishwashers.

An additional and unexpected benefit of adding silica as an anti-veil agent to the detergent composition is that the silica inhibits the formation of brown spots in the dishwasher.

Dark spots are formed by the deposit / in the dishwasher / of iron and / or manganese oxides. The formation of brown spots is a problem of particular concern in regions with hard water. The silica contained in the composition acts on the iron and / or manganese of the washing water by preventing their deposition in the dishwasher in the form of iron and / or manganese oxides.

An object of the present invention is to provide a thixotropic aqueous liquid detergent composition for automatic dishwashers which has improved anti-fogging properties.

Another object of the invention is to provide a thixotropic aqueous liquid detergent composition which is storage stable / easy to pour and easy to disperse in washing water.

Another object of the invention is to provide a method for washing plates / glasses / porcelain / etc. in an automatic dishwasher using a thixotropic aqueous liquid detergent composition in which an auxiliary rinsing is not added or required.

Another object of the invention is to provide a method for washing plates / glasses / porcelain / etc. in an automatic dishwasher using an aqueous liquid detergent composition / method by which the plates / glasses / porcelain / etc./ are dried in the machine 30 without any traces or haze remaining.

Another object of the invention is to provide stable thixotropic aqueous liquid compositions / in particular detergent compositions for automatic dishwashers / by incorporating into the aqueous suspension a small effective proportion of silica δ β- 9 as an anti-veil agent . It is also added a minor proportion of a fatty acid / a metallic salt of fatty acid and / or a clay as thixotropic thickener to inhibit the sedimentation of particles in suspension and to prevent a separation of the phases. .

These and other objects of the present invention will become more apparent from the following detailed description of the invention and its preferred embodiments, and are achieved by incorporating into a liquid aqueous detergent composition a small proportion but effective, silica as an anti-veil agent. The physical stability of the composition is improved by the addition of a fatty acid, a metal salt of fatty acid and / or a thixotropic clay thickener. More particularly, in a particular and preferred aspect of the invention, there is provided a detergent composition normally analogous to an automatic dishwasher gel, in which about 0.5 to 5% silica is incorporated as an anti-veil agent. The particle size of the silica used as an anti-veil agent is approximately 0.1 to 10 micrometers. In a preferred embodiment of the invention, a sufficient proportion of a long chain fatty acid or a metal salt of long chain fatty acid, or either, is added to the composition. of the previous two in admixture with a clay thixotropic thickener, to obtain a thixotropy index of approximately 2.5 to 10 and to inhibit the sedimentation of suspended particles, such as particles of alkali metal salts serving as detergency builders, etc.

In this aspect, the present invention provides an aqueous liquid detergent composition, normally in the gel state, for automatic dishwashers, having thixotropic properties, which comprises, on a weight basis: (a ) 5 to 35% of alkali metal tripolyphosphate; (B) 2.5 to 40% sodium silicate; (c) 0.5 to 5% silica as an anti-veil agent; (d) 0 to 9% of alkali metal carbonate; (e) 0.1 to 5% of organic detersive substance that is dispersible in water and stable with respect to the chlorine bleach; (f) 0 to 5% of foam inhibitor stable with respect to the chlorine bleach; * (g) a chlorine bleach, in an amount suitable to provide about 0.2 to 4% of active chlorine; (h) a thixotropic thickener, in an amount sufficient to give a thixotropic index of about 2.5 to 10; (I) 0 to 8% sodium hydroxide; and (j) additional water.

Also in connection with this particular aspect, the invention provides a method for cleaning dishes in an automatic dishwasher with an aqueous washing bath containing an effective amount of the liquid detergent composition for automatic dishwasher (DLLVA) as described above. According to this aspect of the invention, the DLLVA composition can be easily poured into the dispenser compartment of the automatic dishwasher and, within a few seconds only, it thickens rapidly, returning to its normal gel consistency. or paste so as to remain firmly in place in the dispenser compartment until shear forces are applied to it again, such as £ fc 11 • under the effect of the jet of water delivered by the washing machine. -dishes.

The invention will now be described in more detail in connection with some of its particular embodiments.

The DLLVA products, for example from the previous descriptions of the abovementioned applications GB-2 116 199A and GB-2 140 450A, have rheological properties which are evaluated by determining the viscosity of the product as a function of the shear rate.

These compositions exhibited higher viscosity at a low shear rate and lower viscosity at a high shear rate / results showing effective fluidization and gelation well within the limits of the shear rates encountered in a current dishwasher. In practical terms / these results reflect better pouring and processing characteristics as well as a lower loss in the dispenser compartment of the dishwasher compared to the liquid or gel DLVA products of the prior art. . For applied shear rates corresponding to 3 to 30 rpm / the viscosities (Brookfield) ranged from approximately 10,000 to 30,000 mPa.s to approximately 3000 to 7000 mPa.S / 25 as measured at room temperature using a Brookfield LVT viscometer after 3 minutes using a No. 4 spindle. A shear rate of 7/4 s corresponds to a spindle speed of approximately 3 rpm. An increase of about ten times in the shear rate results in a reduction of about 3-9 times in viscosity. The compositions of the Applicant's prior invention therefore exhibited fluidification thresholds situated at lower shear rates and whose amplitude was notably greater in terms of incremental increase in the shear rate as a function of the incremental decrease in viscosity. This property of the DLLVA products of the prior invention is summarized by a thixotropy index (IT) which is the ratio of the apparent viscosities at 3 rpm and 30 rpm. The compositions of the previous invention have an IT of 2 to 10. The DLLVA compositions must manifest a rapid and massive return to the consistency of the anterior state of rest when the shear force ceases to be applied.

In terms of apparent viscosity / it has been established that as long as the viscosity at room temperature (22 ± 1 ° C) / measured in a Brookfield HATD viscometer using a pin No. 4 at 20 rpm, is in-15 below 20,000 mPa.S / the composition can be easily shaken in such a way that a thixotropic composition can be easily "fluidized" or "liquefied" to allow the product to be dispensed by a vial with a conventional compressible tube or other container. 20 convenient tributor.

The present invention is based on the surprising discovery that it is possible to obtain significantly improved anti-fog properties by adding to the thixotropic aqueous liquid detergent composition a small effective proportion of silica as an anti-fog agent. Physical stability / i.e. resistance to phase separation / sedimentation / etc./ can be obtained by adding to the composition a small effective proportion of a thixo-20 thickening agent and a stabilizing agent.

Anti-veil agents

The silicas which can be used as an anti-veil agent are natural silicas or synthetic silicas which are pyrogenic or precipitated. The silica 25 can be amorphous or crystalline.

9 * V

13

The silica which is used can contain up to approximately 0.1 to 5% of alumina (A ^ O ^) / generally approximately 0.5 to 3%, and more commonly approximately 1% by weight of alumina, relative by weight of silica.

A preferred silica is Syloid 244 which is an amorphous silica with a particle size of about 4 micrometers and which is supplied by WR Grace Co. Another suitable silica is Silox 15, also supplied by WR Grace Co., whose size particle size is approximately 4 micrometers.

Another preferred silica is Huber Zeo 49, supplied by J.M. Huber Corporation, which is an amorphous silica and which contains about 1% alumina (Al 2 O 3).

It has been found that the presence of an Al 2 O 3 level as small as 1% helps to reduce the hydrolysis and subsequent solubility of the silica in the highly alkaline detergent composition for automatic dishwashers.

The particle size of the silica used is an important criterion for obtaining the desired anti-veil properties.

The silica particles which are used are finely divided and may have a particle size of about 0.10 to 10 microns, preferably 0.50 to 8 microns and more preferably about 1.0 to 5.0 micrometers. Silica particles of this size, and in the proportion used here, are not abrasive.

The finely divided silica particles act in dishwashing by coagulating the particulate protein soils and keeping them in suspension to prevent them from settling on clean glasses and plates.

The proportion of silica that can be used to achieve the desired improvement in anti- effect, 2 fr \ i \ i! i 14 - haze depends on the hardness of the water, the detersive compound, the mineral salts and the other ingredients of the DLLVA composition. Silica is particularly effective as an anti-veil agent in hard water having a hardness of, for example, 300 mg / liter or more.

The proportion of silica which is used as an anti-veil agent can be approximately 0.5 to 5%, preferably approximately 1 to 4%, and more preferably, approximately 1.5 to 3%, by weight relative to by weight of the total composition.

Thixotropic thickeners

Thixotropic thickeners or suspending agents which can be used in accordance with the present invention to impart thixotropic properties to the aqueous medium can be organic substances, for example fatty acids or polyvalent metal salts of fatty acids, or mineral substances of the colloidogenic clay type. Thixotropic thickeners must be stable against high alkalinity and stable against chlorine bleaches such as sodium hypochlorite. Preferred thixotropic thickeners include fatty acids, polyvalent metal salts of fatty acids and colloidogenic mineral clays of the smectite and / or attapulgite types. the proportion of thixotropic thickener that is used depends on the particular thickener employed, but sufficient thickener must be added to the composition to give the composition a thixotropy index of about 2.5 to 10.

Preferred fatty acids as thixotropic thickeners are higher aliphatic fatty monocarboxylic acids having about 8 to about 22 carbon atoms, preferably about 10 to 20 carbon atoms, and more preferably, about 12 to 18 atoms ft £.

15 carbon, including the carbon atom of the carboxyl group of the fatty acid. The aliphatic radical can be saturated or unsaturated and it can be straight or branched. 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 can be used. industrial manufacturing processes.

Examples of fatty acids which can be used as thickeners include / for example / decanoic acid / lauric acid / dodecanoic acid / palmitic acid / myristic acid / stearic acid / oleic acid / eicosanoï-15 acid / tallow fatty acid / coconut fatty acid / soy fatty acid and mixtures of these acids. Stearic acid and mixed fatty acids / for example coconut fatty acid / are preferred.

The proportion of fatty acid to be used as a thickener to achieve the desired degrees of thixotropy and physical stability depends on factors such as the nature of the fatty acid / detersive compound / mineral salts / especially tripolyphosphate / and of the other ingredients of the composition DLLVA / 25 as well as the planned conditions of storage and transport.

However / in general / the fatty acid can be used as a thixotropy agent in proportions ranging from about 0/03 to 0/5%, preferably from about 0/03 to 0/2% / and better still / from about 0/05 to 0/15% to obtain the long-term stability and the absence of separation of the phases which are desired.

The polyvalent metal salts of the above fatty acids can also be used in the present invention as thixotropic thickeners. Suitable thixotropic thickeners of the metal salt type are described in the previous French patent application filed under 5 fmmérô 87 12 321.

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

In general, the metals can be present in a state equivalent to pentavalent. Preferably, the metals are used in their highest oxidation states. Obviously, for DLLVA compositions, as well as all other applications where the composition of the invention comes into contact with or can come into contact with articles used for handling, preserving or serving food products or products which can otherwise enter in contact with or consumed by humans or animals, the metal salt should be chosen taking into consideration the toxicity of the metal. In this regard, · calcium and magnesium salts are particularly preferred because they are generally safe food additives.

Many of these metal salts are commercially available. For example, aluminum salts are available in the form of three acid residues, for example aluminum stearate in the form of aluminum tristearate AliC ^ H (COO) ^. Salts with a single acid residue can be used, for example aluminum monostearate Al (OH) 2 (C- ^ H ^ COO) and salts with two acid residues, for example distearate aluminum àI (OH) (CjyH ^ gCOO) 2, and mixtures of two or three of the salts with one, two or three acid residues for metals which, such as Al, have the valence +3, and mixtures of salts with one and two acid residues for the 17 metals which Zn # have the valence +2. It is more preferable to use in predominant proportions the salts with two acid residues of bivalent metals / the salts with three acid residues of trivalent metals, the salts with four acid residues of tetrava-slow metals and salts with five acid residues of pentavalent metals. For example # at least 30% # preferably at least 50% # and better still 80 to 100% # of the totality of the metal must be at the highest possible degree of oxidation # i.e. each site of possible valence is occupied by a fatty acid residue.

Metal salts # as mentioned above # are generally commercially available # but can be easily produced # for example - * - 5 by saponification of a fatty acid # for example animal fat # stearic acid # etc. # or the corresponding fatty acid ester, then treatment with a polyvalent metal hydroxide or oxide # for example # in the case of aluminum salt # with alum # alumina # 20 etc.

The polyvalent metal salts of fatty acids which are preferred as stabilizers are calcium stearate # i.e. calcium distearate # 'magnesium stearate # i.e. 2 ^ distearate magnesium # aluminum stearate # ie aluminum tristearate # and zinc stearate # ie zinc distearate. Mixed fatty acids # such as naturally occurring acids, for example coconut fatty acid # as well as mixed fatty acids resulting from industrial manufacturing processes # are also advantageous to use as inexpensive but effective sources long chain fatty acid.

The proportion of the stabilizing fatty acid salts to be used to obtain the desired improvement O or 18 of physical stability depends on factors such as the nature of the fatty acid salt / the nature and the proportion of the thixotropic agent, detersive compound, mineral salts, in particular tripolyphosphate, au-5 very ingredients of the composition DLLVA, as well as the conditions provided for storage and transport.

In general, however, proportions of stabilizers of the polyvalent metal salt type of fatty acid are in the range of about 0.02 to 1%, preferably about 0.06 to 0.8% and, better still, from about 0.08 to 0.4%, ensure long-term stability and the absence of phase separation at rest or during transport, both at low and at high temperatures, as is required for a commercially acceptable product.

In the present invention, it is also possible to use conventional mineral thixotropic clay thickeners. Clay thickeners can be used in small amounts in combination with fatty acid type thickeners or in combination with polyvalent metal salt type fatty acid thickeners. Clay thickeners can however be used in isolation as thixotropic thickeners.

Preferred clay thickeners include colloidogenic mineral clays of the smectite and / or attapulgite types.

Smectite clays include montmorillonite (bentonite), hectorite, attapul-30 deposit, smectite, saponite and others. Montmorillonite-type clays are preferred and are available under commercial brands such as Thixogel (registered trademark) No. 1 and Gelwhite (registered trademark) GP, H, etc., from Georgia Kaolin Company 7 and 35 Eccagum (registered trademark) ) GP, H, etc., from “fc- 19

Luthern Clay Products. Attapulgite clays include materials commercially available under the trademark Attagel (registered trademark), i.e., Attagel 40, Attagel 50 and Attagel 150, from Engelhard Minerais and Chemicals Corporation. Mixtures of the smectite and attapulgite types, in weight ratios of 4: 1 to 1: 5, are also useful here. Thickening or suspending agents of the foregoing types are well known in the art, and are for example described in the U.S. Patent.

No. 3,985,668 mentioned above. Abrasives or polishing agents should be avoided in DLLVA compositions, as they can damage the surface of fine dishes, crystal, etc.

When used in combination with fatty acids or polyvalent metal salts of fatty acids, thixotropic clay thickeners are used in proportions of 0.1 to 3%, preferably 0.1 to 2.5% and , better still, in proportions of 0.1 to 2%. When the clay thixotropic thickeners are used alone as thixotropic thickeners, they can be used in proportions of about 1.5 to 8%, preferably 2 to 5%, by weight relative to the weight of the composition.

25 In general, the effectiveness of DLLVAs is directly linked to the following factors: (a) active chlorine levels; (b) alkalinity (c) solubility in the washing medium; and (d) inhibiting foam. It is preferable in the present case that the pH 30 of the DLLVA composition is at least about 9.5, preferably about 10.5 to 13.5, and more preferably at least about 11.5 . At relatively low pH values, the DLLVA product is too viscous, that is to say of a solid consistency, and it does not fluidize easily at the intensities of the shear forces which “α.

20 are generated inside the dispenser compartment under normal machine operating conditions. The addition of NaOH is therefore often necessary to raise the pH to within the limits of the above ranges, and to improve the flowability properties. The presence of carbonate is also often required here, as it acts as a buffer that helps maintain the desired pH. However, an excess of carbonate should be avoided, as this may result in the formation of needle-like carbonate crystals, which alters the stability, thixotropy and / or detergent power of the DLLVA product, as well as the suitability of the product. to be dispensed, for example from bottles with compressible tube. Caustic soda (NaOH) performs the additional function of neutralizing the foam inhibitor of the phosphoric or phosphonic acid ester type, when present. Typical proportions are about 0.5 to 3% by weight of NaOH and about 2 to 9% by weight of sodium carbonate in the DLLVA composition, although it should be noted that sufficient alkalinity can be provided by NaTPP and sodium silicate.

NaTPP can be used in the DLLVA composition in an amount between about 8 and 35% by weight, preferably between about 20 and 30% by weight, and should preferably be free of heavy metal which tends to decompose or inactivate the preferred sodium hypochlorite or other chlorine bleaches. The NaTPP can be anhydrous or hydrated, which includes the stable hexahydrate having a hydration level of 6 corresponding to about 18% by weight of water or more. In fact, with regard to the stability of the hexahydrate, the presence of a certain amount of water of hydration is very effective because, as it is believed / it serves to form seeds of the stable hexahydrate / which accelerates the hydration and the solubilization of the remaining NaTPP particles. If only hexahydrate is used, the detergent may be too runny. Conversely / if only anhydrous NaTPP is used / the product may / in some cases / be too thick and / therefore / inappropriate. Particularly preferred DLLVA compositions are obtained using / for example a weight ratio of 0/5: 1 to 2: 1 of anhydrous NaTPP to

NaTPP hexahydrate / ratios in the region of 1: 1 being particularly preferred.

The inhibition of foam is important to increase the efficiency of the dishwasher and to minimize the destabilizing effects which could occur during use due to the presence of excess foam in the machine. The foam can be sufficiently reduced by an appropriate choice of the type and / or the proportion of the detersive substance / which is the main foam-producing component. The degree of foaming also depends / to some extent on the hardness of the washing water contained in the machine / so that a good adjustment of the proportions of NaTPP / which exerts a water softening effect / can help achieve the desired degree of foam inhibition. However / it is generally preferable to include a foam inhibitor or anti-foaming agent / stable vis-à-vis the chlorine bleach. Particularly effective foam inhibitors are the alkyl phosphonic acid esters of formula 0

HO — P — R

GOLD

35 22 available, for example, from the company BASF-Wyandotte (PCUK-PAE), and in particular the acidic phosphoric alkyl esters of formula 0 5 ”.

HO — P —OR

GOLD

available, for example, from Hooker (SAP) and Knapsack (LPKN-158); one or both of the R groups, in each of these types of esters, may each independently represent a C ^2 ”C2Q alkyl group. It is possible to use mixtures of these two types, or of all other types established against the chlorine bleach, or mixtures of mono- and diesters of the same type. Most preferred is a mixture of acidic phosphoric esters of mono- and di (C 1 -C 4 alkyl) such as 1.2 / 1 monostearyl / distearyl acid phosphates (Knapsack). If used, typical proportions of foam inhibitor in the composition are from 0.01 to 5% by weight, preferably from about 0.1 to 0.5% by weight, and more preferably, from about 0.1 to 0.5% by weight, the weight ratio of the detersive component to the foam inhibitor generally being between about 10: 1 and 25 i; i and preferably-between about 4: 1 and 1: 1. Other defoamers which can be used include, for example, known silicones.

Although any chlorine bleach can be used in the compositions of the present invention, for example a dichloro-isocya-nurate, chlorinated dichloro-dimethyl hydantoin or TSP, an alkali metal hypochlorite is preferred, for example a potassium, lithium or magnesium hypochlorite, and in particular sodium hypochlorite. The composition must contain a sufficient proportion of chlorine bleach to provide approximately 0/2 to 4/0% by weight of active chlorine / as determined / for example / by acidification of 100 parts of the composition with an excess of hydrochloric acid. A solution containing about 0/2 to 4.0% by weight of sodium hypochlorite contains or provides about the same percentage of active chlorine. A solution containing about 0.8 to 1.6% by weight of sodium hypochlorite contains about 0.8 to 1/6% by weight of active chlorine and such a solution is particularly preferred. For example, it is advantageous to use a solution of sodium hypochlorite (NaOCl) containing approximately 11 to approximately 14% of active chlorine in proportions of approximately 3 to 20%, preferably approximately 7 to 12%.

Sodium silicate, which gives alkalinity and provides protection for hard surfaces, such as varnishes and patterns from fine porcelain, is used in the composition in a proportion ranging from approximately 2.5 to 40% by weight, preferably about 10 to 35% by weight. The sodium silicate also protects the washing machine against corrosion. At the higher rates which are indicated here, for example at rates higher than about 10% by weight, the silicate also exerts a greater action against the formation of spots. The sodium silicate is generally added in the form of an aqueous solution, preferably having an Na2: SiO2 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 the foam inhibitor, can also be added in the form of an aqueous dispersion or solution.

The detergent useful here should be stable in the presence of the chlorine bleach, especially a bleach hypochlorite, and water dispersible surfactants of the organic anionic surfactant / oxide type are preferred. amine / phosphine oxide, sulfoxide and betaine / the anionic surfactants mentioned first being the most preferred. They are used in proportions ranging from about 0/1 to 5% / preferably from about 0/3 to 2/0%. Particularly preferred surfactants here are mono- and / or di (C 1 -C 4 alkyl) (di-phenyl oxide) -mono- and / or straight chain or branched disulfonates / commercially available / for example under the designations DOWFAX (registered trademark) 3B-2 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 and alkylaryl sulfonates and sec. Alkyl sulfates. Examples are sodium C 1-6 alkyl sulphates such as sodium dodecyl sulphate and (tallow alcohol) sodium sulphate; C1-C6 sodium alkanesulfonates such as sodium hexadecyl-1-sulfonate; and sodium alkylbenzene sulfonates ci2 ci8 te - * - s 3ue clodecyl-benzenesulfonates sodium. The corresponding potassium salts can also be used.

As other suitable additives or detergents, mention may be made of surfactants of the amine oxide type, which typically have the structure I ^ R ^ NO where each R represents a lower alkyl group / for example methyl / and R1 represents an alkyl group. long chain having 8 to 22 carbon atoms / for example a lauryl / myristyl, palmityl or cetyl group. Instead of an amine oxide, a phosphine oxide R ^ R ^ PO or a corresponding surfactant RR ^ SO sulfoxide can be used. Betaine type surfactants typically have the structure R2R1N-R "C00 / where each R" represents a lower alkylene group having 1 to 5 carbon atoms. Particular examples of these surfactants are lauryl dimethylamine oxide / myristyl dimethylamine oxide, the corresponding phosphine oxides and sulfoxides, and the corresponding betaines, including dodecyl dimethylammonium acetate, pentanoate tetra-decyl-diethyl-ammonium, hexadecyl-dimethyl-ammonium hexanoate, etc. To ensure biodegradability, the alkyl groups of these surfactants must be linear, and such compounds are preferred.

Surfactants of the foregoing types, which are all well known in the art, are for example described in U.S. patents. N ° 3 985 668 and 15 4 271 030.

The proportion of water contained in these compositions must obviously be neither too great as to produce an abnormally low viscosity and excessive fluidity, nor too small as to produce an abnormally high viscosity and a low flowability, the thixotropic properties being in each case lessened or eliminated. This proportion is easily determined by routine experimentation in any particular case, and is generally from about 25 to 75% by weight, preferably from about 50 to 65% by weight. In addition, the water should preferably be deionized or softened. These proportions of water in the composition take into account the water added as parts of the liquid solutions of other ingredients, but do not take into account the bound water, for example that of NaTPP hexahydrate.

Other conventional ingredients may be included in these compositions in small amounts, generally less than about 3% by weight, for example a perfume, hydrotropic agents such as benzene- / toluene- / xylene- and cumene sulfonates of sodium / preservatives / colorants and pigments / etc./ all of which are obviously stable with respect to chlorine bleach and high alkalinity (properties of all components).

Particularly preferred substances for providing coloration are chlorinated phthalocyanines and aluminosilicate polysulphides which communicate respectively pleasant green or blue hues.

* -0 The DLLVA compositions of the present invention are easily used in known manner for washing plates / glasses / cups / 'cutlery / etc./ in an automatic dishwasher fitted with a suitable detergent dispenser / in a bath aqueous - * • 5 wash containing an effective amount of the composition.

According to a preferred embodiment of the invention / the aqueous liquid detergent composition for automatic dishwasher is formulated using the ingredients listed below. ·

Component Weight percent

10-25 alkali metal tripolyphosphate

Sodium silicate (47/5%) 15-40 25 Silica as an anti-veil agent 1-4

Alkali metal carbonate (anhydrous) 2-8

Detergent organic substance dispersible in water / stable towards bleaching agent with 3q chlorine 0 / 5-3

Foam inhibitor stable against chlorine bleach 0 / 10-3

Sodium hypochlorite as a bleach 0 / 2-4 35 Fatty acid as a thixotropic thickener. 0 / 03-0 / 5 27

Sodium hydroxide (50%) 2-6

Water Complement

The thixotropic aqueous liquid detergent compositions for automatic dishwashing according to the present invention may contain conventional additives for detergent dishwashing compositions. The compositions can be prepared with the powdered solid detergency builders which are commercially available / and / or the ingredients can be mixed and the compositions ground to a desired particle size.

The invention can be practiced in various ways and a number of particular embodiments will be described by way of illustration with reference to the examples below.

All the quantities and proportions referred to here are expressed by weight relative to the weight of the composition / unless otherwise indicated. Example 1 A thixotropic aqueous liquid detergent composition for automatic dishwashing is prepared from the following ingredients in the indicated proportions.

Component Weight percent 25 Deionized water 26/26

Foam inhibitor / Knapsack LPNK-158 ^ 0.16

Sodium hydroxide (50%) 5.00

Sodium carbonate (anhydrous) 5.00

Sodium tripolyphosphate (anhydrous) 20.00 (2) 30 Anti-veil agent, silica 2.00

Thixotropic thickener, stearic acid 0.10 (3)

Surfactant, Dowfax 3B-2 '' 0.80

Sodium hypochlorite (11%) 9.10

Sodium silicate (1 / 2.23 - 47%) 31.58 35 100.00 "28 (1) Mixture of alkyl esters (ci5" ci8 ^ mono- and di-stearyl phosphoric acid, molar ratio 1: 1.3.

(2) Syloid 244 silica having a particle size of approximately 4 micrometers, available from W.R.

Co.

(3) Na and didecyl (diphenyl oxide) Na disulfonates (45% solution).

The stearic acid is melted and the ingredients are added to the water, in substantially the order shown, and gently stirred until a homogeneous mixture is obtained. The composition is tested by washing glasses and plates at a temperature of 54.4 ° C in hard water (hardness 15 300 mg / liter) in an automatic dishwasher, and finds that clean and dried dishes have no visible haze.

Example 2

In order to demonstrate the effect of the addition of silica as an anti-veil agent, compositions are prepared with and without silica as an anti-veil agent and are compared to a commercially available powdered detergent composition.

The compositions are formulated to contain the following ingredients.

With silica ^ Without silica ^ as agent as agent

Anti-veil component anti-veil_

Deionized water 32.05 34.55

Foam inhibitor, 30 Knapsack LPKN-158 0.16 0.16

Sodium hydroxide (50%) 5.00 5.00

Sodium carbonate (anhydrous) 5.00 5.00

Sodium tripolyphosphate (anhydrous) 20.00 20.00 _ Anti-veil agent, silica (Syloid 244) 2.50 29 * * "

Thixotropic thickener, stearic acid 0/10 0/10

Surfactant, Dowfax 3B-2 0/80 0/80

Sodium hypochlorite (11%) 9/10 9/10

Sodium silicate 5 (1/2/23 - 47%) 25.29 25.29 100/00 100/00

The stearic acid is melted and the ingredients are added to the water, in substantially the order shown, and gently stirred until a homogeneous mixture is obtained. The composition is tested by washing dishes at 54.4 ° C in hard water (hardness of 300 mg / liter).

The two compositions (A) and (B) above are tested and compared to a commercial powdered deter-15ent composition for automatic dishwasher, C. The compositions are tested in a Kenmore automatic dishwasher using the method described in ASTM D-3566-79, except that only four cleaning cycles are used. The formation of veil and the formation of spots are evaluated according to the following scales:

Scale of evaluation of the haze 1. The best, no visible haze 2. Slight haze formation, which becomes visible 25 3. Perceptible haze, which increases 4. Continuous increase of an appreciable haze 5. Formation of haze becoming excessive 6. Strong haze formation, excessive accumulation 7. Continuous increase of excessive haze 30 Scale for assessing spots A. The best, no stains B. Very few visible spots C. Clear spots B. Significant overlap of approximately 50% 35 The results obtained in the fourth cycle t fr ο.

30 are reported in Table 1 below.

TABLE 1

Composition Performance evaluation

Stains Veil 5 (A) With silica as anti-veil agent B-C 1-2 (B) Without silica as anti-veil agent B-C 5-6 (C) Commercial powder detergent B-C 4-5 10 Example 3

Thixotropic aqueous liquid detergent compositions for automatic dishwashing are prepared from the following ingredients in the proportions indicated.

(Ό) (F)

15 With silicav Without silica 'J

as agent as agent

Anti-veil component anti-veil_

Deionized water 32/638 34.638

Green pigment, Graphtol 0.002 0.002

Foam inhibitor, 20 Knapsack LPKN-158 0.160 0.160

Sodium hydroxide (50%) 5,000 5,000

Sodium carbonate (anhydrous) 5,000 5,000

Sodium silicate (1 / 2.35 - 43.5%) 25.300 25.300 25

Sodium tripolyphosphate (anhydrous) 20,000 20,000

Anti-veil agent, silica ^ 2,000

Surfactant, Dowfax 3B-2 ^^ 0.800 0.800 (3)

Stearic acid 0.100 0.100 30 Sodium hypochlorite (11%) 9,000 9,000 100,000 100,000 (1) Silica (Huber Zeo 49) contains approximately 1% alumina (A ^ O ^) and its particle size is approximately 9 micrometers.

(2) Sodium mono- and didecyl- (diphenyl oxide) disulfonates (45% solution) 31. (3.) Emersol 132 # available from Emery Company.

The stearic acid # is melted # and the ingredients are added to the water # substantially in the order indicated # and they are stirred until a 5 is obtained. homogeneous mixture. The compositions are tested by washing dishes at 54 # 4 ° C in hard water (hardness 300 mg / liter).

The two compositions are tested and compared to a commercial powdered detergent composition for an automatic dishwasher, F. The compositions are tested in a Kenmore automatic dishwasher using the method described in ASTM D-3566-79 # except that only four cleaning cycles are used. The formation of spots and the haze were evaluated in the same way as in Example 2 and the results obtained in the fourth cycle are reported in Table 2 below.

TABLE 2

Performance evaluation 20 Spots Veil (D) With silica as anti-veil agent B-C 1-2 (E) Without silica as anti-veil agent B-C 4 (F) Powder detergent 25 commercially B-C 5-6

Example 4

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

Component Weight percent

Deionized water 38 # 79

Thixotropic thickener # aluminum stearate 0 # 25 3t- Thixotropic thickener # clay (Pharmagel H) 1 # 25 32 »J '<t

Sodium silicate (1/2/4 - 47/5%) 17/73

Sodium tripolyphosphate (anhydrous) 12/00

Sodium tripolyphosphate (hexahydrate) 12/00 5 Anti-veil / silica agent 2.00

Sodium carbonate (anhydrous) 5/00

Sodium hypochlorite (11%) 7/61

Surfactant / Dowfax 3B-2 0/80

Foam inhibitor ^^ 0/16

Sodium hydroxide (50%) 2/40

Green pigment / Graphitol 0/01 100.00 (1) 1: 1 mixture of LPKN-158 and PCUK-PAE.

The ingredients are mixed in a conventional manner or are mixed according to the method of the French patent application filed under the number 87 12 321.

The composition was tested by washing dishes at 54.4 ° C in hard water (hardness 300 mg / liter) in an automatic dishwasher. It can be seen that the clean and dried dishes are free from haze.

Liquid theutrotropic detergent compositions for automatic dishwashing have improved properties from the point of view of the haze.

Claims (18)

1. A gel-like thixotropic aqueous liquid detergent composition for automatic dishwashing, which comprises water, at least one ingredient selected from organic detergent / bleach / detergency builder / sequestering agent / a foam inhibitor and their mixtures / .about 0/5 to 5% of silica as an anti-veil agent and a sufficient proportion of a thixotropic thickener to give the composition a thixotropy index of approximately 2/5 to 10. 2. Composition according to claim 1 / characterized in that the silica used as anti-veil agent is present in a proportion of about 1 to 15 4%. 3. Thixotropic aqueous liquid composition for automatic dishwasher / characterized in that it comprises / approximately / by weight: (a) 5 to 35% of detergency builder; (B) 2/5 to 40% sodium silicate; (c) 0/5 to 5% silica as an anti-veil agent / having a particle size of about 0/1 to 10 micrometers; (d) 0 to 9% alkali metal carbonate; (E) 0/1 to 5% detergent organic substance dispersible in water / stable with respect to the chlorine bleach; (f) 0 to 5% foam inhibitor / stable vis-à-vis the chlorine bleach; (G) a chlorine bleach in an amount suitable to provide about 0/2 to 4% active chlorine; (h) a sufficient proportion of a thixotropic thickener to give the composition a thixotropy index of about 2/5 to 10; fc * g. (I) 0 to 8% sodium hydroxide; and (j) additional water. 4. Composition according to claim 3 / characterized in that the thixotropic thickener 5 consists of a long chain fatty acid present in a proportion of about 0.03 to 0.5%. 5. Composition according to claim 3, characterized in that the thixotropic thickener consists of a polyvalent metal salt of long chain fatty acid present in a proportion of approximately 0.02 to 1.0% · 6. Composition according to claim 4, characterized in that it further comprises a clay thixotropic thickener in a proportion of about 0.1 to 3.0%. 7. Composition according to claim 5, characterized in that it further comprises a clay thixotropic thickening agent in a proportion of about 0.1 to 3.0%. 8. Composition according to claim 3, characterized in that the particle size of the silica used as an anti-veil agent is approximately 0.5 to 8.0 micrometers. 9. Thixotropic aqueous liquid composition 25 for automatic dishwasher, characterized in that it comprises, approximately, by weight: (a) 5 to 35% of alkali metal tripolyphosphate; (b) 2.5 to 40% sodium silicate; (C) 1 to 4% silica as an anti-veil agent, 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 detergent organic substance dispersible in water, stable with respect to the chlorine bleach * (f) 0 to 5% of foam inhibitor stable against chlorine bleach; (g) a chlorine bleach in an amount suitable to provide about 0/2 to 4% active chlorine; (h) a sufficient proportion of a thixotropic thickener to give the composition a thixotropy index of approximately 2.5 to 10; (I) 0 to 8% sodium hydroxide: and (j) additional water. 10. Composition according to claim 8, characterized in that the silica used as anti-veil agent contains approximately 0.1 to 5% of alumina, relative to the weight of the silica. 11. Composition according to claim 8, characterized in that the particle size of the silica is approximately 1 to 5 micrometers. 12. Composition according to claim 8, characterized in that the thixotropic thickener comprises a long chain fatty acid having 16 to 20 carbon atoms, which is present in a proportion of about 0.03 to 0.20%. 13. Composition according to claim 8, characterized in that the thixotropic thickener comprises a polyvalent metal salt of long chain fatty acid containing 16 to 20 carbon atoms, which is present in a proportion of approximately 0.06 at 0.8%. 14. Composition according to claim 13, 30 characterized in that the polyvalent metal is chosen from aluminum, calcium, zinc and magnesium. 15. Composition according to claim 12, characterized in that it further comprises a clay thixotropic thickener in a proportion of about 35 0.1 to 2.5%. 4. 36 16. Composition according to. claim 13 / characterized in that it further comprises a clay thixotropic thickener in a proportion of about 0/1 to · 2/5%. 17. Method for cleaning dishes in an automatic dishwasher / characterized in that it consists in bringing soiled dishes in contact / in an automatic dishwasher / with an aqueous washing bath in which an effective amount is dispersed -1 ° cace of the composition of claim 2. 18. Method for cleaning soiled dishes in an automatic dishwasher / characterized in that it consists in bringing soiled dishes in contact / in an automatic dishwasher / with an aqueous washing bath in which is dispersed a effective amount of the composition of claim 8.