DE29823751U1 - Multi-phase detergent tablet with both pressed and non-pressed parts - Google Patents

Description

WO99/27063 PCT/US98/23611

Multiphase detergent tablet with both pressed and non-pressed components

Technical application area

The present invention relates to detergent tablets having both a compressed and at least one non-compressed, non-encapsulating portion.

Technical background

Detergent compositions in tablet form are well known. It is known that detergent compositions in tablet form have several advantages over detergent compositions in particle or liquid form, such as being easy to handle, transport and store. Due to these advantages, detergent compositions in tablet form are becoming increasingly popular among consumers of detergent products.

Detergent tablets are typically prepared by premixing the components in the composition and forming the premixed detergent components into a tablet using a tablet press and compressing the components. However, traditional tablet compression methods have significant disadvantages in that selected components of a detergent composition are adversely affected by the compression pressure in the tablet press.

Therefore, these selected components have not generally been incorporated into prior art detergent tablets without suffering a loss of effectiveness. In some cases, these selected components may even become unstable or inactive as a result of pressing.

In addition, when the components of the detergent composition are pressed in the tablet press, they are brought into close proximity to one another, resulting in reaction of the selected components with one another, instability, inactivity or consumption of the active form of the components.

To avoid the above-mentioned disadvantages, attempts have been made in the prior art detergent tablets to separate the components of the detergent composition which can potentially react with each other when the detergent composition is pressed into tablet form. The separation of the components from each other has been achieved, for example, by producing multiphase tablets (multilayer tablets) in which the reactive components are contained in different layers of the tablet, or by encapsulating and coating the reactive components. These prior art multiphase tablets (multilayer tablets) are usually produced using several compression stages. Therefore, the layers of the tablet which are subjected to more than one compression stage may be subjected to a cumulative and potentially higher total compression pressure. It is also known that increasing the pressure in the tabletting press reduces the dissolution rate of the tablet, which means that these multiphase tablets (multilayer tablets) do not dissolve satisfactorily when used.

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There is therefore a need for an improved detergent tablet that can release active detergent ingredients in a household washing process, thereby achieving improved cleaning effectiveness.
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Summary of the invention

This need is met by the present invention which comprises a detergent tablet having a compressed solid portion and a non-compressed, non-encapsulating portion. The tablet of the present invention releases detergent components previously considered unacceptable for detergent tablets, in addition to effectively separating potentially reactive components. Furthermore, the detergent tablet of the present invention exhibits improved cleaning effectiveness, particularly in automatic domestic dishwashers, over prior art tablets.

According to a first embodiment, the present invention relates to a detergent tablet comprising:

i) a pressed solid portion having at least one depression (hollow form) in the pressed solid portion; and ii) at least one non-pressed, non-encapsulating portion disposed in the at least one depression (hollow form) of the pressed solid portion having a surface area B, wherein the at least one non-pressed, non-encapsulating portion contains at least one detergent active ingredient; wherein the surface area of the detergent tablet, without the at least one depression (hollow form), is A and wherein furthermore the surface area ratio B:A is about 1:50 to about 4:1.

The non-pressed, non-encapsulating portion(s) may be formulated so that at least 90% of the detergent active ingredient is transferred to the

washing liquid, preferably at least 95% of the detergent active ingredient is released into the washing liquid within the first 2 minutes in a household washing process. Alternatively, the pressed solid can be formulated so that at least 90% of the

. 5 of the active detergent ingredient is released into the washing liquid within the first 3 minutes of a household washing process, preferably at least 95 % of the active detergent ingredient is released into the washing liquid within the first 2 minutes of a household washing process.

Examples of detergent actives which may be present in the non-pressed, non-encapsulating portion(s) are enzymes, surfactants, disintegrants, dispersing polymers, bleaching agents, silver treating agents, builders and mixtures thereof, with enzymes and disintegrants being most preferred. If a disintegrant is included, it is preferably a carbonate or bicarbonate salt and an organic acid.

In another embodiment of the invention, the dissolution rate of the at least one non-pressed, non-encapsulating portion is greater than the dissolution rate of the pressed portion as determined using the SOTAX dissolution test method. Alternatively, another object of the invention is for the dissolution rate of the pressed portion to be greater than the dissolution rate of the at least one non-pressed, non-encapsulating portion as determined using the SOTAX dissolution test method.

Therefore, it is a further object of the present invention to provide one or more non-pressed, non-encapsulating portions capable of rapidly and effectively releasing detergent actives in a household laundry process. These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description.

Replacement page

Reference number 298 23 751.2 The Proctej <* fi^ifble Cg£yp»4y. Cas*. %9ii *B

This is immediately apparent from the detailed description and the accompanying claims.

All percentages, ratios and quantities given here are by weight unless otherwise stated. All temperatures are in degrees Celsius ( ⁰ C) unless otherwise stated. All documents cited here are expressly referred to for their relevant proportion.

Detailed description of preferred embodiments

The present invention relates to a detergent tablet and in particular to a detergent tablet for automatic dishwashing comprising at least one compressed solid portion and at least one non-compressed, non-encapsulating portion. The use of the non-compressed, non-encapsulating portion(s) and the compressed portion result in an improved release mechanism for detergent actives in the domestic washing process. Either the non-compressed, non-encapsulating portion(s) or the compressed portion can dissolve or disperse rapidly so that the earliest possible release of the detergent actives occurs in the domestic washing process.

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Case number 298 23 751.2 The Procter &<3jjnlJle*Con^an;ji * Case:"^#&&dgr;&Ggr;&Bgr; - 6 -

The cleaning agent tablet must have an area ratio ß:A of about 1:50 to about 4:1, preferably from about 1:20 to about 1:1, particularly preferably from about 1:10 to about 1:1. Area A is the area of the cleaning agent tablet without the area of the depression (hollow form). Area B is the area of the non-pressed, non-encapsulating portion(s).

The B:A ratio provides the cavity with optimal dissolution kinetics. In addition, the non-compressed, non-encapsulating portion(s) exhibits improved visual visibility.

The detergent tablet, cavity(s) and non-compressed, non-encapsulating portion(s) may be of any size and shape as long as the B:A ratio remains within the range of about 1:50 to about 4:1. If the detergent tablet is to be used in a dispensing device, such as that found in automatic dishwashers, the detergent tablet is preferably of a size suitable for dispensing by the dispensing device.

Therefore, according to the invention, active detergent components of a detergent tablet, which were previously adversely affected by the compression pressure used in the manufacture of the tablets, can now be

. 5 of a detergent tablet. Examples of these components include bleaching agents and enzymes. In addition, these active detergent components can be separated from one another by having one or more compatible components contained in the compressed portion and one or more compatible components contained in the non-compressed, non-encapsulating portion(s) of the tablet. Examples of components that can react with one another and therefore must be separated include bleaching agents, bleach activators or catalysts, and enzymes; bleaching agents and bleach catalysts or activators; bleaching agents and surfactants; alkalinity sources and enzymes.

It may be advantageous to provide the pressed and non-pressed non-encapsulating portion(s) so that they dissolve in the wash water at different dissolution rates. By controlling the dissolution rate of each portion relative to the other and by selecting the active detergent components in the respective portions, the order of their release into the wash water can be controlled and the cleaning effectiveness of the detergent tablet can be improved. For example, it is often preferred that enzymes are released to the wash water before the bleach and/or bleach activator. It may also be preferred that a source of alkalinity is released to the wash water more rapidly than the other components of the detergent tablet. It is also envisaged that it may be advantageous to produce a detergent tablet according to the invention in which the release of certain components of the tablet is delayed relative to other components.

The tablet may also comprise a plurality of depressions (cavities) in the compressed solid portion. This plurality of depressions (cavities) may overlap one another or be clearly separated from one another.
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The tablet may also comprise a plurality of non-compressed, non-encapsulating portions. Such a plurality of non-compressed, non-encapsulating portions may be advantageous as it allows the manufacture of a tablet having, for example, a first and a second and optionally further portions having different dissolution rates. Such performance advantages are achieved by selectively releasing active detergent components into the wash water at different times.

It is preferred that the detergent tablets of the invention are free from unpleasant or noxious odors. If present, these odors can be masked or eliminated. This includes the addition of masking agents, perfumes, odor absorbers such as cyclodextrins and the like.

The detergent tablet may be transparent or opaque, or any possible shade between these two extremes. The compressed solid and the at least one non-compressed, non-encapsulating portion may have the same or a different degree of transparency ranging from completely transparent to opaque. However, it is preferred that they be different. If more than one non-compressed, non-encapsulating portion is present in the detergent tablet, it is possible that each non-compressed, non-encapsulating portion may have the same or a different degree of transparency ranging from completely transparent to opaque. However, it is preferred that they be different.

It is also preferred that more than 90%, more preferably more than 95%, most preferably more than 98% of the at least one non-pressed, non-encapsulating portion is free of visible cracks after one week of storage at ambient conditions. It is also preferred that any gaps between the pressed solid and the at least one non-pressed, non-encapsulating portion have a width of less than 1 mm, more preferably less than 0.75 mm, most preferably less than 0.5 mm after one week of storage at ambient conditions.

The detergent tablets described here preferably have a weight between 15 g and 100 g, more preferably between 18 g and 80 g, most preferably between 20 g and 60 g. The detergent tablets described here which are suitable for use in automatic dishwashing processes most preferably have a weight between 20 and 40 g. The detergent tablets suitable for use in textile washing processes most preferably have a weight between 40 and 100 g, most preferably between 40 and 80 g and most preferably between 40 and 65 g. The weight ratio between the pressed portion and the non-pressed gel portion is generally more than 0.5:1, preferably more than 1:1, more preferably more than 2:1, most preferably more than 3:1 or even more than 4:1, most preferably at least 5:1.

The compressed portions of the detergent tablets described herein have a Child Bite Strength (CBS) which is generally greater than 10 kg, preferably greater than 12 kg, most preferably greater than 14 kg. The CBS is determined according to the U.S. Consumer Product Safety Commission Test Specification.

Child Bite Strength (CBS) test procedure

In this test method, the tablet is placed horizontally between two strips/plates of metal. The upper and lower plates are connected at one side by a hinge so that the plates resemble a human jaw. An increasing downward force is applied to the upper plate to mimic the closing action of the jaw until the tablet breaks. The CBS of the tablet is a measure of the force in kg required to break the tablet.

The dissolution rate of the at least one non-pressed, non-encapsulating portion may be greater than the dissolution rate of the pressed portion as determined using the SOTAX dissolution test method. Alternatively, the dissolution rate of the pressed portion may be greater than the dissolution rate of the at least one non-pressed, non-encapsulating portion as determined using the SOTAX dissolution test method.

The dissolution rate is determined using the SOTAX dissolution test method. For the purposes of the present invention, dissolution of detergent tablets is achieved using a SO-TAX (trade name) apparatus, Model No. AT7, available from SOTAX.

SOTAX dissolution test procedure

The SOTAX device consists of a temperature-controlled water bath with a lid. Seven pots are suspended in the water bath. Seven electric stirrers hang down from the bottom of the lid in positions that correspond to the position of the pots in the water bath. The lid of the water bath also serves as a lid on the pots.

The SOTAX water bath is filled with water and the thermometer is set to 5O ⁰ C. Then each pot is filled with 1 L of deionized water and the stirrer is set to 250 rpm. The lid of the water bath is closed and the temperature of the deionized water in the pots is allowed to equilibrate with the water in the water bath for 1 h.

The compressed portion and the non-compressed non-encapsulating portion(s) are weighed and one tablet is placed in each pot, then the lid is closed. The compressed portion and the non-compressed non-encapsulating portion(s) are visually monitored until they have completely dissolved. The time for the compressed portion and the non-compressed non-encapsulating portion(s) to completely dissolve is recorded. The dissolution rate of the compressed portion and the non-compressed non-encapsulating portion(s) is calculated as the average weight (g) of tablet dissolved in deionized water per min.

Pressed portion

The compressed portion of the detergent tablet comprises at least one active detergent component, but may comprise a mixture of more than one active detergent component which is compressed. Any detergent tablet component commonly used in known detergent tablets is suitable for incorporation into the compressed portion of the detergent tablets of the invention. Suitable active detergent components are described below. Examples of such active detergent components include, but are not limited to, a builder compound, a dispersing polymer, a colorant, a surfactant, a bleach, a bleach activator, a bleach catalyst, an enzyme, a pH buffer, an alkalinity source, and mixtures thereof.

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The active detergent component(s) contained in the pressed layer may optionally be prepared in combination with a carrier and/or a binder, for example a polymer (such as PEG), a liquid silicate. The active detergent components are preferably prepared in particulate form (i.e. in the form of a powder or granules) and they may be prepared by any known method, for example by conventional spray drying, granulation or agglomeration. The particulate active detergent component(s) is (are) then pressed using suitable equipment suitable for the manufacture of pressed tablets, blocks, bricks or briquettes, as further described below.

The pressed solid portion preferably has at least one depression (cavity) on a surface of the pressed solid portion. The non-pressed, non-encapsulating portion(s) is (are) disposed in the depressions (cavities).

The pressed solid portion may also be provided with a coating of a water-soluble material to protect the solid portion. The coating layer preferably comprises a material which solidifies upon contact with the pressed and/or non-pressed portions within preferably less than 15 minutes, more preferably within less than 10 minutes, most preferably within less than 5 minutes, most preferably within less than 60 seconds. Preferably, the coating layer is water-soluble. Preferred coating layers contain materials selected from the group consisting of fatty acids, alcohols, diols, esters and ethers, adipic acid, carboxylic acids, dicarboxylic acids, polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP) ₁ polyacetic acid, polyethylene glycol (PEG) and mixtures thereof. Preferred carboxylic acids or dicarboxylic acids preferably contain an even number of carbon atoms.

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atoms. Preferred carboxylic acids or dicarboxylic acids contain at least 4, particularly preferably at least 6, very particularly preferably at least 8, most preferably 8 to 13 carbon atoms. Preferred dicarboxylic acids include adipic acid, suberic acid, azelaic acid, sebacic acid,

. 5 undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid and mixtures thereof. Preferred fatty acids are those having a carbon chain length of from C12 to C22, most preferably from C18 to C22. The coating layer may also preferably contain a disintegrating agent. Where present, the coating layer generally constitutes at least 0.05%, preferably at least 0.1%, more preferably at least 1%, most preferably at least 2% or even at least 5% of the detergent tablet. However, when the detergent tablet is an automatic dishwashing composition, it is preferred that when the pressed portion is coated, the coating is not a fatty acid.

Non-pressed, non-encapsulating portion

The non-pressed, non-encapsulating portion comprises at least one active detergent component, but may also comprise a mixture of more than one active detergent component. Active detergent components suitable for incorporation into the non-pressed, non-encapsulating portion include components that interact with one or more active detergent components contained in the pressed portion. Preferred components of the non-pressed, non-encapsulating portion are particularly those that are adversely affected by the compression pressure of, for example, a tablet press. Examples of such active detergent components include, but are not limited to, a surfactant, a bleach, a bleach activator, a bleach catalyst, an enzyme, a corrosion inhibitor, a perfume and an alkalinity source. These components are described in more detail below. The active(s)

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Detergent component(s) may be in any form, for example in the form of particles (i.e. a powder or a granule) or in the form of a gel or liquid. The non-pressed, non-encapsulating portion may optionally comprise a carrier component in addition to an active detergent component. The active detergent component may be in the form of a solid, a gel or a liquid before being combined with a carrier component.

The non-pressed, non-encapsulating portion is formulated so that the active detergent component is released substantially completely within a short period of time. Typically, the gel portion is formulated so that at least about 80% of the detergent active ingredient is released into the wash liquid of a household laundry process within the first few minutes, more preferably at least about 90 % of the detergent active ingredient is released within the first three minutes, and most preferably 95% of the detergent active ingredient is released within the first two minutes.

The non-compressed, non-encapsulating portion of the detergent tablet may be in solid form, in gel form, in liquid form or in powder form.

The detergent tablet according to the invention requires that the non-pressed, non-encapsulating portion is supplied to the pressed portion such that the pressed portion and the non-pressed, non-encapsulating portion are in contact with each other. The non-pressed, non-encapsulating portion can be supplied to the pressed portion in solid form or flowable form. If the non-pressed, non-encapsulating portion is in solid form, it is previously manufactured, optionally shaped and then supplied to the pressed portion. The non-pressed, non-encapsulating portion is then fixed to a previously shaped pressed portion, for example by adhesion or by introducing the non-pressed, non-encapsulating portion.

the portion into a cooperating surface of the pressed portion. The pressed portion includes at least one cavity into which the non-pressed, non-encapsulating portion(s) is/are introduced.

The non-pressed, non-encapsulating portion is preferably supplied to the pressed portion in flowable form. The non-pressed, non-encapsulating portion is then fixed to the pressed portion, for example by adhesion, by forming a coating on the non-pressed, non-encapsulating layer to secure it to the pressed portion, or by curing, for example (i) by cooling to a temperature below the melting point at which the flowable composition becomes a solidified melt; (ii) by evaporation of a solvent; (iii) by crystallization; (iv) by polymerization of a polymeric component of the flowable non-pressed, non-encapsulating portion; (v) by pseudoplastic properties when the flowable non-pressed, non-encapsulating portion comprises a polymer and shear forces are applied to the non-pressed, non-encapsulating portion; (vi) by combining a binder with the flowable non-pressed, non-encapsulating portion. In an alternative embodiment, the flowable non-pressed, non-encapsulating portion may be an extrudate which is fixed to the pressed portion, for example using any of the mechanisms described above or by expanding the extrudate to the parameters of a cavity provided in the pressed portion.

The pressed portion comprises at least one cavity into which the non-pressed, non-encapsulating portion(s) is/are introduced. In an alternative embodiment, the surface of the pressed portion comprises more than one cavity into which the non-pressed, non-encapsulating portion can be introduced. The cavity(s) preferably at least partially accommodate one or more non-pressed, non-encapsulating portions. The non-pressed, non-encapsulating portion(s)

The encapsulating portion(s) is then introduced into the cavity(s) (mold(s)) and secured to the encapsulated portion as described above. Alternatively, the detergent tablet contains a cavity (mold) in which there are two non-encapsulated, non-encapsulating portions. The first non-encapsulated, non-encapsulating portion may be added in the form of a liquid which is allowed to set or harden, or it may be added in the form of a pre-prepared gel. These two different non-encapsulated, non-encapsulating portions may have different dissolution rates.

The non-pressed, non-encapsulating portion may comprise particles, for example powders or granules. The particles may be prepared by any known method, for example by conventional spray drying, granulation, encapsulation or agglomeration. The particles may be fixed to the pressed portion by incorporation of a binder or by forming a coating layer over the non-pressed, non-encapsulating portion.

When the detergent tablet comprises more than one non-compressed, non-encapsulating portion, the first and second and optionally further non-compressed, non-encapsulating portions may comprise particles having substantially different average particle sizes. By substantially different average particle size is meant that the difference between the average particle size of the first and second and/or further compositions is more than 5%, preferably more than 10%, more preferably more than 10% or even 20% greater than the smaller average particle size.

The average particle size of the particulate detergent active components used in the present invention is determined using a series of Tyler sieves. The series consists of a number of sieves each having a different sieve opening size.

Samples of a composition of active detergent components are sieved through the series of sieves (typically 5 sieves). The weight of a sample of the composition retained on the sieve is plotted against the sieve opening size. The average particle size of the composition is defined as the sieve opening size passed by 50% by weight of the sample of the composition.

Alternatively, compositions containing more than one active detergent component may have a substantially different density. For example, the difference between the density of the first and second and/or further compositions may be greater than about 5%, preferably greater than about 10%, more preferably greater than about 15% or even about 20%, than the lower density. The density of the particulate composition of the active detergent components may be determined by any known method suitable for measuring the density of a particulate material.

Preferably, the density of the composition of active detergent components is measured using a simple funnel and cup apparatus consisting of a conical funnel rigidly molded to a base and provided with a flap valve at its lower end so that the contents of the funnel can be emptied into an axially aligned cylindrical cup disposed beneath the funnel. The funnel is 130mm high and has internal diameters of 130mm and 40mm at its respective upper and lower ends. It is mounted so that the lower end is disposed 140mm above the upper surface of the base. The cup has an overall height of mm, an internal height of 87mm and an internal diameter of 84mm. Its nominal volume is 500ml.

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A density measurement is made by manually pouring the composition into the funnel. Once the funnel is full, the flap valve is opened and the powder is allowed to run through the funnel, overfilling the cup. The filled cup is removed from the frame and the excess powder is removed from the cup by passing a straight scraper element, such as a knife, over its upper edge. The filled cup is then weighed and the value obtained as the weight of the powder is doubled to give the bulk density in g/l. The measurements are repeated as many times as required.

Tablets in which one or more of the non-compressed, non-encapsulating portions comprise particles and the average particle size and/or density of the first and the further non-compressed, non-encapsulating portions are substantially different from each other are preferred when the first and the second and optionally further non-compressed, non-encapsulating portions are to have different dissolution rates.

When the non-pressed, non-encapsulating portion comprises a solidified melt, the melt is prepared by heating a composition comprising an active detergent component and optionally one or more carrier components to a temperature above its melting point to form a flowable melt. The flowable melt is then poured into a cavity in the surface of the pressed portion and allowed to cool. As the melt cools, it solidifies, assuming the shape of the cavity at ambient temperature. When the composition comprises one or more carrier components, the carrier component(s) may be heated to a temperature above its melting point and then an active detergent component may be added. Carrier components suitable for preparing a solidified melt are typically non-active components heated to a temperature above

their melting point to form a liquid and which can be cooled to form an intermolecular matrix which can effectively enclose the active detergent components. A preferred non-active carrier component is an organic polymer which is solid at ambient temperature. Preferably, the non-active detergent component is polyethylene glycol (PEG). The pressed portion of the detergent tablet preferably has at least one depression (hollow form) which receives the melt.

The flowable non-pressed, non-encapsulating portion may be in a form comprising a dissolved or suspended active detergent component. The flowable non-pressed, non-encapsulating portion may cure over time to form a solid, semi-solid or highly viscous liquid non-pressed, non-encapsulating portion by any of the methods described above. In particular, the flowable non-pressed, non-encapsulating portion may cure by evaporation of a solvent. Solvents suitable for use in the present invention include any known solvent in which a binder is soluble. Preferred solvents may be polar or non-polar and may include water, alcohol (e.g., ethanol, acetone) and alcohol derivatives. In an alternative embodiment, more than one solvent may be used.

The flowable non-pressed, non-encapsulating portion may comprise one or more binders. Suitable for use in the present invention is any binder which has the effect of causing the composition to become solid, semi-solid or highly viscous with the passage of time. Without wishing to be bound by any theory, it is believed that the mechanisms by which the binder causes a non-solid composition to become solid, semi-solid or highly viscous include: a chemical reaction (e.g. chemical cross-linking) or an interaction between two or more components of the respective flowable

Compositions; a chemical or physical interaction between the binder and a component of the composition. Preferred binders include a sugar/gelatin combination, starch, glycerin and organic polymers. The sugar can be any monosaccharide

- 5 (e.g. glucose), disaccharide (e.g. sucrose or maltose) or polysaccharide. The most preferred sugar is the commonly available sucrose. For the purposes of the present invention, gelatin of type A or type B can be used, such as is available from Sigma. Type A gelatin is preferred because it has a higher stability under alkaline conditions than type B. A preferred gelatin also has a bloom strength of between 65 and 300, most preferably between 75 and 100. Preferred organic polymers include polyethylene glycol (PEG) having a molecular weight of from 500 to 10,000, preferably from 750 to 8,000, most preferably from 1,000 to 6,000, available for example from Hoechst.

When the non-pressed, non-encapsulating portion is an extrudate, the extrudate is prepared by premixing the active detergent components with any carrier components to form a viscous paste. The viscous paste is then extruded using suitable, commercially available extrusion equipment, for example a single screw or twin screw extruder, such as that available from APV Baker, Peterborough, U.K.

The extrudate is then cut to the desired size either after introduction into the compressed portion or before introduction into the compressed portion of the detergent tablet. The compressed portion of the tablet includes at least one cavity into which the extruded non-compressed, non-encapsulating portion is introduced.

In a preferred embodiment, the non-pressed, non-encapsulating portion is provided with a coating layer. The coating layer can

be used to fix a non-pressed, non-encapsulating portion to the pressed portion. This can be particularly advantageous if the non-pressed, non-encapsulating portion comprises flowable particles, gels or liquids.

The coating layer preferably comprises a material which solidifies upon contact with the pressed and/or non-pressed non-encapsulating portions within preferably less than 15 minutes, more preferably less than 10 minutes, most preferably less than 5 minutes, and most preferably less than 60 seconds. The coating layer is preferably water soluble. Preferred coating layers comprise materials selected from the group consisting of fatty acids, alcohols, diols, esters and ethers, adipic acid, carboxylic acids, dicarboxylic acids, polyvinyl acetate (PVA), polyvinylpyrrolidone (PVP), polyacetic acid, polyethylene glycol (PEG), and mixtures thereof. Preferred carboxylic acids or dicarboxylic acids preferably contain an even number of carbon atoms. Preferred carboxylic acids or dicarboxylic acids contain at least 4, more preferably at least 6, most preferably at least 8, and most preferably 8 to 13 carbon atoms. Preferred dicarboxylic acids include adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid and mixtures thereof. Preferred fatty acids are those having a carbon chain length of C12 to C22, more preferably C18 to C22. The coating layer may also preferably contain a disintegrating agent. When present, the coating layer generally comprises at least about 0.05%, preferably at least about 0.1%, more preferably at least about 1%, most preferably at least about 2%, or even at least about 5% of the detergent tablet. However, when the detergent tablet is an automatic dishwashing composition, it is preferred that the coating is not a fatty acid.

In a preferred embodiment, the coating layer can encapsulate the detergent tablet. In this embodiment, the coating layer is present in an amount of at least about 4%, more preferably at least about 5%, most preferably at least about 10% of the detergent tablet.

In a preferred embodiment, the pressed and/or non-pressed, non-encapsulating portions and/or the coating layer additionally contain a disintegrating agent. The disintegrating agent may be a disintegrating agent or an effervescent agent. Suitable disintegrating agents include agents which swell on contact with water or facilitate the inflow and/or outflow of water by forming channels in the pressed and/or non-pressed, non-encapsulating portions. Any known disintegrating agent or effervescent agent suitable for use in washing or dishwashing purposes is suitable for use in accordance with the invention. Suitable disintegrating agents include starch, starch derivatives, alginates, carboxymethylcellulose (CMC), cellulose-based polymers, sodium acetate, alumina. Suitable effervescent agents include those which form a gas on contact with water. Suitable effervescent agents may be oxygen, nitrogen dioxide or carbon dioxide-evolving compounds. Examples of preferred effervescent agents can be selected from the group consisting of perborate, percarbonate, carbonate, bicarbonate and carboxylic acids such as citric acid or maleic acid.

An advantage of incorporating a disintegrant into the detergent tablet of the invention is the transportation, storage and handling advantages that can be achieved by increasing the hardness of the detergent tablet without adversely affecting the cleaning effectiveness.

The non-pressed, non-encapsulating portion may additionally contain a drying agent. Any conventional drying agent may be used

(cf. the textbook by Vogel "Practical Organic Chemistry", 5th edition (1989), Longman Scientific & Technical, pp. 165-168, to which reference is expressly made here. Examples of suitable drying agents are anhydrous CaSO ₄ , anhydrous Na ₂ SO ₄ , calcium chloride, sodium sulfite and MgSO ₄ .

- 5 The selection of suitable drying agents may depend on the end use of the tablet. A drying agent for an automatic dishwashing composition detergent tablet for low temperatures is preferably sodium sulfite or calcium chloride, but anhydrous CaSO ₄ may also be used for higher temperatures. When present, the drying agents are present in an amount of from about 0.1 to about 15% by weight, more preferably from about 0.1 to about 10% by weight, most preferably from about 0.5 to about 7% by weight.

When the non-compressed, non-encapsulating portion is a gel fixed to or disposed in a cavity in the compressed solid portion of the detergent tablet, the non-compressed, non-encapsulating portion may additionally contain a thickening system in addition to the at least one active detergent.

When the non-pressed, non-encapsulating portion is a gel, it may contain solid components dispersed or suspended within the gel. The solid components assist in controlling the viscosity of gel formation in combination with the thickening system. When present, the non-pressed, non-encapsulating portion typically contains at least about 15% solid components, more preferably at least about 30% solid components, and most preferably at least about 40% solid components. However, because of pumpability and other processing characteristics, the non-pressed, non-encapsulating portion of the present invention typically contains no more than about 90% solid components when in the form of a gel.

Thickening system

As previously indicated, the detergent tablet of the present invention contains a thickening system in the non-compressed, non-encapsulating portion when the non-compressed, non-encapsulating portion is a gel to impart the appropriate viscosity or thickening to the gel portion. The thickening system typically comprises a non-aqueous liquid diluent and an organic or polymeric gelling additive.

a) Liquid diluent

The term "diluent" as used herein refers to the liquid portion of the thickening system. Although some of the essential and/or optional components of the compositions of the invention may actually dissolve in the "diluent"-containing phase, other components may be present as particulate material present within the "diluent"-containing phase. The term "diluent" as used herein does not necessarily mean that the solvent material can actually dissolve all of the components added to the detergent composition. Suitable types of diluents that may be used in the non-aqueous thickening systems include alkylene glycol mono-lower alkyl ethers, propylene glycols, ethoxylated or propoxylated ethylene or propylene, glycerol esters, glycerol triacetate, low molecular weight polyethylene glycols, methyl esters and low molecular weight amides, and the like.

A preferred type of non-aqueous diluent for use in the present invention comprises the mono-, di-, tri- or tetra-C ₂ -C 3 alkylene glycol mono^-C 1 -alkyl ethers. Specific examples of these compounds include diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, dipropylene glycol monoethyl ether and dipropylene glycol

>o.

monobutyl ether. Diethylene glycol monobutyl ether and dipropylene glycol monobutyl ether are particularly preferred. Compounds of this type are commercially available under the trade names Dowanol, Carbitol and CeIIosolve.

Another preferred type of non-aqueous diluent that can be used in the present invention comprises the low molecular weight polyethylene glycols (PEGs). These materials are those having molecular weights of at least about 150. PEGs having a molecular weight in the range of about 200 to 600 are most preferred.

Yet another preferred type of non-aqueous diluent comprises low molecular weight methyl esters. These materials are those of the general formula: R^C(O)-OCH ₃ , wherein R ¹ ranges from 1 to about 18. Examples of suitable low molecular weight methyl esters include methyl acetate, methyl propionate, methyl octanoate, and methyl dodecanoate.

The non-aqueous organic diluent(s) used should, of course, be compatible and non-reactive with the other components of the composition, e.g. the enzymes used in the detergent tablets of the invention. Such a diluent component is generally used in an amount of from about 10 to about 60 % by weight based on the weight of the composition. More preferably, the low polarity non-aqueous organic diluent comprises from about 20 to about 50% by weight, most preferably from about 30 to about 50% by weight of the composition.

b) Gelling additive

As already indicated above, a gelling agent or additive is added to the non-aqueous diluent of the invention to complete the thickening system. For the formation of the gel, which is necessary for sufficient phase stability and acceptable rheological properties of the

- 5 non-pressed, non-encapsulating portion is required, the organic gelling agent is generally present in a ratio of diluent to gelling agent in the thickening system which is typically in the range of about 99:1 to about 1:1. More preferably, the ratio is in the range of about 19:1 to about 4:1.

The preferred gelling agents of the invention are selected from castor oil derivatives, propylene glycol, polyethylene glycol, sorbitols and related organic thixotropic agents, organic clays, cellulose and cellulose derivatives, pluronics, stearates and stearate derivatives, a sugar/gelatin combination, starches, glycerin, organic acid amides such as N-lauryl-L-glutamic acid di-n-butylamide and mixtures thereof.

The preferred gelling agents are castor oil derivatives. Castor oil is a naturally occurring triglyceride obtained from the seeds of Ricinus Communis, a plant that grows in most tropical and subtropical areas. The primary fatty acid moiety in castor oil triglyceride is ricinoleic acid (12-hydroxyoleic acid). It makes up about 90% of the fatty acid moiety. The remainder consists of dihydroxystearic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and eicosanoic acid residues. By hydrogenating the oil (for example with hydrogen under pressure), the double bonds in the fatty acid residues are converted to single bonds, so that the oil is "hardened". The hydroxyl groups are not attacked by this reaction.

The resulting hydrogenated castor oil therefore contains an average of about three hydroxyl groups per molecule. It is believed that the presence of these three hydroxyl groups is largely responsible for the exceptional

structural properties imparted to the non-pressed, non-encapsulating portion compared to similar liquid detergent compositions that do not contain castor oil with hydroxyl groups in their fatty acid chains. For use in the inventive

. 5 In these compositions, the castor oil should be hydrogenated to an iodine number of less than about 20, preferably less than about 10. The iodine number is a measure of the degree of unsaturation of the oil and is determined by the "Wijis method" which is well known in the art. Unhydrogenated castor oil has an iodine number of about 80 to 90.

Hydrogenated castor oil is a commercially available product sold in various grades under the trademark CASTORWAX.RTM. by NL Industries, Inc., Highstown, New Jersey. Other suitable hydrogenated castor oil derivatives are Thixcin R, Thixcin E, Thixatrol ST, Perchem R and Perchem ST manufactured by Rheox, Laporte. Thixatrol ST is particularly preferred.

Polyethylene glycols, when used as gelling agents rather than solvents, have a molecular weight in the range of about 2,000 to about 30,000, preferably from about 4,000 to about 12,000, most preferably from about 6,000 to about 10,000.

Preferred cellulose and cellulose derivatives when used in the present invention include (i) cellulose acetate and cellulose acetate phthalate (CAP); (ii) hydroxypropylmethylcellulose (HPMC); (iii) carboxymethylcellulose (CMC); and mixtures thereof. The hydroxypropylmethylcellulose polymer preferably has a number average molecular weight of about 50,000 to 125,000 and a viscosity of a 2 wt% aqueous solution at 25 ^° C (ADTMD2363) of about 50,000 to about 100,000 cP. A particularly preferred hydroxypropylcellulose polymer is Methocel® J75MS-N, whose 2.0 wt% aqueous solution at 25 ^° C has a viscosity of about 75,000 cP.

The sugar may be any monosaccharide (e.g. glucose), disaccharide (e.g. sucrose or maltose) or polysaccharide. The most preferred sugar is the commonly available sucrose. For the purposes of the present invention, gelatin of type A or type B may be used.

- 5 den, for example, available from Sigma. Type A gelatin is preferred because it has a higher stability under alkaline conditions than type B. The preferred gelatin also has a bloom strength between 65 and 300, most preferably between 75 and 100.

The non-pressed, non-encapsulating portion of the invention may contain a variety of other components in addition to the thickening agent described above and the detergent active described in detail below. Components such as perfumes and dyes may be included as well as swelling agents/adsorbents, for example carboxymethylcelluloses and starches, to assist in the adsorption of excess diluent or the dissolution or disruption of the non-pressed, non-encapsulating portion in the wash liquid. In addition, hardness modifiers may be incorporated into the thickening system to adjust the hardness of the gel if desired. These hardness control agents are typically selected from various polymers and polyethylene glycols and, when included, are typically used in amounts of less than about 20% by weight, preferably less than about 10% by weight, based on the weight of the solvent in the thickening system. For example, hardeners, e.g. a high molecular weight PEG, preferably with a molecular weight of 10,000 to 200,000 or possibly with an even higher molecular weight, can be added to shorten the curing time of the non-pressed, non-encapsulating portion. Alternatively, water-soluble polymeric materials, e.g. low molecular weight polyethylene glycol, can be added to the cavity (mold) to form an intermediate barrier layer before the non-pressed, non-

i"!-99

encapsulating portion if it is a gel. This accelerates the cooling and hardening of the gel by melting/mixing the water-soluble polymeric material when the gel is fed into the at least one cavity (mold). . 5 In addition, the intermediate layer can act as a barrier layer which prevents components from the gel from mixing with the pressed portion or leaking into it (bleeding).

The addition of an alkaline material such as sodium or potassium hydroxide can also accelerate the curing of the non-pressed, non-encapsulating portion when it is a gel. Preferably, these alkaline materials are added to the cavity before the gel is added. However, in other systems, the alkaline material may be added to the gel composition. These alkaline materials also have the advantage of acting as an additional source of alkalinity that dissolves more slowly and thus has minimal impact on any effervescent system that may be present in the non-pressed, non-encapsulating portion, while still increasing the alkalinity of the wash liquid.

When a gel, the non-compressed, non-encapsulating portion of the invention is formulated such that the gel is a pumpable, flowable gel at slightly elevated temperatures of about 30 ^° C or higher, allowing increased flexibility in the manufacture of the detergent tablet, but which becomes highly viscous or hardens at ambient temperatures so that the gel remains in position in at least one cavity in the pressed solid portion of the detergent tablet during shipping and handling of the detergent tablet. Such hardening of the non-compressed, non-encapsulating portion can be achieved, for example, (i) by cooling to a temperature below the flow temperature of the gel; (ii) by evaporating the diluent or (iii) by polymerizing the gel.

Preferably, the gel portion is formulated such that the gel hardens sufficiently so that the maximum force required to push a probe into the cavity (hollow mold) is preferably in the range of about 0.5 N to about 40 N. This force can be characterized

- 5 are determined by measuring the maximum force required to push a probe fitted with a force gauge a specified distance into the gel. The specified distance can be between 40 and 80% of the total depth of the gel. This force can be measured using a QTS 25 test device using a probe with a diameter of 5 mm. Typical forces measured are in the range of 1N to 25N.

It is also preferred that when a 48 hour old tablet is inverted at ambient conditions for 10 minutes, more preferably 30 minutes, or most preferably 2 hours, the non-compressed, non-encapsulating portion does not drip or separate from the compressed solid portion.

Cleaning agents

The compressed portion of the detergent tablets described herein is prepared by compressing a composition of active detergent components. A suitable composition may comprise a variety of different active detergent components, for example, builder compounds, surfactants, enzymes, bleaches, alkalinity sources, colorants, perfume, lime soap dispersants, organic polymeric compounds including polymeric color transfer inhibiting agents, crystal growth inhibitors, heavy metal ion sequestrants, metal ion salts, enzyme stabilizers, corrosion inhibitors, foam suppressors, solvents, fabric softeners, optical brighteners and hydrotropic agents.

Both the non-pressed, non-encapsulating portion(s) and the pressed portion of the cleaning agent tablet according to the invention contain at least one cleaning agent active ingredient. The non-pressed, non-encapsulating portion(s) usually contain cleaning agents.

- 5 tel active ingredients, such as surfactants, enzymes, bleaches, effervescent agents, silver care agents, builder compounds and the like. The pressed portion generally contains cleaning agent active ingredients, such as builder compounds, surfactants, silicates, pH control agents or buffers, enzymes and bleaches. The cleaning agent active ingredients which can be used according to the invention are described below.

Surfactants

Surfactants are preferred active detergent components of the compositions described herein. Suitable surfactants are selected from anionic, cationic, non-ionic, ampholytic and zwitterionic surfactants and mixtures thereof. Automatic dishwashing products should be low foaming and therefore the surfactant system for use in dishwashing processes must be low foaming or, most preferably, be a low foaming system, usually non-ionic in character. The foaming caused by surfactant systems used in laundry cleaning processes need not be suppressed to the same extent as is required in dishwashing.

A typical listing of anionic, nonionic, ampholytic and zwitterionic classes and species of these surfactants is given in U.S. Patent 3,929,678 (Laughlin and Heuring, issued December 30, 1975). A list of suitable cationic surfactants is given in U.S. Patent 4,259,217 (Murphy, issued March 31, 1981).

A list of surfactants that are typically included in automatic dishwashing detergent compositions can be found in

in-Q9

d iQ9

EP-A-0 414 549 and in PCT patent applications WO 93/08876 and WO 93/08874.

Detergent surfactants included in the fully formulated detergent compositions of the present invention comprise at least 0.01%, preferably about 0.5% to about 50% by weight of the detergent composition, depending on the particular surfactants used and the effects desired. In a highly preferred embodiment, the detergent surfactant comprises about 0.5% to about 20% by weight of the composition.

The cleaning surfactant can be non-ionic, anionic, ampholytic, zwitterionic or cationic. Mixtures of these surfactants can also be used. Preferred cleaning compositions contain anionic cleaning surfactants or mixtures of anionic surfactants with other surfactants, especially non-ionic surfactants.

Non-ionic surfactants

Particularly preferred surfactants in the preferred automatic dishwashing (ADD) compositions of the present invention are low foaming nonionic surfactants (LFNI). The LFNI may be present in amounts of from 0.01 to about 10 weight percent, preferably from about 0.1 to about 10 weight percent, and most preferably from about 0.25 to about 4 weight percent. The LFNI are typically used in ADD because of the improved aqueous film forming effect (particularly on glass) they impart to the ADD product. They also include non-silicone, non-phosphate polymeric materials, as discussed below, which are known to defoam food residues encountered in automatic dishwashing.

Preferred LFNIs include non-ionic alkoxylated surfactants, particularly ethoxylates derived from primary alcohols, and mixtures

the same with more complicated surfactants, for example the polyoxypropylene/polyoxyethylene/polyoxypropylenePO/EO/POJ reverse block polymers. The PO/EO/PO polymer type surfactants are generally known to have a foam suppressing or defoaming effect, especially compared to the common food soiling components such as eggs.

The invention includes preferred embodiments in which LFNI is present and wherein this component is solid at about 35 ^° C (95 ^° F), more preferably at about 25°C (77°F). For ease of manufacture, the preferred LFNI have a melting point between about 25°C and about 60 ^° C (77-140 ^° F), more preferably between about 26.6 and 43.3°C (80-110°F).

In a preferred embodiment, the LFNI is an ethoxylated surfactant derived from the reaction between a monohydroxy alcohol or alkylphenol having from about 8 to about 20 carbon atoms and from about 6 to about 15 moles of ethylene oxide per mole of alcohol or alkylphenol, calculated as an average.

A particularly preferred LFNI is derived from a straight chain fatty alcohol containing from about 16 to about 20 carbon atoms (C ₁₆ -C ₂₀ alcohol), preferably a Cie alcohol, which has been condensed with an average of about 6 to about 15 moles, preferably about 7 to about 12 moles, and most preferably about 7 to about 9 moles of ethylene oxide per mole of alcohol. Preferably, the ethoxylated nonionic surfactant obtained in this way has a narrow ethoxylate distribution compared to the average.

The LFNI may optionally contain propylene oxide in an amount of up to about 15% by weight. Other preferred LFNI surfactants may be prepared by methods described in U.S. Patent 4,223,163 (Builloty, issued September 16, 1980), the contents of which are incorporated herein by reference.

> &mdash;34*

Particularly preferred ADDs in which the LFNI is present make use of ethoxylated monohydroxy alcohol or alkylphenol and additionally contain a polyoxyethylene-polyoxypropylene block polymer compound, wherein the ethoxylated monohydroxy alcohol or alkylphenol portion of the LFNI comprises about 20 to about 100%, preferably about 30 to about 70% of the total LFNI.

Suitable polyoxyethylene-polyoxypropylene block polymer compounds which meet the requirements described above include those based on ethylene glycol, propylene glycol, glycerin, trimethylolpropane and ethylenediamine as the reactive initiator hydrogen compound. Polymeric compounds prepared by sequential ethoxylation and propoxylation of initiator compounds having a single reactive hydrogen atom, such as C ₁₂ -18 aliphatic alcohols, generally do not provide satisfactory foam control in the ADDs of the present invention. Certain of the block polymer surfactant compounds known as PLURONIC® and TETRONIC® from BASF-Wyandotte Corp., Wyandotte, Michigan, are suitable in the ADD compositions of the present invention.

A particularly preferred LFNI contains about 40 to about 70% of a polyoxypropylene/polyoxyethylene/polyoxypropylene block polymer blend consisting of about 75% by weight of the blend of a reverse block copolymer of polyoxyethylene and polyoxypropylene containing 17 moles of ethylene oxide and 44 moles of propylene oxide and about 25% by weight of the blend of a block copolymer of polyoxyethylene and polyoxypropylene initiated with trimethylolpropane and containing 99 moles of propylene oxide and 24 moles of ethylene oxide per mole of trimethylolpropane.

Suitable for use as LFNI in ADD compositions are those LFNI that have relatively low cloud points and a high hy-

·

"35·

dropophilic-lipophilic balance (HLB). The cloud points of 1% solutions in water are generally below about 32°C and preferably below, for example, 10 ⁰ C to achieve optimum control of foam formation over the full range of water temperatures.

LFNIs that may also be used include Olin Corp.'s POLY-TERGENT® SLF-18 nonionic surfactants and any biodegradable LFNIs that have the melting point properties listed above.

These and other non-ionic surfactants are well known in the art and are described in more detail in Kirk Othmer's "Encyclopedia of Chemical Technology", 3rd edition, Volume 22, pages 360-379, "Surfactants and Detersive Systems", which is incorporated herein by reference.

Preferred are ADD compositions containing mixed surfactants with which the foaming (in the absence of a silicone foaming control agent) is less than 5.1 cm (2 inches), preferably less than 2.54 cm (1 inch), as determined as follows.

The devices suitable for these measurements are: a Whirlpool dishwasher (model 900) equipped with a clear plexiglass door, IBM computer for data collection with Labview and Excel software, a distance sensor (Newark Corp. - model 95F5203) using a SCXI interface and a plastic ruler.

The data is collected as follows: the distance sensor is fixed to the lower dishwasher rack on a metal bracket. The sensor is aimed downwards at the rotating dishwasher arm on the bottom of the device (distance about 2 cm from the rotating arm). Each pass of the rotating arm is measured by the distance sensor and recorded. The pulses recorded by the computer are

which is converted into revolutions per minute (rpm) of the floor arm by counting the pulses over a period of 30 s. The speed of the arm rotation is directly proportional to the amount of foam in the device and in the dishwasher pump (i.e. the more foam is produced, the slower the arm rotates).

The plastic ruler is attached to the bottom rack of the dishwasher and extends to the bottom of the appliance. At the end of the wash cycle, the height of the foam is measured using the plastic ruler (viewed through the clear door) and recorded as the foam height.

The following procedure is used to evaluate the ADD compositions for foaming and to evaluate the usefulness of the non-ionic surfactants (to evaluate the non-ionic surfactant separately, a base ADD formulation, such as a cascade powder, is used together with the non-ionic surfactants which are added separately to the dishwasher in glass vials).

First, the machine is filled with water (adjusting the water to the appropriate temperature and hardness) and allowed to run until the rinse cycle. The rpm are monitored during the cycle (approximately 2 min) without adding any ADD product (or surfactants) (a quality control check to ensure that the machine is functioning properly). When the machine begins to fill to perform the wash cycle, the water is again adjusted for temperature and hardness and then the ADD product is added at the bottom of the machine (in the case of separate evaluation of surfactants, the ADD base formulation is added first to the bottom of the machine, then the surfactants are added by placing the glass vials containing the surfactant upside down on the top rack of the machine). The rpm is then monitored during the wash cycle. At the end of the wash cycle, the foam height is measured under

The machine is refilled with water (to adjust the water to the appropriate temperature and hardness) and another rinse cycle is run. The number of revolutions is monitored during this cycle.

The average spin speed is calculated for the first rinse, main wash and final rinse. The spin speed efficiency percentage is then calculated by dividing the average spin speed for the test surfactants by the average spin speed for the control system (base ADD formulation without a non-ionic surfactant). The spin speed efficiency and foam height measurements are used to determine the overall foaming profile of the surfactant.

Non-ionic ethoxylated alcohol surfactant

The alkyl ethoxylate condensation products of aliphatic alcohols with 1 to 25 moles of ethylene oxide are suitable for use according to the invention. The alkyl chain of the aliphatic alcohol can be either straight (unbranched) or branched, primary or secondary and generally contain 6 to 22 carbon atoms. Particularly preferred are the condensation products of alcohols which have an alkyl group with 8 to 20 carbon atoms with 2 to 10 moles of ethylene oxide per mole of alcohol.

Terminated alkyl alkoxylate surfactant

A suitable terminated alkyl alkoxylate surfactant is the epoxy terminated poly(oxyalkylated) alcohols represented by the formula:
30

R ₁ O[CH ₂ CH(CH ₃ )O]X[Ch ₂ CH ₂ O]V[CH ₂ CH(OH)R ₂ ] (I)

·: ·38'

wherein R ₁ is a linear or branched aliphatic hydrocarbon radical having 4 to 18 carbon atoms; R ₂ is a linear or branched aliphatic hydrocarbon radical having 2 to 26 carbon atoms; x is an integer having an average value of 0.5 to 1.5, preferably . 5 of 1; and y is an integer having a value of at least 15, preferably at least 20.

The surfactant of formula (I) preferably contains at least 10 carbon atoms in the terminal epoxide unit [CH ₂ CH(OH)R ₂ ]. Suitable surfactants of formula (I) according to the present invention are the non-ionic surfactants POLY-TERGENT® SLF-18B from ONn Corporation, as described, for example, in WO 94/22800, published on October 13, 1994, by Olin Corporation.

Poly(oxyalkylated) alcohols terminated with ether groups

Preferred surfactants for use in the present invention include ether-terminated poly(oxyalkylated) alcohols of the formula:

R ¹ O[CH ₂ CH(R ³ )O] _x [CH ₂ ] _k [CH(OH)[CH ₂ ]jOR ²

wherein R ¹ and R ² are linear or branched, saturated or unsaturated, aliphatic or aromatic hydrocarbon radicals having 1 to 30 carbon atoms; R ³ is H or a linear aliphatic hydrocarbon radical having 1 to 4 carbon atoms; &khgr; is an integer with an average value of 1 to 30, where if &khgr;> 2, R ³ can stand for identical or different radicals, and k and j are integers with an average value of 1 to 12, preferably 1 to 5.

R ¹ and R ² preferably represent linear or branched, saturated or unsaturated, aliphatic or aromatic hydrocarbon radicals having 6 to 22 carbon atoms, with those having 8 to 18 carbon atoms being the most preferred.

·::■: if:. C: O

.:.. ..· -eisten
are preferred. H or a linear aliphatic hydrocarbon radical having 1 to 2 carbon atoms is most preferred for R ^3. Preferably, &khgr; is an integer having an average value of 1 to 20, particularly preferably 6 to 15.

As stated above, in preferred embodiments, when χ is greater than 2, the R ³ radicals may be the same or different. That is, R ³ may vary between the alkylene oxide units as described above. For example, when χ = 3, R ³ may be selected from ethyleneoxy(EO) or propyleneoxy(PO) and it may vary in the order (EO)(PO)(EO), (EO)(EO)(PO); (EO)(EO)(EO); (PO)(EO)(PO); (PO)(PO)(EO) and (PO)(PO)(PO). Of course, the integer 3 is chosen only by way of example and the variation may be much greater with a higher integer for χ and may, for example, include many (EO) units and a much smaller number of (PO) units.

Particularly preferred surfactants as described above include those having a low cloud point of less than 20 ^° C. These low cloud point surfactants can then be used in conjunction with a high cloud point surfactant as described in detail below to achieve improved grease cleaning effects.

The most preferred ether terminated poly(oxyalkylated) alcohol surfactants are those in which k = 1 and j = 1, so that the surfactants have the formula:

R ¹ O[CH ₂ CH(R ³ )O] _X CH ₂ CH(OH)CH2OR ²

wherein R ¹ , R ² and R ³ are as defined above and χ is an integer with an average value of 1 to 30, preferably 1 to 20 and particularly preferably 6 to 18. Most preferred are surfactants,

wherein R ¹ and R ² are in the range of 9 to 14 carbon atoms, R ³ is H forming ethyleneoxy, and x is in the range of 6 to 15.

The ether terminated poly(oxyalkylated) alcohol surfactants comprise three general components, namely a linear or branched alcohol, an alkylene oxide and an alkyl ether end group. The alkyl ether end group and the alcohol serve as the hydrophobic, oil-soluble portion of the molecule, while the alkylene oxide group forms the hydrophilic, water-soluble portion of the molecule.

These surfactants demonstrate significant improvements in spotting and film-forming properties and greasy soil removal when used in conjunction with high cloud point surfactants compared to conventional surfactants.

In general, the ether-terminated poly(oxyalkylated) alcohol surfactants of the present invention can be prepared by reacting an aliphatic alcohol with an epoxide to form an ether, which is then reacted with a base to form a second epoxide. The second epoxide is then reacted with an alkoxylated alcohol to form the novel compounds of the present invention. Examples of processes for preparing the ether-terminated poly(oxyalkylated) alcohol surfactants are described below.

Preparation of a Ci?/14-alkyl methyl ether

A Ci2/14 fatty alcohol (100.00 g, 0.515 mol) and tin(IV) chloride (0.58 g, 2.23 mmol, available from Aldrich) are combined in a 500 mL three-necked round-bottom flask equipped with a condenser, an argon inlet, an addition funnel, a magnetic stirrer and an internal temperature probe. The mixture is heated to 60 ⁰ C. Epichlorohydrin (47.70 g, 0.515 mol, available from Aldrich) is added dropwise to maintain the temperature between 60 and 65°C. After stirring for an additional hour at

60°C, the mixture is cooled to room temperature. The mixture is treated with a 50% sodium hydroxide solution (61.80 g, 0.773 mol; 50%) while stirring mechanically. After the addition is complete, the mixture is heated at 90 ^° C for 1.5 h, cooled, and filtered with ethanol. The filtrate is separated, and the organic phase is washed with water (100 mL), dried over _MgSO4 , filtered, and concentrated. Distillation of the oil at 100-120 ^° C (0.1 mm Hg) gives the glycidyl ether as an oil.

Preparation of a Cipm-alkyl-Cs/n-ether-endgroup alcohol surfactant

Neodol® 91-8 (20.60 g, 0.0393 mol ethoxylated alcohol, available from Shell Chemical Co.) and stannous chloride (0.58 g, 2.23 mmol) are combined in a 250 mL three-necked round-bottom flask equipped with a condenser, argon inlet, addition funnel, magnetic stirrer, and internal temperature probe. The mixture is raised to 6O ⁰ C, at which time a Ci ₂ /i4 alkyl glycidyl ether (11.00 g, 0.0393 mol) is added dropwise over a period of 15 min. After stirring at 6O ⁰ C for 18 h, the mixture is cooled to room temperature and dissolved in an equal volume of dichloromethane. The solution is passed through a 2.54 cm (1 inch) pad of silica gel while eluting with dichloromethane. The filtrate is concentrated by rotary evaporation and then stripped in a Kugelrohr furnace (100 ⁰ C ₁ 0.5 mm Hg) to give the surfactant in the form of an oil.

For further details on these and other suitable nonionic surfactants, see U.S. Patent Applications No. 60/054,702 (Attorney Docket No. 6781P), No. 60/054,688 (Attorney Docket No. 6779P), and No. 60/057,025 (Attorney Docket No. 6780P), the contents of which are incorporated herein by reference.

Non-ionic ethoxylated/propoxylated fatty alcohol surfactant

The ethoxylated Ce-Cie fatty alcohols and the mixed Ce-Cie ethoxylated/propoxylated fatty alcohols are suitable surfactants for use according to the invention, especially if they are water-soluble. As ethoxylated

. 5 fatty alcohols preferred are the Cio-Cis-ethoxylated fatty alcohols with a degree of ethoxylation of 3 to 50, most preferred among these are the Ci2-Ci8-ethoxylated fatty alcohols with a degree of ethoxylation of 3 to Preferably, the mixed ethoxylated/propoxylated fatty alcohols have an alkyl chain length of 10 to 18 carbon atoms, a degree of ethoxylation of 3 to 30 and a degree of propoxylation of 1 to 10.

Non-ionic EO/PO condensates with propyleneqlvcol

The condensation products of ethylene oxide with a hydrophobic base formed by condensation of propylene oxide with propylene glycol are suitable for use in the present invention. The hydrophobic portion of these compounds preferably has a molecular weight of 1500 to 1800 and is insoluble in water. Examples of compounds of this type include certain commercially available Pluronic&trade; surfactants marketed by BASF.

Non-ionic EO condensation products with propylene oxide/ethylenediamine adducts

The condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide with ethylenediamine are suitable for use in accordance with the invention. The hydrophobic part of these products consists of the reaction product of ethylenediamine with excess propylene oxide and it generally has a molecular weight of 2500 to

3000. Examples of this type of non-ionic surfactant include certain of the commercially available Tetronic&trade; compounds marketed by BASF.

Mixed non-ionic surfactant system

In a preferred embodiment of the present invention, the detergent tablet comprises a mixed non-ionic surfactant system comprising at least one low cloud point non-ionic surfactant and at least one high cloud point non-ionic surfactant.

The term "cloud point" as used here refers to a well-known property of non-ionic surfactants which is a consequence of the surfactant becoming less soluble with increasing temperature, the temperature at which the appearance of a second phase becomes visible being referred to as the "cloud point" (cf. "Kirk Othmer's Encyclopedia of Chemical Technology", 3rd edition, Volume 22, pages 360-379).

A "low cloud point" nonionic surfactant as used herein is defined as a nonionic surfactant system component having a cloud point of less than 30 ^° C, preferably less than 20 ^° C, and most preferably less than 10 ^° C. Typical low cloud point nonionic surfactants include nonionic alkoxylated surfactants, particularly ethoxylates derived from a primary alcohol, and polyoxypropylene/polyoxyethylene/polyoxypropylene (PO/EO/PO) reverse block polymers. These low cloud point non-ionic surfactants also include, for example, an ethoxylated-propoxylated alcohol (eg Poly-Tergent® SLF18 from Olin Corporation), epoxy-terminated poly(oxyalkylated) alcohols (eg non-ionic surfactants of the Poly-Tergent® SLF18B series from Olin Corporation, as described, for example, in WO 94/22800, published on October 13, 1994, from Olin Corporation) and the ether-terminated poly(oxyalkylated) alcohol surfactants.

Nonionic surfactants may optionally contain propylene oxide in an amount of up to 15% by weight. Other preferred nonionic surfactants may be prepared by methods such as those described in U.S. Patent 4,223,163 (Builloty, issued September 16, 1980), which is incorporated herein by reference.

Low cloud point nonionic surfactants also include a polyoxyethylene-polyoxypropylene block polymer compound. Polyoxyethylene/polyoxypropylene block polymer compounds include those based on ethylene glycol, propylene glycol, glycerin, trimethylolpropane and ethylenediamine as the reactive initiator hydrogen compound. Certain of the block polymer surfactant compounds designated PLURONIC®; REVERSED PLURONIC® and TETRONIC® from BASF-Wyandotte Corp., Wyandotte, Michigan, are useful in ADD compositions of the present invention. Preferred examples include REVERSED PLURONIC® 25R2 and TETRONIC® 702. These surfactants are generally useful as low cloud point nonionic surfactants in the present invention.

The "high cloud point" nonionic surfactant used herein is defined as a nonionic surfactant system component having a cloud point greater than 40 ^° C, preferably greater than 50 ^° C, and more preferably greater than 60 ^° C. Preferred is the nonionic surfactant system comprising an ethoxylated surfactant derived from the reaction of a monohydroxy alcohol or alkylphenol containing 8 to 20 carbon atoms with 6 to 15 moles of ethylene oxide per mole of alcohol or alkylphenol on an average basis. Examples of such high cloud point nonionic surfactants include Tergitol 15S9 (sold by Union Carbide), Rhodasurf TMD 8.5 (sold by Rhone Poulenc), and Neodol 91-8 (sold by Shell). 30

For the purposes of the present invention, it is also preferred that the high cloud point non-ionic surfactant also has a hydrophilic

&bull; ^: 45"""'

Lipophilic balance value (HLB value; cf. Kirk Othmer, as stated above) within the range of 9 to 15, preferably 11 to 15. Examples of such materials include Tergitol 15S9 (sold by Union Carbide), Rhodasurf TMD 8.5 (sold by Rho-. 5 ne Poulenc) and Neodol 91-8 (sold by Shell).

Another preferred nonionic surfactant having a high cloud point is derived from a straight chain or preferably branched chain or secondary fatty alcohol containing 6 to 20 carbon atoms (C ₆ -C ₂ o alcohol) including secondary alcohols and branched chain primary alcohols. The nonionic surfactants having a high cloud point are preferably branched or secondary alcohol ethoxylates, more preferably mixed C9/11 or C11/15 branched alcohol ethoxylates condensed with an average of 6 to 15 moles, preferably 6 to 12 moles, most preferably 6 to 9 moles of ethylene oxide per mole of alcohol. The ethoxylated nonionic surfactant derived in this way preferably has a narrow ethoxylate distribution based on the average.

In a preferred embodiment, the detergent tablet comprising such a mixed surfactant system further comprises an amount of water soluble salt to give an electrical conductivity in deionized water, measured at 25 ^° C, of greater than 3 mS/cm, preferably greater than 4 mS/cm, most preferably greater than 4.5 mS/cm, as described in the pending British patent application (Attorney's Reference CM 1573F).

In another preferred embodiment, the mixed surfactant system dissolves in water having a hardness of 1.246 mmoW in any suitable cold-fill automatic dishwasher to form a solution having a surface tension of less than 4 dynes/cm ² at less than 45°C, preferably less than 40 ⁰ C, most preferably less

than 35 ⁰ C, as described in the pending U.S. patent application (Attorney Docket No. 6252).

In another preferred embodiment, the surfactants are mixed with high

. 5 hem cloud point and low cloud point surfactants of the mixed surfactant system are separated such that one of the high cloud point surfactants or the low cloud point surfactants is in a first matrix and the other is in a second matrix as described in pending U.S. patent application (Attorney Docket No. 6252).

For the purposes of the present invention, the first matrix may be a first particulate matrix and the second matrix may be a second particulate matrix. A surfactant may be applied to a particulate matrix using any suitable known method, preferably the surfactant is sprayed onto the particulate material. In a preferred aspect, the first matrix is the pressed portion and the second matrix is the non-pressed portion of the detergent tablet of the invention. Preferably, the low cloud point surfactant is present in the pressed portion and the high cloud point surfactant is present in the non-pressed portion of the detergent tablet of the invention.

Branched alkyl alkoxylate surfactants

Also suitable are the branched nonionic surfactants described in pending U.S. Patent Application No. 60/031,917 (Attorney Docket No. 6404), the disclosure of which is incorporated herein by reference. These branched nonionic surfactants exhibit improved spotting and film-forming effects over conventional linear surfactants in some applications.
30

Anionic surfactant

Essentially any anionic surfactants useful for cleaning purposes are suitable. These may include salts (including, for example, the sodium, potassium, ammonium and substituted ammonium salts such as the mono-, di- and triethanolamine salts) of anionic sulphate, sulphonate, carboxylate and sarcosinate surfactants. Anionic sulphate surfactants are preferred.

Non-limiting examples of surfactants useful in the present invention include the conventional linear or branched Cn-de-alkylbenzenesulfonates and the primary, secondary, linear, branched and random alkyl sulfates, the Cio-Cie alkyl alkoxysulfates, the Cn-Cie alkyl polyglycosides and their corresponding sulfated polyglycosides, the ct-sulfonated C12-C18 fatty acid esters, the _C12 - _Ci8 alkyl and alkylphenol alkoxylates (particularly ethoxylates and mixed ethoxy/propoxy compounds), the C12-C18 betaines and sulfobetaines ("sultaines"), the _C1o - _Ci8 amine oxides and the like. Other conventional surfactants useful are listed in standard textbooks.

Other (further) anionic surfactants include the isethionates, for example the acyl isethionates, N-acyl taurates, fatty acid amides of methyl tauride, alkyl succinates and sulfosuccinates, the monoesters of sulfosuccinate (especially the saturated and unsaturated C^-Cis monoesters), the diesters of sulfosuccinate (especially the saturated and unsaturated C ₆ -Ci ₄ diesters) and the N-acyl sarcosinates. Resin acids and hydrogenated resin acids are also suitable, e.g. rosin, hydrogenated rosin and resin acids and hydrogenated resin acids which occur in or are derived from tallow oil.

Particularly suitable surfactants are the medium chain branched surfactants. These include medium chain branched alkyl sulfates, medium chain branched alkyl alkoxy sulfates and medium chain branched alkyl alkoxylates. There are two types of particularly preferred branched surfactants, namely the Sasol type and the Shell type. The Sasol type surfactants represent a surfactant

A system comprising a branched surfactant mixture, said branched surfactant mixture comprising branched and linear medium chain surfactant compounds, said linear compounds representing more than about 25% and less than about 70% of the weight of the branched surfactant mixture, and wherein the branched medium chain surfactant compounds have the formula:

A ^b -B

wherein A ^b is a hydrophobic radical having a total of about 10 to about 18 carbon atoms divided between a longest chain and at least one short chain, the longest chain being in the range of about 9 to about 17 carbon atoms, with one or more Ci-C3 alkyl radicals branching off from the longest chain, with the proviso that at least one of the branching alkyl radicals is directly bonded to a carbon atom of the longest linear carbon chain at a position within the range between carbon position 3, counting from carbon atom #1 bonded to the B radical, and carbon position ω - 2, where ω is represents the terminal carbon atom, B represents a hydrophilic radical selected from the group consisting of OSO ₃ M, (EO/PO), (EO/PO) _m OSO ₃ M and mixtures thereof, wherein EO/PO represents alkoxy radicals selected from the group consisting of ethoxy, propoxy and mixtures thereof, m represents a number from at least about 1 to about 30 and M represents hydrogen or a cation forming salt, provided that the average total number of carbon atoms in the A ^b radical in the branched surfactant mixture is within the range of greater than about 11 to about 14.5.

The surfactant system comprising shell-type surfactants comprises a branched surfactant mixture, said branched surfactant mixture comprising branched and linear surfactant compounds of medium chain length, said linear compounds comprising less than about 25% by weight of the

branched surfactant mixture, and wherein the branched surfactant compounds with medium chain length have the formula:

A ^b -B

wherein A ^b represents a hydrophobic radical having a total of about 10 to about 18 carbon atoms divided between a longest chain and at least one short chain, the longest chain being in the range of about 9 to about 17 carbon atoms, with one or more Ci-C ₃ alkyl radicals branching off from the longest chain, with the proviso that at least one of the branching alkyl radicals is directly bonded to a carbon atom of the longest linear carbon chain at a position within the range of carbon position 3, counting from carbon atom #1 bonded to the B radical, to carbon position ω - 2, where ω is represents the terminal carbon atom, B represents a hydrophilic radical selected from the group consisting of OSO ₃ M, (EO/PO), (EO/PO) _m OSO ₃ M and mixtures thereof, wherein EO/PO represents alkoxy radicals selected from the group consisting of ethoxy, propoxy and mixtures thereof, m represents a number from at least about 1 to about 30 and M represents hydrogen or a salt forming cation, with the proviso that the average total number of carbon atoms in the A ^b radical in the branched surfactant mixture is within the range of greater than about 11 to about 14.5.

In this regard, see U.S. Patent Application Nos. 60/061,971 (Attorney Docket No. 6881P), filed October 14, 1997; 60/061 975 (Attorney Docket No. 6882P), filed October 14, 1997, 60/062 086 (Attorney Docket No. 6883P), filed October 14, 1997, 60/061 916 (Attorney Docket No. 6884P), filed October 14, 1997, 60/061 970 (Attorney Docket No. 6885P) ₁ filed October 14, 1997, and 60/062 407 (Attorney Docket No. 6886P), filed October 14, 1997, all of which are incorporated herein by reference. Further

Medium chain branched surfactants can be found in U.S. Patent Application Nos. 60/031,845 (Attorney Docket No. 6402P) and 60/031,916 (Attorney Docket No. 6403P).

. 5 Anionic sulfate surfactants suitable for use in the invention include the linear and branched primary and secondary alkyl sulfates, alkyl ethoxy sulfates, fatty oleoyl glycerol sulfates, alkylphenol ethylene oxide ether sulfates, the C ₅ -C ₁₇ -ACyI-N-(C ₁ -C ₄ -alkyl)- and -N-(C _r C ₂ -hydroxyalkyl)-glucamine sulfates and the sulfates of alkyl polysaccharides, for example the sulfates of alkyl polyglucoside (the non-ionic, non-sulfated compounds are described herein).

The alkyl sulfate surfactants are preferably selected from the linear and branched primary C ₁₀ -C ₁₈ alkyl sulfates, preferably the branched chain C n -C ₁₅ alkyl sulfates and the linear chain C ₁₂ -C ₁₄ alkyl sulfates.

The alkyl ethoxysulfate surfactants are preferably selected from the group consisting of the C^-C-18 alkyl sulfates which have been ethoxylated with 0.5 to 20 mol of ethylene oxide per molecule. The alkyl ethoxysulfate surfactant is particularly preferably a _C11 - _C18 alkyl sulfate, most preferably a C^-ds alkyl sulfate which has been ethoxylated with 0.5 to 7, preferably 1 to 5 mol of ethylene oxide per molecule.

In a particularly preferred aspect of the invention, mixtures of the preferred alkyl sulfate and alkyl ethoxy sulfate surfactants are used. Such mixtures are described in PCT patent application WO 93/18124.

Anionic sulfonate surfactants which can be used according to the invention include the salts of linear or branched C5- _C20 -alkylbenzenesulfonates, alkyl ester sulfonates, primary or secondary Ce-C^-alkanesulfonates, _C6 - _C24- olefinsulfonates, sulfonated^ polycarboxylic acids, alkylglycerolsulfonates, fatty

tacylglycerolsulfonates, fatty oleylglycerolsulfonates and any mixtures thereof.

Suitable anionic carboxylate surfactants include the alkyl ethoxycarboxylates, the alkyl polyethoxypolycarboxylate surfactants and the soaps ("alkyl carboxyls"), particularly certain secondary soaps as described herein.

Suitable alkyl ethoxycarboxylates include those having the formula RO(Ch ₂ CH ₂ O)XCH ₂ COCM ⁺ , wherein R is a Ce-Cie alkyl group, χ is in the range of 0 to 10, and the ethoxylate distribution is such that, by weight, the amount of material in which χ = O is less than 20%, and M is a cation.

Suitable alkylpolyethoxy-polycarboxylate surfactants include those having the formula RO-(CHRi-CHR ₂ -O)-R ₃ , wherein R is a C ₆ -Ci ₈ alkyl group, χ is a number from 1 to 25, R ₁ and R ₂ are selected from the group consisting of hydrogen, a methyl acid residue, a succinic acid residue, a hydroxysuccinic acid residue, and mixtures thereof, and R ₃ is selected from the group consisting of hydrogen, a substituted or unsubstituted hydrocarbon having 1 to 8 carbon atoms, and mixtures thereof.

Suitable soap surfactants include secondary soap surfactants which contain a carboxyl moiety attached to a secondary carbon atom. Secondary soap surfactants preferred for use in the present invention are water-soluble members selected from the group consisting of the water-soluble salts of 2-methyl-1-undecanoic acid, 2-ethyl-1-decanoic acid, 2-propyl-1-nonanoic acid, 2-butyl-1-octanoic acid and 2-pentyl-1-heptanoic acid. Certain soaps may also be added as foam suppressors.

· &Ggr;&igr; s

Other suitable anionic surfactants are the alkali metal sarcosinates of the formula R-CON(R ¹ )CH ₂ COOM, in which R is a linear or branched C ₅ -C ₁₇ alkyl or alkenyl group, R ¹ is a C 1 -C ₄ alkyl group and M is an alkali metal ion. Preferred examples are the myristyl and oleoylmethyl sarcosinates in the form of their sodium salts.

Amphoteric surfactant

Amphoteric surfactants suitable for use according to the invention include the amine oxide surfactants and the alkylamphocarboxylic acids.

Suitable amine oxides include those compounds having the formula R ³ (OR ⁴ )xN°(R ⁵ ) ₂ , wherein R ³ is selected from an alkyl, hydroxyalkyl, acylamidopropoyl and alkylphenyl group or mixtures thereof containing 8 to 26 carbon atoms; R ⁴ represents an alkylene or hydroxyalkylene group containing 2 to 3 carbon atoms, or mixtures thereof; x represents a number from 0 to 5, preferably from 0 to 3; and each of the radicals R ⁵ represents an alkyl or hydroxyalkyl group having 1 to 3 ethylene oxide groups or a polyethylene oxide group having 1 to 3 ethylene oxide groups. Preferred are C ₁₀ -C ₁₈ alkyldimethylamine oxide and C 10 -C 12 acylamidoalkyldimethylamine oxide.

A suitable example of an alkylamphodicarboxylic acid is Miranol*™ ⁰ C2M Cone, manufactured by Miranol, Inc., Dayton, NJ. 25

Zwitterionic surfactant

Zwitterionic surfactants may also be incorporated into the detergent compositions. These surfactants can be generally described as derivatives of secondary and tertiary amines, as derivatives of heterocyclic secondary and tertiary amines, or as derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium

&bull; «'

··

Compounds. Betaine and sultaine surfactants are exemplary zwitterionic surfactants for use in the present invention.

Suitable betaines are those compounds of the formula R(R ¹ J ₂ N ⁺ R ² COO', . 5 in which R is a C 1 -C 12 hydrocarbyl group, each of the radicals R ¹ is generally C 1 -C ₃ alkyl and R ² is a C 1 -C 8 hydrocarbyl group. Preferred betaines are C 12-18 dimethylammoniohexanoate and the C 10 -acylamidopropane-(or ethane)dimethyl (or diethyl)betaines. Complex betaine surfactants are also suitable for use according to the invention. 10

Cationic surfactants

The cationic ester surfactants used in the present invention are preferably water-dispersible compounds which exhibit surfactant properties and contain at least one ester (i.e., -COO-) linkage and at least one cationically charged group. Other suitable cationic ester surfactants include choline ester surfactants, such as those described in U.S. Patents 4,228,042, 4,239,660 and 4,260,529.

Suitable cationic surfactants include the quaternary ammonium surfactants selected from mono-C ₆ -C ₁₆ -, preferably Ce-C 12 -N-alkyl or alkenylammonium surfactants, in which the remaining N-positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups.

Cleaning Agent Builder

The present invention may include an optional builder in the product composition. The amount of detergent salt/builder may vary widely depending on the end use of the composition and its desired physical form. When present, the compositions typically contain at least about 1% by weight detergent builder and preferably about 10% by weight detergent builder.

521- " "

to about 80% by weight, more preferably about 15 to about 50% by weight detergent builder. However, this means that lower and higher contents are not excluded.

. 5 Examples of inorganic or P-containing detergent builders include, but are not limited to, the alkali metal ammonium and alkanolammonium salts of polyphosphates (e.g., tripolyphosphates, pyrophosphates, and glassy polymeric metaphosphates), phosphonates, phytic acid, silicates, carbonates (including the bicarbonates and sesquicarbonates), sulfates, and aluminosilicates. However, in some applications, non-phosphate salts are required. Importantly, the compositions of the invention perform surprisingly well even in the presence of so-called "weak" builders (compared to phosphates) such as citrate, or in the so-called "underbuilt" situation that can occur with zeolite or layered silicate builders.

Examples of silicate builders include the alkali metal silicates, particularly those having a SiO2: _Na2O ratio in the range of 1.6:1 to 3.2:1, and layered silicates, e.g., the layered sodium silicates described in U.S. Patent 4,664,839 (HP Rieck, published May 12, 1987). NaSKS-6 is the trademark for a crystalline layered silicate marketed by Hoechst (commonly abbreviated to "SKS-6"). Unlike the zeolite builders, the Na-SKS-6 _silicate builders do not contain aluminum. NaSKS-6 has the 6- _Na2SiO5 morphology form of layered silicate. It can be produced by processes such as those described, for example, in DE-A-34 17 649 and DE-A-37 42 043. SKS-6 is a layered silicate which is highly preferred for use according to the invention, but other such layered silicates can also be used according to the invention, for example those with the general formula NaMSi _x O _2x+ I. yH ₂ O, in which M is sodium or hydrogen, x is a number from 1.9 to 4, preferably the number 2, and y is a number from 0 to 20, preferably the number

&bull; ^: 55 * "

number O. Various other layered silicates from Hoechst include NaSKS-5, NaSKS-7 and NaSKS-11 in the α, ß and γ forms. As indicated above, the 6-Na ₂ SiO 5 (the NaSKS-6 form) is most preferred for use in the present invention. Other silicates may also be used, for example magnesium silicate which may serve as a hardener in granular formulations, as a stabilizer for oxygen bleaches and as a component of foam control systems.

Examples of carbonate salts as builders are the alkaline earth metal and alkali metal carbonates as described in German patent application 23 21 001, published on November 15, 1973.

Aluminosilicate builders may also be added as a detergent salt in accordance with the invention. Aluminosilicate builders are of great importance in most of the high performance granular detergent compositions currently available on the market. Aluminosilicate builders include those with the empirical formula:

M _z [(SiO ₂ )w(AIO ₂ ) _y ].xH ₂ O

wherein z, w and y are integers of at least 6, the molar ratios ζ:y and ζ:w are in the range of 1.0 to about 0.5, and χ is an integer from about 15 to about 264.

Suitable aluminosilicate ion exchange materials are commercially available. These aluminosilicates may have a crystalline or amorphous structure and may be naturally occurring aluminosilicates or synthetically prepared aluminosilicates. A process for preparing aluminosilicate ion exchange materials is described in U.S. Patent 3,985,669 (Krummel et al., published October 12, 1976). Preferred synthetic crystalline aluminosilicates for use in the present invention are

cat ion exchange materials are available under the names Zeolite A, Zeolite P (B), Zeolite MAP and Zeolite X. In a particularly preferred embodiment, the crystalline aluminosilicate ion exchange material has the formula:
. 5

Na ₁₂ [(AIO ₂ )i ₂ (SiO ₂ ) ₁₂ ].xH ₂ O

where x is a number from about 20 to about 30, especially about 27. This material is known as zeolite A. Dehydrated zeolites (x = 0 -10) can also be used according to the invention. The aluminosilicate preferably has a particle size of about 0.1 to 10 pm in diameter.

Organic detergent builders suitable for the purposes of the present invention, but to which the invention is not limited, include a wide variety of polycarboxylate compounds. As used herein, the term "polycarboxylate" refers to compounds having a plurality of carboxylate groups, preferably at least 3 carboxyl groups. A polycarboxylate builder can generally be added to the composition in the acid form, but it can also be added in the form of a neutralized salt. When used in the salt form, alkali metal salts such as sodium, potassium and lithium or alkanolammonium salts are preferred.

Polycarboxylate builders include a variety of categories of useful materials. One important category of polycarboxylate builders comprises the ether polycarboxylates including oxydisuccinate as described in U.S. Patent 3,128,287 (Berg, published April 7, 1964) and U.S. Patent 635,830 (Lamberti et al., published January 18, 1972). In this context, see also the "TMS/TDS" builders of U.S. Patent 4,663,071 (Bush et al., published May 5, 1987). Suitable ether polycarboxylates also include cyclic compounds, particularly

alicyclic compounds, e.g. those described in U.S. Patents 3,923,679, 3,835,163, 4,158,635, 4,120,874 and 4,102,903.

Other useful detergent builders include the ether-.5-hydroxypolycarboxylates, copolymers of maleic anhydride and ethylene or vinyl methyl ether, 1,3,5-trihydroxybenzene-2,4,6-trisulfonic acid and carboxymethyloxysuccinic acid and the various alkali metal, ammonium and substituted ammonium salts of polyacetic acids such as ethylenediaminetetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid, succinic acid, oxydisuccinic acid, polymaleic acid, benzene-1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid and their soluble salts.

Citrate builders, for example citric acid and its soluble salts (especially the sodium salt), are polycarboxylate builders of particular importance. Oxydisuccinates are also particularly suitable in such compositions and combinations.

Also useful in the detergent compositions of the present invention are the S,S-dicarboxy^-oxa-i,6-hexanedioates and related compounds as described in U.S. Patent 4,566,984 (Bush, issued January 28, 1986). Useful succinic acid builders include the Cs-Cao alkyl and alkenyl succinic acids and their salts. A particularly preferred compound of this type is dodecenyl succinic acid. Specific examples of succinate builders include lauryl succinate, myristyl succinate, palymityl succinate, 2-dodecenyl succinate (preferred), 2-pentadecenyl succinate, and the like. Lauryl succinates are the preferred builders in this group and are described in European Patent Application 86 200 690.5/0 200 263, published November 5, 1986. 30

Other suitable polycarboxylates are described in U.S. Patent 4,144,226 (Crutchfield et al, published March 13, 1979) and in U.S. Patent 3

■ ·

&bull; -se "

308,067 (Diehl, published March 7, 1967). See also US Patent 3,723,322 (Diehl).

Fatty acids, eg C1-C4 monocarboxylic acids, may also be incorporated into the compositions or in combination with the above builders, particularly citrate and/or succinate builders, to provide additional builder activity. This use of fatty acids generally results in a reduction in foaming, which should be taken into account by the formulator.
10

Bleach

The bleaching agents of the invention may comprise both chlorine and oxygen bleaching systems. Hydrogen peroxide sources are described in detail in Kirk Othmer's "Encyclopedia of Chemical Technology", 4th Edition (1992, John Wiley & Sons), Volume 4, pp. 271-300, "Bleaching Agents (Survey)", incorporated herein by reference, and include the various forms of sodium perborate and sodium percarbonate, including the various coated and modified forms. An "effective amount" of a hydrogen peroxide source is an amount which is capable of measurably improving stain removal (particularly tea stain removal) from soiled household ware, as compared to a hydrogen peroxide source-free composition, when the soiled household ware is washed by the consumer in the presence of alkali in an automatic household dishwasher.

Generally speaking, a source of hydrogen peroxide is any suitable compound or mixture which produces an effective amount of hydrogen peroxide under consumer use conditions. Levels can vary widely and are typically in the range of from about 0.1 to about 70%, preferably from about 0.5 to about 30%, by weight of the compositions of the invention.

The preferred hydrogen peroxide source used in the invention may be any suitable source, for example hydrogen peroxide itself. For example, perborate such as

. 5 Sodium perborate (any hydrate, but preferably the mono- or tetrahydrate), sodium carbonate peroxyhydrate or equivalent percarbonate salts, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate or sodium peroxide. Also usable are sources of available oxygen such as a persulfate bleach (e.g. OXONE, manufactured by DuPont).

Sodium perborate monohydrate and sodium percarbonate are particularly preferred. Mixtures of any suitable hydrogen peroxide sources may also be used.

A preferred percarbonate bleach comprises dry particles having an average particle size in the range of about 500 pm to about 1000 pm, with no more than about 10% by weight of said particles being smaller than about 200 pm and no more than about 10% by weight of said particles being larger than about 1250 pm. Optionally, the percarbonate may be coated with a silicate, borate or water soluble surfactant. Percarbonate is available from various commercial sources, for example from FMC, Solvay and Tokai Denka.

Although not preferred for compositions of the invention containing detersive enzymes, the compositions of the invention may also contain a chlorine-type bleaching material as the bleaching agent. Such agents are well known and include, for example, sodium dichloroisocyanurate ("NaDCC") or sodium hypochlorite (NaOCl).

a) Bleach activators
30

The peroxy bleach component is formulated according to the invention with an activator (peracid precursor). The activator is present in amounts of about

0.01 to about 15%, preferably from about 0.5 to about 10%, more preferably from about 1 to about 8%, based on the weight of the composition. Preferred activators are selected from the group consisting of tetraacetylethylenediamine (TAED), benzoylcaprolactam (BzCL), A-

_ 5 Nitrobenzoylcaprolactam, 3-chlorobenzoylcaprolactam, benzoyloxybenzenesulfonate (BOBS), nonanoyloxybenzenesulfonate (NOBS), phenylbenzoate (PhBz), decanoyloxybenzenesulfonate (C10-OBS), benzoylvalerolactam (BZVL), octanoyloxybenzenesulfonate ( _C8 -OBS), perhydrolyzable esters and mixtures thereof, most preferred is benzoylcaprolactam and benzoylvalerolactam. Particularly preferred bleach activators in the pH range of about 8 to about 9.5 are those having a leaving OBS or VL group.

Preferred bleach activators are those described in U.S. Patent 5,130,045 (Mitchell et al) and U.S. Patent 4,412,934 (Chung et al) and in pending U.S. Patent Application Nos. 08/064,624, 08/064,623, 08/064,621, 08/064,562, 08/064,564, 08/082,270 and in pending U.S. Patent Application No. 08/133,691 of M. Burns, A.D. Willey, RT. Hartshorn, CK. Ghosh entitled "Bleaching Compounds Comprising Peroxyacid Activators Used With Enzymes" (P&G Case 4890R), all of which are incorporated herein by reference.

According to the invention, the molar ratio of peroxy bleach compound (as AvO) to bleach activator is generally in the range of at least 1:1, preferably from about 20:1 to about 1:1, particularly preferably from about 10:1 to about 3:1.

Quaternary substituted bleach activators may also be included therein. The cleaning compositions of the invention preferably contain a quaternary substituted bleach activator (QSBA) or a quaternary substituted peracid (QSP); more preferably the former. Preferred QSBA structures are also described in US

Patents 5,460,747, 5,584,888 and 5,578,136, which are incorporated herein by reference.

(b) Organic peroxides, in particular diacyl peroxides . 5

These are discussed in detail in Kirk Othmer, "Encyclopedia of Chemical Technology", Volume 17, John Wiley and Sons, 1982, pages 27-90, and particularly pages 63-72, which are incorporated herein by reference. If a diacyl peroxide is used, it is preferably one which has a minimal adverse effect on the spotting/filming properties. Dibenzoyl peroxide is preferred.

(c) Metal-containing bleach catalysts

The compositions and methods of the present invention employ metal-containing bleach catalysts effective for use in ADD compositions. Preferred are manganese and cobalt-containing bleach catalysts.

One type of metal-containing bleach catalyst is a catalyst system comprising a transition metal cation having a defined catalytic bleach activity, such as copper, iron, titanium, ruthenium, tungsten, molybdenum or manganese cations, an auxiliary metal cation having little or no catalytic bleach activity, such as zinc or aluminum cations, and a sequestering agent having defined stability constants for the catalytic and auxiliary metal cations, particularly ethylenediaminetetraacetic acid, ethylenediaminetetra(methylenephosphonic acid) and their water-soluble salts. Such catalysts are described in U.S. Patent 4,430,243.

Other types of suitable bleach catalysts include the manganese-based complexes described in U.S. Patents 5,246,621 and 5,244,594. Preferred examples of these catalysts include

include Mn ^lv ₂ (uO) ₃ (1,4,7-trimethyl-i ,4,7-triazacyclononane) ₂ -(PF ₆ )2, O) ₁ (U-OAc) ₂ (1,4,7-trimethyl-i ^J-triazacyclononaneHCIO^, Mn ^lv ₄ (uO) ₆ (1,4,7-triazacyclononane) ₄ -(CIO ₄ ) ₂ , Mn ¹¹¹ Mn^ ₄ (UO) ₁ (U-OAc) ₂ (1,4,7-trimethyl-1,4,7-triazacyclononane) ₂ -(CIO4) ₃ and mixtures thereof. Further catalysts are described in published European Patent Application 272. Other ligands suitable for use in the invention include ISg-trimethyl-IS^-triazacyclododecane, 2-Methyl-1,4,7-triazacyclononane, 2-methyl-1,4,7-triazacyclononane and mixtures thereof.

The bleach catalysts useful in automatic dishwashing compositions and in concentrated powder detergent compositions can also be selected to be suitable for the present invention. Examples of suitable bleach catalysts are described in U.S. Patents 4,246,612 and 5,227,084.

Other bleach catalysts are described, for example, in published European patent application 408 131 (cobalt complex catalysts), in published European patent applications 503 and 306 089 (metalloporphyrin catalysts), in US patent 4 728 (manganese/multidentate ligand catalyst); in US Patent 4,711,748 and in published European Patent Application 224,952 (manganese adsorbed on an aluminosilicate catalyst), in US Patent 4,601,845 (aluminosilicate support with manganese and zinc or magnesium salt), in US Patent 4,626,373 (manganese/ligand catalyst), in US Patent 4,557 (iron(III) complex catalyst), in German Patent 2,054,019 (cobalt chelating agent catalyst), in Canadian Patent 866,191 (salts containing a transition metal), in US Patent 4,430,243 (chelating agent with manganese cations and non-catalytic metal cations) and in US Patent 4,728,455 (manganese gluconate catalysts).

Preferred cobalt catalysts are those of the formula:

[Co(NH ₃ )n(M') _m ]Y _y

where η stands for an integer from 3 to 5 (preferably the number 4 or 5; most preferably the number 5); M ¹ stands for a labile coordination

. 5 ions residue preferably selected from the group consisting of chlorine, bromine, hydroxide, water and (when m is greater than 1) combinations thereof; m is an integer from 1 to 3 (preferably the number 1 or 2; most preferably the number 1); m+n = 6; and Y is an appropriately selected counter anion present in the number y, where y is an integer from 1 to 3 (preferably the number 2 to 3; most preferably the number 2 when Y is a singly negatively charged anion), to form a salt with balanced charge.

The preferred cobalt catalysts of this type which can be used in accordance with the invention are cobalt pentamine chloride salts of the formula [Co(NH ₃ ) ₅ CI]Y _y and in particular [Co(NH ₃ )SCI]CI ₂ .

Particularly preferred are the compositions according to the invention in which cobalt(III) bleach catalysts of the formula are used:

[Co(NH ₃ ) _n (M) _m (B) _b ]T _y

wherein cobalt is in the +3 oxidation state; η is the number 4 or 5 (preferably the number 5); M is one or more ligands coordinated to the cobalt by one site; m is the number 0, 1 or 2 (preferably the number 1); B is a ligand coordinated to the cobalt by two sites; b is the number 0 or 1 (preferably the number 0) and, if b = 0, then m+n = 6, and if b = 1, then m = 0 and η = 4; and T is one or more suitably selected counter anions present in the number y, where y is an integer to achieve a salt with balanced charge (preferably y is a number from 1 to 3; particularly preferably the

number 2 if T is a singly negatively charged anion) and wherein furthermore said catalyst has a base hydrolysis rate constant of < 0.23 M" ¹ s' ¹ (25°C).

. 5 Preferred T radicals are selected from the group consisting of chloride, iodide, I ₃ ", formate, nitrate, nitrite, sulfate, sulfite, citrate, acetate, carbonate, bromide, PF ₆ ', BF ₄ ', B(Ph) ₄ ", phosphate, phosphite, silicate, tosylate, methanesulfonate and combinations thereof. T may optionally be protonated if more than one anionic group is present in T, such as HPO ₄ ² ", HCO ₃ ', H ₂ PO ₄ ", and the like. In addition, T may be selected from the group consisting of non-traditional inorganic anions, such as anionic surfactants (e.g., linear alkylbenzene sulfonates (LAS), alkyl sulfates (AS), alkyl ethoxy sulfonates (AES), and the like) and/or anionic polymers (e.g., polyacrylates, polymethacrylates, and the like).

The M residues include, without the invention being restricted thereto, for example F ₁ SO ₄ " ² , NCS', SCN", S ₂ O ₃ " ² , NH ₃ , PO ₄ ³ ' and carboxylates (which are preferably monocarboxylates, but more than one carboxylate can also be present in the residue as long as the bond to the cobalt only occurs via one carboxylate per residue, in which case the other carboxylate in the M residue is protonated or can be in its salt form). M can optionally be protonated if more than one anionic group is present in M (eg HPO ₄ ² ", HCO ₃ ", H ₂ PO ₄ ", HOC(O)CH ₂ C(O)O-, and the like). Preferred M residues are substituted and unsubstituted Ci-C ₃₀ carboxylic acids of the formula:

RC(O)O-

wherein R is preferably selected from the group consisting of hydrogen and unsubstituted and substituted C 1 -C ₃₀ - (preferably C ₁ -C ₈ )-alkyl, unsubstituted and substituted C ₆ -C ₃₀ - (preferably C ₆ -C ₈ )-aryl and unsubstituted and substituted C ₃ -C ₃₀ - (preferably C ₅ -C ₈ )-

Heteroaryl, wherein the substituents are selected from the group consisting of -NR' ₃ , -NR ¹ /, -C(O)OR ¹ , -OR ¹ , -C(O)NR' ₂₎ wherein R ¹ is selected from the group consisting of hydrogen and dC ₆ radicals. This substituted R therefore includes the radicals -(CH ₂ ) _n OH and -(CH ₂ ) n NR'4 ⁺ , wherein η is an integer from 1 to 16, preferably from 2 to 10 and most preferably from 2 to 5.

The most preferred M are carboxylic acids having the formula given above, wherein R is selected from the group consisting of hydrogen, methyl, ethyl, propyl, straight or branched C ₄ -C ₁₂ alkyl and benzyl. The most preferred R is methyl. Preferred carboxylic acid M residues include formic acid, benzoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, malonic acid, maleic acid, succinic acid, adipic acid, phthalic acid, 2-ethylhexanoic acid, naphthenic acid, oleic acid, palmitic acid, triflate, tartrate, stearic acid, butyric acid, citric acid, acrylic acid, aspartic acid, fumaric acid, lauric acid, linoleic acid, lactic acid, malic acid and especially acetic acid.

The B residues include carbonate, di- and higher carboxylates (e.g. oxalate, malonate, malic acid, succinate, maleate), picolinic acid and α- and β-amino acids (e.g. glycine, alanine, β-alanine, phenylalanine).

The cobalt bleach catalysts which can be used according to the invention are known and are described, for example, together with their base hydrolysis rates by ML Tobe in "Base Hydrolysis of Transition-Metal Complexes" in "Adv. lnorg. Bioinorg. Mech." (1983), 2, pages 1-94. For example, in Table 1 on page 17, the base hydrolysis rates (referred to as koH) are given for cobalt pentaamine catalysts which are complexed with oxalate (koH = 2.5 x 10" ⁴ M' ¹ s" ¹ (25 ⁰ C)), NCS" (k _0H = 5.0 x 10" ⁴ M" ¹ s" ¹ (25 ⁰ C)), formate (k _OH = 5.8 x 10" ⁴ M" ¹ s" ¹ (25°C)) and acetate (ko _H = 9.6 x 10" ⁴ M" ¹ s' ¹ (25 ⁰ C)). The most preferred cobalt catalysts which can be used according to the invention are cobalt pentaamine acetate salts of the formula [Co(NH ₃ ) ₅ OAc]T _y ,

wherein OAc is an acetate residue, and in particular cobalt pentamine acetate chloride [Co(NH ₃ )SOAc]CI ₂ and [Co(NH ₃ ) ₅ OAc) ₂ ; [Co(NH ₃ )5OAc](PF ₆ ) ₂ ; [Co(NH ₃ ) ₅ OAc](SO ₄ ); [Co(NH ₃ ) ₅ OAc](BF ₄ )2; and [Co(NH ₃ ) ₅ OAc](NO ₃ ) ₂ .

. 5 Cobalt catalysts according to the invention can be prepared by synthetic routes as described in US Patents 5,559,261, 5,581,005 and 5,597,936, the disclosures of which are expressly incorporated herein by reference.

These catalysts may be treated together with additive materials to reduce color changes if this is desired for aesthetic reasons for the product, or to be included in enzyme-containing particles as further discussed below, or the compositions may be prepared to contain "catalyst spots".

As a practical measure, but by no means limiting the invention, the detergent compositions and detergent processes of the present invention can be adjusted to provide active bleach catalyst species in the aqueous wash medium on the order of at least 1 part per 100,000,000 parts, and preferably about 0.01 ppm to about 25 ppm, more preferably about 0.05 to about 10 ppm, and most preferably about 0.1 to about 5 ppm of bleach catalyst species in the wash liquor. To achieve such levels in the wash liquor of an automatic dishwashing process, typical automatic dishwashing compositions of the present invention contain about 0.0005 to about 0.2%, more preferably about 0.004 to about 0.08% bleach catalyst, based on the weight of the detergent compositions.

Controlled release rate

II Cf

The detergent tablet may be provided with a means for controlling the rate of release of the bleaching agent, in particular the oxygen bleaching agent, into the washing solution.

. 5 Controlling the rate of release of the bleach can provide a controlled release of peroxide species into the wash solution. This may include, for example, controlling the release of an inorganic perhydrate salt acting as a source of hydrogen peroxide into the wash solution.

Suitable ways of controlling the release of the bleach may include confining the bleach to either the pressed portion or the non-pressed, non-encapsulating portion. If more than one non-pressed, non-encapsulating portion is present, the bleach may be confined to the first and/or second and/or optionally further non-pressed, non-encapsulating portions. Another way of controlling the rate of release of the bleach may be by coating the bleach with a coating designed to provide the controlled release. The coating may, for example, comprise a material poorly soluble in water or it may be a coating of sufficient thickness so that the kinetics of dissolution of the thick coating provide the controlled release rate.

The coating material can be applied using various methods. A coating material is usually present in a weight ratio of coating material to bleaching agent of 1:99 to 1:2, preferably 1:49 to 1:9.

Suitable coating materials include triglycerides (e.g. (partially) hydrogenated vegetable oil, soybean oil, cottonseed oil), mono- or diglycerides, microcrystalline waxes, gelatin, cellulose, fatty acids and any mixtures thereof.

Other suitable coating materials may include the alkali metal and alkaline earth metal sulfates, silicates and carbonates including calcium carbonate and silicon dioxides.

A preferred coating material, particularly for an inorganic perhydrate salt bleach source, comprises sodium silicate having a SiO ₂ :Na ₂ O ratio of from 1.8:1 to 3.0:1, preferably from 1.8:1 to 2.4:1, and/or sodium metasilicate, preferably applied in an amount of from 2 to 10% (normally 3 to 5%) SiO ₂ based on the weight of the inorganic perhydrate salt. Magnesium silicate may also be included in the coating.

Any inorganic salt coating materials can be combined with organic binder materials to form inorganic salt/organic binder composite coatings. Suitable binders include the C 10 -C ₂₀ alcohol ethoxylates containing from 5 to 100 moles of ethylene oxide per mole of alcohol, and most preferably the primary C ₁₅ -C ₂₀ alcohol ethoxylates containing from 20 to 100 moles of ethylene oxide per mole of alcohol.

Other preferred binders include certain polymeric materials. Examples of such polymeric materials are polyvinylpyrrolidones having an average molecular weight of from 12,000 to 700,000 and polyethylene glycols (PEG) having an average molecular weight of from 600 to 5 x 10 ⁶ , preferably from 1,000 to 400,000, most preferably from 1,000 to 10,000. Other examples of polymeric materials that can be used as binders are copolymers of maleic anhydride with ethylene, methyl vinyl ether or methacrylic acid, wherein the maleic anhydride constitutes at least 20 mole percent of the polymer. These polymeric materials can be used as such or in combination with solvents such as water, propylene glycol and the above-mentioned do-C^ alcohol ethoxylates containing from 5 to 100 moles of ethylene oxide per mole. Other examples

Examples of binding agents include _C10 -C20 mono- and diglycerol ethers and _C1o - _C2o fatty acids.

Cellulose derivatives, such as methylcellulose, carboxymethylcellulose and - 5 hydroxyethylcellulose, and homo- or copolymeric polycarboxylic acids or their salts, are further examples of binders which can be used according to the invention.

One method of applying the coating material involves agglomeration. Preferred agglomeration methods include using one of the organic binder materials described above. Any conventional agglomerator/mixer may be used, such as, but not limited to, pan-type, rotary drum-type, and vertical mixer-type. Molten coating compositions may also be applied by pouring or by spraying onto a moving bed of the bleach.

Other ways of achieving the required controlled release include altering the physical properties of the bleach to control its solubility and its release rate. Suitable ways may also include pressing, mechanical injection, manual injection and adjusting the solubility of the bleach compound by selecting the particle size of a particulate component. 25

Although the selection of particle size will depend on both the composition of the particulate component and the desire to achieve the desired controlled release kinetics, it is desirable that the particle size should be greater than 500 µm, preferably having an average particle diameter of 800 to 1200 µm.

Other ways of achieving controlled release include the appropriate selection of some other component of the detergent composition matrix such that when the composition is introduced into the wash solution, the ionic strength of the environment created thereby enables the desired required controlled release kinetics.

Cleansing enzymes

The compositions of the invention may also contain at least one detersive enzyme. As used herein, the term "detergent enzyme" means any enzyme which has a cleaning, stain removal or other beneficial effect in a composition. Preferred detersive enzymes are hydrolases such as proteases, amylases and lipases. Particularly preferred for automatic dishwashing are amylases and/or proteases which include both the two types currently commercially available and improved types which, while more compatible with a bleach, have a residual degree of bleach deactivation ability.

In general, as mentioned, the preferred compositions contain one or more detersive enzymes. If only one enzyme is used, it is preferably an amylolytic enzyme if the composition is intended for use in automatic dishwashing.

Particularly preferred for automatic dishwashing is a mixture of proteolytic enzymes and amylolytic enzymes. In general, the enzymes to be incorporated include proteases, amylases, lipases, cellulases and peroxidases, as well as mixtures thereof. Other types of enzymes can also be incorporated. They can be of any origin, for example plant, animal, bacterial, fungal and yeast origin. However, their choice is determined by several factors, e.g. the pH activity and/or stability optima, the heat resistance, the

Stability towards active cleaning agents, builders and the like. In this regard, bacterial or fungal enzymes are preferred, for example bacterial amylases and proteases and fungal cellulases.

Enzymes are normally incorporated into the detergent compositions of the present invention in amounts sufficient to provide a "cleaning effective amount". The term "cleaning effective amount" refers to an amount capable of providing a cleaning, stain removal or soil removal effect on substrates such as fabrics, dishware and the like. Since enzymes are catalytic materials, these amounts can be very small. In practice, for current commercial preparations, typical amounts are up to about 5 mg, more preferably about 0.01 mg to about 3 mg, of active enzyme per gram of composition. In other words, the compositions of the present invention typically contain about 0.001 to about 6%, preferably 0.01 to 1%, based on the weight of a commercial enzyme preparation. Protease enzymes are typically present in such commercial preparations in amounts sufficient to provide 0.005 to 0.1 Anson Units (AU) of activity per gram of composition. For automatic dishwashing purposes, it may be desirable to increase the active enzyme content of the commercial preparations to minimize the total amount of non-catalytically active materials added and thereby improve spotting/filming results.

Suitable examples of proteases are the subtilisins obtained from special strains of B. subtilis and B. licheniformis. Another suitable protease is obtained from a Bacillus strain which has a maximum activity over the pH range of 8 to 12 and is developed and marketed by Novo Industries A/S under the name ESPE-RASE®. The production of this enzyme and analogous enzymes is described in British Patent 1 243 784 (Novo). Proteolytic enzymes suitable for the removal of protein-based stains which are commercially available

include those sold under the trade names ALCALASE® and SAVINASE® by Novo Industries A/S (Denmark), MAXATASE® by International Bio-Synthetics, Inc. (Netherlands), and PURA-FECT® by GCI. Other proteases include Protease A (see European Patent Application 130 756, published on 9 January 1985) and Protease B (see European Patent Application 87 303 761.8, filed on 28 April 1987, and European Patent Application 130 756 (Bott et al), published on 9 January 1985).

A particularly preferred protease, referred to herein as "Protease D", is a carbonyl hydrolase variant having an amino acid sequence not present in nature, which has been derived from a precursor carbonyl hydrolase by introducing another amino acid in place of a plurality of amino acid residues at a position in said carbonyl hydrolase equivalent to position +76, preferably also in combination with one or more amino acid residue positions equivalent to those selected from the group consisting of +99, +101, +103, +104, +107, +123, +27, +105, +109, +126, +128, +135, +156, +166, +195, +197, +204, +206, +210, +216, +217, +218, +222, +260, +265 and/or +274 according to the numbering of Bacillus amyloliquefaciens subtilisin as described in WO 95/10615 (Genencor International, published April 20, 1995).

Other preferred protease enzymes include protease enzymes which are a carbonyl hydrolase variant having an amino acid sequence not found in nature which has been derived from a precursor carbonyl hydrolase with other amino acids by replacing a plurality of the amino acid residues, wherein said plurality of amino acid residues replaced in the precursor enzyme correspond to position +210 in combination with one or more of the following residues: +33, +62, +67, +76, +100, +101, +103, +104, +107, +128, +129, +130, +132, +135, +156, +158, +164, +166, +167, +170, +209, +215, +217,

'73

+218 and +222, where the numbered positions correspond to a naturally occurring subtilisin from Bacillus amyloliquefaciens or are equivalent to amino acid residues in other carbonyl hydrolases or subtilisins (e.g. Bacillus lentus subtilisin). Preferred enzymes of this type include those having position changes in +210, +76, +103, +104, +156 and +166.

Useful proteases are also described in the PCT publications: WO 95/30010 (The Procter & Gamble Company, published on November 9, 1995), WO 95/30011 (The Procter & Gamble Company, published on November 9, 1995), WO 95/29979 (The Procter & Gamble Company, published on November 9, 1995).

Amylases suitable for use in the present invention include, for example, α-amylases as described in British Patent 1,296,839 (Novo), RAPI-DASE® from International Bio-Synthetics, Inc., ENDOLASE from Novo Industries, and TERMAMYL® from Novo Industries.

The preferred amylases which can be used according to the invention have in common that they were derived from one or more Bacillus amylases, in particular the Bacillus α-amylases, using sequence-directed mutagenesis, regardless of whether one, two or more amylase strands are the immediate precursors.

As stated, preferred for use in the present invention are amylases having "improved oxidative stability" despite the fact that they are "optional but preferred" materials rather than essential materials. Such amylases are illustrated below, without the invention being limited thereto:

(a) an amylase according to the above-mentioned WO/94/02597 (Novo Nordisk A/S, published on February 3, 1994), further illustrated by a mutant in which the methionine residue present in position 197 of the B. licheniformis a-amyl-

ase known as TERMAMYL® is replaced by alanine or threonine (preferably threonine), or the homologous positional variant of a similar parent amylase, e.g. B. amyloliquefaciens, B. subtilis or B. stearothermophilus;

- 5 (b) Amylases with improved stability as described by Genencor International in a paper entitled "Oxidatively Resistant alpha-Amylases" presented at the 207th American Chemical Society National Meeting, March 13-17, 1994, by C. Mitchinson. It is stated that bleach in automatic dishwashing detergents inactivate α-amylases, but not amylases with improved oxidative stability as prepared by Genencor from B. licheniformis NCIB8061. Methionine (Met) was identified as the most likely residue to be modified. Met was replaced at positions 8,15,197,256,304,366 and 438 at once, yielding specific mutants, among which most important are M197L and M197T, with the M197T variant being the most stable expressed variant. Stability was measured in CASCADE® and SUNLIGHT®;

(c) also preferred according to the invention are amylase variants which have an additional modification in the immediate precursor, available from Novo Nordisk A/S, and those which are designated by the supplier with the trade name DURMAMYL®;

(d) particularly preferred are amylase variants as described in WO95/26397 and in the pending PCT application (Novo Nordisk) PCT/DK96/00056 and which are characterized in that they have a specific activity at a temperature in the range of 25 to 55°C and at a pH in the range of 8 to 10 which is at least 25% higher than the specific activity of Termamyl®, determined using the Phadebas® a-amylase activity assay and prepared from an alkalophilic Bacillus species (e.g. strains NCIB 12289, NCIB 12512, NCIB 12513 and DSM 935) which contain the following amino acid sequence in the N-terminal position: His-His-Asn-Gly-Thr-Asn-Gly-Thr-Met-Met-Gln-Tyr-Phe-Glu-Trp-Tyr-Leu-Pro-Asn-Asp.

Cellulases which can be used in the invention, but are not preferred, are both bacterial and fungal cellulases. Typically they have a pH optimum between 5 and 9.5. Suitable cellulases are described in US Patent 4,435,307 (Barbesgoard et al., published March 6, 1984) which describes fungal cellulase produced from Humicola insolens and Humicola strain DSM1800, or a cellulase 212-producing fungus belonging to the genus Aeromonas, and cellulase extracted from the hepatopancreas of a marine mollusk (Dolabella auricula solander). Suitable cellulases are also described in GB-A-2 075 028; GB-A-2 095 275 and DE-OS-22 47 832. CAREZYME® (Novo) is particularly suitable.

Suitable lipase enzymes for use as detergents include those produced by microorganisms of the Pseudomonas group, for example Pseudomonas spp. ATCC 19.154, as described in British Patent 1 1 372 034. See also the lipases in Japanese Patent Application 53 20 487, laid open on February 24, 1978. This lipase is available from Amano Pharmaceutical Co., Ltd. Nagoya, Japan under the trade name Lipase P "Amano", hereinafter referred to as "Amano-P". Other commercially available lipases include Amano-CES, lipases from Chromobacter viscosum, for example Chromobacter viscosum var. lipolyticum NRRLB 3673, commercially available from Toyo Jozo Co., Tagata, Japan; and also Chromobacter viscosum lipases from US Biochemical Corp., USA, and Disoynth Co., Netherlands, and lipases from Pseudomonas gladioli. The LIPOLASE® enzyme derived from Humicola lanuginosa and commercially available from Novo (see EP-A-341 947) is a preferred lipase for use in the invention. Another preferred lipase enzyme is the D96L variant of the native Humicola lanuginos lipase, as described in WO 92/05249 and in Research Disclosure No. 35944, March 10, 1994, both published by Novo. In general, lipolytic enzymes are less preferred.

/ b

preferably as amylases and/or proteases for automatic dishwashing embodiments of the present invention.

Peroxidase enzymes can be used in combination with oxygen sources, for example percarbonate, perborate, persulfate, hydrogen peroxide and the like. They are typically used for "solution bleaching", i.e. to prevent the transfer of dyes or pigments removed from substrates during washing operations to other substrates in the wash solution. Peroxidase enzymes are well known and include, for example, horseradish peroxidase, ligninase and haloperoxidase, for example chloro- and bromoperoxidase. Peroxidase-containing detergent compositions are described, for example, in International PCT Application WO 89/099813, published October 19, 1989, by O. Kirk, assigned to Novo Industries A/S. The present invention also encompasses peroxidase-free automatic dishwashing composition embodiments.

A wide range of enzyme materials and methods for incorporating them into synthetic detergent compositions are also described in U.S. Patent 3,553,139 (McCarty et al., published January 5, 1971). Enzymes are further described in U.S. Patent 4,101,457 (Place et al., published July 18, 1978) and U.S. Patent 4,507,219 (Hughes, published March 26, 1985). Enzymes for use in detergents can be stabilized by a variety of methods. Enzyme stabilization methods are described and exemplified in U.S. Patent 3,600,319 (Gedge et al., published August 17, 1971) and in published European Patent Application 0 199 405, application no. 86 200 586.5, published October 29, 1986 by Venegas. Enzyme stabilization systems are also described, for example, in U.S. Patent 3,519,570.

Disassembly agents '

As stated above, the detergent tablet according to the invention may also contain a disintegrant. Disintegrants are generally present in the tablet in amounts of about 5 to about 60% by weight, particularly preferably

- 5 preferably from about 20 to about 50% by weight. The disintegrating agent may be a disintegrating agent or an effervescent agent. Suitable disintegrating agents include agents which swell on contact with water or facilitate the inflow and/or outflow of water by forming channels in the pressed and/or unpressed portions. Any known disintegrating agent or effervescent agent suitable for use in laundry or dishwashing purposes may be used in accordance with the invention. Suitable disintegrating agents include starch, starch derivatives, alginates, carboxymethylcellulose (CMC), cellulose-based polymers, sodium acetate, alumina. Suitable effervescent agents include those which evolve a gas on contact with water. Suitable effervescent agents may be oxygen, nitrogen dioxide or carbon dioxide evolving species. Examples of preferred effervescent agents may be selected from the group consisting of perborate, percarbonate, carbonate, bicarbonate and carboxylic acids such as citric acid or maleic acid.

Changes in pH and buffering

The detergent tablet compositions of the present invention may be buffered, i.e., they are relatively resistant to pH drops in the presence of acidic soils. However, other compositions of the present invention may have exceptionally low buffering capacity, or they may be substantially unbuffered. Methods for controlling or varying pH at recommended use levels generally include the use of not only buffers, but also additional alkalis, acids, pH altering systems, two-compartment containers, and the like, and are well known to those skilled in the art.

The preferred compositions of the present invention contain a pH adjusting component selected from water-soluble alkaline inorganic salts and water-soluble organic or inorganic builders. The pH adjusting components are selected so that when the composition is dissolved in water at a concentration of 1000 to 10,000 ppm, the pH remains in the range above about 8, preferably from about 9.5 to about 11. The preferred phosphate-free pH adjusting component of the present invention is selected from the group consisting of

(i) sodium carbonate or sesquicarbonate;

(ii) sodium silicate, preferably anhydrous sodium silicate having a SiO ₂ :Na ₂ O ratio of about 1:1 to about 2:1, and mixtures thereof with limited amounts of sodium metasilicate; (iii) sodium citrate;
(iv) citric acid;
(v) sodium bicarbonate;
(vi) sodium borate, preferably borax;
(vii) sodium hydroxide; and

(viii) Mixtures of (i)-(vii).

Preferred embodiments contain low levels of silicate (ie, about 3 to about 10% SiO ₂ ).

The amount of pH adjusting component in the composition of the invention is preferably from about 1 to about 50% by weight of the composition. In a preferred embodiment, the pH adjusting component is present in the composition in an amount of from about 5 to about 40% by weight, preferably from about 10 to about 30% by weight.

Water-soluble silicates

5· "&Sgr;

The compositions of the invention may further comprise water-soluble silicates. The water-soluble silicates are any silicates which are soluble to such an extent that they do not adversely affect the spotting/film-forming properties of the ADD composition.

Examples of silicates are sodium metasilicate and, more generally, alkali metal silicates, particularly those having a SiO ₂ :Na ₂ O ratio in the range of 1.6:1 to 3.2:1, preferably having a SiO ₂ :Na ₂ O ratio of about 1.0 to about 3.0; and layered silicates, for example the layered sodium silicates described in U.S. Patent 4,664,839 (HP Rieck, published May 12, 1987). NaSKS-6® is a crystalline layered silicate marketed by Hoechst (generally referred to herein as "SKS-6"). Unlike zeolite builders, NaSKS-6 and other water-soluble silicates useful in the present invention do not contain aluminum. NaSKS-6 is the δ-Na ₂ SiO ₅ form of layered silicate and can be prepared by processes such as those described in, for example, DE-A-3 417 649 and DE-A-37 42 043. SKS-6 is a preferred layered silicate for use in accordance with the invention, but other such layered silicates can also be used, for example those having the general formula NaMSi _x O _2x+1 .yH ₂ O, in which M is sodium or hydrogen, χ is a number from 1.9 to 4, preferably 2, and y is a number from 0 to 20, preferably 0. Various other layered silicates from Hoechst include NaSKS-5, NaSKS-7 and NaSKS-11 in the α, ß and γ forms. Other silicates may also be used, for example magnesium silicate, which can serve as a hardening agent in granular formulations, as a stabilizer for oxygen bleaches, and as a component of foam control systems.

&bgr; *

Silicates particularly useful for automatic dishwashing (ADD) applications include granular anhydrous 2-ratio silicates, e.g. BRITESIL® H20 from PQ Corp. and the commonly supplied BRITESIL® H24, although liquid grades of various silicates may be used if the AD D composition is in liquid form. Within safety limits, sodium metasilicate or sodium hydroxide may be used alone or in combination with other silicates in an ADD context to raise the wash pH to the desired level.
10

Chelating agents

The compositions of the invention may optionally contain one or more transition metal selective sequestrants, "chelators" or "chelating agents", for example iron and/or copper and/or manganese chelators. Chelating agents useful in the invention may be selected from the group consisting of aminocarboxylates, phosphonates (especially the aminophosphonates), polyfunctionally substituted aromatic chelators and mixtures thereof. Without being bound by any theory, it is believed that the effect of these materials is due in part to their exceptional ability to control iron, copper and manganese in wash solutions known to decompose hydrogen peroxide and/or bleach activators; other effects include preventing the formation of an inorganic film or preventing deposits. Commercially available chelating agents for use in accordance with the invention include those of the DEQUEST® series and chelating agents from Monsanto, Du-Pont and Nalco, Inc.

Aminocarboxylates which can be used as optional chelating agents are further illustrated by ethylenediaminetetraacetates, N-hydroxyethyl-ethylenediaminetriacetates, nitrillotriacetates, ethylenediaminetetrapropionates, triethylene-

tetramine hexacetates, diethylenetriamine pentaacetates and ethanol diglycines, alkali metal, ammonium and substituted ammonium salts thereof. In general, chelating mixtures can be used for a combination of functions, for example for the control of several transition metals, for the long-term stabilization of a product and/or for the control of precipitated transition metal oxides and/or hydroxides.

Polyfunctionally substituted aromatic chelating agents are also useful in the compositions of the invention (see U.S. Patent 3,812,044 (Connor et al., issued May 21, 1974)). Preferred compounds of this type in the acid form are dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene.

A particularly preferred biodegradable chelating agent for use in the present invention is ethylenediamine disuccinate ("EDDS"), particularly (but not limited to) the [S,S] isomer as described in U.S. Patent 4,704,233 (Hartman and Perkins, issued November 3, 1987). The trisodium salt is preferred, although other forms, e.g., the magnesium salts, may be used.
20

Aminophosphonates are also suitable for use as chelating agents in the compositions of the invention, at least when low levels of total phosphorus in the detergent compositions are acceptable, and include the ethylenediaminetetrakis(methylenephosphonates) and the diethylenetriaminepentakis(methylenephosphonates). Preferably, these aminophosphonates do not contain alkyl or alkenyl groups having more than about 6 carbon atoms.

When used, the chelating agents or transition metal selective sequestrants preferably constitute from about 0.001% to about 10%, more preferably from about 0.05% to about 1%, by weight of the compositions of the invention.

Crystal growth inhibitor component

The detergent tablets may preferably contain a crystal growth inhibitor component, preferably an organodiphosphonic acid component, which is more preferably present therein in an amount of from 0.01 to 5%, most preferably from 0.1 to 2%, based on the weight of the compositions.

An organodiphosphonic acid is understood here to mean an organodiphosphonic acid that does not contain nitrogen as part of its chemical structure. This definition therefore excludes organoaminophosphonates, which may, however, be included in the compositions according to the invention as heavy metal ion sequestrant components.

The organodiphosphonic acid is preferably a C1-C4-diphosphonic acid, in particular a _C2 -diphosphonic acid, for example ethylenediphosphonic acid, or, most preferably, ethane-1-hydroxy-1,1-diphosphonic acid (HEDP), and it may be present in a partially or fully ionized form, in particular as a salt or complex.

Dispersant polymer

Preferred compositions of the invention additionally contain a dispersant polymer. When present, a dispersant polymer is typically present in the compositions of the invention in amounts ranging from 0 to about 25%, preferably from about 0.5 to about 20%, especially from about 1 to about 8%, based on the weight of the composition. Dispersant polymers are useful for improving the film-forming properties of the compositions of the invention, especially in higher pH embodiments, e.g. those in which the pH of the wash liquid exceeds about 9.5.

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Particularly preferred are polymers which prevent the deposition of calcium carbonate or magnesium silicate on dishes.

Dispersant polymers suitable for use in the present invention are further illustrated by the film-forming polymers described in U.S. Patent 4,339,080 (Murphy, issued April 5, 1983).

Suitable polymers are preferably at least partially neutralized polyacrylic acids or alkali metal, ammonium or substituted ammonium (e.g. mono-, di- or triethanolammonium) salts of polycarboxylic acids. The alkali metal, especially the sodium salts, are most preferred. Although the molecular weight of the polymer can vary over a wide range, it is preferably from about 1,000 to about 500,000, more preferably from about 1,000 to about 250,000, and most preferably, particularly when the composition is intended for use in automatic dishwashers in North America, from about 1,000 to about 5,000.

Other suitable dispersant polymers include those described in U.S. Patent 3,308,067, Dispersant Polymer (Diehl, published

March 7, 1967). Unsaturated monomeric acids which can be polymerized to form suitable dispersant polymers include acrylic acid, maleic acid (or maleic anhydride), fumaric acid, itaconic acid, aconitic acid, mesaconic acid, citraconic acid, and methylenemalonic acid. The presence of monomeric segments which do not contain carboxylate residues, such as methyl vinyl ether, styrene, ethylene, and the like, is desirable provided that these segments do not constitute more than about 50% by weight of the dispersant polymer.

Copolymers of acrylamide and acrylate having a molecular weight of from about 3,000 to about 100,000, preferably from about 4,000 to about 20,000, and an acrylamide content of less than about 50%, preferably less than about 20%, based on the weight of the dispersant, may be used.

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Polymers. Most preferably, such a dispersant polymer has a molecular weight of about 4,000 to about 20,000 and an acrylamide content of about 0 to about 15%, based on the weight of the polymer.

Particularly preferred dispersant polymers are modified low molecular weight polyacrylate copolymers. These copolymers contain as monomer units: (a) about 90 to about 10% by weight, preferably about 80 to about 20% by weight of acrylic acid or a salt thereof and (b) about 10 to about 90% by weight, preferably about 20 to about 80% by weight of an acrylic acid monomer or a salt thereof and they have the general formula [(C(R ² )C(R ¹ )(C(O)OR ³ )], in which the apparently unbalanced valences are actually occupied by hydrogen and at least one of the substituents R ¹ , R ² or R ³ , where R ¹ or R ² preferably represents a Ci-Oi-alkyl or C ₁ -hydroxyalkyl group; R ¹ or R ² can be a hydrogen atom and R ³ can be a hydrogen atom or alkali metal salt. Most preferred is a substituted acrylic acid monomer in which R ¹ is methyl, R ² is hydrogen and R ³ is Sodium.

A suitable low molecular weight polyacrylate dispersant polymer preferably has a molecular weight of less than about 1,000, more preferably from about 500 to about 10,000, most preferably from about 1,000 to about 5,000. The most preferred polyacrylate copolymer for use in the present invention has a molecular weight of about 3,500 and consists of about 70% by weight acrylic acid and about 30% by weight methacrylic acid in the fully neutralized form of the polymer.

Other suitable modified polyacrylate copolymers include the low molecular weight copolymers of unsaturated aliphatic carboxylic acids as described in U.S. Patents 4,530,766 and 5,084,535.

In agglomerated forms of the compositions of the invention, aqueous solutions of polymer dispersants can be used as liquid binders to prepare the agglomerate (particularly when the composition consists of a mixture of sodium citrate and sodium carbonate). Particularly preferred are polyacrylates having an average molecular weight of about 1,000 to about 10,000 and acrylate/maleate or acrylate/fumarate copolymers having an average molecular weight of about 2,000 to about 80,000 and a ratio of acrylate to maleate or fumarate segments of about 30:1 to about 1:2. Examples of such copolymers based on a mixture of unsaturated mono- and dicarboxylate monomers are described in European Patent Application 66,915, published December 15, 1982.

Other dispersant polymers useful in the present invention include the polyethylene glycols and polypropylene glycols having a molecular weight of about 950 to about 30,000 which can be obtained from Dow Chemical Company, Midland, Michigan. These compounds, which have a melting point within the range of about 30 to about 100 ^° C, can be obtained, for example, with molecular weights of 1450, 3400, 4500, 6000, 7400, 9500 and 20,000. These compounds are prepared by polymerizing ethylene glycol or propylene glycol with the required number of moles of ethylene or propylene oxide to achieve the desired molecular weight and melting point of each of polyethylene glycol and polypropylene glycol. The polyethylene, polypropylene and mixed glycols are referred to herein using the formula HO(CH ₂ CH ₂ O) ₀₁ (CH ₂ CH(CH ₃ )O) _n (CH(CH ₃ )(CH ₂ O)OOH, where m, η and ϳ are integers satisfying the above molecular weight and temperature requirements.

Other dispersant polymers that can be used in accordance with the invention include the cellulose sulfate esters, e.g. cellulose acetate sulfate, cellulose sulfate, hydroxyethyl cellulose sulfate, methyl cellulose sulfate and hydroxypropyl cellulose.

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loose sulfate. Sodium cellulose sulfate is the most preferred polymer of this group.

Also suitable are cellulose derivatives such as cellulose acetate, cellulose,

- 5 hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose and carboxymethyl cellulose. These dispersant polymers also have the additional advantage of reducing staining and film formation on hydrophobic surfaces, e.g. plastic. Other suitable dispersant polymers are the carboxylated polysaccharides, particularly starches, celluloses and alginates, as described in US Patent 3,723,322 (Diehl, published March 27, 1973); the dextrin esters of polycarboxylic acids as described in US Patent 3,929,107 (Thompson, published November 11, 1975); the hydroxyalkyl starch ethers, starch esters, oxidized starches, dextrins and starch hydrolysates as described in US Patent 3,803,285 (Jensen, published April 9, 1974); the carboxylated starches as described in U.S. Patent 3,629,121 (Eldib, issued December 21, 1971); and the dextrin starches as described in U.S. Patent 4,141,841 (McDonald, issued February 27, 1979). Preferred cellulose-derived dispersant polymers are the carboxymethyl celluloses.

Another group of acceptable dispersants are the organic dispersant polymers such as polyaspartate.

Polymeric soil release aqens

Known polymeric soil release agents, hereinafter referred to as "SRA", may optionally be used in the tablet compositions of the invention. When used, the SRA generally constitutes about 0.01 to 10.0%, usually 0.1 to 5%, preferably 0.2 to 3.0% by weight of the composition.

Preferred SRAs typically have hydrophilic segments that render the surface of hydrophobic fibers, such as polyester and nylon, hydrophilic, and have hydrophobic segments that deposit on hydrophobic fibers and remain attached to them until the completion of the wash and rinse cycles, thereby serving as an anchor for the hydrophilic segments. This may make it possible to more easily remove stains that occur after treatment with SRA in subsequent wash cycles. Alternatively, in automatic dishwashing compositions, these hydrophobically modified polymers prevent redeposition on hydrophobic surfaces such as plastic and provide the additional benefit of improved spotting and film formation on hydrophobic surfaces. The most suitable polymers for these applications are the hydrophobically modified polyacrylates.

The SRAs may comprise a variety of charged, for example anionic or even cationic (cf. US Patent 4,956,447), as well as uncharged monomer units and their structures may be linear, branched or even star-shaped. They may comprise end group residues which are particularly effective in controlling molecular weight or in altering physical or surface active properties. The structures and charge distributions may be adapted for use with different fiber or textile types and for varying detergent or detergent additive products.

Preferred SRAs include oligomeric terephthalate esters, which are typically prepared by processes involving at least one transesterification/oligomerization, often with a metal catalyst such as titanium (IV) alkoxide. These esters can be prepared using additional monomers that can be incorporated into the ester structure at one, two, three, four or more positions, without, of course, forming a densely cross-linked overall structure.

Suitable SRAs include a sulfonated product of a substantially linear ester oligomer consisting of an oligomeric ester backbone of repeating terephthaloyl and oxyalkyleneoxy units and allyl-derived sulfonated end group moieties covalently bonded to the backbone, such as described in U.S. Patent 4,968,451 (JJ Scheibel and EP Gosselink, published November 6, 1990); these ester oligomers can be prepared by (a) ethoxylating allyl alcohol, (b) reacting the product of (a) with dimethyl terephthalate ("DMT") and 1,2-propylene glycol ("PG") in a two-step transesterification/oligomerization process, and (c) reacting the product of (b) with sodium metabisulfite in water; the nonionic, capped 1,2-propylene/polyoxyethylene terephthalate polyesters of U.S. Patent 711,730 (Gosselink et al., published December 8, 1987), e.g., those prepared by transesterification/oligomerization of poly(ethylene glycol) methyl ether, DMT ₁ PG, and poly(ethylene glycol) ("PEG"); the partially and fully anionic, capped oligomeric esters of U.S. Patent 4,721,580 (Gosselink, published January 26, 1988), e.g., oligomers of ethylene glycol ("EG"), PG, DMT, and Na-3,6-dioxa-8-hydroxyoctanesulfonate; the non-ionic, capped block polyester oligomer compounds of U.S. Patent 4,702,857 (Gosselink, published October 27, 1987), which are prepared, for example, from DMT, Me-capped PEG and EG and/or PG or a combination of DMT _, EG and/or PG, Me-capped PEG and Na-dimethyl-5-sulfoisophthalate; and the anionic, particularly sulfoaroyl-terminated terephthalate esters of U.S. Patent 4,877,896 (Maldonado, Gosselink et al., published October 31, 1989), the latter being typical SRAs useful in both laundry detergent and fabric conditioning products, an example of which is an ester composition prepared from m-sulfobenzoic acid monosodium salt, PG and DMT, optionally but preferably also containing added PEG, e.g. PEG 3400.

The SRAs also contain simple copolymer blocks of ethylene terephthalate or propylene terephthalate with polyethylene oxide or polypropylene oxide terephthalate (see US Patent 3,959,230 (Hays, May 25, 1976) and US Patent 3,893,929 (Basadur) July 8, 1975); cellulose derivatives, eg the hydroxyether cellulose polymers available as METHOCEL from Dow; and the C1-C4 alkyl celluloses and _C4 hydroxyalkyl celluloses (see U.S. Patent 4,000,093 (Nicol et al., December 28, 1976). Suitable SRAs characterized by hydrophobic poly(vinyl ester) segments include graft copolymers of poly(vinyl esters), e.g. C1-C4 vinyl esters, preferably poly(vinyl acetate), grafted onto polyalkylene oxide backbones (see European Patent Application 0 219 048 to Kud et al., published April 22, 1987). Commercially available examples include SOKALAN SRA, e.g. SOKALAN HP-22, available from BASF, Germany. Other SRAs are polyesters having repeating units containing 10 to 15 wt.% ethylene terephthalate together with 90 to 80 wt.% polyoxyethylene terephthalate derived from a Polyoxyethylene glycol with an average molecular weight of 300 to 5000. Commercial examples include ZELCON 5126 from Dupont and MILEASE T from ICI.

Another preferred SRA is an oligomer having the empirical formula (CAP) ₂ (EG/PG) ₅ (T) ₅ (SIP)i comprising terephthaloyl (T), sulfoisophthaloyl (SIP), oxyethyleneoxy and oxy-1,2-propylene (EG/PG) units and preferably terminated with end groups (CAP), preferably modified isethionates, e.g. in an oligomer containing 1 sulfoisophthaloyl unit, 5 terephthaloyl units, oxyethyleneoxy and oxy-1,2-propyleneoxy units in a defined ratio, preferably from about 0.5:1 to about 10:1, and two end group units derived from sodium 2-(2-hydroxyethoxy)ethanesulfonate. The SRA mentioned preferably further contain 0.5 to 20% by weight, based on the weight of the oligomer, of a crystallinity-reducing stabilizer, e.g. an anionic surfactant such as linear sodium dodecylbenzenesulfonate or a representative selected from

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the group of xylene, cumene and toluene sulfonates or mixtures thereof, which stabilizers or modifiers can be introduced into the synthesis vessel as set forth in U.S. Patent 5,415,807 (Gosselink, Pan, Kellett and Hall, published May 16, 1995). Suitable monomers for the above-mentioned SRAs include Na 2-(2-hydroxyethoxy)ethanesulfonate, DMT, Na dimethyl 5-sulfoisophthalate, EG and PG.

Another group of preferred SRAs are oligomeric esters containing (1) a backbone of (a) at least one unit selected from the group consisting of dihydroxysulfonates, polyhydroxysulfonates, a unit that is at least trifunctional thereby forming ester bonds leading to a branched oligomer backbone, and combinations thereof; (b) at least one unit that is a terephthaloyl residue; and (c) at least one non-sulfonated unit that is a 1,2-oxyalkyleneoxy residue; and (2) one or more end group moieties selected from non-ionic end group moieties, anionic end group moieties, e.g. alkoxylated, preferably ethoxylated, isethionates, alkoxylated propanesulfonates, alkoxylated propanedisulfonates, alkoxylated phenolsulfonates, sulfoaroyl derivatives, and mixtures thereof. Preferred such esters are those having the empirical formula:

wherein CAP ₁ EG/PG, PEG, T and SIP are as defined above, (DEG) represents di(oxyethylene)oxy units; (SEG) represents units derived from the sulfoethyl ether of glycerol and related molecular units; (B) represents branching units which are at least trifunctional, thereby forming ester bonds to form a branched oligomer backbone; &khgr; represents a number from about 1 to about 12; y' represents a number from about 0.5 to about 25; y" represents a number from 0 to about 12; y ¹ " represents a number from 0 to about 10; y'+y'^y" ¹ represents a total number of

about 0.5 to about 25; ζ represents a number from about 1.5 to about 25; z ¹ represents a number from 0 to about 12; ζ + ζ ¹ represents a total number from about 1.5 to about 25; q represents a number from about 0.05 to about 12; m represents a number from about 0.01 to about 10; and x, y ¹ , y", y ¹ ", z, z', q and m represent the average number of moles of the corresponding units per mole of said ester, said ester having a molecular weight in the range of about 500 to about 5000.

Preferred SEG and CAP monomers for the above esters include Na 2-(2,3-dihydroxypropoxy)ethanesulfonate ("SEG"), Na 2-{2-(2-hydroxyethoxy)ethoxy}ethanesulfonate ("SE3") and its homologues and mixtures thereof and the products of ethoxylation and sulfonation of allyl alcohol. Preferred SRA esters in this class include the product of the transesterification and oligomerization of sodium 2-{2-(2-hydroxyethoxy)ethoxyethanesulfonate and/or sodium 2-[2-{2-(2-hydroxyethoxy)ethoxy}ethoxy]ethanesulfonate, DMT, sodium 2-(2,3-dihydroxypropoxy)ethanesulfonate, EG and PG using a suitable Ti(IV) catalyst and which may be designated as (CAP)2(T)5(EG/PG)i _i4 (SEG)2,5(B)o,i3, where CAP represents (Na ⁺ -O ₃ S[CH ₂ CH ₂ O] ₃₁ S)' and B represents a glycerol moiety, the EG/PG molar ratio being about 1.7:1 as determined by conventional gas chromatography after complete hydrolysis.

Other classes of SRA include (I) non-ionic terephthalates in which diisocyanate coupling compounds are used to form polymeric ester structures (see US Patent 4,201,824 (Violland et al) and US Patent 4,240,918 (Lagasse et al); (II) carboxylate-terminated SRA prepared by addition of trimellitic anhydride to known SRA to convert the terminal hydroxyl groups into trimellitate esters. With a suitable choice of catalyst, the trimellitic anhydride forms bonds to the polymer end groups via an ester of the isolated carboxylic acid of trimellitic anhydride rather than by opening the anhydride bond. Starting materials may be either non-ionic or anionic.

(III) anionic terephthalate-based SRAs of the urethane-linked type (cf. US Patent 4,201,824 (Violland et al)); (IV) poly(vinyl caprolactam) and related copolymers with monomers such as vinyl pyrrolidone and/or dimethylaminoethyl methacrylate, including both nonionic and cationic polymers (cf. US Patent 4,579,681 (Ruppert et al)); (V) graft copolymers in addition to the SOKALAN types from BASF, prepared by grafting acrylic monomers onto the sulfonated polyesters. These SRAs, as stated, have a soil release and redeposition activity similar to that of the known cellulose ethers (cf. EP-A-279 134 (1988, Rhone-Poulenc Chemie); (Vl) grafting of vinyl monomers, such as acrylic acid and vinyl acetate, onto proteins such as caseins (cf. EP-A-457 205 (BASF, 1991)); (VII) polyesterpolyamide SRAs, prepared by condensing adipic acid, caprolactam and polyethylene glycol, in particular for the treatment of polyamide fabrics (cf. Bevan et al, DE 23 35 044 (Unilever N.V., 1974)). Other useful SRAs are described in US patents 4 240 918, 4 787 989, 4 525 524 and 4 877 896 described.

Clay soil removal/anti-redeposition agents

The compositions of the invention may also optionally comprise water-soluble ethoxylated amines having clay soil removal and anti-redeposition properties. Granular compositions containing these compounds typically contain from about 0.01 to about 10.0% by weight water-soluble ethoxylated amines; liquid detergent compositions typically contain from about 0.01 to about 5% by weight.

The most preferred soil release and anti-redeposition agent is ethoxylated tetraethylenepentamine. Exemplary ethoxylated amines are further described in U.S. Patent 4,597,898 (VanderMeer, issued July 1, 1986): Another group of preferred clay soil release and anti-redeposition agents

» 93

Suitable clay soil removal/anti-redeposition agents are the cationic compounds described in European Patent Application 111,965 (Oh and Gosselink, published June 27, 1984). Other clay soil removal/anti-redeposition agents that may be used include the ethoxylated amine polymers described in European Patent Application 111,984 (Gosselink, published June 27, 1984); the zwitterionic polymers described in European Patent Application 112,592 (Gosselink, published July 4, 1984); and the amine oxides described in U.S. Patent 4,548,744 (Connor, published October 22, 1985). Other clay soil removal and/or anti-redeposition agents as are well known may also be used in the compositions of the invention (see U.S. Patent 4,891,160 (VanderMeer, published January 2, 1990) and WO 95/32272 (published November 30, 1995)). Another type of preferred anti-redeposition agents comprises the carboxymethylcellulose (CMC) materials. These materials are well known in the art.

Corrosion inhibitor compound

The detergent tablets according to the invention, which are suitable for use in dishwashing processes, can contain corrosion inhibitors, which are preferably selected from organic silver coating agents, in particular paraffin, nitrogen-containing corrosion inhibitor compounds and Mn(II) compounds, in particular Mn(II) salts of organic ligands.

Organic silver coating agents are described in PCT publication WO94/16047 and in pending European patent application EP-A-0 690 122. Nitrogen-containing corrosion inhibitor compounds are described in pending European patent application EP-A-0 634 478. Mn(II) compounds for use in corrosion inhibition

are described in the pending European patent application EP-A-0 672 749. The organic silver coating agent may be added in an amount of from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, based on the weight of the total composition.

The functional role of the silver coating agent is to form "in use" a protective coating layer on silverware components of the dishwasher load to which the compositions of the invention are to be added. The silver coating agent should therefore have a high affinity for adhesion to solid silver surfaces, particularly when present as a component of an aqueous washing and bleaching solution with which the solid silver surfaces are treated.

Organic silver coating agents suitable for use in the invention include fatty acid esters of mono- or polyhydroxy alcohols having 1 to 40 carbon atoms in the hydrocarbon chain.

The fatty acid portion of the fatty acid ester can be obtained from mono- or polycarboxylic acids having 1 to 40 carbon atoms in the hydrocarbon chain. Suitable examples of monocarboxylic fatty acids include behenic acid, stearic acid, oleic acid, palmitic acid, myristic acid, lauric acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, lactic acid, glycolic acid and ß,ß'-dihydroxyisobutyric acid. Examples of suitable polycarboxylic acids include n-butylmalonic acid, isocitric acid, citric acid, maleic acid, malic acid and succinic acid.

The fatty alcohol residue in the fatty ester can be represented by mono- or polyhydroxy alcohols with 1 to 40 carbon atoms in the hydrocarbon chain. Examples of suitable fatty alcohols include behenyl, arachidyl, cocoyl, oleyl and lauryl alcohol, ethylene glycol, glycerin, ethanol, isopropanol, vinyl alcohol, diglycerin, xylitol, sucrose, erythritol, pentaerythritol, sorbitol or sorbitan.

Preferably, the fatty acid and/or fatty alcohol group of the fatty acid ester addition material has 1 to 24 carbon atoms in the alkyl chain.

Preferred fatty esters according to the invention are ethylene glycol, glycerin and sorbitan esters in which the fatty acid portion of the ester normally comprises a residue selected from behenic acid, stearic acid, oleic acid, palmitic acid or myristic acid.

The glycerol esters are also highly preferred. These are the mono-, di- or triesters of glycerol and the fatty acids defined above.

Specific examples of fatty alcohol esters useful in the present invention include stearyl acetate, palmityl di-lactate, cocoyl isobutyrate, oleyl maleate, oleyl dimaleate and tallow propionate. Fatty acid esters useful in the present invention include xylitol monopalmitate, pentaerythritol monostearate, sucrose monostearate, glycerin monostearate, ethylene glycol monostearate, sorbitan esters. Suitable sorbitan esters include sorbitan monostearate, sorbitan palmitate, sorbitan monolaurate, sorbitan monomyristate, sorbitan monobehenate, sorbitan monooleate, sorbitan dilaurate, sorbitan distearate, sorbitan dibehenate, sorbitan dioleate and also mixed tallow alkyl sorbitan mono- and diesters.

Glycerol monostearate, glycerol monooleate, glycerol monopalmitate, glycerol monobehenate and glycerol distearate are also preferred as glycerol esters.

Suitable organic silver coating agents include triglycerides, mono- or diglycerides and fully or partially hydrogenated derivatives thereof and any mixtures thereof. Suitable fatty acid ester sources include vegetable oils and fish oils and animal fats. Suitable vegetable oils

include soybean oil, cottonseed oil, castor oil, olive oil, peanut oil, safflower oil, sunflower oil, rapeseed oil, grapeseed oil, palm oil and corn oil.

Waxes, including microcrystalline waxes, are suitable organic silver coating agents according to the invention. Preferred waxes have a melting point in the range from 35 to 110 ^° C and generally contain from 12 to 70 carbon atoms. Preferred are petroleum waxes of the paraffin and microcrystalline type, which consist of long-chain saturated hydrocarbon compounds. Alginates and gelatin are suitable organic silver coating agents according to the invention.

Dialkylamine oxides, such as Ci ₂ -C ₂ o-methylamine oxide and quaternary dialkylammonium compounds and salts thereof, for example the C^-Cao-methylammonium halides, are also suitable.

Other suitable organic silver coating agents include certain polymeric materials. Examples of such polymeric materials are polyvinylpyrrolidones having an average molecular weight of 12,000 to 700,000, polyethylene glycols (PEG) having an average molecular weight of 600 to 10,000, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, and cellulose derivatives such as methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose.

Certain perfume materials, particularly those which have a high substantivity to metal surfaces, are also suitable as organic silver coating agents according to the invention. Polymeric soil release agents can also be used as organic silver coating agents.

A preferred organic silver coating agent is a paraffin oil, usually a predominantly branched aliphatic hydrocarbon having a number of carbon atoms in the range of 20 to 50; a preferred

&bull; ^: 97

The paraffin oil used is selected from predominantly branched end compounds with a ratio of cyclic to non-cyclic hydrocarbons of 1:10 to 2:1, preferably 1:5 to 1:1. A paraffin oil which satisfies these requirements and has a ratio of cyclic to non-cyclic hydrocarbons of 32:68 is sold by Wintershall, Salzbergen, Germany, under the trade name WINOG 70.

Suitable nitrogen-containing corrosion inhibitor compounds include imidazole and derivatives thereof such as benzimidazole, 2-heptadecylimidazole and those imidazole derivatives as described in Czech Patent 139 279 and in British Patent GB-A-1 137 741 which also describes a process for preparing imidazole compounds.

Also suitable as nitrogen-containing corrosion inhibitor compounds are pyrazole compounds and their derivatives, in particular those in which the pyrazole is substituted in one of the 1-, 3-, 4- or 5-positions by substituents R ₁ , R ₃ , R ₄ and R ₅ , where R ₁ is H, CH ₂ OH, CONH ₃ or COCH ₃ , R ₃ and R ₅ are C 1 -C 4 -alkyl or hydroxyl and R ₄ is H, NH ₂ or NO ₂ .

Other suitable nitrogen-containing corrosion inhibitor compounds include benzotriazole, 2-mercaptobenzothiazole, 1-phenyl-5-mercapto-1,2,3,4-tetrazole, thionalide, morpholine, melamine, distearylamine, stearoylstearamide, cyanuric acid, aminotriazole, aminotetrazole and indazole.

Also suitable are nitrogen-containing compounds such as amines, in particular distearylamine, and ammonium compounds such as ammonium chloride, ammonium bromide, ammonium sulfate or diammonium hydrogen citrate. 30

The cleaning agent tablets may contain a Mn(II) corrosion inhibitor compound. The Mn(II) compound is preferably used in an amount

-"98

ge of about 0.005 to about 5 wt.%, more preferably from about 0.01 to about 1 wt.%, most preferably from about 0.02 to about 0.4 wt.%, based on the weight of the compositions. Preferably, the Mn(II) compound is incorporated in an amount corresponding to about 0.1-5 ppm to about 250 ppm, more preferably about 0.5 ppm to about 50 ppm, most preferably about 1 ppm to about 20 ppm, based on the weight of the Mn(II) ions in a bleaching solution.

The Mn(II) compound may be an inorganic salt in the anhydrous or in a hydrated form. Suitable salts include manganese sulfate, manganese carbonate, manganese phosphate, manganese nitrate, manganese acetate and manganese chloride. The Mn(II) compound may be a salt or a complex of an organic fatty acid, for example manganese acetate or manganese stearate.

The Mn(II) compound may be a salt or a complex of an organic ligand. In a preferred aspect, the organic ligand is a heavy metal ion sequestering agent. In another preferred aspect, the organic ligand is a crystal growth inhibitor.

Other suitable corrosion inhibitor compounds include mercaptans and diols, especially mercaptans with about 4 to about 20 carbon atoms, such as lauryl mercaptan, thiophenol, thionaphthol, thionalide and thioanthranol. Also suitable are saturated or unsaturated Ci ₀ -C ₂₀ fatty acids or their salts, especially aluminum tristearate. The Ci ₂ -C ₂₀ hydroxy fatty acids or their salts are also suitable. Also suitable are phosphonated octadecane and other antioxidants, such as beta-hydroxytoluene (BHT).

It has been found that copolymers of butadiene and maleic acid are particularly advantageous as corrosion inhibitor compounds, in particular

supplied by Polysciences Inc. under trading number 07787.

Another preferred active detergent component for use in the present invention is a hydrocarbon oil, typically a predominantly long chain aliphatic hydrocarbon having a number of carbon atoms in the range of about 20 to about 50; preferred hydrocarbons are saturated and/or branched hydrocarbons; a preferred hydrocarbon oil is selected from predominantly branched C ₂ -C 45 compounds having a ratio of cyclic to non-cyclic hydrocarbons of from about 1:10 to about 2:1, preferably from about 1:5 to about 1:1. A preferred hydrocarbon oil is paraffin. A paraffin oil meeting the above requirements and having a ratio of cyclic to non-cyclic hydrocarbons of about 32:68 is sold by Wintershall, Salzbergen, Germany, under the trade name WINOG 70.

The detergent tablets suitable for use in dishwashing processes according to the invention may contain a water-soluble bismuth compound, preferably present in an amount of from about 0.005 to about 20% by weight, more preferably from about 0.01 to about 5% by weight, most preferably from about 0.1 to about 1% by weight, based on the weight of the compositions.

The water-soluble bismuth compound can be essentially a salt or complex of bismuth with essentially any inorganic or organic counter anion. Preferred inorganic bismuth salts are selected from the bismuth trihalides, bismuth nitrate and bismuth phosphate. Bismuth acetate and citrate are preferred salts with an organic counter anion.

Dyes

As used herein, the term "colorant" means any substance that absorbs light of a specific wavelength from the visible light spectrum. Such colorants, when added to a detergent composition, have the effect of changing the visible color and hence the appearance of the detergent composition. Colorants may, for example, be either dyes or pigments. Preferably, the colorants are stable in the composition into which they are to be incorporated. Thus, in a composition having a high pH, the colorant is preferably alkali stable and in a composition having a low pH, the colorant is preferably acid stable.

The pressed portion and/or the non-pressed portion may contain a colorant, a mixture of colorants, colored particles or a mixture of colored particles such that the pressed portion and the non-pressed portion have a different visual appearance. Preferably, either only the pressed portion or only the non-pressed portion contains a colorant.

The pressed and/or non-pressed, non-encapsulating portions may also be of one color and contain particles or specks of a different color. For example, the pressed portion may be white with blue specks while the non-pressed, non-encapsulating portion is blue.

When the unpressed portion contains two or more compositions of active detergent components, preferably at least one of them, either the first and second and/or further compositions, contains a colorant. When both the first and second and/or further compositions contain a colorant, it is preferred that the colorants have a different visual appearance.

"&iacgr;&ogr;&igr; ·'

If present, the coating layer preferably contains a colorant. When the pressed portion and the coating layer contain a colorant, it is preferred that the colorants give a different visual effect.

Examples of suitable dyes include reactive dyes, direct dyes, azo dyes. Preferred dyes include phthalocyanine dyes, anthraquinone dyes, quinoline dyes, monoazo, disazo and polyazo dyes. Particularly preferred dyes include anthraquinone, quinoline and monoazo dyes. Preferred colorants include SANDOLAN E-HRL 180% (trade name), SANDOLAN MILLING BLUE (trade name), TURQUOISE ACID BLUE (trade name) and SAN-DOLAN BRILLIANT GREEN (trade name), all available from CIariant UK, HEXACOL QUINOLINE YELLOW (trade name) and HEXACOL BRILLIANT BLUE (trade name), both available from Pointings, UK, ULTRA MARINE BLUE (trade name) available from Holliday or LEVAFIX TURQUISE BLUE EBA (trade name) available from Bayer, USA.

Furthermore, it is preferred that the colorant does not cause any visible discoloration of the plastic, for example of an automatic dishwasher, or of plastic tableware, after a plurality of cycles, particularly preferably after 1 to 50 cycles.

The colorant may be incorporated into the pressed and/or non-pressed portion by any suitable method. Suitable methods include mixing all or selected active detergent components with a colorant in a drum or spraying all or selected active detergent components together with the colorant into a rotating drum. Alternatively, the dye color may be enhanced by previously dissolving the colorant in a

102

compatible solvent before adding the colorant to the composition.

The colorant, when present as a component of the pressed portion, is present in an amount of from about 0.001 to about 1.5%, preferably from about 0.01 to about 1.0 %, most preferably from about 0.1 to about 0.3%. When present as a component of the non-pressed portion, the colorant is generally present in an amount of from about 0.001 to about 0.1%, preferably from about 0.005 to about 0.05%, most preferably from about 0.007 to about 0.02%. When present as a component of the overcoat layer, the colorant is present in an amount of from about 0.01 to about 0.5%, preferably from about 0.02 to about 0.1%, most preferably from about 0.03 to about 0.06%.

Silicone and phosphate ester foam suppressors

The compositions of the invention may optionally contain an alkyl phosphate ester foam suppressor, a silicone foam suppressor, or combinations thereof. Levels are generally from 0 to about 10%, preferably from about 0.001 to about 5%. In general, preferred compositions of the invention (for cost and/or deposition reasons) do not contain foam suppressors or contain foam suppressors only at low levels, for example less than about 0.1% active foam suppressor.

Silicone foam suppression technology and other defoamers useful in the present invention are extensively documented in "Defoaming, Theory and Industrial Applications", Ed. P.R. Garrett, Marcel Dekker, N.Y., 1973, ISBN 0-8247-8770-6, which is incorporated herein by reference (see in particular the chapters entitled "Foam control in Detergent Products" (Ferch et al) and "Surfactant Antifoams" (Blease et al), see also

(see also US patents 3,933,672 and 4,136,045). Highly preferred silicone foam suppressors are the compound types known for use in detergents, for example high-performance granules, although the ones previously only used in liquid high-performance

. 5 types used in cleaning agents can also be incorporated into the compositions according to the invention. For example, polydimethylsiloxanes with trimethylsilyl or alternating endblock units can be used as the silicone. These can be mixed with silicon dioxide and/or with surface-active silicon-free components, illustrated by a foam suppressor containing 12% silicone/silicon dioxide, 18% stearyl alcohol and 70% starch in granular form. A suitable source for the active silicone compounds is Dow Corning Corp.

If it is desired to use a phosphate ester, suitable compounds are described in U.S. Patent 3,314,891 (Schmolka et al, published April 18, 1967), which is incorporated herein by reference. Preferred alkyl phosphate esters contain from 16 to 20 carbon atoms. Particularly preferred alkyl phosphate esters are monostearyl acid phosphate or monooleyl acid phosphate or salts thereof, especially the alkali metal salts, or mixtures thereof.

It has been found that it is preferable to avoid the use of simple calcium precipitating soaps as antifoams in the compositions of the invention because of their tendency to deposit on dishware. In fact, phosphate esters are not entirely free from such problems and the formulator will generally prefer to minimize the level of potentially depositing antifoams in the compositions of the invention.

Enzvm stabilizing system

&bull; · · · ft

&Iacgr;04

The preferred enzyme-containing compositions of the present invention may contain from about 0.001 to about 10% by weight, preferably from about 0.005 to about 15% by weight, most preferably from about 0.01 to about 6% by weight of an enzyme stabilizing system. The enzyme stabilizing system may be any stabilizing system compatible with the detergent enzyme. These stabilizing systems may include calcium ions, boric acid, propylene glycol, a short chain carboxylic acid, a boron-containing acid, chlorine bleach scavengers, and mixtures thereof. These stabilizing systems may also contain reversible enzyme inhibitors, e.g., reversible protease inhibitors. For other suitable enzyme stabilizers and stabilizer systems, see U.S. Patent 4,537,706 (Severson)).

Lime soap dispersant compound

The compositions of active detergent components may contain a lime soap dispersant compound, preferably present in an amount of from about 0.1 to about 40 wt.%, more preferably from about 1 to about 20 wt.%, most preferably from about 2 to about 10 wt.%, based on the weight of the compositions.

A lime soap dispersant is a material that prevents the precipitation of alkali metal, ammonium or amine salts of fatty acids by calcium or magnesium ions. Preferred lime soap dispersant compounds are described in PCT application WO93/08877.

Foam suppression systems

The detergent tablets of the invention, when formulated for use in washing machine compositions, preferably contain a foam suppressor system present in an amount of from about 0.01 to about 15% by weight, preferably from about 0.05 to

about 10% by weight, most preferably from about 0.1 to about 5% by weight, based on the weight of the composition.

Suitable foam suppressing systems for use in accordance with the invention may essentially comprise a known antifoam compound, e.g. silicone antifoam compounds, 2-alkyl and alkanol antifoam compounds. Preferred foam suppressing systems and antifoam compounds are described in PCT application WO93/08876 and in EP-A-0 705 324. 10

Polymeric dye transfer inhibitors

The detergent tablets of the invention may also contain from about 0.01 to about 10% by weight, preferably from about 0.05 to about 0.5% by weight, of polymeric dye transfer inhibiting agents. The polymeric dye transfer inhibiting agents are preferably selected from polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinylpyrrolidone polymers, or combinations thereof.

20 Optical brighteners

Detergent tablets suitable for use in washing processes as described herein may optionally contain from about 0.005 to about 5% by weight of certain types of hydrophilic optical brighteners.

The hydrophilic optical brighteners which can be used according to the invention include those having the structural formula:

Ri

V-N- / _v HH
^- _N \ &igr;&igr; ■v-a yy-c=c SOjM

SUN ₃ M

106

wherein R ₁ is selected from anilino, N-2-bis-hydroxyethyl and NH-2-hydroxyethyl; R ₂ is selected from N-2-bishydroxyethyl, N-2-hydroxyethyl-, 5 N-methylamino, morpholino, chloro and amino; and M represents a salt-forming cation, for example sodium or potassium.

In the above formula, when R ₁ is anilino, R ₂ is N-2-bis-hydroxyethyl and M is a cation such as sodium, the brightener is 4,4'-bis^-anilino-e-iN^-bishydroxyethyl-s-triazine^-yOaminoJ^^'-stilbenedisulfonic acid and the disodium salt. This particular brightener compound is commercially available under the trade name Tinopal-UNPA-GX from Ciby-Geigy Corporation. Tinopal-UNPA-GX is the preferred hydrophilic optical brightener used in the cleaning compositions of the present invention.

In the above formula, when R ₁ is anilino, R ₂ is N-2-hydroxyethyl-N-2-methylamino and M is a cation such as sodium, the brightener is 4,4'-bis[(4-anilino-6-(N-2-hydroxyethyl-N-methylamino)-s-triazin-2-yl)amino]-2,2'-stilbenedisulfonic acid disodium salt. This particular brightener compound is commercially available under the trade name Tinopal 5BM-GX from Ciba-Geigy Corporation.

In the above formula, when R ₁ is anilino, R ₂ is morpholino and M is a cation such as sodium, the brightener is 4,4'-bis[(anilino-6-morpholino-s-triazin-2-yl)amino]-2,2'-stilbenedisulfonic acid sodium salt. This particular brightener compound is commercially available under the trade name Tinopal AMS-GX from Ciby Geigy Corporation.

Clay plasticizer system

Detergent tablets suitable for use in washing-cleaning processes may contain a clay softener system containing a clay mineral compound and optionally a clay flocculant.

The clay mineral compound is preferably a smectite clay compound. Smectite clays are described in U.S. Patents 3,862,058, 3,948,790, 3,954,632 and 4,062,647. European Patents EP-A-299,575 and EP-A-313,146 (both Procter and Gamble Company) describe suitable organic polymeric clay flocculants.

Cationic textile softening compounds

Cationic fabric softening compounds may also be incorporated into the compositions of the invention which are suitable for use in washing processes in a washing machine. Suitable cationic fabric softening compounds include the water-insoluble tertiary amine or di-long chain amide materials as described in GB-A-1 514 276 and EP-B-0 011 340. 20

Cationic textile plasticizers are typically added in total amounts of from about 0.5 to about 15% by weight, preferably from about 1 to about 5% by weight.

Additional materials

Cleaning components or additive materials which may optionally be included in the compositions of the invention may comprise one or more materials to assist or improve the cleaning effect, to treat the substrate to be cleaned, as processing aids or to improve the aesthetic appearance of the compositions. Additive materials which may optionally be included in the compositions of the invention

&bull; · · ■ &diams;

compositions may also be included in the conventionally accepted levels for use (generally, the additive materials will total from about 30 to about 99.9%, preferably from about 70 to about 95% by weight of the compositions), include other active components, for example, colorants, fillers, germicides, hydrotropes, antioxidants, perfumes, solubilizing agents, carriers and processing aids.

Depending on whether greater or lesser compactness is desired, filler materials may also be included in the compositions of the invention. These include sucrose, sucrose esters, sodium sulfate, potassium sulfate and the like in amounts of up to about 70%, preferably from 0 to about 40% of the composition. A preferred filler is sodium sulfate, particularly one of good quality with the lowest levels of trace impurities.

The sodium sulfate used according to the invention preferably has a purity sufficient to ensure its non-reactivity with the bleaching agent; it can also be treated with low levels of sequestering agents, for example phosphonates or EDDS in the magnesium salt form. It should be noted that in order to achieve sufficient purity to avoid decomposition of the bleaching agent, pH-adjusting component additives, which in particular comprise any silicates, are also preferably used according to the invention.

The detergent tablets may also contain processing aids which may assist in the manufacture of the detergent tablet. For example, the pressed solid portion may contain a tableting aid such as stearic acid to facilitate easy removal of the pressed solid portion from the colorants of a tablet press. Hydrotropic materials, e.g. sodium benzenesulfonate, sodium toluenesulfonate _, sodium cumenesulfonate and the like, may also be included therein, for example

for example to better disperse the surfactant. Bleach-stable perfumes (stable also against odor) and bleach-stable dyes, for example those as described in US Patent 4,714,562 (Roselle et al., published December 22, 1987), can also be added to the compositions of the invention in suitable amounts.

Since the compositions of the invention may contain water sensitive components or those components which may react therewith when contacted in an aqueous environment, it is desirable to keep the free moisture content to a minimum, for example 7% or less, preferably 5% or less of the compositions; and to enable packaging which is substantially impermeable to water and carbon dioxide. Coating means have been described previously herein to illustrate the manner in which the components may be protected from one another and from air and moisture. Plastic bottles, including the refillable or recyclable types, and conventional barrier cartons or boxes are other useful means to ensure maximum storage stability. As indicated, if the components are not very compatible, it may also be desirable to coat at least one of these components with a low-foaming nonionic surfactant to protect it. There are numerous waxy materials which can be used to prepare suitably coated particles from these otherwise incompatible components; However, the formulator will prefer materials which do not have a pronounced tendency to deposit or form films on tableware, including plastic tableware.

Form of composition
30

The detergent tablet may have any suitable shape, as long as the area ratio B:A is in the range of about 1:50 to about 4:1, preferably

110

Preferably, the tablet is pressed in a ratio of about 1:20 to about 1:1, particularly preferably about 1:10 to about 1:1. The pressed solid portion may have the same shape or a different shape than the at least one depression (hollow shape) in its surface. The size of the tablet is also correspondingly unlimited. . 5 Preferably, the size is chosen so that storage and use are facilitated and so that the tablet fits into any distribution device such as is used in cleaning, for example the detergent dispenser in an automatic dishwasher.

The pressed solid part and the at least one depression (hollow form) can have a regular or irregular shape. They can have any regular or irregular geometric shape, for example concave, convex, cubic, round, conical, rectangular-prismatic, cylindrical, disc-shaped, pyramid-shaped, tetrahedral, dodecahedral, octahedral, conical, elliptical, rhomboidal or the shape of the number 8 (cf. "CRC Standard Mathematical Tables", 26th edition, Dr. William H. Beyer, editor, pages 127, 128 and 276 to 278). They can even be labels, symbols, caricatures, trademarks, images, for example company logos, cartoon letters, team logos or mascots. Alternatively, the pressed solid portion of the tablet may have a regular shape, such as a rectangular prism or the like, and the at least one cavity may have an irregular shape, such as a company logo, symbol or cartoon letter. It is also possible for both the pressed solid portion and the at least one cavity to have an irregular shape. It is also possible for a plurality of differently shaped cavities to be present in the pressed solid portion of the tablet, such that when the non-pressed, non-encapsulating portion is in each of the different cavities, a detailed image or symbol, such as a flag, crown or emblem, is formed. The use of different compatible colorants

in

ings and dyes in the various non-pressed, non-encapsulating parts is also possible and leads to a more accurate representation of logos, flags and the like. The list of possible shapes and combinations is endless.

The at least one non-pressed, non-encapsulating portion is disposed in the at least one cavity. The at least one non-pressed, non-encapsulating portion may be approximately equal to or slightly less than or slightly greater than the volume of the at least one cavity. However, it is preferred that the at least one non-pressed, non-encapsulating portion be approximately equal to or less than the volume of the at least one cavity. The upper surface of the at least one non-pressed, non-encapsulating portion may be concave or convex.

If a portion of the tablet has straight edges, it is preferred that either the edges are bevelled or rounded. These edges may be present in either or both the pressed solid portion and/or the at least one cavity. In addition, it is preferred that if the tablet has corners, the corners are rounded.

Proceedings

The detergent tablets of the invention are prepared by separately preparing the composition of the active detergent components which respectively form the pressed portion and the non-pressed, non-encapsulating portion(s), molding the pressed solid portion and supplying or fixing the non-pressed, non-encapsulating portion(s) to the recess(es) in the pressed portion.

The pressed portion is prepared by providing at least one active detergent component and optionally premixing it with carrier components. The premixing is carried out in a suitable mixer, for example in a pan mixer, a rotary flow

. 5 mel, a vertical mixer or a high shear mixer. Preferably, the dry particulate components are mixed together in a mixer as described above and liquid components are added to the dry particulate components, for example by spraying the liquid components directly onto the dry particulate components. The resulting composition is then formed into a pressed portion in a pressing stage using any suitable apparatus known in the art. Preferably, the composition is formed into a pressed portion using a tablet press, the tablet being made by pressing the composition between upper and lower dies. In a preferred embodiment of the invention, the composition is introduced into a die cavity of a tablet press and pressed to form a pressed portion using a pressure which is preferably greater than 6.3 kN/cm ² , more preferably greater than 9 kN/cm ² , most preferably greater than 14.4 kN/cm ² .

To produce a tablet according to the invention in which the pressed portion has at least one depression (cavity) for receiving the non-pressed, non-encapsulating portion(s), the pressed portion is produced using a modified tablet press having modified upper and/or lower dies. The upper and lower dies of the modified tablet press are modified such that the pressed portion has one or more depressions (cavity) which form the cavity(s) in which the non-pressed, non-encapsulating portion(s) can be arranged.

113

The pressed portion may be cooled or even frozen before the non-pressed, non-encapsulating portion(s) is/are fed into the at least one mold. This cooling or freezing is particularly advantageous when the non-pressed, non-encapsulating portion is a gel.

As described in detail above, the non-pressed, non-encapsulating portion(s) contains at least one active detergent component. The active detergent component and any other components in the non-pressed, non-encapsulating portion(s) are premixed using any suitable mixing equipment known in the art.

The non-pressed, non-encapsulating portion contains at least one active detergent component. If the non-pressed, non-encapsulating portion contains more than one active detergent component, the components are premixed using any suitable mixing device known in the art. The non-pressed, non-encapsulating portion may additionally optionally contain a carrier with which the active detergent components are combined. The non-pressed, non-encapsulating portion may be prepared in solid or flowable form. Once the composition is prepared, it is added to the pressed portion. The non-pressed, non-encapsulating portion may be added to the pressed portion by manual feeding or using a die-feed extruder or by any other suitable device. When the pressed portion has a cavity, the non-pressed, non-encapsulating portion is preferably fed into the cavity using a precision feeding device, such as a nozzle feeder, such as a loss-in-weight screw feeder, such as available from Optima, Germany, or an extruder.

···· &Iacgr;·14

When the flowable, non-pressed, non-encapsulating portion is in the form of particles, the method comprises feeding a flowable, non-pressed, non-encapsulating portion to the pressed portion in a feeding stage and then coating at least a portion of the non-pressed, non-encapsulating portion with a coating layer such that the coating layer is effective to substantially fix the non-pressed portion to the pressed portion.

When the flowable non-pressed, non-encapsulating portion is fixed to the pressed portion by curing, the method includes a feeding step in which the flowable non-pressed, non-encapsulating portion is fed to the pressed portion, and a subsequent conditioning step in which the non-pressed, non-encapsulating portion is cured. Such a conditioning step may include drying, cooling, binding, polymerizing, etc., the non-pressed, non-encapsulating portion, during which step the non-pressed, non-encapsulating portion becomes solid, semi-solid, or highly viscous. Heat may be applied in the drying step. Heat or exposure to radiation may be used to effect polymerization in a polymerization step.

It is also conceivable that the pressed portion is made with a plurality of cavities. The plurality of cavities is then filled with a non-pressed, non-encapsulating portion. It is also conceivable that each cavity is filled with a different non-pressed, non-encapsulating portion or, alternatively, each cavity can be filled with a plurality of different non-pressed, non-encapsulating portions.

The detergent tablets can be used in a conventional household washing process in which detergent tablets are usually used, e.g., without the invention being limited thereto

&bull; · &diams;

·"· 715

is used in automatic dishwashing and textile washing (laundry).

Dishwashing process
. 5

Suitable methods for washing in a machine or for cleaning dirty dishes are considered.

A preferred dishwasher washing process comprises the treatment of soiled objects selected from earthenware, glassware, silverware, metal parts, cutlery and mixtures thereof with an aqueous liquid in which an effective amount of a detergent tablet according to the invention is dissolved or distributed. An effective amount of the detergent tablet is to be understood as 8 to 60 g of product dissolved or dispersed in a washing solution with a volume of 3 to 10 l, as typical product dosages and washing solution volumes as are usually used in conventional dishwasher washing processes. The detergent tablets preferably have a weight % of 15 to 40 g, particularly preferably 20 to 35 g.
20

Washing machine washing process

Washing machine washing processes are generally understood here to mean the treatment of soiled laundry with an aqueous washing solution in a washing machine in which an effective amount of a washing machine detergent tablet according to the invention is dissolved or distributed. An effective amount of the detergent tablet composition is understood to mean 40 to 300 g of product dissolved or dispersed in a washing solution with a volume of 5 to 65 l ₁ as typical product dosages and washing solution volumes as are usually used in conventional washing machine washing processes.

&bull; ■ · · · I

In a preferred aspect of the application, a distribution device is used in the washing process. The distribution device is charged with the detergent product and is used to introduce the product directly into the drum of the washing machine before the start of the washing cycle. Its volume capacity should be such that it can normally accommodate sufficient detergent product as is normally used in the washing process.

Once the washing machine has been loaded with the laundry, the distribution device containing the detergent product is placed inside the drum. At the start of the washing cycle of the washing machine, water is introduced into the drum and the drum rotates periodically. The shape of the distribution device should be such that it allows the dry detergent product to be received, but also that it allows the release of this product during the washing cycle as a function of the movement when the drum rotates and also as a result of its contact with the washing water.

To allow release of the detergent product during washing, the device may have a number of openings through which the product can pass. Alternatively, the device may be made of a material which is permeable to liquid but impermeable to the solid product so as to allow release of the dissolved product. Preferably, the detergent product is released rapidly at the start of the washing cycle, thereby temporarily maintaining high local concentrations of product in the drum of the washing machine at this stage of the washing cycle.

Preferred distribution devices are reusable and constructed to maintain the integrity of the container both in the dry state and during the wash cycle.

· ^: ·· -117

Alternatively, the dispensing means may be a flexible container, such as a pouch or bag. The bag may be of fibrous construction coated with a water-impermeable protective material so as to retain the contents, as described in published European patent application 0018678. Alternatively, it may be made of a water-insoluble synthetic polymeric material provided with an edge seal or closure designed to rupture in aqueous media, as described in published European patent applications 0011500, 0011501, 0011502 and 0011968. A suitable form of water-dissolvable closure comprises a water-soluble adhesive disposed along and sealing an edge of a bag made from a water-impermeable polymeric film such as polyethylene or polypropylene.

Examples

The following non-limiting examples illustrate the present invention. The compositions exemplified include both automatic dishwasher compositions and washing machine compositions.

Abbreviations used in the examples

In the cleaning agent compositions, the abbreviated component identifications have the following meanings:

STPP Sodium tripolyphosphate

Zeolite Zeolite A

Citrate trisodium citrate dihydrate

Bicarbonate. Sodium bicarbonate

Citric acid anhydrous citric acid

Carbonate, anhydrous sodium carbonate

10

Silicate MetasilJcat PB1
PB4

TAED Plurafac

15

Tergitol

SLF18

25

HEDP DETPMP

30

PAAC BzP

amorphous sodium silicate (SiO ₂ :Na ₂ O ratio = 1.6-3.2) sodium metasilicate (SiO ₂ :Na ₂ O ratio = 1.0)
anhydrous sodium perborate monohydrate

Sodium perborate tetrahydrate with the nominal formula NaBO ₂ .3H ₂ OH ₂ O ₂ tetraacetylethylenediamine mixed Ci ₃ -Ci ₅ -ethoxylated/propoxylated fatty alcohol with an average degree of ethoxylation of 3.8, an average degree of propoxylation of 4.5, sold under the trade name Plurafac by BASF non-ionic surfactant available under the trade name Tergitol 15S9 from Union Carbide poly(oxyalkylated) alcohol with epoxy end groups according to Example III of WO 94/22800, wherein 1,2-epoxydodecane replaces the 1,2-epoxydecane, available under the trade name PoIytergent SLF18D from OLIN. Ethane-1-hydroxy-1,1-diphosphonic acid diethyltriamine penta(methylene)phosphonate, sold by Monsanto under the trade name Dequest 2060

Pentaamine acetate cobalt (III) salt benzoyl peroxide

paraffin

Protease Amylase 480N

Sulfate PEG 3000

PEG6000

Sugar Gelatin

CMC Dodecanedicarboxylic acid Adipic acid Lauric acid BTA PA30

pH value of paraffin oil, sold under the trade name Winog 70 by Wintershall

proteolytic enzyme amylolytic enzyme acrylate/methacrylate (7:3) random copolymer with an average molecular weight of 3500 anhydrous sodium sulfate polyethylene glycol with a molecular weight of about 3000, available from Hoechst polyethylene glycol with a molecular weight of about 6000, available from Hoechst household sugar

Gelatin type A, Bloom strength 65, available from Sigma Carboxymethylcellulose C12-dicarboxylic acid
C6-dicarboxylic acid
C12 monocarboxylic acid benzotriazole

Polyacrylic acid with an average molecular weight of about 4500

measured in a 1 % solution in distilled water at 20 ⁰ C

example 1

A detergent tablet according to the invention can be prepared as follows:

A detergent composition as in Example 2, Formulation A is prepared and placed in a conventional rotary press. The press includes a die shaped to form a cavity in one of the tablet surfaces. A gel matrix formulation as described in Example 2, Formulation A is then prepared. The appropriate amount of non-aqueous solvent is fed to a mixer and a shear force is applied to the solvent at a medium rotational speed (2500-5000 rpm). The appropriate amount of gelling agent is gradually added to the solvent under shear conditions until the mixture is homogeneous. The shear rate of the mixture is gradually increased to high shear conditions of about 10,000 rpm. The temperature of the mixture is increased to a value between 55 and ^60° C. The shearing is then stopped and the mixture is allowed to cool to temperatures between 35 and 45 ^° C. Using a low shear mixer, the remaining components are then added to the mixture in solid form. The finished mixture is then introduced into the cavity (mold) on the compressed tablet body and left until the gel hardens or is no longer flowable.

Example 2

Detergent tablets according to the invention can be formulated as follows:

A B C D E F pressed portion STPP 52.80 50.00 51,00 — 50.00 38.20

"121 *** **

Citrate ~ — — 26.40 — — non-pressed portion 12.80 — 10.00 4.50 — 4.00 Carbonate 15.40 14,00 14,00 — 18.40 15.00 Savinase® 8.00 — 4.50 7.00 4.00 silicate 12.60 14.80 15.00 26.40 5.00 10.10 N76D/S103AA/104I ¹ 7.20 — 11,50 4.50 — — Protease — 1.00 — — -- — Termamyl® 20.00 13,00 — 4.50 — 13,00 Amylase 0.95 0.75 0.75 0.60 2.0 0.85 Amylase^ 15.00 12.00 11,50 13,00 5.00 PB1 12.60 12,50 12,50 1.56 15.70 11,00 Bicarbonat — 12.00 10.00 14,00 5.00 PB4 -- ~ ~ 6.92 — — Citric acid 34,00 — 50.00 38,00 — 34,00 non-ionic surfactant 1.65 1.50 2.00 1.50 0.80 1.65 Dipropylene glycol butyl-
ether — 38,00 __ ~ 48,00 — PAAC __ 0.016 — 0.012 — 0.008 Glycerol triacetate 4.00 ~ 5.00 7.00 4.00 — TAE — — — 4.33 1.30 — Thixatrol ST® 2.00 — ~ — 3.00 HEDP — — — 0.67 — 0.92 Polyethylene glycol ^J - DETPMP — — — 0.65 — — paraffin — 0.50 0.50 0.42 — — BTA — 0.30 0.30 0.24 — — PA30 — — — 3.20 — — sulfate — — — 24.05 5.00 22.07 Div./Water to
compensation q.s. q.s. q.s. q.s. q.s. q.s. Weight (g) 20.00 15.00 20,50 20.00 15.00 30.00

Surfactant ⁴ 2.00 — -- 0.1 1.00 — Metasilicate -- — — 7.00 ~ 41.00 silicate — 11,00 — — 28.00 — Div./Water to
compensation q.s. q.s. q.s. q.s. q.s. q.s. Ratio B : A 1:10 3:1 1:8 1:7 2:1 1:42 Weight (g) 3.50 15.00 3.50 3.00 17,00 5.00 Total weight (g) of
tablet 23,50 30.00 24,00 23,00 32.00 35.00

as stated in US Patent 5,677,272

Amylase enzyme as defined in Novo Nordisk application PCT/DK96/00056 and obtained from an alkalophilic Bacillus species having the following N-terminal sequence.

His-His-Asn-Gly-Thr-Asn-Gly-Thr-Met-Met-Gln-Tyr-Phe-Glu-Trp-Tyr-Leu-Pro-Asn-Asp.

Molecular weight 4 000 - 8 000

the surfactant can be either a non-ionic surfactant, an anionic surfactant or a mixture thereof.

Example 3

Examples of detergent tablets according to the invention which are suitable for use in a dishwasher are explained below.

The compressed portion is prepared by introducing the composition of active detergent components into a die cavity of a modified 12-head rotary tablet press and compressing the composition under a pressure of 13KN/cm ² . The modified tablet press produces a tablet in which the compressed portion has a cavity (cavity). For the purposes of Examples G to L, the uncompressed, non-encapsulating portion is in particulate form. The uncompressed, non-encapsulating portion is added to the cavity of the compressed portion.

123

using a nozzle feeder. The non-pressed, non-encapsulating portion is fixed to the pressed portion by coating the non-pressed, non-encapsulating portion with a coating layer which is in contact with the pressed portion.

G H I J K L non-pressed, non-encapsulating portion 12.80 8.12 9.92 8.00 8.00 8.00 pressed portion Protease 7.20 13,00 6.00 10.00 — 13,00 STPP — 50.00 52.80 45,00 38.20 Amylase Zeolite 30.00 Citrate 26.40 25.00 — — — -- Carbonate — 14,00 15.00 15.40 18.40 15.00 silicate 26.40 14.80 15.0 12.60 10.00 10.10 Protease — — — 1.0 — — Amylase 0.6 0.75 0.75 0.95 2.0 0.85 PB1 1.56 12,50 12.20 12.60 15.70 11,00 PB4 6.92 — — — — ~ non-ionic surfactant 1.50 1.5 1.50 1.65 0.80 1.65 PAAC — 0.016 0.016 0.012 — 0.008 TAE 4.33 — — — 1.30 — HEDP 0.67 — — — — 0.92 DETPMP 0.65 — — — — — paraffin 0.42 0.50 0.5 0.55 0.50 — BTA 0.24 0.30 0.3 0.33 0.33 — PA30 3.2 ~ ~ — — — sulfate 24.05 ~ 2.00 — 5.00. 22.07 Div./Water to
compensation q.s. q.s. q.s. q.s. q.s. q.s. Weight (g) 20.0 20.0 20.0 20.0 12.00 30.0

Metasilicate — 50.02 — 45.10 40,00 50.00 Coating layer - 90,00 82.00 — — 90,00 Bicarbonat — 13,00 20.02 13,00 6.00 13,00 Dodecanedicarbon-
acid — — — 92.00 — — Citric acid — 13,00 14,98 14,00 6.00 13,00 Adipic acid — — 8.00 — — — BzP — — — 9.00 — — Lauric acid 15.00 10.00 10.00 8.00 — 10.00 Citrate 35.00 — — — 40 — Strength — — — — 100 — silicate 42.00 — 48.03 — — — PEG q.s. q.s. q.s. q.s. q.s. q.s. Div./Water to
compensation q.s. q.s. q.s. q.s. q.s. q.s. Div./Water to
compensation 1.00 1.00 1.20 0.80 0.50 1.00 Weight (g) 5.00 3.0 3.0 3.0 15.00 5.0 Weight (g) 1:4 1:9 1:15 1:50 2:1 1:30 Ratio B:A 25g 23g 23g 23g 27g 35g Total weight (g) of
tablet

Example 4

The compressed portion is prepared by introducing the composition of active detergent components into a die cavity of a modified 12-head rotary tablet press and compressing the composition under a pressure of 13KN/cm ² . The modified tablet press produces a tablet in which the compressed portion has a cavity. For the purposes of Examples M to R, the uncompressed, non-encapsulating portion comprises active detergent components and a binder. The uncompressed, non-encapsulating portion is then compressed into the

·

The detergent tablet is then subjected to a conditioning stage during which the non-pressed, non-encapsulating portion hardens.

M N O P Q R non-pressed, non-encapsulating portion — — 21.5 18.92 ~ — pressed portion Tergitol 89.40 — — — — STPP __ 52.00 52.00 52.80 45,00 38.20 PEG3000 86.9 — — — — Citrate 26.40 — — — __ PEG6000 10.60 11,00 -- — 20.00 20.00 Carbonate — 14,00 16,00 15.40 18.40 15.00 BzP silicate 26.40 14.80 15.0 12.60 10.00 10.10 Protease __ — —■ 1.0 — — Amylase 0.6 0.75 0.75 0.95 2.0 0.85 PB1 1.56 12,50 11,50 12.60 15.70 11,00 PB4 6.92 — — — — — non-ionic surfactant 1.50 1.5 1.50 1.65 0.80 1.65 PAAC — 0.016 0.016 0.012 — 0.008 TAE 4.33 — — — 1.30 — HEDP 0.67 — — — — 0.92 DETPMP 0.65 — — — — — paraffin 0.42 0.50 0.5 0.55 0.50 — BTA 0.24 0.30 0.3 0.33 0.33 — PA30 3.2 — — — — — sulfate 24.05 — 2.00 — 5.00 22.07 Div./Water to
compensation q.s. q.s. q.s. q.s. q.s. q.s. Weight (g) 20.0 20.0 20.0 20.0 20.00 30.0

■ ϕ ϕ
■ φ
&bull;&phiv;
ϕ ϕ φφφφ
φφφφ
&phgr; &phgr; ϕ ϕ
ϕ ϕ ϕ ϕ
φI ϕ ϕ
ϕ ϕ
ϕ ϕ φ φ &phgr;&phgr;&phgr;&phgr;
ϕ ϕ ϕ &phgr; &phgr; &phgr;&phgr;&phgr;&phgr; φ φ φφ «
φ φ φ «
φφφφφ < I Φ; φφφφ
ϕ ϕ ϕ ϕ ϕ
φφφφ ϕ ϕ
φφφφ &phgr;
φφφφ &phgr; φφφφ ϕ ϕ &phgr; ϕ ϕ
ϕ ϕ
φ φφφ φ ϕ ϕ ϕ
ϕ ϕ ϕ &phgr; &phgr;
φφφφφ &phgr;
ϕ ϕ ϕ ϕ
ϕ ϕ &bull;&phiv;
&phgr;&phgr;&phgr;&phgr; φ ϕ ϕ ϕ ϕ ϕ

Sugar -- — 53.4 29.04 65.00 65.00 gelatin _. — 15.01 30.00 5.00 5.00 Strength — — — 10.00 — — Water — — 10.00 10.00 10.00 10.00 Div./for compensation Weight (g) 2.5g 5.0g 2.5g 2.5g 10g 3g Ratio B : A 1:3 1:7 1:10 1:1 3:1 1:45 Total weight (g) of
tablet 22.5g 25g 22.5g 22.5g 25g 33g

Claims (11)

1. Dishwasher detergent tablet comprising: 1. a pressed solid portion comprising at least one active cleaning agent component, the pressed solid portion having at least one cavity therein and having a Child Bite Strength (CBS) of greater than 10 kg as determined according to the US Consumer Product Safety Commission Test Specification, and 2. at least one non-pressed, non-encapsulating portion having a surface area B, which is arranged in said at least one recess (hollow form) of the pressed solid portion, wherein said at least one non-pressed, non-encapsulating portion comprises at least one active detergent component and is fixed to the pressed portion by adhesion or by curing;
wherein the surface area of said detergent tablet, excluding the area of said at least one depression (hollow form), is A and wherein furthermore the area ratio B:A is about 1:50 to about 4:1. 2. A detergent tablet according to claim 1, wherein said compressed solid portion has a shape selected from the group consisting of concave, convex, cubic, rectangular prismatic, cylindrical, rounded, frustoconical, disc-shaped, pyramidal, tetrahedral, dodecahedral, octahedral, conical, elliptical, rhombohedral or a figure 8 shape. 3. A detergent tablet according to any one of claims 1 to 2, wherein said pressed solid portion has rounded edges and corners. 4. A detergent tablet according to any one of claims 1 to 3, wherein said at least one cavity has a shape selected from the group consisting of concave, convex, cubic, rectangular prismatic, round, frustoconical, cylindrical, disc-shaped, pyramidal, tetrahedral, dodecahedral, octahedral, conical, elliptical, rhombohedral or a figure 8 shape. 5. A detergent tablet according to any one of claims 1 to 4, wherein said tablet further contains a water-soluble polymeric material forming a barrier layer in said at least one cavity between said compressed solid portion and said at least one non-compressed, non-encapsulating portion. 6. A detergent tablet according to any one of claims 1 to 5, wherein said detergent tablet has an area ratio B:A of 1:20 to 1:1. 7. A detergent tablet according to any one of claims 1 to 6, wherein said active detergent component of said at least one non-pressed, non-encapsulating portion is selected from the group consisting of enzymes, surfactants, polymeric dispersants, disintegrants, bleaches, silver care agents, builders and mixtures thereof. 8. A detergent tablet according to any one of claims 1 to 7, wherein said at least one non-compressed, non-encapsulating portion further contains a swelling agent/adsorbent. 9. A detergent tablet according to any one of claims 1 to 8, wherein said at least one non-compressed, non-encapsulating portion is in solid, particulate, gel or liquid form. 10. A detergent tablet according to any one of claims 1 to 9, which contains an enzyme, wherein the enzyme is selected from the group consisting of amylases, proteases, cellulases, hemicellulases, peroxidases, lipases, phospholipases and mixtures thereof. 11. A detergent tablet according to any one of claims 1 to 10, wherein the detergent tablet additionally contains a disintegrating agent which is a disintegrating agent, an effervescent agent or mixtures thereof.