DE68910701T2 - CAST DETERGENT SYSTEMS. - Google Patents

Description

Field of the invention

The invention relates to a detergent system containing soil-removing detergents, an encapsulated halogen source and an organic component such as a polyalkylene oxide polymer and to the use of the system in cleaning. More specifically, the detergent system of the invention may contain an active, encapsulated halogen source and an organic component, preferably an alkylene oxide polymer, which are co-stable in relatively high concentration during manufacture, storage, distribution, sale and use. Such cleaning systems may be used in a variety of configurations including all-purpose cleaners, laundry detergents, dishwashing detergents, etc., producing an effective concentration of active chlorine for stain removal and sanitation purposes in the presence of organic materials such as defoamers, soil-removing non-ionic surfactants and other polyalkylene oxide polymers.

Background of the invention

Detergent systems have been used for many years in areas of cleaning such as washing clothes, washing dishes, cleaning hard surfaces and other general cleaning applications. Typical detergent systems are concentrates comprising mixtures of cleaning ingredients that are mixed with water shortly before use to form a cleaning agent or a finished application composition

Many detergent systems contain organic substances that act in a variety of ways. Such organic substances can act as defoamers, dispersants, soil-removing surfactants, thickeners, casting agents, anti-redeposition aids, viscosity modifiers, brightening agents, etc. An important class of organic substances are polyalkylene oxide polymers. The polyalkylene oxide polymers derive their properties from the presence of larger polymer units derived from ethylene oxide, propylene oxide, heteropolymers thereof, or block copolymers thereof.

In a number of applications for such detergent systems, the presence of oxidizing available halogens such as chlorine or bromine can be important. Such halogen compounds can clean and remove certain residues such as stains by oxidizing and destroying the color-providing functional groups in the organic molecules. Furthermore, the presence of sufficient concentrations of active chlorine can kill microorganisms and provide an antimicrobial or sanitation effect. However, detergent system manufacturers have been reluctant to produce detergent systems in which organic materials such as polyalkylene oxide polymers and active chlorine-containing substances come into direct contact. Such contact can have undesirable consequences in terms of safety and have application.

In the manufacture of a number of detergent systems, many organic substances are hazardous to contact with active chlorine compounds. At elevated temperatures or at high concentrations, contact of such compounds with active chlorine-containing substances can result in a rapid reaction between the chlorine-containing substances and the organic substances, resulting in the generation of large volumes of smoke or the occurrence of fire. If the detergent systems are successfully manufactured without a rapid reaction between the chlorine and the polyalkylene oxide components, the substances can react slowly during manufacture, packaging, storage, distribution, sale and use, causing a significant loss in the concentration of both the organic substances and the active chlorine substances. Such reactions usually occur at a rate which reduces the concentration of active chlorine in the detergent system below that required for sanitation properties and often even below a concentration required for stain removal. Furthermore, such reactions can reduce the concentration of organic materials to a level that leads in particular to a reduction in the polymer-related properties.

European Patent Application No. 307 587 describes a cast detergent composition comprising an alkali metal silicate, an alkali metal [condensed phosphate], an encapsulated bleaching slurry and optionally additives such as a surfactant, a defoamer, e.g. ethylene oxide copolymer and a propylene oxide copolymer, etc. The encapsulated Bleach source is coated with a first inner layer of a water-soluble release compound and a second outer layer of a cellulose ether.

Brennan et al., U.S. Patent No. 3,637,509 describes dishwashing detergent compositions containing a combination of an alkali metal tripolyphosphate and an organic chlorinating agent, in which the combination is coated with a tetrapotassium pyrophosphate. The coated composition is then combined with other detergent additives.

We have found that active halogen can be lost by spontaneous decomposition of the active chlorine and by reactivity of the chlorine with functional groups commonly found in organic compounds used in detergent systems. Common functional groups reactive with reactive chlorine compounds include olefinic bonds commonly found in unsaturated fatty acids which are a common composition of alkali metal soaps, hydroxyl groups typically found in organic builders, amino groups, ether groups commonly found in polyalkylene oxide polymers and aromatic rings typically found in alkylbenzenesulfonates, alkylphenolethoxylates, etc. In the prior art, the concentration of organic compounds is generally kept below 5 wt.% to reduce the hazardous effects of organic/chlorine interactions.

Accordingly, there is a significant need in the art for detergent systems that contain significantly more effective concentrations (greater than 5% by weight) of organic substances in the form of of surfactants, foam suppressants and other functional substances as well as effective concentrations (greater than 5% by weight) of active halogen-containing compounds.

Brief description of the invention

We have found that a cast solid detergent system containing an effective amount of an alkalinity source, an effective hardness sequestrant, at least 5% by weight of an encapsulated halogen source and at least 20% by weight of an organic material such as a polyalkylene oxide polymer is an effective detergent system which can be used as a general purpose cleaner, laundry detergent, dishwashing detergent, hard surface cleaner and sanitary cleaner as well as for a number of other applications. We have surprisingly found that casting such materials in a solid form results in significant stability of the effective concentration of both halogen and organic materials during manufacture, storage, distribution and use. We have found that the products can substantially maintain an active halogen concentration and an effective organic compound concentration for periods typical of the lifetime of such a product until the product is completely consumed.

Detailed description of the invention

The detergent systems of the invention may contain an effective amount of an alkalinity source, an effective amount of hardness sequestrant at least 5% by weight, up to 60% by weight, an encapsulated halogen source compound and at least 20% up to 50% by weight of an organic composition such as a polyalkylene oxide polymer. The detergent systems of the invention are typically in the form of a cast solid material wherein the material is in the form of an expanded solid mass having a minimum weight of 50 g. held within the disposable container. The detergent system or concentrates may be dispensed from the container or removed from their container and placed in a dispenser for washing and use at the use site.

Inorganic alkalinity source

The detergent system of the invention may contain a source of alkalinity. Sources of alkalinity which have been found to be useful in combination with the other components of the detergent systems of the invention include the following non-limiting list: alkali metal hydroxide, alkali metal phosphate, alkali metal carbonate, alkali metal bicarbonate, alkali metal sequicarbonate, alkali metal borate, alkali metal silicate, and mixtures thereof. Alkali metal hydroxides are typically used where the detergent system requires strong detergency and highest pH. Silicates (M₂O:SiO₂ compounds having a ratio of 2:1 to 1:3.6, where M is an alkali metal ion) are typically a reaction product between an alkali metal hydroxide and silicon oxide. Such silicates are used primarily as sources of alkalinity where moderate potency and pH is required. Carbonate and alkaline borate sources are typically used in compositions that have an alkaline pH but do not have the alkalinity strength of silicates or hydroxides require.

Hardness sequestrant

The detergent system of the invention typically contains a hardness sequestrant to mitigate the deleterious effects of divalent and trivalent metal ions on the components of the detergent system. The detergent systems of the invention may contain both organic and inorganic hardness sequestrants. Such sequestrants are typically in the form of polyanionic materials. Inorganic hardness sequestrants include alkali metal [condensed phosphates] in the form of pyrophosphate, tripolyphosphate, hexametaphosphate, etc. Organic hardness sequestrants include polymeric and copolymeric compositions having pendant carboxylic acid functionalities derived from carboxylic acid containing monomers such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid and mixtures thereof, etc.; Alkali metal salts of organically substituted phosphonic acid and polyphosphonic acid, alkali metal salts of gluconic acid, alkali metal salts of ethylenediaminetetraacetic acid, alkali metal salts of nitrilotriacetic acid and mixtures thereof.

Organic substance

A variety of organic functional materials can be used in the detergent system of the invention. Such functional materials include absorbents, adsorbents, antimicrobials, antioxidants, anti-soiling agents, fragrances, dyes, binders, chelating agents, corrosion inhibitors, coupling agents, defoamers, dispersants, Solubilizers, stabilizers, thickeners and UV absorbers.

Examples of such absorbents and adsorbents include microcrystalline cellulose, zinc ricinoleate, free-flowing maltodextrin, powdered acrylic copolymers, and others. Anti-soiling or anti-soiling agents may include fatty acid amides, fluorocarbon surfactants, complexing phosphate esters, styrene-alkaline anhydride copolymers, and cellulose derivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose, and others. Powder binders may be used as additives in the form of solid materials, which include microcrystalline cellulose, long-chain lactate esters, long-chain oleate esters, polyacrylamides, microcrystalline waxes, polyvinyl alcohol resins, polyethylene, polyvinyl pyrrolidone, and others.

Defoamers that can be used in the detergent system of the present invention include high molecular weight C₁₀₋₄₀ linear primary alcohols, polyalkylene glycols, well-known silicone defoamers, certain acrylate copolymers, and others.

An important class of functional organic materials for the preparation of detergent systems of the invention comprises organic surfactants. A wide variety of surfactants can be used in the detergent system of the invention including anionic surfactants, zwitterionic surfactants (containing both anionic and cationic groups), cationic surfactants and nonionic surfactants. Anionic surfactants include alkyl carboxylate (sodium and potassium soaps), alkyl sulfate, alkyl ether sulfate, alkyl benzene sulfonate, alkyl sulfonate, sulfonated fatty acid esters and sulfosuccinate surfactants.

Non-ionic surfactants, typically in the form of compositions comprising polyalkylene oxide polymers as part of the surfactant molecule, may be useful in the detergent system of the present invention.

Advantageously used non-ionic surfactants used in the composition of the invention are listed in the following non-limiting list of non-ionic detergents of polyoxyalkylenes: C8-C22 normal fatty alcohol-ethylene oxide or propylene oxide condensates, ie condensation products of one mole of fatty alcohol containing 8 to 22 carbon atoms with 2 to 20 moles of ethylene oxide or propylene oxide; polyoxypropylene-polyoxyethylene condensates have the formula HO(C2H4O)x(C3H6O)yH wherein (C2H4O) is at least equal to 15% and (C3H6O)y is equal to 20-90% of the total weight of the compound; Alkylpropoxypropylenepolyoxyethylene condensates of the formula RO(C₃H₆O)x(C₂H₄O)yH wherein R is a C₁-C₁₅ alkyl group and x and y each correspond to an integer value between 2 to 98; polyoxyalkylene glycols as described in US Patent No. 3,048,548; butylene oxide-capped alcohol ethoxylates of the formula R(OC₂H₄)y(OC₄H₉)xOH, wherein R is a C₈-C₁₈ alkyl group and y is 3.5 to 10 and x is 0.5 to 1.5; benzyl ethers of polyoxyethylene condensates of alkylphenols of the formula

wherein R is a C₆-C₂₀ alkyl group and x is an integer value from 5 to 40; and alkylphenoxypolyoxyethyleneethanols of the formula

wherein R is a C₈-C₂₀ alkyl group and x is an integer value from 3 to 20.

Non-surface-active polyoxyalkylene groups

Non-surfactant polyoxyalkylene polymers are used as binders or casting agents in the preparation of the detergent systems of the invention, where the materials of the invention are mixed with the casting agent at elevated temperatures; cooling the mixed material solidifies the casting agent and results in a stable, cast solid. Such polyalkylene oxide polymers include homopolymers of ethylene oxide (EO), homopolymers of propylene oxide (PO), hetero-EO/PO copolymers or block EO/PO copolymers, e.g. those having a molecular weight of 1000 to 10,000, especially 6000 to 8000. These materials are not considered to be surface-active materials in the context of the present invention.

Additional ingredients

The detergent systems of the present invention may contain anti-foaming agents, typically at a level of 0.001% to 2%, preferably 0.05 to 1%. Such foam suppressors or foam control agents include silicone compounds, phosphate esters, microcrystalline slack waxes, etc. More specifically, preferred foam suppressors are silicone materials which are siloxanes having the following formula:

wherein x is a value of 20 to 2000 and R and R', independently of each other, are selected from the group consisting of C1-20 alkyl or alkyl substituted aryl groups. Preferred polydimethylsiloxanes have a molecular weight in the range of 200 to 200,000 and higher are suitable foam control agents. Other foam suppressors include alkyl phosphate esters such as monostearyl phosphate and microcrystalline waxes having a melting point of 65°C to 100°C and having a molecular weight of 400 to 1000.

The detergent system of the invention may contain neutral organic and inorganic fillers such as sulfate and sodium chloride. Organic fillers that may be used in the invention include starch, sugar, alkylene glycols having 1 to 10 carbon atoms, etc. In addition, the compositions may contain proteolytic and starch-splitting enzymes, tarnish inhibitors such as benzotriazole, antibacterial agents, agents for preventing redeposition of soil, soil suspension agents, dyes, odorants, and soil suppressants based on silicate, glass and aluminum.

Method for casting the detergent systems

The components of the detergent systems are typically a disposable container that also serves as a mold. The detergent system can be dispensed from the container or removed from the container prior to insertion into the dispenser. Alternatively, the detergent system components can be cast into a reusable mold, with the cast material removed from the mold and placed in a separate disposable container for shipping and use.

The detergent system can essentially be cast into a mixing unit in any order of material addition. Once uniform, the material is placed in a suitable mold.

A preferred method of pouring the material is to add the low molecular weight and water soluble materials to a mixing chamber in conjugation with any water used in preparing the materials. The higher molecular weight or insoluble materials are then slowly added to the contents of the mixing unit until a uniform suspension is obtained. Finally, the active halogen source can be added to the mixture. The mixture is gently stirred at a slow speed so as not to compromise the integrity of the encapsulated product.

Encapsulated product

The encapsulated halogen sources according to the invention comprise a core of an active halogen compound and at least one coating layer. Preferably, the encapsulated halogen sources comprise a core and two or more coating layers. If one layer is used, it comprises preferably an inorganic layer of a composition compatible with the halogen source. However, certain synthetic detergent coatings may be used. When two layers are used, the first layer typically comprises an inert or inorganic coating agent and the second layer comprises an organic layer or a synthetic detergent layer

Halogen sources

The halogen-releasing substances suitable as core material include halogen moieties capable of releasing active halogen species such as free elemental halogen or -OX-, where X is Cl or Br, under conditions normally encountered in detergent bleach cleaning processes. Preferably, the halogen-releasing compound releases chlorine or bromine species. The most preferred halogen-releasing compound releases chlorine. Chlorine-releasing compounds include potassium dichloroisocyanurate, sodium dichloroisocyanurate, chlorinated trisodium phosphate, calcium hypochloride, lithium hypochloride, monochloramine, dichloramine, pentaisocyanurate, 1,3-dichloro-5,5-dimethylhydantoin, paratoluenesulfondichloramide, trichloromelamine, N-chloromelamine, N-chlorosuccinimide, N,N'-dichloroazodicarbonamide, N-chloroacetylurea, N,N-dichlorobiuret, chlorinated dicyandiamide, trichlorocyanuric acid, and dichloroglycoluril.

Sodium dichloroisocyanurate, potassium dichloroisocyanurate and the dihydrates thereof are the most preferred oxidation chlorine sources suitable as the core substance. These materials are commercially available and can be obtained, for example, from Monsanto or Olin Corp.

Coating materials

The coating of the active halogen source may consist of a single or multiple coating. Single coating layers may consist of virtually any inert organic or inorganic coating material that is stable to a halogen source that is solid at room temperature. In the case that a multiple layer coating is used, the first layer often comprises an inorganic layer, with the second layer comprising an organic layer that may be obtained from various sources.

Almost any substance can be used as a first coating, as long as it is inert, particularly halogen-inert, and solid at normal storage temperatures, typically between -1ºC to 38ºC (300 and 100ºF). The coating material is preferably inert with respect to the core material. If the inner coating material is potentially reactive with the core material, the core material can be initially coated with an inert material to prevent or arrest a reaction between the core and this first coating; the initial coating acts as a chemical barrier between the core and the first and other layers. Usable inorganic substances as coating material include alkalis such as sodium carbonate, sodium bicarbonate, sodium sequicarbonate, sodium borate, potassium bicarbonate, potassium sequicarbonate, potassium borate, phosphates such as diammonium phosphate, monocalcium phosphate, tricalcium phosphate, calcium pyrophosphate, iron pyrophosphate, magnesium phosphate, monopotassium orthophosphate, potassium pyrophosphate, disodium orthophosphate, trisodium orthophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium phosphate glass;

Neutral salts such as zeolites, sodium sulfate, sodium chloride and talc; silicates and silicate hydrates such as sodium metasilicate, sodium equisilicate, dry sodium/potassium silicate water glasses, sodium orthosilicate and mixtures thereof.

An advantageous inorganic initial coating for use in a detergent composition for a halogen bleach core would be an admixture of sodium sulfate and sodium tripolyphosphate. Sodium sulfate and sodium tripolyphosphate are relatively inert with respect to halogen bleaches and they are components that are commonly mixed in detergent compositions.

External coating materials

Almost any substance can be used as an outer coating material as long as it is solid at normal storage temperatures (typically between -1.1ºC (30ºF) and 37.8ºC (100ºF)). A non-exclusive list of compounds that can be used as a second coating layer include alkalis such as sodium carbonate, sodium bicarbonate, sodium sequicarbonate, sodium borate, potassium bicarbonate, potassium sequicarbonate, potassium borate, sodium sulfate hydrate; phosphates such as diammonium phosphates, monocalcium phosphate, tricalcium phosphate, calcium pyrophosphate, ferric pyrophosphate, magnesium phosphate, monopotassium orthophosphate, potassium pyrophosphate, disodium orthophosphate, trisodium orthophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium phosphate glass; neutral salts such as zeolites, sodium sulfate, sodium chloride and talc; Silicates and silicate hydrates such as sodium metasilicate, sodium sequisilicate, dry sodium/potassium silicate water glasses, sodium orthosilicate; organic masking agents such as copolymers of vinyl acetate and Maleic anhydride, copolymers of acrylic acid and maleic anhydride, copolymers of maleic anhydride and itaconic acid, polyacrylic acid; and N-alkyl sulfonate such as octyl sulfonate, sodium carboxymethyl cellulose, hydropropyl cellulose, hydroxyethyl ether of cellulose, hydroxypropyl methyl cellulose; C₁₂₀-C₂₀ fatty acid such as stearic acid, palmitic acid, and N-alkanoic acids; paraffin waxes; microcrystalline waxes; C₁₂₀-C₂₀ and larger primary and secondary solid alcohols; Pluronic surfactants having a molecular weight between 8000 to 16500; primary and secondary alkyl sulfates; and alkyl metal sulfonates and mixtures thereof. The preferred encapsulant has an outer coating which is insoluble in the liquid composition prior to pouring. After the detergent system is cast, the preferred encapsulated products are water soluble to allow release of the halogen into the wash medium.

The synthetic detergent composition used as a coating must remain sufficiently solid at temperatures likely to occur during storage of the product, e.g. temperatures from 15ºC to 50ºC, and must also remain stable at temperatures likely to occur during manufacture of the product until the end use of the mixtures, e.g. temperatures from 15ºC to 95ºC.

Synthetic detergents that can be used include cationic, non-ionic and amphoteric detergent compositions. Examples of anionic detergent systems that can be used in the bleaching compositions of the invention are the higher alkyl mononuclear aromatic alkali metal sulfates and sulfonates, as well as linear alkyl sulforates and sulfonates such as alkylbenzenesulfonates containing 9 to 13 carbon atoms. in the alkyl group, wherein the alkyl group is derived from polypropylene, as described by Lewis in US Patent No. 2,477,382, or wherein the alkyl group is a hexadimer or trimer, as in US Patent No. 3,370,100 to McEwan, or wherein the alkyl group is derived from alpha-olefins, as in US Patent No. 3,214,462 to Swenson. In addition, primary and secondary alkyl sulfates can be used therein,

The soaps are included within the definition of anionic detergents as used herein. Examples of soluble soaps useful in the present invention are the sodium and potassium salts of acyclic monocarboxylic acids having chain lengths of 8 to 22 carbon atoms.

A particularly suitable synthetic detergent for use as a coating according to the invention is pre-oxidized sodium octyl sulfonate. The sodium octyl sulfonate may contain 1,2-alkanebisulfonate as a by-product of the manufacture which does not affect the effectiveness of the sodium octyl sulfonate coating according to the invention.

The organic coating compound is used as a solution in a suitable solvent; water is preferred due to its compatibility with chlorine-releasing agents, its non-flammability and non-toxicity.

The compositions of the invention can be formulated with a detergent builder as a detergent adjuvant, e.g., those mentioned hereinafter, to provide a commercially viable detergent bleach composition.

Inorganic fillers suitable for coatings include alkalis such as sodium bicarbonate, sodium sequicarbonate, sodium borate, potassium bicarbonate, potassium sequicarbonate, potassium borate, phosphates such as diammonium phosphate, monocalcium phosphate monohydrate, tricalcium phosphate, calcium pyrophosphate, iron pyrophosphate, magnesium phosphate, monopotassium orthophosphate, potassium pyrophosphate dry, disodium orthophosphate dihydrate, trisodium orthophosphate decahydrate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium phosphate glass, neutral soluble salts such as sodium sulfate and sodium chloride; silicates, organic sequestrants; and agents for preventing redeposition of dirt

In carrying out the process of the invention, the protective encapsulating materials or coatings of the invention are usually applied using a fluid-bed encapsulating device. Such a device comprises a coating chamber or cylindrical tower in which the coating or encapsulation of the particles is carried out. An unexpanded bed of the particles to be coated is introduced into the apparatus. A nozzle, which constitutes a spray device, is disposed within the apparatus and is vertically adjustably adapted so that the liquid coating material flows out in a downwardly diverging three-dimensional spray pattern which just covers the surface of the bed.

The coating solution is contained in a tank and is fed to the nozzle. Fluidizing gas (typically air) is introduced into the fluidized bed area. The fluidizing gas is heated or cooled, if necessary, to maintain the fluidizing gas within a desired temperature range.

Particles of the halogen source to be coated, having a known weight, are introduced into the apparatus. Air is induced to flow into the fluidized bed, thereby expanding the particle layer, thereby keeping the particles in constant motion within the volume defined by the expanded bed, thus forming a fluidized bed. A solution of a coating substance is sprayed through the nozzle onto the fluidized particle bed until all of the particles in the bed are completely coated. Particles coated by the process described above are completely encapsulated with a closed coating, are free-flowing and are non-agglomerated.

It is important that each particle is completely coated to prevent reaction of the oxidizing halogen source in the detergent system.

If it is desired to apply an initial coating of a coating agent and a subsequent synthetic detergent coating, the double coating can be carried out in a single fluidized bed, either by applying the first coating, emptying the solution tank, filling the solution tank with the second coating solution and then applying the second coating; or with a double coating solution inlet to the nozzle; whereby the fluidized particles in the bed are first coated with the coating agent contained in a solution tank, this first coating is allowed to dry and then a second synthetic detergent coating is applied contained in a second solution tank; both coatings are carried out in accordance with the previous discussion of the fluidized bed process.

A third method for applying a dual coating in a fluidized bed is to coat the core particles with the coating agent in a first fluidized bed apparatus. The coated material is then allowed to dry and placed in a dual fluidized bed apparatus in which the encapsulated product produced in the first fluidized bed is coated with a second coating solution of a synthetic detergent. The fluidized bed process is carried out in accordance with the previous discussion of the fluidized bed process.

Before the encapsulated oxidizing chlorine source is removed from the fluidized bed, the temperature in the bed may be increased to drive off any solvent contained in the encapsulated product. However, the temperature must be maintained below the melting point temperature of the encapsulated product and below the decomposition temperature of the encapsulated core and coating.

The encapsulated halogen bleach sources of the present invention comprise 20 to 90 wt.% halogen bleach source core and 10 to 80 wt.% coating when a single coating is used, and 20 to 90 wt.% halogen bleach source core, 0.5 to 50 wt.% inorganic coating agent, first coating, and 5 to 70 wt.% synthetic coating when a double coating is used.

More specifically, the singly coated halogen bleach source comprises 30 to 80 wt.% halogen bleach source core and 20 to 70 wt.% synthetic coating, and more specifically, 40 to 55 wt.% halogen bleach source core and 45 to 60 wt.% synthetic coating.

A preferred embodiment of the dual coated halogen bleach source comprises 30 to 80 wt.% halogen bleach source core, 5 to 50 wt.% inorganic coating agent, first coating, and 5 to 50 wt.% synthetic coating. In a most preferred embodiment, the encapsulated article comprises 30 to 60 wt.% chlorine bleach source core, 5 to 45 wt.% inorganic coating agent, first coating, and 10 to 35 wt.% detergent, second coating.

Delivery

The cast solid detergent systems of the invention can be dispensed from a manual or automatic dispenser in which a jet of water contacts a surface of the cast material to deliver a concentrate which is directed to the point of use.

The cast material may be contained in a disposable container and introduced into the dispenser in that form. Alternatively, the cast material may be manually discharged from a disposable container directly into a dispenser, with the water jet contacting at least one surface of the material. Typical dispensers are mechanical devices having a nozzle for directing a water jet onto the solid cast material. The dispenser typically includes a housing having internal working parts. The housing typically includes a reservoir portion wherein the mass of the solid block detergent system may be held. The dispenser typically includes a holder onto which the cast material is placed. The holder is typically mounted horizontally within the dispenser and holds the block material in a position adapted to the spray jet. adjacent position. The preferred support comprises a screen secured to the inner walls of the housing, fixedly mounted at a location above the spray jet such that the spray jet contacts the majority of the solid cast detergent system. The spray jet forming nozzle is connected to a pressurized water source via a supply line. The spray jet is controlled by a device which can request the addition of the concentrate obtained by spraying water onto the cast material. Upon receipt of the request, water at a pressure typically greater than 6.9 x 10⁴ Pa (10 psi) is directed through the supply line and nozzle onto substantially the entire lower surface of the cast material. Heated water may be used depending on the formulation. The use of heated water, similarly in all others, increases the delivery rate. The detergent system passes through the screen holder in dissolved form and is directed through the underlying collection section of the housing to the discharge port and through the piping system to a point of use. The point of use may be a dishwashing machine, a station for loading containers such as conveyors or other apparatus containing a concentrate for dilution with additional quantities of water, or another point of use.

Alternatively, the dispenser can be operated manually, whereby a measured amount of concentrate is obtained by manually triggering the spray jet onto the poured material.

We have found that the stability of the chlorine source in the presence of the organic compounds associated with the amount of free water in the cast material. We have found that the detergent systems may require some water for processing during manufacture. Preferably, all water present in the detergent system is in the form of bound water or water of hydration or complexed water which is sequestered and thus removed from reactivity with the components. Free water is water which is available for reaction with the encapsulated chlorine material and is available as a reaction medium between liberated chlorine and any organic material present in the cast material. We have found that maintaining the free water concentration below 10 wt% can help to maintain chlorine availability in the cast material over a considerable period of time, preferably maintaining the free water concentration of less than 5 wt% or more preferably less than 2 wt% can be very effective in maintaining the stability of the material.

Example I Chlorinated all-purpose cleaners

In a corrosion-resistant steel jacket tank equipped with a continuously adjustable turbo stirrer, 10 parts of soft water heated to 76.7ºC (170ºF) were added. 20 parts of polyethylene glycol (CARBOWAX 8000, Union Carbide) were added to the water while stirring in sufficient portions to dissolve the CARBOWAx in the water. Stirring was stopped and 22 parts of a linear alkylbenzene sulfonate, 4 parts of a polyacrylic acid polymer (GOODRITE K-7058D, BF Goodrich), 14.5 parts of a powdered sodium tripolyphosphate and 1 part of a granular sodium tripolyphosphate, 14 parts anhydrous sodium metasilicate and 6 parts sodium bicarbonate. The product was cooled to a temperature below 62.8ºC (145ºF). Thereafter, 8.5 parts of encapsulated sodium dichloroisocyanurate (of Example 11) were added to the tank and the tank contents were gently stirred at a temperature below 62.8ºC (145ºF) in a manner that evenly distributed the encapsulant throughout the product. The material was removed from the tank and 0.19 kg (2 lbs.) of the warm liquid material was placed in polyethylene containers. The containers and their contents were allowed to cool and solidify in an air chiller for 12 to 15 minutes at a temperature of less than -12.2ºC (10ºF).

Example 11

The encapsulated sodium dichloroisocyanurate used in Example 1 was prepared as follows. In a cylindrical fluidized bed encapsulation machine was added 61.25 parts of sodium dichloroisocyanurate. The particles were brought into the fluidized bed state and suspended in air by means of an upwardly moving air stream at a temperature of about 90°C. Onto the heated, suspended particles was sprayed a solution comprising 68.97 parts of soft deionized water, 16.5 parts of sodium sulfate and 5.5 parts of sodium tripolyphosphate. The addition of this solution creates a first inorganic layer of mixed sodium sulfate and sodium tripolyphosphate. After adding the entire inorganic layer, a solution comprising 49.62 parts of linear sodium alkyl sulfonate in 49.62 parts of soft water was then sprayed onto the fluidized particle. This second step creates on the particle an external organic encapsulation layer. Essentially all free water was removed during encapsulation (approximately 151.5 parts were removed)

Example III

Using the process of Example II, the following encapsulated product was prepared. Ingredients Parts by weight Core: Sodium dichloroisocyanurate Coating Sodium sulfate Sodium tripolyphosphate Soft water Hydroxypropyl cellulose Water removed during encapsulation

Example IV

Using the procedure of Example II, an encapsulated chlorine source was prepared using the following ingredients. Ingredients Parts by weight Core: Sodium dichloroisocyanurate Sodium sulfate coating Sodium tripolyphosphate soft water Hydroxyethyl cellulose Water removed during encapsulation

Example V

Using the procedure of Example 11, an encapsulated chlorine source was prepared using the following ingredients. Ingredients Parts by weight Core: Sodium dichloroisocyanurate Coating Sodium sulfate Sodium tripolyphosphate Soft water Methyl cellulose Water removed during encapsulation

Example VI

Example IV was repeated with the encapsulated product of Example II. The material produced exhibited a chlorine stability of 57.5% chlorine maintained at 37.8ºC (100ºF) for two weeks of storage.

Example VII Chlorinated all-purpose cleaner

In a stainless steel mixing tank equipped with a heating and cooling device and a continuously adjustable turbine type stirrer, 10 parts of water and 22 parts of polyethylene glycol (CARBOWAX 8000) were added. The glycol was added at a rate such that it was melted and completely mixed after addition. Into the heated solution were added 20 parts of a linear alkyl sulfonate, 4 parts of polyacrylate polymer, 15.5 parts of sodium tripolyphosphate, 14.0 parts of sodium metasilicate and 6 parts of sodium bicarbonate. The mixing contents were stirred until uniformly distributed and to the mixer was added 8.5 parts of the encapsulated product of Example II. The contents of the mixer were stirred just until uniform. The material prepared above had a chlorine stability of 106.06% chlorine maintained at 37.8ºC (100ºF) for two weeks storage. Table 1 Delivery characteristics of the product of Example VII Grams delivered (average of 5 tests) Temperature

The data in Table 1 demonstrate that the product of Example VII is readily dispensed to most end use locations using warm water, commonly encountered temperatures and pressures. The product can be readily dispensed to any typical end use by controlling either the pressure, temperature or dispensing time.

The product was dispensed by placing the material in a dispenser using a 30 second cycle at either 2.1 x 10⁵Pa or 3.4 x 10⁵Pa (30 or 50 psi) and at temperatures ranging from 48.9ºC to 65.6ºC (120ºF to 150ºF).

Fig. 1 shows a dispenser that can be used. In Fig. 1, there is generally shown a dispenser that includes a container or housing 20. The housing has a generally cylindrical upper reservoir portion 21 that has a cylindrical inner wall 22. The wall 22 defines an inner cavity 23. The upper designation of the reservoir portion 21 defines an access opening 24 into the cavity 23 of the reservoir portion 21.

The inner wall 22 of the housing 20 tapers downwardly and defines a lower funnel-shaped collection section 25 of the housing 20. The inner wall 22 of the housing 20 is designed to form an annular flange 26 that extends circularly around the inner wall 22 of the housing 20 at the junction of the upper reservoir section 21 and the lower collection section 25. The lower designation of the collection section 25 defines an outlet opening 27 of the inner reservoir cavity 23 for the passage of a solution collected in the collection section 25. The outlet opening 27 has a hose clamp boss 28 having a plurality of annular ribs designed to engage the inner walls of a connecting hose or conduit 29.

The outlet port 27 can be connected directly to the point of use of the wash chemical solution by means of a line 29 and it (the chemical solution) is fed thereby by means of gravity or it is fed thereby by means of a wash chemical solvent pump 30 arranged on the line 29.

The housing 20 may be made of any suitable material capable of withstanding exposure to cleaning solutions to withstand corrosion, with construction from stainless steel or molded plastic material being particularly preferred. The housing 20 may be made from a transparent or translucent material which allows the operator to see at a glance the amount of wash chemical in the reservoir section 21 and whether the dispenser 20 needs to be refilled. If the housing 20 is not made from a transparent or translucent material, preferably a portion of the reservoir section 21 is made transparent or translucent to aid in determining when the dispenser 20 should be refilled. A pair of mounting plates 32 are connected to and extend rearwardly from the outer surface of the housing 20 for securely mounting the housing 20 to a vertical side wall

A door 34 (or flap door) is sized to extend completely over and seal the access opening 24. The door 34 is pivotally connected to 35 to allow pivotal movement between a closed position and an open position. The lower collection section 25 of the housing 20 has an outwardly projecting connecting section 36 extending from the collection section 25 and adjacent the outlet opening 27 of the collection section 25. A pipe connector insert 37 is securely mounted within the connector boss 36 and extends through the inner wall 22 of the collection section 25 of the housing 20. A spray forming nozzle 38 is threaded into the end of the pipe connector 37 and is axially directed within the inner cavity 23 of the housing 20 in a direction to direct an upwardly directed spray pattern therefrom. The pipe connector insert 37 is provided with an O-ring seal 39.

A horizontal retaining screen 40 engages and is mounted in a surface-mounted manner on an annular flange portion 26 of the housing 20. The retaining screen 40 has approximately 6.45 cm² (1 inch square) square openings for retaining a solid block of the detergent system 80 without substantial interference from the impinging water spray from the water spray forming nozzle 38 on the bottom surface 81 of the wash chemical block 80 (i.e., the surface is in contact with the retaining screen 40).

A 0.63 to 0.13 cm (1/4 to 1/20 inch) lower screen 41 is located in the collection section 25 of the housing 20 between the spray nozzle 38 and the outlet opening 27 to catch any undissolved clumps of the wash chemical 80 that are small enough to pass through the holding screen 40. This prevents small clumps of the wash chemical 80 from accumulating in the outlet opening 27 or the tubing 29 and blocking the flow of the concentrated wash chemical solution from the dispenser 20.

A water supply line 42 is connected to the tube insert 37 and communicates therewith to provide a source of water flow to the spray-forming nozzle 38. The water supply line 42 passes through one of the fasteners 32 and is thereby structurally supported. A siphon breaker 43 interrupts the water supply line 42. A safety switch 50 is mounted on the door 34 for movement therewith and senses the operative position of the door 34 relative to the access opening 24 of the housing 20. In the preferred embodiment, the safety switch 50 comprises a mercury actuated switch.

Figures 2 and 3 show one embodiment of the product format of the cast detergent systems of the invention. The solid cast detergent system of the invention is packaged in a sealable container 200 comprising a lid 210 and a lower container portion 211. The lid 210 can be made of various materials including paper, film, foil, etc. The lower container can also be made of various materials, however thermoplastic moldable material is preferred. The lid 210 is adhered to the container 211 by a release layer 212 disposed between the lid and the container.

Figure 3 shows a side view of the molded detergent system within its container. In use, the lid 210 is detached from the top of the lower section, exposing the upper surface of the molded material 80. The container can be inserted into the dispenser as a whole without the lid. Alternatively, if the container body 211 is made of a deformable material, it can be deformed to remove the molded material 80 in a solid block which is then inserted directly into the dispenser for use by the water stream.

While the foregoing teachings, examples and data provide a basis for understanding the invention, many embodiments of the invention may be made without departing from the spirit or scope of the invention. Further, the invention is based on the appended claims below.

Claims (44)

1. Solid, cast, active halogen-containing, storage-stable detergent system comprising the following ingredients (a) an effective purifying amount of a source of alkalinity; (b) an effective amount of a hardness sequestrant; (c) 5 to 60% by weight of an encapsulated source of active halogen; and (d) 20 to 50 wt.% of a polyalkylene oxide polymer. 2. A detergent system according to claim 1, wherein the halogen is chlorine. 3. A detergent system according to claim 2, wherein the content of encapsulated source of active chlorine is 15 to 60 wt.%. 4. A detergent system according to claim 2, wherein the content of encapsulated source of active chlorine is 15 to 50 wt.%. 5. A detergent system according to claim 2, wherein the content of the source of encapsulated active chlorine is 20 to 35 wt.%. 6. A detergent system according to claim 2, wherein the encapsulated material comprises 1 to 80 wt.% of a source of active chlorine and 99 to 20 wt.% of an encapsulating layer. 7. A detergent system according to claim 6, wherein the encapsulated layer comprises a synthetic anionic surfactant. 8. A detergent system according to claim 6, wherein the encapsulating layer comprises 10 to 90 wt.% of a first inorganic layer and 90 to 10 wt.% of a second layer. 9. A detergent system according to claim 8, wherein the organic encapsulating layer comprises a cellulose layer, a synthetic anionic surfactant or mixtures thereof. 10. A detergent system according to claim 9, wherein the cellulose layer comprises methylcellulose, a hydroxyalkylcellulose or mixtures thereof. 11. The detergent system of claim 2 wherein the source of active chlorine is selected from the group consisting of trichloroisocyanuric acid, potassium dichloroisocyanurate, sodium dichloroisocyanurate, sodium dichloroisocyanurate dihydrate, and mixtures thereof. 12. The detergent system of claim 1, wherein the polyalkylene oxide polymer composition comprises a polyethylene oxide polymer, a polypropylene oxide polymer, or an ethylene oxide/propylene oxide block copolymer. 13. A detergent system according to claim 12, wherein the alkylene oxide polymer comprises a nonionic surfactant. 14. A detergent system according to claim 13, wherein the nonionic surfactant comprises a block copolymer containing at least one ethylene oxide block and at least one propylene oxide block. 15. A detergent system according to claim 14, wherein the nonionic surfactant comprises an alkylphenol alkoxylate wherein the alkyl group is a C1-12 alkyl and the alkoxylate comprises 2 to 24 moles of ethylene oxide. 16. The detergent system of claim 1, wherein the hardness sequestrant comprises an organic hardness sequestrant or an inorganic hardness sequestrant. 17. A detergent system according to claim 16, wherein the organic hardness sequestrant comprises a polyacrylic acid, an organic phosphonate, or mixtures thereof. 18. A detergent system according to claim 16, wherein the inorganic hardness sequestrant comprises a condensed phosphate hardness sequestrant. 19. A detergent system according to claim 18, wherein the condensed phosphate comprises an alkyl metal tripolyphosphate sequestrant. 20. The detergent system of claim 1 wherein the alkalinity source comprises an alkali metal hydroxide or an alkali metal silicate having an M₂O:SiO₂ ratio of about 2:1 to 1:3.6, where M is an alkali metal. 21. The detergent system of claim 1, wherein the alkalinity source comprises an alkali metal carbonate, an alkali metal bicarbonate, an alkali metal borate, and mixtures thereof. 22. A detergent system according to claim 1, additionally comprising an anionic surfactant. 23. A detergent system according to claim 22, wherein the anionic surfactant comprises an alkyl sulfonate, an alkyl sulfate, an alkylbenzene sulfonate, an alkylbenzene sulfate, or mixtures thereof. 24. Solid, cast, stable, chlorinated laundry detergent comprising (a) 0.1 to 50% by weight of a soil-removing non-ionic surfactant; (b) 0.1 to 95% by weight of an alkalinity source; (c) an effective amount of a hardness sequestrant; (d) 5 to 60% by weight of an encapsulated chlorinated isocyanurate compound; and (e) 20 to 50% by weight of a polyalkylene glycol casting agent. 25. A detergent according to claim 24, wherein the content of encapsulated source of active chlorine is 15 to 30 wt.%. 26. A detergent according to claim 24, wherein the content of the source of encapsulated active chlorine is 20 to 25% by weight. 27. A detergent according to claim 24, wherein the encapsulated material comprises 1 to 80 wt.% of a source of active chlorine and 99 to 20 wt.% of an encapsulating layer. 28. A detergent according to claim 27, wherein the encapsulating layer comprises a synthetic anionic surfactant. 29. A detergent according to claim 27, wherein the encapsulating layer comprises 10 to 90 wt.% of a first inorganic layer and 90 to 10 wt.% of a second layer. 30. A detergent according to claim 29, wherein the organic encapsulating layer comprises a cellulosic layer, a synthetic anionic surfactant, or mixtures thereof. 31. A detergent according to claim 30, wherein the cellulose layer comprises methylcellulose, a hydroxyalkylcellulose or mixtures thereof. 32. A laundry detergent according to claim 24, wherein the detergent additionally comprises an effective amount of an agent for preventing redeposition of soils. 33. A detergent according to claim 32, wherein the soil redeposition preventing agent comprises a carboxymethyl cellulose composition. 34. A detergent according to claim 24, wherein the detergent additionally comprises a dye, a fragrance, an anti-soil redeposition agent, a whitening agent or mixtures thereof. 35. The detergent of claim 24, wherein the chlorinated isocyanurate compound is selected from the group consisting of trichloroisocyanuric acid, potassium dichloroisocyanurate, sodium dichloroisocyanurate, sodium dichloroisocyanurate dihydrate, and mixtures thereof. 36. A detergent according to claim 35, wherein the nonionic surfactant comprises a block copolymer comprising at least one ethylene oxide block and at least one propylene oxide block. 37. A detergent according to claim 36, wherein the nonionic surfactant comprises an alkylphenol alkoxylate, wherein the alkyl group is C1-12 alkyl and the alkoxylate comprises 2 to 24 moles of ethylene oxide. 38. A detergent according to claim 24, wherein the hardness sequestrant comprises an organic hardness sequestrant or an inorganic hardness sequestrant. 39. A detergent according to claim 38, wherein the organic hardness sequestrant comprises a polyacrylic acid, an organic phosphonate, or mixtures thereof. 40. A detergent according to claim 38, wherein the inorganic hardness sequestrant comprises a condensed phosphate hardness sequestrant. 41. A detergent according to claim 40, wherein the condensed phosphate comprises an alkali metal tripolyphosphate sequestrant. 42. A detergent according to claim 24, wherein the source of alkalinity comprises an alkali metal hydroxide or an alkali metal silicate having an M₂O:SiO₂ ratio of about 2:1 to 1:3.6, wherein M is an alkali metal. 43. A detergent according to claim 24, additionally comprising an anionic surfactant. 44. A detergent according to claim 24, additionally comprising a quaternary fabric softener.