WO1996040856A1 - Toilet bowl cleaners containing urease inhibitors - Google Patents

Abstract

Hard surface cleaning compositions comprising urease inhibitors are provided. These include toilet bowl and urinal cleaners comprising an effective amount of a urease inhibitor to inhibit the enzyme urease and provide for increased sanitation and/or cleaning benefits to toilet bowls and urinals, as well as articles of manufacture comprising urease inhibitors for use in the urinal or toilet tank.

Description

TOILET BOWL CLEANERS CONTAINING UREASE INHIBITORS

FIELD OF THE INVENTION This invention relates to toilet bowl cleaners containing an effective amount of urease enzyme inhibitor to prevent the build-up of soapy scums, bacterial slime and/or mineral deposits on the surface of toilet bowls and urinals. The present compositions comprise a urease inhibitor and optional ingredients such as surfactants, builders, perfumes, abrasives, dyes, enzymes, biocides, oxidizing agents, reducing agents, and/or other carrier and adjunct materials.

BACKGROUND OF THE INVENTION

This invention relates to a method of cleaning and sanitizing toilet bowls and urinals. The invention is also directed to maintaining toilet bowls, urinals, sinks, showers and other hard surface areas in a state of sanitation. More particularly, it relates to a method wherein a urease enzyme inhibitor is employed in an effective amount to retard the bacterial mediated deposition of minerals, dirt and waste products onto the surface of a toilet bowl or urinal. By the practice of this invention, urease enzymes associated with microorganisms are inhibited in vitro, thereby retarding the cycle of bacterial growth/mineralization of toilet bowls or urinals. There has been a long standing need to retard the growth of bacteria associated with human waste receptacles. Periodic scouring and thorough sanitizing of toilet bowls and urinals are necessary to ensure a safe level of hygiene. The development of the flush toilet provided an efficient means of removing waste products thereby reducing the level of human exposure to microorganisms. However, the normal act of flushing, aside from removal of the waste material, only provides for a turnover of the toilet bowl water with a modest degree of rinsing, but does not provide the necessary mechanical action needed to dislodge bacteria which collect and adhere to receptacle walls. Because these organisms have the ability to rapidly proliferate, only a residual amount of bacteria need remain after flushing to re-inoculate the toilet bowl. These resident bacteria immediately begin to modify their host environment, resulting in the formation of undesirable odors and the build¬ up of dirt and minerals which facilitates the further entrainment of waste products Toilet bowl surface modification by bacteria thereby reduces the efficiency of waste product removal by flushing.

As the waste water turnover becomes less effective, the rate of bacterial growth and soiling of the toilet bowl or urinal increases resulting in a compromise to the level of hygiene. The frequency of thorough scouring and re-sanitizing of toilet bowls and urinals is therefore dependent on the ability of bacteria to proliferate within the waste receptacle area.

The enzyme urease is produced by a number of bacterial species such as Proteus mirabilis, Proteus vulgaris, Morganelli morganii (formerly Proteus morganii) and Providencia rettgeri (formerly Proteus rettgerii), all of which are well-known urinary tract microorganisms. The ability of these microorganisms to produce urease in the urinary tract, which contains substantial amounts of urea, provides an environment wherein urease enzyme splits urea according to the scheme:

H-NCONH₂ + 2 H-O 2 NH₃ + H-CO₃

The release of ammonia causes an increase in the alkalinity of the urine affording an environment favorable to the formation of minerals such as struvite, (MgNH₄PO₄ ^• 6H-O) and calcium phosphate (Ca^PO -), which are predominant components of infected urinary calculi, also known as "kidney stones".

While not intending to be limited by theory, it is now hypothesized that a similar mechanism for the increase in alkalinity due to the presence of urease enzymes could possibly apply in the toilet bowl or urinal. A clean, smooth porcelain surface would not initially provide a hospitable environment for the growth of bacteria. However, upon standing exposed to exogenous microorganisms having urease enzymes following toilet bowl usage, the urease enzymes that are now present, regardless of origin, can begin to cause a rise in the water alkalinity. This increase in pH has the effect of reducing the solubility of certain dissolved minerals which then begin to deposit onto the surface of the toilet bowl. After several usages, a thin irregular surface is present on the toilet bowl or urinal surface which can entrain waste material, including bacteria, thus effectively reducing the efficiency of the toilet flush to remove all waste products. The entrained bacteria will gradually accumulate with each usage cycle. As the sanitation of the toilet bowl decreases, the rate at which further minerals, scums and soil are deposited increases. In addition to the soil, dirt and mineral deposits, an environment will be created that is conducive to further inoculation by aerobic and anaerobic microorganisms. In the case of toilet tank dispensed liquid cleaners or solid cake dispensers that may be placed directly into the urinal or hung in the toilet tank or bowl, the compositions of these articles typically include water soluble salts in the form of surfactants, buffers and builders. However, if the activity of the urease enzymes in the flush bowl is not held in check, the very composition of these typical toilet "sanitizers" may actually exacerbate the problem of mineralization. The cations of water soluble salts present in the "sanitizer" formulations will increase the concentration of dissolved "minerals" in the toilet bowl water, and depending on the inherent conditions of the urinal or toilet bowl, may provide a further source of "minerals" for deposition onto the surface of the toilet bowl. Buffers are incoφorated into these "sanitizer" formulations for the purpose of mediating the toilet water pH levels but, due largely to the prodigious activity of urease enzymes, these attempts at alkalinity management can only be marginally effective. Indeed, given the amount of dissolved urea and other bacterial nutrients present in only one urinary void volume, an un-flushed toilet will soon overwhelm the buffer capacity of normal toilet tank introduced sanitizers.

Liquid cleaners that are used to scrub or scour urinals or toilet bowls may leave behind various levels of minerals or bacteria depending on the efficiency of the cleaning. Traditionally, this act of sanitizing urinals and toilet bowls is not performed with any great deal of pleasure, but instead is a task of necessity, done primarily to ensure hygiene. It is therefore a matter of circumstance that the effectiveness of a liquid or solid cleaner used for scrubbing and scouring be as broadly effective as possible. The inclusion of urease enzyme inhibitors will act on all urease present in the bowl or urinal and therefore render inactive any urease that remains adhered to the toilet bowl after cleaning. A urinal or toilet bowl cleaned with the present invention will not leave behind active urease enzymes which will be in a position to further accelerate the already inexorable process of toilet soiling and mineral deposition.

Accordingly, the present invention provides for the cleaning and sanitation of toilets/ urinals by the in vitro inhibition of urease enzymes. The goals/benefits to be observed by inhibition of urease enzymes in the toilet or urinal include one or more of:

• Slow down the deposition of minerals on the toilet/urinal walls, thereby reducing the ability of bacterial nutrients to remain after flushing; • Reduce the entrainment of dirt and other waste products onto the surface of the bowl;

• Provide for easier cleaning and sanitizing.

An object of this invention is to provide an improved method for cleaning and sanitizing toilet bowls, urinals and other sanitary waste receptacles. It is another object herein to provide cleaners which deliver a urease inhibitor to toilet bowls or to the flush tanks thereby affecting the ability of bacteria to mediate the environment of toilet bowl water. It is a further object herein to provide cleaning compositions and processes which employ a urease inhibitor to increase the time that toilets can remain in a sanitary condition by inhibiting the urease enzymes associated with bacteria from creating a hospitable environment for growth. These and other objects are secured by the present invention, as will be seen from the following disclosures.

BACKGROUND ART Various references relate to urease inhibitors and their preparation. See for example U.S. Pat. No. 4,242,325 issued December 30, 1980; U.S. Pat. No. 4,182,881 issued January 8, 1980; U.S. Pat. No. 4,668,667 issued May 26, 1987; U.S. Pat No. 4,800,194 issued January 24, 1989; U.S. Pat. No. 4,225,526 issued September 30, 1980; U.S. Pat. No. 4,221,730 issued September 9, 1980; U.S. Pat. No. 4,222,948 issued September 16, 1980; U.S. Pat. No. 4,454,126 issued June 12, 1984; U.S. Pat. No. 4,517,007 issued May 14, 1985; U.S. Pat. No. 4,499,107 issued February 12, 1985; U.S. Pat. No. 4,157,396 issued June 5, 1979; U.S. Pat. No. 4,083,996 issued April 11, 1978; and DDR Pat. No. 241,012 issued November 26, 1986. SUMMARY OF THE INVENTION

The present invention encompasses toilet bowl or urinal cleaners comprising at least about 0.001 % by weight of a urease inhibitor, from about 1% to about 99%, preferably from about 10% to about 85%, by weight of a surfactant and the balance comprising an effective carrier and adjunct ingredients. Adjunct ingredients optionally include but are not limited to builders, buffers, bleaches, filler salts, abrasives, perfumes, enzymes, biocides, oxidizing agents, reducing agents, and dyes.

The present invention also relates to a method of inhibiting urease enzyme activity in a toilet bowl or urinal by placing a composition in the toilet flush tank or urinal stream comprising at least about 0.001 % by weight of a urease inhibitor, from about 1% to about 99%, preferably from about 10% to about 85%, by weight of a surfactant, the balance comprising an effective carrier and adjunct ingredients. Adjunct ingredients optionally include but are not limited to builders, buffers. bleaches, filler salts, perfumes, enzymes, biocides, oxidizing agents, reducing agents, and dyes.

The present invention also encompasses a method of inhibiting urease enzymes in a toilet bowl or urinal comprising contacting the surface of a toilet bowl or urinal with a composition comprising at least about 0.001 % by weight of a urease inhibitor, from about 1% to about 99%, preferably from about 1% to about 85%, by weight of a surfactant, the balance comprising an effective carrier and adjunct ingredients. Adjunct ingredients can optionally include but are not limited to builders, bleaches, buffers, filler salts, perfumes, dyes and abrasives. All percentages, ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (° C) unless otherwise noted. All documents cited are, in relevant part, incoφorated herein by reference. DETAILED DESCRIPTION OF THE INVENTION The materials, methods and articles of manufacture of the present invention comprise the following urease inhibitors and optional ingredients as well as the preferred embodiments listed herein, but the cited examples are not meant to diminish or limit in scope or puφose the practice of the present invention. These articles of manufacture include solid cakes or other such dispensing devices for placing into the toilet bowl or urinal an amount of urease inhibitor in an amount sufficient to inhibit the enzyme urease.

What is meant by the term microorganisms as described in the present invention are bacteria, yeast, fungi, protozoa and other microscopic organisms, whether they are naturally exogenous or endogenous to humans, that naturally produce, contain, or otherwise utilize urease enzymes. Urease Inhibitors. A large number of urease inhibitors are known, some having been puφosefully synthesized by the pharmaceutical industry, and others whose original use was for puφoses outside the realm of urease inhibition, but which can also be suitably employed to act as structural mimics of urea. These latter compounds include low molecular weight, water soluble materials which act as an irreversible substrate or modifier of the active site of the urease enzyme.

Among the low molecular weight urease inhibitors that are thought to serve as substrate mimics are hydroxamic acid and the substituted hydroxamic acids. Acetohydroxamic and propionhydroxamic acid are the most common of the acyl substituted hydroxamic acids. These two compounds, as well as the parent hydroxamic acid and the alkali or alkaline earth salts of said acids, are particularly efficacious in inhibiting urease enzyme activity in vitro. They are also particularly compatible with surfactants and other detersive ingredients that are found in common toilet bowl cleaners and flush tank additives.

A variety of phosphorus compounds have been prepared for in vivo use against urease activity. Traditionally phosphorus compounds found wide use in the laundry industry as detergent builders until environmental concerns predicated their removal. Suφrisingly, the level of phosphorus compound needed to prevent substantial urease activity in toilet bowls and urinals described in the present invention, does not begin to approach the quantity once used in laundry product. Many of the pharmaceutical industry generated products are compatible with the environment due to their bio-degradability and the structure and oxidation state of the phosphorus containing moiety.

In particular, phosphorus triamides of the general formula:

O

R HPfNH^ wherein R is hydrogen, phenyl, substituted phenyl, alkyl, alkenyl, and other suitable moieties or preferably N-(diarr__nophospninyl)arylcarboxamides of the formula:

wherein R is 3-pyridyl, 2-furanyl, 2-naphthyl, cinnamenyl, benzyl, phenyl, and substituted phenyl are efficacious as urease inhibitors in a toilet bowl cleaner and flush tank additive when added in an amount sufficient to inhibit the enzyme urease. Other preferred urease inhibitors have the general formula:

where R¹, R², R³, and R⁴ is more preferably hydrogen, nitro, halogen, amino, C alkyl, C_M alkoxy, trifluormethyl, cyano, phenoxy, phenyl, and mixtures thereof. A further embodiment of the present invention includes urease inhibitors of the general formula

wherein;

R¹ and R² are the same or different and are hydrogen or alkyl having from 1 to about 4 carbon atoms;

R³ is oxygen or sulfiir; and R⁴, R⁵ and R⁶ are the same or different and are hydrogen, alkyl, arylamino, diarylamino, halogen, hydroxy, mercapto, alkylmercapto, alkyl mercapto, O-diamino- phosphinyl, S-diaminophosphinyl, N-diaminophosphinyl, diaminophosphonyl, amino, cyano, nitro, alkylamino, dialkylamino, arylmercapto, isocyano, isocyanato, trihalo- methyl, alkoxy, thiocyano, alkanoyl, or any two R⁴, R⁵ and R⁶ group taken together may form an alkylene or alkenylene chain which may optionally include one or more divalent oxygen, nitrogen, or sulfur moieties forming a 3,4,5 or 6 membered fused ring structure.

A variety of nitrogen containing compounds have been prepared for in vivo use against urease activity. Traditionally these oxime, keto oxime and ortho hydroxy acetophenone oxime derivatives have found use as metal chelating agents and have been used in sunscreen formulations. Suprisingly, these materials are effective urease inhibitors when used in vivo in the present invention for the prevention of microscopic organism urease enzyme activity which leads to the loss of sanitary conditions in the toilet bowl and urinal. The present invention also relates to a composition and method of inhibiting urease activity comprising an effective amount of one or more oxime compounds having the formula

M NOR3 R¹— (NR⁶ — C— C-R2 wherein R¹ and R² are independently selected from the group consisting of alkyl, aryl, and heteroaryl, or R¹ and R² may be covalently bonded together to form a cyclic alkyl; M is selected from the group consisting of =O, =S, -SR⁴ and -OR⁴ (when M is -OR⁴ or -SR⁴, there is a hydrogen bonded to the carbon to which M is bonded and R⁴ is selected from the group consisting of hydrogen, alkyl, aryl and heteroaryl); R³ is selected from the group consisting of hydrogen, alkyl, aryl and heteroaryl; R⁶ is selected from the group consisting of hydrogen, alkyl, aryl and heteroaryl; and i is selected from the group consisting of 1 and 0.

When R¹ is aryl, it is preferably selected from substituted and unsubstituted, preferably 2-furanyl, 3-furanyl, 2-thienyl, 2-pyrrolyl, 3-pyrrolyl and phenyl. Also preferred are these aryl substituted with Cl-C₆ alkyl, C C₆ alkoxy, amino, halogen, hydroxy, mercapto, alkyl mercapto, O-diamino-phosphinyl, S-diamino-phosphinyl, diaminophosphinyl, diaminophosphonyl, cyano, nitro, alkylamino, di-alkylamino, aryl mercapto, isocyanato, trihalomethyl, alkoxy, thiocyano, and alkanoyl. When R¹ is alkyl, it is preferably selected from substituted and unsubstituted, preferably unsubstituted Cj-Cjg alkyl, more preferably C C^ straight chain.

When R² is aryl, it is preferably selected from substituted and unsubstituted, preferably 2-furanyl, 3-furanyl, 2-thienyl, 3-thienyl, 2-pyrrolyl, 3-pyrrolyl and phenyl. Also preferred are these aryl substituted with C_j-Cg alkyl, Ci-Cg alkoxy, amino, halogen, hydroxy, mercapto, alkyl mercapto, O-diamino-phosphinyl, S-diamino- phosphinyl, diaminophosphinyl, diaminophosphonyl, cyano, nitro, alkylamino, di- alkylamino, aryl mercapto, isocyanato, trihalomethyl, alkoxy, thiocyano, and alkanoyl. When R² is alkyl, it is preferably selected from substituted and unsubstituted, preferably unsubstituted Ci- g alkyl, more preferably Cι-C₁₂ straight chain.

When R³ is aryl, it is preferably substituted or unsubstituted phenyl. When R³ is alkyl, it is preferably selected from substituted and unsubstituted, preferably unsubstituted Cj-Cig alkyl, more preferably C C^ straight chain. R³ is most preferably hydrogen.

When R⁴ is aryl, it is preferably substituted or unsubstituted phenyl. When R⁴ is alkyl, it is preferably selected from substituted and unsubstituted, preferably unsubstituted Cι-Cιg alkyl, more preferably C_j-C^ straight chain. R⁴ is most preferably hydrogen.

When R⁶ is aryl, it is preferably substituted or unsubstituted phenyl. When R⁶ is alkyl, it is preferably selected from substituted and unsubstituted, preferably unsubstituted C Cig alkyl, more preferably C1-C12 straight chain. R⁶ is most preferably hydrogen. Preferred compounds for use in the present invention include syn- and anti- forms or mixtures thereof.

In particular, oximes of the general formula:

NOH

R- ² wherein R is hydrogen; or R and R² are the same or different Cι-C₂2 alkyl and branched alkyl, Ct-C₂2 alkenyl or branched alkenyl; an aryl group substituted with one or more amino, heterocyclic rings, preferably 2-furanyl, substituted 2- furanyl, 3-furanyl, and substituted 3-furanyl wherein the fiiranyl substituents are one or more alkyl, amino, cyano, nitro, alkylamino, dialkylamino, aryl mercapto, isocyanato, trihalomethyl, alkoxy, thiocyano, alkanoyl and halogen moieties; in the case where two aryl or two heterocyclic rings or one of each are present that contain more than one substituent, for example, when R or R² each comprise an aryl or heterocyclic ring such as a 2,4-dichlorofuranyl, 2-chloro-4-methylfuranyl, or a tri- substituted heterocyclic moiety such as 3,4,5-trichlorofuranyl; or R and R² taken together may form an alkylene or alkenylene chain which may optionally include one of more divalent oxygen, nitrogen, or sulfur moieties forming a 3, 4, 5 or six membered fused ring structure; are efficacious as urease inhibitors in a toilet bowl cleaner and flush tank additive when added in an amount sufficient to inhibit the enzyme urease.

In particular, keto oximes of the general formula:

wherein R is hydrogen; or R and R² are the same or different C C₂₂ alkyl and branched alkyl, C1-C22 alkenyl or branched alkenyl; aryl groups substituted by one or more halogen, hydroxy, mercapto, alkyl mercapto, O-diaminophosphinyl, S- diaminophosphinyl, diaminophosphinyl, diaminophosphonyl, amino, cyano, nitro, alkylamino, dialkylamino, aryl mercapto, isocyanato, trihalomethyl, alkoxy, thiocyano, alkanoyl; or R and R² taken together may form an alkylene or alkenylene chain which may optionally include one of more divalent oxygen, nitrogen, or sulfur moieties forming a 3, 4, 5 or six membered fused ring structure; R and R² each comprise a heterocyclic ring, preferably 2-fiιranyl, substituted 2-furanyl, 3-furanyl, and substituted 3-furanyl; are efficacious as urease inhibitors in a toilet bowl cleaner and flush tank additive when added in an amount sufficient to inhibit the enzyme urease. The furanyl substituents can be substituted by one or more alkyl, amino, cyano, nitro, alkylamino, dialkylamino, aryl mercapto, isocyanato, trihalomethyl, alkoxy, thiocyano, alkanoyl and halogen moieties and mixtures thereof. For example, R or R² may each comprise the same or different di-substituted aryl or heterocyclic moiety such as 2,4-dichlorofuranyl, 2-chloro-4-methylfuranyl, or a tri-substituted moiety such as 2,4,6-trichlorophenyl, or 3,4,5-trichlorofuranyl.

Also suφrisingly efficacious as a urease inhibitor in a toilet bowl cleaner and flush tank additive when added in an amount sufficient to inhibit the enzyme urease is violuric acid and derivatives of violuric acid having the general formula:

wherein R and R² can be the same or different and are hydrogen, Cι-C₂₂ alkyl and branched alkyl, Cι-C₂2 alkenyl or branched alkenyl; an aryl or heterocyclic ring substituted by one or more amino, halogen, hydroxy, mercapto, alkyl mercapto, O- diaminophosphinyl, S-diaminophosphinyl, diaminophosphinyl, diaminophosphonyl, cyano, nitro, alkylamino, dialkylamino, aryl mercapto, isocyanato, trihalomethyl, alkoxy, thiocyano, alkanoyl or mixtures thereof.

Urease inhibitors preferably comprise from about 0.001% to about 20%, more preferably from about 0.1% to about 10%, and most preferably from about 0.1% to about 2%, by weight of the composition.

Surfactants. Surfactants can provide enhanced sanitizing performance through breakup and emulsification of soils, deposited minerals, or waste products and thus facilitate the contacting of the urease inhibitor with any entrained urease enzyme. When the urease inhibitors herein are formulated with surfactants, the resulting compositions will generally comprise from about 5% to about 99%, by weight surfactant and from about 0.001 % to about 20 %, by weight urease inhibitor.

Any surfactant used for the puφose of the present invention must not react with or form a complex with the urease inhibitor such that the inhibitor is rendered inactive, and the surfactant must be otherwise compatible with the urease inhibitor and the mode chosen for delivering the urease inhibitor to the situs of need. Anionic surfactants operable in combinations for use in practicing the present invention can be broadly described as the water-soluble salts, particularly the alkali metal salts, of organic sulfuric acid reaction products having in their molecular structure an alkyl or alkaryl radical containing from 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. (Included in the term alkyl is the alkyl portion of higher acyl radicals.) Important examples of the anionic surfactants which can be employed in the practicing of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C₈-C₁₈ carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonate, in which the alkyl group contains from about 9 to about 15 carbon atoms, (the alkyl radical can be a straight or branched aliphatic chain); paraffin sulfonate surfactants having the general formula RSO₃M wherein R is a π primary or secondary alkyl group containing from about 8 to about 22 carbon atoms (preferably 10 to 18 carbon atoms) and M is an alkali metal, e.g., sodium or potassium; sodium alkyl glyceryl ether sulfonates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about 1 to about 10 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfates with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contain products of fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amides of a methyl tauride in which the fatty acids, for example, are derived from coconut oil and sodium or potassium beta-acetoxy- or beta-acetamido- alkanesufonates where the alkane has from 8 to 22 carbon atoms.

Nonionic surfactants which can be used in practicing the present invention can be of three basic types— the alkylene oxide condensates, the amides and the semi polar nonionics. A thorough description of these nonionic surfactants can be found in U. S. Patent No. 4,308,625, Kitko, issued January 5, 1982 column 6 line 19 - column 7 line 36 and incoφorated herein by reference.

Builders. Optional ingredients employed in the present invention contain inorganic and or organic builders to assist in mineral hardness control. If used, these builders typically comprise from about 5% to about 80% by weight of the compositions.

Inorganic builders include, but are not limited to, the alkali metal, ammonium and alkanolammonium salts of polyphosphates (exemplified by the triphosphates, pyrophosphates, and glassy polymeric meta-phosphates), phosphonates, phytic acid, silicates, carbonates (including bicarbonates and sesquicarbonates), sulphates, and aluminosilicates. However, non-phosphate builders are required in some locales.

Examples of silicate builders are the alkali metal silicates, particularly those having a SiO₂ : Na-O ratio in the range of 1.6 : 1 to 3.2 :1 and layered silicates, such as the layered sodium silicates described in U.S. patent 4,664,839, issued May 12, 1987 to H. P. Rieck, available from Hoechst under the trademark "SKS"; SKS-6 is an especially preferred layered silicate builder

Organic builders suitable for the puφoses of the present invention include, but are not restricted to, a wide variety of poly carboxylate compounds, such as ether polycarboxylates, including oxydisuccinate. as disclosed in Berg, U.S. Pat. No

3,128,287, issued April 7, 1964 and La berti et al., U.S. Pat. No. 3,635,830, issued January 18, 1972. See also "TMS/TDS" builders of U.S. Pat No. 4,663,071, issued to Bush et al., on May 5, 1987.

Other useful builders include the ether hydroxypolycarboxylates, copolymers of maleic anhydride with ethylene or vinyl methyl ether, 1,3,5-trihydroxybenzene- 2,4,6-trisulfonic acid, and carboxymethyloxysuccinic acid, the various alkali metal, ammonium and substituted ammonium salts of polyacetic acids such as ethylenediamine tetraacetic acid and nitrilotriacetic acid, as well as poly carboxylates such as mellitic acid, succinic acid, oxydisuccinic acid, polymaleic acid, benzene 1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and soluble salts thereof. Citrate builders, e.g., citric acid and soluble salts thereof (particularly sodium salt), are preferred polycarboxylate builders that can also be used in granular compositions, especially in combination with zeolite and/or layered silicate builders.

Inert Salts. The inert salts (filler salts) used in the compositions of the present invention can be any water-soluble inorganic or organic salt or mixtures of such salts which do not destabilize the surfactant. For the puφosed of the present invention, "water-soluble" means having a solubility in water of at least 1 gram per 100 grams of water at 20° C. Examples of suitable salts include various alkali metal and/or alkali earth metal sulfate, chlorides, borates, bromides, fluorides, phosphates, carbonates, bicarbonates, citrates, acetates, lactates, etc. Specific examples of suitable salts include sodium sulfate, sodium chloride, potassium chloride, sodium carbonate, potassium sulfate, lithium chloride, lithium sulfate, tripotassium phosphate, sodium borate, potassium bromide, potassium fluoride, sodium bicarbonate, magnesium sulfate, magnesium chloride, sodium citrate, sodium acetate, magnesium lactate, sodium fluoride. The preferred salts are inorganic salts preferably the alkali metal sulfates and chlorides . Particularly preferred salts, because of their low cost are sodium sulfate and sodium chloride. The salts are present in the compositions at levels of from 0% to 40%, preferably 10% to 20%.

Lithium sulfate in cake compositions at a level of from 0.1% to 0.8% by weight of the cake has been found to be an effective stability agent for the cake in the presence of trace hypochlorite solution. It provides solubility control benefits. A preferred range is 0.2% to 0 7%.

Abrasives. An essential component of many solid toilet bowl cleaning compositions is the abrasive material added to facilitate the action of scouring. Abrasive scouring cleansers provide a convenient and useful means for carrying out the sanitizing of toilet bowls and urinals. The particulate abrasive material within such compositions serves to abrade and loosen soil adhering to hard surfaces and further serves to create more intimate contact between hard surface stain and the surfactant and/or bleaching agents also present in the cleansing compositions.

Abrasive cleaners have traditionally contained water-insoluble, relatively hard, particulate mineral material as the abrasive agent. The most common such abrasive agent is finely divided silica sand having particle size varying between about 1 and 300 microns and specific gravity of about 2.1 or higher. While such material is generally very effective in scouring soil and stains from the surfaces being treated, abrasive material of this type tends to be difficult to rinse away from the toilet bowl or urinal surface. It is a further object of the present invention to provide a toilet bowl or urinal cleaner that will leave low levels of abrasive residue to accommodate the trapping of bacteria or other waste products that will facilitate the production of urease thus further producing soiling of the toilet bowl or urinal.

It has been discovered that abrasive compositions of this desired type can be realized by utilizing a particular type of expanded perlite abrasive in combination with the surfactants, filler material, urease inhibitors and other optional scouring material ingredients listed herein. The abrasive materials suitable to the present invention are those contained in U.S. Pat. No. 4,051,056, Hartman, issued September 27, 1977 and included herein by reference. Perfumes. Perfumes are an important ingredient especially for the Solid Cake composition embodiment. Liquid, solid powder or solid cakes can be made with perfume and no dye. Perfume is usually used at levels of from 0% to 30%, but levels of 5% and 25% and 10% to 20% perfumes are preferred for Solid Cake compositions. In U.S. Pat. No. 4,246,129, Kacher, issued January 20, 1981 (incoφorated herein by reference), certain perfume materials are disclosed which perform the added function of reducing the solubility of anionic sulfonate and sulfate surfactants. At higher levels of perfumes, e.g., over 12%, the softness of solid cake embodiments could be a problem. This is particularly so in compositions based on alkali metal alkyl sulfate surfactants. Dyes. Dyes may be include at levels of from abut 0.5% to 12%, preferably

1.5% to 5%. Cakes can be made with 1.5% dye and no perfume. Examples of suitable dyes are Alizarine Light Blue B (C.I. 63010), Carta Blue VP (C.I. 24401), Acid Green 2G (C.I. 42085), Astrogen Green D (C.I. 42040), Supranol Cyanine 7B (C.I. 42675, Maxilon Blue 3RL (C.I. Basic Blue 80), Drimarine Blue Z-RL (C.I. Reactive Blue 18), Alizarine Light Blue H-RL (C.I. Acid Blue 182), FD&C Blue No 1 and FD&C Green No. 3. (See the patents of Kitko, U.S. Pat. No. 4,248,827 issued February 3, 1981 and U. S. Pat. No. 4,200,606, issued April 29, 1980, both incoφorated herein by reference.) C.I. refers to Color Index.

Optional Adjuncts Ingredients. As a preferred embodiment, the conventional adjunct ingredients employed herein can be selected from typical components such as enzymes (compatible with the applicable urease inhibitor), especially proteases, lipases, cellulases, oxidizing and reducing agents, anti-microbial agents, color speckles, suds boosters, suds suppressors, anti-tarnish and/or anti-corrosion agents, soil-suspending agents, optical brightners, germicides, alkalinity sources, hydrotropes, anti-oxidants, enzyme stabilizing agents, solvents, clay soil removal/anti-redeposition agents, polymeric dispersing agents, dye transfer inhibiting agents, including polyamine N-oxides such as polyvinylpyrrolidone and copolymers of N- vinyl imidazole and N- vinyl pyrrolidone, etc. However, the formulator must ensure that the selected adjunct ingredients are compatible with and do not interfere with the activity of the chosen urease enzyme inhibitor.

Solid Cakes for Dispensing Cleaners

Particularly desirable devices for cleaning and sanitizing toilets and urinals are those comprising a solid cake composition. In this type of device a measured amount of water enters the device during one flush cycle and remains in contact with the cake between flushes, thereby forming a concentrated solution of the composition which is dispensed into the flush water during the next flush. The advantages of such devices are that the chemical composition can be packaged and shipped in more concentrated form than aqueous solutions of the chemicals. Also, the problems of liquid spillage resulting from breakage of the dispensers during shipment or handling is eliminated. Especially preferred devices for automatic dispensing of chemicals from solid cake composition into the toilet are those described in U.S. Pat. No. 4.171,546, Dirksing, issued October 23, 1979; U.S. Pat. No. 4,208,747, Dirksing, issued June 24, 1980; U.S. Pat. No. 4, 186,856, Dirksing, issued February 5, 1980; U.S. Pat. No. 4,476,046 issued October 9, 1984; all of which are incoφorated herein by reference.

Water-soluble inert salts such as alkali metal chlorides and sulfates are used in such compositions to act as a "filler" so that the composition can be formed into cakes of desirable size without using excessive amounts of active ingredients. The predominant ingredients of the cake compositions are usually the surfactant, the filler salt and optionally perfume Anionic, nonionic, ampholytic, zwitterionic or cationic surfactants are used The surfactant or surfactant mixture should be solid at temperatures up to about 100° F. (40° C). Anionics and nonionics and mixtures thereof are useful. Anionics are the most preferred.

The prior art anionic surfactant cakes can be described as essentially the water-soluble alkali metal salts, of organic sulfuric reaction products having in their molecular structure an alkyl or an alkylaryl radical containing from 8 to 22 carbon atoms and are described in detail in the section titled "Surfactants".

The following is a description of an embodiment of the present invention, whereby a urease inhibitor in an effective amount to inhibit the urease enzyme is formulated into a solid cake for use in urinals, toilet bowls, or toilet flush tanks. The following description of this embodiment of the invention, the manner and process of making and using it, pertains to magnesium alkyl sulfate. It will be understood that other alkali earth metal alkyl sulfates and other selected non-alkali metal alkyl sulfates can be used.

Cakes can contain alkali metal alkyl sulfates at levels of 2% to 25%, more or less, of the total cake surfactant content.

All percentages and ratios herein are "by weight" unless specified otherwise. The compositions herein will be described with particular reference to their use in conjunction with dispenser or other articles which dispense chemicals into the flush water of toilets or directly into the flush path of urinals or toilet bowls, although it is to be understood that said compositions can be used in other applications where a solid cake surfactant composition is desired.

The cake compositions of the present invention comprise from about 20% to about 90% of an alkali earth metal and/or suitable transition metal alkyl sulfate surfactant wherein the alkyl group has a carbon chain length of from 8 to 22 carbon atoms, preferably from 10 to 16 carbon atoms. Preferred surfactants are buffered; magnesium alkyl sulfate, calcium alkyl sulfate, tin alkyl sulfate, aluminum alkyl sulfate, and zinc alkyl sulfate. The cakes of this embodiment of the invention contain at least 0.001 % to about 20 % of hydroxamic acid or a suitable alkyl substituted hydroxamic acid. Preferred alkyl hydroxamic acids are acetohydroxamic acid, propionhydroxamic acid and their water soluble alkali or alkaline earth salts or mixtures thereof. However, the formulator may wish to use other suitable alkyl, aryl, or substituted arylhydroxamic acids and their water soluble alkali or alkaline earth salts. The cakes of this invention optionally contain from about 1.5% to 2.5% of a suitable dye and/or perfume. Some cake compositions contain from 40% to 70% surfactant, from 10% to 20% perfume and from 0.1 % to about 10 %, by weight urease inhibitor. The cakes preferably weigh from 20 grams to 80 grams. It has been found that cakes having a pH of from 6 to about 10 are stable. The cakes of this invention preferably have a moisture content of 1% to 10%.

Other Optional Cake Ingredients

The embodiment of this invention as a cake may contain various optional materials in the compositions herein. See U.S. Pat. No. 4,278,571, Choy, issued July 14, 1981, and incoφorated herein by reference, for an extensive list of them. Steps for Making the "Surfactant -Cake" Embodiment of This Invention The following method for making the "surfactant-cake" embodiment of this invention is herein provided and is not meant to be limiting or exclusive in its description. The formulator may also wish to substitute materials and adjust the formulation as conditions dictate based on several factors such as, the nature of the urease inhibitor, the final desired pH of the cake, the surfactant, and the amount and content of optional ingredients.

1. Charge a Crutcher mixer equipped with agitation and recirculation with an alkali metal alkyl sulfate (e.g., sodium lauryl sulfate).

2. Add more or less of a stoichiometric amount of magnesium sulfate with agitation and recirculation. 3. Mix and recirculate.

4. Add a sufficient amount of a buffer salt, preferably sodium carbonate, to insure that the pH of the reaction solution is 6 to 10, preferably 7 to 9.

5. Mix and recirculate for about 30 minutes.

6. Add a sufficient amount of propionhydroxamic acid sodium salt with agitation and recirculation.

7. Mix and recirculate for about 30 minutes.

8. Pump the buffered solution to a storage tank (optional).

9. Pump the buffered reaction product solution onto drum roll dryers having a temperature of from about 120° C to about 140° C. Drying conditions should maintain the pH of 6 to 10.

10. If fatty alcohol is to be added, determine how much is in the dried product of step 9

1 1. Agglomerate in an amalgamator the dried flakes of Step 9 along with other ingredients such as extra filler salt, perfume, dyes, free fatty alcohol etc. Amalgamate.

12. Plod the amalgamated mixture of step 9 and then extrude into strips

13. Cut into cakes. 14. Place the cakes into dosing dispensers and seal.

Cake Firmness The firmness of the cake is measured by the use of a penetrometer. Acceptable penetrometer readings are from 40 to 110 and preferably between 40 and 80 using a Lab-Line Universal Penetrometer equipped with wax penetration needle ASTM D 1321, Cat. No. 4101. Operation:

Level base and place 100 g. and 50 g. weights on plunger top. Place bar on cut end beneath penetrometer needle, raised to the zero position. Lower needle (via elevator screw) until needle just touches plug end. Depress trigger for 10 seconds (needle will lower into cake, then release). To read hardness, lower depth gauge bar until it just touches plunger.

Hardness readings are taken directly from the gauge, in units of tenths of millimeters.

Raise the needle to zero position, remove plug, and record plug hardness temperature.

Dispensing Means of Solid Cake Embodiment Dispensing means which can be used to dispense compositions of the present invention Solid Cake Embodiment into the toilet flush water are exemplified by those described in U.S. Pat. Nos. 3,831,205, 3,241,074, 3,504,384, 2,688,754, 4,036,407, 4, 171,546, 4,208,747, and 4,186,856, above noted and incoφorated herein by reference.

LIQUID EMBODIMENT A liquid toilet bowl/urinal cleaner comprising an effective amount of a urease inhibitor to inhibit the enzyme urease is prepared by standard methods and comprises the following:

Component Formuk i No. (Weigh t %)

Isopropanol 6.0 5.4 2.0

Butoxypropanol 3.0 — 3.0

Monoethanolamine 0.50 0.40 0.50

Cocoamidopropylhydroxy sultaine 0.16 — 0.075

Sodium lauryl sulfate 0.02 — —

Ethyleneglycolmonohexyl ether — 0.90 —

Ethyleneglycolmonobutyl ether — 1.0 —

Linear alkylbenzenesulfonate — 0.07 —

C9 alkylphenolethoxylate — 0 03 — C8, 10-hydroxyrnethylglycinate — — 0.075

Sodium acetate — — 0.05

Ammonia — 0.10 —

Potassium Acetohydroxamate 5.0

N-(4-aminophenyl)phosphorotriamide 2.0

N-(diaminophosphinyl)-3-pyridinecarboxamide 3.0

Perfume 0.13 — 0.11

De-ionized water balance balance balance

SYNTHESIS OF UREASE INHIBITORS

Compounds which are useful in the practice of this invention can be prepared in accordance with the following reaction schemes. The following is a scheme depicting the general reaction sequence for preparing N-(diaminophosphinyl)alkyl- and N-(diamino-phosphinyl)arylcarboxamides of the following formula: SCHEME 1

R— C - ✓"' ° + . T PVC-1₅ __. τ> -C - _ϊ'° HCOzH \ \ NH₂ N=PCl₃

in which R is as defined herein above The aforementioned Scheme 1 is described in U.S. Pat. No 4,242,325. Bayless et al.. issued December 30, 1980; U.S. Pat. No. 4, 182,881, Bayless et al., issued January 8, 1980; and U.S. Pat. No. 4,668,667, Moorehead et al., issued May 26, 1987 and included herein by reference.

The following is a scheme depicting the general reaction sequence for preparing alkyl and arylhydroxamic acids of the following formula:

SCHEME 2

in which R is as defined herein above. The aforementioned Scheme 2 is described in more detail in "Advanced Organic Chemistry", Jerry March, 4th ed , Wiley & Sons, pg. 418; Tsumaki, et al., Synth. Commim. 1983, 13, 1053; and U.S. Pat. No. 4, 157,396, Tanaka et al., issued June 5, 1979 and included herein by reference.

The following is a scheme depicting the general reaction sequence for preparing catechol derivatives of the following formula:

SCHEME 3

HNRlR²

in which R_j, R₂, R₃, R₄, R₅, and R^ are as defined herein above.

The aforementioned Scheme 3 is described in more detail in East German Patent No. 128,315, Roth, et al.; Synthesis of Phenyl Phosphorodiamidates, Part I., Arch. Pharm., 314, pp. 85-91, (1980) and references cited therein, V. V. Katyshkima and M. Ya. Kraft, J. Gen. Chem. USSR 26, 3407 - 12 (1956), and L. G. Dulog, et al. in U. S. Pat. Nos. 3,767,733 (1973) and 3,812,033 (1974) and references cited therein. Accordingly this reaction scheme will not be described herein in any great detail other that providing the illustrative examples that follow.

Synthesis of oximes and keto oximes of the present invention is described in more detail in U.S. Pat No. 5,364,617, Bush et al., issued November 15, 1994, incoφorated herein by reference.

PREPARATION EXAMPLE 1 N-(diaminophosphinyl)acylcarboxamides: N-(diaminophosphinyl)-3-methylbutanamide 14 g of 3-methylbutanamide is dissolved in 300 mL of carbon tetrachloride. 14 g of phosphorous pentachloride is added to the resulting solution at room temperature and the mixture is stirred for 30 minutes. 3.1 g of 99% formic acid is added dropwise to the mixture for 30 minutes. Then, gaseous ammonia is introduced therein under cooling to - 20° C. The mixture is warmed to room temperature and stirred at room temperature for 30 minutes. The resulting crystals are filtered out and extracted with 100 mL of methanol while they are kept warm. The extract is concentrated and recrystallized from methanol to obtain 8 g of the intended product compound. Melting point: 170° C (dec). Η NMR (d6-DMSO): 0.80 - 0.88 δ (6H, doublet), 1.80 - 1.94 δ (IH multiple.), 1.98 - 2.00 δ (2H, doublet), 3.90 δ (4H, singlet), 8.80 δ (IH, singlet). IR (cm-1) v = 3100 - 3400 (N-H), 1620 (C=O) and 1200 (P=O).

PREPARATION EXAMPLE 2 N-(diaminophosphinyl)arylamides: N-(diaminophosphinyl)-4-chlorobenzamide Part A. Preparation of 4-chloro-N-(dichlorophosphinyl benzamide.

A suspension of 68 g (0.44 mole) of 4-chlorobenzamide, 91 g (0.44 mole) of phosphorous pentachloride and 700 mL of carbon tetrachloride is heated at 65 - 70° C for 25 min. The solution is cooled to 20° C and 20.7 g (0.44 mole) of 97% formic acid is added dropwise. After the HCl gas evolution has nearly stopped, ca. 30 min., the precipitate is collected by filtration, washed with carbon tetrachloride and air- dried to give 103 g, mp 114.5 -115.5° C.

Part B. Preparation of N-(diaminophosphinvπ-4-chlorobenzamide. To a suspension of 103 g (0.38 mole) of 4-chloro-N-(dichlorophosphinyl)- benzamide in 1000 mL of chloroform is added 65 g (3.8 mole) of anhydrous ammonia. A temperature of 0° C is maintained over the 30 min. addition period. After stirring for 60 min., the crude product is filtered, washed with cold distilled water and air-dried to give 81 g. Recrystallization from 3000 mL of distilled water gives a yield of 48 g. Mp softens, shrinks 182 - 340° C.

PREPARATION EXAMPLE 3 Catechol phosphoramides:

2-amine-2-oxide- 1 ,3,2-benzodioxaphosphole A. Preparation of Phosphorylchloride intermediate. A stirred mixture of 33.0 g (0.30 mole) of catechol, 110 mL (184 g, 1.2 mole) of phosphorous oxychloride, and 0.99 g of potassium chloride is heated in a flask equipped with a condenser attached to a sodium hydroxide trap separated by a drying tube. The solution becomes homogeneous at about 100° C and evolution of hydrogen chloride begins shortly thereafter. The mixture is heated at reflux (1 10° C) for 8 hr., and then excess phosphorous oxychloride is removed by vacuum distillation. The sticky, cream colored residue is washed with 9: 1 ether-hexane, filtered, and dried under vacuum over P-O₅ at 35° C. to give 33 g (65%) of still somewhat sticky solid, mp 107 - 125° C B Preparation of 2-amine-2-oxide-l,3.2-benzodioxaphosphole The crude solid from above is stirred with 1000 mL of methylene chloride, filtered to remove about 4.5 g of residue, and the filtrate is placed in an addition funnel. The filtrate is then added dropwise to 750 mL of cold (0° C) ether which is continually saturated with ammonia gas. The addition is complete in 1.5 hr., and then stirring and ammonia addition are continued for another 30 minutes during which time the ice bath is removed. The mixture is filtered, washed well with ether, and then dried under nitrogen to give 19.4 g of product contaminated with ammonium chloride. A portion of this material is washed with ice- water to give (with much loss of product) a white solid, mp 125° - 150° C. Η NMR (d6-DMSO); 6.61 δ (2H, broad singlet) and 5.05 δ (IH, broad singlet).

PREPARATION EXAMPLE 4 Substituted Hydroxamic Acids: 2-(para-methoxybenzamide)-acetohydroxamic acid A solution comprising 112 g (2.0 moles) of potassium hydroxide in 500 mL of methanol is added to a solution comprising 69.5 g (1.0 mole) of hydroxylamine hydrochloride in 500 mL of methanol. Inorganic salts formed are filtered off. To the filtrate, 142.4 g (0.6 moles) of the ethyl ester of p-methoxy hippuric acid is added. The mixture is stirred for one hour at room temperature and allowed to stand overnight. The reaction solution is distilled at 60° C under reduced pressure to remove the solvent. The residue is dissolved in 500 mL of water. Acetic acid is added to the residue under cooling to make the solution pH 5.0. Crystalline masses formed are recovered by filtration and recrystallized from ethanol. There is thus obtained 113.8 g of the object material which exhibits the melting point of 161 - 161.5⁰ C. The yield is 84.6 g. PREPARATION EXAMPLE 5

Aryl Keto Oximes: di-(5-methyl-2-furyl)ethanedione monooxime 5-methylfurfural ( 1 1.0 gm, 0.1 mole) is dissolved in 30 mL of absolute ethanol and placed into a 100 mL flask equipped with a magnetic stirring bar and positive nitrogen pressure. 3,4-dimethyl-5-(2-hydroxyethyl)thiazolium iodide catalyst (0.1 gm) is added to the reaction flask along with triethylamine (0.8 gm). The flask is heated in an oil bath at 85° C for 2 hours. An additional 0.1 gm of catalyst and 0 8 gm of triethylamine is added and heating is continued for an additional 4 hours. The crude reaction mixture is cooled and filtered to remove the catalyst and is placed in a freezer at -5° C for 24 hours. The resulting crystals are filtered and washed with ethanol and dried under vacuum (0.1 mmHg). This affords approximately 8.2 gm of a yellow solid di-l,2-(5-methyl-2-furyl) 2-hydroxyethanone The di-l,2-(5-methyl-2-furyl) 2-hydroxyethanone (8.0 gm) is dissolved in 80 mL of absolute ethanol and placed in a 250 mL flask equipped with a magnetic stirrer. Separately, a solution of copper(II) sulfate pentahydrate and 38 mL of water is made and then poured into the flask containing the di-l,2-(5-methyl-2-furyl) 2- hydroxy-ethanone. This mixture is heated to 80° C for 4 hours. 8 mL of pyridine is added and the reaction is heated at 80° C for 4 hours. The reaction is cooled and washed with methylene chloride (200 mL) and hydrochloric acid (50 mL). The resulting methylene chloride layer is separated and dried with anhydrous magnesium sulfate and decolorized with activated charcoal. Removal the volatiles by rotary evaporation after filtration results in 4.5 gm of solid di-(5-methyl-2-furyl) ethanedione.

Di-(5-methyl-2-furyl) ethanedione (4.0 gm) is dissolved in 20 mL of methanol and placed in a 250 mL flask equipped with a magnetic stirring bar. A solution of hydroxylamine hydrochloride (1.3 gm) in 8 mL of deionized water is added to the flask and then cooled to -5° C. A solution of sodium hydroxide (2.26 gm) in 10 mL of water is added to the flask dropwise and stirred for 1 hour. Acetic acid (2.3 gm) is added followed by 100 mL of saturated sodium chloride and 200 mL of methylene chloride. The resulting methylene chloride layer is separated and washed with 100 mL of saturated sodium bicarbonate solution and then dried over anhydrous magnesium sulfate and clarified with activated charcoal. The resulting methylene chloride solution is filtered and concentrated by rotary evaporation to give 1.8 gm of solid di-(5-methyl-2-furyl) ethandione monooxime. Extraction of the water washes with methylene chloride results in an additional 2 gm of product. The two products are combined and recrystallized fro 20% water/ethanol. PREPARATION EXAMPLE 6

Substituted violuric acids 1,3-dimethylvioluric acid In a 3 -liter round bottomed flask, 35 gm of sodium is allowed to react with 500 mL of absolute ethanol under reflux. One hundred eighty grams of ethyl malonate and 85 gm of dry dimethylurea (dissolved in 500 mL of absolute ethanol) is then added and the mixture refluxed for 12 hours. At the completion of the reaction, 800 mL of hot water and 90 mL of concentrated hydrochloric acid is added with stirring. The mixture is filtered and placed in a refrigerator overnight. The resulting white solid: m p. 120-123° C, yield 25 %. This solid, dimethylbarbituric acid, is placed in a 1 -liter flask with 50 mL of concentrated hydrochloric acid, heated and stirred until dissolved. Twenty grams of sodium nitrite in 10 % solution is added with stirring (violent gas evolution ensues) Pale-pink needles in 50-60% yield precipitate and is recrystallized from ethanol; m.p. 139-140° C

Claims

What is Claimed is:

1. A toilet bowl or urinal cleaner comprising:

(a) at least 0.001 %, by weight of a urease enzyme inhibitor;

(b) from 1 % to 99 %, by weight of a surfactant; and

(c) the balance comprising carrier and adjunct ingredients

2. An article of manufacture designed for placement in the water of the toilet bowl or flush tank of the toilet, said article dispensing a urease inhibitor in sufficient amount to inhibit the enzyme urease comprising:

(a) at least 0.001 %, by weight of a urease inhibitor;

(b) from 1 % to 99 %, by weight of a detersive material; and

(c) the balance comprising carrier and adjunct ingredients.

3. A method of cleaning the surface of a toilet bowl or urinal comprising contacting said surface with a composition containing a sufficient amount of a urease inhibitor to inhibit the enzyme urease on the surface of said bowl or urinal.

4. A composition or method according to any of Claims 1-3 wherein said urease inhibitor is hydroxamic acid, substituted hydroxamic acid, or a suitable alkali metal or alkaline earth metal salt of hydroxamic acid, substituted hydroxamic acid, or mixtures thereof.

5. A composition or method according to any of Claims 1-3 wherein said urease inhibitor is a phosphorotriamide of the formula:

O

RNHPOH-^

wherein R is hydrogen, phenyl, substituted phenyl, alkyl, alkenyl, or mixtures thereof

6. A composition or method according to any of Claims 1-3 wherein said urease inhibitor is an N-(diaminophosphinyl)arylcarboxyamide of the formula: o o

I I II

R— C-NH-P— NH₂ I NH₂ wherein R is 3-pyridyl, 2-fiιryl, 2-naphthyl, cinnamenyl, benzyl, phenyl, substituted phenyl, or mixtures thereof.

7. A composition or method according to any of Claims 1-3 wherein said urease inhibitor is an N-(diaminophosphinyl)arylcarboxyamide of the formula:

wherein R¹, R², R³ and R⁴ are hydrogen, nitro, halogen, amino, Cl-4 alkyl, Cl-4 alkoxy, thrifluoromethyl, cyano, phenoxy, phenyl, or mixtures thereof.

A composition or method according to any of Claims 1-3 wherein said urease inhibitor is a phosphoramide of the formula:

wherein Rland R are the same or different and are hydrogen or alkyl having from 1 to 4 carbon atoms, R? is oxygen or sulfur, and R⁴, R^ or R^ are the same or different and are hydrogen, alkyl, N-diaminophosphinyl, O- diaminophosphinyl, S-diamino-phosphinyl, aryl amino, diarylamino, halogen, hydroxy, mercapto, alkyl mercapto, alkylmercapto, diaminophosphinyl, amino, cyano, nitro, alkylamino, dialkylamino, arylmercapto, isocyano, isocyanato, trihalomethyl, alkoxy, thiocyano, alkanoyl, or any two R⁴, R^ or R > group together may from an alkylene or alkenylene chain which may optionally include one or more divalent oxygen, nitrogen, or sulfur moieties forming a 3, 4, 5, or 6 membered fused ring structure.

A composition or method according to any of Claims 1-3 wherein said urease inhibitor is an oxime compound having the formula

M NOR3 Rl— (NR⁶),— C-C-R2 wherein R^J and R² are independently selected from the group consisting of alkyl. aryl, and heteroaryl, or Rl and R² may be covalently bonded together to form a cyclic alkyl, M is selected from the group consisting of =O. =S, -SR⁴ and -OR⁴, and when M is -OR⁴ or -SR⁴, there is a hydrogen bonded to the carbon to which M is bonded and R⁴ is selected from the group consisting of hydrogen, alkyl, aryl and heteroaryl; R³ is selected from the group consisting of hydrogen, alkyl, aryl and heteroaryl; R^ is selected from the group consisting of hydrogen, alkyl, aryl and heteroaryl; and i is selected from the group consisting of 1 and 0.

10. A composition or method according to any of Claims 1-3 wherein said urease inhibitor is a violuric acid derivative of the formula:

wherein R and R are the same or different, hydrogen, Cl-22, alkyl, Cl-22 branched alkyl, Cl-22 alkenyl, Cl-22 branched alkenyl, an aryl or heterocyclic ring having one or more substituents, said substituents are members selected from the group consisting of alkyl, amino, halogen, hydroxy, mercapto, alkyl mercapto, O-diaminophosphinyl, S- diaminophosphinyl, diaminophosphinyl, diaminophosphonyl, cyano, thiocyano, dialkylamino, isocyanato, trihalomethyl, alkoxy, thiocyano, alkanoyl and mixtures thereof.

11. A composition of method according to any of Claims 1, or 4-10 wherein said adjunct ingredients are members selected from the group consisting of builders, buffers, bleaches, filler salts, abrasives, perfumes, dyes, enzymes, biocides, oxidizing agents, reducing agents, and mixtures thereof.