MXPA99007376A - In-tank toilet cleansing block - Google Patents

Abstract

Disclosed herein is a toilet cleansing block containing a polyacrylate polymer and a lauryl benzene sulfonate salt surfactant. The block is essentially free of other polymers that sequester ions. The block is for immersion in toilet tanks, and inhibits toilet bowl ring and stain formation, particularly those caused by iron oxide.

Description

BLOCK E FOR TANK AND FOR RETREAT CLEANING ICA BACKGROUND TECHNICAL FIELD The present invention relates to cleaning blocks suitable for immersion in toilet tanks. The blocks are formulated to inhibit the formation of toilet rings and surface stains. Several cleaning blocks are known for use in toilet tanks and other water tanks. Such cleaning blocks typically contain a surface tension modifying agent for cleaning, and often fillers, binders, colorants, extrusion aids and perfumes. They are designed to slowly release these materials to the toilet bowl each time the toilet water is run. See, v. g. , U.S. Patent No. 5,336,427. The description of this Patent, and of all other publications alluded to herein, are incorporated by reference as if fully set forth herein. Such blocks should not include materials that leave undesirable residues in the toilet bowl, which are unacceptable to the environment, or have unpleasant odors. Although the blocks that have these desired attributes have been created, there are products between desired characteristics for each formulation. In particular, there is great difficulty in formulating a block that is long lasting, which also inhibits sufficiently formation of rings and stains in the toilet bowl.

Certain polymers have been added to help in this regard. See, v. g. , U.S. Patents, Nos. 4,861, 51 1, 4,899,398, 4,283,300, 4,302,350, and 4,428,872. However, such polymers are relatively expensive, may require high concentrations in the toilet bowl in order to be effective, and in some cases may be counterproductive. For example, in the U.S. Patent. , No. 4,861, 51 1 a mixture of polyacrylate polymer is established with substantial amounts of an expensive polymer that is required to achieve adequate results, particularly with respect to iron oxide deposits. Thus, it can be seen that there is a need for an improved toilet cleaning block. WO-A-92 03532 describes a process for the production of toilet cleaning blocks by extruding a mixture of ingredients suitable for the bar-shaped block. The mixture to be extruded comprises, on the basis of the total weight of the mixture, (i) from 5 to 85% by weight of one or more anionic surface active agents; and (ii) from 0.5 to 40% by weight of one or more rheological control agents. Example 17 thereof describes a cleaning block comprising 10% "Carbopol" acrylic acid polymer and 50.5% sodium dodecylbenzene sulfonate.

WO-A-96 28536 discloses a cleaning block for slow release toilet comprising one or more water soluble polymers.

The polymers are derivatives of one or more carboxy-containing monomers, ethylenically unsaturated, and have an average molecular weight greater than 50,000.

DESCRIPTION OF THE INVENTION In one aspect, the invention provides a water reservoir cleaner (eg, in block form) having 1% -15% (preferably 1% -10%) by weight of a polymer selected from the group that It consists of a polyacrylic acid and alkali metal salts of polyacrylic acid. There is also 20% -70% by weight of an alkali metal salt of a laurylbenzene sulfonate. The block may also have a dye, a charge / density aid (eg, sodium sulfate) and a fragrance / extrusion aid (eg, pine oil). Importantly, the block is formed to have less than 1% of other "Sequestering Polymers", preferably none. Apart from the fact that other polymers can be expensive, they can inhibit the ability of the compositions of the present invention to cleanse stains. A "Sequestering Polymer" is a polymer that sequesters iron oxide when added only with iron oxide to the water in the toilet bowl. Typically these are polymers that contain a carboxylic acid functionality (eg, in at least one of the monomers). See, v. g. , Patent of E. U. No. 4,861, 51 1. The polymer is preferably sodium polyacrylate homopolymer in a form having an average molecular weight below 10,000. One version is sold by Rohm & Haas Co. as Acusol 445 N D with a molecular weight of 4,500. Other preferred polymers are potassium polyacrylate and the same polyacrylic acid. In another embodiment, the invention provides a method for cleaning a toilet bowl. One submerges one of the above blocks in a water tank for a toilet bowl, allows a portion of the block to dissolve to create a polymer concentration dissolved in the toilet tank water of at least .1 ppm to 1.2 ppm , and then let the water run out of the toilet. The selection of coloring agent that gives color will depend to a large extent on the color desired for the water to which the toilet cleaning composition is dispensed. A preferred coloring agent is Acid Blue 9, without opposing that this dye contains manganese. Other suitable colorants are described in the U.S. Patent. No. 5,336,427. The amount of coloring agent or dye to be supplied to the water will depend on the desired intensity of color and the cost of the colorant. The absorbance of the coloring agent can be determined for laboratory purposes by the use of a spectrophotometer, such as a Perkin-Elmer Model 552 spectrophotometer. The amount of coloring agent delivered to the toilet bowl must be sufficient to provide an absorbance in a cell 1 cm spectrophotometry from approximately 0.02 absorbance units ("au °) to approximately 0.2 au when measured at its maximum wavelength This is because consumers typically believe that a colored cleaning product does not work longer when it has an intensity Color below this range To achieve a suitable density such that the block will not float, and to keep costs to a minimum, inert load / density auxiliaries (typically 5% -65% by weight) are preferably added. Inert salts are preferred for this purpose such as inorganic or organic salts soluble in water (or mixtures of such salts s) Examples include various sulfates, chlorides, borates and citrates of alkali metal and / or alkaline earth metal. Specific inert salts are sodium sulfate, calcium sulfate, sodium chloride, potassium sulfate, sodium carbonate, lithium chloride, tripotassium phosphate, sodium borate, potassium fluoride, sodium bicarbonate, calcium chloride, magnesium chloride , sodium citrate, magnesium sulfate, and sodium fluoride. To achieve an even longer life (greater than 15 days in typical use, preferably greater than 30 days) a binder may also be included in the block in substitution of part of an inert filler. The preferred binders are those based on cellulose. Especially preferred binders are hydrated cellulose materials such as hydroxy alkyl cellulose (especially hydroxy ethyl cellulose or hydroxy propyl cellulose). Rubber binders can also be used. Examples are guar, xanthine, tragacanth, carraginan, karaya or algin. A perfume or fragrance can also be added, depending on the type of aroma to be imparted. For example, essences of pine, citrus and potpourri can be used. A particularly preferred pine essence can be provided by Unipine 85, a pine oil from Bushe, Boake and Alien, inc. It has the added advantage of facilitating the extrusion of the blocks during manufacturing. The block may also contain other anionic surface tension modifying agents. See, generally, the Patent of E. U. No. 5, 336,427.

The objects of the present invention therefore include providing a water reservoir cleaner of the above type: (a) which is effective to inhibit the formation of rings and stains in the toilet bowl (particularly those due to iron oxide); (b) that maintains the toilet bowls in a clean condition in normal use for an extended period; and (c) that use environmentally acceptable and inexpensive components. These and still other objects and advantages of the present invention (see, methods for using these blocks) will be apparent from the description that follows. The following description is only of the preferred embodiments. Thus, the claims must be viewed in order to understand the full scope of the invention.

WAYS TO CARRY OUT THE I NVENTION Preferred cleaning block for use in a Vanishtm Power System dispenser (sold by S.C. Johnson &Son, Inc.) are: I ngredient% in Weight Preferred Alternative Acid Blue Dye Rank # 9 20 8-25% (100% powder) Sodium polyacrylate 1-10% (Acusol 445 ND) Unipine 85 (pine oil) 6 3-8% Sulfonate lauryl benzene 55 40-60% sodium (Ufaryl DL-85) Sodium sulfate 6 rest When a block is formed to be inserted directly into a toilet tank, 5-15% (v. G., 6%) may be a binder such as hydroxy ethyl cellulose (eg, replaces sodium sulfate with HEC). We first create a homogenous mix using a mixer such as a tape mixer. The mixture is then fed to the barrel of a screw extruder and passed through the extruder to form a continuous extrudate which is then cut to the desired block size. The pressure across the die can be approximately 3.45-8.62 MPa. The barrel of the extruder can be maintained at less than 35 ° C, (v. G., An ambient temperature) by means of cooling water circulated by an external jacket of the barrel. The die head can be heated to ensure a smoother surface of the extruded product. The block in the form of continuous extrusion begins to cure upon leaving the extruder, and therefore can be cut into cleaning blocks of required size by conventional cutting means downstream of the die and before substantially complete curing. The "block" does not need to be rectangular. It can be a tablet, disc, brick, or other solid mass with or without cracks, holes or the like, and does not need to be formed by extrusion (although extrusion is preferred). Thus, any solid form mass is understood to be a "block" for purposes of this Patent. To use the blocks of the present invention, we place a block in a conventional toilet tank and let the toilet run in the usual manner.

COMPARATIVE TESTS We hang a mild steel plate (approximately 7.6 cm x 15.2 cm x 25.4 cm) in the toilet tank. This plate formed and released rust to the tank water. Using vinyl-coated spring clips in two corners, we suspended a white ceramic mosaic so that half of the mosaic stood approximately vertically in the water in the toilet bowl. We then place a test product or no product (control) in the toilet tank. We let the toilet run periodically according to a protocol that represented the average use of the consumer (10 washes per day, no nighttime washing, etc.). We then monitored with instruments any coloration that occurred in the white mosaic using a Minolta Chroma Meter CR300 with DP310 processor, which measured Hunter? By? E in the mosaic by comparing measurements above and below the water line, and comparing a measurement taken in the time 0 with the measurements in later times. We then visually monitor the appearance of the mosaic and the toilet bowl. We compared the invention with equal amounts of a product containing 3% styrene / maleic anhydride polymer (Versaflex 157 from National Starch), and with a control. The following are TE values: 3% Acusol 3% Versaflex Control 21 days .93 2.1 1 1.14 We also compared the invention with controls in a shorter period, although with greater exposure to iron oxide: 3% Acusol Without Without Without Treatment Treatment 7 days 0.17 1 .48 1 .28 1 .49 14 days 0.17 2.65 2.57 2.60 The invention showed a strong ability to reduce inorganic staining at very low concentrations (0.1 ppm). We believe that this is due to a uniquely effective complex formation of the soluble cations and insoluble particles.

APPLICABILITY IN DUSTRIAL The invention is useful for maintaining the cleanliness of toilet bowls associated with toilet tanks. It must also have application in other water storage systems (eg, urinal tanks).

Claims (1)

REVIVAL NAMES 1. A water reservoir cleaning block comprising from 1% to 15% by weight of a sequestering polymer selected from the group consisting of a polyacrylic acid and an alkali metal salt of polyacrylic acid, and from 20% to 70% by weight of an alkali metal salt of a lauryl benzene sulfonate, characterized in that: the cleaner contains less than 1% of any other sequestering polymer in addition to said selected polymer; and the block further comprises a dye containing manganese. 2. The cleaning block of claim 1, wherein the cleaner is essentially free of any other sequestering polymer in addition to said selected polymer. 3. The cleaning block of claim 1 or claim 2, wherein the salt is sodium lauryl benzene suifonate. 4. The cleaning block of any one of claims 1 to 3, wherein the sequestering polymer is a sodium polyacrylate having an average molecular weight below 5,000. A method for cleaning a toilet bowl comprising the steps of: immersing a block of the cleaning block of any one of claims 1 to 4 in a water tank for the toilet bowl; dissolving a sufficient amount of the block to create a dissolved concentration of the selected polymer in the toilet tank of between 0.1 ppm and 3 ppm; and let the water run from the toilet. 6. The method of claim 5, wherein the dissolved concentration is between 0.1 ppm and

1.2 ppm.