Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
1997-04-24
2001-02-06
Gupta, Yogendra (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S192000
Reexamination Certificate
active
06184192
ABSTRACT:
CROSS REFERENCES TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to cleansing blocks suitable for immersion in toilet tanks. The blocks are formulated to inhibit formation of toilet rings and surface stains.
Various cleansing blocks for use in toilet tanks and other water reservoirs are known. Such cleansing blocks typically contain a surfactant for cleaning, and often fillers, binders, colorants, extrusion aids and perfumes. They are designed to slowly release these materials into the toilet basin each time the toilet is flushed.
One particularly desirable form of such cleansing blocks are those that release chlorine compounds into the water supply to help clean and disinfect the toilet basin. See e.g. U.S. Pat. No. 5,336,427. The disclosure of this patent, and of all other publications referred to herein, are incorporated by reference as if fully set forth herein. However, chlorinated cleansing blocks can have a relatively short usage life.
Creating longer life chlorinated cleansing blocks has been a significant challenge. Among other things, such cleansing blocks should not include materials which leave undesirable residues in the toilet bowl, which are environmentally unacceptable, which have unpleasant odors, or which have incompatibility with other components. For example, cellulose ether binders are known to prolong the life of some toilet cleansing blocks. See e.g. U.S. Pat. No. 4,269,723. However, they can be unstable in the presence of chlorine releasing compounds. Also, chlorine releasing agents can interfere with some dyes used in such blocks.
Thus, it can be seen that a need exists for an improved toilet chlorinated cleansing block.
BRIEF SUMMARY OF THE INVENTION
In one aspect, the invention provides a water reservoir cleanser (e.g., in block form) having 1%-40% of a chlorine releasing agent selected from the group consisting of chloroisocyanurates, hypochlorites, chlorosuccinimides, chloramine T (sodium para-toluene sulfochlorine), and chlorodimethyl hydantoins; 1% to 20% cellulose ether binder; and at least 10% of a surfactant (preferably an anionic surfactant). There is also at least 2% of a stabilizer selected from the group consisting of mineral oil, isobornyl acetate, C
12
-C
20
linear alcohols, and fragrance oils that have a specific gravity of less than 1 and are chlorine stable.
Examples of fragrance oils of this type are pine oil, Quest Q-7940A (Quest International Fragrances USA Inc. —herbal/pine), IFF Cloriffic 630 (International Flavors And Fragrances Inc. —lemon/citrus), and Takasago AG 4761-BHT (Takasago International Corporation —apple). It is especially preferred that such fragrance oils have a specific gravity between 0.83 and 0.98 and be essentially insoluble in water. One especially preferred fragrance oil is Unipine 85, a pine oil from Bushe, Boake and Allen, Inc. This fragrance oil has the added advantage of facilitating extrusion of the blocks during manufacture.
A test which can be performed to determine if a fragrance is chlorine stable is as follows. A small amount of solid chlorine containing compound is placed into a beaker. A sufficient amount of fragrance is added to substantially coat all of the particulate. The sample is observed periodically over a 24 hour period. The fragrance is considered stable as long as (1) there is no observable chemical reaction (e.g., exothermic, combustion); (2) there is no detectable strong chlorine odor from the sample; (3) there is no discoloration of the sample; and (4) the fragrance's characteristic odor has not significantly changed.
To achieve long life a cellulose ether binder is included in the block. Preferred cellulose ether binders are hydrated cellulose materials such as hydroxy alkyl celluloses such as hydroxy ethyl cellulose, hydroxypropyl methyl cellulose, and hydroxy propyl cellulose. Examples of other cellulose ether binders are methyl cellulose, ethyl cellulose, sodium carboxymethyl cellulose, ethyl hydroxyethyl cellulose, and carboxymethyl cellulose. It is believed that the stabilizer reduces the hydrolyzing effect of the bleach on the cellulose ether binder.
For toilet cleaning blocks, anionic surfactants are especially preferred, such as sodium dodecyl benzene sulfonate and sodium lauryl sulfate. However, a wide variety of surfactants (anionic, nonionic, cationic, zwitterionic), are suitable for use in toilet cleansing blocks (see e.g. U.S. Pat. No. 5,336,427).
Preferred chlorine releasing agents are alkali metal and alkaline earth metal hypochlorites, and alkali metal dichloroisocyanurates.
Surprisingly, even though the block has a bleach, the block can also include dye. In this regard, I have found that the stabilizer also reduces the oxidizing effect of the bleach on the dye. The choice of the dye/coloring agent will largely depend on the color desired for the water into which the lavatory cleanser composition is to be dispensed and its tendency not to stain porcelain. A preferred coloring agent is Acid Blue 9. Other suitable dyes are described in U.S. Pat. No. 5,336,427.
The amount of coloring agent or dye to be dispensed into the water will depend on the color intensity desired and the cost of the dye. The absorbance of the coloring agent may be determined for laboratory purposes through the use of a visible spectrophotometer, such as a Perkin-Elmer Model 552 spectrophotometer.
The amount of coloring agent delivered in the toilet bowl should be sufficient to provide an absorbance in a 1 cm spectrophotometric cell of from about 0.02 absorbance units (“a.u.”) to about 0.2 a.u. when measured at its wavelength maxima. This is because consumers typically believe that a colored cleansing product is no longer working when it has a color intensity below this range.
Also, a filler/density aid, and various other conventional additives such as borax or ascorbic acid can be included. For example, to achieve adequate density so that the block won't float, and to keep costs to the minimum, inert fillers/density aids are preferably added. Inert salts are preferred for this purpose such as water-soluble inorganic or organic salts (or mixtures of such salts). Examples include various alkali metal and/or alkaline earth metal sulfates, chlorides, borates, and citrates. Specific inert salts are sodium sulfate, sodium sulfonate, calcium sulfate, sodium chloride, potassium sulfate, sodium carbonate, lithium chloride, tripotassium phosphate, sodium borate, potassium fluoride, calcium chloride, magnesium chloride, sodium citrate, magnesium sulfate and sodium fluoride. The filler/density aid is typically present in an amount from about 0% to about 60%, preferably about 10% to about 40% by weight.
In another embodiment, the invention provides a method of cleaning a basin of a toilet. One immerses one of the above blocks in a water reservoir for a toilet basin, allows a portion of the block to dissolve in the toilet tank water, and then flushes the toilet.
The objects of the present invention therefore include providing a water reservoir cleaner of the above kind:
(a) that is effective in inhibiting toilet bowl stain formation;
(b) which maintains toilet basins in a clean condition for an extended period;
(c) which uses environmentally acceptable and inexpensive components; and
(d) which compatibly uses a chlorine releasing agent for cleaning, a cellulose ether for extended life, and a dye for providing an easy way for a consumer to tell when a replacement is needed.
These and still other objects and advantages of the present invention (e.g., methods for using these blocks) will be apparent from the description which follows. The following description is merely of the preferred embodiments. Thus, the claims should be looked to in order to understand the full scope of the invention.
MODES FOR CARRYING OUT INVENTION
Cleansing blocks for use in a toilet tank are:
REFERENCES:
patent: 2578270 (1951-12-01), Strain
patent: 2913460 (1959-11-01), Brown et al.
patent: 2980622 (1961-04-01)
Gupta Yogendra
Petruncio John M
S. C. Johnson & Son Inc.
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