Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Alkali metal carbonate – bicarbonate – or sesquicarbornate...
Reexamination Certificate
1999-09-10
2003-08-26
Kopec, Mark (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Alkali metal carbonate, bicarbonate, or sesquicarbornate...
C510S224000, C510S229000, C510S233000, C510S317000, C510S318000, C510S361000, C510S440000, C510S435000, C510S477000, C510S478000, C510S531000, C510S533000
Reexamination Certificate
active
06610645
ABSTRACT:
FIELD OF THE INVENTION
The invention is directed to an inexpensive builder material for use in detergent compositions. More particularly, the invention provides a selected crystalline calcium carbonate material substantially having a rhombohedral crystalline structure with {1,0-1,1} crystallographic indices. This very inexpensive builder material is especially suitable for use in detergent compositions used in fabric laundering, bleaching, automatic or hand dishwashing, hard surface cleaning and in any other application which requires the use of a builder material to remove water hardness.
BACKGROUND OF THE INVENTION
It is common practice for formulators of cleaning compositions to include, in addition to a cleaning active material, a builder to remove hardness cations (e.g. calcium cations and magnesium cations) from washing solution which would otherwise reduce the efficiency of the cleaning active material (e.g. surfactant) and render certain soils more difficult to remove. For example, laundry detergent compositions typically contain an anionic surfactant and a builder to reduce the effects of hardness cations in wash solutions. In this context, the builder sequesters or “ties up” the hardness cations so as to prevent them from hindering the cleaning action of the anionic surfactant in the detergent composition.
As is well known, water-soluble phosphate materials have been used extensively as detergency builders. However for a variety of reasons, including eutrophication of surface waters allegedly caused by phosphates, there has been a desire to use other builder materials in many geographic areas. Other known builders include water-soluble builder salts, such as sodium carbonate, which can form precipitates with the hardness cations found in washing solutions. Unfortunately, the use of such builders alone does not reduce the level of hardness cations at a sufficiently rapid rate. For practical purposes, the acceptable level is not reached within the limited time required for the desired application, e.g. within 10 to 12 minutes for fabric laundering operations in North America and Japan.
Moreover, some of these water-soluble builder salts, while attractive from the point of view of cost, have several disadvantages, among which are the tendency of the precipitates formed in aqueous washing solutions (e.g. insoluble calcium carbonate) to become deposited on fabrics or other articles to be cleaned. One alleged solution to this problem has been to include a water-insoluble material which would act as a “seed crystal” for the precipitate (i.e. calcium carbonate). Of the many materials suggested for such use, very small particle size calcite has been the most popular.
However, the inclusion of calcite in detergent compositions has been problematic because of the sensitivity of the hardness cation/salt anion (e.g. calcium/carbonate) reaction product to poisoning by materials (e.g. polyacrylate or certain anionic surfactants) which may be present in the washing solution. Without being limited by theory, the poisoning problem prevents the reaction product from forming in that crystallization onto the seed crystal is inhibited. Consequently, calcite typically has to be produced in a very small particle size in order to have a larger surface area which is harder to poison. This, however, renders the very small calcite particle dusty and difficult to handle. Moreover, the required particle sizes are so small (at least having 15 m
2
/g or more of surface area) that manufacturing of such calcite particles is extremely expensive. For example, production of such small calcite particles may require a controlled “growing” process which is extremely expensive. Another problem associated with the use of calcite as a “seed crystal” for the poisons and precipitates in washing solutions is the difficulty experienced in adequately dispersing the calcite in the washing solution so that it does not deposit on fabrics or articles which have been subjected to cleaning operations. Such deposits or residues are extremely undesirable for most any cleaning operation, especially in fabric laundering and tableware cleaning situations.
The prior art is replete with suggestions for dealing with the handling and dispersability problems associated with calcite. One previously proposed means for handling calcite is to incorporate it into a slurry, but this involves high storage and transportation costs. Another proposed option involves granulating calcite with binding and dispersing agents to ensure adequate dispersment in the wash solution. However, this option also has been difficult to implement effectively in modern day detergent compositions because the calcite granules have poor mechanical strength which continue to make them difficult to handle and process. Additionally, effective binding and dispersing agents for the calcite have not been discovered to date. Specifically, most of the binding and dispersing agents proposed by the prior art are themselves poisons which reduce the “seed activity” of the calcite. Consequently, it would be desirable to have an improved inexpensive builder material which overcomes the aforementioned limitations and is easy to handle, readily dispersible in washing solutions and exhibits improved builder performance.
Several additional builder materials and combinations thereof have also been used extensively in various cleaning compositions for fabric laundering operations and dish or tableware cleaning operations. By way of example, certain clay minerals have been used to adsorb hardness cations, especially in fabric laundering operations. Further, the zeolites (or aluminosilicates) have been suggested for use in various cleaning situations. Various aluminosilicates have also been used as detergency builders. For example, water-insoluble aluminosilicate ion exchange materials have been widely used in detergent compositions throughout the industry. While such builder materials are quite effective and useful, they account for a significant portion of the cost in most any fully formulated detergent or cleaning composition. In addition, such builders have a limited calcium sequestration capacity, and thus, are not very effective in hard water. Therefore, it would be desirable to have a builder material which performs as well as or better than the aforementioned builders, and importantly, is also less expensive.
Accordingly, despite the aforementioned disclosures, there remains a need in the art for an inexpensive builder material for use in detergent compositions which exhibits superior performance and is less expensive to manufacture in that it does not require a very small particle size. There is also a need in the art for such a builder material which is easy to handle (i.e., is not “dusty”), easy to process and readily disperses in washing solutions.
BACKGROUND ART
The following references are directed to builders for various detergent compositions: Atkinson et al, U.S. Pat. No. 4,900,466 (Lever); Houghton, WO 93/22411 (Lever); Allan et al, EP 518 576 A2; (Lever); Zolotoochin, U.S. Pat. No. 5,219,541 (Tenneco Minerals Company); Gamer-Gray et al. U.S. Pat. No. 4,966,606 (Lever); Davies et al, U.S. Pat. No. 4,908,159 (Lever); Carter et al, U.S. Pat. No. 4,711,740 (Lever); Greene, U.S. Pat. No.4,473,485 (Lever); Davies et al, U.S. Pat. No. 4,407,722 (Lever); Jones et al, U.S. Pat. No. 4,352,678 (Lever); Clarke et al, U.S. Pat. No. 4,348,293 (Lever); Clarke et al, U.S. Pat. No. 4,196,093 (Lever); Benjamin et al, U.S. Pat. No. 4,171,291 (Procter & Gamble); Kowalchuk, U.S. Pat. No. 4,162,994 (Lever); Davies et al, U.S. Pat. No. 4,076,653 (Lever); Davies et al, U.S. Pat. No. 4,051,054 (Lever); Collier, U.S. Pat. No. 4,049,586 (Procter & Gamble); Benson et al, U.S. Pat. No. 4,040,988 (Procter & Gamble); Cherney, U.S. Pat. No. 4,035,257 (Procter & Gamble); Curtis, U.S. Pat. No. 4,022,702 (Lever); Child et al, U.S. Pat. No. 4,013,578 (Lever); Lamberti, U.S. Pat. No. 3,997,692 (Lever); Cherney, U.S. Pat. No. 3,992,314 (Procter & Gamble); Child, U.S. Pat. No.3,979,314 (Leve
Capeci Scott William
Hoffman William Marion
Pancheri Eugene Joseph
Rohrbaugh Robert Henry
Weitzel Rose Marie
Boyer Charles
Kopec Mark
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