WO1998040457A1

WO1998040457A1 - Builder mixture containing crystalline calcium carbonate builder for use in detergent compositions

Info

Publication number: WO1998040457A1
Application number: PCT/US1998/004471
Authority: WO
Inventors: Eugene Joseph Pancheri; Kevin David Moe; Rose Marie Weitzel
Original assignee: The Procter & Gamble Company
Priority date: 1997-03-11
Filing date: 1998-03-06
Publication date: 1998-09-17

Abstract

A detergent composition containing an inexpensive detergent builder mixture including aluminosilicate and a selected crystalline calcium carbone is provided. Specifically, the crystalline calcium carbonate has a substantially rhombohedral crystal structure with {1,0,-1,1} crystallographic indices. The crystalline calcium carbonate can be calcite that has been specially modified to a rhombohedral crystal structure with {1,0,-1,1} indices. The crystalline calcium carbonate of the present invention is extremely inexpensive because it can be readily formed from inexpensive naturally occurring calcite, and it performs well even when used at large median particle sizes.

Description

BUILDER MIXTURE CONTAINING CRYSTALLINE CALCIUM CARBONATE BUILDER FOR USE IN DETERGENT COMPOSITIONS

FIELD OF THE INVENTION The invention is directed to an optimally selected builder mixture for use in detergent compositions. More particularly, the invention provides a selected crystalline

10 calcium carbonate material substantially having a rhombohedral crystalline structure with { 1,0,-1,1 } crystallographic indices in combination with aluminosilicate builders. This builder mixture 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.

15 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

20 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

25 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

30 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

35 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^/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. Patent 4,900,466 (Lever); Houghton, WO 93/2241 1 (Lever); Allan et al, EP 518 576 A2; (Lever); Zolotoochin, U.S. Patent No. 5,219,541 (Tenneco Minerals Company); Garner-Gray et al, U.S. Patent No. 4,966,606 (Lever); Davies et al, U.S. Patent No. 4,908, 159 (Lever); Carter et al, U.S. Patent No. 4,71 1 ,740 (Lever); Greene, U.S. Patent No. 4,473,485 (Lever); Davies et al, U.S. Patent No. 4,407,722 (Lever); Jones et al, U.S. Patent No. 4,352,678 (Lever); Clarke et al, U.S. Patent No. 4,348,293 (Lever); Clarke et al, U.S. Patent No. 4,196,093 (Lever); Benjamin et al, U.S. Patent No. 4,171,291 (Procter & Gamble); Kowalchuk, U. S. Patent No. 4,162,994 (Lever); Davies et al, U.S. Patent No. 4,076,653 (Lever); Davies et al, U.S. Patent No. 4,051,054 (Lever); Collier, U.S. Patent No. 4,049,586 (Procter & Gamble); Benson et al, U.S. Patent No. 4,040,988 (Procter & Gamble); Cherney, U.S. Patent No. 4,035,257 (Procter & Gamble); Curtis, U.S. Patent No. 4,022,702 (Lever); Child et al, U.S. Patent 4,013,578 (Lever); Lamberti, U.S. Patent No. 3,997,692 (Lever); Cherney, U.S. Patent 3,992,314 (Procter & Gamble); Child, U.S. Patent No. 3,979,314 (Lever); Davies et al, U.S. Patent No. 3,957,695 (Lever); Lamberti, U.S. Patent No. 3,954,649 (Lever); Sagel et al U.S. Patent 3,932,316 (Procter & Gamble); Lobunez et al, U.S. Patent 3,981,686 (Intermountain Research and Development Corp.); Mallow et al, U.S. Patent 4,828,620 (Southwest Research Institute); Bjorklund et al, "Adsorption of Anionic and Cationic Polymers on Porous and Non-porous Calcium Carbonate Surfaces," Applied Surface

Science 75 pp. 197-203 (1994); Wierzbicki et al, "Atomic Force Microscopy and Molecular Modeling of Protein and Peptide Binding to Calcite," Calcified Tissue International 54, pp. 133-141 (1994); Park et al, "Tribological Enhancement of CaCθ3 Dissolution during Scanning Force Microscopy," Langmuir, pp. 4599-4603, 12 (1996); and Nancollas et al, "The Crystallization of Calcium Carbonate," Journal of Colloid and Interface Science, Vol. 37, No. 4, pp. 824-829 (Dec. 1971). SUMMARY OF THE INVENTION

The aforementioned needs in the art are met by the present invention which provides a detergent builder mixture of aluminosilicate and a calcium carbonate that is in an especially selected crystalline form. Specifically, the crystalline calcium carbonate has a substantially rhombohedral crystal structure with { 1,0,-1,1 } crystallographic indices. The crystalline calcium carbonate and aluminosilicate are included in a detergent composition at selected weight ratios for optimal performance, both from a detergency "building" standpoint and a cleaning standpoint. The crystalline calcium carbonate can be calcite that has been specially modified to the rhombohedral crystal structure with { 1,0,-1,1 } indices. The crystalline calcium carbonate of the present invention is extremely inexpensive because it can be readily formed from inexpensive naturally occurring calcite and it performs well even when used at large median particle sizes.

In accordance with one aspect of the invention, a detergent composition is provided. The detergent composition comprises: (a) an effective amount of a builder mixture of aluminosilicate and a crystalline calcium carbonate, the crystalline calcium carbonate substantially having a rhombohedral crystalline structure with { 1 ,0,- 1,1 } crystallographic indices, wherein the aluminosilicate and the crystalline calcium carbonate are included in a weight ratio range of from about 10: 1 to about 1 : 10; and (b) at least about 1% by weight of a detersive surfactant.

In a preferred aspect of the invention, a detergent composition having especially preferred features is provided. This detergent composition comprises: (a) from about 0.1% to about 80% by weight of a mixture of aluminosilicate and crystalline calcium carbonate, the crystalline calcium carbonate substantially having a rhombohedral crystalline structure with {1,0,-1,1} crystallographic indices and a surface area of from about 0.01 m^ g to about 4 m^/g, wherein the aluminosilicate and the crystalline calcium carbonate are included in a weight ratio range of from about 10: 1 to about 1 : 10; (b) at least about 1% by weight of a detersive surfactant; and (c) from about 2% to about 80% by weight of sodium carbonate, wherein the sodium carbonate and the crystalline calcium carbonate are in a weight ratio range of about 1:1 to about 5:1; wherein the detergent composition is substantially free of phosphates. This detergent composition is substantially free of phosphates.

The invention also provides a method for laundering soiled fabrics comprising the steps of contacting the soiled fabrics with an aqueous solution containing an effective amount of a detergent composition as described herein. Also provided is a method for cleaning surfaces comprising the steps of contacting the surfaces with an aqueous solution containing an effective amount of a detergent composition as described herein. Any of the detergent compositions described herein may be in the form of a laundry bar. In yet another method aspect of the invention, a method of removing calcium hardness ions from an aqueous solution is provided. This method comprises the step of dispersing the builder mixture of aluminosilicate and crystalline calcium carbonate substantially having a rhombohedral crystalline structure with { 1,0,-1,1 } crystallographic indices into the aqueous solution, the calcium hardness ions crystallizing on the crystalline calcium carbonate resulting in the removal of the calcium hardness ions from the aqueous solution.

Accordingly, it is an object of the invention to provide a detergent composition containing an inexpensive builder material which exhibits superior performance and is less expensive to manufacture in that it does not require a very small particle size. It is also an object of the invention to provide such a builder material which is easy to handle (i.e., is not "dusty"), easy to process and readily disperses in washing solutions. These and other objects, features and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiment and the appended claims.

All percentages, ratios and proportions used herein are by weight (anhydrous basis) unless otherwise specified. All documents including patents and publications cited herein are incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 illustrates a crystalline calcium carbonate structure in accordance with the invention; and Figs. 2-8 illustrate naturally occurring crystalline calcium carbonate structures that are commonly found in nature (Fig. 8 is a partial perspective depicting only the top portion of the crystal), all of which are outside the scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The detergent composition containing the builder mixture of the invention can be used in a variety of applications including, but not limited to, fabric laundering, fabric or surface bleaching, automatic or hand dishwashing, hard surface cleaning and any other application which requires the use of a builder to remove water hardness.

As used herein, the phrase "effective amount" means that the level of the builder mixture in the composition is sufficient to sequester an adequate amount of hardness in the washing solution such that the detersive surfactant is not overly inhibited. As used herein, the word "crystalline" means a mixture or material having a regularly repeating internal arrangement (i.e., "lattice") of its atoms and external plane faces. As used herein, the phrase "substantially having a rhombohedral crystalline structure" means a crystal having the form of a parallelogram and no right angles (e.g., as depicted in Fig. 1). As used herein, "{ 1,0,-1,1 } crystallographic indices" refers to a specific set of crystal planes on a hexagonal coordinate system which defines a selected crystalline structure (also referenced as the "Miller indices" for a hexagonal coordinate system). As used herein, the phrase "crystalline calcium carbonate" refers to the chemical entity, calcium carbonate, in crystalline form, of which the most common form is referenced as "calcite". Also see standard texts on all of these subjects, such as Blackburn et al, Principles of Mineralogy, 2nd Ed., pp. 21-51 (1994) and Klein et al, Manual of Mineralogy, p. 405 et seq (1977). Builder Mixture

The builder mixture used in the present invention includes aluminosilicate and a selected crystalline calcium carbonate as detailed hereinafter. Preferably, the aluminosilicate and crystalline calcium carbonate are present in the detergent composition in a weight ratio range of from about 1 : 10 to about 10: 1, more preferably from about 1 :5 to about 5: 1, even more preferably from about 1 :3 to about 3: 1, and most preferably from about 1 :3 to about 2:1. In this way, it has been found that builder and cleaning performance of the detergent composition is maximized while simultaneously maintaining a cost effective formula in that a significant portion of the builder mixture is comprised on the inexpensive crystalline calcium carbonate. The actual amount of the builder mixture used in the detergent composition of the invention will vary widely depending upon the particular application. However, typical amounts are from about 0.1% to about 80%, more typically from about 4% to about 60%, and most typically from about 6% to about 40%, by weight of the detergent composition.

The aluminosilicate is preferably selected from the group consisting of zeolite A, zeolite MAP, zeolite X and mixtures thereof. Most preferably, the aluminosilicate is zeolite. Generally speaking, suitable aluminosilicate builders include those having the empirical formula:

M_z[(A10₂)_z (Siθ2)_y]-xH₂0 wherein z and y are integers of at least 6, the molar ratio of z to y is in the range from 1.0 to about 0.5, and x is an integer from about 15 to about 264. Other useful aluminosilicate ion exchange materials are commercially available. These aluminosilicates can be crystalline or amorphous in structure and can be naturally-occurring aluminosilicates or synthetically derived. A method for producing aluminosilicate ion exchange materials is disclosed in U.S. Patent 3,985,669, Krummel, et al, issued October 12, 1976. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations Zeolite A, Zeolite P (B), Zeolite MAP and Zeolite X. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material has the formula:

Na₁₂[(Alθ2)i2(Siθ2)i2]-xH₂0 wherein x is from about 20 to about 30, especially about 27. This material is known as Zeolite A. Dehydrated zeolites (x = 0 - 10) may also be used herein. Preferably, the aluminosilicate has a particle size of about 0.1-10 microns in diameter.

The crystalline calcium carbonate used in the detergent composition of the present invention has a substantially rhombohedral crystalline structure 10 as depicted in Fig. 1. This crystalline calcium carbonate is defined by { 1,0,-1,1 } crystallographic or Miller indices. It has been suφrisingly found that by judiciously selecting a crystalline calcium carbonate of such a crystalline configuration, superior builder performance (i.e., removal of water hardness) can be achieved when used in typical detergent compositions for laundering soiled clothes. The median particle size of this crystalline calcium carbonate as detailed hereinafter is not required to be in the very small range (e.g., less than about 2 microns with a surface areas at least about 15 m^/g).

While not intending to be bound by theory, it is believed that the outer surfaces, e.g., 12, 14 and 16 depicted in Fig. 1, have a significantly high population of oxygen atoms which lends the entire crystalline structure to have more of an affinity to calcium cations which is the predominant source of water hardness. Those skilled in the art will appreciate that this is a crystal having { 1 ,0,- 1,1 } crystallographic indices and its crystal faces are defined thereby. By contrast, Figs 2-8 define crystal structures of crystalline calcium carbonate or calcite which do not substantially have a rhombohedral crystalline structure with { 1,0,-1,1 } crystallographic indices. Moreover, all of the crystal faces or cleavage planes of the calcite crystal structures depicted in Figs. 2-8 can have a much higher population of calcium atoms, thereby creating a strong positive charge on the outer surfaces of these crystals. This, as those skilled in the art will appreciate, does cause these crystalline structures to be less effective at sequestering water hardness cations.

Specifically, Fig. 2 depicts a crystalline calcium carbonate having a rhombohedral structure 18, but with {0,1,-1,2} crystallographic indices. Fig. 3 illustrates crystalline calcium carbonate or calcite in a cubic crystal structure 20 having {0,2,-2,1 } crystallographic indices. Fig. 4 depicts a hexagonal crystal structure 22 with { 1,0,-1,0} and {0,0,0,1 } crystallographic indices, while Fig. 5 shows a prismatic structure 24 with {1,0,- 1,0} and {0,1,-1,2} crystallographic indices. Fig. 6 depicts a crystalline calcium carbonate structure 26 having {2,1,-3,1 } crystallographic indices, and Fig. 7 illustrates a scalenohedral calcite crystal structure 28 with {2,1,-3,1 } and small faces with the preferred { 1,0-1,1 } crystallographic indices. Lastly, Fig. 8 illustrates a top partial perspective view of yet another calcium carbonate crystalline structure 30 which has {0, 1,-1,2}, {2,1,-3,1 } and { 1,0,-1,0} crystallographic indices.

Figs. 3, 4, 5 and 7 depict the most common calcite crystals found in nature. It should be understood that none of these calcite crystal structures are in the form of Fig. 1 which is within the scope of the invention. Furthermore, it is believed that the calcite crystal structures of Figs. 2-8 do not perform as well as the Fig. 1 structure because the Figs. 2-8 structures have a high population of calcium atoms at their respective crystal planes (i.e., outer surfaces), thereby resulting in poor performance relative to water hardness cation sequestration. To the contrary, as mentioned previously, the calcite crystal depicted in Fig. 1 has a high population of oxygen atoms and low population of calcium atoms on its respective cleavage planes (i.e., { 1,0,-1,1 } crystallographic indices) rendering it a particularly effective seed crystal for water hardness cation (e.g., calcium cations) sequestration. This results in a superior performing detergent composition as the deleterious effects of water hardness on surfactant performance is eliminated or severely inhibited.

The "crystalline" nature of the builder material can be detected by X-ray Diffraction techniques known by those skilled in the art. X-ray diffraction patterns are commonly collected using Cu Ka_jpha radiation on an automated powder diffractometer with a nickel filter and a scintillation counter to quantify the diffracted X-ray intensity. The X-ray diffraction diagrams are typically recorded as a pattern of lattice spacings and relative X-ray intensities. In the Powder Diffraction File database by the Joint Committee on Powder Diffraction Standards - International Centre for Diffraction Data, X-ray diffraction diagrams of corresponding preferred builder materials include, but are not limited to, the following numbers: 5-0586 and 17-0763.

The median particle size of the builder is preferably from about 0.2 microns to about 20 microns, more preferably from about 0.3 microns to about 15 microns, even more preferably from about 0.4 microns to about 10 microns, and most preferably from about 0.5 microns to about 10 microns. While the crystalline calcium carbonate builder used in the detergent composition herein performs at any median particle size, it has been found that optimum overall performance can be achieved within the aforementioned median particle size ranges.

The phrase "median particle size" as used herein means the particle size as measured by the particle's diameter of a given builder in which 50% by weight of the population has a higher particle size and 50% has a lower particle size. The median particle size is measured at its usage concentration in water (after 10 minutes of exposure to this water solution at a temperature of 50F to OOF) as determined by conventional analytical techniques such as, for example, microscopic determination using a scanning electron microscope (SEM), Coulter Counter or Malvern particle size instruments. In general, the particle size of the builder not at its usage concentration in water can be any convenient size. In addition to the median particle size or in the alternative to it, the crystalline calcium carbonate builder preferably has selected surface area for optimal performance. More specifically, the crystalline calcium carbonate has a surface area of from about 0.01 m^/g to about 12 m^/g, more preferably from about 0.1 m^/g to about 10 m^/g, even more preferably from about 0.2 ^/g to about 5 m^/g, and most preferably from about 0.2 m^/g to about 4 m^/g. Other suitable surface area ranges include from about 0.1 m^/g to about 4 m^/g and from about 0.01 m^/g to about 4 m^/g. The surface areas can be measured by standard techniques including by nitrogen adsoφtion using the standard Bruauer, Emmet & Teller (BET) method. A suitable machine for this method is a Carlo Erba Soφty 1750 instrument operated according to the manufacturer's instructions. The crystalline calcium carbonate builder used in the detergent composition herein also unexpectedly has improved builder performance in that it has a high calcium ion exchange capacity. In that regard, the builder material has a calcium ion exchange capacity, on an anhydrous basis, of at least about 100 mg equivalent of calcium carbonate hardness/gram, more preferably at least about 200 mg, and even more preferably at least about 300 mg, and most preferably from at least about 400 mg, equivalent of calcium carbonate hardness per gram of builder. Additionally, the builder unexpectedly has an improved calcium ion exchange rate. On an anhydrous basis, the builder material has a calcium carbonate hardness exchange rate of at least about 5 ppm, more preferably from about 10 ppm to about 150 ppm, and most preferably from about 20 ppm to about 100 ppm, CaCθ3/minute per 200 ppm of the builder material. A wide variety of test methods can be used to measure the aforementioned properties including the procedure exemplified hereinafter and the procedure disclosed in Corkill et al, U.S. Patent No. 4,605,509 (issued August 12, 1986), the disclosure of which is incoφorated herein by reference.

In a preferred embodiment of the invention, the detergent composition is substantially free of phosphates and phosphonates. As used herein, "substantially free" means has less than 0.01% by weight of a given material. Alternatively, or in addition to the foregoing phosphate limitation, the detergent composition is substantially free of soluble silicates, especially if magnesium cations are part of the water hardness composition in the particular use and the detergent composition of the invention does not include an auxiliary builder to sequester such cations. In this regard, superior performance of the detergent composition containing the aforedescribed builder can be achieved if the detergent composition is substantially free of polycarboxylates, polycarboxylic oligomer/polymers and the like. It has also been found that optimal performance can be achieved using such materials in the detergent composition so long as the polycarboxylate is pre-blended with the surfactant before exposure to the crystalline calcium carbonate, either during manufacture of the detergent composition or during use. In another preferred aspect of the invention, the detergent composition is substantially free of potassium salts, or if they are present, are included at very low levels. Specifically, the potassium salts are included at levels of about 0.01% to about 5%, preferably at about 0.01% to about 2% by weight of the detergent composition.

Preferably, if sodium sulfate and sodium carbonate are included in the detergent composition, they are preferably in a weight ratio of about 1 :50 to about 2: 1, more preferably from about 1 :40 to about 1 : 1, most preferably from about 1 :20 to about 1 : 1 of sodium sulfate to sodium carbonate. While not intending to be bound by theory, it is believed that excessive amounts of sulfate relative to carbonate may interfere with the builder performance of the crystalline calcium carbonate. Preferably, if sodium carbonate is included in the detergent composition, it is included preferably in a weight ratio of about 1 : 1 to about 20: 1 , more preferably from about 1 : 1 to about 10:1, most preferably from about 1 :1 to about 5:1 of sodium carbonate to crystalline calcium carbonate builder. Additionally or in the alternative, sodium carbonate is present in the detergent composition in an amount of from about 2% to about 80%, more preferably from about 5% to about 70%, and most preferably from about 10% to about 50% by weight of the detergent composition.

The crystalline calcium carbonate in accordance with the invention (Fig. 1) can be made in a variety of ways so long as the resulting crystal substantially has a rhombohedral crystalline structure with { 1 ,0,- 1,1 } crystallographic indices. By way of example, naturally occurring calcite such as the one depicted in Fig. 5 can be mined or commercially purchased and subjected to a selected milling process in which the calcite is crushed or ground such that it is cleaved to form the aforementioned crystalline calcite structure (Fig. 1 ). While not intending to be bound by theory, it is believed that the { 1 ,0,- 1 , 1 } crystallographic indices define "low stress" planes of larger naturally occurring calcite along which cleavage can occur if milled with selected process parameters.

One convenient apparatus in which such milling can occur is an Alpine Fluid Bed Jet Mill (Model 100 AFG Fluid Bed Jet Mill commercially available from Hosokawa Micron, Alpine, Germany). This apparatus can be used in conjunction with an Air Classifier such as Alpine Air Classifier (Model 50 ATP Air Classifier commercially available from Hosokawa Micron - Alpine, Germany). Calcite can be purchased from

Omya, Inc., or Quincy Carbonates and subjected to the aforementioned apparatus operated with the valve (El 2) set open, throttle flap valve set to adjust air chamber to 0 air pressure, Air Classifier speed set at 8000 φms, grinding valve set at 5 bar pressure, and the product feed screw set at 35% of maximum. The Air Classifier and Fluid Bed Jet Mill are run until the desired crystalline calcium carbonate builder is obtained. Actual time and various other process parameters are within the purview of the skilled artisan. Detergent Compositions

The detergent compositions of the invention can contain all manner of organic, water-soluble detergent compounds, inasmuch as the builder material are compatible with all such materials. In addition to a detersive surfactant, at least one suitable adjunct detergent ingredient is preferably included in the detergent composition. The adjunct detergent ingredient is preferably selected from the group consisting of auxiliary builders, enzymes, bleaching agents, bleach activators, suds suppressers, soil release agents, brighteners, perfumes, hydrotropes, dyes, pigments, polymeric dispersing agents, pH controlling agents, chelants, processing aids, crystallization aids, and mixtures thereof. The following list of detergent ingredients and mixtures thereof which can be used in the compositions herein is representative of the detergent ingredients, but is not intended to be limiting.

Detersive Surfactant Preferably, the detergent compositions herein comprise at least about 1%, preferably from about 1% to about 55%, and most preferably from about 10 to 40%), by weight, of a detersive surfactant selected from the group consisting of anionic surfactants, nonionic surfactants, cationic surfactants, zwitterionic surfactants and mixtures. Nonlimiting examples of surfactants useful herein include the conventional Cj j-C_jg alkyl benzene sulfonates ("LAS") and primary, branched-chain and random C10-C20 alkyl sulfates ("AS"), the C_{j Q}-Cj secondary (2,3) alkyl sulfates of the formula CH₃(CH₂)_x(CHOSθ3^"M⁺) CH3 and CH3 (CH₂)y(CHOSθ3^"M⁺) CH₂CH where x and (y + 1) are integers of at least about 7, preferably at least about 9, and M is a water-solubilizing cation, especially sodium, unsaturated sulfates such as oleyl sulfate, the C10-C18 alkyl alkoxy sulfates ("AE_XS"; especially EO 1-7 ethoxy sulfates), Cio-Cj alkyl alkoxy carboxylates (especially the EO 1-5 ethoxycarboxylates), the C J O- 18 gtycerol ethers, the C₁ Q-C \ g alkyl polyglycosides and their corresponding sulfated polyglycosides, and Ci2-C_jg alpha-sulfonated fatty acid esters. If desired, the conventional nonionic and amphoteric surfactants such as the C^-Cj alkyl ethoxylates ("AE") including the so- called narrow peaked alkyl ethoxylates and Cg-Cι₂ alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C^-Cj betaines and sulfobetaines ("sultaines"), C_jo-C_jg amine oxides, and the like, can also be included in the overall compositions. The Cio-C_jg N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples include the Cι₂-Cιg N-methylglucamides. See WO 9,206,154. Other sugar-derived surfactants include the N-alkoxy polyhydroxy fatty acid amides, such as C_{j Q}-C jg N-(3- methoxypropyl) glucamide. The N-propyl through N-hexyl C^-C_jg glucamides can be used for low sudsing. C 10-C20 conventional soaps may also be used. If high sudsing is desired, the branched-chain Cjo-Cjg soaps may be used. Mixtures of anionic and nonionic surfactants are especially useful. Other conventional useful surfactants are listed in standard texts.

It should be understood, however, that certain surfactants are less preferred than others. For example, the Cj j-Cj alkyl benzene sulfonates ("LAS") and the sugar based surfactants are less preferred, although they may be included in the compositions herein, in that they may interfere or otherwise act as a poison with respect to the builder material.

Adjunct Detergent Ingredients The detergent compositions can include additional detergent ingredients and/or, any number of additional ingredients can be incoφorated in the detergent composition during subsequent steps of the present process. These adjunct ingredients include other detergency builders, bleaches, bleach activators, suds boosters or suds suppressers, anti-tarnish and anticorrosion agents, soil suspending agents, soil release agents, germicides, pH adjusting agents, non-builder alkalinity sources, chelating agents, smectite clays, enzymes, enzyme-stabilizing agents and perfumes. See U.S. Patent 3,936,537, issued February 3, 1976 to Baskerville, Jr. et al., incoφorated herein by reference. Although much less preferred, minor amounts of other builders can be generally selected from the various water-soluble, alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates, polyphosphonates, carbonates, borates, polyhydroxy sulfonates, polyacetates, carboxylates, and polycarboxylates. Preferred are the alkali metal, especially sodium, salts of the above. If used, those preferred for low level use herein are the phosphates, carbonates, C 1 Q. \ g fatty acids, polycarboxylates, and mixtures thereof. Still others include sodium tripolyphosphate, tetrasodium pyrophosphate, citrate, tartrate mono- and di-succinates, and mixtures thereof (see below).

In comparison with the much less preferred soluble sodium silicates, crystalline layered sodium silicates exhibit a clearly increased calcium and magnesium ion exchange capacity. In addition, the layered sodium silicates prefer magnesium ions over calcium ions, a feature necessary to insure that substantially all of the "hardness" is removed from the wash water. These crystalline layered sodium silicates, however, are generally more expensive than soluble silicates as well as other builders. Accordingly, in order to provide an economically feasible laundry detergent, the proportion of crystalline layered sodium silicates used must be determined judiciously.

The crystalline layered sodium silicates suitable for use herein preferably have the formula NaMSi_x0_{2x+ 1}.yH₂0 wherein M is sodium or hydrogen, x is from about 1.9 to about 4 and y is from about 0 to about 20. More preferably, the crystalline layered sodium silicate has the formula

NaMSi₂0₅.yH₂0 wherein M is sodium or hydrogen, and y is from about 0 to about 20. These and other crystalline layered sodium silicates are discussed in Corkill et al, U.S. Patent No. 4,605,509, previously incoφorated herein by reference.

Although preferably omitted from the compositions, low levels of inorganic phosphate builders may be used which include sodium and potassium tripolyphosphate, pyrophosphate, polymeric metaphosphate having a degree of polymerization of from about 6 to 21, and orthophosphates. Examples of polyphosphonate builders are the sodium and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane 1-hydroxy-l, 1 -diphosphonic acid and the sodium and potassium salts of ethane, 1,1,2-triphosphonic acid. Other phosphorus builder compounds are disclosed in U.S. Patents 3,159,581 ; 3,213,030; 3,422,021 ; 3,422,137; 3,400,176 and 3,400,148, all of which are incoφorated herein by reference.

Other less preferred examples of nonphosphorus, inorganic builders are tetraborate decahydrate and silicates having a weight ratio of SiO_ to alkali metal oxide of from about 0.5 to about 4.0, preferably from about 1.0 to about 2.4. Water-soluble, nonphosphorus organic builders useful herein include the various alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxy sulfonates. Examples of polyacetate and polycarboxylate builders are the sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diamine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid.

Although preferably used only at low levels (and more preferably omitted from the compositions), polymeric polycarboxylate builders are set forth in U.S. Patent 3,308,067, Diehl, issued March 7, 1967, the disclosure of which is incoφorated herein by reference. Such materials include the water-soluble salts of homo- and copolymers of aliphatic carboxylic acids such as maleic acid, itaconic acid, mesaconic acid, fumaric acid, aconitic acid, citraconic acid and methylene malonic acid. Some of these materials are useful as the water-soluble anionic polymer as hereinafter described, but only if in intimate admixture with the non-soap anionic surfactant.

Other polycarboxylates are the polyacetal carboxylates described in U.S. Patent 4,144,226, issued March 13, 1979 to Crutchfield et al, and U.S. Patent 4,246,495, issued March 27, 1979 to Crutchfield et al, both of which are incoφorated herein by reference. These polyacetal carboxylates can be prepared by bringing together under polymerization conditions an ester of glyoxylic acid and a polymerization initiator. The resulting polyacetal carboxylate ester is then attached to chemically stable end groups to stabilize the polyacetal carboxylate against rapid depolymerization in alkaline solution, converted to the corresponding salt, and added to a detergent composition. Still other polycarboxylate builders are the ether carboxylate builder compositions comprising a combination of tartrate monosuccinate and tartrate disuccinate described in U.S. Patent 4,663,071, Bush et al., issued May 5, 1987, the disclosure of which is incoφorated herein by reference.

Bleaching agents and activators are described in U.S. Patent 4,412,934, Chung et al., issued November 1, 1983, and in U.S. Patent 4,483,781 , Hartman, issued November 20, 1984, both of which are incoφorated herein by reference. Chelating agents are also described in U.S. Patent 4,663,071, Bush et al., from Column 17, line 54 through Column 18, line 68, incoφorated herein by reference. Suds modifiers are also optional ingredients and are described in U.S. Patents 3,933,672, issued January 20, 1976 to Bartoletta et al., and 4,136,045, issued January 23, 1979 to Gault et al., both incoφorated herein by reference.

Suitable smectite clays for use herein are described in U.S. Patent 4,762,645, Tucker et al, issued August 9, 1988, Column 6, line 3 through Column 7, line 24, incoφorated herein by reference. Suitable additional detergency builders for use herein are enumerated in the Baskerville patent, Column 13, line 54 through Column 16, line 16, and in U.S. Patent 4,663,071, Bush et al, issued May 5, 1987, both incoφorated herein by reference.

In order to make the present invention more readily understood, reference is made to the following examples, which are intended to be illustrative only and not intended to be limiting in scope. EXAMPLE I

Calcium Sequestration and Rate of Sequestration Test The following illustrates a step-by-step procedure for determining the amount of calcium sequestration and the rate thereof for the crystalline calcium carbonate builder used in the compositions described herein. 1. Add to 750 ml of 35°C distilled water, sufficient water hardness concentrate to produce 171 ppm of CaC03;

2. Stir and maintain water temperature at 35°C during the experiment;

3. Add 1.0 ml of 8.76% KOH to the water;

4. Add 0.1085 gm of KC1; 5. Add 0.188 gm of Glycine;

6. Stir in 0.15 gm ofNa₂CO3;

7. Adjust pH to 10.0 using 2N HC1 and maintain throughout the test; 8. Stir in 0.15 gm of a builder according the invention and start timer;

9. Collect an alliquot of solution at 30 seconds, quickly filter it through a 0.22 micron filter, quickly acidify it to pH 2.0 - 3.5 and seal the container;

10. Repeat step 9 at 1 minute, 2 minutes, 4 minutes, 8 minutes, and 16 minutes; 11. Analyze all six alliquots for CaCθ3 content via ion selective electrode, titration, quantitative ICP or other appropriate technique;

12. The Sequestration rate in ppm CaC03 sequestered per 200 ppm of builder is 171 minus the CaCθ3 concentration at one minute;

13. Amount of sequestration (in ppm CaCθ3 per gram/liter of builder) is 171 minus the CaCU3 concentration at 16 minutes times five.

For the builder material particle sizes according to the instant invention which are on the low end of the median particle size range, a reference sample is needed which is run without hardness in order to determine how much of the builder passes through the filter. The above calculations should then be corrected to eliminate the contribution of the builder to the apparent calcium concentration.

EXAMPLES II-IV Several detergent compositions made in accordance with the invention and specifically for top-loading washing machines are exemplified below. The base granule is prepared by a conventional spray drying process in which the starting ingredients are formed into a slurry and passed though a spray drying tower having a countercurrent stream of hot air (200-300°C) resulting in the formation of porous granules. The admixed agglomerates are formed from two feed streams of various starting detergent ingredients which are continuously fed, at a rate of 1400 kg/hr, into a Lodige CB-30 mixer/densifier, one of which comprises a surfactant paste containing surfactant and water and the other stream containing starting dry detergent material containing aluminosilicate and sodium carbonate. The rotational speed of the shaft in the Lodige CB-30 mixer/densifier is about 1400 φm and the mean residence time is about 5-10 seconds. The contents from the Lodige CB-30 mixer/densifier are continuously fed into a Lodige KM-600 mixer/densifier for further agglomeration during which the mean residence time is about 6 minutes. The resulting detergent agglomerates are then fed to a fluid bed dryer and to a fluid bed cooler before being admixed with the spray dried granules. The remaining adjunct detergent ingredients are sprayed on or dry added to the blend of agglomerates and granules.

II III IV

Base Granule Calcite (rhombohedral, { 1,0,-1,1 }) 3.0 16.0 1 1.0

Aluminosilicate 15.0 2.0 11.0

Sodium sulfate 10.0 10.0 19.0 Sodium polyacrylate polymer 3.0 3.0 2.0

Polyethylene Glycol (MW=4000) 2.0 2.0 1.0

Cj2-13 linear alkylbenzene sulfonate, Na 6.0 6.0 7.0

Cj4_i6 secondary alkyl sulfate, Na 3.0 3.0 3.0 C i4_ 15 alkyl ethoxylated sulfate, Na 3.0 3.0 9.0

Sodium silicate - 0.1 0.2

Brightener 24⁶ 0.3 0.3 0.3

Sodium carbonate 7.0 7.0 25.7

DTPA ¹ 0.5 0.5 - Admixed Agglomerates

C_j4_i5 alkyl sulfate, Na 5.0 5.0 _

^12-13 li^near alkylbenzene sulfonate, Na 2.0 2.0 -

NaKCa(C03)2 - 7.0 -

Sodium Carbonate 4.0 4.0 - PolyethyleneGlycol (MW=4000) 1.0 1.0 -

Admix ^c12-15 ^alky' ethoxylate (EO = 7) 2.0 2.0 0.5

Perfume 0.3 0.3 1.0

Polyvinylpyrrilidone 0.5 0.5 - Polyvinylpyridine N-oxide 0.5 0.5 -

Polyvinylpyrrolidone-polyvinylimidazole 0.5 0.5 -

Distearylamine & Cumene sulfonic acid 2.0 2.0 -

Soil Release Polymer 2 0.5 0.5 -

Lipolase Lipase ( 100.000 LU/I)⁴ 0.5 0.5 - Termamyl amylase (60 KNU/g)⁴ 0.3 0.3 -

C AREZYME® cellulase (1000 CEVU/g)⁴ 0.3 0.3 -

Protease (40mg/g)5 0.5 0.5 0.5

NOBS ³ 5.0 5.0 -

Sodium Percarbonate 12.0 12.0 - Polydimethylsiloxane 0.3 0.3 -

Miscellaneous (water, etc.) balance balance balance

Total 100.0 100.0 100.0

1 Diethylene Triamine Pentaacetic Acid

^Made according to U.S. Patent 5,415,807, issued May 16, 1995 to Gosselink et al ^ Nonanoyloxybenzenesulfonate

⁴ Purchased from Novo Nordisk A/S

5 Purchased from Genencor " Purchased from Ciba-Geigy

EXAMPLES V-VII The following detergent compositions accordance with the invention are especially suitable for front loading washing machines. The compositions are made in the manner of Examples II - IV.

(% Weight)

V VI VII

Base Granules

Na₂Ca2(Cθ3)3 _ 8.0 Calcite (rhombohedral, { 1 ,0,- 1,1 }) 12.0 24.0 8.0

Aluminosilicate 12.0 - 8.0

Sodium sulfate 6.0 6.0 6.0

Acrylic Acid/Maleic Acid Co-polymer 4.0 4.0 4.0

Cl2-13 line^ar alkylbenzene sulfonate, Na 8.0 8.0 8.0 Sodium silicate - 0.1 0.2

Carboxymethylcellulose 1.0 1.0 1.0

Brightener 47 0.3 0.3 0.3

Silicone antifoam 1.0 1.0 1.0

DTPMPA 1 0.5 0.5 0.5 Admixed

C 12- 15 alkyl ethoxylate (EO=7) 2.0 2.0 2.0 ^c12-15 ^alky' ethoxylate (EO=3) 2.0 2.0 2.0

Perfume 0.3 0.3 0.3

Sodium carbonate 13.0 13.0 13.0 Sodium perborate 18.0 18.0 18.0

Sodium perborate 4.0 4.0 4.0

TAED ² 3.0 3.0 3.0

Savinase protease (4.0 KNPU/g)³ 1.0 1.0 1.0

Lipolase lipase (100.000 LU/1)³ 0.5 0.5 0.5 Termamyl amylase (60 KNU/g)³ 0.3 0.3 0.3

Sodium sulfate 3.0 3.0 5.0

Miscellaneous (water, etc.) balance balance balance

Total 100.0 100.0 100.0

1 Diethylene Triamine Pentamethylenephosphonic Acid 2 Tetra Acetyl Ethylene Diamine

3 Purchased from Novo Nordisk A S

EXAMPLE VIII The following detergent composition according to the invention is in the form of a laundry bar which is particularly suitable for handwashing operations.

(% Weight)

VIII Coconut Fatty Alkyl Sulfate 30.0

Sodium Tripolyphosphate 1.0

Tetrasodium Pyrophosphate 1.0

Sodium Carbonate 20.0

Sodium Sulfate 5.0 Calcite (rhombohedral, { 1,0,-1,1 }) 20.0

Aluminosilicate 10.0

Coconut Fatty Alcohol 2.0

Perfume 1.0

Miscellaneous (water, etc.) balance

Total 100.0

Having thus described the invention in detail, it will be clear to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is described in the specification.

Claims

WHAT IS CLAIMED IS:

1. A detergent composition characterized by:

(a) an effective amount of a builder mixture of aluminosilicate and a crystalline calcium carbonate, said crystalline calcium carbonate substantially having a rhombohedral crystalline structure with { 1,0,-1,1 } crystallographic indices, wherein said aluminosilicate and said crystalline calcium carbonate are included in a weight ratio range of from 10:1 to 1:10; and

(b) at least l% by weight of a detersive surfactant.

2. A detergent composition according to claim 1 wherein said aluminosilicate is selected from the group consisting of zeolite A, zeolite MAP, zeolite X and mixtures thereof.

3. A detergent composition according to claims 1-2 wherein said weight ratio range is from 1: 1 to 5: 1.

4. A detergent composition according to claims 1-3 wherein said detergent composition is substantially free of phosphates.

5. A detergent composition according to claims 1-4 wherein said detergent composition is substantially free of soluble silicates.

6. A detergent composition according to claims 1-5 wherein said detergent composition is substantially free of polycarboxylates.

7. A detergent composition according to claims 1-6 further characterized by from 0.01% to 5% of potassium salts.

8. A detergent composition according to claims 1-7 wherein said crystalline calcium carbonate has a surface area of from 0.1 mr/g to 4 m^/g.

9. A method of removing calcium hardness ions from an aqueous solution characterized by the step of dispersing a builder mixture of aluminosilicate and crystalline calcium carbonate substantially having a rhombohedral crystalline structure with { 1,0,-1, 1 } crystallographic indices into said aqueous solution, said calcium hardness ions crystallizing on said crystalline calcium carbonate resulting in the removal of said calcium hardness ions from said aqueous solution.

10. A method for laundering soiled fabrics characterized by the step of contacting said soiled fabrics with an aqueous solution containing an effective amount of a detergent composition according to claim 1.