WO1997033966A1

WO1997033966A1 - Compaction/crushing process for making a crystalline builder material

Info

Publication number: WO1997033966A1
Application number: PCT/US1997/003208
Authority: WO
Inventors: Eugene Joseph Pancheri; Frank Andrej Kvietok; Robert Henry Rohrbaugh; Rose Marie Weitzel
Original assignee: The Procter & Gamble Company
Priority date: 1996-03-13
Filing date: 1997-02-28
Publication date: 1997-09-18
Also published as: AR009942A1

Abstract

A process for making a builder material suitable for use in detergent compositions is provided. The process is a compaction or crushing process including the steps of mixing an encapsulating material with a crystalline material having crystalline microstructures containing carbonate, calcium and at least one water-soluble cation, and thereafter, subjecting the mixture to a compaction or crushing step. The process may be employed to produce builder material 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.

Description

COMPACTION/CRUSHING PROCESS FOR MAKING A CRYSTALLINE BUILDER MATERIAL

FIELD OF THE INVENTION

The invention is directed to a compaction or crushing process for producing an inexpensive builder material with improved performance for use in detergent compositions. More particularly, the invention provides a compaction or crushing process for making a detergent composition by mixing an encapsulating material with a crystalline material having crystalline microstructures containing carbonate, calcium and at least one water-soluble cation, and thereafter, subjecting the mixture to a compaction or crushing step. The process may be employed to produce builder material 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 and render certain soils more difficult to remove. For example, detergent compositions typically contain an anionic surfactant and a builder to reduce die 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. finely divided calcite has been the most popular.

However, the inclusion of calcite in detergent compositions is problematic because of the sensitivity of the hardness cation/salt anion (e.g. calcium/carbonate) reaction product to poisoning by materials (e.g. polyacrylate) 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 reduced to a very small particle size (in order to have a larger surface area which is harder to poison) rendering it dusty and difficult to handle. 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 a process for making an improved 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. Therefore, it would be desirable to have a process for making 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 a process for making a builder material that exhibits improved performance and is less expensive than previous builders. There is also a need for such a process which renders the builder less susceptible to poisoning problem associated with ingredients such as anionic surfactants that are commonly used in detergent compositions. Also, there remains a need for such a process which produces a builder which is easy to handle, process and disperse in washing solutions.

BACKGROUND ART

The following references are directed to builders for cleaning 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): Gamer-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); Sagei et al U.S. Patent 3,932.316 (Procter & Gamble); Lobunez et al, U.S. Patent 3.981.686 (Intermountain Research and Development Corp.); and Mallow et al, U.S. Patent 4,828,620 (Southwest Research Institute).

The following references relate to crystalline minerals: Friedman et al, "Economic Implications of the Deuterium Anomaly in the Brine and salts in Searles Lake. California," Scientific Communications 0361 -0128/82/32. pp 694-699. Bischoff et al. "Gaylussite Formation at Mono Lake. California." Geochtmica et Cosmochimtca Ada Vol 55, ( 1991 ) pp 1743- 1 747, Bischoff "Catalvsis. Inhibition, and The Calcite-Aragonite Problem. " American Journal of Science. Vol 266. February 1968, pp 65-90, Aspden. "The Composition of Solid Inclusions and the Occurrence of Shortite in Apatites from the Tororo Carbonatite Complex of Eastern Uganda." Mineralogtcal Magazine. June 1981 , Vol 44, pp 201 -4 : Plummer and Busenberg, "The

Solubilities of Calcite. Aragonite and Vateπte in CO₂-H₂O Solutions Between 0 and 90ºC and an Evaluation of the Aqueous Model for the System CaCO₃-CO₂-H₂O." Geochtmica et Cosmochimtca Act a Vol 46, pp 101 1- 1040. Milton and Axelrod. "Fused Wood-ash Stones Fairchildite (n. sp. ) K₂CO₃ CaCO₃, Buetschliite (n sp ) 3K₂CO₃ 2CaCO₃ 6H₂O and Calcite, CaCO₃. Their Essential Components," U. S. Geological Survey, pp 607-22. Evans and Milton, "Crystallography of the Heating Products of Gaylussite and Pirssomte." Abstracts of AC A Sessions on Mineralogtcal Crystallography, pp 1 104: Johnson and Robb, "Gaylussite: Thermal Properties by Simultaneous Thermal Analysis." American Mineralogist Vol 58, pp 778-784, 1973, Cooper. Gittins and Tuttle, "The System Na₂CO₃-K₂CO₃-CaCO₃ at 1 Kilobar and its Significance in Carbonatite Petrogenesis," American Journal of Science, Vol.275, May. 1975, pp 534-560: Smith. Johnson and Robb, "Thermal Synthesis of Sodium Calcium Carbonate-A Potential Thermal Analysis Standard," humica Acta, pp. 305-12. Fahey, "Shortite. a New

Carbonate of Sodium and Calcium," U S Geological Survey, pp 514-518.

The following reference relates to starches/sugars: F. Hemainz Bermudez de Castro, et al, International Journal of Mineral Processing, Vol 37, 1993, pp.283-298.

SUMMARY OF THE INVENTION

The needs in the art described above are satisfied by the present invention which provides a convenient process for making builder material which has substantially improved performance and is significantly less expensive than previous builders. The builder material has improved performance in that it unexpectedly has a high calcium ion exchange capacity and rate, and is easy to handle, process and disperse in washing solutions. Moreover, the builder material is less susceptible to the poisoning problem associated with anionic surfactants, such as linear alkylbenzene sulfonates ("LAS") In its broadest aspect, the invention is directed to a compaction or crushing process involving mixing an encapsulating material, such as a carbohydrate, with a builder material having at least one crystalline microstructure including a carbonate anion, calcium cation and at least one water-soluble cation, and thereafter, compacting or crushing the mixture into the improved builder material. The microstructure should have a sufficient number of anions and cations so as to be "balanced" or "neutral" in charge. As used herein, the term "agglomerates" refers to particles formed of the starting ingredients (liquid and/or particles) which typically have a smaller median particle size than the formed agglomerates. As used herein, the term "enrobed" means that the encapsulating material substantially covers the crystalline material or the crystalline material is substantially embedded in the encapsulating material regardless of the overall shape of the materials together, e.g. agglomerates, extrudate or particles. As used herein, the phrase "glass phase" or "glassy" materials refers to microscopically amorphous solid materials having a glass transition phase. T_g. As used herein, the phrase "continuous phase" refers to a single fused mass of individual or discrete particles. As used herein, the phrase "median particle size" means the "mean" particle size in that about 50% of the particles are larger and about 50% are smaller than this particle size as measured by standard sieve analysis.

As used herein, the phrase "crystalline microstructure" means a crystal form of molecules having a size ranging from a molecular-size structure to larger combinations or aggregations of molecular-size crystal structures. The crystal m icrostructure can be uniformly layered, randomly layered or not layered at all. All percentages, ratios and proportions used herein are by weight, unless otherwise specified. All documents including patents and publications cited herein are incorporated herein by reference.

In accordance with one aspect of the invention, a compaction process for making a builder material is provided. The process comprises the steps of: (a) inputting an encapsulating material and a crystalline material including a crystalline microstructure in which a carbonate anion. a calcium cation and at least one water-soluble cation are contained into a mixer to form a mixture therein: (b) compacting the mixture of the crystalline material and the encapsulating material so as to form agglomerates containing the crystalline material enrobed with the encapsulating material; and (c) grinding the agglomerates into particles, thereby forming the builder material.

In another aspect of the invention, a crushing process for producing a builder material is provided. The process comprises the steps of: (a) inputting an encapsulating material and a crystalline material including a crystalline microstructure in which a carbonate anion, a calcium cation and at least one water-soluble cation are contained into a mixer to form a mixture therein; (b) crushing the mixture of the crystalline material and the encapsulating material so as to form agglomerates containing the crystalline material enrobed with the encapsulating material; and (c) grinding the agglomerates into particles, thereby forming the builder material.

In still another aspect of the invention, a highly preferred process is provided. A process for producing a builder material comprising the steps of: (a) inputting a solid carbohydrate material and crystalline material into a mixer to form a mixture; (b) compacting or crushing the mixture of the crystalline material and the carbohydrate material so as to form agglomerates containing the crystalline material enrobed with the carbohydrate material, (c) grinding the agglomerates into particles, (d) separating the particles into undersized particles and oversized particles, wherein the undersized particles have a median particle size of less than about 150 microns and the oversized particles have a median particle size of at least about 1 100 microns, and (e) recycling the undersized particles and the oversized particles back to the compacting or crushing step.

Accordingly, it is an object of the invention to provide a process for making a builder material that exhibits improved performance and is less expensive than previous builders It is also an object of the invention to provide such a process which renders the builder less susceptible to poisoning problem associated with ingredients such as anionic surfactants that are commonly used in detergent compositions. Also, it is an object of the invention to provide for such a process which produces a builder which is easy to handle, process and disperse 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, drawing and the appended claims.

BRIEF DESCRIPTION OF THE DRAWING

Fig 1 is a schematic flow diagram of an embodiment of the process in which the undersized particle recycling step is completed by feeding the undersized particles back to the compacting or crushing step while the oversized particles are fed back to the grinding step

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Process

The process of the invention unexpectedly provides a means by which a builder material suitable for use in detergent compositions can be prepared. By using this process, the builder material produced is less susceptible to "poisoning" that occurs from ingredients such as anionic surfactants, especially LAS. during cleaning operations. Additionally, the process unexpectedly prevents the crystalline material used in the builder from degradation during processing.

Turning now to Fig 1 which provides a schematic flow diagram of one embodiment of the process 10. the first step of the process 10 involves inputting an encapsulating material 12. preferably a glassy carbohydrate material, to a mixer 13 which can take the form of any known mixing apparatus such as a Lόdige KM Ploughshare mixer commercially available from Lodige The encapsulating material 12 is preferably a carbohydrate material that can be in the crystalline or glassy amorphous phase with the glass phase being most preferred Also, crystalline material 14 as described hereinafter in detail is fed to the mixing apparatus 13 to form a mixture 15 of the crystalline material 14 and the encapsulating material 12. The input weight ratio of the crystalline material 14 to the encapsulating material 12 is preferably from about 1 :20 to about 10: 1. more preferably from about 1 :5 to about 5: 1. and most preferably from about 1 : 1 to about 3: 1. Additionally, it is preferred that the median particle size of the encapsulating material 12 is from about 5 microns to about 1000 microns, more preferably from about 25 microns to about 750 microns, and most preferably from about 50 microns to about 500 microns. It has been found that preheating the encapsulating material 12 renders the process more efficient. As regards the crystalline material 14. the preferred median particle size is from about 0.1 microns to about 50 microns, more preferably from about 0.3 microns to about 25 microns, even more preferably from about 0.5 microns to about 18 microns, and most preferably from about 0.7 microns to about 10 microns.

The mixture 15 is then fed to a compacting or crushing apparatus 16 which includes a Fitzpatrick Chilsonater commercially available from the Fitzpatrick Company, a Carver press. mortar and pestle combination or similar types of apparatus. In this step, the crystalline material 14 and the encapsulating material 12 are subjected to relatively high pressure compaction or crushing to form agglomerates 18, wherein the pressure in the compactor 16 is preferably from about 2 atmospheres to about 10.000 atmospheres, more preferably from about 10 atmospheres to about 5000 atmospheres, and most preferably from about 20 atmospheres to about 1000 atmospheres. Alternatively, a high pressure crushing operation can occur in place of the aforementioned compaction or crushing step to produce cmshed particles.

Preferably, the median residence time of the crystalline material 14 and the

encapsulating material 12 in the compacting crushing apparatus 16 is from about 0.01 seconds to about 300 seconds, more preferably from about 0.05 seconds to about 120 seconds, and most preferably from about 0.1 second to about 5 seconds. The temperature during compaction or crushing is preferably in the range from 0°C to about 150°C.

The agglomerates 18 or cmshed particles are then subjected to grinding apparatus 20 which can be completed in any known grinding apparatus such as a hammer mill. The resulting particles 22 are screened in screening apparatus 24 to provide particles 30 having a median particle size in a range from about 20 microns to about 2000 microns, more preferably from about 100 microns to about 1400 microns, and more preferably from about 150 microns to about 1 100 microns.

Optionally, the process further comprises the step of screening or separating the particles 22 into undersized or "fines" 28 and oversized or "overs" 26 particles, wherein the undersized particles 28 have a median particle size of less than about 150 microns and the oversized particles 26 have a median particle size of at least 1 100 microns. In this regard, the

aforementioned undersized particles 28 are recycled back to compacting or crushing apparatus 16. while the oversized particles are sent back to the grinding apparatus 20. Past conventional wisdom by the skilled artisan would have recycled the oversized particles 30 and undersized particles 32 back to the mixer 13. However, the recycle steps described herein do not follow this scheme, but rather, recycle back to the compacting or crushing apparatus 16 and/or grinding step 20 as appropriate. Optionally, the oversized particles 26 may be recycled back to the compacting or crushing apparatus 16. although this is not shown in Fig. 1.

Optionally, one or more processing aids or lubricants can be added to the compacting or crushing apparatus 16 or at some other point in the process 10 so as to enhance the formation of agglomerates 18. By way of example, processing aids include magnesium stearate. talc

(magnesium silicate), liquid paraffin, stearic acid, boric acid, calcium stearate. sodium stearate, soap powder, graphite, paraffin wax and polyethylene glycols.

Encapsulating Material

The process includes an encapsulating material which preferably is a carbohydrate material derived from one or more at least partially water-soluble hydroxylic compounds.

wherein at least one of said hydroxylic compounds has an anhydrous, nonplasticized, glass transition temperature. Tg . of about 0°C or higher, most preferably from about 40 °C to about 200 °C. Further the carbohydrate material has a hygroscopic ity value of less than about 80%. The encapsulating materials useful herein are preferably selected from the following.

1. Carbohydrates, which can be any or mixture of: i) Simple sugars (or

monosaccharides): ii) Oligosaccharides (defined as carbohydrate chains consisting of 2- 10 monosaccharide molecules); iii) Polysaccharides (defined as carbohydrate chains consisting of at least 35 monosaccharide molecules): and iv) Starches. Such sugars as disclosed in U.S.

Patent 4.908,159. Davies et al, issued March 13. 1990 are also acceptable.

Both linear and branched carbohydrate chains may be used. In addition chemically modified starches and poiy-/oligo-saccharides may be used. Typical modifications include the addition of hydrophobic moieties of the form of alkyl, aryl, etc. identical to those found in surfactants to impart some surface activity to these compounds.

In addition, the following classes of materials may be used as an adjunct with the carbohydrate or as a substitute.

2. All natural or synthetic gums such as alginate esters, carrageenin, agar-agar, pectic acid, and natural gums such as gum Arabic, gum tragacanth and gum karaya.

3. Chitin and chitosan.

4. Cellulose and cellulose derivatives. Examples include: i) Cellulose acetate and Cellulose acetate phthalate (CAP); ii) Hydroxypropyl Methyl Cellulose (HPMC); iii)

Carboxymethylcellulose (CMC); iv) all enteric/aquateric coatings and mixtures thereof. 5. Silicates. Phosphates and Borates.

6. Poiyvinyl alcohol (PVA).

7. Polyethylene giycol (PEG).

8. Nonionic surfactants including but not limited to polyhydroxy fatty acid amides. Materials within these classes which are not at least partially water soluble and which have glass transition temperatures, Tg, below the lower limit herein of about 0°C are useful herein only when mixed in such amounts with the hydroxylic compounds useful herein having the required higher Tg such that the particles produced has the required hygroscopic ity value of less than about 80%.

Glass transition temperature, commonly abbreviated "Tg", is a well known and readily determined property for glassy materials. This transition is described as being equivalent to the liquification, upon heating through the Tg region, of a material in the glassy state to one in the liquid state. It is not a phase transition such as melting, vaporization, or sublimation. See William P. Brennan. '"What is a Tg?' A review of the scanning calorimetry of the glass transition". Thermal Analysis Application Study #7, Perkin-Elmer Corporation. March 1973 for further details. Measurement of Tg is readily obtained by using a Differential Scanning Calorimeter.

For purposes of the present invention, the Tg of the hydroxylic compounds is obtained for the anhydrous compound not containing any plasticizer (which will impact the measured Tg value of the hydroxylic compound). Glass transition temperature is also described in detail in P. Peyser. "Glass Transition Temperatures of Polymers", Polymer Handbook, Third Edition, J. Brandrup and E. H. Immergut (Wiley-Interscience: 1989), pp. VI/209 - VI/277.

At least one of the hydroxylic compounds useful in the present process preferably has an anhydrous, nonplasticized Tg of at least 0 °C, and for particles not having a moisture barrier coating, at least about 20 °C, preferably at least about 40 °C. more preferably at least 60 °C, and most preferably at least about 100 °C. It is also preferred that these compounds be low temperature processable, preferably within the range of from about 40 °C to about 200 °C. and more preferably within the range of from about 60 °C to about 160 °C. Preferred such hydroxylic compounds include sucrose, glucose, lactose, and maltodextrin.

The "hygroscopicity value", as used herein, means the level of moisture uptake by the builder material, as measured by the percent increase in weight of the particles under the following test method. The hygroscopicity value required for the builder material is determined by placing 2 grams of particles (approximately 500 micron size particles: not having any moisture barrier coating) in an open container petri dish under conditions of 90 °F and 80% relative humidity for a period of 4 weeks. The percent increase in weight of the particles at the end of this time is the particles hygroscopicity value as used herein Preferred particles have hygroscopicity value of less than about 50%, more preferably less than about 10%.

The weight ratio of the encapsulating material to crystalline material in the builder material produced by the process described herein is from about 4 : 1 to about 1 : 99, preferably from about 2:1 to about 1 : 50. more preferably from about 1 : 1 to about 1 : 30. and most preferably from about 1 : 2 to about 1: 20.

Crystalline Material

The crystalline material that is used in the process described herein is "crystalline" in that it includes a crystalline microstructure of a carbonate anion. calcium cation and a water- soluble cation. This crystalline materials itself has "builder activity" in that it has the ability to sequester hardness from aqueous cleaning solutions It should be understood that the crystalline material may be comprised of multiple crystalline microstructures or be entirely comprised of such microstructures. Also, each crystalline microstmcture can include multiple carbonate anions. calcium cations and water-soluble cations, examples of which are presented hereinafter The builder material in the process invention preferably include an effective amount of the crystalline material. By "effective amount" as used herein, it is meant that the level of the crystalline material in the composition is sufficient to sequester an adequate amount of hardness in the washing solution such that the active cleaning ingredient is not overly inhibited. The actual amount will vary widely depending amount the particular application of the cleaning or detergent composition. However, typical amounts are from about 2% to about 80%, more typically from about 4% to about 60%, and most typically from about 6% to about 40%, by weight of the cleaning composition.

The "crystalline" nature of the crystalline 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 K_alpha 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 crystalline materials include, but are not limited to, the following numbers 21 -0343, 21 - 1287 21-1348. 22-0476, 24- 1065, 25-0626, 25-0627, 25-0804, 27-0091 , 28-0256, 29- 1445, 33- 1221 , 40-0473. and 41-1440.

As mentioned previously, a preferred embodiment of the crystalline material envisions having the crystalline microstmcture with the following general formula (M_x)_i Ca_y (CO₃)_z

wherein x and i are integers from 1 to 15, y is an integer from 1 to 10, z is an integer from 2 to 25, M_i include various cations, at least one of which is a water-soluble cation, and the equation Σ i = 1-15(x_i multiplied by the valence of M_i) + 2y = 2z is satisfied such that the formula has a neutral or "balanced" charge. Of course, if anions other than carbonate are present, their particular charge or valence effects would be added to the right side of the above-referenced equation.

Preferably, the water-soluble cation is selected from the group consisting of water- soluble metals, hydrogen, boron, ammonium, silicon, tellurium and mixtures thereof. More preferably, the water-soluble cation is selected from the group consisting of Group I A elements (Periodic Table). Group IIA elements (Periodic Table). Group IIIB elements (Periodic Table), ammonium, lead, bismuth, tellurium and mixtures thereof Even more preferably, the water- soluble cation is selected from the group consisting of sodium, potassium, hydrogen, lithium ammonium and mixtures thereof The most preferred are sodium and potassium, wherein sodium is the very most preferred In addition to the carbonate anion in the crystalline microstmcture of the crystalline material described herein, one or more additional anions may be incorporated into the crystalline microstmcture so long as the overall charge is balanced or neutral. By way of a nonlimitmg example, anions selected from the group consisting of chloride, sulfate. fluoride, oxygen, hydroxide, silicon dioxide, chromate. nitrate, borate and mixtures thereof can be used in the crystalline material Those skilled in the art should appreciate that additional water-soluble cations, anions and combinations thereof beyond those of which have been described herein can be used in the crystalline microstructure of the crystalline material without departing from the scope of the invention It should be understood that waters of hydration may be present im the aforementioned components.

Particularly preferred materials which can be used as the crystalline microstructures in the crystalline material are selected from the group consisting of Na₂Ca(CO₃)₂, K₂Ca(CO₃)₂- Na₂Ca₂(CO₃)₃, NaKCa(CO₃)₂, NaKCa₂(CO₃)₃, K₂Ca₂(CO₃)₃, and combinations thereof An especially preferred material for the builder described herein is Na₂Ca(CO₃)₂ Other suitable materials for use in the crystalline material include any one or combination of

Afghanite. (Na.Ca,K)₈(Si,Al)₁₂O₂₄(SO₄,Cl,CO₃)₃•(H₂O);

Andersonite. Na₂Ca(UO₂)(CO₃)₃•6(H₂O);

Ashcroftin eY. K₅Na₅(Y,Ca)₁₂Si₂₈O₇₀(OH)₂(CO₃)₈•n(H₂O), wherein n is 3 or 8;

Beyeπte, (Ca.Pb)Bi₂(CO₃)₂O₂;

Borcaπte. Ca₄MgB₄O₆(OH)₆(CO₃)₂;

Burbankite, (Na.Ca)₃(Sr,Ba.Ce)₃(CO₃)5; Butschliite, K₂Ca(CO₃)₂;

Cancrinite, Na₆Ca₂Al₆Si₆O₂₄(CO₃)₂:

Carbocemaite, (Ca,Na)(Sr,Ce,Ba)(CO₃)₂;

Carletonite, KNa₄Ca₄Si₈O_{1 8}(CO₃)₄(OH,F)•(H ₂O);

Davyne, (Na,Ca,K)₈AI₆Si₆O₂₄(Cl,SO₄,CO₃)_2-3;

Donnayite Y, Sr₃NaCaY(CO₃ )₆•3(H₂O);

Fairchildite, K₂Ca(CO₃)₂;

Ferrisurite, (Pb,Ca)₃(CO₃)₂(OH,F)(Fe,Al)₂Si₄O_{1 0}(OH)₂•n(H₂O), wherein n is an integer from

1 to 20;

Franzinite, (Na,Ca)₇(Si,AI)_{1 2}O₂₄(SO₄,CO₃,OH,Cl)₃•(H₂O);

Gaudefroyite, Ca₄Mn₃(BO₃)₃(CO₃)(O,OH)₃;

Gaylussite, Na₂Ca(CO₃ )₂•5(H₂O);

Girvasite, NaCa₂Mg₃(PO₄)₂[PO₂(OH)₂](CO₃(OH)₂•4(H₂O);

Gregoryite, NaKCa(CO₃)₂;

Jouravskite, Ca₆Mn₂(SO₄-CO₃)₄(OH)_{1 2}•n(H₂O), wherein n is 24 or 26;

KamphaugiteY, CaY(CO₃ )₂(OH)•(H₂O);

Kettnerite. CaBi(CO₃)OF or CaBi(CO₃)F;

Khanneshite, (Na,Ca)₃(Ba,Sr,Ce,Ca)₃(CO₃)₅;

LepersonniteGd, Ca(Gd,Dy)₂(UO₂)₂₄(CO₃)₈(Si₄O_{1 2})O_{1 6}•60(H₂O);

Liottite, (Ca,Na,K)₈(Si,Al)₁₂O₂₄(SO₄,CO₃,Cl,OH)₄•n(H₂O), wherein n is 1 or 2;

MckelveyiteY, Ba₃Na(Ca,U)Y(CO₃)₆•3(H₂O);

Microsommite, (Na,Ca,K)_7-8(Si,Al)₁₂O₂₄(Cl,SO₄,CO₃)_{2- 3};

Mroseite, CaTe(CO₃)O₂;

Natrofairchildite, Na₂Ca(CO₃)₂;

Nyerereite, Na₂Ca(CO₃)₂;

RemonditeCe, Na₃(Ce,La,Ca,Na,Sr)₃(CO₃)₅;

Sacrofanite, (Na,Ca,K)₉(Si,AI)₁₂O₂₄[(OH)₂,SO₄,CO₃,Cl₂]_x•n(H₂O), wherein x is 3 or 4 and n is an integer from 1 to 20;

Schrockingerite, NaCa₃(UO₂)(CO₃)₃(SO₄)F•10(H₂O);

Shortite, Na₂Ca₂(CO₃)₃;

Surite, Pb(Pb,Ca)(Al,Fe,Mg)₂(Si,Al)₄O_{1 0}(OH)₂(CO₃)₂;

Tunisite, NaCa_nAl₄(CO₃)₄(OH)₈Cl, wherein n is 1 or 2;

Tuscanite, K(Ca,Na)₆(Si,AI)_{1 0}O₂₂[SO₄,CO₃,(OH)₂]•(H₂O);

Tyrolite, CaCu₅(AsO₄)₂(CO₃)(OH)₄•6(H₂O);

Vishnevite, (Na,Ca,K)₆(Si,AI)₁₂O₂₄(SO₄,CO₃,Cl₂)_2-4•n(H₂O); and Zemkorite, Na₂Ca(CO₃)₂

As currently contemplated, the crystalline material is preferably made by blending thoroughly the carbonate anions, calcium cations and water-soluble cations in the form of neutral salts and heating the blend at a temperature of from about 350°C to about 700°C for at least 0.5 hours, preferably in a CO₂ atmosphere. After the heating is complete, the resulting crystalline microstructures or material undergoes sufficient grinding and/or crushing operations, either manually or using conventional apparatus, such that the crystalline material is suitably sized for incorporation into the cleaning composition. The actual time, temperature and other conditions of the heating step w ill vary depending upon the particular starting materials selected. By way of example, in a preferred embodiment, equimolar amounts of sodium carbonate (Na₂CO₃) and calcium carbonate (CaCO₃) are blended thoroughly and neated in a CO₂ atmosphere at a temperature of 550°C for about 200 hours and then crushed to achieve the desired crystalline material.

Other exemplary methods of making the crystalline material include: heating Shortite or Na₂Ca₂(CO₃)₃ in a CO₂ atmosphere at a temperature of 500°C for about 180 hours; heating Shortite or Na₂Ca₂(CO₃)₃ and sodium carbonate in a CO₂ atmosphere at a temperature of 600°C for about 100 hours: heating calcium oxide (CaO) and NaHCO₃ in a CO₂ atmosphere at a temperature of 450°C for about 250 hours; and adding Ca(OH)₂ or Ca(HCO₃)₂ to a concentrated solution of NaHCO₃ or Na₂CO₃, collecting the precipitate and drying it. It will be appreciated by those skilled in the art that lower and higher temperatures for the aforedescribed methods is possible provided longer heating times are available for the lower temperatures and pressurized CO₂ atmospheres are available for the higher temperatures.

Additionally, use of a rotating or stirred reactor can reduce greatly the required heating or reaction time to obtain the desired crystalline microstmcture crystalline material. The form and/or size of the starting materials can have positive effects on the processing time. By way of example, starting materials having a smaller median particle size can increase the speed of conversion in the absence of precondiditioning steps. In a an exemplary preferred mode, the starting materials are in the form of agglomerates having a median particle size in a range of from about 500 to 25.000 microns, most preferably from about 500 to 1000 microns.

A combination of two or more of the methods described herein can be used to achieve a crystalline material suitable for use in the compositions herein. Another variation of the methods described herein contemplates blending and heating an excess of one of the starting ingredients (e.g. Na₂CO₃) such that the balance of the starting ingredient can be used as an active ingredient in the cleaning composition in which the crystalline material is contained. Additionally, seed crystals of the crystalline material may be used to enhance the speed or time it takes to form the crystalline material from the starting components (e.g. use crystalline Na₂Ca(CO₃)₂ as a seed crystal for heating/reacting Na₂CO₃ and CaCO₃ or especially for the Ca(OH)₂ and NaHCO₃ reaction). Various water-soluble cations can be readily substituted for other water-soluble cations in the methods or processes described herein. For example, sodium (Na) can be wholly or partially substituted with potassium (K) in any of the aforementioned methods of making the crystalline material.

Builder Material

The builder material produced by the process described herein unexpectedly has improved builder performance in that they have a high calcium ion exchange capacity. In that regard, the builder material has a calcium ion exchange capacity, on an anhydrous basis, of from about 100 mg to about 700 mg equivalent of calcium carbonate hardness/gram, more preferably from about 200 mg to about 650 mg. and even more preferably from about 300 mg to about 600 mg. and most preferably from about 350 mg to about 570 mg. equivalent of calcium carbonate hardness per gram of builder. Additionally, the builder material produced unexpectedly has 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. CaCO₃/minute per 200 ppm of the crystalline 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 incorporated herein by reference.

The particle size diameter of the builder material in an aqueous solution is preferably from about 0.1 microns to about 50 microns, more preferably from about 0.3 microns to about 25 microns, even more preferably from about 0.5 microns to about 18 microns, and most preferably from about 0.7 microns to about 10 microns. While the builder material used in the

compositions herein perform unexpectedly superior to prior builders at any particle size diameter, it has been found that optimum performance can be achieved within the

aforementioned particle sized diameter ranges. The phrase "particle size diameter" as used herein means the particle size diameter of a given builder material at its usage concentration in water (after 10 minutes of exposure to this water solution at a temperature of 50F to 130F) 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. Adjunct Builders

One or more auxiliary builders can be used in conjunction with the builder material produced by the process invention herein to further improve the performance of the

compositions into which the builder material is incorporated. For example, the auxiliary builder can be selected from the group consisting of aluminosilicates. crystalline layered silicates. MAP zeolites, citrates, amorphous silicates, polycarboxylates, sodium carbonates and mixtures thereof. Another particularly suitable option is to include amorphous material coupled with the crystalline microstructures in the builder material. In this way. the builder material includes a "blend" of crystalline microstructures and amorphous material or microstructures to give improved builder performance. Other suitable auxiliary builders are described hereinafter.

Optionally, the compositions into which the builder material made by the present process is incorporated can also comprise a detergent aluminosilicate builder which are referenced as aluminosilicate ion exchange materials and sodium carbonate. The

aluminosilicate ion exchange materials used herein as a detergent builder preferably have both a high calcium ion exchange capacity and a high exchange rate. Without intending to be limited by theory, it is believed that such high calcium ion exchange rate and capacity are a function of several interrelated factors which derive from the method by which the aluminosilicate ion exchange material is produced. In that regard, the aluminosilicate ion exchange materials used herein are preferably produced in accordance with Corkill et al, U.S. Patent No. 4.605,509 (Procter & Gamble), the disclosure of which is incorporated herein by reference.

Preferably, the aluminosilicate ion exchange material is in "sodium" form since the potassium and hydrogen forms of the instant aluminosilicate do not exhibit the as high of an exchange rate and capacity as provided by the sodium form. Additionally, the aluminosilicate ion exchange material preferably is in over dried form so as to facilitate production of crisp detergent agglomerates as described herein. The aluminosilicate ion exchange materials used herein preferably have particle size diameters which optimize their effectiveness as detergent builders. The term "particle size diameter" as used herein represents the average particle size diameter of a given aluminosilicate ion exchange material as determined by conventional analytical techniques, such as microscopic determination and scanning electron microscope (SEM). The preferred particle size diameter of the aluminosilicate is from about 0.1 micron to about 10 microns, more preferably from about 0.5 microns to about 9 microns. Most preferably, the particle size diameter is from about 1 microns to about 8 microns.

Preferably, the aluminosilicate ion exchange material has the formula

Na_z[(AlO₂)_z.(SiO₂)_y]xH₂O wherein z and y are integers of at least 6. the molar ratio of z to y is from about 1 to about 5 and x is from about 10 to about 264. More preferably, the aluminosilicate has the formula

Na₁₂[(AlO₂)_{1 2}.(SiO₂)₁₂]xH₂O

wherein x is from about 20 to about 30, preferably about 27. These preferred aluminosilicates are available commercially, for example under designations Zeolite A, Zeolite B and Zeolite X. Alternatively, naturally-occurring or synthetically derived aluminosilicate ion exchange materials suitable for use herein can be made as described in Krummel et al. U.S. Patent No. 3.985.669. the disclosure of which is incorporated herein by reference.

The aluminosilicates used herein are further characterized by their ion exchange capacity which is at least about 200 mg equivalent of CaCO₃ hardness/gram, calculated on an anhydrous basis, and which is preferably in a range from about 300 to 352 mg equivalent of CaCO₃ hardness/gram. Additionally, the instant aluminosilicate ion exchange materials are still further characterized by their calcium ion exchange rate which is at least about 2 grains

Ca⁺⁺/gallon/minute/-gram/gallon, and more preferably in a range from about 2 grains

Ca ^{+ +}/gallon/minute/-gram/gallon to about 6 grains Ca⁺⁺/gallon/minute/-gram/gallon.

Detersive Surfactant

Preferably, the compositions into which the builder material made according to the instant process invention will 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 C _{1 1}-C _{1 8} alkyl benzene sulfonates ("LAS") and primary, branched-cham and random C _{1 0}-C₂₀ alkyl sulfates ("AS"), the C _{1 0}-C _{1 8} secondary (2.3) alkyl sulfates of the formula CH₃(CH₂)_x(CHOSO₃-M⁺) CH₃ and CH₃ (CH₂)_y(CHOSO₃-M⁺) CH₂CH₃ 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 -C_{1 8} alkyl alkoxy sulfates ("AE_XS"; especially EO 1 -7 ethoxy sulfates), C ₁₀ -C _{1 8} alkyl alkoxy carboxylates (especially the EO 1-5 ethoxycarboxylates), the C _{10 - 1 8} glycerol ethers, the C₁₀-C _{1 8} alkyl polyglycosides and their corresponding sulfated polyglycosides, and C ₁₂-C _{1 8} alpha-sulfonated fatty acid esters. If desired, the conventional nonionic and amphoteric surfactants such as the C ₁₂-C_{1 8} alkyl ethoxylates ("AE") including the so-called narrow peaked alkyl ethoxylates and C₆-C ₁₂ alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C ₁₂-C_{1 8} betaines and sulfobetaines ("sultaines"), C₁₀-C _{1 8} amine oxides, and the like, can also be included in the overall compositions. The C_{1 0}-C _{1 8} N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples include the C ₁₂-C _{1 8} N- methylglucamides. See WO 9.206.154. Other sugar-derived surfactants include the N-alkoxy polyhydroxy fatty acid amides, such as C ₀₁ -C _{1 8} N-(3-methoxypropyl) glucamide. The N- propyl through N-hexyl C ₁₂-C _{1 8} glucamides can be used for iow sudsing C ₁₀-C₂₀ conventional soaps may also be used. If high sudsing is desired, the branched-chain C _{1 0}-C_{1 6} 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 C _{1 1} -C_{1 8} alkyl benzene sulfonates ("LAS") are less preferred, although they may be included in the compositions into which the builder is incorporated. in that they may interfere or otherwise act as a poison with respect to the builder material.

Adjunct Detergent Ingredients

The builder material made by the present process can include additional detergent ingredients and/or, any number of additional ingredients when inco rporated in cleaning compositions These adjunct ingredients include other detergency builders, bleaches, bleach activators, suds boosters or suds suppressors, 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 Febmary 3, 1976 to Baskerville, Jr. et al., incoφorated herein by reference.

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

Preferred for use herein are the phosphates, carbonates. C _{1 0- 1 8} fatty acids, polycarboxylates, and mixtures thereof. More preferred are sodium tripolyphosphate, tetrasodium pyrophosphate, citrate, tartrate mono- and di-succinates, and mixtures thereof (see below).

In comparison with amorphous 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 amorphous 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_xO_{2x+ 1 .y}H₂O

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

NaMSi₂O_5.yH₂O

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 incorporated herein by reference.

Specific examples of inorganic phosphate builders are 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- 1 , 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 incorporated herein by reference.

Examples of nonphosphoms, 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, nonphosphoms 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, nitriiotriacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid.

Polymeric polycarboxylate builders are set forth in U.S. Patent 3,308,067, Diehl, issued March 7. 1967, the disclosure of which is incorporated 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 methyiene 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 suitable polycarboxylates for use herein are the polyacetal carboxylates described in U.S. Patent 4, 144,226, issued March 13, 1979 to Cmtchfield et al, and U.S. Patent 4,246,495, issued March 27, 1979 to Cmtchfield et al, both of which are incorporated 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. Particularly preferred 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 incorporated 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 incorporated 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, incorp orated 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 incorporated 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, incorporated 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 incorporated 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 builder material produced by the instant process invention described herein.

1. Add to 750 ml of 35°C distilled water, sufficient water hardness concentrate to produce 171 ppm of CaCO₃;

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 KCl;

5. Add 0.188 gm of Glycine;

6. Stir in 0.15 gm of Na₂CO₃; 7 Adjust pH to 10.0 using 2N HCl 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:

1 1. Analyze all six aliquots for CaCO₃ content via ion selective electrode, titration. quantitative ICP or other appropriate technique;

12. The Sequestration rate in ppm CaCO₃ sequestered per 200 ppm of builder is 171 minus the CaCO₃ concentration at one minute;

13. Amount of sequestration (in ppm CaCO₃ per gram/liter of builder) is 171 minus the

CaCO₃ 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 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.

EXAMPLE II

This example illustrates the compaction or crushing process of the invention. A powdered sucrose having a particle size of 300 microns with a moisture content of less than 5% is mixed together at a ratio of 1 : 1 with Na₂Ca(CO₃)₂. A portion of this mixture, about 0.2 -0.3 grams, of this mixture is then placed in the tablet die. The die was fashioned from three parts, which could be completely disassembled. The anvils, face diameter of 1.4 cm. have highly polished faces. The third part provides for alignment of the two anvils and containment of the sample. The top anvil is then placed into position and the entire assembly is placed between the platen of a hydraulic press capable of delivering 24,000 pounds of applied load. Pressure, 418 atmospheres, is then applied to the tablet die and held for 1 minute. The pressure is released, the die disassembled and the resulting agglomerate is removed from the die and subjected to standard grinding and sieving operations to form particles having a median particle size of 500 microns.

EXAMPLE III

This example also illustrates the compaction or crushing process. A maltodextrin powder, Lodex-10™ (American Maize Co.) having a dextrose equivalent of 10, a particle size of 300 microns and a moisture content of less than 5% is mixed together at a ratio of 1 : 1 with Na₂Ca(CO₃)₂- A portion of this mixture, 0.2 -0.3 grams, of this mixture is then placed in a tablet die. The die is fashioned from three parts, which can be completely disassembled. The anv iIs. face diameter of 1 4 cm. have highly polished faces. The third part provides for alignment of the two anvils and containment of the sample. The top anvil is then placed into position and the entire assembly is placed between the platen of a hydraulic press capable of delivering 24.000 pounds of applied load Pressure, 418 atmospheres, is then applied to the tablet die and held for 1 minute. The pressure is released, the die disassembled and the resulting agglomerate is removed from the die and subjected to standard grinding and sieving operations to form particles having a median particle size of 500 microns.

Hav ing 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

1. A process for producing a builder material characterized by the steps of:

(a) inputting an encapsulating material and a crystalline material including a

crystalline microstmcture in which a carbonate anion, a calcium cation and at least one water-soluble cation are contained into a mixer to form a mixture therein;

(b) compacting said mixture of said crystalline material and said encapsulating material so as to form agglomerates containing said crystalline material enrobed with said encapsulating material; and

(c) grinding said agglomerates into particles, thereby forming said builder material

2. The process of claim 1 wherein the median residence time of said crystalline material and said encapsulating material in said mixer is from 0.01 seconds to 300 seconds.

3 . The process of claims 1-2 wherein the weight ratio of said crystalline material to said encapsulating material in said inputting step is from 1 : 20 to 50 : 1 .

4. The process of claims 1-3 wherein the median particle size of said encapsulating material in said inputting step is from 5 microns to 1000 microns.

5. The process of claims 1-4 wherein the median particle size of said crystalline material in said inputting step is from 0.1 microns to 50 microns .

6. The process of claims 1-5 wherein said encapsulating material in said inputting step is substantially in the glass phase.

7. The process of claims 1-6 further characterized by the step of separating said particles into undersized particles and oversized particles, wherein said undersized particles have a median particle size of less than 150 microns and said oversized particles have a median particle size of at least 1 100 microns.

8. The process of claim 7 further characterized by the steps of recycling said undersized particles back to said compacting step and recycling said oversized particles back to said grinding step.

9. The process of claim 7 further characterized by the steps of recycling said undersized particles and said oversized particles back to said compacting step.

10 . A process for producing a builder material characterized by the steps of:

(a) inputting an encapsulating material and a crystalline material including a

(b) crushing said mixture of said crystalline material and said encapsulating material so as to form agglomerates containing said crystalline material enrobed with said encapsulating material; and

(c) grinding said agglomerates into particles, thereby forming said builder

material .