WO2003040226A1

WO2003040226A1 - Physical methods of dispersing characteristic use particles and compositions thereof

Info

Publication number: WO2003040226A1
Application number: PCT/US2001/046793
Authority: WO
Inventors: Charles A. Cody; Manshi Sui; Youssef-Sadek Awad
Original assignee: Shamrock Technologies, Inc.
Priority date: 2001-11-08
Filing date: 2001-11-08
Publication date: 2003-05-15

Abstract

The present invention provides compositions that are capable of being dispersed in a target medium. The compositions include characteristic use particles entrapped within a physical entrapment phase, wherein the physical entrapment phase is dispersible in the target medium. Accordingly, the compositions of the present invention physically prevent the agglomeration or self-association of the characteristic use particles. Also disclosed are processes for manufacturing compositions that are capable of being dispersed in a target medium.

Description

PHYSICAL METHODS OF DISPERSING CHARACTERISTIC USE PARTICLES AND COMPOSITIONS THEREOF

SPECIFICATION

FIELD OF THE INVENTION The present invention relates to a method of dispersing a characteristic use particle in a target medium. In particular, the present invention relates to the use of a physical entrapment phase to prevent agglomeration of the characteristic use particles.

BACKGROUND OF INVENTION Small characteristic use particles, i.e., having an average diameter of less than about 15μ (microns), have been used in numerous applications to impart certain desirable characteristics to a target medium. Target medium, as used herein, means any liquid, semi-solid or solid medium into which the characteristic use particle is added. Characteristic use particle, as used herein, means a particle of a material that confers a desired benefit. For example, small amounts (e.g., about 1 to 2% by weight) of powdered or small particle size polytetrafluoroethylene (PTFE) have been incorporated in a variety of compositions to provide the following favorable and beneficial characteristics: (i) in inks PTFE provides excellent mar and rub resistance characteristics; (ii) in cosmetics PTFE provides a silky feel; (iii) in sunscreens PTFE provides increased UN shielding or SPF (sun protection factor); (iv) in grease and oils PTFE provides superior lubrication; and (v) in coatings and thermoplastics PTFE improves abrasion resistance, chemical resistance, weather resistance, water resistance, and film hardness.

Without wanting to be limited by any one theory, it is believed that these small characteristic use particles are able to impart their desirable characteristics as a result of the unique chemical properties of the materials of which they are comprised. Unfortunately, those same unique chemical properties typically cause the particles to agglomerate or self associate. Additionally, when the characteristic use particles are placed in chemically distinct media, such as a hydrophobic characteristic use particle in a hydrophillic medium, agglomeration or self-association is well known to occur. Characteristic use particles are, therefore, typically difficult to disperse and stabilize. For example, it is well known that PTFE is very difficult to disperse and stabilize (i.e., suspend) in target fluid systems (e.g., water, oils, solvents, coatings, and inks) and target semi-solid or solid systems (e.g., polymers, plastics, nylon). As a result, special chemical additives referred to as compatibilizing agents (e.g., surfactants, wetting agents, surface treating agents, etc.) are typically employed to assist dispersion and/or suspension of these particles in the target fluid, semi-solid or solid system. In addition to added cost, these compatabilizing agents can cause deleterious effects or alter the performance of the target system in which they are incorporated. In general, the compatiblizing agents are molecules having (i) at least one portion that is a chemical group that strongly associates with, or the surface of, a characteristic use particle and (ii) at least one other portion that is a chemical group that associates with a target medium. They serve, therefore, to chemically alter the surface properties of the characteristic use particle by forming an intermediary phase between the self-associating material and the other chemicals in the target medium, typically through complex chemical interactions, such as covalent bonding, ionic interactions, hydrogen bonding, hydrophillic interactions, hydrophobic interactions, van der Waals interactions and the like. Thus, there is a need to develop new dispersion methods and composition to eliminate the need for these compatibilizing agents that function via these complex chemical interactions.

It is, therefore, an object of the present invention to provide methods and compositions, which disperse self-associating materials in a target medium using less than the typical amounts of compatiblizing agents for the material being dispersed in the target medium. Thus, the instant compositions and methods do not rely solely on chemical interactions in order to prevent agglomeration.

SUMMARY OF THE INVENTION The present invention provides compositions that are capable of being dispersed in a target medium. These compositions include characteristic use particles entrapped within a physical entrapment phase, wherein the physical entrapment phase is dispersible in the target medium. As a result, the compositions of the present invention physically prevent the agglomeration or self-association of the characteristic use particles.

In another embodiment, the present invention provides processes for manufacturing compositions that are capable of being dispersed in a target medium. One process includes the steps of: mixing a precursor with a characteristic use particle in a processing medium in which the physical entrapment phase precursor is dispersible; converting the precursor into a physical entrapment phase which is not dispersible in said processing medium, thereby entrapping the characteristic use particle within the physical entrapment phase; and separating the physical entrapment phase from the processing medium to obtain said composition. The product obtained according from this process is also encompassed by this invention.

In still another embodiment, the present invention provides a method of conferring a desired benefit to a target medium. The method includes the step of adding to a target medium a composition that is capable of being dispersed in the target medium. The composition includes characteristic use particles entrapped within a physical entrapment phase that is dispersible in the target medium, wherein the characteristic use particles confer the desired benefit to the target medium. In still another embodiment, the present invention provides compositions having a target medium, characteristic use particles dispersed within the target medium, and a physical entrapment phase dispersed within the target medium. For compositions with characteristic use particles of two microns or more these compositions have a grind gauge improvement of greater than or equal to 1 unit in comparison to the grind gauge for the composition without the physical entrapment phase. For compositions of less than 2 micron in size the Malvern method may be used to quantitate a decrease of 10% of more, preferably 25% or most preferably 50% in particle size.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages of the present invention will be more fully appreciated from a reading of the detailed description when considered with the accompanying drawings, wherein: Figures 1 A to 1C are illustrations of the phases obtained by mixing characterstic use particles with a precursor in a process medium;

Figures 2 A to 2F are illustrations of the phases obtained when a triggering agent is added to process medium including characteristic use particles and a precursor.

Figures 3 A and 3B are photographs of polyethylene and polyethylene containing organoclay, respectively;

Figures 4A and 4B are photographs of PTFE dispersions in polyethylene; Figures 5 A and 5B are photographs of PTFE dispersions in polyethylene;

Figures 6 A and 6B are photographs of PTFE dispersions in polyethylene;

Figures 7 A and 7B are photographs of PTFE dispersions in mineral oil; Figures 8 A and 8B are photographs of PTFE dispersions in isopropyl alcohol;

Figure 9 is an illustration of the test tube used to determine the settling rate for compositions according to the invention;

Figures 10A and 10B are graphs of the ratio of the settling rate versus the weight percent of organoclay; and

Figures 11A to 1 IE are photographs of TiO₂ dispersions in mineral oil. Figure 12A-B. Malvern results for pure powder submicron PTFE. Pure powder submicron PTFE was mixed with IPA and sonicated for two minutes. IPA was used as a dispersant in Malvern. Figure 12B represents cumulative data. The results indicate that the mean value=0.317 μm and 97.89% of the particle size is under 1 μm.

Figure 13 A-B. Malvern results for 80% PTFE/20% organoclay. The powder was mixed with IPA and sonicated for two minutes. PA was used as a dispersant in Malvern. Figure 13B represents cumulative data. The results indicate that the mean value = 1.642 μm and 72.74%> of the particle size is under 1 μm. Figure 14 A-B. Malvern results for submicron PTFE in IPA. The dispersion was diluted with IPA and sonicated for two minutes. IPA was used as a dispersant in Malvern. Figure 14B represents cumulative data. The results indicate that the mean value = .198 μm and 100% of the particle size is under 1 μm. Figure 15 A-B. Malvern results for submicron PTFE in IPA/Quat.

The dispersion was diluted with IPA and sonicated for two minutes. PA was used as a dispersant in Malvern. Figure 15B represents cumulative data. The results indicate that the mean value = .197 μm and 100%_> of the particle size is under 1 μm.

DETAILED DESCRIPTION OF THE INVENTION It has been surprisingly found that dispersion of particles of a self- associating material in a target medium can be significantly improved if the particles are occluded in a physical entrapment medium, wherein the physical entrapment medium is dispersible, or can be made to be dispersible, in the target medium. The compositions of the present invention, therefore, are able to overcome the need for special compatabilizing agents, which rely solely on chemical interactions to prevent agglomeration in the target medium. The terms "disperse," "dispersible" or "dispersion," as used herein, means that a referenced component is finely divided or scattered within a medium. Preferably, the dispersed component does not phase separate into its own pure phase for at least about 1 hour, more preferably for at least about one day, and most preferably for at least about one week after mixing the dispersible component in a target medium. Furthermore, when phase separation or settling of the dispersed component does occur, the sediment is "soft," which means that the sediment can be readily re-dispersed by gentle agitation, e.g., shaking by hand. Preferably, the compositions of the present invention have substantially less than the typically effective amount of compatabilizing agents for the characteristic use particles in the target medium. The phrase "substantially less than the typically effective amount," as used herein, means that less than about 70%>, preferably less than about 60%>, and more preferably less than about 50%> by weight of the referenced material is present in the composition in comparison to the amount typically used. The term "about," as used herein, means ±10% of the stated value. For example, if the characteristic use material was Dupont PTFE 30, a suspension of PTFE in water with surfactant, the surfactant can also be included when Dupont PTFE 30 is occluded into a physical entrapment phase. The amount of surfactant present in Dupont PTFE 30, however, would be substantially less than the typically effective amount of surfactant sufficient to disperse PTFE in a target medium. Furthermore, compatabilizing agents, which do not disperse the characteristic use particles in the target medium, can be present for any other component in the compositions of the present invention, e.g., a compatibilizing agent for dispersing the physical entrapment phase in the target medium. For example, such compatabilizing agents can be added during the manufacturing process of the characteristic use particle or the physical entrapment phase, or can be used to fine tune the performance of the inventive composition in the target medium.

The compositions of the present invention include characteristic use particles and a physical entrapment phase that physically entraps the characteristic use particles, thereby physically preventing the agglomeration or self-association of the characteristic use particles. The physical entrapment phase is preferably dispersible in the target medium via normal mixing methods known in the art. The compositions of the present invention include from about 1.0% to about 99.0%> by weight, preferably from about 2.5% to about 50% by weight, and more preferably from about 5% to about 25% by weight of a physical entrapment phase; and include from about 99% to about 1.0% by weight, preferably from about 92.5%o to about 50% by weight, and more preferably from about 95% to about 75%> by weight of a characteristic use particle.

Because of the higher particle count for smaller characteristic use particles (less than 2μ) the compositions of the present invention also include from about 1% to 99%), more preferably from about 5%o to about 75%> and most preferably from about 10%> to 60% by weight of the physical entrapment phase, and from about 99%o to 1%, more preferably from about 95% to 25% and most preferably from about 90%) to 40%) by weight of the characteristic use particle. These weight percentages do not include any compatabilizing agents or other ingredients, such as pigments, fillers, resins, etc., that may be present in the composition of the present invention. Typically, the compositions of the present invention are dispersible in the target medium at a concentration of less than about 50%, preferably less than about 20%>, and more preferably less than about 5.0% by weight of the target medium plus the instant composition. The present invention is also directed to a target medium having dispersed therein a physical entrapment phase and one or more types of characteristic use particles. Target medium, as used herein, means any desired liquid or solid medium into which the characteristic use particles can be dispersed. As will be discussed in further detail below, the dispersibility of the physical entrapment phase in the target medium can be readily controlled. Thus, the physical entrapment phase can be tailored to be dispersible in virtually any given hydrophobic or hydrophillic target medium. Hereinafter, hydrophobic can be referenced as "HB" and hydrophillic can be referenced as "HP."

Nonlimiting examples of suitable hydrophobic target media (e.g., less than lgram solubility in 100 grams of water at room temperature) include hydrocarbon-based compositions, such as motor oil, grease, mineral oil; solvents, such as aromatics like toluene and benzene; unsaturated hydrocarbons, such as cyclo- hexane and pentachloroethylene; formamides; acetones of C6 or higher carbon content; alcohols with carbon chain lengths of C5 or higher; resins used as binders, fillers, and film formers; coatings, such as paints, lacquers, and clean coats; inks, such as flexogravure, and heat set; plastics and polymers, such as nylon, polystyrene, polyethylene, polypropylene, polyurethane, terephthalate, polyvinyl chloride, polyglycols, and copolymers and terpolymers having any combination of the monomers thereof chloro, fluor and nitro solvents; and mixtures thereof. Nonlimiting examples of hydrophillic target media (e.g., greater than or equal to lgram solubility in 100 grams of water) include water of neutral, acidic, or basic pH; linear and branched Cl to C4 alcohols; Cl to C4 glycols; organic acids and their alkali metal salts dissolved in water, such as acetic acid, formic acid, propionic acid, and butyric acid; ionic fluids containing water and water soluble electrolytes; Cl to C3 amines; and low molecular weight organic sulfonic acids (both aromatic and aliphatic) and their salts; and mixtures thereof. Characteristic use particles are made of a material that confers a desired benefit to a target medium. Typically, these particles have an average diameter of less than about 15μ (microns) preferably less than about lOμ (microns), and more preferably less than about lμ (microns). Many characteristic use particles have a tendency to agglomerate or self-associate. Accordingly, when dispersed in a target medium, suitable characteristic use particles in the compositions of the present invention (e.g., with a physical entrapment phase) have a Hegman grind gauge improvement of greater than or equal to about 1 unit, preferably greater than or equal to about 1.5 units, more preferably greater than or equal to about 2.0 units, and most preferably greater than or equal to about 2.5 units in comparison to the Hegman grind gauge value of a dispersion of the characteristic use particles in the target medium (e.g., without a physical entrapment phase). Further details regarding the Hegman grind gauge improvement are provided below. For compositions with characteristic use particles of two microns or more these compositions have a grind gauge improvement of greater than or equal to 1 unit in comparison to the grind gauge for the composition without the physical entrapment phase. For compositions of less than 2 micron in size the Malvern method may be used to quantitate a decrease of 10%> or more, preferably 25%> or most preferably 50%> in particle size.

Suitable characteristic use particles include, but are not limited to, polymers having one or more monomers, resins, binders, metal oxides, pigments, extenders, dyes, film forming agents, anticorrosive agents, matting/flattening agents, rheological modifiers, biocides, inorganic fillers, and flow modifiers. Further nonlimiting examples of suitable characteristic use particles include, polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PPE), polyethylene terephthalate (PET), polystyrene, polycarbonate, polymethyl methacrylates, polybutadiene, titanium dioxide (TiO ), magnesium oxide (MgO), zinc oxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃), calcium carbonate (CaCO₃), lead chromate (PbCrO₄), barium sulfate (BaSO₄), molybdate orange, hansa yellow, phthalocyanine blue, phthalocyanine green, carbazole violet, carbon black, rubinine red, talc, china clay, mica, feldspar, and waxes. Preferred characteristic use particles include PTFE, PE, PPE, TiO₂, carbon black, and CaCO₃. The compositions of the present invention also include a physical entrapment phase, which prevents the agglomeration or self-association of the characteristic use particles via a physical mechanism. Although the physical entrapment phase preferably comprises particles that are readily dispersible in the target medium, the physical entrapment phase can also be a continuous phase that is readily dispersible in the target medium, such as a coascervate or gel. Without wanting to be limited by any one theory, it is believed that the physical entrapment particles are of a sufficient numerical advantage to block or otherwise physically prevent agglomeration or self-association of the characteristic use particles. Accordingly, it is preferred to have a number ratio of physical entrapment particles to characteristic use particles of greater than about 10:1, more preferably greater than about greater than about 25: 1, and most preferably greater than about 100: 1

Typically, the physical entrapment phase is obtained by mixing, by any known means or mechanism, a precursor of the physical entrapment phase with the characteristic use particle in a process medium in which the precursor is dispersible or soluble. The mode of incorporation can be mechanical in nature, such as stirring, and also can be any form or method of separating flocculates, agglomerates, or clumps of the particles known to those skilled in the art of disperse systems. Nonlimiting examples include utilizing sonic energy, cavitation, thermal energy, mechanical mixing, compatabilizing agents (e.g., surfactants) for the precursor and the process medium, and solubilization (e.g., sugar or salts in water). Note that the mode of dispersion can include the use of one or more compatibilizing agents, such as surfactants, which function through chemical interactions between the precursor and the process medium. Such compatibilizing agents are distinguished from the compatibilizing agents that are typically used to disperse the characteristic use particles in the target medium.

Once the precursor is well dispersed or dissolved along with the characteristic use particles in the process medium, a triggering mechanism is employed. The triggering mechanism converts the precursor into the physical entrapment phase, so that the physical entrapment phase is no longer dispersible or soluble in the process medium. Without wanting to be limited by any one theory, it is believed that the dispersibility of the precursor is caused to change quickly enough to entrap the characteristic use particles, which were mixed with the precursor in the process medium. The resulting composition (or "composite"), which contains a mixture of the physical entrapment phase and the characteristic use particles, is then separated by any known method, such as filtration, centrifugation, evaporation, etc. The recovered composite is then available for additional processing, such as (i) drying by any known means to remove all or part of the process medium, and (ii) grinding or milling into a powder. Although the recovered composition can contain some of the processing medium, e.g., water, it is preferred to obtain compositions that are substantially free of the process medium, i.e., compositions having less than about 10%), preferably less than about 5%>, and most preferably less than about 2.5% of the processing medium by weight of the recovered composition. Since the physical entrapment phase in the recovered composition is readily dispersible, or can be made readily dispersible in a target medium, it is believed that the characteristic use particles are also dispersed along with the physical entrapment phase in the target medium.

The physical entrapment phase can be formed by any known triggering mechanism to change the dispersibility of the precursor in the process medium, as long as the mechanism provides the following: 1. dispersibility of the precursor in the process medium;

2. a change in dispersibility of the precursor in the process medium, which change in dispersibility can be triggered on demand;

3. the resulting physical entrapment phase physically entraps the characteristic use particles; and 4. the triggered physical entrapment phase can be dispersed, or can be made to be disposed, into a target medium. The triggering mechanism can include changing the reaction conditions (e.g., changing the temperature, pressure, volume, concentration of the precursor, pH, and any combination of thereof), subjecting the dispersed precursor to external stimuli, removing an external stimuli, adding a triggering agent to react with the precursor, and any combination thereof. Examples of useful precursors include, but are not limited to, smectite- type clays (e.g., montmorillonite, bentonite, beidellite, hectorite, saponite, and stevensite) or organic cations, silicates, organic acids, colloidal salts, one reactant species used to form hydrous oxides that is soluble in the process medium (e.g., soluble metal salts), thixotropic agents, and pectin gels, such as Jello. Examples of useful triggering agents include, but are not limited to, organic cations for smectite- type clays or smectite-type clays for organic cations to obtain organoclays; the other reactant of a hydrous oxide to obtain a hydrous oxide by hydrolysis or precipitation with alkali, alkali for water soluble silicates to obtain Si0₂ by precipitation; metal salts for organic acids to obtain organic salts by precipitation; acid or base for acrylic polymers to obtain acrylic polymers by changing pH. Preferred physical entrapment phases obtained by reacting a triggering agent with a precursor include organoclay and hydrous oxide.

Nonlimiting examples of triggering mechanisms include application of or change in light, acoustics, temperature, pressure, volume of solvent, salt concentration, pH, electrolytic concentration, electromagnetic waves (e.g., microwaves, UN, and visible light), hydrophillicity (e.g., HP to HB), hydrophobicity (e.g., HB to HP), solubility (e.g., cause precipitation), electricity, and combinations thereof. As discussed previously, the recovered composite can be further processed, e.g., dried and ground. In one embodiment of the present invention, the recovered composite (e.g., when containing hydrous metal oxides) can be further processed by reacting it with dilute acids or electrolytes to provide peptization, i.e., the formation of a colloidal solution or dispersion. Dilute acid, as used in this particular embodiment, means having a concentration of less than about IN.

Examples of suitable dilute acids include, but are not limited to, inorganic acids, such as sulfuric acid (H₂SO₄), hydrochloric acid (HC1), perchloric acid (HClO₄), and phosphoric acid (H₃PO₄); and organic acids, such as acetic acid (CH₃COOH), formic acid (HCOOH), propionic acid (CH₃CH₂COOH), butyric acid (CH₃CH₂CH₂COOH), chloroacetic acid (CH₂ClCOOH), dichloroacetic acid (CHCl₂COOH), and trichloroacetic acid (CCl₃COOH); and mixtures thereof. Without the benefit of a physical entrapment phase, as shown in Figures 1A to 1C, the characteristic use particle, e.g., white virgin PTFE powder, will agglomerate when mixed in the process medium, e.g., water. While mechanical energy or agitation is applied to overcome the high self-association energy of the PTFE, a highly hydrophillic fine particle size material, such as bentonite clay, can be added as the precursor so that the precursor and the PTFE are well dispersed in the process medium in a high state of division. As a result, individual PTFE particles are separated during agitation and surrounded by many individual hydrophillic clay particles. At this point, if agitation is discontinued, the PTFE particles will phase separate due to the high tendency to self-associate, while the hydrophillic clay particles remain dispersed in the water.

In contrast, in one embodiment of the present invention, as illustrated in Figures 2A - 2F, agitation is continued and a triggering agent (e.g., an organic cation) is added to the well dispersed mixture of precursor and PTFE particles in the process medium. The triggering agent reacts with or causes the precursor to become hydrophobic (e.g., by ion exchange to form an organoclay) and form a hydrophobic physical entrapment phase. As a consequence, the highly dispersed formerly hydrophillic precursor now agglomerates and physically traps the PTFE in the agglomeration process. The order of addition can be varied to some extent as long as the HB characterisitc use particle and the HP precursor are both dispersed before triggering the HP to HB switch of the precursor. For example, the precursor can be either the organic cation or the smectite-type clay. Thus, the HP precursor can be added to water or another processing medium with agitation followed by the HB PTFE. Upon obtaining a good dispersion by agitation or other methods, the triggering agent can be added to change the HP precursor to the HB physical entrapment phase. For example, the triggering agent can be a smectite-type clay for an organic cation precursor, or the triggering agent can be an organic cation for a smectite-type clay precursor. After the HP to HB transition occurs, the resulting coagulate can be recovered, dried and powdered. The PTFE is entrapped within the physical entrapment phase to form a composite composition that can be incorporated into a target medium. The physical entrapment phase is selected so that its chemical characteristics are highly compatible with a target medium into which it can be incorporated. Upon addition to the target medium, the physical entrapment phase can readily disperse to provide a system having large numbers of well dispersed particles. Without wanting to be limited by any one theory, it is believed that individual particles of PTFE are unable to agglomerate because each particle is surrounded by many physical entrapment particles that block reagglomeration. This mechanism of PTFE dispersion is achieved physically, and there is little or no need for chemical compatibilizers, which modify the surface properties of the PTFE particles. This technology can even be incorporated into the synthetic process of many characteristic use particle. For example, PTFE is usually synthesized in water, collected, and then dried. In accordance with the present invention, a hydrophillic precursor can be added to the aqueous system being used to form the PTFE at any step of the synthetic process. The hydrophillic precursor can, therefore, be present during the formation of the PTFE or added when the synthesis is completed. After synthesis of the PTFE is complete, the triggering mechanism can be activated to convert the hydrophillic precursor into a physical entrapment phase. The resulting coagulate can then be collected and dried. This would result in a physically entrapped PTFE composite composition that is ready for use. This newly discovered process and compositions obtain therefrom are not restricted to PTFE but can be applied to any characteristic use material that is not easily dispersible in the desired target medium. Nonlimiting examples of suitable materials that can be used for the characteristic use material have been provided above. For example, paraffin wax particles are difficult to disperse in many systems of application, because paraffin wax particles are chemically incompatible with many chemicals. Once dispersed, they have a tendency to reagglomerate without the use of special chemical compatibilizing agents. The present invention avoids such dispersion and agglomeration difficulties.

In one embodiment, smectite-type clays and in particular bentonite clay can be selected as the HP precursor. Bentonite clay is highly dispersible in water and results in numerous particles with an extremely high surface area. On average, one can approximate a bentonite clay particle in water as having the dimensions of 0J μ in length, 0J μ in width, and 10 A in thickness. This clay also is well known to contain exchangeable cations on its surface, which can be used to trigger the HP to HB transition. When dispersed in water, the surface exchangeable cations, such as Na+, Ca²⁺ and Mg ²⁺, can be exchanged with organic cations, such as quaternary ammonium chlorides ("quats"), to form the well known organoclays. The formation and use of organoclays are described in United States Patent Nos. 5,759,938 issued June 2, 1998 to Cody et al.; 5,735,943 issued April 7, 1998 to Cody et al; 5,725,805 issued March 10, 1998 to Kemnetz et al.; 5,696,292 issued December 9, 1997 to Cody et al.; 5,667,694 issued September 16, 1997 to Cody et al.; and 5,634,969 issued June 3, 1997 to Cody et al.; and 4,664,820 issued May 12, 1987 to Magauran et al.; which are all incorporated herein by reference in their entirety.

Also described in the above-referenced patents are additives which can be employed to assist in organoclay dispersion. Examples of suitable additives include, but are not limited to, polar activators, such as acetone; preactivators, such as 1,6 hexane diol; intercalates, such as organic anions; and mixtures thereof. Such additives are also described in United States Patent Nos. 5,075,033 issued December 24, 1991 to Cody et al.; 4,894,182 issued January 16, 1990 to Cody et al.; and 4,742,098 issued May 3, 1988 to Finlayson et al.; which are all incorporated herein by reference in their entirety.

Organoclays may be prepared by reacting a certain type of clay with an organic cation. Any clay, which can be reacted with one or more organic cations to provide a HP to HB change, can be used in the compositions of the present invention. Preferable clays are smectite-type clays having a cationic exchange capacity of at least about 50 milliequivalents per 100 grams of clay as determined by the well known ammonium acetate method. The smectite-type clays are well known in the art and are available from a variety of sources. The clays can also be converted to the sodium form if they are not already in this form. This can conveniently be done by preparing an aqueous clay slurry and passing the slurry through a bed of cation exchange resin in the sodium form. Alternatively, the clay can be mixed with water and a soluble sodium compound, such as sodium carbonate, sodium hydroxide, etc., and the mixture sheared, such as with a pugmiU or extruder. Conversion of the clay to the sodium form can be undertaken at any point before reaction with the organic cation.

Smectite-type clays prepared synthetically by either a pneumatolytic or, preferably, a hydrothermal synthesis process can also be used to prepare these novel organic clay complexes. Representative of smectite-type clays useful in the present invention include, but are not limited to, the following: Montmorillonite having the general formula [(Al₄._xMg_x)Si₈O₂₀(OH)₄._/F_/]_xR⁺ where 0.55 < x ≤lJ0, f< 4 and R is selected from the group consisting of Na, Li, NH₄, and mixtures thereof;

Bentonite having the general formula

[(Al₄-_xMg_x)(Si₈._yAl_y)O₂₀(OH)₄-_/F_/]_(x+y)R⁺ where 0 < x < 1.10, 0 < y < 1.10, 0.55 <(x+y) ≤I.IO, f < 4 and R is selected from the group consisting of Na, Li, NH₄ and mixtures thereof; Beidellite having the general formula

[(Al_4+y)(Si₈._x-_yAl_x+y)O₂₀(OH)₄-_/F_/]_xR⁺ where 0.55 < x < 1.10, 0 < y < 0.44, f < 4 and R is selected from the group consisting of Na, Li, NH₄ and mixtures thereof; Hectorite having the general formula

[(Mg₆._xLi_x)Si₈O₂₀(OH)₄._/F_/]_xR⁺ where 0.57 < x ≤ lJ5, f< 4 and R is selected from the group consisting of Na, Li, NH₄, and mixtures thereof;

Saponite having the general formula [(Mg₆-_yAl_y)(Si₈-_x-_yAl_x+y)O₂₀(OH)₄._/F_/]_xR⁺ where 0.58 < x < 1J8, 0 < y < 0.66, f < 4 and R is selected from the group consisting of Na, Li, NH , and mixtures thereof; and

Stevensite having the general formula [(Mg₆._x)Si₈O₂₀(OH)₄-_/F_/]_2xR⁺ where 0.28 < x < 0.57, f = 4 and R is selected from the group consisting of Na, Li, NH₄, and mixtures thereof. The preferred clays used in the present invention are bentonite and hectorite, with bentonite being the most preferred. The clays may be synthesized hydrothermally by forming an aqueous reaction mixture in the form of a slurry containing mixed hydrous oxides or hydroxides of the desired metals with or without, as the case may be, sodium (or alternate exchangeable cation or mixture thereof) fluoride in the proportions defined by the above formulas and the preselected values of x, y and f for the particular synthetic smectite desired. The slurry is then placed in an autoclave and heated under autogenous pressure to a temperature within the range of approximately 100° to 325° C, preferably 275° to 300° C, for a sufficient period of time to form the desired product. Formulation times of 3 to 48 hours are typical at 300° C. depending on the particular smectite-type clay being synthesized and the optimum time can readily be determined by pilot trials.

Representative hydrothermal processes for preparing synthetic smectite clays are described in U.S. Pat. Nos. 3,252,757, 3,586,478, 3,666,407, 3,671,190, 3,844,978, 3,844,979, 3,852,405 and 3,855,147, all of which are herein incorporated by reference.

The organic cation which is reacted with the smectite-type clay must have a positive charge localized on a single atom or on a small group of atoms within the compound. The organic cation is preferably an ammonium cation which contains at least one linear or branched, saturated or unsaturated alkyl group having 12 to 22 carbon atoms. The remaining groups of the cation are chosen from (a) linear or branched alkyl groups having 1 to 22 carbon atoms; (b) aralkyl groups which are benzyl and substituted benzyl moieties including fused ring moieties having linear or branched 1 to 22 carbon atoms in the alkyl portion of the structure; (c) aryl groups such as phenyl and substituted phenyl including fused ring aromatic substituents; (d) beta, gamma-unsaturated groups having six or less carbon atoms or hydroxyalkyl groups having two to six carbon atoms; and (e) hydrogen.

The long chain alkyl radicals may be derived from natural occurring oils including various vegetable oils, such as corn oil, coconut oil, soybean oil, cottonseed oil, castor oil and the like, as well as various animal oils or fats such as tallow oil. The alkyl radicals may likewise be petrochemically derived such as from alpha olefins.

Representative examples of useful branched, saturated radicals include 12-methylstearyl and 12-ethylstearyl. Representative examples of useful branched, unsaturated radicals include 12-methyloleyl and 12-ethyloleyl. Representative examples of unbranched saturated radicals include lauryl; stearyl; tridecyl; myristyl (tetradecyl); pentadecyl; hexadecyl; hydrogenated tallow, docosanyl. Representative examples of unbranched, unsaturated and unsubstituted radicals include oleyl, linoleyl, linolenyl, soya and tallow.

Additional examples of aralkyl, that is benzyl and substituted benzyl moieties, would include those materials derived from, e.g., benzyl halides, benzhydryl halides, trityl halides, α-halo-α-phenylalkanes wherein the alkyl chain has from 1 to 22 carbon atoms, such as 1-halo-l-phenylethane, 1 -halo- 1 -phenyl propane, and 1-halo-l-phenyloctadecane; substituted benzyl moieties, such as would be derived from ortho-, meta- and para-chlorobenzyl halides, para-methoxybenzyl halides, ortho-, meta- and para-nitrilobenzyl halides, and ortho-, meta- and para-alkylbenzyl halides wherein the alkyl chain contains from 1 to 22 carbon atoms; and fused ring benzyl-type moieties, such as would be derived from 2-halomethylnaphthalene, 9-halomethylanthracene and 9-halomethylphenanthrene, wherein the halo group would be defined as chloro, bromo, iodo, or any other such group which serves as a leaving group in the nucleophilic attack of the benzyl type moiety such that the nucleophile replaces the leaving group on the benzyl type moiety.

Examples of aryl groups would include phenyl such as in N-alkyl and N,N-dialkyl anilines, wherein the alkyl groups contain between 1 and 22 carbon atoms; ortho-, meta- and para-nitrophenyl, ortho-, meta- and para-alkyl phenyl, wherein the alkyl group contains between 1 and 22 carbon atoms, 2-, 3-, and

4-halophenyl wherein the halo group is defined as chloro, bromo, or iodo, and 2-, 3-, and 4-carboxyphenyl and esters thereof, where the alcohol of the ester is derived from an alkyl alcohol, wherein the alkyl group contains between 1 and 22 carbon atoms, aryl such as a phenol, or aralkyl such as benzyl alcohols; fused ring aryl moieties such as naphthalene, anthracene, and phenanthrene. The β, γ-unsaturated alkyl group may be selected from a wide range of materials. These compounds may be cyclic or acyclic, unsubstituted or substituted with aliphatic radicals containing up to 3 carbon atoms such that the total number of aliphatic carbons in the β, γ-unsaturated radical is 6 or less. The β, γ-unsaturated alkyl radical may be substituted with an aromatic ring that likewise is conjugated with the unsaturation of the β, γ-moiety or the β, γ-radical is substituted with both aliphatic radicals and aromatic rings.

Representative examples of cyclic β, γ-unsaturated alkyl groups include 2-cyclohexenyl and 2-cyclopentenyl. Representative examples of acyclic β, γ-unsaturated alkyl groups containing 6 or less carbon atoms include propargyl; allyl(2-propenyl); crotyl(2-butenyl); 2-pentenyl; 2-hexenyl; 3-methyl-2-butenyl; 3-methyl-2-pentenyl; 2,3-dimethyl-2-butenyl; l,l-dimethyl-2-propenyl; 1,2-dimethyl propenyl; 2,4-pentadienyl; and 2,4-hexadienyl. Representative examples of acyclic-aromatic substituted compounds include cinnamyl(3-phenyl-2-propenyl); 2-phenyl-2-propenyl; and 3-(4-methoxyphenyl)-2-propenyl. Representative examples of aromatic and aliphatic substituted materials include 3-phenyl-2-cyclohexenyl; 3-phenyl-2-cyclopentenyl; l,l-dimethyl-3-phenyl-2-propenyl; l,l,2-trimethyl-3-phenyl-2-propenyl; 2,3-dimethyl-3-phenyl-2-propenyl; 3,3-dimethyl-2-phenyl-2-propenyl; and 3-phenyl-2-butenyl. The hydroxyalkyl group is selected from a hydroxyl substituted aliphatic radical wherein the hydroxyl is not substituted at the carbon adjacent to the positively charged atom, and the group has from 2 to 6 aliphatic carbons. The alkyl group may be substituted with an aromatic ring independently from the 2 to 6 aliphatic carbons. Representative examples include 2-hydroxy ethyl (ethanol); 3-hydroxypropyl; 4-hydroxypentyl; 6-hydroxyhexyl; 2-hydroxypropyl (isopropanol); 2-hydroxybutyl; 2-hydroxypentyl; 2-hydroxyhexyl; 2-hydroxycyclohexyl; 3-hydroxycyclohexyl; 4-hydroxycyclohexyl; 2-hydroxycyclopentyl; 3-hydroxycyclopentyl; 2-methyl-2-hydroxypropyl; 1 , 1 ,2-trimethyl-2-hydroxypropyl; 2-phenyl-2-hydroxyethyl; 3-methyl-2-hydroxybutyl; and 5-hydroxy-2-pentenyl. The organic cation can thus be considered as having at least one of the following formulae: + f¹ Rι R₂ — X — R or

R, — Y- ^■ R<

R₃

wherein X is nitrogen or phosphorus, Y is sulfur, ι is the long chain alkyl group and R₂, R₃ and R are representative of the other possible groups described above.

A preferred organic cation contains at least one linear or branched, saturated or unsaturated alkyl group having 12 to 22 carbon atoms and at least one linear or branched, saturated or unsaturated alkyl group having 1 to 12 carbon atoms. The preferred organic cation may also contain at least one aralkyl group having a linear or branched, saturated or unsaturated alkyl group having 1 to 12 carbons in the alkyl portion. Mixtures of these cations may also be used. Especially preferred organic cations are an ammonium cation where Ri and R₂ are hydrogenated tallow and R₃ and R₄ are methyl or where R_\ is hydrogenated tallow, R₂ is benzyl and R₃ and R are methyl or a mixture thereof such as 90% (equivalents) of the former and 10%> (equivalents) of the latter.

The amount of organic cation reacted with the smectite-type clay depends upon the specific clay and the desired degree of hydrophdbicity. Typically, the amount of cation ranges from about 90 to about 150%), preferably from about 100 to about 130% and most preferably from about 100 to about 116%) of the cation exchange capacity of the clay. Thus, for example, when bentonite is used, the amount of cation reacted with the clay will range from about 85 to about 143 miUiequivalents, preferably from about 95 to about 124 miUiequivalents and most preferably from about 95 to about 110 miUiequivalents per 100 grams of clay, 100%o active basis. As is apparent to those of ordinary skill in the art, the cation exchange ratio of the clay is on the basis of the original clay and is determined by the ammonium acetate method. As is also apparent to those of ordinary skill in the art, other methods to obtain the cation exchange ratio include testing various organic cation to clay ratios and identifying the ratio that provides the desired characteristics, e.g., a maximum amount of organoclay dispersion in a selected target medium or a desired degree of hydrophobicity.

The anion, which will normally accompany the organic cation, is typically one which will not adversely affect the reaction product or the recovery of the same. Such anions may be exemplified by chloride, bromide, iodide, hydroxyl, nitrite and acetate in amounts sufficient to neutralize the organic cation.

The preparation of the organic cationic salt (i.e., the organic cation paired with the anion) can be achieved by techniques well known in the art. For example, when preparing a quaternary ammonium salt, one skilled in the art would prepare a dialkyl secondary amine, for example, by the hydrogenation of nitriles, see U.S. Pat. No. 2,355,356, and then form the methyl dialkyl tertiary amine by reductive alkylation using formaldehyde as a source of the methyl radical. According to procedures set forth in U.S. Pat. Nos. 3,136,819 and 2,775,617, quaternary amine halide may then be formed by adding benzyl chloride or benzyl bromide to the tertiary amine. The contents of these three patents are hereby incorporated by reference. As is well known in the art, the reaction with benzyl chloride or benzyl bromide can be completed by adding a minor amount of methylene chloride to the reaction mixture so that a blend of products which are predominantly benzyl substituted is obtained. This blend may then be used without further separation of components to prepare the organophilic clay. Illustrative of the numerous patents which describe organic cationic salts, their manner of preparation and their use in the preparation of organophilic clays are commonly assigned U.S. Pat. Nos. 2,966,506, 4,081,496, 4,105,578, 4,116,866, 4,208,218, 4,391,637, 4,410,364, 4,412,018, 4,434,075, 4,434,076, 4,450,095 and 4,517,112, the contents of which are incorporated by reference. In a typical organoclay/PTFE composition, virgin PTFE typically would have a density of about 2.2 g/cc. One gram of PTFE occupies a volume of about 4.546 x 10 ^"7 m³ (1 x 10 ^"6 m³ ÷ 2.2). Since a particle of virgin PTFE has an average diameter of about 3μ (3 x 10 ^"6 m), the volume occupied by an average PTFE particle is about 1.414 x. 10 ^"17 m³ (volume = 4/3πr³ = 4/3π(1.5 x 10 ^"6 m)³). Thus one gram of PTFE contains about 3.22 x 10¹⁰ particles (4.546 x 10 ^"7 m³/g ÷ 1.41372 x 10 ^~17 m³/PTFE particle). Furthermore, in a typical organoclay/PTFE composition, the bentonite clay would have a density of about 5 g/cc, and one gram of bentonite clay occupies a volume of about 2.0 x 10 ^" m . Since an average single platelet of bentonite clay has the approximate dimensions of OJμ x OJμ x 10 ^"9 m, the volume occupied by an average single platelet of bentonite clay is about 1.0 x 10^"23 m³ (volume = 1 x w x h = (1.0 x 10 ^"7 m)² x (1.0 x 10 ^"9 m)). Thus, one gram of bentonite clay contains about 2.0 x 10¹⁶ particles (2.0 x 10 ^"7 m³/g ÷ 1.0 x 10^"23 mVs ngle plate).

Thus, for a typical PTFE particle of about 3 μ in diameter and a density of about 2.2 grams per ml, the number of particles present in 1 gram of PTFE powder will be approximately 3.2 x 10¹⁰ particles. In comparison, using the dimensions of a bentonite clay platelet given above and assuming a density of about 5 grams per cc, 1 gram of clay will contain approximately 2 x 10¹ particles. Thus, for a mixture of 1 gram of clay with 1 gram of PTFE particles, there are approximately 625,000 clay particles that can be converted to the HB physical entrapment phase (e.g., as organoclay) per PTFE particle. Accordingly, in a dry coagulate composition (e.g., organoclay and PTFE), each PTFE particle would be physically blocked from self- agglomeration with another PTFE particle as each PTFE particle would be surrounded by approximately 625,000 discrete organoclay particles.

Examination of the surface area relationship between PTFE and the FTP precursor that is switched to a HB physical entrapment phase is equally instructive. Many bentonite clays are known to possess a surface area of several hundred meters squared per gram, wherein the large surface area is maintained for well dispersed organoclay that is obtained from the bentonite clay. In comparison, one gram of PTFE with an average particle diameter of about 3μ will have an approximate surface area of 1 meter squared. Therefore, each square meter of PTFE surface area is surrounded by hydrophobic particles having a surface area of several hundred square meters. Thus, the surface of each discreet PTFE particle would be physically blocked from the surface of another PTFE particle by the organoclay particles, thereby preventing self-association of the PTFE particles. Organoclays based on smectite-type clays are preferred physical entrapment phase, since they are relatively inexpensive and can be readily synthesized in forms that are easily dispersible into numerous hydrophobic target media. Numerous organic cations, such as quaternary ammonium compounds or quats, are commercially available for the HP to HB conversion of the clay, and these quats have distinct chemical moieties that can be tailored to accommodate the chemical properties of a target medium. For example, tallow based quats can be employed for hydrocarbon based systems, whereas quats containing benzyl can be used in target media including aromatic functional groups.

In another embodiment of the present invention, hydrous oxides can be utilized to form a physical entrapment phase that can be dispersed in a hydrophillic target medium. Hydrous oxides can be formed in water by precipitation or hydrolysis of water soluble metal salts, thereby providing a useful mechanism to entrap characteristic use particles. The recovered mixture of hydrous oxide and characteristic use particles ("composition") can then be peptized in water to form a highly dispersed colloidal network surrounding the characteristic use particles. Peptization is the formation of a colloidal dispersion or sol. Colloidal solutions or dispersion are intermediate in character between a true solution and a suspension, wherein the the dispersion has particles in the size range of between about 1 and about 100 mμ. The extremely small colloidal particle size provides a high numerical ratio of physical entrapment phase to characteristic use particles. A wide variety of hydrous oxides and the process of peptizing these hydrous oxides are well known in the art, as described in Weiser, The Colloidal Salts. (McGraw-Hill Book Co., 1928) and Weiser, The Hydrous Oxides, (McGraw-Hill Book Co., 1926), both of which are incorporated herein by reference.

A nonlimiting example of a hydrous oxide is stannic oxide, which is readily formed by the addition of alkali to SnCl₄ or SnBr . Hydrous stannic oxide can then be peptized by dilute mineral acids. Since the target medium is hydrophillic, e.g., water, after the precipitation is triggered the composite can be filtered. While containing water, the composite composition can be added to the target medium and peptized, or the composite composition can be naturally peptized in an acidic target medium. It is not necessary to dry or grind the composition. Other representative examples of hydrous oxides include, but are not limited to, SiO_2j TiO₂ and Al(OH)₃. When dispersed in a target medium, the compositions of the present invention (e.g., characteristic use particles entrapped in a physical entrapment phase) have a Hegman grind gauge improvement of greater than or equal to about 1 unit, preferably about 1.5 units, more preferably greater than or equal to about 2.0 units, and most preferably greater than or equal to about 2.5 units in comparison to the Hegman grind gauge value of a dispersion of the characteristic use particles in the target medium (e.g., without a physical entrapment phase). For the grind gauge values obtained herein, two samples are prepared in the exact same manner (e.g., same materials, apparatus, mixing settings, methods, etc.) except the control sample will include the characteristic use particle alone in the target medium and the test sample will include the characteristic use particles and the physical entrapment phase in the target medium.

The grind gauge test used herein is an adaptation of the Carlstadt Test Method for Fineness of Grind Determination described in ASTM Dl 316-68, which ' was approved in 1968 and re-approved in 1979. Utilizing a Hegman grind gauge, this test assesses the size and the prevalence of the larger or coarser particles and agglomerates, but does not provide information on the average particle size of the powder. A Hegman grind gauge reading of 0 translates to a particle size of about 100 μ; a reading of 1 translates to a particle size of about 85 μ; a reading of 2 translates to a particle size of about 75 μ; a reading of 3 translates to a particle size of about 62 μ; a reading of 4 translates to a particle size of about 50 μ; a reading of 5 translates to a particle size of about 37 μ; a reading of 6 translates to a particle size of about 25 μ; a reading of 7 translates to a particle size of about 17 μ; and a reading of 8 translates to a particle size of less than about 2 μ. The procedure for the grind gauge test is as follows.

A calibrated Hegman production grind gauge with scraper (No. 440C at the bottom of the gauge; No. 5254 on the side of the gauge) is first cleaned with a lint-free rag and appropriate cleaning solution, such as butyl carbitol, PA, or acetone. Approximately 0.2 grams of the test mixture is then placed in both channels of the grind gauge. If the target medium is a solid at room temperature, the test mixture can be heated to a temperature above the melting temperature of the target medium before applying the test mixture onto the grind gauge, and the grind gauge can also be heated to the same temperature. Grasping the scraper in both hands in a nearly vertical position (e.g., the angle between the draw down blade and the surface of the gauge should be between 80 and 90 degrees), the sample is drawn down the gauge using a smooth, steady stroke that should take at least 3 seconds and no longer than 10 seconds. Sufficient pressure is used so that the center and side portions of the gauge are wiped clean.

The reading must be taken on the draw down within 10 to 20 seconds after completion. The grind of the test sample is determined by examining the scratches and/or strays. Scratches are particles larger than the diameter of the film thickness. Strays are scratches that are non-continuous. The grind gauge reading is the point at which three or more scratches and/or strays are present. The procedure is repeated at least twice, and the readings are averaged.

The compositions of the present invention also help to prevent the formation of or decrease the amount of clusters or agglomerates of the characteristic use particles. In other words, the entrapment of the characteristic use particles in the physical entrapment phase can improve the free flowing nature of the characteristic use particles. This desirable result can be directly measured by following two reproducible methodologies to determine the decrease in the amount of clusters and agglomerates provided by the compositions of the present invention: (i) a sieve test and (ii) a particle size analysis.

A sample of the compositions of the present invention, i.e., characteristic use particles entrapped in a physical entrapment phase, has a 1 minute sieve weight %> result of greater than or equal to about 10%>, preferably greater than about 20%), and most preferably greater than about 30%> improvement in comparison to the 1 minute sieve weight %> result of a sample of pure characteristic use particles (i.e., as purchased commercially and without a physical entrapment phase). Similarly, a sample of the compositions of the present invention, i.e., characteristic use particles entrapped in a physical entrapment phase, has an agglomerated particle size decrease of greater than or equal to about 10%o, preferably greater than about 20%, and most preferably greater than about 30% in comparison to the agglomerated particle size results of a sample of pure characteristic use particles. The agglomerated particle size of the samples can be determined on instrumentation, such as a Malvern Mastersizer 2000.

The first methodology performs a sieve test analysis for a fixed amount of a composition sample. The initial step includes making an estimate of the sieve size that would pass about 40%> by weight of a control sample, i.e., a sample of pure characteristic use particles, in a 3 minute run. After thoroughly cleaning the sieve, about 3 to 5 grams of control sample is placed onto the sieve, and both the control sample and the sieve are weighed. The sieve containing the control sample is then placed in a Micron Air Jet Sieve unit (commercially available from Micron Powder Systems of Hosokawa Mircon Company located in Summit, New Jersey) and covered with a plastic lid. The control sample is screened for a period of 180 seconds in manual mode while recording the vacuum pressure. Upon completion, the sieve and the remaining residue is weighed, and the weight percentage that passed through the sieve is calculated.

If the weight percent passing through the sieve exceeds 45%> or is below 35%, the next appropriately sized sieve is selected, and the above steps are repeated for the control sample. Once an appropriate sieve size is found, i.e., a sieve size that allows from about 35%> to about 45%> by weight of the control sample to pass through the sieve, the above steps are repeated using the sample. Additional data can be obtained by recording the weight percent of the test sample passing through the sieve at 1, 2, and 3 minute intervals.

The second methodology includes the use of a computerized Malvern particle size analyzer in which a small amount of the test sample is analyzed, and the results can be compared to a control sample. A Malvern Mastersizer 2000 dry unit, Scirocco 2000 Model #APA 2000, is commercially available from Malvern Instruments Ltd., located in Worchestershire, United Kingdom. Both dry and wet samples can be tested.

For a dry sample, the procedure is as follows. First, both the feed tray and feed chamber are cleaned. Next, from about 2 to about 4 grams of the sample is loaded into the feed tray. After selecting the Dry PTFE SOP (Standard Operating Procedure) and entering the appropriate label or identification information, analysis of the sample is initiated by right-clicking on the START icon. The Dry PTFE SOP is provided in the Table A below. Upon completion of the analysis, a graph representing the particle size distribution data and corresponding volume percent data can be obtained by selecting the RECORDS tab, right-clicking to highlight the desired record, and then selecting the RESULTS ANALYSIS (BU) tab.

Table A. PTFE Dry SOP

For a wet sample (e.g., a target medium containing the composite or target medium containing the control), the procedure is as follows. After selecting the Wet PTFE SOP, a manual measurement is initiated by first selecting the OPTIONS icon. The Wet PTFE SOP is provided below in Table B. After entering the appropriate information (e.g., material under analysis and the target medium in wliich it is dispersed), the liquid sample well is checked to ensure that it is empty. If the sample well is not empty, it can be drained by right-clicking the EMPTY button on the ACCESSORY menu. The empty liquid sample well is then cleaned by filling it with Malvern' s proprietary cleaning solution and initiating a cleaning cycle by right- clicking the CLEAN icon. Next, the proper liquid is selected to flush the Hydro Unit. Using a pipette, the wet sample is slowly transferred into the sample well until the system prompts the user to stop adding more of the sample and initiate analysis. Analysis of the wet sample is initiated by right-clicking the START icon. Upon completion of the analysis, a graph representing the particle size distribution data and corresponding volume percent data can be obtained by selecting the RECORDS tab, right-clicking to highlight the desired record, and then selecting the RESULTS ANALYSIS (BU) tab.

Table B. PTFE Wet SOP

* The dispersant name and its refractive index can be changed for a particular dispersant used. Table C lists the various uses for compositions comprising small particle size PTFE.

TABLE C¹

BENEFITS SOUGHT APPLICATION Film or Coating Auto Topcoat Transparency Optical Fibers

Textile Fibers

UN Packing

Clear UN Protection of Wood

Rub/Scratch Resistance Ink

Ink Jet

Toners

Can Coatings

Auto Topcoat

Thermoplastics

UN Packing

Feel, Texture Textile Fibers Thermoplastics Cosmetics Thin Films

UN Resistance Cosmetics (SPF)

Clear Coat for Wood

Marine Coatings

AutoTopcoat

Textile Fibers (Clothing, Rugs, etc.)

Weather/Chemical Resistance Electronics (Water, Water Vapor) Oxidation Resistance Marine Paint (Antifoullant) Chemical Storage and Reaction Tanks Can Coating (Food) Wood Treatment

Lubrication Auto Motor Oils

Gear Lubricants

Bearings, Shick 50

Bowling Alleys

Thermoplastics (Processing Aid)

Mold Release

Fiber Manufacturing

1 Submicron PTFE powder can be added directly to the system of use, or predispersed into a carrier liquid or fluid and the carrier then added to the system of use. EXAMPLES These examples further describe and demonstrate embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration and are not to be construed as limitations of the present invention, as many variations thereof are possible without departing from the spirit and scope of the invention.

Common Ingredients Unless specified otherwise, the following ingredients were used in the examples.

The Shamrock Technologies data sheet describes SST-4 as an off-white free-flowing PTFE powder, wherein the PTFE particles have an average diameter of 4 microns, a specific gravity of about 2.15, an onset of melting at about 200°C, and a crystalline point of 321°C. SST-3D is a white free-flowing PTFE powder, wherein the PTFE particles have an average diameter of 5 microns, a specific gravity of about 2J5, an onset of melting at about 200°C, and a crystalline point of 321°C.

Common Apparatus Unless specified otherwise, the following instruments were used in the examples.

Example 1. Dispersions of PTFE and PTFE/Organoclay in Organic Solvents 250 ml of hot tap water at ~60°C was placed in a Warring Blender. While mixing at a setting of 6, 10 grams of PTFE (Grade SST 4) was slowly added and mixed for about 5 minutes. Three grams of quat (methyl benzyl dehydrogenated tallow ammonium chloride, sold under the tradename Kemamine BQ-9701C by Witco Corp.) was slowly added to the water/PTFE mixture and mixed for about 5 minutes. Then, 4.23 grams of hectorite clay (commercially available as Bentone MA from Rheox Inc.) was added to the water/PTFE/quat mixture for about 5 minutes. The resulting mixture was transferred to a glass jar and the material floating at the top ("coalgulate") was collected and dried in an oven at 50 °C for 24 hours. After drying, the coagulate composition was ground with a spatula on a glass plate to a powdery consistency.

2.3 grams of the PTFE/organoclay composition was added to 50 grams of toluene in a glass beaker and mixed in a Hamilton Beach model 936-2 (commercially available from Hamilton Beach, Inc. located in Washington, North Carolina) at a Variac setting of 40 for about a minute on a magnetic stirrer. This step was repeated in separate glass beakers, which respectively contained 50 grams of Sunpar LW 120 oil (produced by Exxon Corp.) and 50 grams of Magiesol 47 (produced by Magie Bros. Oil Co.). As a control, 2.3 grams of the same PTFE was added and mixed in the same amount of each solvent above. When these test mixtures were checked under the microscope, the PTFE/organoclay was well dispersed in the toluene, i.e., showed virtually no aggregates. However, the other two PTFE/organoclay test samples showed some aggregates. The pure PTFE test samples showed a significant number of aggregates.

0.25 grams of acetone was added to each test sample having aggregates, i.e., all test samples except for the PTFE/organoclay test sample in toluene. After adding the acetone, each test sample was mixed in the Hamilton Beach for about one minute. When these test mixtures were checked under the microscope, the PTFE was well dispersed in all of the PTFE/organoclay test samples. However, all of the pure PTFE test samples still showed a significant amount of aggregates. The results are summarized in the Table 1.

Table 1. Dispersion of PTFE and PTFE/Organioclay in Organic Solvents

The results of this experiment show that the PTFE/organoclay composition significantly increases the dispersion of PTFE in organic solvents as compared with the dispersion of PTFE alone.

Example 2. Dispersions of PTFE and PTFE/Organoclay in Polyethylene

Preparation of Bentonite Clay Slurry

Solid bentonite clay was dispersed by slowly mixing about 3%> by weight of bentonite in 97%> by weight of water at room temperature. This mixture was mixed for 8 hours in a high-speed mixer to obtain a clay slurry. Without wanting to be limited to any one theory, it is believed that this mixing step helps to separate out the individual platelets of the bentonite clay. After allowing the clay mixture to stand for 24 hours at room temperature, the clay slurry was separated from the waste that settled to the bottom by decanting. A small portion of the clay slurry was then weighed and placed in an oven for 2 hours at 100 °C to evaporate out all of the water. The dried clay was then weighed to determine the solid weight percentage of the clay in the slurry. The solid weight percentage of the clay was about 1.57%» by weight of the clay surry. Preparation of the Organoclay

Organoclay powder was then obtained as follows. A portion of the bentonite clay slurry was weighed, heated to 55 °C, and mixed in a blender at high speed. Using the solid weight percentage of the clay obtained from the procedure above (e.g., 1.57%), a quat to clay solid weight ratio of 0.6:1.0 was selected, and the appropriate amount of quat was added to the clay slurry. After mixing for an additional 5 minutes, the mixture was allowed to stand for about 30 minutes. Thereafter, the coagulate floating at the top was collected, filtered, and washed with water. The resulting solid was dried in an oven at 55°C for 24 hours. The resulting dried solids were ground in a mortar and pestle to obtain a fine powder of organoclay.

Preparation of PTFE/Organoclay Powder Samples

A portion of the clay slurry was placed in a beaker and weighed. The clay slurry was heated to 55 °C while mixing with a magnetic stirrer bar. The heated clay slurry was divided into three equal portions and transferred into three blenders. PTFE (commercially available as SST 3D from Shamrock Technologies, Inc.) was then slowly added while mixing at high speed to each blender according to the proportions provided in Table 2 and using the solid weight percentage of the clay obtained from the previous step. Table 2. Formulation of PTFE/Organoclay powder

* % of total weight of physical entrapment phase and characteristic use particles

After mixing for five additional minutes, quat was added to each blender according to the weight percentages provided in Table 2. After mixing for an additional 5 minutes, the mixture was allowed to stand for about 30 minutes. Thereafter, the coagulate floating at the top of each blender was collected, filtered, and washed with water. The resulting composite compositions (i.e., Samples I-III) were dried in an oven at 55 °C for 24 hours. The resulting dry composite compositions were ground in a mortar and pestle to obtain a fine powder mixture of organoclay and PTFE.

Preparation of PTFE Dispersions in Polyethylene

PTFE dispersions in powdered polyethylene (PE S394-N1 commercially available from Shamrock Technologies) were prepared by adding the respective components, as provided in Table 3, in a glass bottle and mixing the dry components by shaking for about 3 minutes. The resulting dry powder mixtures were placed in a metal panel, which was placed on a hot plate. The panel was heated enough to melt the polyethylene, and a spatula was used to mix the molten polyethylene using a backward and forward motion for 15 times (one time constituted one backward and one forward motion). A drop of the hot polyethylene mixture was placed on a hot glass slide. A glass cover was placed on top of the glass slide to make a thin film, and the thin film was inspected under the microscope. The resulting observations are provided in Table 3.

^a 5 grams of PTFE/Organoclay Sample I from Table 2 was used. ^b 5 grams of PTFE/Organoclay Sample II from Table 2 was used. ^c 5 grams of PTFE/Organoclay Sample im from Table 2 was used.

These results show that organoclay significantly improves the dispersion of PTFE in polyethylene.

Example 3. Dispersions of PTFE and PTFE/Organoclay in Mineral Oil

Preparation of Clay Slurry

The clay slurry was prepared as described in Example 2. However, samples of this clay slurry was centrifuged for various time periods (from 1 minute to 9 minutes) to determine the time needed to remove most of the large, undissolved foreign particles, as observed under a microscope. The optimum time was determined to be about 5 minutes, and the entire clay sample was centrifuged for about 5 minutes. The solid weight percent of the bentonite clay slurry was then determined as described in Example 2.

Preparation of the Organoclay/PTFE

In order to determine the appropriate amount of quat needed to react with the clay, five organoclay/PTFE powder mixtures were obtained according to the different mass proportions provided below in Table 4. Table 4. Formulation of PTFE/Organoclay powder

PTFE SST-3D (commercially available from Shamrock Technologies, Inc.) In each of the above five samples, the clay slurry was placed in a 250 ml beaker and heated on a hot plate to 65 °C. The heated clay slurry was transferred into a 1 liter blender. The PTFE was slowly added and mixed for about 3 minutes with the blender set at speed 1. While the PTFE was being mixed, the quat was dissolved in 120 grams of water at a temperature of 65 °C. The quat solution was then poured into the blender and mixed with the PTFE and clay for about 10 minutes with the blender set at speed 1.

Each organoclay/PTFE mixture was then poured into ajar and allowed to stand for about 1 hour. The organoclay/PTFE agglomerated at the top of liquid mixture and eventually provided a two phase system: the bottom phase was clear water; the top phase was the organoclay/PTFE. The aqueous phase containing the clay slurry has been a brownish-clay color before the quat was added. The top phase agglomerate was separated, filtered, and rinsed with water. Then the composite composition was dried in an oven at 50 °C for 24 hours. Finally the dry composite composition was ground with a spatula on a lab bench for approximately 10 minutes. Table 5. Visual Observations of Samples at Various Quat/clay Ratios

According to the observations provided in the table above, a Quat to clay weight ratio range from about 0.6 to about 1 was found to be effective in converting the clay into organoclay. A Quat to clay weight ratio range from about 0.7 to about 1 was preferred, and a ratio range from about 0.8 to about 1 was more preferred.

Preparation of the PTFE dispersions in Mineral Oil

Mineral oil and acetone were added to six plastic containers according to the proportions provided in Table 6 below. While stirring with a magnetic stirrer, the dried solids were added to the mineral oil/acetone mixture. Table 6. Formulation of PTFE Dispersions in Mineral Oil

Organoclay having Quat/Clay ratio of 0.8/1 from Sample V in Table 4 was used.

The samples were then mixed for a period of about 3 minutes with the stirrer speed setting at 4 on the magnetic plate. The samples were observed under the microscope and the observations were recorded. Thereafter, the samples were then mixed in a Waring blender for a period of about 10 minutes at a speed setting of 1, and were again observed visually and at a magnification of 125x. Finally, the Control Samples, Invention Example 7 and Comparative

Example G were sonicated for a period of about 5 minutes at full intensity in a model UC 100 Sonicator (Vibray Cell), (commercially availably from Sonics Materials Company located in Danbury, Connecticut). These samples were again observed visually and at a magnification of 125x. Invention Example 8 and Comparative Example H were separately mixed and ground using the horizontal mill (4 passes at a RPM of 2600 with 0.8-1.0 mm ceramic beads), which is commercially available as Mini Motormill 100 from Eiger Machinery Inc. These samples were again observed visually and at a magnification of 125x. Table 7. Visual and Microscopic Observations of Mineral Oil Dispersions

The visual observations of the solutions and the microscopic pictures, shown in Figures 7A and 7B, of the samples of Invention Example 8 and Comparative Example H showed that organoclay (OC) helps to disperse PTFE in mineral oil.

Example 4. Dispersion of Polyethylene in Isopropyl Alcohol

Preparation of Clay Slurry.

A clay slurry using bentonite clay was prepared according to Example 3. Preparation of Organoclay/PE and Organoclay/PTFE

Two samples were prepared according to a ratio of 0.75 grams of quat to 1 gram of clay. The clay slurry above was found to have 1.57 % by weight of clay. Bentonite clay contains 3 % by weight of Na and quat contains 7 % by weight of Cl. The proportions for the samples are provided in the Table 8 below. Table 8. Formulation of Organoclay/PE and Organoclay/PTFE

WVP means Diaken F104 white virgin PTFE particles, Shamrock Technology designation Powdertex 53

²PE was S-395N1, which is commercially available from Shamrock Technology and which has an average diameter of 5 microns.

The clay slurry was placed in a 500 ml beaker and heated on a hot plate at a temperature of about 70 °C. The heated clay slurry was transferred into a 1 liter blender. The blender was set at a mixing speed of 1, and PE powder was slowly added and mixed for about 3 minutes. While PE was being mixed in the clay solution, quat was dissolved in 150 grams of hot water at a temperature of about 65 °C. This quat solution was then poured into the blender and mixed with the PE and clay for about 10 minutes. The organoclay/PE mixture ("OC/PE mixture") was then poured into a jar to observe how the OC/PE agglomerated to the top of the jar. After allowing the sample to stand for about 30 minutes, the OC/PE mixture was filtered and the solids of each sample were dried in an oven at 50 °C for about 24 hours. This procedure was repeated for the OC/WVP sample (white virgin PTFE).

Dispersions of these samples in isopropyl alcohol were then prepared according to the proportions provided in the Table 9. Table 9. Formulation of PE Dispersions in IPA

rganoclay weight ratio of 0.75/1 for Quat/Clay ¹ Sample IX from Table 8 was used.

The dried solids (OC/PE) were ground with a spatula on a glass plate for approximately 10 minutes. 0.2 grams of PE and OC/PE were then separately placed in two 15 ml. test tubes. Then 10 ml of isopropyl alcohol (IPA) was added to each test tube. Both samples were shaken by hand for a period of 10 seconds and pictures were taken at a magnification of 125x, as illustrated by Figures 8 A and 8B. The visual and microscopic observations are provided in the Table 10 below. Table 10. Visual and Microscopic Observations of IPA Samples

The visual and microscopic observations reported in Table 10 for of Invention Example 8 and Comparative Example I show that OC/PE disperses well in EPA without any agglomeration, as illustrated by Figure 8 A. In contrast, as shown in Figure 8B, PE does not disperse well in IPA, as evidenced by the large amounts of PE agglomerates.

Samples of the OC/WVP, which were obtained above, and WVP without OC were also analyzed by conducting a rubbing test. The procedure is as follows: approximately 0.5 grams of WVP and OC/WNP were separately placed next to each other on a rubber mouse pad, and an index finger was used to spread out the dry powders on the mouse pad. The OC/WNP spread out very easily, while the WVP particles adhered to each other to form larger balls or aggregates of particles.

Example 5. Grind Gauge and Settling Tests for Dispersions of PTFE in Mineral Oil

Preparation of Clay Slurry.

A clay slurry using bentonite clay was prepared according to Example 3.

Preparation of Organoclay/PTFE Powder

According to a previous experiment in Example 3, it was found that about 0.6 grams of quat is required for 1 gram of clay to effectively convert the bentonite clay into organoclay. Using the 0.6:1 ratio, seven samples having varying organoclay to PTFE ratios were prepared according the proportions provided in Table 11 below, wherein SST-3D PTFE was used.

Table 11. Formulation of OC/PTFE Powder

* No correction was made for weight loss of by product NaCl when organoclay is formed

Using the proportions in the above table, Samples XI-XVII were separately prepared as follows. The clay slurry was placed in a 250 ml. beaker and enough water was added to reach the 200 ml mark, and the sample was then heated to 65 °C. After transferring the heated clay slurry to a 1 liter blender, PTFE was slowly added to the mixture in the blender while mixing at a blender speed setting of 1. While the PTFE/clay mixture was being mixed for about 3 minutes, the appropriate quantity of quat according to the proportions in the above table, was dissolved in 120 grams of hot water at 65 °C. The quat solution was then added to the mixture in the blender and mixed for about 10 minutes at a blender speed setting of 1. The resulting organoclay/PTFE mixture ("OC/PTFE") was then poured into ajar and allowed to sit for about 30 minutes. The OC/PTFE, which agglomerated at the top of the jar, was separated by filtration, and the solids were dried in an oven for about 24 hours at 65 °C. The dried sample was then ground for about 2 minutes in a Bel Art grinding machine.

Preparation of PTFE dispersions in Mineral Oil

Seven PTFE dispersions in mineral oil, using the OC/PTFE powders obtained in the previous step were prepared according to the proportions provided in Table 12 below.

* PTFE concentration was fixed at 3.2 g PTFE to 160 g mineral oil ^a Sample XI from Table 11 was used. ^b Sample XII from Table 11 was used.

⁰ Sample XIII from Table 11 was used. ^d Sample XIV from Table 11 was used. ^e Sample XV from Table 11 was used. ^f Sample XVI from Table 11 was used. ^s Sample XVII from Table 11 was used.

Containers were first filled with mineral oil and acetone according to the proportions in the above table. The mineral oil/acetone mixtures were then placed in a 1 liter blender and mixed for a few seconds at a speed setting of 2 while the OC/PTFE was added. The total mixture was then mixed for a period of about 2 minutes at the blender speed setting of 7. The samples were then placed in 75 ml test tubes to study the settling rate as a function of organoclay concentration, as described below. A grind gauge test was also performed to check agglomeration and particle size, as described below.

Settling Test for Mineral Oil Dispersions The seven 75 ml test tubes prepared above were filled to a top line height of 7.03 inches from the bottom of the test tubes. Three additional lines were drawn on each of the test tubes: (i) a first line at about 6.25 inches below the top line height; (ii) a second line at about 5.69 inches below the top line; and (iii) a third line at 3.34 inches from the top line, as illustrated in Figure 9. The time needed for phase separation, i.e., settling, was observed and recorded by tracking the progress of the top of the white phase from the top line. As the top of the white phase decreased in height, the amount of a clear mineral oil phase increased on top of the white phase. The settling time results are summarized in Table 13 below. Table 13. S ettling Time Results

* No correction was made for weight loss of byproduct NaCl

The first and second columns represent the mass % of PTFE and organoclay, respectively, for each sample. The fourth, fifth and sixth columns show the time required for the PTFE and organoclay to settle up to lines 1, 2, and 3, respectively. These results show that as the concentration of organoclay increases the settling rate decreases. In other words, adding more OC to each sample will result in a longer settling time for the PTFE. In fact, the OC/PTFE in Samples 15 and 16 did not even settle to line 1 even after 361 hours (roughly 2 weeks). Graphical illustrations of these results are provided in Figures 10A and 10B, which plot the ratio (of the settling rate to Sample 10) versus the organoclay wt. %. Furthermore, the OC/PTFE material of Samples 11-14 "soft settled," which means that the settled material is readily re-dispersed with gentle mixing of the test tube by hand. In contrast, the material of Sample 10 "hard settled," which means that settled material was difficult to redisperse, even after vigorous shaking of the test tube by hand.

Grind Gauge Observations for the Mineral Oil Dispersions

Each sample in Table 13 was shaken by hand just right before the grind gauge test was performed. Using a 5-ml plastic pipette, about 2 ml of each sample was placed on top of the grind gauge. The draw down was performed and the observations were recorded. These observations correspond to samples 10 to 16 from Table 12. Table 14. Observations of Mineral Oil Dispersion under the Grind Gauge

NPPJ is another type of grind gate, wherein a value of 10 means ~25μ; 8 means ~20μ, 6 means ■15μ, 4 means ~10μ, 2 means ~5μ, and 0 means ~lμ.

The results in Table 14 show that organoclay can help PTFE dispersion in mineral oil even at a low OC wt% of 1.0. As the concentration of organoclay increases, the particle size decreases, as well as the number of large particle size aggregates (scatter). Example 6: Dispersion of TiO? in Mineral Oil

Preparation of Clay Slurry

The clay slurry was prepared as described in Example 2, however a 36 x 20 Mark III Centrifuge (commercially available from ATM/Delaval Co.) was used after mixing the bentonite clay in water for about 5i hours. The centrifuge was operated at about 1625 RPM and an air pressure setting of 7 psi, which was previously determined to be the equivalent of 8.85 GPM. It took about 5 3/4 hours for all of the clear clay surry to overflow the bowl centrifuge.

The solid weight percent of the bentonite clay was then determined as described in Example 2, however these samples were tested: a 5 gram sample, a 10 gram sample, and a 15 gram sample. The solid clay weight percentage was averaged for the three samples, and was determined to be 2.120%.

Preparation of Organoclay/TiO?

According to previous experiments, it was found that the optimum weight ratio was about 0.7 to 0.8 gram of quat for every gram of clay. A 0.8 g quat to 1 g clay ratio was selected to insure that adequate quat was present. Using that quat/clay ratio, eight organoclay/TiO₂ samples were prepared according to the proportions provided in Table 15 below.

Table 15. Formulation of OC/TiO₂

*Not corrected for NaCl by-product

Using the proportions in the above table, Samples XNIII-XXIX were each prepared separately as follows. The clay slurry was placed in a 700 ml. beaker and then heated to 60°C. After transferring the heated clay slurry to a Waring blender, titanium dioxide was slowly added to the clay slurry while mixing at a blender speed setting of 6. The titanium dioxide is commercially available in KR 2078 from Kronos, Inc., located in Hightstown, New Jersey. While the TiO₂/clay mixture was being mixed for about 3 minutes, the appropriate amount of quat, according to the proportions in the above table, was dissolved in 100 grams of hot water at 65°C. The quat solution was then added to the mixture in the blender and mixed for about 5 minutes at a blender speed setting of 4. The resulting organoclay/TiO₂ mixture ("OC/TiO₂") was then poured into ajar and allowed to sit for about 30 minutes. The OC/TiO₂, wliich agglomerated at the top of the jar, was separated by filtration, and the recovered agglomerate was dried in an oven for about 24 hours at 55°C. The dried sample was then ground for about 2 minutes in a Bel Art grinding machine. Preparation of TiO? in Mineral oil

Five TiO₂ dispersions in mineral oil, using the TiO₂/PTFE powders obtained in the previous step were prepared according to the proportions provided in Table 16 below. Table 16. Formulations of TiO in Mineral Oil

Sample XXV from Ta le 11 was used. ^b Sample XXV from Table 11 was used. ^c Sample XXIV from Table 11 was used. ^d Sample XXIII from Table 11 was used. ^e Sample XXI from Table 11 was used.

Five containers were first filled with mineral oil and acetone according to the proportions in the above table. The mineral oil/acetone mixtures were then placed in a Waring blender and mixed for about 1 minute at a blender setting of 2 while the OC/TiO₂ was added. The total mixture was then mixed for a period of about 2 minutes at a blender speed setting of 6. The samples were then placed in separate containers to study the settling rate as a function of organoclay concentration and to perform the Hegman grind gauge test to check agglomeration and particle size. The results and observations are provided in Table 17 below. Pictures were also take at 125x magnification. Table 17. Results and Observations of TiO₂ Dispersions in Mineral Oil

The results in Table 17 show that organoclay can help TiO₂ dispersion in mineral oil even at a low OC concentration of 5.0% by weight and significant increases TiO₂ dispersion at an OC concentration of 40.0% by weight. In fact, as the concentration of OC was increased from 0 to 40% by weight, a corresponding improvement of the Hegman grind gauge reading was observed from 0 to 5.5.

Example 7. Determining Size Profiles of the Clusters and Agglomerates of the Characteristic Use Particles

The following four samples were tested using the above-described automatic sieve test for three minutes under vacuum at approximately 14 inches of H₂O: (i) a S395 Nl polyethylene sample, (ii) an organoclay/S395 Nl polyethylene sample, (iii) a Powdertex 53 PTFE sample, (iv) and an organoclay/Powdertex 53 PTFE sample. The organoclay/S395 Nl polyethylene sample and the organoclay/Powdertex 53 PTFE sample were respectively prepared according to Example 4 described above, except that the samples were ground in a Waring blender for about 30 seconds at a speed setting of 7. The results of the screening test are provided below in Table 18.

Table 18. Screen Test Results for Polyethylene and PTFE

mes s ze screen was use .

2 ^' A #50 mesh size screen was used.

As provided in Table 18, both organoclay/Polyethylene and organoclay/PTFE refect a dramatic improvement in screening rate (e.g., wt. % collected underneath the screen per total time of screening) in comparison to pure PE and PTFE as indicated in the first minute. Without wanting to be limited by any one theory, it is believed that this data reflects the decreased size and occurrence of clusters and/or agglomerates of the PTFE and polyethylene particles resulting from the addition of organoclay.

The same four samples were tested in the Malvern particle size analyzer, as described above. The results are provided below in Table 19. Table 19. Malvern Particle Size Results for Polyethylene and PTFE

As provided in Table 19, the Malvern analysis provides a significant decrease in the volume weighted mean size of the clusters and/or agglomerates of the samples having organoclay compared to the pure samples of Powdertex 53 PTFE and S395 Nl polyethylene. These results are in accordance with the screen test results provided in Table 18.

Example 8. A Dispersion of Hydrous Oxide/PTFE in Water About 5 grams of TiOSO are dissolved in about 100 ml of aqueous, IN H₂SO₄ at 25°C in a small beaker. Concurrently, about 3.42 grams of SST-4 type PTFE (commercially available from Shamrock Technologies) is added to 250 ml of hot water at about 90° C in another beaker. While stirring rapidly, the solution of TiOSO₄ and H₂SO₄ is slowly added to the 250 ml of hot PTFE/water mixture over a period of about 60 seconds. Two minutes after the addition is completed, the mixture is filtered to recover the precipitated hydrous titanium dioxide having the entrapped PTFE ("the composite"). This composite is about a 50/50 mixture of PTFE physically entrapped in the hydrous oxide, because hydrous oxides can contain a variable amount of water.

Before drying, the composite can then be further processed to improve dispersion in the target media. For example, the composite can be peptized before adding the composite to a hydrophillic target medium. This can be done by rapidly stirring into the composite obtained above about 250 ml of .05N aqueous HC1, wherein the hydrous titanium dioxide is peptized by the dilute acid solution.

Example 9. Preparation of Carbon Black/Organoclay Compositions

After removing impurities from about 5 gallons of clay as provided in Example 6, 500 ml. of clean clay slurry containing 2.12% by weight solids heated to 65 °C. After transferring the heated clay slurry to a Waring blender, 53 grams of pigment grade carbon black (commercially available from Cabot Corporation) is slowly added to the clay slurry while mixing at a blender speed setting of 7. While the carbon black/clay mixture is mixed for about an additional 5 minutes, a quat solution is separately prepared by adding 7.42 grams of dry 2M2HT quat (commerically available from Witco Corp. as Adogen 442-100P) to 125 ml. water at about 65 °C and mixing for about 5 minutes. The quat solution is then added to the carbon black/clay mixture in the blender and mixed for about an additional 10 minutes at a blender speed setting of 4. The resulting organoclay/carbon black mixture ("OC/CB") is then poured into ajar and allowed to sit for about 30 minutes. The agglomerated OC/CB is separated by filtration, washed with about 250 ml. of water at about 65°C, and the recovered agglomerate is dried in an oven for about 24 hours at about 60°C. The dried sample can then be ground into powder form.

Example 10. Preparation of Calcium Carbonate/Organoclay Compositions

After removing impurities from about 5 gallons of clay as provided in Example 6, 500 ml. of clean clay slurry containing 2.12% by weight solids heated to 65 °C. After transferring the heated clay slurry to a Waring blender, 126.14 grams of calcium carbonate (commercially available from Omya, Inc. as omyacarb 3) is slowly added to the clay slurry while mixing at a blender speed setting of 7. While the carbon black/clay mixture is mixed for about an additional 5 minutes, a quat solution is separately prepared by adding 7.42 grams of dry 2M2HT quat (commerically available from Witco Corp. as Adogen 442-100P) to 125 ml. water at about 65 °C and mixing for about 5 minutes. The quat solution is then added to the calcium carbonate/clay mixture in the blender and mixed for about an additional 10 minutes at a blender speed setting of 4. The resulting organoclay/calcium carbonate mixture ("OC/CC") is then poured into ajar and allowed to sit for about 30 minutes. The agglomerated OC/CC is separated by filtration, washed with about 250 ml. of water at about 65°C, and the recovered agglomerate is dried in an oven for about 24 hours at about 60°C. The dried sample can then be ground into powder form.

Example 11. Preparation of Submicron PTFE Materials and Methods Submicron PTFE in IPA was formulated as follows.

White virgin paste (WNP) PTFE, irradiated at 28 mrads was gently added to IPA to a concentration of 25% while mixing. Using a horizontal mill with 0.6 to 0.8 mm beads, the pre dispersion PTFE was ground at 3500 RPM. To avoid settling the pre-dispersion mixture was constantly mixed. After 5 passes the 100% of the particles were less than 0.5μ (Figure X). It is expected that the dispersion will be completely submicron after 7 to 10 passes.

Pure submicon powder PTFE was formulated as follows. To three gallons of hot water (60°C) 1600 grams of submicon PTFE/IPA was gently added and mixed for 15 minutes. The mixture was then allowed to sit for 30 minutes. During this time, the PTFE floats to the top of the water/IP A mixture. The PTFE is removed to an aluminum tray and dried in the oven at approximately 60°C. The remaining water EPA mixture is filtered using a #1 filter paper and an air vacuum or water vacuum.

Submicon PTFE in IPA-Quat was formulated at the following concentrations: 25% WNP 104 28 MR 2M2HT powder/ 2% Quat, 113% IPA. 2% Quat was dissolved in IPA. 25% IPA was gently added to the IPA-Quat solution while mixing. A horizontal mill was used to grind the pre-dispersion PTFE while contantly mixing. The particle size was checked after 5 passes and found to be less than .5μ. The procedure for filtering and drying the submicon PTFE is as described above.

Submicron organoclay PTFE powder was produced as follows. For preparation of submicron clay in water a 20% white clay slurry was circulated in a horizontal mill. The particle size was checked after 15 minutes. The clay will normally be of submission size after between 25-30 minutes. The amount of clay to be added to the submission PTFE is calculated to be in a ratio of one part solid clay to 0.4 part of Quat. To three gallons of hot water (60°C) the clay slowly is added and mixed at high speed. 1500 gms of submicron PTFE-IPA-Quat was gently added while constantly mixing. The solution was mixed for 15 minutes. After mixing the solution was allowed to sit for 30. The wet organoclay PTFE mixture was filtered and washed with warm water followed by drying in oven at a maximum temperature of 60°C. The PTFE was air milled. The final ratio will be approximately 25 parts PTFE to 7 parts organoclay (21.87% organoclay and 78.13% PTFE).

Malvern analysis of the resulting submicron PTFE compositions are depicted in Figures 12-15,

Claims

1. A composition that is capable of being dispersed in a target medium, comprising characteristic use particles entrapped within a physical entrapment phase, wherein the physical entrapment phase is dispersible in the target medium.

2. The composition according to claim 1, wherein said composition is substantially free of a process medium.

3. The composition according to claim 2, wherein a mixture of the composition in the target medium has a Hegman grind gauge improvement of greater than or equal to 1 unit compared to the Hegman grind gauge value of a mixture of the pure characteristic use particles in the target medium.

4. The composition according to claim 1, wherein the physical entrapment phase comprises a plurality of physical entrapment particles.

5. The composition according to claim 4, wherein the number ratio of physical entrapment phase particles to characteristic use particles is greater than or equal to about 10:1.

6. The composition according to claim 4, wherein said characteristic use particle is selected from the group consisting of polymers having one or more monomers, resins, binders, metal oxides, pigments, extenders, dyes, film forming agents, anticorrosive agents, matting/flattening agents, rheological modifiers, biocides, inorganic fillers, flow modifiers, and mixtures thereof; and wherein said physical entrapment phase particles are selected from the group consisting of organoclays, hydrous oxides, SiO₂, organic salts, acrylic polymers, and mixtures thereof.

7. The composition according to claim 6, wherein said characteristic use particle is selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PPE), polyethylene terephthalate (PET), polystyrene, polycarbonate, polymethyl methacrylates, polybutadiene, titanium dioxide (TiO₂), magnesium oxide (MgO), zinc oxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃), calcium carbonate (CaCO₃), lead chromate (PbCrO₄), barium sulfate (BaSO₄), molybdate orange, hansa yellow, phthalocyanine blue, phthalocyanine green, carbazole violet, carbon black, rubinine red, talc, china clay, mica, feldspar, waxes, and mixtures thererof; and wherein said physical entrapment phase particles are selected from the group consisting of organoclay and hydrous oxides.

8. The composition according to claim 4, wherein said physical entrapment particles are obtained by reacting a precursor with a triggering agent.

9. The composition according to claim 8, wherein said precursor is a smectite-type clay and said triggering agent is an organic cation.

10. The composition according to claim 9, wherein said precursor is selected from the group consisting of montmorillonite, bentonite, beidellite, hectorite, saponite, stevensite, and mixtures thereof; and said organic cation has a formula

wherein X is nitrogen or phosphorus, Y is sulfur, is the long chain, linear or branched, saturated or unsaturated alkyl group and R₂, R and R₄ can be independently selected from the group consisting of linear or branched alkyl groups having 1 to 22 carbon atoms; aralkyl groups which are benzyl and substituted benzyl moieties including fused ring moieties having linear or branched 1 to 22 carbon atoms in the alkyl portion of the structure; aryl groups; beta, garnma-unsaturated groups having six or less carbon atoms or hydroxyalkyl groups having two to six carbon atoms; and hydrogen.

11. The composition according to claim 10, wherein said characteristic use particles are selected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black, CaCO₃, and mixtures thereof.

12. The composition according to claim 8, wherein said precursor is metal salt and said triggering agent is selected from the group consisting of an acid and a base.

13. The composition according to claim 12, wherein said metal salt is a water soluble metal salt.

14. The composition according to claim 12, wherein said composition is further peptized with dilute mineral acids.

15. The composition according to claim 14, wherein said characteristic use particles are selected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black, CaCO₃, and mixtures thereof.

16. The composition according to claim 2, wherein a mixture of the composition has a 1 minute sieve weight % result of greater than or equal to about 10% in comparison to a 1 minute sieve weight % result of a sample of pure characteristic use particles.

17. The composition according to claim 1, wherein the composition has a particle size decrease of greater than or equal to about 10% in comparison to the particle size results of pure characteristic use particles.

18. A process for manufacturing a composition that is capable of being dispersed in a target medium, comprising:

(A) mixing a physical entrapment phase precursor with a characteristic use particle in a processing medium in which the precursor is dispersible;

(B) converting the precursor into a physical entrapment phase which is not dispersible in said processing medium, thereby entrapping the characteristic use particle within the physical entrapment phase; and

(C) separating the physical entrapment phase having the characteristic use particles entrapped therein from the processing medium to obtain said composition.

19. The process according to claim 18 further comprising drying the composition and grinding the dried composition.

20. The process according to claim 18, wherein the precursor is converted into the physical entrapment phase by adding a triggering agent to the processing medium.

21. The process according to claim 20, wherein the physical entrapment phase comprises a plurality of physical entrapment particles.

22. The composition according to claim 21 , wherein the number ratio of physical entrapment phase particles to characteristic use particles is greater than or equal to about 10:1.

23. The process according to claim 21 , wherein said process medium is hydrophillic; said physical entrapment phase precursor is a smectite-type clay; and said triggering agent is one or more organic cations.

24. The process according to claim 23, wherein said clay is selected from the group consisting of montmorillonite, bentonite, beidellite, hectorite, saponite, stevensite, and mixtures thereof; said organic cation has a formula +

wherein X is nitrogen or phosphorus, Y is sulfur, R_\ is the long chain, linear or branched, saturated or unsaturated alkyl group and R₂, R₃ and R-i can be independently selected from the group consisting of linear or branched alkyl groups having 1 to 22 carbon atoms; aralkyl groups which are benzyl and substituted benzyl moieties including fused ring moieties having linear or branched 1 to 22 carbon atoms in the alkyl portion of the structure; aryl groups; beta, garnma-unsaturated groups having six or less carbon atoms or hydroxyalkyl groups having two to six carbon atoms; and hydrogen; and said characteristic use particle is selected from the group consisting of polymers having one or more monomers, resins, binders, metal oxides, pigments, extenders, dyes, film forming agents, anticorrosive agents, matting/flattening agents, rheological modifiers, biocides, inorganic fillers, flow modifiers, and mixtures thereof.

25. The process according to claim 24, wherein said characteristic use particle is selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PPE), polyethylene terephthalate (PET), polystyrene, polycarbonate, polymethyl methacrylates, polybutadiene, titanium dioxide (TiO₂), magnesium oxide (MgO), zinc oxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃), calcium carbonate (CaCO₃), lead chromate (PbCrO₄), barium sulfate (BaSO ), molybdate orange, hansa yellow, phthalocyanine blue, phthalocyanine green, carbazole violet, carbon black, rubinine red, talc, china clay, mica, feldspar, waxes, and mixtures thereof.

26. The process according to claim 25, wherein said characteristic use particles are selected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black, CaCO₃, and mixtures thereof.

27. The process according to claim 21 , wherein said process medium is hydrophillic; said physical entrapment phase precursor is a metal salt; and said triggering agent is selected from the group consisting of an acid and a base.

28. The process according to claim 27, wherein said metal salt is a water soluble metal salt.

29. The process according to claim 27, further comprising adding a dilute acid.

30. The process according to claim 29, wherein said characteristic use particle is selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PPE), polyethylene terephthalate (PET), polystyrene, polycarbonate, polymethyl methacrylates, polybutadiene, titanium dioxide (TiO₂), magnesium oxide (MgO), zinc oxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃), calcium carbonate (CaCO₃), lead chromate (PbCrO ), barium sulfate (BaSO₄), molybdate orange, hansa yellow, phthalocyanine blue, phthalocyanine green, carbazole violet, carbon black, rubinine red, talc, china clay, mica, feldspar, waxes, and mixtures thereof.

31. The process according to claim 30 wherein said characteristic use particles are selected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black, CaCO₃, and mixtures thereof.

32. A product obtained according to the process of any one of claims 18, 23, and 27.

33. The product according to claim 32, wherein a mixture of the composition in the target medium has a Hegman grind gauge improvement of greater than or equal to 1 unit compared to the Hegman grind gauge value of a mixture of the pure characteristic use particles in the target medium.

34. The product according to claim 32, wherein a mixture of the composition has a 1 minute sieve weight % result of greater than or equal to about 10% in comparison to a 1 minute sieve weight % result of a sample of pure characteristic use particles.

35. The product according to claim 32, wherein the composition has a particle size decrease of greater than or equal to about 10% in comparison to the particle size results of pure characteristic use particles.

36. A method of conferring a desired benefit to a target medium, comprising adding to a target medium a composition that is capable of being dispersed in the target medium, wherein said composition comprises characteristic use particles entrapped within a physical entrapment phase that is dispersible in the target medium, wherein said characteristic use particles confer the desired benefit to the target medium.

37. The method according to claim 36, wherein said composition is substantially free of a process medium.

38. The method according to claim 36, wherein a mixture of the composition in the target medium has a Hegman grind gauge improvement of greater than or equal to 1 unit compared to the Hegman grind gauge value of a mixture of the pure characteristic use particles in the target medium.

39. The method according to claim 36, wherein the physical entrapment phase comprises a plurality of physical entrapment particles.

40. The method according to claim 39, wherein the number ratio of physical entrapment phase particles to characteristic use particles is greater than or equal to about 10:1.

41. The method according to claim 39, wherein said characteristic use particle is selected from the group consisting of polymers having one or more monomers, resins, binders, metal oxides, pigments, extenders, dyes, film forming agents, anticorrosive agents, matting/flattening agents, rheological modifiers, biocides, inorganic fillers, flow modifiers, and mixtures thereof; and said physical entrapment phase particles are selected from the group consisting of organoclays, hydrous oxides, SiO , organic salts, acrylic polymers, and mixtures thereof.

42. The method according to claim 41, wherein said target medium is selected from the group consisting of hydrocarbon-based compositions, solvents, unsaturated hydrocarbons, formamides, acetones of C6 or higher carbon content, alcohols with carbon chain lengths of C5 or higher, resins, fillers, film formers, coatings, inks, polymers, chloro, fluor and nitro solvents, water of neutral, acidic, or basic pH, linear and branched Cl to C4 alcohols, Cl to C4 glycols, organic acids and their alkali metal salts, ionic fluids containing water and water soluble electrolytes, Cl to C3 amines, and low molecular weight organic sulfonic acids and their salts; said characteristic use particle is selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PPE), polyethylene terephthalate (PET), polystyrene, polycarbonate, polymethyl methacrylates, polybutadiene, titanium dioxide (TiO₂), magnesium oxide (MgO), zinc oxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃), calcium carbonate

(CaCO₃), lead chromate (PbCrO₄), barium sulfate (BaSO₄), molybdate orange, hansa yellow, phthalocyanine blue, phthalocyanine green, carbazole violet, carbon black, rubinine red, talc, china clay, mica, feldspar, waxes, and mixtures thereof; and said physical entrapment phase particles are selected from the group consisting of organoclay and hydrous oxides.

43. The method according to claim 42, wherein said characteristic use particles are selected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black, CaCO₃, and mixtures thereof.

44. A composition comprising (A) a target medium; (B) characteristic use particles dispersed within the target medium; and

(C) a physical entrapment phase dispersed within the target medium, wherein the composition has a grind gauge improvement of greater than or equal to 1 unit in comparison to the grind gauge for the composition without the physical entrapment phase.

45. The composition according to claim 44, wherein the physical entrapment phase comprises a plurality of physical entrapment particles.

46. The composition according to claim 45, wherein the number ratio of physical entrapment phase particles to characteristic use particles is greater than or equal to about 10:1.

47. The composition according to claim 45, wherein said target medium is selected from the group consisting of hydrophobic target media and hydrophillic target media; said characteristic use particle is selected from the group consisting of polymers having one or more monomers, resins, binders, metal oxides, pigments, extenders, dyes, film forming agents, anticorrosive agents, matting/flattening agents, rheological modifiers, biocides, inorganic fillers, flow modifiers, and mixtures thereof; and said physical entrapment phase particles are selected from the group consisting of organoclays, hydrous oxides, SiO₂, organic salts, acrylic polymers, and mixtures thereof.

48. The composition according to claim 47, wherein said target medium is selected from the group consisting of hydrocarbon-based compositions, solvents, unsaturated hydrocarbons, formamides, acetones of C6 or higher carbon content, alcohols with carbon chain lengths of C5 or higher, resins, fillers, film formers, coatings, inks, polymers, chloro, fluor and nitro solvents, water of neutral, acidic, or basic pH, linear and branched Cl to C4 alcohols, Cl to C4 glycols, organic acids and their alkali metal salts, ionic fluids containing water and water soluble electrolytes, Cl to C3 amines, and low molecular weight organic sulfonic acids and their salts; said characteristic use particle is selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PPE), polyethylene terephthalate (PET), polystyrene, polycarbonate, polymethyl methacrylates, polybutadiene, titanium dioxide (TiO₂), magnesium oxide (MgO), zinc oxide (ZnO), ferrous oxide (FeO), ferric oxide (Fe₂O₃), calcium carbonate (CaCO ), lead chromate (PbCrO₄), barium sulfate (BaSO₄), molybdate orange, hansa yellow, phthalocyamne blue, phthalocyanine green, carbazole violet, carbon black, rubinine red, talc, china clay, mica, feldspar, waxes, and mixtures thereof; and said physical entrapment phase particles are selected from the group consisting of organoclay and hydrous oxides.

49. The composition according to claim 48, wherein said characteristic use particles are selected from the group consisting of PTFE, PE, PPE, TiO₂, carbon black, CaCO₃, and mixtures thereof.

50. The composition according to claim 7 wherein the characteristic use particle is a submicron particle.

51. The process according to claim 25 wherein the characteristic use particle is a submicron particle.

52. The process according to claim 30 wherein the characteristic use particle is a submicron particle.

53. The process according to claim 42 wherein the characteristic use particle is a submicron particle.

54. The method according to claim 48 wherein the characteristic use particle is a submicron particle.