MXPA01005066A - Process for treating particles, and their use in dispersions - Google Patents

Abstract

A process for treating particles comprising the steps of:(i) contacting the particles with a compound of Formula (I) wherein at least one of R1, R2 and R3 is hydroxyl or a hydrolysable group;and (ii) contacting the particles with a compound of Formula (II) wherein X is an anion and R4 is either:a divalent group -(CyH2y)-, branched or unbranched, wherein y is a whole number from 1 to 40, or a C6-C40 aromatic group, and t is either 0 or 1.

Description

PROCEDURE TO TREAT PARTICLES AND ITS USE IN DISPERSIONS TECHNICAL FIELD In one of its aspects, the present invention relates to the treatment of particles, specifically inorganic hydroinsoluble compounds. The treated particles are useful as intermediates for the production of a particulate material that is useful specific, but not exclusive¬ , in the formation of polymer compounds, especially rubbers and plastics.

PREVIOUS TECHNIQUE _. ^ Crude polymers, whether rubber or plastic, rarely have the physical or chemical properties inherent in their pure state necessary to make useful articles. The polymers must, therefore, be compounds by mixing with additional ingredients or "additives". The polymeric additives may include one or more of: secondary polymers, oils to spread the rubber, fillers, antioxidants, coloring pigments, stabilizers, flame retardants, processing aids and other auxiliary chemicals. For rubbers, this list can be extended to include curatives (vulcanizing agents), such as sulfur or organic peroxides; curing accelerators, such as di-benzothiazyl disulfide (MBTS) and tetramethylthiuram disulfide (TMTD), as well as inorganic curing activators, such as zinc oxide, lead monoxide (PbO, litharge), minium (Pb304) and the like . Regardless of whether they are plastic or rubber properties that are to be improved, the selected additive materials must be intimately mixed with the polymer in the composition stage (to obtain a homogeneous dispersion), in order to achieve the maximum improvements. . Conventionally, this mixture is usually carried out in an open mill, in a mixing extruder or in an internal mixer (such as the Henschel, We-lex or Banbury types), using one or more stages until the desired degree of dispersion is achieved . Quite often, it is difficult to achieve a satisfactory dispersion of the additive in the polymer in a reasonable time, resulting in heterogeneity, which results in unacceptable physical properties or appearance in the formed article. To improve the dispersion, a long mixing time or a multi-stage mixing cycle must be employed, which reduces the productivity in the mixing plant and is therefore undesirable. In industry, it is known that the mixture of inorganic chemicals, such as inorganic activators used in the rubber industry, presents special difficulties in this regard, due to the inherently much greater hardness and viscosity of these chemicals in relation to the polymer matrix. A general method to facilitate the mixing and dispersion of these inorganic materials into polymeric compounds in the factory is to use an inorganic material with a very fine particle size. However, this inevitably generates dust during handling of the material and during the mixing process and, in many cases, these dust particles are toxic or otherwise unacceptable from the point of view of workers' health. The dust losses also change the ratio of the chemicals to the base polymer with respect to the originally intended one; This can result in poor processing or poor finishing properties in the compound. In some specific cases (ie with talc), very fine particles can act as a lubricant and actually contribute to a poor mixture of the mass, in this case reducing the shear necessary for dispersion. In other cases, especially when polar ingredients have to be mixed in a non-polar polymer, agglomeration of the particles may occur during mixing, resulting in undesirable heterogeneity and unsatisfactory physical properties. To mitigate the above problems, the addition of the inorganic chemicals to the base polymer in a predispersed form is well known in the art., for example in the form of fine particles joined in a medium of low viscosity (or binder), such as polymer or oil, or combinations of these with additional additives. This bonded form of inorganic chemicals solves the dust problem in the rubber composition plant and also greatly shortens the dispersion time of the inorganic materials in the polymeric compound, particularly if the binder is chemically similar to the base polymer and the viscosity of the predispersion keeps a close correspondence with the rest of the compound. From a compositional point of view, it is desirable to have a minimum amount of binder, which will facilitate dispersion and at the same time eliminate dust formation during processing. These types of "concentrates" or "dispersions" therefore typically contain from about 50% to 95% by weight of the active inorganic chemical dispersed in a suitable binder (practically, this corresponds to a range of 100 to 1,900 parts). by weight of inorganic chemical per 100 parts by weight of binder). Many of these materials can be purchased commercially from a number of suppliers in the rubber industries. Non-limiting examples of such materials attached to commercial polymers used in the rubber industry are: RHENOGRAN ZnO-85 (85 weight percent zinc oxide dispersed in an EPDM / EVA binder), POLY-DISPERSION * PLD-90 (90 percent of lead monoxide dispersed in polyisobutylene), RHENOGRAN5 Pb3O4-90 (90 percent red lead oxide dispersed in EPDM / EVA), all from Rhein-Chemie Corporation and Rhein Chemie Reinau GmbH. You can also use cheaper oil-based binders; while these are directed to the problem of dust, they do not offer such good or rapid dispersion, since the presence of oil reduces the friction necessary to cause the inorganic materials to crumble during mixing. The presence of oil can also produce other changes in physical properties (ie, softening) or appearance (color), which are not undesirable. An example of the last type of dispersion is Polydex ™ PPD (ZnO) 75, a mixture of 75 percent ZnO in a light processing oil from Polychem. In the plastics industry, it is often desired to modify the viscosity (ie, the "melt index", hardness, color, light stability and / or other properties of the base polymer in order to make it processable). or suitable for its intended end-use application.Once again, these additives (chemicals), in their pure form, can be added directly to the entire plastic during the processing phase (composition), although it is more common to use the materials as concentrates in liquid or pellet form in order to obtain a better dispersion and a better process control Again, these concentrates consist of a dispersion of fine particles of the additive in a suitable vehicle or "binder", which may be similar or identical to the base polymer or can be another compatible polymer or a combination of polymers and oil.In addition, other ingredients can be included (eg, soaps, compatibilizing agents and dispersion aids) at the base of the binder. This concentrated form is used almost exclusively to introduce inorganic dyes into plastics in which the high hardness and high melting point of the additives cause dispersion problems. Many companies currently supply concentrates of inorganic and organic additives to the plastics industry; Non-limiting examples of the latter materials include: ComPETe ™, CELPRO ™, Holoflake ™, Hanna-FX ™ (MA Hanna Color), BARKOLEN * (SPUR1"as), POLYPLUS ™ (PolyTech South Inc.), CEK CONCENTRA- TES ™, COLORPLAST ™, CONCORDE ™ (CEK Concentrates) and the like Conventionally, these predispersed forms of inorganic additives for use in the rubber and plastics industries have been produced by dry mechanical mixing of the ingredients - that is, the additive in question is simply mechanically mixed with the binder material, unfortunately, this approach only serves to transfer the problems of mixing and dust from the rubber mixing plant to that of the dispersion supplier, Moreover, the relatively high percentage of inorganic material with respect to the desirable binder in these dispersions generally requires long mixing times or the use of special high-energy mixing equipment ("HIDM"), that either reduce productivity or add to production costs. Most desirably would be a dispersion manufacturing process that could be essentially free of dust and that required little mixing energy to disperse the inorganic auxiliary material in a polymeric binder. A known easy method for preparing fine particle size materials from coarser commercial ones is wet milling, using a ball mill, colloid mill or steam jet mill or other equipment, as described in "et Grinding" , in Ullmann's Encyclopedia of Industrial Chemistry, Vol. B2, sec. 5-36. As the fine particles produced are continuously in a wet state, they have little tendency to become dust carried by the air. However, the concentration of the fine particles in the wetting medium is necessarily low to maintain the fluidity required for satisfactory grinding and, therefore, the particles must be insoluble in the grinding medium. When other means than water is used during the size reduction procedure, additional risks must be considered, such as flammability and / or toxicity. In addition, the resulting dispersions typically require concentration (i.e., removal of the solvent) before they can still be dispersed in a binder. What is more, it is difficult to dry such fine particles without generating dust at any other point in the process or without causing agglomeration (particle growth) during the drying stage. When possible, it would be preferred to produce masterbatches, dispersions and concentrates of these particles in suitable binders while the particles are still in a finely divided wet state. It is also preferable for economics and safety perspectives that the wetting medium is water. An additional benefit of using water is that it is generally a non-solvent for most of the organic and inorganic additives sold as dispersions. In addition, a number of prior art references show how to make "mother mixtures" of fillers and "dispersions" of other chemicals in polymers using fine particles dispersed in an aqueous state. For example, Burke (U.S. Patent 3,689,451, U.S. Patent 3,689,452, U.S. Patent 3,700,690, U.S. Patent 3,716,513 and U.S. Patent 3,840,382) shows how to use an aqueous dispersion of never dried alkaline silica pigment or a mixing an aqueous dispersion of never dried alkaline silica pigment and carbon black to prepare a masterbatch of these fillers in a rubber matrix at levels of <; 100 phr of filler (ie, less than about 50% by weight of the dispersant filler in a rubber matrix). The rubbers should be used as solutions in water immiscible solvents. Typically, large quantities of auxiliary chemicals are also to be employed to ensure the transfer of the silica from the aqueous suspension to the organic phase. In related patents (U.S. Patent 3,686,219 and U.S. Patent 3,694,398), Burke shows how to prepare similar masterbatches from finely dispersed particles (aqueous) silica using the rubber in the form of an aqueous emulsion - that is, a latex. However, all of Burke's prior patents are restricted to the use of never-ending silica or combinations of never-dried silica and carbon black (ie, conventional rubber fillers). The levels of the inorganic material in the finished dried masterbatch are, furthermore, restricted to a low concentration and the binder is restricted to elastomers. As far as the inventor knows, commercial master mixes made by Burke's methods are not available at present. Contrary to the apparent lack of commercial availability of silica mother mixtures, it has been possible to obtain masterbatches of carbon black and rubbers prepared with both aqueous emulsions of polymers (that is, the latex resulting from the emulsion polymerization) and with solutions of polymers in hydrocarbons (that is, as they result when the polymer is soluble in the polymerization medium) from several suppliers over a number of years (Copolymer Div. of DSM, Bayer Inc., Goodyear, etc.). These masterbatches are usually prepared by grinding the carbon black in a wet aqueous state and then intensively mixing the black suspension with a polymer "cement" in solution or emulsion polymer latex, with or without added oil, followed by coagulation and drying . In all commercial master mix products, the black filler levels are < 100 phr (ie, less than about 50% by weight of the dispersed filler in a rubber matrix). When the polymer is available as an aqueous emulsion (ie, latex), several methods are available for the incorporation of auxiliary chemicals to form dispersions; the coprecipitation methods of Leo and Johansson (US Pat. No. 4,110,240) can be used to prepare concentrates containing 80-99.5% by weight of auxiliary chemicals (excluding fillers), whether organic or inorganic, in the polymeric binder. Kanou et al. (U.S. Patent 4,713,411) disclose a different coprecipitation process for producing a pigment composition using a special water-soluble polymer binder, which is then rendered insoluble by changes in pH. However, many polymers, especially plastics, are prepared by a solution polymerization process and are not readily available in the form of latex. Despite previous efforts in the prior art, there remains a need for an efficient form of production of masterbatches, dispersions or concentrates of inorganic additive materials as a binder.

DESCRIPTION OF THE INVENTION It is an object of the present invention to obviate or mitigate at least one of the aforementioned drawbacks of the prior art. It is another object of the present invention to provide a new process for treating particulate material. Accordingly, in one of its aspects, the present invention provides a method for treating particles and making them hydrophobic, which process consists of the following steps: (i) contacting the particles with a compound of Formula I: R2-Si-H (I) RJ where at least one of R, R and R is hydroxyl or a hydrolyzable group, and (ii) contacting the particles with a compound of Formula II: CH2 = CH- [-R4 -] t-CH2-X (II) where X is an anion and R4 is or a divalent group - (CyH2y) -, branched or unbranched, where y is an integer from 1 to 40, or an aromatic group Cs_C4o, and t is 0 or 1. In another of its aspects, the present invention provides a method for treating particles, consisting of the step of contacting particles having one or more of the following formulas: (from where : P is a particle; Ra and Rb may be the same or different and each is selected from the group consisting of C? _o alkyl, C 2-4 alkenyl or mono- or C 3-0 diunsaturated and aromatic C 6-40, and w is an integer in the range of 1 to 106 or more; with a compound of Formula II: CH2 = CH- [-R4-] t-CH2-X (II) where X is an anion and R4 is a divalent group - (CyH2y) -, branched or unbranched, where y is a integer from 1 to 40, or a C6-C40 aromatic group, and t is 0 or 1.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will be described with reference to the accompanying drawings, wherein: Figure 1 illustrates an embodiment of the present method. Figure 2 illustrates a first example of product use of a product of the present process illustrated in Figure 1. Figure 3 illustrates a second example of product use of a product of the present process illustrated in Figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION Throughout this description, the invention is illustrated in relation to silica as a particle having surface hydroxyl groups, but it should be appreciated that the invention is applied to the use of other similar materials and to understand the description in consecuense. Thus, the present invention is particularly useful in the treatment of water-insoluble inorganic compounds. Preferably, the water-insoluble inorganic compounds useful for the treatment are those compounds in which the chemical formula contains an oxygen atom, more preferably those compounds in which the formula also contains a metal atom. More than one metal atom may be present in the chemical formula. Examples of suitable groups of compounds useful with oxygen atoms can be selected from the group consisting of oxides, hydroxides, borates, sulfates, carbonates, silicates, phosphates, chromates and the like. Non-limiting examples of suitable compounds containing oxygen atoms and metal atoms can be selected from the group consisting of silicon dioxide (silica), titanium oxide (titania, both the rutile and anatase forms), ferric oxide. , ferric oxide hydrate, ferrous oxide, antimony oxide, barium carbonate, zinc oxide, zinc borate, lead oxide (including red lead oxide), dibasic lead phosphite, lead silicate, tribasic lead sulfate and its mixtures Other suitable compounds containing metal atoms and oxygen atoms, especially those which are water insoluble or only slightly soluble in water, will be readily apparent to those skilled in the art based on the above discussion. For example, a particularly preferred application of the present invention is to render hydrophobic dye or pigment particles that are typically used in the plastics industry. Non-limiting examples of suitable particles of this type can be selected from the group consisting of -FeOOH (goethite), -FeOOH (lepidocrocite), -Fe203 (hematite), -Fe203 (magemite) and Fe304. Preferred particles for the production of masterbatches by this invention are the precipitated silica. In a preferred embodiment, the treatment is carried out in an aqueous dispersion or suspension of the particles. In general, the precise constitution of the suspension is not particularly restricted, as long as it is a mobile suspension and remains so during the treatment procedure. Practically, it is preferred that the suspension contain the maximum amount by weight of particles to be treated that still allow it to remain mobile. The maximum weight that allows to maintain the mobility will vary directly according to the particle size of the silica and inversely with the concentration of superficial silanol groups. Practically, concentrations of between 20 and 25 weight percent silica in water are usually possible with dry precipitated silicas and somewhat lower concentrations for never-dried silicas (ie, filter cakes), as will be discussed below. The dried amorphous silica suitable for use according to the invention may have an agglomerated average particle size of between 0.1 and 100 microns, preferably between 0.1 and 50 microns and, more preferably, between 1 and 25 microns. It is preferred that less than 10 percent by volume of the agglomerated particles are below 5 microns or above 50 microns in size. Even more, a suitable dry amorphous silica has a BET surface area, measured according to DIN (Deutsche Indie Norm) 66131, of between 50 and 450 square meters per gram and a DBP absorption, measured according to DIN 53601, of between 150 and 400 grams per 100 grams of silica, and a loss by drying, measured according to DIN ISO 787/11, from 0 to 10 weight percent. If a wet silica filter cake is used, it can be made by filtering and optionally washing silica prepared by any known means, as described in Ullmann's Encyclopedia of Indial Chemistry, Vol. A23, pages 642-643, VCH Publishers, e1993 . The filter cake has a preferred solids content of between 10 and 30 percent by weight, more preferably between 15 and 25 percent by weight, and can be redispersed in water according to the present process to obtain a concentration of silica between 5 and 20 weight percent and, more preferably, between 8 and 12 weight percent. It is preferred to use a cake of the silica filter. It is more preferable to use a silica filter cake that is formed from precipitated silica by means of carbon dioxide or hydrochloric acid or a combination thereof and it is more preferable to wash the filter cake with water prior to redispersion to remove the dissolved salt byproducts. If an unfiltered suspension prepared from the known reaction of an alkali metal silicate solution with mineral acid or carbon dioxide is used, it is preferred that the solids content of the never filtered suspension be between 5 and 30, more preferably between 5 and 20 and, more preferably, between 10 and 20 weight percent of silica. The preferred particles for the production of dispersions by this invention are those compounds which contain metal and oxygen atoms which form a subgroup within the materials which are widely referred to as "pigments" in the language of the rubber and rubber indies. of plastic. Although these materials may not be used in these indies as pigments in the true sense, this terminology has remained because the materials were originally used in the paint indy. In a preferred embodiment, the treatment is carried out in an aqueous dispersion or suspension of the pigment particles. In general, the precise composition of the suspension is not particularly restricted, as long as it is a mobile suspension and remains so during the treatment process. In practice, it is preferred that the suspension contains the maximum amount by weight of particles to be treated that still allows it to remain mobile. The maximum weight that will allow to maintain the mobility will vary directly according to the particle size of the filler and the degree of crystallinity of the filler and inversely with the concentration of superficial hydroxyl groups. The shape of the particles also influences the concentration that can be achieved; higher concentrations can be achieved with rounded particles than with particles having a highly structured surface. Typically, concentrations of between 30-60 weight percent of pigment in water with dry pigments and somewhat lower concentrations for never-dried pigments (ie, filter cakes) can be achieved, as will be discussed below. The maximum operative concentration is better determined by experimentation. The dry pigments for use according to the invention can have an agglomerated average particle size of between 0.01 and 500 microns, preferably between 0.1 and 50 microns and, more preferably, between 1 and 10 microns. It is preferred that less than 10 volume percent of the agglomerated particles are below 0.1 microns or above 100 microns in size. If a cake of the pigment filter is used, it can be redispersed in water according to the present process to obtain a concentration with which it can be worked. It is preferred to use cake of the pigment filter and it is most preferable to wash the filter cake with water prior to redispersion to remove the dissolved salt byproducts. Whether a dispersion or masterbatch is desired, the temperature of the suspension of the silica or pigment particles suitable for practicing the invention may be between 0 ° C and 100 ° C if the process is carried out at atmospheric pressure, or between 0 ° C and 135 ° C if the operation is carried out in a pressure vessel. It is most preferable to carry out the process at atmospheric pressure, in which case the preferred temperature is between 0 ° C and 95 ° C and, more preferably, between 10 ° C and 90 ° C. The selection of atmospheric pressure or of a pressure vessel is within the scope of one skilled in the art considering a number of factors, including the temperature and the respective volatilities of the specific reagents chosen for the process. When volatility is a problem, the container can be equipped with a reflux condenser. It is desirable, before addition to the silica or pigment particles of the compound of Formula I, to vigorously stir the suspension. It is preferred to have a suspension pH in the range of 4 to about 6.5, more preferably from about 4.5 to about 6.5. If necessary, the pH can be adjusted by the addition of acid or alkali, for example mineral acid, alkali metal hydroxide, alkaline earth hydroxide, ammonium hydroxide and the like. These can be added as such or in aqueous solution. In the compound of Formula I, it is preferred that the three groups R1, R2 and R3 are all easily hydrolysable. Suitable R1 groups include hydroxyl groups and hydrolyzable groups of formula 0CpH2p + 1, where p has a value of 1 to 10. The alkyl chain may be interrupted by oxygen atoms to give groups, for example, of formula CH30CH20-, CH3OCH2OCH20-, CH3 (0CH2) 40-, CH3OCH2CH20-, C2H5OCH20-, C2H5OCH2OCH20-, or C2H5OCH2CH20-. Other suitable hydrolysable groups include phenoxy, acetoxy, chlorine, bromine or iodine. R2 and R3 can take the same values as R1. It will be understood, of course, that one, two or all three R 1, R 2 and R 3 can be selected from groups of formula 0CpH 2p + 1 as defined above, phenoxy, acetoxy, hydroxyl, chlorine, bromine or iodine. Preferably, only one or two of R1, R2 and R3 is hydroxyl and, more preferably, none is hydroxyl. Non-limiting examples of groups R2 and R3 which are not hydrolyzable include C? -10 alkyl, C2-? 0 mono- or di-unsaturated alkenyl, and phenyl. It is preferred that R1, R2 and R3 are all the same and are CH30-, C2H50- or C3H80-. More preferably, they are all CH30- or C2H50-. The next step of the present process consists in contacting the particles with a compound of Formula II: CH2 = CH- [-R-] t-CH2-X (II) where X is an anion and R4 is a divalent group - ( CyH2y) -, branched or unbranched, where y is an integer from 1 to 40, or an aromatic group C6_C40, and t is 0 or 1. Preferably, R4 is - (CyH2y) -, where y is from 1 to 2 and more preferably, t is 0 to 1, even more preferably t is 0 - that is, that the compound of Formula II is CH2 = CH-CH2-X. Preferably, X is selected from the group consisting of acetate, chloride, bromide, iodide, cyanide, thiocyanide, isothiocyanide and sulfate. It is preferred to contact the particles with the compound of Formula II in the presence of a catalyst. The catalyst can be added separately to the suspension, either before or after the addition of the compound of Formula II, or it can be added with the compound of Formula II, that is, by dissolving or suspending the catalyst therein. The choice of the catalyst is within the scope of a person with ordinary skill in the art. The catalyst is such that it is capable of promoting hydrosilylation between the compound of Formula II and the reaction product of the particles and the compound of Formula I. In one embodiment, the catalyst is an inorganic catalyst. As used herein, the term "inorganic catalyst" is intended to include organometallic catalysts. Preferably, the inorganic catalyst consists of a noble metal or a transition metal. More preferably, the transition metal is selected from Group VIII of the Periodic Table. See, for example, J. Mol. Ca-tal. 81 (1993), p. 207-214 (Tanaka et al.). Even more preferably, the inorganic catalyst consists of platinum. A non-limiting example of said catalyst is halo-platinic acid (e.g., chloroplatinic acid). More preferably, the platinum catalyst is one that is highly effective in promoting hydrosilylation reactions in an aqueous medium. Such catalysts are described by Kobayashi et al. in U.S. Patent 5,908,951. In other embodiments, the catalyst is an organic catalyst. Preferably, the organic catalyst consists of a free radical generating compound. The choice of such suitable compound is within the scope of a person with ordinary skill in the art. Even more preferably, the organic catalyst is selected from the group consisting of peroxides, persulfates, azo catalysts and mixtures thereof. A non-limiting example of an azo catalyst consists of azobisisobutyronitrile. It is preferred that the azo catalyst be a water soluble one - see U.S. Patent 5,908,951 [Kobayashi et al.] For a discussion of particularly preferred organic catalysts useful in the present process. It is even more preferable that the water soluble azo catalyst have a half-life of 10 hours between 25 ° C and 100 ° C and, more preferably, have a half-life of 10 hours between 40 ° C and 90 ° C. Said water-soluble azo catalysts are marketed by Wako Chemical USA, Inc. under the trade names VA-044, V-50, VA-061, V-501 VA-086. In yet another embodiment, the catalyst can be hydrogen peroxide. When the catalyst used is an inorganic silylation catalyst, it is preferred to add the catalyst as a solution or suspension in the compound of Formula II; when a free radical catalyst is employed, it is preferred to add the catalyst after having added the compound of Formula II to the suspension.

With reference to Figure 1, and without wishing to be bound by any particular theory or mode of action, a preferred embodiment * of the present process is illustrated which illustrates two ways by which hydrosilylation can be carried out. The product of the present process described hitherto preferably results in an aqueous suspension or dispersion of particles (ie, which has not yet contacted a polymer or other substrate to be filled), which can still be treated to produce a particulate material that can be advantageously dispersed in a binder material. For example, the functionality of a coupling agent can be formed on the surface of the particles in situ using the approach described in co-pending Canadian Patent Application 2,254,315, filed on November 20, 1998 - see Figure 2 of the present application for an illustrative embodiment of this approach. Alternatively, or in addition, the particles can still be hydrophobicized by forming a de-aminohydrocarbonosilane moiety, which can be formed on the surface of the particles in situ using the approach described in co-pending Canadian Patent Application 2,254,559, filed on 20 November 1998 - see Figure 3 of the present application for an illustrative embodiment of this approach. The still more treated particles can be used as an agent for formation of composition among a multitude of materials, including, but not limited to, the following: predispersion of chemical additives, polymers, alchemical paints, toners such as those used in photocopiers, modified plastics and vulcanized rubber. Embodiments of the present invention will be illustrated in relation to the following Example, which should not be used as a determinant or limiting of the scope of the invention.

EXAMPLE 1 In this Example, the following materials were used: Hi-Sil * 233 Triethoxysilane Chloroplatinic acid Allyl bromide Sodium tetrasulfide Oleilamine ® Buna cement CB-24 (polybutadiene) in hexane Sundex * 8125 Vulcanox * 4020 N-Oleyl chloride N- (trimethoxysilyl) propyl ammonium In a 4 L glass beaker, in a fume hood, 510 grams of Hi-Sil® 233 (amorphous precipitated silica from PPG Industries) and 2.040 grams of water were combined and The resulting mixture was stirred with an air-operated agitator equipped with a radial propellant until a uniform suspension was obtained. The pH of the suspension was adjusted to 5.5 with dilute HCl. The beaker was placed on a hot plate and the suspension heated to 60 ° C with high agitation. Triethoxysilane (40.0 grams, 240 mmol) was added at the vortex dropwise over 5 minutes. After 10 minutes of stirring, allyl bromide (25.0 grams, 207 mmol) was added dropwise to the stirred suspension. Using a pipette, 5.0 ml of a 0.5% solution of chloroplatinic acid in methanol was added to the suspension. After 2 hours of further stirring at 59-60 ° C, a commercial aqueous solution of sodium tetrasulfide (38.8 grams of 34% by weight Na2S) was added in one portion. The suspension immediately turned greenish gray. The viscosity increased somewhat and then decreased after 5 minutes. The agitator power was adjusted to maintain circulation.

After two hours and twenty minutes of additional agitation, the color had turned pale to a dirty white. The stirring was switched off and the beaker was removed from the heat source. The suspension was covered with a plastic wrap and allowed to settle overnight in a quiescent state at room temperature. The next morning, the material of the beaker was again placed under agitation at room temperature. A pH check using a pH meter gave a reading of 8.4. Commercial distilled oleylamine (Akzo ARMEEN OLD, 14.6 grams, ~ 55 mmol) was dissolved in 50 ml of methanol and the resulting solution was added at vortex for 5 minutes in 1 ml aliquots. Heating was started and the suspension was maintained between 40 ° C and 50 ° C for two hours. The pH dropped uniformly during this period of an 8, 8 initial to a final 8.5. The pH was then adjusted to 7.5 with dilute hydrochloric acid. The suspension was cooled to room temperature and then quantitatively transferred to a 2 L plastic bucket in a fume hood using a spatula and a small amount (~ 55 ml) of wash water.

Polybutadiene cement (3.188 grams of 20% by weight Buna CB-24 in hexane), Sundex 8125 aromatic processing oil (191 grams) and Vulcanox 4020 antioxidant (5.0 grams) were then added. The mixture was stirred manually for 5 minutes with a spatula. The mixture was then placed under agitation using the previously used air agitator and propellant combination. After several minutes, most of the treated silica was collected by the organic phase and a small volume of turbid water was removed. Then N-oleyl-N- (trimethoxysilyl) propylammonium chloride (9.6 grams of a 50% by weight solution in methanol) was added to the aqueous phase and mixing was continued for several minutes to obtain a clear aqueous phase. crystalline Coagulation was performed in a fume hood to remove the solvent. The mixture was slowly added to stirred water maintained at 92-95 ° C with low pressure steam. The aqueous coagulation serum remained clear throughout the coagulation. The lump was isolated by sieving through a 1 mm screen, washed with water and then dried for 4 hours at 85 ° C. The yield of product was 1,327 grams, dry basis. Although the present invention has been described with reference to preferred embodiments and illustrative examples, those skilled in the art will understand, of course, that various modifications of these preferred embodiments and illustrative examples can be made without departing from the spirit and scope of the invention. All publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extent as if it were specifically and individually indicated that each publication, patent or individual patent application was incorporated. as a reference in its entirety.

Claims (42)

Claims

1. A process for treating particles and making them hydrophobic, which process consists of the following steps: (i) contacting the particles with a compound of Formula I: R1 R -Si-H (I) RJ where at least one of R1, R2 and R3 is hydroxyl or a hydrolyzable group, and (ü) contacting the particles with a compound of Formula II: CH2 = CH- [-R-] t-CH2-X (II) where X is an anion and R4 is or a divalent group - (CyH2y) -, branched or unbranched, where y is an integer from 1 to 40, or an aromatic group C6-C40, and t is 0 or 1.

2. The process defined in claim 1, wherein each of R1, R2 and R3 is hydroxyl or a hydrolyzable group.

3. The process defined in claim 1, wherein the hydrolysable group has the formula 0CpH2p + 1, where p has a value of 1 to 10.

4. The process defined in claim 1, wherein the hydrolysable group is selected from -Cl and -Br.

5. The process defined in claim 1, wherein R 4 is a straight chain C 1 -C 40 alkylene radical.

6. The process defined in claim 1, wherein R 4 is a straight chain Ci-Cio alkylene moiety.

7. The process defined in claim 1, wherein R 4 is a straight chain C 1 -C 5 alkylene radical.

8. The process defined in claim 1, wherein R 4 is a phenyl group.

9. The process defined in claim 1, wherein X is selected from the group consisting of acetate, chloride, bromide, iodide and sulfate.

10. The process defined in claim 1, wherein the particles consist of water-insoluble inorganic compounds.

11. The process defined in claim 1, wherein the particles are selected from the group consisting of silica, titanium oxide, ferric oxide, ferric oxide hydrate, ferrous oxide, antimony oxide, barium carbonate, zinc oxide, zinc borate, lead oxide (including red lead oxide), dibasic lead phosphite, lead silicate, tribasic lead sulphate and mixtures thereof.

12. The process defined in claim 1, wherein Step (ii) is carried out in the presence of a catalyst.

13. The process defined in claim 11, wherein the catalyst is an inorganic catalyst.

14. The process defined in claim 12, wherein the inorganic catalyst contains a transition metal.

15. The process defined in claim 13, wherein the transition metal is selected from Group VIII of the Periodic Table.

16. The process defined in claim 12, wherein the inorganic catalyst contains platinum.

17. The process defined in claim 12, wherein the inorganic catalyst contains a haloplatinum acid.

18. The process defined in claim 11, wherein the catalyst is an organic catalyst.

19. The process defined in claim 17, wherein the organic catalyst contains a free radical generating compound.

20. The process defined in claim 17, wherein the organic catalyst is selected from the group consisting of peracids, peroxides, persulfates, an azocatalyst and mixtures thereof.

21. The process defined in claim 17, wherein the organic catalyst consists of azobisisobutyroni-trile.

22. The process defined in claim 17, wherein the organic catalyst consists of hydrogen peroxide.

23. A process for treating particles, consisting of the step of contacting particles having one or more of the following formulas: pi (d) pi (e) where: P is a particle; Ra and R may be the same or different and each is selected from the group consisting of C 1-40 alioyl, C 2-40 alkenyl mono- or di-saturated C 3-4 aromatic C 3-4, and vi is an integer in the range of 1 to 10s or more; ^ with a compound of Formula II: ™ CH2 = CH- [-R-] t-CH2-X (II) wherein X is an anion and R4 is a divalent group - (CyH2y) -, branched or unbranched, where and is an integer from 1 to 40, or an aromatic group C6-C40, and t is 0 or 1"

24. The process defined in claim 23, wherein each of R1, R2 and R3 is hydroxyl or a hydrolyzable group.

25. The process defined in claim 23, wherein the hydrolysable group has the formula 0CpHp + 1, where p has a value of 1 to 10.

26. The process defined in claim 23, wherein R 4 is a straight chain C 1 -C 40 alkylene radical.

27. The process defined in claim 23, wherein R 4 is a straight chain C -C 0 alkylene radical.

28. The process defined in claim 23, wherein R 4 is a straight chain C 1 -C 5 alkylene radical.

29. The process defined in claim 23, wherein R 4 is a phenyl group.

30. The process defined in claim 23, wherein X is selected from the group consisting of acetate, chloride, bromide, iodide and sulfate.

31. The process defined in claim 23, wherein the particles consist of water-insoluble inorganic compounds.

32. The process defined in claim 23, wherein the particles are selected from the group consisting of silica, titanium oxide, ferric oxide, ferric oxide hydrate, ferrous oxide, antimony oxide, barium carbonate, zinc oxide, zinc borate, lead oxide (including red lead oxide), dibasic lead phosphite, lead silicate, tribasic lead sulphate and mixtures thereof.

33. The process defined in claim 23, wherein the process is carried out in the presence of a catalyst.

34. The process defined in claim 33, wherein the catalyst is an inorganic catalyst.

35. The process defined in claim 34, wherein the inorganic catalyst contains a transition metal.

36. The process defined in claim 34, wherein the transition metal is selected from Group VIII of the Periodic Table.

37. The process defined in claim 34, wherein the inorganic catalyst contains platinum.

38. The process defined in claim 34, wherein the inorganic catalyst contains a haloplatinum acid.

39. The process defined in claim 33, wherein the catalyst is an organic catalyst.

40. The process defined in claim 39, wherein the organic catalyst contains a free radical generating compound.

41. The process defined in claim 39, wherein the organic catalyst is selected from the group consisting of peroxides, persulfates, azobisisobutyronitrile and mixtures thereof. 42 The process defined in claim 39, wherein the organic catalyst consists of azobisisobutyronitrile.