MXPA98001507A - Polymerization process for precipitation paraproducir an adsorbient polymer capable of attraping solid and liquid particles and the product of mi - Google Patents

Abstract

A process for producing a microporous oil-sorbent polymer comprising the steps of: dissolving a polyunsaturated monomer in an organic silicone solvent to provide a monomer mixture containing more than 90% by weight of the polyunsaturated monomer; polymerizing said monomers by polymerization by precipitation, under an inert atmosphere to precipitate micro-particles, microporous in the form of micro-particles, agglomerates, and aggregates having an apparent bulk density from about 0.02 gm / cm 2 to about 0.01 gm / cm 2 and capable of adsorbing at least about 20% of the weight of the organic materials based on the total weight of the polymer plus the organic material adsorbed

Description

PROCESS OF POLYMERIZATION BY PRECIPITATION TO PRODUCE AN ADSORBENT POLYMER CAPABLE OF ATTRACTING SOLID PARTICLES AND LIQUIDS AND THE PRODUCT OF THE SAME CROSS REFERENCE WITH THE RELATED APPLICATION This application is a continuation in part of the application Series No. 08 / 486,107 filed on June 7, 1995 and of the application Series No. 08 / 486,455 filed on June 7, 1995, which is a continuation in part of the application Series No. 08 / 327,580 filed on October 24, 1994, abandoned. BACKGROUND OF THE INVENTION A. Field of the Invention The present invention relates to a process of polymerization by precipitation to produce an oil adsorbent polymer in the form of unitary microparticles, aggregates and agglomerates of micro-particles capable of trapping any solid. oleophilic and / or oleophilic liquid compound desired for its release. More particularly, the present invention relates to a process for producing a highly degraded and highly porous pleophilic polymer in the form of individual microparticles; the aggregates of micro-particles; and conglomerates of aggregates (agglomerates) of microparticle spheres characterized by a unit particle size of about 0.1 to about 100 microns, preferably about 0.1 to about 80 microns, preferably having an average particle size of about 5 to about 12 microns and an oil absorbency of at least about 80% by weight or greater, based on the weight of the adsorbed oil plus the microparticle adsorbent polymer. The present invention is also directed to complete units of oil adsorbent microparticle aggregates, produced by the process having sizes above about 3000 microns, preferably less than about 1000 microns. The microparticles produced by the process of the present invention have extremely low apparent bulk densities in the range from about 0.02 gm / cc to about 0.1 gm / cc, preferably from about 0.03 gm / cc to about 0.07 gm / cc, more preferably from about 0.03 gm / cc to about 0.04-0.05 gm / cc. The icro-particles produced by the process of the present invention are capable of sustaining and releasing oils, creams, cleansers, oleophilic drugs and other active organic compounds and compositions, for use in the pharmaceutical, chemical process, cleaning, and pharmaceutical industries. cosmetics B. Background Previous disclosures of polymer particles appear in US Patents 3,493,500 and 3,658,772, which were published respectively on February 3, 1970 and April 25, 1972. They teach the production of aqueous suspensions of polymer particles to starting from acrylic acid monomer and / or acrylamide monomer in an aqueous reaction medium at a pH of 1-4. Both patents teach that the resultant polymer suspensions that were not characterized in terms of particle size or structure were suitable for use as flocculation agents for the treatment of waste water. It was subsequently discovered that polymers could be made into a porous macroparticle form by a variety of techniques. The technique has established that "the type of polymerization technique used is an important factor in the determination of the resulting product". See US Patent 4,962,170, in column 2, line 4. As stated in the '170 patent in column 2, line 7-11 ,. "Within each type of polymerization, there are process alternatives, which can have a significant impact on the resulting product" "the differences in the polymerization techniques are enough that a procedure used in a type of polymerization technique will not necessarily have the same effect if used in another polymerization technique ". In this way, there is a significant degree of unpredictability in the matter. The porous polymer particles are capable of being prepared by one of two precipitation polymerization processes in a single solvent system, or suspension polymerization in a two-phase liquid system. The precipitation polymerization technique is presented in U.S. Patents 4,962,170 and 4,962,133, both of which were issued on October 9, 1990. The '170 patent discloses a process of precipitation polymerization where the monomers described are soluble in a single solvent system, while the resulting polymer, which is insoluble, precipitates the solution once a critical size is obtained. In the process of '170, the monomer solution consists exclusively of one or more types of polyunsaturated monomer. Since each monomer is polyunsaturated, each monomer also functions as a degradant, resulting in a highly degraded polymer particle. Similar to the '170 patent, the' 130 patent also utilizes the precipitation polymerization process to produce a porous polymer particle. However, other than the '170 patent, where the monomer solution consists exclusively of polyunsaturated monomers, the process' 130 discloses that the monomer solution can include a monosaturated monomer in combination with a polyunsaturated monomer, wherein the polyunsaturated monomer can comprise up to 90% by weight of the total weight of the monomers. Since the precipitation polymerization technique depends on the formation of the polymer aggregates of precipitated polymer particles, the monomer solution is not vigorously stirred during the polymerization to avoid separation of the aggregated polymer particles. U.S. Patent 5,316,774 is directed to a suspension polymerization process, again limited to a maximum of 90% by weight of polyunsaturated monomers based on the total weight of the monomers. Accordingly, it is an object of the present invention to provide a process for making sorbent micropolymers from a monomer solution containing more than 90% by weight, preferably from about 92% to 100% by weight of polyunsaturated monomers , based on the total weight of the monomers in the monomer solution. The process of '133 is limited to a solvent system that is an aqueous / organic azeotropic mixture. Since the organic solvent can not be separated from the water in an azeotropic mixture, the azeotropic solutions present special problems of waste disposal. According to the above, it is an object of the present invention to provide a process for making micropolymers oil adsorbents that do not require an azeotropic solution. In addition, the particles produced by the '133 process vary extensively in size from approximately less than 1 micron in average diameter for unit particles to approximately twelve hundred microns in an average diameter for conglomerates of condensed aggregates. The great variety in size limits the usefulness and properties of polymer particles. In accordance with the above, it is also an object of the present invention to provide a process for making polymer microparticles of a smaller distribution of different size. Another process published in the art to produce microscopic polymers is a suspension polymerization in itself where an active ingredient included within the monomer mixture is retained in the polymer formed at the termination of the polymerization. Examples of the suspension polymerization in itself are included in US Pat. No. 4,724,240, where the polymerization of a monounsaturated monomer and a polyunsaturated monomer in an aqueous / polyvinylpyrrolidone system containing an emollient, as the active agent, produced only microparticles. relatively large, which have an average diameter "between 0.25 to 0.5 mm" (250 to 500 microns) that contains the emollient inside, at the termination of the polymerization. A problem with a particle that has an average diameter of 250-500 microns, is that in which the particle is able to be detected when touched. This is an undesirable property if the particle is to be used in a lotion or cream or other cosmetic formulations. Accordingly, it is also an object of the present invention to provide a process that is capable of making polymer particles having a smaller average diameter, eg, 0.5μm to 120μm, for a softer surface feel; as well as aggregates and complete units of aggregates capable of trapping oleophilic solids and viscous liquids. A second problem with the process of the '240 patent is that it is limited to those active ingredients that are capable of dissolving in the organic solvent. The polymeric microparticles of the present invention are capable of adsorbing organic compounds and organic compositions containing hydrophobic compounds dissolved in an organic solvent, as well as solid organic compounds trapped within an interior of an open center of an aggregate conglomerate of micro spheres. -particle. In addition, the active ingredient (s), which can be patented, must be provided in volume to the polymer manufacturer in such a way that they can be trapped in the particles during the polymerization process. To overcome these problems, it is a further object of the present invention to provide polymeric microparticle aggregates having an internal vacuum volume, defined within a continuous chain or conglomerate of aggregated micro-particle spheres, which are capable of absorbing and trapping hydrophobic and fluid solids, within the interior surface area of each open sphere, in large quantities, so that they can be loaded into the interior volume surrounded by the micro-particle spheres with adsorbed active hydrophobic organic ingredient (s) in solid form or dissolved in solvent, and charged on the outer surface area of the aggregate spheres with any hydrophilic compound, in solid form or as a viscous solution or dispersion in organic solvent base. A third problem with the '240 process is that it is not suitable for use when the active ingredient is a mixture of compounds that differ significantly from others in lipophilicity. In such a situation, the most lipophilic of the active ingredients would be selectively isolated in the pores of the polymer made by the '240 process. To overcome this problem, the process of '240, would have to be applied separately to each of the active ingredients, and subsequently the resulting products would be mixed. However, such additional processing and mixing is expensive. According to the above, it is a further object of the present invention to provide a process for producing a micro-particle aggregate wherein the micro-particle aggregate is capable of adsorbing a plurality of organophilic active ingredients. SUMMARY OF THE INVENTION It was unexpectedly discovered that the process of the present invention is capable of producing microparticles and microparticle aggregates having a high compound adsorbency for oleophilic compounds, and can be made in a variety of size distributions of particle by a precipitation polymerization process. The present invention is directed to a process for making a porous polymer aggregate formed from a plurality of micro-particles exhibiting a high oil adsorbency. The method of the present invention comprises the steps of: dissolving at least one and preferably at least - io ¬ two polyunsaturated monomers, preferably also an effective amount of an organic polymerization initiator, in a water-immiscible organic solvent and a silicone solvent that is inert (non-reactive) with respect to the monomers and the resulting polymer to provide a monomer mixture; in the preferred embodiment, the silicone solvent also acts as a solvent, so that a separate solvent is not needed; continue the agitation at a rate that does not break the aggregates into smaller aggregates or individual spheres, for example, using a peripheral speed for a rotating vane impeller of approximately 0.1 to 0.2 meters per second above approximately 15 meters per second, per example, 30 rpm, during the polymerization of the monomers in the suspended micro-droplets to produce microporous polymer microparticles, and micro-particle aggregates in the form of aggregate spheres having a volume of interior space surrounded by aggregate spheres; and separating the microporous polymer microparticle aggregates from the organic solvent to produce microporous, oil adsorbing polymer microparticles having a diameter of from about 0.1 to about 100 microns, preferably from about 0.1 to about 80 microns. Aggregates, or complete units of microparticles, can be made to have diameters from about 1 to about 500 μm and a new and unexpected adsorbent capacity for oleophilic compounds, both in solid form and in liquid form. Preferably more than 99% of the aggregates and agglomerates are less than 500 μm, preferably less than about 100 μm. The present invention is further directed to microparticles of oil adsorbents, microporous and microparticle aggregates of a polymer comprising at least one and preferably at least two polyunsaturated monomers, the microparticles and the aggregates of microparticles were characterized by having a volume of space surrounded by aggregated micro-particle spheres and having an average unitary micro-particle diameter of less than 10 microns, preferably less than about 8 microns, having a total adsorption capacity for organic liquids, for example , mineral oil which is at least 80% by weight, preferably at least approximately 85% by weight, based on the total weight of the adsorptive microparticles plus the adsorbed oil. In a preferred embodiment, the complete microparticle units, or aggregated spheres of microparticles of the present invention, are characterized by an average unit diameter of from about 5 to about 500 microns, preferably about 5 μm to about 100 μm, some aggregates having a diameter from about 2 to about 100 μm, having other diameters from about 20 to about 80 microns. BRIEF DESCRIPTION OF THE DRAWINGS Figures 1 and 2 are graphs showing the timing disconnection of Silicone Fluid (DC 244) and vitamin E acetate, respectively, from Poly-Pore L of Example 1, (tested under 10 liter / min of the air velocity) compared to the vaporization of these materials from an open non-sorbent (empty) incineration capsule; and Figures 3-5 are photographs of the microparticles of Example 1, amplified 100, 1500 and 10000 times, respectively. DETAILED DESCRIPTION OF THE INVENTION The present invention has two aspects. In its first aspect, it addresses a process for making a polymer by the process of precipitation polymerization in a porous micro-particle form, including aggregates of the micro-particles, and complete units or aggregate conglomerates that are capable of slurping high volumes of oleophilic compounds (hydrophobic) in solid and / or liquid forms. The oleophilic compounds are adsorbed in an open interior area surrounded by aggregated micro-particles. The preferred process of the present invention comprises the steps of: dissolving at least one and preferably at least two polyunsaturated monomers, preferably together with an effective amount of an organic polymerization initiator, in a silicone fluid solvent in water-immiscible water, to provide a monomer mixture; slowly stir the dissolved monomers and the silicone solvent; continue the slow agitation during the polymerization of the monomers in the silicone fluid to produce microporous polymer microparticles and aggregates thereof; and separating the microporous and agglomerated polymer microparticles, from the silicone solvent to produce oil microporous, microporous polymer microparticles and aggregates in the form of spheres, sphere aggregates and sphere agglomerates having a smaller diameter at about 500 microns, preferably less than about 100 microns, more preferably less than about 80 microns, and a new and unexpected adsorptive capacity for oleophilic compounds, both in solid form and in liquid form. The term "sorptive" (or "sorption") is used herein to refer to the ability or ability of the microparticles of the present invention to both adsorb and sorbate oleophilic materials. However, the amount of organic (oleophilic) liquid that is adsorbed is negligible in comparison to the amount of solids and / or liquids that are adsorbed between the agglomerated spherical micro-particles. In the micro-particles that are treated, matter freely uses the term "adsorptive", such as in "total adsorptive capacity" or in "adsorptive capacity that flows freely". However, it is understood that these references in the matter to "total adsorptive capacity" inherently include the total adsorptive and absorptive abilities of a particle, unless otherwise defined. Similarly, references in the subject to "free flowing adsorptive capacity" also inherently include both absorptive and adsorptive capabilities. The process of the present invention copolymerizes at least one and preferably at least two polyunsaturated (polyethylenically unsaturated) monomers, preferably allyl methacrylate, and an ethylene glycol dimethacrylate. Both allyl methacrylate and ethylene glycol dimethacrylate are diunsaturated monomers. The diunsaturated monomers also function as degrading agents.

The highly degraded polymer microparticles of this invention are prepared by polymerizing one and preferably at least two monomers having at least two unsaturated bonds (hereinafter referred to as "polyunsaturated" monomers) said polymerized monomers being, including not more than about 40%, preferably not more than about 9% of the total weight of the mononunsaturated comonomer monomer. Examples of polyunsaturated monomers may be poly-acrylates ("poly" means two or more), -methacrylates, or -itaconates of: ethylene glycol, propylene glycol; di-, tri-, tetra-, or poly-ethylene glycol and propylene glycol; trimethylpropane, glycerin, erythritol, xylitol, pentaerythritol, dipentaerythritol, sorbitol, mannitol, glucose, sucrose, cellulose, hydroxylcellulose, methylcellulose, 1,2 or 1,3-propanediol, 1,3 or 1,4-butanediol, 1,6-exanediol, , 8-octanediol, cyclohexanediol, or cyclohexanetriol. Similarly, the compounds can be used as bis (acrylamido or methacrylamido). These compounds are, for example, methylene amide bis (acrylic or methacrylic), 1,2-dihydroxy-ethylene bis (acrylyl or methacryl) amide, hexamethylene-bis (acryl or methacryl) amide.

Another group of useful monomers may be represented by vinyl di or poly esters, such as divinylpropyleneourea, divinyl-oxalate, -malonate, succinate, -glutamate, -adipate, -sebacate, -maleate, fumarate, -citraconate, and -mesaconate.

Other suitable polyunsaturated monomers include benzene, divinyl toluene, diallyl tartrate, allyl pyruvate, allyl maleate, divinyl tartrate, triallyl melamime, N, N'-methylene bis acrylamide, glycerin dimethacrylate, glycerin trimethacrylate, maleate of diallyl, divinyl ether, diallyl monoethylene glycol citrate, ethylene glycol vinyl allyl citrate, allyl vinyl maleate, diallyl itaconate, ethylene glycol dicalcitic acid diester, divinyl sulfone, 1, 3, 5-triacryltriazine hexahydro , triallyl phosphate, diallyl ether of benzene phosphonic acid, triethylene glycol polyester of maleic anhydride, polyallyl sucrose, polyallyl glucose, sucrose diacrylate, glucose dimethacrylate, di-, tri-, and tetra pentaerythritol. acrylate or methacrylate, trimethylol propane di- and triacrylate or methacrylate, sorbitol dimethacrylate, 2- (1-aziridinyl) -ethyl-methacrylate, tri-ethanolamide-di-acrylate or dimethacrylate, tri triethanolamine acrylate or trimethacrylate, tartaric acid dimethacrylate, triethylene glycol dimethacrylate, bis-hydroxyethylacetamide dimethacrylate and the like.

Other polyethylene-unsaturated crosslinking monomers include ethylene glycol diacrylate, diallyl faphthalate, trimethylolpropanetrimethacrylate, polyvinyl esters and ethylene glycol polyallyl, glycerol, pentaerythritol, diethylene glycol, monothio- and dithio-glycol derivatives, and resorcinol; divinylketone, divinyl sulfide, allyl acrylate, diallyl fumarate, diallyl succinate, diallyl carbonate, diallyl malonate, diallyl oxalate, diallyl adipate, diallyl sebacate, diallyl tartrate, diallyl silicate, triallyl tricarballylate, aconitrate triallyl, triallyl citrate, triallyl phosphate, divinyl naphthalene, divinylbenzene, trivinylbenzene; alkylodivinylbenzenes, having from 1 to 4 alkyl groups of 1 to 2 carbon atoms substituted in the benzene nuclei; alkyltrivinylbenzenes having from 1 to 3 alkyl groups of 1 to 2 carbon atoms substituted in the benzene nuclei; trivinilnaphthalenes, and polyvinylantracenos. In addition, methacrylic or acrylic coated end siloxanes and polysiloxanes, methacryloyl coated end urethanes, the urethane acrylates of polysiloxane alcohols and bisphenol A bis methacrylate and ethoxylated bisphenol A bis methacrylate, are also suitable as polyunsaturated monomers.

Still another group of monomers are represented by ethylene vinyl diols or polymers, propylene, butylene, and the like, glycols, glycerin, penta erythritol, sorbitol, di or polyallyl compounds such as those based on glycols, glycerin, and the like, or combinations of vinyl allyl or vinyl acryloyl compounds such as, vinyl methacrylate, vinyl acrylate, allyl methacrylate, allylic acrylate, methacrylate methacrylate, or methallyl acrylate. In addition, aromatic, cycloaliphatic and heterocyclic compounds are suitable for this invention. These compounds include divinyl benezen, divinyl toluene, divinyl diphenyl, divinyl cyclohexane, trivinyl benzene, divinyl pyridine, and divinyl piperidine. In addition, divinyl ethylene or divinyl propylene urea and similar compounds can be used, for example, as described in U.S. Patent 3,759,880; 3,992,562; and 4,013,825, which are incorporated herein by reference. Silicones and methacryloyl or acryloyl-coated end polysiloxanes, such as those described in US Pat. Nos. 4,276,402; 4,341,889, French Patent 2,465,236, and German Publication Patent GER OLS 3,034,505, which are incorporated herein by reference, are suitable for this invention. The methacryloyl-coated end urethanes, such as those described in US Pat. Nos. 4,224,427; 4,250,322; and 4,423,099, German Publications GER OLS Nos. 2,365,631 and 2,542,314, Japanese Patent Applications Nos. 85 / 233,110; 86 / 09,424, and 86 / 30,566, and in British Patent 1,443,715, are suitable for this invention. The urethane acrylates of polysiloxane alcohols as described in U.S. Patent 4,543,398 and 4,136,250 and Bis A-bisol methacrylate bis A and ethanolated bisphenol bis A methacrylate are also suitable monomers for this invention. Suitable monoethylenically unsaturated monomers, in an amount of above about 40% by weight, preferably not more than about 9% by weight, based on the total weight of the monomers, for preparing the polymer microparticles include, ethylene, propylene, isobutylene, disobutylene, styrene, ethylvinylbenzene of vinyl pyridine, vinyltoluene, and dicyclopentadiene; ethers of methacrylic and acrylic acid, including esters of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, amyl, hexyl, octyl, ethylhexyl, decyl, dodecyl, cyclohexyl, isobornyl, phenyl, benzyl, alkylphenyl, ethoxymethyl, ethoxyethyl, ethoxyproyl, propoxymethyl, propoxyethyl, propoxypropyl, ethoxyphenyl, ethoxybenzyl, and ethoxycyclohexyl; vinyl esters, including vinyl acetate, vinyl propionate, vinyl butyrate and vinyl laurate, vinyl acetones, including vinyl methyl acetone, vinyl ethers, including methyl vinyl ether, vinyl ethyl ether, vinyl propyl ether, and isobutyl vinyl ether; and the similar. Other monosaturated monomer materials, which may be used according to the present invention, in an amount of above about 40% by weight or less, preferably not more than about 25% by weight, and more preferably not more than about 9% by weight, based on the total weight of the monomers in the monomer solution, include alkyl hydroxy esters of alpha, beta-unsaturated carboxylic acids such as 2-hydroxy methacrylate or methacrylate ethylacrylate, hydroxypropyl acrylate or methacrylate and the similar. Various acrylic or methacrylic acid derivatives, other than the esters mentioned above, are also suitable as monosaturated starting monomer materials for use in the formation of unsaturated polymer microparticles of the present invention. This includes, but is not limited to the following monomers: methacrylyl glycolic acid, glycol monometacrylates, glycerol, and other polyhydric alcohols, monometacrylates of dialkylene glycols and polyalkylene glycols, and the like. The corresponding acrylates in each example can be replaced by the methacrylates. Examples include the following: 2-hydroxyethyl acrylate or methacrylate, diethylene glycol acrylate or methacrylate, 2-hydroxypropyl acrylate or methacrylate, 3-hydroxypropyl acrylate or methacrylate, tetraethylene glycol acrylate or methacrylate, pentaethylene glycol acrylate or methacrylate, acrylate or dipropylene glycol methacrylate, acrylamide, methacrylamide, methylolacrylamide methylolacrylamide of diacetone acrylamide, and any acrylate or methacrylate having one or more branched or straight chain alkyl groups of 1 to 30 carbon atoms, preferably 5 to 18 carbon atoms , and the similar. Other suitable examples include isobornyl methacrylate, phenoxyethyl methacrylate, isodecyl methacrylate, stearyl methacrylate, hydroxypropyl methacrylate, cyclohexyl methacrylate, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, 2-acrylamido propane sulphonic acid, 2-ethylexyl methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate and methoxyethyl methacrylate.

Examples of monosaturated monomers containing carboxylic acid groups as functional groups and suitable for use as starting materials according to the invention, include the following: acrylic acid, methacrylic acid, itaconic acid, aconitic acid, cinnamic acid, crotonic acid, mesaconic acid, maleic acid, fumaric acid and the like. The partial esters of the above acids are also suitable as monosaturated monomers for use in accordance with the invention. Examples of such esters include the following: mono-2-hydroxypropyl aconite, mono-2-hydroxyethyl maleate, mono-2-hydroxypropyl fumarate, mono-ethyl itaconate, monosylic acid monomethyl ester of itaconic acid, monosylic acid monosylic acid ester malefic, and the similar. Examples of suitable monosaturated monomers containing amino groups as functional groups include the following, diethylaminoethyl acrylate or methacrylate, dimethylaminoethyl acrylate or methacrylate, onoethylaminoethyl acrylate or methacrylate, tertiary butylaminoethyl methacrylate, para-amino styrene, ortho-amino styrene , 2-amino-4-vinyl toluene, piperidinoethyl methacrylate, morpholinoethyl methacrylate, 2-vinyl pyridine, 3-vinyl pyridine, 4-vinyl pyridine, 2-ethyl-5-vinyl pyridine, acrylate and methacrylate of dimethylaminopropyl, vinyl dimethylaminoethyl ether, vinyl dimethylaminoethyl sulfide, vinyl diethyl ether, ethyl vinyl ether, methacrylate of 2-pyrrolidinoethyl, propylacrylate or methacrylate of 3-dimethylaminoethyl-2-hydroxy, acrylate or methacrylate of 2-aminoethyl , isopropyl methacrylamide, acrylamide or N-methyl methacrylamide, 2-hydroxyethyl acrylamide or methacrylamide, ammonium chloride or 1-methacryloyl-2-hydroxy-3-trimethyl sulfoethylate, 2- (1-aziridinyl) ethyl methacrylate, and the like. Polyethylenically unsaturated monomers, which ordinarily act as if they had only one unsaturated group, such as isopropene, butadiene, and chloroprene, should not be calculated as part of the content of the polyunsaturated monomer, but as part of the content of the monethylenically unsaturated monomer. The process of the present invention preferably uses an effective amount of an organic polymerization initiator to cause polymerization to occur in the organic phase solvent. However, other methods for initiating polymerization can be used instead, such as UV light, actinic radiation, or the like. By way of example, suitable organic initiators include organic peroxide initiators, such as dibenzoyl peroxide or t-butyl peroctoate, or azo initiators. Preferred initiators are azo initiators, such as 2,2'-azobisisobutyronitrile, and 2, 2'-azobis (2,4-dimethylpentanenitrile). A particularly preferred azo initiator is 2,2'-azobis (2,4-dimethylpentanenitrile, which is commercially available under the trade name VAZO 52 from DuPont, Wilmington, Del. An effective typical amount of organic initiator relative to dry monomer it was found to be about 0.2-2% by weight, preferably about 1-1.2% by weight Examples of redox systems include secondary or tertiary amines and combinations of peroxide and amine (preferably tertiary) .The ratio between the peroxide and the Amine can vary, for example, from 0.1 to 5 moles of amine per mole of peroxide It is useful to first dissolve the peroxide in one part of the solvent, and separately dissolve the amine in the other part of the solvent, then mix the part of peroxide with the monomer solution at room temperature and, subsequently, add the amine part.The charge of the amine and peroxide part can be done at the beginning of the reaction. or in portions through the reaction period. These amines are generally of the formula R2NH or R3N, wherein R is an alkyl or a substituted alkyl, cycloalkyl, aryl group. Preferably the amine is a tertiary amine. Illustrative reducing agents of this invention are methylbutylamine, bis (2-hydroxyethyl) butylamine, butyldimethylamine, dimethylamine, dibenzylethylamine, diethylmethylamine, dimethylpentylamine, diethylamine, 2,2 ', 2"-trihiroxydipropylethylamine, di-n-propyleneamine, 2, 2 ', 2"-trimethyltributylamine, triethylamine, dimethylaminoacetal, pentylhexylamine, triethanolamine, trihexylamine, trimethylamine, trioctadecylamine, trisopropylamine, tetramethylenediamine, and para-aminobenzoic acid esters, for example, p-dimethylamino-2-ethylhexyl-benzoate, dimethylaminoethyl acetate , 2- (n-butoxy) ethyl-4-dimethylaminobenzoate, ethyl benzoate of 2- (dimethylamino), ethyl-4-dimethylaminobenzoate, methyldiethanolamine, dibutylamine, N, N-dimethylbenzylamine, ethylethylamine, dipentylamine and Fe2 + peroxide. Other preferred initiators are selected from inorganic initiators such as sodium, potassium, or persulfates of ammonia and hydrogen peroxide. In the preferred process of the present invention, the monomers and the organic initiator are dissolved in a silicone solvent to produce the organic phase. Suitable silicone solvents are set forth in U.S. Patent No. 5,189,012, incorporated herein by reference. Other substantially hydro-immiscible organic solvents, including aliphatic and aromatic hydrocarbons, may be combined with the silicone solvent. Typical of these solvents are toluene, cyclohexane, fluorite silicones, chlorinated solvents, such as, trichlorethylene, trichloromethane, dichloromethane, and the like, and one or more of the heptanes, alone or in combination. The polymerization is carried out by dissolving the monomers or their mixtures in an inert silicone solvent, which does not react with the monomers or the resulting polymer. Based on the weight parts of the monomer and the solvent, adding up to 100 parts by weight, the monomers are used from 0.1 to less than 25 parts by weight, preferably, from 2 to less than 25 parts by weight, and , more preferably, from 5 to 20 parts by weight. Correspondingly, the solvent is from more than 60 parts by weight, preferably more than 70 parts by weight, more preferably more than 75-80 parts by weight up to 99.9 parts by weight, preferably from more than approximately 75 parts by weight to approximately 98 parts by weight, and more preferably, from about 80 parts by weight to about 95 parts by weight. No surfactant or dispersion aid is required. Preferred silicone solvents include those solvents set forth in U.S. Patent No. 5,189,102, incorporated herein by reference. Preferably, the solvent is relatively volatile, having a boiling point of less than about 200 ° C, preferably less than about 180 ° C in an atmosphere, and is water-immiscible. Removal of the solvent can be done by evaporation, for example, by heat and / or vacuum, or the solvent can be allowed to adsorb between the agglomerated polymeric microparticles. The polymer can be washed with a suitable solvent, for example, the same solvent used in the polymerization, before it is dried. Suitable solvents that can be used together with the silicone solvent include a wide range of substances, notably inert, non-polar organic solvents. Some of the most convenient examples are alkanes, cycloalkanes, and aromatics. Specific examples of such solvents are alkanes of from 5 to 12 carbon atoms, straight or branched chain cycloalkanes of from 5 to 8 carbon atoms, benzene, and alkyl substituted benzenes, such as toluene and the xylenes. Solvents of another type include C-C2o alcohols / perfluorite polyethers, silicone oils. Examples of silicone oils are polydimethylcyclosiloxane, hexamethyldisiloxane, cyclomethicone, dimethicone, amodimethicone, trimethylsilylamodimethicone, polysiloxane-polyalkyl copolymers (such as dimethicone stearyl and dimethicone cetyl), dialkoxydimethyl polysiloxanes (such as dimethicone stearoxi), polyquaternium 21, betaine propyl PG dimethicone, dimethicone copolyol and dimethicone cetilica copolyol. Removal of the solvent can be done by solvent extraction, evaporation, or similar conventional operations. In carrying out the process of the present invention, the monomer (s) dissolved in the silicone solvent phase is polymerized under an inert atmosphere (e.g., Argon or Nitrogen). The polymerization reaction in the slowly stirred reaction mixture is allowed to proceed (for example, 10-100 rpm when shaking the blade) when increasing the reaction temperature. As discussed in Example 1, some polymerization was observed in the stirred reaction mixture at about 46 ° C. Massive polymerization was observed at approximately 53 ° C. Then, the mixture is preferably heated to 60 ° C-75 ° C to drive the polymerization reaction to completion.

Once the polymerization is completed, the microporous polymer microparticles and the resulting microparticle aggregates are separated from the reaction mixture, such as by filtration or by purification. Once the polymer microparticles and the aggregates thereof have been separated from the water-immiscible organic solvent, they are converted into the oil adsorbent polymer microparticles of the present invention, adsorbing the outside of the spheres the compounds oleophilic in an interior space defined between agglomerated and aggregated unitary micro-particles, surrounded by aggregated micro-particles, capable of trapping solids and liquids containing oleophilic compounds much better than the micro-particles of the prior art. However, the present invention is also directed to a composition of microparticles adsorbents of oil and microporous matter and aggregates thereof in the form of microparticle spheres, and aggregates thereof, comprising a polymer formed at polymerize at least two polyunsaturated monomers (each containing at least two carbon double bonds), optionally including one or more mononosaturated monomers, in an amount of above 40% by weight, preferably not more than about 9% by weight, based on the total weight of the monomers The resulting micro-particles, in the form of spheres having an average unit diameter of less than about 2 microns, preferably less than about 1 micron, have a total adsorption capacity for mineral oil that is at least about 80% by weight , preferably at least about 85% by weight, based on the total weight of the polymer plus the adsorbed oil. The meaning of the phrase "unit diameter" refers to the average diameter of the individual particle, not the diameter of the agglomerates. The average unit diameter of the individual microparticles is more preferably from about 0.5 to about 2 microns; more preferably, from about 0.5 to about 1 micron; while the diameter of the agglomerates is preferably from about 5 to about 20 microns, preferably from about 5 to about 12 microns. Preferably, the microparticles of the present invention have a total mineral oil sorption capacity of about 82-93% by weight; more preferably, about 84% by weight or more; more preferably from about 85-93% by weight or more. The microparticles of the present invention appear as a white powder and constitute discrete free-flowing solid particles even when charged with a lipophilic material up to their "free-flowing" absorption capacity. In preferred oil and microporous sorbent microparticles of the present invention, two diunsaturated monomers, one of the polyunsaturated monomers being an ethylene glycol dimethacrylate, preferably monoethylene glycol dimethacrylate is polymerized with another polyunsaturated monomer, for example, allyl methacrylate. The preparation of such a microparticle is described in Example 4 herein, wherein the other diunsaturated monomer is allylic methacrylate in a preferred molar ratio of about 1: 1.2 allylic methacrylate: monoethylene glycol dimethacrylate. Table I compares the oil adsorption of the microparticles of the Examples with the oil adsorption reported for the copolymer microparticles of US Patent 4, 962.133, and those of a commercially available oil sorbent product. Table I states that the polymers of the present invention, which contain polyunsaturated monomer (s), have a higher total adsorption capacity of mineral oil over the copolymers of the prior art, for example, DC 6603. In particular, the polymer of Example 1 exhibited a total mineral oil sorption capacity of 91.1% by weight, compared to 89.6% by weight for copolymer LMA / EDGM and 83.5% by weight for the commercially available product (Dow Corning Product No.6603). The abbreviations used herein are identified as follows: BMA butyl methacrylate EGDMA monoethylene glycol dimethacrylate AMA allyl methacrylate MMA methyl methacrylate EXAMPLE 1 An oleophilic porous terpolymer was produced by the precipitation polymerization technique, by slowly mixing in 2000 milliliters of the polymerization reactor equipped with an agitator blade, 1.80 grams of butyl methacrylate monomer or 5.9 mole percent, 10.75 grams of allyl methacrylate monomer, or 39.4 mole percent, and 23.45 grams of ethylene glycol dimethacrylate monomer or 54.7 mole percent. Cyclometicon DC 244 fluid was added as the solvent to the reactor in the amount of 564 grams. The monomers were soluble in the solvent. The mixture including monomers, solvent and 0.72 grams of VAZO 52 catalytic initiator, was purified with Argon. At the agitation speed of 30 rpm, the system was heated to about 45 ° C until the polymerization was started, at which time the temperature was increased to 65 ° C for six hours, in order to complete the polymerization. During this time, the terpolymer was precipitated from the solution. The polymerization produced unit particles of a diameter less than about one micron. Some unit particles adhered together, providing agglomerates of the order of magnitude from about 20 to 80 microns in diameter. Some agglomerates adhered additionally and were fused and welded together, forming aggregates of complete units of sustained agglomerates without cohesion of the magnitude type from about 200 to 800 microns in diameter. The mixture was filtered to remove excess solvent, and a bark of wet powder was dried in a vacuum oven. A dry hydrophobic terpolymer powder consisting of unitary, agglomerated particles, and aggregates was isolated. The total adsorption capacity was determined by the addition of an incremental amount of liquid (mineral oil) up to a known amount of powder, using a moderate mixture until the powder no longer flowed free and still adsorbing liquid. The total adsorption capacity was determined by the following calculation: TAC% = (dust weight + liquid L) - (initial dust weight_)? 100 powder weight + liquid EXAMPLE 2 Example 1 was repeated for each of the series of monomer systems shown in Table 1. In each case, the submicron sized copolymer powders were produced employing a stirring speed of about 30 rpm. The initiator was VAZO 52. The adsorption capacities of various polymeric powders for mineral oil were determined and shown in the Table, together with the molar proportions of monomers EXAMPLE 3 The equipment of Example 1 was employed, and 12,585 grams of monomer were copolymerized. of allyl methacrylate, or 46 mole percent, and 23.45 grams of ethylene glycol dimethacrylate monomer, or 54 mole percent. The result of the adsorption capacity for mineral oil using several monomers is shown in Table 1.

TABLE 1 The abbreviations used in Table 1 are: BMA butyl methacrylate LMA methacrylate lauryl AMA methacrylate allyl EGDM ethylene glycol dimethacrylate EXAMPLE 4 (Poly-Poro ™ L 200) An oleophilic porous copolymer was produced by the precipitation polymerization technique by slowly mixing in 2 liters of the Polemerization Reactor equipped with an agitator type paletea, 12.55 grams of allylic methacrylate or 46 mole percent, and 23.45 grams of ethylene glycol dimethacrylate or 54 mole percent. The cyclometicon DC 244 fluid as the solvent was added to the reactor in the amount of 564 grams. The monomers were soluble in the solvent. The mixture that includes monomer, solvent and 0.72 grams of catalytic initiator, VAZO 52 was purified with Argon. At the agitation speed of 30 rpm, the system was heated to about 45 ° C until the polymerization was started, at which time the temperature was increased to 65 ° C for six hours, in order to complete the polymerization. During this time, the polymer was precipitated from the solution. The polymerization produced unit particles of a diameter less than about one micron. Some unitary particles were also adhered and were fused and welded together, forming complete units of aggregates freely sustained from agglomerates of the order of magnitude from about 5 to 100, preferably from 5 to about 80 microns, microns in diameter. The mixture was filtered to remove excess solvent, and a bark of wet powder was dried in a vacuum oven. A dry hydrophobic polymeric powder consisting of unitary, agglomerated, and aggregate particles, or agglomerate conglomerates was isolated, having a total adsorption capacity for light mineral oil of 11.2 grams per gram of polymer, and an apparent density of 0. 034 g / cm3. The particles had a particle size distribution as follows: The total adsorption capacity was determined by adding incremental amounts of liquid (mineral oil) to a known amount of powder, using a moderate mixture, until the powder no longer flowed freely and still adsorbing liquid. The adsorption capacities for various oleophilic materials are as follows: EXAMPLE 5 The copolymer of Example 4 was charged with a solution of metalonic acid / salicylic acid to a container of 12 grams per gram, and dried in an oven at 80 ° C to evaporate the methanol. The dry polymer powder was fine, white powder, with 78.3% unsubstituted salicylic acid, that is, 2.8 grams per gram. Non-renewed salicylic acid is not photosensitive, nor explosive, considering that free salicylic acid is both photosensitive and explosive. Salicylic acid is an antiseptic and antifungal agent. EXAMPLE 6 A solution was made by dissolving 1 gram of dibenzolic peroxide in 8 grams of chloroform. The solution was adsorbed on 1 gram of the polymer of Example 4, then the chloroform was evacuated, and the unrenewed dibenzolic peroxide polymer system was pulverized into a fine, white powder. Usually dibenzolic peroxide is sensitive to shock and has a tendency to explode on contact with metals. The non-renewed benzoic peroxide polymer system was inactive to friction, to collide and contact metals, considering that, the benzolic peroxide is explosive. The charge capacity of dibenzolic peroxide was 50%, that is, 1 gram per gram. EXAMPLE 7 Retinol was dissolved in the same amount of ether of 5.5 grams of the solution that was adsorbed on 1 gram of polymer powder of Example 4. Then, the ether was evacuated by vacuum and a light yellow powder of free flow was obtained. The capacity of Retinol was 2.75 grams per gram, that is, 73%. Usually Retinol is in the form of sticky crystals, and is photosensitive, and irritating to the skin, it is used in cosmetic formulations and as a vitamin,

Claims (27)

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the property described in the following claims is claimed as property.

1. A process for producing a microporous oil adsorbing polymer comprising the steps of: dissolving a polyunsaturated monomer in a silicone solvent to provide a monomer mixture containing more than 60% by weight of the polyunsaturated monomer; polymerizing said monomer by precipitation polymerization, under an inert atmosphere to precipitate microparticles, microporous in the form of microparticles, agglomerates, and aggregates having an apparent bulk density from about 0.02 gm / cm3 to about 0.01 gm / cm3 and are capable of adsorbing at least about 80% of the weight of the oleophilic materials based on the total weight of the polymer, plus the oleophilic material adsorbed.

2. The process according to claim 1, characterized in that said polyunsaturated monomer is an ethylene glycol dimethacrylate selected from the group consisting of monoethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and triethylene glycol dimethacrylate.

3. The process according to claim 2, characterized in that said ethylene glycol dimethacrylate is monoethylene glycol dimethacrylate.

4. The process according to claim 3, characterized in that another polyunsaturated monomer is dissolved in said silicone solvent, said other monomer being methacrylate allyl in a molar ratio of allylic methacrylate: monoethylene glycol dimethacrylate of 1: 1 to 1: 2.

5. The process according to claim 4, characterized in that the ratio of allylic methacrylate to ethylene glycol dimethacrylate is about 1:12.

6. The process according to claim 1, characterized in that it further includes adding a polymerization initiator to said monomer mixture.

7. The process according to claim 6, characterized in that said polymerization initiator is an initiator of the azo nitrile type.

8. The process according to claim 1, characterized in that the average unit particle diameter is from about 1 to about 50 microns.

9. The process according to claim 1, characterized in that the particle diameter is from about 0.1 to about 100 microns.

The process according to claim 9, characterized in that the average unit particle diameter is less than about 2 microns.

11. A process for producing microporous and oleophilic micro particles of high adsorption capacity, said particles being in the form of oleophilic and microporous spherical unit particles; and agglomerates of said micro-particles in asymmetric form, said particles being characterized by an apparent bulk density from about 0.02 to about 0.1 gm / cm3, said process comprises the steps of: (a) mixing a solution comprising from about 0.1 to about 25 parts by weight of one or more polyunsaturated monomers, and from 75 to 99.9 parts by weight of a silicone solvent; (b) polymerizing said monomer (s) by precipitation polymerization in said silicone solvent to form said microporous and oleophilic microparticles and agglomerates of microparticles; and (c) separating said microparticles and agglomerates from said silicone solvent to provide said microporous and oleophilic microparticles and the agglomerates thereof.

12. The process according to claim 11, characterized in that said apparent bulk density is from about 0.02 to about 0.07 g / cm3.

13. The process according to claim 12, characterized in that said bulk density is from about 0.03 to about 0.06 g / cm3.

14. The process according to claim 11, characterized in that said microparticle agglomerates have a mean diameter in the range from about 5 to about 80 microns.

15. The process according to claim 14, characterized in that said microparticle aggregates have a mean diameter in the range from about 5 to about 20 microns.

16. The process according to claim 15, characterized in that said microparticle aggregates have an average diameter in the range from about 5 to about 12 microns.

17. The process according to claim 11, characterized in that said microparticles are the product of the polymerization of one or more polyunsaturated degrading monomers of methacrylate or acrylate.

18. The process according to claim 17, characterized in that said micro-particles are the product of the polymerization of said one or more polyunsaturated acrylate-degrading monomers.

19. The process according to claim 17, characterized in that said micro-particles are the product of the polymerization of said one or more polyunsaturated methacrylate-degrading monomers.

20. The process according to claim 1, characterized in that said micro-particles are further characterized by having a particle size distribution, where all of said micro-particles have a particle size of between about 0.1 and about 80 microns.

21. An oil-microporous sorbent microparticle comprising a polymer of allylic methacrylate and an ethylene glycol dimethacrylate, in a molar ratio of from about 1: 1 to about 1: 2, said particle was characterized as having an average unit diameter of less than about 80 microns, an apparent bulk density from about 0.02 to about 0.07 g / cm3, and a total adsorption capacity for the mineral oil that is 80% by weight or greater, based on the total weight of polymer and adsorbed oil.

22. The microparticle according to claim 21, characterized in that the total adsorption capacity for the mineral exceeds 85%.

23. The microparticle according to claim 22, characterized in that the total adsorption capacity for the mineral exceeds 90%.

24. The microparticle according to claim 21, characterized in that said ethylene glycol dimethacrylate is a member selected from the group consisting of monoethylene glycol dimethacrylate, diethylene glycol dimethacrylate and triethylene glycol dimethacrylate.

25. The microparticle according to claim 24, characterized in that said ethylene glycol dimethacrylate is monoethylene glycol dimethacrylate.

26. The microparticle according to claim 23, characterized in that said total adsorption capacity for mineral oil is 85-93% by weight or greater, based on the weight of the polymer, plus the mineral oil adsorbed.

27. The microparticle according to claim 11, characterized in that the average unit particle diameter is from about 1 to about 20 microns