MXPA97007175A - Process to produce a sorbent copolymer of oil and my product - Google Patents

Abstract

The present invention is directed to a porous copolymer micro-particle having a high oil adsorption. The method of the present invention comprises the steps of: dissolving at least two polyunsaturated monomers in an organic solvent immiscible with water to provide a monomer mixture containing more than about 60%, preferably 100% by weight of monomers polyunsaturated, adding the monomer mixture to an aqueous solution which preferably has an effective amount of a suspension stabilizer dissolved therein to form a two-phase organic / aqueous liquid system, vigorously stirring the biophase liquid system at a rate sufficient to cause the water-immiscible organic phase to be suspended as micro-droplets in the aqueous phase, continue vigorous stirring during the polymerization of the monomers in the suspended micro-droplets to produce a microporous polymer microparticle, and separate the microporous polymer micro-particle the organic solvent to produce a micro-particle the microporous polymer and oil sorbent having an average unit diameter of less than about 25 micron

Description

PROCESS TO PRODUCE A SORBENT COPOLYMER OF OIL AND THE PRODUCT OF THE SAME CROSS REFERENCE WITH THE RELATED TECHNIQUE This application is a continuation in part of the application Serial No. 08 / 486,107 filed on June 7, 1995.

BACKGROUND OF THE INVENTION A ^. Field of the Invention The present invention relates to a process for producing an oil-sorbent polymer in the form of micro-particles. More particularly, the present invention relates to a process for producing a very porous and highly crosslinked hydrophobic polymer characterized by an average unit particle size of about 1 to about 102 microns and an oil sorbency of 72% by weight or greater. The present invention is also directed to the oil sorbent micro-particles produced by the process. The micro-particles produced by the process of the present invention have the ability to contain and release oleophilic and hydrophilic oils, creams, cleaners, medicaments and other organic active compounds and other hydrophilic active compounds as well as compositions for P1131 / 97MX used in the cosmetics, cleaning, chemical process and pharmaceutical industries.

B. Background The first disclosures of polymer particles appear in U.S. Patent Nos. 3,493,500 and 3,658,772, which were published on February 3, 1970 and April 25, 1972, respectively. These teach the production of aqueous suspensions of polymer particles 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, which were not characterized by particle size or structure, were suitable for use as flocculating agents for the treatment of sewage. Subsequently, it was discovered that polymers could be manufactured in particulate form per sheet 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 United States Patent No. 4,962,170 in column 2, line 4. As stated in column 2, lines 7-11 of the '170 patent, "within each type of polymerization, there are alternatives to Pl .31 / 97MX procedure that have a significant impact on the resulting product "" [t] he differences in polymerization technique are sufficient in such a way that a procedure used in a type of polymerization technique will not necessarily have the same effect if it is used in another polymerization technique. "Thus, there is an important degree of lack of prediction in the art.Polous polymeric particles have the ability to be prepared by one of two processes - precipitation polymerization in a a single solvent or suspension polymerization in a two-phase liquid system The precipitation polymerization technique is presented in U.S. Patent Nos. 4,962,170 and 4,962,133, both published on October 9, 1990. The '170 patent presents a process of polymerization by precipitation, where the monomers presented are soluble in the system of a single solvent e, while the resulting polymer, which is insoluble, precipitates from the solution once the critical size is obtained. In the process of '170, the monomer solution consists exclusively of one or more types of polyunsaturated monomer. Because each monomer is polyunsaturated, each monomer also functions as a crosslinker, resulting in a very high polymer particle.

Pl .31 / 97MX crosslinked. Like the '170 patent, the' 133 patent also uses the precipitation polymerization process to produce a porous polymer particle. However, unlike the process of '170, where the monomer solution consists exclusively of polyunsaturated monomers, the process of '133 presents the monomer solution which 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 monomers. U.S. Patent No. 5,316,774 is directed to a suspension polymerization process, again limited to a maximum of 90% by weight of polyunsaturated monomers based on total weight of monomers. Accordingly, an object of the present invention is to provide a process for making sorbent microparticles from a monomer solution containing more than 90%, preferably from about 92% to 100% polyunsaturated monomers. , by weight based on the total weight of monomers in the monomer solution. The '133 process is limited to a solvent system that is an aqueous / organic azeotrope. Because in an azeotrope, the organic solvent can not Fl .31 / 97MX separated from water, azeotropic solutions present special problems of waste disposal. In accordance with the above, an object of the present invention is to provide a process for manufacturing sorbent micropolymers that do not require an azeotropic solution. In addition, the particles produced by the '133 process vary widely in size from less than about 1 micron in average diameter for unit particles to approximately one thousand two hundred microns in average diameter for clusters of molten aggregates. The great variability in size limits the usefulness and properties of polymer particles. In accordance with the foregoing, it is also an object of the present invention to discover a process for making polymer microparticles of a less diverse size. Another process presented in the art for producing microscopic polymers is suspension polymerization in itself where the precipitating agent is the active ingredient around which the polymerization occurs. Examples of the suspension polymerization in itself include U.S. Patent No. 4,724,240, wherein the polymerization of a monounsaturated monomer and a polyunsaturated monomer in an aqueous / polyvinylpyrrolidone system containing an emollient, as the active agent , produced relatively large microparticles, which have an average diameter "between 0.25 to 0.5 mm" (250 to 500 microns) that inside them already contain the emollient. A problem with a particle that has an average diameter of 250-500 microns is that the particle can be perceived by touch. This is an undesirable property if the particle will be used in a lotion or cream or in other cosmetic formulations. Accordingly, an object of the present invention is also to provide a process that is capable of manufacturing polymer particles having a smaller diameter for a softer or finer perception. A second problem with the process of the '240 patent is that it is limited to those active ingredients that are capable of dissolving the solvent. In addition, the active ingredient (s) that can be privately owned must be provided in bulk to the polymer manufacturer, so that they are trapped in the particles during the polymerization process. To overcome these problems, a further objective of the present invention is to provide polymeric microparticles having evacuated pores that are capable of being impregnated with hydrophobic fluids in large quantities, so that they can be loaded with privately owned active ingredients by any individual manufacturer that incorporate them as release agents in their technology.

A third problem with the '240 process is that it is not adapted to be used when the active ingredient is a mixture of components that differ significantly from each other in their oleophilicity. In this situation, the most oleophilic active ingredient would be selectively isolated in the pores of the polymer manufactured by the '240 process. To overcome this problem, the '240 process would have to be applied separately to each of the active ingredients and after that, the resulting products would be mixed. However, this additional processing and mixing is expensive. In accordance with the above, a further objective of the present invention is to provide a process for producing a microparticle, wherein the microparticle is capable of receiving a plurality of active ingredients.

SUMMARY OF THE INVENTION It was unexpectedly discovered that the process of the present invention is capable of producing microparticles which not only have a high oil adsorbent, but also exhibit a substantially uniform particle size. The present invention is directed to a process for manufacturing a porous polymer with micro-particulate size that exhibits a high sorbency of oil.

The method of the present invention comprises the steps of: dissolving at least two polyunsaturated monomers together with an effective amount of an organic polymerization initiator in an organic solvent immiscible with water to provide a monomer mixture; adding the monomer mixture to an aqueous solution which preferably has an effective amount of a suspension stabilizer dissolved therein to form a two-phase organic / aqueous liquid system; vigorously stirring the biphasic liquid system at a rate sufficient to cause the water-immiscible organic phase to be suspended as micro-droplets in the aqueous phase, - continue vigorous agitation during the polymerization of the monomers in the suspended micro-droplets for produce a microporous polymer micro-particle; and separating the microporous polymer microparticle from the organic solvent to produce a microporous polymer microporous polymer and oil sorbent having an average unit diameter of less than about 25 microns and a total mineral oil suction capacity of 72% in weight or greater, calculated as percent of adsorbed oil, based on the total weight of the polymer plus the oil adsorbed. The present invention is further directed to microporous microporous adsorbent microparticles of oleophilic and hydrophilic material comprising a polymer consisting of at least two polyunsaturated monomers, the microparticles being characterized as having an average unit diameter of less than about 50 microns, preferably less than about 25 microns and a total mineral oil sorption capacity that is 72% by weight or greater, preferably at least about 80%. In a preferred embodiment, the microparticles of the present invention are characterized by an average unit diameter of from about 1 to about 50 microns, more preferably from about 1 to about 20 microns, more preferably, from about 1 to about 16 microns or less than about 20 microns.

BRIEF DESCRIPTION OF THE FIGURE Figure 1 is an analysis of the particle size distribution of a mixture of various micro-particle products produced by the process of the present invention as measured in a MICROTRAC Full-Range Particle Analyzer. , (See. 4.12), a dispersion is reflected approximately 100 microns, an average unitary diameter of approximately 15 microns and that 80% of the particles of the mixture have a size between 6.2 and 32.7 microns.

DETAILED DESCRIPTION OF THE INVENTION The present invention has two aspects. In its first aspect it is directed to a process for manufacturing a polymer in the form of porous microparticles that is capable of sorbing high volumes of oleophilic and hydrophilic liquids. The process of the present invention comprises the steps of: dissolving at least two polyunsaturated monomers, preferably together with an effective amount of an organic polymerization initiator in an organic solvent immiscible with water to provide a monomeric mixture; adding the monomer mixture to an aqueous solution which preferably has an effective amount of a suspension stabilizer dissolved therein to form a two-phase organic / aqueous liquid system, - vigorously agitating the two-phase liquid system at a rate sufficient to cause the phase water-immiscible organic is suspended as micro-droplets in the aqueous phase, for example, at a tip velocity of 1 to about 15 meters per second, preferably from about 5 to about 10 meters per second, more preferably a approximately 8 meters per second; continue the vigorous stirring during the polymerization of the monomers in the suspended micro-droplets to produce microporous polymer microparticles; and separating the microporous polymer microparticle from the organic solvent to produce a microporous microporous polymer and oil sorbent microparticle having an average unit diameter of less than about 25 microns and a total mineral oil sorption capacity of 72%. in weight or greater, based on total weight of oil adsorbed plus polymer. The term "with sorption capacity" ("sorption") is used herein to refer to the ability of the microparticles of the present invention to both adsorb and absorb oleophilic and hydrophilic materials. In the discussion of micro-particles, the technique vaguely uses the term "adsorption", as in "total adsorption capacity" or in "free-flowing adsorption capacity". However, it is understood that references in the art to "total adsorption capacity" inherently include total capabilities I MI / i 'II. of absorption and adsorption of a particle, unless defined otherwise. Likewise, references in the art to "free-flowing adsorption capacity" also inherently include both adsorption capacity and absorption. The process of the present invention copolymerizes at least two polyunsaturated monomers (polyethylenically unsaturated), preferably allyl methacrylate and an ethylene glycol dimethacrylate. Both allyl methacrylate and ethylene glycol dimethacrylate are di-unsaturated monomers. The di-unsaturated monomers also function as crosslinking agents. The highly crosslinked polymer microparticles of this invention are prepared by polymerizing monomers having at least two unsaturated bonds (hereinafter referred to as "polyunsaturated" monomers) the monomers to be polymerized include no more than about 40%, preferably no more than about 9% of the total monomer weight of the monounsaturated comonomers. 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; trimethylol propane, glycerin, erythritol, xylitol, pentaerythritol, dipentaerythritol, sorbitol, mannitol, glucose, sucrose, cellulose, hydroxylcellulose, methyl cellulose, 1,2 or 1,3-propanediol, 1,3 or 1,4-butanediol, 1,6-hexanediol , 1,8-octanediol, cyclohexanediol, or cyclohexanothiol. Similarly, bis (acrylamido or methacrylamido) compounds can be used. These compounds are, for example, methylene bis (acrylic or methacryl) amide, 1,2-dihydroxy-ethylene bis (acrylic or methacryl) amide, hexamethylene-bis (acrylic or methacryl) amide. Another group of useful monomers could be represented by di or polyvinyl esters, such as for example divinyl propylene urea, divinyl oxalate, -malonate, -succinate, -glutamate, -adipate, -sebacate, -maleate, -fumarate, -citraconate, and -mesaconato. Other suitable polyunsaturated monomers include divinyl benzene, divinyl toluene, diallyl tartrate, allyl pyruvate, allyl maleate, divinyl tartrate, triallyl melamine, N, N'-methylene bis acrylamide, glycerin dimethacrylate, glycerin trimethacrylate, diallyl maleate, divinyl ether, diallyl monoethylene glycol, ethylene glycol vinyl allyl citrate, allyl vinyl maleate, diallyl itaconate, ethylene glycol diester of itaconic acid, divinyl sulfone, hexahydro 1,3,5-triacryltriazine, triallyl phosphite, diallyl ether of benzenephosphonic acid, ethylene glycol ester of i i) 11-itaconic acid, divinyl sulfone, hexahydro-l, 3, 5-triacriltriazine, triallyl phosphite, diallyl ether of benzene phosphonic acid, maleic anhydride polyester of triethylene glycol, polyallyl sucrose, polyallyl glucose, sucrose diacrylate, glucose dimethacrylate, di-, tri- and tetra-acrylate or pentaerythritol methacrylate, di and triacrylate or trimethylol propane methacrylate, dimethate sorbitol crilate, 2- (1-aziridinyl) -ethyl methacrylate, diacrylate or dimethacrylate. tri-ethanolamine, triacrylate or triethlonamine trimethacrylate, tartaric acid dimethacrylate, triethylene glycol dimethacrylate, bis-hydroxy ethylacetamide dimethacrylate and the like. Other suitable polyethylenically unsaturated crosslinking monomers include ethylene glycol diacrylate, diallyl phthalate, trimethylolpropanetrimethacrylate, polyvinyl and polyallyl ethers of ethylene glycol, 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, thialyl silicate, triallyl tricarballylate, triallyl, triallyl citrate, phosphate I I I '' triallyl, divinyl naphthalene, divinylbenzene, trivinylbenzene; alkyldivinylbenzenes having from 1 to 4 alkyl groups of 1 to 2 carbon atoms substituted in the benzene nucleus, - alkyltrivinylbenzenes having from 1 to 3 alkyl groups of 1 to 2 carbon atoms substituted in the benzene nucleus; trivinilnaphthalenes, and polyvinylantracenos. In addition, siloxanes and polysiloxanes of end terminated with acryl or methacryl, end urethanes with methacryloyl, urethane acrylates of polysiloxane alcohols and bisphenol A bis methacrylate and ethoxylated bisphenol A bis methacrylate, which are also suitable as polyunsaturated monomers . Another group of monomers is represented by the di or polyvinyl ethers of ethylene, propylene, butylene and the like, glycols, glycerin, pentaerythritol, sorbitol, di or polyallyl compounds, such as those based on glycols, glycerines and the like or combinations of compounds of vinyl allyl or vinyl acryloyl, such as for example vinyl methacrylate, vinyl acrylate, allyl methacrylate, allyl acrylate, methallyl methacrylate or methallyl acrylate. In addition, the aromatic, cycloaliphatic and heterocyclic compounds are suitable for this invention. These compounds include divinyl benzene, divinyl toluene, divinyl diphenyl, divinyl cyclohexane, trivinyl benzene, divinyl pyridine, and divinyl ii / i'f-. piperidine. Additionally, divinyl ethylene or divinyl propylene urea and similar compounds can be used, for example, as described in U.S. Patent Nos. 3,759,880; 3,992,562; and 4,013,825, which are incorporated herein by reference. The siloxanes and polysiloxanes end-terminated with acryloyl or methacryloyl such as those described in U.S. Patent Nos. 4,276,402; 4,341,889, French Patent 2,465,236 and German Patent Publication GER OLS 3,034,505, which are incorporated herein by reference, are suitable for this invention. The methacryloyl-terminated end urethanes, such as those described in U.S. Patent Nos. 4,224,427; 4,250,322; and 4,423,099, the 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, British Patent 1,443,715, are suitable for this invention. Urethane acrylates of polysiloxane alcohols as described in Patent US Nos. 4,543,398 and 4,136,250 and bisphenol A bis methacrylate and bis methacrylate ethoxylated bisphenol A monomers are also suitable for this invention. Suitable monoethylenically unsaturated monomers, in an amount up to about 40%, of 1 - . 1 - 1 i i l \. preferably no more than about 9% by weight, based on the total weight of monomers, for preparing polymer micro-particles include ethylene, propylene, isobutylene, di-isobutylene, styrene, vinyl pyridine ethylvinylbenzene, vinyltoluene, and dicyclopentadiene; esters of acrylic and methacrylic acid including methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, amyl, hexyl, octyl, ethylhexyl, decyl, dodecyl, cyclohexyl, isobornyl, phenyl, benzyl, alkylphenyl, ethoxymethyl, ethoxyethyl , ethoxypropyl, propoxymethyl, propoxyethyl, propoxypropyl, ethoxyphenyl, ethoxybenzyl, and etoxiciclohexil esters, - vinyl esters, including vinyl acetate, vinyl propionate, vinyl butyrate and vinyl laurate, vinyl ketones, including vinyl methyl ketone ,. vinyl ethyl ketone, vinyl isopropyl ketone, and methyl isopropenyl ketone, vinyl ethers, including vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether and vinyl isobutyl ether; and the like. Other monounsaturated monomeric materials that can be used in accordance with the present invention, in an amount of up to about 9% by weight, based on total weight of the monomers in the monomer solution include hydroxyalkyl esters of alpha, beta unsaturated carboxylic acids, such as for example 2-hydroxy ethylacrylate or methacrylate, hydroxypropyl acrylate I 1 I il / '! / I-I \ or methacrylate and the like. Many acrylic or methacrylic acid derivatives, in addition to the mentioned esters, are also suitable as initial monounsaturated monomeric materials for use in the formation of the unsaturated polymer microparticles of the present invention. These include, but are not limited to, the following monomers: methacrylyl glycolic acid, glycol monometacrylates, glycerol monomers, and other polyhydric alcohols, dialkylene glycol monomethacrylates and polyalkylene glycols and the like. The corresponding acrylates in each case can be replaced by the methacrylates. Examples include: acrylate or methacrylate, 2-hydroxypropyl acrylate or methacrylate, diethylene glycol methacrylate or acrylate, 2-hydroxypropyl methacrylate or acrylate, 3-hydroxypropyl methacrylate or acrylate, tetraethyleneglycol acrylate or methacrylate pentaethylene methacrylate acrylate or dipropylene glycol, acrylamide, methacrylamide, diacetone acrylamide, methylolacrylamide, methylol methacrylamide and any acrylate or methacrylate having one or more alkyl groups straight or branched chain of 1 to 30 carbon atoms, preferably 5 to 18 carbon atoms carbon, and the like. Other suitable examples include isobornyl methacrylate, phenoxyethyl methacrylate, methacrylate of 1Ml i) II isodecyl, stearyl methacrylate, hydroxypropyl methacrylate, cyclohexyl methacrylate, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, 2-acrylamido propanesulfonic acid. , 2-ethylhexyl methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate and methoxyethyl methacrylate. Examples of monounsaturated momomeres containing carboxylic acid groups as functional groups and which are suitable for use as raw materials according to the invention include the following: acrylic acid, methacrylic acid, itaconic acid, aconitic acid, cinnamic acid, crotonic acid, acid mesaconico, maleic acid, fumaric acid and the like. The partial esters of the above acids are also suitable as monounsaturated monomers for use in accordance with the invention. Cases of these esters include the following: aconite, mono-2-hydroxypropyl, mono-2-hydroxypropyl maleate, mono-2-hydroxypropyl fumarate, mono-ethyl itaconate, monomethyl cellosolve ester of itaconic acid, monomethyl ester cellosolve of maleic acid and the like. Examples of suitable monounsaturated monomers containing amino groups as functional groups include the following: methacrylate or diethylaminoethyl acrylate methacrylate or dimethylaminoethyl acrylate, methacrylate or monoethylaminoethyl acrylate, tert-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, methacrylate and dimethylaminopropyl acrylate, vinyl ether dimethylaminoethyl, dimethylaminoethyl vinyl sulfide, dimethylaminoethyl vinyl ether, ammonium methyl vinyl ether, 2-pyrrolidinoethyl methacrylate, 3-dimethylaminoethyl-2-hydroxy-propyl methacrylate or acrylate, 2-aminoethyl methacrylate or acrylate, isopropyl methacrylamide, methacrylamide or N-methyl acrylate, methacrylate or 2-hydroxyethyl acrylate, l-methacryloyl-2-hydroxy-3-trimethyl ammonium chloride or sulfomethylate , methacrylate. 2- (1-aziridinyl) ethyl, and the like. Polyethylenically unsaturated monomers which ordinarily act as when they have only one unsaturated group, such as isoprene, butadiene and chloroprene, should not be calculated as part of the polyunsaturated monomer content, but as part of the content of the monoethylenically unsaturated monomer. The process of the present invention preferably uses an effective amount of an organic polymerization initiator to cause the polymerization to be carried out in the organic phase solvent. However, other methods of initiating the polymerization can be used instead of this, such as for example UV light, actinic radiation or the like. By way of example, suitable organic initiators include organic peroxide organizers, such as dibenzoyl peroxide or t-butyl peroctoate, or azo initiators. Preferred initiators are the azo initiators, such as, for example, 2'-azobisisobutyronitrile and 2,2'-azobis (2,4-dimethyl pentanenitrile). A particularly preferred azo initiator is 2, 2'-azobis (2,4-dimethylpentanenitrile), which is commercially available under the tradename VAZO 52 from DuPont, Wilmington, Dela. A typical effective amount of organic initiator relative to the dried monomer was found to be about 0.5-2% by weight, preferably about 1-1.2% by weight. Examples of redox systems include secondary or tertiary amines and combinations of amine (preferably tertiary) and peroxide. The ratio between the peroxide and the amine may vary 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 dissolve the amine separately in another part of the solvent, then mix the peroxide part with the monomer solution at room temperature and, subsequently, add the amine part. The charge of the peroxide and amine part can be carried out at the beginning of the reaction or in portions throughout the reaction period. These amines generally have the formula R2NH or R3N wherein R is an alkyl group or an alkyl, cycloalkyl or substituted aryl group. Preferably, the amine is a tertiary amine. Illustrative reducing agents of this invention are methylbutyl amine, bis (2-hydroxyethyl) butyl amine, butyldimethyl amine, dimethyl amine, dibenzylethyl amine, diethylmethyl amine, dimethylpentyl amine, diethyl amine, 2 ', 2"-trihydroxydipropyl ethyl amine, di-n-propylene amine, 2, 2 ', 2"-trimethyltributyl amine, triethyl amine, dimethyl aminoacetal, pentylhexyl amine, triethanolamine, trihexyl amine, trimethyl amine, trioctadecyl amine, tripropyl amine, triisopropyl amine, tetramethylene diamine, and ester of para-amino benzoic acid, for example, p-dimethyl amino-2-ethylhexyl-benzoate, dimethyl aminoethyl acetate, 2- (n-butoxy) ethyl 4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate, ethyl-4-dimethylamino benzoate, methyldiethanolamine, dibutyl amine, N, N-dimethylbenzylamine, methylethyl amine, dipentyl amine and Fe + peroxide. Other preferred initiators are selected from inorganic inhibitors such as for example sodium, potassium or ammonium persulfates, and hydrogen peroxide. In the preferred process of the present invention, the monomers and the organic initiator are dissolved in an organic solvent substantially immiscible with water, porogen, to produce the organic phase. Organic solvents substantially immiscible in water include aliphatic and aromatic hydrocarbons. Typical solvents are toluene, cyclohexane, silicone solvents, including fluoro silicones, chlorinated solvents, such as for example trichlorethylene, tetrachloromethane; dichloromethane and the like, and one or more of the heptanes alone or in combination. Based on considerations of boiling point, volatility, toxicity and solubility, a heptane is the most preferred solvent, most preferably using n-heptane. Polymerization is achieved by dissolving the monomers or their mixtures in a solvent that does not swell or dissolve the resulting polymer. Based on the weight parts of the monomer and the solvent totaling 100 parts by weight, the monomers are used from 0.1 to less than about 25 parts by weight, preferably from about 2 to less than about 25 parts by weight, and more preferably, from about 5 to about 20 parts by weight. Correspondingly, the solvent is present from more than about 75 parts by weight to about 99.9 parts by weight, preferably, from more than about 75 parts by weight to about 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. In most cases, the alcohols can be used as the monomeric solvent. Preferably, the solvent is relatively volatile, has a boiling point less than about 200 ° C, preferably less than about 180 ° C at one atmosphere and is miscible in water. The removal or removal of the solvent can be achieved by evaporation, for example, by heat and / or vacuum. The polymer can be washed with a suitable solvent, for example, the same solvent used in the polymerization before drying it. Suitable solvents include a wide range of substances, non-polar and notably inert organic solvents. Some examples include alkanes, cycloalkanes, and aromatics. Specific examples of these solvents are alkanes of from 5 to 12 atoms M l ll carbon, 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 other types include C4-C10 alcohols. to the perfluoro polyethers, and to the silicone oils. Examples of silicone oil are poly-dimethylcyclosiloxane, hexamethyldisiloxane, cyclomethicone, dimethicone, amodimethicone, trimethylsilylamodimethicone, polysiloxane-polyalkyl copolymers (such as stearyl dimethicone and cetyl dimethicone), dialkoxydimethylpolysiloxanes (such as stearoxi dimethicone), polyquaternium 21, dimethicone propyl PG-betaine, dimethicone copolyol and cetyl dimethicone copolyol. Removal or elimination of the solvent can be carried out by means of solvent extraction, evaporation or similar conventional operations. The process of the present invention also uses an aqueous phase. The aqueous phase comprises an aqueous solution preferably (optionally) having an effective amount of a suspension stabilizer dissolved therein. Suspension stabilizers are well known in the art. Suitable suspension stabilizers include starch, gum arabic, polyvinyl alcohol, sodium polymethacrylate, magnesium silicate, sodium bentonite clay, and methyl cellulose, hydroxide of 1: 1; magnesium (Mg (OH)); polyvinylpyrrolidone (PVP); polyvinyl alcohol (PVOH), - calcium phosphate; magnesium phosphate, -lignites. A preferred suspension stabilizer is methyl cellulose, such as for example that which is commercially available from Dow Chemical Company, Midland, MI. with the Methocel A4C Premium brand. In the development of the process of the present invention, the organic phase is combined in an inert atmosphere (eg, argon or nitrogen) with an aqueous phase. The combination is usually carried out at approximately room temperature (approximately 23 ° C). The combined phases must be shaken vigorously. Stirring may begin during or after the combination of the two phases. Preferably, vigorous stirring is used during the combination of the two phases. More preferably, the organic phase is added slowly with vigorous stirring or moving vigorously to a larger volume of the aqueous phase. By the phrase "vigorous agitation" as used herein, it is meant that the stirring rod or impeller is rotated between about 800-2000 revolutions per minute ("rpm") preferably at about 1400-1600 rpm. The function of the vigorous agitation is - to facilitate the separation of the organic phase into micro-droplets, which, with the help of the suspension stabilizer, are I 1 I. i / il isolate each other as discrete mini-reaction vessels that are surrounded by water. In the process of the present invention, water functions not only to separate the micro-droplets, but also as a heat transfer vehicle to transfer heat from the micro-droplets of monomers to initiate the exothermic polymerization reactions that occur in each micro-droplet. The polymerization reaction is allowed to proceed in the vigorously stirred reaction mixture raising the reaction temperature. As shown in Example 1, at about 46 ° C, some precipitation is observed in the stirred reaction mixture. At about 53 ° C, a massive polymerization is observed. The mixture is then heated preferably to 75 ° C to drive the polymerization reaction to completion. Once the polymerization is complete, the resulting microporous polymer microparticles are separated from the reaction mixture, for example by filtering or sieving. However, at this point the separated particles are filled with the water-immiscible organic solvent of the reaction mixture. By selecting an organic solvent that is also volatile, the solvent is easily removed from the pores of the Pl -1? 1 / 97MX copolymer particles, preferably by steam distillation or with another washing process, such as vacuum distillation. Once the microporous polymer microparticles have been separated from the water-immiscible organic solvent, so that their lipophilic micropores are evacuated, they become the microporous and oil-sorbent copolymer microparticles of the present invention. Alternatively, the organic solvent may remain in place as an active material (suspension polymerization in itself). Thus, the present invention is also directed to a composition of material - a microporous microparticle and an oleophilic and hydrophilic adsorbent comprising a polymer formed by the copolymerization of at least two polyunsaturated monomers (each of which contains at least two carbon-to-carbon double bonds) optionally including one or more monounsaturated monomers, in an amount of up to about 40%, preferably not more than about 9% by weight, based on total weight of the monomers, the microparticle is characterized by having an average unit diameter of less than about 50 microns, preferably less than about 25 microns, and a total sorption capacity of mineral oil which is at least about 72% by weight, preferably at least about 80% by weight, based on the total weight of the polymer plus the mineral oil adsorbed. The phrase "average unit diameter" refers to the average diameter of the individual particle and not to the diameter of the agglomerates that may be formed from time to time due to static loading or for other reasons. The average unit diameter of the microparticle is more preferably from about 1 to about 20 microns; more preferably, from about 1 to about 16 microns. The typical particle size distribution extends to approximately 100 microns with particles generally not less than 1 micron in size. See, for example, Figure 1. Figure 1 is a particle size distribution of a mixture of several of the microparticle products produced in accordance with the examples herein, which reflect a dispersion of about 100 microns, an average unit diameter of approximately 15 microns, and that 80% of the microparticles in the mixture have a size between 6.2 and 32.7 microns and a minimum size of at least 1 micron. Preferably, the micro-particle of the present PL .31 / 97MX invention has a total mineral oil sorption capacity of approximately 74% by weight or greater; more preferably, about 76% by weight or greater; more preferably about 78-93% by weight or greater, based on the total weight of the polymer plus the mineral oil. The sorption capacity of light mineral oil of the polymers of the present invention is not expected to exceed about 95% by weight. The micro-particles of the present invention appear as a white powder and constitute free-flowing discrete solid particles even when charged with an oleophilic and / or hydrophilic material for their "free-flowing" sorption capacity. In a preferred microporous and oil sorbent microparticle of the present invention, a mono-unsaturated monomer of butyl methacrylate is copolymerized with two di-unsaturated monomers - one of the poly-unsaturated monomers is an ethylene glycol dimethacrylate, preferably dimethacrylate of monoethylene glycol. The preparation of this microparticle is described in Example 1 herein, wherein the other unsaturated monomer is allyl methacrylate and the ratio or molar ratio of butyl methacrylate: allyl methacrylate: monoethylene glycol dimetharylate was within a molar ratio preferred monomers from 1: 3 to 5: 5 to 7, E1431 / 97MX respectively, more preferably about 1: 4: 6.1. Table I compares the oil adsorption of the (terpolymer) microparticle of Example 1 with the reported oil adsorption of the copolymer microparticles of U.S. Patent No. 4,962,133 and that of a sorbent product of oil commercially available. The data relating to the copolymer of U.S. Patent No. 4,962,133 was selected because the copolymers of '133 employ a monounsaturated monomer and a unsaturated monomer. Table I states that the polymers of the present invention, which contain at least two polyunsaturated monomers, have a higher total mineral oil adsorption capacity on both BMA / EGDM copolymers and a commercially available copolymer (MMA / EGDM) . In particular, the polymer of Example 1 exhibited a total mineral oil adsorption capacity of 78.3% by weight, compared to 72.2% by weight for the best reported BMA / EGDM copolymer of the prior art and 64% for the product commercially available (Dow Corning Product No. 5640). The abbreviations used in this and in Table I are identified as follows: E 1., 1/9 / M / BMA butyl methacrylate EGDMA monoethylene glycol dimethacrylate AMA allyl methacrylate MMA methyl methacrylate TABLE I Monomers Proportion Solvent Total Capacity of Molar Capacity Adsorption of Adsor-Mineral Oil in Weight g / g BMA / EGDM1 1: 4 Hexane 70.6% 2.4 BMA / EGDM1 1: 1.5 Hexane 70.6 ?, 2.4 BMA / EGDM1 1.5: 1 Hexane 12.2% 2.6 BMA / EGDM1 4: 1 Hexane 54.5% 1.2 BMA / AMA / EGDM 1: 4: 6 Heptane 78.3% 3.6 MMA / EGDM: '1: 1.1 - 64% 1.8 1 Data taken from Table XIV of the Patent of the United States No. 4,962,133 based on particles that were prepared by precipitation of particles in an azeotrope. 2 Particle produced by Example 1 of the present invention.

Product No. 5640 Dow Corning that has a reported average diameter of approximately 25 microns.

EXAMPLE 1 In particular, 1.75 grams of Methocel A4C Premium were dissolved in 191.1 grams of water in a 2000 ml, three neck resin flask equipped with a stirrer, a thermometer, a condenser and an argon purge. A solution of 17.53 grams of allyl methacrylate, 2.93 grams of butyl methacrylate, 38.23 grams of monoethylene glycol dimethacrylate, 81.07 grams of n-heptane solvent and 0.73 grams of VAZO 52 were bubbled with argon for 10 minutes. The resulting mixture was added slowly to the stirred aqueous solution at 1,500 rpm of Methocel at 23 ° C under an argon atmosphere. The temperature rose to 46 ° C with constant stirring when precipitation started. Mass polymerization was observed at 53 ° C. The reaction mixture was then heated to 75 ° C and this temperature was maintained for an additional six hours. After which, the reaction mixture was subjected to steam distillation to remove heptane and residual monomers. The terpolymer beads were separated from the reaction mixture by filtration. The separated terpolymer beads were washed with deionized water and dried in an oven at 60 ° C. The dry terpolymer was a white, odorless soft powder having a total sorption capacity (ie, "adsorption capacity" in the art) of light mineral oil of 78.3% by weight, a ratio or molar ratio of butyl methacrylate: allyl methacrylate: dimethacrylate I 1 Ml / 'i < M \ monoethylene glycol of approximately 1: 4: 6.1 and a corresponding ratio or proportion in weight percent of 5:30:65.

EXAMPLE 2 Example 1 was repeated, except that the ratio or proportion in percent by weight of the preferred monomers was respectively 8:27:65. The total sorption capacity was comparable with the value obtained in the previous example.

EXAMPLE 3 Example 1 was repeated, except that methyl methacrylate was used instead of allyl methacrylate. The total sorption capacity of mineral oil for the resulting terpolymer was 73.7% by weight.

EXAMPLE 4 Example 1 was repeated, with the exception that dibenzoyl peroxide replaced VAZO 52 as initiator. The total capacity of light mineral oil for the resulting terpolymer was 74% by weight.

EXAMPLE 5 Example 1 was repeated, the total capacity of P1431 / 97MX Sorption of light mineral oil for the resulting product was found to be 78% by weight.

EXAMPLES 6-11 Example 1 was repeated, except that the ratio or proportion in percent by weight ("% P") of the monomers were as follows: P1431 / 97MX

Claims (30)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. A process for producing a microporous, adsorbent, oleophilic and hydrophilic copolymer comprising the steps of: dissolving at least two polyunsaturated monomers in an organic solvent sub-substantially immiscible with water to provide a monomer mixture containing more than about 60% by weight of polyunsaturated monomers; combining the monomer mixture with an aqueous solution to form a diphasic liquid system comprising an organic phase immiscible in water containing the dissolved monomers and an aqueous phase; vigorously stirring the biphasic liquid system at a rate sufficient to cause the water-immiscible organic phase containing the dissolved monomers to be suspended as micro-droplets in the aqueous phase; polymerizing the monomers in the suspended micro-droplets during vigorous stirring, to produce a micro-particle of microporous copolymer therein;

   Pl .31 / 97MX separating the microporous polymer microparticle from the substantially water immiscible organic solvent to produce a microporous, hydrophilic, oleophilic, adsorptive polymer microparticle characterized by having an average unit diameter of less than about 50 microns.
2. 2. The process according to claim 1, wherein one of the polyunsaturated monomers is an ethylene glycol dimethacrylate, selected from the group consisting of monoethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate and mixtures of the same.
3. 3. The process according to claim 2, wherein the ethylene glycol dimethacrylate is monoethylene glycol dimethacrylate. The process according to claim 3, wherein another of the polyunsaturated monomers is allyl methacrylate in a molar ratio or ratio of allyl methacrylate: monoethylene glycol dimethacrylate of 4: 6. 5. The process according to claim 3, wherein the solvent immiscible in water is an aromatic or aliphatic hydrocarbon. 6. The process according to claim 5, wherein the organic solvent substantially immiscible in r 1 M] / 9; MX water is a heptane. The process according to claim 6, wherein the heptane is n-heptane. The process according to claim 5, wherein the aqueous phase further includes a suspension stabilizer selected from the group consisting of starch, gum arabic, polyvinyl alcohol, sodium polymethacrylate, magnesium silicate, sodium bentonite, methyl cellulose, and mixtures thereof. 9. The process according to claim 8, wherein the suspension stabilizer is a methylcellulose. 10. The process according to claim 9, further includes adding a polymerization initiator to the monomers. The process according to claim 1, wherein the monounsaturated monomers comprise 9% by weight or less, based on total weight of monomers in the organic phase. The process according to claim 11, wherein the monounsaturated monomers comprise from 0% to about 5% by weight, based on total weight of monomer of the organic phase. The process according to claim 10, wherein the polymerization initiator is also an azo nitrile type initiator. Pl A .1 / 97MX

   14. The process according to claim 10, wherein the average unit particle diameter is from about 1 to about 25 microns. 15. The process according to claim 14, wherein "the average unit particle diameter is from about 1 to about 16 microns." 16. The process according to claim 1, wherein the microparticles are further characterized by having a distribution of particle size, wherein a majority of the microparticles have a particle size between about 6.2 and about 32.7 microns 17. The process according to claim 1, wherein the microparticles are further characterized as having a bulk density of about 0.02 to about 0.1 gram per cubic centimeter. The process according to claim 17, wherein the microparticles are further characterized as having a bulk density of about 0.02 to about 0.07 grams per cubic centimeter. 19. The process according to claim 18, wherein the microparticles are further characterized as having an apparent density of about 0.03 to about 0.05 grams per cubic centimeter. 20. A micro-porous micro-particle and oil and water adsorbent characterized in that it comprises a copolymer of allyl methacrylate and ethylene glycol dimethacrylate, in a molar ratio of about 0.5 to 2, the particle is characterized by having a unit diameter medium less than about 50 microns and a total sorption capacity of mineral oil that is 72% by weight or greater. The microparticle according to claim 20, wherein the ratio or molar ratio of allyl methacrylate to ethylene glycol dimethacrylate is about 1: 1.22. 22. The micro-particle according to the claim

   20, wherein the ethylene glycol dimethacrylate is a member selected from the group consisting of monoethylene glycol dimethacrylate, diethylene glycol dimethacrylate and triethylene glycol dimethacrylate. 23. The micro-particle according to the claim

   20, wherein the ethylene glycol dimethacrylate is monoethylene glycol dimethacrylate. The microparticle according to claim 20, wherein the total adsorption capacity of mineral oil is 85% by weight or greater.

   25. The microparticle according to claim 24, wherein the total adsorption capacity of mineral oil is 90% by weight or greater. 26. The micro-particle according to claim 20, wherein the average unit diameter is at least

   1 micron 27. The microparticle according to claim 20, wherein the ratio or molar ratio of allyl methacrylate: monoethylene glycol dimethacrylate is about 1: 1-2. 28. The microparticle according to claim 26, wherein the average unit particle diameter is from about 1 to about 20 microns. 29. The microparticle according to claim 28, wherein the average unit particle diameter is from about 1 to about 16 microns. 30. The microparticle according to claim 20, further characterized by having a particle size distribution extending to no more than about 100 microns.

   SUMMARY OF THE INVENTION The present invention is directed to a porous copolymer microparticle having a high oil adsorbency. The method of the present invention comprises the steps of: dissolving at least two polyunsaturated monomers in an organic solvent immiscible with water to provide a monomer mixture containing more than about 60%, preferably 100% by weight of monomers polyunsaturated, - adding the monomer mixture to an aqueous solution which preferably has an effective amount of a suspension stabilizer dissolved therein to form a two-phase organic / aqueous liquid system; vigorously stirring the biphasic liquid system at a rate sufficient to cause the water-immiscible organic phase to be suspended as micro-droplets in the aqueous phase, - continue vigorous agitation during the polymerization of the monomers in the suspended micro-droplets for produce a microporous polymer micro-particle; and separating the microporous polymer microparticle from the organic solvent to produce a microporous and sorbent polymer microparticle.

   1 1 II / 1 II oil having an average unit diameter of less than about 25 microns. 1 1 Ml / 'i / I IX