Title of Invention	PROCESS FOR PREPARATION OF ALKOXYSILANES
Abstract	Alkoxysilancs are prepared by a process which uses microwave or RF energy. Thus, silicon metal and a copper catalyst are exposed to microwave radiation in the presence of an appropriate hydroxy compound, such as, an alcohol, and a catalyst, to yield the corresponding trialkoxysilane. The desired alkoxysilanes are prepared with high selectivity and at lower temperatures and shorter times than traditional approaches allow.

Title of Invention

PROCESS FOR PREPARATION OF ALKOXYSILANES

Abstract

Alkoxysilancs are prepared by a process which uses microwave or RF energy. Thus, silicon metal and a copper catalyst are exposed to microwave radiation in the presence of an appropriate hydroxy compound, such as, an alcohol, and a catalyst, to yield the corresponding trialkoxysilane. The desired alkoxysilanes are prepared with high selectivity and at lower temperatures and shorter times than traditional approaches allow.

Full Text	BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention generally relates to a process for the preparation of alkoxysilanes, most preferably trialkoxysilanes, utilizing microwave or RF energy. More particularly, the present invention relates to a process for the preparation of alkoxysilanes wherein silicon metal and a copper catalyst are exposed to microwave or RF radiation in the presence of an appropriate alcohol and a catalyst to yield the corresponding trialkoxysilane. 2. DESCRIPTION OF THE PRIOR ART Alkoxysilanes, specifically trialkoxysilanes, and particularly trimethoxysilane and triethoxysilane are important items of commerce. The alkoxysilanes serve as raw materials in the production of coupling agents that are critical to many industrial segments including adhesive and sealants, coatings, plastics, fabrics, medical devices, cosmetics and others. Although there are many reports of methods to produce trialkoxysilanes none provide a simple and sustainable process. Alkoxysilanes are well known in industry and are used in the • preparation of organosilanes that are suitable for use in many applications including their use as coupling agents. Traditional chemical approaches to alkoxysilanes include the hydrochlorination of silicon metal with subsequent hydrosilylation and esterification. The first step of this three step process requires a significant equipment investment due to the high temperatures required and corrosion which results. A direct two step method was subsequently developed which involved the direct reaction of alcohols with silicone metal. This process was limited to methanol as alcohols of higher chain length proved to be unreactive or to have little reactivity towards silicon metal under the process conditions. The use of methanol, while useful in creating a trialkoxysilane which can be further reacted, is limited by the elimination of the toxic methanol as a byproduct upon cure or by reaction with moisture. Improvements in the direct chemistry approach that allowed preparation with higher chain alcohols utilized a heat transfer agent, such as, a solvent, temperatures of 230 °C to 240 °C, and very long reaction times. The catalyst choice is reported to be critical as the catalyst must have solubility in the solvent. Copper II salts of carboxylic acids were found to perform effectively. Both the direct process and the hydrochlorination process are reported to be used within the industry. Fluidized bed processes are also reported, however, they are reported to suffer from hot spots and a significant reduction in selectivity. U.S. Patent Number 3,071,700 describes a process for the production of alkoxysilanes where finely divided silicon is reacted in the liquid phase by contact with alcohols and phenols yielding a mono-, di-, tri- and tetramethoxysilanes. The direct synthesis of trialkoxysilanes is disclosed in U.S. Patent Number 3,775,077 by Rochow. The patent teaches the preparation of trialkoxysilanes by directly reacting a copper - silicon mass suspended in a silicone oil with an alcohol at 250 °C - 300 °C. The copper - silicon mass contains about 10 weight percent copper and is prepared by heating the copper - silicon mass in excess of 1000 °C. The method results in low yields of the trialkoxysilane. U.S. Patent Number 3,775,457 teaches the use of polyaromatic hydrocarbon oils as solvents for the direct process using finely divided silicon with cuprous chloride as catalyst. Although the cuprous chloride results in a yield improvement versus the activated copper - silicon mass of U.S. 3,775,077 the use of cuprous chloride results in the need for expensive corrosion resistant materials of construction for the reactor and related equipment. Additionally, the use of cuprous chloride acts to catalyze the reaction of the trialkoxysilane to the tetraalkoxysilane which reduces the yield of the trialkoxysilane. Additionally, when methanol is a reactant for producing trimethoxysilane, the use of cuprous chloride leads to formation of HCI which will react with some of the methanol to yield methyl chloride and water. This result leads to inefficiency with regard to the methanol usage. Water produced by the reaction can react with the trialkoxysilane and tetraalkoxysilane to produce soluble and gelled siloxanes thus further reducing the efficiency of the reaction. The presence of water can also adversely affect the silicon conversion. Other patents, for example the Japanese Kokai Tokkyo Koho 55-28928, 55-28929, 55-76891, 57-108094, and 62-96433 which disclose the use of cuprous or cupric chloride are subject to the same limitations. U.S. Patent Number 4,727,173 discloses the use of copper (II) hydroxide as catalyst which avoids the limitations associated with cuprous chloride and provides high selectivity to the trialkoxysilanes. The preferred solvents are diphenyl ether, polyaromatic hydrocarbons and alkylated benzenes such as dodecylbenzene. However, when copper (II) hydroxide is used in combination with alkylated benzenes, such as dodecylbenzene, the direct synthesis of trialkoxysilanes becomes unstable after about 25 - 35 weight percent of the silicon has been reacted. When methanol is the alcohol reactant at temperatures above 220 °C, the trimethoxysilane content declines after approximately 90-95 weight percent to approximately 50-60 weight percent and recovers again to 80-95 weight percent after approximately 60 percent silicon conversion. Coupled with the loss of selectivity is the enhanced formation of methane, water and dimethyl ether. Methane and dimethyl ether formation represent inefficient use of the alcohol reagent. The problems associated with water generation are noted above. Alcohol dehydration and dehydrogenation are troublesome with the use of ethanol and other higher homologs in the direct synthesis approach. At some temperatures (>250 °C) alkenes, and aldehydes are formed in significant amounts at the expense of the desired trialkoxysilane. The presence of these undesired products can also have a negative effect on the catalytic activity in terms of inhibition. At lower temperatures ( the alcohol decomposition products are less prevalent but the direct synthesis is impractically slow. Japanese Kokai Tokkyo Koho 55-2641 discloses the use of cyclic ethers to improve reactivity and selectivity to triethoxysilane when the direct synthesis is conducted in dodecylbenzene at these low temperatures. Cyclic ethers such as dibenzo-18-crown-6 are quite expensive. Others such as 12-crown-4 are toxic. A process for producing controlled selectivity mixtures of trialkoxysilane and tetraalkoxysilane is described in U.S. Patent Number 4,762,939. The use of a mixed solvent system is useful in controlling the selectivity between the tri- and tetra-substituted products over a wide range. An inert solvent along with a solvent that promotes the reactivity of the trialkoxysilane with alcohol to produce the tetraalkoxysilane represent the preferred mixture. The teachings are especially designed to produce the tetraalkoxysilane. U.S. Patent Number 4,762,938 describes the preparation of alkoxysilanes by reacting halosilanes with monhydric alcohols and a trialkyl phosphite. In reactions using chlorosilanes, the hydrogen chloride that is formed during the esterification must be removed quickly from the reaction mixture in order to ensure complete reaction, to obtain a hydrogen chloride free product and to prevent undesirable side reactions. To achieve this it is often necessary to utilized complex and expensive manufacturing processes and plants and is difficult to achieve in an industrial scale. In addition the resulting product mixture contains the strong smelling trialkyl phosphite and the close boiling points between the phosphite and products may make purification difficult. A process for producing trialkoxysilanes including an activation step wherein elemental silicon and copper catalysts are activated, a reaction step wherein an alcohol is reacted with the activated silicon/catalyst complex and a purification step wherein a halide is introduced into the reaction mixture is described in U.S. Patent Number 4,931,578. This process results in a more stable product. Although high levels of silicon conversion and high selectivity are reported, the activation sequence and overall time make this process unattractive. U.S. Patent Number 5,103,034 discloses a process to make alkyldialkoxysilanes and trialkoxysilanes using silicon metal and either an alcohol, an acetal and/or an orthocarboxylic acid ester. Over all conversions of silicon and the selectivity to the trialkoxysilane are both very low. U.S. Patent Number 5,527,937 discloses a process for the Direct Synthesis of triethoxysilane wherein copper chloride is the catalyst and tri- or tetra- toluenes and/or their alkyl substituted derivatives are the solvents and dimethylsilicone is used as an antifoaming agent. The polyphenyl solvents are expensive heat transfer agents. U.S. Patent 5,728,858 teaches the use of a reducing agent to improve the activity of the silicon-copper catalyst. Improved yields of the trialkoxysilanes are cited with the use of the alkylated benzene and polyaromatic solvents. Activation of the silicon-copper catalyst can generate impurities that can adversely effect the reaction so efforts must be taken to remove them prior to the reaction. Reaction times are also very long making the process impractical from a commercial perspective. The use of surface active additives in the direct synthesis of trialkoxysilanes is described in U.S. Patent Number 5,783,720. The additives which are described as silicone antifoaming compounds and fluorosilicone polymers are stated to shorten the reaction induction time and time to steady state rates. Extreme care must be taken to ensure the products are not contaminated with the surface-active agents and that such surface-active agents do not induce any adverse pathways in the reaction. Contamination of the products can cause severe application performance problems. U.S. Patent Number 6,242,628 describes the preparation of alkoxysilanes by reaction of a chlorosilane and an alcohol. The process as described is cited as producing low acidic chloride containing products and involves addition of a metal alcoholate to the separated product to neutralize the acid component followed by reduced pressure distillation. If the neutralization is carried out at relatively high temperatures the neutralization process gives rise to secondary reactions which result in a reduction of product yield. The presence of the acid chloride in the reaction mixture requires the use of expensive corrosion resistant equipment. U.S. Patent Number 6,380,414 describes a process wherein trialkoxysilanes are prepared by the reaction of silicon metal and an alcohol in the presence of copper (II) oxide. The use of copper (II) oxide is described to produce an alkoxysilane in high conversion from the silicon and with high selectivity with regard to trialkoxysilane to tetraalkoxysilane. The process is limiting as the copper (II) oxide is required to be of a very narrow particle size distribution and is preferably generated from freshly precipitated copper (II) oxide. Additionally, the time to reach conversion is very long requiring 22 to 28 hours. JP-A-101168084 relates to the preparation of trialkoxysilanes by reacting silicon metal and alcohol over a copper (II) oxide catalyst which has water content of may require a thermal pretreatment of the catalyst and hence an additional reaction step. EP-A 0 517 398 discloses a process for preparing trialkoxysilanes * by reacting silicon with a solution of hydrogen fluoride or a salt which can be hydrolyzed to form hydrogen fluoride in a liquid primary or secondary alcohol, with or without the addition of a copper catalyst. However, the use of hydrogen fluoride is problematic, since hydrogen fluoride is extremely toxic and can attack glass. Furthermore, the actual reaction has to be preceded by a pretreatment step in this process since CuF2 itself is inactive as a catalyst. The use of a copper salt as catalyst whose anion contains at least one non-hydrolyzable fluorine atom for preparing trialkoxysilanes is disclosed in U.S. Patent Number 6,410,771. The non-hydrolyzable fluorine containing catalyst can also be used with additional copper containing catalysts. Good conversion and selectivity are described, however, very long reaction times are required to complete the reaction. U.S. Patent Number 6,580,000 and U.S. Patent Number 6,680,399 disclose the preparation of alkoxysilanes by reacting silicon metal with an alcohol in the presence of a cupric bis(diorganophosphate) catalyst. The reaction is carried out in a polymeric form of ethyl orthosilicate as solvent. The preferred catalyst is cupric bis(diethyl phosphate). The use of the cupric bis(diorganophosphate) while favoring the selectivity of the trialkoxysilane does not afford the selectivity associated with other catalysts. Additionally, the ethyl orthosilicate solvent contains 28% of one of the reaction products, tetraethoxysilane (TEOS). The presence of the product (TEOS) in the reaction mixture makes quantitative analysis difficult and shifts the equilibrium to the tetra substituted silicon. Very long reaction times are required to achieve the results disclosed. Lipschutz, et al., in Organic Letters, 5(17),3085-3088, describes the reduction of dialkyl ketones to trialkylsilyl ethers using copper hydride - ligand complex under classical synthetic conditions and with sodium tert- butoxide in the presence of microwave radiation. Microwave and RF irradiation can accelerate the rate of chemical reactions by way of localized superheating of the reaction mixture. In the presence of a metal catalyst this effect is further enhanced. In many cases, microwave and RF heating is more energy efficient than conventional heating methods. Silicon nitride and oxide films and nanowires have been prepared in a microwave plasma environment. Crystalline silicon nanoparticles have been produced by the microwave decomposition of silane. However, there are no reports of a process for preparation of alkoxysilanes which employs microwave or RF irradiation. In view of the deficiencies of the known art, there remains a need for a simple direct synthesis process without the need for pre or post treatment, which can be completed in a reasonable period of time with high conversion and selectivity towards the trialkoxysilane. The use of controlled microwave or RF generator provides such a process directed to preparation of alkoxysilanes by. applying microwave or RF irradiation to silicon and alcohol in the presence of a catalyst. SUMMARY OF THE INVENTION Accordingly, the present invention provides a process for preparation of an alkoxysilane represented by the formula: wherein n is from 0 to about 2; and wherein each R is independently selected from a linear, branched or cyclic alkyl of 1-12 carbon atoms, aryl, and acyl, wherein at least one of the alkyl, aryl and acyl groups is optionally substituted by at least one alkyl, alkoxy, halo, cyano or aryl; the process including the step of: contacting elemental silicon and a hydroxy compound represented by the formula: ROH wherein R is selected from a linear, branched or cyclic alkyl of 1-12 carbon atoms, aryl, and acyl, wherein at least one of the alkyl, aryl and acyl groups is optionally substituted by at least one alkyl, alkoxy, halo, cyano or aryl; wherein the contacting is carried out in the presence of a catalyst including at least one of copper, zinc, and nickel, and a non-ionizing radiation selected from microwave, radio frequency (RF), and a combination thereof, at a temperature, pressure, and length of time sufficient to form the alkoxysilane. Such alkoxysiianes have not been previously prepared by the use of microwave and/or RF energy. The use of microwave and/or RF energy overcomes the problems associated with the prior art. The use of microwave energy in the present invention yielded the desired alkoxysilane products with high conversion and high selectivity. Further, because an effective conversion can be achieved at much lower temperatures and shorter times than previously known, the present process produces fewer and lower levels of undesirable by-products and offers significant economic advantages. Still further, the present process affords a simple, clean, rapid, sustainable, tow temperature, short induction time, short reaction time, high conversion, and highly selective route to alkoxysilanes. DETAILED DESCRIPTION The present invention provides a process to prepare trialkoxysilanes of the formula HSi(OR)3 wherein R is an aikyl group containing at least 1 carbon atom. The production of the trialkoxysilane and tetraalkoxysilane is preferred with the production of the trialkoxysilane being particularly preferred. The alkoxysilane is represented by the formula: Preferably, n is from 0 to about 2, more preferably n is from about 1 to about 2, and most preferably, n is 0, 1 or 2. Preferably, each R is independently selected from methyl, ethyl, propyl, and butyl. Preferably, the hydroxy compound is selected from methanol, ethanol, and a mixture thereof. The hydroxy compound can be a mixture of at least two alcohols. Preferably, the alkoxysilane is triethoxysilane or trimethoxysilane. The process includes reacting an alcohol with a slurry of silicon metal and a copper catalyst with or without an inert solvent in the presence of a microwave field or RF field. The process of the present invention produces preferably the trialkoxysilane in high selectivity with high silicon conversion in relatively short time cycles. Activation of the silicon metal and catalyst are also not required. The process can be run as a batch, semi-continuous or continuous process. Metallic silicon used as one of the reactants in the present invention is suitably one having a purity of 80% by weight or more. Metallic silicon having up to about 1% by weight of Al, Fe, Ca, Mg, Zn, Ti, Cr, Ni, Mn, Ba, Cu, Zr and other impurities can be used. The metallic silicon used in the invention is suitably granular. There is little limitation of the size of the metallic silicon particle. Particle size of the metallic silicon can range from 50 to 700 microns, with particle size of about 200 microns being preferred. The alcohols used in the invention having one or more carbon atoms can be straight chain or branched chain, including, methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert- butanol and the like. Among the alcohols methanol and ethanol are most preferred. The alcohols are preferably of a purity of 95% or more. The alcohols do not need to be anhydrous but should contain a low level of water preferably of about 500 ppm. Alcohols that are not anhydrous can be treated with a dehydrating agent to reduce the water content. The feed rate of the alcohol to the reaction system can vary depending upon the reaction with the minimum feed rate being at least from 0.2 mL/min. The alcohol can be diluted with an inert solvent or can be accompanied by an inert gas feed. The catalyst used in this invention is not particularly restricted and can be those conventionally used, such as copper catalysts, zinc catalysts, nickel catalysts and the like. Preferably, the catalyst is selected from copper(O), copper(l) salts, copper(ll) salts, copper (II) hydroxide, zinc(O), zinc(ll), nickel(O), nlckel(ll), salts thereof, complexes thereof, and any mixtures thereof. While not limiting copper catalysts are preferred. Specifically, copper salts such as cuprous chloride, cupric chloride, copper bromide, copper iodide, copper fluoride, copper carbonate, copper sulfate, copper acetate, copper oxalate, copper thiocyanate and the like; copper containing inorganic compounds such as cuprous hydroxide, cupric hydroxide, copper cyanide, copper sulfide, copper oxide, and the like; organic copper compounds, such as copper methoxide, copper ethoxide, copper allyloxide, copper acetate, copper stearate, copper tetramethylheptanedionate, copper acetylacetonate, copper naphthenate, copper phenylate, pentafluorphenylcopper dimer, copper bis(diorganophoshate) such as copper bis(diethylphosphate) and the like; and metallic copper can be used. No particular preparation method or purification method is required for any of the catalysts with the exception of ensuring low-moisture contents. The catalyst can be supplied to the reaction system in the form of a mixed powder with metallic silicon or as supported with or on metallic silicon or in a fixed or non-fixed bed. If desired the catalyst and silicon metal can be subjected to an activation treatment either in the presence or absence of a microwave or RF field. The amount of catalyst used in the invention is minimally 0.001 moles. The catalyst can be added continuously or in multiple additions over a period of time, such as, preferably, over the course of the reaction. For example, the catalyst may be added over a period of time to ensure the presence of catalyst at a sufficient level throughout the process cycle. The solvent can be the alcohol or a suitably inert solvent. There is no specific limitation for the solvent, so far as it is inert to the silicon metal, catalyst and alcohol. However, stable solvents having a relatively high boiling temperature are preferred. Solvents transparent to microwave radiation are also preferred. Examples of solvents include but are not limited to paraffinic hydrocarbons, such as octane, decane, dodecane, tetradecane, hexadecane, octadecane, eicosane, alkylbenzene hydrocarbons, such as diethylbenzene, cymene, butylbenzene, butyltoluehe, octylbenzene, dodecylbenzene, and the like, and hydrogenated products thereof, diphenyl, diphenyl ether, monoethyldiphenyl, diethyldiphenyl, triethyldiphenyl, and hydrogenated products thereof, alkylnaphthalene hydrocarbons and hydrogenated products thereof, and triphenyl hydrocarbons and hydrogenated products thereof. High boiling heat transfer agents include polyaromatic hydrocarbons, such as, THERMINOL and MARLOTHERM, of which MARLOTHERM is preferred. These can be used singly or in combination of two or more thereof. The reaction can be conducted under an atmospheric, pressurized or depressurized condition. Reaction under atmospheric conditions is preferred due to the economic advantage of the simple apparatus. The reaction is conducted at a temperature, pressure, and length of time sufficient to form the alkoxysilane. Thus, the preferred temperature is from about 100 °C to about 300 °C; the preferred pressure is atmospheric pressure, and the reaction time is from about 1 minute to about 10 hours. The microwave reaction was carried out in a Milestone Ethos microwave unit. The Ethos can be configured to run in closed vessel or open vessel format. Both modes can be used to generate the alkoxysilanes. The Ethos unit was modified to include a pressure monitor, addition port for alcohol introduction, an entry port for a mechanical stirrer and an exit port for product collection. The microwave power level is usually in the range of 200 to 1000 watts in a field from about 3 Hz to 300 GHz. Microwave units manufactured by other suppliers that are capable of running open and closed vessels are also appropriate for the reaction with modifications. The reaction can be run in a batch, semicontinuous or continuous manner. In the batch reaction, the appropriate alcohol is introduced into the reaction mixture which is a slurry of metallic silicon and the copper catalyst and the reaction products are collected and purified. In the continuous manner, the reaction slurry is continuously passed through a microwave or RF field. The alcohol and solvent are continuously recycled into the reaction mixture with product being separated and purified. The amount of material that can be produced is limited only by the size or number of microwave generating units and the process design. In the continuous process, one preferred approach would be the use of a multiple number of microwave generators designed in parallel. The silicon metal and catalyst can be introduced as a slurry or in a metal/catalyst bed system. The bed system can be designed to allow for replenishment of the catalyst and silicon metal as necessary. The alcohol can be introduced in conjunction with the slurry or separately. A recycle loop can be designed to ensure appropriate residence time to meet productivity requirements. . Alternatively, a reactor train can be employed wherein the slurry or reaction mixture without a fixed bed is pumped through a series of reactors to maximize residence time and productivity. After the appropriate residence time the reaction mixture is passed through an evaporation unit where ethanol is flashed off and returned to the feed unit. The reacted mixture is then transported to a vessel where the products are separated and purified by distillation. In both the batch and continuous process the reactor can either be a traditional glass kettle or a glass tube within a microwave or RF waveguide. Other materials that are transparent to microwave or RF can be used. Additionally, the glass reactor can be enclosed within a metal jacket providing the jacket or this outer reactor does not interfere with transmission of the microwaves. In either case, the microwave or RF field generator is part of the reactor. Depending upon whether or not the reaction mixture is slurried or the silicon/catalyst are part of a bed type system a filter may need to be installed to collect solid material prior to the mixture entering the evaporator. The above referred to evaporator will also require a chiller to condense the ethanol flashed off which can either be part of the evaporator or a separate unit. In one preferred embodiment of the present invention, the alkoxysilane product is distilled to separate a major product from other minor products or to form a higher purity alkoxysilane. The unreacted silicon can be recycled and design provisions can be made to add catalyst throughout the reaction if desired. In another preferred embodiment of the present invention, any unreacted silicon metal or hydroxy compound, if present, is recycled. In the practice of the process of the present invention, contacting is preferably carried out to produce at least a 40% conversion, more preferably at least a 70% conversion and, most preferably at least a 95% conversion. In still another preferred embodiment of the present invention, the alkoxysilane product is the only product formed or, alternatively, is a mixture of trialkoxysilane and tetraalkoxysilane wherein the ratio of trialkoxysilane to tetraalkoxysilane is at least 2:1, more preferably at least 6:1, and most preferably the ratio of trialkoxysilane to tetraalkoxysilane is at least 9:1. In a particularly preferred embodiment of the present invention, contacting is carried out to produce at least a 70% conversion and a ratio of trialkoxysilane to tetraalkoxysilane of at least 9:1. The actual number of reactors required would be dependent upon the production rate. A process that has several smaller units versus one larger unit would most be preferred. A design which represents a pilot plant approach rather than a production facility approach as it utilizes several small vessels to achieve the volume equal to one large unit is preferred. The alkoxysilanes according to the. present invention have utility as coupling agents, in adhesives, sealants, construction materials, coatings, plastics, fabrics, medical devices, and cosmetics. Example 1 A three necked 1 liter round bottom flask inside a Milestone Multi- Syn Ethos Microwave chamber was fitted with a condenser and receiver, a mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was oven dried at 80C and dried when set up using a heat gun and nitrogen flush. To the dried apparatus was added 20 grams (0.714 moles) of finely ground (200 mesh) silicon metal, 0.85 grams (1.66 mole %) of cuprous oxide, 1.17 grams (1.66 mole %) of cuprous chloride, 0.75 grams (1.66 mole %) of copper powder and 500ml of Marlotherm SH. The mixture was vigorously stirred to form a slurry. The microwave unit power source was turned on with an initial power level of 975 watts and the mixture was exposed to the microwave until a temperature of 190°C was achieved (22 minutes). The microwave power level was subsequently adjusted (335 - 1000 watts) over the course of the reaction to maintain the temperature at approximately 190°G. Once the reaction mixture reached 190°C, anhydrous ethanol was metered in at a rate of 8.1 milliliters/minute using a peristaltic pump. Immediately, liquid began to distill from the reaction flask with an average head temperature of 95°C. The reaction was continued until 1.5 liters of ethanol were added (185 minutes). Excess ethanol and the desired product, triethoxysilane co-distilled from the reaction mixture. The product composition was analyzed by Si-NMR spectroscopy. Silicon conversion was determined by filtering the reaction mixture and repeatedly washing the collected solid residue with hot water, acetone and diethyl ether. The silicon conversion was calculated to be 87%. Selectivity calculated from the silicon conversion was determined to favor triethoxysilane by 100%. Example 2 A three necked 1 liter round bottom flask inside a Milestone Multi- Syn Ethos Microwave chamber was fitted with a condenser and receiver, a mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was oven dried at 80°C and dried when set up using a heat gun and nitrogen flush. To the dried apparatus was added 20 grams (0.714 moles) of finely ground (200 mesh) silicon metal, 0.85 grams (1.66 mole %) of cuprous oxide, 1.17 grams (1.66 mole %) of cuprous chloride, 0.75 grams (1.66 mole %) of copper powder and 500ml of Marlotherm SH. The mixture was vigorously stirred to form a slurry. The microwave unit power source was turned on with an initial power level of 975 watts and the mixture was exposed to the microwave until a temperature of 190°C was achieved (20 minutes). The microwave power level was subsequently adjusted (300 - 1000 watts) over the course of the reaction to maintain the temperature at approximately 190°C. Once the reaction mixture reached 190°C, anhydrous ethanol was metered in at a rate of 8.1 milliliters/minute using a peristaltic pump. Immediately, liquid began to distill from the reaction flask with an average head temperature of 95°C. The reaction was continued until 1.5 liters of ethanol were added (185 minutes). Excess ethanol and the desired product, triethoxysilane co-distilled from the reaction mixture. The product composition was analyzed by Si-NMR spectroscopy. Silicon conversion was determined by filtering the reaction mixture and repeatedly washing the collected solid residue with hot water, acetone and diethyl ether. The silicon conversion was calculated to be 95%. Selectivity calculated from the silicon conversion was determined to favor triethoxysilane by 100%. Example 3 A three necked 1 liter round bottom flask inside a Milestone Multi- Syn Ethos Microwave chamber was fitted with a condenser and receiver, a mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was oven dried at 80°C and dried when set up using a heat gun and nitrogen flush. To the dried apparatus was added 20 grams (0.714 moles) of finely ground (200 mesh) silicon metal, 3.56 grams (5 mole %) of cuprous chloride and 500ml of Marlotherm SH. The mixture was vigorously stirred to form a slurry. The microwave unit power source was turned on with an initial power level of 975 watts and the mixture was exposed to the microwave until a temperature of 190°C was achieved (17 minutes). The microwave power level was subsequently adjusted (375 - 1000 watts) over the course of the reaction to maintain the temperature at approximately 190°C. Once the reaction mixture reached 190°C, anhydrous ethanol was metered in at a rate of 7.7 milliliters/minute using a peristaltic pump. Immediately, liquid began to distill from the reaction flask with an average head temperature of 95°C. The reaction was continued until 1.5 liters of ethanol were added (194 minutes). Excess ethanol and the desired product, triethoxysilane co-distilled from the reaction mixture. The product composition was analyzed by Si-NMR spectroscopy. Silicon conversion was determined by filtering the reaction mixture and repeatedly washing the collected solid residue with hot water, acetone and diethyl ether. The silicon conversion was calculated to be 70%. Selectivity calculated from the silicon conversion was determined to favor triethoxysilane by 100%. Example 4 A three necked 1 liter round bottom flask inside a Milestone Multi- Syn Ethos Microwave chamber was fitted with a condenser and receiver, a mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was oven dried at 80°C and dried when set up using a heat gun and nitrogen flush. To the dried apparatus was added 20 grams (0.714 moles) of finely ground (200 mesh) silicon metal, 3.56 grams (5 mole %) of cuprous chloride and 500ml of Mariotherm SH. The mixture was vigorously stirred to form a slurry. The microwave unit power source was turned on with an initial power level of 975 watts and the mixture was exposed to the microwave until a temperature of 190°C was achieved (20 minutes). The microwave power level was subsequently adjusted (600 - 1000 watts) over the course of the reaction to maintain the temperature at approximately 180°C. Once the reaction mixture reached 190°C, anhydrous methanol was metered in at a rate of 7.9 milliliters/minute using a peristaltic pump, immediately, liquid began to distill from the reaction flask. The reaction was continued until 1.5 liters of ethanol were added (189 minutes). Excess methanol and the desired product, trimethoxysilane co-distilled from the reaction mixture. The product composition was analyzed by Si-NMR spectroscopy. Silicon conversion was determined by filtering the reaction mixture and repeatedly washing the collected solid residue with hot water, acetone and diethyl ether. The silicon conversion was calculated to be 70%. Selectivity calculated from the silicon conversion was determined to favor trimethoxysilane by 100%. Example 5 A three necked round 1 liter round bottom flask inside a Milestone Ethos microwave unit was fitted with a condenser and receiver, a mechanical stirrer, a nitrogen line and ethanol entrance port and a thermocouple. The apparatus was dried by use of a heat gun with a continual nitrogen flush throughout the system. To the dried apparatus was added 20 grams (0.71 moles) of finely ground (200 mesh) silicone powder, 2.11 grams (3 mole %) of Cuprous Chloride and 500 ml of Marlotherm SH. The mixture was heated to 190°C using a microwave power of up to 950 W, this taking approximately 19 minutes. The microwave power level was subsequently adjusted (385 - 1000 watts) over the course of the reaction to maintain the temperature at approximately 190°C. Once the reaction reached 190°C anhydrous ethanol was metered in at a rate of 8.0 milliliters per minute using a peristaltic pump. Immediately liquid was observed to distill from the reaction flask with an average head temperature of 95°C. The reaction was continued until 1.5 liters of ethanol were added (187 minutes). The resulting distillate was collected and analyzed by Si-NMR spectroscopy for the presence of triethoxysilane, tetraethoxysilane and other alkoxysilanes. Selectivity calculated from silicon conversion was determined to favor TES at 90%. Silicon conversion was calculated to be 70%. The present invention has been described with particular reference to the preferred embodiments. It should be understood that variations and modifications thereof can be devised by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the present invention embraces all such alternatives, modifications and variations that fall within the scope of the appended claims. 1. A process for preparation of an alkoxysilane represented by the formula: wherein n is from 0 to about 2; and wherein each R is independently selected from the group consisting of: a linear, branched or cyclic alkyl of having 1 to 12 carbon atoms, aryl, and acyl, wherein at least one of said alkyl, aryl and acyl groups is optionally substituted by at least one alkyl, alkoxy, halo, cyano or aryl; said process comprising the step of: contacting elemental silicon and an hydroxy compound represented by the formula: ROH wherein R is selected from the group consisting of: a linear, branched or cyclic alkyl having 1 to 12 carbon atoms, aryl, and acyl, wherein at least one of said alkyl, aryl and acyl groups is optionally substituted by at least one alkyl, alkoxy, halo, cyano or aryl; wherein said contacting is carried out in the presence of at least one catalyst selected from the group consisting of: copper, zinc, and nickel, a non-ionizing radiation selected from the group consisting of: microwave, radio frequency (RF), and a combination thereof, and at a temperature, pressure, and time sufficient to form said alkoxysilane. 2. The process of claim 1, wherein n is from 0 to about 1 3. The process of claim 1, wherein n is 1 or 2. 4. The process of claim 1, wherein each R is independently selected from the group consisting of: methyl, ethyl, propyl, and butyl. 5. The process of claim 1, wherein said hydroxy compound is selected from the group consisting of: methanol, ethanol, and a mixture thereof. 6. The process of claim 1, wherein said hydroxy compound is a mixture of at least two alcohols. 7. The process of claim 1, wherein said the alkoxysilane is triethoxysitane. 8. The process of claim 1, wherein said the alkoxysilane is trimethoxysilane. 9. The process of claim 1, wherein the contacting step is carried out in the presence of a solvent. 10. The process of claim 9, wherein said solvent is a non-reactive high-boiling solvent. 11. The process of claim 9, wherein said solvent is said hydroxy compound. 12. The process of claim 1, wherein said catalyst is selected from the group consisting of: copper(O), copper(l) salts, copper(ll) salts, copper (II) hydroxide, zinc(0), zinc(ll), nickel(O), nickel(ll), salts thereof, complexes thereof, and any mixtures thereof. 13. The process of claim 12, wherein said catalyst is selected from the group consisting of: cuprous halide, cupric hydroxide, cuprous hydroxide, copper carbonate, copper sulfate, copper carboxylate, copper thiocyanate, copper cyanide, copper sulfide, copper oxide, copper alkoxide, copper tetramethylheptanedionate, copper acetylacetonate, copper naphthenate, copper phenylate, pentafluorphenylcopper dimer, copper bis(diorganophoshate) and a mixture thereof. 14. The process of claim 13, wherein said catalyst is selected from the group consisting of: copper fluoride, cuprous chloride, cupric chloride, copper bromide, copper iodide, copper methoxide, copper ethoxide, copper allyloxide, copper stearate, copper acetate, copper oxalate, copper bis(diethylphosphate) and a mixture thereof. 15. The process of claim 1, wherein said microwave is one selected from the group consisting of: a monomode microwave, a multimode microwave, and a combination thereof. 16. The process of claim 1, wherein said radio frequency is from about 3 Hz to about 300 GHz. 17. The process of claim 1, wherein said process is selected from the group consisting of: a batch process, continuous process, semi- continuous process, and a combination thereof. 18. The process of claim 1, further comprising distilling said alkoxysilane to form a higher purity alkoxysilane. 19. The process of claim 1, further comprising recycling any unreacted silicon metal or hydroxy compound. 20. The process of claim 1, wherein said catalyst is added over a period of time. 21. The process of claim 1, wherein contacting is carried out to produce at least a 40% conversion. 22. The process of claim 1, wherein the conversion is at least 70%. 23. The process of claim 1, wherein the conversion is at least 95%. 24. The process of claim 1, wherein the alkoxysilane product is a mixture of trialkoxysilane and tetraalkoxysilane. 25. The process of claim 1, wherein the alkoxysilane product is a single silane product. 26. The process of claim 24, wherein the ratio of trialkoxysilane to tetraalkoxysilane is at least 2:1. 27. The process of claim 24, wherein the ratio of trialkoxysilane to tetraalkoxysilane is at least 6:1. 28. The process of claim 24, wherein the ratio of trialkoxysilane to tetraalkoxysilane is at least 9:1. 29. The process of claim 27, wherein contacting is carried out to produce at least a 70% conversion. Alkoxysilancs are prepared by a process which uses microwave or RF energy. Thus, silicon metal and a copper catalyst are exposed to microwave radiation in the presence of an appropriate hydroxy compound, such as, an alcohol, and a catalyst, to yield the corresponding trialkoxysilane. The desired alkoxysilanes are prepared with high selectivity and at lower temperatures and shorter times than traditional approaches allow.

Full Text

BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention generally relates to a process for the
preparation of alkoxysilanes, most preferably trialkoxysilanes, utilizing
microwave or RF energy. More particularly, the present invention relates to
a process for the preparation of alkoxysilanes wherein silicon metal and a
copper catalyst are exposed to microwave or RF radiation in the presence
of an appropriate alcohol and a catalyst to yield the corresponding
trialkoxysilane.
2. DESCRIPTION OF THE PRIOR ART
Alkoxysilanes, specifically trialkoxysilanes, and particularly
trimethoxysilane and triethoxysilane are important items of commerce. The
alkoxysilanes serve as raw materials in the production of coupling agents
that are critical to many industrial segments including adhesive and
sealants, coatings, plastics, fabrics, medical devices, cosmetics and
others. Although there are many reports of methods to produce
trialkoxysilanes none provide a simple and sustainable process.
Alkoxysilanes are well known in industry and are used in the •
preparation of organosilanes that are suitable for use in many applications
including their use as coupling agents.
Traditional chemical approaches to alkoxysilanes include the
hydrochlorination of silicon metal with subsequent hydrosilylation and
esterification. The first step of this three step process requires a significant
equipment investment due to the high temperatures required and corrosion
which results.

A direct two step method was subsequently developed which
involved the direct reaction of alcohols with silicone metal. This process
was limited to methanol as alcohols of higher chain length proved to be
unreactive or to have little reactivity towards silicon metal under the
process conditions. The use of methanol, while useful in creating a
trialkoxysilane which can be further reacted, is limited by the elimination of
the toxic methanol as a byproduct upon cure or by reaction with moisture.
Improvements in the direct chemistry approach that allowed
preparation with higher chain alcohols utilized a heat transfer agent, such
as, a solvent, temperatures of 230 °C to 240 °C, and very long reaction
times. The catalyst choice is reported to be critical as the catalyst must
have solubility in the solvent. Copper II salts of carboxylic acids were
found to perform effectively. Both the direct process and the
hydrochlorination process are reported to be used within the industry.
Fluidized bed processes are also reported, however, they are reported to
suffer from hot spots and a significant reduction in selectivity.
U.S. Patent Number 3,071,700 describes a process for the
production of alkoxysilanes where finely divided silicon is reacted in the
liquid phase by contact with alcohols and phenols yielding a mono-, di-, tri-
and tetramethoxysilanes.
The direct synthesis of trialkoxysilanes is disclosed in U.S. Patent
Number 3,775,077 by Rochow. The patent teaches the preparation of
trialkoxysilanes by directly reacting a copper - silicon mass suspended in a
silicone oil with an alcohol at 250 °C - 300 °C. The copper - silicon mass
contains about 10 weight percent copper and is prepared by heating the
copper - silicon mass in excess of 1000 °C. The method results in low
yields of the trialkoxysilane.

U.S. Patent Number 3,775,457 teaches the use of polyaromatic
hydrocarbon oils as solvents for the direct process using finely divided
silicon with cuprous chloride as catalyst. Although the cuprous chloride
results in a yield improvement versus the activated copper - silicon mass
of U.S. 3,775,077 the use of cuprous chloride results in the need for
expensive corrosion resistant materials of construction for the reactor and
related equipment. Additionally, the use of cuprous chloride acts to
catalyze the reaction of the trialkoxysilane to the tetraalkoxysilane which
reduces the yield of the trialkoxysilane.
Additionally, when methanol is a reactant for producing
trimethoxysilane, the use of cuprous chloride leads to formation of HCI
which will react with some of the methanol to yield methyl chloride and
water. This result leads to inefficiency with regard to the methanol usage.
Water produced by the reaction can react with the trialkoxysilane and
tetraalkoxysilane to produce soluble and gelled siloxanes thus further
reducing the efficiency of the reaction. The presence of water can also
adversely affect the silicon conversion. Other patents, for example the
Japanese Kokai Tokkyo Koho 55-28928, 55-28929, 55-76891, 57-108094,
and 62-96433 which disclose the use of cuprous or cupric chloride are
subject to the same limitations.
U.S. Patent Number 4,727,173 discloses the use of copper (II)
hydroxide as catalyst which avoids the limitations associated with cuprous
chloride and provides high selectivity to the trialkoxysilanes. The preferred
solvents are diphenyl ether, polyaromatic hydrocarbons and alkylated
benzenes such as dodecylbenzene. However, when copper (II) hydroxide
is used in combination with alkylated benzenes, such as dodecylbenzene,
the direct synthesis of trialkoxysilanes becomes unstable after about 25 -
35 weight percent of the silicon has been reacted. When methanol is the
alcohol reactant at temperatures above 220 °C, the trimethoxysilane
content declines after approximately 90-95 weight percent to approximately
50-60 weight percent and recovers again to 80-95 weight percent after

approximately 60 percent silicon conversion. Coupled with the loss of
selectivity is the enhanced formation of methane, water and dimethyl ether.
Methane and dimethyl ether formation represent inefficient use of the
alcohol reagent. The problems associated with water generation are noted
above.
Alcohol dehydration and dehydrogenation are troublesome with the
use of ethanol and other higher homologs in the direct synthesis approach.
At some temperatures (>250 °C) alkenes, and aldehydes are formed in
significant amounts at the expense of the desired trialkoxysilane. The
presence of these undesired products can also have a negative effect on
the catalytic activity in terms of inhibition. At lower temperatures ( the alcohol decomposition products are less prevalent but the direct
synthesis is impractically slow. Japanese Kokai Tokkyo Koho 55-2641
discloses the use of cyclic ethers to improve reactivity and selectivity to
triethoxysilane when the direct synthesis is conducted in dodecylbenzene
at these low temperatures. Cyclic ethers such as dibenzo-18-crown-6 are
quite expensive. Others such as 12-crown-4 are toxic.
A process for producing controlled selectivity mixtures of
trialkoxysilane and tetraalkoxysilane is described in U.S. Patent Number
4,762,939. The use of a mixed solvent system is useful in controlling the
selectivity between the tri- and tetra-substituted products over a wide
range. An inert solvent along with a solvent that promotes the reactivity of
the trialkoxysilane with alcohol to produce the tetraalkoxysilane represent
the preferred mixture. The teachings are especially designed to produce
the tetraalkoxysilane.
U.S. Patent Number 4,762,938 describes the preparation of
alkoxysilanes by reacting halosilanes with monhydric alcohols and a trialkyl
phosphite. In reactions using chlorosilanes, the hydrogen chloride that is
formed during the esterification must be removed quickly from the reaction
mixture in order to ensure complete reaction, to obtain a hydrogen chloride

free product and to prevent undesirable side reactions. To achieve this it
is often necessary to utilized complex and expensive manufacturing
processes and plants and is difficult to achieve in an industrial scale. In
addition the resulting product mixture contains the strong smelling trialkyl
phosphite and the close boiling points between the phosphite and products
may make purification difficult.
A process for producing trialkoxysilanes including an activation step
wherein elemental silicon and copper catalysts are activated, a reaction
step wherein an alcohol is reacted with the activated silicon/catalyst
complex and a purification step wherein a halide is introduced into the
reaction mixture is described in U.S. Patent Number 4,931,578. This
process results in a more stable product. Although high levels of silicon
conversion and high selectivity are reported, the activation sequence and
overall time make this process unattractive.
U.S. Patent Number 5,103,034 discloses a process to make
alkyldialkoxysilanes and trialkoxysilanes using silicon metal and either an
alcohol, an acetal and/or an orthocarboxylic acid ester. Over all
conversions of silicon and the selectivity to the trialkoxysilane are both very
low.
U.S. Patent Number 5,527,937 discloses a process for the Direct
Synthesis of triethoxysilane wherein copper chloride is the catalyst and tri-
or tetra- toluenes and/or their alkyl substituted derivatives are the solvents
and dimethylsilicone is used as an antifoaming agent. The polyphenyl
solvents are expensive heat transfer agents.
U.S. Patent 5,728,858 teaches the use of a reducing agent to
improve the activity of the silicon-copper catalyst. Improved yields of the
trialkoxysilanes are cited with the use of the alkylated benzene and
polyaromatic solvents. Activation of the silicon-copper catalyst can
generate impurities that can adversely effect the reaction so efforts must

be taken to remove them prior to the reaction. Reaction times are also
very long making the process impractical from a commercial perspective.
The use of surface active additives in the direct synthesis of
trialkoxysilanes is described in U.S. Patent Number 5,783,720. The
additives which are described as silicone antifoaming compounds and
fluorosilicone polymers are stated to shorten the reaction induction time
and time to steady state rates. Extreme care must be taken to ensure the
products are not contaminated with the surface-active agents and that
such surface-active agents do not induce any adverse pathways in the
reaction. Contamination of the products can cause severe application
performance problems.
U.S. Patent Number 6,242,628 describes the preparation of
alkoxysilanes by reaction of a chlorosilane and an alcohol. The process as
described is cited as producing low acidic chloride containing products and
involves addition of a metal alcoholate to the separated product to
neutralize the acid component followed by reduced pressure distillation. If
the neutralization is carried out at relatively high temperatures the
neutralization process gives rise to secondary reactions which result in a
reduction of product yield. The presence of the acid chloride in the
reaction mixture requires the use of expensive corrosion resistant
equipment.
U.S. Patent Number 6,380,414 describes a process wherein
trialkoxysilanes are prepared by the reaction of silicon metal and an alcohol
in the presence of copper (II) oxide. The use of copper (II) oxide is
described to produce an alkoxysilane in high conversion from the silicon
and with high selectivity with regard to trialkoxysilane to tetraalkoxysilane.
The process is limiting as the copper (II) oxide is required to be of a very
narrow particle size distribution and is preferably generated from freshly
precipitated copper (II) oxide. Additionally, the time to reach conversion is
very long requiring 22 to 28 hours.

JP-A-101168084 relates to the preparation of trialkoxysilanes by
reacting silicon metal and alcohol over a copper (II) oxide catalyst which
has water content of may require a thermal pretreatment of the catalyst and hence an additional
reaction step.
EP-A 0 517 398 discloses a process for preparing trialkoxysilanes
*
by reacting silicon with a solution of hydrogen fluoride or a salt which can
be hydrolyzed to form hydrogen fluoride in a liquid primary or secondary
alcohol, with or without the addition of a copper catalyst. However, the use
of hydrogen fluoride is problematic, since hydrogen fluoride is extremely
toxic and can attack glass. Furthermore, the actual reaction has to be
preceded by a pretreatment step in this process since CuF2 itself is inactive
as a catalyst.
The use of a copper salt as catalyst whose anion contains at least
one non-hydrolyzable fluorine atom for preparing trialkoxysilanes is
disclosed in U.S. Patent Number 6,410,771.
The non-hydrolyzable fluorine containing catalyst can also be used
with additional copper containing catalysts. Good conversion and
selectivity are described, however, very long reaction times are required to
complete the reaction.
U.S. Patent Number 6,580,000 and U.S. Patent Number 6,680,399
disclose the preparation of alkoxysilanes by reacting silicon metal with an
alcohol in the presence of a cupric bis(diorganophosphate) catalyst. The
reaction is carried out in a polymeric form of ethyl orthosilicate as solvent.
The preferred catalyst is cupric bis(diethyl phosphate). The use of the
cupric bis(diorganophosphate) while favoring the selectivity of the
trialkoxysilane does not afford the selectivity associated with other
catalysts. Additionally, the ethyl orthosilicate solvent contains 28% of one
of the reaction products, tetraethoxysilane (TEOS). The presence of the

product (TEOS) in the reaction mixture makes quantitative analysis difficult
and shifts the equilibrium to the tetra substituted silicon. Very long reaction
times are required to achieve the results disclosed.
Lipschutz, et al., in Organic Letters, 5(17),3085-3088, describes the
reduction of dialkyl ketones to trialkylsilyl ethers using copper hydride -
ligand complex under classical synthetic conditions and with sodium tert-
butoxide in the presence of microwave radiation. Microwave and RF
irradiation can accelerate the rate of chemical reactions by way of localized
superheating of the reaction mixture. In the presence of a metal catalyst
this effect is further enhanced. In many cases, microwave and RF heating
is more energy efficient than conventional heating methods. Silicon
nitride and oxide films and nanowires have been prepared in a microwave
plasma environment. Crystalline silicon nanoparticles have been produced
by the microwave decomposition of silane. However, there are no reports
of a process for preparation of alkoxysilanes which employs microwave or
RF irradiation.
In view of the deficiencies of the known art, there remains a need for
a simple direct synthesis process without the need for pre or post
treatment, which can be completed in a reasonable period of time with high
conversion and selectivity towards the trialkoxysilane. The use of
controlled microwave or RF generator provides such a process directed to
preparation of alkoxysilanes by. applying microwave or RF irradiation to
silicon and alcohol in the presence of a catalyst.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a process for
preparation of an alkoxysilane represented by the formula:

wherein n is from 0 to about 2; and wherein each R is independently
selected from a linear, branched or cyclic alkyl of 1-12 carbon atoms, aryl,
and acyl, wherein at least one of the alkyl, aryl and acyl groups is optionally
substituted by at least one alkyl, alkoxy, halo, cyano or aryl;
the process including the step of:
contacting elemental silicon and a hydroxy compound represented
by the formula:
ROH
wherein R is selected from a linear, branched or cyclic alkyl of 1-12
carbon atoms, aryl, and acyl, wherein at least one of the alkyl, aryl and acyl
groups is optionally substituted by at least one alkyl, alkoxy, halo, cyano or
aryl;
wherein the contacting is carried out in the presence of a catalyst
including at least one of copper, zinc, and nickel, and a non-ionizing
radiation selected from microwave, radio frequency (RF), and a
combination thereof, at a temperature, pressure, and length of time
sufficient to form the alkoxysilane.
Such alkoxysiianes have not been previously prepared by the use of
microwave and/or RF energy. The use of microwave and/or RF energy
overcomes the problems associated with the prior art.
The use of microwave energy in the present invention yielded the
desired alkoxysilane products with high conversion and high selectivity.
Further, because an effective conversion can be achieved at much
lower temperatures and shorter times than previously known, the present
process produces fewer and lower levels of undesirable by-products and
offers significant economic advantages.

Still further, the present process affords a simple, clean, rapid,
sustainable, tow temperature, short induction time, short reaction time, high
conversion, and highly selective route to alkoxysilanes.
DETAILED DESCRIPTION
The present invention provides a process to prepare trialkoxysilanes
of the formula HSi(OR)3 wherein R is an aikyl group containing at least 1
carbon atom. The production of the trialkoxysilane and tetraalkoxysilane is
preferred with the production of the trialkoxysilane being particularly
preferred.
The alkoxysilane is represented by the formula:

Preferably, n is from 0 to about 2, more preferably n is from about 1
to about 2, and most preferably, n is 0, 1 or 2.
Preferably, each R is independently selected from methyl, ethyl,
propyl, and butyl.
Preferably, the hydroxy compound is selected from methanol,
ethanol, and a mixture thereof. The hydroxy compound can be a mixture
of at least two alcohols.
Preferably, the alkoxysilane is triethoxysilane or trimethoxysilane.
The process includes reacting an alcohol with a slurry of silicon
metal and a copper catalyst with or without an inert solvent in the presence
of a microwave field or RF field.

The process of the present invention produces preferably the
trialkoxysilane in high selectivity with high silicon conversion in relatively
short time cycles.
Activation of the silicon metal and catalyst are also not required.
The process can be run as a batch, semi-continuous or continuous
process.
Metallic silicon used as one of the reactants in the present invention
is suitably one having a purity of 80% by weight or more. Metallic silicon
having up to about 1% by weight of Al, Fe, Ca, Mg, Zn, Ti, Cr, Ni, Mn, Ba,
Cu, Zr and other impurities can be used. The metallic silicon used in the
invention is suitably granular. There is little limitation of the size of the
metallic silicon particle. Particle size of the metallic silicon can range from
50 to 700 microns, with particle size of about 200 microns being preferred.
The alcohols used in the invention having one or more carbon
atoms can be straight chain or branched chain, including, methanol,
ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-
butanol and the like. Among the alcohols methanol and ethanol are most
preferred. The alcohols are preferably of a purity of 95% or more. The
alcohols do not need to be anhydrous but should contain a low level of
water preferably of about 500 ppm. Alcohols that are not anhydrous can
be treated with a dehydrating agent to reduce the water content.
The feed rate of the alcohol to the reaction system can vary
depending upon the reaction with the minimum feed rate being at least
from 0.2 mL/min. The alcohol can be diluted with an inert solvent or can
be accompanied by an inert gas feed.
The catalyst used in this invention is not particularly restricted and
can be those conventionally used, such as copper catalysts, zinc catalysts,
nickel catalysts and the like.

Preferably, the catalyst is selected from copper(O), copper(l) salts,
copper(ll) salts, copper (II) hydroxide, zinc(O), zinc(ll), nickel(O), nlckel(ll),
salts thereof, complexes thereof, and any mixtures thereof.
While not limiting copper catalysts are preferred. Specifically,
copper salts such as cuprous chloride, cupric chloride, copper bromide,
copper iodide, copper fluoride, copper carbonate, copper sulfate, copper
acetate, copper oxalate, copper thiocyanate and the like; copper containing
inorganic compounds such as cuprous hydroxide, cupric hydroxide, copper
cyanide, copper sulfide, copper oxide, and the like; organic copper
compounds, such as copper methoxide, copper ethoxide, copper
allyloxide, copper acetate, copper stearate, copper
tetramethylheptanedionate, copper acetylacetonate, copper naphthenate,
copper phenylate, pentafluorphenylcopper dimer, copper
bis(diorganophoshate) such as copper bis(diethylphosphate) and the like;
and metallic copper can be used.
No particular preparation method or purification method is required
for any of the catalysts with the exception of ensuring low-moisture
contents.
The catalyst can be supplied to the reaction system in the form of a
mixed powder with metallic silicon or as supported with or on metallic
silicon or in a fixed or non-fixed bed. If desired the catalyst and silicon
metal can be subjected to an activation treatment either in the presence or
absence of a microwave or RF field.
The amount of catalyst used in the invention is minimally 0.001
moles. The catalyst can be added continuously or in multiple additions
over a period of time, such as, preferably, over the course of the reaction.
For example, the catalyst may be added over a period of time to ensure
the presence of catalyst at a sufficient level throughout the process cycle.

The solvent can be the alcohol or a suitably inert solvent. There is
no specific limitation for the solvent, so far as it is inert to the silicon metal,
catalyst and alcohol. However, stable solvents having a relatively high
boiling temperature are preferred. Solvents transparent to microwave
radiation are also preferred.
Examples of solvents include but are not limited to paraffinic
hydrocarbons, such as octane, decane, dodecane, tetradecane,
hexadecane, octadecane, eicosane, alkylbenzene hydrocarbons, such as
diethylbenzene, cymene, butylbenzene, butyltoluehe, octylbenzene,
dodecylbenzene, and the like, and hydrogenated products thereof,
diphenyl, diphenyl ether, monoethyldiphenyl, diethyldiphenyl,
triethyldiphenyl, and hydrogenated products thereof, alkylnaphthalene
hydrocarbons and hydrogenated products thereof, and triphenyl
hydrocarbons and hydrogenated products thereof.
High boiling heat transfer agents include polyaromatic
hydrocarbons, such as, THERMINOL and MARLOTHERM, of which
MARLOTHERM is preferred. These can be used singly or in combination
of two or more thereof.
The reaction can be conducted under an atmospheric, pressurized
or depressurized condition. Reaction under atmospheric conditions is
preferred due to the economic advantage of the simple apparatus.
The reaction is conducted at a temperature, pressure, and length of
time sufficient to form the alkoxysilane. Thus, the preferred temperature is
from about 100 °C to about 300 °C; the preferred pressure is atmospheric
pressure, and the reaction time is from about 1 minute to about 10 hours.
The microwave reaction was carried out in a Milestone Ethos
microwave unit. The Ethos can be configured to run in closed vessel or
open vessel format. Both modes can be used to generate the

alkoxysilanes. The Ethos unit was modified to include a pressure monitor,
addition port for alcohol introduction, an entry port for a mechanical stirrer
and an exit port for product collection.
The microwave power level is usually in the range of 200 to 1000
watts in a field from about 3 Hz to 300 GHz. Microwave units
manufactured by other suppliers that are capable of running open and
closed vessels are also appropriate for the reaction with modifications.
The reaction can be run in a batch, semicontinuous or continuous
manner. In the batch reaction, the appropriate alcohol is introduced into
the reaction mixture which is a slurry of metallic silicon and the copper
catalyst and the reaction products are collected and purified.
In the continuous manner, the reaction slurry is continuously passed
through a microwave or RF field. The alcohol and solvent are continuously
recycled into the reaction mixture with product being separated and
purified.
The amount of material that can be produced is limited only by the
size or number of microwave generating units and the process design. In
the continuous process, one preferred approach would be the use of a
multiple number of microwave generators designed in parallel.
The silicon metal and catalyst can be introduced as a slurry or in a
metal/catalyst bed system. The bed system can be designed to allow for
replenishment of the catalyst and silicon metal as necessary. The alcohol
can be introduced in conjunction with the slurry or separately. A recycle
loop can be designed to ensure appropriate residence time to meet
productivity requirements.
. Alternatively, a reactor train can be employed wherein the slurry or
reaction mixture without a fixed bed is pumped through a series of reactors

to maximize residence time and productivity. After the appropriate
residence time the reaction mixture is passed through an evaporation unit
where ethanol is flashed off and returned to the feed unit. The reacted
mixture is then transported to a vessel where the products are separated
and purified by distillation.
In both the batch and continuous process the reactor can either be a
traditional glass kettle or a glass tube within a microwave or RF waveguide.
Other materials that are transparent to microwave or RF can be used.
Additionally, the glass reactor can be enclosed within a metal jacket
providing the jacket or this outer reactor does not interfere with
transmission of the microwaves. In either case, the microwave or RF field
generator is part of the reactor.
Depending upon whether or not the reaction mixture is slurried or
the silicon/catalyst are part of a bed type system a filter may need to be
installed to collect solid material prior to the mixture entering the
evaporator. The above referred to evaporator will also require a chiller to
condense the ethanol flashed off which can either be part of the evaporator
or a separate unit.
In one preferred embodiment of the present invention, the
alkoxysilane product is distilled to separate a major product from other
minor products or to form a higher purity alkoxysilane.
The unreacted silicon can be recycled and design provisions can be
made to add catalyst throughout the reaction if desired.
In another preferred embodiment of the present invention, any
unreacted silicon metal or hydroxy compound, if present, is recycled.
In the practice of the process of the present invention, contacting is
preferably carried out to produce at least a 40% conversion, more

preferably at least a 70% conversion and, most preferably at least a 95%
conversion.
In still another preferred embodiment of the present invention, the
alkoxysilane product is the only product formed or, alternatively, is a
mixture of trialkoxysilane and tetraalkoxysilane wherein the ratio of
trialkoxysilane to tetraalkoxysilane is at least 2:1, more preferably at least
6:1, and most preferably the ratio of trialkoxysilane to tetraalkoxysilane is
at least 9:1.
In a particularly preferred embodiment of the present invention,
contacting is carried out to produce at least a 70% conversion and a ratio
of trialkoxysilane to tetraalkoxysilane of at least 9:1.
The actual number of reactors required would be dependent upon
the production rate. A process that has several smaller units versus one
larger unit would most be preferred. A design which represents a pilot
plant approach rather than a production facility approach as it utilizes
several small vessels to achieve the volume equal to one large unit is
preferred.
The alkoxysilanes according to the. present invention have utility as
coupling agents, in adhesives, sealants, construction materials, coatings,
plastics, fabrics, medical devices, and cosmetics.
Example 1
A three necked 1 liter round bottom flask inside a Milestone Multi-
Syn Ethos Microwave chamber was fitted with a condenser and receiver, a
mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was
oven dried at 80C and dried when set up using a heat gun and nitrogen
flush. To the dried apparatus was added 20 grams (0.714 moles) of finely
ground (200 mesh) silicon metal, 0.85 grams (1.66 mole %) of cuprous
oxide, 1.17 grams (1.66 mole %) of cuprous chloride, 0.75 grams (1.66

mole %) of copper powder and 500ml of Marlotherm SH. The mixture was
vigorously stirred to form a slurry. The microwave unit power source was
turned on with an initial power level of 975 watts and the mixture was
exposed to the microwave until a temperature of 190°C was achieved (22
minutes). The microwave power level was subsequently adjusted (335 -
1000 watts) over the course of the reaction to maintain the temperature at
approximately 190°G. Once the reaction mixture reached 190°C,
anhydrous ethanol was metered in at a rate of 8.1 milliliters/minute using a
peristaltic pump. Immediately, liquid began to distill from the reaction flask
with an average head temperature of 95°C. The reaction was continued
until 1.5 liters of ethanol were added (185 minutes). Excess ethanol and
the desired product, triethoxysilane co-distilled from the reaction mixture.
The product composition was analyzed by Si-NMR spectroscopy. Silicon
conversion was determined by filtering the reaction mixture and repeatedly
washing the collected solid residue with hot water, acetone and diethyl
ether. The silicon conversion was calculated to be 87%. Selectivity
calculated from the silicon conversion was determined to favor
triethoxysilane by 100%.
Example 2
A three necked 1 liter round bottom flask inside a Milestone Multi-
Syn Ethos Microwave chamber was fitted with a condenser and receiver, a
mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was
oven dried at 80°C and dried when set up using a heat gun and nitrogen
flush. To the dried apparatus was added 20 grams (0.714 moles) of finely
ground (200 mesh) silicon metal, 0.85 grams (1.66 mole %) of cuprous
oxide, 1.17 grams (1.66 mole %) of cuprous chloride, 0.75 grams (1.66
mole %) of copper powder and 500ml of Marlotherm SH. The mixture was
vigorously stirred to form a slurry. The microwave unit power source was
turned on with an initial power level of 975 watts and the mixture was
exposed to the microwave until a temperature of 190°C was achieved (20
minutes). The microwave power level was subsequently adjusted (300 -
1000 watts) over the course of the reaction to maintain the temperature at

approximately 190°C. Once the reaction mixture reached 190°C,
anhydrous ethanol was metered in at a rate of 8.1 milliliters/minute using a
peristaltic pump. Immediately, liquid began to distill from the reaction flask
with an average head temperature of 95°C. The reaction was continued
until 1.5 liters of ethanol were added (185 minutes). Excess ethanol and
the desired product, triethoxysilane co-distilled from the reaction mixture.
The product composition was analyzed by Si-NMR spectroscopy. Silicon
conversion was determined by filtering the reaction mixture and repeatedly
washing the collected solid residue with hot water, acetone and diethyl
ether. The silicon conversion was calculated to be 95%. Selectivity
calculated from the silicon conversion was determined to favor
triethoxysilane by 100%.
Example 3
A three necked 1 liter round bottom flask inside a Milestone Multi-
Syn Ethos Microwave chamber was fitted with a condenser and receiver, a
mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was
oven dried at 80°C and dried when set up using a heat gun and nitrogen
flush. To the dried apparatus was added 20 grams (0.714 moles) of finely
ground (200 mesh) silicon metal, 3.56 grams (5 mole %) of cuprous
chloride and 500ml of Marlotherm SH. The mixture was vigorously stirred
to form a slurry. The microwave unit power source was turned on with an
initial power level of 975 watts and the mixture was exposed to the
microwave until a temperature of 190°C was achieved (17 minutes). The
microwave power level was subsequently adjusted (375 - 1000 watts) over
the course of the reaction to maintain the temperature at approximately
190°C. Once the reaction mixture reached 190°C, anhydrous ethanol was
metered in at a rate of 7.7 milliliters/minute using a peristaltic pump.
Immediately, liquid began to distill from the reaction flask with an average
head temperature of 95°C. The reaction was continued until 1.5 liters of
ethanol were added (194 minutes). Excess ethanol and the desired
product, triethoxysilane co-distilled from the reaction mixture. The product
composition was analyzed by Si-NMR spectroscopy. Silicon conversion

was determined by filtering the reaction mixture and repeatedly washing
the collected solid residue with hot water, acetone and diethyl ether. The
silicon conversion was calculated to be 70%. Selectivity calculated from
the silicon conversion was determined to favor triethoxysilane by 100%.
Example 4
A three necked 1 liter round bottom flask inside a Milestone Multi-
Syn Ethos Microwave chamber was fitted with a condenser and receiver, a
mechanical stirrer, and nitrogen and ethanol inlet ports. All glassware was
oven dried at 80°C and dried when set up using a heat gun and nitrogen
flush. To the dried apparatus was added 20 grams (0.714 moles) of finely
ground (200 mesh) silicon metal, 3.56 grams (5 mole %) of cuprous
chloride and 500ml of Mariotherm SH. The mixture was vigorously stirred
to form a slurry. The microwave unit power source was turned on with an
initial power level of 975 watts and the mixture was exposed to the
microwave until a temperature of 190°C was achieved (20 minutes). The
microwave power level was subsequently adjusted (600 - 1000 watts) over
the course of the reaction to maintain the temperature at approximately
180°C. Once the reaction mixture reached 190°C, anhydrous methanol
was metered in at a rate of 7.9 milliliters/minute using a peristaltic pump,
immediately, liquid began to distill from the reaction flask. The reaction
was continued until 1.5 liters of ethanol were added (189 minutes). Excess
methanol and the desired product, trimethoxysilane co-distilled from the
reaction mixture. The product composition was analyzed by Si-NMR
spectroscopy. Silicon conversion was determined by filtering the reaction
mixture and repeatedly washing the collected solid residue with hot water,
acetone and diethyl ether. The silicon conversion was calculated to be
70%. Selectivity calculated from the silicon conversion was determined to
favor trimethoxysilane by 100%.
Example 5
A three necked round 1 liter round bottom flask inside a Milestone
Ethos microwave unit was fitted with a condenser and receiver, a

mechanical stirrer, a nitrogen line and ethanol entrance port and a
thermocouple. The apparatus was dried by use of a heat gun with a
continual nitrogen flush throughout the system. To the dried apparatus
was added 20 grams (0.71 moles) of finely ground (200 mesh) silicone
powder, 2.11 grams (3 mole %) of Cuprous Chloride and 500 ml of
Marlotherm SH. The mixture was heated to 190°C using a microwave
power of up to 950 W, this taking approximately 19 minutes. The
microwave power level was subsequently adjusted (385 - 1000 watts) over
the course of the reaction to maintain the temperature at approximately
190°C. Once the reaction reached 190°C anhydrous ethanol was metered
in at a rate of 8.0 milliliters per minute using a peristaltic pump.
Immediately liquid was observed to distill from the reaction flask with an
average head temperature of 95°C. The reaction was continued until 1.5
liters of ethanol were added (187 minutes). The resulting distillate was
collected and analyzed by Si-NMR spectroscopy for the presence of
triethoxysilane, tetraethoxysilane and other alkoxysilanes. Selectivity
calculated from silicon conversion was determined to favor TES at 90%.
Silicon conversion was calculated to be 70%.
The present invention has been described with particular reference
to the preferred embodiments. It should be understood that variations and
modifications thereof can be devised by those skilled in the art without
departing from the spirit and scope of the present invention. Accordingly,
the present invention embraces all such alternatives, modifications and
variations that fall within the scope of the appended claims.

1. A process for preparation of an alkoxysilane represented by
the formula:

wherein n is from 0 to about 2; and wherein each R is independently
selected from the group consisting of: a linear, branched or cyclic alkyl of
having 1 to 12 carbon atoms, aryl, and acyl, wherein at least one of said
alkyl, aryl and acyl groups is optionally substituted by at least one alkyl,
alkoxy, halo, cyano or aryl;
said process comprising the step of:
contacting elemental silicon and an hydroxy compound represented
by the formula:
ROH
wherein R is selected from the group consisting of: a linear,
branched or cyclic alkyl having 1 to 12 carbon atoms, aryl, and acyl,
wherein at least one of said alkyl, aryl and acyl groups is optionally
substituted by at least one alkyl, alkoxy, halo, cyano or aryl;
wherein said contacting is carried out in the presence of at least one
catalyst selected from the group consisting of: copper, zinc, and nickel, a
non-ionizing radiation selected from the group consisting of: microwave,
radio frequency (RF), and a combination thereof, and at a temperature,
pressure, and time sufficient to form said alkoxysilane.
2. The process of claim 1, wherein n is from 0 to about 1
3. The process of claim 1, wherein n is 1 or 2.
4. The process of claim 1, wherein each R is independently
selected from the group consisting of: methyl, ethyl, propyl, and butyl.

5. The process of claim 1, wherein said hydroxy compound is
selected from the group consisting of: methanol, ethanol, and a mixture
thereof.
6. The process of claim 1, wherein said hydroxy compound is a
mixture of at least two alcohols.
7. The process of claim 1, wherein said the alkoxysilane is
triethoxysitane.
8. The process of claim 1, wherein said the alkoxysilane is
trimethoxysilane.
9. The process of claim 1, wherein the contacting step is carried
out in the presence of a solvent.
10. The process of claim 9, wherein said solvent is a
non-reactive high-boiling solvent.
11. The process of claim 9, wherein said solvent is said hydroxy
compound.
12. The process of claim 1, wherein said catalyst is selected from
the group consisting of: copper(O), copper(l) salts, copper(ll) salts, copper
(II) hydroxide, zinc(0), zinc(ll), nickel(O), nickel(ll), salts thereof, complexes
thereof, and any mixtures thereof.
13. The process of claim 12, wherein said catalyst is selected
from the group consisting of: cuprous halide, cupric hydroxide, cuprous
hydroxide, copper carbonate, copper sulfate, copper carboxylate, copper
thiocyanate, copper cyanide, copper sulfide, copper oxide, copper
alkoxide, copper tetramethylheptanedionate, copper acetylacetonate,

copper naphthenate, copper phenylate, pentafluorphenylcopper dimer,
copper bis(diorganophoshate) and a mixture thereof.
14. The process of claim 13, wherein said catalyst is selected
from the group consisting of: copper fluoride, cuprous chloride, cupric
chloride, copper bromide, copper iodide, copper methoxide, copper
ethoxide, copper allyloxide, copper stearate, copper acetate, copper
oxalate, copper bis(diethylphosphate) and a mixture thereof.
15. The process of claim 1, wherein said microwave is one
selected from the group consisting of: a monomode microwave, a
multimode microwave, and a combination thereof.
16. The process of claim 1, wherein said radio frequency is from
about 3 Hz to about 300 GHz.
17. The process of claim 1, wherein said process is selected from
the group consisting of: a batch process, continuous process, semi-
continuous process, and a combination thereof.
18. The process of claim 1, further comprising distilling said
alkoxysilane to form a higher purity alkoxysilane.
19. The process of claim 1, further comprising recycling any
unreacted silicon metal or hydroxy compound.
20. The process of claim 1, wherein said catalyst is added
over a period of time.
21. The process of claim 1, wherein contacting is carried out to
produce at least a 40% conversion.

22. The process of claim 1, wherein the conversion is at least
70%.
23. The process of claim 1, wherein the conversion is at least
95%.
24. The process of claim 1, wherein the alkoxysilane product is a
mixture of trialkoxysilane and tetraalkoxysilane.
25. The process of claim 1, wherein the alkoxysilane product is a
single silane product.
26. The process of claim 24, wherein the ratio of trialkoxysilane
to tetraalkoxysilane is at least 2:1.
27. The process of claim 24, wherein the ratio of trialkoxysilane
to tetraalkoxysilane is at least 6:1.
28. The process of claim 24, wherein the ratio of trialkoxysilane
to tetraalkoxysilane is at least 9:1.
29. The process of claim 27, wherein contacting is carried out to
produce at least a 70% conversion.

Alkoxysilancs are prepared by a process which uses microwave or RF energy. Thus, silicon metal and a copper
catalyst are exposed to microwave radiation in the presence of an appropriate hydroxy compound, such as, an alcohol, and a catalyst,
to yield the corresponding trialkoxysilane. The desired alkoxysilanes are prepared with high selectivity and at lower temperatures
and shorter times than traditional approaches allow.

Documents:

1642-KOLNP-2009-(08-09-2014)-CORRESPONDENCE.pdf

1642-KOLNP-2009-(08-09-2014)-PA.pdf

1642-KOLNP-2009-(20-06-2014)-CORRESPONDENCE.pdf

1642-KOLNP-2009-(20-06-2014)-OTHERS.pdf

1642-KOLNP-2009-(23-06-2014)-CORRESPONDENCE.pdf

1642-KOLNP-2009-(23-06-2014)-OTHERS.pdf

1642-KOLNP-2009-(24-07-2013)-FORM-13.pdf

1642-kolnp-2009-abstract.pdf

1642-kolnp-2009-claims.pdf

1642-KOLNP-2009-CORRESPONDENCE-1.1.pdf

1642-KOLNP-2009-CORRESPONDENCE-1.2.pdf

1642-kolnp-2009-correspondence.pdf

1642-kolnp-2009-description (complete).pdf

1642-KOLNP-2009-FORM 1-1.1.pdf

1642-kolnp-2009-form 1.pdf

1642-KOLNP-2009-FORM 18.pdf

1642-kolnp-2009-form 2.pdf

1642-kolnp-2009-form 3.pdf

1642-kolnp-2009-form 5.pdf

1642-kolnp-2009-international publication.pdf

1642-kolnp-2009-international search report.pdf

1642-KOLNP-2009-PA.pdf

1642-kolnp-2009-pct request form.pdf

1642-kolnp-2009-specification.pdf

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Patent Number

263954

Indian Patent Application Number

1642/KOLNP/2009

PG Journal Number

49/2014

Publication Date

05-Dec-2014

Grant Date

27-Nov-2014

Date of Filing

01-May-2009

Name of Patentee

PROCHIMIE INTERNATIONAL,LLC

Applicant Address

P.O. BOX 87, SOUTHFIELD, MA 01259 UNITED STATES OF AMERICA

Inventors:

#	Inventor's Name	Inventor's Address
1	BOWMAN, MATTHEW, DANIEL	95 HOCKCANUM BOULEVARD, APT. #3750, VERNON, CT 06066
2	ROSTON, WILLIAM, A.	P.O. BOX 87, SOUTHFIELD, MA 01259
3	CODY, ROBERT, D.	6050 MAIN STREET, STRATFORD, CN 06614

PCT International Classification Number

C07F 7/02

PCT International Application Number

PCT/US2007/021465

PCT International Filing date

2007-10-05

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	60/872,383	2006-12-01	U.S.A.