- 2014-12-01 (x)
- 2000-02-15 (x)
- Kenney, Malcolm E. (x)
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Show moreBackground of the invention: The present invention relates to a novel method of preparing alkoxysilanes and oligomeric alkoxysiloxanes. The method comprises reacting a metal silicate with an acid selected from the group consisting of sulfurous acid and acids with a pKa greater than about 2.5 in the presence of an alcohol. The resultant product is then reacted with an alcohol to form the alkoxysilane or oligomeric alkoxysiloxane, depending on the starting silicate. This method is particularly valuable since the reaction conditions are mild and the reactants are readily available. Several methods of producing alkoxysilanes are known in the art. The most well known and often used of these methods involves the reaction of silicon tetrachloride with an alcohol. Despite the high yields which can be obtained, this method is disadvantageous in that it is a 2-step process initially requiring the formation of silicon tetrachloride. In order to avoid this roundabout approach, a method has been developed that yields alkoxysilanes by a 1-step reaction using elemental silicon and alcohols. Unfortunately, elemental silicon is generally produced from silica by a very endothermic and thus costly reaction. Several routes to oligomeric alkoxysiloxanes have also been developed. For instance, in one route silicon tetrachloride is treated with a limited amount of water to form a reaction mixture from which an appropriate chlorosiloxane is isolated. The chlorosiloxane is then treated with an alcohol to yield the alkoxysiloxane. Such routes, often yield mixtures from which it is difficult to separate the desired alkoxysiloxane. Kenney (et al.) in U.S. Pat. No. 4.717.773 teach an alternative route to alkoxysilanes and oligomeric alkoxysiloxanes comprising reacting a metal silicate with a strong acid-alcohol solution and then esterifying the resultant product with an alcohol. The only acids taught in this work are strong acids such as HC1. The present inventors have now discovered that alkoxysilanes and oligomeric alkoxysiloxanes can be made by reacting metal silicates with an acid selected from the group consisting of sulfurous acid or acids with a pKa greater than about 2.5 and then esterifying the resultant product with an alcohol. Summary: The present invention relates to a novel method of preparing alkoxysilanes. The method comprises reacting a metal orthosilicate with an acid selected from the group consisting of sulfurous acid and acids with a pKa greater than about 2.5 in the presence of an alcohol. The product is then esterified by reacting it with ROH to form Si(OR).sub.4 wherein R is an alkyl of 1-20 carbon atoms. The present invention also relates to a novel method of preparing oligomeric alkoxysiloxanes. The method comprises reacting a metal silicate having a framework that is the same as that of the desired alkoxysiloxane or is similar to it with an acid selected from the group consisting of sulfurous acid and acids with a pKa greater
http://www.google.com/patents?vid=USPAT5183914
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Show moreBackground of the invention: In the past, silicon phthalocyanines generally have been made by the cyclization of a ring precursor. One such method involves reacting a diiminoisoindoline with a tetrachlorosilane. An example of this route is: ##STR1##A disadvantage of this method is that it gives byproducts which are difficult to separate. The products are thus difficult to purify. Moreover certain phthalocyanine molecules are difficult, if not impossible, to assemble by this method. Summary of the invention: The present invention provides a simple, flexible, convenient method for making silicon phthalocyanines and naphthalocyanines by inserting silicon into metal-free phthalocyanines and metal-free naphthalocyanines. The method comprises: providing a metal-free phthalocyanine or metal-free naphthalocyanine; reacting the metal-free phthalocyanine or metal-free naphthalocyanine with HSiCl.sub.3 to provide a reaction product; then reacting the reaction product with water; and extracting a silicon phthalocyanine or a silicon naphthalocyanine. The invention also relates to novel phthalocyanines and naphthalocyanines. The phthalocyanines and naphthalocyanines are useful as photosensitizers and as dyes. Detailed description of the invention: The present invention provides a simple, flexible, convenient method for making silicon phthalocyanines and silicon naphthalocyanines, hereinafter collectively referred to as "macrocycles", by inserting silicon into metal-free phthalocyanines and metal-free naphthalocyanines. The method is useful for making known compounds as well as novel compounds. The method comprises the following steps: first providing a metal-free phthalocyanine or a metal-free naphthalocyanine preferably having some substituent groups to make it soluble. The metal-free phthalocyanine or metal-free naphthalocyanine is then reacted with trichlorosilane, in a trichlorosilane to macrocycle ratio of from about 100:1 to about 1:1, preferably from about 30:1 to 10:1. The metal-free phthalocyanine or metal-free naphthalocyanine is preferably reacted with HSiCl.sub.3 in the presence of an amine and an organic solvent. Preferably the amine is substituted with three alkyl groups, each alkyl group having from 1 to 10 carbon atoms; tri-n-propylamine is the preferred amine. The organic solvent employed in this step is inert and has a boiling point below 200.degree. C. Suitable solvents include, for example, tetrahydrofuran, toluene, acetonitrile and CH.sub.2 Cl.sub.2 ; CH.sub.2 Cl.sub.2 is preferred. Benzene is less preferred. The reaction mixture is then hydrolyzed; and the hydrolysate is extracted with a volatile organic solvent. Preferably the volatile organic solvent has a boiling point below about 220.degree. C. Preferred volatile solvents include, for example, toluene and CH.sub.2 Cl.sub. 2. The phthalocyanines are useful as photosensitizers, as discussed in U.S. Pat. No. 5,166,179 issued Nov. 24, 1992 and U.S. Pat. No. 5,484,778 issued Jan. 16 1996.
http://www.google.com/patents?vid=USPAT5872248
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Show moreCross-reference to related applications: This application is related to a prior U.S. application Ser. No. 08/542,081, filed Oct. 12, 1995, now allowed entitled "Sheet and Tube Siloxane Polymers", in the name of Timothy Chi-Shan Chao, Malcolm E. Kenney, and Dimitris E. Katsoulis. The application is assigned jointly to Case Western Reserve University, Cleveland, Ohio, and Dow Corning Corporation, Midland, Mich. Background of the invention: This invention is directed to silicone compounds, and methods of making silicate-based sheet and tube type siloxane polymers. Silicones are made from silica by reducing it in an electric furnace to elemental silicon, i.e.,SiO.sub.2 +2C.fwdarw.Si+2CO. The elemental silicon is treated with RC1, typically methyl chloride, in the "Direct Process", as the basis of commercial production, i.e.,Si+2RCl.fwdarw.R.sub.2 SiCl.sub.2 Hydrolysis of the organochlorosilanes gives siloxane structures which are used in the manufacture of many silicone products, i.e.,nMe.sub.2 SiCl.sub.2 +2nH.sub.2 O.fwdarw.nMe.sub.2 Si (OH).sub.2 +2nHCln[Me.sub.2 Si(OH).sub.2 ].fwdarw.HO(Me.sub.2 SiO).sub.n H+(n-1)H.sub.2 O. Alternative routes to silicones involving the preparation of silicone pollers from silicate materials are embodied in U.S. Pat. No. 3.661,846 (May 9, 1972). The copending U.S. application Ser. No. 08/542,081, is an improvement and furtherance of the efforts described in the '846 patent to find other unique approaches in the manufacture of silicones. This present invention is a modification of the process generally described in the '081 application. Thus, according to the '081 application, sheet or tube silicates are reacted with an alkenyl group containing chlorosilane to produce an alkenylsiloxy polymer. The alkenylsiloxy polymer is then further reacted with a hydrosilane in the presence of a platinum catalyst to produce an organopolysiloxane polymer. In this present invention, however, sheet or tube silicates are reacted with an organo-H-chlorosilane to produce an organosiloxane polymer with pendent .tbd.Si--H groups. The organosiloxane polymer with pendent .tbd.Si--H groups is then further reacted with an olefin in the presence of a platinum catalyst to produce the organopolysiloxane polymer. In the '081 application, four of the four reactants contain the silicon atom. In the present invention, only three of the four reactants contain the silicon atom. Thus, the term hydrosilation applies to the addition of Si--H across any unsaturated species, i.e..tbd.SiH+CH.sub.2 .dbd.CH(R).sub.n Si.tbd..fwdarw..tbd.Si--CH.sub.2 CH.sub.2 --R.sub.n --Si.tbd. (I)or.tbd.SiH+CH.sub.2 .dbd.CHR.fwdarw..tbd.Si--CH.sub.2 CH.sub.2 --R(II). Silanes and siloxanes that contain a silicon bound hydrogen atom can add across the double bond. Typically, these reactions are conducted in the presence of a platinum catalyst or a catalyst which is a complex of platinum.
http://www.google.com/patents?vid=USPAT5627241
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Show moreBackground of the invention: This invention is directed to silicone compounds, and methods of making silicate-based sheet and tube type siloxane polymers. Silicones are made from silica by reducing it in an electric furnace to silicon metal, i.e. SiO.sub.2 +2 C.fwdarw.Si+2 CO The silicon metal is treated with RCl, typically methyl chloride, in the "Direct Process", as the basis of commercial production, i.e. Si+2 RCl.fwdarw.R.sub.2 SiCl.sub.2. Hydrolysis of the organochlorosilanes gives siloxane structures which are used in the manufacture of many silicone products, i.e. nMe.sub.2 SiCl.sub.2 +2nH.sub.2 O.fwdarw.n[Me.sub.2 Si(OH).sub.2 ]+2nHCl.fwdarw.n[Me.sub.2 Si(OH).sub.2 ].fwdarw.HO(Me.sub.2 SiO).sub.n H+(n-1) H.sub.2 O. Alternative routes to silicones involving the preparation of silicone polymers from silicate materials are embodied in U.S. Pat. No. 3,661,846 (May 9, 1972). This invention is an improvement and furtherance of the efforts described in the '846 patent to find other unique approaches in the manufacture of silicones. Brief summary of the invention: One object of this invention is to provide new, simple, and versatile routes, to siloxane polymers having segments derived from silicate structures by using readily accessible starting materials, that in many cases, give nontoxic byproducts. Another object is to prepare distinctively shaped organosiloxanes, useful as additives in conventional amorphous silicone materials such as resins, fluids, and gums; and to create "supramolecular" structures that offer benefits in the areas of gels, cosmetics, rheological additives, greases, elastomers, sealants, fire resistant materials, and molecular reinforcement. These and other objects of the invention will become apparent from a consideration of the detailed description.
http://www.google.com/patents?vid=USPAT5605982
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Show moreField of the invention: The subject invention relates to a process for the production of a sulfur dioxide sorbent useful for the removal of SO.sub.2 from flue gas. Particularly, the invention relates to a process for the hydration of a reactant containing Ca.sub.3 SiO.sub.5 admixed with about 3% of a compound such as gypsum that facilitates the conversion of the Ca.sub.3 SiO.sub.5 to the desired product, or Ca.sub.2 SiO.sub.4, or both the mixture and Ca.sub.2 SiO.sub.4, to any of which optionally has been added a silica source, to a finely divided product whose main active components include the calcium silicate CaO--SiO.sub.2 --H.sub.2 O, or in cement chemist's notation C--S--H, and calcium hydroxide. The invention also relates to the sorbent itself and the use thereof for the desulfurization of sulfur-containing flue gas. Background of the invention: It has long been known that the flue gas produced at coal-burning facilities and power plants contains dangerous levels of toxic SO.sub.2 gas. Many methods have been advanced over the years as a means of desulfurizing the emissions from such facilities. U.S. Pat. Nos. 4,931,264 and 4,804,521 proposed the use of a system which combines Ca(OH).sub.2 and fly ash to solve this problem. The process disclosed by these patents involves contacting the sulfur-containing gas with a slurry containing a calcium alkali and a calcium-reactive silica or alumina which has been heated to a temperature sufficient to produce the sulfur-absorbing components. While this process is effective for removing sulfur from flue gas, it has a number of drawbacks. Among these drawbacks is the fact that only some of the components of the reaction mixture are capable of yielding products that can take up SO.sub.2 efficiently. Thus, much of the sorbent produced is composed of species which do not take up SO.sub.2 efficiently. The average percent conversion or utilization of the calcium for groups of representative Ca(OH).sub.2 -fly ash sorbents made from Illinois, Appalachian, and Powder River basin fly ashes is only 42%, 48%, and 52% as measured with a sandbed sorption test apparatus loaded with 1 g of sorbent and 40 g of sand through which a gas composed of 1000 ppm of SO.sub.2 in N.sub.2 at a temperature of 64.degree. C. and a relative humidity of 60% is passed at a flow rate of 5 L/min for 1 hour. This is disclosed in Singer et al., "Suitability of Available Fly Ashes In Advocate Sorbents" 1991 EPRI-EPA-DOE SO.sub. 2 Control Symposium. Some of the species which do not take up SO.sub.2 efficiently are toxic, and all must ultimately be disposed of. The transportation of spent sorbent and other byproducts and the subsequent disposal thereof is very costly and will become more costly as disposal sites become filled.
http://www.google.com/patents?vid=USPAT5403808
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