Title of Invention

IMPROVED PROCESS FOR PREPARATION OF SALTS OF FATTY ACYL ISETHIONATES USING HETEROGENEOUS CATALYST AND CATALYST THEREOF

Abstract

The present invention encompasses an improved process for preparation of tensio-active agents of formula I. using at least one heterogeneous meso-porous type of catalyst. Wherein carboxylic acids used of the formula II. Wherein, R1 is aliphatic, acyclic, linear or branched, saturated or unsaturated or mixed linear chain hydrocarbon having 8 to 31 carbon atoms is reacted with hydroxysulfonic acid salt of formula III. Where, R2 is linear, saturated or unsaturated or aromatic hydrocarbon having 2 to 7 carbon atoms and M is alkali metals or ammonium radical.

Full Text

FORM 2 THE PATENTS ACT 1970 (39 OF 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See section 10 & rule 13) 1. "Improved process for preparation of salts of fatty acyl isethionates using heterogeneous catalyst and catalyst thereof 2. Applicant: a) Sawant Manohar Ramchandra b) Department of Chemistry Institute of Chemical Technology University of Mumbai Nathalal Parekh Marg, Matunga. Mumbai 400 019, Maharashtra, India. c) Indian The following specification particularly describes the invention and the manner in which it is to be performed. Field of invention: The present invention relates to the problem of catalyst-product separation, recyclability and water generation in the process. It has been shown that meso-porous molecular sieves type of heterogeneous catalysts (M4lS family) is easily separable and recyclable and good absorbent. Such catalyst can be used at low temperature. Hence this is an attractive method for many of the temperature sensitive substrates using meso-porous molecular sieves type of heterogeneous catalysts (M4lS family). The product of salt of fatty acyl isethionates is always contaminated with antifoamers(silicon oil), viscosity modifier(paraffin wax, fatty acid ester) or excess of fatty acid used in the process which consequently affects the purity of salt of fatty acyl isethionates. The present invention relates to an improved process for the manufacture of salt of fatty acyl isethionates by using meso-porous molecular sieves type of heterogeneous catalysts (M41S family). This invention is an attractive method for catalyst product separation and recyclability. The water generated in the process is adsorbed on the catalyst due to its adsorption property which leads to increase in reaction rate at low temperature. Background of invention: This invention relates to the preparation of esters of fatty acids with isethionates. These compounds are well known as valuable synthetic dispersants and detergents, wetting agents and materials which are particularly useful in the manufacture of toilet soaps. A variety of ways of making these compounds has been describe in the art US patent no. 3383396, US patent no.3420857 and US patent no. 3420858 disclose methods for the formation of salts of fatty acyl isethionates to obtained products which have reduced amounts of esters of higher molecular weight fatty acids and unreacted lower molecular weight fatty acid. These patents note that temperatures below 450°F significantly reduced reaction rates. These patents also list a number of reaction promoters for the direct esterification, including salts of strong acids and weak bases, Zinc Oxide and Magnesium Oxide and acids. 1 US patent no. 3429136 discloses a method for making salt of fatty acyl isethionates in which reaction is quenched at about 330°F by injecting cold water. The patent states that this quenching method is carried out without detectable amounts of hydrolysis. US patent no. 3745181 discloses the preparation of salt of fatty acyl isethionates by trans esterification reaction. Patents states that high purity products may be obtained using reaction times of 10- 90 minutes and temperatures from 125-200°C. Examples run at less than 200°C, however, seem to result in decreased yield. US patent no. 4405526 discloses a method for producing salt of fatty acyl isethionates having a yellowness index less than about 6.0. The process uses a catalyst comprising a mixture of zinc oxide and an organic sulfonic acid and heating a reaction at about 200°C to about 225°C until the desired product is formed. US patent no. 6184399 Bl discloses a method for producing salt of fatty acyl isethionates. The process uses a catalyst comprising a mixture of zinc oxide and phosphoric acid and heating a reaction at about 200°C to about 250°C. The esterification reaction substantially ceases after some time due to increase in viscosity of the reaction mass. Silicon oil, which lowers the viscosity of the reaction mixture, is than added to a reaction mixture and esterification resumes. Another major disadvantage of the process of US patent no. 6184399 Bl is, the use of water soluble transition metal salts as a catalyst, which gets consumed to form product in the form of salt of transition metal ion and high reaction temperature. US patent no. 3383396 uses dissolved Zirconium and US patent no 6184399 Bl uses zinc oxide and phosphoric acid as a catalyst which get consumed in the reaction to form less pure product and stoichiometric amount of catalyst. Thus the process is uneconomical. US patent no. 4515721 discloses a process for producing salt of fatty acyl isethionates wherein the method comprises a) heating an excess of the fatty acids with the isethionate until the water of condensation is removed; b) quenching the crude product by immersion in an excess of cooled liquid in which the ester product is insoluble but unreacted excess fatty acids are soluble, c) Filtering the slurry to separate the pure product. Isopropanol is the preferred quenching liquid, but fatty alcohols, fatty alcohol ethoxylates, polyethylene glycols, fatty triglycerides, fatty esters and paraffins may also be used as a quenching liquid. The patent notes that the presence of a certain amount of 2• such quenching liquids is acceptable and may actually facilitate detergent formulation. The method of this patent recites a temperature range of 200-250°C, but all of the examples appears to be run at 250 C. US patent no. 4536338 discloses a method for producing salts of fatty acyl isethionates through direct esterification where in: catalyst is quenched by an alkaline compound at the end of the esterification to inhibit transesterification between isethionate and later added stearic acid. The process uses a catalyst such as acidified zinc oxide, strong acids or soluble zinc salts at about 200°C to about 260°C with 233°C being standard. The patent also mentioned that increasing levels of zinc oxide to achieve faster rates of reaction gives a gritty feel to toilet bars made with the material. US patent no 6184399Bl or as in EP-A-0246471 use defoamers like silicone oil, paraffin wax. U.S. patent no. 3320292, U.S. patent no 3394155 and U.S. patent no. 3383396 uses a fluid, semi-solid or solid paraffin or excess of fatty acids. As a consequence product is always contaminated with silicon oil, paraffin wax or excess of acid, which restricts the applications of the product in the formulations where purity of the product is desired. Objectives of Invention: The objects of present invention is to provide a process for manufacture of salts of fatty acyl isethionates which may conveniently be run at temperatures not exceeding 180°C, without substantial loss in yield or reduction in reaction rates. It is also an objective of this invention to provide a process with appreciable savings in energy cost compare to processes run at higher temperatures. It is another objective of this invention to provide a process for manufacture of salts of fatty acyl isethionates which have good lathering property, reduced odor and color problems, especially when the material blended to make toilet bars. It is a further object of this invention to provide a process for manufacture of salts of fatty acyl isethionates by using meso-porous molecular sieves type of heterogeneous catalysts (M41S family) for cost effectiveness as well as minimization of the use of reaction additives. 3 Summary of invention: The present invention encompasses an improved process for preparation of tensio-active agents of formula: using at least one heterogeneous meso-porous type of catalyst. Wherein carboxylic acids used of the formula: Wherein, R1 is aliphatic, acyclic, linear or branched, saturated or unsaturated or mixed linear chain hydrocarbon having 8 to 31 carbon atoms is reacted with hydroxysulfonic acid salt of formula: Where, R2 is linear, saturated or unsaturated or aromatic hydrocarbon having 2 to 7 carbon atoms and M is alkali metals or ammonium radical. Detailed description of the invention: The present invention encompasses an improved process for preparation of tensio-active agents of formula: using at least one presence of meso-porous molecular sieves as heterogeneous catalyst at temperatures below 195 degrees C. The process of invention comprising steps: a) reacting carboxylic acid having general formula: Wherein, R| is aliphatic, acyclic, linear or branched, saturated or unsaturated or mixed linear chain hydrocarbon having 8 to 31 carbon atoms with hydroxysulfonic acid salt of general formula: Where, R2 is linear, saturated or unsaturated or aromatic hydrocarbon having 2 to 7carbon atoms and M is alkali metals or ammonium radical in molar ratios in presence of meso-porous molecular sieves (M41S) as heterogeneous catalyst at reaction temperatures 4 below 195 degrees C in a reactor equipped with nitrogen purge line, stirrer, and condenser. b) filtering the reaction mass to separate catalyst. c) cooling of product at room temperature. The reaction carried out with molar amounts of reactants and no antifoamers or viscosity regulators are added. The reaction is carried out in the temperature range of 150-195°C in presence of mesoporous molecular sieves type of heterogeneous catalysts (M41S family). Heterogeneous catalyst of the type M41S is a new family of meso-porous molecular sieves. They have pore size varying from approximately 50 °A to greater than 100°A and specific surface areas above 700 m2/g and hydrocarbon sorption capacity of 0.7cc/g. taking these points into consideration we have designed M41S type of catalyst which is highly porous and has higher specific surface area which make them suitable candidates for use as a catalyst. Due the adsorption capacity of the proposed catalyst, during the reaction the water generated is adsorbed to some extent and minimizes the foam. Thus the present invention fits in the frame of green technology. Meso-porous catalysts are used due to its adsorption capacity, they absorbs water and minimized the formation of foam. In the present invention equimolar amount of fatty acid and hydroxyalkane sulfonic acid salt is used with meso-porous type of catalysts, 100% conversion of the reactants is not possible practically in any of the existing reaction, so some fatty acid is left unreacted, which helps to maintain the reaction in stirrable form. Examples of fatty acids suitable in the process having formula: Particularly suitable fatty acids used are, where R1 is aliphatic, acyclic, linear or branched, saturated or unsaturated or mixed linear chain hydrocarbon having 8 to 31 carbon atoms preferably 8-22 carbon atoms. Preferred fatty acids are lauric acids, myristic acids, palmitic acid, stearic acid, oleic acids, coconut fatty acid, tallow fatty acids. Examples of hydroxyalkane sulfonic acid salts used in the present invention include compounds of the formula: 5 Where, R2 is linear, saturated or unsaturated or aromatic hydrocarbon having 2 to 7carbon atoms and M is alkali metals or ammonium radical. Preferably sodium salts are used. A particularly sodium salt of hydroxyethane sulfonic acid is used. In the present process, reaction is carried out in the presence of M41S type of catalysts, prepared by templated mechanism with or without hydrothermal (treatment. Most preferred templates are EO-PO (ethylene oxide-propylene oxide) block copolymers (di, tri), liquid crystals, surfactants like CTAX (Cetyl trimethyl ammonium halide where, X= CI, Br), polymeric surfactants (sugar based), Gemini surfactants, molecular sieves, proteins, and Deoxy-ribose nucleic acid. In the present invention Deoxy-ribose nucleic acid is used as a template. In the present invention M41S type of the catalyst includes silica, alumina, aluminium silicates, aluminium phosphates, silicates and phosphates of 1st ,2nd and 3rd transition series elements. To improve the activity of the catalyst as per the reaction condition these can be doped with 1st 2nd and 3rd transition series elements. Aluminium, zinc and zirconium based catalyst are used in the range of 0.02 to 5% calculated on the total amount of the starting materials. Particularly 0.02 to 1 weight %. The present process is performed between the temperature ranges of 150-195°C at atmospheric pressure and particularly carried out in a temperature range of 150-170°C. The process of the invention is suitably performed by adding preferred fatty acids are lauric acids, myristic acids, palmitic acid, stearic acid, oleic acids, coconut fatty acid, tallow fatty acids, hydroxyalkane sulfonic acid salt, selected catalyst in a reactor equipped with nitrogen purge line, stirrer, and condenser. The reaction temperature is increased between 150-195°C more particularly between 150-170°C. Once the reaction is maintained between 150-160°C temperature, reaction mass is stirred for an hour. Reaction time may vary from l-4hours according to reaction conditions maintained. After the reaction mass is filtered to separate the catalyst, product is cooled to room temperature. Once the starting materials and catalyst has been mixed in the reaction vessel and the reaction temperature is attained, homogenization of the reactants takes place, catalyst is added. One skilled in art will be able ;o determine the other conventional additives, e.g. viscosity modifiers. 6 According to the present invention, the ratio of fatty acid to hydroxyethane sulfonic acid salt is in the range of 1:1 to 1:10; particularly in the range of 1:1 to 1:5 and more particularly in the range 1.02:1.0 ie., approximately in equimolar ratios. The present invention using equimolar amounts of reactants has specific advantage of high conversion of sodium isethionate and selectivity of 100%. Further no fatty acid needs to be distilled off, providing for an economical use of starting materials, short reaction temperature and time, heterogeneous catalysts whose properties are defined above and high yields. The final product is substantially very less odorous and white in colour than the product obtained by known processes. The process of invention does not affect the active content, physico-chemical properties of the surfactant and physical properties. Thus the obtained product can be utilized for applications which are untouched, or wherein purity and colour of the product is major criteria. For an instant, the product prepared by the present process can be used in cosmetic formulations, detergents, and delivery systems. The process of invention can be understood with following examples but not limited to these. Example 1: In a typical experimental procedure sodium isethionate (1.0 mole), moles of fatty acid (1.02 moles) and catalyst aluminium containing molecular sieves (0.5 weight %) were added to three necked 100 mL round bottom flask. The mixture was stirred vigorously and temperature was allowed to rise with stirring. The reaction temperature was maintained preferably in the range of 120-240 degree C, particularly at 200 degree C. Reaction mass was heated with stirring for 4 hours. The reaction was cooled at room temperature. The isolated reaction product (80%) was determined by Epton titration. Example 2: The charge similar to that given in example 1 was taken except all three substances were pulverized and charged. The isolated reaction product obtained was 82%. Example 3: The charge similar to that given in example 1 was taken except the isethionates was added first and than fatty acid was added followed by catalyst. The isolated reaction product obtained was 70%) and colour of the obtained product was dark. 7 Example 4; The charge similar to that given in example 1 was taken except fatty acid was added first then isethionates followed by catalyst. The isolated reaction product obtained was 87% and colour of the product was white. Example 5: The charge similar to that given in example 1 was taken except that 2 moles was used instead of 1.02 moles. The isolated reaction product obtained was 85%. Example 6; The charge similar to that given in example 1 was taken except that catalyst used was 0.02 and 1 weight% instead of 0.5 wt%. The isolated reaction product was 78% and 86% respectively. Example 7: The charge similar to that given in example 1 was taken except that temperature in the range of 120-240 degree C T0C 120 140 160 180 200 220 240 Isolated Yield(%) 20 45 92 89 89 89 89 Example 8: The charge similar to that given in example 1 was taken except that the mass was heated for range of 0.5-2 hours Time(h) 0.5 1.0 1.5 2 Isolated Yield(%) 72 93 93 93 Example 9: As per mentioned in example 1 process was carried out. The subsequent run were taken on different meso-porous type of the catalysts particularly Aluminium Phosphates, Aluminium Silicates, Zirconium silicates, zinc silicates, Zirconium Phosphates and Zinc Phosphates. Results are set forth in table 1. 8 Catalyst Percent Conversion Aluminium Phosphates 90.0 Aluminium Silicates 89.5 Zirconium silicates 86.2 zinc silicates 85.0 Zirconium Phosphates 87.4 Zinc Phosphates 84.3 9 Claims: I Claim, 1. A process for preparing salt of fatty acyl isethionate having formula: Wherein, R1 represents aliphatic, acyclic, linear or branched, saturated or unsaturated or mixed linear chain hydrocarbon having 8 to 22 carbon atoms Wherein, R2 represents linear, saturated or unsaturated or aromatic hydrocarbon having 2 to 7carbon atoms and M is alkali metals or ammonium radical comprising steps: (a) reacting carboxylic acid having formula: with hydroxysulfonic acid salt of general formula: wherein Ri and R2 as defined earlier in molar ratios in presence of meso-porous molecular sieves (M41S) as heterogeneous catalyst at reaction temperatures below 195 degrees C in a reactor equipped with nitrogen purge line, stirrer, and condenser. (b) filtering the reaction mass to separate catalyst (c) cooling of product at room temperature. 2. A process as claimed in claim 1 wherein reaction temperature is increased between 120 to l95°C more particularly in the range 150 to l70°C for 1 to 4 hours. 3. A process claimed in claim 1 wherein the ratio of fatty acid to hydroxyethane sulfonic acid salt is in the range of 1:1 to 1:10; particularly in the range of 1:1 to 1:5 and more particularly in the range 1.0:1.02 to 1.02:1.0 i.e., approximately in equimolar ratios. 10 4. The process as claimed in claim 1 wherein meso-porous molecular sieves (M41S) as heterogeneous catalyst is 0.01% to 5 % by weigh, based on total weight of fatty acid and hydroxyalkane sulfonic acid. 5. The process as claimed in claim 1 wherein meso-porous molecular sieves (M41S) based on aluminium, zinc and zirconium in the range of in the range of 0.02 to 1 weight %. 6. The process as claimed in claim 1 wherein fatty acid is first melted completely and then mixture of catalyst and hydroxyalkane sulfonic acid salt is added to react. 7. Heterogeneous catalyst of meso-porous molecular sieves (M41S) type as claimed in claim 1 wherein M41S type of catalysts is templated catalyst selected from silica, alumina, aluminium silicates, aluminium phosphates, silicates and phosphates of 1st ,2nd and 3rd transition series elements and doped with 1st 2nd and 3r transition series elements. 8. Heterogeneous catalyst of meso-porous molecular sieves (M41S) type as claimed in claim 6 wherein templated catalyst is synthesized by templated mechanism using Template acidic DNA (deoxy ribose nucleic acid) as template from calf thymus. 9. Heterogeneous catalyst as claimed in claim 6 wherein heterogeneous catalyst has pore size varying from approximately 50 °A to greater than 100°A and having meso-pores more than 70 % with narrow pore size distribution attributes specific surface areas above 700 m2/g and hydrocarbon sorption capacity of 0.7cc/g. 10. A process for preparing salt of fatty acyl isethionate and heterogeneous catalyst for use therein substantially as herein described in text and examples

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938-mum-2005-abstract(20-6-2008).doc

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938-mum-2005-cancelled pages(20-6-2008).pdf

938-mum-2005-claims(granted)-(20-6-2008).doc

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938-mum-2005-claims.doc

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938-mum-2005-correspondence(20-6-2008).pdf

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938-mum-2005-description (provisional).pdf

938-mum-2005-form 1(12-8-2005).pdf

938-mum-2005-form 18(20-9-2006).pdf

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938-mum-2005-form 3(12-8-2005).pdf

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