# US 5,688,982 A · No-bleach process for making sulfonated fatty acid alkyl ester surfactant > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,688,982 A - Document ID: US5688982A - Status: Granted - Kind: A - Application number: 08/303,283 - Filed: 1994-09-08 - Granted: 1997-11-18 - Earliest claimed: 1993-08-20 - Assignees: The Procter & Gamble Company - Inventors: Vajih A. Khan; Michael T. Creedon; Benjamin E. Chapman - Web page: https://patentgrep.com/patent/US5688982A ## CPC - C07C 303/44: Separation; Purification - C07C 303/32: of salts of sulfonic acids - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS ## Abstract An improved, no -bleach process for the production of sulfonated fatty acid alkyl ester surfactants containing sulfonated fatty acid alkyl esters and less than 10% of sulfonated fatty acid disalt, fatty acid salt (soap), and fatty acid alkyl ester impurities, said process comprising sulfonating fatty acid alkyl esters, reacting with a C.sub.1 to C.sub.8 alcohol, and continuously neutralizing with an alkoxide in a substantially anhydrous medium of a C.sub.1 to C.sub.8 alcohol, wherein the process does not consist of a ## Claims ### Claim 1 A no-bleach process for preparing a sulfonated fatty acid alkyl ester surfactant comprising, by weight of the surfactant, from about 90% to 100% of sulfonated fatty acid alkyl esters and less than about 10% of impurities selected from the group consisting of sulfonated fatty acid salts, fatty acid salts, fatty acid alkyl esters, and mixtures thereof; said process comprising the steps of: a) sulfonating fatty acid alkyl esters; b) reacting the product of step a) with about 10% to about 20%, by weight of the product of step a), of a substantially anhydrous C.sub.1 to C.sub.8 alcohol; c) continuously neutralizing the product of step b) with an alkoxide of the formula (R.sub.2 O.sup.-).sub.n M.sup.n+ having a concentration of from about 5% to 35% by weight, in a substantially anhydrous medium of a C.sub.1 to C.sub.8 alcohol; wherein R.sub.2 is on the average a C.sub.1 to C.sub.8 alkyl, M is an alkali metal or alkaline earth metal cation, or a mixture thereof, and n is 1 when M is an alkali metal cation and n is 2 when M is an alkaline earth metal cation; d) filtering the product of step c); and e) purifying the product of step d) in a column of activated carbon; wherein the total amount of alcohol in step c) is from about 30% to 65% by weight, the temperature during step c) is from about 30.degree. to 70.degree. C. and the pH during step c) is from about 3 to 11; and wherein the process does not consist of a bleaching step. ### Claim 2 (depends on 1) The process of claim 1 wherein the alcohol in step b) comprises a C.sub.1 to C.sub.6 alcohol. ### Claim 3 (depends on 1) The process of claim 1 wherein the alcohol in step b) is methanol. ### Claim 4 (depends on 1) The process of claim 1 wherein step c) comprises continuously neutralizing the product of step b) with the alkoxide having a concentration of from about 10% to 25% in a substantially anhydrous medium of a C.sub.1 to C.sub.8 alcohol. ### Claim 5 (depends on 3) The process of claim 3 wherein step c) comprises continuously neutralizing the product of step b) with the alkoxide having a concentration of from about 10% to 25% in a substantially anhydrous medium of methanol. ### Claim 6 (depends on 1) The process of claim 1 wherein the total amount of alcohol in step c) is from about 30% to 40%. ### Claim 7 (depends on 3) The process of claim 3 wherein the total amount of alcohol in step c) is from about 30% to 40%. ### Claim 8 (depends on 5) The process of claim 5 wherein the total amount of alcohol in step c) is from about 30% to 40%. ### Claim 9 (depends on 1) The process of claim 1 wherein the temperature during the neutralizing step c) is from about 40.degree. to 60.degree. C. ### Claim 10 (depends on 3) The process of claim 3 wherein the temperature during the neutralizing step c) is from about 40.degree. to 60.degree. C. ### Claim 11 (depends on 5) The process of claim 5 wherein the temperature during the neutralizing step c) is from about 40.degree. to 60.degree. C. ### Claim 12 (depends on 8) The process of claim 8 wherein the temperature during the neutralizing step c) is from about 40.degree. to 60.degree. C. ### Claim 13 (depends on 1) The process of claim 1 wherein the pH during the neutralizing step c) is from about 6 to about 8. ### Claim 14 (depends on 3) The process of claim 3 wherein the pH during the neutralizing step c) is from about 6 to about 8. ### Claim 15 (depends on 5) The process of claim 5 wherein the pH during the neutralizing step c) is from about 6 to about 8. ### Claim 16 (depends on 8) The process of claim 8 wherein the pH during the neutralizing step c) is from about 6 to about 8. ### Claim 17 (depends on 12) The process of claim 12 wherein the pH during the neutralizing step c) is from about 6 to about 8. ### Claim 18 (depends on 1) The process of claim 1 for preparing the sulfonated fatty acid alkyl ester surfactant of claim 1 wherein the sulfonated fatty acid alkyl esters are of the formula: ##STR9## wherein R is on the average a C.sub.10 to C.sub.16 alkyl, R.sub.1 is on the average a C.sub.1 to C.sub.6 alkyl, and M is selected from the group consisting of sodium, lithium, potassium, calcium, magnesium, and mixtures thereof; said process comprising: a) sulfonating fatty acid alkyl esters of the formula RCH.sub.2 COOR.sub.1 wherein R and R.sub.1 are the same as defined above; b) reacting the product of step b) with about 10% to 20%, by weight of the product of step a), of a C.sub.1 to C.sub.6 alcohol; and c) continuously neutralizing the product of step b) with the alkoxide having a concentration of from about 10% to 25%, by weight, in a substantially anhydrous medium of a C.sub.1 to C.sub.6 alcohol; wherein R.sub.2 is on the average a C.sub.1 to C.sub.6 alkyl and M is the same as defined above. ### Claim 19 A no-bleach process for preparing a sulfonated fatty acid methyl ester surfactant comprising, by weight of the surfactant, from about 90% to 100% of sulfonated fatty acid methyl esters and less than about 10% of impurities selected from the group consisting of sulfonated fatty acid salts, fatty acid salts, fatty acid methyl esters, and mixtures thereof; said process comprising the steps of: a) sulfonating fatty acid methyl esters; b) reacting the product of step a) with about 5% to about 25%, by weight of the product of step a), of a substantially anhydrous C.sub.1 to C.sub.6 alcohol; c) continuously neutralizing the product of step b) with an alkoxide of the formula (R.sub.2 O.sup.-).sub.n M.sup.n+ having a concentration of from about 5% to 35% by weight, in a substantially anhydrous medium of a C.sub.1 to C.sub.6 alcohol; wherein R.sub.2 is on the average a C.sub.1 to C.sub.8 alkyl, M is an alkali metal cation or alkaline earth metal cation, or a mixture thereof and n is 1 when M is an alkali metal cation and n is 2 when M is an alkaline earth metal cation; d) filtering the product of step c); and e) purifying the product of step d) in a column of activated carbon; wherein the total amount of alcohol in step c) is from about 30% to 65% by weight, the temperature during step c) is from about 30.degree. to 70.degree. C. and the pH during step c) is from about 5 to 9; and wherein the process does not consist of a bleaching step. ### Claim 20 (depends on 18) The process of claim 18 wherein the alcohol in step b) is methanol, the alkoxide in Step c) is (CH.sub.3 O--).sub.n M.sup.n+, and the alcohol in step c) is methanol. ### Claim 21 (depends on 20) The process of claim 20 wherein the concentration of methoxide in methanol is from about 10% to 25% by weight and the total amount of methanol in step c) is from about 30% to 40%. ### Claim 22 (depends on 20) The process of claim 20 wherein the temperature is from about 40.degree. to 60.degree. C. ### Claim 23 (depends on 21) The process of claim 21 wherein the temperature is from about 40.degree. to 60.degree. C. ### Claim 24 (depends on 20) The process of claim 20 wherein the pH is from about 6 to 8. ### Claim 25 (depends on 21) The process of claim 21 wherein the pH is from about 6 to 8. ### Claim 26 (depends on 22) The process of claim 22 wherein the pH is from about 6 to 8.