Patent EA-004124-B1 (EA)
Title: Solid amphoteric surfactants
Inventor: FRICK HENDRICK PETRUS
IPC: C11D1/90
Filed: 2001-09-10
Abstract: 1. A solid amphoteric surfactant product consisting essentially of: water; any residual salt; and a surfactant which is a carboxyalkylated, sulphonoalkylated or phosphonoalkylated derivative of an amine said amine comprising a hydrophobic long chain aliphatic substituent characterised in that: (A) said surfactant constitutes more than 80% of the total weight of the product; (B) the long chain aliphatic substituent consists essentially of a single homologue having more than 13 carbon atoms; (C) the salt (e. g. alkalimetal chloride and ammonium chloride content is less than 10% based on the total weight of the product ; and (D) the water content is between 1 and 12.5% based on the total weight of the product. 2. A product according to claim 1, wherein said long chain aliphatic constituent has from 14 to 25 carbon atoms. 3. A product according to either of claims 1 and 2, wherein the salt content is less than 6% based on the total weight of the product. 4. A product according to claim 3, wherein the concentration of salt is less than 5% based on the total weight of product. 5. A product according to claim 4, wherein the concentration of salt is less than 3% based on the total weight of product. 6. A product according to claim 5, wherein the concentration or salt is less than 2% based on the total weight of product. 7. A product according to any foregoing claim, wherein the water content is from 2 to 12% by weight based on the total weight of product. 8. A product according to any foregoing claim, wherein the water content is from 4 to 8% based on the total weight of the product. 9. A product according to any foregoing claim, wherein said long chain aliphatic substituent consists of more than 90% by weight of a single homologue. 10. A product according to claim 9, wherein said long chain aliphatic substituent comprises from 94 to 99% by weight of a single homologue. 11. A product according to any foregoing claim, wherein said long chain aliphatic substituent is a straight chain alkyl or alkyl amido alkylene group. 12. A product according to any foregoing claim, wherein said surfactant has the formula wherein R is a long chain aliphatic group having more than 13 carbon atoms; R<1> and R<11> are each hydrogen or a methyl, ethyl or hydroxyethyl group; X is a carboxy, sulphono or phosphono group, n is 0 or 1 and m is 1 or 2. 13. A product according to claim 12, wherein X is a carboxy group. 14. A product according to either of claims 12 and 13, wherein n is 1. 15. A product according to any of claim 12 to 14, wherein m is 1. 16. A product according to any of claims 12 to 15, wherein R<1> and R<11> are each methyl groups. 17. A product according any of claims 12 to 16, wherein R is an alkyl or alkylamidopropyl group. 18. A product according to any foregoing claim wherein said surfactant constitutes more than 90% of said composition. 19. A product according to claim 12, comprising more than 90% by weight thereof of lauryl amido propyl betaine. 20. A product according to any foregoing claim, wherein the total inorganic salt is less than 10% by weight. 21. A product according to claim 20, wherein the total inorganic salt is less than 5% by weight. 22. A mixture of two or more different surfactant products according to any foregoing claim. 23. A method of making a product according any of claims 1 to 21, which comprises drying an aqueous solution of said surfactant at a temperature below the softening point of said product. 24. A method according to claim 23, which comprises freeze-drying. 25. A method according to either of claims 23 and 24, which comprises the steps of reacting an amine capable of forming, onchloromethylation, a betaine according to any of claims 1-21, with alkali metal chloroacetate to form an aqueous solution of said surfactant and alkali metal chloride; reducing the salt content of said solution to less than 10% by weight of the surfactant; and drying said solution to a moisture content of less than 10% by weight. 26. A method according to claim 25, wherein said alkali metal is sodium. 27. A method according to claims 23 and 24, which comprises the steps of reacting an amine capable of forming, onchloromethylation, a betaine according to any of claims 1-21, with epichlorohydrin and sodium bisulfite with forming of aqueous solution of said surfactant and sodium chloride; reducing the salt content of said solution to less than 10% by weight of the surfactant; and drying said solution to a moisture content of less than 10% by weight.