(19) TZZ¥Z_T (11) EP 3 064 487 A1 (12) EUROPEAN PATENT APPLICATION published in accordance with Art. 153(4) EPC (43) Date of publication: (51) Int Cl.: 07.09.2016 Bulletin 2016/36 C07C 231/02 (2006.01) B01F 17/28 (2006.01) C07C 233/47 (2006.01) C07C 233/49 (2006.01) (2006.01) (2006.01) (21) Application number: 14857866.9 C11D 1/04 C11D 1/10 C11D 17/04 (2006.01) A61K 8/44 (2006.01) (2006.01) (2006.01) (22) Date of filing: 30.10.2014 A61Q 5/02 A61Q 19/10 (86) International application number: PCT/JP2014/078856 (87) International publication number: WO 2015/064678 (07.05.2015 Gazette 2015/18) (84) Designated Contracting States: • ISHII, Hiroji AL AT BE BG CH CY CZ DE DK EE ES FI FR GB Kawasaki-shi GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO Kanagawa 210-8681 (JP) PL PT RO RS SE SI SK SM TR • INO, Masahiro Designated Extension States: Kawasaki-shi BA ME Kanagawa 210-8681 (JP) (30) Priority: 31.10.2013 JP 2013226965 (74) Representative: Nicholls, Kathryn Margaret Mewburn Ellis LLP (71) Applicant: Ajinomoto Co., Inc. City Tower Tokyo 104-8315 (JP) 40 Basinghall Street London EC2V 5DE (GB) (72) Inventors: • HATTORI, Gaku Kawasaki-shi Kanagawa 210-8681 (JP) (54) AQUEOUS SOLUTION CONTAINING N-LONG-CHAIN ACYL ACIDIC AMINO ACID AND/OR SALT THEREOF, AND METHOD FOR PRODUCING SAME (57) The present invention provides a method of pro- in a water solvent at pH 10 - 13 to form an N-C8-22 acyl ducing an aqueous solution containing an N-C8-22 acyl acidic amino acid salt, and the second step for adjusting acidic amino acid and/or a salt thereof and having pH 8.4 the pH of the aqueous solution after the first step to 8.4 - 9.5, including the first step for reacting an acidic amino - 9.5. acid and/or a salt thereof with a C 8-22 fatty acid chloride EP 3 064 487 A1 Printed by Jouve, 75001 PARIS (FR) EP 3 064 487 A1 Description Technical Field 5 [0001] The present invention relates to an aqueous solution containing an N-long chain acyl acidic amino acid (spe- cifically an N-C8-22 acyl acidic amino acid) and/or a salt thereof, and a production method thereof. Background Art 10 [0002] Since N-long chain acyl acidic amino acid salt has a surface active action, a sterilizing action, a metal corrosion suppressive action and the like, it is useful as a starting material of detergents, dispersing agents, emulsifiers, antibacteri al agents, preservatives and the like. Particularly, it is highly useful as a starting material of detergents such as shampoo, body shampoo and the like since it is mild to the skin. [0003] As a method of synthesizing N-long chain acyl acidic amino acid (e.g., N-long chain acylglutamic acid) or a salt 15 thereof, a method including condensing acidic amino acid (e.g., glutamic acid) or a salt thereof and long chain fatty acid chloride in a water solvent, or a mixed solvent of hydrophilic organic solvent such as acetone, t-butanol, propylene glycol and the like and water, in the presence of a base is known (Schotten-Baumann reaction, see, for example, patent document 1). In patent document 1, however, the obtained N-long chain acyl acidic amino acid is precipitated to recover same as a solid, and the utility of the aqueous solution per se after the reaction has not been evaluated. 20 [0004] In addition, N-long chain acyl acidic amino acid dipeptide is known as a substance that improves water resistance and creaky feeling of detergents containing N-long chain acyl acidic amino acid (patent document 2). However, N-long chain acyl acidic amino acid dipeptide needs to be obtained by acylating acidic amino acid dipeptide by the Schotten- Baumann reaction and the like, and is an expensive substance difficult to obtain. 25 [Document List] Patent Documents [0005] 30 patent document 1: JP-A-10-81656 patent document 2: JP-A-10-121091 SUMMARY OF THE INVENTION 35 Problems to be Solved by the Invention [0006] When an aqueous reaction solution containing N-long chain acyl amino acid and/or a salt thereof obtained by the Schotten-Baumann reaction of acidic amino acid and/or a salt thereof with long chain fatty acid chloride can be 40 directly utilized as a detergent and the like or a starting material thereof, the production step and facility can be simplifie d by the omission of the recovery, washing and drying processes of the N-long chain acyl amino acid and/or a salt thereof, and a low environmental load type production process which is completely free from waste liquids can be achieved. [0007] To handle the aforementioned aqueous reaction solution directly as a detergent and the like or a starting material thereof, the aqueous reaction solution is required to show stability to high temperature and low temperature. In addition, 45 unreacted acidic amino acid and/or a salt thereof (e.g., glutamic acid, glutamate) present in the aqueous reaction solution are/is converted to lactam (e.g., pyroglutamic acid, pyroglutamate) due to an intramolecular condensation reaction under high temperature conditions. Also, there is a problem that the solubility of N-long chain acylglutamic acid and/or a salt thereof obtained by the Schotten-Baumann reaction decreases during the low temperature preservation of the aqueous reaction solution, thus resulting in precipitation. 50 [0008] The present invention has been made by taking note of the above-mentioned situation, and aims to provide an aqueous solution containing N-long chain acyl amino acid and/or a salt thereof having superior stability at high temperature and low temperature. Means of Solving the Problems 55 [0009] The present inventors have conducted intensive studies in an attempt to achieve the above-mentioned object, and found that an aqueous solution containing N-C8-22 acyl acidic amino acid and/or a salt thereof having superior stability at low temperature and high temperature can be obtained by reacting acidic amino acid and/or a salt thereof 2 EP 3 064 487 A1 with C8-22 fatty acid chloride in a water solvent at pH 10 - 13, and adjusting the pH of the aqueous reaction solution to fall within a certain range. The present invention based on the finding is as described below. [1] A method of producing an aqueous solution comprising an N-C8-22 acyl acidic amino acid and/or a salt thereof 5 and having pH 8.4 - 9.5, comprising the first step for reacting an acidic amino acid and/or a salt thereof with a C 8-22 fatty acid chloride in a water solvent at pH 10 - 13 to form an N-C8-22 acyl acidic amino acid and/or a salt thereof, and the second step for adjusting the pH of the aqueous solution after the first step to 8.4 - 9.5. [2] The production method of the aforementioned [1], wherein the pH of the aqueous solution after the first step is 10 adjusted to 8.6 - 9.2. [3] The production method of the aforementioned [1] or [2], wherein the acidic amino acid and/or a salt thereof are/is one or more selected from glutamic acid, aspartic acid and salts thereof. [4] The production method of the aforementioned [1] or [2], wherein the acidic amino acid and/or a salt thereof are/is glutamic acid and/or a sodium salt thereof. 15 [5] The production method of any one of the aforementioned [1] - [4], wherein the C 8-22 fatty acid chloride is one or more selected from octanoyl chloride, decanoyl chloride, lauroyl chloride, myristoyl chloride, palmitoyl chloride, and coconut oil fatty acid chloride. [6] The production method of any one of the aforementioned [1] - [4], wherein the C 8-22 fatty acid chloride is lauroyl chloride and/or coconut oil fatty acid chloride. 20 [7] The production method of any one of the aforementioned [1] - [4], wherein the C 8-22 fatty acid chloride is coconut oil fatty acid chloride. [8] The production method of any one of the aforementioned [1] - [7], wherein the reaction of the first step is performed in the presence of sodium hydroxide. [9] The production method of any one of the aforementioned [1] - [8], further comprising a step for pressure filtration. 25 [10] The production method of any one of the aforementioned [1] - [9], wherein the water solvent does not contain a substantially hydrophilic organic solvent. [11] The production method of any one of the aforementioned [1] - [10], wherein the aqueous solution after the second step comprises 1.0 - 10.0 wt% of the acidic amino acid and/or a salt thereof, and 10.0 - 30.0 wt% of the N- C8-22 acyl acidic amino acid and/or a salt thereof. 30 [12] The production method of any one of the aforementioned [1] - [11], wherein the aqueous solution after the second step further comprises an N-C 8-22 acyl acidic amino acid dipeptide and/or a salt thereof. [13] The production method of the aforementioned [12], wherein a content of the N-C8-22 acyl acidic amino acid dipeptide and/or a salt thereof in the aqueous solution is 0.5 - 5.0 wt%. [14] The production method of any one of the aforementioned [1] - [13], wherein the aqueous solution after the 35 second step further comprises an N-C 8-22 acyl acidic amino acid tripeptide and/or a salt thereof.