Patent GB-474082-A (GB)
Title: Process for avoiding or delaying the formation of precipitates in aqueous liquids or for redissolving the same, particularly the precipitates formed owing to the hardness of water
IPC: C02F5/12
Filed: 1936-03-24
Abstract: In processes involving the addition to impure water of substances which ordinarily form precipitates therewith, the formation of the precipitates is prevented or delayed, or if already formed the precipitates are redissolved, by the addition of an aminocarboxylic acid (or a salt thereof) containing more than one carboxylic group per amino nitrogen atom standing in a -position thereto, and containing also an organic radicle, but free from an alkyl or cycloalkyl radicle having ten or more carbon atoms when the whole molecule contains only 2 carboxylic acid groups.  The addition may be used in washing processes, and in dyeing processes using dyestuffs sensitive towards chalk. Aminocarboxylic acids specified are trimethylamine - a .a <1>.a <11> - tricarboxylic acid, iminodiacetic acid, N-alkyl-, N-aryl, N-aralkyl, or N-oxyalkyl-imino-diacetic acids, N-aryliminodiacetic acids containing an acid group in the aryl nucleus in o-position to the imino group, e.g. anthranilic-N.N-diacetic acid, hydrazinodiacetic acids, hydroxylamino diacetic acids, aminocarboxylic acids derived from ethylene diamine and polyamines, C-phenyl trimethylamine-a .a <1>.a <11>-tricarboxylic acid, C-methyl (or dimethyl) trimethylamine - a .a <1>.a <11> - tricarboxylic acid, and N-(1-carboxy-cyclohexyl) imino-diacetic acid. Substances specified for use in conjunction with the aminocarboxylic acids are soaps or other detergents such as salts of sulphonated aliphatic and aromatic hydrocarbons, e.g. alkylated naphthalene sulphonic acids, water soluble salts of acid sulphuric acid esters of higher aliphatic alcohols such as lauryl, cetyl or oleyl alcohol, and salts of condensation products of fatty acids with hydroxy or aminoalkylsulphonic acids.  Further ingredients may be added such as sodium sulphate, sodium carbonate, silicates and phosphates, oxidizing and reducing agents such as perborates and hydrosulphite, or organic solvents.  In examples: (1) the sodium salt of trimethylamino-a .a <1>.a <11>-tricarboxylic acid is added to hard water, which on addition of soap gives a strongly foaming solution, giving no precipitate when boiled with sodium carbonate or caustic soda; iminodiacetic acid may replace the tricarboxylic acid; (2) a cotton fabric, impregnated with chalky soap, is boiled with the liquor of (1), thus removing most of the chalky soap; (3) hard water is boiled with sodium metasilicate-pentahydrate and the sodium salt of the acid of (1), giving a clear solution; (4) a solution of a mixture of aminocarboxylic acids obtained by hydrolyzing albumen is heated with monochloracetic acid and sodium carbonate to give a water-softening product; (5) cotton is dyed with Sirius light green BL in presence of sodium sulphate and the sodium salt of methyliminodiacetic acid using hard water; (6) cotton goods are dyed with Indanthrene scarlet B in presence of the sodium salt of anthranilic-N.N-diacetic acid; (7) the water-softening agent in (1) is replaced by C - phenyl - trimethylamino - a .a <1>.a <11> - tricarboxylic acid, or the corresponding C-dimethyl acid or N-(1-carboxycyclohexyl) imino diacetic acid; (8) in a dyeing process involving impregnation with 2.3-hydroxy-naphthoic acid-b -naphthylamide, the sodium salt of imino-disuccinic acid is added to the impregnation bath; (9) ethylene-bis-(iminodiacetic) acid is used as water-softening agent; (10) cotton goods are dyed as in (6) using as the water-softening agent N(b  - p - hydroxyphenyl - a  - carboxy)-ethyl iminodiacetic acid; (11) a detergent agent is prepared by mixing the sulphuric ester of oleyl alcohol with sodium perborate, sodium silicate, the sodium salt of trimethylamine-a .a <1>.a <11>-tricarboxylic acid and sodium chloride; (12) cotton is washed with soap and sodium carbonate in iron-containing water in presence of the sodium salt of the acid used in (11) above; (13) a concentrated sodium sulphate solution is added to a barium chloride solution containing the sodium salt of trimethylamine-a .a <1>.a <11>-tricarboxylic acid giving a very fine suspension of barium sulphate, which may be used for delustring artificial silk. Specification 461,328 is referred to.  C - Phenyl - trimethylamine - a .a <1>.a <11> - tricarboxylic acid is obtained by condensing a -aminophenylacetic acid with chloracetic acid.  C - Dimethyl - trimethylamine - a .a <1>.a <11> - tricarboxylic acid and N - (1 - carboxycyclohexyl) imino-diacetic acid are obtained similarly from a -aminodimethylacetic and a -aminohexahydrobenzoic acids respectively. Imino-disuccinic acid is obtained as sodium salt by saponifying the tetraethyl ester with alcoholic caustic soda. Ethylene-bis-(iminodiacetic) acid is obtained by saponifying the corresponding nitrile or by condensing chloracetic acid with ethylene diamine.  N - (b  - p - hydroxyphenyl - a  - carboxy) - ethyliminodiacetic acid is obtained by condensing chloracetic acid with p-hydroxyphenylalanine.  Hydrazino-diacetic acid and hydroxylaminodiacetic acid are obtained by reacting chloracetic acid with hydrazine and hydroxylamine respectively.ALSO:A washing-composition comprises a washing agent and an aminocarboxylic acid (or a salt thereof) containing more than one carboxylic group per amino nitrogen atom standing in a -position thereto, and containing also an organic radicle, but free from an alkyl or cycloalkyl radical having ten or more carbon atoms when the whole molecule contains only 2 carboxylic groups.  Other ingredients may be added such as sodium sulphate, sodium carbonate, silicates and phosphates, oxidizing or reducing agents such as perborates and hydrosulphites and organic solvents. Washing agents specified are soaps, salts of sulphonic acids of aliphatic and aromatic hydrocarbons, e.g. alkylated naphthalene sulphonic acids, water-soluble salts of acid sulphuric esters of higher aliphatic alcohols such as lauryl, cetyl or oleyl alcohol, salts of condensation products of fatty acids with hydroxy- or aminoalkylsulphonic acids.  Types of aminocarboxylic acids referred to are trimethylamine-a , a <1>, a <11>-tricarboxylic acids, iminodiacetic acid and its N-alkyl, N-aryl, N-aralkyl- or N-oxyalkylderivatives, acids obtained by reacting excess chloracetic acid with hydrazine, hydroxylamine, ethylene diamine, or polyamines.  A semi-colloidal suspension of barium sulphate is made by adding sodium sulphate to a barium chloride solution containing the sodium salt of trimethylamine a , a <1>, a <11>-tricarboxylic acid.  Specification 461,328 is referred to.ALSO:Aminocarboxylic acids (or salts thereof) containing more than one carboxylic group per amino nitrogen atom standing in a -position thereto, and containing also an organic radicle, but free from an alkyl or cycloalkyl radicle having ten or more carbon atoms when the whole molecule contains only two carboxylic acid groups, are used as water-softening agents.  They may be used in conjunction with other substances such as sodium sulphate, sodium carbonate, silicates, phosphates, oxidizing or reducing agents such as perborates and hydrosulphite, and organic solvents. Aminocarboxylic acids specified are trimethylamine-a .a 1.a 11-tricarboxylic acid, iminodiacetic acid or N-alkyl-, N-aryl, N-aralkyl- or N-oxyalkyliminodiacetic acids such as N-methyliminodiacetic acid or anthranilic-N.N-diacetic acid, hydrazino- and hydroxylamino-diacetic acids, products of reaction of excess of chloracetic acid on ethylene diamine or polyamines such as ethylene-bis-(iminodiacetic) acid, C-phenyltrimethylamine-a .a 1.a 11-tricarboxylic acid, N-(1 - carboxycyclohexyl) iminodiacetic acid, C-methyl (or dimethyl)-trimethylamine-a .a 1.a 11-tricarboxylic acid, an acid obtained by reacting chloracetic acid with a mixture of aminocarboxylic acids obtained by completely hydrolyzing albumen, iminodisuccinic acid and N - (b  - p - hydroxyphenyl - a  - carboxy) - ethyliminodiacetic acid.  Specification 461,328, [Group III], is referred to.