Patent GB-626380-A (GB)
Title: Improvements in the treatment of polyamides
IPC: C08J3/02
Filed: 1947-02-13
Abstract: Natural or artificial polyamides or polyureas are swollen and/or dissolved in solutions of strong monobasic or dibasic mineral acids in media which ionize the acids less than does water.  The media are aqueous solutions of alkali, alkaline earth or ammonium salts of the acids or hydroxylated organic solvents, e.g. alcohols such as methyl alcohol, or ethylene glycol, hydroxy - ethers, hydroxy ketones, aliphatic acids such as acetic acid or hydroxy acids such as lactic acid, or aromatic substituted aliphatic alcohols such as benzyl alcohol or anisyl alcohol.  The hydroxylated organic solvents may also contain the salts above referred to.  In aqueous media the total concentration of negative radicals must not be less than 4 gram equivalents/litre. Suitable acids are hydrochloric, nitric and sulphuric.  Swelling processes are applicable in dyeing or finishing of yarns, threads or fabrics.  Solutions according to the invention may be used for making artificially spun fibres or as textile finishing compositions.  The process is also applicable for extracting proteins from materials containing them.  In the examples: (1) nylon yarns or fabrics are swollen in aqueous HCl containing CaCl2 and washed.  Affinity for dyestuffs and elasticity is increased; (2) nylon or polyhexamethylene urea is dissolved in ethyl alcoholic HCl.  The solution may be used for finishing yarns or fabrics; (3) nylon or polyhexamethylene urea is dissolved in methyl alcoholic HCl.  Fibres may be formed by dry or wet spinning of the solution; (5) degummed silk is swollen with formic acid, and HCl gas passed in until the silk dissolves.  The solution may be wet or dry spun to fibres; (6) casein, soya bean or peanut protein or the flesh or skins of animals or fish is dissolved in alcoholic HCl; (7) proteins or a mixture thereof with synthetic polyamides are dissolved in a solution containing HCl and CaCl2; (8) disintegrated peanuts or grass is extracted with alcohol to remove fats and then with alcoholic HCl to separate protein which is recovered by neutralizing or driving off the HCl and adding excess alcohol.ALSO:Natural or artificial polyamides or polyureas are swollen and/or dissolved in solutions of strong monobasic or dibasic mineral acids in media which ionise the acids less than does water.  The media are aqueous solutions of alkali, alkaline earth or ammonium salts of the acids or hydroxylated organic solvents, e.g. alcohols such as methyl alcohol, or ethylene glycol, hydroxy-ethers, hydroxyketones, aliphatic acid such as acetic acid or hydroxy acids such as lactic acid or aromatic substituted aliphatic alcohols such as benzyl alcohol or anisyl alcohol.  The hydroxylated organic solvents may also contain the salts above referred to.  In aqueous media the total concentration of negative radicals must not be less than 4 gram equivalents/litre. Suitable acids are hydrochloric, nitric and sulphuric.  Swelling processes are applicable in dyeing or finishing of yarns, threads or fabrics.  Solutions according to the invention may be used for making artificially spun fibres or as textile finishing compositions.  The process is also applicable for extracting proteins from material containing them.  In the examples: (1) nylon yarns or fabrics are swollen in aqueous HCl containing CaCl2 and washed; affinity for dyestuffs and elasticity is increased; (2) nylon or polyhexamethylene urea is dissolved in ethyl alcoholic HCl.  The solution may be used for finishing yarns or fabrics; (3) nylon or polyhexamethylene urea is dissolved in methyl alcoholic HCl.  Fibres may be formed by dry or wet spinning of the solution; (5) degummed silk is swollen with formic acid, and HCl gas passed in until the silk dissolves.  The solution may be wet or dry spun to fibres; (6) casein, soya bean or peanut protein or the flesh or skins of animals or fish are dissolved in alcoholic HCl; (7) proteins or a mixture thereof with synthetic polyamides are dissolved in a solution containing HCl and CaCl2; (8) disintegrated peanuts or grass is extracted with alcohol to remove fats and then with alcoholic HCl to separate protein which is recovered by neutralizing or driving off the HCl and adding excess alcohol.ALSO:Natural or artificial polyamides or polyureas are swollen and/or dissolved in solutions of strong monobasic or dibasic mineral acids in media which ionise the acids less than does water. The media are aqueous solutions of alkali, alkaline earth or ammonia salts of the acids or hydroxylated organic solvents, e.g. alcohols such as methyl alcohol, or ethylene glycol, hydroxy-ethers, hydroxy-ketones, aliphatic acids, such as acetic acid or hydroxy acids such as lactic acid or aromatic substituted aliphatic alcohols such as benzyl alcohol or anisyl alcohol.  The hydroxylated organic solvents may also contain the salts above referred to.  In aqueous media the total concentration of negative radicals must not be less than 4 gram equivalents/litre.  Suitable acids are hydrochloric, nitric and sulphuric.  Swelling processes are applicable in dyeing or finishing of yarns, threads or fabrics.  Solutions according to the invention may be used as textile finishing compositions.  In the examples: nylon yarns or fabrics are swollen in aqueous HCl containing CaCl2 and washed.  Affinity for dyestuffs and elasticity is increased. Nylon or polyhexamethylene urea is dissolved in ethyl alcoholic HCl.  The solution may be used for finishing yarns or fabrics. Casein, soya bean or peanut protein or the flesh or skins of animals or fish are dissolved in alcoholic HCl.  Proteins or a mixture thereof with synthetic polyamides are dissolved in a solution containing HCl and CaCl2.  Disintegrated peanuts or grass is extracted with alcohol to remove fats and then with alcoholic HCl to separate protein which is recovered by neutralising or driving off the HCl and adding excess alcohol.