Patent GB-723130-A (GB)
Title: New linear polyamides
IPC: D01F6/60
Filed: 1952-01-30
Abstract: New linear thread-forming polyamides having an increased affinity for acid dyestuffs and other acid treating agents contain a plurality of -NH-CO- groups each separated by a number of methylene groups and either (a) a minor proportion, not exceeding 1/5 th of the number of the -NH-CO-groups present, of substituted or unsubstituted benzimidazole or benzodi-imidazole nuclei within the polymer chain, or (b) a minor proportion, preferably not exceeding 1/150 th of the number of the -NH-CO- groups present, of substituted or unsubstituted benzimidazole or benzodi-imidazole nuclei as chain terminating groups.  The polyamides of section (a) are made by condensing polyamide forming components in presence of a substance containing a benzimidazole or benzo-di-imidazole nucleus and two groups capable of taking part in the amide formation and there are specified: (1) diaminopentyl-benzodi-imidazole; (2) the diamine of formula <FORM:0723130/IV (a)/1> (3) 2 - (o  - carboxybutyl) - benzimidazole - 5 - carboxylic acid; (4) the dicarboxylic acid of formula <FORM:0723130/IV (a)/2> (5) the 2 - amino - alkyl - benzimidazole - 5 - carboxylic acids of formula <FORM:0723130/IV (a)/3> where X is 1 or more; (6) the 5-(carboxy-alkoxy)-2-(aminoalkyl)-benzimidazoles of formula <FORM:0723130/IV (a)/4> where X is 1 or more and Y is 3 or more.  The polyamides of section (b) are obtained by condensing polyamide forming components in presence of a substance containing a benzimidazole or benzodi-imidazole nucleus and one group capable of taking part in the amide formation and there are specified: (1) 2-(o -carboxybutyl)-benzimidazole, and (2) 2-(o -carboxyoctyl)-benzimidazole.  In examples: (1) and (2) epsilon - caprolactam and 2 - (o  - aminopentyl)-benzimidazole - 5 - carboxylic acid are heated in presence of water for 20 hours to 260 DEG  C.; (3) epsilon - caprolactam and 2 - (o  - aminopropyl) - benzimidazole - 5 - carboxylic acid are heated in presence of water for 6 hours to 250 DEG  C.; (4) a mixture of (a) epsilon-caprolactam, (b) the salt of 2,21-(di-o -aminopentyl)-benzo-1,2,4,5-di-imidazole and 2-(o -carboxybutyl) - benzimidazole - 5 - carboxylic acid, and (c) the salt of adipic acid and hexamethylene diamine is polycondensed at 255-260 DEG  C.; (5) the salt of adipic acid and hexamethylene diamine and 2-(o -aminopentyl)-benzimidazole-5-carboxylic acid are heated in presence of water first in an autoclave and then under atmospheric pressure; (6) epsilon-caprolactam and 2-(o -aminopentyl) - benzimidazole - 5 - carboxylic acid are heated in an open vessel for 8 hours at 250 DEG  C.  The Specification also refers to polyamides from the salt of adipic acid and hexamethylene diamine and 2-(o -aminopentyl)-benzimidazole - 5 - carboxylic acid and polyamides from the salt of sebacic acid and hexamethylene diamine and the salt of hexamethylene diamine and 2-(o -carboxybutyl)-benzimidazole-5-carboxylic acid.ALSO:The following derivatives of benzimidazole and benzodi-imidazole are specified as intermediates in the manufacture of polyamides (see Group IV (a)) (1) 2-(w-carboxybutyl) benzimidazole prepared from o-phenyl diamine-dihydrochloride and adipic acid; (2) 2-(o -carboxy-octyl)benzimidazole prepared from o-phenylene diamine-dihydrochloride and sebacic acid; (3) the diamine of formula <FORM:0723130/IV (b)/1> prepared from 3,4,31,41-tetra-amino-diphenyl-tetrahydrochloride and aminocaproic acid hydrochloride; (4) the dicarboxylic acid of formula <FORM:0723130/IV (b)/2> prepared from 1,2,4,5-tetra-aminobenzene tetrahydrochloride and adipic acid; (5) the 2-amino-alkyl benzimidazole-5-carboxylic acids of formula <FORM:0723130/IV (b)/3> where X is one or more prepared from 3,4-diaminobenzoic acid and the desired amino carboxylic acid; (6) the 5-(o -carboxy-alkoxy)-2-(o -amino-alkyl)benzimidazoles of formula <FORM:0723130/IV (b)/4> where X is 1 or more and Y is 3 or more.  An example is 5-(o -carboxy-butoxy)-2-(5-aminopentyl)-benzimidazole obtained by reacting the sodium salt of N-benzoyl-p-aminophenol with gamma-chlorovaleronitrile in alcohol solution, nitrating the N-benzoyl-p-aminophenoxyvaleronitrile in glacial acetic acid, reducing the nitro group and boiling the 1-amino-2-benzoylamino-5-o -cyanbutyloxy-benzene with dilute hydrochloric acid in presence of epsilon-aminocaproic acid hydrochloride; (7) diamino-pentylbenz-di-imidazole obtained by reacting 1,3,4,6-tetra - aminobenzene - tetrahydrochloride with episolon - aminocaproic acid; (8) 2 - (o  - carboxybutyl) - benzimidazole - 5 - carboxylic acid obtained from 3,4-diaminobenzoic acid and adipic acid.