Patent GB-811696-A (GB)
Title: Improvements in finishing leather
IPC: C08G69/02
Filed: 1957-05-15
Abstract: The polyamides are prepared from (1) 15-85 parts by weight with reference to the entire polyamide-forming initial material of linear polyamide-forming compounds of the dicarboxylic acid-diamine type, the dicarboxylic acids being those which have carboxylic groups connected by a chain of 6-12 carbon atoms, the said chain containing a lateral branch of 7-10 carbon atoms; and (2) 85-15 parts by weight of linear polyamide-forming compounds. The solvent comprises one or more monohydric or polyhydric alcohols, preferably having 1-4 carbon atoms in the molecule. Specified acids in (1) are 1-nonyl-octane dicarboxylic acid-(1.8) and 1-octyl-nonane dicarboxylic acid-(1.9). Specified amines are 4 : 41-diaminodicyclohexyl, 4 : 41 - diaminodicyclohexylmethane, which are preferred in (1), and ethylene diamine, tetramethylene diamine, octamethylene diamine, decamethylene diamine, hexamethylene diamine, 1 - aminopropanol - (3) and metaphneylene diamine.  Specified acids in (2) are adipic, sebacic, suberic, decamethylene dicarboxylic and heptamethylene dicarboxylic acids and their derivatives capable of polyamide formation.  The diamines and dicarboxylic acids may be added as a salt formed by interaction or by themselves.  Lactams such as caprolactam, oenanthlactam and caprylic lactam may be present in (2).  The condensation may be carried out at 140-300 DEG  C. or more, preferably in an indifferent gas atmosphere, either under pressure or without pressure or at reduced pressure, and preferably in the presence of a catalyst such as benzoic acid, acetic acid or adipic acid.  In Example I a salt of 4 : 41-diaminodicyclohexylmethane and 1 - octyl - nonane dicarboxylic acid-(1.9) is condensed with caprylic lactam and hexamethylene diamine adipic acid salt at 260 DEG  C. in a current of nitrogen at normal atmospheric pressure.  In Example II a salt of 1-octyl-nonane dicarboxylic acid-(1.9) and hexamethylene diamine, caprylic lactam, adipic acid and 1-aminopropanol-(3) are heated in an autoclave under their own pressure at 280 DEG  C. in the presence of acetic acid, and when pressure equilibrium is established the water formed is distilled off and the condensate maintained at 280 DEG  C. under a nitrogen atmosphere.  Examples 1-6 describe the finishing of leather employing the following polyamides: (1) condensate of the salt of 1-nonyl - octane dicarboxylic acid - (1.8 and 4 : 41 - diaminodicyclohexylmethane, caprylic lactam, caprolactam and hexamethylene diamine adipate; (2) condensate of the salt of 1 - octyl - nonane dicarboxylic acid - 1(1.9) and 4 : 41 - diaminodicyclohexylmethane, caprylic lactam and hexamethylene diamine adipate; (3) condensate of same compounds as in (1); (4) condensate of the salt of 1-nonyl-octane dicarboxylic acid - (1.8) and 4 : 41-diaminodicyclohexylmethane, and caprylic lactam; (5) condensate of a salt of which the acid component is a mixture of 1-nonyl-octane dicarboxylic-(1.8) and 1-octyl-nonane dicarboxylic acid-(1.9) and the basic component is hexamethylene diamine, 4 : 41-diaminodicyclohexylmethane adipate, caprolactam and hexamethylene diamine sebacate; (6) condensate of a salt whose acid component is as in (5) and whose basic component is octamethylene diamine, caprylic lactam, caprolactam, hexamethylene diamine adipate and sebacate, and the condensate of a salt whose acid component is as in (5) and whose basic component is 4 : 41-diaminodicyclohexylmethane, caprolactam and hexamethylene diamine adipate.