Patent GB-875994-A (GB)
Title: Production of polyamides
IPC: C08G69/20
Filed: 1958-08-05
Abstract: A process for the polymerization of e -caprolactam and its homologues comprises heating a monomeric lactam having at least six carbon atoms in the lactam ring under substantially anhydrous conditions in the presence of (a) a catalytic amount of an alkali or alkaline earth metal, including magnesium or of a compound of such a metal or of an organo-metallic compound of aluminium or zinc which acts as an anionic polymerization catalyst, (b) a compound containing at least one tertiary nitrogen atom, one group linked to the nitrogen atom being a carbonyl, thiocarbonyl, sulphonyl, phosphinyl or thiophosphinyl group and a second being a carbonyl, thiocarbonyl, sulphonyl, phosphinyl, thiophosphinyl or nitroso group and (c) at least 0,25 mol per mol of compound (b) of a primary or secondary amine.  Specified lactams are e -caprolactam, methyl-cyclohexanone iso-oxime, cycloheptanone iso-oxime, cyclo-octanone iso-oxime, cyclopentadecanone iso-oxime and cyclic hexamethylene adipamide. Specified catalysts (a) are sodium, potassium, lithium, calcium, strontium, barium and magnesium and the hydrides, borohydrides, oxides, hydroxides and carbonates thereof, lithium butyl, potassium ethyl, sodium propyl, sodium phenyl, diphenyl magnesium, zinc diethyl, tri-isopropyl aluminium, di-isobutyl aluminium hydride, ethyl magnesium chloride, methyl magnesium bromide, phenyl magnesium bromide, sodium amide, magnesium amide and magnesium anilide.  Many promoters (b) including compounds formed in situ in the reaction mixture are specified, examples being N-acetyl pyrrolidone, N-phenyl succinimide, N-methyl phthalimide, N, N-diacetyl methylamine, triacetamide, N, N1-di(phenyl carbamyl)-N, N1-dimethylurea, ethylene disuccinimide, N-acetyl-N-ethyl-p-toluene sulphonamide, N-acetyl saccharin, N, N-di (p-toluenesulphonyl) anilide, N-nitroso- 2-pyrrolidone, N-methyl-N-nitrosourethane, N-nitroso-N-methyl-p-toluene sulphonamide and N-(dimethyl phosphonyl)-e -caprolactam. Specified primary and secondary amine regulators are methylamine, ethylamine, n-propylamine, iso-propylamine, n-butylamine, t-butylamine, n-pentylamine, t-amylamine, n-hexylamine, 2-ethyl hexylamine, n-octylamine, n-decylamine, laurylamine, cetylamine, n-hexadecylamine, stearylamine, allylamine, o -decenylamine, oleylamine, benzylamine, phenethylamine, cyclohexylamine, cyclopentylamine, cyclopentenylamine, aniline, o-, m- and p-toluidines, 2, 4-, 2,5- and 3, 5-xylidines, a -and b -naphthylamines, furfurylamine, thenylamine, dimethylamine, diethylamine, di-(2-ethylhexyl)amine, diallylamine, dicyclohexylamine, methylethylamine, N-(n-butyl)-N-(2-ethylhexyl) amine, N-methyl-N-allylamine, N-(n-butyl)-N-propenylamine, N-cyclohexyl-N-ethylamine, piperidine, piperazine, morpholine, p-chloroaniline, anisidine, ethyl glycinate, methyl-o -aminoheptanoate, sodium o -amino caproate, N-(b -aminoethyl) acetamide, hexamethylene diamine, diethylene triamine, 1, 2-bis-(3-aminopropoxy) ethane and compounds formed in situ in the reaction mixtures.  In the examples e -caprolactam is polymerized in the presence of sodium hydride and (1) n-hexylamine and N-acetyl-e -caprolactam; (2) N-acetyl-e -caprolactam and t-dodecylamine; (3) bis-(4-isocyanatophenyl) methane and aniline; (4) 1,2-bis (3-aminopropoxy) ethane and N-acetyl-e -caprolactam; (5) N-acetyl-e -caprolactam and di-n-butylamine; (6) M-acetyle -caprolactam and water (to form aminocaproic acid in situ) and (7) and (8) N-acetyl-e -caprolactam and aniline.