Patent GB-631020-A (GB)
Title: Improvements in polyamides and processes for their production
IPC: C08G69/42
Filed: 1947-07-10
Abstract: Polymers suitable for forming into films, filaments, or fibres are produced by condensing, in substantially equimolecular proportions, a dicarboxylic acid containing one or more sulphone groups in its chain with a compound containing two primary amino groups and one or more secondary amino groups.  Preferably the number and spacing of the sulphone groups and of the secondary amino groups are identical. Suitable acids and amines, the preparation of some of which is described [see Group IV (b)] are sulphone acids: b -b 1-sulphone dipropionic-, g -g 1-sulphone dibutyric, d -d 1-sulphone divaleric acids and their homologues, and diphenyl sulphone 4-41-dicarboxylic, sulphone diglycollic, sulphone dilactic acids; amines: diethylene triamine, triethylene tetramine, 1.7 - diamino - 4 - aza - heptane, 1.9-diamino - 5 - aza - nonane, 1.11 - diamino - 6-aza - undecane, 1.12 - diamino - 3.10 - diazadodecane, 1.16 - diamino - 7.10 - diaza - hexadecane, 4.41 - diamino - diphenylamine.  The condensation may be carried out in solution in phenol, cresols, or xylenols.  In place of using the free dicarboxylic acids, their esters, amides, or nitriles may be used, and acidylated amines, e.g. the formylamino compounds may replace the free amines.  In an example (3), equimolecular amounts of d -d -sulphone divaleric acid and 1.9-diamino-5-aza nonane are heated together in boiling meta-cresol. The Specification as open to inspection under Sect. 91 comprises also the use of the diprimary diamines, e.g. ethylene, diamine, trimethylene diamine and tetra-, penta-, hexa-, and decamethylene diamines.  Dicarboxylic acids containing keto groups are also specified, such as g  - keto - pimelic, d  - keto - azelaic, g  - g 1-diketo sebacic, acetone dicarboxylic, b -ketoadipic, and benzo-phenone-4,41-dicarboxylic acids, for reaction with polyamines containing two primary and one or more secondary amino groups.  It is also stated that polymers may be formed by reacting together a di-isocyanate and a dicarboxylic acid, either or both of which contains one or more sulphone groups.  This subject-matter does not appear in the Specification as accepted.ALSO:Dicarboxylic acids containing sulphone groups and amines containing two primary and one or more secondary amino groups are prepared for use in making polyamides (see Group IV (a)). Mono-sulphone dicarboxylic acids are obtained by condensing an o -halogen carboxylic acid, salt, ester, or nitrile with sodium or potassium sulphide, or condensing an o -halogen carboxylic acid with an alkali metal salt of an o -mercapto-carboxylic acid, ester or nitrile, then oxidising the thio-ether to sulphone and hydrolysing.  Dicarboxylic acids having two sulphone groups are obtained by condensing an o -halogen carboxylic acid, salt, ester, or nitrile with a dimercaptan alkali-metal salt or condensing an o -mercapto-carboxylic acid sodium salt with a dihalide or adding acrylonitrile to a dimercaptan and oxidising to form the sulphone. b -b 1-sulphone dipropione acid is formed by adding acrylonitrile to hydrogen sulphide, oxidising and hydrolysing.  In examples: (1) d -d 1-sulphone divaleric acid is prepared by first condensing excess 1.4-dichlorobutane with sodium cyanide to form chlorovaleronitrile which is then condensed with Na2S.9H2O to form thiodivaleronitrile.  This is oxidised with hydrogen peroxide and hydrolysed; (2) 1.9-diamino-5-aza-nonane is obtained by first condensing 1.4-dichlorobutane with phthalimide. The mono-phthalimido-chloro-butane is separated from diphthalimido-butane and condensed with excess 1.4-diamino-butane and the product hydrolysed with hydrochloric acid in an autoclave or by boiling with hydrazine hydrate in a solvent to yield the triamine.