Patent GB-627205-A (GB)
Title: Improvements in or relating to the production of polymeric materials
IPC: C08G73/14
Filed: 1945-03-15
Abstract: Polyamides are prepared by condensing in substantially equimolecular proportions a diprimary diamine with (1) a tricarboxylic acid which contains an imide-forming pair of carboxyl groups which are separated by three atoms, and a carboxyl group which is separated from each of the others by a number of atoms other than two, or with an amide-forming derivative of such an acid, no carbon atom in said acid or derivative having two free carboxyl groups directly attached to it; or (2) a tetracarboxylic acid which is such that an imideforming pair of carboxyl groups may be selected which are separated by two or three atoms, and said pair having been selected in each possible way the then-remaining carboxyl groups are an imide-forming pair and are separated by three atoms, or with an amide-forming derivative of such an acid, no carbon atom in said acid or derivative having two free carboxyl groups directly attached to it; or (3) a tetracarboxylic acid which contains a pair of carboxyl groups directly attached to one carbon atom, and which is converted by loss of one of said carboxyl groups into a tricarboxylic acid as defined in claim 1, or with an amide-forming derivative of a tetracarboxylic acid, said derivative containing a pair of unsubstituted carboxyl groups directly attached to one carbon atom and being converted by loss of one of said carboxyl groups into an amide-forming derivative of a tricarboxylic acid as defined in claim 1.  The atoms joining the carboxyl groups are preferably carbon atoms.  The products are infusible, insoluble resins, unless the diamine is employed, at least in part, as its formyl derivative, when linear, fibre-forming polymers are obtained.  Other linear polymer-forming reactants may be present, e.g. aminocarboxylic acids such as e -aminocaproic acid, or dibasic acids, e.g. adipic, suberic, sebacic, with diamines, e.g. as listed below.  Polyester-forming reactants (e.g. glycerol or glycol) may also be present, giving a modified glyptal resin.  The viscosity of the polymers may be stabilized by using .2-5 per cent excess diamine or polycarboxylic acid or .2-5 per cent of a monoamine or monocarboxylic acid or amide-forming derivative thereof.  The polymerization may be carried out at 150-300 DEG  C. in a solvent, e.g. phenol, cresol or xylenol, or a non-solvent diluent.  The resins may be used to form films, coating materials, or moulded articles, and may be admixed with drying oils, plasticizers and other resinous materials.  The fibre-forming polymers may be spun by wet-, dry- or melt-spinning processes, at 10-30 DEG  C. above the melting point of the polymer, and they may be admixed with sulphonamide, phenolic, urea and thiourea plasticizers, which may be left in the shaped articles, or extracted therefrom.  The polymer may be mixed with phenol, the mixture spun and the filaments solidified, and the phenol removed. The polymers may be mixed with cellulose acetate, aceto-butyrate, butyrate, aceto-stearate, ethyl cellulose, oxyethyl cellulose, oxyethyl cellulose acetate, benzyl cellulose and other cellulose derivatives, plasticizers, softening agents, dyestuffs and pigments.  In examples, 1.3.5-pentane tricarboxylic acid is heated with hexamethylene diamine with and without its formyl derivative, and with and without hexamethylene diammonium adipate; also in examples, 1.3.3.5-pentane tetracarboxylic acid is heated with N,N1-diformyl hexamethyllene diamine and hexamethylene diammonium adipate, carbon dioxide being evolved during the initial heating. Other acids specified are 1.3.6-hexane-tricarboxylic acid, 1.3.7-heptane-tricarboxylic acid, 1.1.3-propane-tricarboxylic, methane tetracetic and carboxy-methane-triacetic.  Amide-forming derivatives are the esters, anhydrides, or acid chlorides, e.g. the 3.31-diester of 1.3.3.5-pentane tetracarboxylic acid.  Diamines specified are tetramethylene diamine, octamethylene diamine, 1.4-diaminocyclohexane, g g -diaminodipropyl ether and b b -diamino-diethyl sulphide.ALSO:1,3,3,5-Pentane tetracarboxylic acid is obtained by condensing one mol. malonic ester with two mols. acrylonitrile or acrylic ester followed by saponification of the ester or nitrile obtained.  1,3,5-Pentane tricarboxylic acid is obtained by decarboxylation of 1,3,3,5-pentane tetracarboxylic acid. 1,1,3-Propane tricarboxylic acid is obtained by condensing one mol. malonic ester and one mol. acrylonitrile to give CN.CH2.CH2.CH-(COOC2H5)2 followed by saponification.  Tri- and tetracarboxylic acids of the above types may be prepared by first reacting sodium malonic ester with a halonitrile, haloester, or dihalide, followed by reacting the product with an unsaturated nitrile followed by hydrolysis and decarboxylation if necessary. 1,3,6-Hexane-tricarboxylic acid is obtained by condensing Na malonic ester with a g -cyano- or carbalkoxy-propyl halide and with a acrylonitrile followed by saponification.  1,3,6,8-Octane tetracarboxylic acid is obtained by reacting 2 mols. Na malonic ester with 1 mol. ethylenedichloride and 2 mols. acrylonitrile followed by saponification.  The acids are condensed with diprimary amines to form polyamides (see Group IV (a)).