Patent GB-724759-A (GB)
Title: Preparation of films and filaments
Filed: 1952-05-08
Abstract: <PICT:0724759/IV (a)/1> <PICT:0724759/IV (a)/2> Fibres or films of high molecular weight polymers are obtained from di- or polyfunctional intermediates which are monomers or low molecular weight polymers, incapable themselves of forming coherent films or fibres, by causing the intermediates to react at interfaces of controlled shape between two phases, at least one of which is liquid, each containing an intermediate, and removing or withdrawing the fibres or films thus obtained, preferably immediately after they are formed, from the place of their formation.  The process may be carried out by bringing together a liquid phase comprising one of the intermediates (e.g. a liquid organic diamine or a solution of an organic diamine) and another liquid phase comprising the coacting polymer-forming intermediate (e.g. a solution of an organic dicarboxylic acid halide) to form a liquid-liquid interface, controlling the shape of the interface until a shaped polymer has formed, and then withdrawing the polymer from the interface. Preferably, the polymer is withdrawn continuously from the interface as a continuous self-supporting film or filament.  When it is desired to produce an infusible and insoluble film or fibre, there may be included in at least one of the liquid phases a condensation polymer-forming intermediate containing three or more functional groups so that a cross-linked polymeric structure is obtained. Such a polyfunctional intermediate may be the sole intermediate in its liquid phase.  Preferably, the intermediates in the two phases should react quickly so that the film or filament can be pulled away from the interface at a rapid rate.  One of the intermediates may be a low molecular weight organic compound having two similar or dissimilar reactive groups selected from the group consisting of amino and amidino-NHR, where R is H or alkyl; phenolic-OH; and -SH; and the second intermediate may be a low molecular weight compound having two reactive groups each of which is capable of reacting with ethyl alcohol at room temperature to yield a compound having two ester groups. Preferably, both reactants are dissolved in diluents and preferably the solvent used for one reactant is immiscible with the solvent for the other.  As shown in Fig. 1, a tank 1 contains a solution of one of the intermediates, while the liquid containing the other intermediate is introduced through the tube 2, flared at the delivery end 3.  At the area of contact of the bubble-shaped pool of reactant liquid 4 at the end of tube 2 with the liquid in tank 1, a high molecular weight polymer forms very rapidly and is drawn away in the form of a filament 5.  The filament 5 may be wound up directly or led over rollers 6-10 and washed prior to collection.  If the end 3 of tube 2 is of elongated, instead of circular shape, a ribbon or film of polymer may be obtained.  In an example, a solution of adipyl chloride in chlorobenzene is fed through the tube 2 (Fig. 1), into a solution of hexamethylene diamine in water at 25 DEG  C.  A polyamide is formed instantaneously upon contact of the two solutions and is continuously pulled away as a filament from the place of formation and wound upon a bobbin.  It is washed in methanol.  It may be stretched in the swollen state immediately after spinning and may be hot-drawn at 150 DEG  C. after washing and drying.  The operation may be varied by extruding the diamine solution into the adipyl chloride solution.  The diamine solution may be a solution of a mixture of hexamethylene diamine and 2-methyl hexamethylene diamine, and instead of adipyl chloride there may be used sebacyl chloride.  If desired, multi-filament yarns may be obtained by extruding one reactant or a solution thereof through a multi-hole spinneret into a solution of the other reactant.  The filaments obtained have the structure of collapsed tubes with or without coalescence of the inner surfaces to form filaments having a rod-like cross-section which may have a length to width ratio of 10 : 1 up to 50 : 1 or larger.  A solution of terephthaloyl chloride in chlorobenzene may be extruded into an aqueous solution of hexamethylene diamine to form a multi-filament yarn. As shown in Fig. 2, tank 20 contains two solutions of quickly-reacting intermediates in liquid diluents.  The lighter solution 22 floats on top of the denser solution 21.  A film of high molecular weight polymer quickly forms at the interface 23 and separates the liquids so that the reaction stops until the film is removed.  The film 24 may be removed from the tank in a continuous manner.  When removed from the middle of the tank as shown, the film obtained has a laminated structure, but if desired means may be provided for keeping the single films apart as they are withdrawn. If desired, a bar may be placed across the width of the tank close to one end so that a single-layer film may be withdrawn between the bar and the end wall of the bath.  The apparatus shown in Fig. 2 may be used to obtain a filament.  The film of polymer at the interface 23 is picked up at one point and pulled away.  In being drawn in this way the film continuously forming at the interface collapses on itself to form a crenulated filament.  If desired a composite filament may be produced from a three-layered bath with polymer forming continuously at the two interfaces.  Thus, the lower layer may be a solution of adipyl chloride in carbon tetrachloride, the middle layer an aqueous solution of hexamethylene diamine, and the upper layer a solution of a di-isocyanate, glycol dichloroformate, a disulphonyl halide or adipyl chloride in benzene.  In an example, hexamethylene diamine is dissolved in dilute caustic soda solution; benzene is floated on the top and to it is added a solution of terephthaloyl chloride in benzene.  A film is formed at the benzene-water interface and is continuously pulled away as a film or filament. Among the intermediates which may be used are: dicarboxylic acid halides and primary or secondary diamines, phosphoric anhydrides of dicarboxylic acids and diamines, dicarboxylic acid halides and thiourea, dithiobiuret or guanidine; diiso- or diisothio-cyanates and diamines (forming polyureas or polythioureas), phosgene and diamines, bis-azlactones and diamines, mixed anhydrides of dicarboxylic acids and trifluoracetic acid with diamines, glycol - chloroformates and diamines, dicarboxylic acid halides and aminoalkyl thiols or aminoalkyl phenols.  For obtaining polysulphonamide films or filaments there may be used disulphonic acid halides and diamines, guanidine, thiourea or dithiobiuret; or disulphonyl dilactams and diamines.  For obtaining polyester films or filaments there may be used dicarboxylic acid halides and dihydric phenols or dithiols; mixed anhydrides of dicarboxylic acids and trifluoracetic acid with dithiols or dihydric phenols; disulphonic acid halides and dihydric phenols or dithiols.  In an example, an aqueous solution of piperazine is covered with a solution of hexamethylene diisocyanate in iso-octane.  The two layers are heated to 90 DEG  C. and the film formed at the interface is withdrawn continuously.  In another example, a solution of 2,2-bis-(4-hydroxyphenyl)-propane in dilute caustic soda is floated on a solution of isophthaloyl chloride in carbon tetrachloride.  The film which is formed at the interface is withdrawn continuously.  When a film or filament of a cross-linked polymer is required, at least one of the liquid phases may contain, as polyfunctional intermediate, the chloride of tricarballylic acid, trimesic acid trimellitic acid, mellophanic acid, pyromellitic acid, naphthalene tricarboxylic acid or camphoronic acid; pentaglycerol trichloroformate, benzene trisulphonic acid chloride, diaminophenols, pyrogallol, purpurin, triethylene tetramine, triaminobenzenes, spermine, polymers containing recurring primary amino or acid halide groups, or triethanolamine.  In an example, a solution of diglycolyl chloride in carbon tetrachloride is extruded into an aqueous solution of a mixture of hexamethylene diamine and bis-(3-aminopropyl)-amine. A continuous filament is pulled away from the interface and subjected to stretching while in swollen state.  The filament obtained is of a rubber-like nature.  Other examples describe the production of filaments or films from diglycolyl chloride and a mixture of hexamethylene diamine and 2,5,8-tris-(aminomethyl) nonane; from adipyl chloride and tricarballylyl chloride in one of the liquid phases and hexamethylene diamine, with or without bis-(3-aminopropyl)-amine in the other; from sebacyl chloride and a mixture of hexamethylene diamine and diethylene triamine; from ethane dithiol and a mixture of m-benzene disulphonyl chloride and tricarballylyl chloride; from 1,5-pentane dithiol and a mixture of isophthaloyl chloride and trimesoyl chloride; from succinyl chloride and a mixture of piperazine and triethylene tetramine; from adipyl chloride and a mixture of m-phenylene diamine and triethylene tetramine; from hexamethylene di - isocyanate and 2,5,8 - tris - (aminomethyl)-nonane; and from a poly-primary amine (prepared by reacting ammonia with a copolymer of vinyl acetate and allyl glycidyl ether) and sebacyl chloride.  Specified solvent diluents for the intermediates include: water, formamide, tetramethylene cyclic sulphone, benzene, toluene, xylene, cyclohexane, trichloroethylene, chlorobenzene, nitrobenzene, ligroin, iso-octane, ethyl ether, ethyl acetate, methyl amyl ketone, o-chlorobenzotrifluoride, ethylene dichloride, carbon tetrachloride, chloroform, thiophene and ethylene chlorobromide. Soluble alkali hydroxides or carbonates may be present as hydrochloric acid acceptors in the aqueous phase when preparing filaments or films from diacid halides and co-reactants.  The reaction temperature is ordinarily room temperature but a temperature between the freezing points and the boiling p