DE1520339A1 - Process and device for the continuous production of synthetic linear polymers of high molecular weight - Google Patents

Description

Process and apparatus for the continuous production of synthetic linear polymers of high molecular weight The invention relates to an improved method and apparatus for the production of polymers of high molecular weight, especially those produced by reactions of the condensation mode are produced, for example polyamides, polyesters or the like. In particular the invention relates to an improved method and apparatus for the continuous production of linear poly carbonamides of this type, which are distinguished by a high molecular weight and include those which in particular in the manufacture of shaped objects, z. B. fibers, threads or the like. Are useful.

The production of the linear condensation polymers from polymer forming reactants has increasing technical importance in the various Industries. Because of this growing technical interest and of this increasing importance are improved working methods and new devices, which result in improved product quality in a more economical way lead, required.

In the formation of such linear polymers, in particular of the type which properties include film and fiber-forming properties, the polymer end product can consist of a poly carbonamide, which is made of liquid Compositions containing polycarbonamide-forming reactants is formed. In an example of the formation of v @ n polycarbonamide @ such as polyamide (nylon) or the like. is a solution of a polycarboxylic amide-forming composition or mass, which usually contains water or another solvent, superatmospheric Pressures and polycarbonamide biodegradation temperatures are subjected to polycondensation or to cause a polycarbonamide formation reaction. When the polycondensation of the Polycarbonamidbidldenden mass or composition progresses, the viscosity decreases the polycarbonamide reaction mass in a well-known way to until the desired degree of polymerization is obtained.

The previous poly carbonamide-forming compositions or masses comprise water solutions of hexamethylenediamine and adipic acid, the production of these solutions being technically associated with a great deal of time and handling. It was previously assumed that for Considerable mixing of filaments or fibers of high quality and excellent properties thermal degradation of the polymer during Removal is one of the critical difficulties of all prior art polycarbonamide formation processes.

So far, all efforts have been made to z. B. adipic acid and hexamethylenediamine, in the absence of a suitable solvent due to the strong tendency of these reactants to form of agglomerate masses unsuccessful, which due to the low heat transfer or Thermal conductivity coefficient and the smooth surface of the agglomerate mass are not can be melted for reactant purposes.

These agglomerate masses remaining in the unmelted state produce an inhomogeneous reactant system which prevents the polymerization, causes an excessive pressure drop and unnecessary interruption or Caused stoppage in the technical continuous polymerizer.

Et is therefore a rater Zwook inventing the SelLaf. fung one new and novel device and an improved method of manufacture of polycarbonamides in the absence of repellent for the polycarbonamide reactants.

Another purpose of the invention is to provide a new device and a process for the production of polycarbonamides, which is more economical than the previously known working methods.

Another purpose of the invention is to provide a device and a process for the production of polycarbonamides, which the thermal Decreases or eliminates degradation of the polymer during its formation.

Another purpose of the invention is to create e Xer nouot and novel arrangement and working method for the production of polycarbonamides in a shorter time than was previously possible.

Other purposes and advantages of the invention will become apparent from the description below in conjunction with the drawing The purposes of the invention are achieved by simultaneously supplying controlled volumes of refined heramethylenediamine and saturated adipic acid to a reaction zone at high temperature with a high surface area to volume ratio under appropriate flow or deformation and pressure conditions. a back hold or stay in the reaction zone for a short period of time causes the reactants to <remove> from the reaction zone to a subsequent zone with low pressure, in which the separation of dmapf from the polymer-forming reactants is allowed and then a work-up or polymerization of the reactants up to the desired degree of polymerization in one StaniaidR checkout completion- Device (standard screw finisher) or a similar finishing device that is suitable for this purpose causes. The vapors generated in the zone of reduced pressure are used by suitable or convenient means, e.g. B. subjected to a spray condensation or filtering in order to recover evaporated hexamethylenediamine in this stage and the recovered hexamethylenediamine is returned to the beginning of the process in the crystal after the necessary purification by refining or some other means.

The new features that are characteristic of the invention are viewed, are explained in more detail below with reference to the drawing.

In the figure shown there is a flow sheet or diagram in which a polymerisadon procedure carried out in accordance with the invention is explained.

Although generally forming any suitable polymer Mass with the novel device and according to the improved method of operation of the invention, those materials are preferred which Such polycondensation can enter into and compounds or products of high molecular weight, z. B. those with fiber-forming properties can produce. The novel process according to the invention will be described with reference thereto.

Polymer-forming compositions or masses which are suitable for the Manufacture of fiber-forming polymers suitable can be made by any Be the type from which polycarbonamides are made and the present description is directed below, for example, on the production of polycarbonamides, which include the technically produced polyamides (nylon fabrics).

In the figure is a schematically illustrated embodiment of the new process for the preparation of linear polymers, which according to the invention are considered, Nutert. This is done from an adipose melter 1 melted adipic acid of high purity through a pipe 2 to a pump 3, where it is pressurized to a blow-in or injection line or loop (injection loop) 4 is pumped within a reaction zone 5. the Molten adipic acid is under high pressure at the injection or injection line 4 with controlled volumes of refined hexamethylenedamine under the same pressure combined, which from a hexamethylenediamine melting device 6 via a line 7 was fed to a pump 8.

As a particular example, the melting devices for Adipic acid and refined @hexamethylenediamine consist of vessels, which with a steam jacket, and means for stirring or agitation of the Content included. The temperature of the adipic acid within the pinic acid melting device Came between 160 ° and 200 ° C and the temperature of the hexamethylene dimain can wipe 20 ° and 50 ° C. An inert gas pressure can be applied to the contents of each of the vessels if necessary, agen -be used.

The pumps 3 and 8 can be of any suitable type for handling hot liquids which can deliver controlled volumes of the hot liquid at pressures up to 176 kgXc = 2 (2500 @@@). A particular example of a suitable pump is a "Zenith" gear pump, which with which with rwe. ra., approx @ P ungaleitungen (steam tracer lines) fitted around the pump body il; The water vapor lines can be arranged around all the lines which lead from the chemicals to the pumps and from the pumps to the reaction aone, if it is desired and necessary to maintain the adipic acid and the hexamethylenediataine in the desired temperature ranges.

Because of the well-known liquidity and reaction of molten Adipic acid and refined hexamethylene <diamine when brought together or Mixing these compounds in high concentrations, she creates Injection or injection line or loop 4 a means to hen in wesentlic pure fused adipic acid and refined hexamethylenediamine in the absence a solvent, e.g. B. to mix laser so that a homogeneous, of agglomerate lumps free mix is obtained.

The injection loop 4 may comprise any suitable device to directly supply the stock-taking liquid at high speeds under turbulent flow conditions at a Reynolds number of 5000 or above X dllnffl filt; n wingsen zizi and can consist of a restrictive or restrictive device in (leur:.:: ri? ~:.: bo:::: ':.' tI ~. 5 n rju's zc. (h tudii. o).

The hot reaction participant insignia, which are turbulent or mixed with hot air flow, pass under pressure, as shown, through a line 9 to the reaction zone 5, which consists of a preheating section 16 and a pressure reducing section 17. The reaction zone 5 can be any device of such a design that it has a high surface area to volume ratio for the reacting liquids, good heat transmission or ärmeltiungseignesnchaftne possesses una @ hehon can withstand pressures. A custom or gatigiiete @@@ genete device consists of a bundle of heat exchange tubes, the reaction liquids being gelaitot within the tubes and heat transfer media such as high pressure water vapor or a "Dowtherm" agent in the area surrounding the tubes.

In a particular example, the reaction 4 can be liquid within the injection or injection loop and the preheating section of the reaction zones essentially in the same volumes and under pressures of about 70.3 to 176 kg / cm2 (1000 to 2500 psig) positive pressure at temperatures of 250 ° to 400 ° C. For a working method on a kentitnuierlichen basis the reactions should be,, consistingn such a design or from the heating section and the pressure reducing section Have dimensions that the Reatkiosniquidketen therein a residence time of 10 minutes to 120 minutes.

The reaction liquids and partially reversed polymer formed in the reaction zone leave the reaction zone shown by a Line 18 and go through pressure regulating devices 28, the pressure regulating device 28 can be any suitable device for regulating or controlling the pressure of the reaction liquids within the pressure reducing or pressure returning device 17 to pressures between 0 atm and 1.76 atm (0 and 25 psig) can consist of any manually operated or automatic pressure control valve which is generally known in technical engineering.

Then the pressure control valve 28 through a line 29 leaving material includes unreacted liquid adipine sutures and unreacted hexamethylenediamine, partially polymerized hexamethylene ammonium adipate, reaction water, which in the condensation polymerization the reactants formed and both in liquid phase as well as vapor phase, udn hexamethylenediamine vapor.

This mixture passes through line 29 to eiasm Dampt. separator 10, in which there is primary or main separation of the liquid components the mixing statute! det.

For a particular example, the steam separator 10 can be cylindrical or be stumpkeglies vessel, in which the mixture from the line 29 essentially is introduced fangestial to the circular cross-section of the vessel and in swirling or whirling around the sides of the vessel against the collection head or truncated portion falls to exit for further polymerization, and the steam rising from the middle of the vessel to the upper one To be withdrawn at the end of the same. Suitable facilities for feeding or Delivery of heat to the steam dispenser can optionally be provided.

The liquid epolymer material, which undergoes further polymerisation can enter, escapes from the steam separator 1Q as shown, through a line 12 to the finishing direction or the "finisher" 13, in which the final stage the polymerization takes place. The finishing device or the Ficishmr can be of any suitable design for providing good heat transfer and good mixing conditions for the polymer fed in here and there are For this purpose, many embodiments are known in the art.

In a particular example, the finisher or finishing facility 13 from a horizontal screw * or screw end processing device what happens in the atmospheric, subatomic or supra-atmospheric Pressure is operated with the temperature of the reaction mass therein between 260 ° and 300 ° C depending on the desired polymer properties. the Residence of the polymer material within the finisher or the finishing device can be between ao minutes and 3 levels.

Polynerieates with the desired properties come out of the finisher or the finisher as shown by line 14 to one Block 15, which is any subsequent polymer forming or storage working method may include e.g. B. the spinning of fibers or thread or a tape continuation of the Polymerizats (banding) with subsequent shredding for Storage purposes or mix for later use.

The separated emerging from the upper end of the Daapfabscheiders 10 As shown, dampers passed through a line 11 to a sprinkler capacitor 19, in which the unreacted hexamethylenediamine vapor and partially polymerized Material to be condensed. Cooling water enters the spray condenser 19 a guide 20 and condenses water and hexamethylenedimaindemap and partially polymerized material, which from the @ as shown, through a line 21 to a filter 22 passes, wherein the wet and hexamethylenediamine of the partial polymerized material are separated; the condensed hexampethylene diamine and Water passes through a line 23 to a storage container 24 for crude diamine and the partially polymerized material is passed through line 25 to fabrication waste or some other remoteness. The crude diamine can use the standard refining process returned and, if desired, the diamine melt direction 6 for reuse are fed in the process.

Optionally, a gas that is inert to the system can be used in countercurrent to the of the polymer in the process in order to support the removal of water from the steam and the regulation of the degree of polymerisation of the polymer. In this case, the gas, which is inert to the system, enters the process, as shown, through a line 26 and is carried in counter-current to the flow of the polymer from line 12 and comes out of the Daupfabscheider 10 through a line 11, is not in the preheating condenser condenses and leaves the system through a line 27 to a recovery system for the inert gas for reuse or it is disposed of as a waste product.

As can be seen from the above description, the process according to the invention completely eliminates the need for the addition and removal of large amounts of water. This enables previously unknown and unexpected savings in thermal energy, which must be added to the process, the formation of polyhedra with the desired properties in extremely short periods of time and a @pchst amlichen III L., u

Claims (6)

Patent claims 1. Process for the continuous production of synthetic linear polymers of high molecular weight, characterized in that that a) essentially solvent-free polycarbonamide-forming reactants provides in the liquid state and b) continuously the solvent-free liquid Reactants in essentially equal proportions for a polycarbonamide forming temperature and pressure and under vortex motion (rheological Vortex) mixes whereby a homogeneous mixture of the reactants is formed will. 2. The method according to claim 1, characterized in that the rheological turbulence at a Reynolds number above 5000. 3. The method according to Anspnch 1 or 2, characterized in that the Polycarbonamide formation temperature is between 250 ° and 400 ° C. 4. The method according to any one of claims 1 to 3, characterized by @, that the polycarbonamide formation pressure is between 70.3 and 176 atd (1000 and 2500 psig) lies. 5. Device for the continuous production of synthettschen linear polymers of high molecular weight according to any one of claims 1-4, characterized in that it is a hexamethylenedimine melting vessel, an adipic acid melting vessel and pre-heated injection coils for mixing substantially pure molten Adipic acid and refined hexamethylenediamine form a homogeneous, lump of agglomerates comprises free mixture, wherein a substantially sepsis-free polymer reaction mass is obtained. 6. Apparatus according to claim 5, characterized in that it has a Facility for the continuous combination of refined liquid hexamethylenediamine and molten adipic acid in substantially equal amounts under flowing or Flow conditions at a Reynolds number above 5000 includes.