CH255374A - Process for the preparation of a new, high polymer, linear ester. - Google Patents

Description

  

  Process for the preparation of a new, high polymer, linear ester. The present invention relates. relates, for example, to a process for the preparation of a young, highly polymeric, linear ester, which is obtained in that a mixture of 11101 diphenyl-4,4'-dicarboxylic acid or one of its functional derivatives and min least ., T 11o, 1 hexamethylene glycol is heated under such conditions,

  At least during the final phase of the reaction, both the volatile by-products and the excess glycol should be removed and heating should be continued until the filaments formed from the molten product can be drawn out by cold drawing, larynx fibers grasp.



       Al '; functional derivatives of diphenyl dicarboxylic acid conjugate the aliphatic, cyeloaliphatic or aromatic esters (insehliesslich half esters) in question, B.

         jjiedrigj- alkyl esters, for example those formed from methyl, ethyl, propyl, butyl, amyl alcohol, hexyl or heptyl alcohol, and aryl esters, for example olehe,

      which arise from phenol or its iloijiologen. This also includes the Siitjrehalogenide or ammonium or amine salts, such as <I> z. B. </I> those made of trimethylamine or triethvlamin. Usually the esters are derived from alcohols or phenols.

         so live. Boiling points which are below the boiling point of the glycol used. When the mixture is heated, the components first react to form low molecular weight linear polyesters.

    If a dicarboxylic acid is used, the reaction is a direct esterification or, if an ester of a dicarboxylic acid is used, an ester exchange. If a dicarboxylic acid is used, it is advisable to use a large excess of glycol, based on the dicarboxylic acid, e.g.

   B. to use 4 or 5 times the molecular weight, since the use of such proportions facilitates the esterification and the heating usually has to take place at a temperature which is close to or above the boiling point of the mixture. If a dicarboxylic acid ester is used, lower ones are often sufficient. Amounts of glycol, e.g. B. about up to 21 / times the molecular amount, but larger amounts can also be used if desired.

   The heating for loading the ester exchange takes place usually at a temperature above the melting point of the reaction mixture and above the boiling point of the alcohol or phenol to be removed, but below the boiling point of the glycol to be used. The heating is carried out under conditions such that the displaced alcohol or phenol is removed from the reaction zone, usually by means of conventional distillation equipment.

   If no further distillation of the expelled alcohol or phenol is noticeable, so. the ester interchange can be considered complete.



  When using a: Dihalide of the dicaTboxylic acid is expedient in the presence of a diluent such. B. an inert organic liquid, and in the presence of a base, usually a tertiary organic base such as pyridine, N-methylp.iperidine, N-dimethylaniline or N-diethylaniline, .erhitzt.



       When using ammonium or amine salts of the dicarboxylic acid, ammonia or an amine is evolved, which is removed from the reaction mixture during heating.



       If desired, you can use a catalyst for ester exchange or a mixture of such catalysts to facilitate the implementation of the constituents. As, such come z. B. in question lithium, sodium, potassium, calcium, beryllium, magnesium, zinc, cadmium, Alumi nium, chromium, molybdenum, manganese, iron, cobalt., Nickel, copper, silver, mercury, tin, lead, bismuth, antimony , Platinum and palladium.

   Suitable proportions are 0.025-0.1 percent by weight of the dicarboxylic acid ester used. The ester exchange catalysts can be used as such in the form of powder, chips, chips, strips, wires or in any suitable form.

   The alkali metals, earth alkali metals or magnesium are expediently in the form of alcoholates, which are formed by dissolving them in the glycol to be used or in a monohydric alcohol such as methyl or ethyl alcohol. The alkali metals can also be in the form of their carbonates or other alkaline salts, eg. B. borates can be used.

   The magnesium can be used in the form of its oxide.



  The conversion of the low molecular weight products into high molecular weight fiber-forming products requires heating to a temperature above the boiling point of the glycol used under such conditions that the glycol is removed from the reaction zone. During this heating stage or during part of it, the pressure will advantageously be reduced ver in order to facilitate faster removal of the glycol.

   Pressures of 20 mm to 0.1 mm of mercury are particularly suitable, but higher or lower pressures can also be used if desired. During this stage of heating; Ester exchange catalysts can be present.



  The heating should preferably be in the absence of oxygen and expedient by means of a stream of an oxygen-free gas, e.g. B. nitrogen, which is passed through and / or over the reaction mass, take place.



  Although the formation of the high polymer linear esters has been described as a two-step method for reasons of convenience. so in practice the stages will merge. How. Already mentioned, be a main requirement for a satisfactory production of fiber-forming, linea ren polyesters high molecular weights in the most complete possible removal of the volatile materials and in the further He heat until a satisfactory, fiber-forming ability, that is, from the melt of the Reaction product threads can be formed,

   which, by cold drawing, can be drawn into pliable, strong fibers.



  After the end of the heating process, the product can be ejected or otherwise removed in molten form from the vessel in which it was formed and then dried. The ejected pole @ # - m: it can be formed in blocks, scraps and other shapes.

      <I> Example: </I> 2 parts of ethyldiphenyl-4,4'-dicarboxylate, 1.2 parts of hexamethylene glycol, 0.006 part of lithium and 0.1 part of magnesium are mixed with one another and in a with a steam outlet pipe and a gas The vessel provided with the supply line is heated to? olf 'C. whereby one through the gas supply;

  an oxygen-free nitrogen flow through the molten mass. The ester has ended after 4 hours.

   The temperature is raised to 47 ° C and for an hour the left, liiizf @ n is continued under atmospheric pressure and schliel@li.ch is achieved for a further 11/2 hours under a pressure of 3 mm of mercury. At this point, the

  Selinielre filaments form, which can be stretched into fibers W1st. The melt is ejected from the n1 vessel and cooled.



  The product obtained in this way, namely high oly meres 11.-c-xamethylendipheny l-4,4'-dic # arboxylate .. is a pale colored, hard product from Sinli. ? 10-g14 "C.

   It can be spun from the wool into threads which, if drawn out to their non-original length, can be grounded with the formation of supple, strong fibers which, in characteristic X-ray interference images, have a molecular orientation along the fiber axis . The fibers are suitable for <B> r </B> lOxt11 (- l 'eelie.

 

Claims (1)

PATENT CLAIM: Process for producing a. new. highly polymeric, linear ester, characterized in that a mixture of once diphenyl-4,4'-dicarboxylic acid or one of its functional derivatives and at least one 111o1 hexamethylene glycol is heated under such conditions, that at least during the final phase of the reaction both the volatile by-products and the excess glycol are removed and the heating is carried out until the filaments formed from the molten product can be drawn out of usable fibers by cold drawing. The new high-polymer, linear ester, namely high-polymer diphenyl - 4,4 '- di- earboxylate, is a pale yellow, hard product with a melting point of 210-214 C, which can be spun from the melt into threads which are several times larger The original length can be extended to form supple, strong fibers which, in characteristic X-rays, have a molecular orientation along the fiber axis and are suitable for textile purposes.