Process for producing polyamide that is stable during processing

Abstract

Process for producing polyamides that are stable during processing, by treating the polyamide during the solid-phase postcondensation process with a gas which comprises carrier gas (inert gas), water, and acid, or an anhydride or lactone or a mixture of these or, respectively, comprises ammonia, or amine, or a mixture of these, at a temperature from 130 to 200° C. and at a pressure of from 0.01 to 10 bar.

1 - 13 . (canceled) 
     
     
         14 . A process for producing polyamides that are stable during processing, which comprises treating the polyamide during the solid-phase postcondensation process with a gas which comprises carrier gas (inert gas), water, and acid, or an anhydride or lactone or a mixture of these or, respectively, comprises ammonia, or amine, or a mixture of these, at a temperature from 130 to 200° C. and at a pressure of from 0.01 to 10 bar. 
     
     
         15 . The process of producing polyamide according to  claim 14 , wherein, based on the polyamide, the amount used is from 0.001 to 10% by weight of acid, or anhydride, or lactone, or a mixture of these, or, respectively, ammonia, or amine, or a mixture of these. 
     
     
         16 . The process for producing polyamide according to  claim 14 , wherein the water is added
 a. to the mixture made of inert gas and acid, or anhydride, or lactone, or a mixture of these or, respectively, ammonia, or amine, or a mixture of these, or   b. to the inert gas, or   c. in the form of aqueous acid, or anhydride, or lactone, or a mixture of these or, respectively, aqueous ammonia, or amine, or a mixture of these.   
     
     
         17 . The process for producing polyamide according to  claim 14 , wherein a steam-volatile acid, anhydride, or lactone, or a mixture of these, or, respectively, ammonia, or amine, or a mixture of these, is directly heated with the inert gas/water mixture and passed into the postcondensation apparatus. 
     
     
         18 . The process for producing polyamide according to  claim 14 , wherein a non-steam-volatile acid, or anhydride, or lactone, or a mixture of these or, respectively, an amine, or a mixture of these, is distributed in the form of very fine droplets in water with the aid of an ultrasound atomizer in the range from 25 kHz to 3 MHz, and this mixture is passed into the inert gas, and then also into the solid-phase-postcondensation apparatus. 
     
     
         19 . The process for producing polyamide according to  claim 14 , wherein gas comprises from 0.001 to 20% by weight of water. 
     
     
         20 . The process for producing polyamide according to  claim 14 , wherein the inert gas used comprises nitrogen or argon. 
     
     
         21 . The process for producing polyamide according to  claim 14 , wherein the acid used comprises formic acid, acetic acid, propionic acid, or a mixture thereof. 
     
     
         22 . The process for producing polyamide according to  claim 14 , wherein the acid used comprises phosphoric acid or a mixture made of phosphoric acid and formic acid, or propionic acid. 
     
     
         23 . The process for producing polyamide according to  claim 14 , wherein the acid used comprises diethylenetriaminepenta(methylenephosphonic acid) (DTPMP), or a mixture made of DTPMP with phosphoric acid and/or formic acid, or propionic acid. 
     
     
         24 . The process for producing polyamide according to  claim 14 , wherein the anhydride used comprises succinic anhydride, glutaric anhydride, maleic anhydride, or phthalic anhydride. 
     
     
         25 . The process for producing polyamide according to  claim 14 , wherein the lactone used comprises butyrolactone, valerolactone, or caprolactone. 
     
     
         26 . A pellet or granule which comprises the polyamide produced according to  claim 14 . 
     
     
         27 . A process for producing a foil, a monofil, or a fiber which comprises the polyamide produced according to  claim 14 .