CH280367A - Process for the production of a mixed polyamide. - Google Patents

Description

  

  Process for the production of a mixed polyamide. Subject of the main patent and the additional patent 1 # Tr. 276921 are processes for the production of polyamides, which are characterized, among other things, by unusual heat resistance. These processes are characterized in that endomethylene caprolactam or endoethylene caprolactam are heated to between 180 and 300 ° C. These polyamides have melting points or decomposition points of more than 400 ° C. and therefore cannot be processed into threads or fibers by the melt spinning process.

   Only a dry or wet spinning process from an organic solvent can be used for spinning this new class of polyamides. The choice of suitable solvents that dissolve these polyamides in sufficient quantities is very limited. Mostly these are difficult to access and therefore expensive substances with physiologically unpleasant properties. Another disadvantage is the necessity. to recover the solvent from which the polyamide is spun and the losses that are inevitable.

   The aforementioned disadvantages of spinning from solvents contribute to a considerable complication of the spinning equipment and to a considerable increase in the cost of fertility products based on pure bicyclic lactam poly- nides.



  It has now been found that by polymerizing together bicyclic lactams with monoeyclic lactams it is possible to obtain mixed polymers which can be spun with normal melt spinning machines without any difficulty. The melting points of the mixed polymers are between those of the two individual components and almost correspond to the mixing ratio.

   For example, the mixed polymer of 70 parts of α-caprolactam and 30 parts of endoethylene-caprolactam melts at 270 ° C. and can be used smoothly in one of the usual melt spinning devices, e.g. B. the grate spinning machine according to Swiss Patent No. 211636 or in a spinning apparatus according to Swiss Patent No. 265481.

   The melting point of the copolymer can be increased even further by increasing the proportion of bicyclic lactam. The high temperatures of more than 300 C then necessary to spin Ver easily lead to decomposition phenomena and Spinnstörun conditions.



  The water absorption is also increased with these polyamides, which makes the woven and knitted fabrics made from such threads and fibers much more comfortable to wear, provided they come into direct contact with the skin. For example, while the polyamides based on E-caprolactam (Perlon) and hexamethylene diammonium adipate (nylon) only have a water absorption of 3.5 to 4,

  0% at 20 C and 65% rel. Humidity, this rises to 6 with a copolymer made of 70% a-caprolaetam and 30% endoäthyiencaprolactam,

  7% on. The content of low molecular weight fractions in these mixed polyamides corresponds very precisely to the mixing ratio used. Since the bicyelic lactams, as has been found, are 100% in polymeric form in the mixed polymers, it is possible to

   Mixed polymers of monoeyclic and bicyclic lactams, for example e-caprolactam; to achieve their salary. is very low in low molecular weight proportions.

    
EMI0002.0020
  
    The copolymer <SEP> from <SEP> content <SEP> of <SEP> low-molecular <SEP> components
<tb> 100 <SEP>% <SEP> a-Caprolaetazn <SEP> 11-131 / o
<tb> <B> 801/0 </B> <SEP> <SEP> 20% <SEP> Endoethylene aprolactam <SEP> <B> 8-101 / 0 </B>
<tb> 60% <SEP> <SEP> 401/0 <SEP> <SEP> 6- <SEP> 71 / o
<tb> 40% <SEP> <SEP> 60% <SEP> <SEP> 4- <SEP> 5%
<tb> 201 / o <SEP> <SEP> <B> 801/0 </B> <SEP> <SEP> 2- <SEP> 311 / o
<tb> <B> 1.001 / 0 </B> <SEP>:

  > <SEP> 0 is the subject of the patent. a process for the production of a mixed polyamide with a melting point of up to 300 ° C, which is characterized in that endoethylene caprolactam of the formula (i) is heated to 180 to 300 ° C together with α-caprolaetam.

 

Claims (1)

PATENT CLAIM: Process for the production of a mixed polyamide with a melting point of up to 300 C, characterized in that endo-ethylene caprolactam of the formula EMI0002.0029 Example: A mixture of 70 parts of a-caprolactam, 30 parts of endoäthylencaprolactam and 10 parts of "water as a reaction accelerator is heated in the autoclave in an oxygen-free atmosphere for 2 hours to 280 and then degassed for 8 hours at the same temperature under atmospheric pressure after releasing the pressure and dehydrates .. The viscous polymerisation product solidifies to form a white to gray opaque plastic that melts at 270 ° C. Cold, stretchable threads can be drawn from the melt, which after the reek process have high longitudinal strength. The threads show 7.4 to 7, 8% extractable components and take in the conditioning apparatus at 20 C and 65% rel. Humidity 6.7% water. The polymerization can also be carried out in the presence of an organic solvent, e.g. B. a phenol, make. heated to 180 to 300 C together with e-Caprolaetam. SUBClaims: 1. Method according to patent claim, characterized in that the reaction mixture is kept at the polymerization temperature until no more volatile components escape. 2. The method according to claim, characterized in that the polymerization is carried out in the presence of a reaction accelerator. 3. The method according to claim, characterized in that the polymerization is carried out in the presence of a solvent.