Method for obtaining para-type wholly aromatic polyamide particles
The invention pertains to a method for obtaining para-type wholly aromatic polyamide particles, comprising the steps: a) introducing an aramid polymer solution into a water-based coagulating liquid to obtain a hydrous shaped product; and b) subjecting the never-dried or partly-dried shaped product having a water content of 10 to 99% by weight to freeze-grinding. These aramid polymer particles can be used as a filler material.
1. A method for obtaining para-type wholly aromatic polyamide particles, comprising:
a) introducing an aramid polymer solution into a water-based coagulating liquid to obtain a hydrous shaped product;
b) prior to freeze-grinding, the hydrous shaped product is not dried or is only partially dried to obtain a never-dried or partially-dried shaped product having a water content of 10-99% by weight, and
c) subjecting the never-dried or partly-dried shaped product to freeze-grinding.
2. The method according to claim 1 , wherein the shaped product is subjected to a washing step prior to subjecting the never-dried or partly-dried shaped product to freeze-grinding.
3. The method according to claim 1 , wherein the shaped product is never-dried prior to subjecting to freeze-grinding.
4. The method according to claim 3 , wherein the para-type wholly aromatic polyamide is poly-p-phenyleneterephthalamide.
5. The method according to claim 1 , wherein para-type wholly aromatic polyamide particles are obtained having a particle size distribution d50 less than 75 μm.
6. The method according to claim 5 , wherein para-type wholly aromatic polyamide particles are obtained having a particle size distribution d50 less than 50 μm.
7. The method according to claim 5 , wherein para-type wholly aromatic polyamide particles are obtained having a particle size distribution d50 less than 30 μm.
8. The method according to claim 1 , wherein the shaped product is fibrid, fibril, pulp, layered particle, or floc.