Modified aramid pulp and friction material comprising modified aramid pulp

Abstract

Instant invention pertains to an aramid pulp comprising polyoxazoline. Also claimed is a method for manufacturing the aramid pulp comprising polyoxazoline comprising: —combining aramid short-cut, partly fibrillated aramid short-cut or aramid pulp with polyoxazoline in an aqueous solution to form a mixture, —subjecting the mixture to a refining step to form an aqueous slurry of the aramid pulp. Further, the invention is directed to a paper comprising the aramid pulp comprising polyoxazoline and a friction material comprising said paper and/or said aramid pulp comprising polyoxazoline.

1 . An aramid pulp comprising polyoxazoline. 
     
     
         2 . The aramid pulp according to  claim 1  comprising 0.1 to 10 wt % of polyoxazoline, based on the weight of the dried pulp. 
     
     
         3 . The aramid pulp according to  claim 1 , wherein the polyoxazoline is a poly-alkyl-2-oxazoline. 
     
     
         4 . The aramid pulp comprising polyoxazoline according to  claim 1  wherein the polyoxazoline covers at least part of the surface of the aramid pulp. 
     
     
         5 . The aramid pulp according to  claim 1  comprising fiber stems and fibrils. 
     
     
         6 . The aramid pulp according to  claim 1  having a specific surface area in the range of 2 to 20 m 2 /g. 
     
     
         7 . A paper comprising the aramid pulp according to  claim 1 . 
     
     
         8 . The paper of  claim 7  comprising 2-70 wt % of the aramid pulp, based on the weight of the paper. 
     
     
         9 . The paper of  claim 7  comprising a filler and a resin, based on the weight of the paper. 
     
     
         10 . The paper of a  claim 7  wherein the resin is a thermoset resin. 
     
     
         11 . The paper of  claim 7  being a friction paper, a separator paper or a honeycomb paper. 
     
     
         12 . A friction material comprising the aramid pulp comprising polyoxazoline according to a  claim 1 . 
     
     
         13 . A method for manufacturing the aramid pulp comprising polyoxazoline according to  claim 1  comprising:
 combining aramid short-cut, partly fibrillated aramid short-cut or aramid pulp with polyoxazoline in an aqueous solution to form a mixture,
 subjecting the mixture to a refining step to form an aqueous slurry of the aramid pulp. 
 
 
     
     
         14 . The method according to  claim 13 , wherein the aqueous slurry of the aramid pulp is subjected to a dewatering step to form a dewatered pulp having a water content in the range of 40-80 wt %, based on the weight of the dewatered pulp. 
     
     
         15 . The method according to  claim 14 , wherein the dewatered pulp is subjected to a drying step to form a dried pulp having a water content in the range of 2 to 20 wt %, based on the weight of the dried pulp, optionally followed by subjecting the dried pulp to an opening step.