Melam granulate material and process for preparation thereof

Abstract

Melam granulate materials include (i) melam particles, (ii) 0.5-8 wt. %, relative to the total weight of the melam granulate material, of a polymeric binding agent which bonds the melam particles to each other, and (iii) 0-12 wt. %, relative to the total weight of the melam granulate material, of water, wherein the melam granulate material consists of granules with a median particle size (d50) in the range of 100-1000 μm, and wherein the granulate material has a Carr-P bulk density in the range of 400-1000 kg/m 3 .

1 . A melam granulate material comprising:
 (i) melam particles,   (ii) 0.5-8 wt. %, relative to the total weight of the melam granulate material, of a polymeric binding agent which bonds the melam particles to each other, and   (iii) 0-12 wt. %, relative to the total weight of the melam granulate material, of water, wherein   the melam granulate material consists of granules with a median particle size (d50) in the range of 100-1000 μm, and wherein   the granulate material has a Carr-P bulk density in the range of 400-1000 kg/m 3 .   
     
     
         2 . The melam granulate material according to  claim 1 , wherein the median particle size (d50) is in the range of 200-900 μm. 
     
     
         3 . The melam granulate material according to  claim 1 , wherein the granulate material has a d10 of at least 10 μm, and/or a d90 of at most 3000 μm. 
     
     
         4 . The melam granulate material according to  claim 1 , wherein the granulate material comprises water in an amount of 0-12 wt. %, relative to the total weight of the granulate material. 
     
     
         5 . The melam granulate material according to  claim 4 , wherein the granulate material comprises water in an amount of 1-10 wt. %, relative to the total weight of the granulate material. 
     
     
         6 . The melam granulate material according to  claim 1 , wherein the amount of the polymeric binding agent is in the range of 1-6 wt. %, relative to the total weight of the granulate material. 
     
     
         7 . The melam granulate material according to  claim 1 , wherein the polymeric binding agent comprises polyvinyl alcohol, polyvinylpyrrolidone and/or polyvinylcaprolactam, preferably polyvinylpyrrolidone. 
     
     
         8 . The melam granulate material according to  claim 1 , wherein the melam particles have a median primary particle size (d50) in the range of 0.1-50 μm. 
     
     
         9 . A flame retardant polymer composition which comprises the melam granulate material according to  claim 1 . 
     
     
         10 . A process for the preparation of a flame retardant polymer composition which comprises:
 (a) melt processing of a thermoplastic polymer thereby forming a polymer melt,   (b) adding the melam granulate material according to  claim 1  to the thermoplastic polymer prior or during the melt-processing,   (c) dispersing the melam granulate material into the polymer melt,   (d) extruding the polymer melt comprising the granulate material dispersed therein,   (e) cooling and granulating the extruded polymer melt, and   (f) collecting the resulting granulated material.   
     
     
         11 . A flame retardant polymer composition comprising:
 a thermoplastic polymer,   the melam granulate material according to  claim 1  dispersed in the thermoplastic polymer, and   0.5-8 wt. %, relative to the amount of melam granulate material, of a water soluble polymer.   
     
     
         12 . The flame retardant polymer composition according to  claim 11 , wherein the water soluble polymer is selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone and polyvinylcaprolactam.