Process for producing hydrogenated polymers
View Patent ↗The present invention relates to a process for the hydrogenation of an unsaturated polymer comprising hydrogenation of an unsaturated polymer in a reaction mixture comprising hydrazine, an oxidizing agent and a catalyst and the reduction or elimination of residual free hydrazine from the hydrogenated polymer, whereby the residual free hydrazine is reduced or eliminated from the reaction mixture by contacting it with an adsorbent and/or absorbent which is a solid material which has the ability to absorb and/or absorb hydrazine. The absorbent and/or absorbent is chosen from activated carbon, carbon black, silicates, chalk, talcum or transition metal containing solids.
1. Process for the hydrogenation of an unsaturated polymer comprising hydrogenation of an unsaturated polymer in a reaction mixture comprising hydrazine, an oxidizing agent and a catalyst and the reduction or elimination of residual free hydrazine from the hydrogenated polymer characterized in that the residual free hydrazine is reduced or eliminated from the reaction mixture by contacting it with an adsorbent and/or absorbent which is a solid material that has the ability to adsorb and/or absorb the hydrazine.
2. Process according to claim 1 , wherein the adsorbent or absorbent is chosen from activated carbon, carbon black, silicates, chalk, talcum or transition metal containing solids.
3. Process according to claim 1 , wherein the adsorbent and/or absorbent is activated carbon or carbon black.
4. Process according to claim 1 , wherein the adsorbent and/or absorbent is in contact with the reaction mixture after hydrogenation and before separation of the hydrogenated polymer from the reaction mixture.
5. Process according to claim 1 , wherein the adsorbent and/or absorbent is added to the reaction mixture.
6. Process according to claim 1 , wherein from 0,0001–10% parts by weight adsorbent and/or absorbent is added based on 100 parts by weight hydrogenated polymer.
7. Process according to claim 5 , wherein the adsorbent and/or absorbent is not separated from the hydrogenated polymer but further mixed with the hydrogenated polymer.
8. Process according to claim 7 , wherein from 10–100 parts by weight additional adsorbent and/or absorbent is used based 100 parts by weight hydrogenated polymer.
9. Process according to claim 1 , wherein the hydrogenated polymer is in a latex form.
10. Process according to claim 1 , wherein the unsaturated polymer is acrylonitrile-butadiene rubber (NBR).
11. Process according to claim 1 , wherein the hydrogenation is carried out in the presence of a catalyst which contains an element from group 13 of the periodic system.