| 摘要 |
A solution of chlorinated rubber is brought into contact with water heated to a temperature sufficient to evaporate the solvent, and the precipitate is removed from the place of its precipitation as quickly as possible. The solution may be flowed on to the surface of moving water, or it may be introduced into the bottom of vessel, whereupon the chlorinated rubber rises to the surface, or it may be led below the surface of the water which is agitated. The solvent may be recovered. Wetting or emulsifying agents may be added to the precipitating liquid, or the solution may be emulsified prior to precipitation. The chlorinated rubber may be stabilized by treatment with alkali. If hydroxides are employed, ordinary temperatures are sufficient; with weaker alkalies, a temperature of 40-45 DEG C. up to the boiling point of the solution is necessary. The stabilization may be performed prior to precipitation, or the alkali may be added to the precipitation, or the alkali may be added to the precipitating bath. Numerous examples are given of which the following is typical-2 litres of 18,8 per cent solution of chlorinated rubber are emulsified with 30 gms. calcined soda in 1/2 litre of water, and stirred for 6-8 hours at 80 DEG C. The stabilized chlorinated rubber is precipitated in flowing water at 90-95 DEG C., washed and dried at 60 DEG C.
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