Improvements in the procedure for mass preparation of polymers and copolymers based on vinyl chloride, in two stages. (Machine-translation by Google Translate, not legally binding)

摘要

Improvements in the process of mass preparation of polymers and copolymers based on vinyl chloride, in two stages, characterized in that it consists in carrying out the homopolymerization or copolymerization operations carried out, in a first stage, in an installation provided with a device of agitation at high speed, a prepolymerization until a conversion percentage of the monomer (s) of the order of 7 to 15% and preferably close to 8 to 10% is obtained and this in the presence of a catalyst of rapid decomposition having with preferably, an average duration of less than a few hours, at the temperature at which the prepolymerization is carried out, and then in a second stage, the complement of the polymerization operation in one or several devices provided with stirring devices capable of being operated at slow speed, however, this speed remains sufficient to ensure a good thermostatization of the reaction medium until the end of the reaction, and this in the presence of a slow decomposition catalyst having an average duration of the order of 5 to 10 times that of the fast decomposition catalyst used in the course of the prepolymerization step and in the reaction conditions prevailing in the course of the second stage called polymerization complement. (Machine-translation by Google Translate, not legally binding)