The invention relates to a process for the preparation of vinyl chloride homopolymers and co-polymers in the form of latex. According to this process, an emulsion or microsuspension polymerization operation of the corresponding monomer (s) is carried out with stirring, by intensifying the heat exchanges by continuous condensation of a fraction of the monomer composition used, in the form of vapors of the reaction medium, and by continuous reflux into said medium of this liquefied composition, then performs, also with stirring, a degassing operation of the polymerisate formed, the stirring being ensured by a paddle stirrer, with rotary shaft, and at least one deflector. P1 being the polymerization period which precedes the beginning of the reflux, P2 the reflux period, P3 the period which separates the end of the reflux and the start of degassing and P4 the degassing period, the peripheral speed of rotation is maintained. agitator in two separate intervals determined for a sufficiently high proportion, up to 100%, of the duration of each of the periods P1 and P3 on the one hand and of the duration of each of the periods P2 and P4 on the other hand. This process makes it possible to reduce the amount of crusts formed, without reducing the conversion rate of the monomer or monomers used and without leading to a higher polymerization time. A subject of the invention is also the resulting latexes as well as the homo- and co-polymers derived from said latexes.
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