| 摘要 |
PROBLEM TO BE SOLVED: To defoam a vinyl chloride paste resin latex without causing quality deterioration by passing the latex containing bubbles formed when unreacted monomer is vacuum-recovered from the latex by steam blowing or heating through a cooling section arranged in the space of a recovery equipment or in an evacuation pipe. SOLUTION: The latex is fed from the pretreatment step through a feed line 2 at a temperature near the treatment temperature into a vacuum recovery tank 1 and is kept at a constant temperature by means of a heating jacket 8. While a coolant is passed through a condenser 4 arranged in the vapor phase of the tank 1, saturated steam is introduced through a steam introduction line 11 from the bottom of the tank 1. The degree of vacuum in the tank 1 is regulated so that the pressure may be kept at the saturated pressure at the treatment temperature, and unreacted monomer is recovered from a vacuum line 7. In a cooling section, saturated steam in the form of bubbles is cooled and condensed to defoam the latex. The condenser is desirably a coil, jacket, multi-pipe cylinder or like type. It is desirable that the temperature in the cooling section is lower than the saturation temperature of the operating pressure.
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