Method for removing and recovering reaction monomer
A vinylidene chloride, unreacted technology, applied in the field of vinylidene chloride-based resin slurry, can solve problems such as difficulty, temperature and separation tank temperature drop, poor thermal stability, etc.
Patent Information
- Authority / Receiving Office
- CN · China
- Current Assignee / Owner
- Publication Date
- 2003-06-11
- Estimated Expiration
- Not applicable · inactive patent
Smart Images
Figure 1
Abstract
Description
technical field
[0001] The present invention relates to removing unreacted vinylidene chloride-based resins while preventing quality deterioration such as coloring of vinylidene chloride-based resins from a vinylidene chloride-based resin slurry (slurry) containing unreacted monomers obtained by polymerization in an aqueous medium. A method of monomer, and a method of recovering unreacted monomer. Background technique
[0002] In the past, as a method of separating and removing residual monomers from vinyl chloride-based resin slurries, it was proposed in JP-A-51-135990 to polymerize vinyl chloride or a monomer mixture mainly composed of vinyl chloride in an aqueous medium. , in the process of transferring the obtained vinyl chloride resin slurry to the separation tank with a pipeline, the slurry is rapidly heated to a temperature of 80-150°C by blowing water vapor into the slurry or performing external heating while blowing water vapor , and the...
Examples
Embodiment 1
[0085] polymerization
[0086] In a stainless steel polymerization vessel with an internal volume of 150 liters, 60 kg of deionized water in which 50 g of methylcellulose was dissolved was added as a suspending agent, and 41 kg of vinylidene chloride monomer and 9 kg of vinyl chloride monomer were thrown into it under stirring. and 100 g of isopropyl peroxydicarbonate as a polymerization initiator. While stirring the mixture, the temperature was raised to 45°C to start polymerization. Then, the polymerization was continued for 30 hours while continuously raising the temperature to 55° C. to obtain a polymer slurry containing unreacted monomers.
[0087] mixing of steam
[0088] Next, install a steam mixer on the way from the bottom of the polymerization vessel to the unreacted monomer removal vessel to mix the steam and increase the temperature of the slurry to 80-90°C.
[0089] stress reliever
[0090] Then, the slurry was transferred to an unreacted monomer removal...