SU494393A1 - Method for isolating chlorinated polyvinyl chloride - Google Patents

Description

one

The invention relates to the isolation of polymers from solutions of organic solvents; it can be used in the chemical industry.

A known method for separating chlorinated polyvinyl chloride from a solution of an organic solvent, such as carbon tetrachloride, chlorobenzene, tetrachloroethane, dichloroethane, is sprayed into hot circulating water. The disadvantage of the known method is the relatively low productivity of the expander and the high residual content of organic solvent in crude siol.

The purpose of the invention is to intensify the process of isolating chlorinated polyvinyl chloride from chlorine-containing solutions without reducing the quality of the target

(product. The goal is achieved by the fact that the landing process is carried out in the presence of -caprolactam with its content in the circulating water of 0.020, 3 weight. Reducing the content of caprolactam in the circulating water does not lead to the achievement of the goal. When the content of -caprolactam in the circulating 0.02-0.03 wt.% are observed, along with an increase in the productivity of the landing craft, an increase in the chlorobenzene content in the raw product to 18-20 6 and a deterioration in the quality of the resin; instead of decreasing the chlorobenzene content, an increase of up to 15% and a deterioration in the quality of the resin. Product In these cases, it is less homogeneous, significant inclusions of insoluble particles appear, the presence of which worsens the external

type and solubility of podiyera.

Intensification of the landing process allows an increase in the load on the Vtsc & s apparatus to 800 l / h, i.e. the power is increased by 30, while the chlorobenzene content in the raw resin remains as high as 12%,

Example. Before starting, the precipitation system is filled with condensate at a temperature through the circulation tank. After the whole system is filled with water, steam is opened to the heater and the nozzles, after which the system is heated to 94-98 ° C. Upon reaching the specified temperature, a 20% aqueous solution of caprolacta is fed into the circulating water of the precipitation system at a rate of 2 liters / hour. When the content of -caprolactus in the circulation at | De reaches a concentration of 0.015, the solution of chlorinated polyvinyl chloride in chlorobenzene through the nozzles is started to flow at a rate of 600 l / h.

For spraying the polymer solution in the stand-off column, steam is fed into the same nozzles at a pressure of 1.5-5 atm. Circulation water is sampled to determine the content of ε-caprolactam and the crude resin to determine the chlorobenzene content.

When the content in the circulating water 0,015 Bec.JS-caprolactam is not

the chlorobenzene content in the crude resin decreases, therefore, the load on the landing craft does not increase. No process intensification is observed. The feed rate of the pacTBopia polymer per expander is 600 l / h.

П р | Г | ГТр 2 The process of polymer extraction is similar.

I to example I, but the content of -caprolac6 tama in circulating water is supported by 0.02 weight. With a load on the landing craft the same as in. In Example I, the chlorobenzene content in the raw product is halved, which allows for an increase in the productivity of the apparatus up to 750 l / h, and an increase in the load entails an increase in the chlorobenzene content in the crude product up to 12%.

I

Froze In this example, the content is: -caprolactam in the circulating water 0.03. Increasing the concentration of κ caprolshtam to such an amount allows 1/3 to intensify the landing process, i.e. increase the productivity of the landing craft up to 800 l / h, keeping the chlorobenzene content in the crude resin at 12%

The results of the experiments are given in table. I.

T a b i c i

If it is necessary to save chlorobenzene, the load on the landing f annapaT remains unchanged, i.e., yo up to 600 l / chao. The content of chlorobenzene in the crude resin is added by Privat | T twice, i.e. until 6%.

PRI n e r 4. The process of water and water processes under the anadogchen example of I.I. At a maintenance-caprodahtana 0.015 weight. in tsirkul znonoy water, the content of hdorbenoda.in the raw resin does not decrease, i.e. 12% remains. The rate of delivery of the polymer solution to the expander in this example, and in all subsequent ones, is up to 600 liters / hour.

Claims (1)

EXAMPLE 5: The content of caprolactam in circulating water is under-maintained, it holds 0.02 weight. When loading the formula of the invention. A method for separating chlorinated polyvinyl chloride from its solution in an organic solvent by spraying the resin solution into a hot circulator. 600 d / vac, the chlorobenzene content in the raw product is halved. those. it is equal to 6%. ,,,; ... , .:. PRI me R 6. Concentration. caprolachtam in circulating water is 0.03 wt. .. Increasing the concentration of -caprolactam to such a level allows halving the chlorobenzene content in the raw product. G The results of the experiments are given in table. 2.. Table 2 water, characterized in that, in order to intensify the process, the landing of chlorinated polyvinyl chloride is carried out in the presence of β-caprolactam with its content in circulating water 0.02-0.03 weight ..