Method for improving synthesis efficiency of polyvinyl chloride resin

A technology of polyvinyl chloride resin and synthesis efficiency, which is applied in the field of polyvinyl chloride polymerization process, can solve the problems of reduced molecular weight and degree of polymerization of resin, reduced molecular weight and degree of polymerization, and poor mechanical properties of products, so as to improve production efficiency and improve production efficiency. The effect of high polymerization efficiency and production efficiency

Active Publication Date: 2014-03-26
CHINA PETROLEUM & CHEM CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above-mentioned patents and documents all prepare polyvinyl chloride resin through the method of post-heating of vinyl chloride polymerization. Compared with the constant temperature polymerization process adopted by most existing industrial devices, this late-stage heating process has higher production efficiency, but the performance of the resin and the product are at the same time. There will be some changes, mainly in that the molecular weight and degree of polymerization of the resin will decrease in varying degrees, and the mechanical properties of the product will deteriorate in varying degrees.
This is because the molecular weight of polyvinyl chloride is a function of its polymerization temperature. As the polymerization temperature rises, the molecular weight and degree of polymerization decrease. Increasing the polymerization temperature in the later stage of the polymerization reaction will inevitably lead to an increase in the proportion of low-molecular-weight products, which will lead to physical damage of PVC resin products. Deterioration of mechanical properties

Method used

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  • Method for improving synthesis efficiency of polyvinyl chloride resin
  • Method for improving synthesis efficiency of polyvinyl chloride resin

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] Component:

[0050] Vinyl chloride 100 parts.

[0051] Butyl acrylate 1.3 parts.

[0052] 150 parts of deionized water.

[0053] Dispersion system High degree of alcoholysis polyvinyl alcohol / low degree of alcoholysis polyvinyl alcohol / hydroxypropyl methylcellulose, the ratio is 3:2:1,

[0054] 0.08 parts.

[0055] Initiation system Cumyl peroxyneodecanoate, 0.1 parts.

[0056] Chain extender Diallyl terephthalate, 0.08 parts.

[0057] PH regulator ammonium bicarbonate, 0.001 parts.

[0058] Terminator Diethylhydroxylamine, 0.015 parts.

[0059] Operation method:

[0060] Step 1: Rinse the polymerization tank clean, apply anti-sticking tank agent and rinse, add deionized water, dispersant, initiator, pH regulator in the formula amount under vacuum, add 0.65 parts of butyl acrylate, and then use nitrogen Replace and evacuate.

[0061] Step 2: Turn on the jacketed hot water bath, raise the temperature of the water phase system, and reach the pro...

Embodiment 2

[0063] Embodiment 2: In the second step of the operation method, keep the treatment temperature at 97° C. for 20 minutes. The components and other operation methods are the same as in Example 1. The polymerization yield and basic properties of the resin are shown in Table 1.

Embodiment 3

[0064] Embodiment 3: In the second step of the operation method, keep the treatment temperature at 65° C. for 40 minutes. The components and other operation methods are the same as in Example 1. The polymerization yield and basic properties of the resin are shown in Table 1.

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Abstract

The invention provides a method for improving synthesis efficiency of polyvinyl chloride resin and belongs to the field of polyvinyl chloride polymerization processes. The method is characterized in that a constant-temperature polymerization process is adopted in polyvinyl chloride polymerization, and specifically comprises the steps of performing high-temperature treatment on a water phase containing an initiating agent before polymerizing, and performing constant-temperature treatment for 10-60 minutes after heating to the temperature which is 1-50 DEG C higher than than the needed temperature of the constant-temperature polymerization process. The method is easily operated and stably controlled in actual production; the basic performances of the resin obtained through polymerization and the resin obtained through the 'constant-temperature polymerization process' have no obvious differences, and the production efficiency of the polyvinyl chloride resin is improved and can be 5-10 percent higher than that of the traditional 'constant-temperature polymerization process'.

Description

technical field [0001] A method for improving the synthesis efficiency of polyvinyl chloride resin belongs to the field of polyvinyl chloride polymerization technology. Background technique [0002] At present, most polyvinyl chloride products are made by adding raw materials and additives such as vinyl chloride, deionized water, initiator system, dispersion system, pH regulator, chain transfer agent, etc. into the polymerization kettle, and raising the polymerization system in the kettle through a jacketed water bath. Temperature, constant temperature reaction at a certain temperature required by the process, adding a terminator when the polymerization conversion rate meets the process requirements, and then removing unreacted vinyl chloride monomer in the polymerization system, centrifuging to remove the suspension and drying to obtain polyvinyl chloride resin. The resin obtained by this constant temperature polymerization has stable performance and good product performan...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C08F214/06C08F2/38C08F2/44
Inventor梁斌张磊于永玲李留忠王晶张立红朱卫东
OwnerCHINA PETROLEUM & CHEM CORP