Preparation process of chlorinated polyvinyl chloride resin

A technology of chlorinated polyvinyl chloride and polyvinyl chloride resin, which is applied in the field of production of chlorinated polyvinyl chloride resin, can solve the problems of not strictly controlling the speed of chlorine flow, poor heat resistance stability, and drop in reaction pressure, so as to ensure chlorination Uniformity, ensuring heat resistance stability, and increasing the effect of heat resistance stability

Active Publication Date: 2009-12-16
SHANGHAI CHLOR ALKALI CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main disadvantage is that the presence of solvents causes environmental pollution and poor thermal stability
[0004] Also have water or hydrochloric acid to be the chlorination process of suspension medium, as in patent USP 5821304 (1998), USP 5981663 (1999), USP 6187868 (2001), PVC resin is suspended in the liquid phase, after adding initiator, dispersant, A two-stage chlorination process of low temperature (30-90°C) and high temperature (90-130°C) is adopted, but the speed of chlorine flow is not strictly controlled, and the method of natural pressure reduction and temperature reduction is adopted after chlorination, so that CPVC resin can be used at high temperature. The residence time under the condition is too long, resulting in poor thermal stability of CPVC resin
[0005] These patents adopt two-stage chlorination technology, and the main problems are: (1) the initial chlorine flow rate is too fast, and the local chlorination uniformity of the resin decreases; The rapid capture, termination and rapid pressure release of unreacted chlorine free radicals make the resin stay at high temperature for too long

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] In a 100L enamel reaction kettle, add 15Kg of PVC resin with a polymerization degree of 700 and 85Kg of deionized water, and use different types of initiators under the same operating conditions except for different initiator conditions. The amount of the initiator is 0.5% (wt %) of PVC consumption, namely 250g weight concentration is that 30% hydrogen peroxide, 75g azobisisobutyronitrile and 100g weight concentration are 75% dibenzoyl peroxide, then add 300g weight concentration 25% After the silica sol, feed nitrogen for 30 minutes, and at the same time, feed steam into the jacket to raise the temperature to 60°C, turn off nitrogen, feed chlorine gas with a flow rate of 12L / min for 5 minutes, and then close the tail gas valve. Minutes; heat up to 115°C and keep the temperature constant, adjust the chlorine flow rate of 24L / min for 90 minutes; heat up to 130°C and keep the temperature constant, adjust the chlorine flow rate of 12L / min for 45 minutes, at this time the to...

Embodiment 2

[0029] In a 100L enamel reaction kettle, add 15Kg of PVC resin with a polymerization degree of 700 and 85Kg of 10% concentration hydrochloric acid, and use different types of initiators under the same operating conditions except for different initiator conditions. The amount of the initiator is 0.5% (wt %) of PVC consumption, namely 250g weight concentration is that 30% hydrogen peroxide, 75g azobisisobutyronitrile and 100g weight concentration are 75% dibenzoyl peroxide, then add 300g weight concentration 25% After the silica sol, feed nitrogen for 30 minutes, and at the same time, feed steam into the jacket to raise the temperature to 60°C, turn off nitrogen, feed chlorine gas with a flow rate of 12L / min for 5 minutes, and then close the tail gas valve. Minutes; heat up to 115°C and keep the temperature constant, adjust the chlorine flow rate of 24L / min for 90 minutes; heat up to 130°C and keep the temperature constant, adjust the chlorine flow rate of 12L / min for 45 minutes,...

Embodiment 3

[0033] In a 100L enamel reaction kettle, add 15Kg of PVC resin with a polymerization degree of 700 and 85Kg of deionized water, and use different types of initiators under the same operating conditions except for different initiator conditions. The amount of the initiator is 1.0% (wt %) of PVC consumption, promptly add the dibenzoyl peroxide of 500g weight concentration 30% hydrogen peroxide, 150g azobisisobutyronitrile and 200g weight concentration 75%, then add 300g weight concentration 25% silicon After the sol, feed nitrogen for 30 minutes, and at the same time, feed steam into the jacket to raise the temperature to 60°C, turn off the nitrogen, feed chlorine gas with a flow rate of 12L / min for 5 minutes, then close the tail gas valve, keep the temperature at 100°C, and maintain the chlorine flow rate for 40 minutes Raise the temperature to 115°C and keep the temperature constant, adjust the chlorine flow rate of 24L1 / min for 90 minutes; raise the temperature to 130°C and ke...

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PUM

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Abstract

The invention discloses a method for preparing chlorinated polyvinyl chloride resin. The invention adopts water or hydrochloric acid as the suspending medium, and polyvinyl chloride is suspended in the liquid phase with a solid content (wt) not higher than 30%. Control the chlorine flow rate and chlorination reaction temperature of the three stages of chlorination, and pass chlorine gas that does not exceed 20% of the theoretical chlorine content to make the chlorine content of the resin reach 66-70%. After acid filtration, neutralization, water washing, and centrifugation , drying, to obtain high heat-resistant stability suitable for the production of corrosion-resistant, high-temperature pipe resin.

Description

technical field [0001] The invention relates to a method for producing chlorinated polyvinyl chloride resin (CPVC), especially a water phase suspension chlorination method. Background technique [0002] Chlorinated polyvinyl chloride resin (CPVC) is an important polymer material. According to different production processes, its chlorine content is also different, and its application is also different. The chlorine content of CPVC produced by solvent method is generally 62-65%. It is mainly used for coatings and adhesives. The water-phase suspension chlorination technology is adopted. The chlorine content of CPVC resin after chlorination is 66-70%, because the resin has It is characterized by high temperature resistance, corrosion resistance and good dielectric properties. It is widely used in hot water pipes, power pipes, oil pipelines and chemical corrosion-resistant pipes. It is especially suitable for corrosion-resistant and high-temperature-resistant pipes for electrolyt...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F114/06C08F8/22
Inventor 陈斌武岳群袁茂全胡妹华蔡华明
Owner SHANGHAI CHLOR ALKALI CHEM
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