Process for manufacturing chlorinated polyvinylchloride

Patent metadata

Field	Value
Publication number	US-10370463-B2
Application number	US-201515326796-A
Country	US
Kind code	B2
Filing date	Jul 21, 2015
Priority date	Jul 22, 2014
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

The present disclosure provides a process for the chlorination of polyvinyl chloride. PVC obtained during the suspension polymerization reaction is directly used for chlorination without filtration, drying and re-slurrying. The present process is carried out in the absence of additional chemicals/reagents; also reheating during the chlorination reaction is not required. CPVC manufactured using the process of the present disclosure has whiteness index greater than 85, yellowness index lower than 4 and thermal stability in the range of 300 to 550 seconds at 210° C.

First claim

The invention claimed is:

1. A process for the preparation of chlorinated polyvinyl chloride (CPVC); said process comprising the following steps:
i. polymerizing vinyl chloride in the presence of at least one dispersing agent, at a temperature in the range of 50 to 80° C. to obtain a reaction mixture, wherein the conversion of monomer is greater than 86%;
ii. separating unreacted vinyl chloride from said reaction mixture to obtain a slurry comprising polyvinyl chloride; and
iii. reacting said slurry with chlorine in the presence of at least one irradiation source of wavelength ranging from 254 to 530 nm, under agitation at a speed ranging from 100 to 1600 rpm, for a time period ranging from 2 to 12 hours while maintaining a temperature in the range of 50 to 80° C. to obtain chlorinated polyvinyl chloride (CPVC).

2. The process as claimed in claim 1 , wherein said dispersing agent in step (i) is polyvinyl alcohol.

3. The process as claimed in claim 1 , wherein said dispersing agent in step (i) is partially hydrolyzed polyvinyl alcohol.

4. The process as claimed in claim 1 , wherein said irradiation source in step (iii) is selected from the group consisting of ultra violet (UV) lamps, light-emitting diodes (LEDs) and LASERs.

5. The process as claimed in claim 1 , wherein said irradiation source in step (iii) has power ranging from 0.01 to 0.04 Watt/g of PVC.

6. The process as claimed in claim 1 , wherein said CPVC has whiteness index greater than 85, yellowness index lower than 4 and thermal stability in the range of 300 to 550 seconds at 210° C.

Assignees

• Reliance Industries Ltd

Inventors

• Munshi Pradip
• Mathur Ajit Behari
• Ingle Ninad Deepak
• Kapadia Pradeep Paresh
• Jasra Raksh Vir

Classifications

• C08F8/22 Primary

  by reaction with free halogens · CPC title

• C08F114/06

  Vinyl chloride · CPC title