Production method for chlorinated vinyl chloride resin

A technology of chlorinated vinyl chloride and a manufacturing method, which is applied to the manufacturing field of chlorinated vinyl chloride resins, and can solve the problems of poor heat resistance stability, no control, and inability to obtain transparent molded products.

CN106103501AInactive Publication Date: 2016-11-09SEKISUI CHEM CO LTD +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2016-11-09
Estimated Expiration
Not applicable · inactive patent

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Abstract

The present invention provides a production method for a chlorinated vinyl chloride resin that has excellent heat stability (initial colorability, and heat-resistance stability) and that can be used to obtain a transparent molded product. The present invention is a production method for a chlorinated vinyl chloride resin wherein a reaction liquid that comprises a vinyl chloride aqueous suspension that contains a vinyl chloride resin is thermally chlorinated in a sealable reaction vessel, the production method having a step (1) wherein the reaction liquid is heated, chlorine is introduced into the reaction vessel when the temperature is 55-70 DEG C, and thermal chlorination is started, a step (2) wherein the temperature inside the reaction vessel is increased while being kept at or below the glass transition temperature of a partially chlorinated vinyl chloride resin, and a step (3) wherein, after the chlorine content percentage of the partially chlorinated vinyl chloride resin is 58 weight% or more, thermal chlorination is performed at a prescribed temperature that is 85 DEG C or more but less than 115 DEG C. In steps (1)-(3), the net agitation power (Pv) inside the reaction vessel is 0.2-2.5 w / m3 per 1 m3 of the reaction liquid.
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Description

technical field

[0001] The present invention relates to a method for producing a chlorinated vinyl chloride-based resin having high initial coloring properties, high heat resistance stability, excellent thermal stability, and a transparent molded product. Background technique

[0002] Chlorinated vinyl chloride resins are produced by post-chlorination of vinyl chloride resins, and have the advantages of vinyl chloride resins, such as excellent weather resistance, flame retardancy, and chemical resistance, and are compatible with vinyl chloride resins. It is 20 to 40°C higher than the heat deflection temperature, so it can be suitably used in applications requiring heat resistance of 100°C, such as heat-resistant pipes, heat-resistant joints, heat-resistant valves, and heat-resistant plates.

[0003] However, since chlorinated vinyl chloride resins have a high heat distortion temperature, they must be heated and melted at high temperatures in order to be molded into heat-resi...

Examples

Embodiment 1

[0075] Put 200 kg of deionized water and 56 kg of vinyl chloride resin with an average degree of polymerization of 600 into a glass-lined reaction container with an internal volume of 300 liters, stir to disperse the vinyl chloride resin in water to form a water suspension state, and then heat the inside of the reaction container Instead, the aqueous suspension was warmed to 70°C.

[0076] Then, after reducing the pressure in the reaction vessel to remove oxygen (oxygen content 100 ppm), chlorine (oxygen content 50 ppm) was introduced so that the chlorine partial pressure was 0.4 MPa to start thermal chlorination (chlorination start temperature 70° C.).

[0077] Then, the temperature was raised to 90° C. over 1.1 hours so as to reach a temperature not higher than the glass transition temperature of the partially chlorinated vinyl chloride resin.

[0078] In addition, the glass transition temperature of a partially chlorinated vinyl chloride resin is calculated|required by DSC ...

Embodiment 2

[0086] Put 200 kg of deionized water and 56 kg of vinyl chloride resin with an average degree of polymerization of 600 into a glass-lined reaction container with an internal volume of 300 liters, stir to disperse the vinyl chloride resin in water to form a water suspension state, and then heat the inside of the reaction container Instead, the aqueous suspension was warmed to 70°C.

[0087] Then, after reducing the pressure in the reaction vessel to remove oxygen (oxygen content 100 ppm), chlorine (oxygen content 50 ppm) was introduced so that the chlorine partial pressure was 0.4 MPa to start thermal chlorination (chlorination start temperature 70° C.).

[0088] Then, the temperature was raised to 95° C. over 1.4 hours so as to reach a temperature not higher than the glass transition temperature of the partially chlorinated vinyl chloride resin.

[0089]Thereafter, after the chlorine content of the partially chlorinated vinyl chloride resin was 60.7% by weight, the temperature...

Embodiment 3

[0095] Put 200 kg of deionized water and 56 kg of vinyl chloride resin with an average degree of polymerization of 600 into a glass-lined reaction container with an internal volume of 300 liters, stir to disperse the vinyl chloride resin in water to form a water suspension state, and then heat the inside of the reaction container Instead, the aqueous suspension was warmed to 70°C.

[0096] Then, after reducing the pressure in the reaction vessel to remove oxygen (oxygen content 100 ppm), chlorine (oxygen content 50 ppm) was introduced so that the chlorine partial pressure was 0.4 MPa to start thermal chlorination (chlorination start temperature 70° C.).

[0097] Then, the temperature was raised to 100° C. over 2.0 hours so as to reach a temperature not higher than the glass transition temperature of the partially chlorinated vinyl chloride resin.

[0098] In addition, the glass transition temperature of a partially chlorinated vinyl chloride resin is calculated|required by DSC...