Process for preparing tetrvfluoroethylene-hexafluoropropylene copolymer

A technology of hexafluoropropylene and tetrafluoroethylene, which is applied in the field of preparation of tetrafluoroethylene and hexafluoropropylene copolymers, can solve problems such as impact, copolymer structure, uneven molecular weight, and quality influence of processed products

Inactive Publication Date: 2004-03-24
ZHEJIANG JUHUA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, such treatment will generally be accompanied by pollution from dust and other foreign impurities (due to the relatively high static electricity of the powder), which will affect the quality of processed products.
[0021] In addition, when the polymer is separated from the reactant for a long time, and when the temperature is relatively high, additional processes may occur, resulting in crosslinking, branching, etc. of the polymer, and correspondingly in the structure and molecular weight of the copolymer. Inhomogeneous, resulting in gel, which leads to a large amount of waste and a bad influence on the quality of the product during processing, especially in the preparation of films, pipes and other electrical products

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] A 1.3L reactor made of stainless steel is equipped with a stirrer and a heating jacket, the airtightness is checked with nitrogen, the vacuum is evacuated to a residual pressure of 8-10mm Hg, and cooled to -20°C. Then add 300g fluorine-containing solvent (octafluorocyclobutane) to the reactor, 200g pre-added monomer mixture (wherein containing 80% mol of HFP, 20% mol of TFE), and then the reactor is heated to 50°C under stirring , and then 0.8 g of perfluorocyclohexyl peroxide (in the form of a 12% solution dissolved in R113) was added thereto. At this time, the set pressure of the reactor is 1.5 MPa, which is maintained by periodically adding a monomer mixture with a HFP content of 12% mol and a TFE content of 88% mol during the copolymerization process. Copolymerization was carried out until 295 g of additional mixture was consumed. The total process time is 3.5 hours. After the end of the copolymerization process, cool the reaction product in the form of a copolyme...

Embodiment 2

[0042] Add 650g of pre-adding monomer mixture to the prepared reactor described in Example 1, containing HFP83%mol, TFE is 17%mol, the mixture is heated to 45°C under stirring and 1g perfluorocyclohexyl peroxide is added (It is dissolved in R113, which is a 12% solution). At this time, the set pressure is 1.4 MPa, and the copolymerization process is carried out in the monomer medium under the specified temperature and pressure conditions. The pressure was kept constant by adding additional monomer mixture (containing 15% mol HFP, 85% mol TFE). After 50 g of these mixtures were consumed, 0.07 g of methanol was added to the reactor and the copolymerization process was continued. The total process time is 3 hours. The total additional monomer mix was 290 g. The reactant dissolved in the HFP medium in the form of copolymer emulsion is post-treated. The specific operation is the same as that shown in Example 1, but it should be cooled to 5° C. before pressure delivery, and the se...

Embodiment 3

[0044]Copolymerization flow process is similar with example 2, but adds 650g pre-adding mixture (containing HFP86%mol, TFE14%mol) to reactor, mixture is heated to 25 ℃ under stirring, before reactor adds 1g perfluoropropyl peroxide ( 10% solution dissolved in R113). The set pressure of 1.1 MPA is maintained constant by adding the mixture (content 13% HFP mol, TFE 87% mol). After 50 g of this mixture had been consumed, 0.04 g of methanol was added to the reactor for a total run time of 3.5 hours. The additional amount of mixture was 295 g. The aftertreatment process is the same as in Example 1, but the reactant is cooled to 25° C. (the pressure is 0.7 MPa). The pressure difference between the reactor and the post-processing equipment is 0.08MPa. The temperature of post-processing equipment should be increased in stages, first heated to 60°C (pressure 0.3MPa), and then heated to 120°C (pressure 0.09MPa). The copolymer powder was not heated for 4 hours at 120°C and a residual...

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Abstract

The present invention discloses a preparation method of tetrafluoroethylene-hexafluoropropylene copolymer, and is characterized by that it adopts the following steps: making specified monomer implement copolymerization in monomer medium or fluorine-contained solvent whose atmospheric ozone is safe, its temp. is at 25-50 deg.C and pressure is 1.1-1.5 MPa, initiator is perfluorinated initiator group, in the course of polymerization process using pre-added mixture and post-added mixture, then removing unreacted monomer, heating the obtained copolymer powder to remove residual initiator, after the copolymerization process is completed, cooling resultant of reaction, reducing pressure to 0.3-1.0 MPa and placing it into a closed container, then removing unreacted monomer and solvent by utilizing the measure of progressively heating while stirring so as to obtain the invented product.

Description

technical field [0001] The invention relates to a preparation method of tetrafluoroethylene and hexafluoropropylene copolymer. The copolymer is a valuable industrial material, which has high thermal stability, good mechanical and physical performance index, good chemical stability and high dielectric performance. TFE and HFP copolymers are widely used in electronic technology (wire and cable insulation), chemical industry (for equipment linings such as pipes, pipe joints, containers and towers), aviation, radio, electronics, medicine and other national economic fields. [0002] In order to ensure the preparation of TFE and HFP copolymers with high thermal stability, the copolymerization process is consciously carried out in fluorinated solvents or monomer media (using organic fluorinated peroxides). Background technique [0003] It is well known that TFE and fluorinated olefin monomers, including HFP, copolymerization method, the above-mentioned T...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F214/26C08F214/18
Inventor 叶志翔黄华章许生来陆建平余考明洛给诺娃尼娜尼卡拉耶芙娜杰留若夫尤里马特维耶维奇哈恰特良沙利别克沙卡维奇孔其基娜柳特米拉格奥尔基夫娜别列济娜卡利娜格利高利耶芙娜孔谢托夫维达利瓦西里耶维奇
Owner ZHEJIANG JUHUA CO LTD
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