Method for preparing high-gloss PTFE (Polytetrafluoroethylene) dispersion concentrated solution

A polytetrafluoroethylene, high-gloss technology, applied in the chemical industry, can solve the problem of low gloss of the emulsion, achieve the effect of reducing crystallinity, improving gloss, and good leveling

Active Publication Date: 2011-06-08
ZHONGHAO CHENGUANG RES INST OF CHEMICALINDUSTRY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the disclosed technical scheme, the addition of modifiers and dispersants in emulsion polymerization is not controlled, and more surfactants are added in the post-treatment process, so that the gloss of the emulsion is not high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] In an autoclave with a volume of 50L, add 30L of deionized water, 0.4g of ammonium persulfate, 15g of succinic acid, 250g of 10% ammonium perfluorooctanoate solution, and 1kg of paraffin, then seal the reactor, and heat the reactor. To 50 ℃, the reaction kettle is evacuated and replaced, and the oxygen content test is carried out. When the oxygen content in the reaction kettle is less than or equal to 20PPM, it is qualified. After the oxygen content is qualified, the temperature of the kettle is raised to 70 ° C and the TFE monomer is added to the reactor to a pressure of 2.0MPa, and the reaction is started. When the TFE monomer feeding amount reaches 3.5kg, it is continuously added dropwise to the reactor. % perfluorooctanoic acid ammonium solution (i.e. 75g ammonium perfluorooctanoate), control its adding speed, ensure that it is all added when the TFE monomer feeding amount reaches 11kg, stop stirring when the TFE monomer feeding amount reaches 7kg, and stop dripping ...

Embodiment 2

[0020] In an autoclave with a volume of 50L, add 30L of deionized water, 0.4g of ammonium persulfate, 15g of succinic acid, 250g of 10% ammonium perfluorooctanoate solution, and 1kg of paraffin, then seal the reactor, and heat the reactor. To 50 ℃, the reaction kettle is evacuated and replaced, and the oxygen content test is carried out. When the oxygen content in the reaction kettle is less than or equal to 20PPM, it is qualified. After the oxygen content is qualified, the temperature of the kettle is raised to 70° C. and the TFE monomer is added to the reactor to a pressure of 2.0MPa, and the reaction is started. When the feed amount reaches 3.5kg, the continuous dropwise addition of 750g to the reactor is 10% perfluorooctanoic acid. Ammonium solution (i.e. 75g ammonium perfluorooctanoate), control its adding speed to ensure that it is all added when the TFE monomer feeding amount reaches 11kg, stop stirring when the TFE monomer feeding amount reaches 7kg, and stop dripping t...

Embodiment 3

[0022] In an autoclave with a volume of 50L, add 30L of deionized water, 0.4g of ammonium persulfate, 15g of succinic acid, 250g of 10% ammonium perfluorooctanoate solution, and 1kg of paraffin, then seal the reactor, and heat the reactor. To 50 ℃, the reaction kettle is evacuated and replaced, and the oxygen content test is carried out. When the oxygen content in the reaction kettle is less than or equal to 20PPM, it is qualified. After the oxygen content is qualified, the temperature of the kettle is raised to 70° C. and the TFE monomer is added to the reactor to a pressure of 2.0MPa, and the reaction is started. When the feed amount reaches 3.5kg, the continuous dropwise addition of 750g to the reactor is 10% perfluorooctanoic acid. Ammonium solution (i.e. 75g ammonium perfluorooctanoate), control its adding speed to ensure that it is all added when the TFE monomer feeding amount reaches 11kg, stop stirring when the TFE monomer feeding amount reaches 7kg, and stop dripping t...

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Abstract

The invention provides a method for preparing high-gloss PTFE (Polytetrafluoroethylene) dispersion concentrated solution. The method comprises the steps of: adding deionized water, an initiator, a dispersing agent, a stabilizing agent and polymeric monomers into a high pressure reactor to carry out emulsion polymerization reaction to obtain modified PTFE polymer solution and subjecting the modified PTFE polymer solution to aftertreatment concentration to obtain the PTFE dispersion concentrated solution, wherein the polymerization reaction comprises two steps of: adding modified monomers which are 0.02%-0.5wt% of the polymeric monomers into a polymerizer when the feed quantity of the polymeric monomers reaches to 10%-50% of total feed quantity to reduce the crystallinity of a PTFE product and the change internal structures of PTFE primary particles and controlling the adding quantity of the dispersing agent in the polymerization reaction and adopting an adding mode of stepwise and continuously adding in drops to ensure that the particles of the PTFE dispersion solution are shaped like full balls and uniformly distributed and enhance the gloss of the PTFE dispersion solution.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a preparation method of a high gloss polytetrafluoroethylene dispersion concentrate. Background technique [0002] Fluorine coatings of water-based polytetrafluoroethylene (PTFE) have been studied since the 1940s. Due to the strong electronegativity of the fluorine atom and the extremely small particle radius, the fluorine coating of polytetrafluoroethylene in which the carbon-carbon main chain fully wraps elemental fluorine has excellent weather resistance, durability, solvent resistance and corrosion resistance, etc. Excellent performance. The vast majority of fluorine coatings currently on the market are solvent-based products. With environmental protection regulations restricting volatile organic compound (VOC) emissions and the requirements of low-carbon chemicals that save energy consumption, water-based fluorine-containing coatings have become one of the focuses of resea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F214/26C08F214/28C08F216/14C08F2/22C08F6/20
Inventor 张建新胡显权何炯姚权卫秦向明张春静罗湘华苏小龙
Owner ZHONGHAO CHENGUANG RES INST OF CHEMICALINDUSTRY CO LTD
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