Carboxyl nitroso-fluoro rubber (CNR) solution polymerization process

A technology of carboxynitroso fluorine and rubber solution, applied in the field of organic fluorine chemistry, can solve the problems of polymer separation difficulties, heat transfer, mass transfer deterioration, temperature out of control, etc., to avoid explosion hazards, easy separation, and improve mass transfer Effect

Active Publication Date: 2012-10-17
CHINA BLUESTAR CHENGRAND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If the above-mentioned ternary bulk is directly polymerized, polymers with high viscosity will be formed in the middle and later stages of the reaction, which will greatly deteriorate the heat and mass transfer in the kettle, and even cause temperature out of control and explosion.
And if the above-mentioned ternary body is polymerized in the presence of FC-75 (a perfluorinated mixture), F113 (trifluorotrichloroethane) or FC-43 (perfluorotri-n-butylamine) inert solvent, although it can Improve heat transfer and mass transfer, but the presence of these solvents makes both monomers and polymers soluble in them. Since the polymers and solvents are miscible, it is very difficult to separate the solvents from the polymers produced by the reaction.

Method used

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  • Carboxyl nitroso-fluoro rubber (CNR) solution polymerization process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Replace the polymerization kettle with nitrogen and then evacuate it, pass through the jacket with ethanol at -65°C to circulate the cooling medium, cool the polymerization kettle to -30°C, and use the vacuum state of the polymerization kettle to add nitrosoperfluoro one by one by suction Butyric acid 100g, dichloromethane 4.6kg. Turn on the agitator of the polymerization kettle, and continue to feed -65°C ethanol into the jacket as a circulating cold medium. When the temperature of the polymerization kettle reaches -45°C, add 3.0 kg of nitrosotrifluoromethane. resulting in an increase in the temperature of the kettle. Due to the continuous refrigeration of the circulating cold medium, the temperature of the kettle dropped again. When the temperature in the reactor dropped to -55°C, 3.1kg of tetrafluoroethylene was added.

[0023] After the feeding was completed, the temperature of the polymerization kettle was allowed to rise naturally, and when the temperature inside...

Embodiment 2

[0026] The polymerization kettle was evacuated after being replaced with nitrogen, and -70°C ethanol was passed through the jacket to circulate the cold medium, and the polymerization kettle was cooled to -40°C. Utilizing the vacuum state of the polymerization kettle, 100 g of nitrosoperfluorobutyric acid and 5.0 kg of dichloromethane were sequentially added by suction. Turn on the agitator of the polymerization kettle, and continue to feed -70°C ethanol into the jacket to circulate the cold medium. resulting in an increase in the temperature of the kettle. Due to the continuous cooling of the circulating low-temperature cold medium, the temperature of the kettle dropped again. When the temperature in the reactor dropped to -60°C, 3.3 kg of tetrafluoroethylene was added.

[0027] After the feeding was completed, the temperature of the polymerization kettle was allowed to rise naturally, and when the temperature inside the kettle rose to -45°C, the terpolymerization reaction s...

Embodiment 3

[0030] The polymerization kettle was evacuated after being replaced with nitrogen, and a low-temperature cold medium of ethanol at -68°C was introduced into the jacket to cool the polymerization kettle to -35°C. Utilizing the vacuum state of the polymerization kettle, 110 g of γ-nitrosoperfluorobutyric acid and 5.5 kg of dichloromethane were sequentially added by suction. Turn on the agitator of the polymerization tank, and continue to feed -68°C ethanol as a low-temperature cold medium into the jacket. When the temperature of the polymerization tank reaches -45°C, add 3.1 kg of nitrosotrifluoromethane. resulting in an increase in the temperature of the kettle. Due to the continuous refrigeration of the circulating low-temperature cold medium, the temperature of the kettle dropped again. When the temperature in the reactor dropped to -65°C, 3.5 kg of tetrafluoroethylene was added.

[0031] After the feeding was completed, the temperature of the polymerization kettle was allow...

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Abstract

The invention relates to a process for synthesizing a crude carboxyl nitroso-fluoro rubber (CNR) by copolymerizing trifluoronitrosomethane, tetrafluoroethylene and perfluoro(nitrosobutanoic acid) in a dichloromethane solvent under low temperature, belonging to the technical field of organofluorine chemistry. The method is characterized by displacing gas in a polymerizer with nitrogen, and then vacuumizing the polymerizer; pumping a circulating low-temperature cold medium into a jacket; adding perfluoro(nitrosobutanoic acid), dichloromethane, trifluoronitrosomethane and tetrafluoroethylene in sequence; displacing the residual gas in the polymerizer with nitrogen after the reaction is completed; opening a bottom valve of the polymerizer to discharge dichloromethane; taking the CNR from the upper part of the polymerizer; and obtaining the crude CNR through aftertreatment procedures such as washing, dehydration and low molecule removal and the like. The CNR solution polymerization process has the following technical effects: mass and heat transfer conditions of polymerization reaction are greatly improved, so that the reaction is carried out stably in the easily controlled state, and the explosion danger is avoided; and the polymer and the solvent are simple and convenient to separate, and the yield is high.

Description

technical field [0001] The invention relates to a solution polymerization method of fluororubber, in particular to a new process of copolymerizing nitrosotrifluoromethane, tetrafluoroethylene and nitrosoperfluorobutyric acid into carboxynitrosofluororubber, which belongs to organic fluorine field of chemical technology. Background technique [0002] Carboxyl-nitroso fluororubber (Caboxyl-Nitroso Rubber, referred to as CNR) is composed of nitrosotrifluoromethane (one monomer), tetrafluoroethylene (two monomers), nitroso perfluorobutyric acid (three monomers) The three monomers are terpolymerized at low temperature to obtain raw rubber, and then vulcanized and cross-linked to become an elastomer (rubber). Half of the main chain of the CNR polymer is a carbon-carbon bond (-C-C-), the other half is a nitrogen-oxygen bond (-N-O-), and the carbon atoms are all connected to fluorine atoms, which has good chemical stability; the main chain has a large number of The nitrogen-oxygen...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G73/24
Inventor 杨晓勇周楠吴勇黎爽徐亭罗凯沈佶邓清田宋升
Owner CHINA BLUESTAR CHENGRAND CO LTD
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