CN108219053B - Polytetrafluoroethylene resin for thin-wall heat exchanger tube and preparation method thereof - Google Patents
Polytetrafluoroethylene resin for thin-wall heat exchanger tube and preparation method thereof Download PDFInfo
- Publication number
- CN108219053B CN108219053B CN201711455640.1A CN201711455640A CN108219053B CN 108219053 B CN108219053 B CN 108219053B CN 201711455640 A CN201711455640 A CN 201711455640A CN 108219053 B CN108219053 B CN 108219053B
- Authority
- CN
- China
- Prior art keywords
- monomer
- deionized water
- resin
- polymerization
- reaction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F216/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical
- C08F216/12—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical by an ether radical
- C08F216/14—Monomers containing only one unsaturated aliphatic radical
- C08F216/1408—Monomers containing halogen
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/12—Polymerisation in non-solvents
- C08F2/16—Aqueous medium
- C08F2/22—Emulsion polymerisation
- C08F2/24—Emulsion polymerisation with the aid of emulsifying agents
- C08F2/28—Emulsion polymerisation with the aid of emulsifying agents cationic
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Polymerisation Methods In General (AREA)
Abstract
The invention provides a polytetrafluoroethylene resin for processing thin-wall heat exchange tubes and a preparation method thereof, wherein a dispersing agent, an emulsion stabilizer and a pH value regulator are added into a water phase, then a tetrafluoroethylene monomer and an initial modified monomer are introduced, a peroxide initiator is added for copolymerization, when the feeding amount of a polymerized monomer reaches 60-80% of the total feeding amount, a second modified monomer is added, the tetrafluoroethylene monomer is continuously added, the reaction pressure polymerization is maintained, and the polytetrafluoroethylene resin is prepared by discharging, coagulating and drying the emulsion after the polymerization is finished. The resin polymerized by the method is suitable for being processed into a thin-wall heat exchange tube by a paste extrusion process, and the prepared heat exchange tube has good thermal stability, high bending life and good steam permeability resistance.
Description
Technical Field
The invention belongs to the field of macromolecules, and relates to polytetrafluoroethylene dispersion resin and a preparation method thereof.
Background
The polytetrafluoroethylene heat exchanger is a tube type heat exchanger, and the material of a heat exchange tube of the polytetrafluoroethylene heat exchanger is polytetrafluoroethylene. Compared with metal and other nonmetal heat exchangers, the fluoroplastic pipe heat exchanger has excellent anti-corrosion property in a strong acid environment and can be used for a long time; under different engineering application conditions, the method has no special requirements on smoke components and has strong applicability; under different engineering application conditions, no special requirements are required on the wall temperature and the acid dew point, and no corrosion condition exists; the material has the advantages of self-cleaning property, anti-sticking property, easy cleaning and the like. The polytetrafluoroethylene thin-walled tube heat exchanger is suitable for the fields of deep recovery of flue gas waste heat, improvement of desulfurization efficiency, wet dust removal, chimney whitening elimination and the like in thermal power plants, waste incineration and the like, and is a key point of attention in the field of environmental protection at present.
In order to make the polytetrafluoroethylene heat exchange tube suitable for the above working conditions, it is required to have good thermal stability, low vapor permeability and good bending resistance. However, conventional PTFE has a linear and regularly rigid polymer chain structure, and therefore has a high crystallinity and a high melt viscosity, and thus has problems such as a large void ratio in the product and poor bending resistance.
Chinese patent CN101328235A describes a method for preparing dispersion modified polytetrafluoroethylene by adding as little perfluoropropyl vinyl ether as possible, which has good properties and high yield.
Chinese patent CN102344519A describes a method for producing modified polytetrafluoroethylene dispersion resin suitable for processing capillary tubes. In the method, perfluoropropyl vinyl ether is added as a modifier, and difluoromethane is added as a chain transfer agent to obtain the polytetrafluoroethylene dispersion resin with the compression ratio of 1600: 1.
U.S. Pat. No. 4,182,6802 discloses a process for the preparation of tetrafluoroethylene fine powder resin by emulsion polymerization using perfluoropropyl vinyl ether as a modifier, a core of a relatively large amount of modified monomer polymerized with tetrafluoroethylene, and a shell of a relatively small amount of modified monomer polymerized with tetrafluoroethylene, wherein the total content of the modified monomer is about 0.06%. The resin can be paste-extruded at a high compression ratio.
Chinese patent CN106866866A discloses a preparation method of polytetrafluoroethylene dispersion resin for extruded tubes, which prepares polytetrafluoroethylene dispersion resin with a core-shell structure by controlling polymerization reaction pressure, and improves the paste extrusion performance of the resin.
However, none of the above techniques effectively improves the thermal stability, low vapor permeability and bending resistance of the polytetrafluoroethylene resin for heat exchanger tubes.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the polytetrafluoroethylene resin for the thin-wall heat exchanger tube and the preparation method thereof, the resin has a core-shell structure, different modified monomers are added in different polymerization stages, so that irregular groups are added on macromolecular chain links, the highly linear structure of PTFE is damaged, the PTFE is converted from a rigid chain to a flexible chain, the bending resistance is improved, the melt viscosity of an ion shell is reduced, the primary ion sintering is better during processing, and the porosity is reduced.
The technical scheme of the invention is as follows:
a polytetrafluoroethylene resin for thin-walled heat exchanger tubes, the resin being prepared by a process comprising the steps of:
adding a dispersing agent, an emulsion stabilizer, a pH value regulator and a peroxide initiator into a water phase, stirring to form an oil-in-water type fine dispersion, introducing a tetrafluoroethylene monomer and an initial modified monomer for copolymerization, adding a second modified monomer for continuous polymerization after the feeding amount of the tetrafluoroethylene monomer reaches 25-37.5% of the feeding amount of water, and discharging, coagulating and drying the emulsion after the polymerization is finished to obtain the polytetrafluoroethylene dispersion resin; the resin properties include: standard relative density SSG: 2.155-2.165, the thermal instability index TII is less than 5, and the tensile porosity index SVI is less than 60; the initial modifier is one or more of perfluoromethyl vinyl ether, perfluoroethyl vinyl ether and perfluoropropyl vinyl ether, and the second modifying monomer is hexafluoropropylene.
According to the invention, the amount of the initial modifier is 0.10 to 0.35 percent, preferably 0.12 to 0.23 percent, based on the weight of the deionized water in the polymerization system.
According to the invention, the second modifier is used in an amount of 0.02 to 0.10%, preferably 0.03 to 0.07%, by weight of the deionized water in the polymerization system.
According to the invention, the dispersant is one of ammonium perfluorooctanoate, perfluoro or fluoropolyether carboxylate, perfluoro or fluoroalkyl carboxylate; preferably, the perfluoro or fluoroalkyl carboxylic acid salt is perfluoroalkyl ammonium carboxylate or fluoroalkyl ammonium carboxylate; the dosage of the dispersant is 0.1 to 10 percent of the weight of the deionized water in the polymerization system.
According to the invention, the peroxide initiator is an organic peroxide, preferably benzoyl peroxide or succinic acid peroxide; the dosage of the organic initiator is 0.005-0.05 percent of the weight of the deionized water in the polymerization system, and preferably 0.01-0.03 percent.
According to the invention, the pH value regulator is succinic acid, and the addition amount of the succinic acid is 0.05-1% of the mass of the deionized water. The emulsion stabilizer is solid paraffin or saturated hydrocarbon with more than 12 carbon atoms, and preferably the solid paraffin or purified paraffin; the dosage of the stabilizer is 2.0-8.0% of the mass of the deionized water, and preferably 3.0-6.0%.
According to the invention, the tetrafluoroethylene monomer is a high-purity tetrafluoroethylene monomer, and the purity of the tetrafluoroethylene monomer is higher than 99.999%;
according to the invention, the deionized water is high-purity deionized water, and the resistivity of the deionized water is higher than 15M omega.CM;
according to the invention, the polymerization reaction temperature is controlled to be 60-90 ℃; preferably 70-85 ℃;
according to the invention, the polymerization reaction time is 3.5-4 h;
according to the invention, the oxygen content in the polymerization reaction must be lower than 30ppm, and when the polymerization reaction is carried out until the solid content of the emulsion is 25-35%, preferably 30%, stirring is stopped, the gas-phase monomer is recovered, and evacuation and discharge are carried out.
A preparation method of polytetrafluoroethylene resin for a thin-wall heat exchanger tube comprises the following steps: 1) adding deionized water, a dispersing agent and a stabilizing agent into a closed reaction kettle to form a liquid phase, replacing air in the reaction kettle with nitrogen, and adding an initial modifying agent into the reaction kettle when the oxygen content in the reaction kettle is less than 30 ppm; 2) raising the temperature of the reaction kettle to 60-90 ℃, adding a gas-phase tetrafluoroethylene monomer until the pressure in the reaction kettle is 2.0-2.8 MPa, adding an initiator, and starting a polymerization reaction; carrying out polymerization reaction until the input amount of the gas-phase tetrafluoroethylene monomer is 25-37.5% of the weight of the deionized water, and recovering the gas-phase monomer until the pressure in the reaction kettle is 0-0.1 Mpa; 3) adding a certain amount of second modifier into the gas-phase tetrafluoroethylene monomer again to perform polymerization reaction; the polymerization reaction is carried out until the input amount of the gas-phase tetrafluoroethylene monomer is 40 to 50 percent of the weight of the deionized water, and the reaction is finished; controlling the pressure to be 2.0-3.0 MPa during the reaction period in the process; 4) recovering the gas-phase monomer, cooling and discharging to obtain polytetrafluoroethylene polymerization liquid; 5) coagulating, cleaning and drying the polytetrafluoroethylene polymer solution obtained in the step 4) to obtain the polytetrafluoroethylene dispersion resin.
According to the invention, preferably, the input amount of the gas phase tetrafluoroethylene monomer in the step 2) is 30-34% of the weight of the deionized water; recovering the gas-phase monomer until the pressure in the reaction kettle is 0.05 Mpa; step 3), the input amount of the tetrafluoroethylene monomer is 43-48% of the weight of the deionized water; the pressure is controlled to be 2.2-2.8 MPa during the reaction period.
According to the present invention, it is preferable that the initiator is added during the reaction in step 3) and step 4) as appropriate according to the change of the polymerization rate, and the number of times of addition is determined according to the reaction rate.
According to the invention, the resin or the resin prepared by the preparation method is used for processing thin-wall heat exchange tubes.
The invention has the beneficial effects that:
according to the invention, through process design, the polytetrafluoroethylene resin with the core-shell structure is provided, and different modified monomers are added at different stages in the polymerization reaction, so that the highly linear macromolecular structure of PTFE is destroyed, the PTFE macromolecules are converted from a rigid chain to a flexible chain, the bending resistance of the PTFE is improved, the melt viscosity of an ion shell is reduced, the primary ion sintering during processing is better, and the porosity is reduced. Resin properties include SSG (standard relative density): 2.155-2.165, TII representing thermal stability < 5, SVI representing low porosity < 60. The resin polymerized by the method is suitable for being processed into a thin-wall heat exchange tube by a paste extrusion process, and the prepared heat exchange tube has good thermal stability, high bending life and good steam permeability resistance.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
The present invention is illustrated by the following examples, which are not intended to limit the scope of the invention.
Example 1:
cleaning a 2000L stainless steel high-pressure reaction kettle equipped with a stirring and temperature control system (circularly heating and circularly cooling water), adding 1400L deionized water, 60kg paraffin wax, 1300g succinic acid and 6000ml of 30 percent (by weight) ammonium perfluorooctanoate solution, stirring at 20 r/min, vacuumizing, charging nitrogen for three times until the oxygen content is below 30ppm, vacuumizing to-0.098 Mpa, introducing 2100 g perfluoropropyl vinyl ether into the reaction kettle, adjusting the temperature control system to control the temperature in the polymerization kettle to be 70 ℃, increasing the rotating speed to be 45 r/min, continuously introducing tetrafluoroethylene monomer, keeping the internal pressure of the reaction kettle to be 2.8Mpa, simultaneously adding 180g succinic acid peroxide as an initiator, starting the reaction, controlling the temperature in the polymerization kettle to be 85 ℃ by using the temperature control system in the reaction process, and recovering gas-phase monomer to the reaction kettle to be 0.05Mpa when the input amount of the tetrafluoroethylene monomer is 420kg, introducing 700g of hexafluoropropylene, continuing to introduce the tetrafluoroethylene monomer, keeping the internal pressure of the reaction kettle at 1.6Mpa, reacting for 3.5 hours, stopping continuously adding the tetrafluoroethylene monomer after the monomer is added to reach 630kg, continuing to react until the internal pressure of the kettle is 0.1Mpa, stopping reacting, discharging, condensing and drying the emulsion to obtain 583kg of modified polytetrafluoroethylene resin. The resins were tested for SSG, TII and SVI using the methods described in ASTM D4895.
Example 2:
cleaning a 2000L stainless steel high-pressure reaction kettle equipped with a stirring and temperature control system (circulating heating and circulating cooling water), adding 1300L deionized water, 60kg paraffin, 900g succinic acid, 30% (weight percent) H (CF)2CF2)3COONH48000ml of solution is stirred to 20 r/min and vacuumized, nitrogen is filled for three times for replacement until the oxygen content is below 30ppm, then the solution is vacuumized to-0.098 Mpa, 2300 g of perfluoropropyl vinyl ether is introduced into the reaction kettle, a temperature control system is adjusted to control the temperature in the polymerization kettle to be 75 ℃, the rotating speed is increased to 45 r/min, the tetrafluoroethylene monomer is continuously introduced, the internal pressure of the reaction kettle is kept to be 2.6Mpa, 210g of succinic acid peroxide as an initiator is added for starting the reaction, the temperature in the polymerization kettle is controlled to be 80 ℃ by the temperature control system in the reaction process, the gas-phase monomer is recovered until the input amount of the tetrafluoroethylene monomer is 440kg, the pressure in the reaction kettle is 0.05Mpa, 600g of hexafluoropropylene is introduced, the tetrafluoroethylene monomer is continuously introduced, the internal pressure in the reaction kettle is kept to be 1.8Mpa, the addition of the tetrafluoroethylene monomer is stopped after the input amount of the tetrafluoroethylene monomer reaches 650kg, the reaction was continued until the pressure in the kettle became 0.1Mpa, and 583kg of modified polytetrafluoroethylene resin was obtained after discharging, coagulation and drying of the emulsion. The resins were tested for SSG, TII and SVI using the methods described in ASTM D4895.
Example 3:
cleaning a 2000L stainless steel high-pressure reaction kettle equipped with a stirring and temperature control system (circularly heating and circularly cooling water), adding 1400L deionized water, 60kg paraffin wax, 1200g succinic acid and 12000ml of 30 percent (weight percentage) ammonium perfluorooctanoate solution, stirring for 20 r/min, vacuumizing, charging nitrogen for three times for replacement until the oxygen content is below 30ppm, vacuumizing to-0.098 Mpa, introducing 1800 g perfluoropropyl vinyl ether into the reaction kettle, adjusting the temperature control system to control the temperature in the polymerization kettle to be 75 ℃, increasing the rotating speed to be 45 r/min, continuously introducing a tetrafluoroethylene monomer, keeping the internal pressure of the reaction kettle to be 2.1Mpa, simultaneously adding 310g succinic peroxide as an initiator to start the reaction, controlling the temperature in the polymerization kettle to be 80 ℃ by using the temperature control system during the reaction, recovering a gas-phase monomer to the reaction kettle to be 0.05Mpa when the input amount of the tetrafluoroethylene monomer is 520kg, and (3) after 870g of hexafluoropropylene is introduced, continuing introducing the tetrafluoroethylene monomer, keeping the internal pressure of the reaction kettle at 1.8Mpa, reacting for 3.7 hours, stopping continuously adding the tetrafluoroethylene monomer after the monomer is added to reach 670kg, continuing to react until the internal pressure of the kettle is 0.1Mpa, stopping reacting, and discharging, condensing and drying the emulsion to obtain 612kg of modified polytetrafluoroethylene resin. The resins were tested for SSG, TII and SVI using the methods described in ASTM D4895.
Table 1 determination of the physical and mechanical properties and processability of polytetrafluoroethylene resins:
Claims (12)
1. the polytetrafluoroethylene resin for processing the thin-wall heat exchange tube is characterized by comprising the following steps: adding a dispersing agent, an emulsion stabilizer and a pH value regulator into a water phase which uses deionized water as a raw material, then introducing a tetrafluoroethylene monomer and an initial modified monomer, adding a peroxide initiator for copolymerization, adding a second modified monomer when the feed amount of the tetrafluoroethylene monomer reaches 25-37.5% of the feed amount of water, continuing adding the tetrafluoroethylene monomer, maintaining reaction pressure for polymerization, and discharging, condensing and drying the emulsion after polymerization to obtain the polytetrafluoroethylene dispersion resin;
the resin properties include: standard relative density SSG: 2.155-2.165, the thermal instability index TII is less than 5, and the tensile porosity index SVI is less than 60;
the initial modified monomer is one or more of perfluoromethyl vinyl ether, perfluoroethyl vinyl ether and perfluoropropyl vinyl ether; the second modified monomer is hexafluoropropylene;
the pH value regulator is succinic acid, and the addition amount of the succinic acid is 0.05-1% of the mass of the deionized water.
2. The resin of claim 1, wherein the initial modifying monomer is present in an amount of from 0.10% to 0.35% by weight of the deionized water in the polymerization system; the dosage of the second modified monomer is 0.02-0.10% of the weight of the deionized water in the polymerization system.
3. The resin of claim 2, wherein the initial modifying monomer is present in an amount of from 0.12% to 0.23% by weight of the deionized water in the polymerization system; the dosage of the second modified monomer is 0.03-0.07% of the weight of the deionized water in the polymerization system.
4. The resin of claim 1, wherein the dispersant is a fluoropolyether carboxylate or a fluoroalkyl carboxylate; the dosage of the dispersant is 0.1 to 10 percent of the weight of the deionized water in the polymerization system.
5. The resin of claim 1, wherein the peroxide initiator is benzoyl peroxide or succinic acid peroxide; the dosage of the peroxide initiator is 0.005-0.05 percent of the weight of the deionized water in the polymerization system.
6. The resin of claim 1 wherein the peroxide initiator is present in an amount of from 0.01% to 0.03% by weight of the deionized water present in the polymerization system.
7. The resin according to claim 1, wherein the emulsion stabilizer is paraffin wax or a saturated hydrocarbon having more than 12 carbon atoms; the dosage of the emulsion stabilizer is 2.0-8.0% of the mass of the deionized water.
8. The resin of claim 1, wherein said tetrafluoroethylene monomer is a high purity tetrafluoroethylene monomer having a purity of greater than 99.999%; the deionized water is high-purity deionized water, and the resistivity of the deionized water is higher than 15M omega.CM.
9. The process for producing a polytetrafluoroethylene resin according to any one of claims 1-8, comprising the steps of:
1) adding deionized water, a dispersing agent, an emulsion stabilizer and a pH value regulator into a closed reaction kettle to form a liquid phase, replacing air in the reaction kettle with nitrogen, and adding an initial modified monomer into the reaction kettle when the oxygen content in the reaction kettle is less than 30 ppm;
2) raising the temperature of the reaction kettle to 60-90 ℃, adding a gas-phase tetrafluoroethylene monomer until the pressure in the reaction kettle is 2.0-2.8 MPa, adding an initiator, and starting a polymerization reaction; carrying out polymerization reaction until the input amount of the gas-phase tetrafluoroethylene monomer is 25-37.5% of the weight of the deionized water, and recovering the gas-phase monomer until the pressure in the reaction kettle is 0-0.1 MPa;
3) adding a certain amount of second modified monomer, and adding a gas-phase tetrafluoroethylene monomer again for polymerization reaction; the polymerization reaction is carried out until the input amount of the gas-phase tetrafluoroethylene monomer is 40 to 50 percent of the weight of the deionized water, and the reaction is finished; controlling the pressure to be 2.0-3.0 MPa during the reaction period in the process;
4) recovering the gas-phase monomer, cooling and discharging to obtain polytetrafluoroethylene polymerization liquid;
5) coagulating, cleaning and drying the polytetrafluoroethylene polymer solution obtained in the step 4) to obtain the polytetrafluoroethylene dispersion resin.
10. The method for preparing polytetrafluoroethylene resin according to claim 9, wherein said polymerization temperature in step 2) is controlled at 70-85 ℃; the polymerization reaction time in the step 3) is 3.5-4 h.
11. The method for producing a polytetrafluoroethylene resin according to claim 9, wherein: step 2), the input amount of the gas phase tetrafluoroethylene monomer is 30-34% of the weight of the deionized water; recovering the gas-phase monomer until the pressure in the reaction kettle is 0.05 MPa; step 3), the input amount of the tetrafluoroethylene monomer is 43-48% of the weight of the deionized water; the pressure is controlled to be 2.2-2.8 MPa during the reaction period.
12. Use of the resin according to any one of claims 1 to 8 or of the resin obtained by the preparation process according to any one of claims 9 to 11 for the manufacture of thin-walled heat exchange tubes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711455640.1A CN108219053B (en) | 2017-12-28 | 2017-12-28 | Polytetrafluoroethylene resin for thin-wall heat exchanger tube and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711455640.1A CN108219053B (en) | 2017-12-28 | 2017-12-28 | Polytetrafluoroethylene resin for thin-wall heat exchanger tube and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108219053A CN108219053A (en) | 2018-06-29 |
| CN108219053B true CN108219053B (en) | 2020-11-10 |
Family
ID=62649227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711455640.1A Active CN108219053B (en) | 2017-12-28 | 2017-12-28 | Polytetrafluoroethylene resin for thin-wall heat exchanger tube and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108219053B (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102086243B (en) * | 2010-12-01 | 2012-08-08 | 中昊晨光化工研究院 | Method for preparing high-gloss PTFE (Polytetrafluoroethylene) dispersion concentrated solution |
| CN103665240B (en) * | 2013-12-11 | 2015-09-30 | 中昊晨光化工研究院有限公司 | The preparation method of polytetrafluoroethyldispersion dispersion resin |
| CN104311717B (en) * | 2014-11-17 | 2016-05-25 | 中昊晨光化工研究院有限公司 | A kind of preparation method and products therefrom that squeezes effective polytetrafluoroethyldispersion dispersion resin |
-
2017
- 2017-12-28 CN CN201711455640.1A patent/CN108219053B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN108219053A (en) | 2018-06-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5883157B2 (en) | Low temperature fluorine-containing elastomer and method for producing the same | |
| RU2478654C2 (en) | Method of producing fine polytetrafluorethylene powder | |
| JP5881269B2 (en) | Fluoroethercarboxylic acid and method for producing the same, surfactant, method for producing fluoropolymer using the same, and aqueous dispersion | |
| JP5983633B2 (en) | Method for producing polytetrafluoroethylene fine powder | |
| US20150183946A1 (en) | Process for producing fluorinated copolymer | |
| US9624329B2 (en) | Process for producing fluorinated copolymer | |
| WO2009142080A1 (en) | Method for producing polytetrafluoroethylene fine powder | |
| CN111040058A (en) | Process for producing aqueous polytetrafluoroethylene dispersion | |
| US20100029878A1 (en) | Method for producing fluoropolymer using fluorocarboxylic acid compound | |
| US20180201708A1 (en) | Fluororesin and method for its production | |
| EP3950748A1 (en) | Method for producing fluorine-containing polymer, aqueous dispersion liquid, and fluorine-containing polymer composition | |
| EP2162388B2 (en) | Process for removing fluorinated compounds from an aqueous phase originating from the preparation of fluoropolymers | |
| CN108219053B (en) | Polytetrafluoroethylene resin for thin-wall heat exchanger tube and preparation method thereof | |
| CN111057178B (en) | Preparation method of low-pressure-change fluorine-containing elastomer | |
| CN103665238B (en) | A kind of synthetic method of fluorubber of wide-molecular weight distribution | |
| JP2010229164A (en) | Fluoropolymer production method | |
| CN102344519A (en) | Production method of modified polytetrafluoroethylene dispersion resin suitable for processing capillary tubes | |
| CN101230118B (en) | Production method of high molecular weight polytetrafluoroethylene dispersion resin suitable for processing biaxial stretching film | |
| CN112300314B (en) | Tetrafluoroethylene modified fluororubber and preparation method thereof | |
| JP2009029724A (en) | Carboxylic acid derivative, method for producing carboxylic acid derivative | |
| CN106008783A (en) | Modified polytetrafluoroethylene resin | |
| US10611859B2 (en) | Process for producing fluorinated polymer | |
| CN115678180B (en) | Preparation method of high-impact polyvinyl chloride | |
| JPS6129366B2 (en) | ||
| CN117510698A (en) | Reactive fluorine-containing surfactant, and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |