WO2001014430A1 - Method for stabilizing fluorocopolymers - Google Patents
Method for stabilizing fluorocopolymers Download PDFInfo
- Publication number
- WO2001014430A1 WO2001014430A1 PCT/JP2000/005674 JP0005674W WO0114430A1 WO 2001014430 A1 WO2001014430 A1 WO 2001014430A1 JP 0005674 W JP0005674 W JP 0005674W WO 0114430 A1 WO0114430 A1 WO 0114430A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- copolymer
- fluorine
- stabilizing
- reheating
- fluorinated
- Prior art date
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
- C08F6/00—Post-polymerisation treatments
- C08F6/001—Removal of residual monomers by physical means
- C08F6/005—Removal of residual monomers by physical means from solid polymers
-
- 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
- C08F8/00—Chemical modification by after-treatment
- C08F8/50—Partial depolymerisation
-
- 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
- C08F214/00—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 a halogen
- C08F214/18—Monomers containing fluorine
- C08F214/26—Tetrafluoroethene
- C08F214/262—Tetrafluoroethene with fluorinated vinyl ethers
-
- 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
- C08F2800/00—Copolymer characterised by the proportions of the comonomers expressed
- C08F2800/20—Copolymer characterised by the proportions of the comonomers expressed as weight or mass percentages
-
- 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
- C08F2810/00—Chemical modification of a polymer
- C08F2810/10—Chemical modification of a polymer including a reactive processing step which leads, inter alia, to morphological and/or rheological modifications, e.g. visbreaking
Definitions
- the present invention relates to a method for stabilizing a fluorine-containing copolymer, and more particularly to a method for improving the thermal stability of a melt-processable fluorine-containing copolymer.
- a final product is produced from an emulsion copolymer of tetrafluoroethylene and hexafluoropropylene by a solution method
- bubbles or voids due to volatile substances may be generated in the final product.
- This volatile material is generated due to polymer ends and polymer backbone which are unstable to heat and Z or shear forces.
- volatile substances remain in the processed polymer, and bubbles and voids may be generated when processed into a final product as described above.
- Japanese Unexamined Patent Publication No. 56-444883 discloses that after melt processing, tetrafluoroethylene-hexafluoropropylene copolymerization is carried out under open conditions, specifically in an electric furnace. Disclosed is a method for reducing the volatile content of the copolymer to 70% or less of the initial volatile content by heating the body while standing on a dish or a net. However, when processing under open conditions, it is inevitable that foreign matter is mixed in during the heating operation. In addition, the volatile content can be reduced by standing and heating.However, if the filling thickness of the copolymer is increased, the processing time is prolonged due to the influence of the diffusion of the volatile content, and the processing in the packed layer is not performed. Larger dishes or nets are required for non-uniform and thinner fills, which requires larger equipment.
- An object of the present invention is to provide a method capable of efficiently reducing the volatile content of a melt-processable fluorine-containing copolymer which has been heated and melted without using a large-sized apparatus, while avoiding contamination of foreign substances. It is to be.
- the above object is achieved by heating and melting a melt-processable fluorine-containing copolymer and then reheating the fluorine-containing copolymer in a closed container in a non-stationary state.
- This is achieved by a method for stabilizing a fluorine-containing copolymer, which reduces the volatile content of the fluorocopolymer to 30% or less of the initial volatile content.
- volatile content in this specification refers to the weight of the copolymer lost when the dried copolymer is heated at 380 ° C for 30 minutes under an absolute pressure of about 1 OmmHg, Of the dry copolymer to the weight of the dry copolymer (%).
- the melt-processable fluorine-containing copolymer to be subjected to the method of the present invention may be any of the conventionally known melt-processable fluorine-containing copolymers.
- TFE tetrafluoroethylene
- HFP xafluoropropylene
- E perfluoroalkyl butyl ether
- VdF vinylidene fluoride
- the HFP content is 8-25 weight 0 /.
- Per full O b alkyl Bulle ether Honoré content 0-5 wt 0/0 der Ru T FE- HF P- Pas one full O b vinyl ether copolymer may be preferably examples shown.
- perfluoroalkylbier ether is preferably of the formula:
- the melt-processable fluorine-containing copolymer is produced from the above-mentioned monomer by emulsion polymerization or suspension polymerization.
- these polymers may be a tetrafluoroethylene-hexafluoropropylene copolymer (FEP), a TFE-perfluorovinylether copolymer (PFA), or a TFE-HFP-perfluoroalkylalkyl copolymer.
- FEP tetrafluoroethylene-hexafluoropropylene copolymer
- PFA TFE-perfluorovinylether copolymer
- TFE-HFP-perfluoroalkylalkyl copolymer a tetrafluoroethylene-hexafluoropropylene copolymer
- the copolymer is preferably 0.1 to! It has a melt viscosity of O OkPas.
- the fluorine-containing copolymer is heated and melted at a temperature of 360 to 430 ° C. for 10 minutes or less, and then the melting point of the fluorine-containing copolymer is increased from 130 ° C. , Preferably in the range of 150 ° C. to the melting point of the fluorine-containing copolymer.
- the first-stage heating may be heating using an extruder, or may be heating performed by standing still on a plate in an electric furnace in which measures are taken to prevent foreign substances from being mixed.
- the processing temperature in the first step is lower than 360 ° C, unstable components at the terminal and main chain of the copolymer are not sufficiently stabilized, and the second step of reheating treatment reduces the volatile matter content. Even when dissolved in the final product, foaming may occur.
- the heating temperature at this time is lower than 130 ° C., not only the treatment time is increased, but also the volatile matter content cannot be sufficiently reduced.
- hot air having a superficial velocity in the apparatus of 0.8 mZs or less, preferably 0.05 to 0.5 m / s, is used as a heating source, or hot air under the above conditions. And heat transfer from the device wall.
- the copolymer floats and mixes under the influence of the hot air flow and pressure when the copolymer is continuously charged and discharged. Therefore, it is difficult to perform an operation to obtain a copolymer containing a uniform volatile component.
- the apparatus used in the method of the present invention is not an open type, but an apparatus that can be hermetically closed at the time of treatment, and may be a vertical tower or a horizontal apparatus.
- the term "closed container” means a batch type, even if it is a continuous type, in which the atmosphere inside the container does not come into direct contact with the external atmosphere during the heat treatment, and the Except for the part that enters and exits the body, it means a device that can introduce only air in which the number of foreign particles and the maximum diameter of the foreign material are controlled by a filter or the like into the device.
- the internal atmosphere is always completely external You do not need to be isolated from
- non-stationary state excludes a case where the copolymer is left standing and heated in a container such as a dish.
- a container such as a dish
- the state of the moving layer in which the particles of the copolymer form a packed layer inside the container and move continuously in the apparatus according to the charging speed and finally discharged out of the apparatus In the case of a batch type, the copolymer is forcibly suspended and fluidized by a stirrer or the like.
- the equipment used for reheating may be a batch type or a continuous type, but by continuously charging and discharging the copolymer, the temperature distribution and the distribution of the volatile matter reduction rate are controlled within a relatively narrow range.
- a fluorinated copolymer free from foaming can be produced stably.
- a moving bed type apparatus in which the fluorocopolymer is charged from the upper part, heated while moving from the upper part to the lower part by gravity, and discharged from the lower part to make it flow is advantageous. It is.
- a stirrer such as a hot air dryer or a conductive heat transfer dryer.
- a device that continuously cools the fluorocopolymer is installed, and it can be cooled to a temperature below the temperature at which it can be finally filled and shipped, specifically to 60 ° C or less. It is.
- volatile content refers to the weight of the copolymer lost when the dried copolymer is heated at 380 ° C. for 30 minutes under an absolute pressure of about 1 O mmHg, before heating. Copolymer Expressed as a percentage (%) based on the weight.
- the presence or absence of foreign matter is determined by molding a ⁇ 12 Omm disc-shaped sheet having a thickness of about 3 mm at 370 ° C and visually checking the sheet for the presence of foreign matter.
- TFE-HFP-perfluoropropyl butyl ether fluorocopolymer prepared by suspension polymerization was used.
- this copolymer After washing and drying this copolymer, it was extruded at a temperature of 370 ° C. and a residence time of 2 minutes by a single screw extruder having an inner diameter of 95 mm and a cylinder of L ⁇ D30.
- the extruded fluorinated copolymer was pelletized by a pelletizer, continuously charged into a moving bed designed to have a residence time of 5 hours at 200 ° C, and reheated. After removing foreign matter through a filter (3m particles cut 99.97%), hot air was continuously supplied to the reheating device as a heating source at a superficial velocity of 0.35 m / s.
- the height of the reheating device is 365 Omm and the inside diameter is 85 Omm.
- a cone-shaped punching metal is installed at the bottom of the device to separate the hot air inlet from the moving bed and facilitate the discharge of pellets.
- Pellets continuously discharged from the reheating device are continuously charged into the cooling device
- the volatiles content of the pellets recovered from the chiller was 0.23% by weight, which was 26% of the initial volatiles content (0.88% by weight). No foaming was observed in the foaming test, and no foreign matter was included.
- Example 1 the pellets collected after extrusion and before reheating had a volatile content of 0.
- Example 2 the pellet collected after extrusion and before reheating was allowed to stand at a thickness of about 20 mm on a dish in an electric furnace, and reheated at 200 ° C for 5 hours.
- the volatile matter content after reheating was 0.31% by weight, which was reduced to 35% of the initial volatile matter content, and no foaming occurred in the foaming test.
- foreign substances were mixed in from the outside, and a plurality of black foreign substances were visually observed.
- Example 2 The same fluorinated copolymer as specified in Example 1 was subjected to a single-screw extruder having a cylinder with an inner diameter of 95 mm and an LZD of 30 at a temperature of 375 ° C and a residence time of 2 minutes. Extruded. The extruded pellets are transported by air through a filter (39.9 particles cut 99.7%) to prevent direct contact with the outside, and have a residence time of 1.5 hours at 235 ° C. The moving bed designed so as to be continuously charged was continuously charged, and reheated by hot air in the same manner as in Example 1.
- the pellets discharged from the extruder had a volatiles content of 0.14% by weight, which was 16% of the initial volatiles content. No foaming was observed in the foaming test.
- Example 2 the volatile content of the pellets collected after extrusion and before reheating was 0.68% by weight, and foaming occurred in the foaming test.
- Example 2 the pellet collected after extrusion and before reheating was allowed to stand at a thickness of about 15 Omm on a dish in an electric furnace, and reheated at 235 ° C for 1.5 hours.
- the volatile content of the upper part of the deposited pellet (part from the surface of the pellet deposited layer to a depth of 25 mm) was 0.18% by weight, and no foaming was observed in the foaming test.
- the volatile content of the lower part close to the dish (the part of O 3 mm from the surface of the dish) is 0. It was 41% by weight, and decreased only to 47% of the initial volatile matter content, and foaming was observed in the foaming test. This is because the pellet layer filled on the plate was thick, and the effect of volatiles could not be ignored, and the volatiles could not be reduced sufficiently at the bottom of the plate.
- Comparative Example 2 foreign matter was mixed in from the outside during the reheating stage in the electric furnace, and a plurality of foreign matters were visually confirmed. Foreign matter was found not only in the upper layer but also in the lower layer.
- the pellets extruded in the same manner as in Example 2 were continuously charged into a moving bed in a vertical cylindrical container designed to have a residence time of 24 hours at 120 ° C and reheated. Was.
- the hot air was passed through a filter (99.97% cut of 3111 particles) and then continuously supplied as a heating source to the cylindrical vessel at a superficial velocity of 0.4 O m / s.
- the volatile content of the pellets discharged from the cylindrical container was 0.56% by weight, which was reduced to only 64% of the initial volatile content, and foaming was observed in the foaming test.
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP00954959A EP1227110B1 (en) | 1999-08-25 | 2000-08-24 | Method for stabilizing fluorocopolymers |
DE60025734T DE60025734T2 (de) | 1999-08-25 | 2000-08-24 | Verfahren zur stabilisierung von fluorcopolymeren |
US10/069,345 US6846904B1 (en) | 1999-08-25 | 2000-08-24 | Method for stabilizing fluorocopolymers |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11/238250 | 1999-08-25 | ||
JP23825099A JP4449111B2 (ja) | 1999-08-25 | 1999-08-25 | 含フッ素共重合体の安定化方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2001014430A1 true WO2001014430A1 (en) | 2001-03-01 |
Family
ID=17027392
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2000/005674 WO2001014430A1 (en) | 1999-08-25 | 2000-08-24 | Method for stabilizing fluorocopolymers |
Country Status (6)
Country | Link |
---|---|
US (1) | US6846904B1 (ja) |
EP (1) | EP1227110B1 (ja) |
JP (1) | JP4449111B2 (ja) |
CN (1) | CN1176954C (ja) |
DE (1) | DE60025734T2 (ja) |
WO (1) | WO2001014430A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002050135A1 (fr) * | 2000-12-21 | 2002-06-27 | Daikin Industries, Ltd. | Procede de pretraitement de stabilisation destine a un polymere contenant du fluor |
US6846904B1 (en) * | 1999-08-25 | 2005-01-25 | Daikin Industries, Ltd. | Method for stabilizing fluorocopolymers |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6743508B2 (en) * | 2002-01-17 | 2004-06-01 | Daikin America, Inc. | Fep pellet |
US7423087B2 (en) * | 2004-04-30 | 2008-09-09 | E.I. Du Pont De Nemours And Company | Reduced fuming fluoropolymer |
JP5332617B2 (ja) * | 2006-12-08 | 2013-11-06 | ダイキン工業株式会社 | フルオロモノマーの回収方法 |
EP3112397A1 (en) * | 2011-07-05 | 2017-01-04 | Asahi Glass Company, Limited | Treatment method for fluororesin pellets |
EP3323839B1 (en) * | 2015-07-14 | 2020-11-11 | Daikin Industries, Ltd. | Fluororesin and molded article |
JP7476802B2 (ja) * | 2018-12-27 | 2024-05-01 | Agc株式会社 | 粒子の製造方法および成形体の製造方法 |
WO2022181842A1 (ja) | 2021-02-26 | 2022-09-01 | ダイキン工業株式会社 | 含フッ素共重合体 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4578455A (en) * | 1983-03-24 | 1986-03-25 | Basf Aktiengesellschaft | Process and apparatus for removing volatile constituents from polymer melts or pastes |
CA1248292A (en) * | 1984-05-10 | 1989-01-03 | Marlin D. Buckmaster | Melt-processible tetrafluoroethylene copolymers and processes for preparing them |
JPH08239420A (ja) * | 1995-03-06 | 1996-09-17 | Mitsubishi Gas Chem Co Inc | 重合反応生成物の精製方法 |
EP0764668A1 (en) * | 1995-09-22 | 1997-03-26 | Dupont-Mitsui Fluorochemicals Co., Ltd. | Method of manufacturing modified polytetrafluoroethylene fine powder |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5644883B2 (ja) | 1974-02-26 | 1981-10-22 | ||
US4420449A (en) * | 1982-04-19 | 1983-12-13 | Synergistics Chemicals Limited | Process for producing articles from polytetrafluoroethylene |
US4576857A (en) * | 1983-03-14 | 1986-03-18 | E. I. Du Pont De Nemours And Company | Melt-fusible polyimides |
US5235995A (en) * | 1989-03-27 | 1993-08-17 | Semitool, Inc. | Semiconductor processor apparatus with dynamic wafer vapor treatment and particulate volatilization |
US5534592A (en) * | 1995-09-22 | 1996-07-09 | The Goodyear Tire & Rubber Company | High performance blend for tire treads |
JP3852136B2 (ja) | 1996-09-09 | 2006-11-29 | ダイキン工業株式会社 | 含フッ素重合体の安定化方法 |
JP4449111B2 (ja) * | 1999-08-25 | 2010-04-14 | ダイキン工業株式会社 | 含フッ素共重合体の安定化方法 |
US6476181B1 (en) * | 2001-06-01 | 2002-11-05 | E. I. Du Pont De Nemours And Company | Increased volatile removal during solid phase processing of nylon 6 by temperature programming |
-
1999
- 1999-08-25 JP JP23825099A patent/JP4449111B2/ja not_active Expired - Lifetime
-
2000
- 2000-08-24 DE DE60025734T patent/DE60025734T2/de not_active Expired - Fee Related
- 2000-08-24 US US10/069,345 patent/US6846904B1/en not_active Expired - Lifetime
- 2000-08-24 WO PCT/JP2000/005674 patent/WO2001014430A1/ja active IP Right Grant
- 2000-08-24 CN CNB008120129A patent/CN1176954C/zh not_active Expired - Lifetime
- 2000-08-24 EP EP00954959A patent/EP1227110B1/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4578455A (en) * | 1983-03-24 | 1986-03-25 | Basf Aktiengesellschaft | Process and apparatus for removing volatile constituents from polymer melts or pastes |
CA1248292A (en) * | 1984-05-10 | 1989-01-03 | Marlin D. Buckmaster | Melt-processible tetrafluoroethylene copolymers and processes for preparing them |
JPH08239420A (ja) * | 1995-03-06 | 1996-09-17 | Mitsubishi Gas Chem Co Inc | 重合反応生成物の精製方法 |
EP0764668A1 (en) * | 1995-09-22 | 1997-03-26 | Dupont-Mitsui Fluorochemicals Co., Ltd. | Method of manufacturing modified polytetrafluoroethylene fine powder |
Non-Patent Citations (1)
Title |
---|
See also references of EP1227110A4 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6846904B1 (en) * | 1999-08-25 | 2005-01-25 | Daikin Industries, Ltd. | Method for stabilizing fluorocopolymers |
WO2002050135A1 (fr) * | 2000-12-21 | 2002-06-27 | Daikin Industries, Ltd. | Procede de pretraitement de stabilisation destine a un polymere contenant du fluor |
Also Published As
Publication number | Publication date |
---|---|
EP1227110B1 (en) | 2006-01-25 |
EP1227110A4 (en) | 2003-05-07 |
EP1227110A1 (en) | 2002-07-31 |
CN1371393A (zh) | 2002-09-25 |
JP4449111B2 (ja) | 2010-04-14 |
JP2001064317A (ja) | 2001-03-13 |
CN1176954C (zh) | 2004-11-24 |
US6846904B1 (en) | 2005-01-25 |
DE60025734T2 (de) | 2006-11-09 |
DE60025734D1 (de) | 2006-04-13 |
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