CN111057178B - Preparation method of low-pressure-change fluorine-containing elastomer - Google Patents
Preparation method of low-pressure-change fluorine-containing elastomer Download PDFInfo
- Publication number
- CN111057178B CN111057178B CN201911417577.1A CN201911417577A CN111057178B CN 111057178 B CN111057178 B CN 111057178B CN 201911417577 A CN201911417577 A CN 201911417577A CN 111057178 B CN111057178 B CN 111057178B
- Authority
- CN
- China
- Prior art keywords
- low
- pressure
- preparation
- fluorine
- 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
- 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
- C08F214/22—Vinylidene fluoride
- C08F214/222—Vinylidene fluoride 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
- 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
- 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
- C08F214/28—Hexyfluoropropene
- C08F214/282—Hexyfluoropropene 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
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The invention belongs to the field of high polymer materials, and particularly relates to a preparation method of a low-pressure-change fluorine-containing elastomer. The preparation method comprises the following steps: (1) adding deionized water, an emulsifier and a pH regulator into a reaction kettle, heating to 70-90 ℃, starting to add the blending monomer, stopping adding the blending monomer after the pressure in the reaction kettle reaches 1.5-2.5MPa, and adding an initiator to start polymerization; (2) in the reaction process, adding iodine-containing olefin, simultaneously supplementing a blending monomer to maintain the pressure in the reaction kettle to be 1.5-2.5MPa, and stopping the reaction until the specific gravity of the polymer emulsion is 1.11-1.15; (3) and after the polymer emulsion is cooled, coagulating, washing, drying, plasticating and molding to obtain the low-pressure-change fluorine-containing elastomer. The fluorine-containing elastomer prepared by the invention has the advantages of better vulcanization performance and smaller compression deformation.
Description
Technical Field
The invention belongs to the field of high polymer materials, and particularly relates to a preparation method of a low-pressure-change fluorine-containing elastomer.
Background
Due to excellent heat resistance, liquid resistance and oil resistance, and good physical and mechanical properties, electrical insulation and radiation resistance, the fluorine elastomer is widely applied to the fields of aviation, aerospace, automobiles, petrochemical industry and the like. In particular, peroxide-cured fluoroelastomers have been attracting attention in recent years because of their low curing temperature and their excellent resistance to acid media and water vapor media.
World patent WO2008050588, published in 2008, provides a fluoroelastomer for fuels, and compositions thereof. The fluorine-containing elastic die pressing product contains iodine end capping, 10-40% of tetrafluoroethylene, 80-30% of vinylidene fluoride, 10-30% of hexafluoropropylene, 20-180mL/g of intrinsic viscosity, 2-20 of distribution coefficient, excellent die pressing performance, excellent chemical stability, excellent thermal stability and excellent economic benefit.
Chinese patent No. cn201080015457.x published in 2010 provides a fluoroelastomer mixture that provides a molded article having low hardness and excellent low fuel permeability while maintaining the cold resistance of a cold-resistant fluororubber, a composition for peroxide vulcanization containing the fluoroelastomer mixture, and a molded article obtained from the composition for peroxide vulcanization. The technical scheme is realized by blending two fluorine-containing elastomers, wherein one fluorine-containing elastomer contains a vulcanization point monomer, and the fluorine content of the other fluorine-containing elastomer is 70%.
US20100068436, published in 2010, provides a fluoroelastomer for molded fuel system components and compositions thereof, having good moldability, cure properties, chemical stability, thermal stability and economy. The technical scheme is characterized in that the end capping is carried out by TFE (mass fraction is 10-40%), VDP (mass fraction is 80-30%), HFP 10-30% and RBrnIm. Intrinsic viscosity 20-180mL/g, Mw/Mn2-20, molecular weight distribution unimodal or multimodal.
Chinese patent CN201310293100.3 published in 2013, which adopts alkyl iodide RIx added with chain transfer agent to prepare peroxide vulcanized fluororubber, has lower crosslinking temperature.
The above method, in which the C-I bond is only at the end of the polymerized long chain, results in a low crosslink density and a large compression set of the fluoroelastomer.
In the chinese patent No. cn201410777750.x published in 2014, it is mentioned that the peroxide-vulcanized fluororubber product obtained by the preparation method of the peroxide-vulcanized fluororubber can be vulcanized by using peroxide, so as to reduce the crosslinking temperature and greatly improve the permanent compression deformation performance after the hot air aging. The invention adopts the method of adding a vulcanization point monomer, wherein the vulcanization point monomer is vinyl bromide, 1-difluoro-2-vinyl bromide, acrylonitrile or 3-butenenitrile, so as to realize peroxide vulcanization.
The technology of the patent adopts bromine-containing olefin, and the obtained product has low vulcanization speed and large compression deformation.
Bromotrifluoroethylene, iodotrifluoroethylene, and combinations thereof are used as cure site monomers in the CN200380108604.8 patent.
CN1138797C A peroxide curable fluoroelastomer capable of producing a cured product having outstanding heat resistance properties using iodine as a crosslinking site and having the general formula I-R-I wherein R is a divalent fluorocarbon group of 2 to 8 carbon atoms and 2, 2-difluoroiodoethylene.
In the two patents, a single vulcanization point monomer chain is short, and a single vulcanization point monomer contains two iodine atoms, so that a net structure is easily generated in the polymerization process, and the viscosity of the elastomer is increased.
US5225504 uses a general formula of XF2 ═ CFO [ CF2CF (CF3) O ] m (CF2) nX where X is bromine or iodine, the structural chain length is too long, stability during polymerization is poor, and the product affects vulcanization.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the method overcomes the technical problems in the prior art, and provides the method for preparing the low-pressure-change fluorine-containing elastomer, and the prepared low-pressure-change fluorine-containing elastomer has the advantages of low compression deformation rate and good vulcanization performance.
The preparation method of the low-pressure-change fluorine-containing elastomer comprises the following steps of:
(1) adding deionized water, an emulsifier and a pH regulator into a reaction kettle, heating to 70-90 ℃, starting to add the blending monomer, stopping adding the blending monomer after the pressure in the reaction kettle reaches 1.5-2.5MPa, and adding an initiator to start polymerization;
(2) in the reaction process, adding iodine-containing olefin, simultaneously supplementing a blending monomer to maintain the pressure in the reaction kettle to be 1.5-2.5MPa, and stopping the reaction until the specific gravity of the polymer emulsion is 1.11-1.15;
(3) and after the polymer emulsion is cooled, coagulating, washing, drying, plasticating and molding to obtain the low-pressure-change fluorine-containing elastomer.
The blending monomer is prepared from the following raw materials in percentage by weight: 20-60% of vinylidene fluoride, 10-50% of tetrafluoroethylene, 0-50% of hexafluoropropylene and 0-30% of perfluoroalkyl ether.
The dosage of the iodine-containing olefin is 1-3wt% of the blending monomer.
The iodine-containing olefin is RfI, wherein Rf is fluorine-containing or non-fluorine-containing olefin. Preferably, the olefin containing iodine is C3F5I、C3H5I、C4F7I、C4H7I、C5F9I、C5H9I、C6F11I、C6H11I、C7F13I or C7H13One or two of I. More preferably, the iodoolefin is C3F5I、C4F7I or C5F9One or two of I.
The dosage of the emulsifier is 0.1-2wt% of the deionized water.
The dosage of the initiator is 0.01 to 0.05 weight percent of the blending monomer, and the initiator is persulfate or persulfate-bisulfite.
The dosage of the pH regulator is 0.01-0.5wt% of deionized water, and the pH regulator is borax, disodium hydrogen phosphate or dipotassium hydrogen phosphate.
The polymerization reaction temperature is 70-110 ℃, and the polymerization reaction time is 3-10 hours.
And (3) carrying out performance test on the prepared low-pressure-change fluorine-containing elastomer:
the Mooney viscosity value is more than 30 and less than 100 when measured at 121 ℃.
The resulting fluoroelastomer can be crosslinked by a peroxide, and the crosslinking agent is preferably an organic peroxide such as 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane or dicumyl peroxide. Vulcanizing agent, accelerant or filler can be added in the cross-linking process for cross-linking.
Compared with the prior art, the invention has the following beneficial effects:
compared with the prior peroxide vulcanized fluorine-containing elastomer, the fluorine-containing elastomer prepared by the invention has the advantages of lower compression deformation rate and better vulcanization performance.
Detailed Description
The present invention will be further described with reference to the following examples.
The starting materials used in the examples are all commercially available except where otherwise indicated.
Vinylidene fluoride, VDF.
Tetrafluoroethylene, TFE.
Hexafluoropropylene, HFP.
Perfluoroalkyl ethers, PMVE.
Example 1
According to VDF: TFE: HFP: PMVE 50: 15: 25: 10 wt% to prepare the blending monomer for polymerization.
6L of deionized water is added into a 10L polymerization reaction kettle to serve as a reaction medium, 9.5g of disodium hydrogen phosphate serves as a pH regulator, 10g of ammonium perfluorooctanoate serves as an emulsifier, and the lower the gas phase oxygen content of the polymerization kettle is, the better the gas phase oxygen content is, the lower the gas phase oxygen content is, at least 20ppm below. After the oxygen content is qualified, the temperature of the polymerization kettle is raised to 80 ℃, the mixed monomer is added into the reaction kettle, and the pressure of the reaction kettle is kept at 2.2 MPa. 20g of potassium persulfate was added to the reactor to initiate polymerization, and the mixed monomer was continuously fed into the reactor to maintain a constant pressure reaction. 60gC is added in the reaction process3F6And (I) monomers. After the polymerization reaction is carried out for 5 hours, the specific gravity of the polymer emulsion is 1.13, after the polymerization is finished, the reactants are condensed, washed and dried after being cooled, and finally plasticated and molded by an open mill to obtain the product of the invention.
The product of the invention is added with vulcanizing agent 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, accelerant triallyl isocyanurate and filler carbon black N990, and then is crosslinked at 150 ℃.
The determination shows that the compression deformation (200 ℃ for 48h) of the crosslinked fluorine elastomer of the product is 13 percent, and the tensile strength is 23.7 MPa.
Example 2
The other conditions were the same as in example 1 except that the blending monomer was VDF: TFE: PMVE 60: 20: 20 (wt%); 50g C was added during the reaction4H7I; the polymerization temperature is 90 ℃, the polymerization pressure is 2.1MPa, the polymerization time is 3h, and the specific gravity of the polymer emulsion is 1.12.
The determination shows that the compression deformation (200 ℃ for 48h) of the crosslinked fluorine elastomer of the product is 15 percent, and the tensile strength is 22.3 MPa.
Example 3
Other conditions were the same as in example 1 except thatCharacterized in that the blending monomer used is VDF: TFE: HFP 60: 10: 30 (wt%); 30g C was added during the reaction3H5I; the polymerization temperature is 85 ℃, the polymerization pressure is 2.0MPa, the polymerization time is 4h, and the specific gravity of the polymer emulsion is 1.11.
The determination shows that the compression deformation (200 ℃ for 48h) of the crosslinked fluorine elastomer of the product is 17 percent, and the tensile strength is 21.9 MPa.
Example 4
The other conditions were the same as in example 1 except that the blending monomer was VDF: TFE: HFP 60: 15: 25 (wt%); 40g C was added during the reaction5F9I; the polymerization temperature is 85 ℃, the polymerization pressure is 2.0MPa, the polymerization time is 4h, and the specific gravity of the polymer emulsion is 1.15.
The determination shows that the compression deformation (200 ℃ for 48h) of the crosslinked fluorine elastomer of the product is 15 percent, and the tensile strength is 20.4 MPa.
Comparative example 1
The other conditions were the same as in example 1 except that the blending monomer was VDF: TFE: HFP: PMVE 50: 15: 25: 10 (wt%); the polymerization temperature is 85 ℃, the polymerization pressure is 2.0MPa, and the polymerization time is 4 h. The product is added with vulcanizing agent bisphenol AF, accelerator benzyl triphenyl phosphorus chloride, acid-absorbing agent magnesium oxide, calcium hydroxide and filler carbon black N990, and then is crosslinked at 170 ℃.
The compression set (200 ℃ C. 48h) of the crosslinked fluoroelastomer was found to be 40% and the tensile strength was found to be 13.6 MPa.
Comparative example 2
The other conditions were the same as in example 1 except that the blending monomer was VDF: TFE: PMVE 65: 20: 15 (wt%); the polymerization temperature is 90 ℃, the polymerization pressure is 2.1MPa, and the polymerization time is 3 h. The product is added with vulcanizing agent bisphenol AF, accelerator benzyl triphenyl phosphorus chloride, acid-absorbing agent magnesium oxide, calcium hydroxide and filler carbon black N990, and then is crosslinked at 170 ℃.
The compression set (200 ℃ C. 48h) of the crosslinked fluoroelastomer was found to be 35% and the tensile strength was found to be 14.2 MPa.
The starting materials and test conditions for examples 1-4 and comparative examples 1-2 are shown in Table 1.
TABLE 1 raw materials and test cases for examples 1-4 and comparative examples 1-2
Of course, the foregoing is only a preferred embodiment of the invention and should not be taken as limiting the scope of the embodiments of the invention. The present invention is not limited to the above examples, and equivalent changes and modifications made by those skilled in the art within the spirit and scope of the present invention should be construed as being included in the scope of the present invention.
Claims (6)
1. A preparation method of low-pressure-change fluorine-containing elastomer is characterized by comprising the following steps: the method comprises the following steps:
(1) adding deionized water, an emulsifier and a pH regulator into a reaction kettle, heating to 70-90 ℃, starting to add the blending monomer, stopping adding the blending monomer after the pressure in the reaction kettle reaches 1.5-2.5MPa, and adding an initiator to start polymerization;
(2) in the reaction process, adding iodine-containing olefin, simultaneously supplementing a blending monomer to maintain the pressure in the reaction kettle to be 1.5-2.5MPa, and stopping the reaction until the specific gravity of the polymer emulsion is 1.11-1.15;
(3) after the polymer emulsion is cooled, coagulating, washing, drying and plasticating to obtain the low-pressure-change fluorine-containing elastomer;
the blending monomer is prepared from the following raw materials in percentage by weight: 50% of vinylidene fluoride, 15% of tetrafluoroethylene, 25% of hexafluoropropylene and 10% of perfluoromethyl vinyl ether;
the olefin containing iodine is C3F5I。
2. The process for the preparation of a low-rheology fluoroelastomer according to claim 1, characterized in that: the dosage of the iodine-containing olefin is 1-3wt% of the blending monomer.
3. The process for the preparation of a low-rheology fluoroelastomer according to claim 1, characterized in that: the dosage of the emulsifier is 0.1-2wt% of the deionized water.
4. The process for the preparation of a low-rheology fluoroelastomer according to claim 1, characterized in that: the dosage of the initiator is 0.01 to 0.05 weight percent of the blending monomer, and the initiator is persulfate or persulfate-bisulfite.
5. The process for the preparation of a low-rheology fluoroelastomer according to claim 1, characterized in that: the dosage of the pH regulator is 0.01-0.5wt% of deionized water, and the pH regulator is borax, disodium hydrogen phosphate or dipotassium hydrogen phosphate.
6. The process for the preparation of a low-rheology fluoroelastomer according to claim 1, characterized in that: the polymerization reaction temperature is 70-110 ℃, and the polymerization reaction time is 3-10 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911417577.1A CN111057178B (en) | 2019-12-31 | 2019-12-31 | Preparation method of low-pressure-change fluorine-containing elastomer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911417577.1A CN111057178B (en) | 2019-12-31 | 2019-12-31 | Preparation method of low-pressure-change fluorine-containing elastomer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111057178A CN111057178A (en) | 2020-04-24 |
| CN111057178B true CN111057178B (en) | 2022-03-29 |
Family
ID=70305821
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911417577.1A Active CN111057178B (en) | 2019-12-31 | 2019-12-31 | Preparation method of low-pressure-change fluorine-containing elastomer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111057178B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115725016B (en) * | 2021-08-31 | 2024-05-14 | 中昊晨光化工研究院有限公司 | Ether modified fluororubber and preparation method thereof |
| CN115466344B (en) * | 2022-09-21 | 2023-12-12 | 四川道弘新材料有限公司 | Transparent peroxyfluororubber intelligent wearing material and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55108410A (en) * | 1979-02-14 | 1980-08-20 | Daikin Ind Ltd | Fluorine-containing polymer and composition thereof |
| CN1422285A (en) * | 2000-02-17 | 2003-06-04 | 杜邦唐弹性体公司 | Process for producing fluoroelastomers |
| CN1464885A (en) * | 2000-09-22 | 2003-12-31 | 杜邦唐弹性体公司 | Process for producing fluoroelastomers |
| CN1665852A (en) * | 2002-07-11 | 2005-09-07 | 杜邦唐弹性体公司 | Peroxide curable fluoroelastomers |
| CN106317290A (en) * | 2015-07-08 | 2017-01-11 | 中昊晨光化工研究院有限公司 | Perfluoroether elastomer and preparation method thereof |
-
2019
- 2019-12-31 CN CN201911417577.1A patent/CN111057178B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55108410A (en) * | 1979-02-14 | 1980-08-20 | Daikin Ind Ltd | Fluorine-containing polymer and composition thereof |
| CN1422285A (en) * | 2000-02-17 | 2003-06-04 | 杜邦唐弹性体公司 | Process for producing fluoroelastomers |
| CN1464885A (en) * | 2000-09-22 | 2003-12-31 | 杜邦唐弹性体公司 | Process for producing fluoroelastomers |
| CN1665852A (en) * | 2002-07-11 | 2005-09-07 | 杜邦唐弹性体公司 | Peroxide curable fluoroelastomers |
| CN106317290A (en) * | 2015-07-08 | 2017-01-11 | 中昊晨光化工研究院有限公司 | Perfluoroether elastomer and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111057178A (en) | 2020-04-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111057178B (en) | Preparation method of low-pressure-change fluorine-containing elastomer | |
| JP2015500377A (en) | Low temperature fluorine-containing elastomer and method for producing the same | |
| KR20190130135A (en) | Process for preparing aqueous latex comprising particles of fluoropolymer | |
| CN110713564A (en) | Wide-temperature-range perfluoroether rubber and synthesis method thereof | |
| WO1999036473A1 (en) | Fluororesin composition | |
| CN114106495A (en) | Modified perfluoroether fluororubber and preparation method and application thereof | |
| CN104558364A (en) | Fluoroelastomer and preparation method thereof | |
| CN115677936A (en) | Preparation method of perfluoropolymer emulsion, perfluoroelastomer and preparation method of perfluoroelastomer | |
| CN115368495B (en) | Perfluoroether elastomer and preparation method and application thereof | |
| US20140308468A1 (en) | Tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer having an increased melting temperature | |
| CN108017746B (en) | Peroxide vulcanized fluororubber with low compression set and preparation method thereof | |
| JP2008231330A (en) | Radiation-crosslinked fluorine-containing copolymer | |
| JP2008231331A (en) | Radiation-crosslinked fluorine-containing copolymer | |
| US10144792B2 (en) | Method for producing electric wire, method for producing molded artile, and method for producing resin material containing modified fluororesin | |
| CN109715718A (en) | Fluoroelastomer composition | |
| CN116162199A (en) | Fluororubber raw rubber and preparation method thereof | |
| CN114230737B (en) | Perfluoro ether fluororubber and preparation method and application thereof | |
| CN110627942B (en) | Fluorine-containing thermoplastic elastomer, preparation method and application thereof | |
| CN115725016B (en) | Ether modified fluororubber and preparation method thereof | |
| CN111072839B (en) | Large-crosslinking-density rapidly-vulcanized fluorine-containing elastomer and preparation method thereof | |
| KR100899134B1 (en) | Perfluoro-elastomer and manufacturing method with improved resistance to plasma | |
| RO110509B1 (en) | Fluor elastomer copolymers which are vulcanized with ions | |
| CN111057189B (en) | Fluorine-containing polymer and method for producing same | |
| CN113861328A (en) | Peroxide vulcanized fluororubber with low compression deformation and preparation method thereof | |
| EP3592788B1 (en) | Fluorinated thermoplastic elastomers |
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 |