CN109529906B - Catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and preparation method thereof - Google Patents
Catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and preparation method thereof Download PDFInfo
- Publication number
- CN109529906B CN109529906B CN201811588779.8A CN201811588779A CN109529906B CN 109529906 B CN109529906 B CN 109529906B CN 201811588779 A CN201811588779 A CN 201811588779A CN 109529906 B CN109529906 B CN 109529906B
- Authority
- CN
- China
- Prior art keywords
- catalyst
- cobalt
- methyl ether
- nitrogen
- synthesizing
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/24—Nitrogen compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/082—Decomposition and pyrolysis
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
- C07C41/01—Preparation of ethers
- C07C41/05—Preparation of ethers by addition of compounds to unsaturated compounds
- C07C41/06—Preparation of ethers by addition of compounds to unsaturated compounds by addition of organic compounds only
Abstract
The invention discloses a catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and a preparation method thereof. The catalyst consists of a carrier and cobalt-nitrogen doped carbon, wherein the carrier is carbon powder or Ce-Al2O3The cobalt-nitrogen doped carbon is generated by high-temperature in-situ pyrolysis of cobalt phthalocyanine in a nitrogen atmosphere, wherein the mass of the cobalt element is 1-9% of the total mass of the catalyst. The preparation method comprises the steps of placing cobalt phthalocyanine, a carrier and an auxiliary agent in a ball mill for full ball milling, and then roasting for 1-10 hours at the temperature of 400-1000 ℃ in a nitrogen atmosphere. The catalyst is applied to the reaction of catalytically synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether, has high catalytic activity and product selectivity, is simple and environment-friendly in preparation method, is easy to separate, can be recycled and has good industrial application prospect.
Description
Technical Field
The invention relates to a catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and a preparation method thereof, belonging to the field of catalysts.
Background
With the development of technology, the integration level of electronic products is higher and higher, and in order to ensure stable functions and long service life, it is extremely important to clean the electronic products efficiently. The CFC (CFC-113) cleaning agent is generally used in the past in the electronic industry, but is forbidden at present due to the serious destructive effect on the ozone layer and the strong greenhouse effect. The substitute HCFC (HCFC-141b, HCFC-225) cleaning agent is about to be eliminated and limited due to higher Ozone Depletion Potential (ODP) and Global Warming Potential (GWP) and longer atmospheric residence time. Hydrofluoroether series cleaning agents have good cleaning ability, good material compatibility, an ODP value of 0, a low GWP value and a short atmospheric lifetime, and are therefore commonly recognized by the environmental protection agency of the United states and Europe as an ideal alternative to HCFC cleaning agents. 1,1,2,3,3, 3-hexafluoropropyl methyl ether is one of the series of hydrofluoroethers, and the synthesis thereof has been studied in large quantities at home and abroad in recent years, but there are few reports in the literature.
US 20030209685a1 discloses a process for the synthesis of 1,1,2,3,3, 3-hexafluoropropyl methyl ether starting from hexafluoropropene and methanol using 45% by mass KOH solution as catalyst, which process gives a high yield (85%) of 1,1,2,3,3, 3-hexafluoropropyl methyl ether, but is not ideal and has the following major disadvantages: the KOH solution with high concentration has stronger corrosivity and is easy to corrode equipment; the strong base is used as a homogeneous catalyst, is not easy to separate and difficult to recycle, and moreover, the generated waste alkali can cause serious environmental pollution; in addition, the content of the generated heavy components is also high (9%), so that the further refining is difficult, and the product quality is difficult to ensure. Japanese scientists have also reported a method for the synthesis of 1,1,2,3,3, 3-hexafluoropropyl methyl ether (Angew. chem. int. Ed.2005,44,1128-3)4As a catalyst, the experimental result shows that the yield of the 1,1,2,3,3, 3-hexafluoropropyl methyl ether by adopting the method can reach 83 percent,although the method avoids the use of strong base and cannot cause the problem of environmental pollution, the noble metal Pd is used as the catalyst, the cost of the catalyst is higher, and the homogeneous Pd catalyst is not easy to separate and difficult to recycle, so that the preparation cost of the 1,1,2,3,3, 3-hexafluoropropyl methyl ether is higher.
The method has the problems of equipment corrosion, serious environmental pollution, high catalyst cost, difficult product quality guarantee and the like.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides the catalyst for synthesizing the 1,1,2,3,3, 3-hexafluoropropyl methyl ether and the preparation method thereof, wherein the catalyst has the advantages of no corrosion to equipment, environmental protection and no pollution, low cost, easy separation, high catalytic activity and high selectivity.
The catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether consists of a carrier and cobalt-nitrogen doped carbon, wherein the carrier is carbon powder or Ce-Al2O3In one of the catalyst, the cobalt-nitrogen doped carbon is generated by high-temperature in-situ pyrolysis of cobalt phthalocyanine in a nitrogen atmosphere, wherein the mass of the cobalt element is 1-9% of the total mass of the catalyst.
Preferably, the carrier is Ce-Al2O3。
Preferably, the mass of the cobalt element is 5-9% of the total mass of the catalyst.
The invention also provides a preparation method of the catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether, which comprises the following steps:
(1) adding cobalt phthalocyanine, a carrier and an auxiliary agent into a ball-milling tank filled with zirconium beads respectively, wherein the auxiliary agent is a nitrogen-containing compound, the mass of cobalt element is 1% -9% of the total mass of the catalyst, the molar ratio of the cobalt phthalocyanine to the auxiliary agent is 1: 1-5, mixing, and placing the mixture into a ball mill for full ball milling for 0.5-12 h;
(2) and (2) roasting the mixture obtained in the step (1) in a nitrogen atmosphere furnace at 400-1000 ℃ for 1-10 h to obtain the catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether.
Preferably, the auxiliary agent in the step (1) is one or more of urea, 1, 10-phenanthroline, dicyanodiamine and melamine.
Preferably, the molar ratio of the cobalt phthalocyanine to the auxiliary in the step (1) is 1: 2-5.
Preferably, the ball milling time in the step (1) is 0.5-8 h.
Preferably, the roasting temperature in the step (2) is 500-900 ℃, and the roasting time is 2-6 h.
The catalyst is suitable for the reaction of synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether by hexafluoropropylene and methanol. After the reaction, the catalyst may be separated from the reaction mixture by centrifugation, standing, decantation, or the like.
Compared with the prior art, the catalyst provided by the invention has the following advantages:
(1) different from the traditional KOH or noble metal Pd catalyst, the catalyst has no corrosion to equipment, is cheap and easy to obtain, does not pollute the environment, does not use any organic solvent in the preparation process of the catalyst, and belongs to a cheap, green and environment-friendly catalyst;
(2) the catalyst exists in a catalytic system in a solid form, the separation and recovery of the catalyst can be realized by a simple solid-liquid separation means after the reaction is finished, and the catalyst does not have metal precipitation, so that the product quality is higher;
(3) the catalyst is used for catalyzing and synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether, the product selectivity is high, and the selectivity of 1,1,2,3,3, 3-hexafluoropropyl methyl ether is as high as 99.9%.
Detailed Description
The following description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical solutions and their inventive concepts equally or alternatively within the technical scope of the present invention.
The carbon powder related by the invention is VXC-72R which is purchased from Shanghai Kainen chemical Co.
Ce-Al relating to the invention2O3The preparation method can be referred to in int.J.Hydrogen Energy.2016,41,10473-10482.
Example 1
Preparation of catalyst with cobalt element content of 1%
Respectively adding 1g of cobalt phthalocyanine, 8.58g of carbon powder and 0.42g of urea into a ball milling tank filled with zirconium beads, then fully milling for 2 hours in a ball mill, then placing the obtained mixture in a nitrogen atmosphere furnace, roasting for 10 hours at the temperature of 600 ℃, naturally cooling to room temperature, and then taking out to obtain the synthetic 1,1,2,3,3, 3-hexafluoropropyl methyl ether catalyst C1.
Example 2
Preparation of catalyst with cobalt element content of 9%
9g of cobalt phthalocyanine and 0.06gCe-Al are respectively added into a ball milling tank filled with zirconium beads2O30.94g of urea, then placing the mixture into a ball mill for full ball milling for 6h, then placing the obtained mixture into a nitrogen atmosphere furnace, roasting the mixture for 8h at the temperature of 700 ℃, naturally cooling the mixture to room temperature, and then taking the mixture out to obtain the synthetic 1,1,2,3,3, 3-hexafluoropropyl methyl ether catalyst C2.
Example 3
Preparation of catalyst with 5% cobalt element content
Respectively adding 5g of cobalt phthalocyanine, 4.26g of carbon powder and 0.74g of dicyandiamide into a ball milling tank filled with zirconium beads, then fully milling for 5 hours in a ball mill, then placing the obtained mixture in a nitrogen atmosphere furnace, roasting for 3 hours at the temperature of 800 ℃, naturally cooling to room temperature, and then taking out to obtain the synthetic 1,1,2,3,3, 3-hexafluoropropyl methyl ether catalyst C3.
Example 4
Preparation of catalyst with cobalt element content of 2%
Respectively adding 2g of cobalt phthalocyanine and 5.8gCe-Al into a ball milling tank filled with zirconium beads2O32.2g of melamine, then placing the melamine in a ball mill for full ball milling for 0.5h, then placing the obtained mixture in a nitrogen atmosphere furnace, roasting the mixture for 6h at the temperature of 900 ℃, naturally cooling the mixture to room temperature, and then taking the mixture out to obtain the synthesized 1,1,2,3,3, 3-hexafluoropropyl methyl ether catalyst C4.
Example 5
Preparation of catalyst with cobalt element content of 6%
Respectively adding 6g of cobalt phthalocyanine, 0.22g of carbon powder, 3.78g of 1 and 10-phenanthroline into a ball milling tank filled with zirconium beads, then fully milling for 12 hours in a ball mill, then placing the obtained mixture into a nitrogen atmosphere furnace, roasting for 9 hours at the temperature of 400 ℃, naturally cooling to room temperature, and taking out to obtain the synthetic 1,1,2,3,3, 3-hexafluoropropyl methyl ether catalyst C5.
Example 6
Preparation of catalyst with cobalt element content of 8%
Adding 8g of cobalt phthalocyanine and 0.23gCe-Al into a ball milling tank filled with zirconium beads2O31.77g of melamine, then placing the melamine in a ball mill for full ball milling for 8h, then placing the obtained mixture in a nitrogen atmosphere furnace, roasting for 1h at the temperature of 1000 ℃, naturally cooling to room temperature, and then taking out to obtain the synthetic 1,1,2,3,3, 3-hexafluoropropyl methyl ether catalyst C6.
The invention relates to an evaluation method of a catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether, which comprises the following steps: sequentially adding a catalyst, methanol and acetonitrile into a stainless steel autoclave with mechanical stirring, electric heating, a thermocouple and pressure display, controlling the stirring speed to be 600r/min, stirring until the mixture is uniformly mixed, heating to 80 ℃, introducing 100g of hexafluoropropylene into the autoclave through a gas mass flow meter, reacting for 10 hours, cooling to room temperature, centrifuging the obtained reaction liquid at high speed in a centrifuge, pouring out a clear liquid, and analyzing by gas chromatography. The catalysts prepared in examples 1 to 6 were evaluated with respect to C1, C2, C3, C4, C5 and C6, respectively. The reaction results are shown in Table 1. Table 1 reaction results.
| Catalyst and process for preparing same | Conversion rate% | Selectivity% |
| C1 | 84.6 | 99.9 |
| C2 | 91.9 | 99.9 |
| C3 | 87.5 | 99.9 |
| C4 | 89.7 | 99.9 |
| C5 | 91.6 | 99.9 |
| C6 | 93.5 | 99.9 |
Claims (2)
1. The catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether is characterized by comprising a carrier and cobalt-nitrogen doped carbon, wherein the carrier is carbon powder or Ce-Al2O3The cobalt-nitrogen doped carbon is generated by high-temperature in-situ pyrolysis of cobalt phthalocyanine and an auxiliary agent in a nitrogen atmosphere, wherein the mass of cobalt element is 1-9% of the total mass of the catalyst, the auxiliary agent is a nitrogen-containing compound, and the nitrogen-containing compound is one or more of urea, 1, 10-phenanthroline, dicyanodiamine and melamine.
2. A preparation method of a catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether comprises the following steps:
(1) to the direction ofAdding cobalt phthalocyanine, a carrier and an auxiliary agent into a ball-milling tank filled with zirconium beads respectively, wherein the auxiliary agent is a nitrogen-containing compound, the mass of cobalt element is 1% -9% of the total mass of the catalyst, the molar ratio of the cobalt phthalocyanine to the auxiliary agent is 1: 1-5, mixing, and placing the mixture into a ball mill for full ball milling for 0.5-12 h; the nitrogen-containing compound is one or more of urea, 1, 10-phenanthroline, dicyanodiamine and melamine, and the carrier is carbon powder or Ce-Al2O3；
(2) And (2) roasting the mixture obtained in the step (1) in a nitrogen atmosphere furnace at 400-1000 ℃ for 1-10 h to obtain the catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811588779.8A CN109529906B (en) | 2018-12-25 | 2018-12-25 | Catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811588779.8A CN109529906B (en) | 2018-12-25 | 2018-12-25 | Catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109529906A CN109529906A (en) | 2019-03-29 |
| CN109529906B true CN109529906B (en) | 2021-06-15 |
Family
ID=65857926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811588779.8A Active CN109529906B (en) | 2018-12-25 | 2018-12-25 | Catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109529906B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3558721A (en) * | 1967-12-22 | 1971-01-26 | Allied Chem | Method for the preparation of fluorinated ethers |
| CN1049670A (en) * | 1989-04-20 | 1991-03-06 | 奥西蒙特公司 | The method for preparing peroxide perfluoropolyethers |
| CN1232444A (en) * | 1996-09-17 | 1999-10-20 | 巴斯福股份公司 | Process for producing n-butylalkyl ethers |
| CN101508625A (en) * | 2009-03-31 | 2009-08-19 | 四川大学 | Method for synthesis of alkyl substituted benzene with direct cross coupling of cobalt salt catalysed fragrant halogen and haloalkane |
| CN101884937A (en) * | 2010-08-17 | 2010-11-17 | 天津久聚能源科技发展有限公司 | Preparation method of carbon supported cobalt phthalocyanine catalytic material |
| CN102489328A (en) * | 2011-12-02 | 2012-06-13 | 东华大学 | Carbon-loaded pyridine-nitrogen-modified cobalt-phthalocyanine catalyst, and preparation method and application thereof |
| CN103739450A (en) * | 2013-12-30 | 2014-04-23 | 山东华夏神舟新材料有限公司 | Preparation method of hydrofluoroether |
| CN106824244A (en) * | 2017-01-24 | 2017-06-13 | 中南民族大学 | A kind of application of nitrogen-doped carbon material parcel Co catalysts in reductive coupling reaction prepares secondary-amine compound |
| CN107051566A (en) * | 2017-03-22 | 2017-08-18 | 湖北大学 | The method that the preparation method of azepine carbon coating cobalt catalyst and unsaturated compound based on above-mentioned catalyst are catalyzed transfer hydrogenation |
| CN107353184A (en) * | 2017-06-19 | 2017-11-17 | 山东东岳化工有限公司 | A kind of method that hydrofluoroether is prepared using 1,1,1,2 HFC-134as as raw material |
-
2018
- 2018-12-25 CN CN201811588779.8A patent/CN109529906B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3558721A (en) * | 1967-12-22 | 1971-01-26 | Allied Chem | Method for the preparation of fluorinated ethers |
| CN1049670A (en) * | 1989-04-20 | 1991-03-06 | 奥西蒙特公司 | The method for preparing peroxide perfluoropolyethers |
| CN1232444A (en) * | 1996-09-17 | 1999-10-20 | 巴斯福股份公司 | Process for producing n-butylalkyl ethers |
| CN101508625A (en) * | 2009-03-31 | 2009-08-19 | 四川大学 | Method for synthesis of alkyl substituted benzene with direct cross coupling of cobalt salt catalysed fragrant halogen and haloalkane |
| CN101884937A (en) * | 2010-08-17 | 2010-11-17 | 天津久聚能源科技发展有限公司 | Preparation method of carbon supported cobalt phthalocyanine catalytic material |
| CN102489328A (en) * | 2011-12-02 | 2012-06-13 | 东华大学 | Carbon-loaded pyridine-nitrogen-modified cobalt-phthalocyanine catalyst, and preparation method and application thereof |
| CN103739450A (en) * | 2013-12-30 | 2014-04-23 | 山东华夏神舟新材料有限公司 | Preparation method of hydrofluoroether |
| CN106824244A (en) * | 2017-01-24 | 2017-06-13 | 中南民族大学 | A kind of application of nitrogen-doped carbon material parcel Co catalysts in reductive coupling reaction prepares secondary-amine compound |
| CN107051566A (en) * | 2017-03-22 | 2017-08-18 | 湖北大学 | The method that the preparation method of azepine carbon coating cobalt catalyst and unsaturated compound based on above-mentioned catalyst are catalyzed transfer hydrogenation |
| CN107353184A (en) * | 2017-06-19 | 2017-11-17 | 山东东岳化工有限公司 | A kind of method that hydrofluoroether is prepared using 1,1,1,2 HFC-134as as raw material |
Non-Patent Citations (3)
| Title |
|---|
| "Cobalt-doped graphitic carbon nitride photocatalysts with high";Pei-Wen Chen;《Applied Surface Science》;20160919;第392卷;第608-615页 * |
| "First-Row Late Transition Metals for Catalytic Alkene Hydrofunctionalisation: Recent Advances in C-N, C-O and C-P Bond Formation";Sophie Bezzenine-Lafollée et al.;《molecules》;20171104;第22卷(第1901期);第1-29页 * |
| "钴基氮掺杂介孔碳材料的合成及其在醇氧化偶联反应中的应用研究";李宁;《万方数据》;20181219;第44页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109529906A (en) | 2019-03-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Sanz et al. | A new approach to the reduction of carbon dioxide: CO2 reduction to formate by transfer hydrogenation in i PrOH | |
| CN109675602B (en) | Supported cobalt-nitrogen doped carbon catalyst and preparation method and application thereof | |
| CN107556186B (en) | A method of adipic acid is prepared by glucaric acid | |
| CN107961797B (en) | Regeneration method of amination catalyst for preparing polyether amine by hydroamination of polyether polyol | |
| CN105777488B (en) | A kind of method that catalysis prepares fatty alcohol | |
| CN106513028B (en) | A kind of catalyst and preparation method thereof and the application in reduction nitro compound | |
| CN101462967A (en) | Method for converting arylamine polyhalide | |
| CN106466640A (en) | The iridium catalyst of efficient cryogenic anti-poison guard catalyst formic acid hydrogen manufacturing and its preparation method and application | |
| CN103664656A (en) | Synthesis and application of quaternary ammonium salt ionic liquid based on heteropolyacid | |
| CN107954833B (en) | Method for preparing 2,2,3,3, 3-pentafluoropropanol | |
| CN114272932B (en) | Nickel-cerium biochar catalyst and preparation method and application thereof | |
| CN102423707A (en) | Preparation method and application method of iron-zirconium composite oxide catalyst | |
| CN101367041A (en) | Preparation of solid base catalyst, uses of the same in hydroxide aldehyde condensation reaction | |
| JP6212221B2 (en) | Process for producing polyoxymethylene dimethyl ether carbonylated product and methyl methoxyacetate | |
| CN105664953B (en) | A kind of catalyst compounded and preparation process and application of urea alcoholysis synthesizing ethylene carbonate | |
| CN109529906B (en) | Catalyst for synthesizing 1,1,2,3,3, 3-hexafluoropropyl methyl ether and preparation method thereof | |
| CN106881121A (en) | A kind of phosphorus doping carbon material hydrogenation catalyst, Its Preparation Method And Use | |
| CN113731441A (en) | Cobalt-reduced graphene oxide Co/rGO catalyst and preparation method and application thereof | |
| CN110054582A (en) | A kind of preparation method of 3- amino-N- ethyl carbazole | |
| CN108299240B (en) | Method for preparing isophorone diisocyanate | |
| CN108424359B (en) | Ruthenium complex in water phase for catalyzing CO2Method for preparing formate/formic acid by hydrogenation reduction | |
| CN112250551A (en) | Method for synthesizing hydrofluoroether by gas phase method | |
| CN101798272A (en) | Method for synthesizing para aminophenylmethylether by catalytic hydrogenation of paranitroanisole | |
| CN115260252B (en) | Synthesis method and application of novel perimidine type complex | |
| CN105457655B (en) | The preparation method of catalyst for preparation of ethanediol by dimethyl oxalate hydrogenation |
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 |