CN104628594B - Preparation method of high-purity methyl hydrazine - Google Patents
Preparation method of high-purity methyl hydrazine Download PDFInfo
- Publication number
- CN104628594B CN104628594B CN201510056062.9A CN201510056062A CN104628594B CN 104628594 B CN104628594 B CN 104628594B CN 201510056062 A CN201510056062 A CN 201510056062A CN 104628594 B CN104628594 B CN 104628594B
- Authority
- CN
- China
- Prior art keywords
- methyl hydrazine
- extractant
- water
- rectifying column
- trifluoroacetic acid
- 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
Abstract
The invention discloses a preparation method of high-purity methyl hydrazine. Aiming at the problems that in the prior art, process safety is poor in the high-purity methyl hydrazine preparation process, product is easy to decompose, turns yellow and is low in purity, and methyl hydrazine contains impurities, in the preparation method disclosed by the invention, ionic liquid and fluorine-containing organic salt constitute a composite extraction agent, high-purity methyl hydrazine is prepared through extractive distillation. The preparation method comprises the following steps of based on 42% methyl hydrazine aqueous solution as a raw material, carrying out extractive distillation on the raw material in a rectifying tower by using the extraction agent, wherein the fraction on the tower top is methyl hydrazine, and the fraction at the tower bottom is a mixture of the extraction agent and water; introducing a material from the bottom of the rectifying tower into a distillation still, separating the mixture of the extracting agent and the water through atmospheric distillation, wherein a distillation still distillate is the water, residual liquid is the extraction agent, and the extraction agent returns to the rectifying tower. The method disclosed by the invention is used for preparing high-purity methyl hydrazine.
Description
Technical field
The invention belongs to the purification technique field of fine chemicals, more particularly to a kind of high-purity methyl hydrazine point
From purification technique.
Background technology
Methyl hydrazine is a kind of critically important hydrazine derivative, is important in the fields such as medication chemistry, biochemical industry and pesticide
Intermediate, the double elements liquid propellant of its oxidant composition such as with dinitrogen tetroxide in national defence, telecommunication satellite, manned flies
The fields of space technology such as ship, space shuttle are widely used.Methyl hydrazine requires that in field of space technology application methyl hydrazine impurity contains
Less than 1%, otherwise impurity reduces can the stability of propellant combustion to amount；Original of the methyl hydrazine as medicine intermediate triazine ring
When requiring that impurity content is less than 0.2% during material, otherwise impurity makes triazine ring yield decline 5%.
87.5 DEG C of boiling point under methyl hydrazine normal pressure, 100 DEG C of boiling point under water normal pressure, both can form maximum azeotrope thing under normal pressure；
The presence of azeotropism causes the separating difficulty of methyl hydrazine and water larger.At present, it is industrially dense using water absorbing agent elder generation absorption quality
The water spent in the methyl hydrazine aqueous solution for 40%, then rectification obtain 98% methyl hydrazine.Chinese patent CN
201310077319.X discloses a kind of method that employing ethylene glycol prepares high-purity methyl hydrazine as water absorbing agent, and the method passes through
Ethylene glycol elder generation absorption quality fraction is water in 40% methyl hydrazine aqueous solution, and the method for then rectification prepares 98% methyl
Hydrazine.In realizing the implementation process of foregoing invention, there are the following problems：(1) water absorbing agent and mass concentration are 40% methyl hydrazine water
Meeting very exothermic when solution mixes so that mixture temperature is drastically raised, decomposition product cause product purity low and turn yellow, and separate
There is potential safety hazard in process, methyl hydrazine decomposes reaction equation is as follows：
2CH3NHNH2+4H2O→4NH3↑+2CH3OH+O2↑
CH3NHNH2→CH3N=NH+H2 ↑
(2) need ethylene glycol as water absorbing agent, ethylene glycol is inevitably entered in methyl hydrazine, which is affected in propellant
The application of aspect；(3) methyl hydrazine purity is only 98%, and the patent is not disclosed impurity composition and its content.
The content of the invention
The defect existed for background technology or deficiency, it is an object of the invention to provide a kind of system of high-purity methyl hydrazine
Preparation Method.The method separation process safety is good, does not result in decomposition product and flavescence, will not add impurities in methyl hydrazine,
Purity is high simultaneously.
Ionic liquid is a kind of new liquid with special nature, is in a liquid state at room temperature, generally by organic sun
Ion and organic or inorganic anion composition.As ionic liquid will not volatilize the characteristic with low-steam pressure so that ionic liquid
Will not enter in product as during extractant.
Salt also has the characteristic that will not be volatilized with low-steam pressure under the conditions of rectification so that during salt distillation, salt will not also enter
Enter in product, but generally salt has the shortcomings that easily crystallization, cause distillation system pipeline blockage, heat transfer property to deteriorate, it is impossible to just
Often operate.
The present invention is dissolved in fluorine-containing organic salt in ionic liquid and constitutes composite extractant, changes the relative of methyl hydrazine and water
Volatility, breaks the azeotropic balance of methyl hydrazine and water, so as to realize the preparation of high-purity methyl hydrazine.
In order to realize above-mentioned technical assignment, the present invention takes following technical scheme to be achieved：A kind of high-purity methyl
The preparation method of hydrazine, it is characterised in that as raw material, the equipment for adopting is rectifying column and distillation to the methyl hydrazine aqueous solution with 42%
Kettle, comprises the following steps：
(1) raw material is separated into rectifying column, with ionic liquid and fluorine-containing organic salt composition composite extractant, extractant
Rectifying column, operating pressure 5kPa～10kPa, 18.96 DEG C～32.94 DEG C of tower top temperature, bottom temperature 51.51 are entered from tower top
DEG C～64.82 DEG C, extractant is 1.5～3 with the mass ratio of raw material：1, overhead fraction is methyl hydrazine, and tower reactor fraction is extractant
With the mixture of water；
(2) material from tower bottom of rectifying tower enters distillating still, divides the mixture of extractant and water by air-distillation
Open, stillage is water, residual liquid is extractant, extractant returns rectifying column.
The cation of the ionic liquid is 1- ethyl-3-methylimidazole cationes, 1- ethyl -3- trifluoromethyl imidazoles sun
Ion, 1- butyl -3- methyl imidazolium cations or 1- butyl -3- trifluoromethyl imidazoles cationes, the anion of ionic liquid is
Tetrafluoroboric acid anion, hexafluorophosphoric acid anion or trifluoroacetic acid anion.
The fluorine-containing organic salt is trifluoroacetic acid lithium, trifluoroacetic acid sodium or trifluoroacetic acid potassium.
In the extractant, the mass fraction of fluorine-containing organic salt is 3%～10%.
The extractant, preferably consists of 1- butyl -3- trifluoromethyl imidazoles Tetrafluoroboric acid ionic liquids and trifluoropropyl
Sour lithium, the wherein mass fraction of trifluoroacetic acid lithium are 5%～7%.
It is an advantage of the current invention that：
(1) present invention avoids the occurrence of the phenomenon of very exothermic in distillation process, and product is not decomposed, prepared high-purity
The water white transparency methyl hydrazine product of degree, and separation process is safe；
(2) present invention adopts ionic liquid and fluorine-containing organic salt as extractant, and extractant will not be entered in methyl hydrazine, first
Other impurity are not detected by base hydrazine, its application in terms of propellant is not affected；
(3) documents CN 201310077319.X methyl hydrazines purity is only 98%, in contrast, the methyl of the present invention
Hydrazine purity is higher, up to 99.9%.
Description of the drawings
Preparation technology flow charts of the Fig. 1 for high-purity methyl hydrazine
Label in accompanying drawing is represented respectively：T, rectifying column, SEP, distillating still, H1, rectifying column condenser, H2, rectifying column are again
Boiling device, S1-S5 are logistics.
The present invention is discussed further with reference to embodiment, but does not limit the scope of the invention.
Specific embodiment
Referring to Fig. 1, according to technical scheme, in below example, (packed tower, tower diameter are Φ to rectifying column T
60mm, built-in 5*5 rustless steels θ ring fillers, bed stuffing height is 0.8m) and distillating still SEP (10L, 316L stainless steel).
Methyl hydrazine-aqueous mixtures logistics S1 enters rectifying column T from middle part, and extractant stream S3 of circulation is from away from tower top filler
Rectifying column is entered at layer 0.1m, logistics S4 of rectifying column T overhead extractions is methyl hydrazine, the extractant of rectifying column T tower reactors extraction
Mixing logistics S2 with water is fed as distillating still SEP；Distillating still SEP distillate flows S5 are water, and raffinate stream S3 is circulation
Extractant.
The detection method of the present invention is as follows：Methyl hydrazine purity is using the gas Chromatographic Determination for being equipped with TCD detectors；Methyl hydrazine
Middle determination of water is determined using Karl_Fischer method；In methyl hydrazine, metallic element adopts Atomic Absorption Spectrometry.
The embodiment that inventor is given is presented herein below, the invention is not restricted to these embodiments.
Embodiment 1：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 5kPa, 18.96 DEG C of tower top temperature, 51.51 DEG C of bottom temperature, extractant are 3 with raw materials quality ratio：1；Distillating still SEP normal pressures
Operation.The composition of extractant such as table 1 below.The mass fraction 94.25% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.92%, logistics S4 is not detected by other impurity.
1 extractant of table is constituted
| Component | Mass fraction/% |
| 1- ethyl-3-methylimidazole tetrafluoroborates | 97 |
| Trifluoroacetic acid sodium | 3 |
Comparative example：
According to the method described in documents CN 201310077319.X, it is 42% by 19kg methyl hydrazines mass fraction
Methyl hydrazine aqueous solution be added in the ethylene glycol that 19kg mass fractions are 95%, rectification is carried out after the completion of waiting to absorb water.Absorbed water
In journey, temperature rises to 135 DEG C from 25 DEG C, while the methyl hydrazine that rectification is obtained is yellow liquid.Assay products after the completion of rectification：First
Base hydrazine mass fraction 98.02%, quality of glycol fraction 1.10%, unknown component mass fraction 0.88%.
Embodiment 2：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 10kPa, 32.94 DEG C of tower top temperature, 64.82 DEG C of bottom temperature, extractant are 3 with raw materials quality ratio：1；Distillating still SEP normal pressures
Operation.The composition of extractant such as table 2 below.The mass fraction 95.13% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.93%, logistics S4 is not detected by other impurity.
2 extractant of table is constituted
| Component | Mass fraction/% |
| 1- ethyl -3- trifluoromethyl imidazoles hexafluorophosphates | 90 |
| Trifluoroacetic acid potassium | 10 |
Embodiment 3：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 5kPa, 18.96 DEG C of tower top temperature, 51.51 DEG C of bottom temperature, extractant are 2.3 with raw materials quality ratio：1；Distillating still SEP is normal
Press operation.The composition of extractant such as table 3 below.The mass fraction 96.77% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.95%, logistics S4 is not detected by other impurity.
3 extractant of table is constituted
| Component | Mass fraction/% |
| 1- butyl -3- Methylimidazole. trifluoroacetates | 93 |
| Trifluoroacetic acid lithium | 7 |
Embodiment 4：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 7kPa, 24.95 DEG C of tower top temperature, 57.17 DEG C of bottom temperature, extractant are 2.4 with raw materials quality ratio：1；Distillating still SEP is normal
Press operation.The composition of extractant such as table 4 below.The mass fraction 94.53% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.91%, logistics S4 is not detected by other impurity.
4 extractant of table is constituted
| Component | Mass fraction/% |
| 1- butyl -3- trifluoromethyl imidazoles hexafluorophosphates | 95 |
| Trifluoroacetic acid potassium | 5 |
Embodiment 5：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 10kPa, 32.94 DEG C of tower top temperature, 64.82 DEG C of bottom temperature, extractant are 1.8 with raw materials quality ratio：1；Distillating still SEP is normal
Press operation.The composition of extractant such as table 5 below.The mass fraction 94.15% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.93%, logistics S4 is not detected by other impurity.
5 extractant of table is constituted
| Component | Mass fraction/% |
| 1- butyl -3- trifluoromethyl imidazoles trifluoroacetates | 94 |
| Trifluoroacetic acid lithium | 6 |
Embodiment 6：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 5kPa, 18.96 DEG C of tower top temperature, 51.51 DEG C of bottom temperature, extractant are 1.9 with raw materials quality ratio：1；Distillating still SEP is normal
Press operation.The composition of extractant such as table 6 below.The mass fraction 99.85% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.94%, logistics S4 is not detected by other impurity.
6 extractant of table is constituted
| Component | Mass fraction/% |
| 1- butyl -3- trifluoromethyl imidazoles tetrafluoroborates | 95 |
| Trifluoroacetic acid lithium | 5 |
Embodiment 7：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 5kPa, 18.96 DEG C of tower top temperature, 51.51 DEG C of bottom temperature, extractant are 1.5 with raw materials quality ratio：1；Distillating still SEP is normal
Press operation.The composition of extractant such as table 7 below.The mass fraction 99.94% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.95%, logistics S4 is not detected by other impurity.
7 extractant of table is constituted
| Component | Mass fraction/% |
| 1- butyl -3- trifluoromethyl imidazoles tetrafluoroborates | 94 |
| Trifluoroacetic acid lithium | 6 |
Embodiment 8：
According to flow implementation the present embodiment as shown in Figure 1.By the methyl hydrazine aqueous solution logistics S1 (methyl that temperature is 50 DEG C
Methyl hydrazine flow 7.98kg/h, discharge 11.02kg/h in hydrazine aqueous solution) send into rectifying column T middle part.Rectifying column T operation pressures
Power 5kPa, 18.96 DEG C of tower top temperature, 51.51 DEG C of bottom temperature, extractant are 1.7 with raw materials quality ratio：1；Distillating still SEP is normal
Press operation.The composition of extractant such as table 8 below.The mass fraction 99.92% of water, methyl hydrazine mass fraction in logistics S4 in logistics S5
99.93%, logistics S4 is not detected by other impurity.
8 extractant of table is constituted
| Component | Mass fraction/% |
| 1- butyl -3- trifluoromethyl imidazoles tetrafluoroborates | 93 |
| Trifluoroacetic acid lithium | 7 |
Claims (2)
1. a kind of preparation method of high-purity methyl hydrazine, it is characterised in that the methyl hydrazine aqueous solution with 42% as raw material, employing
Equipment is rectifying column and distillating still, is comprised the following steps：
(1) raw material is separated into rectifying column, with ionic liquid and fluorine-containing organic salt composition composite extractant from rectifying column
Portion enters rectifying column, operating pressure 5kPa～10kPa, 18.96 DEG C～32.94 DEG C of tower top temperature, and 51.51 DEG C of bottom temperature～
64.82 DEG C, composite extractant is 1.5～3 with the mass ratio of raw material：1, overhead fraction is methyl hydrazine, and tower reactor fraction is compound extraction
Take the mixture of agent and water；
(2) material from tower bottom of rectifying tower enters distillating still, divides the mixture of composite extractant and water by air-distillation
Open, stillage is water, residual liquid is composite extractant, composite extractant returns rectifying column,
The cation of the composite extractant intermediate ion liquid is 1- ethyl-3-methylimidazole cationes, 1- ethyl -3- fluoroforms
Base glyoxaline cation, 1- butyl -3- methyl imidazolium cations or 1- butyl -3- trifluoromethyl imidazoles cationes, the compound extraction
Take agent intermediate ion liquid anion be Tetrafluoroboric acid anion, hexafluorophosphoric acid anion or trifluoroacetic acid anion, it is described multiple
Close extractant in fluorine-containing organic salt be trifluoroacetic acid lithium, trifluoroacetic acid sodium or trifluoroacetic acid potassium, it is in the composite extractant, fluorine-containing
The mass fraction of organic salt is 3%～10%.
2. the preparation method of high-purity methyl hydrazine as claimed in claim 1, it is characterised in that the composite extractant is by 1- fourths
Base -3- trifluoromethyl imidazoles Tetrafluoroboric acid ionic liquids and trifluoroacetic acid lithium composition, in composite extractant, trifluoroacetic acid lithium
Mass fraction is 5%～7%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510056062.9A CN104628594B (en) | 2015-02-03 | 2015-02-03 | Preparation method of high-purity methyl hydrazine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510056062.9A CN104628594B (en) | 2015-02-03 | 2015-02-03 | Preparation method of high-purity methyl hydrazine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104628594A CN104628594A (en) | 2015-05-20 |
| CN104628594B true CN104628594B (en) | 2017-04-12 |
Family
ID=53207889
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510056062.9A Active CN104628594B (en) | 2015-02-03 | 2015-02-03 | Preparation method of high-purity methyl hydrazine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104628594B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7267197B2 (en) * | 2016-11-08 | 2023-05-01 | マセソン トライ－ガス， インコーポレイテッド | Method for removing moisture from hydrazine and method for stabilizing and drying hydrazine |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2851768A1 (en) * | 2003-02-27 | 2004-09-03 | Isochem Sa | Production of anhydrous monomethylhydrazine useful in the space industry comprises adding ethylenediamine to an azeotropic aqueous solution and distilling the mixture |
| CN101397264A (en) * | 2007-09-28 | 2009-04-01 | 赛拓有限责任公司 | Method for manufacturing monomethyl hydrazine |
| CN103396335A (en) * | 2013-08-21 | 2013-11-20 | 上海海唇机械设备工程技术有限公司 | Content-adjustable methylhydrazine synthetic-fluid refining apparatus and method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102977109B (en) * | 2012-11-21 | 2015-02-11 | 西安近代化学研究所 | Method for separating triethylene diamine from ethanol amine by ionic liquid extraction and distillation |
-
2015
- 2015-02-03 CN CN201510056062.9A patent/CN104628594B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2851768A1 (en) * | 2003-02-27 | 2004-09-03 | Isochem Sa | Production of anhydrous monomethylhydrazine useful in the space industry comprises adding ethylenediamine to an azeotropic aqueous solution and distilling the mixture |
| CN101397264A (en) * | 2007-09-28 | 2009-04-01 | 赛拓有限责任公司 | Method for manufacturing monomethyl hydrazine |
| CN103396335A (en) * | 2013-08-21 | 2013-11-20 | 上海海唇机械设备工程技术有限公司 | Content-adjustable methylhydrazine synthetic-fluid refining apparatus and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104628594A (en) | 2015-05-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3847756A (en) | Recovery of diethyl ether from an olefin hydration product stream by extractive distillation with water | |
| CN102502500A (en) | Device for producing hydrogen chloride by resolving hydrochloric acid | |
| CN102898405A (en) | Process for preparing epoxypropane by directly using epoxidation propylene through hydrogen peroxide | |
| CN101522650B (en) | Method for the continuous separation of mixtures comprising morpholine (MO), monoaminodiglycol (ADG), ammonia, and water by means of distillation | |
| CN105732393A (en) | Synthesizing method of 2-nitropropane | |
| CN104610022A (en) | Method for separating ethanol-propyl acetate azeotrope through continuous extractive rectification | |
| CN104628594B (en) | Preparation method of high-purity methyl hydrazine | |
| CN104603101B (en) | The purification process of acetonitrile | |
| CN106008186B (en) | A kind of separation method of isopropanol, acetone and water mixed solution | |
| CN107954874A (en) | A kind of method for preparing benzoic ether | |
| CN104610021B (en) | A kind of method of mixed solvent continuous extraction rectification separating alcohol toluene azeotropic mixture | |
| KR20080098377A (en) | Process for the separation by distillation of dinitrotoluene from process wastewater from the preparation of dinitrotoluene by nitration of toluene by means of nitrating acid | |
| DE2943984A1 (en) | METHOD AND DEVICE FOR THE CONTINUOUS PRODUCTION OF TRIOXANE | |
| US3098017A (en) | Process of separating unsymmetrical dimethylhydrazine from aqueous solutions containing same | |
| CN106831338B (en) | Preparation method of high-purity difluoroethanol | |
| CN113461544B (en) | Method for treating mixed liquid containing acetonitrile, triethylamine and water | |
| US3574276A (en) | Method for transporting acetylene | |
| CN105347319A (en) | Method for removing organic impurities in hydrazine hydrate prepared through ketazine method | |
| EP3310752B1 (en) | Method for preparation of n-butyl nitrite | |
| CN111233718B (en) | Method for continuously synthesizing perchloromethylmercaptan | |
| CN104628593B (en) | A kind of method preparing high-purity methyl hydrazine | |
| CN104529697B (en) | A kind of method that reclaims high-purity octafluorocyclobutane from monochlorodifluoromethane cracking raffinate | |
| CN106831339A (en) | A kind of method for isolating and purifying trifluoroethanol and water azeotropic mixture | |
| CN103819304A (en) | Process for decolorizing high-boiling epoxy mixture and extracting trichloropropane in high-boiling epoxy mixture | |
| CN112479806A (en) | Separation method of mixture of 2-chloro-3, 3, 3-trifluoropropene and 2-chloro-1, 1,1, 2-tetrafluoropropane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |