Tetrafluoromethane(CarbonTetrafluoride)
carbon tetrafluoride
CAS: 75-73-0
Molecular Formula: CF4
Tetrafluoromethane(CarbonTetrafluoride) - Names and Identifiers
| Name | carbon tetrafluoride |
| Synonyms | Tetrafluoromethane carbon tetrafluoride Tetrafluoromethane(FC-14) CARBON TETRAFLUORIDE (R-14) Carbon tetrafluoride (FC-14) Tetrafluoromethane(CarbonTetrafluoride) |
| CAS | 75-73-0 |
| EINECS | 200-896-5 |
| InChI | InChI=1/CF4/c2-1(3,4)5 |
Tetrafluoromethane(CarbonTetrafluoride) - Physico-chemical Properties
| Molecular Formula | CF4 |
| Molar Mass | 88 |
| Density | (solid, -195°) 1.98; d (liq, -183°) 1.89 |
| Melting Point | −184°C(lit.) |
| Boling Point | −130°C(lit.) |
| Water Solubility | mL/100mL in H2O: 0.595 (10°C), 0.490 (20°C), 0.366 (40°C) [LAN05] |
| Vapor Density | 3.04 (vs air) |
| Merck | 13,1827 |
| Stability | Stable. Incompatible with zinc, alkaline earth metals, Group I metals, aluminium and its alloys. Non-flammable. |
| Refractive Index | 1.1510 |
| Physical and Chemical Properties | Colorless, odorless and tasteless gas. Melting Point -150 °c (-184 °c), boiling point 128 °c, density 1.96g/cm3. Slightly soluble in water. It is very stable to heat and less active than carbon tetrachloride in chemical properties. |
| Use | Plasma etching process for various integrated circuits, also used as laser gas and refrigerant |
Tetrafluoromethane(CarbonTetrafluoride) - Risk and Safety
| Hazard Symbols | F - Flammable |
| Safety Description | 38 - In case of insufficient ventilation, wear suitable respiratory equipment. |
| UN IDs | UN 1982 2.2 |
| WGK Germany | 3 |
| RTECS | FG4920000 |
| TSCA | T |
| Hazard Note | Non-flammable |
| Hazard Class | 2.2 |
| Toxicity | LCLo inhalation in rat: 895000ppm/15M |
Tetrafluoromethane(CarbonTetrafluoride) - Nature
Open Data Verified Data
Tetrafluoromethane is a colorless, non-flammable gas. Compressed gas at room temperature. Is one of the most stable organic compounds, at 900 C, CF4 does not react with Cu, Ni, W, Mo, only in the carbon arc temperature slow decomposition. When burning with combustible gases, it will decompose to produce toxic fluoride. In case of high fever, the internal pressure of the container increases, and there is a risk of cracking and explosion.
Last Update：2024-01-02 23:10:35
Tetrafluoromethane(CarbonTetrafluoride) - Preparation Method
Open Data Verified Data
each was prepared by fluorination reaction using activated carbon and fluorine as raw materials. In a reaction furnace equipped with activated carbon, a high-concentration fluorine gas was slowly introduced, and the reaction temperature was controlled by heating by a heater, feeding rate of fluorine and cooling of the reaction furnace. The product is dedusted, alkali washed to remove impurities such as HF, CoF2, S1F4, C02, and then dehydrated to obtain a crude product with a content of about 85%. The crude product is introduced into a low-temperature rectification kettle for batch crude distillation, and 02, N2 and H2 are removed by controlling the distillation temperature to obtain high-purity cf4.
Last Update：2024-07-01 17:28:57
Tetrafluoromethane(CarbonTetrafluoride) - Use
Open Data Verified Data
is the most widely used plasma etching gas in the microelectronics industry, tetrafluoromethane high purity gas and tetrafluoromethane high purity gas, high purity oxygen mixture, can be widely used in silicon, silicon dioxide, silicon nitride, the etching of thin film materials such as phosphosilicate glass and tungsten is also widely used in surface cleaning of electronic devices, solar cell production, laser technology, low temperature refrigeration, leakage inspection, and detergent in printed circuit production.
Last Update：2022-01-01 09:31:18
Tetrafluoromethane(CarbonTetrafluoride) - Safety
Open Data Verified Data
can cause rapid asphyxia. Head Pain, Nausea, and Vomit may result after contact. In the process of treating tetrafluoromethane can be considered according to non-toxic or low toxic gas, but its combustion with combustible gas, will be decomposed to produce toxic fluoride. Asphyxiation gas at high concentrations. Non-combustible compressed gas. Store in a cool, ventilated warehouse. The bin temperature should not exceed 30 ℃. Keep away from fire and heat source. Protection from direct sunlight. Should be stored separately from flammable and combustible materials.
Last Update：2022-01-01 09:31:18
Tetrafluoromethane(CarbonTetrafluoride) - Reference Information
| NIST chemical information | information provided by: webbook.nist.gov (external link) |
| EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
| Introduction | Tetrafluoromethane (Tetrafluoromethane), also known as carbon tetrafluoride, colorless, tasteless, odorless gas. Do not dissolve in water, under normal pressure 25 ℃ for 0.0015, soluble in chloroform and benzene. This product is non-toxic and non-flammable. There is a high concentration of anesthesia. Its high purity gas and its mixture of high purity oxygen are the plasma etching gas with the largest consumption in the microelectronic industry at present, and can also be used as a low-temperature refrigerant and a low-temperature insulation medium. Chemical stability and thermal stability are good, inert to many reagents, at 1000 deg C without hydrolysis. Does not react with copper, nickel and tungsten at room temperature. Due to the strong chemical stability of the C- F bond, perfluorocarbons typified by CF4 can be considered to be substantially non-toxic. FIG. 1 shows the chemical structure of tetrafluoromethane. |
| stability | tetrafluoromethane (CF4) has high stability, belongs to completely non-combustible gas, does not react with acid at room temperature, alkali and oxidant reaction, below 900 ℃ does not react with Cu,Ni,W,Mo and other transition metals, below 1000 ℃ does not react with carbon, hydrogen and CH4. It can react with liquid ammonia-sodium metal reagent at room temperature, and CF4 can react with alkali metal, alkaline earth metal and SiO2 at high temperature to generate corresponding fluoride. CF4 begins to decompose at 800 ° C., and can react with CO and CO2 to form COF2 under the action of arc. Some people also try to synthesize other fluorocarbons by polymerizing CF4 at the temperature of carbon arc. |
| Application | carbon tetrafluoride is the most widely used plasma etching gas in the microelectronics industry, widely used in silicon, silicon dioxide, silicon nitride, etching of phosphosilicate glass and tungsten and other thin film materials, surface cleaning of electronic devices, production of solar cells, laser technology, low-temperature refrigeration, gas insulation, leak detection agents, control of space rocket attitude, detergent, lubricant and brake fluid in printed circuit production also have a large number of applications. Because of its strong chemical stability, CF4 can also be used in metal smelting and plastic industry. The characteristics and development trend of electronic gas used in ultra-large-scale integrated circuits are ultra-pure, ultra-clean, multi-variety and multi-specification. In order to promote the development of domestic microelectronic industry, more and more attention is paid to the development of special electronic gas production technology. At present, carbon tetrafluoride (CF4) has occupied the etching gas market for a long time with its relatively low price, and therefore has a broad development potential. examples of downstream products: silicon thin film materials, silicon dioxide thin film materials, silicon nitride thin film materials, phosphorus silicon glass thin film materials, tungsten thin film materials and other thin film materials, electronic device surface cleaning agents, solar cells, detergent, lubricant, brake fluid, safe self-explosion and explosion-proof dry powder fire extinguisher. |
| synthesis method | at present, the main methods for preparing tetrafluoromethane CF4 in industry are direct fluorination of alkanes, fluorination of chlorofluoromethane, hydrofluoromethane fluorination and direct synthesis of fluorocarbon, etc. The direct fluorination of alkanes is the earliest industrial process for the preparation of fluorinated alkanes, but the reaction is extremely exothermic and difficult to control, requiring special measures. The Dupont (France) patent describes a process for the preparation of tetrafluoromethane CF4 by reacting methane with Cl2 and HF in the gaseous state in the presence of a catalyst. The reaction scheme is as follows: CH4 4Cl2 4hf--cf4 8HCl. The reaction is carried out in a catalyst-filled tubular reactor or fluidized bed reactor using metal oxides or halides previously activated with HF as catalyst, in particular Al2O3,Cr2O3 and cocl2. The amount of Cl2 and HF and the reaction temperature are beneficial to the formation of CF4. The reaction temperature is controlled at 450~550 ℃, and the contact time of the reactants is 0.5 ~ 5s. The advantages of this method are mature technology, simple operation and easy availability of raw materials. However, this method also has the disadvantages that the reaction is not easy to control, the product is complex, and the yield is low, which will eventually be eliminated by other processes. |
| preparation of tetrafluoromethane CF4 by fluorination of chlorofluoromethane | a patent issued by OKAM Corporation of Japan reports a process for producing high-purity tetrafluoromethane CF4 by multi-stage reaction. In the first reaction, CF3Cl was reacted with HF in a fluidized bed reactor filled with CrO2F2 catalyst. The reaction scheme was as follows: CF3Cl HF---CF4 HCl. The catalyst used can be used through the reaction of Cr (III) hydroxide with HF at 200~600 ℃, or CrF3? 3H2O in the presence of O2 in 350~750 deg C under heating. The mass ratio of CF3Cl to HF is controlled at 1:2 to 8, the gas space velocity is 10 to 150h-1, and the reaction temperature is 380 to 420 °c. The gas generated in the first stage is subjected to water washing, alkali washing and drying, and then is subjected to the reaction in the second stage. In the second-stage reaction, HF is introduced to control the mass ratio of CF3Cl to HF to be 1:0.3~5, and the space velocity of the gas to be 10~300h-1, the reaction temperature was not changed. In this way, the mole fraction of unreacted CF3Cl can be controlled below 15 × 10-6, and the product has a high purity. The fluorination of chlorofluoromethane has the advantages of simple process, safe operation, no need to use expensive F2 in most cases, and low equipment investment. However, with the gradual disabling of CFC and HCFC, the source of raw materials for the process is limited and will eventually be discontinued. |
| Direct synthesis of fluorocarbon | carbon tetrafluoride (CF4) was first prepared by direct reaction of fluorocarbon, after continuous development and improvement, this method has now become one of the most important methods for the preparation of perfluoroalkane in industry. The Patent of Kanto Japan Electrochemical Co., Ltd. describes a process for preparing high-purity CF4 by reacting carbon with F2 in the presence of an anti-explosive agent. Fluorinated halogens are used as explosion inhibitors, in particular brf3. Petroleum coke with a mesh size of 0.25 was used, and the reactor was made of corrosion-resistant mild steel. The advantages of the direct reaction method of fluorocarbon are that the raw materials are easy to obtain, the reaction is controllable, and the product purity is high. It is said that the method has been industrialized by the US Air Products Company (AP), and the purity of the product is more than 99.99%, which can meet the needs of the electronic industry. |
| note | store in a cool, ventilated non-combustible gas warehouse. Keep away from fire and heat source. Storage temperature should not exceed 30 ℃. It should be stored separately from easy (possibly) combustible and oxidant, and mixed storage should not be avoided. The storage area shall be equipped with emergency treatment equipment for leakage. |
| Use | coolant for refrigerants, solvents, lubricants, insulating materials, infrared wave detectors. It is also used to make cryogenic liquid pressure gauges or as an inert gas, or in plasma etching processes and laser gases for various integrated circuits. plasma etching process for various integrated circuits, also used as laser gas and refrigerant |
| production method | by reaction of carbon with fluorine, or carbon monoxide with fluorine, or silicon carbide with fluorine, or fluorspar and petroleum coke in the electric furnace reaction, or difluoro dichloromethane and hydrogen fluoride reaction, or carbon tetrachloride and silver fluoride reaction, or carbon tetrachloride and hydrogen fluoride reaction, can produce tetrafluoride. The reaction between carbon tetrachloride and hydrogen fluoride is carried out in a high-temperature nickel tube filled with chromium hydroxide. The reacted gas is washed with water and washed with alkali to remove acid gas, and then the water in the gas is removed by freezing and silica gel, finally, the product is obtained by distillation. |
| category | compressed and liquefied gases |
| toxicity grade | low toxicity |
| Acute toxicity | inhalation-rat LCL0: 895000 PPM/15 min |
| storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; It is stored separately from flammable materials |
| extinguishing agent | Water |
| DOT Classification | 2.2 (Nonflammable gas) |
| toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
Last Update：2024-04-10 22:29:15
