The method of obtaining freon
(57) Abstract:The invention relates to the production of freon by fluorination of tetrafluoroethylene with fluorine inert liquid. The process is carried out in the environment fluoride liquid at a temperature from -55 ° C to -80oWith the presence of deformity and triptorelin, the total content of which is 110-5- 2,110-2about. % based on the original tetrafluoroethylene. This increases the yield of the target product. table 1. The invention relates to organic chemistry, more precisely, to obtain saturated acyclic compounds containing fluorine, namely to methods for freon.The freon is used as the refrigerant gas dielectric reagent for dry etching in the manufacture of integrated circuits, solvent during polymerization.Known methods for producing the freon hydropericardium chlorohydrocarbons at high temperatures [Industrial organofluorine products. Handbook Ed. by B. N. Maksimova. L.: Chemistry, 1990, S. 97 - 98].There are also known methods of fluorination of ethylene using as a fluorinating agents ftory the ilen passed over cobalt fluoride at a temperature of 75 450oC, contact time more than 10 seconds. For carrying out this method is required for efficient heat transfer.A method of obtaining freon from tetrafluoroethylene using as a fluorinating agent of elemental fluorine [application of Japan Kokai Tokkyo Koho 02-134438, class C 07 C 19/08, op. 21.05.1990, Chem. Abstr., 113: u]. Fluoridation by this method is carried out in the liquid or gaseous perchloromethane when the ratio of the tetrafluoroethylene (TPV): forlorned 1:100 mol. So, during fluorination in the environment R-114 with a ratio of R-114: TPV 40:1 at a temperature of 80oC the resulting output to 87.9%. Such withdrawal cannot be considered high.The closest analogue (prototype) of the present invention is a method for freon from tetrafluoroethylene fluoridation elemental fluorine [RF patent 2124493, class C 07 C 19/08, 17/04, op. 10.01.1999]. The process is carried out at a temperature from minus 50 to minus 62oC in the environment of perfluorocarbon liquids containing 8 to 11 wt.% stable retroperitoneal-2-pentafluoropropionic radical, with a ratio of fluorine:TPV 1:1-1,1). However, the yield of the target product by this method is limited by the fact that stable retroperitoneal-2 pentacerotidae the 6oC [A. Lovley, D. roeg, U. Postelnik Aliphatic fluorine-containing compounds. M. : 1961, S. 83]. Thus, when the temperature of the synthesis of this compound freezes on the walls of the reactor and difficult removal of heat from the reaction zone, which creates hazardous conditions. As education pertemanan decreases and the output of freon per reacted TPV. Increase in the yield of the target product contributes to carrying out the process at lower temperatures, however, the use of the presence in the solution retroperitoneal-2-pentafluoropropionic radical does not allow you to lower the temperature of synthesis.The problem faced by the inventors, it was the reduction of the process temperature. To solve this task allowed the use as solvents of low-melting fluorosurfactants and fluorinated liquids.The essence of the developed method is that the freon is obtained by fluorination of tetrafluoroethylene elemental fluorine, which may be injected into the process as in the fluorine-containing diluent, and without it. The process is carried out in the presence of a mixture of deformity and triptorelin. The total content of deformity and triptorelin van, refrigerant R-11(portreporter), or Halocarbon R-21 (fertiliser).The process of fluorination is conducted at temperatures from minus 55 to minus 80oC.Thus, the differences of the proposed invention are:
- carrying out fluorination of tetrafluoroethylene in the presence of a mixture of deformity and triptorelin, the total content of which 110-5to 2,110-2vol.%, regarding input Tetrafluoroethane;
- use as solvents fluorinated fluid type of freon R-11, R-21, perftorgeksan;
- carrying out the process at temperatures from minus 55 to minus 80oC.The process in these terms provides a higher output based on TPV and fluorine, when this technology becomes safer by reducing local stress and improve heat transfer through the walls of the reactor, because, in contrast to the known method (prototype), is excluded namerzanie of perftoran on the walls of the reactor.A practical embodiment of the method is as follows: to a reactor with a volume of 0.3 DM3made of stainless steel and equipped with a shirt that served liquid nitrogen, fittings and bubblers input TPV and perakim nitrogen to the required temperature, purge nitrogen gas to remove air, and then served TPV with a speed of 1 l/h and fluorine (pure or diluted gaseous diluent), in a molar ratio TPV:d 1:1-1,1.The process can be carried out at temperatures from minus 40 to minus 80oC. the Choice of temperature range due to the fact that at temperatures above minus 40oC reduced output HFEs, and at lower than -80oC, reduced conversion of TPV, which would reduce the performance of the process.The choice of inert diluent does not affect the results of the process.Modifying reagent molar ratio higher than the stoichiometric does not lead to a deterioration of the output, however, increased loss of fluoride.The decrease in the total content of deformity and triptorelin below 110-5vol.% reduces the selectivity of the process, and the increase above 2,110-2vol.% reduces the TPV conversion.The resulting gaseous products were analyzed by gas chromatography. The content of fluorine in the gas synthesis was assessed photometrically (zirconium-alizarin method) and chemically (titration with alkali using phenolphthalein). When calculating the output of the HFEs by fluorine have used the Examples of the process of fluorination in the above-described conditions are presented in the table. From the presented results, it follows that when carrying out the process according to the invention the yield of the target product is 95-99%. The method of obtaining freon fluoridation of tetrafluoroethylene with fluorine in inert fluid, wherein the fluorination is carried out in the environment fluoride liquid at a temperature from -55 ° C to -80oC in the presence of deformity and triptorelin, the total content of which is 1 x 10-5- 2.1 x 10-2vol.% based on the original tetrafluoroethylene.
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for purifying octafluoropropane. Method is carried out by interaction of crude octafluoropropane comprising impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that are able to remove indicated impurities up to the content less 0.0001 wt.-% from indicated crude octafluoropropane. The impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurities represent at least one compound taken among the group consisting of chloropentafluoroethane, hexafluoropropene, chlorotrifluoromethane, dichlorodifluoromethane and chlorodifluoromethane. Adsorbent represents at least one substance taken among the group consisting of activated coal, molecular sieves and carbon molecular sieves. Crude octafluoropropane comprises indicated impurities in the amount from 10 to 10 000 mole fr. by mass. Invention proposes gas, etching gas and purifying gas comprising octafluoropropane with purity degree 99.9999 wt.-% and above and containing chlorine compound in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluoropropane.
EFFECT: improved purifying method.
13 cl, 11 tbl, 12 ex
SUBSTANCE: invention relates to versions of producing 2,3,3,3-tetrafluoropropene (1234yf). One of the versions involves (a) contacting 1,1,1-trifluoro-2,3-dichloropropane (243 db) with hydrogen fluoride (HF) in the presence of a zinc-chromium catalyst to form a compound of formula CF3CHFCH2X, where X is Cl or F; and (b) dehydrohalogenation of the compound of formula CF3CHFCH2X to form 1234yf.
EFFECT: use of the present method enables to obtain 2,3,3,3-tetrafluoropropene using only readily available starting materials and enables to avoid toxic by-products.
56 cl, 5 ex, 1 tbl
SUBSTANCE: invention relates to method of obtaining 1,1,1-trifluoro-2,3-dichloropropane (243db), which includes contact of 3,3,3-trifluoropropene (1243zf) with chlorine in presence of catalyst, including activated coal, aluminium oxide and/or transition metal oxide.
EFFECT: method is clean and efficient.
75 cl, 7 ex, 5 tbl
SUBSTANCE: invention relates to a method of obtaining a compound of formula CF3CHFCH2X, where X represents Cl or F, including a contact of 3,3,3-trichloropropene (1243zf) with a compound of formula AB, selected from Cl2, Br2, I2, ClF, ClBr and ICl, and HF in the presence of a zinc-chrome catalyst with formation of the compound of formula CF3CHFCH2X.
EFFECT: claimed method makes it possible to use easily available initial materials.
13 cl, 5 ex
SUBSTANCE: invention relates to method for fluorinating halogenated olefines, involving reaction of elementary fluorine in presence of anhydrous HF with halogenated olefine of formula CXR1=CYR2 (I), where: R1 is selected from group consisting of F, Cl, Br, I, Rf1, ORf1; R2 is selected from group consisting of H, F, Cl, Br, I, Rf2, ORf2; X is selected from group consisting of H, F, Cl, Br, I; Y is selected from group consisting of H, F, Cl, Br, I; and Rf1 and Rf2, identical or different from each other, are independently selected from linear or branched C1-C20 fluoroalkyl or C1-C20 fluoroxyalkyl containing one or more oxygen atom in chain; and Rf1 and Rf2 can be contained in structure of fluorinated cycloalkyl, where anhydrous HF is used as only reaction medium.
EFFECT: technical result is high output and selectivity in product obtained by bonding of fluorine to carbon-carbon double bond, without need in use of complex equipment.
8 cl, 5 ex