Abstract:
La présente invention concerne un procédé de fabrication du 1,1,1,2,3,3-hexafluoropropane de haute pureté et une composition renfermant principalement du 1,1,1,2,3,3-hexafluoropropane, apte à être utilisée comme agent de nettoyage dans l'industrie des semi-conducteurs.
Abstract:
A process is disclosed for reducing the mole ratio of (1) compounds of the formula Y 1 Y 2 C=CF 2 wherein Y 1 and Y 2 are each independently H, F, CI, Br, C 1 -C 6 alkyl or C 1 -C 6 haloalkyl containing no more than 3 chlorine substituents, 2 bromine substituents and 1 iodo substituent to (2) saturated compounds of the formula C d H e F f CI g Br h I k wherein d is an integer from 1 to 10, and e+f+g+h+k is equal to 2d+2, provided that g is 0, 1, 2 or 3, h is 0, 1 or 2 and k is 0 or 1 and/or unsaturated compounds of the formula Y 3 Y 4 C=CY 5 Y 6 , wherein Y 3 , Y 5 and Y 6 are each independently H, F, CI Br, C1-C6 alkyl or C1-C6 haloalkyl containing no more than 3 chlorine substituents, 2 bromine substituents and 1 iodo substituent, provided that Y 5 and Y 6 are not both F, and Y 4 is C 1 -C 6 alkyl or C 1 -C 6 haloalkyl containing no more than 3 chlorine substituents, 2 bromine substituents and 1 iodo substituent, in a mixture. The process involves contacting the mixture with at least one selective removal agent selected from the group consisting of SO 3 and RSO 3 H, wherein R is selected from the group consisting of F, CI, OH, C 1 -C 8 alkyl, C 1 -C 8 fluoroalkyl, and C 1 -C 8 fluoroalkoxyalkyl containing no more than two ether oxygens to selectively react the formula Y 1 Y 2 C=CF 2 compounds.
Abstract:
A process for producing hexafluoroethane, comprising a step of distilling a crude hexafluoroethane containing chlorine compounds each having two carbon atoms to distill out hexafluoroethane as a top flow from the top of a distillation column and separate a hexafluoroethane mixture containing the chlorine compounds as a bottom flow from the bottom, and a step of contacting the bottom flow with hydrogen fluoride in the gas phase at a temperature of 300 to 500 °C in the presence of a fluorination catalyst to fluorinate the chlorine compounds. This process provides hexafluoroethane which can be used mainly as a cleaning gas in the production process of a semiconductor device.
Abstract:
Higher diamondoid derivatives capable of taking part in polymerization reactions are disclosed as are intermediates to these derivatives, polymers formed from these derivatives and methods for preparing the polymers.
Abstract:
A process for purifying octafluorocyclobutane according to the present invention is characterized by contacting a crude octafluorocyclobutane containing impurities with an impurity decomposing agent under elevated temperature and then with an adsorbent to substantially remove the impurities from the crude octafluorocyclobutane. According to the purification process or preparation process of octafluorocyclobutane of the present invention, the impurities such as fluorocarbon can be substantially removed and a high-purity octafluorocyclobutane can be easily obtained. The octafluorocyclobutane obtained by the purification process of the present invention is substantially free of impurities and therefore, can be used as an etching or cleaning gas for use in the production process of a semiconductor device or the like.
Abstract:
A process for purifying octafluoropropane according to the present invention comprises the step of contacting a crude octafluoropropane containing impurities with an impurity decomposing agent under elevated temperature and then with an adsorbent to substantially remove the impurities from the crude octafluoropropane. According to the pruification process or preparation process of octafluoropropane of the present invention, the impurities such as chlorine compounds can be substantially removed and a high-purity octafluoropropane can be easily obtained. The octafluoropropane obtained by the purification process of the present invention is substantially free of impurities and therefore, can be used as an etching or cleaning gas for use in the production process of a semiconductor device and the like.
Abstract:
A method of reducing the formation of coke deposits on the heat-transfer surfaces of an ethylene dichloride to vinyl chloride pyrolysis furnace comprising exposing the heat transfer surfaces of said pyrolysis furnace to a phosphite selected from the group consisting of phosphites with the general formula: wherein A1, A2 and A3 are selected from the group consisting of OR1, -SR2 and Cl, wherein R1 and R2 are selected from the group consisting of alkyl, aryl, alkylaryl and arylalkyl, wherein A1, A2 and A3 may be the same or different, provided that at least one of A1, A2, and A3 is not Cl.