E.i. Dupont De Nemours and Company

Frederick W Mader

Harold L Jackson

Richard E Fernandez

Wendel R Cassel

George R Coraor

Neville Everton Drysdale

Rudolf E Svadlenak

A process for halogen exchange fluorination by contacting a halocarbon having a replaceable halogen other than fluorine with KF.nHF wherein n is 0.5-3 to provide a fluorinated hydrocarbon having at least one more fluorine than the starting halocarbon and, optionally, regenerating the KF.nHF with additional HF, or in a continuous process, with excess HF in the feed.

Halogen exchange fluorination

A process for halogen exchange fluorination by contacting a halocarbon having a replaceable halogen other than fluorine with CsF or RbF.multidot.nHF wherein n is 0.5-3 to provide a fluorinated hydrocarbon having at least one more fluorine than the starting halocarbon and, optionally, regenerating the MF.multidot.nHF with additional HF, or in a continuous process, with excess HF in the feed.

An aldehyde in a mixture containing hemiacetals and hydrates of the aldehyde is purified by treating the mixture with an effective amount of microwave radiation to decompose the hemiacetals and hydrates. Liberated water and/or alcohol is immediately removed with an adsorbent.

Process for the purification of aldehydes

A continuous process for florinating haloalkanes containing at least one nonfluorine halogen atom wherein antimony pentachloride is reacted with HF to produce an antimony (V) chlorofluoride and HCl is removed. The antimony chlorofluoride thus produced is then transferred to a separate reaction zone where it is reacted with the haloalkane, thereby replacing a portion of the nonfluorine halogen in the haloalkane with fluorine of the antimony (V) chlorofluoride.

Fluorination process

Process of drying water-wet solid materials, which process comprises, in a system, A. forcibly contacting the water-wet solid material with circulating vapor of a fluorocarbon having a fluorine to carbon atom ratio of at least 1.0 and a boiling temperature of less than about 80.degree. C at atmospheric pressure, said fluorocarbon vapor being at a temperture above about 100.degree. C and said contacting being carried out in the absence of a substantial amount of a noncondensable gas, such as air or nitrogen, B. passing the resulting mixture of fluorocarbon vapor and water vapor from step (a) through a zone maintained at a temperature less than 100.degree. and at least 1.degree. C above the atmospheric pressure boiling temperature of the fluorocarbon to condense a substantial portion of the water vapor but not a substantial portion of the fluorocarbon vapor and, preferably, so that the partial pressure of the water in the remaining vapor mixture is less than about 25 cm of mercury, C. heating the vapor mixture from step (b) to a temperature above about 100.degree. C and recycling the mixture to step (a), D. repeating steps (a), (b) and (c), while maintaining substantially constant in the system the amount of fluorocarbon vapor, until the solid material is substantially free of water and contains only fluorocarbon vapor on its surfaces and/or occluded in its interstices, and thereafter E. removing and recovering from the solid material the fluorocarbon vapor values and F. recovering solid material which is substantially free of water and fluorocarbon.

Drying of water-wet solid materials

Process for continuously transferring heat to a moving band of solid material, for example, a textile, a film, particles, or any shaped or unshaped article, the band preferably comprising a disperse dyeable synthetic polymer, for example, a polyester or polyamide, said process comprising passing the band through a substantially enclosed purging-drying region containing the superheated condensable vapor of a liquid having an atmospheric pressure boiling point of less than 120.degree. C., thence immediately thereafter through a substantially enclosed, heat-transfer region containing the superheated condensable vapor of a fluorocarbon having a fluorine to carbon atom ratio of at least 1.5, a solubility parameter of not more than 6.5 and a molecular weight of at least about 300, the pressure in the heat transfer region being no greater than that in the purging-drying region, thence immediately thereafter through a substantially enclosed purging region containing dry steam, the pressure in the purging region being no less than that in the heat-transfer region, and thereafter recovering the band of material, said process characterized by efficient heat transfer resulting from rapid convective movement of superheated fluorocarbon in the heat-transfer region and by minimum loss of such vapor to the atmosphere.

Process for continuously transferring heat to a moving band

Process for substantially quantitatively removing and recovering a volatile, organic, water-immiscible wetting liquid from a solid material which is wet therewith, which process comprises intimately contacting the solid material first with the superheated vapor of a water-immiscible, organic stripping liquid and thereafter with dry steam, said contacting taking place in an environment substantially free of noncondensable gas, condensing the mixture of organic vapor and steam to form a two-phase liquid mixture consisting of liquid organic phase and liquid water phase, and separating the liquid organic phase and the liquid water phase.

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Kennett Square, PA, United States of America

Frederick W Mader