Patent GB-922650-A (GB)
Title: Improvements relating to processes for propagating chemical reactions
IPC: C08G63/78
Filed: 1959-09-04
Abstract: A process for propogating a chemical reaction in a liquid reaction mass which is at chemical equilibrium and which contains incompletely reacted reactants and at least one relatively volatile product of the reaction that must be removed to enable the reaction to be driven to a desired degree of completion comprises removing the reaction product from the mass by a process which includes the steps of applying the mass to at least a part of a surface of revolution having an upright axis, the mass being applied thereto in such a way that it is caused to flow downwardly over the surface in a film under the influence of gravity and at a temperature and reduced pressure which are such that at least a portion of said reaction product will leave the film by evaporation, so shifting the equilibrium in a direction to permit incompletely reacted reactants to react further, wiping the surface so as to remove the liquid residue of said film therefrom, the wiping step being so performed as simultaneously to accelerate the downward movement of said residue, which latter includes the desired reaction product and to recover the removed residue.  Preferably evaporation is effected in a thin film using the apparatus described in Specification 825,438 in which the liquid falls down under gravity, under vacuum, the evaporating surface being wiped with a plurality of axially overlapping wiping edges of separate wiping elements, the working faces of which have oblique slots which remove the liquid.  The removed liquid may be reapplied to the surface located below the first portion.  The process may be applied to the manufacture of (a) dioctyl phthalate or esters derived from carbonic, oxalic, succinic, glutaric, adipic, pimelic, sebacic, hexadecamethylene dicarboxylic or phthalic acids with ethylene glycol, polyethylene glycol, propylene glycol, trimethylene glycol, hexamethylene glycol or decamethylene glycol; and to polyesters derived from lactic acid, o -hydroxy decanoic acid and o -hydroxy-caproic acid (b) polyamides derived from pimelic, sebacic, phthalic and hexadecamethylene dicarboxylic acids, with pentamethylene diamine, benzidene, phenylene diamine and propylene diamine and from 5-amino caproic acid, 10-aminoundecanoic acid and caprolactam.  (c) Polyethers derived from ethylene glycol, propylene glycol, trimethylene glycol, hexamethylene glycol, tripropylene glycol (d) polyanhydrides derived from adipic acid, pimelic acid, suberic acid, and hexadecamethylene dicarboxylic acid and (e) polyacetals derived from hydroxy aldehydes hydroxyketones or propionaldehydes, butyraldehyde benzaldehyde with glycols and (f) mixed polyesters-polyamides prepared by heating a mixture containing a dibasic acid , a glycol and a diamine.  Specification 596,392 also is referred to.ALSO:A process for propagating a chemical reaction in a liquid reaction mass which is at chemical equilibrium and which contains incompletely reacted reactants and at least one relatively volatile product of the reaction that must be removed to enable the reaction to be driven to a desired degree of completion comprises removing the reaction product from the mass by a process which includes the steps of applying the mass to at least a part of a surface of revolution having an upright axis, the mass being applied thereto in such a way that it is caused to flow downwardly over the surface in a film under the influence of gravity and at a temperature and reduced pressure which are such that at least a portion of said reaction product will leave the film by evaporation, so shifting the equilibrium in a direction to permit incompletely reacted reactants to react further, wiping the surface so as to remove the liquid residue of said film therefrom, the wiping step being so performed as simultaneously to accelerate the downward movement of said residue, which latter includes the desired reaction product and to recover the removed residue. Preferably evaporation is effected in a thin film using the apparatus described in Specification 825,438 in which the liquid falls down under gravity, under vacuum, the evaporating surface being wiped with a plurality of axially overlapping wiping edges of separate wiping elements, the working faces of which have oblique slots which remove the liquid.  The removed liquid may be reapplied to the surface located below the first portion.  The process may be applied to the manufacture of (a) polyesters derived from carbonic, oxalic, succinic, glutaric, adipic, pimelic, sebacic, hexadecamethylene dicarboxylic or phthalic acids with ethylene glycol, polyethylene glycol, propylene glycol, trimethylene glycol, hexamethylene glycol or decamethylene glycol; and to polyesters derived from lactic acid, o -hydroxy decanoic acid and o -hydroxycaproic acid, (b) polyamides derived from pimelic, sebacic, phthalic and hexadecamethylene dicarboxylic acids, with pentamethylene diamine, benzidene, phenylene diamine and propylene diamine and from 5-amino caproic acid, 10-aminoundecanoic acid and caprolactam, (c) polyethers derived from ethylene glycol, propylene glycol, trimethylene glycol, hexamethylene glycol, tripropylene glycol, (d) polyanhydrides derived from adipic acid, pimelic acid, suberic acid, and hexadecamethylene dicarboxylic acid and (e) polyacetals derived from hydroxy aldehydes, hydroxy ketones or propionaldehydes, butyraldehyde benzaldehyde with glycols and (f) mixed polyesters-polyamides prepared by heating a mixture containing a dibasic acid, a glycol and a diamine.  Specification 596,392 also is referred to.ALSO:A process for propagating an esterification reaction in a liquid reaction mass which is at chemical equilibrium and which contains incompletely reacted reactants comprises removing the water of esterification from the mass by a process which includes the steps of applying the mass to at least a part of a surface of revolution having an upright axis, the mass being applied thereto in such a way that it is caused to flow downwardly over the surface in a film under the influence of gravity and at a temperature and reduced pressure which are such that at least a portion of said water will leave the film by evaporation, so shifting the equilibrium in a direction to permit incompletely reacted reactants to react further, wiping the surface so as to remove the liquid residue of said film therefrom, the wiping step being so performed as simultaneously to accelerate the downward movement of said residue, which latter includes the desired ester and to recover the removed residue. Preferably evaporation is effected in a thin film using the apparatus described in Specification 825,438 in which the liquid falls down under gravity, under vacuum, the evaporating surface being wiped with a plurality of axially overlapping wiping edges of separate wiping elements, the working faces of which have oblique slots which remove the liquid.  The removed liquid may be reapplied to the surface located below the first portion.  The process may be applied to the manufacture of dioctyl phthalate by reacting phthalic anhydride with 2-ethylhexyl alcohol in the presence of carbon dioxide, which acts as a sweep gas and a mild catalyst. Zinc fluoride or zinc chloride may also be used as catalyst.  The preparation of dioctyl and didecyl azelates, and of dioctyl sebacate, is referred to.  Specification 596,392 also is referred to.