摘要:
A process for the removal of acids from reaction mixtures, comprising at least one product of value which is sparingly soluble in water, by at least one unpolar amine as an auxiliary base, which includes: a) reacting the auxiliary base with the acid with formation of a salt; b) reacting the salt formed in step a) with a further base which accepts the acid with liberation of the auxiliary base and combines with the acid to be accepted from the auxiliary base to form a salt which is very readily soluble in water; c) extraction of the mixture obtained in step b) with water or an aqueous medium, wherein the salt of the further base dissolves in the aqueous phase and the product of value, or the solution of the product of value, in a suitable solvent and the auxiliary base form at least one separate nonaqueous phase; and d) removal by distillation of at least part of any solvent present from the at least one nonaqueous phase obtained in step c), to form two nonmiscible liquid phases.
摘要:
A process for the removal of acids from reaction mixtures, comprising at least one product of value which is sparingly soluble in water, by at least one unpolar amine as an auxiliary base, which includes: a) reacting the auxiliary base with the acid with formation of a salt; b) reacting the salt formed in step a) with a further base which accepts the acid with liberation of the auxiliary base and combines with the acid to be accepted from the auxiliary base to form a salt which is very readily soluble in water; c) extraction of the mixture obtained in step b) with water or an aqueous medium, wherein the salt of the further base dissolves in the aqueous phase and the product of value, or the solution of the product of value, in a suitable solvent and the auxiliary base form at least one separate nonaqueous phase; and d) removal by distillation of at least part of any solvent present from the at least one nonaqueous phase obtained in step c), to form two nonmiscible liquid phases.
摘要:
The present invention relates to a process for the production of isocyanates, preferably diisocyanates and polyisocyanates of the diphenylmethane series (MDI), by reacting an amine with phosgene in the liquid phase or in the gas phase to form the corresponding isocyanates, subsequent removal of the solvent in at least two steps to obtain at least two solvent streams, individual treatment of the at least two solvent streams, and re-circulation of at least a portion of the solvent streams.
摘要:
The present invention relates to a process for the production of isocyanates, preferably diisocyanates and polyisocyanates of the diphenylmethane series (MDI), by reacting an amine with phosgene in the liquid phase or in the gas phase to form the corresponding isocyanates, subsequent removal of the solvent in at least two steps to obtain at least two solvent streams, individual treatment of the at least two solvent streams, and recirculation of at least a portion of the solvent streams.
摘要:
The invention relates to a process for preparing methylenedi(phenyl isocyanate), which comprises (a) the phosgenation of two-ring and/or multiring methylenedi(phenylamine), (b) the fractionation of the crude methylenedi(phenyl isocyanate) obtained to give two-ring and multiring isomers, (c) the purification and/or fractionation of the resulting mixture of two-ring isomers of methylenedi(phenyl isocyanate) and (d) the storage of the mixtures obtained in step (c) or in step (b), wherein part of the stored mixtures is reused by means of recirculation in at least one of steps (b) or (c).
摘要:
A process is proposed for preparing isocyanates by thermally cleaving carbamates to obtain a carbamate cleavage gas comprising the corresponding isocyanate and the corresponding alcohol, which comprises quenching the carbamate cleavage gas in the presence of an ether which functions as an inhibitor for the reverse reaction of the isocyanate with the alcohol.
摘要:
The present invention relates to an implantable chamber (1) with a connecting element (2), comprising a connecting sleeve (6) and a surrounding contact surface (7), an insert element (3), comprising an insert sleeve (8) and a surrounding abutment surface (9). The insert sleeve (8) is inserted into the connecting sleeve (6) of the connecting element (2). The implantable chamber (1) further comprises a cap (4) with a surrounding edge (11), the cap (4) partly covering the connecting element (2) and the insert element (3), leaving an opening (13) on one side. The implantable chamber (1) contains a passive resonance circuit (14) with an inductance and a capacitance, the passive resonance circuit (14) surrounding at least part of a cavity (15) inside the insert element (3).
摘要:
A pipe anchor having: a base cradle with a lug; a top cradle with a lug and secured to the base cradle so as to encircle a pipe within the base cradle and the top cradle; a locking mechanism with opposite mating components attached to the base cradle and the top cradle; at least one lug attached to the pipe; and insulation material filling a space between the pipe and the cradles, wherein the insulation material engages the at least one lug of the pipe and the lugs of the cradles.