摘要:
A process for production of polyamines of the diphenylmethane series through a condensation reaction of aniline with formaldehyde in the presence of an acid catalyst, neutralization of the acid catalyst after reaction completion, and distillation of the resultant polyamine mixture is described. The key feature of the process is the abrupt increase in reaction temperature after the condensation reaction or after the first rearrangement step.
摘要:
A process for the selective removal of sulfur-containing gases from industrial gases or waste gases by treatment of gases with basic substances, characterized in that the basic substances are carrier materials containing tertiary amino groups corresponding to the following formula: ##STR1## in which m and n individually are 1 or 2,x and y individually are from 0 to 10 and preferably 0 to 2,R and R' individually are hydrogen or alkyl andR" is hydrogen or methyl.
摘要:
The invention provides a process for the preparation of polyamines of the diphenylmethane series. This process comprises a) reacting aniline and formaldehyde in a molar ratio of 1.5:1 to 6:1, in the presence of an acid catalyst at temperatures of 20° C. to 100° C., in which the water content in the acid reaction mixture is
摘要:
This invention relates to an improved process for the preparation of polynuclear aromatic polyamines in which the reaction product is prepared by condensing aniline with formaldehyde in the presence of water and acidic catalysts and is worked up by extraction with a hydrophobic solvent. The acid catalyst that accumulates in the aqueous phase during the extraction process is reused.
摘要:
The invention provides an improved process for preparing diamines and polyamines from the diphenylmethane series by reacting aniline and formaldehyde in the presence of an acid catalyst, the improvement involving the aniline containing less than about 3 wt. % of diamines and polyamines from the diphenylmethane series, based on the weight of the aniline.
摘要:
The invention provides a process for the preparation of polyamines of the diphenylmethane series. This process comprises a) reacting aniline and formaldehyde in a molar ratio of 1.5:1 to 6:1, in the presence of an acid catalyst at temperatures of 20° C. to 100° C., in which the water content in the acid reaction mixture is
摘要:
Polyisocyanates of the diphenyl methane series having reduced color values are obtained by a) reacting aniline and formaldehyde in the presence of an acid catalyst to form a polyamine, b) neutralizing the reaction mixture containing polyamine with a base, c) separating the neutralized mixture into the aqueous and the organic phases, d) adding a base to the organic phase and then e) phosgenating the resulting polyamine to produce the corresponding polyisocyanate.
摘要:
The invention relates to an improved process for the production of polynuclear aromatic polyamines by condensation of aniline with formaldehyde in the presence of water and acidic catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent, the acid catalyst accumulating in the aqueous phase of the extraction step being reused.
摘要:
The invention relates to an improved process for the production of polynuclear aromatic polyamines by condensation of aniline with formaldehyde in the presence of water and acidic catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent, the acid catalyst accumulating in the aqueous phase of the extraction step being reused.
摘要:
The present invention relates to an improved process for the preparation of multinuclear aromatic polyamines by the condensation of aniline with formaldehyde in the presence of water and acid catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent. The acid catalyst obtained in the aqueous phase of extraction is reused.