Abstract: The invention relates to a method for producing diaminodiphenyl alkanes, wherein an aromatic amine, which can be substituted or unsubstituted, is reacted with a C1-C3 aldehyde in the presence of a heterogeneous catalyst, said catalyst being a mesoporous acidic ion exchanger based on a divinylbenzene/styrene copolymer and the catalyst having acid centers in a concentration of 2 to 6 eq/kg measured according to DIN 54403 and the average pore diameter of the catalyst particles being 10 to 32 nm measured according to ASTM D 4222, and the content of polynuclear compounds in the reaction mixture being >10 and ˜15% by weight.

Abstract: The invention relates to a process for preparing methylenediphenyldiamine (MDA), comprising the following steps a) to c): a) converting formaldehyde and aniline to aminal b) removing water from the aminal obtained in step a) to establish a water content of 0 to 5% by weight based on the aminal, and c) adding an acidic catalyst to the aminal having a water content of 0 to 5% by weight, which comprises using formaldehyde in step a) in the form of highly concentrated formaldehyde with a CH2O content of >50% by weight and preparing the formaldehyde by oxidative dehydrogenation from methanol.

Abstract: The present disclosure relates to compositions, systems, and methods of forming an amine (e.g., methylenedianiline (MDA)) using an acid catalyst including, for example, a metal oxide-silica catalyst calcined at temperature(s) of about ?500° C. to form a solid acid silica-metal oxide catalyst. A metal oxide of a solid acid silica-metal oxide catalyst may comprise alumina. A process for making a solid acid silica-metal oxide catalyst may comprise calcining an amorphous alumina-silica material at temperature(s) of about ?500° C. and/or under an anhydrous and/or inert atmosphere. A rearrangement reaction of the condensation product of aniline and formaldehyde in the presence of a solid acid silica-metal oxide catalyst may yield more MDA and/or more desirable isomer(s) of MDA than reactions performed with a corresponding catalyst calcined at temperature(s) of less than 500° C.

Abstract: The invention relates to a method for producing diaminodiphenyl alkanes, wherein an aromatic amine, which can be substituted or unsubstituted, is reacted with a C1-C3 aldehyde in the presence of a heterogeneous catalyst, said catalyst being a mesoporous acidic ion exchanger based on a divinylbenzene/styrene copolymer and the catalyst having acid centers in a concentration of 4 to 6 eq/kg as measured according to DIN 54 403 and the average pore diameter of the catalyst particles being 10 to 32 nm as measured according to ASTM D 4222 10, and the content of polynuclear compounds in the reaction mixture being ?10% by weight.

Abstract: The present disclosure relates to compositions, systems, and methods of forming an amine (e.g., methylenedianiline (MDA)) using an acid catalyst including, for example, a metal oxide-silica catalyst calcined at temperature(s) of about ?500° C. to form a solid acid silica-metal oxide catalyst. A metal oxide of a solid acid silica-metal oxide catalyst may comprise alumina. A process for making a solid acid silica-metal oxide catalyst may comprise calcining an amorphous alumina-silica material at temperature(s) of about ?500° C. and/or under an anhydrous and/or inert atmosphere. A rearrangement reaction of the condensation product of aniline and formaldehyde in the presence of a solid acid silica-metal oxide catalyst may yield more MDA and/or more desirable isomer(s) of MDA than reactions performed with a corresponding catalyst calcined at temperature(s) of less than 500° C.

Abstract: The present invention provides a method of preparing polymethylene-polyphenyl-polyamine (briefly referred to as polyamine, DAM), in which a high gravity rotating bed is used as the mixing reactor of formaldehyde and aniline hydrochloride, the mixing solution of aniline hydrochloride and circulation solution and the formaldehyde are fed into the high gravity rotating bed reactor proportionally to carry out mixing and condensation reaction under a condition of a very high gravity; the materials leaving the high gravity rotating bed reactor is introduced into a stirred vessel to proceed with the pre-condensation reaction and obtain a condensation solution; and the process steps of heating, molecular rearrangement, neutralization, water washing and purification, etc. are completed to obtain the refined DAM.

Abstract: The invention relates to a method for producing diaminodiphenyl alkanes, wherein an aromatic amine, which can be substituted or unsubstituted, is reacted with a C1-C3 aldehyde in the presence of a heterogeneous catalyst, said catalyst being a mesoporous acidic ion exchanger based on a divinylbenzene/styrene copolymer and the catalyst having acid centers in a concentration of 2 to 6 eq/kg measured according to DIN 54 403 and the average pore diameter of the catalyst particles being 10 to 32 nm measured according to ASTM D 4222, and the content of polynuclear compounds in the reaction mixture being >10 and ?15% by weight.

Abstract: The invention relates to a method for producing diaminodiphenyl alkanes, wherein an aromatic amine, which can be substituted or unsubstituted, is reacted with a C1-C3 aldehyde in the presence of a heterogeneous catalyst, said catalyst being a mesoporous acidic ion exchanger based on a divinylbenzene/styrene copolymer and the catalyst having acid centers in a concentration of 4 to 6 eq/kg as measured according to DIN 54 403 and the average pore diameter of the catalyst particles being 10 to 32 nm as measured according to ASTM D 4222 10, and the content of polynuclear compounds in the reaction mixture being ?10% by weight.

Abstract: 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.

Abstract: Di- and polyamines of the diphenylmethane series are produced by a) converting nitrobenzene and methanol in the presence of a catalyst to aniline, formaldehyde and carbon monoxide, and then b) converting the aniline and formaldehyde produced in step a) in the presence of an acid catalyst to di- and polyamines of the diphenylmethane series, and c) converting the carbon monoxide produced in step a) with chlorine to phosgene.

Abstract: A process is described for preparing diaminodiarylmethanes comprising the steps a) reacting an aromatic amine with a methylene-donating agent in the presence of homogeneous acid catalysts, b) removing the homogeneous acid catalyst from the reaction product, c) working up and purifying the reaction product, which comprises removing the homogeneous acid catalyst from the reaction mixture by adsorption to a solid adsorbent.

Abstract: Method of preparing diaminodiphenylmethane and higher homologues thereof from aniline and formaldehyde in the presence of heterogeneous solid acid catalysts selected from (a) delaminated zeolites and/or (b) metal silicate catalysts having an ordered mesoporous pore structure and/or (c) delaminated phyllosilicates.

Abstract: A process for preparing methane diphenyl diamine (MDA) or a mixture of methane diphenyl diamine (MDA) and its higher homologues with a controlled isomer distribution using a modified zeolite having “shape selectivity”. The mixture contains compounds having the following general formula (I): where R represents a hydrogen atom or a C1 to C8 (iso)alkyl group, a C4 to C10 cycloalkyl group or a C6 to C12 aromatic group and n is a whole number greater than or equal to one so as to give a functionality of 2 to 6.

Abstract: A process for preparing methane diphenyl diamine (MDA) or a mixture of methane diphenyl diamine (MDA) and its higher homologues with a controlled isomer distribution using a silanised zeolite have “shape selectivity”. The mixture contains compounds having the following general formula (I): where R represents a hydrogen atom or a C1 to C8 (iso) alkyl group, a C4 to C10 cycloalkyl group or a C6 to C12 aromatic group and n is a whole number greater than or equal to one so as to give a functionally of 2 to 6.

Abstract: Described is a triarylmethane dye of the formula I where R1 and R2 are independently methyl, ethyl or hydroxyethyl, Q is substituted or unsubstituited phenyl or naphthyl and A? is the equivalent of an anion. It does not detach carcinogenic Michler's ketone.

Abstract: Process for the production of methylenedianiline and its higher homologous products which comprises reacting aniline, or one of its derivatives, and formaldehyde, or one of its precursors, in one or two reactors in the presence of a solid acid catalyst selected from a zeolite or a silico-alumina, distilling off the reaction water or the water added with the reagents.

Abstract: Disclosed herein is a process for preparing a reaction product containing methylene diphenylamine, comprising reacting aniline and formaldehyde in the presence of an acid catalyst wherein the acid level of the resulting reaction mixture is reduced during digestion of the reaction mixture.

Abstract: The present invention concerns a process for the production of methylenedianiline (MDA) having a high monomer content.

Abstract: A method of reacting a solution comprising a mixture of chemical compounds which are in chemical equilibrium with one another with at least one further chemical compound (9) is provided. The method comprises the following steps: fractionation of the solution by means of a separation method to give at least two fractions (5, 6) which are enriched in different chemical compounds of the mixture; and reaction of a fraction (5) with the further chemical compound or compounds (9). The fractionation is advantageously carried out using a film evaporator (1). Unreacted fractions (6) can be recirculated via a residence time vessel (3) back to the fractionation step. The method is particularly suitable for reactions of an aqueous formaldehyde solution in which various components of the solution (formaldehyde, methylene glycol, polyoxymethylene glycols) react in different ways.

Abstract: In a process for preparing aromatic polyamine mixtures which contain compounds of the formula (I), H2N—A—CH2—B—NH2  (I) where A and B are 1,4-phenylene radicals each of which independently of one another can have 1 to 4 substituents selected from C1-20 alkyls and halogens, a compound of the formula (IV) H—A—NH—CH2—HN—B—H  (IV) and/or a compound of the formula (V) H—A—NH—CH2—B—NH2  (V) where A and B are substituted as above, are reacted at from 20° C. to 200° C.

Abstract: The invention relates to immobilized palladium complexes, to a process for their preparation, to their use as catalysts and to a process for the preparation of arylamines using immobilized palladium complexes.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and their use.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to their use.

Abstract: The invention relates to a process for the fractionation and purification of mixtures of aromatic polyamines and to the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and the use thereof.

Abstract: Disclosed herein is a process for preparing a reaction product containing methylene diphenylamine comprising reacting aniline with an aldehyde, in the presence of a low level of an acid wherein the acid level is reduced before digesting reaction mixture at a high temperature which is sufficient to effect a rearrangement of the intermediates to produce a reaction product containing methylene diphenylamines and low levels of impurities.

Abstract: Process for the preparation of 4,4'-diaminodiphenylmethane and its derivatives.4,4'-diaminodiphenylmethane and its derivatives are prepared by the condensation of aniline, or its derivative, and aldehyde, or its precursor and/or isomerization of appropriate intermediate products. The reaction proceeds with zeolites acting as catalysts; these catalysts, which are selected in accordance with the reaction to be effected, are preferably zeolites based on Si, Al and B; Si, Al and Ti; Ti and Fe; ZSM-5; or Y zeolites.

Abstract: Bis-(amino-nitrophenyl)-methane can be produced in one stage with an approximately quantitative yield by condensing o-nitraniline and formaldehyde in water at a temperature of between 20.degree. and 40.degree. C. in the presence of sulfuric acid, and subsequently rearranging the formed methylene-bis-(o-nitraniline) by treatment of the reaction mixture at a temperature of between 90.degree. and 100.degree. C.

Abstract: The invention relates to compounds of the formula ##STR1## wherein R.sup.1 is hydrogen or an acyl group in which a non-aromatic hydrocarbon group of 1 to 6 carbon atoms is attached to the CO-group and R.sup.2 is H or NO.sub.2, if R.sup.1 is an acyl group, or is NO.sub.2, if R.sup.1 is hydrogen.

Abstract: Polyamines are prepared from aromatic amines and aliphatic aldehydes or ketones using cationic or acid ion exchange resins as a catalyst in an essentially oxygen-free atmosphere with the aromatic amines being distilled and protected from the atmosphere.

Abstract: An improvement is described in the process of preparing polymethylene polyphenyl polyamines by condensing aniline and formaldehyde in the presence of an acid catalyst in the initial condensation. The improvement enables the amount of acid which has to be neutralized at the end of the reaction to be substantially reduced or eliminated entirely. This is accomplished without sacrifice of the high level of 4,4'-isomer of di(aminophenyl)methane normally present in the diamine content of the polyamines when a mineral acid catalyst is employed in the condensation.

Abstract: Covers a method of preparing diaminodiphenylmethanes and higher homologues thereof which comprises the step of condensing aniline and formaldehyde in the presence of a molybdenum aluminide catalyst.

Abstract: Covers a method of preparing diaminodiphenylmethanes and higher homologues thereof which comprises the step of condensing aniline and formaldehyde in the presence of a silver tungstate catalyst.

Abstract: Covers a method of preparing diaminodiphenylmethanes and higher homologues thereof which comprises the step of condensing aniline and formaldehyde in the presence of a tungsten boride or sulfide catalyst.

Abstract: Covers a method of preparing diaminodiphenylmethanes and higher homologues thereof which comprises the step of condensing aniline and formaldehyde in the presence of a tungsten silicide catalyst.