Aromatic polyamines and their preparation

Claim 3

The method of claim 1 wherein the solid acidic catalyst is an acid activated clay and wherein the temperature selected for determining the 2,4'-isomer concentration is said second temperature.

Claim 4

The method of claim 1 wherein said solid acidic catalyst is selected from the group consisting of silica-alumina catalysts and silica-magnesia catalysts and wherein the temperature selected for determining the 2,4'-isomer concentration is said first temperature.

Claim 5

The method of claim 1 wherein the solid acidic catalyst and aniline are preheated to the reaction temperature prior to reacting the aniline and formaldehyde.

Claim 6

In a process for producing a reaction product of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylene polyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 15wt. % and about 95 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture which comprises: A. heating an aniline-formaldehyde mixture containing from about one to about ten mols of aniline for each mol of formaldehyde; B. in the presence of a solid acidic siliceous catalyst of the group consisting of acid-activated siliceous clays and silica-alumina of silica-magnesia catalysts; C. at a reaction temperature within the range of about 80° to 300° C.; and D. controlling the proportion of 2,4'-diaminodiphenylmethane in the said reaction products by controlling the reaction temperature within said range when the catalyst is an acid-activated siliceous clay and by controlling the starting temperature of the reaction within said range when the catalyst is silica-alumina or silica-magnesia.

Claim 7

In a process for producing a reaction product of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylene polyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 15wt. % and about 95 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture which comprises: A. heating an aniline-formaldehyde mixture containing from about one to about ten mols of aniline for each mol of formaldehyde; B. in the presence of a solid acidic siliceous catalyst of the group consisting of acid-activated siliceous clays and silica-alumina of silica-magnesia catalysts; C. at a reaction temperature within the range of about 80° to 300° C.; and D. controlling the proportion of 2,4'-diaminodiphenylmethane in the said reaction products by controlling the reaction temperature within said range when the catalyst is an acid-activated siliceous clay and by controlling the starting temperature of the reaction within said range when the catalyst is silica-alumina or silica-magnesia.

Claim 8

The method of claim 5 wherein comprises conducting the process of said claim and then, E. digesting the reaction product at a temperature of about 175° to about 200° C, in presence of the catalyst for about one to about five hours to convert secondary polyamine groups in the polyamines of the reaction prdouct to polymethylene polyphenylpolyamines.

Claim 9

In a process for producing a reaction poduct of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylenepolyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 15 and about 95 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture while avoiding the presence of secondary polyamines therein which comprises the steps of: A. reacting about 1 to about 10 mols aniline per mol formaldehyde in the presence of a solid acidic siliceous catalyst of the group consisting of acid-activated siliceous clays and silica-alumina of silica-magnesia catalysts at a first temperature within the range of about 80° to about 150° C. to thereby provide a reaction product comprising diaminodiphenylmethane isomers, secondary amines and higher molecular weight condensation products of aniline and formaldehyde; B. heating said mixture at a second temperature within the range of about 175° to about 250° C. for about 1 to about 5 hours to thereby convert said secondary amines to polyaminopolyphenylmethane compounds; C. controlling the proportion of 2,4'-diaminodiphenylmethane in said reaction products by controlling thetemperature within the ranges of steps (A) or (B)l when the catalyst is an acid-activated siliceous clay and by controlling the starting temperature within the range of step (A) when the catalyst is silica-alumina or silica-magnesia; and D. recovering said diaminodiphenylmethane isomers and higher molecular weight condensation products from the reaction mixture.

Claim 10

In a process for producing a reaction poduct of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylenepolyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 15 and about 95 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture while avoiding the presence of secondary polyamines therein which comprises the steps of: A. reacting about 1 to about 10 mols aniline per mol formaldehyde in the presence of a solid acidic siliceous catalyst of the group consisting of acid-activated siliceous clays and silica-alumina of silica-magnesia catalysts at a first temperature within the range of about 80° to about 150° C. to thereby provide a reaction product comprising diaminodiphenylmethane isomers, secondary amines and higher molecular weight condensation products of aniline and formaldehyde; B. heating said mixture at a second temperature within the range of about 175° to about 250° C. for about 1 to about 5 hours to thereby convert said secondary amines to polyaminopolyphenylmethane compounds; C. controlling the proportion of 2,4'-diaminodiphenylmethane in said reaction products by controlling thetemperature within the ranges of steps (A) or (B)l when the catalyst is an acid-activated siliceous clay and by controlling the starting temperature within the range of step (A) when the catalyst is silica-alumina or silica-magnesia; and D. recovering said diaminodiphenylmethane isomers and higher molecular weight condensation products from the reaction mixture.

Claim 11

In a process for producing a reaction product of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylenepolyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 30 and about 95 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture which comprises: A. heating an aniline-formaldehyde mixture containing from about 1 to about 10 mols of free aniline for each mol of formaldehyde; B. with an acid-activated siliceous clay catalyst; C. at a reaction temperature within the range of about 80° to 250° C.; and D. controlling the proportion of 2,4'-diaminodiphenylmethane in the said reaction products by controlling the reaction temperature within said range.

Claim 12

In a process for producing a reaction product of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylenepolyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 30 and about 95 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture which comprises: A. heating an aniline-formaldehyde mixture containing from about 1 to about 10 mols of free aniline for each mol of formaldehyde; B. with an acid-activated siliceous clay catalyst; C. at a reaction temperature within the range of about 80° to 250° C.; and D. controlling the proportion of 2,4'-diaminodiphenylmethane in the said reaction products by controlling the reaction temperature within said range.

Claim 13

In a process for producing a reaction product of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylenepolyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 15 wt. % and about 50 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture which comprises: A. heating an aniline-formaldehyde mixture containing from about 1 to about 10 mols of free aniline for each mol of formaldehyde; B. with a silica-alumina or silica-magnesia catalyst; C. at a reaction temperature within the range of about 80° to 250° C.; and D. controlling the proportion of 2,4'-diaminodiphenylmethane in the said reaction products by controlling the starting temperature of the reaction within said range.

Claim 14

In a process for producing a reaction product of aniline and formaldehyde which contains a diaminodiphenylmethane mixture together with a mixture of polymethylenepolyphenylpolyamines having from two to four methylene groups, the method of obtaining between about 15 wt. % and about 50 wt. % of 2,4'-diaminodiphenylmethane in said diaminodiphenylmethane mixture which comprises: A. heating an aniline-formaldehyde mixture containing from about 1 to about 10 mols of free aniline for each mol of formaldehyde; B. with a silica-alumina or silica-magnesia catalyst; C. at a reaction temperature within the range of about 80° to 250° C.; and D. controlling the proportion of 2,4'-diaminodiphenylmethane in the said reaction products by controlling the starting temperature of the reaction within said range.

Claim 15

The method of claim 9 wherein the catalyst is a silica-alumina cracking catalyst.

Claim 16

The method of claim 9 wherein the catalyst and the aniline are preheated to the reaction temperature before the formaldehyde is admixed therewith.

Claim 17

A process for producing a reaction product of aniline and formaldehyde as defined in claim 5 wherein the reaction temperature is within the range of about 120° to about 200° C.