The present invention is directed to a method for making a di(aminoaryl)fluorene compound that includes the steps of: (a) reacting a fluorenone compound according structure (I) with excess aminobenzene according to structure (II) wherein: each R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.12, and R.sup.13 is independently a group that is inert in the polymerization of epoxy compounds, and R.sup.11 is H or (C.sub.1-C.sub.6)alkyl, in the presence of an acid catalyst, in a liquid medium comprising an aromatic or substituted aromatic solvent having a boiling point of greater than or equal to 150° C. and in the presence of an acid catalyst, in a liquid medium comprising an aromatic or substituted aromatic solvent having a boiling point of greater than or equal to 150° C. and from which the di(aminoaryl)fluorene compound is crystallizable, to form a crude product mixture comprising the di(aminoaryl)fluorene compound, (b) crystallizing di(aminoaryl)fluorene compound in the product mixture, and (c) separating the product mixture into crystallized di(aminoaryl)fluorene compound and a filtrate. ##STR00001##

The present invention is directed to a method for making a di(aminoaryl)fluorene compound that includes the steps of: (a) reacting a fluorenone compound according structure (I) with excess aminobenzene according to structure (II) wherein: each R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.12, and R.sup.13 is independently a group that is inert in the polymerization of epoxy compounds, and R.sup.11 is H or (C.sub.1-C.sub.6)alkyl, in the presence of an acid catalyst, in a liquid medium comprising an aromatic or substituted aromatic solvent having a boiling point of greater than or equal to 150° C. and in the presence of an acid catalyst, in a liquid medium comprising an aromatic or substituted aromatic solvent having a boiling point of greater than or equal to 150° C. and from which the di(aminoaryl)fluorene compound is crystallizable, to form a crude product mixture comprising the di(aminoaryl)fluorene compound, (b) crystallizing di(aminoaryl)fluorene compound in the product mixture, and (c) separating the product mixture into crystallized di(aminoaryl)fluorene compound and a filtrate. ##STR00001##

A method of removing carbon dioxide from a carbonate-containing diaminoalkane solution, the method including passing the carbonate-containing diaminoalkane solution through a membrane module, and a method of preparing diaminoalkane including the same.

A method of removing carbon dioxide from a carbonate-containing diaminoalkane solution, the method including passing the carbonate-containing diaminoalkane solution through a membrane module, and a method of preparing diaminoalkane including the same.

In one embodiment, the invention presents a process for the preparation of N-alkyl polyamines that includes (i) the conversion of an amino alcohol to an aminoalkyl alkylating agent with a halo or aldehyde reactive group and (ii) the addition of amines to an amine-containing alkylating agent to make an N-alkyl polyamine.

In one embodiment, the invention presents a process for the preparation of N-alkyl polyamines that includes (i) the conversion of an amino alcohol to an aminoalkyl alkylating agent with a halo or aldehyde reactive group and (ii) the addition of amines to an amine-containing alkylating agent to make an N-alkyl polyamine.

A process for fine purification of isophoronediamine (IPDA), including producing IPDA by aminating hydrogenation of isophorone nitrile in the presence of at least ammonia, hydrogen, a a hydrogenation catalyst and optionally further additions to obtain a crude IPDA, and subjecting the crude IPDA to a fine purification via two vacuum distillation columns, wherein in the first vacuum distillation column the removal of any remaining relatively low-boiling byproducts is effected and in the second vacuum distillation column the IPDA is obtained in pure form as tops and thus separated from the organic residues, and wherein the first vacuum distillation column has vacuum distillation column has a partial condenser fitted to it.

A process for fine purification of isophoronediamine (IPDA), including producing IPDA by aminating hydrogenation of isophorone nitrile in the presence of at least ammonia, hydrogen, a a hydrogenation catalyst and optionally further additions to obtain a crude IPDA, and subjecting the crude IPDA to a fine purification via two vacuum distillation columns, wherein in the first vacuum distillation column the removal of any remaining relatively low-boiling byproducts is effected and in the second vacuum distillation column the IPDA is obtained in pure form as tops and thus separated from the organic residues, and wherein the first vacuum distillation column has vacuum distillation column has a partial condenser fitted to it.

A process for fine purification of isophoronediamine (IPDA), including producing IPDA by aminating hydrogenation of isophorone nitrile in the presence of at least ammonia, hydrogen, a a hydrogenation catalyst and optionally further additions to obtain a crude IPDA, and subjecting the crude IPDA to a fine purification via two vacuum distillation columns, wherein in the first vacuum distillation column the removal of any remaining relatively low-boiling byproducts is effected and in the second vacuum distillation column the IPDA is obtained in pure form as tops and thus separated from the organic residues, and wherein the first vacuum distillation column has vacuum distillation column has a partial condenser fitted to it.

The present invention relates to a process for purifying ethylenediamine (EDA) by distillation, wherein the process comprises the steps a) and b). In step a), a mixture (G1) comprising water, EDA and N-methylethylenediamine (N-MeEDA) is fed into a distillation apparatus (D1), and the major part of the water comprised in the mixture (G1) is separated off overhead at a pressure of greater than 4.8 bara. From the bottom of (D1), the water-enriched mixture (G2) is fed into a distillation apparatus (D2) in step b). At the top of (D2), the major part of the N-MeEDA is distilled off. The stream (S3) obtained from the bottom of (D2) comprises EDA, with the components water and N-MeEDA comprised in the mixture (G1) having been largely or completely removed. Further distillation steps can optionally be carried out in order to obtain pure EDA, for example when diethylenetriamine (DETA) is additionally comprised in the mixture (G1). If ammonia is additionally comprised in the mixture (G1), an ammonia removal is preferably additionally carried out before carrying out the step a) in the process of the invention.