Abstract: An in-line spectrometric method for determining the distillation residue content in an opaque, dark-colored mixture containing an isocyanate and tar-like materials (residue) during the isocyanate production process. A probe capable of directing light at wavelengths of from 1050 to 2150 nm is inserted in a stream of the residue-containing mixture and light is transmitted through the stream. Light absorption data is collected and a near-infrared spectrum is generated. The residue content is then determined using a chemometric model. Knowledge of the residue content makes it possible to control and optimize the distillation process.

Abstract: The present invention is directed to a process for the catalytic hydrogenation of a starting material containing 4,4'-diamino-diphenylmethane (4,4'-MDA) or its mixtures with 2,4'-diamino-diphenylmethane, 2,2'-diamino-diphenylmethane and/or higher ring compounds of the diphenylmethane series to a hydrogenation product having a trans-trans isomer content of 4,4'-diamino-dicyclohexylmethane (4,4'-HMDA) of about 15 to 40 weight percent, based on the diamine content of the hydrogenated product, by continuously hydrogenating in at least one fixed bed reactor at a temperature of about 100.degree. to 190.degree. C. and a pressure of about 50 to 350 bar in the presence of a ruthenium catalyst on a catalyst support having a BET surface area of about 70 to 280 m.sup.2 /g and an average pore diameter d.sub.p of about 10 to 320 .ANG., the catalyst being prepared by impregnating the catalyst support to a penetration depth of at least about 50 .mu.

Abstract: The invention is directed to a process for the production of an isocyanate which is both stable and liquid at room temperature comprising reacting pure diphenylmethane diisocyanate or crude diphenylmethane diisocyanate with a diol of the formula, ##STR1## wherein R is a C.sub.2 to a C.sub.5 aliphatic radical, at a temperature of from 20.degree. to 110.degree. C., in a ratio such that the resultant product has an isocyanate group content of from 20 to 30%, by weight and to the products produced therefrom.

Abstract: The present invention is directed to a process for the catalytic hydrogenation of di(4-aminophenyl)methane to a liquid di(4-aminocyclohexyl)methane containing from 15 to 40% by weight of the trans,trans isomer comprising hydrogenating di(4-aminophenyl)methane at a hydrogen pressure of at least 500 psi and at a temperature of from 100.degree. to 300.degree. C., in the presence of a ruthenium catalyst supported on an inert carrier, said catalyst being moderated with from 65 to 700% by weight, based on the weight of the ruthenium of a compound selected from the group consisting of nitrates and sulfates of alkali metals and alkaline earth metals.

Abstract: The present invention relates to an improved process for the catalytic hydrogenation of di(4-amino-phenyl)methane to a liquid di(4-aminocyclohexyl)methane mixture containing from 15 to 40% by weight and preferably from 18.5 to 23.5% by weight, of the trans, trans isomer. The invention resides in the use of an unsupported ruthenium dioxide catalyst under specific process conditions. During the hydrogenation reaction, a pressure of at least 2500 psi and a temperature of from 150.degree. to 210.degree. C. must be maintained.

Abstract: The present invention relates to an improved process for the catalytic hydrogenation of di(4-aminophenyl) methane to a liquid di(4-aminocyclohexyl) methane mixture containing from 15 to 40% by weight of the trans, trans isomer. The invention resides in the use of a ruthenium-on-alumina catalyst, the use of an aliphatic alcohol during hydrogenation and the use of ammonia during hydrogenation, with the hydrogenation being conducted under specific process conditions. The hydrogenation reaction is conducted for no more than about sixty minutes at a temperature of from 150.degree. to 217.degree. C. and at a hydrogen pressure of at least 500 psi.

Abstract: The present invention is directed to a room temperature storage stable liquid isocyanate comprising the reaction product of a diphenylmethane diisocyanate and an N-substituted ethanolamine of the formula: ##STR1## wherein R represents a C.sub.6 -C.sub.10 aryl and wherein at least one R.sub.1 represents hydrogen and the other R.sub.1 is selected from the group consisting of hydrogen, C.sub.1 to C.sub.3 alkyl and phenyl.