The present invention relates to urethane, thiourethane and urea adducts of tertiary amines and the use thereof as catalysts for the crosslinking of aliphatically, cycloaliphatically, araliphatically or aromatically bonded isocyanate groups with one another. The catalysts according to the invention have the particular advantage that they are thermolatent.

The present invention relates to urethane, thiourethane and urea adducts of tertiary amines and the use thereof as catalysts for the crosslinking of aliphatically, cycloaliphatically, araliphatically or aromatically bonded isocyanate groups with one another. The catalysts according to the invention have the particular advantage that they are thermolatent.

An embodiment relates to an isocyanate composition with improved stability and reactivity and a plastic optical lens using the same. The isocyanate composition has improved stability since the content of chlorine in the composition is adjusted to 22-500 ppm, and thus the isocyanate composition can prevent the deterioration in reactivity even in the long-term storage. Therefore, the isocyanate composition according to an example, even when used after long-term storage after preparation, can be prepared, through polymerization with a thiol-based compound, as a polythiourethane-based optical material with excellent physical properties, such as refractive index, Abbe number, transparency, glass transition temperature, and yellowness, and thus the isocyanate composition is useful in fields of glass lenses, a camera lens, and the like.

The present invention relates to a method for preparing an aliphatic isocyanate capable of suppressing the occurrence of side reactions and the production of by-products. The method for preparing an aliphatic isocyanate comprises a step of reacting a salt of an aliphatic amine with phosgene, wherein the reaction step comprises a first reaction step in which phosgene is primarily added and reacted with the salt of an aliphatic amine salt at a temperature of 80 to 100° C., and a second reaction step in which phosgene is secondarily added and reacted with the resultant product of the first reaction step at a temperature of 120 to 160° C., and wherein the amount of the primarily added phosgene is a certain ratio of the total amount of the phosgene.

The invention relates to a method for recovering monomer diisocyanates, which are solid at room temperature, from a distillation residue, said method comprising the following steps: (i) preparing at least one residue which contains diisocyanates, which are solid at room temperature, and (ii) separating the residue in at least one kneader-dryer, paddle-dryer and/or roller-dryer in the presence of less than 2 wt % bitumen, based on the mass of the residue prepared in step (i), into a gaseous portion, containing monomer diisocyanate that is solid at room temperature, and a brittle residue depleted of diisocyanate, which is solid at room temperature.

The present application provides a material for efficiently removing active hydrogen-containing compounds such as alcohol compounds. The present application uses an active hydrogen-containing organic compound scavenger having a bromine content of from 38 to 78 wt % represented by the formula (1) (wherein R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C.sub.1-4 alkyl group, each R.sup.3 independently represents a hydrogen atom, a C.sub.1-4 alkyl group or a bromine atom, m represents at least one selected from the group consisting of 0, 1, 2 and 3, and n represents a real number of 0 or more) (wherein the isocyanate compound may be a single species or a mixture of two or more species, and in the case of a mixture, n represents an average n of the mixture).

The present application provides a material for efficiently removing active hydrogen-containing compounds such as alcohol compounds. The present application uses an active hydrogen-containing organic compound scavenger having a bromine content of from 38 to 78 wt % represented by the formula (1) (wherein R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C.sub.1-4 alkyl group, each R.sup.3 independently represents a hydrogen atom, a C.sub.1-4 alkyl group or a bromine atom, m represents at least one selected from the group consisting of 0, 1, 2 and 3, and n represents a real number of 0 or more) (wherein the isocyanate compound may be a single species or a mixture of two or more species, and in the case of a mixture, n represents an average n of the mixture).

A process for preparing an aromatic isocyanate by direct carbonylation of a nitro aromatic compound by reacting the nitro aromatic compound with carbon monoxide in the presence of a catalyst, characterized in that the catalyst contains a multi metallic material comprising one or more binary intermetallic phases of the general formula A.sub.xB.sub.y wherein: A is one or more element selected from Ni, Ru, Rh, Pd, Ir, Pt and Ag, B is one or more element selected from Sn, Sb, Pb, Zn, Ga, In, Ge and As, x is in the range 0.1-10, y in is in the range 0.1-10.

A process for preparing an aromatic isocyanate by direct carbonylation of a nitro aromatic compound by reacting the nitro aromatic compound with carbon monoxide in the presence of a catalyst, characterized in that the catalyst contains a multi metallic material comprising one or more binary intermetallic phases of the general formula A.sub.xB.sub.y wherein: A is one or more element selected from Ni, Ru, Rh, Pd, Ir, Pt and Ag, B is one or more element selected from Sn, Sb, Pb, Zn, Ga, In, Ge and As, x is in the range 0.1-10, y in is in the range 0.1-10.

A difunctional biphenyl compounds corresponding to formula (I)

##STR00001##

wherein Alk, Alk and R are as defined in the description. These compounds are suitable as hardeners for thermosetting resins, especially epoxy resins.