Abstract: The present invention is directed to a process for the production of polyamines of the diphenylmethane series having a high diamine content and a low 2,2'-diamino-diphenylmethane content by condensing aniline with formaldehyde in the presence of hydrochloric acid as catalyst, neutralizing the acid catalyst at the end of the condensation reaction and working up the polyamine mixture thus obtained by distillation, characterized in that(a) in a first reaction stage, from 2.0 to 3.5 moles of aniline are reacted with 1 mole of formaldehyde in the presence of hydrochloric acid or a condensation product produced from 2.0 to 3.5 moles of aniline and 1 mole of formaldehyde in the absence of acid catalyst is reacted in the presence of hydrochloric acid at a degree of protonation maintained at 40 to 60% at temperatures below 50.degree. C.

Abstract: This invention relates to a process for the production of non-cellular polyurethane ureas elastomers using a chain-extender mixture produced from asymmetrically alkyl-substituted anilines by condensation with formaldehyde. The chain-extending agents used in the instant invention show medium reactivity to compounds containing isocyanate groups. These chain-extending agents may be processed both in high-pressure and in low-pressure metering and mixing units because they are either liquid at room temperature or can be melted at relatively low temperatures (below 55.degree. C.). The homogeneous, i.e. non-cellular, polyurethane urea elastomers obtained in the instant invention are distinguished by having excellent mechanical properties.

Abstract: A process is provided for making an aromatic polyamine by condensing an aromatic amine with formaldehyde wherein the reaction mixture is maintained at a boiling temperature under reflux and formaldehyde is mixed with the stream of condensed vapors returning to the reactor from the reflux condenser. The process produces a diphenylmethane polyamine particularly well suited for phosgenation to form the corresponding polyisocyanate.

Abstract: Triaryl-methane dyestuffs which are free from sulfonic acid and carboxylic acid groups and are selected from the group consisting of dyestuffs having one of the following four formulae: ##STR1## wherein R is alkyl, aralkyl, cycloalkyl or aryl; R.sub.1 is hydrogen, alkyl, aralkyl or cycloalkyl; R.sub.2 is alkyl, aralkyl, cycloalkyl or aryl; R.sub.1 and R.sub.2 additionally including divalent alkylene when joined together with the nitrogen or with a carbon atom in the o-position in the ring A to form a heterocyclic ring; R.sub.3 is hydrogen, alkyl, aralkyl, aryl, aralkoxy, aryloxy, halogen, carboxylic acid ester radical, carbonamido, sulfonamido, cyano, nitro, alkylsulfonyl, aryalkylsulfonyl, arylsulfonyl or acyl; and X is the radical of an anion; ##STR2## wherein R is alkyl or cycloalkyl; R.sub.1 is hydrogen, alkyl, aralkyl, cycloalkyl or aryl; R.sub.2 is alkyl, cycloalkyl, aralkyl or aryl, halogen or cyano; R.sub.1 and R.sub.

Abstract: A process for condensing aromatic amines with formaldehyde in the presence of water is disclosed whereby an inhomogeneous mixture of a reaction product containing a large amount of 4,4'-diamino diphenylmethane is obtained which inhomogenity is due to a large quantity of water which is either present at the beginning of the condensation reaction or which if the reaction is carried out in the presence of relatively small amounts of water is obtained by the subsequent addition of water. The two phases are separated into an organic phase which is directly worked up by distillation without the necessity of an alkaline treatment. The aqueous phase is recycled to the beginning of the process. The process has the advantage of elimination of a salt free effluent, no consumption of acid catalyst and elimination of the need for alkaline reagents.

Abstract: The present invention relates to stable solutions of urea diisocyanates in diisocyanates which are free from urea groups which solutions are prepared by a process which comprises reacting in the absence of a solvent at a temperature from about -20.degree.C to about 80.degree.C an organic diisocyanate with a bis-secondary diamine such that the NCO/NH-ratio is from 2.5 : 1 to 20 : 1. The solutions of the invention are well-suited for use as isocyanate component for the preparation of polyurethane resins by the isocyanate polyaddition process.

Abstract: A process for the production of aromatic polyamines comprising condensing primary or secondary aromatic amines with formaldehyde or a formaldehyde precursor in the presence of an acid catalyst and liberating the polyamines on completion of condensation by the addition of a basically reacting reagent, wherein a mixture containing amine, catalyst, aldehyde, precondensates formed therefrom, and water, issuing from a mixer at a maximum temperature of about 40.degree.C., is separated intoA. a side stream in which the heat liberated from the reacting mixture is dissipated in a heat exchanger following dilution of the total quantity of mixture of amine and catalyst, cooled to below about 40.degree.C., required for the reaction and the mixture thus obtained is reintroduced at a temperature of at most about 40.degree.C. into the mixer where formaldehyde is added, andB. a main stream which is pumped, through a reaction zone kept at a maximum of about 40.degree.C.