Basf Aktiengesellschaft

Friedrich Towae

Franz Merger

Gerhard Nestler

Hans Hellbach

Wolfgang Harder

Rolf Platz

Erich Penzel

Hans-Martin Hutmacher

Waldemar Koehler

Gunther Isbarn

Otto Mattner

Ludwig Schroff, Deceased

The invention describes a process for the preparation of N,o-substituted mono- and/or polyurethanes of formula

Process for the preparation of N,o-substituted mono- and/or polyurethanes

A process for the preparation of aliphatic, cycloaliphatic, arylaliphatic and aliphatic-cycloaliphatic di- and polyurethanes wherein primary aliphatic, cycloaliphatic, arylaliphatic or aliphatic-cycloaliphatic di- or polyamines are reacted with urea and a primary or secondary aliphatic alcohol at temperatures of above 190.degree. C. to 300.degree. C., following which ammonia and other by-products are separated from the aliphatic, cycloaliphatic, arylaliphatic or aliphatic-cycloaliphatic di- or polyurethane product.

Process for the preparation of aliphatic di- and polyurethanes

Process for the preparation of N,o-substituted mono-and/or polyurethanes

Hexamethylene 1,6-diisocyanate and/or isomeric aliphatic diisocyanates where alkylene is of 6 carbon atoms, preferably 2-methylpentamethylene 1,5-diisocyanate and/or 2-ethyltetramethylene 1,4-diisocyanate, are prepared by a process wherein the corresponding dialkylurethanes are vaporized, without decomposition, at from 220.degree. to 300.degree. C., advantageously under reduced pressure, the dialkylurethane vapors are subjected to thermal cleavage under reduced pressure, preferably from 0.1 to 200 mbar, and at above 300.degree. C., preferably from 310.degree. to 480.degree. C. The cleavage products are fractionally condensed with the product obtained in the first condensation stage consisting predominantly of the diisocyanates, while that obtained in the second condensation stage is the alcohol.

Preparation of hexamethylene 1,6-diisocyanate and/or isomeric

A method for the production of N-aryl substituted di- and polyurethanes in high yield, by the reaction of an aromatic di- or polyamine with urea and alcohol at high temperatures. The di- and polyurethanes thus produced have utility as isocyanate precursors.

Process for the preparation of N-aryl di- or polyurethanes

This invention discloses a non-phosgene process for the preparation of 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate by the reaction of the precursor diamine with urea and an aliphatic alcohol in the presence of a dialkyl carbonate and an alkyl carbonate. The intermediate diurethane is separated from starting materials and by-products and thermally cleaved to alcohol and diisocyanate which are separated by fractional condensation of the products from the vapor state. This process gives high yields of the desired diisocyanate and lends itself particularly to continuous processing.

Multiple-step process for the preparation of

Hexamethylene diisocyanate and/or isomeric alkylene diisocyanates having 6 carbon atoms in the alkylene radical, preferably 2-methylpentamethylene 1,5-diisocyanate and/or 2-ethyltetramethylene 1,4-diisocyanate are prepared without the use of phosgene in a multiple-step process by means of

Multiple-step process for the preparation of hexamethylene

N- and O-substituted carbamates are prepared by reacting urea with an aminopropanol at 140.degree. C. or above. The compounds obtained by the novel process are useful starting materials for the preparation of textile finishing agents, stabilizers, plasticizers, dyes and crop protection agents.

Preparation of carbamates

A process for the pyrolysis of mono-, di-, and polyurethanes to the corresponding mono-, di-, and polyisocyanates wherein the urethane to be cleaved is heated under pressure and sprayed through a nozzle into a pyrolysis chamber maintained at reduced pressure. The isocyanate and alcohol cleavage products are separated by fractional condensation.

Process for the preparation of isocyanates through the thermal cleavage

A process for the preparation of an aliphatic, cyclo-aliphatic, and/or aliphatic-cycloaliphatic di- and/or polyurethane comprising the steps of

Process for the preparation of an aliphatic, cycloaliphatic, and/or

Organic isocyanates, preferably alkyl, mono-, di- and/or polyisocyanates or aryl-mono-, di- and/or polyisocyanates, are prepared by thermally cleaving the corresponding urethanes at temperatures of 175.degree. C. to 600.degree. C. in the presence of carbon, preferably in an agitated carbon bed or in a fluidized bed containing carbon.

Process for the preparation of isocyanates by thermal cleaving of

1-Alkenyl isocyanates are prepared by reacting aldehydes with carbamates to give N-(1-alkenyl)-carbamates and splitting these compounds at elevated temperatures. The 1,2-unsaturated isocyanates obtained are valuable starting materials for the preparation of pest control agents, dyes, drugs, textile water repellents, detergents, plastics, bleaches and adhesives, since they possess an activated double bond or an activated .alpha.-carbon atom, in addition to a reactive isocyanate group.

Preparation of 1-alkenyl isocyanates

Carbonates are prepared by reacting carbamic acid esters with alcohols at above 140.degree. C., the ammonia formed being stripped from the reaction mixture during the reaction by passing an inert gas or vapor therethrough. The carbonates obtainable by the process of the invention are valuable starting materials for the preparation of dyes, crop protection agents and plastics.

Preparation of carbonates

A process for the preparation of an aryl mono-, di-, and/or polyurethane comprising the steps of A. reacting a primary aromatic mono-, di-, and/or polyamine with an O-alkyl carbamate in the presence of an alcohol at temperatures greater than 160.degree. C., and

Process for the preparation of an aryl mono-, di-, and/or polyurethane

A process for the production of mixtures of diphenylmethane diisocyanates and polyphenyl polymethylene polyisocyanates comprising the steps of

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Ludwigshafen, Germany

Friedrich Towae