Bayer Aktiengesellschaft

Hans J Scholl

Rainer Welte

Josef Pedain

Hartmut Nefzger

Helmut Reiff

Hanns-Peter Muller

Gert Jabs

Bernd Quiring

Ulrich Nehen

Gunter Gleitsmann

Polyols are conditioned and stabilized by mixing them at 0 to 150.degree. C. with from about 0.0001 to about 1% by weight, based on the quantity of polyol, of a silylated acid corresponding to the formula:

Process for conditioning and stabilizing polyols

A process for the purification of organic polyisocyanates by mixing of the polyisocyanate with from 0.001 to 1% by weight of compounds containing trimethylsilyl groups at temperatures of from 20.degree. to 150.degree. C. The resultant mixture of organic polyisocyanates and compounds containing trimethylsilyl groups is optionally treated by degasification or distillation. These purified polyisocyanates are suitable for the production of polyurethane plastics, and in particular, polyurethane foams.

Process for the purification of polyisocyanates, the polyisocyanates

The present invention relates to a process for the preparation of substantially closed-cell rigid foams containing urethane, urea, biuret, and isocyanurate groups comprising reacting, at an index of greater than 110, organic polyisocyanates with relatively high molecular weight polyots consisting of mixtures of (i) polyesters containing at least two hydroxyl groups and having an OH value of greater than 150 and/or polyethers containing at least two hydroxyl groups and having an OH value of greater than 200, and (ii) polyoxyalkylene polyethers containing ethylene oxide residues and least two hydroxyl groups and having an OH value of less than 100, in the presence of isocyanate trimerization catalysts and water as blowing agent. The foams of the invention can optionally be prepared optionally, in the further presence chain-extending and/or crosslinking agents and auxiliaries. and/or additives. The present invention also relates to a method using the foams of the invention as insulating materials and/or for reinforcing mechanical structural components.

Process for the preparation of substantially closed-cell rigid foams

The present invention relates to a process for the production of primary amines containing aliphatically or cycloaliphatically bound amino groups, characterized in that the isocyanate groups of organic isocyanates containing aliphatically and/or cycloaliphatically bound isocyanate groups are formylated with formic acid in a first reaction step and the N-formyl groups are subsequently converted into amino groups. The present invention also relates to polyamine mixtures obtained by this process and containing

Process for the production of organic amines, polyamine mixtures and

Disclosed herein are liquid polyisocyanate mixtures containing isocyanurate groups and having an NCO content of 15 to 30% by weight obtainable by partial trimerization of the isocyanate groups of polyisocyanate mixtures of the diphenyl methane series containing 80 to 100% by weight diisocyanatodiphenyl methane isomers and 0 to 20% by weight higher than difunctional polyisocyanates of the diphenyl methane series, 40 to 80% by weight of the diisocyanatodiphenyl methane isomers consisting of 4,4'-diisocyanatodiphenyl methane, 20 to 60% by weight of 2,4'-diisocyanatodiphenyl methane and 0 to 8% by weight of 2,2'-diisocyanatodiphenyl methane and the percentages shown adding up to 100.

Polyisocyanate mixtures containing isocyanurate groups, a process for

The present invention is directed to a process for the production of isocyanurate polyisocyanates containing aliphatically and/or cycloaliphatically bound isocyanate groups by trimerizing a portion of the isocyanate groups of organic diisocyanates containing aliphatically and/or cycloaliphatically bound isocyanate groups in the presence of a trimerization catalyst and terminating the trimerization reaction at the desired degree of trimerization by the addition of a catalyst poison, characterized in the quaternary ammonium fluorides are used as the catalyst. The present invention is also directed to the use of these isocyanurate polyisocyanates for the production of polyurethane lacquers.

Process for the production of polyisocyanates containing isocyanurate

Improved microcapsules contain at least one wall which is the reaction product of at least one isocyanate-reactive group and an aromatic isocyanate which has the formula: ##STR1## in which n=8 to 20. The microcapsules are useful in carbonless copy paper.

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Cologne, Germany

Hans J Scholl