Bayer Aktiengesellschaft

Ulrich Nehen

Manfred Dahm

Norbert Weimann

Gert Jabs

Hanns P Muller

Walter Schafer

James M Barnes

Albert Awater

Rudiger Schubart

Ernst Roos

Manfred Hajek

Artur Haus

Hans J Scholl

Jurgen Weisser

Klaus Rath

Novel microcapsules are characterized in that their walls are made of reaction products of guanidine compounds and polyisocyanates or contain such reaction products. Dispersions containing such microcapsules can be prepared by replacing the amines, amino alcohols or hydrazine compounds in processes known per se for preparing microcapsule dispersions from polyisocyanates and amines, amino alcohols or hydrazine compounds by guanidine compounds. The present invention also relates to no-carbon copy papers containing dyestuff precursors in microcapsules whose walls are made of reaction products of guanidine compounds and polyisocyanates or contain such reaction products.

Microcapsules having walls made of polyisocyanate/guanidine reaction

Foamed microbeads with a shell and an encased core are characterized in that the shell is a reaction product of an NCO-containing carbodiimide and a polyamine, and the core is at least partly filled with a polymeric carbodiimide or its reaction product with a polyamine, and in that the foamed microbeads are self-supporting and can be laden with hydrophilic and if appropriate hydrophobic liquids.

Foamed microbeads and a process for their preparation

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.

Microcapsules with improved polyurea walls

Microcapsules having a hydrophobic core material and capsule walls formed by the reaction of water-insoluble polyamines with water-soluble bisulphite adducts of polyisocyanates, a process for the production thereof which is characterized in that a mixture of a hydrophobic core material and water-insoluble polyamines is emulsified in water or in an aqueous protective colloid solution to the required particle size, water-soluble bisulphite adducts of polyisocyanates in the form of powders or aqueous solutions are added and the mixture is left to react to completion at temperatures of from 1.degree. to 140.degree. C., and applications thereof.

Microcapsules having walls of polyaddition products of water-insoluble

Production of microcapsules having walls of polyaddition products of

A process for encapsulating products in a polymer by interfacial polymerization, in which a stabilized dispersion of droplets of a first liquid which is to be encapsulated or a stabilized dispersion of solid particles which are to be encapsulated is formed in a continuous phase of a second liquid, and wherein one of the two capsule wall-forming reaction components is present in free form while the other of the two capsule wall-forming reaction components is present in reversibly blocked form, both reaction components are present in the first or second liquid without reacting with one another and the reaction component which is present in reversibly blocked form is deblocked by means of water present in the second or first liquid and then reacts with the reaction component present in free form to form a polymeric capsule wall, the droplets of the first liquid or the solid particles being encapsulated in small capsules consisting of polymeric material.

Process for the production of microcapsules

The invention relates to a pressure-sensitive, carbonless copying system and to a process for the production of pressure-sensitive, carbonless copying system wherein a non-aqueous, substantially solvent free printing ink containing micro-capsules which contain dye-precursors, is applied by wet and dry offset and book printing techniques to all or part of at least one surface of a paper substrate; and to printing inks comprising

Copying systems, a process for their production, and suitable printing

Polyurethane foams which are free from the usual discoloration particularly in the center of a block thereof are prepared from a foamable reaction mixture containing A. a heterocyclic mercapto compound of the formula ##SPC1## In which X = --o--, --s--, --nh--, --n--(c.sub.1 -c.sub.12)--alkyl, --N--(C.sub.5 -C.sub.6)--cycloalkyl--, --N--phenyl, --N--(C.sub.7 -C.sub.12)--aralkyl, --N--(C.sub.7 --C.sub.12)--alkylaryl-- or --N--CO--(C.sub.1 -C.sub.6)--alkyl, ##EQU1## ##SPC2## R = H, (C.sub.1 -C.sub.12)--alkyl, (C.sub.1 -C.sub.12)--alkoxycarbonyl--, (C.sub.1 -C.sub.12)--alkoxy and B. a phenol of the general formula ##SPC3## In which R.sup.1 and R.sup.3 may be the same or different and denote C.sub.1 -C.sub.9 --alkyl--, C.sub.5 -C.sub.6 --cycloalkyl--, C.sub.7 -C.sub.9 --alkylaryl--, indanyl or norbornyl groups and R.sup.2 = R.sup.1 or --CH.sub.2 --CH.sub.2 --COO--(C.sub.1 -C.sub.12)--alkyl.

Growing community of inventors

Leverkusen, Germany

Ulrich Nehen