Bayer Aktiengesellschaft

Jurgen Grammel

Josef Pedain

Wilhelm Thoma

Klaus Nachtkamp

Klaus Noll

Hermann Neumaier

Paul J Bocks

Reinhard Halpaap

Dieter Dieterich

Helmut Reiff

Walter Meckel

Walter Schroer

Wolfgang Wenzel

Antonio Aguado

The present invention therefore relates to a process for the preparation of aqueous solutions or dispersions of polyurethane-polyureas by the reaction in the aqueous phase of prepolymers which contain chemically built-in hydrophilic groups and/or external emulsifiers which are not bound chemically as well as at least two free isocyanate groups with organic compounds containing at least two primary and/or secondary amino groups, characterized in that the isocyanate prepolymer which has been hydrophilically modified and/or contains an external emulsifier is mixed, in the absence of water, with compounds containing at the most one free primary or secondary amino group and at least one blocked group which releases a free primary or secondary amino group in the presence of water and a total of at least two at least partially blocked primary and/or secondary amino groups, and the mixture is subsequently mixed with water. The invention also relates to the dispersions or solutions obtained by this process and to their use for coating flexible and rigid substrates.

Process for the preparation of aqueous polyurethane dispersions and

A process is described for the preparation of predominantly linear polyurethane solutions which comprises

Process for the preparation of viscosity stable polyurethane solutions

This invention relates to coating agents and dressing agents for leather and leather substitutes with improved resistance to plasticizer migration, greater hardness and folding strength, a dry hand and resistance to aqueous alcoholic solutions, based on linear or only slightly branched thermoplastic polyurethane ureas built up from the following components

Coating and dressing agents for leather and leather substitutes based on

The present invention relates to a process for the preparation of aqueous solutions or dispersions of polyurethanes, in which process prepolymers which have at least two free isocyanate groups and contain chemically-fixed hydrophilic groups and/or external emulsifiers which are not chemically fixed are reacted with chain lengthening agents in the aqueous phase, characterized in that the isocyanate prepolymer which is hydrophilically modified and/or contains an external emulsifier is mixed with chain lengthening agents selected from the group consisting of azines and hydrazones in the absence of water and the mixture obtained is then mixed with water. The present invention also relates to the dispersions or solutions which can be obtained by this process. Lastly, this invention relates to the use of the dispersions or solutions which can be obtained by this process for coating flexible substrates.

This invention relates to a process for the production of water dispersible polyurethanes by reacting polyisocyanates with sulphonate group containing diols. The sulphonate diols have the general formula: ##STR1## WHEREIN A and B, which may be the same or different, each represents a divalent aliphatic hydrocarbon group containing from 1 to 6 carbon atoms,

Aqueous polyurethane dispersions from solvent-free prepolymers using

The present invention relates to water-dispersible polyurethane elastomers having a substantially linear molecular structure, characterized by

Production of water-dispersible polyurethanes having ionic groups and

This invention relates to the coating of textile sheets with polyurethane pastes by the reversal process for producing very soft coating articles with a hand resembling that of napa leather. The particular properties of the coating are obtained by using bonding pastes which contain a mixture which can be cross-linked by the action of heat, consisting of polyurethane hydrazodicarbonamides and melamine-formaldehyde resins and/or urea-formaldehyde resins.

Soft textile coatings resembling napa leather

This invention discloses a composite material consisting of layers of a plastic sheet, a polyurethane ionomer latex foam and a textile material.

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Cologne, Germany

Jurgen Grammel