Akzona Incorporated

Akzo N.v.

Werner Klostermeier

Hans G Zengel

Manfred F Bergfeld

Gerhard Meyer

Jeffery D Lasher

Peter Hentschel

Christof Josefiak

Membranes are disclosed which are suitable for hemodialysis and/or hemofiltration, prepared from aliphatic diisocyanates, particularly cycloaliphatic diisocyanate such as cyclohexane diisocyanate-(1,4), particularly the transisomer and at least one compound which displays two active hydrogen atoms. For the reaction a molar ratio of soft segment to hard segment from 0 to 0.20, particularly from 0 to 0.1, is employed. Serving particularly for construction of the hard segments are compounds such as hydrazine, ethylene diamine, ethylene glycol and butanediol-(1,4). It is recommended to prepare the addition polymer in the presence of a aprotic solvent and a dissolving coagent such as lithium chloride or calcium chloride. Polyethers such as polyethylene glycol are particularly suitable for construction of the soft segment. The membrane is characterized by an ultrafiltration rate of from 0.5 to 300, particularly 0.5 to 100 ml/h.m.sup.2.Torr, and a dialytic permeability for vitamin B.sup.12 of 0.5 to 20.10..sup.-3 cm./min.

Membranes of diisocyanate addition polymers for hemodialysis and/or

A laminate comprising an insoluble, intractable relatively thick layer of a polyimide bonded tightly onto a metallic substrate without the necessity for an intermediate adhesive bonding layer and a process for preparing such by directly extruding a polyamic acid polyimide-precursor onto said substrate and converting said polyamic acid to the polyimide in a single pass in at least two heating stages.

Thick polyimide-metal laminates with high peel strength

An improved process for the preparation of nitrosobenzene by catalytically reducing nitrobenzene with the use of a reducing agent selected from the group consisting of aliphatic compounds containing from about 1 to about 20 carbon atoms, cycloaliphatic compounds containing from about 4 to about 12 carbon atoms, benzene, naphthalene, and ethylenically unsaturated compounds containing from about 2 to about 10 carbon atoms is disclosed. The improvement comprises performing the reduction in the presence of from about 0.05 to about 4.0 moles of water per mole of nitrobenzene.

Process for the preparation of nitrosobenzene

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Klingenberg, Germany

Werner Klostermeier