Vianova Kunstharz A.g.

E.i. Dupont De Nemours and Company

Vianova Resins Ag

Herbert Matzer

Georg Pampouchidis

Helmut Honig

Willibald Paar

Manfred Valtrovic

Klausjoerg Klein

Helmut Hoenig

A two-component concentrate which includes an aqueous dispersion of a cathodically depositable binder having groups comprising active hydrogen that are cross-linkable using blocked polyisocyanate, as the binder component, and an anhydrous, organic solution of an oxime-blocked isocyanate-functional adduct of aromatic polyisocyanate and at least one compound comprising at least one group capable of addition towards isocyanate and at least one tertiary amino group, as the cross-linking component is used for the preparation of cathodic electrodeposition coating compositions.

Concentrate suitable for the preparation of cathodic electrodeposition coating compositions

The invention relates to a process for the preparation of pigment paste resins for cathodically depositable coating compositions, wherein diepoxide compounds which contain polyoxyalkylene structures and alkyl and/or alkylene and/or hydroxyalkyl radicals having more than 3 carbon atoms are first reacted to form epoxy resin/amine adducts and final products with oxazolidine structures are obtained by a partial or complete reaction of secondary amino groups with formaldehyde.

Pigment paste resins for cathodically depositable coating compositions

Crosslinking components for cationic paint binders which are reaction products of hydroxyl-functional carbamate compounds with half-blocked diisocyanates are described. The carbamate compounds are reaction products of cyclic organic carbonates with aliphatic monoamines and/or diamines and/or triamines and/or tetraamines and/or alkanolamines, all such amines having primary and/or secondary amino groups. The crosslinking components produced according to the invention, in combination with resin components carrying hydroxyl groups and/or primary or secondary amino groups, preferably with those based on epoxide/amine adducts or containing similar molecular units, give binders which can be baked at temperatures of 140.degree. C. and higher.

Crosslinking components for cathodically depositable paint binders

Preparation of pigment paste resins for cathodically depositable coating compositions based on epoxy resin-amine adducts obtained from unmodified or modified epoxy resins, which by partial or complete reaction of secondary amino groups with formaldehyde contain oxazolidine structures; whose tertiary amino groups introduced via primary-tertiary diamines are quaternized to at least 20 mol % using an organic acid and a monoglycidyl compound and which in a solution adjusted with water to a correct application viscosity contain a total of 80 to 100 millimoles of acid per 100 g of solid resin are described. The pigment pastes possess, both in concentrated and dilute form, a stability which meets practical requirements and, because of their rheology, are readily processed to ensure formation of defect-free films both during deposition and crosslinking by stoving. The applied films have good properties.

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Graz, Austria

Herbert Matzer