Vianova Kunstharz A.g.

Gerhard Schmolzer

Rudolf Schipfer

Wolfgang Daimer

Heiner Verdino

Gunther Monschein

Gerhard Meglitsch

Cathodically depositable paint binders based on epoxy resin/amine adducts modified with diamine bridges which carry longer-chained substituents are described. The diamine bridges are the reaction products of diprimary amines and mono- and diepoxy compounds. The modified epoxy resin/amine adducts have low viscosities and low glass transition temperatures in spite of their high molecular weights. The stoved films, even with higher film thickness, have flawless surfaces and excellent mechanical properties.

Reacting polyamine/monoepoxide modifier, polyepoxy resins and amines

Crosslinking components for paint binders containing hydroxyl groups, tertiary and/or secondary and/or primary amino groups, particularly for cathodically depositable paints, which can be crosslinked by transesterification and/or transamidation and/or transurethanization, containing for each molecule at least 0.5 transesterifiable groups obtained from CH-activated esters and at least 0.5 blocked isocyanate groups. The crosslinking components are produced by partial transesterification of a polyol, preferably a triol, with a CH-activated ester, preferably a malonic acid diester, and subsequent reaction with a partially blocked polyisocyanate. Paint binders containing the crosslinking components cure at low-bake temperatures to provide films with good surface characteristics.

Crosslinking components for paint binders and process for their

Cationic paint binders based on polyether urethanes are formed by selective reaction of one NCO-group of a diisocyanate which contains NCO-groups of different reactivities with the primary hydroxyl groups of a polyhydroxypolyether in the presence of 1,4-diazabicyclo-2,2,2-octane (DABCO) as catalyst, and subsequently reacting the remaining NCO-group of the diisocyanate with the secondary amine. The binders which are largely free of low molecular basic by-products are used for formulating paints, particularly cathodically depositable electrodeposition paints, which are water-dilutable after protonation.

Cationic paint binders based on polyether urethanes and process for

Modified epoxy resin/amine adduct by reacting polyamine/monoepoxide

Cationic paint binders based on polyether urethanes are formed by selective reaction of one NCO-group of a diisocyanate which contains NCO-groups of different reactivities with the primary hydroxyl groups of a polyhydroxypolyether in the presence of 1,4-diazabicyclo-2,2,2-octane (DABCO) as catalyst, and subsequently reacting the remaining NCO-group of the diisocyanate with a secondary amine. The binders which are largely free of low molecular basic by-products are used for formulating paints, particularly cathodically depositable electrodeposition paints, which are water-dilutable after protonation.

Cationic paint binders, particularly binders of the type used in cathodic electrodeposition coatings which crosslink through transesterification, transamidation, transurethanization, or through the reaction of chain end double bonds catalyzed with a reaction product of lead(II) oxide with compounds carrying .beta.-hydroxyamino structure are described. The catalysts of the invention provide very good stability and good compatibility in aqueous cationic paint materials.

Catalyzed cationic paint binders

The invention discloses crosslinking components for hydroxy and/or primary and/or secondary amine groups containing cationic resins which can be used as binders for stoving paints, particularly for cathodically depositable electrodeposition paints. The crosslinking components are obtained through partial transesterification of transamidation of oligomeric KNOEVENAGEL-reaction products of C-H-active esters and carbonyl compounds with polyols or amines. The products can also be obtained through partial transesterification or transamidation of the C-H-active esters and subsequent KNOEVENAGEL-reaction.

Hardener component for stoving paint binders and process of producing

Cationic synthetic resin binders free of epoxy groups for the formulation of electrodeposition paints are described. The binders are the reaction product of an epoxy resin carrying at least two epoxy groups and having an epoxy equivalent of 190 to 1000, with from 0.1 to 1.0 amino groups per available epoxy group of a secondary amine carrying carboxylic acid amide groups. Upon being crosslinked on stoving with a suitable hardening component, the binders have improved water dilutability, permitting a reduction of the degree of neutralization necessary for electrodeposition application and improved intercoat adhesion to addition coats. These improved characteristics are significant with respect to an increase of current yield and in adhering additional coatings of a paint system.

Cathodically depositable paint binders based on the reaction product of

A process for producing improved crosslinking components for paint binders which can be crosslinked through transesterification is described. The process is characterized in that an ester of malonic or cyano-acetic acid or aceto-acetic acid is reacted in a KNOEVENAGEL-reaction with a carbonyl compound, preferably with formaldehyde, and the reaction products are polymerized, optionally utilizing free-radical initiators, to provide a polymer having a molecular weight of between about 300 and 6000. The crosslinking components prepared according to the invention provide an unsaponifiable base structure and permit the preparation of products with high functionality. The crosslinking components are preferably utilized in binder systems for cathodically depositable paints.

Crosslinking component for paint binders and process for producing such

Cathodically depositable paint binders, water-soluble upon neutralization with acids, and the method of preparing the paint binders based on amine-epoxy adducts which crosslink at elevated temperature through polyurethane formation are described. The paint binders are prepared by reacting per mole of expoxide groups of a polymer having an epoxy equivalent of between about 180 and 1500 from about 3 to 70 mole percent of a polyisocyanate adduct having substantially no free NCO content and carrying per molecule at least one carboxyl group. Basic functionality is provided by reacting the epoxy-containing polymer, before or after reaction with the polyisocyanate adduct, with secondary aliphatic amines and/or alkanol amines. The binders, in addition to providing stable aqueous solutions when neutralized with an inorganic or organic acid, have good resistance to corrosion and solvents.

Cathodically depositable paint binders and process for producing same

Binders for cathodically depositable aqueous coating compositions comprising a basic binder system which is blend or partial reaction product of a basic macromolecular component and an acidic macromolecular component, the ratio between acid and basic binders as expressed by amine value and acid value ranges from 97:3 and 65:35, and included in the coating composition is at least one resin component modified with a compound of the general formula

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Graz, Austria

Gerhard Schmolzer