Hoechst Aktiengesellschaft

Hoechst Ak

Gerhard Johannes

Gerhard Brindopke

Helmut Durr

Dieter Steidl

Dieter Plath

Klaus Esser

Hermann Hotze

Hans-Joachim Konig

Diedrich Schneider

Erwin Gemmer

Gerhard Dullis

Gunter Reinhard

Fali Shroff

Finely divided coating agents based on (A) oligomers and/or polymers containing OH groups and (B) blocked polyisocyanates and, if required, further conventional additives, in which the component (B) contains at least one acylurethane possessing groups of the formula --CO--NH--CO--XR.sup.1 (I), wherein X represents oxygen or nitrogen, and, when X is oxygen, R.sup.1 represents alkyl, alkoxyalkyl, hydroxyalkyl, aryl, aralkyl or cycloalkyl, and, when X is nitrogen, the radical XR.sup.1 represents the group ##STR1## wherein R.sup.2 is C.sub.1-11 -alkylene, C.sub.1-11 -alkenylene, or unsubstituted or alkyl-substituted phenylene having up to 8 carbon atoms in the alkyl radical, and Y and Z together form an oxygen atom, or are identical or different and each denote hydrogen or C.sub.1-5 -alkyl, the coating agent being present in powder form or in the form of a dispersion. The coating agent is used for coating articles exposed to weather, and as top coats and primers.

Finely divided coating agent containing polymers having hydroxyl groups

Process for the preparation of acylurethanes by reacting a urethane with compounds containing hydroxyl groups, which comprises reacting a hydroxy compound (A) with a urethane (B) in the form of an imide of the formula ##STR1## to give an acylurethane containing at least one grouping of the formula --CO--R--CO--NH--COOR.sup.1 (II). In these formulae,

Process for the preparation of acylurethanes, and the use thereof

The invention relates to a process for preparing compositions for coating metal substrates or work pieces in an aqueous bath, in which the substrate forms the cathode. In this process 5-35% by weight of at least one epoxy resin, 2-20% by weight of at least one ketone and/or hydrocarbon resin, 15-60% by weight of at least one cationic synthetic resin having functional groups--this compound is a 10-50% by weight dispersion or solution--, 5-30% by weight of at least one organic cross-linking agent, which is solid at ambient temperature and 0-73% by weight of pigments and/or conventional adjuvants are processed together in one or more stages in a grinding apparatus to form a homogeneous coating composition. At least one stage being a wet operation. The composition has a particle size of less than 100 .mu.m, preferably less than 15 .mu.m. The grinding bath is adjusted with water to the solids content required for application. The particles obtained by the process are more homogeneous, with the result that, when applied to the object which is to be coated, a uniform layer thickness of the coating is obtained, which shows an increased impact strength.

Process for preparing heat-curable, water-dilutable coating compositions

Preparation of heat-curable, water-dilutable coating compositions based on (A) epoxy resins free from amino groups, (B) an aqueous dispersion or solution of saturated polyester resins or the modification products thereof with oils, (C) organic cross-linking agents and optionally (D) pigments and/or conventional adjuvants, in specific proportions, these components being processed together in one or more stages, while being comminuted from their original particle size, to form a homogeneous coating composition which has a particle size of less than 100 .mu.m, and the use of the coating compositions thus obtained as coating agents, particularly for coating metal substrates, by the use of current-free methods of application or electrostatic spraying.

A powder binder composition comprising a mixture of

Powder binder composition comprising an epoxy resin, a polyester resin

An article comprising a metal substrate in the form of a pipe or a container, said substrate being coated with a hardened epoxy resin composition formed from (A) a solid epoxy resin based on epichlorohydrin and a component selected from the group consisting of (a) 4,4'-diphenylolpropane, (b) 4,4'-diphenylolmethane and (c) a combination of (a) and (b), (B) from 1 to 12% by weight based on the epoxy resin of at least one hardener for said epoxy resin selected from the group consisting of (d) compounds of formula ##STR1## wherein R is hydrogen or an alkyl group of 1 to 6 carbon atoms or an aromatic hydrocarbon residue with 6 to 10 carbon atoms, (e) compounds of formula ##STR2## wherein R is hydrogen or an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon residue with 6 to 10 carbon atoms and (f) an adduct of any one of compounds (d) and (e) to an epoxy resin with an epoxy equivalent weight of from 50 to 2000, (C) a flow agent, (D) a thixotropic agent and a process of coating such metal substrate by means of heating said substrate to a temperature above the melting temperature of the epoxy resin component of an epoxy resin coating composition and sufficient to cure the said epoxy resin and powder-coating the said epoxy resin composition onto the hot surface of the substrate to provide a substantially uniform coating thereon by immediate hardening without any further processing step by means of the heat capacity of the hot substrate.

Resin coated metal substrates

A process for the manufacture of a powdered coating material having a basis of hardenable synthetic resins, hardeners and pigments selected from the group consisting of metals, metal alloys, and mica for coatings with a metallic appearance wherein the single components are mixed in a finely divided state under an atmosphere of a protective gas and wherein the mixture is plasticized, under homogenization, at a temperature at which the viscosity of the synthetic resin is higher than the drop viscosity, but at most sufficiently high as to guarantee the flow, is homogenized by shearing stress and transformed into a powdered state, a powdered coating material prepared by said process and an article being coated with said coating material.

Growing community of inventors

Taunusstein, Germany

Gerhard Johannes