Scm Corporation

The Glidden Company

Kirk J Abbey

James R Erickson

Ju-Chui Lin

Gary P Craun

Barbara L Kunz

Gary M Carlson

David J Foss

Peter V Robinson

New Cobalt (II) nitrilomethylidyne dipyrrole complexes such as Cobalt (II) 2,2'-[trimethylenebis(nitrilomethylidyne)]-dipyrrole, Cobalt(II) 2,2'[o-phenylenebis(nitrilomethylidyne)]-dipyrrole and their basic ligand complexes are effective catalysts for molecular weight control in acrylate/methacrylate polymerization. The Cobalt (II) complex of a nitrilomethylidyne dipyrrole comprises the structure: ##STR1## where R is a diradical selected form trimethylene bis-, o-phenylenebis, or ethylenebis. The process comprises polymerizing monomers, especially including methacrylic monomer or methacrylic/acrylic monomer, in the presence of azo initiator and between 0.0001% and 0.01% of Cobalt (II) 2,2'-[trimethylenebis (nitrilomethylidyne)]-dipyrrole and/or Cobalt (II) 2,2'-[-phenylenebis (nitrilomethylidyne]-dipyrrole complexes to produce low molecular weight acrylate polymers and copolymers.

Cobalt (II) complex catalyst for polymerization of monomers

A new transesterification catalyst comprises an epoxide and a non-acidic nucleophilic onium salt. Coating compositions having hydroxyl functional resin components and carboxylic ester components adapted for curing by transesterification following application to a substrate are formulated with in-situ formed cure catalyst comprising a non-acidic nucleophile and an epoxide-to-product coatings that readily cure by transesterification. Such coatings including polyesters, polyepoxides, and polyacrylates are useful in formulating high solids coatings and powder coatings having exceptional physical properties. Extremely low-temperature cure coatings were obtained by transesterifying mixtures of polyols and polymeric esters having multiple activated ester linkages having the structure ##STR1## wherein R' is lower alkyl and Y is --OH and O-alkyl radicals. These coatings provide low-temperature cure coatings for paper, plastic, and wood in addition to metal substrates.

Epoxy/nucleophile transesterification catalysts and thermoset coatings

The blocked isocyanate crosslinker commonly used in conventional electrocoat compositions are difficult to incorporate satisfactorily into latex paint compositions for such application. An improved homogenized feed process for incorporating such water insoluble crosslinking agents into the latex particle during emulsion polymerization of reactive (hydroxy functional) vinyl monomers provides thermosetting latex of high cleanliness. The invention pertains to an improved cationic, amine-stabilized electrocoating composition and process.

Process for preparing a cationic amine-stabilized latex thermosetting

New siloxane-esters, useful as powder coating resins, are prepared by random condensation polymerization of a hindered glycol and a hydroxy functional silicone having about two ##STR1## groups per molecule wherein R is lower alkyl or phenyl groups and the remaining silicone valences form ring-structured siloxanes. Improved powder properties, including tack temperatures of 150.degree. F. to 220.degree. F., are believed to result in part from the hindered glycols especially those having carboxylic functionality.

Silicone-ester powder coating compositions

New Cobalt(II) nitrilomethylidyne dipyrrole complexes such as Cobalt(II) 2,2'-[trimethylenebis(nitrilomethylidyne)]-dipyrrole, Cobalt(II) 2,2'-[o-phenylenebis(nitrilomethylidyne)]-dipyrrole and their basic ligand complexes are effective catalysts for molecular weight control in acrylate/methacrylate polymerization. The process comprises polymerizing monomers, especially including methacrylic monomer or methacrylic/acrylic monomer, in the presence of azo initiator and between 0.0001% and 0.01% of Cobalt(II) 2,2'-[trimethylenebis(nitrilomethylidyne)]-dipyrrole and/or Cobalt(II) 2,2'-[o-phenylenebis(nitrilomethylidyne)]-dipyrrole complexes to produce low molecular weight acrylate polymers and copolymers.

Low molecular weight polymers and copolymers

A cathodic electrocoating paint composition that yields solvent-resistance films is shown. The paint binder consists essentially of:

Method for cathodic electrocoating composition comprising pigmented

Polyesters containing tertiary ester linkages and pendant methylene unsaturation along the polymer chain are prepared from dialkyl 2,2-dimethyl-4-methyleneglutarate by transesterification with sterically structured polyols, preferably neopentyl glycol. The resultant sterically hindered polyesters are useful as hardeners and resin binders for high solids coatings.

Polyesters derived from 2,2-dimethyl-4-methyleneglutaric acid and

Cationic electrocoat latices, containing blocked isocyanate crosslinker and which are usually unstable toward pumping and shear forces, can be stabilized by conducting the emulsion polymerization in a solvent-water mixture containing from about 20 to 30 percent solvent. Ethanol is a preferred solvent. Preferably the crosslinker is first emulsified and then added to the emulsion polymerization system prior to or during polymerization to produce mechanically stable latex that is virtually free of grit.

Electrocoating process using shear stable cationic latex

Dimethacrylate esters of a diol are linearly copolymerized by step dimerization of methacrylate groups of a dimethacrylate ester in the presence of a non-peroxide free radical initiator and a Cobalt (II) catalyst complex for chain transfer to monomer to produce a linear polyester polymer having 2,2-dimethyl-4-methylene glutarate structural units in the polymer chain.

Linear addition polyester copolymers

The process comprises polymerizing monomers, especially including methacrylic monomer, in the presence of azo catalyst and between 0.0001% and 0.01% of Cobalt (II) dimethylglyoxime pyridine or similar Cobalt (II) complexes to produce a low molecular weight polymer or copolymer.

An improved cathodic electrocoating composition comprises an aqueous suspension of synthetic, cation-active, film-forming latex particles characterized by a latex gel content that is not substantially above about 10%.

Cathodic electrocoating composition compounded with latex binder and

Emulsion polymers produced by polymerizing ethylenically unsaturated monomers in an aqueous medium can be substantially improved by incorporating into the monomer mixture a minor amount of blend of epoxy resin and glycidyl acrylate. The epoxy modified emulsion polymers are particularly useful as ambient or low temperature thermosetting latices for film-forming coatings.

Epoxy modified emulsion polymers

An improved cathodic electrocoating composition comprises an aqueous suspension of cation-active, film-forming, amino-stabilized synthetic latex binder particles characterized by being practically free of amino monomer and amino initiator fragments and containing not substantially more than about 15% of low molecular weight material including solvents based on the latex solids content.

Cathodic electrocoating composition compounded with latex binder

Improved gloss retention of a cured film deposited by cathodic electrocoating is obtained when the principal binder is an aqueous suspension of synthetic, cation-active, film-forming, emulsion-polymerized latex particles, which latex is characterized by Tg of at least about 20.degree. and desirably even higher.

Cathodic electrocoating composition compounded with latex binder for

An aqueous polymeric composition comprises a stabilized mixture of an amino polymer and an oxirane polymer stabilized in water which maintains the polymers non-reactive. The composition can be cured in use at relatively low temperatures by evaporation of water whereby the amino groups coreact with the oxirane groups to provide a cured composition such as a protective coating or an adhesive.

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Cleveland, OH, United States of America

Kirk J Abbey