The Glidden Company

Scm Corporation

Ju-Chui Lin

Kirk J Abbey

Gary P Craun

Gary M Carlson

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

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

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

New siloxane-polyesters, siloxane-ethers and siloxane-ether-polyesters, useful as powder coating resins, are prepared by reacting rigid diacids, neopentyl glycol, trimellitic anhydride with up to 90 percent hydroxyl functional silicone having about two .dbd.Si(R)--OH groups per molecule where R is lower alkyl or phenyl groups and the remaining silicon valences form ring-structured siloxanes. Improved powder properties, including crystallinity and tack temperatures of 50.degree.-90.degree. C., are believed to result in part from the rigidity provided by both the specific diacids and the cyclic silicones. The siloxane resins are hard at room temperature and can be powdered by methanical grinding. Powder coatings formulated from these resins are particularly suitable for coating metal and glass substrate.

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Strongsville, OH, United States of America

Ju-Chui Lin