Engineering Properties

The CompCote® Finish is a true transition layer

In the realm of polymer - metal bonding, there has been no known true transition layer. Methods that are currently utilized are: mechanical/chemical roughening of the metal substrate and/or the use of additional adhesion promoters and primers. On aluminum, the surface is often anodized or treated with a chemical conversion coating. The CompCote® finish offers, for the first time, the benefits of a true transition layer through metallurgical bonding to the aluminum surface and chemical bonding to a polymer layer, e.g. paints, lacquers, primers, adhesives, etc...

Schematic of a CompCote® bonding layer sequence  

The CompCote® Finish offers chemical bonding

Comprehensive investigation showed conclusively the presence of electroactive polymer modifier in the CompCote® finish, a prerequisite for true chemical bonding of subsequent polymer layers.

High Intensity Infrared Spectrographic Analysis

Standard anodic finish shows only inorganic IR absorbances.

CompCote® finish shows organic and inorganic IR absorbances.

The CompCote® Finish has "Bridges for Bonding"

Other scientific tests show the presence of free polymer ligands as bonding sites for subsequent organic coatings such as inks, adhesives, primers, glues, paints, lacquers and vulcanizing agents.

High magnification TEM shows fibrous "bridges" between the The CompCote® finish and the adhesion promoter

The CompCote® Finish shows interfacial interaction

Transmission Electron Microscopy shows CompCote® finish interacts with screen print inks, resulting in a deeper intrusion of the inks and chemical bonding. Type II finishes show only a mechanical attachment of the ink with 4X less intrusion depth.

CompCote® A + Screen Print Ink: intrusion approximately 40nm

Type II + Screen Print Ink: intrusion approximately 10nm

The CompCote® Process can eliminate critical and costly process steps

In a comprehensive bonding study a CompCote® A finish, hot water sealed, was compared with a conventional anodic finish that was nickel acetate and sodium dichromate sealed as was the typical process scheme for “optimal bonding” for this product. Peel tests were done comparing the bond strengths after the surfaces were degreased, treated with an adhesion promoter and over-molded with a rubber compound. The CompCote® finish exhibited comparable peel strengths without the use of any heavy metal seals and made, in addition, the degreasing step obsolete.

The CompCote® process therefore enabled a cheaper, safer, and more environmentally friendly solution.

For more details read the paper: "Insights regarding the Adhesion Mechanism for Supplementary Organic Coatings on Porous Anodic Films".