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Rubber Adhesion Promoters | ECOS

Superior Adhesion of Rubber to Steel Cord for Durable Tires, Belts & Hoses

Cobalt compounds play an essential role in manufacturing high-quality and durable steel-reinforced radial tires, conveyor belts, and hoses. These metal-based adhesion promoters are integrated into the bonding layer during the rubber curing process, offering two main benefits. Firstly, cobalt influences sulphidation and the growth of copper sulphide layers, enhancing the initial adhesion between rubber and steel cord. Secondly, cobalt improves adhesion retention, particularly in corrosive and humid environments. 
 
Selecting an appropriate rubber adhesion promoter is crucial to obtain the desired properties in your formulation, including strength, durability, and resistance to heat, corrosion, and humidity. A wide range of solutions can be provided, depending on your particular needs. 

cobalt-based chemicals for brass coated steel belts

Need help choosing the right Rubber Adhesion Promoter for you?

Cobalt Carboxylate Rubber Adhesion Promoters 


Cobalt carboxylates are well-known adhesion promoters, primarily used by the tire industry to enhance and preserve the bond between rubber and steel cord in steel belted radial tires.  

Integrating cobalt carboxylates into the bonding system significantly boosts resistance to heat, humidity, and corrosive environments. Typical cobalt ligands include stearates, resinates and neodecanoates. 

ECOS R 8  Cobalt resinate with 8% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications. 
ECOS S 9.3  Cobalt stearate with 9,3% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications. 
ECOS S 9.5  Cobalt stearate with 9,5% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications. 
ECOS O 17   Cobalt resinate with 17% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications. 
ECOS D 20.5 P Cobalt neodecanoate with 20,5% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications. 
ECOS B 22.5 C  Cobalt boro-acylate with 22,5% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications. 

Cobalt Polymer Rubber Adhesion Promoters


The future use of traditional cobalt-based chemicals is becoming increasingly uncertain due to regulatory developments. Concerns are growing regarding the hazardous characteristics of currently used cobalt compounds.  

To address this uncertainty, we have introduced the ECOS NewRAP portfolio, based on patented technology. In NewRAP products, cobalt is incorporated into a polymeric structure, limiting the bio-accessibility of the metal. 

Interested in reading more on our efforts to create safe, low-toxic chemicals with improved environmental impact? Read our information on the replacement of traditional cobalt products.     

ECOS NR 6 Boron-containing cobalt polymer with 14-16% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications. 
ECOS NR 14 Cobalt polymer with 15,5-17,5% metal content. 
Used as rubber adhesion promoter in steel-reinforced rubber applications.

Your experienced partner for Rubber Adhesion Promoter solutions! 
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If you cannot find your desired product in our overview, please note that Umicore is capable of developing customized solutions tailored to your distinct formulation or process requirements. With extensive experience in manufacturing cobalt adhesion promoters, we have the proficiency to finetune the chemical composition of our products and develop new types of adhesion promoters. Our R&D department is eager to assist with analysis and testing in our specialized rubber laboratory. Additionally, our pilot plant capabilities ensure a smooth scale-up of your tailor-made adhesion promoter

Thomas Schollaert

Thomas Schollaert

Commercial Director Metal Carboxylates & Organics
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