Chlorinated Rubber

Chlorinated rubber coatings are formulated from natural rubber resins. They are typically known for coating swimming pools.  However, they are used for a wide variety of other applications including marine structure, laboratories, bridges and road structures, plants and tanks. 

These coatings are formulated by decreasing the molecular weight of the natural rubber resin through degradation.  Next, it is chlorinated to replace bonds and form a polymer. Saturating the rubber in hot carbon tetrachloride does this process.  The final step is plasticization, which gives the rubber its final protective properties.

Chlorinated rubber has low solid content and has good solubility in most solvents. The type and amount of solvent used will vary with the type of application process being used.  Emission regulations have put pressure on the amount of solvents being used in the formulation. VOC limitations have caused the sales of chlorinated rubber to decrease dramatically. Regulations are expected to amplify within the next few years and the decrease in chlorinated rubber sales will follow.

The coating is easier to apply than most epoxies, having no pot life and reducing the errors encountered in mixing.   Chlorinated rubber has a high weight and viscosity making it somewhat difficult to work with. The fast-drying chlorinated rubber forms a tough, glossy coating with a smooth finish that is re-coatable. The resulting product provides for high impermeability.  It is one of the more resistant coatings, and can protect against most chemicals, acids and alkalis, weather, salt and oils. The coating is not very resilient against heat. It becomes flexible and degrades under very high temperatures. Due to the high amount of chlorine in the compound, it is non-flammable.

Advantages

• Rapid drying and recoating
• Good in water immersion
• Good durability
• Easy to topcoat and repair
• Good general chemical resistance

Disadvantages

• High VOC content
• Low film build
• Susceptible to solvent attack
• Abrasive blasting of surface required