Rohm and Haas


High Performance Hydrophobic Copolymer Pigment Dispersant


TAMOL 165A pigment dispersant is a high-performance dispersant for latex gloss through flat paint. It is an ammonium salt of a hydrophobic copolymer dispersant which provides enhanced properties to latex paints resulting from improved water resistance properties, including the following:

  • Wet Adhesion
  • Early Blister Resistance
  • Water Spot Resistance
  • Corrosion Resistance

Wet adhesion is one of the most important properties for exterior paints. Without wet adhesion, properties such as resistance to dirt, alkali attack, chalking, cracking and flaking are meaningless.

Water causes the paint film to soften and swell. Unless the adhesion to the substrate is strong, blisters will form. Early blistering usually indicates that future adhesion failures are likely for that film. Even though the blisters disappear when the paint film dries, the bond between the paint film and the substrate is weakened.

The most important factor for minimizing adhesion loss is binder choice. Other factors influencing adhesion are the presence of water-sensitive ingredients such as surfactants, thickeners and dispersants. A balance is required to use the minimum level of additives to maintain application, performance and stability of the paint. In fog box tests, TAMOL 165A pigment dispersant provided significant advantages in early blister and wet adhesion compared to other polyacid and hydrophobic copolymer dispersants. In addition, it showed excellent gloss, corrosion resistance, and color acceptance.

TAMOL 165A pigment dispersant is highly compatible with HEUR rheology modifiers such as ACRYSOL™ RM-825 and RM-2020NPR.

Typical Physical Properties
These properties are typical but do not constitute specifications.


Light yellow slightly hazy liquid

Chemical type

Hydrophobic copolymer polyelectrolyte

pH (as shipped)

8.5 to 9.0

Solids, %


Brookfield Viscosity, cP as shipped

160 to 400

Specific gravity


Density, lb/gal




Bulking Value, gal/lb


Dispersing Efficiency

TAMOL 165A pigment dispersant should be tested at 0.3% to 1.0% active ingredient based on total pigment weight. It is important to determine the proper level for the finished paint formulation. If a low level is used, the dispersion may be incomplete providing an inadequate grind that will not maximize gloss, hiding, or stability. High levels of dispersant may lead to increased water sensitivity.

For more information about formulating with TAMOL 165A pigment dispersant, contact your local Rohm and Haas Technical Representative.

Material Safety Data Sheets

Rohm and Haas Material Safety Data Sheets (MSDS) contain pertinent information that you may need to protect your employees and customers against any known health or safety hazards associated with our products.

Under the OSHA Hazard Communication Standard, workers must have access to and understand MSDS on all hazardous substances to which they are exposed. Thus, it is important that you provide appropriate training and information to your employees and make sure they have available to them MSDS on any hazardous products in their workplace.

Rohm and Haas Company sends MSDS for all its products, whether or not they are considered OSHA-hazardous, to both the "bill to" and/or "ship to" locations of all its customers upon initial shipment, including samples. If you do not have access to one of these MSDS, please contact your local Rohm and Haas representative for an additional copy.

Updated MSDS are sent upon revision to all customers of record. In addition, MSDS are sent annually to all customers receiving products deemed hazardous under the Superfund Amendments and Reauthorization Act.

MSDS should be obtained from your suppliers of other materials recommended in this bulletin.

Rohm and Haas Company is a member of the American Chemistry Council and is committed to ACC’s Responsible Care® Program.