Coating Additives

Coating Additives

Nacorr rust and corrosion inhibitors (Table 1) are metal or amine salts of modified sulfonic acids used to impart corrosion inhibition in aqueous and solvent-borne coatings. These products are liquid for ease of incorporation and, in addition to their primary function as an inhibitor, they can provide:

	Synergy with anti-corrosive pigments
	Improved pigment dispersion and gloss when incorporated in grinds (solvent-borne coatings)
	Reduction in cure temperature in amino crosslinked systems
	Protection in both clearcoats and pigmented systems
	An alternative for anti-corrosive pigments that are environmentally unacceptable

NACORR® USE LEVELS/INCORPORATION

Generally, additional levels of 1-3% on total weight of the paint are effective in enhancing corrosion protection.

Methods of incorporation vary depending on the individual formulations and their respective components. Suggested methods of incorporation based upon system types follows:

Solvent Based Systems

Nacorr can be post-added to the finished paint with mild agitation or can be added to the mill base.

When added to the mill base at levels of one- fourth to one-half of the recommended overall addition level, Nacorr can help with pigment dispersion. The amount added is dependent on the type pigment used. Typically, TiO2 may require only one-fourth of the Nacorr charge while carbon black and most organic pigments require one-half. In preparing the mill base, premix the resin, solvents and Nacorr before adding the equipment.

Water Reducible Systems

If there is water in the mill base, Nacorr may not be effective in dispersing the pigment. If possible, remove the water from the mill base and add it to the letdown. Otherwise post-add under high agitation.

If there is no water in the mill base, add 0.5- 1.0% of the Nacorr to the mill base. This should be done by premixing the Nacorr, solvent and resin before the pigment is added. The balance of the Nacorr should be added to the letdown before any water addition.

Nacorr 1754 can be post-added directly without the addition of co-solvent or neutralizing amine.

Emulsions, Colloids and Dispersions

Systems with no co-solvents:
Post-add the Nacorr under high agitation during letdown prior to any water addition.

Systems with co-solvents:
Nacorr should be premixed with the coalescing solvent prior to addition. A typical ratio of 1:1 is recommended. Next add the mixture under high agitation to the system prior to any water addition.

Systems containing co-solvents and amines:
Premix the Nacorr, coalescent and amine. Add this mixture under high agitation prior to any water. A typical starting ratio of the premix is 50% Nacorr by weight, 45% coalescent by weight and 5% amine by weight where it is used in the paint as a neutralizing agent.

Powder Coatings

Dry blend the Nacorr XR-6401 with the pre-mix at approximately 1.0 - 3.0% based on total weight of the formulation. Nacorr XR-6401 demonstrates a catalytic effect in glycoluril crosslinked powder coatings.