Coil Coating

Pigment concentrate system

Dear Sir or Madam. We are going to start the development of a new solvent borne pigment concentrate system soon. How can we start the evaluation and which BYK additives can be recommended?

In this case our wetting and dispersing additives called DISPERBYK should be used. We recommend preparing single pigment pastes. First thing to check is the mill base viscosity. While using a proper wetting and dispersing additive the viscosity should be lowered significantly. A low(er) mill base viscosity already indicates a good wetting and dispersing of the pigment. Next we recommend preparing white mixtures using the pastes, e.g. white with carbon black, with iron oxide red, with phthalo blue etc. These white mixtures need to be applied, rub out and high speed stirring stability should be tested, too. The mixtures should be stored in hot box for at least 3 days at 50°C. After storage in hot box the application will be repeated the same way as before. A good mixture shows high gloss, good levelling and low delta E values (< 0.5) before and after storage and also during storage there may not be a big change in colour and gloss. We recommend testing DISPERBYK-110DISPERBYK-180 for Titanium dioxide and inorganic pigments. DISPERBYK-170DISPERBYK-171DISPERBYK-174 and DISPERBYK-2025 can be used for all kind of pigments including carbon black. It is difficult to find a solution based on one single wetting and dispersing additive. A typical solution could be DISPERBYK-110 used on Titanium dioxide and DISPERBYK-2025 on all other pigments. For starting point formulations and starting point dosages please contact us. The dosages (depending on the type of pigment) can strongly vary.

Anti-Popping for NIR

We are looking for an anti popping additive to be used in a solvent borne Polyester / Melamine coil coating topcoat used on a NIR line. The curing time is only 3-4s and we found solvent popping. What additive can you recommend?

Please test BYK-392. It is an acrylate based products and works also in NIR systems as anti popping additive. We recommend testing 1% delivery form on total formulation.

Abrasion resistance

Our PUR based coil coating topcoat shows insufficient abrasion resistance during Taber abraser test. The gloss is app. 40 units at 60°. What additive can you recommend?

Please test CERAFLOUR 981. It is PTFE wax additive and will improve abrasion resistance in your coating. Please try 0.5% wax on total formulation. CERAFLOUR 981 is a micronized 100% wax additive and can be post added with medium shear force.