The development of a novel polymer composition for use in waterborne primers with excellent anti-knot bleeding properties
When the waterborne primers of today are applied on wood in most cases discoloration of the topcoat occurs. This is caused by organic wood components that are extracted when these primers are applied. These components then migrate to the coating surface and cause discoloration. This is particularly pronounced on the knots where the concentration of resins and tannins are high. In this contribution we describe the development of a waterborne wood primer that exhibits excellent anti-knot bleeding properties. In the approach we have taken, we have eliminated several of the drawbacks of the current state-of-the-art polymers and primers. In particular, we will discuss the role of the polymerization process and the polymer composition on the knot bleeding properties and we will show that these two synergistically act together. By combining the right polymerization process with the optimal polymer composition, aqueous wood primers have been developed that exhibit a significant step-change in anti-knot bleeding performance.
Jurgen Scheerder*, Hinke Malda, Derrick Twene and Ad Overbeek DSM NeoResins+ , Sluisweg 12, 5145 PE, Waalwijk, The Netherlands