Ronald Tennebroek

New generation decorative paint technology

The growth of waterborne paints in the higher performance decorative paint segments (like in high gloss paints, trim paints and also in stains and varnishes) has been slowed down due to a lack of open time, rheology, film build and scratch resistance. Over the years the improvement of the open time has been an intense area of research, but to date the typical paint rheology and brushing performance of a solvent based paint could not be achieved in a waterborne system. In this paper very low viscosity oligomers are presented as a solution for the open time problem. These oligomers remain liquid even after the evaporation of water and are self-crosslinking to achieve good final properties. The oligomers are combined with a dispersed polymer to reduce tack free times of the resulting coatings and to increase the rate of development of the properties. A model system is described where this effect is demonstrated.

Detection of coalescing agents in water-borne latex emulsions using an environment sensitive fluorescent probe

In this paper we report the determination of partitioning of coalescing agents (organic co-solvents) in water-borne latex emulsions by means of a fluorescence method. An environment-sensitive fluorescent probe was copolymerized via emulsion polymerization. The presence of organic co-solvents inside the polymer particles is revealed by the photophysical properties of the probe. In particular, the position of the fluorescence emission maximum of co-polymerized can be used to measure the amount of coalescing agent present in the polymer particles. The spectral shifts are shown to be due to the softening of the matrix, rather than to solvation of the probe by the added co-solvent.

Probing of cosolvents in polymer latex materials by using solvatochromic fluorescence

The process of film formation is of great importance for the application of organic coatings. In waterborne coatings, organic cosolvents are still indispensable, but regulations force the industry to reduce their amounts. Here we describe a method that uses the solvatochromic fluorescence of a probe molecule copolymerized in an emulsion polymerization process with different monomers to shed light on the partitioning of cosolvents in polymer latex materials. The formulation of the latex with organic cosolvents that are not very water soluble leads to a quantifiable redshift of the emission of the probe. The transfer of the cosolvent upon mixing of cosolvent‐containing and cosolvent‐free compartments can also be monitored.