For "additives" read "functional modifier"
For "additives" read "functional modifier"
Keywords: Coatings, Solvents, Additives
Another international conference in which the Paint Research Association played a major part was AddCoat 2001, held at Orlando, Florida, 29-31 January this year. It dealt with developments in the technologies and markets for additives for coatings, printing inks and adhesives.
Jon Graystone of the UK's PRA made an interesting and timely comment on what"additives" really define and suggested alternative terminology. This was the essence of his address.
As a descriptive term "additives" leaves something to be desired. It fails to do justice to the indispensable role played by these key formulating components without which most coatings would not be commercially viable. Arguably a better collective term would be "functional modifier". Additives "rule" every aspect of wet and dry coating behaviour,including rheology, surface energy, biochemistry, electromagnetic and many other properties. Although there are scientific principles to be followed, much formulating is entirely empirical.
There were several papers on additives for water-borne coatings and latex paints, which covered progress in wetting and dispersing agents, thickeners and rheology modifiers, plus another PRA paper on the solubility behaviour of PMMA-PEG graft copolymers in aqueous solutions.
In a session dealing with application, the emphasis was on additives to promote flow, overcome cratering and orange peel in UV and radiation cured coatings. Some were promoting silicone additives; others preferred silicone-free additives, such as polysiloxanes. Other sessions dealt with film formation;performance; and processing, handling and storage.
John Bean
