Recent Developments In The Quantitative Determination Of Volatiles And Odor In Energy Curable Coatings

Recent advancements in Analytical instrumentation have increased our
understanding of the factors which determine the quantity and chemical
composition of volatile components which may be released from materials coated
with Energy Curable Materials. In addition, the correlation of the chemical
composition with perceived odor permits us to address complex issues such as
degree of cure in a direct and quantitative manner.

The perception of odor associated with all types of coating technologies is an
issue which is currently of great interest to the entire coatings industry, from raw
material suppliers to the end consumer. The origin of such odors is not always well
defined. In the case of waterborne technology, the odor of ammonia which is
frequently used has become accepted essentially as a characteristic aspect of the
technology itself. In a similar manner, the solvent odor associated with
solventborne technology has also become accepted over many years of use.
These odors arise from components of the coating which are intended to volatilize,
and which represent significant percentages of the coating composition.

In the case of Energy Curable coatings, the amount of volatiles present is
typically less than 5000 ppm. The actual odor typically perceived from such
materials is in general not related to the odor of the solvent in which the material
was produced, particularly for Energy Curable materials as they are manufactured
today. In addition, new chemical species are generated in the curing process,
either by photofragmentation of the photoinitiator, or by radical fragmentation in an
Electron Beam. The purpose of this Paper is not to generate a list of materials
which are related to the perceived odor of Energy Curable coatings, but to discuss
methods for their analysis.