Dispersing agents for UV curable systems
UV curing or more precisely UV & EB curing refers to the method of drying the films.
UV uses ultraviolet light and EB uses high energy electron beams and these types of systems are used in everyday use from cereal boxes, coatings onto CD’s and DVD’s, inks and coatings on magazines and floor coverings. The list of items that can be coated with UV or EB systems is quite extensive and beyond this introduction.
The advantages of UV & EB are well-documented, particularly when used with manufactured products that require fast processing and/or on substrates that are sensitive to heat. In addition, UV & EB is considered environmentally responsible since most of the solvents in traditional processes may be eliminated, thanks to the special capabilities of UV & EB curing.
Dispersing agents are used extensively in UV & EB inks and the list of inks are shown below:
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Inkjet
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Gravure
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Flexography
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Letterpress
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Offset lithography
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Screen printing
These inks are from very low viscosity (inkjet) to paste inks (screen inks) and dispersing agents are utilised to help with the wetting of the pigments, fillers, matting agents etc.
Technical Blogs
Dispersing agents perform by the anchoring of the surfactant onto the particle substrate and then acting as a barrier to stop the re-agglomeration of the particles. This concept is often referred to as steric stabilisation.
The new hyperdispersant has three functions, firstly a powerful amine anchoring group that latches onto the pigment substrate, secondly a tail section that floats within the UV medium and thirdly a capping group that further enhances steric hindrance between pigment particles.
