Energy-curable inks

Much has already been published concerning the composition of energy-curable resin systems for use In coatings and Inks, and the basic approach to the development of such vehicles Is well known (Refs. 1, 2, 3). A typical formulation contains an oligomer, which may or may not contain reactive functional groups (e.g., double bonds), a cross-linking agent, a reactive diluent (for viscosity control), and a photosensitizer or photolnltlator. 

Uses Defoamer in inks and coalings, solventless, solv., waterborne, and energy-curable systems, food-contact inks and coatings defoamer in food-confact paper coatings, paper/paperboard food pkg. adhesives Regulatory FDA21CFR 175.105,175.300,176.170,176.180,176.200, 176.210... 

A radiation curable ink that can be cured to a sufficient extent even when a low-energy light source, such as an LED, is used has been developed. Special t q)es of curable polymers are required. A... 

K. Harada, K. Shinjo, S. Tsuji, and Y. Kurabayashi, Active energy ray curable ink jet recording liquid composition and ink jet recording method using the same, US Patent 8 408 690, assigned to Canon Kabushiki Kaisha (Tokyo, JP), April 2,2013. 

The primary resins used in this market are the radiation-curable epoxy acrylates, accounting for 60% of the resins used. A small amoimt of cycloaliphatic epoxies are also used in UV-curable inks and resists. Phenol and cresol epoxy no-volacs, and bisphenol A based epoxies are used in thermally cured formulations. The epoxy novolacs are used where higher heat resistance is needed such as in solder masks. Both free-radical and cationic-curable UV inks and colored base coats have grown rapidly because of the needs for higher line speeds, faster cleanup or line turnaround, less energy consumption, less capital for a new hne, and fewer emissions. 

It is well-established that water-based and solvent-based inks rely on absorption into the surface of porous media as well as evaporation as part of the drying and adhesion process, whereas UV (and EB) curable inks are energy-reacted to adhere to the surface of porous and non-porous substrates. Free radical UV inks, for exam-... 

The ultraviolet curing of Inks and coatings has also received new attention. The renewed Interest In curing Inks has been Influenced by ecological and economic considerations.. The Inks can be formulated as solvent free systems which are sensitized to mercury 3650A irradiation. The curing energy is only a fraction of that needed with heat curable systems. 

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