RadTech 2022 spotlights next-level formulations

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One of the highlights of RadTech’s conferences are the sessions on new technologies. To Rad Tech 2022three sessions were devoted to higher-level formulations, with applications ranging from food packaging, wood coatings, automotive coatings, and more.

Higher level formulations I

Ashland’s Bruce Fillipo opened the Next Level Formulations I session with “Impact of Monomers on Fiber Optic Coatings,” an overview of the impact of polyfunctionals on fiber optics.

“We could achieve the properties of a synergistic monofunctional monomer with polyfunctional ones – viscosity suppression and improved solubility,” Filippo noted. “The improved homogeneity of the formulation facilitates the homogeneous curing of polyacrylates.

“Vinylpyrrolidone has measured the best overall properties imparted to a primary optical fiber formulation, including excellent viscosity suppression, superior elongation and tensile strength, and a cure rate greater than or equal to that of other acrylates monofunctional ones evaluated,” added Fillipo. “The targeted properties in fiber optic coatings are similar to other UV-curable applications such as inks and specialty coatings.”

Marcus Hutchins of Allnex followed with “Achieving Ultra Low Gloss Coatings Through Oligomer Design and Technology”. Hutchins discussed paths to 100% UV coatings with matting agents, for example for wood.

“Options for further gloss reduction include resins with lower functionality and developing matting agents,” added Hutchins. “The decrease in gloss can lead to scuff marks. You can create a wrinkle effect with excimer curing. Equipment setup is key to ensuring a smooth surface without flaws.

“Low matte finishes and high performance coatings are becoming a reality,” added Hutchins. “UV-curable materials can effectively matt through molecule design and technology, reducing the amount of matting agents needed and improving resistance to burnishing and staining.”

Richard Plenderleith of Sartomer then spoke on “Strategies to reduce the potential for migration in the graphic arts”. Plenderleith pointed out that around 70% of packaging is for food packaging.

Plenderleith added that standard UV inks are not suitable for direct food packaging, while low migration UV inks are needed for indirect food packaging.

“The selection of optimized raw materials is essential to minimize the risk of migration,” said Plenderleith. “Problems can arise from roller contamination during printing, UV lamps not drying throughout, or defect migration during storage. UV systems are part of the industry’s growth of food packaging because it is a solvent-free technology.

Plenderleith pointed out that food packaging requirements are becoming stricter.

“We are seeing a strong movement towards UV LEDs, and the development of effective solutions that meet LED curing requirements is essential,” he added. “Improving reactivity while reducing migration and risk requires us to work on both photoinitiators and acrylates.”

Camila Baroni of IGM Resins closed Next Level Formulations I with “The synergistic effect of combining amino-functional materials with type I photoinitiators”.

“From the data presented so far, it appears that some of the acrylated amines are good oxygen scavengers and have potential as synergists in the presence of type 1 photoinitiators,” Baroni said. “The more reactive amines caused an undesirable yellowing effect of the cured film. We assumed that yellowing could be reduced by adjusting the acrylated amine content.

Higher level formulations II

Next Level II formulations started with “Small Particle Sizes Pack a Punch: Additive Options to Improve Surface Performance of UV Coatings Using Crosslinkable Dispersions, Nanoparticles, or Wax Options micronized”, presented by Brent Laurenti of BYK USA. Laurenti discussed UV curing additives, SiO2 nanomaterials, additives and PTFE-free wax technology.

“PTFE-free waxes give us better leveling performance in some applications, and they’re 100 percent biodegradable,” Laurenti said. “It can go into almost any coating formulation.”

Next was Tony Wang from Allnex, who talked about “LED amplifiers to improve LED surface hardening for litho or flexo applications”.

“Oxygen inhibition quenches or eliminates free radical polymerization,” Wang noted. “It is harsher in thin or low-viscosity coatings, such as packaging coatings and inks. This can create a sticky surface. Surface curing is more difficult for LED curing due to low intensity and short wavelength lock. »

Evonik’s Kai Yang then discussed “Promoting energy-curable adhesion to a difficult substrate – from an additive aspect”.

“PDMS (polydimethylsilozanes) are the simplest class of siloxanes, and provide very low surface tension and are very stable,” Yang observed. “It offers good gliding properties. We have improved the compatibility by organic modification, which controls its hydrophobicity and hydrophilicity. The desired properties can be adapted by structural variation. We have found that higher polarity improves solubility in the UV matrix. TEGO Glide helps control the properties of organomodified siloxanes, while Tego RAD improves glide and release.

Jason Ghaderi of IGM Resins closed Next Level Formulations II with his talk on “Urethane Acrylate Oligomers: Sensitivity of Cured Films to UV Light and Moisture with and without UV Absorbers”.

“All of the UA-oligomer-based formulas showed no yellowing to the naked eye and virtually no yellowing or discoloration as measured by the spectrophotometer,” Ghaderi said. “The soft urethane acrylate oligomers showed low tensile strength and low modulus while exhibiting high elongation. high tensile and modulus with low elongation UV absorbers and HALS are observed to interfere with curing and therefore crosslinking of the cured film is less than that of the system without these two elements.

Higher level III formulations

Next Level Formulations III featured Joe Lichtenhan of Hybrid Plastics Inc., who covered “POSS Additives for Dispersion and Viscosity Control”, an overview of POSS additives and how they can be considered smart hybrid additives for coating systems.

Lichtenhan was followed by Yang from Evonik, whose second presentation was “The Use of Silica Additives in UV Printing Inks”.

“In UV/EB curing formulations, surface-treated silica is the preferred product because exceptional stability might be easier to achieve while maintaining good viscosity for printing applications,” Yang noted.

“UV Curable Coating Options for Interior Automotive Applications,” by Kristy Wagner, Red Spot Paint, was next.

“UV-curable clear and pigmented coatings have been shown to not only meet but exceed today’s stringent OEM specifications for interior automotive applications,” Wagner observed.

Mike Idacavage, Radical Curing LLC, concluded with “low-viscosity urethane oligomers that function as reactive thinners,” which he says could be used in inkjet, spray coating, and paint applications. 3D printing.

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