New dispersing resin from Rohm and Haas
Specialty materials company Rohm and Haas, a graphics arts supplier known for emulsion products, recently introduced two dispersing resin products for organic pigments in aqueous media. These new styrene, acrylic-based polymers, Morcryl 410 and Morcryl 460 Plus dispersing resins, allow increased pigment loadings at higher pigment to binder ratios without compromising color density and viscosity stability.
According to Kay Sanborn, technical service scientist for graphic arts at Rohm and Haas, ‘Previous resin options required minimum thresholds such as two or four parts pigment to one part binder, but these new Morcryl products allow six to one ratios, which are game-changing advances in ink manufacturing.’ Laboratory testing has shown that these offerings make possible dispersions with pigment loadings of more than 40 percent. ‘Inks prepared with dispersions at higher pigment loadings print more strongly at very thin film applications to produce higher quality detail,’ added Sanborn.
Supplied in liquid form, flexible Morcryl 410 and 460 Plus resins allow printers to control performance no matter what kind of processes they run. The products enable broader compatibility with pigment types and other additives including conventional and neutral letdowns, an advantage when employing these resins in formulations destined for in-plant dispensing equipment.
‘We've challenged these resins in every way we can think of,’ said Sanborn. ‘We've shut presses off and left ink in the pan anywhere from four hours to an entire weekend. They didn't dry on anilox rolls or etched cylinders, and they print well even after 60 hours in the pan.’
These newer dispersing resins also offer advantages for increasingly popular neutral pH processes. Neutral pH emulsions keep viscosity stable while offering good resolubility, dry speed balance and excellent transfer properties, all of which affect runability. Dispersions based on Morcryl 410 and 460 Plus can be used with these emulsions and enhance the finished product, adding improved transparency with outstanding trapping, water resistance, and clarity/gloss.