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Rheological measurements of cure rate of UV inks
Author(s) -
Otsubo Yasufumi,
Amari Takeshi,
Watanabe Koichiro
Publication year - 1986
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1986.070310713
Subject(s) - magenta , cyan , materials science , photoinitiator , composite material , curing (chemistry) , rheometer , light intensity , activation energy , monochromatic color , viscosity , exponential decay , photopolymer , rheology , uv curing , optics , inkwell , polymerization , chemistry , polymer , physics , monomer , organic chemistry , nuclear physics
The dynamic viscosity of UV inks during curing was measured at various film thickness using an oscillating plate rheometer. Logarithmic plots of the dynamic viscosity versus exposure energy are closely related by two‐straight lines. A useful concept in discussing the curability is the minimum exposure energy difined as the exposure energy at the intersection of two lines. On exposure to a monochromatic light of 365 nm, the minimum exposure energy increases exponentially with film thickness; this resulting from an exponential decay of the light intensity with depth in the film. Magenta ink shows the fatest cure rate at a given thickness, followed by yellow, cyan, and black inks in that order. The difference in cure rate is attributed to different absorbances of pigments. The UV curability on direct exposure to UV lamp is predicted from the spectral sensitivity of the photoinitiator and the viscosity data obtained during curing under 365 nm light. The model calculation shows good agreement with the experimental results.