UV Curable Formulations for UV-C LEDs

Abstract

We investigated the formulations of acrylates which were applicable to UV-C LED lamps. The mixtures of acrylate monomers and photoinitiators were placed on silicon wafer or sandwiched between a silicon plate and a CaF 2 plate to obtain sample films. The films were irradiated by UV-C LED lamps which emit 265, 285, and 300 nm-lights. The effect of initiators, irradiation wavelength, and atmosphere on the conversion of the acryl unit was investigated using FT-IR spectroscopy. We found that the photoinitiator O-benzoyl 2,3-butanedione monooxime was the most effective photoinitiator for 265-nm light. The effect of atmosphere in the system was clearly observed.

A new safranin based three-component photoinitiating system for high resolution and low shrinkage printed parts via digital light processing

“…where 3 I and 3 A are the molar extinction coefficient of initiator and absorber (when present), respectively, and [I] and [A] are the concentration of initiator and absorber, respectively. Based on the values reported for the molar extinction coefficients in the literature 45,49 and keeping in mind that no absorber was used in this study, the D p of 3KSRD sample was found to be signicantly smaller than that of 1KTPO (i.e., 40 vs. 600 mm). It approves that SFH + had a dual-function as photosensitizer and photoabsorber in the system.…”

Hybrid UV LED Device for Simulating Spectrum of High-Pressure Mercury Lamp: Evaluation in UV Curing Process

“…Figure 4 shows the effect of long wavelength for compensating the low intensity of the shortwavelength UV LED emission. Experiment (2) shows the thickness of the un-polymerized layer achieved with the 365 nm and 310 nm LEDs. Experiments (5) and 7 were performed with 365 and 310 nm irradiation, respectively.…”

“…For UV LEDs to gain prominence, their UV curing performance must be comparable to that of the classical high-pressure or medium-pressure mercury lamps. Okamura et al presented the optimal formulation of monomers and photoinitiators for use with UV-C LEDs (265, 285, and 300 nm peaks) and pointed out that the UV-C LED is effective for addressing oxygen inhibition for UV curing of resins under air [2]. Taki et al compared the network structures formed by the high-pressure mercury lamp and 365 nm UV LED.…”

Comparison of Network Structure Photopolymerized under UV-LED and High-Pressure Mercury Lamp with Different Photoinitiators

“…Recently, the group of Fouassier and Lalevèe investigated novel photoinitiators for LED projector 3D printing [14][15][16][17][18]. Moreover, Okamura et al used different types and formulations of photoinitiators to compare the performance of deep UV-LED with the typical highand medium-pressure mercury lamps and metal halide lamp [19]. They mainly focused on the sensitivity of the photoinitiator and conversion of C=C bond, and also briefly discussed the crosslinked structure of UV-cured monomers.…”