Naslov
Evaluation of light stability of liquid crystal inks

Autori
Jakovljević, Maja ; Klanjšek Gunde, Marta ; Lozo, Branka

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
5th International Joint Conference on Environmental and Light Industry Technologies - Book of abstracts / Borberly, A. - Budimpešta : Rejtõ Sándor Faculty of Light Industry and Environmental Engineering, Óbuda University, 2015, 113-120

ISBN
978-615-5460-60-9

Skup
5th International Joint Conference on Environmental and Light Industry Technologies

Mjesto i datum
Budimpešta, Mađarska, 19.11.2015. - 20.11.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
thermochromic printing inks; liquid crystals; leuco dyes; light stability

Sažetak
Thermochromic (TC) inks change their colour by exposure to different temperature. The two most important types apply liquid crystals (TLCs) or leuco dye-based composites. The composites with leuco dyes change colour reversibly by selective absorption of the incident light. Contrary, TLCs do not absorb visible light, but reflect it within a narrow spectral region, which produces practically monochromatic colours such as in rainbow (iridescent colours), frequently named as "colour play". The TC inks are used in security printing, brand protection, smart packaging, medical applications, marketing and novelty printing. TC printing inks have low stability against high temperature and light. The leuco dye - based inks are proved to have poor stability of pigment capsules, polymer envelopes and binder against light and high temperatures, but the stability of TLC inks has not yet been evaluated. Therefore, the TLC inks were printed on paper - based substrates and exposed to daylight for varying time periods. The changes to the dynamic colour due to exposure to daylight were measured, using Ocean Optics spectrophotometer with 50 mm integrating sphere operating in (8°:di) measuring geometry, within 400-700 nm spectral region. The results show poor stability of dynamic colour against daylight, thus the thermochromic effect in TLC inks disappears in a short time.

Izvorni jezik
Engleski

Znanstvena područja
Grafička tehnologija

POVEZANOST RADA