Aromatic ring-fluorinated trimethine cyanine dyes having a triflate, tetrakis(pentafluorophenyl)borate, and tetraphenylborate as counter anions were synthesized. The photostability of the cyanine dyes in CH₂Cl₂ (concentration: 5×10^－6 M) under white LED irradiation in an incubator at 25℃ was examined. As a result, the dye having the tetraphenylborate as the counter anion shows remarkably low photostability, whereas the dyes having the triflate or the tetrakis(pentafluorophenyl)borate have high photostabilities. Furthermore, in order to confirm the detailed mechanism of photolysis, the high resolution mass spectrum (HRMS) of the dichloromethane solution, in which the dye was decomposed by the LED irradiation, was measured. Consequently, it was confirmed that a singlet oxygen generated by the dye excitation was added to the double bond of the dye and was converted into aldehydes and lactam through the generation and decomposition of dioxetane.

The stability of copper chlorophyllin dye, a derivative of the naturally occurring chlorophyll, was improved by the intercalation into the interlayer space of a layered inorganic host material. As the layered inorganic compounds, hydrotalcite was used. The copper chlorophyllin could be inserted between the layers either by the reconstruction method or by the ion exchange method. We found the preparation condition for the composite materials that successfully included the dye molecules between the layers. The obtained composite samples showed high durability under visible light irradiation. The intercalation of the copper chlorophyllin into the hydrotalcite layers effectively suppressed the elution of the dye molecules by water or ethanol. We proposed the potential application of these highly stable composite materials as environmentally friendly natural dye-based colorants.

The relationship between crystal packing and solid-state fluorescence quantum yield (Φ_f) in pyrazine monoboron complexes 1～6 was investigated. The maximum fluorescence wavelength (F_max) of the BPh₂ complexes 4～6 was blue-shifted (524～628 nm) and the Φ_f values were higher (0.13～0.29) than those of the corresponding BF₂ complexes 1～3 (F_max: 531～672 nm, Φ_f: 0.04～0.13), probably due to inhibition of the intermolecular interactions. Despite weaker intermolecular interactions of the dimethylamino-substituted BPh₂ complex 6 compared to non-substituted BF₂ complex 1, 6 (Φ_f = 0.13, F_max = 628 nm) had the same Φ_f value as 1 (Φ_f = 0.13, F_max = 542 nm) due to red-shifted F_max, which promoted non-radiative processes.

The properties of a novel pressure sensitive adhesive (PSA) based on tackifier (TF) surface segregation were compared with the general PSAs with or without conventional TF. The peel strengths of the general PSAs were relatively high at room temperature, but decreased drastically under high temperatures, such as 85℃. On the other hand, the PSA based on TF surface segregation maintained high peel strength to Polyolefin or ABS under high temperatures. The PSA based on TF surface segregation is suitable for laminating decorative films to automobile parts that require heat resistance.

We have developed a plate-like titania based material (LPT-106) as a pigment for novel design. A coating film containing LPT-106 shows high brilliance and smooth gloss with low graininess. This design is different from existing pearl pigments. This unique design is due to the following two points. Firstly, the particles are relatively thin so that ratio of light scattered at the particle edge is low and, secondly, multiple reflection is caused by particles with low reflectance.