In Japan the act partially amending the Food Sanitation Act will be enforced on 1st June 2020 and the Positive List (PL) system will be promulgated by the government.
However, it needs more 1～2 years more to complete the PL and discussion of printing ink is a future theme. The EU is discussing the regulation of printing ink and we need to follow EU’s movement.
D65 is the mainstream light source typically used in industry for light appraisal, however, in the graphic industry, D50 is used instead. D50 light appraisal fluorescent lamp (AAA fluorescent lamp) has been the standard light for printed matter observation and appraisal. The problem with AAA fluorescent lamp is discussed by comparing the suggested specifications for printed matter observations and the mechanism of D50 light. Also, the different mechanisms between LED lamps (next generation lamps in recent years) and various high color rendering lamps are discussed. A summary of the interim report (mid-February) from the Japanese Society of Printing Science and Technology about various LED lamp's evaluation tests and analysis data is also included to solve the problem of the visual performance discrepancy between AAA fluorescent light and high color rendering LED lights. There are also several suggestions for new evaluation criteria for the future which can be discussed among readers.
There are many types of printed matter that we see on a daily basis. For example, newspapers, magazines, food / cosmetic packages, beverage cans, and the like. In recent years, as information technology has spread, a very severe environment has developed where the demand for printed materials is decreasing due to the spread of electronic hardware such as smartphones and tablets. On the other hand, fields in which printing provides added value such as flexible packaging, packages, labels, etc. have remained strong, and printing still supports a rich commodity economy and plays an important role.
In addition to conventional measures for safety and health, environmental protection and resource protection on a global scale have also become important environmental measures for printing inks. As environmental awareness increases around the world, sustainable development goals (hereinafter referred to as “SDGs”) have been set and environmentally friendly inks that meet various environmental guidelines have been developed to reduce environmental impact.
We are convinced that printing inks that contain a high content derived from natural materials, such as rosin in rosin-modified phenolic resin and plant-derived fatty acids in fatty acid esters, in addition to vegetable oils, can greatly contribute to SDGs, and recently this fact has been re-recognized.
Here, we will explain our approach to environmentally friendly inks and printed materials in response to changes in global environmental awareness.
Analysis of the composition is important for the characterization of copolymers. Recently, the importance of analyzing not only the average composition but also the composition distribution, that is, the analysis of the molecular weight dependence of the composition has been increasing. GPEC, which is solvent gradient HPLC, is effective for analyzing the composition distribution of copolymers. Further, by using two-dimensional HPLC combining GPEC and SEC, detailed composition distribution analysis of the copolymer becomes possible. In this lecture, the composition distribution analysis of copolymers using GPEC and two-dimensional HPLC will be explained.
2-(2-hydroxyphenyl)-2H-benzotriazole derivatives show excited state intramolecular proton transfer (ESIPT) due to the formation of intramolecular hydrogen bonding between the hydroxyl group and the nitrogen atom in the benzotriazole group. Therefore, they are known to cause efficient non-radiative deactivation and show no fluorescence, and they are widely used as ultraviolet absorbers. We synthesized 2-(2-hydroxyphenyl)-2H-benzotriazole derivatives having an amino group, a monobutylamino group or a dimethylamino group at 5 position and found that they showed fluorescence in spite of having molecular structure capable of causing ESIPT. Characteristic absorption at the long-wavelength ultraviolet area of these derivatives didn't show significant change in the solvent which has hydrogen bonding acceptor inhibiting intramolecular hydrogen bonding. It may show that these derivatives have relatively weak intramolecular hydrogen bonding and the efficiency of the ESIPT is low. In addition, the higher the electron-donating of the substituent at the 5-position, the stronger the fluorescence. The electron-donating property of these substituents may reduce the proton acceptability of the benzotriazole group in the excited state, suppress ESIPT, and develop fluorescence.