Automation and economization in printing as well as increased use of advanced related materials have been reducing differences in print quality between wet and dry lithographic processes. Because of this, driography printing has been receiving renewed attention. Four major issues regarding driographic inks are discussed: surface chemical consideration of the plate, peeling mechanism or kinetic evaluation of inks, characteristics necessary for inks and compositions of inks.

View full abstract

Recently, ultraviolet-ray curing (UVC) system has widely been applied to the offset printing. But this UVC system has some problems: influece of ink color to the curing rate, insufficient curing of thick ink film, color change by UV irradiation, poor adhesive property to special plastics (PP and others) etc. So, EBC system is greatly expected to solve these problems. We studied mainly basic research on the curing and adhesive properties of vehicles aiming at the application of EBC system to lithographic inks. Qualities necessary for acrylate monomers are low P. I. I. value, high reactivity and good physical property. At the optimum vehicles for EB curable inks, a combination of diallylisophthalate prepolymer and dipentaerythritol hexa acrylate is selected, while a combination of chlorinated polyethylene resin and hydroxypivalylaldehyde modified trimethylolpropane diacrylate is desirable for selecting materials with good adhesive property to plastic sheets. We also studied the difference between the curing behavior of inks and the adhesie behavior of vehicles in UVC and EBC systems. In the case of UVC, the curing property of inks depends on color shade and additives, while in EBC it does not depend on them. Referring to the adhesive behavior to plastic substrates, especially the adhesive behavior of the chlorinated polyethylene contained vehicle, the UV and EB cured materials were analyzed by ESCA. As the result, in the case of EB curing, many chlorine atoms are recognized at the interface of adhesion to PP sheets, while in the case of UV curing they are not observed.

View full abstract

The development of computer technology has brought our society the diverse information media, for example electronic publishing, from traditional and conventional printing media. One of the most remarkable medium among them is CD-ROM with its huge storage capacity and the capability in random access. However, at present CD-ROM has only its physical format standardised, leaving its logical format behind. Besides, the programs to run CD-ROM a developed by a number of companies in thier own ways. For the facts written above, users are forced to handle such discs in limitted ways and these discs have no compatibility with each other. Prior to other productions, Toppan has introduced “High Sierra Fomat” as the file structure and has been developed CD-ROM discs which are to be used in universed publishing media. In this chapter, standardizing CD-ROM file structure and its requirements are discussed.

View full abstract

The RGB and XYZ colorimetric systems were published by the international commission of illumination (CIE) in 1931. The values for each of three factors of color: (1) the relative spectral power distribution of illuminants, (2) the spectral reflectance factor of colorants and (3) the retinal color matching functions, are multiplied for each wavelength and summed. Then tristimulus values X, Y, Z are obtained. From these values, the chromaticity coordinates x, y are calculated and plotted on a CIE chromaticity diagram, where the dominant wavelengh and the excitation purity can be read.

View full abstract