By applying paint to hot-dip Zn alloy coated steel sheet, it is possible to improve its resistance to corrosion and elaborate its design. While a variety of types of Zn alloy coated steel sheet have been developed in recent years, the nature of any under-paint corrosion experienced by these materials remains unclear. Therefore, this study used painted hot-dip Zn alloy coated steel sheet to investigate under-paint corrosion associated with an accelerated corrosion test. Particular attention was devoted to the composition ratio and elemental distribution of the coated layer in various types of hot-dip Zn alloy coated steel sheet. The base materials used were hot-dip Zn-5%Al-1%Mg alloy coated steel sheet, hot-dip 60%Zn-40%Sn alloy coated steel sheet, and hot-dip Zn coated steel sheet. The evaluation was carried out by external observation, measurement of corrosion potential, SEM-EDX analysis, and X-ray diffraction. As a result, it was found that the corrosion resistance of painted hot-dip Zn alloy coated steel sheet was likely to be greatly affected by the type and distribution of the additive element in each coating layer.

In the present study, the utilization of a fiber coating system was attempted with flocking equipment targeted for exhibition display materials, instead of a hand-held portable one. In this paper, two samples assumed as exhibition display materials were manufactured with the fiber coating system. As a result, it was confirmed that it was possible to apply the fiber coating system using the flocking equipment for exhibition display materials. Moreover, the flocking evaluation was carried out under various coating conditions to investigate efficient flocking methods over large areas with complex shapes. In the case of a coating distance of less than 20 cm, it was found that the flocking amounts increased as the coating angle became larger. Therefore, when the flocked surface is a horizontal plane, flocking from the vertical direction is effective. On the other hand, at a distance of 30 cm, the flocking amounts hardly depended on the coating angle because of the effect of air pressure on the function of the fiber coating system.

Hydrophobicity of a solid surface is divisible into two categories: static hydrophobicity and dynamic hydrophobicity. For improved performance of water-repellent surfaces, dynamic hydrophobicity has been investigated frequently as an important subject in various industrial fields. Conventionally, dynamic hydrophobicity has been evaluated by measuring the motion of water droplets laid “gently” on an inclined surface. However, from a practical standpoint (e.g. rain dropping onto a building roof), the droplet motion on a surface must be considered for various situations, such as “impact”. Recent collaborative discussions related to surface chemistry or materials science and fluid mechanics are increasing and becoming indispensable for elucidating the dynamic hydrophobicity on a solid surface. Furthermore, recently developed hydrophobic materials such as solid-liquid bulk composites provide unique dynamic hydrophobicity, which is difficult to understand from knowledge of normal solid hydrophobic materials. This paper presents recent research topics related to dynamic hydrophobicity.

In the present article we have summarized our research work related to synthesis and investigation of several new types of cationic gemini surfactants containing different headgroups (i.e. pyridinium, imidazolium, pyrrolidinium, piperidinium, morpholinium). We have used three different principal methodologies to develop several new types of gemini surfactants: (1) regioselective co-bromination protocol followed by quaternization (2) regioselective epoxy ring opening reactions followed by quaternization (3) Alkylation reactions followed by quaternization. These cationic surfactants have been investigated for their surface and physicochemical properties and the studies have established these surfactants to be superior compared to conventional/commercially available cationic surfactants.

Additives for paint take important roles to improve paint properties such as surface characteristics. Many additives have interfacial activity.

These give large effect, even in addition of a small amount, on the other hand, significant problem occurs in case of improper use of additives.

In this report, functional mechanisms and problems of additives, especally anti-foarming agents and levering agents are described.

To strengthen the management system for preventing occupational accidents and health problems (such as bile duct cancer problem) associated with chemicals, Industrial Safety and Health Law has been revised. All enterprises (manufacturers, distributors and users) shall be required to carry out risk assessment of chemicals. However, as many enterprises are inexperienced in the field of risk assessment of chemicals, the full implementation of the revised Law seems to be a challenging task. This paper describes the response of enterprises to the revised Law, using various reference materials from the Ministry of Health, Labour and Welfare, such as “Guideline for the investigations of danger or harmful chemicals”, as well as how to use the relevant IT tools (Control bonding and ECETOC TRA).