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Two types of self-repairing coatings for the protection of Al and its alloys are reviewed: (1) organic coatings with capsules containing repairing agent and (2) porous anodic oxide films with inhibitor solution stored in the pores of the oxide film. First, polyurethane microcapsules containing liquid surface-repairing agents were synthesized and polyurethane coating with the capsules was painted on Al alloy specimens. After mechanical damage to the coating, self-repairing occurred by the reaction of water vapor in the air with the repairing agents released from the capsules. Second, porous-type anodic oxide films were formed on Al alloys, and the pores of the anodic oxide films were filled with inhibitor solutions, followed by application of a covering polyurethane layer. Inhibitors released from the pores efficiently protected the Al alloy substrate from corrosion arising from induced mechanical damage.

We encountered cases of headache exacerbation in migraine patients living in the Tokyo metropolitan area following the Great East Japan Earthquake in the present study. We investigated the effects of the disaster situation on patients with migraine headaches following the Great East Japan Earthquake as well as their physical symptoms and psychological states using a questionnaire. The questionnaire survey was also conducted to clarify the prevalence of patients with headaches prior to earthquakes. The recovery rate was 65.7% (71/108 people). The seventy-one patients with migraines included 68 female patients (95.8%) and 19 patients that had migraines with an aura (26.8%). The exacerbation of headaches was observed in 24.6% of the migraine patients after the earthquake. Furthermore, a degraded psychological state was noted in patients with worsening headaches who began taking medication for insomnia. However, the disaster situation did not directly affect headache symptoms. Some of the patients examined (7.0%) had headaches prior to earthquakes in the Tokyo metropolitan area. These results indicate that the exacerbation of headaches was observed in migraine patients who exhibited co-morbidities including insomnia and anxiety in the Tokyo metropolitan area away from the affected area. We also showed that some of these patients had headaches prior to earthquakes.

In a previous study, self-healing polyurethane coatings with microcapsules containing healing agents have been developed for the protection of metal from corrosion. At the initial stage of the development of these coatings, we synthesized the microcapsules containing healing agents by adding organic solvents to inhibit the solidification of the whole capsule. In this study, the structure of the capsules formed with different solvents, such as chlorobenzene, toluene and xylene was examined. We also evaluated the self-healing ability of coatings with these capsules after damaging the coating by scratching. The amount of healing agents contained in capsules depends on the kind and the amount of solvents added. In the capsule formed with 20 or 50 wt%-chlorobenzene, there is almost no healing agent of liquid phase, while in the capsule formed with 70 wt%-chlorobenzen healing agents are contained. Toluene and xylene are more effective inhibitors than chlorobenzene. The capsule formed with 70 wt%-toluene or xylene contains much more amounts of the healing agent of liquid phase than that formed with 70 %-chlorobenzene, and the coatings with the former capsules have an appreciable self-healing ability.

Self-healing coatings with capsules containing healing agents have been developed for the corrosion protection of metal. In this paper, polyurethane capsules were synthesized under different conditions to examine the size and shape of capsules, and selfhealing ability of coatings with capsules dispersed was examined after damaging the coated layer by scratching with a cutter blade. The size and shape of capsules depended on the concentration of chlorobenzene in cyclohexanone used as a solvent of prepolymer solution. The capsule formed with 70 % of chlorobenzene gave a self-healing capability to the coated layer by releasing the healing agent after damaging. The amount of glycerol added for the formation of the polyurethane capsule shell affected the self-healing ability of the coated layer. The coating with the capsule formed with small amounts of glycerol showed a high healing ability, while, with large amounts of glycerol, the selfhealing ability was relatively low.

Introduction Many kinds of metals are used as structural material in the building or other constructions. It is important to protect the metal from corrosion, because the corrosion of the metal may cause a significant damage of the building and the constructions. One way of the corrosion protection of the metal is to cover with organic or inorganic coatings, isolating the metal substrate from water or oxygen. When some parts of the coating is removed mechanically or chemically, the corrosion of the material may occur at the damaged areas. Therefore, it is necessary to keep the paint layer protective by a periodic painting that costs much labor and expense. From the point of view of time- and money-saving, we started to develop a “self-healing coating” on the metals for corrosion protection. When the organic coating is damaged by mechanical impulsions, the coating at the damaged areas is healed automatically without painting again, heating or any other external treatments.The above concept is accomplished by the following process. Micro capsules that contain reactive liquid agents are dispersed in coatings (Fig. 1-a). The reactive liquid agent in the capsule is easy to react with water or oxygen in the air to form an organic compound with properties similar to those of the coatings. When the coating is damaged to form flaws, the capsule is also destructed (Fig. 1-b). Then, the reactive liquid agent included in the capsule flows out, and the flaw is filled with the organic compound after reacting with water or oxygen in the air (Fig. 1-c). In the present investigation, capsules that contain a prepolymer agent were dispersed in polyurethane coatings to examine the self-healing ability of the coating. The effect of glycerol on the formation of the capsule was also examined. Experimental At First, 7.7 g of tolylene-2,4-diisocyanate (TDI) and 1.3 g of glycerol were added to 18 g of cyclohexanone, and mixed by stirring with a magnetic stirrer at 600 rpm and 75 ˚C for 24 h. In the period, a prepolymer is formed in cyclohexanone by the reaction shown in Fig. 2. Then, 9.5 g of isophorone diisocyanate and 17 g of chlorobenzene were added to 11 g of the prepolymer/cyclohexanone to obtain a prepolymer solution. Micro droplets of the prepolymer solution were dropped into an aqueous solution containing 3 g of sodium dodecyl sulfate (SDS) and 0.10 – 0.50 g of glycerol. The droplet of the prepolymer solution reacts with SDS/glycerol solution at the interface between two phases to form polyurethane capsules as shown in Fig. 3, since the prepolymer solution doesn’t dissolve in the toSDS/glycerol solution, As a result of the reaction, capsules, which have a polyurethane shell and contain high reactive liquid, were obtained. The capsules collected on a filter were observed by scanning electron microscopy (SEM).The polyurethane dispersed with the microcapsules was coated on Al substrate by spreading 1.5 g of the prepolymer solution containing 10 mg of the capsules after mixing with ethylene glycol ultrasonically, and then kept at room temperature for 48 h to allow the polymerization of the prepolymer and the evaporation of ethylene glycol. Self-healing ability of the coating was evaluated by SEM after damaging the coating with a sharp blade at the pressure of 6.1 MPa. Results and Discussions Fig. 4 shows SEM images of micro capsules synthesized with a) 0.5 and b) 0.1 g of glycerol. All the capsules are spherical, and some of them are coalescent, forming clusters. Fig. 5 shows distribution of the diameter of the micro capsules synthesized with different amounts of glycerol. The most frequent diameter of capsules synthesized with 0.5 g and 0.1 g of glycerol is 4.0 and 3.2 µm, suggesting the coalescence of capsules is easier with larger amounts of glycrol. All the coatings with capsules showed self-healing after damaging with the blade, and the healing effect was more remarkable with smaller amounts of glycerol. Figure 1