ヘキサメチレンテトラミンによる亜鉛の防錆

気相防錆剤に関する研究 第6報

抄録

The vapor phase rust-inhibiting papers, powders, tablets and oils were prepared of hexamethylenetetramine (HMT) as a vapor phase rust-inhibitor with various sub-components. Their rust-inhibiting effects for zinc were investigated and the rust-inhibiting mechanism was discussed. The results are summarized as follows: (1) Milk casein as a binder for a vapor phase rust-inhibiting paper exhibited better rust-inhibiting effects than polyvinyl alcohol and gum arabic. The effect was excellent when the content of milk casein was larger than 9%. The good effect would be resulted from the water-proof property of casein. (2) HMT should excellent rust-inhibiting effects in the forms of papers, tablets and oils, whereas it gave no good effect in the form of powder, since the extender contacted directly with the surfaces of zinc test pieces. (3) The surfaces of zinc test pieces were corroded slightly in the rust-inhibiting test of HMT, under a severe condition of test for 4 months at 40°C and 100% R. H., but corroding specks were so slight as not to be identified by x-ray diffraction. (4) The rust-inhibiting effect of HMT is superior to that of DICHAN, and the following mechanism was supposed. Since HMT is hygroscopic, it reduces the moisture in the sealed atmosphere, and it decomposes on absorption of water. Formaldehyde, one of the decomposition products, prevents the zinc surface from being corroded and ammonia, another product, gives an atmosphere-controlling effect by neutralizing acidic substances in the sealed atmosphere.