In the previous report, the author has investigated calcium rosin which was used generally as a basic ingredient for brittle lacquer, in order to find out the structural model of coating.
From the result, it is inferred, as for the structural model, that calcium-salt distributed uniformly in rosin acid and that the latter is considered as a binder.
In order to confirm fully the inference, rosin acid and its pure calcium-salt which are components of calcium rosin are prepared as the samples, and the calcium rosin having arbitrary calcium content is made again by dissolving both samples in benzene.
The author has investigated these samples through various observations, such as X-ray diffraction, electron microscopy, and differential thermal analysis, etc.
As the result, it has been concluded that pure calcium-salt is formed as fine grain and distributed uniformly in rosin acid behaving as a binder, in the structural model of brittle coating using calcium rosin as a basic ingredient.