The Voet's Theory are widely applied to control flow properties of printing inks. The author analyzed the slope and the intercept “γ0” of the Voet's methode for existing printing inks, and obtained following results. (i) If power law is allowed to apply to the characteristic flow of printing inks, the slope is inversely proportional to “n” which is non newtonian index. (slope is the defference of radius for a log (100"/10")). (ii) The intercept “γ0” represents the consistency of printing inks to the time-scale of experimental investigation-one second, in case of constant slope. That is, if “λ0” shows linear function of retardation time, the following eqnation is held. γ0=3.47 λ 0 sl where, sl in slope : This equation means that the behavior of inks is rich viscoous, visco-elastic or elastic by λ0_??_1. (iii) The linear equation represented by “γ-log t” is not signification from visco-elastic behavior, but the same equation et=a'+b'log t, (et : strain, a', b' : constant.) is held in the range σ<σ0. This equation shows a creep phenomena based on the Eyrings theoy. (iv) Lower yield valne fL obtained from flow curves is of universal validity, for the use of yield values.
The retarding action of calcium hydroxide in dehydration of calcium orthoplumbate hydrates has been investigated by differential thermal analysis (DTA) in the previous paper. Authors found that the retarding action is closely correlated to the presence of the calcium hydroxide liberated. Such a phenomenon as the inhibition of dehydration is believed as that the crystals of calcium hydroxide produced by the hydration link together to form a three-dimensional network and that hydrated calcium orthoplumbate fills up the space existing in the calcium hydroxide network. Above conclusion is based on both the activation energy of the hydrate and its loss of weight. In this paper, the dehydration of calcium orthoplumbate hydrates will be identified by thermogravimetric analysis (TGA) pattern, and the information thus obtained will be used for comparison to analyzing the dehydration behavior of crystalline water and negative catalytic effects of calcium hydroxide by differential thermal analysis. The activation energy (E) was obtained from the continuous record of weight change as a function of time and temperature. Authors used the Freeman's method derived from the theoretical consideration. The plot of Δlog (dw/dt) /Δlog Wγvs.Δ (T-1) /Δlog Wr should give a straight line; the slope of this line will be E. For the purpose of this plot, dw and Wr can be determined directly from the thermogram. The reaction order (X) is obtained from the value of intercept of graph. The results of present experiments will support the conclusion of the previous paper. Thus, the method of thermogravimetric analysis can be used to obtain information about the kinetics and the reaction order of simple dehydration reactions. Several factors which may influence the patterns have not been examined, such as pressure, aomosphere and particle size. However, the present work appears to demonstrate that the dehydration of crystalline water in the hydrate mixture was retarded by the presence of the calcium hydroxide liberated; this conclusion has been based on both the activation energy of the hydrate and its loss of weight by thermogravimetric analysis and differential thermal analysis (in previous paper)
The following facts were observed regarding the process and products of the hydration of calcium orthoplumbate at various temperatures in an atmosphere of nitrogen-water vapor : i) In the hydration process, the mole ratio of CaO/PbO2 in calcium orthoplumbate decreased linearly, while that of H2O/CaO decreased step-by-step with the increase in temperature. ii) The powder which appeared in the hydration process changed in the color parallel with the liberation process of calcium oxide from the anhydrous compound. iii) The composition and nature of completely-hydrated products at various temperature were examined by X-ray diffraction analysis, thermo balance analysis and infrared absorption spectrum. The results of all the methods showed good agreement. In this paper, the hydration products at various temperature were examined by X-ray diffraction analysis and electron microscopy, and the information thus obtained was used for analyzing the soluble behavior of the calcium oxide from anhydrous compound and dehydration behavior of calcium orthoplumbate hydrates. The results of present experiment supported the conclusion of the previous paper, and results of electron microscopy and X-ray diffraction analysis agree well with the thermogravimetric analysis and other analysis. The comparison of the electron micrograph in the present experiment with the thermogravimetric analysis suggests that the dehydrtion of crystalline waterin the hydrate mixture was retarded by the presence of the calcium hydroxide liberated. That is, the behavior of the binding of calcium hydroxide to hydrate is believed as follows : the crystals of calcium hydroxide produced by the hydration link together to form a three-dimensional network and that hydrated calcium orthoplumbate fills up the space existing in the calcium hydroxide network. The three-dimensional network of calcium hydroxide may be a linkage consisting of crystals of a spherical form, as suggested by the results of Sato, because the values of the reaction order in this study agree with those of Sato.