Journal of the Japan Society of Colour Material
Online ISSN : 1883-2199
Print ISSN : 0010-180X
ISSN-L : 0010-180X
Volume 38 , Issue 10
Showing 1-4 articles out of 4 articles from the selected issue
  • Huziya NAKAHARA, Akira NAGAE, Sigeo OKADA
    1965 Volume 38 Issue 10 Pages 415-423
    Published: October 30, 1965
    Released: November 20, 2012
    JOURNALS FREE ACCESS
    The authors reported the studies previously on the preparation of the HgS-CdS pigments and the relations between the blending composition and coloring of the HgS-CdS systems, and between the crystal structure and the blending composition or thermal treatment temperature.
    This report deals colors and crystal structures of the pigments in HgS-CdS-ZnS systems.
    Hg, Cd and Zn were coprecipitated as sulfides by Na2S solution from their chloride solutions. The coprecipitates were filtrated, dried, ground and then calcined for 3 hrs. at 350°C.
    X-ray diffraction studies were carried out using a Toshiba diffractometer, and measurements of diffuse reflectance spectra were made with a Hitachi spectro photometer (Beckmann type).
    The values of the energy gap were calculated from the wave lengths corresponding to the intersection of the straight-line extrapolation above and below the short wave length knee of the reflectance curve, i.e., the same procedure was used as that employed by Larach, Shrader and Stocker. (Phys. Rev. 108,587 (1957))
    Results :
    1. ZnS has not the same property of extender as BaSO 4. It makes the solid solution with HgS, CdS. and HgS-CdS.
    2. The colors obtained in this study with the HgS-CdS-ZnS systems ranged from light yellow (lemon) to dark maroon, depending on the content of each component of the samples.
    3. As the amounts of CdS or ZnS increase, the colors of the pigments shift toward the hypochromic hues, and this effect of ZnS in greater than CdS. In case of HgS, it shifts toward the bathochromic hues.
    4. The crystal structures of the solid solutions tend to be hexagonal with increasing CdS contents. and to be cubic with increasing HgS or ZnS contents.
    The interplaner spacing becomes smaller with increasing ZnS contents.
    5. The values of the energy-gap calculated from the reflectance curves increase with increasing ZnS or CdS contents, but decrease with increasing HgS contents.
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  • Takeo IMAI, Toshio ÔKAWA
    1965 Volume 38 Issue 10 Pages 424-429
    Published: October 30, 1965
    Released: November 20, 2012
    JOURNALS FREE ACCESS
    Polyester resins containing ethylenic unsaturation have been used for the purpose of undercoating the. exterior of railroad cars because they possess fast-drying property when applied as thick films. It is, considered that the films coated on rolling stocks are affected by the mechanical stresses resulted from running, and if films can not resist to the vibration and/or deformation of substrates they will soon fail by such external influences. Then for this use, it is important to investigate mechanical properties of paint films, but it is considerably difficult. The free films of polyester can not be handled without difficulty for reason of their brittleness. It is said that when a vibrometer is employed, the dynamic visco-elastic properties of attached paint films can be obtained. In this study, the resonance curves of film-substrate system were measured with a vibrometer.
    On a film-substrate system, the natural resonance frequency (N. R. F.) of the system shifts to ν from ν1 which is N. R. F. of the substrate. If a steel substrate, thickness and density of which are h1 and ρ1 respectively, is coated on both sides with a paint rayer of thickness h2/2, the dynamic modulus of elasticity E2 (dynamic Young's Modulus) of the coated film is calculated by
    E2= {(1+ρ2h21h1) (ν/ν1) 2-1} E1/ (1+h2/h1) 3-1
    where E1 is the modulus of elasticity of substrate, and ρ2 is the density of the film. The loss tangent, tan δ2, of the film is given by the following equation tanδ2= (1+ρ2h21h1) (ν/ν1) 2tanδ-tarδ1/ (1+ρ2h21h1) (ν/ν1) 2-1
    tanδ=Δν/ν=Δ/π
    where δ an δ1 are the loss angles measured about the film-substrate system and the steel substrate alone respectively, and Δν is the band widths of the system. Band width is the term expressing the range of frequencies for which the resonance amplitude falls within limit not less than 1/√2 of its maximum value. Δ is the logarithmic decrement of the system when forced oscillation was interrupted.
    Experiments were performed as follows. A steel panel, with or without polyester coatings, is hungwith threads at two positions corresponding to its nodes. A vibrating current from a variable audio oscillator is fed to the electromagnet located under one end of the panel, and drives it. The oscillation of the other end of the panel is picked up with another electromagnet, and is received by a receiving set assembled with an amplifier, an octave filter and an oscillograph. The measurements were carried out in a conditioned room kept at 20±1°C.
    In this study, varying amount of catalyzing agent against polyester base was used, and five varieties of composition were prepared. The changes of visco-elasticity in curing duration and the variations of complex modulus with frequency and temperature were measured. It seems that less catalyst retards the curing rate and derives loose linking structure.
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  • Kazuyuki MIHARA, Kiyoshi NAGAKURA
    1965 Volume 38 Issue 10 Pages 430-440
    Published: October 30, 1965
    Released: November 20, 2012
    JOURNALS FREE ACCESS
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  • Yasuaki SUGA, Yoshito NISHIZAWA, Shiunrô UEMURA
    1965 Volume 38 Issue 10 Pages 441-450
    Published: October 30, 1965
    Released: November 20, 2012
    JOURNALS FREE ACCESS
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