Journal of the Japan Society of Colour Material
Online ISSN : 1883-2199
Print ISSN : 0010-180X
ISSN-L : 0010-180X
Volume 56 , Issue 8
Showing 1-7 articles out of 7 articles from the selected issue
  • Keizo MAKUUHI, Toru TAKAGI, Hiroyuki NAKAYAMA
    1983 Volume 56 Issue 8 Pages 505-508
    Published: August 20, 1983
    Released: November 20, 2012
    JOURNALS FREE ACCESS
    The film properties of thermosettable emulsions prepared by radiation method and persulfate method with same monomer composition were compared to make clear the features of the radiation-induced emulsion polymerization. The radiation method was superior to the persulfate method in the physical and chemical properties of the cured films. However, the surface gloss of the pigmented films from the radiation method were inferior to those from the persulfate method. The reason for the low surface gloss was investigated. The reaction products of glass which was used as reaction vessel with monomers were found to decrease the gloss. With ESCA (Electron Spectroscopy for Chemical Analysis) of the pigmented film it was found that there were much amount of isolated melamine resins in the radiation emulsion film than in the persulfate emulsion film. The isolated melamine resins on the film surface caused by poor mutual solubility of the emulsion was found to decrease the surface gloss.
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  • Minoru KOBAYASHI
    1983 Volume 56 Issue 8 Pages 509-517
    Published: August 20, 1983
    Released: November 20, 2012
    JOURNALS FREE ACCESS
    The sequence distribution of styrene (St) -methyl methacrylate (MMA) -n-butyl acrylate (BA) terpolymers was studied by 1H-NMR. The terpolymers with several monomer compositions were synthesized by radical polymerization in solvents with various conversions. In 1H-NMR spectra of terpolymers, the effects of diamagnetic shielding by the phenyl ring neighboring to MMA unit found in St-MMA copolymer were similarly observed. The methoxy proton resonances resolved into several peaks as a result of those effects were assigned to the individual microstructures of MMA-centered triads. The averaged diad concentrations about MMA unit (P2 {MS}, P2 {MM} and P2 {MB}, S : St, M : MMA, B : BA) as an estimation of sequence distribution, were calculated from the ratios for those peaks on some assumptions. The assumptions are as follows; 1) The “coisotactic parameter” for St-MMA copolymer proposed by Ito et al, is equal to it for terpolymers. 2) The P2 {MiMj} is equal to P2 {MiMj}. (the assumption of statistical simplification for multicomponent copolymer proposed by Ham). The observed P2 {MiMj} values agreed with the values calculated from monomer reactivity ratios. This result suggests that the above assumptions are appropriate.
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  • Minoru KOBAYASHI
    1983 Volume 56 Issue 8 Pages 518-524
    Published: August 20, 1983
    Released: November 20, 2012
    JOURNALS FREE ACCESS
    The effects of sequence distribution on the glass transition temperature (Tg) of styrene-methyl methacrylate-n-butyl acrylate terpolymers were studied. The terpolymers with various monomer compositions were synthesized by radical polymerization in solvents with high conversions. The Tg of these polymers was observed by thermomechanical analysis. The averaged diad concentrations (P2 {MiMj}) as an estimation of sequence distribution of terpolymers, were calculated from monomer reactivity ratios. The modified Gibbs-Dimarzio equation for copolymer proposed by Uematsu et al, was extended to terpolymers so as to explain the relation between observed Tg and P2 {MiMj}. The equation is as follows;
    DTg3Σi=1P2 {MiMj} Tgi+3Σi, j=1i≠j P2 {MiMj} Tgij
    Tgi : Tg of homopolymer i, (K)
    Tgij : Tg for different bond i-j, (K)
    The observed Tg values were higher than the values predicted from the general Fox's equation.
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  • Eiki TAKESHIMA, Toshinori KAWANO, Hisao TAKAMURA, Shigemichi KATOU
    1983 Volume 56 Issue 8 Pages 525-534
    Published: August 20, 1983
    Released: November 20, 2012
    JOURNALS FREE ACCESS
    Black panel temperatures were held higher than the standard in sunshine weatherometer testing, and the properties of coating film as deteriorated on thermosetting or thermoplastic resin coated steel sheets were examined in view of appearance change and chemical changes in coating resin. As a result :
    (1) Coating resin as found on polyester resin coated steel sheets deteriorates in photo-oxidation mode because of alternate effects of Uv × Hu and Te × Hu, and the following rate equation holds.
    In r=-20,000/RT 30. 44
    With testing temperature rise, the deterioration condition differs from that in outdoor weathering testing.
    (2) Coating resin as found on silicone polyester resin coated steel sheets deteriorates in photothermal reaction mode because of an alternate effect of Te × Hu, and the following rate equation holds.
    In r=-30,000/RT+ 44. 45
    The deterioration condition, however, differs depending on the testing temperature.
    (3) Coating resin as found on polyvinyl chloride resin coated steel sheets deteriorates in photooxidation mode because not so much of Te as of Uv or Hu, and the following rate reaction holds.
    In r=-15,000/RT+22. 00
    The condition of a coating film deteriorated is hardly influenced by testing temperature at all, however, film cracking is apt to occur with temperature rise.
    Note : r : acceleration ratio
    R : gas constant
    T : testing temperature (°K)
    Uv : quantity of integrated ultraviolet rays
    Hu : integrated time of maximum humidity
    Te : integrated time of maximum temperature
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  • Yoshio TAHARA, Jiichi SAITO, Ken-ichi KANNO, Masayuki SUZUKI, Yuichi S ...
    1983 Volume 56 Issue 8 Pages 535-539
    Published: August 20, 1983
    Released: November 20, 2012
    JOURNALS FREE ACCESS
    Coulostatic method which is easily usable to high impedance system was applied for corrosion rate measurement of coated steels. Polarization resistance, differential capacity of double layer, etc. were obtained from overvoltage variation after supplying a known small quantity of charge to primer coated mild steel immersed in 3% NaCl solution. Time variations of the parameters obtained were in good agreement with observation results of the coated steel surface.
    It was found that an increase in corrosion rate is detectable by the coulostatic method as the decrease in polarization resistance before the deterioration or degradation of paint film becomes to be remarkable.
    Measurement by the coulostatic method could be carried out easily without ohmic drop correction even when the electrical resistance of coated film was very high.
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  • Souichi MUROI
    1983 Volume 56 Issue 8 Pages 540-555
    Published: August 20, 1983
    Released: November 20, 2012
    JOURNALS FREE ACCESS
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  • Hiroshi UTSUGI
    1983 Volume 56 Issue 8 Pages 556-562
    Published: August 20, 1983
    Released: November 20, 2012
    JOURNALS FREE ACCESS
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