Carbon black (CB) /metal phthalocyanine (MPC) composite films were prepared by electroless plating method. Application of the composite films to black matrix of liquid crystalline display was discussed. The electroless plating of the composite film was performed by the immersion of an indium tin oxide (ITO) plate, which was short-circuited with an aluminum plate, into a dispersion containing CB, MPC, 0.1 M HC1 and 2 mM surfactant containing an azobenzene group. Stable composite films were obtained using a dispersion containing less than 70 wt% of CB content. The absorbance of the composite film in visible region increased with CB. When the content of CB and the thickness of the film were 70 wt% and 1μm, respectively, the lowest absorbance of the composite film in visible region was greater than 3. The maximum reflectance of the each composite film we prepared was less than 7%.
Rheological properties of disperse system of magnetic metal powder treated by dispersant (L-95) in mineral oil were studied. In a steady shear measurement, shear -thinning behavior was observed, however, a plateau region appeared in the region of middle shear rate. In a stress growth measurement, the times when the maximum value of stress appeared are almost the same for all samples. The longer the rest period, the larger the maximum value of stress is. In dynamic viscoelastic measurements, the values of storage modulus were almost constant irrespective of frequency at small strain amplitude up to 5%. However, with increasing strain amplitude, the value of storage modulus decreased and a minimum in the frequency dependence of storage modulus was observed in lower frequency region. These phenomena are associated with breaking down and formation of the flocculated network structure formed by metal powder in shear field. Viscoelastic values decreased with increasing strain and the strain amplitude at which the value began to decrease reduced with the concentration. The effects of steady shear flow on dynamic measurements for the suspensions having flocculated structure were studied by transient unidirectional shear flow experiment such as the parallel superposition of steady shear flow and small amplitude oscillatory shear. Storage modulus decreased with increasing strain amplitude in high strain region. The higher the concentration, the smaller was the strain region in which the non-linear behavior was observed. The dynamic viscosity took a maximum tentatively prior to decrease, because the rupture of the flocculated network structure caused an increase in the internal friction. The recovery of the network structure after cessation of steady shear was examined by time dependence of storage modulus. In the initial time region the value of storage modulus increased, however the value decreased rapidly after reaching a maximum and attained an equilibrium for larger strain amplitude. This result can be explained by alteration of network structure formed by metal powder.
Surfaces of mild steel were treated by the electropolymerization of 2-vinylpyridine and acrolein (Ac) and the properties of surface-treated and coated mild steel were evaluated. The corrosion resistance and wet-adhesivity of coated mild steel were found to increase by the Ac-electropolymerization treatment.