New type triazine resin was synthesized to improve and fill for urushi, and physical properties of mixed urushi/triazine resin coating films were studied. Main results were as follows, (1) Triazine resin had a good mixing state with urushi. Separation, post-thickening and gelation were not recognized during storage. (2) Fall of the stress-strain properties and room temperature E' was not recognized, but with increasing content of triazine resin, high temperature E' and Tg fell. However, it was expected to fill for urushi, because these were not serious matters, in practical application. (3) Transparency of urushi film rose with increasing content of triazine resin. Consequently, it was expected to improve the color development of urushi enamel films. From the results presented above, it was considered that triazine resin synthesized in this experiment had a good compatibility with urushi and it was effective to improve and fill for urushi.
Needless to say, controling the pigment dispersion in paint manufacturing process is one of the most important point. And checking the upper particle size with a grinding gauge has been the most popular and conventional method for measuring the pigment dispersion level. According to the recent and quick development of computor system, measuring equipments of particle distribution are also getting pretty reasonable progress and some of these might make it possible to evaluate the pigment dispersion level by measuring the particle distribution without thinning its enamel sample. As a newly modified and combined evaluation method for pigment dispersion, measuring particle distribution was studied in our laboratory by the application of image processor system. Based on our experience, studying and results, measuring the particle distribution through image processor system might be positively recommended by the author for a very reliable and practical evaluation method of the pigment dispersion level.
Inorganic polymer is more excellent in heat and flame resistance than organic polymers. Generally speaking, inorganic polymers are hard and brittle compared with organic polymers. Inorganic polymer blends with organic polymer were attempted to improve the above mentioned defects, but they were inferior in heat and flame resistance to sole inorganic polymer. To overcome these difficulty, authors studied a new type of Non-Aqueous polymer Dispersion (NAD) with polyalkoxysiloxane as dispersant. The NAD was obtained by polymerizings acrylic monomers (as organic polymer component) with a polymerization initiator in a aliphatic hydrocarbon solution of polyalkoxysiloxane (as an inorganic polymer component). The NAD thus obtained was stable polymer dispersion and showed following characterstics. 1) Excellent in film-formability compared with sole polyalkoxysiloxane. 2) Superior in curability, heat resistance, flame resistance and water vapor permeability to acrylic polymer-polyalkoxysiloxane blends. The new non-aqueous polymer dispersion with polyalkoxysiloxane as dispersant would offer an inorganic/organic polymers composite with above mentioned unique characteristics
The catalytic effects of carboxylic acid and dibutyl tin dilaurate (DBTDL) on the reaction kinetics of two-component acrylic urethane coatings were discussed. Reaction of a biuret of hexamethylene diisocyanate with acrylic polyol in the film state follows the second order reaction, and the temperature dependency of the rate constants fits for the Arrhenius equation. It is clearly observed that carboxylic acid shows strong catalytic effect on reactivity of isocyanate group and the rate constant increases with increase incarboxylic acid contents for the system without DBTDL. However, the effect of DBTDL on the reactivity of isocyanate groups for the system having carboxylic acid is much less than that of the system without carboxylic acid.
The preparation of monodispersed Phthalocyanine Blue pigment by means of PVD method that coat the Cu-Phthalocyanine Blue pigment having sublimation nature on the surface of spheric poly-styrene particles was examined. The L-value in Lab indicate system was influenced by flow amounts of nitrogen gas and pressure inside of PVD reactor. Achieving the PVD at the flow amount of relatively small amount, for example, under 10 ml/min, relatively high pressure, for example, 2 Torr to 2.5 Torr, was advisable as treating pressure, and at the flow amount of relatively large amount, for example, around 20 ml/min, relatively low pressure, for example, in the neighbourhood of 1.5 Torr, was advisable as treating pressure. From the observation result of SEM, it is considered that the vapor of Phthalocyanine Blue forms it's crystal becoming incorporated onto properly melted polymer surface by the heat emitted from the heater for sublimation.
In order to scrutinize water absorption process in coatings closely duplicating the actual state of the film on a substrate, a system for monitoring the variation of the parallel capacitance of coatedelectrode in water has been devised. A micro-computer is involved for the data acquisition and theirprocessing. Water content in the film can be calculated from the parallel capacitance by Brasher's equation. A coating composed of epoxy/blocked polyisocyanate was examined. When baked at lowest temperature, the Arrhenius plot exhibited good linear relationships as for permeability, diffusion and solubility coefficient. With the specimens baked at the higher temperatures, however, data are fluctuated above and breaks of gradients are perceivable. These can be ascribed to the glass transition temperature with the highly crosslinked films existent in the ranges where the present measurement were made.