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Volume 62, Issue 12
Displaying 1-6 of 6 articles from this issue
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Kazunobu TAKAHASHI1989 Volume 62 Issue 12 Pages 715-719
Published: December 20, 1989
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSA simple method for the simultaneous determination of tributyltin (TBT) and triphenyltin (TPT) leached from antifouling paint into seawater by the capillary gas chromatography with flame photometric detection (GC-FPD) was developed. The triorganotin compounds, in the chlorides, were extracted with hexane, followed by hydrogenation by sodium borohydride to yield tributyltin hydride (TBTH) and triphenyltin hydride (TPTH). These hydrides were analyzed by the GC-FPD equipped with a 610 nm interference filter to monitor the SnH molecular emission. GC conditions were as follows : fused wilica capillary column, HiCap-CBP 1-W 25-300 (25 m×0.53 mm I. D.); column temp.; 70°C (1 min) -10°C/min-240°C (10 min); injection temp., 250°C; detector temp., 300°C; carrier gas, nitrogen (1.0 kg/cm2); detector, FPD. The detection limits of this method were 0.05 ng for TBTC and 0.2 ng for TPTC. The recoveries of TBTC (28 μg/l) and TPTC (90 μg/l) from seawater were 98.5-101.1% and 92.9-102.8%, respectively.View full abstractDownload PDF (569K) -
Kouichi ANDOU1989 Volume 62 Issue 12 Pages 720-727
Published: December 20, 1989
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSIn this study, an evaluation work was carried out as to the smoothness of coated film, through computer-aided calculation of film thickness distribution in the point-symmetric spray pattern, formed by modelled paint particles injected from plural spraying apparatus placed with equal distance each other. The values for this evaluation were obtained by division of standard deviation in the film thickness distribution by their average figure. Such evaluation has become available for the film thickness distribution provided by any automatic industrial paint coating system, using continuously moving products conveyer and spray gun reciprocator, because the film thickness distribution formed by plural sprayers having equal distances, can be simply converted to the distribution obtained in such automatic system. The calculation and analysis for this evaluation were made subject to variation of paint particles distribution and variation of pitch length of overlapped film. The variation of paint particles distribution was shown by changing the distribution volumes as thecenter area and peripheral area of the pattern differently.
As the results, it was found that change in evaluation values under the variation of over lapped pitches a wave-like curve, and that shorter pitch didnot mean better smoothness. It can be said that the maximum overlap pitch among those which carry the minimum evaluation values, is the most effective diameter of a spray pattern. Changing of position, where the distribution volume changed gives greater influence to the evaluation value. When the position is consistent and only distribution volume differs, difference at peripheral area of the pattern gives greater influence than difference at central area.View full abstractDownload PDF (1139K) -
Takeshi AMARI, Koichiro WATANABE1989 Volume 62 Issue 12 Pages 728-736
Published: December 20, 1989
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSElectrical conductivity Σ, and rheological properties such as apparent viscosity η, storage modulus G', and dynamic viscosity η' for suspensions of carbon black in linseed oil, were investigated at various concentrations of carbon black. The electrical conductivity and shear stress were measured as a function of rate of shear using a modified Couette type viscometer, and the dynamic viscoelastic properties were measured at the frequencies ranging from 10-2 to 10 rad/sec using a computer controlled rheometer, in which the strain amplitude was held constant throughout the measurement.
Peculiar rheological properties in the suspension of carbon black are attributable to the process of formation and breaking down of the flocculated structure of the dispersed carbon black particles.
In the flow field, Σ and η show the different types of concentration dependence, and their shear rate dependence are also different. η increases exponentially with concentration, especially at low rate of shear. It is presumable that the value of η will diverge, when concentration reaches the critical value and an infinite network structure formed by dispersed particles is built up in the whole system. Electrical conductivity increases exponentially with concentration at the exponent of about 4 above a critical concentration which is much smaller than that for viscosity.
In the concentration region above 5%, the storage modulus measured at small amplitude of oscillatory shear takes an equilibrium value in the low frequency region. The equilibrium value depends on the density of network structure formed by dispersed particles and increases exponentially with concentration above a critical concentration. The magnitude of exponent and critical concentration are the same order as those for electrical conductivity. The process of structural formation seems to be similar to that of gelation and these phenomena can be represented by the percolation theory.
In the flow field, in which the rate of shear is suddenly reduced, Σ and η increase, whereas Σ reaches a maximum and then decreases with reconstructing the structural chains. These phenomena are attributed to the kinetic process of formation and breaking down of flocculated structure. The time profile of the electrical conductivity is correspond to that of the storage modulus after cessation of a large amplitude of oscillatory shear.View full abstractDownload PDF (1132K) -
Yukiko HIGASHINO1989 Volume 62 Issue 12 Pages 737-743
Published: December 20, 1989
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe analysis method for paint solvents, which differ in characteristics of volatility and polarity, was studied.
As a result, a more accurate and reliable analysis method for the solvents was established by using multidimensional procedure (simultaneous measurement by a polar and a nonpolar columns with two different detectors) on the capillary gas chromatography.
1. Two chromatograms, which differ in the characteristics of separation and sensitivity, were acquired by the polar and nonpolar columns equiped with the different detectors (TCD and FID). By analyzing these chromatograms, the accuracy in identification increased sharply and the time required for the analysis was shortened.
2. The retention index of acetates as adopted astandard made it possible to efficiently compare retention time measured separately in the two columns.
3. The difference of the retention index in the two columns, witch depends on function groups, enabled more accurate identification.View full abstractDownload PDF (834K) -
Itsuo NISHIYAMA, Kenzo TAKAHASHI1989 Volume 62 Issue 12 Pages 744-748
Published: December 20, 1989
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSFor adhesive strength measurement of coating film, qualitative method, such as cross cut test as a typical example, is still dominating. And quantitative data which should serve for the development of paints, the durability test of coating film and deterioration behavior analysis are hardly available under the present situation.
However, adhesive strength is the fundamental property to coated products and the development of an instrument is strongly desired.
Considering the method to cut coated films interfacially, the authers have developed an “surface and interfacial cutting meter” which has the features such as; (1) applicable to an extensive range of coating films, (2) comparatively easy to measure, (3) quantitatively measurable of coating film.
By this method, coated film is cut from the surface with a cutting blade, then the blade is balanced when it reaches interface and is moved along the interface. Shear strength and adhesive strength can be calculated from the cutting force into coating film and the cutting force along the interface respectively, using the “metal cutting theory” developed by Merchant.
This method is applicable to coating films in an extensive range, not only to single layar film but also to each layar of multiple layer films.View full abstractDownload PDF (586K) -
Tomosaburo KAWAHARA, Takashi NAKAJIMA1989 Volume 62 Issue 12 Pages 749-754
Published: December 20, 1989
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESS
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