All issues
Predecessor
Volume 41, Issue 12
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
-
Shiro KUROIWA1968 Volume 41 Issue 12 Pages 587-593
Published: December 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSFlow properties of a commercial acrylic emulsion containing carboxyl group were studied. The pH and the solids concentration of the emulsion were 6. 1 and 40%, respectively. Viscosity was measured with a capillary viscometer and a rotational viscometer as a function of temperature, pH and solids concentration. The ranges. of temperature, pH and solids concentration studied were 20-60°C, 4. 4-9. 15 and 33.3-40%, respectively. The pH was changed by the addition of either hydrochloric acid or aqueous ammonia. The range of shear-rate measured by the two viscometers was 1-104sec-1.
Temperature and concentration dependencies of the viscosity followed the Andrade and the Richardson equation, respectively. Abrupt changes in viscosity and the non-Newtonian index were observed near the inflection point pH 7. 5-8.0 of the emulsion. The flow data followed the Casson equation in the high shear-rate range but not in the low shear-rate range. The Asbeck's residual viscosity and equilibrium yield were estimated from the linear part of the Casson's plots, which were very similar to the values for paint systems as reported by Asbeck and others. Critical volume concentration of the dispersed phase was calculated to be 51% which was independent of the pH change. The shape factor of the parti cles calculated was 0.52 at pH 7. 6 and 0.23 at pH 6. 1, which was much smaller than the value 2. 5 for the spherical rigid particles.
It is concluded that the Casson equation is useful to analyze the flow properties of polymer emulsions in high shear-rate range but further studies are needed to explain the critical volume concentration and the shape factor obtained in the present studyView full abstractDownload PDF (754K) -
Reactivity of Methallyl AlcoholHiroshi MAEDA, Koichi HASEGAWA, Kiyoshi FUKAI1968 Volume 41 Issue 12 Pages 594-601
Published: December 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe monomer reactivity ratios for the systems, methallyl alcohol (MAA) -styrene (ST) and MAA-methylmethacrylate (MMA), have been measured at 60°, 70° and 80°C, obtaining the following results.
ST (M1)-MAA (M2) MMA (M1) -MMA (M2)
Temp. 60° 70° 80° 60° 70° 80°
r1 5.24 4.70 4.13 3.64 3.35 3.35
r2 0.004 0.011 0.016 0.030 0.041 0.052
As the MAA content in the monomer mixture was increased, the rate of copolymerization reaction as well as the viscosity of benzene solution of the copolymer were decreased.
Two acrylic resins were prepared from styrene 20 moles, n-butyl acrylate 10 moles, acrylic acid 1 mole, and either β-hydroxylethyl methacrylate or MAA 5 moles, which were blended with a butylated melamine-formaldehyde resin at the solids weight ratio 70/30 and two white enamels were prepared. The enamels were applied on steel panels and baked at 150° for 20° minutes, and their film properties were compared. The films obtained from the acrylics containing MAA were superior in gloss, light fastness, hardness and turpentine-oil resistance to those obtained from 8-hydroxylethyl methacrylate, while the other properties were move or less the same.View full abstractDownload PDF (776K) -
Solid Solution Pigments of QuinacridoneKunihiko TAKAGI, Kazuyuki KUROSU, Isao FUJII1968 Volume 41 Issue 12 Pages 602-613
Published: December 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe effects of solid solution formation on the properties of pigments were studied. Two component systems consisting of unsaturated quinacridone and disubstituted one were used for the study. The substituent of the latter component was either Cl or CH3,. The solid solutions were prepared by mixing the amorphous components prepared by the acid pasting method and refluxing the resulting mixture in N-methyl-2-pyrrolidone for 6 hrs. The pigments thus prepared were used to formulate lacquers, and the dominant wave length _??_d, purity Pe and luminosity Y were measured with a spectral photometer. The formation of solid solution was followed by the X-ray diffraction method. Thermal properties of the product were measured by differential thermal analysis. The shape and particle size were exmined by an electron microscope.
It was found that there existed a pertially miscible intermediate phase. The electron micrographs of each component and of the solid solutions revealed that the particle size of solid solution generally lied between those of the two components, and the shape was nearly square. The formation of solid solution made _??_d shift to shorter wave length, Pe become slightly higher, and Y become slightly smaller as compared with those of the simple mixture of two components.View full abstractDownload PDF (2256K) -
Toyohiko YOSHIDA1968 Volume 41 Issue 12 Pages 614-620
Published: December 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (707K) -
Kazuo MURATA, Masayoshi IWAI1968 Volume 41 Issue 12 Pages 621-623
Published: December 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (538K) -
Solution and Copolymerization of Vinyl acetateHiroshi KAKIUCHI1968 Volume 41 Issue 12 Pages 624-630
Published: December 30, 1968
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (875K)
- |<
- <
- 1
- >
- >|