Studies on Formation of Wooden Bases for Wood Finish (1)

On Extender Pigments Used in Formation of Wooden Bases

Abstract

Extender pigments (Tonoko, Sabituti, Zinoko, ) have been used as wood filler for wood. finish over the past many years.
The author elected 13 sorts of extender pigments for this experiment.
These samples are studied by differential thermal analysis, thermal gravimetric analysis, grain size analysis, infra-red absorption spectras, X-ray diffraction patterns, and electron micrographs.
1) It became clear by chemical analysis that these samples contained such clay minerals. as Si0₂, Al₂O₃, Fe₂O₃, and K₂O.
2) As the results of grain analysis, grain size below 5μ distributed over 30%.
3) Differential thermal analysis curves of No.12 and No.13 samples had endthermic peaks at nearly 600°C. Therefore these samples were clearly recognized as Kaolin mineral. Other samples showed unclear peaks of endotherm and exotherm.
4) Thermal gravimetric analysis on the samples of No.12 and No.13 showed remarkable decrease under the temperature between 400°C and 600°C. Especially the sample of No.13 agreed with decrease of Kaolin minerals. Other samples did not show significant decrease.
5) It was confirmed by infra-red absorption bands of nearly 3,710 cm^-1 and 3,625-3,630 cm^-1 that the samples except No.10 contained Kaolin mineral and mica mineral.
6) By X-ray diffraction patterns, mica mineral was found in all samples. Kaolin mineral was found in all samples except No.10.
Quartz was found in all samples except No.4 ; Felspar was found in No.4, No.5, No.12 and No.13 ; Chlorite in No.1, No.2 and No.5 ; Cristobalite in No.10 and montmorillonite in No.4.