1662
Author
Kenjo, Toshiko
Title Of Article Chaper
Effect of pH on the hardening of Japanese lacquer films
Title Of Journal Book
Science for conservation
Issue
15
Pages
44204
Language Of Text
Japanese
Literature Type
Serial
Literature Level
Analytic
Abstract
The effect of several electrolytes on the hardening of Japanese lacquer was studied through IR spectroscopy. A definite amount of an electrolyte was mixed with raw lacquer which, after pH measurement, was applied on a polyethylene sheet to make a lacquer film. The electrolytes tested were NaCl, Na<sub>2</sub>CO<sub>3</sub>, HC1, H<sub>3</sub>PO<sub>4</sub>, and (COOH)<sub>2</sub> and the amount of each electrolyte added varied from 0.025 to 2.0%. The results are as follows: 1) The ratio of the absorbance at 993 cm<sub>-1</sub> to that 985 cm<sub>-1</sub>, serves as an indicator of hardening. For all the films investigated, it was found that they were in the tack-free state when their ratios were equal to or above 12. Therefore, the hardening time has been defined to be the point when theabove ratio becomes 12. 2) No significant correlation was observed between the hardening time and the kind of anions added. 3) the pH dependence of hardening was observed. Assuming that hardening time acceptable for practical use is less than 24 hrs., the optimum pH for the hardening of lacquer was found to be from 4.5 to 6. -- AATA
pub_id
1662