Develpment of a new cleaning medhod uging cellulose nanofiber for paper artifact with copper corrosion

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K13421
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 03060:Cultural assets study-related
• Research Institution: Tokyo National University of Fine Arts and Music (2020-2023); Independent Administrative Institution National Institutes for Cultural Heritage Tokyo National Research Institute for Cultural Properties (2019)
• Principal Investigator: Kida Keiko 東京藝術大学, 大学院美術研究科, 准教授 (20634918)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 紙の保存修復 / セルロースナノファイバー / 緑青焼け

Outline of Final Research Achievements

One of the most notable deterioration phenomena of paper cultural property is the "corrosion" of paper by metal ions. In this study, we investigated a cleaning process that does not leave metal ions on cultural property materials by capturing metal ions, which are the cause of paper deterioration, using a gel made of TEMPO-oxidized cellulose nanofiber (TOCN) derived from plant fibers. We obtained several types of gels made of fibers that are said to be derived from commercially available wood pulp and TEMPO-oxidized, and confirmed their various characteristics as gels to be used for cleaning. We tried to clean simulated deteriorated paper materials using these gels, excluding those with a pH of 5 or less. Elemental analysis of the paper materials before and after the treatment using EDX showed that the Cu content in the paper materials tended to decrease significantly before and after the gel cleaning.

Free Research Field

保存科学

Academic Significance and Societal Importance of the Research Achievements

日本の紙質文化財修理処置の現場では、「焼け」に効果的な処置方法が見出されておらず、水による洗浄のみを行っている。焼けの要因となる金属イオンを捕獲する手法としては、一般的にはキレート剤の使用が行われてきているが、紙資料においては、キレート剤の残留が懸念されるため、積極的に使用されていない。本研究では、植物繊維由来の新規な材料としてセルロースナノファイバ―からなるゲルを選定し、洗浄に用いるゲルとしての各種特性を確認し、これらを用いて模擬劣化紙資料の洗浄処置を試みた。その結果、紙資料中のCu成分が、ゲルの洗浄前後で、大きく減少する傾向がみられ、洗浄材料としての可能性を見いだした。