ブックタイトルConservation and Restoration of Western Paper

概要

Conservation and Restoration of Western Paper

2. Formation of hydrogen peroxideFe 2+ +HOO・+ H+ Fe 3+ + H 2 O 2H 2 O 2 decomposed by iron(II) into ahydroxyl radical and a hydroxide ion.Fe 2+ + H 2 O 2→Fe 3+ + HO・+ OH-(Fenton Reaction) 3The degree of corrosion will depend onthe ink composition and quantity, the paperproperties, and the storage environment.Corrosion is easily observed as the darkeningof the support near the ink from excess iron(II) ions, and brittleness, cracking and loss ofinked areas (Photo 15).In the last two decades, great attentionhas been paid to issues surrounding irongall ink, as witnessed by extensive researchforums in the Netherlands, Germany, theUnited States, Canada and other countries.Several excellent articles and websitesprovide information on all aspects ofiron gall ink corrosion, and research intotreatment protocols, notably The Iron GallInk Website, and Metamorfoze, the DutchNational Programme for the Preservation ofPaper Heritage. The latter includes an onlinetool called the Ink Corrosion Prognosis? a computer simulation that can be used toestimate the risk of iron gall ink corrosionby helping collections managers to identifyartifacts at high risk, to outline conservationpriorities and to decide on mitigationstrategies. 4In Canada, informal surveys of provincialarchives suggest that almost all Canadiandocuments up to the early 20th centurywere executed in iron gall ink. Specificcollections materials, such as letterpresscopybooks, exhibit severe degradation andloss from ink corrosion. Significant fadingof iron gall inks has also been noted. LACand the Canadian Conservation Institute(CCI) have worked closely to performresearch into treatment options, developrisk assessment tools to assist collectionsmanagers in identifying vulnerable areas,deliver workshops to introduce new testingPhoto 15 Iron gall ink corrosion mechanismPhoto 16 Calcium phytate treatment64