Treatment of ink corrosion

Until recently, the process of ink corrosion could not be stopped.
During a two year research project by Dr. Johan Neevel, conservation
chemist at the Central Research Laboratory Amsterdam, the acid in
the ink, as well as the iron proved to cause ink corrosion. Acid
accelerates the hydrolytic degradation of the cellulose and iron
accelerates the oxidative degradation.

In order to test the action of different conservation treatments, a
simulation experiment for ink corrosion was developed. In this
experiment accelerated aging of test sheets was applied. These
sheets were written on with an irongall ink of a composition,
representative of ancient ink recipes. The bursting index was
measured after ageing of the screen patterns made with this ink.

Bursting at the ink lines indicated the occurrence of ink corrosion.
A treatment with an aqueous solution of phytate, a natural
anti-oxidant present in plant seeds was demonstrated to inhibit the
oxidation. A treatment with aqueous magnesium phytate, followed by a
deacidification with aqueous calcium and magnesium bicarbonate
provided the best protection against ink corrosion. The half-value
period for the bursting index increased from 6 to 70 days of
accelerated ageing (90 degrees C., RH cycling between 80 % and 35%).

Further research in cooperation with paper conservators will focus
on the development of practical phytate-based conservation
treatments of manuscripts and pen drawings.

Part of this research will be published in 'Restaurator' 16, (3)
(1995), pp. 143-160

Relating to his research project on ink corrosion, Johan Neevel
would like to obtain recipes of irongall inks from the period
1400-1750. These recipes should preferably be translated in modern
English, French or German.

To respond or to get more information about this research project,
please contact:

    Dr. Johan Neevel
    Central Research Laboratory Amsterdam
    Gabriel Metsustraat 8,
    1071 EA Amsterdam
    The Netherlands
    +31 20 6735162
    Fax: +31 20 6751661

or to my E-mail address

IJsbrand Hummelen,
Co-ordinator,  Department of conservation and restoration research
Central Research Laboratory Amsterdam

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                  Conservation DistList Instance 9:18
                Distributed: Wednesday, August 23, 1995
                        Message Id: cdl-9-18-001
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