早期失效保护修复材料对壁画的影响

Influences of degraded conservation polymer materials on wall paintings

摘要：现存的馆藏壁画和部分原址壁画中，为了加固、保护壁画颜料层，在20世纪70—90年代，曾经大量使用加固剂和封护剂对壁画颜料层进行保护修复。受当时修复材料和施工工艺的局限，经过仅40余年的变化，一些早期的保护修复有机材料老化，导致许多壁画出现了新问题，主要表现为眩光、变色、龟裂、起翘等病害，严重影响壁画的长期保存和展陈。文章列举了国内外早期修复材料因老化失效而损害壁画的几桩案例，讨论了现代有机材料的老化对壁画保存的不利影响，并对修复材料的“失效”概念进行了界定和阐述。可以认为，修复材料老化导致壁画外观的变化及保护材料未失效但造成壁画性质改变引发潜在病害的两种情况中任意一种，均可视为修复材料“失效”，为了长久保护壁画必须予以清除。最后探讨了清除失效修复材料时使用凝胶清洗和微乳液清洗等方法的有效性和前瞻性。

During the period of time from 1970 to 1990, large quantities of polymeric materials were applied to painted artifacts in museums or in situ to wall painting to stabilize and protect pigment layers. At that time, about 40 years ago, both suitable conservation materials and application techniques were undeveloped and limited. Now those aged protecting organic layers, such as acrylic polymer and Sanjia resin, have caused new problems for conservation. Challenges include gloss, yellowing, craquelure, flaking, etc. This paper lists a few cases that illus- trate how degraded polymers have destroyed wall paintings and how they have had negative effects on wall paint- ings. Then, the concept of ＂degradation＂ was defined, illustrated and categorized into two groups. A situation failing into either category could be considered ＂degraded＂ protecting layer and must be removed for long - term protection of the mural paintings. Finally, effectiveness and long - time effect of gel cleaning and micro - emulsion cleaning techniques were discussed.