JPH0924506A - Unearthed cultural relic and its preservation treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To preserve unearthed cultural relics stably for a long time almost without suffering from deformation and shrinkage even at a normal temperature by impregnating the cultural relics with a solution consisting of glyoxal and catalyst and curing the solution. SOLUTION: This method for treating unearthed cultural relics for preservation is, for example, to water-wash a wooden article as cultural relics (ST1), then investigate by an actual survey and take a photograph of the site (ST2). In addition, the wooden article is soaked in water (ST3), and lignin penetrating into the relics and pigments contained in the soil are eluted in the water. After that, the moisture is wiped off the surface of the article (ST4), and the wooden article is soaked in a solution consisting of glyoxal and catalyst while stirring the solution (ST5). Further, the wooden article is left alone for a few days so that the solution permeates the wooden article sufficiently (ST6). During this permeation period, the solution of glyoxal and catalyst chemically reacts with cellulose contained in the wooden article to cause a crosslinkage. Following this phenomenon, the wooden article is taken out of the solution, then the solution is washed off by water (ST7) and the wooden article is naturally dried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unearthed cultural relic that enables long-term preservation of relics excavated from various burial mounds, archaeological sites, etc. with little deformation and discoloration, and a method for preserving the same.

[0002]

[Prior Art] Unearthed cultural relics, which are the cultural heritage of humankind,
It is a valuable material for knowing the state of the past, and it is desirable to preserve it in its original state for many years. Relics excavated from ruins are usually buried in clay layers and impregnated with water in a supersaturated state. This is because over a long time since the wooden products and the like were buried, cellulose, lignin and pectin contained in the cellulose collapsed and flowed out, and water was impregnated in place of them. Therefore, at the time of excavation, the relic retains its external shape due to water content, but shrinks as the drying progresses, and finally deforms or crushes to the extent that the original shape is not retained. Therefore, in order to maintain the original shape of the relic, it has been possible to prevent deformation by preparing a material that replaces water and taking a dehydration / replacement method.

The conventional treatment methods include a method of impregnating a water-soluble resin polyethylene glycol, a method of impregnating tertiary butyl alcohol and polyethylene glycol, followed by vacuum freeze-drying, and dehydration with a lower alcohol (methanol or the like). , A method of impregnating with a higher alcohol after that, and the like are generally used.

[0004]

However, the above processing methods (1) to (3) have the following drawbacks, and improvements are desired. That is, in the treatment method, since the difference between the molecular weight of water 18 and the molecular weight of polyethylene glycol is about 4,000, the remnants after treatment are likely to be deformed and contracted, and the remnants with a short impregnation period are large for several months. The relic takes several years. In the treatment method, the drawbacks of the treatment method are compensated, the deformation is small, and the treatment period is short, but the strength is weak and the equipment requires a large amount of cost. In the treatment method, since the higher alcohol is poorly water-soluble, the higher alcohol cannot be impregnated unless it is completely dehydrated with a lower alcohol or the like as a pretreatment.

Therefore, in view of the above problems, an object of the present invention is to provide an unearthed cultural relic that can be preserved for a long period of time without being affected by humidity and the like even at room temperature. Another object of the present invention is to provide a method for preserving excavated cultural relics that is simple in equipment and operation, low in cost, and capable of preserving a large amount of relics at room temperature in a short period of time.

[0006]

[Means for Solving the Problems] In order to achieve the former purpose, the excavated cultural relics of the present invention are
It is characterized by being impregnated and solidified with a solution in which a catalyst is added to glyoxal. In order to achieve the latter purpose, the method for preserving excavated cultural artifacts of the present invention is
The excavated cultural relic is immersed in a solution containing a catalyst added to glyoxal, left for several days, taken out of the solution, washed with water, and dried.

Since the excavated culture relic of the present invention is obtained by impregnating and solidifying a solution of glyoxal with a catalyst added thereto, it is unlikely to be deformed or shrunk even at room temperature and can be stably stored for a long period of time. it can. Further, the preservation treatment method of the present invention is for producing the above-mentioned excavated cultural relics, but according to this treatment method, the cellulose and glyoxal remaining in the cultural relics are crosslinked and solidified by a chemical reaction, That is, since the cellulose is solidified and strengthened in the solution in its original shape, its original shape is maintained for a long time even when the relic is dried. Moreover, since glyoxal and a catalyst are used, it is not only harmless to the human body, it is also easy to use equipment and processing operations, and it is possible to store large amounts of relics at room temperature in a short period of time at low temperature. Become.

The term "cultural relics" as used in the present invention means wood products (wood chips, logs, etc.) excavated from various archaeological sites, burial mounds, metal products (circular mirrors, copper bars, swords, fishing hooks, ironware, etc.), earthen products. (Earthenware, etc.), animal products (textiles, human bones, animal bones, etc.), animal and plant excavated goods (leaves, fruits, hemp fabrics, etc.) , Paper, seeds, lacquered products, etc. are suitable objects.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. However, in this embodiment, a wooden product will be described as an example of a cultural relic excavated from a ruin. FIG. 1 is a flow chart showing a series of steps for preserving the wooden product. The wood product may be stored by suddenly immersing it in a solution of glyoxal and a catalyst, but in practice it is better to carry out a pretreatment to ensure storage.

First, in step (hereinafter abbreviated as ST) 1, wood products are washed with water to remove dirt and impurities,
An actual survey and a photograph are taken (ST2). Then, the wooden product is once immersed in water (ST3), and the form of short-term storage is taken to elute the lignin and the pigment in the soil that are soaked in the relic into the water. The steps from ST1 to ST3 are the pretreatment steps.

After that, the process proceeds to a preservation treatment step, in which water adhering to the surface of the wooden product is removed in ST4, and then the wooden product is immersed in a solution containing a catalyst added to glyoxal and stirred (ST5). Here, as is well known, glyoxal has yellow columnar crystals, a melting point of 15 ° C., and a boiling point of 51 ° C., and is soluble in water. The catalyst used is a phosphorus compound and / or a chloride compound, and examples of the phosphorus compound include phosphoric acid, pyrophosphoric acid, polyphosphoric acid, diphosphoric acid, diphosphorus pentaoxide, and ammonium diphosphate, and ammonium chloride as the chloride compound. ,
Calcium chloride is suitable. The glyoxal compound produced by adding the above catalyst to glyoxal is harmless to the human body and can be treated with peace of mind.

Specifically, 100% by weight of glyoxal
On the other hand, about 2% by weight of phosphorus pentaoxide as a catalyst, 3% by weight of ammonium chloride as another catalyst, and 4% of calcium chloride.
% By weight is added, the wood product is dipped in this solution and stirred. Then, the solution is left as it is for 3 to 10 days (4 days in this embodiment) to allow the solution to sufficiently penetrate into the wooden product (ST.
6).

During this infiltration period, a chemical reaction takes place between the solution of glyoxal and the catalyst and the cellulose contained in the wood product, resulting in cross-linking. During a long time in the soil, lignin and pectin that make up the wood part flow out,
Porous wood is very brittle and shrinks violently when dried. However, since the cellulose crosslinked with the glyoxal compound is solidified and strengthened in the shape in the solution, the wood product infiltrated with the solution maintains its original shape even when dried.

By the way, when the excavated relics are preserved, the relics are fragile as described above. Therefore, if a rapid chemical reaction is caused, there is a risk of deformation or cracking. It is desirable to slowly infiltrate the solution and allow it to react slowly over time. Therefore, the catalyst is selected according to the wood product to be preserved, and the treatment period is set according to the reaction rate. The liquid temperature at the time of permeation may be room temperature, but if the liquid temperature is raised, the reaction time is shortened and cross-linking proceeds faster.

After the permeation period has elapsed, the wood product is taken out of the solution, washed with water to wash away the solution (ST7),
Allow to air dry (ST8). In the natural drying process, the weight of the wooden product is measured at regular intervals (for example, every hour), and when the weight reaches the equilibrium state, the preservation process of the wooden product is completed. As described above, since the glyoxal compound and cellulose are cross-linked with each other in the preserved wood product, it does not easily deform or shrink even at room temperature and can be stably preserved for a long period of time.

As described above, in the preservation treatment method of the present invention, the treatment steps are simpler and the equipment may be simpler than the conventional treatment methods 1 to. Moreover, the glyoxal and catalyst used for the treatment do not contain toxic substances, generate no harmful gas even when they react, and can be stored and handled easily. The treatment period varies depending on the nature and size of the relics to be treated, but is shortened to about 1/6 to 1/2 as compared with the conventional treatment method. For example, it takes 90 days for the conventional polyethylene glycol impregnation (the above-mentioned conventional treatment method) to preserve 10 × 10 × 10 cm cubic wooden products, and the impregnation of higher alcohols (the above-mentioned conventional treatment method). It takes 30 days, but in the present invention, 15
It only takes days.

Further, what must be paid special attention to in the preservation of the cultural relics is the change in shape during the preserving process and the secular change after the preserving process. In the present invention, the relics are immersed in the solution as described above. Since it utilizes a chemical reaction such that the remaining cellulose is strengthened by cross-linking, it has no deformation, its chemical properties are stable, and it can be stored almost semipermanently.

In the present invention, the specific gravity after drying is 0.6 to 0.8. The specific gravity of the conventional polyethylene glycol impregnation is 1.2 and that of the higher alcohol impregnation is 0.
It is smaller than 82 and lighter than before. In addition, in the above-described embodiment, the description has been made mainly on wooden products, but by appropriately selecting the catalyst, it is possible to give flexibility to the cloth, paper, etc. of the relics, and it is possible to use weathered and deteriorated ancient paper and old paper. It is also excellent for storing documents.

In the treatment method of the present invention, when the cellulose itself is lacking due to oxidation, carbonization, pressure, corrosion, etc., or the strength of the entire relic is further increased, it is attempted to strengthen the cellulose. By filling the gap between them with higher alcohol or the like to reinforce it, stronger solidification can be achieved. The process of impregnating the higher alcohol or the like is performed between ST6 and ST7 in FIG.

[0020]

EFFECTS OF THE INVENTION Since the excavated culture relic of the present invention is obtained by impregnating and solidifying a solution containing a catalyst added to glyoxal, it is unlikely to be deformed or shrunk even at room temperature, and can be stably stored for a long period of time. be able to. Further, the preservation treatment method of the present invention can effectively produce the above cultural relics. According to this preservation treatment method, the cellulose and glyoxal remaining in the cultural relics are cross-linked and solidified by a chemical reaction, that is, the cellulose is solidified and strengthened in the form of the solution, so the relics are dried. However, its original shape is maintained for a long time. Moreover, since glyoxal and a catalyst are used, it is not only harmless to the human body, it is also easy to use equipment and processing operations, and it is possible to store large amounts of relics at room temperature in a short period of time at low temperature. Become.

[Brief description of drawings]

FIG. 1 is a process chart for explaining a procedure of a storage processing method of the present invention.

Claims (4)

[Claims] 1. An excavated cultural relic characterized in that the excavated cultural relic is impregnated and solidified with a solution containing a catalyst added to glyoxal. 2. The excavated cultural relic according to claim 1, wherein the catalyst is a phosphorus compound and / or a chloride compound. 3. A method of preserving excavated cultural artifacts, which comprises immersing the excavated cultural artifacts in a solution containing a catalyst added to glyoxal, leaving the solution for several days, removing from the solution, washing with water, and drying. 4. The method for preserving excavated cultural artifacts according to claim 3, wherein the catalyst is a phosphorus compound and / or a chloride compound.