JPH04356401A - Unearthed cultural inheritance and its preservation - Google Patents

Abstract

PURPOSE:To provide a cultural inheritance preservable over a long period without being influenced by humidity, etc., even at normal temperatures, and the preservation method therefor. CONSTITUTION:The objective preservation process made up of (A) a process where a unearthed woodchip 1 (cultural inheritance) is immersed in a water-soluble solvent 3 in a vessel 2 to replace the impregnated water in said woodchip 1 by the water-soluble solvent 3, (B) a second process where the resulting woodchip 1 is immersed in a poorly water-soluble solvent 7 in a thermostat 6 to replace the impregnated water-soluble solvent in the woodchip 1 by the poorly water-soluble solvent 7, and (C) a third process designed to solidify the resulting woodchip 1 impregnated with said poorly water-soluble solvent. The method can preserve the woodchip 1 semipermanently through a short time treatment in the state maintained before unearthing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to excavated cultural relics excavated from various ancient tombs and ruins that can be preserved for a long period of time in the state before excavation, and a method for preserving the same.

0002

[Prior Art] In general, excavated cultural relics are human cultural heritage, and are not only of interest to modern people in learning about ancient lifestyles, but also important as human cultural heritage from the perspective of learning from the past. . Therefore, it is desirable that excavated cultural relics be preserved for a long time in their original state.

By the way, not only artifacts excavated from ruins, but also artifacts discovered on land, especially artifacts excavated from ditches around ruins, are usually buried in clay layers, so they are impregnated with water to a supersaturated state. . For this reason, after excavation, the main component of cultural relics, especially wooden relics, is cellulose, which disintegrates and flows out.
At first, it barely maintains its appearance due to water content, but
As it dries, it undergoes severe shrinkage and is finally deformed to the point where it no longer retains its original shape. Therefore, conventional methods for preserving excavated cultural relics include impregnating them with PEG (polyethylene glycol), a water-soluble resin, or impregnating them with tertiary butyl alcohol and PEG in a certain ratio and vacuum freeze-drying them. Generally adopted.

0004

[Problems to be Solved by the Invention] However, in this PEG impregnation method, the difference between the molecular weight of the water contained in the artifact (about 18) and the molecular weight of PEG (generally 4000) is abnormally large, and rapid impregnation is difficult. When processed, artifacts undergo severe shrinkage, which not only prevents them from retaining their original shape before excavation, but also causes problems such as cracks. In order to prevent this, the artifact is immersed in water placed in a thermostatic water tank, and PEG is dissolved in the water at a rate of, for example, 1% every few days, gradually increasing the concentration of PEG.
Replace the PEG with the water content of the relic. For this reason, processing usually takes several months to several years for large artifacts, and due to the long processing period, it is not possible to deal with the large number of excavated artifacts. Moreover, since PEG is water-soluble and absorbs moisture from the air, defects such as deformation and cracking of artifacts often occur after preservation treatment, and consideration must be taken to create a low-humidity surrounding environment. There is a problem with sexuality.

On the other hand, even in the vacuum freeze-drying method, since 50 to 60% PEG is impregnated inside the artifact, a similar low-humidity environment is required for preservation. Therefore, in view of the above-mentioned problems, an object of the present invention is to provide excavated artifacts that can be preserved for a long period of time even at room temperature without being affected by humidity or the like. Another object of the present invention is to significantly shorten the number of days required for preservation treatment, to allow excavated artifacts to retain their original shape for a long period of time, and to maintain their original shape even under humidity conditions in the preservation environment. The purpose is to provide a possible preservation method for excavated artifacts.

[0006]

[Means for Solving the Problems] The excavated cultural relic of the present invention that achieves the above object is characterized by being made by impregnating and solidifying the excavated cultural relic with a poorly water-soluble solvent. In addition, the preservation method includes two steps: immersing the cultural relic in a water-soluble solvent to replace the impregnated water with a water-soluble solvent, and immersing the cultural relic in a slightly water-soluble solvent to impregnate the cultural relic with a water-soluble solvent. A preservation method [Method ■] consisting of a step of replacing the material with a poorly water-soluble solvent, and a step of solidifying the cultural relic impregnated with the poorly water-soluble solvent.
, or a step of immersing the cultural relic in a water-soluble solvent to replace the impregnating water of the cultural relic with a water-soluble solvent; and immersing the cultural relic in a slightly water-soluble solvent to replace the impregnating water-soluble solvent of the cultural relic with the slightly water-soluble solvent. This is a preservation method [Method 2] which consists of a step of replacing at least 40% with a water-soluble solvent and a slightly water-soluble solvent, and a step of freezing and drying the cultural relic impregnated with a water-soluble solvent and a slightly water-soluble solvent under vacuum.

[0007] Since the cultural relics of the present invention are impregnated with a poorly water-soluble solvent and solidified, they can be preserved semi-permanently without being deformed by humidity or the like even if placed in a room temperature environment after preservation treatment. In particular, since the impregnated solvent is poorly water-soluble, no problems such as deformation or cracking occur even under humid storage environments. Although there is no particular method for obtaining this type of cultural relic with excellent long-term preservation, it is best to use the preservation method (1) or (2) of the present invention. According to method ■, ■, conventional PEG
Not only can the treatment period be reduced by more than 1/5 compared to the impregnation method or the vacuum freeze-drying method, but the storage performance after treatment is also excellent. Methods (1) and (2) are as follows.

First, in preservation method (2), the excavated cultural relic is immersed in a water-soluble solvent to replace the water contained in the relic with the water-soluble solvent. In this process, an artifact is obtained in which the supersaturated water impregnating the artifact is completely replaced with a water-soluble solvent. Next, the relic is immersed in a slightly water-soluble solvent to replace the impregnated water-soluble solvent with the slightly water-soluble solvent, thereby obtaining a relic in which the water-soluble solvent and the slightly water-soluble solvent have completely replaced. Finally, the cultural relic of the present invention can be obtained by cooling and solidifying the relic impregnated with the poorly water-soluble solvent in air at room temperature and pressure.

[0009] In the present invention, the water-soluble solvent is not limited as long as it can replace the water impregnated with the relic, but it is preferably soluble in water at room temperature and pressure for convenience of processing. Examples of such solvents include lower alcohols (eg, ethyl alcohol, methyl alcohol, propyl alcohol), water-soluble or slightly water-soluble solvents such as acetone, and the like. The poorly water-soluble solvent can be substituted for the above-mentioned water-soluble solvent, and is not limited, but especially considering the preservation environment of the artifact, it may be insoluble or only slightly soluble in water, and solid at room temperature. is preferred. Specifically, higher alcohols (eg, cetyl alcohol, stearyl alcohol, behenyl alcohol), etc. are shown. In addition, when using these solvents, the temperature is set according to the melting point of each solvent, and the solvent is liquefied.

In preservation method (2), the impregnating water of the cultural relic is replaced with a water-soluble solvent, and after the impregnating water is completely replaced with the water-soluble solvent, the impregnating water-soluble solvent is mixed with a slightly water-soluble solvent for at least 40 minutes.
Replace up to %. Thereafter, if the relic containing water-soluble and slightly water-soluble solvents is frozen and dried under vacuum, only the water-soluble solvent will evaporate and disappear from the relic, resulting in the cultural relic of the present invention.

[0011] Regarding the replacement ratio of the water-soluble solvent and the poorly water-soluble solvent in method (2), it is sufficient that the water-soluble solvent used in the first impregnation is replaced by at least 40% with the poorly water-soluble solvent used in the subsequent impregnation. It is preferably about 45 to 60%, particularly about 50%. The water-soluble solvent used in method ① is almost the same as the above method ②, but it is the freezing point of tertiary butyl alcohol, about 23°C, and it is easy to quickly freeze after impregnation, and it is easy to vaporize under vacuum. Tertiary butyl alcohol is most suitable. Further, the poorly water-soluble solvent may be appropriately selected from the above-mentioned examples.

[0012] The cultural relics referred to in the present invention include wooden products (pieces of wood, dugout canoes, etc.), metal products (round mirrors, bronze bells, swords, fishhooks, ironware, etc.) excavated from various ruins, ancient tombs, etc.
Earthen products (earthenware, etc.), animal products (textiles, human bones, animal bones, etc.),
Contains various artifacts of flora and fauna (leaves, nuts, linen fabrics, etc.).

[0013]

EXAMPLES The preservation method for obtaining excavated cultural relics according to the present invention will be explained below based on examples. However, in this embodiment, a piece of wood will be explained as an example of an excavated artifact discovered from a ruin.

First, in the preservation method (2), as shown in FIG. 1(a), methyl alcohol 3 is placed as a lower alcohol among the water-soluble solvents in the previous example in a suitable container 2, and a piece of wood 1 is placed in this methyl alcohol 3. Soak for one to several days. During soaking, the impregnated water in the wood piece 1 is gradually replaced with methyl alcohol 3, and eventually all the impregnated water in the wood piece 1 is replaced with methyl alcohol 3. After the soaking is completed, the wood pieces 1 are taken out from the container 2. As a result, a piece of wood 1 in which all the water impregnated in the tissue has been replaced with methyl alcohol 3 is obtained. In addition, during the above-mentioned soaking, as the impregnated moisture in the wood piece 1 leaches into the methyl alcohol 3, the methyl alcohol 3
As the concentration of alcohol decreases, replace it with fresh methyl alcohol several times during the process.

After this, as a pretreatment for the next step, the process shown in FIG.
), a mixture 5 of equal amounts of methyl alcohol, which is a lower alcohol, and stearyl alcohol, which is a higher alcohol, is placed in a constant temperature chamber 4, and a piece of wood 1 is immersed in the mixture 5 for several days. At this time, the melting point of stearyl alcohol is approximately 5
Since the temperature is 6°C, the mixed liquid 5 is kept at 58°C. This pretreatment prevents cracking and shrinkage of the wood chips caused by the concentration difference between the wood chips and the lower alcohol (methyl alcohol) that impregnates the wood chips when they are immersed in higher alcohol (stearyl alcohol) as a slightly water-soluble solvent in the next step. This is to prevent

Thereafter, as shown in FIG. 1(c), stearyl alcohol 7 dissolved at about 60° C. as a higher alcohol, a poorly water-soluble solvent, is placed in the thermostat 6, and the wood piece 1 is immersed in the stearyl alcohol 7. Then, leave it for several days while maintaining the temperature at about 60°C. As a result, the methyl alcohol in the wood piece 1 is completely replaced with the stearyl alcohol 7 in the thermostatic chamber 6. During replacement, the methyl alcohol in the wood piece 1 leaches into the stearyl alcohol 7 in the incubator 6, but since the boiling point of methyl alcohol is approximately 60°C, all of the methyl alcohol evaporates, and the liquid in the incubator 6 is all stearyl alcohol. It becomes 7. Incidentally, the boiling point of stearyl alcohol 7 is about 210°C. After the replacement is completed, the wood piece 1 is taken out from the thermostatic chamber 6.

Finally, the cultural relic of the present invention is obtained by cooling and solidifying the wood piece 1 at room temperature. This cultural relic (piece of wood) retains its original form before being excavated, and can be preserved semi-permanently without deforming at all. Next, the preservation method (2) will be described. Method (2) is almost the same as Method (2) up to the intermediate steps; first, tertiary butyl alcohol, which is a lower alcohol, is placed in a container as a water-soluble solvent. Soak excavated artifacts (wood chips) in butyl alcohol for one to several days to replace all of the impregnated moisture in the wood chips with butyl alcohol. Of course, as with the previous method (2), the concentration of butyl alcohol decreases due to moisture in the wood chips during soaking, so replace it with fresh butyl alcohol as appropriate.

As in method ①, as a pretreatment for the next step, a mixture of equal amounts of tertiary butyl alcohol, a lower alcohol, and stearyl alcohol, a higher alcohol, is placed in a constant temperature chamber, and several pieces of wood are added to the mixture. Leave it in for a day. This pretreatment prevents the wood chips from cracking or shrinking due to the difference in concentration between tertiary butyl alcohol and stearyl alcohol in the next step. At this time, the melting point of tertiary butyl alcohol is about 23°C, and that of stearyl alcohol is about 56°C.
Therefore, the mixture is kept at about 40°C.

Thereafter, the wood pieces are immersed for several days in stearyl alcohol, which is a higher alcohol as a slightly water-soluble solvent. Here, when the tertiary butyl alcohol impregnated into the wood piece has been replaced by approximately 50% of the stearyl alcohol, the immersion is terminated and the wood piece is taken out. Then, after quickly freezing in a freezer, the wood pieces are frozen and dried under vacuum using a vacuum freeze-drying device. As a result, all of the impregnated tertiary butyl alcohol in the wood piece is sucked out and disappears, but stearyl alcohol remains in the structure of the wood piece because it is a hard-to-sublimate solid. As the drying progresses, the wood pieces solidify and become the cultural relics of the present invention. Of course, the cultural relics (pieces of wood) obtained can be preserved forever in their original form before excavation.

[0020]

[Effects of the Invention] Since the excavated cultural relics and the method for preserving the same according to the present invention are constructed as explained above, the following effects can be achieved. (1) Cultural relics are impregnated and solidified with a poorly water-soluble solvent, and can be preserved for a long period of time (semi-permanently) without changing their original condition due to the effects of humidity, etc.

(2) Storage methods ■ and ■ are conventional PE
Compared to the G-impregnation method and the vacuum freeze-drying method, the processing period required for preservation is significantly shortened, and moreover, a large number of excavated artifacts can be preserved at the same time. (3) Furthermore, preservation methods ① and ③ allow the excavated artifacts to retain their original form before being excavated, and can be preserved semi-permanently at room temperature without deformation or decay caused by humidity.

(4) In addition, excavated artifacts treated by preservation methods ① and ② are impregnated with a poorly water-soluble solvent and solidified, so compared to the method of impregnating water-soluble PEG, the excavated artifacts are It does not absorb moisture present in the surrounding storage environment, and does not cause any problems such as deformation or cracking over time. (5) The cultural relics and preservation method of the present invention having the above excellent effects (1) to (4) are incomparable,
This is extremely important for long-term preservation of excavated artifacts as valuable cultural heritage of humanity.

[Brief explanation of drawings]

FIG. 1 is a process diagram for explaining the procedure of the preservation method of the present invention.

[Explanation of symbols]

1 Piece of wood (excavated artifact) 2 Container 4.6　Thermostat

Claims (6)

[Claims] Claim 1: Impregnating excavated cultural relics with a poorly water-soluble solvent.
An excavated cultural relic characterized by being solidified. 2. The excavated cultural relic according to claim 1, wherein the poorly water-soluble solvent is a higher alcohol. Claim 3: A step of immersing the excavated cultural relic in a water-soluble solvent to replace the impregnated water of the cultural relic with a water-soluble solvent, and a step of immersing the cultural relic in a poorly water-soluble solvent to impregnate the cultural relic with a water-soluble solvent. 1. A method for preserving excavated cultural relics, comprising the steps of: replacing the relic with a poorly water-soluble solvent; and solidifying the cultural relic impregnated with the slightly water-soluble solvent. 4. The method for preserving excavated cultural relics according to claim 3, wherein the water-soluble solvent is a lower alcohol and the slightly water-soluble solvent is a higher alcohol. Claim 5: A step of immersing the excavated cultural relic in a water-soluble solvent to replace the impregnation water of the cultural relic with a water-soluble solvent; and a step of immersing the cultural relic in a slightly water-soluble solvent to impregnate the cultural relic with a water-soluble solvent. A process of replacing at least 40% of the water-soluble solvent with a slightly water-soluble solvent, and a process of freezing and drying the cultural relic impregnated with the water-soluble solvent and the slightly water-soluble solvent under vacuum. Preservation method. 6. The method for preserving excavated cultural relics according to claim 5, wherein the water-soluble solvent is tertiary butyl alcohol and the slightly water-soluble solvent is a higher alcohol.