Glyoxal composite dehydration method for water-saturated wood lacquerware artifacts

Abstract

The present invention discloses a glyoxal composite dehydration method for water-saturated wood lacquerware artifacts, relating to a method for protecting water-saturated wood lacquerware artifacts. The method comprises the following steps: 1. placing the artifact to be cleaned on a cleaning table for cleaning; 2. immersing the cleaned artifact in a 40% glyoxal composite solution, and covering the portion exposed above the liquid with a plastic film to prevent shrinkage and deformation; 3. After the artifact reaches a constant weight, an initiator is added to the glyoxal to initiate the process for 4 hours; 4. After initiation, the artifact surface is cleaned, the artifact is again placed in glyoxal, and 3% soluble starch is added to the solution, soaking for 24 hours before removal. The present invention has the following advantages: after using the glyoxal composite dehydration method for water-saturated wood lacquerware artifacts, the paint film retains its original color and gloss, the wood base structure is significantly enhanced, the artifact shrinkage rate in all directions is less than 3%, and problems such as moisture absorption, acid reversion, and blanching are avoided. This method meets the basic requirements for cultural relic protection and lays a solid foundation for the subsequent repair of the base and painted decoration of the wood lacquerware artifacts.

Description

Technical Field

[0001] The invention relates to a protection method for water-saturated wood lacquerware cultural relics, in particular to a glyoxal composite dehydration method for water-saturated wood lacquerware cultural relics; specifically, it relates to a dehydration, drying and fixing method for water-saturated wood lacquerware cultural relics obtained by archaeological excavation. Background Art

[0002] Lacquerware has a long history in China, dating back to before the Shang and Zhou dynasties, according to ancient texts. However, recent archaeological excavations, such as those unearthed from Jingtou Mountain, indicate that lacquerware was used in my country far earlier than documented, dating back at least 8,300 years. Excavated lacquerware, exposed to long-term corrosion from water, salts, and microorganisms in the burial environment, has severely degraded its polysaccharide components (cellulose and hemicellulose), and its cell walls have been severely damaged. Especially in areas with abundant groundwater, the moisture content of unearthed lacquerware can reach as high as 1,900%. Without proper dehydration and reinforcement before drying, these water-saturated lacquerware will severely deform, crack, and even fail.

[0003] Traditional methods for dehydrating, shaping, and reinforcing water-saturated lacquerware include natural drying, alum, sucrose, resin, and PEG methods, but these methods each have disadvantages such as a narrow scope of application, acid absorption and deliquescence, susceptibility to mildew, poor permeability, and low strength. The glyoxal filling dehydration method involves directly soaking water-saturated lacquerware in a certain concentration of glyoxal (generally 40%). After sufficient penetration, the water is allowed to evaporate naturally, and the glyoxal remaining in the object serves to fill and reinforce the shape of the object. This method has the advantages of universal applicability, ease of operation, and good permeability for the dehydration and shaping of water-saturated lacquerware. However, during use, since the replacement of water molecules by glyoxal is a reversible process, when the relative humidity of the environment is high, glyoxal precipitation will occur, which is a common problem of moisture absorption, acid reversion, and whitening, affecting the dehydration effect of water-saturated lacquerware artifacts. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a method for the composite dehydration of water-saturated wooden lacquerware cultural relics with glyoxal.

[0005] The object of the present invention is achieved like this:

[0006] After the glyoxal small molecules have completely penetrated into the interior of the wood lacquerware artifact, a triethanolamine solution with a concentration of 1 to 5% is added thereto to initiate an in-situ polymerization reaction of the glyoxal small molecules, which is reacted for 4 hours to generate a long molecular chain structure; then a soluble starch with a concentration of 1 to 10% is added and reacted for 24 hours to cause an in-situ cross-linking reaction of the molecular chain structure to form a spatial network structure; this structure can play a good supporting and solidifying role inside the wood lacquerware artifact. When the artifact is taken out of the glyoxal solution and dried naturally in the shade, it will not suffer from defects such as shrinkage, cracking and deformation. At the same time, due to the in-situ polymerization and cross-linking reaction of the glyoxal small molecules, the molecular weight becomes larger and it is not easy to precipitate from the interior of the wood lacquerware artifact.

[0007] Specifically:

[0008] 1. Components of glyoxal materials (weight percentage)

[0009] 40% glyoxal, 60% water.

[0010] 2. Preparation method of glyoxal material

[0011] 40% glyoxal (analytical grade) was purchased.

[0012] 3. Glyoxal composite dehydration method

[0013] The following steps are involved:

[0014] ① Place the artifacts and cultural relics that need to be cleaned on the cleaning table and choose an appropriate cleaning method;

[0015] When cleaning wooden lacquerware artifacts, generally do not use the brushing method. Instead, gently scrub and be sure to control the strength. For large particles of dirt that are easy to remove, use distilled water or ultrapure water for cleaning. For stains that are difficult to remove with distilled water or ultrapure water, use surfactants for cleaning. For dirt formed by metal rust, if the above cleaning still does not achieve the desired effect, you can use a chelating agent for cleaning.

[0016] ② Soak the cleaned utensils in 40% glyoxal compound solution, and cover the exposed part with plastic film to prevent shrinkage and deformation;

[0017] ③ When the object reaches constant weight, add initiator to glyoxal and initiate for 4 hours;

[0018] The initiator is triethanolamine.

[0019] ④ After the initiation is completed, the surface of the object is cleaned, and the object is placed in glyoxal again, and 3% soluble starch is added and soaked for 24 hours before being taken out.

[0020] The present invention has the following advantages and positive effects:

[0021] After the water-saturated wooden lacquerware cultural relics were dehydrated using the glyoxal composite dehydration method, the paint film maintained its original color and gloss, the wooden body structure was significantly enhanced, the shrinkage rate of the objects in all directions was less than 3%, and there were no problems such as moisture absorption, acid reversion and whitening. It meets the basic requirements of cultural relics protection and lays a solid foundation for the next step of wooden lacquerware cultural relics repair and painting. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the working mechanism of the present invention.

[0023] Figure 2 It is a comparative picture before and after dehydration of the present invention. DETAILED DESCRIPTION

[0024] The following is a detailed description with reference to the accompanying drawings and embodiments:

[0025] 1. Working Mechanism of the Invention

[0026] like Figure 1 , to solve the problems of glyoxal dehydration method, the study proposed a glyoxal composite dehydration method for saturated wood lacquerware cultural relics; after the glyoxal small molecules completely penetrate into the interior of the wood lacquerware cultural relics, they generate a long molecular chain structure, and after cross-linking polymerization, the molecular chain structure undergoes an in-situ cross-linking reaction to form a spatial network structure; this structure can play a good supporting and solid role inside the wood lacquerware cultural relics. When the objects are taken out of the glyoxal solution and dried naturally in the shade, there will be no shrinkage, cracking, deformation and other defects. At the same time, due to the in-situ polymerization and cross-linking reaction of the glyoxal small molecules, the molecular weight becomes larger, and it is not easy to precipitate from the interior of the wood lacquerware cultural relics.

[0027] The novelties of the present invention are:

[0028] Early dehydration methods for water-saturated wood lacquerware involved simply soaking the wood in a glyoxal-water solution, allowing it to fill and reinforce the interior of the wood, preventing shrinkage and deformation during drying. However, because the glyoxal is simply a physical filling within the wood, small molecules of glyoxal are prone to precipitation when the external environment changes. This manifests as moisture absorption, acid reversion, and whitening of the wood lacquerware, significantly affecting its appearance and preservation.

[0029] The glyoxal composite dehydration method developed by the present invention involves adding an initiator to glyoxal to cause an in-situ polymerization reaction within the wooden base of a cultural relic, forming a molecular chain structure. A cross-linking agent is then added to cross-link the molecular chains in situ to form a spatial network structure. This structure adheres to the cell walls within the wooden base through chemical or hydrogen bonding, providing excellent support and solidification during drying of the water-saturated lacquerware cultural relic, preventing shrinkage, cracking, and deformation. Furthermore, due to the in-situ polymerization and cross-linking reaction of the small glyoxal molecules, their molecular weight increases, making them less likely to precipitate from the interior of the cultural relic.

[0030] After the water-saturated wooden lacquerware cultural relics were dehydrated using the glyoxal composite dehydration method, the paint film maintained its original color and gloss, the wooden body structure was significantly enhanced, the shrinkage rate of the objects in all directions was less than 3%, and there were no problems such as moisture absorption, acid reversion and whitening. It meets the basic requirements of cultural relics protection and lays a solid foundation for the next step of wooden lacquerware cultural relics repair and painting.

[0031] 2. Experimental situation

[0032] 1. Dehydration operation steps

[0033] The cleaned wooden lacquerware is measured, weighed, photographed, and then subjected to dehydration protection treatment.

[0034] 1) Osmosis treatment: First, place the cleaned objects in a suitable dehydration container and add a 40% glyoxal aqueous solution that is more than 5 times the volume of the objects.

[0035] 2) Initially, the objects float on the surface of the dehydration liquid. Use appropriate weights such as glass plates to sink the objects into the liquid surface, or use plastic film to cover the surface of the objects to prevent shrinkage and deformation during the dehydration process.

[0036] 3) Observe the dehydration of the device every day for 1 to 2 months, and measure and record the specific gravity and pH value of the dehydrated solution.

[0037] 4) Observe the dehydration of the device every week for 3 months to 6 months, and measure and record the specific gravity and pH value of the dehydrated water.

[0038] 5) After the object is completely submerged in the dehydration solution, remove the glass plate, weigh the dehydrated object, and measure and record the specific gravity and pH value of the dehydration solution.

[0039] 6) Observe the objects regularly, weigh the dehydrated objects, measure and record the specific gravity and pH value of the dehydrated solution, and take out the objects only after the quality of the objects stabilizes.

[0040] 2. Dehydration polymerization

[0041] 1) Clean the surface of the object with clean water, add 3% triethanolamine solution to glyoxal and soak the wood and rotten lacquerware for 4 hours to trigger them, then prepare 3% soluble starch solution and soak for 24 hours, and then take the object out of the soaking solution.

[0042] 2) Place the objects removed in a light-proof, ventilated environment with minimal humidity changes to dry naturally. During the drying process, regularly observe the drying condition of the objects and use sandbags, homemade shaping tools, etc. to prevent deformation of the objects.

[0043] 3) Record the data change process of the object's weight.

[0044] 3. Dehydration effect evaluation (stability of external dimensions)

[0045] Table 1: Dimensions before and after dehydration

[0046]

[0047] From this we can see that glyoxal dehydration strengthens lacquer wood artifacts. After dehydration, the dimensions of the lacquer wood artifacts are stable, and the shrinkage rate is less than 1%, which fully meets the requirements of cultural relic protection.

[0048] like Figure 2 , it can be seen that there is little change before and after dehydration.

Claims

1. A glyoxal composite dehydration method for water-saturated wood lacquerware cultural relics, characterized by: Glyoxal composite dehydration method: ① Place the artifacts and cultural relics that need to be cleaned on the cleaning table and choose an appropriate cleaning method; When cleaning wooden lacquerware artifacts, do not use a brush. Instead, gently scrub with the proper amount of force. Use distilled or ultrapure water to clean large, easily removable particles of dirt. Use a surfactant to clean stains that are difficult to remove with distilled or ultrapure water. If the above cleaning methods do not work for metal rust, use a chelating agent to clean. ② Soak the cleaned utensils in a 40% by weight aqueous solution of glyoxal, and cover the exposed part with plastic film to prevent shrinkage and deformation; ③ When the object reaches constant weight, add initiator to glyoxal and initiate for 4 hours; The initiator is triethanolamine; the triethanolamine is a 3% triethanolamine solution; ④ After the initiation is completed, clean the surface of the object, put the object into glyoxal again, add 3% soluble starch and soak it for 24 hours before taking it out.

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