A sodium hydroxide solution and method for removing oil stains from ancient paper documents.

Abstract

This invention discloses a method for removing oil stains from ancient Tibetan paper documents, comprising the following steps: Step 1: preparing a alkali solution; Step 2: applying the alkali solution to the oil stains on the ancient Tibetan paper documents, avoiding the text and patterns on the documents; Step 3: allowing the solution to stand until the oil stains are fully dissolved; Step 4: wiping away the dissolved oil stains; Step 5: repeating steps 1-4 until all oil stains on the ancient Tibetan paper documents are completely removed. This invention significantly improves the oil stain removal effect and reduces cleaning time and frequency by introducing alkali as a cleaning agent. Furthermore, alkali is non-corrosive to Tibetan paper, effectively removing surface oil stains without damaging the paper fibers, thus maintaining the integrity and historical information of the documents. Simultaneously, alkali is a natural alkali mineral of the sulfate soda ash group, which does not pollute the environment during Tibetan paper processing and is harmless to the health of operators, further reducing safety risks during the cleaning process.

Description

Technical Field

[0001] This invention relates to the field of Tibetan paper ancient book restoration technology, and in particular to an alkaline solution for removing oil stains from Tibetan paper ancient books and documents and a method for removing oil stains. Background Technology

[0002] Tibetan paper books and documents record thousands of years of history, serving as important carriers and invaluable legacies of Tibetan traditional culture and history. These documents not only contain rich knowledge in multiple fields such as history, philosophy, religion, art, and medicine, but also reflect the lifestyle, ideology, and social changes of the Tibetan people, possessing irreplaceable value for studying Tibetan history and culture and inheriting Tibetan spiritual civilization. However, during the preservation and transmission of these documents, the oil stains caused by the constant use of butter lamps in monasteries are the most common problem in the restoration of Tibetan paper books and documents.

[0003] The biggest difference between Tibetan paper ancient books and other ancient books and documents in my country is that Tibetan paper is made from the roots of the wolfsbane plant through a special process, and its material is different from that of straw paper. Therefore, if you use methods for removing oil stains from straw paper to remove oil stains from Tibetan paper ancient books and documents, such as alcohol, potassium permanganate, oxalic acid, and baking soda, although you can remove the oil stains, it will cause secondary damage to the Tibetan paper ancient books and documents, affecting their original state and preservation period.

[0004] Traditional Tibetan paper document restoration techniques for removing oil stains vary. Lighter stains can be removed using heat transfer, while heavier stains can be removed using pyridine dissolution. However, pyridine, an organic solvent, is difficult to degrade due to its toxicity. Therefore, after removing the oil stains, the paper must be immediately and repeatedly rinsed with plenty of water to remove any remaining pyridine residue. This process is cumbersome and can easily damage the paper. Furthermore, as mentioned above, methods such as alcohol, potassium permanganate, and oxalic acid are also commonly used for removing oil stains from ancient documents. However, these methods are frequently used for oil stain removal in other domestic ancient document restorations. In the restoration of Tibetan paper documents, removing oil stains is not only inefficient but also prone to causing secondary damage to the documents, including:

[0005] First, the corrosive effect on Tibetan paper: While these chemical cleaners remove oil stains, they also damage the fibers of Tibetan paper, causing the paper to become brittle, yellow, or even fall off.

[0006] Second, the operation is complicated: the concentration and operation time of these chemical reagents need to be strictly controlled, otherwise it is easy to cause over-cleaning or incomplete cleaning.

[0007] Third, environmental and health risks: These chemical cleaning agents pose potential threats to the environment and the health of operators, and improper use and handling may cause pollution and health problems.

[0008] Fourth, for some stubborn oil stains, traditional cleaning methods are not ideal, often requiring multiple treatments, which is time-consuming, laborious, and difficult to achieve the desired results.

[0009] In conclusion, existing methods for restoring ancient books and documents are insufficient in terms of restoring paper-based ancient books and documents, and are unable to meet the high standards required for modern cultural relic protection. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art. This invention proposes a method for removing oil stains from Tibetan ancient books and documents. It uses alkali flowers collected from natural lakes in Tibet and processed after treatment as a cleaning agent. This not only has a high cleaning ability, but is also non-corrosive to Tibetan paper, effectively removing oil stains while maintaining the integrity of the documents.

[0011] A soda solution for removing oil stains from ancient paper documents, the soda solution being prepared through the following steps:

[0012] Step 1: Collect soil alkali and let it sit for 1-2 years;

[0013] Step 2: Take the appropriate weight of alkali soil according to the requirements and stir-fry it at a temperature of 90℃-100℃ to prepare alkali flowers;

[0014] Step 3: Weigh the dried alkali flowers and add warm water, stirring thoroughly to dissolve them and obtain an alkali flower solution.

[0015] Further, in step 1, soil alkali is collected from Tibetan lakes at an altitude of over 4000 meters in September-October. The soil alkali is a natural alkali of the sulfate soda ash group minerals.

[0016] Furthermore, in step 2, the temperature for stir-frying the alkali soil is 95℃.

[0017] Furthermore, the ambient temperature during the stir-frying of the alkali soil in step 2 is 10℃-20℃.

[0018] Furthermore, in step 2, stir-fry the alkali soil for 30 minutes to 1 hour until it turns vermilion.

[0019] Further, the specific steps of step 3 are as follows: weigh 5g of alkali flowers, add 95mL of warm water at 40℃-50℃ and stir to dissolve.

[0020] An oil stain removal method based on alkaline solution includes the following steps:

[0021] Step 1: Take the prepared alkaline solution;

[0022] Step 2: Apply the alkaline solution to the oil stains on the Tibetan paper ancient books and documents, avoiding the text and patterns on the documents;

[0023] Step 3: Let stand until the oil stains are fully dissolved;

[0024] Step 4: Wipe away the dissolved oil stains to remove them;

[0025] Step 5: Repeat steps 1-4 until all the oil stains on the ancient paper documents are completely removed.

[0026] Furthermore, the settling time in step 3 is 2-3 minutes.

[0027] Therefore, the present invention employs the above-mentioned method for removing oil stains from ancient paper documents, which has the following beneficial effects:

[0028] First, this invention uses alkali soil collected from natural lakes in Tibet as raw material, and after processing, prepares alkali flowers, which are then used to remove oil stains from the surface of Tibetan paper ancient books and documents. This is a new use of alkali soil from natural lakes in Tibet. At the same time, it also expands the new technology means in the field of cultural relic protection and fills the gap in the decontamination technology in the restoration of ancient books and documents made of special Tibetan paper.

[0029] Secondly, traditional methods for restoring ancient books and documents often use chemical reagents, while this invention utilizes natural raw materials—alkali soil from natural lakes on the Tibetan Plateau—which not only has better environmental friendliness but also has a good oil stain removal effect.

[0030] Third, comparative experiments demonstrate the high efficiency and safety of this method. The oil stains on Tibetan ancient books and documents treated with alkali were completely removed, and the paper fibers remained intact. Furthermore, the method is simple to operate and easy to promote and apply.

[0031] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating the working process of the method proposed in this invention.

[0033] Figure 2a The pH value before removing oil stains from Tibetan ancient books and documents using alkali in the example. Figure 2b The pH value of the paper after removing oil stains from ancient Tibetan documents using alkali in the example.

[0034] Figure 3 This is a comparison of the results of dissolving ghee using different solvents in the examples.

[0035] Figure 4 The results of the saponification reaction of edible alkali and alkali flowers with ghee in the examples are compared.

[0036] Figure 5 The images show the fiber structure of Tibetan paper after treatment with different solvents in the examples.

[0037] Figure 6The images show the paper damage after being treated with different solvents in the examples. Detailed Implementation

[0038] In the description of this invention, it should also be noted that, unless otherwise expressly specified and limited, these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0039] This invention discloses an alkaline solution for removing oil stains from ancient paper documents, which is prepared through the following steps:

[0040] Step 1: Take soil alkali and leave it for 1-2 years to evaporate the moisture;

[0041] Step 2: Take the appropriate weight of alkali soil according to the requirements and stir-fry it at a temperature of 90℃-100℃ to prepare alkali flowers;

[0042] Step 3: Weigh the dried alkali flowers and add warm water, stirring thoroughly to dissolve them and obtain an alkali flower solution.

[0043] Specifically, the alkaline soil refers to the alkaline soil of Tibetan lakes at an altitude of over 4,000 meters during September and October.

[0044] Under room temperature conditions of 10℃-20℃, stir-fry the alkali soil at a temperature of 90℃-100℃ for 30 minutes to 1 hour until the alkali soil turns vermilion. At this point, the alkali soil has completely removed moisture, thus obtaining the prepared alkali flower.

[0045] Next, weigh 5g of alkali flower, add 95mL of warm water at 40-50℃ and stir to dissolve, thus obtaining an alkali flower solution.

[0046] like Figure 1 As shown, based on the aforementioned alkaline solution, this invention also discloses an oil stain removal method for removing oil stains from ancient paper documents, comprising the following steps:

[0047] Step 1: Take the prepared alkaline solution;

[0048] Step 2: Use a clean brush to apply the alkaline solution to the oil stains on the Tibetan paper ancient books and documents, avoiding the writing and patterns on the documents. Let it sit for 2-3 minutes until the oil stains are fully dissolved.

[0049] Step 3: Take another clean cotton swab or brush and gently wipe the oil stain to remove it;

[0050] Step 4: Repeat steps 1-3 until all the oil stains on the Tibetan paper documents are removed and the Tibetan characters are still clearly preserved on the paper.

[0051] To improve cleaning efficiency, this invention introduces alkali flakes, obtained from processed alkaline soil from natural lakes in the plateau region, as a cleaning agent. This significantly enhances the oil removal effect and reduces cleaning time and frequency. Furthermore, alkali flakes are non-corrosive to Tibetan paper, effectively removing surface oil stains without damaging the paper fibers, thus preserving the integrity of the documents and historical information. As a natural raw material, the semi-finished alkali flakes are environmentally friendly and harmless to operators during the treatment of oil stains on Tibetan paper, further reducing safety risks during the cleaning process. Example 1

[0052] Take 500g of alkali soil that has been stored for 1-2 years, stir-fry it at 90℃ to prepare alkali flowers, weigh out the dried alkali flowers, add warm water and stir thoroughly to dissolve, and obtain alkali flower solution. Example 2

[0053] Take 500g of alkali soil that has been stored for 1-2 years, stir-fry it at 95℃ to prepare alkali flowers, weigh out the dried alkali flowers, add warm water and stir thoroughly to dissolve them to obtain alkali flower solution. Example 3

[0054] Take 500g of alkali soil that has been stored for 1-2 years, stir-fry it at 100℃ to prepare alkali flowers, weigh out the dried alkali flowers, add warm water and stir thoroughly to dissolve them to obtain alkali flower solution. Example 4

[0055] Applications of the alkaline flower solution prepared using the above examples:

[0056] When grease is heated under alkaline conditions, it undergoes a saponification reaction, forming sodium fatty acids and glycerol. This increases its water solubility and creates surface activity, making the grease easy to remove. Grease stains are mainly composed of low-polarity molecules such as fatty acids. Alcohol also has relatively low polarity; according to the principle of "like dissolves like," grease can dissolve in alcohol. Potassium permanganate is a strong oxidizing agent capable of reacting with organic matter. When a potassium permanganate solution comes into contact with grease, the high-valence manganese ions in the potassium permanganate react with the hydrocarbons in the organic matter, oxidizing them into carbon dioxide and water, thus decomposing the grease. However, ghee is animal fat, and its main components are carbon oxides (fat, triglycerides, etc.). Therefore, potassium permanganate may not be suitable for removing grease from ancient texts.

[0057] To verify the effectiveness of the oil stain removal method proposed in this invention, the following comparative experiments were conducted to compare its stain removal effect with that of different cleaning solutions:

[0058] 1. Comparison of pH levels before and after alkali removal of oil stains from ancient Tibetan paper documents using alkali-processed clay.

[0059] Experimental method: A portable pH meter was used to measure the pH value of the ancient paper documents before and after the oil stains were removed.

[0060] Experimental results: such as Figures 2a-2b As shown, the pH before treatment was 5.45, and the pH after treatment was 7.25, thus proving that the cleaning efficiency of the method proposed in this invention is high.

[0061] 2. Comparison of the solubility of alkali, baking soda, potassium permanganate, and 75% alcohol in oil stains.

[0062] Experimental method: Melt the ghee, add it to the above solution, gently shake, and observe the dissolution result.

[0063] Experimental results: Ghee drops dissolved quickly in sodium carbonate and baking soda, but dissolved slightly slower in baking soda. However, due to the low temperature of the sodium carbonate and baking soda solutions, some ghee solidified. Ghee drops rapidly solidified into round beads in 70% alcohol and could not dissolve. Ghee drops formed an oil film on the surface of potassium permanganate solution and could not dissolve. Figure 3 As shown.

[0064] 3. Comparison of saponification reactions of different concentrations of edible alkali and alkali flowers with oil stains on Tibetan ancient paper documents.

[0065] Experimental method: Take an excess of ghee and immerse it in 1%, 5% and 10% sodium hydroxide and edible alkali solutions respectively, and observe the rate at which the saponification reaction reaches saturation.

[0066] Experimental results: After 1 hour of observation, oil droplets appeared on the surface of edible alkali solutions of different concentrations, while no obvious oil droplets were observed on the surface of the sodium hydroxide solution. This indicates that the sodium hydroxide solution has a stronger ability to remove grease. Figure 4 As shown.

[0067] 4. Comparison of damage to Tibetan paper caused by different treatment methods

[0068] Experimental Methods: After treating Tibetan paper with solvents of the same concentration, the microstructure of the paper was observed under a microscope: 1) The Tibetan paper was slightly moistened with pure water, made into a slide, and observed under a microscope at 40x magnification; 2) The Tibetan paper was soaked in 0.5%-3% potassium permanganate solution for 15 minutes, rinsed with pure water, and then soaked in oxalic acid solution of the same concentration, rinsing until nearly colorless (about 1 minute), and then rinsed clean with pure water; 3) The Tibetan paper was soaked in 1%-10% alkaline soil solution and edible alkali solution for 1 hour, and then rinsed clean with pure water.

[0069] Experimental Results: 1) In the glass slides made after wetting Tibetan paper with pure water, the paper fibers are interwoven, forming a complex three-dimensional structure with a large number of vessels and other tissues. 2) The Tibetan paper appears slightly thinner to the naked eye, but still retains good toughness when gently stretched. Under a microscope at 40x magnification, the paper fibers show no obvious breakage, shrinkage, or structural changes, indicating that this treatment method does not cause significant damage to the paper in the short term. After soaking for 1 hour, the paper becomes noticeably thinner, and after rinsing with oxalic acid, its color becomes significantly lighter and its toughness decreases. After soaking for more than 3 hours, the paper breaks apart and becomes misshapen, with a large amount of viscous substance accumulating at the bottom of the beaker. However, under a microscope at 40x magnification, the fibers still show no obvious changes. Therefore, it can be seen that potassium permanganate-oxalic acid solution does not significantly damage the paper fibers, but it corrodes other components such as starch in the paper, making it prone to breakage. 3) When soaked in alkali and edible alkali solutions, the paper becomes slightly thinner but still retains good toughness. When the prepared slides were observed under a microscope at 40x magnification, no obvious breakage, shrinkage, or structural changes were observed in the Tibetan paper fibers. This indicates that the treatment method causes minimal damage to the Tibetan paper. Figures 5-6 As shown.

[0070] The results of the comparative experiments above show that:

[0071] (1) Highly efficient cleaning. Alkali can effectively remove oil stains from ancient paper documents (pH=5.45 before treatment, pH=7.25 after treatment), indicating high cleaning efficiency. Moreover, it will not damage the paper, which is conducive to protecting the integrity and historical value of ancient books.

[0072] (2) Easy to operate. The process of using alkali flower as a cleaning agent is simple to operate, requiring no complicated technology or equipment, which lowers the technical threshold for repair work and is suitable for large-scale application.

[0073] (3) Environmentally friendly and harmless. Soil alkali is a natural and environmentally friendly material. It does not produce harmful substances during use, does not pollute the environment, and is harmless to the health of operators, thus reducing the safety risks of the cleaning process.

[0074] (4) Reduce restoration costs. Compared with traditional chemical cleaners, alkali soil is cheaper and does not require additional treatment equipment. It only requires heating to remove water and prepare alkali flowers, which can significantly reduce the total cost of ancient book restoration.

[0075] (5) Protecting and passing on cultural heritage. Using efficient and safe cleaning methods to better protect and restore Tibetan paper books and documents will help protect and pass on cultural heritage.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An alkaline solution for removing oil stains from ancient paper documents, characterized in that, The alkaline solution is prepared by the following steps: Step 1: Collect soil alkali and let it sit for 1-2 years; Step 2: Take the appropriate weight of alkali soil according to the requirements and stir-fry it at a temperature of 90℃-100℃ to prepare alkali flowers; Step 3: Weigh the dried alkali flowers and add warm water, stirring thoroughly to dissolve them and obtain an alkali flower solution; Step 1: Collect soil alkali from Tibetan lakes at an altitude of over 4000 meters in September-October. The soil alkali is a natural alkali of sulfate soda ash group minerals. In step 2, the temperature for stir-frying the alkali soil is 95℃; The ambient temperature during the stir-frying of the alkali soil in step 2 is 10℃-20℃; In step 2, stir-fry the alkali soil for 30 minutes to 1 hour, until the alkali soil turns vermilion red; The specific steps for step 3 are as follows: Weigh 5g of alkali flowers, add 95mL of warm water at 40℃-50℃ and stir to dissolve.

2. A method for removing oil stains based on the alkaline solution according to claim 1, characterized in that, Includes the following steps: Step 1: Take the prepared alkaline solution; Step 2: Apply the alkaline solution to the oil stains on the Tibetan paper ancient books and documents, avoiding the text and patterns on the documents; Step 3: Let stand until the oil stains are fully dissolved; Step 4: Wipe away the dissolved oil stains to remove them; Step 5: Repeat steps 1-4 until all the oil stains on the ancient paper documents are completely removed.

3. The method for removing oil stains with an alkaline solution as described in claim 2, characterized in that, The settling time in step 3 is 2-3 minutes.

Images