Modification method and application of paper cultural relic repairing agent

Abstract

The invention belongs to the technical field of protection of paper cultural relics, and relates to a modification method and application of a paper cultural relic repairing agent, the modification method of the paper cultural relic repairing agent is characterized in that glycerol triglycidyl ether is used for modifying the paper cultural relic repairing agent, and the capacity of the paper cultural relic repairing agent for inhibiting handwriting blooming and fading and the normal-temperature heat resistance are enhanced; the paper cultural relic repairing agent is composed of alum, gelatin and water, and the mass ratio of the alum to the gelatin to the water is 2: 3: 100. The volume ratio of the glycerol triglycidyl ether to the water is (1-3): 100. According to the modification method, the problems of blooming and color fading in the paper aging process can be remarkably improved, meanwhile, more stable heat resistance is achieved at the normal temperature, and long-term preservation of paper cultural relics is extremely facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of paper cultural relics protection, and relates to a modification method and application of a paper cultural relics repair agent. Background Art

[0002] Paper cultural relics refer to cultural heritages such as ancient books, documentary archives, calligraphy, paintings, rubbings, letters, etc. with paper as the carrier. As a carrier for recording historical and cultural information, paper cultural relics have extremely high historical value, cultural value, and artistic value. However, due to the fragility of paper, it is easily damaged by environmental factors, and paper cultural relics are non-renewable. Once damaged, they cannot be restored. Therefore, it is crucial to repair and protect paper cultural relics in a timely manner.

[0003] Currently, the method of applying gelatin and alum on damaged paper is commonly used to achieve special purposes for paper and mounting protection. Specifically, alum and gelatin are mixed with water to form a gelatin-alum solution. Since the gelatin in the gelatin-alum solution is a sizing agent, and the alum is a sizing precipitant, when the gelatin-alum solution is brushed on the back of the paper, the alum has the power to prevent bleeding and spreading, and the gelatin has the function of fixing colors and preventing blooming, which can well repair and protect paper cultural relics. However, the existing gelatin-alum solution still has the following problems in the repair and protection of paper cultural relics:

[0004] (1) Since a large amount of text or patterns are recorded on paper cultural relics, during the aging process of paper cultural relics as the paper ages, the color diffusion on the paper cultural relics causes bleeding of the handwriting or patterns, resulting in picture pollution and then blooming and fading phenomena. However, the existing gelatin-alum solution cannot improve the blooming and fading problems during the aging process of paper.

[0005] (2) Changes in the external environment during the aging of paper cultural relics also cause changes in the properties of the paper, resulting in the influence on the performance of the paper. When the existing gelatin-alum solution is used to repair and protect paper cultural relics, due to the large difference in the properties of the gelatin-alum solution, the heat resistance of the paper is unstable in the normal temperature range, and the performance of the paper decreases, which is not conducive to the long-term preservation of paper cultural relics.

[0006] In summary, it is necessary to modify the gelatin-alum solution to solve the technical problems that it cannot improve the blooming and fading problems during the aging process of paper and its heat resistance is unstable at normal temperature. Summary of the Invention

[0007] In view of the technical problems that the existing gelatin-alum solution cannot improve the blooming and fading problems during the aging process of paper and its heat resistance is unstable at normal temperature, the present invention provides a modification method and application of a paper cultural relics repair agent.

[0008] The present invention uses glycerol triglycidyl ether to modify sizing alum solution under a specific ratio, which can significantly improve the problem of bleeding and fading during the aging process of paper, and has more stable heat resistance at room temperature, which is extremely beneficial to the long-term preservation of paper cultural relics.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A method for modifying a paper cultural relics restorant, using glycerol triglycidyl ether to modify the paper cultural relics restorant, enhancing the ability of the paper cultural relics restorant to inhibit bleeding and fading of handwriting and heat resistance at room temperature;

[0011] The paper cultural relics restorant is composed of alum, gelatin and water; the mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether and water is (1-3):100.

[0012] Further defined, the glycerol triglycidyl ether is diglycidyl glycerol triglycidyl ether or triglycidyl glycerol triglycidyl ether.

[0013] Further defined, the specific process of using glycerol triglycidyl ether to modify the paper cultural relics restorant is:

[0014] S1. Soak gelatin in water and stir evenly at a temperature of 60°C ± 5°C to obtain a gelatin solution;

[0015] S2. Add alum to the above gelatin solution and stir evenly at a temperature of 75°C ± 5°C to obtain a sizing alum solution;

[0016] S3. Add glycerol triglycidyl ether to the above sizing alum solution and stir evenly at a temperature of 75°C ± 5°C to complete the modification of the paper cultural relics restorant.

[0017] Further defined, in the steps S1 to S3, the stirring time is 2h to 3h; the stirring speed is 500r / s.

[0018] An application of glycerol triglycidyl ether as a modifier in improving the performance of a paper cultural relics restorant.

[0019] An application of glycerol triglycidyl ether as a modifier in improving the performance of a paper cultural relics restorant in inhibiting bleeding and fading of handwriting.

[0020] An application of glycerol triglycidyl ether as a modifier in improving the heat resistance at room temperature of a paper cultural relics restorant.

[0021] Further defined, the paper cultural relics repair agent is composed of alum, gelatin and water, and the mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether and water is (1-3):100.

[0022] Further defined, the glycerol triglycidyl ether is diglycidyl glycerol triglycidyl ether or triglycidyl glycerol triglycidyl ether.

[0023] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0024] 1. The present invention uses glycerol triglycidyl ether to modify the size alum solution under a specific ratio, which can significantly improve the problem of bleeding and fading during the aging process of paper, and has more stable heat resistance at room temperature, which is extremely beneficial to the long-term preservation of paper cultural relics.

[0025] 2. The present invention finds through research that adding glycerol triglycidyl ether to the size alum solution results in a smaller change in the contact angle of the paper cultural relics repair agent before and after aging, indicating that after sizing the paper surface with glycerol triglycidyl ether as a modifier and the size alum solution, the bleeding and fading phenomena during the aging process of paper can be significantly inhibited. In addition, it also shows that applying the modified paper cultural relics repair agent (size alum solution) on the surface of paper cultural relics does not affect the expression of painting and calligraphy techniques such as rendering effects.

[0026] 3. The present invention finds through research that adding glycerol triglycidyl ether to the size alum solution makes the paper cultural relics repair agent have extremely small differences in properties before and after high-temperature degradation, with stable properties, more stable heat resistance at room temperature and not affecting the heat resistance in other temperature ranges, which is extremely beneficial to the long-term preservation of paper cultural relics.

[0027] 4. The present invention also finds through research that adding glycerol triglycidyl ether to the size alum solution makes the paper cultural relics repair agent not show the phenomenon of turning white and discoloring caused by obvious precipitation of white crystal particles after 15 cycles of aging. It indicates that after sizing the paper surface with glycerol triglycidyl ether as a modifier and the size alum solution, the phenomenon of turning white and discoloring during the aging process of paper cultural relics can be significantly inhibited.

[0028] 5. The present invention uses glycerol triglycidyl ether as a modifier to improve the performance of the paper cultural relics repair agent (size alum solution), specifically manifested in inhibiting the phenomenon of turning white and discoloring during the aging process of paper and inhibiting the phenomenon of bleeding and fading of handwriting during the aging process of paper, making the modified paper cultural relics repair agent have more stable heat resistance at room temperature, significantly enhanced tensile mechanical strength and deformation toughness, and providing a new method for the repair and protection of paper cultural relics. Description of the Drawings

[0029] Figure 1Effect diagrams of stress and strain of different modifiers;

[0030] Figure 2 Folding endurance results of different modifiers;

[0031] Figure 3 Effect of modifier concentration on hydrophilicity and hydrophobicity;

[0032] Figure 4 Column chart of hydrophilic and hydrophobic effects at modifier concentration;

[0033] Figure 5 Morphology diagrams of film aging before and after modification; where: a1 is the gelatin film before aging; a2 is the gelatin film after 15 cycles of aging; b1 is the modified gelatin film before aging; b2 is the modified gelatin film after 15 cycles of aging; c1 is the alum-gelatin film before aging; c2 is the alum-gelatin film after 15 cycles of aging; d1 is the modified alum-gelatin film before aging; d2 is the modified alum-gelatin film after 15 cycles of aging;

[0034] Figure 6 and Figure 7 Water resistance test results of different paper cultural relic restoration agents before and after aging;

[0035] Figure 8 Trend diagrams of contact angle changes of gelatin films and modified gelatin films at different aging degrees;

[0036] Figure 9 Trend diagrams of contact angle changes of alum-gelatin films and modified alum-gelatin films at different aging degrees;

[0037] Figure 10 Thermal stability analysis results of gelatin films and modified gelatin films at different aging degrees;

[0038] Figure 11 Thermal stability analysis results of alum-gelatin films and modified alum-gelatin films at different aging degrees;

[0039] Figure 12 Infrared stacked images of modified gelatin films and modified alum films at different aging degrees;

[0040] Figure 13 For the amide I band (1600 - 1700 cm -1) Column chart of protein secondary structure content. Specific implementation manners

[0041] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the following implementation cases.

[0042] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present invention pertains.

[0043] Technologies, methods, and equipment known to those of ordinary skill in the relevant fields may not be discussed in detail, but where appropriate, such technologies, methods, and equipment shall be regarded as part of the specification.

[0044] It should also be understood that the specific embodiments described above are only for explaining the present invention, and the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

[0045] The present invention provides a method for modifying a paper cultural relics restorative. Glycerol triglycidyl ether is used to modify the paper cultural relics restorative, enhancing the ability of the paper cultural relics restorative to inhibit the bleeding and fading of handwriting and its heat resistance at room temperature.

[0046] In the present invention, the paper cultural relics restorative is composed of alum, gelatin, and water; the mass ratio of alum, gelatin, and water is 2:3:100; the volume ratio of glycerol triglycidyl ether and water is (1 - 3):100.

[0047] Preferably, the volume ratio of glycerol triglycidyl ether and water is 1:100, 2:100, and 3:100.

[0048] In the present invention, the glycerol triglycidyl ether is diglycidyl glycerol triglycidyl ether or triglycidyl glycerol triglycidyl ether.

[0049] In the present invention, the specific process of using glycerol triglycidyl ether to modify the paper cultural relics restorative is as follows:

[0050] S1. Soak the gelatin in water and stir evenly at a temperature of 60°C ± 5°C to obtain a gelatin solution;

[0051] S2. Add alum to the above gelatin solution and stir evenly at a temperature of 75°C ± 5°C to obtain a gelatin-alum solution;

[0052] S3. Add glycerol triglycidyl ether to the above gelatin-alum solution and stir evenly at a temperature of 75°C ± 5°C to complete the modification of the paper cultural relics restorative.

[0053] The present invention also provides an application of glycerol triglycidyl ether as a modifier in improving the performance of a paper cultural relics restorative.

[0054] Specifically, when glycerol triglycidyl ether is used as a modifier in improving the performance of paper cultural relics restorers, it is used in improving the performance of paper cultural relics restorers in inhibiting the bleeding and fading of handwriting; and it is used in improving the normal temperature heat resistance of paper cultural relics restorers.

[0055] In the present invention, the paper cultural relics restorer is composed of alum, gelatin and water, and the mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether and water is (1-3):100.

[0056] Preferably, the volume ratio of glycerol triglycidyl ether and water is 1:100, 2:100 and 3:100.

[0057] Preferably, the glycerol triglycidyl ether is diglycidyl glycerol triglycidyl ether or triglycidyl glycerol triglycidyl ether.

[0058] The following describes in detail the above-protected technical solutions of the present invention through several groups of examples.

[0059] It should be noted that the materials and instruments used in the following examples are shown in Table 1 and Table 2 respectively. Other materials, such as chemical reagents and drugs, which are not specifically stated, are all conventional and commercially available products in the art.

[0060] Table 1 Materials Used in Examples

[0061] Reagent Manufacturer Gelatin Shandong Keyuan Biochemical Co., Ltd. Alum Shandong Keyuan Biochemical Co., Ltd. Glycerol triglycidyl ether Shanghai Aladdin Biochemical Technology Co., Ltd.

[0062] Table 2 Instruments Used in Examples

[0063] Instrument Name Model Manufacturer Humid heat aging test chamber HCP Memmert (Shanghai) Trading Co., Ltd. Thermogravimetric analyzer Themys one Setaram Instrumentation France Video optical contact angle tester OCA20 Dataphysics GmbH

[0064] Example 1

[0065] The method for modifying the paper cultural relics restorer provided in this example uses glycerol triglycidyl ether to modify the paper cultural relics restorer, enhancing the ability of the paper cultural relics restorer to inhibit the bleeding and fading of handwriting and its normal temperature heat resistance.

[0066] In this example, the paper cultural relics restorer is composed of alum, gelatin and water. The mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether and water is 1:100.

[0067] Calculated according to 300 mL of water, alum is 6 g, gelatin is 9 g, and glycerol triglycidyl ether is 3 mL.

[0068] In this example, the glycerol triglycidyl ether is triglycidyl glycerol triglycidyl ether.

[0069] In this embodiment, the specific process of modifying the paper cultural relics repair agent with glycerol triglycidyl ether is as follows:

[0070] S1. Soak 9 g of gelatin in 300 mL of water and stir evenly at 60 °C for 2 h to obtain a gelatin solution.

[0071] Specifically, weigh 9 g of gelatin and put it into a beaker, then add 300 mL of ultrapure water to soak the gelatin for 30 min to swell it. Subsequently, place the beaker in a constant temperature water bath heating magnetic stirrer and heat and stir to dissolve it at 60 °C at a stirring speed of 500 r / s for 2 h to obtain a gelatin solution.

[0072] S2. Add 6 g of alum to the above gelatin solution and continue to heat and stir at 75 °C at a stirring speed of 500 r / s for 2 h until evenly mixed to obtain a gelatin-alum solution;

[0073] S3. Add 3 mL of glycerol triglycidyl ether to the above gelatin-alum solution and continue to heat and stir at 75 °C at a stirring speed of 500 r / s for 3 h until evenly mixed to complete the modification of the paper cultural relics repair agent and obtain a modified paper cultural relics repair agent.

[0074] Example 2

[0075] The method for modifying the paper cultural relics repair agent provided in this embodiment uses glycerol triglycidyl ether to modify the paper cultural relics repair agent, enhancing the ability of the paper cultural relics repair agent to inhibit the bleeding and fading of handwriting and its heat resistance at room temperature.

[0076] In this embodiment, the paper cultural relics repair agent is composed of alum, gelatin and water. The mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether and water is 2:100.

[0077] Calculated according to 300 mL of water, the alum is 6 g, the gelatin is 9 g, and the glycerol triglycidyl ether is 6 mL.

[0078] In this embodiment, the glycerol triglycidyl ether is triepoxypropyl glycerol triglycidyl ether.

[0079] In this embodiment, the specific process of modifying the paper cultural relics repair agent with glycerol triglycidyl ether is as follows:

[0080] S1. Soak 9 g of gelatin in 300 mL of water and stir evenly at 60 °C for 2 h to obtain a gelatin solution.

[0081] Specifically, weigh 9 g of gelatin and put it into a beaker. Then add 300 mL of ultrapure water and soak for 30 min to swell the gelatin. Subsequently, place the beaker in a constant temperature water bath heating magnetic stirrer and heat and stir to dissolve at a stirring speed of 500 r / s at a temperature of 60 °C for 2 h to obtain a gelatin solution.

[0082] S2. Add 6 g of alum to the above-mentioned gelatin solution, and at a temperature of 75 °C, continue to heat and stir at a stirring speed of 500 r / s for 2 h until evenly mixed to obtain a sizing solution;

[0083] S3. Add 6 mL of glycerol triglycidyl ether to the above-mentioned sizing solution, and at a temperature of 75 °C, continue to heat and stir at a stirring speed of 500 r / s for 3 h until evenly mixed to complete the modification of the paper cultural relics repair agent and obtain a modified paper cultural relics repair agent.

[0084] Example 3

[0085] The method for modifying the paper cultural relics repair agent provided in this example uses glycerol triglycidyl ether to modify the paper cultural relics repair agent, enhancing the ability of the paper cultural relics repair agent to inhibit the bleeding and fading of handwriting and its heat resistance at room temperature.

[0086] In this example, the paper cultural relics repair agent is composed of alum, gelatin and water. The mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether and water is 3:100.

[0087] Calculated according to 300 mL of water, 6 g of alum, 9 g of gelatin, and 9 mL of glycerol triglycidyl ether.

[0088] In this example, the glycerol triglycidyl ether is triepoxypropyl glycerol triglycidyl ether.

[0089] In this example, the specific process of using glycerol triglycidyl ether to modify the paper cultural relics repair agent is as follows:

[0090] S1. Soak 9 g of gelatin in 300 mL of water and stir at a temperature of 60 °C for 2 h until evenly mixed to obtain a gelatin solution.

[0091] Specifically, weigh 9 g of gelatin and put it into a beaker. Then add 300 mL of ultrapure water and soak for 30 min to swell the gelatin. Subsequently, place the beaker in a constant temperature water bath heating magnetic stirrer and heat and stir to dissolve at a stirring speed of 500 r / s at a temperature of 60 °C for 2 h to obtain a gelatin solution.

[0092] S2. Add 6 g of alum to the above-mentioned gelatin solution, and at a temperature of 75 °C, continue to heat and stir at a stirring speed of 500 r / s for 2 h until evenly mixed to obtain a sizing solution;

[0093] S3. Add 9 mL of glycerol triglycidyl ether to the above alum solution, and continue to heat and stir at a stirring speed of 500 r / s at a temperature of 75 °C for 3 h until evenly mixed, completing the modification of the paper cultural relics repair agent to obtain a modified paper cultural relics repair agent.

[0094] Example 4

[0095] The method for modifying the paper cultural relics repair agent provided in this example uses glycerol triglycidyl ether to modify the paper cultural relics repair agent, enhancing the ability of the paper cultural relics repair agent to inhibit the bleeding and fading of handwriting and its heat resistance at room temperature.

[0096] In this example, the paper cultural relics repair agent is composed of alum, gelatin, and water. The mass ratio of alum, gelatin, and water is 2:3:100; the volume ratio of glycerol triglycidyl ether to water is 1:100.

[0097] Calculated based on 300 mL of water, alum is 6 g, gelatin is 9 g, and glycerol triglycidyl ether is 3 mL.

[0098] The difference between this example and Example 1 is that the glycerol triglycidyl ether is diglycidyl glycerol triglycidyl ether. The rest is the same as Example 1.

[0099] Example 5

[0100] In this example, mainly glycerol triglycidyl ether is used as a modifier to modify the paper cultural relics repair agent, thereby improving the performance of the paper cultural relics repair agent.

[0101] In this example, the paper cultural relics repair agent is composed of alum, gelatin, and water. The mass ratio of alum, gelatin, and water is 2:3:100; the volume ratio of glycerol triglycidyl ether to water is 2:100.

[0102] Calculated based on 300 mL of water, alum is 6 g, gelatin is 9 g, and glycerol triglycidyl ether is 6 mL.

[0103] The modification method in this example is the same as that in Example 1 to obtain a modified paper cultural relics repair agent. Then, the obtained paper cultural relics repair agent is applied to the paper cultural relics to be repaired and protected, and then placed in a cold air atmosphere to naturally dry at 18 °C for 72 h. After drying, the repair and protection of the paper cultural relics are completed.

[0104] Next, the performance of the above modified paper cultural relics repair agent is characterized and tested through experiments to verify its repair and protection effects on paper cultural relics. At the same time, in order to highlight the technical effects of the present invention, the following comparative examples are set.

[0105] Comparative Example 1

[0106] This comparative example provides a method for preparing a gelatin solution, which is as follows:

[0107] Weigh 6 g of gelatin and put it into a beaker. Use a pipette to transfer 200 mL of ultrapure water to soak for 30 min to swell the gelatin solid particles. Then put a magnetic stir bar into the beaker, and then place the beaker in a constant temperature water bath heating magnetic stirrer at a temperature of 60 °C and a stirring speed of 500 r / s. After heating and stirring for 2 h until the gelatin is dissolved, a gelatin solution is obtained.

[0108] Comparative Example 2

[0109] This comparative example provides a method for preparing a glue alum solution, which is as follows:

[0110] Weigh 9 g of gelatin and put it into a beaker. Use a pipette to transfer 300 mL of ultrapure water to soak for 30 min to swell the gelatin. Then put a magnetic stir bar into the beaker, and then place the beaker in a constant temperature water bath heating magnetic stirrer at a temperature of 60 °C and a stirring speed of 500 r / s. After heating and stirring for 2 h until the gelatin is dissolved, a gelatin solution is obtained. Then weigh 6 g of alum and add it to the gelatin solution, and raise the temperature to 75 °C and continue heating and stirring for 2 h to prepare a glue alum solution.

[0111] Comparative Example 3

[0112] This comparative example provides a method for modifying a gelatin solution, which is as follows:

[0113] Weigh 6 g of gelatin and put it into a beaker. Use a pipette to transfer 200 mL of ultrapure water to soak for 30 min to swell the gelatin. Then put a magnetic stir bar into the beaker, and then place the beaker in a constant temperature water bath heating magnetic stirrer at a temperature of 60 °C and a stirring speed of 500 r / s. After heating and stirring for 2 h until the gelatin is dissolved to obtain a gelatin solution. Use a pipette to transfer 2 mL of glycerol triglycidyl ether into the beaker, and raise the temperature to 75 °C and continue heating and stirring for 3 h to modify the gelatin solution with glycerol triglycidyl ether to obtain a modified gelatin solution. Preferably, the glycerol triglycidyl ether is triepoxypropyl glycerol triglycidyl ether.

[0114] Furthermore, the performance characterization and testing of each sample in the examples and comparative examples are as follows.

[0115] 1. Strain folding resistance analysis before and after modification with different modifiers

[0116] Take the glue alum solution corresponding to Comparative Example 2 (denoted as unmodified or AFG unmodified), the modified paper cultural relics repair agent modified with triepoxypropyl glycerol triglycidyl ether in Example 1 (denoted as AFG 3-ring modified or 3-ring modified), and the modified paper cultural relics repair agent modified with diepoxypropyl glycerol triglycidyl ether in Example 4 (denoted as AFG 2-ring modified or 2-ring modified) as test samples.

[0117] Apply the above three test samples to the paper respectively, and then test the stress-strain performance and folding endurance of the paper at the initial stage and after 15 cycles of aging. The cyclic aging is carried out in a damp-heat aging chamber. First, carry out low-temperature and high-humidity aging treatment at a temperature of 25°C and a relative humidity of 80% for 24 hours; then change the conditions of the damp-heat aging chamber, change the environment to a temperature of 55°C and a relative humidity of 30% for high-temperature and low-humidity aging treatment for 24 hours. The above dry-wet alternation is one cycle of aging, and each test sample is subjected to 15 cycles of aging. Then test the stress-strain performance and folding endurance of the paper, as shown respectively in Figure 1 and Figure 2 shown.

[0118] See Figure 1 and Figure 2 It can be seen that compared with the paper treated with Comparative Example 2, the stress strength of the paper treated with Example 1 and Example 4 is significantly improved; it shows that the modifier glycerol triglycidyl ether acting on the paper significantly enhances the tensile mechanical strength and deformation toughness of the paper. At the same time, it is also found through experiments that when using triglycidyl glycerol ether for modification, while maintaining a high stress strength, the strain degree of the paper is continuously increasing. Preferably, the modification effect of using triglycidyl glycerol ether as a paper temperature repair agent is better.

[0119] 2. Influence of modifier concentration on hydrophilicity and hydrophobicity

[0120] Take the alum solution corresponding to Comparative Example 2 and the modified paper cultural relics repair agents obtained in Examples 1 to 3 as test samples.

[0121] Use a pipette to measure 40 mL of each test sample and evenly place it in a square plastic petri dish, and then place it in a cold air atmosphere to naturally dry at an environment of 18°C for 72 hours. After drying, slowly peel off each obtained film and put it into a plastic-sealed film for storage, and record it as an unmodified sizing film, a 1% concentration modifier sizing film, a 2% concentration modifier sizing film, and a 3% concentration modifier sizing film.

[0122] According to the conventional test method, test the hydrophilic and hydrophobic properties of the above unmodified sizing film, 1% concentration modifier sizing film, 2% concentration modifier sizing film, and 3% concentration modifier sizing film. The results are as shown in Figure 3 and Figure 4 shown.

[0123] From Figure 3 and Figure 4It can be seen that adding a modifier with a volume concentration of 1% does not significantly change the hydrophilicity and hydrophobicity of the gelatin alum film. However, as the concentration of the modifier increases, the hydrophilicity of the gelatin alum film increases significantly, and the stability of the hydrophilicity and hydrophobicity of the modified gelatin alum film cannot be maintained. Since the hydrophilicity and hydrophobicity directly affect the writing effect of the paper, in order to ensure that the modifier does not affect the writing technique effect of the paper, a volume concentration of 1% is preferably selected as the optimal ratio of the modifier.

[0124] 3. Aging morphology diagrams before and after modification

[0125] Take the gelatin solution of Comparative Example 1, the gelatin alum solution corresponding to Comparative Example 2, the modified gelatin solution of Comparative Example 3, and the modified paper cultural relics restorant of Example 1 as test samples.

[0126] Use a pipette to measure 40 mL of each test sample and evenly pour it into a square plastic petri dish. Then place it in a cold air atmosphere and let it dry naturally at 18 °C for 72 h. After drying, slowly peel off each obtained film and put it into a plastic film for preservation, and record them as gelatin film, gelatin alum film, modified gelatin film, and modified gelatin alum film in turn.

[0127] Cut the above four films into 4 cm × 2 cm sizes. After marking the cut films, place them in a damp heat aging oven at a temperature of 25 °C and a relative humidity of 80% for low-temperature and high-humidity aging treatment for 24 h. Then change the conditions of the damp heat aging oven, and change the film environment to a temperature of 55 °C and a relative humidity of 30% for high-temperature and low-humidity aging treatment for 24 h. The above dry-wet alternation is 1 cycle of aging, and each test sample is subjected to 15 cycles of aging. Compare the morphology of the obtained aged films with the original films to explore the influence of the aging environment on the four films. The results are as Figure 5 shown.

[0128] See Figure 5 , by observing and comparing images c2 and d2, it can be seen that after 15 cycles of aging, the shape of the gelatin alum film shrinks and twists, changing from a rectangular film to a cylindrical shape; the color changes from transparent to white and then gradually turns yellow; while the gelatin film added with the modifier glycerol triglycidyl ether remains flat. The reason for the appearance of a small number of bubbles is that during the aging cycle, when the environment changes from a low-temperature and high-humidity environment to a high-temperature and low-humidity environment, the flat film has a large contact area with the mold, and too much water vapor cannot be completely released from the film surface in contact with the mold, thus forming bubbles.

[0129] By observing and comparing images a2 and b2, it can be seen that after 15 cycles of aging, the corners of the gelatin film are distorted, and the main part bulges and is no longer flat; the corners of the gelatin alum film added with the modifier glycerol triglycidyl ether remain flat, and the appearance of a small number of bubbles is normal.

[0130] From the above results, it can be seen that using glycerol triglycidyl ether to modify the paper cultural relics repair agent can ensure the flatness of paper cultural relics. It shows that after sizing the paper surface with a modifier, the curling that occurs during the aging process of the paper and the deformation and fracture that occur under the action of stress stretching can be significantly inhibited.

[0131] 4. Water resistance test before and after modification

[0132] Take the gelatin solution of Comparative Example 1, the glue alum solution corresponding to Comparative Example 2, the modified gelatin solution of Comparative Example 3, and the modified paper cultural relics repair agent of Example 1 as test samples.

[0133] Use a pipette to measure 40 mL of each test sample and evenly pour it into a square plastic petri dish. Then place it in a cold air atmosphere and let it dry naturally at 18 °C for 72 h. After drying, slowly peel off each obtained film and put it into a plastic seal for storage, and record them as gelatin film (denoted as GF), glue alum film (denoted as AGF), modified gelatin film (denoted as GF+ or crosslinked GF), and modified glue alum film (denoted as AGF+ or crosslinked AGF) in turn.

[0134] Cut the above four films into 4 cm × 2 cm sizes. After marking the cut films, place them in a damp heat aging oven at a temperature of 25 °C and a relative humidity of 80% for low-temperature and high-humidity aging treatment for 24 h. Then change the conditions of the damp heat aging oven, change the film environment to a temperature of 55 °C and a relative humidity of 30% for high-temperature and low-humidity aging treatment for 24 h. The above dry-wet alternation is 1 cycle of aging. Each test sample is subjected to 1 cycle of aging, 4 cycles of aging, 7 cycles of aging, and 15 cycles of aging, and the water contact angles of the obtained aged films and the original films are compared.

[0135] Put the above films before and after aging into water, and take pictures every 20 seconds to observe the change of the contact angle. The contact angle photos are as Figure 6 and Figure 7 .

[0136] At the same time, measure the contact angle size at different times, and the results are as Figure 8 and Figure 9 shown. Figure 8 and Figure 9 In, 0, 1, 4, 7, 15 respectively refer to the number of cycles of aging. For example, AGF+4 means that the modified glue alum film has undergone 4 cycles of aging.

[0137] See Figures 6 - 9It can be seen that the contact angles of the gelatin film and the alum-gelatin film without the modifier glycerol triglycidyl ether before and after aging are smaller than those of the modified gelatin film and the modified alum-gelatin film with the modifier. This indicates that after adding the modifier, as the aging process deepens, the change in the contact angle within one minute is smaller and more stable; and the stability of the modified alum film is more obvious than that of the modified gelatin film. This shows that the modification with the modifier does not significantly change the surface hydrophilicity and hydrophobicity of the film, so that the modified alum-gelatin water applied on the paper surface does not affect the expression of painting and calligraphy techniques such as the rendering effect. And it can effectively prevent problems such as the bleeding of handwriting and the pollution of the picture caused by the change of the contact angle of the alum-gelatin film on the paper surface during the aging process.

[0138] 5. Thermal stability analysis before and after modification

[0139] Take the gelatin solution of Comparative Example 1, the alum-gelatin solution corresponding to Comparative Example 2, the modified gelatin solution of Comparative Example 3, and the modified paper cultural relics restorant of Example 1 as test samples.

[0140] Use a pipette to measure 40 mL of each test sample and evenly place it in a square plastic petri dish, and then place it in a cold air atmosphere to naturally dry at 18 °C for 72 h. After drying, slowly peel off the obtained films and put them into plastic seal bags for storage, and record them as gelatin film (GF), alum-gelatin film (AGF), modified gelatin film (GF+), and modified alum-gelatin film (AGF+) in turn.

[0141] Cut the above four films into 4 cm × 2 cm sizes, mark the cut films, and place them in a thermo-humidity aging chamber at 25 °C and 80% relative humidity for low-temperature and high-humidity aging treatment for 24 h. Then change the conditions of the thermo-humidity aging chamber, change the film environment to 55 °C and 30% relative humidity for high-temperature and low-humidity aging treatment for 24 h. The above dry-wet alternating aging is carried out for 1 cycle of aging. Each test sample is subjected to 1 cycle of aging, 4 cycles of aging, 7 cycles of aging, and 15 cycles of aging. Thermal stability analysis is carried out on the aged films and the original films respectively, and the results are as Figure 10 and Figure 11 shown.

[0142] See Figure 10From the thermogravimetric curves (TG) and derivative thermogravimetry (DTG) of gelatin samples before and after adding the modifier glycerol triglycidyl ether at different aging degrees, it can be found that with the deepening of the aging degree, the remaining mass percentage of the samples after thermal decomposition of the gelatin films before and after modification at 600 °C continuously increases. The unmodified gelatin film is more likely to lose free water, and there is even a process of slowly losing free water in the normal temperature environment, and the free water escape rate is the largest at 70 °C. While the free water escape rate of the modified gelatin film reaches the peak only at 140 °C. In other temperature ranges, there is little difference in the change compared with the unmodified gelatin film. This indicates that the gelatin film after adding the modifier has more stable heat resistance at normal temperature and does not affect the heat resistance in other temperature ranges.

[0143] See Figure 11 , by comparing the thermogravimetric curves (TG) and derivative thermogravimetry (DTG) of the alum - gelatin samples before and after modification at different aging degrees, it can be found that with the deepening of the aging degree, the remaining mass percentage of the samples after thermal decomposition of the alum - gelatin films before and after modification at about 600 °C continuously increases, but the change range of the modified alum - gelatin film is smaller. The unmodified alum - gelatin film is more likely to lose free water, and there is even a process of slowly losing free water in the normal temperature environment, and the free water escape rate is the largest at about 75 °C. While the free water escape rate of the modified alum - gelatin film reaches the peak only at about 130 °C. In other temperature ranges, there is little difference in the change compared with the unmodified alum - gelatin film. This indicates that the alum - gelatin film after adding the modifier has more stable heat resistance at normal temperature and does not affect the heat resistance in other temperature ranges.

[0144] 6. Infrared secondary structure analysis before and after modification

[0145] Take the modified gelatin solution of Comparative Example 3 and the modified paper cultural relics restorant of Example 1 as test samples.

[0146] Use a pipette to measure 40 mL of each test sample and evenly pour it into a square plastic petri dish, then place it in a cold air atmosphere and let it dry naturally at 18 °C for 72 h. After drying, slowly peel off the obtained films and put them into plastic seal bags for storage, and record them as modified gelatin film (GF+) and modified alum - gelatin film (AGF+) in turn.

[0147] Cut the above two films into pieces of 4 cm × 2 cm respectively. After marking the cut films, place them in a damp heat aging box at a temperature of 25 °C and a relative humidity of 80% for low-temperature and high-humidity aging treatment for 24 h. Then change the conditions of the damp heat aging box, change the film environment to a temperature of 55 °C and a relative humidity of 30% for high-temperature and low-humidity aging treatment for 24 h. The above dry-wet alternating aging is carried out for 1 cycle of aging. Each test sample is subjected to 1 cycle of aging, 4 cycles of aging, 7 cycles of aging and 15 cycles of aging. Infrared secondary structure analysis is carried out on the aged films and the original films respectively. The results are as Figure 12 and Figure 13 shown.

[0148] See Figure 12 and Figure 13 It can be seen that after modifying the sizing alum solution with glycerol triglycidyl ether, the proportion of the α-helix content in the sizing alum film decreases significantly, while the proportion of the random coil content increases significantly, making the free volume between molecules increase and the molecules move more easily. It shows that the addition of the modifier glycerol triglycidyl ether can break the hydrogen bonds in the sizing alum film, thereby weakening the intermolecular force in the sizing alum film; and the decrease of the intermolecular force makes the free volume between molecules increase and the molecules move more easily. Therefore, the flexibility of the sizing alum film is improved, and thus the phenomenon that the modified alum film is flatter macroscopically can be explained from the change of the microscopic structure.

[0149] To sum up, through the study of the effect of adding the modifier glycerol triglycidyl ether on the paper cultural relics restorant (sizing alum solution), it is found that the restorability of the paper cultural relics restorant (sizing alum solution) can be improved through modification, which is specifically reflected in the following aspects:

[0150] (1) The change in the contact angle of the sizing alum film without adding the modifier before and after aging is large, while the change in the contact angle of the sizing alum film with the modifier before and after aging is small. It shows that after sizing the paper surface with this modifier, the phenomenon of ink bleeding and fading during the aging process of the paper can be significantly inhibited, thus improving the problems of color diffusion and picture pollution on paper cultural relics.

[0151] (2) The properties of the gelatin film (and the sizing alum film) without adding the modifier before and after high-temperature degradation have large differences, which is not conducive to the long-term preservation of paper cultural relics; after high-temperature degradation, the differences in the properties of the modified gelatin film and the modified sizing alum film with the modifier before and after aging are extremely small, and the properties are stable, indicating that it has more stable heat resistance at room temperature and will not affect the heat resistance in other temperature ranges, which is extremely conducive to the long-term preservation of paper cultural relics.

[0152] (3) After 15 cycles of aging, the gelatin film without the modifier shrank and distorted, while the gelatin film with the modifier remained flat. This shows that applying sizing treatment to the paper surface with this modifier can significantly inhibit curling, deformation, and fracture under stress stretching during paper aging. After 15 cycles of aging, white crystal particles precipitated from the alum - gelatin film, showing an obvious whitening phenomenon, while this phenomenon was less obvious in the alum - gelatin film with the modifier. This shows that applying sizing treatment to the paper surface with this modifier can significantly inhibit the whitening and discoloration phenomenon during paper aging.

[0153] Obviously, the above - mentioned embodiments are only examples for clear illustration, rather than limitations on the implementation manners. For those of ordinary skill in the art, based on the above description, other different forms of changes or variations can be made. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for modifying a paper cultural relic restoration agent, characterized in that The paper cultural relics restorant is modified with glycerol triglycidyl ether to enhance its ability to inhibit the bleeding and fading of handwriting and its heat resistance at room temperature. The paper cultural relics restorant is composed of alum, gelatin and water, and the mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether to water is (1-3):

100.

2. The modification method of the paper cultural relic restoration agent according to claim 1, characterized in that The glycerol triglycidyl ether is diglycidyl glycerol triglycidyl ether or triglycidyl glycerol triglycidyl ether.

3. The method for modifying the paper cultural relic restoration agent according to claim 1, wherein, The specific process of modifying the paper cultural relics restorant with glycerol triglycidyl ether is as follows: S1. Soak gelatin in water and stir evenly at a temperature of 60°C ± 5°C to obtain a gelatin solution. S2. Add alum to the above gelatin solution and stir evenly at a temperature of 75°C ± 5°C to obtain a gelatin-alum solution. S3. Add glycerol triglycidyl ether to the above gelatin-alum solution and stir evenly at a temperature of 75°C ± 5°C to complete the modification of the paper cultural relics restorant.

4. The method for modifying the paper cultural relic restoration agent according to claim 1, characterized in that In the above steps S1 to S3, the stirring time is 2h-3h; the stirring speed is 500r / s.

5. Application of glycerol triglycidyl ether as a modifier in improving the performance of paper cultural relics restorants.

6. Application of glycerol triglycidyl ether as a modifier in improving the performance of paper cultural relics restorants in inhibiting the bleeding and fading of handwriting.

7. Application of glycerol triglycidyl ether as a modifier in improving the room temperature heat resistance of paper cultural relics restorants.

8. The application according to any one of claims 5-7, characterized in that, The paper cultural relics restorant is composed of alum, gelatin and water, and the mass ratio of alum, gelatin and water is 2:3:100; the volume ratio of glycerol triglycidyl ether to water is (1-3):

100.

9. The application according to any one of claims 5-7, characterized in that, The glycerol triglycidyl ether is diglycidyl glycerol triglycidyl ether or triglycidyl glycerol triglycidyl ether.

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