Application of ammonium chloride T and drawing cultural relic surface lead returning cleaning method

Abstract

The invention provides application of ammonium chloride T and a drawing cultural relic surface lead return cleaning method, ammonium chloride T is used for drawing cultural relic surface lead return cleaning, a lead return area on the surface of a drawing cultural relic is subjected to lead return cleaning through an aqueous solution of ammonium chloride T, and the lead return phenomenon on the surface of the drawing cultural relic can be effectively removed; the original color of the painting cultural relics before lead returning is recovered, and the technical problem that in the prior art, when a hydrogen peroxide aqueous solution is adopted for conducting lead returning cleaning on the painting cultural relics, the painting cultural relics are prone to being damaged is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of painting and cultural relic protection, and particularly relates to an application of ammonium chloride T and a method for cleaning lead on the surface of a painting and cultural relic. Background Art

[0002] Lead white (basic lead carbonate) has always been an important white pigment that dominates painting relics. As early as the Qin Dynasty, archaeological excavations and historical materials have proved that lead compounds such as lead powder have been used in painting in my country. As time goes by, the lead white in the painting reacts with the sulfide in the air, turning the original white pigment into gray or even black. This is the lead reversion phenomenon of lead white pigment. The lead reversion phenomenon seriously affects the accuracy of the information recorded in the painting relics themselves, and greatly damages the cultural and historical value of the painting relics.

[0003] In the prior art, the main method for cleaning the lead return phenomenon on the surface of paintings and cultural relics is to use hydrogen peroxide solution for cleaning, by dipping hydrogen peroxide solution and applying it on the lead return area on the surface of paintings and cultural relics, until the lead return phenomenon is eliminated, and then using distilled water or tea to remove the residual hydrogen peroxide solution. However, hydrogen peroxide has strong oxidizing and diffusibility. When using hydrogen peroxide solution for lead return cleaning, it will accelerate the aging of fibers in paintings and cultural relics. At the same time, hydrogen peroxide solution is easy to diffuse on paintings and cultural relics and is not easy to remove, which will cause unnecessary damage to the pigment around the lead return area, accelerate the aging of paintings and cultural relics, and cause irreparable damage to paintings and cultural relics. Therefore, a more gentle and safe method for cleaning the lead return on the surface of paintings and cultural relics is urgently needed. Summary of the invention

[0004] In order to solve the technical problem that the painting cultural relics are easily damaged when the lead return phenomenon on the surface of the painting cultural relics is mainly carried out by using hydrogen peroxide aqueous solution in the prior art, the present invention provides an application of ammonium chloride T and a method for cleaning the lead return on the surface of the painting cultural relics.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides the use of ammonium chloride T in cleaning lead from the surface of paintings and cultural relics.

[0007] Optionally, the mass concentration of the aqueous solution of ammonium chloride T is 1% to 6%.

[0008] In a second aspect, the present invention provides a method for cleaning lead on the surface of a painting or cultural relic, the method comprising the steps of:

[0009] S1: Remove dust from the surface of painting artifacts;

[0010] S2: Dip in the aqueous solution of ammonium chloride T and apply it on the lead-returned area on the surface of the painting;

[0011] S3: repeat step S2 until the lead return phenomenon on the surface of the painting artifact is eliminated and the lead return area returns to its original color;

[0012] S4: Dip ultrapure water to clean the surface of the painting artifact to remove the aqueous solution of ammonium chloride T remaining on the surface of the painting artifact.

[0013] Optionally, in step S2, the mass concentration of the aqueous solution of ammonium chloride T is 1% to 6%.

[0014] The beneficial effects of the present invention are:

[0015] (1) The present invention provides an application of ammonium chloride T and a method for cleaning lead on the surface of a painting or cultural relic. The ammonium chloride T is used for cleaning lead on the surface of a painting or cultural relic. By using an aqueous solution of ammonium chloride T to clean the lead on the surface of the painting or cultural relic, the lead on the surface of the painting or cultural relic can be effectively removed, and the painting or cultural relic can be restored to its original color before the lead is removed. This avoids the technical problem of easily causing damage to the painting or cultural relic when using an aqueous solution of hydrogen peroxide to clean the lead on the painting or cultural relic in the prior art.

[0016] (2) The method for cleaning the surface of paintings and cultural relics provided by the present invention is simple to operate and easy to implement. In addition, since the aqueous solution of ammonium chloride T is weakly alkaline, it can also neutralize the acidic substances in the paintings and cultural relics, which is beneficial to the long-term preservation of the paintings and cultural relics. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The tensile strength test results of the samples after the samples were coated with aqueous solutions of ammonium chloride T with different mass fractions in the present invention;

[0018] Figure 2 It is the folding endurance test result of the sample after the sample is coated with the aqueous solution of ammonium chloride T with different mass fractions in the present invention;

[0019] Figure 3 The whiteness test results of the samples after the samples were coated with aqueous solutions of ammonium chloride T with different mass fractions in the present invention;

[0020] Figure 4 It is the test result of the visible light reflectance of the sample after coating by the lead-return cleaning method for the surface of the painting cultural relic provided by the present invention;

[0021] Figure 5 The tensile strength test results of the samples after coating by the method for cleaning the surface of the painting cultural relics provided by the present invention and the prior art;

[0022] Figure 6The folding endurance test results of the sample after coating by the lead-return cleaning method on the surface of the painting cultural relic provided by the present invention and the prior art;

[0023] Figure 7 It is a schematic diagram of the effect of lead returning and cleaning the surface of a painting cultural relic provided by the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with specific embodiments.

[0025] It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the claims in the application.

[0026] Sample 1

[0027] Dissolve 1.0 g of chloramine T in 99 mL of deionized water and stir evenly to prepare a 1% by mass chloramine T aqueous solution.

[0028] Sample 2

[0029] Dissolve 2.0 g of chloramine T in 98 mL of deionized water and stir evenly to prepare an aqueous solution of chloramine T with a mass fraction of 2%.

[0030] Sample 3

[0031] Dissolve 3.0 g of chloramine T in 97 mL of deionized water and stir evenly to prepare a 3% by mass chloramine T aqueous solution.

[0032] Sample 4

[0033] Dissolve 4.0 g of chloramine T in 96 mL of deionized water and stir evenly to prepare an aqueous solution of chloramine T with a mass fraction of 4%.

[0034] Sample 5

[0035] Dissolve 5.0 g of chloramine T in 95 mL of deionized water and stir evenly to prepare a 5% by mass chloramine T aqueous solution.

[0036] Sample 6

[0037] Dissolve 6.0 g of chloramine T in 94 mL of deionized water and stir evenly to prepare an aqueous solution of chloramine T with a mass fraction of 6%.

[0038] The aqueous solution of ammonium chloride T prepared in the above samples 1 to 6 is applied to the surface of the painting and cultural relics for lead removal, specifically including:

[0039] S1: Remove dust from the surface of painting artifacts;

[0040] S2: Dip in the aqueous solution of ammonium chloride T and apply it on the lead-returned area on the surface of the painting;

[0041] S3: repeat step S2 until the lead return phenomenon on the surface of the painting artifact is eliminated and the lead return area returns to its original color;

[0042] S4: Dip ultrapure water to clean the surface of the painting artifact to remove the aqueous solution of ammonium chloride T remaining on the surface of the painting artifact.

[0043] Furthermore, in the method for cleaning the surface of paintings and cultural relics provided in the present invention, in step S1, a dust blower can be used to remove dust on the surface of the paintings and cultural relics; in steps S2 and S3, a wool brush can be used in the process of dipping in the aqueous solution of ammonium chloride T and ultrapure water, and the number of repetitions can be 2 to 3 times to reduce damage to the surface of the paintings and cultural relics.

[0044] In order to verify the beneficial effects of the present invention, the applicant used the aqueous solution of ammonium chloride T prepared in samples 1 to 6 to conduct relevant verifications, as follows:

[0045] 1. Preparation of simulated samples of lead return of painting cultural relics

[0046] 5.0g of gelatin was dissolved in 100mL of deionized water to prepare glue, 10.0g of lead white (basic lead carbonate) was added to the glue, and stirred with a magnetic stirrer for 10 minutes to form a uniform lead white pigment paste. Uniform rice paper was selected, and the prepared lead white pigment paste was evenly applied on the surface of the paper with a brush, and dried naturally at room temperature to obtain a lead white painting simulation sample.

[0047] Take 0.1g of sodium sulfide and dissolve it in 100mL of deionized water. Spray the sodium sulfide solution evenly on the surface of the white painting simulation sample to simulate the lead return state of the painting cultural relic and obtain a simulated sample of the lead return of the painting cultural relic.

[0048] 2. Conduct verification test

[0049] (1) Test on the influence of tensile strength and folding endurance of materials

[0050] Prepare ultrapure water with a mass fraction of ammonium chloride T of 0%, and obtain aqueous solutions of ammonium chloride T with mass fractions of 1%, 2%, 3%, 4%, 5%, and 6% prepared in samples 1 to 6, and evenly apply them on blank rice paper respectively. Dry and heat age them in an environment of humidity of 70% and temperature of 80°C for 15 days. The obtained samples are named samples No. 0, 1, 2, 3, 4, 5, and 6, respectively, to obtain paper aging samples treated with aqueous solutions of ammonium chloride T with different mass fractions.

[0051] In order to verify the effect of the ammonium chloride T aqueous solution used in the present invention on the tensile strength and folding endurance of the painting cultural relics after the lead treatment, the national standard method GB / T453-2002 was used to measure the tensile strength of all samples (constant speed addition method), and the national standard method GB / T2679.5-1995 was used to measure the folding endurance of all samples (MIT folding endurance instrument method). The test results are shown in the figure. Figure 1 and Figure 2 shown.

[0052] Reference Figure 1 and Figure 2 It can be intuitively concluded that after 15 days of wet heat aging, the tensile strength and folding endurance of the rice paper coated only with ultrapure water having an ammonium chloride T mass fraction of 0% and the rice paper coated with the ammonium chloride T aqueous solution having a mass concentration of 1% to 6% provided in the present invention are very similar. This test result shows that the ammonium chloride T aqueous solution having a mass concentration of 1% to 6% provided in the present invention has very little effect on the tensile strength and folding endurance of the rice paper, that is, it has very little effect on the durability of the rice paper, and can avoid the technical problem of the hydrogen peroxide aqueous solution used in the prior art accelerating the aging of the fibers in the painting cultural relics due to its strong oxidizing property.

[0053] (2) Test on the influence of material whiteness

[0054] Prepare ultrapure water with a mass fraction of ammonium chloride T of 0%, and obtain aqueous solutions of ammonium chloride T with mass fractions of 1%, 2%, 3%, 4%, 5%, and 6% prepared in samples 1 to 6, and evenly apply them on blank rice paper respectively. Dry and heat age them in an environment of humidity of 70% and temperature of 80°C for 15 days. The obtained samples are named samples No. 0, 1, 2, 3, 4, 5, and 6, respectively, to obtain paper aging samples treated with aqueous solutions of ammonium chloride T with different mass fractions.

[0055] In order to verify the effect of the ammonium chloride T aqueous solution used in the present invention on the whiteness of the painting cultural relics after the lead treatment, this test adopts the national standard method GB / T7974-2013 to measure the whiteness of all samples. The test results are as follows: Figure 3 shown.

[0056] Reference Figure 3It can be seen that compared with the No. 0 sample coated with ultrapure water with a mass fraction of 0% ammonium chloride T, the rice paper coated with the ammonium chloride T aqueous solution with a mass concentration of 1% to 6% provided in the present invention has an increase of about 1 to 2 units of whiteness after aging, which is within an acceptable range. In addition, as the concentration of the ammonium chloride T aqueous solution gradually increases, the whiteness shows a weak upward trend. In summary, the difference in whiteness between the rice paper coated with the ammonium chloride T aqueous solution and the rice paper not coated with the ammonium chloride T aqueous solution is small, indicating that the use of the surface lead cleaning method for painting cultural relics provided in the present invention will not significantly change or interfere with the whiteness characteristics of the painting cultural relics.

[0057] (3) Test on the influence of color difference on materials

[0058] Prepare ultrapure water with a mass fraction of ammonium chloride T of 0%, and obtain aqueous solutions of ammonium chloride T with mass fractions of 1%, 2%, 3%, 4%, 5%, and 6% prepared in samples 1 to 6, and evenly apply them on blank rice paper respectively. Dry and heat age them in an environment of humidity of 70% and temperature of 80°C for 15 days. The obtained samples are named samples No. 0, 1, 2, 3, 4, 5, and 6, respectively, to obtain paper aging samples treated with aqueous solutions of ammonium chloride T with different mass fractions.

[0059] In order to verify the effect of the ammonium chloride T aqueous solution used in the present invention on the color difference of the painted cultural relics after the lead treatment of the painted cultural relics, this test adopts the national standard method GB / T40969-2021 to measure the color difference of all samples, and the test results are shown in Table 1.

[0060] Table 1 Color difference of samples after cleaning with ammonium chloride T solution

[0061] Sample No. L* a* b* ΔE 0 79.99 -0.55 7.89 - 1 79.26 0.16 8.52 1.20 2 78.91 0.04 7.88 1.23 3 78.86 0.02 7.98 1.27 4 78.78 -0.05 8.00 1.31 5 80.24 -0.07 9.09 1.32 6 78.73 -0.09 8.63 1.53

[0062] Referring to Table 1, it can be seen that the color difference fluctuation range of samples 1 to 6 coated with the aqueous solution of ammonium chloride T with a mass concentration of 1% to 6% provided by the present invention and aged for 15 days is less than 2 compared to sample 0 coated with ultrapure water with a mass fraction of ammonium chloride T of 0% and aged for 15 days, indicating that the surface lead cleaning method of paintings and cultural relics provided in the present invention has a relatively slight effect on the color of paintings and cultural relics, and the impact produced is small, so it will not cause obvious interference or change to the color presentation of paintings and cultural relics. In summary, it can be seen that after the surface lead cleaning method of paintings and cultural relics provided in the present invention is used to clean the surface lead of paintings and cultural relics, it will not have a negative impact on the substrate of the paintings and cultural relics, and can quickly restore the lead-returned area of ​​the paintings and cultural relics to the original color.

[0063] (4) Test on the influence of visible light reflectivity on painting relics

[0064] In order to verify the effect of the lead-return cleaning method provided by the present invention on the visible light reflectance of the painting cultural relic, this experiment tested the reflectance of the lead white painting simulation sample and the lead-return simulation sample of the painting cultural relic in the visible light wavelength range of 350nm to 800nm, and adopted the lead-return cleaning method provided by the present invention, the ammonium chloride T aqueous solution with a mass fraction of 3% prepared in sample 3 was applied to the lead-return simulation sample of the painting cultural relic for lead-return cleaning, and then the reflectance in the visible light wavelength range of 350nm to 800nm ​​was obtained. The test results are as follows: Figure 4 shown.

[0065] Reference Figure 4 It can be seen that the visible light reflectivity of the lead white painting simulation sample is between 64.4% and 66.3%. After the lead return phenomenon occurs, the visible light reflectivity of the lead return simulation sample of the painting cultural relic is reduced to between 8.7% and 24.1%. After the lead return cleaning method for the surface of the painting cultural relic provided in the present invention is used for lead return cleaning, its visible light reflectivity is restored to between 66.2% and 68.4%. In summary, after the surface lead return cleaning method for the surface of the painting cultural relic provided in the present invention is used to clean the surface lead return of the painting cultural relic, the visible light reflectivity of the lead return area of ​​the painting cultural relic can be restored to the level before the lead return phenomenon occurs.

[0066] (5) pH of aqueous ammonium chloride T solutions with different mass concentrations

[0067] Table 2 pH values ​​of aqueous solutions of ammonium chloride T at different mass concentrations

[0068]

[0069] Referring to Table 2, the pH values ​​of the aqueous solutions of ammonium chloride T with a mass concentration of 1% to 6% provided in the present invention are shown.

[0070] According to Table 2, in the ammonium chloride T aqueous solution with a mass concentration of 1% to 6% provided in the present invention, as the mass concentration of ammonium chloride T in the ammonium chloride T aqueous solution increases, its pH value also slowly increases and tends to be stable, and the ammonium chloride T aqueous solution is weakly alkaline, while ultrapure water without ammonium chloride T is weakly acidic. Therefore, in the process of lead recovery and cleaning on the surface of paintings and cultural relics, the use of ammonium chloride T of the present invention can neutralize the acidic substances in the paintings and cultural relics, which is beneficial to the long-term preservation of the paintings and cultural relics.

[0071] In summary, the ammonium chloride T of the present invention has little effect on the tensile strength, folding endurance and whiteness of the base material of painting cultural relics such as rice paper, and can use its own weak alkalinity to neutralize the acidic substances in the painting cultural relics, which is beneficial to the long-term preservation of the painting cultural relics.

[0072] (6) Test on the influence of tensile strength and folding endurance of painting cultural relics

[0073] Furthermore, in order to verify the difference between the method for cleaning the surface of painted cultural relics provided by the present invention and the method for cleaning the surface of painted cultural relics using hydrogen peroxide in the prior art in terms of tensile strength and folding endurance, this experiment used the 3% ammonium chloride T aqueous solution prepared in Sample 3 to coat the samples, and used the 3% hydrogen peroxide aqueous solution to coat the samples, and then all the samples were subjected to artificial accelerated aging operations, and the national standard method GB / T453-2002 was used to measure the tensile strength of all the samples (constant rate addition method), and the national standard method GB / T2679.5-1995 was used to measure the folding endurance of all the samples (MIT folding endurance instrument method). The test results are as follows: Figure 5 and Figure 6 shown.

[0074] Reference Figure 5 and Figure 6 It can be seen that after the sample is coated with a 3% mass fraction of hydrogen peroxide aqueous solution in the prior art, the tensile strength and folding resistance of the sample are significantly reduced; while after the sample is coated with the lead-returning cleaning method for the surface of the painting cultural relic provided by the present invention, the tensile strength and folding resistance of the sample are significantly better than the tensile strength and folding resistance of the rice paper coated with hydrogen peroxide aqueous solution in the prior art. It can be seen that the lead-returning cleaning method for the surface of the painting cultural relic provided in the present invention can significantly reduce the damage to the painting cultural relic compared with the prior art, is more conducive to preserving the original mechanical properties of the painting cultural relic, and provides strong support for the long-term preservation of the painting cultural relic.

[0075] (7) The effect of lead removal on the surface of paintings and cultural relics

[0076] See also Figure 7 , which shows a schematic diagram of the effect of using the lead-returning cleaning method for the surface of a painting cultural relic provided by the present invention to carry out lead-returning cleaning. Figure 7 Comparison of the front and back of the rice paper before and after lead cleaning shows that the present invention uses an aqueous solution of ammonium chloride T to clean the lead-returned area on the surface of the painting cultural relic, which can effectively remove the lead-returned phenomenon on the surface of the painting cultural relic, restore the painting cultural relic to its original color before the lead-returning, and avoids the technical problem of easily causing damage to the painting cultural relic when using an aqueous solution of hydrogen peroxide to clean the lead-returned area in the prior art.

[0077] In summary, the application of the ammonium chloride T provided in the present invention and the use of the ammonium chloride T for cleaning the lead return on the surface of paintings and cultural relics not only has no negative impact on the material of the paintings and cultural relics themselves, but also can restore the visible light reflectivity of the lead return area of ​​the paintings and cultural relics to the level before the lead return phenomenon occurs, which can significantly reduce the damage to the paintings and cultural relics, is more conducive to preserving the original mechanical properties of the paintings and cultural relics, and is conducive to the long-term preservation of the paintings and cultural relics.

[0078] It should be noted that in the experiment of the present invention, a more common substrate in painting cultural relics, namely rice paper, was selected as the material for the experiment, but the lead recovery and cleaning method of painting cultural relics of the present invention is not limited to painting cultural relics with rice paper as the substrate. Those skilled in the art can specifically select the application scenario of the present invention according to actual usage requirements.

[0079] It should be noted that the above embodiments are only detailed implementation methods of the present invention. Any steps disclosed in this specification, unless otherwise specified, can be equivalent or replaced by methods with similar intentions. All disclosed features, methods, reagents or steps, except for conflicting features / methods / reagents / steps, can be combined in any way.

Claims

1. Application of ammonium chloride T in cleaning lead from the surface of paintings and cultural relics.

2. The use according to claim 1, characterized in that: The mass concentration of the aqueous solution of ammonium chloride T is 1% to 6%.

3. A method for cleaning the surface of a painting cultural relic from lead, characterized in that: The method for cleaning the surface of a painting cultural relic from lead comprises the following steps: S1: Remove dust from the surface of painting artifacts; S2: Dip in the aqueous solution of ammonium chloride T and apply it on the lead-returned area on the surface of the painting; S3: repeat step S2 until the lead return phenomenon on the surface of the painting artifact is eliminated and the lead return area returns to its original color; S4: Dip ultrapure water to clean the surface of the painting artifact to remove the aqueous solution of ammonium chloride T remaining on the surface of the painting artifact.

4. The method for cleaning the surface of paintings and cultural relics according to claim 3, characterized in that: In step S2, the mass concentration of the aqueous solution of ammonium chloride T is 1% to 6%.

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