Impregnation deacidification method for improving deacidification quality of batch paper documents

Abstract

The invention provides a dipping deacidification method for improving the deacidification quality of batch paper literatures, and belongs to the technical field of paper literature preservation. The method comprises the following steps: classifying according to the smoothness of paper, preparing deacidification liquids with different mass concentrations, preparing a low-concentration deacidification liquid for low-smoothness literatures, preparing a high-concentration deacidification liquid for high-smoothness literatures, dipping the literatures with different smoothness in the deacidification liquids with corresponding mass concentrations, and performing pressure conversion in the dipping process, and the permeation of the deacidification substance in the literature is improved. Through classified deacidification, proper loading of deacidification substances after batch literatures are impregnated can be improved, excessive loading or insufficient loading of the deacidification substances in some literatures is avoided, and the loading uniformity of the deacidification substances in the batch literatures is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of paper document preservation, and in particular relates to an immersion deacidification method for improving the deacidification quality of batch paper documents. Background Art

[0002] Paper documents gradually become acidified during the preservation process, and the paper turns yellow and brittle. If this continues, the paper gradually becomes fragile and powdery. This is a global problem in the preservation process of paper documents. The world's cultural heritage industry has conducted extensive deacidification protection tests on the entire paper documents that have been acidified. From the perspective of environmental safety analysis, an organic solvent is used to prepare a suspension deacidification solution for immersion deacidification. The paper documents do not swell or deform, and the deacidification medium is not flammable or explosive, does not pollute the environment, and has no odor. It has the advantages of safety and reliability, and has become the mainstream technical direction for the current batch deacidification of paper documents.

[0003] The impregnation deacidification protection of paper documents is to load alkaline deacidification materials into the acidified paper documents through the impregnation process, and retain a certain amount of alkali reserves inside the acidified documents. During the preservation process of the documents, the alkaline deacidification materials gradually release alkaline ions to react with the free acid ions in the acidified documents to neutralize the acid and base, reduce the acidity of the document paper, slow down the damage to the paper caused by acidification, and extend the life of the document paper.

[0004] The document is impregnated and deacidified for protection. It is necessary to control the alkali reserve of the document after impregnation and deacidification protection to be between 0.8 and 1.5 mol / Kg (measurement method: GB / T 24998—2010).

[0005] A suspended deacidifying solution is prepared by using an organic solvent for immersion deacidification. A batch of whole paper documents are immersed in the deacidifying solution in a static manner. The deacidifying solution carries the deacidifying particles and flows from bottom to top between the pages of the document. After the deacidifying particles enter the narrow gap space of the document pages, the deacidifying particles close to the surface of the paper are carried by the directional flow of the deacidifying solution and pass through the capillary fibers on the surface of the paper. After immersion, the pages of the document are closed and the directional flow of the deacidifying solution stops. The deacidifying substances carried by the deacidifying solution that originally flowed inside the document pages are retained by the capillary fibers on the surface of the paper and become the deacidifying substances loaded inside the document.

[0006] However, due to the wide range of sources and long time span of batch documents, the pulp components and papermaking processes of the document papers are different, resulting in large differences in the surface morphological characteristics of the document papers. In the practice of impregnation deacidification, the morphological characteristics of the paper surface affect the loading of deacidification substances inside the document during the impregnation process. The rougher the paper surface, the more capillary fibers are exposed on the paper surface. At the end of the document impregnation, the more deacidification substances are retained by the capillary fibers on the paper surface; the smoother the paper surface, the fewer capillary fibers are exposed on the paper surface. At the end of the document impregnation, the less deacidification substances are retained by the capillary fibers on the paper surface. The coarser the paper fibers are, the greater the porosity of the paper is. At the end of the document impregnation, more deacidification substances are retained in the pores and gaps on the paper surface, and vice versa. The differences in the surface characteristics of batch document papers result in different amounts of deacidification substances being loaded on these acidified paper documents after batch impregnation with deacidification liquid. In practice, it is often found that after the deacidification of batch documents, some documents are always overloaded with deacidification materials, while others are underloaded with deacidification materials, which seriously reduces the overall deacidification effect of the batch document deacidification. Therefore, there is an urgent need for a deacidification method that can control the appropriate amount of deacidification materials loaded inside the documents during the deacidification process of batch paper documents. Summary of the invention

[0007] The purpose of the present invention is to provide an immersion deacidification method which can control the appropriate amount of deacidification material loaded inside the document by classifying the paper characteristics, thereby improving the deacidification quality of batch paper documents. The immersion deacidification method provided by the present invention can control the appropriate amount of deacidification material loaded inside the batch of immersed documents.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] The present invention provides an immersion deacidification method for improving the deacidification quality of batch paper documents, comprising the following steps:

[0010] (1) Testing the smoothness s of paper documents to obtain documents with different smoothness: s < 30 means documents that are easy to load with deacidified materials, 30 ≤ s ≤ 90 means documents that are normally loaded with deacidified materials, and s > 90 means documents that are difficult to load with deacidified materials;

[0011] (2) Mixing the deacidified material and the solvent to obtain deacidified solutions with different mass concentrations N, wherein the deacidified solution with a concentration of 0.1 g / L < N ≤ 1 g / L is used for documents that are easy to load with deacidified materials, the deacidified solution with a concentration of 1 g / L < N ≤ 4 g / L is used for documents that are normally loaded with deacidified materials, and the deacidified solution with a concentration of 4 g / L < N ≤ 8 g / L is used for documents that are difficult to load with deacidified materials;

[0012] (3) The documents with different smoothness in step (1) are immersed in the deacidification solutions with different mass concentrations obtained in step (2) to obtain documents loaded with deacidification; during the immersion process, the pressure is changed from high to low and then to high in a cycle.

[0013] Preferably, the solvent in step (2) is a fluorocarbon solvent.

[0014] Preferably, the deacidified substance in step (2) comprises one or more of magnesium hydroxide, calcium hydroxide, magnesium oxide and calcium oxide.

[0015] Preferably, in step (2), the deacidified solution of 0.3g / L<N≤0.6g / L is used for easy loading of deacidified documents, the deacidified solution of 2g / L<N≤3g / L is used for normal loading of deacidified documents, and the deacidified solution of 4g / L<N≤6g / L is used for difficult loading of deacidified documents.

[0016] Preferably, the impregnation cycle pressure in step (3) is 500-10 5 Pa.

[0017] Preferably, during the impregnation process in step (3), the pressure is cyclically changed from high to low and then to high for 3 to 5 times.

[0018] Preferably, during the impregnation process in step (3), the pressure is cyclically changed from high to low and then to high for 4 to 5 times.

[0019] Preferably, during the impregnation process in step (3), the time for the pressure to change from high to low and from low to high is independently 5 to 30 minutes.

[0020] Preferably, during the impregnation process in step (3), the time for the pressure to change from high to low and from low to high is independently 10 to 30 minutes.

[0021] The invention provides an immersion deacidification method for improving the deacidification quality of batch paper documents, comprising the following steps: (1) testing the smoothness s of paper documents to obtain documents with different smoothness, wherein s<30 is a document that is easy to load with deacidification material, 30≤s≤90 is a document that is normally loaded with deacidification material, and s>90 is a document that is difficult to load with deacidification material; (2) mixing deacidification material and solvent to obtain deacidification liquid with different mass concentrations N, wherein the deacidification liquid with 0.1 g / L<N≤1 g / L is used for documents that are easy to load with deacidification material, the deacidification liquid with 1 g / L<N≤4 g / L is used for documents that are normally loaded with deacidification material, and the deacidification liquid with 4 g / L<N≤8 g / L is used for documents that are difficult to load with deacidification material; (3) immersing the documents with different smoothness in the step (1) in the deacidification liquids with different mass concentrations obtained in the step (2) to obtain documents loaded with deacidification material; and the pressure is changed from high to low and then to high in a cycle during the immersion process. The present invention classifies the paper according to the smoothness, and prepares deacidification liquid of different mass concentrations, wherein the low-concentration deacidification liquid is used for the documents of low smoothness, and the high-concentration deacidification liquid is used for the documents of high smoothness, and then the documents of different smoothness are immersed in the deacidification liquid of the corresponding mass concentration, and the pressure is cyclically changed during the immersion process, and the classified immersion deacidification can improve the appropriate loading of the deacidification material after the immersion of the batch documents, avoid excessive loading or insufficient loading of the deacidification material inside some documents, and improve the uniformity of the loading of the deacidification material inside the batch documents. The results of the embodiment show that after adopting the method of the present invention, for the batch paper with a smoothness of less than 30, the alkali reserve obtained by loading the deacidification material is reduced from 1.0 to 2.0 mol / kg of the original method to 0.9 to 1.4 mol / kg, and for the batch paper with a smoothness of more than 90, the alkali reserve obtained by loading the deacidification material is increased from 0.5 to 0.8 mol / kg of the original method to 0.9 to 1.1 mol / kg. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention provides a flow chart of an immersion deacidification method for improving the deacidification quality of batch paper documents. DETAILED DESCRIPTION

[0023] The present invention provides an immersion deacidification method for improving the deacidification quality of batch paper documents, comprising the following steps:

[0024] (1) Testing the smoothness s of paper documents to obtain documents with different smoothness: s < 30 means documents that are easy to load with deacidified materials, 30 ≤ s ≤ 90 means documents that are normally loaded with deacidified materials, and s > 90 means documents that are difficult to load with deacidified materials;

[0025] (2) Mixing the deacidified material and the solvent to obtain deacidified solutions with different mass concentrations N, wherein the deacidified solution with a concentration of 0.1 g / L < N ≤ 1 g / L is used for documents that are easy to load with deacidified materials, the deacidified solution with a concentration of 1 g / L < N ≤ 4 g / L is used for documents that are normally loaded with deacidified materials, and the deacidified solution with a concentration of 4 g / L < N ≤ 8 g / L is used for documents that are difficult to load with deacidified materials;

[0026] (3) The documents with different smoothness in step (1) are immersed in the deacidification solutions with different mass concentrations obtained in step (2) to obtain documents loaded with deacidification; during the immersion process, the pressure is changed from high to low and then to high in a cycle.

[0027] The present invention detects the smoothness s of paper documents to obtain documents with different smoothness.

[0028] The present invention has no particular limitation on the source of the paper document, and any paper document that needs to be deacidified can be selected.

[0029] The present invention preferably uses a smoothness detector to detect the paper smoothness s according to standard GB / T456-89 (air leakage method).

[0030] Smoothness s<30, the paper surface is rough and loose, with many exposed capillary fibers, which is easy to load deacidified documents.

[0031] Smoothness s>90, the paper surface is smooth and firm, with few exposed capillaries, making it difficult to load deacidified documents.

[0032] 30≤smoothness s≤90 is the literature for normal loading and deacidification.

[0033] The present invention mixes the deacidified material and the solvent to obtain deacidified liquids with different mass concentrations N.

[0034] In the present invention, 0.1g / L<N≤1g / L of deacidified liquid is used for documents that are easy to load with deacidified materials, 1g / L<N≤4g / L of deacidified liquid is used for documents that are normally loaded with deacidified materials, and 4g / L<N≤8g / L of deacidified liquid is used for documents that are difficult to load with deacidified materials. Preferably, 0.3g / L<N≤0.6g / L of deacidified liquid is used for documents that are easy to load with deacidified materials, 2g / L<N≤3g / L of deacidified liquid is used for documents that are normally loaded with deacidified materials, and 4g / L<N≤6g / L of deacidified liquid is used for documents that are difficult to load with deacidified materials.

[0035] In the present invention, the solvent is preferably a fluorocarbon solvent.

[0036] The present invention has no particular limitation on the specific source of the fluorocarbon solvent, and commercial products known to those skilled in the art can be used. In an embodiment of the present invention, the fluorocarbon solvent is HJF fluorocarbon solvent produced by Hongjia Fluorine Technology Co., Ltd.

[0037] In the present invention, the deacidified material preferably includes one or more of magnesium hydroxide, calcium hydroxide, magnesium oxide and calcium oxide. In the present invention, the particle size of the deacidified material is preferably 10 nm to 8 μm.

[0038] After obtaining documents with different smoothness and deacidification solutions with different mass concentrations N, the present invention immerses the documents with different smoothness in the deacidification solutions with different mass concentrations to obtain documents loaded with deacidification.

[0039] The present invention has no particular limitation on the amount of deacidification solution used during immersion, and it only needs to be enough to cover the amount specified in the literature.

[0040] In the present invention, the pressure during the impregnation process is cyclically changed from high to low and then to high.

[0041] In the present invention, the impregnation cycle pressure is preferably 500 to 10 5 Pa; the time from high to low pressure and from low to high pressure in the impregnation process is preferably 5 to 30 minutes, more preferably 10 to 30 minutes; the number of cyclic changes from high to low to high pressure in the impregnation process is preferably 3 to 5 times, more preferably 4 to 5 times. The pressure changes from high to low to high once.

[0042] In the present invention, the process of changing the pressure from high to low and then to high during the impregnation process is preferably: the pressure is changed from 10 5 Pa is reduced to 500Pa, and then the pressure is increased from 500Pa to 10 within 5 to 30 minutes. 5 Pa (1 cycle), 3 to 5 cycles during the entire immersion process.

[0043] In the present invention, during the impregnation process, the deacidified substances carried by the deacidified liquid are filled into the cracks and gaps on the surface of the paper. The present invention controls the pressure, number of cycles and method during the impregnation process within the above range, so that the deacidified substances carried by the deacidified liquid can be fully filled into the cracks and gaps on the surface of the paper.

[0044] After the impregnation is completed, the present invention preferably removes the solvent from the impregnated document to obtain the acid-free document after the solvent is removed.

[0045] In the present invention, the method for removing the solvent treatment is preferably drying, more preferably hot air drying or vacuum drying; further preferably, hot air at 30-45°C is introduced into the cabinet containing the impregnated documents, and the ventilation time is controlled according to the size of the cabinet or the gas in the closed cabinet containing the impregnated documents is exhausted, and the pressure of the gas in the cabinet is controlled between 500 and 5000 Pa, and the weight gain of the documents after drying does not exceed 4-8%.

[0046] The present invention analyzes the surface characteristics of paper, formulates paper classification indicators, prepares corresponding deacidification liquid, and implements a method of matching the deacidification liquid on demand to achieve appropriate loading of deacidification materials for batch document immersion deacidification, avoids excessive loading of the deacidification materials inside some documents and insufficient loading of the deacidification materials inside some documents, effectively improves the uniformity of loading the deacidification materials inside the batch documents, thereby improving the deacidification quality of batch document immersion deacidification, and the method is simple.

[0047] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Example 1

[0049] (1) Using a smoothness tester to test the smoothness s of paper documents according to the standard GB / T456-89 (air leakage method), select the documents with a smoothness s < 30, which are easy to load and deacidify;

[0050] (2) mixing magnesium oxide (particle size 10 nm to 8 μm) and a fluorocarbon solvent to obtain a deacidification solution with a mass concentration of 0.5 g / L;

[0051] (3) Immersing the easily deacidified document in step (1) in the deacidifying solution in step (2), during which the pressure is increased from 10 to 10 within 15 minutes. 5 Pa decreased to 500Pa, and then increased from 500Pa to 10 within 15min. 5 Pa, cycled 3 times, and the deacidified literature was obtained after drying.

[0052] Example 2

[0053] (1) Using a smoothness tester to test the smoothness s of paper documents according to the standard GB / T456-89 (air leakage method), documents with a smoothness s>90 are selected as documents that are difficult to load and deacidify;

[0054] (2) mixing magnesium oxide (particle size 10 nm to 8 μm) and a fluorocarbon solvent to obtain a deacidification solution with a mass concentration of 5 g / L;

[0055] (3) The hard-to-load deacidified document in step (1) is immersed in the deacidified solution in step (2), and the pressure is increased from 10 to 10 within 5 minutes during the immersion process. 5 Pa decreased to 500Pa, and then increased from 500Pa to 10 within 5min. 5 Pa, cycled 5 times, and the deacidified literature was obtained after drying.

[0056] Example 3

[0057] (1) Using a smoothness tester to test the paper smoothness s of paper documents according to the standard GB / T456-89 (air leakage method), documents with a smoothness s between 30 and 90 are selected as documents with normal loading and deacidification;

[0058] (2) mixing magnesium oxide (particle size 10 nm to 8 μm) and a fluorocarbon solvent to obtain a deacidification solution with a mass concentration of 2.5 g / L;

[0059] (3) Immerse the normally loaded deacidified document in step (1) in the deacidified solution in step (2), and during the immersion process, the pressure is increased from 10 to 10 within 10 minutes. 5 Pa decreased to 500Pa, and then increased from 500Pa to 10 within 10min. 5 Pa, cycled 4 times, and the deacidified literature was obtained after drying.

[0060] Comparative Example 1

[0061] (1) mixing magnesium oxide (particle size 10 nm to 8 μm) and a fluorocarbon solvent to obtain a deacidification solution with a mass concentration of 1 g / L;

[0062] (2) Immerse the batch of paper documents that have not been measured and classified for smoothness in the deacidification solution of step (1), and during the immersion process, the pressure is increased from 10 to 10 within 10 minutes. 5 Pa decreased to 500Pa, and then increased from 500Pa to 10 within 10min. 5 Pa, cycled 4 times, and the deacidified literature was obtained after drying.

[0063] Comparative Example 2

[0064] (1) mixing magnesium oxide (particle size 10 nm to 8 μm) and a fluorocarbon solvent to obtain a deacidification solution with a mass concentration of 4 g / L;

[0065] (2) Immerse the batch of paper documents that have not been tested and classified for smoothness in the deacidification solution of step (1), and during the immersion process, the pressure is increased from 10 to 10 within 10 minutes. 5 Pa decreased to 500Pa, and then increased from 500Pa to 10 within 10min. 5 Pa, cycled 4 times, and the deacidified literature was obtained after drying.

[0066] The alkali reserves in the literature after loading the deacidified materials in Examples 1 to 3 and Comparative Examples 1 to 2 were tested, and the results are shown in Table 1.

[0067] Table 1 Alkali reserves in the literature after loading deacidification in Examples 1 to 3 and Comparative Examples 1 to 2

[0068]

[0069] After adopting the method of the present invention, for batch paper with a smoothness of less than 30, the alkali reserve obtained by loading the deacidified material is reduced from 1.0 to 2.0 mol / kg in the original method to 1.0 to 1.5 mol / kg, and for batch paper with a smoothness of more than 90, the alkali reserve obtained by loading the deacidified material is increased from 0.5 to 0.8 mol / kg in the original method to 0.9 to 1.2 mol / kg.

[0070] In summary, the method of the present invention can avoid excessive or insufficient loading of the deacidified material in some documents, and improve the uniformity of loading the deacidified material in batches of documents.

[0071] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An immersion deacidification method for improving the deacidification quality of batch paper documents, comprising the following steps: (1) Testing the smoothness s of paper documents to obtain documents with different smoothness: s < 30 means documents that are easy to load with deacidified materials, 30 ≤ s ≤ 90 means documents that are normally loaded with deacidified materials, and s > 90 means documents that are difficult to load with deacidified materials; (2) Mixing the deacidified material and the solvent to obtain deacidified solutions with different mass concentrations N, wherein the deacidified solution with a concentration of 0.1 g / L < N ≤ 1 g / L is used for documents that are easy to load with deacidified materials, the deacidified solution with a concentration of 1 g / L < N ≤ 4 g / L is used for documents that are normally loaded with deacidified materials, and the deacidified solution with a concentration of 4 g / L < N ≤ 8 g / L is used for documents that are difficult to load with deacidified materials; (3) immersing the documents with different smoothness in step (1) in the deacidification solutions with different mass concentrations obtained in step (2) to obtain documents loaded with deacidification; The pressure during the impregnation process changes cyclically from high to low and then to high.

2. The immersion deacidification method according to claim 1, characterized in that: The solvent in step (2) is a fluorocarbon solvent.

3. The immersion deacidification method according to claim 1, characterized in that: The deacidified material in step (2) includes one or more of magnesium hydroxide, calcium hydroxide, magnesium oxide and calcium oxide.

4. The immersion deacidification method according to claim 1, characterized in that: In the step (2), the deacidified solution of 0.3g / L<N≤0.6g / L is used for easy loading of deacidified documents, the deacidified solution of 2g / L<N≤3g / L is used for normal loading of deacidified documents, and the deacidified solution of 4g / L<N≤6g / L is used for difficult loading of deacidified documents.

5. The immersion deacidification method according to claim 1, characterized in that: The circulating pressure of the impregnation in step (3) is 500 to 10 5 Pa.

6. The immersion deacidification method according to claim 1, characterized in that: During the immersion process in step (3), the pressure is cyclically changed from high to low and then to high for 3 to 5 times.

7. The immersion deacidification method according to claim 6, characterized in that: During the impregnation process in step (3), the pressure is cyclically changed from high to low and then to high for 4 to 5 times.

8. The immersion deacidification method according to claim 1, characterized in that: During the immersion process in step (3), the time for the pressure to change from high to low and from low to high is independently 5 to 30 minutes.

9. The immersion deacidification method according to claim 8, characterized in that: During the immersion process in step (3), the time for the pressure to change from high to low and from low to high is independently 10 to 30 minutes.

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