CN107326742A - A kind of depickling of paper fibre and reinforcement guard method - Google Patents

Abstract

The invention belongs to the technical field of paper cultural relics protection, and specifically relates to a deacidification and reinforcement protection method for paper fibers. The method uses water as a solvent, calcium hydroxide as a deacidification agent, and water-soluble cellulose as a coating agent, through the interaction of composite components, and finally obtains a multi-phase highly dispersed paper deacidification reinforcing and protecting agent. Wherein, the concentration of water-soluble cellulose is 0.5-10 g/L, the concentration of alkaline deacidification agent is 0.05-2 g/L, and the solvent is water. The protective agent prepared by the method of the present invention is a dispersion system with regular nano-particle morphology and uniform distribution, which has good paper deacidification effect, reinforcement and reinforcement effect, certain alkali retention and is suitable for handwriting on paper such as ink. No impact, green and environmental protection, easy to use.

Description

A method for deacidification and reinforcement protection of paper fibers

technical field

The invention belongs to the technical field of paper cultural relics protection, and in particular relates to a method for protecting paper fibers.

Background technique

Paper cultural relics have played a very important role in the inheritance of human culture, and their scientific protection has attracted widespread attention internationally. There are more than tens of millions of ancient books in our country, as well as documents, newspapers, and periodicals published before the founding of the People's Republic of my country. They record in detail the important events that occurred in the course of our country's history, and have extremely high academic value. However, with the passage of time, the limitations of objective factors such as storage conditions and the environment, a large number of paper cultural relics face a series of problems such as accelerated damage and damage, which greatly reduces their usability and preservation life. Among them, the aging and acidification of paper fibers have become two serious problems faced by ancient paper books. The reason for paper aging is the breakage of fiber polymers, the main component of paper, which reduces the mechanical strength of paper and leads to irreversible damage such as embrittlement and pulverization. . The reason for the acidification of paper is that the glucose unit in the cellulose molecule is hydrolyzed under acidic conditions, which significantly reduces the degree of polymerization (Xi Sancai, Wan Li. The development history and prospect of paper cultural relics protection in Nanjing Museum. Beijing: Science Press, 2008 ; Liu Jiazhen. Principles and methods of ancient book protection. Beijing: National Library Press, 2015; Area, MC; Cheradame , H. Bioresources , 2011, 4 , 5307; 1978.).

According to literature reports, the commonly used methods for paper deacidification are divided into gas phase method and liquid phase method. Deacidification agents are various alkaline substances with stable chemical properties. For example, the Library of Congress of the United States uses diethyl zinc as a deacidification agent, and Barrow, an American paper protection expert, uses alkaline earth metal carbonates as a deacidification agent. The University of Chicago Library uses Organic magnesium carbonate is a deacidifying agent, Austrian scientist Mohan used hydroxide nanoparticle suspension etc. (Williamss, JC USP: 3969549,1976; Barrow, WJ The American Archivist , 1965, 2 , 285; T. RSC Adv ., 2015, 42 , 32950; Tian Zhouling, Zhonghua Paper , 2013, 34 , 90.). Organosilane coupling agents are commonly used for paper reinforcement, such as APTMS, APTES, AMDES, etc. (Ipert, S.; Dupont, AL Polym. Degrad. Stabil ., 2006, 12 , 3448; Dupont, AL; Lavedrine, B. Polym. Degrad. Stabil ., 2010, 12 , 2300; Souguir, Z.; Dupont, AL Biomacromolecules , 2011, 6 , 2082.). Generally speaking, the current various paper deacidification methods have various problems such as harsh conditions, poor safety, poor dispersion, low alkali retention, certain environmental pollution, and new damage to paper documents. And there is an urgent need to have other multi-functional protections such as reinforcement and antibacterial while deacidification protection.

Therefore, using a simple method to obtain a highly dispersed micro-nano deacidification agent with a certain amount of alkali retention; and integrating deacidification, reinforcement and other functions into integrated protection is currently the most interesting research topic in this field one. The protective agent prepared by the method of the invention has regular nanoparticle morphology, large specific surface, uniform solution system and good dispersibility, is beneficial to surface modification and assembly for actual paper fiber protection needs, and has development potential and application prospect. However, there are no reports in this regard so far.

Contents of the invention

The purpose of the present invention is to propose a simple, convenient, economical and reasonable protection method for deacidification and reinforcement of paper fibers.

The synthetic method of the paper fiber deacidification reinforcing protective agent that the present invention proposes, concrete steps are as follows:

(1) Dissolving the water-soluble cellulose in deionized water; the concentration of the obtained solution water-soluble cellulose is 0.5~10 g/L;

(2) Add nano calcium hydroxide to the above solution, the concentration of calcium hydroxide is 0.05 ~ 2 g/L;

(3) Place the above-mentioned solvent on a magnetic stirrer and stir at a temperature of 10-60°C for 0.5-24 hours to obtain a highly dispersible nano-deacidification reinforcing and protecting agent;

(4) The preparation of the paper pattern shall be in accordance with ISO 7213, and the paper shall be cut into several sizes of 1.5 cm×18 cm;

(5) Take the cut paper and place it in a certain amount of protective agent at a temperature of 10-40°C for 10-30 minutes;

(6) After the paper sample is processed and dried, a part of the paper is placed in an oven for dry heat aging treatment, to be characterized.

The water-soluble cellulose in step (1) can be methyl cellulose or hydroxyethyl cellulose or the like.

The nano calcium hydroxide in step (2) is hexagonal, spindle-shaped, and about 5-20 nm in size.

In step (3), the magnetic stirring speed is 100-1000 rpm, the temperature is 10-60° C., and the time is 0.5-24 hours.

In step (4), the paper pattern can be machine-made paper and handmade paper of the Republic of China with serious acidification.

The method of combining the paper sample and the protective agent in step (5) can be dipping, dripping, spraying, etc., at a temperature of 10-40°C and a time of 10-30 minutes.

After the paper pattern is treated in step (6), it can be dried naturally or at low temperature at a temperature of 10-50°C.

The deacidification component in the protective agent prepared by the method of the present invention is composed of calcium hydroxide nanoparticles with regular morphology, and the solution system has good dispersibility, and the solvent is a water solvent, which is green and environmentally friendly without polluting the environment, and the process of protecting paper is easy to handle. The time is short, has no effect on the handwriting on paper, is safe and non-toxic, and is suitable for mass production. The protective agent has good paper deacidification effect, reinforcing effect, and moderate alkali retention. Therefore, this nano-calcium hydroxide deacidifying reinforcing protective agent is expected to be widely used in the field of paper protection with severe acidification and embrittlement.

The method of the invention has a high yield and is suitable for batch preparation. The conditions are simple and easy to control, the cost of the process conditions is low, the preparation efficiency is high, the product quality and yield are high, and there is good application and industrialization prospect.

Description of drawings

Figure 1 is a transmission electron microscope (TEM) image of calcium hydroxide A in the protective agent.

Figure 2 is an X-ray powder diffraction (XRD) pattern of A.

Figure 3 is a diagram of the electromotive potential (Zeta-potential) of A.

Figure 4 is a microscope image (200X) of Minguo paper.

Figure 5 is a microscope image (50X) of handmade bamboo paper.

Figure 6 is a microscope image (200 times) of Minguo paper treated with protectant product B.

Figure 7 is a scanning electron microscope (SEM) image of Minguo paper treated with protectant product B.

Figure 8 is the X-ray powder diffraction (XRD) pattern of Minguo paper treated with protective agent product B.

Fig. 9 is a micrograph (50 times) of the handmade bamboo paper treated with protectant product B.

detailed description

Example 1

Dissolve 0.4 g of methylcellulose in 200 mL of deionized water, stir at room temperature for 3 h, then add 0.4 g of Ca(OH) ₂ (namely product A), and then add deionized water to 300 mL. After stirring at room temperature for 1 h. Get protective agent B.

Example 2

The experiment was carried out in a method similar to that of Example 1, but the mass of A was changed to 0.015 g to obtain protective agent C.

Example 3

The experiment was carried out in a method similar to that of Example 1, but the mass of methyl cellulose was changed to 1.0 g to obtain protective agent D.

Example 4

The experiment was carried out in a method similar to Example 1, but the methyl cellulose was changed to hydroxyethyl cellulose, and the mass was 3 g to obtain the protective agent E.

Example 5

Take several cut pieces of Republic of China paper, apply protective agent B drop by drop to the front and back of the paper, keep it for 20 minutes, take out the paper, and let it dry naturally.

Example 6

Carry out experiment with the method similar to embodiment 5, but change the Republic of China paper into handmade bamboo paper.

Example 7

Carry out experiment with the method similar to embodiment 5, but change protective agent B into C.

Example 8

Carry out experiment with the method similar to embodiment 5, but change protective agent B into D.

Example 9

Carry out experiment with the method similar to embodiment 6, but change protective agent B into E.

The photomicrographs of the above products were taken on the Dino-Lite AM4113ZT instrument, the scanning electron micrograph (SEM) was taken on the Philips XL30 D6716 instrument, and the lens photo (TEM) was taken on the JEOL JEM-2010 instrument. Fig. 1 is the transmission electron micrograph of the calcium hydroxide A that adopts in the embodiment 1, it can be seen that A has a spindle-shaped appearance, is made up of the nano-spindle-shaped particle of about 10 nm, uses XRD (in Rigaku D/Max-IIA A type X-ray diffractometer (see Figure 2) was used to characterize A, which proved to be hexagonal Ca(OH) ₂ (JCPDS: 84-1266). The zeta potential of deacidification agent A at pH=10 ( Measured by Nano-ZS90 zetasizer) shows that it is -17 (see Figure 3). Micrographs of the Republic of China paper and bamboo paper used in the experiment are shown in Figure 4 and 5, respectively. The weight of the Republic of China paper is 51.5 g/m ^2. Bamboo paper has a quantitative weight of 30.47 g/m ^2. The photomicrograph of the Republic of China paper treated with protective agent B (Figure 6) shows that the paper has no obvious changes after treatment, and the writing on the paper is not blurred, and the edge of the writing is not affected by diffusion, etc. The SEM photo (Figure 7) shows that the protective agent is distributed evenly on the surface and inside of the paper fiber, which can better neutralize the free acid inside the paper and resist the erosion of external acidic components. The XRD pattern (Figure 8) shows that the The acid agent is retained in the paper fiber by calcium hydroxide and calcium carbonate. The pH value of the paper after protection treatment is measured with a magnetic pH meter (PHSJ-4F), referring to the method of GB/T 13528-2015. The chromaticity of the paper Refer to CIE- L *, a *, b * method, use color difference meter (NR10QC) to measure, refer to GB/T 453-2002 method to use tensile tester (Hangzhou Zhibang ZB-WLQ) to measure tensile strength. After treatment with protective agent B The pH value of the paper increased from 4.18 to 9.73, the color difference change ΔE *=2.34, and the tensile strength increased from 0.78 KN/m to 1.62 KN/m, which indicated that the pH value and tensile strength of the treated paper were greatly improved , the change in color difference is not obvious. The pH values of the Republic of China paper treated with protective agents C and D are 8.68 and 9.07, respectively, and the tensile strength is increased to 1.47 and 2.01 KN/m, indicating that the concentration of the components in the protective agent is between It can be adjusted according to needs to a certain extent. In addition, after replacing the Republic of China paper with bamboo paper, the bamboo paper microscope photo is shown in Figure 9. After the treatment, the paper fiber has no obvious change, the pH value is increased from 4.39 to 9.81, and the tensile strength is increased from 4.39 to 9.81. 0.617 KN/m is improved to 2.012 KN/m; And after water-soluble cellulose is replaced by hydroxyethyl cellulose, the pH of bamboo paper is 9.27, and the tensile strength is 1.583 KN/m.Illustrate that this protective agent component can It is highly adjustable and has a certain degree of universality in the treatment of acidified and embrittled paper. It is also suitable for a variety of paper types such as machine-made paper and handmade paper.

Since this type of protective agent is composed of calcium hydroxide spindle-shaped nanoparticles with regular appearance, it has a large specific surface area, which is conducive to the exposure of more active sites. At the same time, the system is a uniformly dispersed solution system, using water as a solvent, which is safe and environmentally friendly. The process of protecting the paper is simple, takes a short time, and has no effect on the handwriting on the paper. It has good paper deacidification and strengthening effects, moderate alkali retention. Therefore, this protective agent is expected to be widely used in the protection field of acidified and embrittled paper. Because this product has the above potential application value, and the preparation conditions are simple and easy to control, the process conditions are low in cost, the preparation efficiency is high, the product quality and yield are high, so this product has good application and industrialization prospects. In addition, this method is universal, and the composition and properties of the obtained protective agent product can be controlled by further adjusting the composition of the deacidification agent and the content and type of the reinforcing agent, so as to further adjust its performance. The research on this system can not only provide simple, safe, green and environmentally friendly paper deacidification and reinforcement protection products, but also has extensive significance for prolonging the life of paper cultural relics and even cultural inheritance.

Claims (7)

1. a method for deacidification and reinforcement protection of paper fibers, characterized in that, the specific steps are as follows: (1) Dissolving the water-soluble cellulose in deionized water; the concentration of the obtained solution water-soluble cellulose is 0.5~10 g/L; (2) Add nanometer calcium hydroxide in the above solution, the concentration of calcium hydroxide is 0.05 ~ 2 g/L; (3) Place the above solvent on a magnetic stirrer and stir at a temperature of 10-60°C for 0.5-24 hours to obtain a highly dispersible nano deacidification reinforcing and protecting agent; (4) The preparation of the paper pattern shall be in accordance with ISO 7213, and the paper shall be cut into several sizes of 1.5 cm×18 cm; (5) Take the cut paper and place it in the protective agent prepared above at a temperature of 10-40°C for 10-30 minutes; (6) The paper sample is dried after treatment, and a part of the paper is placed in an oven for dry heat aging treatment, to be characterized. 2. The method for deacidification and reinforcement protection of paper fibers according to claim 1, characterized in that the water-soluble cellulose described in step (1) is methyl cellulose or hydroxyethyl cellulose. 3. The deacidification and reinforcing protection method of paper fibers according to claim 1, characterized in that the nano-calcium hydroxide described in step (2) is hexagonal, spindle-shaped, and the size is 5-20 nm size. 4. The method for deacidification and reinforcement protection of paper fibers according to claim 1, characterized in that the magnetic stirring speed of the system in step (3) is 100-1000rpm. 5. The method for deacidification and reinforcement protection of paper fibers according to claim 1, characterized in that the paper pattern in step (4) is acidified Republic of China machine-made paper or handmade paper. 6. The method for deacidification and reinforcement protection of paper fibers according to claim 1, characterized in that the combination of the paper sample and the protective agent in step (5) is dipping, dripping or spraying. 7. The method for deacidification, reinforcement and protection of paper fibers according to claim 1, characterized in that the paper pattern in step (6) is dried naturally or at low temperature after treatment, at a temperature of 10-50°C.