阅读说明：本技术 一种纸质文物保护液的制备及应用方法 (Preparation and application method of paper cultural relic protection solution ) 是由 张秀梅 陈佳琪 于 2021-07-16 设计创作，主要内容包括：本发明提出了一种纸质文物保护液的制备及应用方法,将水性聚氨酯丙烯酸酯-环氧丙烯酸酯共混保护液配制成不同的浓度,涂覆于模拟纸质文物宣纸上,室温悬挂干燥后对纸张进行紫外固化,纸质文物保护液包括以下重量份原料：水性聚氨酯丙烯酸酯30份；环氧丙烯酸酯3-9份；光引发剂0.6-0.8份；无水乙醇20-26份；蒸馏水80-104份。本发明制备步骤简单,易操作,选择含有亲水性基团的聚氨酯丙烯酸酯与环氧丙烯酸酯进行共混,避免了最终产物因外加乳化剂残留而影响宣纸作品性能。应用此纸质保护液不仅能提高宣纸的强度,还能延缓纸张老化,延长纸质文物保存时间,提高其观赏和研究价值；紫外固化方法避免了加热固化对文物的破坏,具有很高的可操作性。(The invention provides a preparation and application method of a paper cultural relic protection solution, which comprises the following steps of preparing the water-based polyurethane acrylate-epoxy acrylate blended protection solution into different concentrations, coating the protection solution on simulated paper cultural relic rice paper, and carrying out ultraviolet curing on the paper after the paper is hung and dried at room temperature, wherein the paper cultural relic protection solution comprises the following raw materials in parts by weight: 30 parts of waterborne polyurethane acrylate; 3-9 parts of epoxy acrylate; 0.6-0.8 part of photoinitiator; 20-26 parts of absolute ethyl alcohol; 80-104 parts of distilled water. The preparation method has simple preparation steps and easy operation, and the polyurethane acrylate containing hydrophilic groups and the epoxy acrylate are selected for blending, so that the influence of the final product on the performance of the rice paper due to the addition of the emulsifier residue is avoided. The application of the paper protection solution can not only improve the strength of rice paper, but also delay the aging of the paper, prolong the preservation time of the paper cultural relics and improve the ornamental and research values of the paper cultural relics; the ultraviolet curing method avoids damage of heating curing to the cultural relics and has high operability.)

1. A preparation and application method of paper cultural relic protection liquid is characterized in that the water-based polyurethane acrylate-epoxy acrylate blended protection liquid is prepared into different concentrations, coated on the rice paper of the simulated paper cultural relic, and subjected to ultraviolet curing after being hung and dried at room temperature;

the aqueous polyurethane acrylate-epoxy acrylate blended protective solution for protecting the paper cultural relics comprises the following components in parts by weight: 30 parts of waterborne polyurethane acrylate; 3-9 parts of epoxy acrylate; 0.6-0.8 part of photoinitiator; 20-26 parts of absolute ethyl alcohol; 80-104 parts of distilled water; the method is characterized by comprising the following steps:

1) weighing a certain weight part of waterborne polyurethane acrylate and epoxy acrylate in a three-neck flask, and placing the three-neck flask in a water bath to stir and disperse uniformly;

2) adding distilled water and ethanol in a certain mass ratio into a beaker and uniformly mixing;

3) slowly dripping the water/ethanol mixed solvent in the step 2) into the step 1), stirring at a high speed while dripping, and uniformly dispersing to realize the conversion from an oil phase to a water phase, thereby obtaining the water-based polyurethane acrylate-epoxy acrylate blended emulsion;

4) preparing the aqueous polyurethane acrylate-epoxy acrylate blended emulsion obtained in the step 3) into blended emulsions with different mass concentrations, adding a certain amount of photoinitiator, and carrying out ultrasonic mixing to obtain a paper cultural relic protection solution;

5) and (4) uniformly coating the paper cultural relic protection solution obtained in the step (4) on the simulated paper cultural relic rice paper, and curing under an ultraviolet lamp after the simulated paper cultural relic rice paper is hung and dried at room temperature.

2. The preparation method of the paper cultural relic protection solution according to claim 1, which is characterized by comprising the following steps: the waterborne polyurethane acrylate in the step (1) serves as a polymer emulsifier, and is mixed and stirred with the epoxy acrylate in a water bath at the temperature of 30 ℃ for 0.5h, and the stirring speed is 250 r/min.

3. The preparation method of the paper cultural relic protection solution according to claim 1, which is characterized by comprising the following steps: the epoxy acrylate content in the step (1) is 0%, 10%, 20% and 30% of the mass of the waterborne polyurethane acrylate.

4. The preparation method of the paper cultural relic protection solution according to claim 1, which is characterized by comprising the following steps: the water/ethanol mass ratio in the step (2) is 8: 2.

5. The preparation method of the paper cultural relic protection solution according to claim 1, which is characterized by comprising the following steps: the stirring time in the step (3) is 1h, and the stirring speed is 800 r/min.

6. The preparation method of the paper cultural relic protection solution according to claim 1, which is characterized by comprising the following steps: in the step (4), the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-acetone (Irgacure1173), and the content of the photoinitiator is 2% of the total amount of the system.

7. The preparation method of the paper cultural relic protection solution according to claim 1, which is characterized by comprising the following steps: in the step (5), the power of the ultraviolet curing machine is 2kw, and the illumination time is 1 min.

Technical Field

The invention relates to paper cultural relic protection, in particular to a preparation method and an application method of a water-based polyurethane acrylate-epoxy acrylate blended protection solution for paper cultural relic protection.

Background

The papermaking technology is one of four ancient inventions in China, and makes remarkable contribution in civilized inheritance and record in the world. Libraries and archives all over the world currently store a large number of paper cultural relic works, including: ancient documents, books, paintings, warps, contracts, notes, etc., which have left behind the treasure of immeasurable value for the development and culture prosperity of society. However, the ancient book cultural relics are aged and damaged due to the influence of temperature, humidity, light, external force and the like, and the preservation value of the cultural relics is greatly lost. In addition, the main raw material of the paper for the paper cultural relics is plant fiber, and hydroxyl groups among the fibers are combined through hydrogen bonds to form the physical strength of the paper, but the moisture absorption of the hydroxyl groups easily causes the increase of the water content of the paper, greatly influences the strength of the paper and is not beneficial to the long-term storage of the paper cultural relics.

Photo-aging is one of the main causes of aging of paper materials, and ultraviolet radiation accelerates the aging speed of paper materials, so that protection of the paper materials against ultraviolet rays is very important in protection of the paper materials. There are a variety of strengthening liquids used for paper cultural relic protection: research on strengthening and protecting paper cultural relics by using fluorine-containing polymer, cultural relic protection and archaeological science, 2004(04), 1-5, and report that paper is protected by blending 1, 6-hexamethylene isocyanate tripolymer and normal-temperature curing type fluorine resin. The method can improve the tensile strength of the paper, but the room-temperature curing fluororesin has larger relative molecular mass, is difficult to permeate into the fiber, only forms a film-shaped structure on the surface of the paper, and has weaker protection effect on the interior of the paper. Chinese patent (202010197071.0) 'an amphiphilic cationic chitosan-phosphate starch composite reinforcement liquid for paper protection' uses chitosan and hydroxypropyl distarch phosphate as raw materials to prepare a paper protection reinforcement liquid, and the reinforcement liquid has good biocompatibility and degradability, good permeability and wettability to paper fibers, and can effectively improve the strength of paper cultural relics and delay the thermal aging of paper. Most of the currently used paper cultural relic protection liquid stays in the process of improving the strength and surface treatment, and the research on the ultraviolet aging resistance of paper is less, so that the research and development of the reinforcing liquid for paper cultural relic protection, which can improve the strength of the paper and has the ultraviolet aging resistance, has higher application value.

Disclosure of Invention

Aiming at the situation, in order to overcome the defects of the prior art, the invention aims to provide a preparation method and an application method of a water-based polyurethane acrylate-epoxy acrylate blended protection solution for protecting paper cultural relics, which can effectively improve the strength of paper of the paper cultural relics, delay the aging of the paper and realize the protection of the paper cultural relics.

The technical scheme adopted by the invention is that the aqueous polyurethane acrylate-epoxy acrylate blending protective solution for protecting paper cultural relics comprises the following components in parts by weight: 30 parts of waterborne polyurethane acrylate; 3-9 parts of epoxy acrylate; 0.6-0.8 part of photoinitiator; 20-26 parts of absolute ethyl alcohol; 80-104 parts of deionized water.

The invention solves the problems by the following technical scheme, and comprises the following steps:

1) weighing a certain weight part of waterborne polyurethane acrylate and epoxy acrylate in a three-neck flask, and placing the three-neck flask in a water bath to stir and disperse uniformly;

2) adding distilled water and ethanol in a certain mass ratio into a beaker and uniformly mixing;

3) slowly dripping the water/ethanol mixed solvent in the step 2) into the step 1), stirring at a high speed while dripping, and uniformly dispersing to realize the conversion from an oil phase to a water phase, thereby obtaining the water-based polyurethane acrylate-epoxy acrylate blended emulsion;

4) preparing the aqueous polyurethane acrylate-epoxy acrylate blended emulsion obtained in the step 3) into blended emulsions with different mass concentrations, adding a certain amount of photoinitiator, and carrying out ultrasonic mixing to obtain a paper cultural relic protection solution;

5) and (4) uniformly coating the paper cultural relic protection solution with different concentrations obtained in the step (4) on the simulated paper cultural relic rice paper, and curing the simulated paper cultural relic rice paper in an ultraviolet curing machine after the simulated paper cultural relic rice paper is hung and dried at room temperature to obtain a cured paper sheet.

Stirring the aqueous polyurethane acrylate and the epoxy acrylate in the step (1) in a water bath at the temperature of 30 ℃ for 15min, wherein the stirring speed is 250 r/min;

the epoxy acrylate content in the step (1) is 0-30% of the content of the waterborne polyurethane acrylate, and the mixing and stirring are continued in a water bath at the temperature of 30 ℃ for 30 min;

the mass ratio of the distilled water to the ethanol in the step (2) is 8: 2;

the stirring time in the step (3) is 1h, and the stirring speed is 800 r/min;

in the step (4), the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-acetone (Irgacure1173), and the content of the photoinitiator accounts for 2% of the total amount of the system.

In the step (5), the power of the ultraviolet curing machine is 2kw, and the curing time is 1 min.

The invention has the beneficial effects that:

the preparation method has simple preparation steps and easy operation, the adopted raw material water-based polyurethane acrylate contains hydrophilic groups, and the hydrophilic groups are used as a high-molecular emulsifier to be blended with the epoxy acrylate, so that no additional emulsifier is needed in the emulsification process, and the influence of the emulsifier residue on the product performance of a final product is avoided. The waterborne polyurethane acrylate takes water as a solvent, and has good heat resistance, weather resistance and flexibility; meanwhile, the epoxy acrylate has good water resistance and high curing speed, and can effectively solve the problems of poor water resistance and solvent resistance and the like of the waterborne polyurethane acrylate by blending with the waterborne polyurethane acrylate.

The molecular terminals of the raw materials of the water-based polyurethane acrylate and the epoxy acrylate contain carbon-carbon double bonds, and the carbon-carbon double bonds are easy to be excited and opened by ultraviolet light to generate crosslinking, and a hydrophobic network structure is formed among fibers to limit the water absorption and swelling of the fibers, so that the water resistance and the wet strength of paper sheets are improved, and meanwhile, the ultraviolet absorption property of the paper sheets can effectively resist the irradiation of the ultraviolet light and delay the aging of the paper sheets.

The invention can be effectively used for protecting paper cultural relics, can improve the strength of the paper cultural relics, plays a role in aging resistance, and is a novel method for preparing the paper cultural relic protection solution.

Drawings

FIG. 1 is an infrared spectrum of (a) a blank pattern, (b) a pattern coated with a protective solution, and (c) a pattern coated with a protective solution and cured by ultraviolet light. In FIG. 1(b), 1720cm appears in addition to the cellulose characteristic spectrum band in FIG. 1(a)^-1A peak of C ═ O stretching vibration, 1629cm^-1At a sum of 810.4cm^-1The stretching vibration peak of-C-indicates that the protective solution is successfully coated in the paper; 1629cm in FIG. 1(c)^-1At a sum of 810.4cm^-1The characteristic absorption peak of-C-is gradually weakened, which shows that the polymerization reaction of-C-under the irradiation of ultraviolet light is the principle of the strengthening of the rice paper.

FIG. 2 is a micro-topography of Xuan paper base paper (a), Xuan paper aged by ultraviolet light (b), Xuan paper coated with protective solution (c) and Xuan paper aged by ultraviolet light (d). After the rice paper is coated by the protective solution, the diameter of the fibers of the paper becomes thicker, the surface is smoother, and a polymer protective film is formed on the surface of the rice paper, so that the fibers in the rice paper are protected. After ultraviolet light aging, the surface of crude fiber in the rice paper body paper is wrinkled, the fillers in the fiber structure are reduced to some extent, and part of substances are drawn and adhered; and after the paper pattern treated by the protective liquid is aged, the fiber is thicker than the fiber aged by the blank paper pattern, and the fiber has no fracture phenomenon, which shows that the coated protective liquid can effectively inhibit the aging of the paper.

Fig. 3 shows the change of appearance of rice paper after being coated with a paper protective solution having a mass concentration of 15%. As can be seen from the figure, after the protective solution coating, the handwriting of the paper has no obvious change, namely, the dip coating does not influence the definition of the graph and text (paper appearance observation (a: blank rice paper; b: coated rice paper)).

Detailed Description

The following further describes embodiments of the present invention with reference to specific examples. These embodiments are merely illustrative of the present invention and are not intended to limit the scope of the present invention. In addition, after reading the teaching of the present invention, those skilled in the art can make various changes or modifications to the invention, and these equivalents also fall within the scope of the claims appended to the present application.

Example 1:

1) weighing 30 parts of waterborne polyurethane acrylate in a three-neck flask, and placing the three-neck flask in a water bath at 30 ℃ to stir and disperse uniformly;

2) adding 80 parts of distilled water and 20 parts of ethanol in a certain mass ratio (8:2) into a beaker, and uniformly mixing;

3) slowly dripping the water/ethanol mixed solvent in the step 2) into the step 1), stirring at high speed for 1h while dripping, and uniformly dispersing to realize the conversion from an oil phase to a water phase to obtain the water-based polyurethane acrylate-epoxy acrylate blended emulsion;

4) weighing 0.6 part of photoinitiator, adding the photoinitiator into the aqueous polyurethane acrylate-epoxy acrylate blended emulsion obtained in the step 3), and carrying out ultrasonic mixing to obtain a paper cultural relic protection solution;

5) respectively preparing the paper cultural relic protection solution obtained in the step 4) into solutions with the mass fraction of 0-25%, uniformly coating the solutions on the simulated paper cultural relic rice paper, flattening and drying at room temperature, curing for 1min in an ultraviolet curing machine, and taking out for later use.

Example 2:

1) weighing 30 parts of waterborne polyurethane acrylate and 3 parts of epoxy acrylate in a three-necked flask, and placing the three-necked flask in a water bath at the temperature of 30 ℃ to stir for 0.5h for uniform dispersion;

2) 88 parts of distilled water and 22 parts of ethanol in a certain mass ratio (8:2) are added into a beaker and uniformly mixed;

3) slowly dripping the water/ethanol mixed solvent in the step 2) into the step 1), stirring at high speed for 1h while dripping, and uniformly dispersing to realize the conversion from an oil phase to a water phase to obtain the water-based polyurethane acrylate-epoxy acrylate blended emulsion;

4) and then 0.66 part of photoinitiator is weighed and added into the water-based polyurethane acrylate-epoxy acrylate blended emulsion for ultrasonic mixing to obtain the paper cultural relic protection solution.

5) Respectively preparing the paper cultural relic protection solution obtained in the step 4) into solutions with the mass fraction of 0-25%, uniformly coating the solutions on the simulated paper cultural relic rice paper, flattening and drying at room temperature, curing for 1min in an ultraviolet curing machine, and taking out for later use.

Example 3:

1) weighing 30 parts of waterborne polyurethane acrylate and 6 parts of epoxy acrylate in a three-necked flask, and placing the three-necked flask in a water bath at the temperature of 30 ℃ to stir for 0.5h for uniform dispersion;

2) adding 96 parts of distilled water and 24 parts of ethanol in a certain mass ratio (8:2) into a beaker, and uniformly mixing;

3) slowly dripping the water/ethanol mixed solvent in the step 2) into the step 1), stirring at high speed for 1h while dripping, and uniformly dispersing to realize the conversion from an oil phase to a water phase to obtain the water-based polyurethane acrylate-epoxy acrylate blended emulsion;

4) and then 0.72 part of photoinitiator is weighed and added into the water-based polyurethane acrylate-epoxy acrylate blended emulsion for ultrasonic mixing to obtain the paper cultural relic protection solution.

5) Respectively preparing the paper cultural relic protection solution obtained in the step 4) into solutions with the mass fraction of 0-25%, uniformly coating the solutions on the simulated paper cultural relic rice paper, flattening and drying at room temperature, curing for 1min in an ultraviolet curing machine, and taking out for later use.

Example 4:

1) weighing 30 parts of waterborne polyurethane acrylate and 9 parts of epoxy acrylate in a three-necked flask, and placing the three-necked flask in a water bath at the temperature of 30 ℃ to stir for 0.5h for uniform dispersion;

2) adding 104 parts of distilled water and 26 parts of ethanol in a certain mass ratio (8:2) into a beaker, and uniformly mixing;

3) slowly dripping the water/ethanol mixed solvent in the step 2) into the step 1), stirring at high speed for 1h while dripping, and uniformly dispersing to realize the conversion from an oil phase to a water phase to obtain the water-based polyurethane acrylate-epoxy acrylate blended emulsion;

4) and then 0.78 part of photoinitiator is weighed and added into the water-based polyurethane acrylate-epoxy acrylate blended emulsion for ultrasonic mixing to obtain the paper cultural relic protection solution.

5) Respectively preparing the paper cultural relic protection solution obtained in the step 4) into solutions with the mass fraction of 0-25%, uniformly coating the solutions on the simulated paper cultural relic rice paper, flattening and drying at room temperature, curing for 1min in an ultraviolet curing machine, and taking out for later use.

The results of the papers treated with the protective solutions obtained in examples 1, 2, 3 and 4 according to the invention are shown in Table 1:

TABLE 1 Effect of different protective solutions on paper Properties

The dry and wet tensile strength test of the paper in the table is determined according to national standard GB/T12914-; the tearing degree of the paper is determined according to the national standard GB/T455-2002 of China; the whiteness of the paper is measured according to the national standard GB/T22879-2008.

Aging test: modern calligraphy rice paper is used for replacing simulated paper cultural relics, and a 365nm ultraviolet light accelerated simulated aging method is adopted, wherein the ultraviolet aging time is 48 hours. The comparison of the performance indexes of the rice paper treated by the protective solution with the mass fraction of 15 percent and the blank rice paper before and after aging is shown in Table 2:

TABLE 2 comparison of Performance index before and after UV aging of Xuan paper

Tests show that the strength of the paper is improved by coating the waterborne polyurethane acrylate-epoxy acrylate blended paper cultural relic protective solution on the rice paper and curing the cultural relic protective solution for 1min by ultraviolet light, wherein after the protective solution of the embodiment 1 is coated, the dry tensile strength of the rice paper is improved from 595N/M to 1240N/M, the wet tensile strength is improved from 85N/M to 638N/M, the tearing strength is improved from 50.3mN to 156.3mN, and the whiteness is only reduced by 3% compared with that of the blank rice paper; after the ultraviolet light is accelerated to age for 48 hours, the strength performance of the paper after aging treated by the protective solution is better than that of the paper after aging of blank rice paper, and the dry tensile strength is improved by 1 time; the wet tensile strength is improved by 7 times compared with that of blank rice paper after aging; the tearing strength is improved by 2 times.

In conclusion, the polyurethane acrylate containing hydrophilic groups and the epoxy acrylate are selected to be blended to prepare the synthetic paper cultural relic protection solution, so that the tensile strength and the tearing strength of the rice paper can be improved, the aging of the paper can be delayed, the preservation time of the paper cultural relic can be prolonged, the ornamental value and the research value of the paper cultural relic can be improved, the damage of heating and curing on the paper cultural relic can be avoided by the ultraviolet curing method, and the ultraviolet curing method has high operability.