阅读说明：本技术 一种基于纳米氢氧化钙的壁画表面聚丙烯酸树脂清除用有机凝胶及其制备方法 (Organic gel for removing polyacrylic resin on surface of mural based on nano calcium hydroxide and preparation method thereof ) 是由 李炫华 朱金萌 于 2020-06-12 设计创作，主要内容包括：本发明涉及一种基于纳米氢氧化钙的壁画表面聚丙烯酸树脂清除用有机凝胶及其制备方法,将纳米氢氧化钙和环氧树脂加入乙酸乙酯溶液中搅拌静止12-24h即制成聚丙烯酸树脂清洗凝胶。制备方法极为简单,省时、不需加热且成本低。在制备过程中,纳米氢氧化钙与乙酸乙酯反应生成乙酸钙作为交联剂从而促进凝胶形成。乙酸钙不仅无毒,且是一种食品防腐剂,极大提高了该凝胶的安全性。清除壁画表面聚丙烯酸树脂聚合物的实验表明,其去除率可达95％以上。另外,根据壁画表面聚丙烯酸树脂量,可以从70％-85％灵活调整乙酸乙酯的百分含量,以便获得最佳清洗效果。该凝胶具有极好的工业生产前景,且可推广到其他文物如石质和纸质文物表面高分子聚合物的清洗中。(The invention relates to a nano calcium hydroxide-based organic gel for removing polyacrylic resin on the surface of a mural and a preparation method thereof, wherein nano calcium hydroxide and epoxy resin are added into an ethyl acetate solution, stirred and stood for 12-24h to prepare the polyacrylic resin cleaning gel. The preparation method is extremely simple, time-saving, free from heating and low in cost. In the preparation process, the nano calcium hydroxide reacts with ethyl acetate to generate calcium acetate as a cross-linking agent so as to promote the formation of gel. The calcium acetate is not only non-toxic, but also is a food preservative, and the safety of the gel is greatly improved. Experiments for removing polyacrylic resin polymers on the surface of the mural show that the removal rate can reach more than 95%. In addition, according to the amount of polyacrylic resin on the surface of the mural, the percentage content of the ethyl acetate can be flexibly adjusted from 70% to 85% so as to obtain the best cleaning effect. The gel has excellent industrial production prospect and can be popularized to the cleaning of high molecular polymers on the surfaces of other cultural relics such as stone and paper cultural relics.)

1. The organic gel for removing the polyacrylic resin on the surface of the mural based on the nano calcium hydroxide is characterized by comprising 10-20% of the nano calcium hydroxide, 5-10% of epoxy resin and 70-85% of ethyl acetate in percentage by mass.

2. The method for preparing the organic gel for removing the polyacrylic acid resin on the surface of the mural based on the nano calcium hydroxide according to claim 1, which is characterized by comprising the following steps: adding the nano calcium hydroxide powder and the epoxy resin into an ethyl acetate solution, stirring for 30min, and standing for 12-24h to obtain the organic gel for removing the polyacrylic resin on the surface of the mural based on the nano calcium hydroxide; the mass fractions of the nano calcium hydroxide, the epoxy resin and the ethyl acetate are respectively 10-20%, 5-10% and 70-85%.

3. The method of claim 2, wherein: the nano calcium hydroxide powder is prepared by a method with the patent number of 201711361358.7 d.

Technical Field

The invention belongs to the technical field of ancient mural protection materials, and relates to a nano calcium hydroxide-based organic gel for removing polyacrylic resin on the surface of a mural and a preparation method thereof.

Background

The polyacrylic resin is a mural organic polymer protective material which is widely used at home and abroad. The material has the advantages of strong adhesion, simple construction, small influence on mural color and the like (Chinese cultural relics, 2004,01,81-86), and has good effect on repairing and protecting national murals such as Dunhuang murals, India, Italy and the like in China at present. However, the material is easy to age, turn yellow and become brittle, so that the mechanical property is reduced and even the material fails; after a long time a secondary reinforcement is needed, and the aged material has a very negative effect on the secondary reinforcement and therefore needs to be removed. Since the protection concept lags behind, the mural is protected by sealing polyacrylic resin in the last century, so that the surface of the mural is covered by a layer of polyacrylic resin film, the film is not breathable, the water vapor exchange between the interior of the mural and the outside is blocked, and the mural expands and pulverizes for a long time, so that the mural is urgently needed to be removed. In addition, when polyacrylic resins are used to reinforce murals, excessive material removal is required because improper or careless application of such materials can cause glare on the murals and thus affect the ornamental value of the murals. Polyacrylic resin is needed in most cases in the process of removing murals, and the murals need to be removed after being removed and entering the room for restoration.

The current methods of removal are as follows: (1) the cotton swab dipped with ethyl acetate is used for wiping, the method has extremely low efficiency and poor effect, and care must be taken to avoid influencing the mural; (2) by utilizing microemulsion, the microemulsion contains cleaning agent such as ethyl acetate, experiments prove that the microemulsion has excellent cleaning effect and high efficiency on polyacrylic resin, however, the system contains a large amount of water and surfactant, and easily causes damage to murals (adv. colloid. interface Sci.2014,205, 361-371); (3) the preparation principle of the organogel is that macromolecules are connected with each other by using a cross-linking agent to form a network structure, a cleaning agent is coated in the network while the gel is formed, water and a surfactant are not used in the preparation of the organogel, the cleaning effect is good, the removal rate is high (more than 80%), but the preparation is very complex and time-consuming, an inert gas is used, heating is needed, the preparation process needs repeated cleaning (24 hours are needed for cleaning each time), at least 4-5 days are needed for successfully preparing the cleaning gel, in addition, the content of the cleaning agent in the gel can only be calculated through a finally prepared gel finished product and cannot be adjusted in advance, and more importantly, the cross-linking agent used for preparing the gel has high toxicity (appl. Phys. A2015,121, 857-868).

Disclosure of Invention

Technical problem to be solved

In order to avoid the defects of the prior art, the invention provides a nano calcium hydroxide-based organic gel for removing polyacrylic resin on the surface of a mural and a preparation method thereof.

Technical scheme

The organic gel for removing the polyacrylic resin on the surface of the mural based on the nano calcium hydroxide is characterized by comprising 10-20% of the nano calcium hydroxide, 5-10% of epoxy resin and 70-85% of ethyl acetate in percentage by mass.

The preparation method of the organic gel for removing the polyacrylic acid resin on the surface of the mural based on the nano calcium hydroxide is characterized by comprising the following steps: adding the nano calcium hydroxide powder and the epoxy resin into an ethyl acetate solution, stirring for 30min, and standing for 12-24h to obtain the organic gel for removing the polyacrylic resin on the surface of the mural based on the nano calcium hydroxide; the mass fractions of the nano calcium hydroxide, the epoxy resin and the ethyl acetate are respectively 10-20%, 5-10% and 70-85%.

The nano calcium hydroxide powder is prepared by a method with the patent number of 201711361358.7 d.

Advantageous effects

The invention provides a nano calcium hydroxide-based organic gel for removing polyacrylic resin on the surface of a mural and a preparation method thereof, which are characterized in that nano calcium hydroxide and epoxy resin are added into an ethyl acetate solution, stirred and kept still for 12-24 hours to prepare the polyacrylic resin cleaning gel. The preparation method is extremely simple, time-saving, free from heating and low in cost. In the preparation process, the nano calcium hydroxide reacts with ethyl acetate to generate calcium acetate as a cross-linking agent so as to promote the formation of gel. The calcium acetate is not only non-toxic, but also is a food preservative, and the safety of the gel is greatly improved. Experiments for removing polyacrylic resin polymers on the surface of the mural show that the removal rate can reach more than 95%. In addition, according to the amount of polyacrylic resin on the surface of the mural, the percentage content of the ethyl acetate can be flexibly adjusted from 70% to 85% so as to obtain the best cleaning effect. The gel has excellent industrial production prospect and can be popularized to the cleaning of high molecular polymers on the surfaces of other cultural relics such as stone and paper cultural relics.

Compared with the prior art, the preparation process of the organic gel for removing the polyacrylic acid resin on the surface of the mural based on the nano calcium hydroxide is extremely simple, time-saving, low in energy consumption and low in cost. More importantly, the gel takes calcium acetate generated in the reaction process as a cross-linking agent, and is non-toxic and high in safety. The cleaning result shows that the removal rate of the gel on polyacrylic resin on the surface of the mural can reach more than 95 percent, and the gel shows excellent effect. Meanwhile, the content of the ethyl acetate scavenger can be flexibly adjusted according to the amount of the polyacrylic resin on the surface of the specific mural, so that the best cleaning effect can be obtained. From the practical production perspective, the material has good industrial production application prospect. Meanwhile, the polyacrylic resin scavenging gel based on the nano calcium hydroxide on the surface of the mural can be popularized to the organic polymer cleaning of other cultural relics such as stone, paper and the like.

Detailed Description

The invention will now be further described with reference to the examples: