KR101088361B1 - Improved Method of Polymer Impregnation Process for Stones by Using Surface Treatment Agent - Google Patents

Abstract

The present invention relates to an easy removal of residual material remaining on the surface by applying a treatment agent to the surface of the stone cultural heritage material in the preservation process of impregnating and polymerizing the monomer compound in the stone cultural property to preserve the damaged stone cultural property, more specifically It is a surface treatment agent of stone cultural properties as a pretreatment process and contains a perfluoro alkyl group with an average molecular weight of 1,000 to 10,000. It is a fluorine-based water-repellent agent with ionic functionalities, and has the same polarity as water or alcohol having 1-2 carbon atoms. The method of coating the surface of the stone prior to monomer impregnation with a surface treating agent which dissolves 0.5 to 10 wt% in a solvent to apply the surface of the stone is directed to a technique for facilitating removal of residues remaining on the surface of the rock. When the present invention is used in the preservation process of the masonry, there is an advantage that it is possible to easily remove foreign substances or residues, and also increase the water repellency of the treated masonry.

Masonry, Preservation, Impregnation, Surface Treatment, Water Repellent, Fluorine Compound

Description

Improved Method of Polymer Impregnation Process for Stones by Using Surface Treatment Agent}

The present invention relates to an easy removal of residual material remaining on the surface by applying a treatment agent on the surface of the stone cultural heritage material in the preservation process of impregnating and polymerizing the monomer compound in the stone cultural property to preserve the damaged stone cultural property.

The present invention is to impregnate monomer by applying pressure in monomer impregnation treatment technology, especially pressurized vessel, which is proposed as one of the preservation treatment technology of all the stone products, among which the stone cultural property, which is composed of naturally obtained rock. The present invention relates to a process improvement method of a preservation technology in which a polymer material is finally impregnated through polymerization. Specifically, when using the impregnation treatment agent and the adhesive or reinforcing agent for the preservation treatment of the stone as described above, the present invention relates to a technology that facilitates the removal of residues remaining on the surface of the rock after the treatment. In more detail, as a preservation treatment technology of stone cultural properties, when silicate-based water-repellent or acrylic monomers are used to repair cracks, peeling and dropping of rocks, or to improve water repellency and physical properties of rocks, they are formed on the surface after polymerization. It is a technology that facilitates the removal of foreign substances or residues and improves the water repellency of stone cultural properties. According to the previous technology, the water-repellent curing treatment technology using acrylic polymer developed by JBach of Germany shows that foreign substances are deposited on the surface of the rock by applying the animal glue to the surface of the rock in the impregnation process of the water-repellent hardener and removing it after treatment. The technique which does not remain is used. However, after the impregnation treatment, the glue on the surface of the rock may remain, and the remaining glue is a foreign substance, which may cause decay in a humid environment, which may adversely affect the surface of the rock such as weathering due to biochemical contamination. In practice, however, complete removal is not easy. However, according to the present invention, the removal of foreign matter remaining on the rock surface after the water-repellent hardening treatment can be almost perfect and easy and can be achieved and remaining on the rock surface after the impregnation treatment has the advantage that can be improved rather than water repellency.

An object of the present invention is an improved polymer impregnation treatment method of a stone using a surface treatment agent for the preservation treatment of damaged stone cultural properties in the stone culture agent treatment method in which the polymer material is impregnated by applying a pressure in the pressure vessel to impregnate and polymerize the monomer. After the impregnation of monomer in the stone to facilitate the removal of the foreign matter applied to the surface of the stone.

The present invention is to be used on the surface before impregnating the treatment agent, that is, the monomer for preservation treatment in order to achieve the above object and at the same time do not interfere with the impregnation of the monomer should be made to effectively impregnate the surface after polymerization of the impregnated monomer It is the selection of surface treatment agent to be able to easily remove the remaining foreign substances and to finish the preservation treatment without removing the surface treatment agent after the impregnation treatment process is completed.

It is a surface treatment agent of stone cultural properties as a pretreatment process and contains a perfluoro alkyl group with an average molecular weight of 1,000 to 10,000. It is a fluorine-based water-repellent agent having an ionic functional group. The present invention relates to a method of applying a surface treatment agent which dissolves 0.5 to 10 wt% in a solvent to apply a stone surface to a surface of a stone before monomer impregnation.

In the pressure impregnation process in which the acrylic monomer is impregnated into the rock using pressure, the impregnation effect is not lowered, and the polymer foreign substances generated after the polymerization process are easily removed from the stone surface from the monomer remaining on the surface after the impregnation. As a result, it is possible to prevent discoloration due to the polymer material remaining on the surface, thereby minimizing the change in the intrinsic color of the stone. Thus, the pressure impregnation treatment technology has been improved as a preservation treatment technology of stone, in particular, a preservation treatment technology of cultural properties. In addition, the last remaining surface treatment agent as a side effect serves to improve the water repellency to block the weathering element of the rock.

Referring to the configuration of the present invention in detail as follows.

The improved polymer impregnation treatment method of the stone using the surface treatment agent for the preservation treatment of the damaged stone cultural property according to the present invention is a stone material in the stone culture agent treatment method in which the polymer material is impregnated by applying the pressure in the pressure vessel to impregnate and polymerize the monomer. Before impregnating the monomer in the masonry to apply a solution-like surface treatment agent to facilitate the removal of residual foreign matter on the surface of the masonry.

In addition, it is appropriate to have affinity with some rock constituents while having a low affinity with a damage inhibitor of a stone such as water while having an appropriate functional group in the molecular structure. However, they should not directly react with the constituents of the rock, adversely affecting the rock tissue and causing no damage.

As a surface treatment agent that can satisfy these conditions, the water-repellent agent applicable to the surface of the stone can be divided into fluorine-based and silicon-based.Since the silicon-based group has a strong affinity with the silica component which is the main component of the rock After treatment, effective removal is difficult or the components are denatured, which may cause discoloration or structural degradation. The water repellent effect is relatively lower than that of fluorine. However, the fluorine-based water repellent is not only a water repellent effect but also affinity with rocks and other polymer impregnated materials and can be properly removed from the surface can be said to be a more effective surface treatment agent for treatment before impregnation for the purpose of the present invention.

Fluorocarbon chains with respect to hydrocarbon chains in fluorine-based water repellents have very high surface activity, which significantly reduces surface free energy. This is because of the strong water repellent effect. In other words, when the surface of the stone is covered with -CF ₃ or -CF ₂ , it exhibits a much larger contact angle θ than the surface covered with -CH ₃ or -CH ₂ .

The contact angle is the angle formed by the surface when it is thermodynamically balanced on the surface, and the angle varies depending on the state of the surface and the type of liquid. Therefore, the contact angle shows the surface energy and the degree of uniformity and hydrophilicity of the surface. Therefore, fluorine-based water repellent should have sufficient water repellency to maintain the contact angle to water more than 60 degrees. In addition, it must have heat resistance at 200 ℃ to withstand the vacuum oven which is the impregnation process of masonry.

 The surface treatment agent has small surface energy, excellent water repellency, moderate molecular weight, high molecular weight enough to not penetrate into the capillary or rock through which monomer penetrates, and remains after impregnation treatment, so it is in contact with water, which is the most damaging factor of masonry. It should be possible to prevent weathering by water repellent function. Therefore, the average molecular weight is 1,000 to 10,000, more preferably 1,500 to 3,000 compound containing a perfluoro alkyl (perfluoro alkyl) group is characterized in that the fluorine-based water-repellent agent having an ionic functional group. When the molecular weight of the fluorinated water-repellent agent is more than 10,000, it is relatively inexpensive and does not dissolve well in a solvent such as alcohol or water, which does not adversely affect the treated object. Therefore, it is difficult to find other suitable solvents and is uniform due to its high viscosity at the effective concentration. One surface coating is difficult and there is a problem that does not have sufficient adhesion to the surface of the stone to be treated.

Part of the molecular chain of the fluorine-based water-repellent agent has an ionic functional group to maintain proper affinity with the surface constituents of the material to be treated and does not penetrate deeply into the treatment material without interfering with the impregnation of the subsequently impregnated material. Water repellency by functional groups.

The fluorine-based water-repellent is dissolved in a polar solvent such as water or carbon atoms of 1-2 alcohols in 0.5 ~ 10wt%, it is also excellent in convenience because it can be applied to the surface of the stone as a low viscosity solution. If the polar solvent is used in an amount of 0.5 wt% or less, sufficient releasability may not be exhibited in the removal of monomers and polymers that may have surface retention and adhesion, and at the same time, there may be a decrease in water repellent effect. On the other hand, when it is used more than 10wt%, it is difficult to apply uniform surface by simple method such as brushing or spraying as viscosity increases due to high concentration, and harmful effect and expensive that can occur as too much amount remains on the surface for a long time The waste of the surface treatment agent is concerned.

The solution in which the fluorine-based water repellent is dissolved in a polar solvent is applied to the surface of the stone culture material by brushing or spraying to perform impregnation treatment.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are intended to illustrate the present invention and do not limit the present invention.

1. Experimental Materials

The rock specimens are granite which is most used as a material of stone cultural property, and it uses P-stone produced in Pocheon-si, Gyeonggi-do, and N-stone weathered in Namsan area in Gyeongju-si. The size of the specimen was used by cutting into a cube cube for impregnation test of 50 × 50 × 50mm. As the impregnation agent, methyl methacrylate (MMA), an acrylic monomer, was used. As an initiator, benzoyl peroxide (BPO) of peroxide type was used as a radical initiator. The monomer and the initiator were used as they were without purification. The surface treating agent was dissolved in ethanol by dissolving a perfluorinated alkyloxy oligomer (Solvay Solexis, Fluorolink F-10) having an average molecular weight of 2,400 to 3,100, to give a surface treating agent solution of about 10% concentration (hereinafter referred to as "F-10"). It was prepared and used.

2. Impregnation of polymer through monomer impregnation and polymerization

Experiments were carried out using rock specimens completely dried in a vacuum oven. The dried specimen was cooled to room temperature in the absence of moisture, and then applied with F-10 twice using a spray. When the specimen was prepared, the weight was measured to determine the weight before impregnation. The initiator was dissolved in 1wt% of the monomer to make a solution, and the resulting solution was stored in a refrigerator to keep it as safe as possible. Rock specimens and monomers were placed in a container and placed in an autoclave designed to withstand a maximum pressure of 35 atm and then slowly pressurized at 6 atm for 12 hours. The impregnated rock specimens were removed with the monomer on the surface, wrapped with aluminum foil, and sealed using a bag and a zipper bag. The sealed rock specimens were polymerized in a water bath at 70 ° C. for 8 hours to impregnate the polymer with pores in the rock.

3. Results

(1) release

During the polymerization process after impregnating the acrylic monomer, a phenomenon that the monomer remaining on the surface of the rock or flowing out from the inside is polymerized and coated on the surface occurs. If this happens, it should be removed from the rock surface to prevent any heterogeneity. However, the impregnating agent polymerized between the micropores of the rock is not easy to remove. To compensate for this, the fluorine-based surface treatment agent F-10 was treated on the rock surface, and then B72 was coated on the surface and then removed to examine the releasability. 1 is a photograph comparing the releasability by surface treatment of F-10 on the rock. F-10 untreated specimens did not drop B72 completely on the rock surface, but fell well on rocks impregnated with F-10. It can be seen that when F-10 is applied to the rock surface before the impregnation treatment, it is easy to remove the residual polymer material on the surface.

(2) water repellency

F-10 is a material that can be used as a water repellent such as metal, stone, and paper. Especially, when F-10 is treated on the surface of a ceramic material such as rock, a good water repellent effect can be expected. 2 is a measurement of the contact angle with water of the untreated rock specimens and F-10 surface treatment specimens. It was confirmed that the contact angle of the F-10-treated rock specimens increased by about 1.6 times.

3 is a result of measuring the water absorption rate of pocheonseok. Untreated rock reached saturation absorption in about 2 days, while Pocheon stone treated with F-10 showed lower than saturation water absorption after 10 days. The water absorption rate and the rate of absorption were lowest for the specimens which were simultaneously impregnated with F-10 and polymethyl methacrylate (PMMA).

4 is a result of measuring the water absorption of Namsanite. Untreated rock specimens are close to saturation absorption in about two days. F-10-treated specimens had water repellency and approached saturated water absorption only after 5 days. Since Namsan stone has a larger pore size than Pocheon Stone, F-10 could not expect good water repellency only by repulsive force on the surface. The impregnated specimens, on the other hand, had PMMA filling the pores, preventing the absorption of water from the source, causing the water absorption rate to drop below about 50%. The specimens treated with F-10 and PMMA showed the lowest water absorption.

(3) impregnation

Pocheon and Namsan rock specimens were treated with F-10 and polymerized after impregnation with MMA. Table 1 shows the change in impregnation rate of rock specimens according to F-10. In both Pocheon and Namsan, F-10 treated specimens showed lower PMMA impregnation rates than F-10 untreated specimens. F-10 occupies a portion of the pores where MMA is impregnated on the surface, which reduces the amount of PMMA impregnated.

Table 1.

Impregnation rate%  Before polymerization  After polymerization   Pocheon Stone   F-10 untreated 0.31% 0.28%   F-10 treated 0.33% 0.27%   Namsan   F-10 untreated 1.73% 1.42%   F-10 treated 1.54% 1.32%

On the other hand, it is easy to remove the residues generated on the surface and has the property of having a uniform color. 5 is a view showing the surface characteristics according to the F-10 treatment. As shown in the figure, the F-10 treated specimens had a uniform color and were easy to remove residues, whereas the F-10 untreated specimens were difficult to remove.

1 is a photograph showing a comparison of the surface release property of the surface treatment agent treated and untreated rock specimens.

Figure 2 is a photograph measuring the contact angle of the rock specimens according to the surface treatment agent treatment.

Figure 3 is the change in water absorption rate of F-10 treated Pocheonseok (P-stone) with time.

Figure 4 is a change in water absorption rate of F-10 treated N-stone (N-stone) over time.

5 is a surface photograph of F-10 treated and untreated P-stone.

Claims (3)

In the stone culture agent preservation treatment of impregnating and polymerizing the monomer by applying a pressure to the stone culture agent so as to impregnate the inside of the stone,  As a surface treatment agent of stone cultural properties as a pretreatment process, it contains a perfluoro alkyl group having an average molecular weight of 1,500 ~ 3,000. It has an ionic functional group and has heat resistance at 200 ° C. A fluorine-based water-repellent agent that can maintain a contact angle of 60 degrees or more. A surface treatment agent which is dissolved in water or a carbonaceous solvent such as 1-2 alcohols by about 0.5 to 10 weight percent and applied to the stone surface is applied to the surface of the stone before monomer impregnation. How to. delete delete

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