• 보존과학연구
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• s.29
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• pp.65-90
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• 2008

This study examines the status and the physical features of Paraloid B-72 layers with examination of microstructure and analysis of organic matters. Paraloid B-72 layers were coated on samples from the colour layer of outer wall painting in Mireuk hall in Geumsan temple. On the basis of the previous examination result, it has made the samples which are similar to outer wall in Mireuk hall in Geumsan temple. The samples can be divided into two, one; 5% Paraloid B-72 coating and another is without coating. Then samples have been experimented under the compulsive environments of infrared radiation and immersion, thereafter compared the results of the damages and physical features between two samples. As a result of the comparison, the sample with Paraloid B-72 had more serious cracks, exfoliations and peeling layers than that of without Paraloid B-72. Otherwise, in the examination of ultraviolet radiation, the sample with Paraloid B-72 coating showed weaker physical properties, less density in structure of colour layer and less hardness in surface of colour layer than the sample without coating. The percentage of moisture content after the ultraviolet radiation was higher in the sample without Paraloid B-72 than the sample with Paraloid B-72 coating. Observing the conditions before the ultraviolet radiation, the sample with Paraloid B-72 coating demonstrated lower rate in moisture evaporation rate than the sample without Paraloid B-72. As a consequence, in examination of this samples, the change of physical features are increased in the sample with Paraloid B-72 coating than that without Paraloid B-72 when compulsive environment of heat, moisture and ultraviolet rays for a short term are imposed.

• Korean Journal of Heritage: History & Science
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• v.50 no.3
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• pp.88-109
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• 2017

As the technique to remove Paraloid B-72, which is known as an irreversible material, the method using organic solvent and heating, though the ways vary depending on the kind of material to be removed, has been usually used, but it has yet to apply to mud mural because of the technical limit in processing and the potential risk of damage and, moreover, the removal efficiency which also remains unproven. Thus, in a bid to seek the way to safely remove Paraloid B-72 contained in mural, the test was conducted in a way of applying a compress method, which is deemed most efficient. The solvents which are proven to be Paraloid B-72 were applied to the absorbents such as active carbon fiber and methyl cellulose and then were eluted to the surface of mud mural sample which was prepared in the same size and condition for a certain time before evaluating the stability and removal efficiency. Such test was intended to identify the applicability to the mural of Mireukjeon Hall at Geunsansa Temple, which had been treated with Paraloid B-72 for preservation in the past. As a result, the way of mixing the absorbent such as active carbon fiber and Xylene alone or with other quick vaporable solvents proved to be most efficient in removing Paraloid B-72 from mud mural and particularly Acetone:Xylene(1:1wt%) was found to be the most stable among others. Such a test outcome is expected to be a useful data for removing Paraloid B-72 from the mural of Mireukjeon Hall at Geunsansa Temple as well as for restoring other mural cultural assets in the coming days.

• 보존과학연구
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• s.29
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• pp.183-197
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• 2008

Paraloid B-72 of acrylic resins has been widely used as consolidant for bronze artifacts conservation. In previous study, xylene was appropriate for paraloid B-72 when bronze artifacts consolidated. In this study, we compared the coating properties of paraloid B-72 in various concentration levels. The surface before and after coating were observed by optical microscope and AFM. Thickness and adhesive strength of films were tested. For testing coating stability, we performed yellowing test and EIS. After these experiments, we concluded 15wt% paraloid B-72 was adequate concentration for bronze artifacts conservation when paraloid B-72 used in xylene as solvent. Because 15wt% paraloid B-72 has the lowest polarity and high hydrophobic.

• Journal of Conservation Science
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• v.22
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• pp.61-76
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• 2008

We examined characterizations of Paraloid B72 films when it dissolved in four different solvents-acetone, MEK, toluene and xylene. The surface before and after coating were observed by optical microscope and AFM. Thickness and contact angle of films was measured and surface energy was calculated for grasping properties of films. We also tested adhesive strength of films by scratch tester and durability of films by performing yellowing test. The result was that xylene has better coating property than other solvents. Because 10% Paraloid B72 in xylene film is even, non-mottled, thin, stabilized in yellowish and has proper hydrophobic, we confirmed xylene is good solvent for bronze artifact conservation. However, other tests will need for finding appropriate concentration of Paraloid B72.

• 한국문화재보존과학회:학술대회논문집
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• 2007.10a
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• pp.43-45
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• 2007

• Journal of Conservation Science
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• v.34 no.6
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• pp.569-580
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• 2018

The possibility of applying poulticing was studied for removing Paraloid B72, a resin used for fixing an earthen mural painting. Five types of poultices were selected from clay and gel types, and acetone, ethanol, and methyl ethyl ketone(MEK) were used as mixed solvents. The possibility of mixing between the poultice and solvent was investigated, and then the spreadability, fluidity, acidity, drying properties, and solubility of the poultices were examined to confirm the characteristics. A poultice agent, which is suitable for applying to a mural painting, was selected and applied to a painting layer sample coated with Paraloid B72. As a result, all painting layers were good condition at under 50% of the solvent. The removal efficiency of Paraloid B72 was more effective when most of the solvents were used at 50%, rather than at 25%. However, it is difficult to mix 50% of MEK and ethanol with the gel-type poultices. When used at 25%, the removal performance was poorer than that at 50%, but the mixing with all the poultices was successful. In addition, the adsorption and removal power of the gel-type poultice were better than those of the clay-type, but the latter was expected to be more suitable in short-time cases due to its high drying speed. The results of this study show that the dissolution performance varies depending on the poultices and solvents. Hence, the poultice and solvent should be selectively applied, considering the fixative of the mural to be removed.

• Journal of Conservation Science
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• v.27 no.2
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• pp.135-144
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• 2011

When metal artifacts have to undergo conservation treatment, the person in charge of the treatment selects and uses various coating mixtures based on his judgment regarding their condition, material, or environment. Since the kinds of coating mixtures or solvents make a difference in the set time of cyanoacrylate adhesives, they have something to do with the efficiency of the conservation treatment. This study examines the effects and causes that affect the set time of cyanoacrylate adhesives according to the kinds of coating mixtures and solvents and suggests ways to increase the set time. As a result, it is thought that as the surface roughness gets flatter, the wettability of adhesive is improved further, which increases the set time. Moreover, the C-F binding of V-Flon, C-O-C absorption peak, molecular weight of the coating mixtures, and glass transition temperature (Tg) were the factors that significantly affected the set time. According to the result of measuring the set time based on the result of superficial and chemical analysis, relative difference was shown according to the kind and viscosity of adhesive, but all the adhesives indicated the following order of the set time: V-Flon > Paraloid B-72 (in xylene) > Paraloid NAD-10 > Paraloid B-72 (in acetone).

• Journal of the Korean Society of Costume
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• v.57 no.9
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• pp.67-75
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• 2007

The purpose of this research is to conserve of golden decoration(Jikgeumdan) of Chima(skirt) and Jeogori(Korean jacket) of the costumes excavated from Hangju Gi' tomb(17th Century) of Joseon dynasty$(1392{\sim}1910)$ and to focus on the development of conservation skill to prevent flakings of gold leaves in gilt paper strips. Up to the present, in case of golden decorations of costumes excavated from tombs of Joseon dynasty, some of gold leaves in gilt paper strips of costumes were flaked away by deterioration of adhesives in tombs. However, most of gold leaves were flaked away and totally lost by wet cleaning for eliminating contaminants after excavation. In order to prevent flaking, preliminary experiments for re-adhesion of gold leaves have been carried out. Firstly, simulation was performed using gold leaf which was available in the market. Adhesives used in this research were water-soluble adhesives(hide glue(cow, rabbit), glue made from air bladders of sciaenoid fish and Primal AC-3444 of acrylic emulsion) and solvent-soluble adhesives(acrylic adhesive Paraloid B-67 and B-72). Because of difficulty in wetting and spreading of adhesive solutions into the interface between gold leaf and Korean paper, water-soluble adhesives were not proper for adhesion of gold leaf and Korean paper. Solvent-soluble adhesives were easily infiltrated into interface between gold leaf and Korean paper and the adhesive force was also satisfied. From this result, the researchers chose more flexible Paraloid B-72$(Tg\;40^{\circ}C)$ 1% solution than Paraloid B-67$(Tg\;50^{\circ}C)$ for adhesion of gold leaf and Korean paper. Secondly, using Paraloid B-72 1% solution, the estimations of re-adhesions of gold leaves in gilt paper strips of Jeogori were carried out. When Paraloid B-72 1% solution was injected three times into the interface between gold leaf and Korean paper, the re-adhesion was most effective. On the basis of the results in these preliminary experiments, re-adhesions of gold leaves in gilt paper strips of Chima and Jeogori were carried out on condition of three times injections of Paraloid B-72 1% solution before wet cleaning. After wet cleaning, the most of the gold leaves were survived, which was confirmed by both the examination with the naked eye and the microscopic examination.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.8
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• pp.1315-1324
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• 2009

This study is on the consolidation process of the conservation process of fabric with golden thread found in relics. Gold film was glued to pieces of Korean paper and satin using hide glue, which is a natural adhesive and resin Paraloid B-72, which is a liquid type adhesive. This study examines the types and concentration of the adhesives that are appropriate for consolidating gold film on fabric. The advantage of hide glue is that it is harmless to humans and has a high stability. This glue is also believed to be the closest to the adhesive that was used when the relic was originally made. Its weakness is that it is stiff and weaker than chemical glues, but after being washed with water the adhesion level increases. Therefore, hide glue is appropriate in the following instances: a) when washing after consolidation b) when the substrate of gold threads are significantly damaged, and c) when treating greater sized relics that take a longer time to work on. However, Paraloid B-72 has a better adhesion and flexibility than hide glue, but tends to spread out into a greater area, and the area where it is applied tends to absorb less water than before the application. In addition, it is noxious and can be harmful in long-term exposure. Therefore, Paraloid-72 is appropriate in the following instances: a) when consolidating the fabric after washing, and b) when working on smaller relics and consolidating smaller parts of a relic. The necessary concentration levels for consolidants for gold film are 30% for liquid type hide glue and at least 10% for Paraloid B-72 in order for the gold film to stay intact on the fabric during washing, consolidation, exhibition, and conservation.

• 보존과학연구
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• s.21
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• pp.77-99
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• 2000

Tumuli located in Chodang-dong in Kangreung City are sitesexcavated by the Museum of Kangreung University in 1993.Ofthese sites, a gilt bronze crown and gilt bronze sword with ring pommel with a tri-leaf ornament were excavated from the B-16tumulus. Underneath the gilt bronze crown was the gilt bronzes word with ring pommel with tri-leaf ornament, and these artifacts were treated with Polyurethane foams on the spot followed by special measures for conservation. This manuscript describes measures for conservation andanalysis with regard to the gilt bronze crown, gilt bronze sword with ring pommel with tri-leaf ornament and gilt bronze beltornaments. Bronze on the gilt bronze crown was completely corroded, therefore it was consolidated together with soil in the back of the artifact with Paraloid B72 after cleaning. Polyurethanefoams bottom was finished by applying the mixture of Epoxy resinAW106 and HV935K with soil. On the sword with ring pommel, the wooden part of the hilt was coated with Paraloid B72 (in Xylene) and the blade was consolidated with Paraloid NAD-10 30% after desalting with Sodium sesquicarbonate method. The gilt bronzebelt ornaments were treated with 3% Benzotriazole, coated with Paraloid B72 and then joined by using Cyanlacrylate. Specimens for the gilt bronze crown and gilt bronze belt ornaments were produced and gilding layers were examined under a metallographic microscope. The gilt bronze crown and the gilt bronze belt ornament maintained relatively good gilding quality with uniform gilding layers. Analysis of wood for the sheath of the sword with ring pommel revealed it to be Juglans mandshurica. Further more, analysis of constituents for a blue colored grassbead from dissolution of Polyurethane foams found it to be from the $Na_2O$-CaO-$AI_2O_3$-$SiO_2$ family.