KR20190126508A - Method for separating the highly luminous nacre of shell using hydrochloric acid and acetic acid - Google Patents

Abstract

The present invention relates to a method for separating a shell nacreous layer having a high gloss, which can obtain a nacreous layer by treating the same with a mixed solution of hydrochloric acid and acetic acid. By using the method, it is possible to separate the nacreous layer having an intact appearance, thereby being able to provide household goods, furniture, sculptures, accessories manufactured by the nacreous layer, and cosmetic raw material manufactured by pulverizing the nacreous layer.

Description

Method for separating the highly luminous nacre of shell using hydrochloric acid and acetic acid}

The present invention relates to a shell nacre separation method characterized in that the shell is treated with a mixture of hydrochloric acid and acetic acid to obtain a nacre with high gloss.

The shell with nacres consists of three layers: the stratum corneum, the rhomboid layer, and the nacre layer. The stratum corneum (periostracum) consists of a thin outer epidermis called conchiolin. The prismatic layer is the white part of the middle layer, which is composed of crystals of calcium carbonate, and the various beautiful colors that appear on the shell surface are mainly represented by. The nacre layer is the inner layer of the shell, which consists of multiple thin layers and is glossy and composed of calcium carbonate and conchiolin.

Due to the stratum corneum, periculum and nacre, the use of shell is very diverse. It is powdered and used as a mordant, fertilizer, etc. as a powder, antacid, burned shellfish, and as a cosmetic raw material to emphasize brilliance and functionality. come. In addition, the nacres of shells were mainly used as ornaments for various ornaments or furniture.In particular, the mother-of-pearl used in Najeon lacquerware utilizes the mother-of-pearl obtained from the abalone shells. Therefore, the abalone shells were processed thinly and pasted on furniture, boards and other items to make them into crafts. However, in order to obtain the nacre from the abalone shell due to the rigidity of the shell, a method of physically giving a strong force to the shell was used. Such a method takes a long time, making it difficult to manufacture a bulk material, and has been a major deterrent to the popularization of decorative mother-of-pearl products.

As a method of obtaining a nacre from a shell, an example of chemical peeling of an abalone shell using an aqueous hydrochloric acid solution of 30 wt% to 35 wt% is disclosed in Korean Patent Application Laid-Open No. 10-2011-0017537. Since hydrochloric acid is a hydrogen chloride (HCl) gas dissolved in water, the maximum concentration of hydrochloric acid produced by the manufacturer is approximately 35 wt% because of its volatility. However, the use of high concentration of hydrochloric acid solution to dissolve the abalone shell calcium carbonate and light protein is an unfavorable method from an environmental point of view, and the problem of wastewater treatment after abalone shell treatment should also be improved (strongly acidic hydrochloric acid-). Neutralization of the waste liquid consumes a large amount of alkali and water), and is not good for the environmental aspects of the handler who handles strong acids. In addition, the treatment of the abalone shell using a strongly acidic solution serves to increase the surface roughness of the nacre, thereby lowering the surface brightness unique to the nacre, thereby making it difficult to obtain a high-quality nacre. Since the nacres are alternately stacked with calcium carbonate and concholine, which is a light protein having hydrophobic properties, it is known that the surface-gloss is severely damaged since the strong acid will cause the interlayer delamination, which varies the degree of dissolution between layers. Therefore, in order to separate high quality nacres, rapid surface peeling by strong acids should be avoided, while using a principle of a buffer solution that suppresses the strength of strong acids, and using a method of high chemical affinity with hydrophobic conchiolin. You need to implement

In Korean Patent Laid-Open Publication No. 10-2011-0017537, a transparent lacquer is also coated to protect the inner surface of the abalone shell during the treatment of strongly acidic hydrochloric acid solution, and during treatment, the acidic solution partially penetrates between the coating film and the abalone shell. Even if it is not peeled off, in order to use the finally obtained nacre as a decorative material such as lacquer lacquer, the process of removing the lacquer layer must be performed, and for this purpose, an organic solvent such as acetone or thinner must be used. It is also undesirable for obtaining nacres. Therefore, in order to protect the inner surface of the abalone shell it is necessary to coat with an environmentally friendly material.

The inventors of the present invention have a high gloss without damaging the surface of the nacre by using such an easy method when the shell is treated with a mixture of hydrochloric acid and acetic acid at a low concentration while studying a method for obtaining a high-quality nacre from the shell. It was confirmed that the nacre can be obtained to complete the present invention.

Japanese Registered Patent No.4458439 (Name of the Invention: Method of Separating Shell-Paper of Abalone, Method of Producing Shell-Pearl Separation of Abalone, and Method of Making Nacreous Separation, Applicant: SHINGY: KK, Registered Date: February 19, 2010) Japanese Patent No. 5844979 (Invention name: Manufacturing method of cosmetic raw material, Applicant: MIKIMOTO PHARMACEUT CO LTD and MIE UNIV, Registered date: November 27, 2015) Japanese Laid-Open Patent No. 2001-055524 (name of the invention: a method for producing shell shell, and a coloring material using the same, Applicant: TOKYO KIYUUEI: KK, registered date: February 27, 2001) Republic of Korea Patent Application Publication No. 10-2011-0017537 (Invention name: method for separating nacres of abalone clam shell, Applicant: Jeollanam-do, Publication Date: February 22, 2011) Republic of Korea Patent Application Publication No. 10-2014-0040591 (Invention name: method for separating nacres from shells of shellfish, Applicant: Hwang Ui-Sik, Publication Date: April 03, 2014)

An object of the present invention is to provide a method for separating a shell nacre, characterized in that the shell is treated with a mixture of hydrochloric acid and acetic acid to obtain a nacre with high gloss.

The present invention relates to a method for separating a shell nacre by treating the shell with a mixed solution of hydrochloric acid and acetic acid to obtain a nacre with high gloss. Hydrochloric acid in the mixture is preferably 3 to 15 wt%, more preferably 9 to 15 wt%, acetic acid is 20 to 60 wt%, more preferably 20 to 35 wt%.

The shell may be selected from the group consisting of abalone shell, horn conch shell, oyster shell and pearl shell.

Before the shell is treated with a mixed solution of hydrochloric acid and acetic acid, a step of applying a tallow can be added.

During the treatment of the mixed solution of hydrochloric acid and acetic acid in the shell, the step of physically removing the foreign matter attached to the outer surface of the shell may be added.

The present invention provides a shell mother layer having a high gloss, characterized in that obtained by this method.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a method for separating a shell nacre by treating the shell with a mixed solution of hydrochloric acid and acetic acid to obtain a nacre with high gloss. The shell may be selected from the group consisting of abalone shell, horn conch shell, oyster shell and pearl shell.

Before the shell is treated with a mixed solution of hydrochloric acid and acetic acid, a step of applying a tallow (bovine oil) may be added. By applying the tallow on the inside of the shell, it is possible to prevent corrosion of the nacre inner layer of the shell when the acid treatment is prolonged. At this time, the tallow is easy to remove even after separating the nacre. The tallow can be used by coating the inner surface of the shell after melting in the liquid phase in a dryer maintained at 50 ~ 70 ℃. Uji is an animal fat component, which is not only environmentally friendly to be used for food but also can be easily removed with a general detergent, and thus may be a preferred acid-resistant coating material. Paint, wax, transparent lacquer and resin, which are used as a coating for shells when using an acid treatment method for obtaining a nacre, are organic compounds, and thus, organic solvents such as acetone and thinner are consumed in a large amount to remove them.

The mixed solution is an aqueous solution, preferably 3 to 15 wt%, more preferably 9 to 15 wt% of hydrochloric acid in the mixed solution. In addition, it is preferable that acetic acid is 20 to 60 wt%, but acetic acid may be sufficiently separated even if only 20 to 35 wt% is treated, so it is not necessary to use a high concentration of acetic acid. However, when the hydrochloric acid is less than 3 wt% or acetic acid is less than 20 wt% may not be suitable because the separation of nacres may not be good or the separation time of the nacres may be significantly longer. In addition, when the hydrochloric acid in the mixed solution exceeds 15 wt%, the shell pearl layer may cause chemical change and corrosion due to the high concentration of acid treatment, thereby discoloring or deteriorating the color or surface of the nacre layer. The denatured nacres are not suitable for use in other processed or cosmetic ingredients.

Acetic acid in the mixed solution has a carboxyl group and has high chemical affinity with hydrophobic conchiolin in the shell to facilitate separation of the nacres of the shell.

During the treatment of the mixed solution of hydrochloric acid and acetic acid in the shell, the step of physically removing the foreign matter attached to the outer surface of the shell may be added, the physical removal is 7 to 13 minutes from the start of the treatment of the mixed solution It is preferable to carry out the process, and the method of rubbing a shell using a brush etc. can be used.

The present invention provides a shell pearl layer, characterized in that obtained by such a method, it can provide accessories, furniture, various household goods, cosmetic raw materials prepared by powdering such accessories made from the mother layer.

The nacres of the shell are alternately stacked with calcium carbonate, which is easily dissolved in acid, and conchiolin, a light protein having hydrophobic properties. In the present invention, in the acid treatment of the shell, when using only strong acid as an acid treatment liquid for treating the shell, While hydrochloric acid dissociates completely into H ⁺ and Cl ^- with strong acids, H ⁺ ions readily dissolve calcium carbonate, but due to different chemical similarities to the conchiolin material, the conchiolin protein layer is degraded at a rate similar to the calcium carbonate layer, or It becomes difficult to dissolve. Therefore, the nacres which are separated by treating the shell with hydrochloric acid, which is a strong acid, will increase the degree of surface roughness, thereby severely inhibiting the luster of the nacres. From this point of view, when the weak acid acetic acid is mixed with the strong acid as in the present invention, the strength of the strong acid is suppressed by the common ion effect, and acetic acid and conchiolin (-COOH) having a carboxyl group (-COOH) Hydrogen bonds are formed, and the conchiolin layer in the nacre of the shell is much more easily separated. Therefore, the surface roughness of the nacres treated in the acidic aqueous solution mixed with hydrochloric acid, which is a strong acid, and acetic acid having a carboxyl group, is much reduced compared to when only hydrochloric acid, which is a strong acid, is used. It is preferable to mix and process acetic acid which has a carboxyl group.

The common ionic effect described above and the hydrogen bond between acetic acid and conchiolin are as shown in Schemes 1 to 3 below.

Scheme 1

CH ₃ COOH (acetic acid) ↔ H ⁺ (proton) + CH ₃ COO ^- (acetate ion)

Scheme 2

CH ₃ COO ^- (acid ions) + H ⁺ (from hydrochloric acid, HCl) → CH ₃ COOH (acetic acid)

Scheme 3

-CO ₂ ^- (protein) + H ⁺ (acid _{solution) ↔ -CO 2 H ---- HO 2} CCH 3 ( acetate)

When hydrochloric acid, a strong acid, is added to the acetic acid solution in the chemical equilibrium state of Scheme 1, hydrogen ions (H ⁺ ) completely dissociated in hydrochloric acid are combined with acetic acid ions (CH ₃ COO ⁻ ) in Scheme 1 (CH ₃ COOH). Is produced (Scheme 2), the strength of hydrochloric acid and the degree of dissociation of acetic acid decrease. The study of the interaction between acetic acid and protein (poly-L-glutamic acid and serum albumin) has been published by JR Cann (Biochemistry, 1971, Vol. 10, pp. 3707-3712).

Scheme 3 shows that a protein molecule having a carboxyl group in an acidic solution performs hydrogen bonding with an acetic acid molecule having a carboxyl group. Because of the high degree of nonpolarity, the wettability of the protein layer in acetic acid solution is equal to the tendency to be greater than that of water molecules.

Therefore, as a preferred method for separating high-quality nacres with improved surface smoothing of the shells by degrading the light protein conchiolin material having the insoluble properties of the nacres of the shell at the same rate as the decomposition rate of the calcium carbonate layer. It is suggested that it is most suitable to use a mixed solution of hydrochloric acid which is a strong acid and acetic acid having a carboxyl group as in the present invention.

The present invention relates to a method for separating a shell nacre, characterized in that the shell is treated with a mixed solution of hydrochloric acid and acetic acid to obtain a nacre, wherein the nacre can be separated from the nacre with an intact appearance. Household goods, furniture, sculptures, accessories, cosmetic raw materials prepared by powdering it can be provided.

1 is a photograph showing a process of treating a solution of hydrochloric acid (left) and a mixture of hydrochloric acid and acetic acid (right) in an abalone shell.
FIG. 2 is an enlarged photograph of an abalone shell inner surface (pearl layer) obtained by treating a hydrochloric acid solution, and is shown by treated hydrochloric acid solution concentration.
FIG. 3 is a 40 times magnification of the inner surface (pearl layer) of an abalone shell obtained by treating an acid or mixed acid solution other than hydrochloric acid, and is shown by treated acid type or concentration.
Figure 4 is a microscope picture of 40 times magnification of the acid-treated and coated with tallow inside the abalone shell.
FIG. 5 is a graph and photograph showing the reflectance (%) of the inner surface of the abalone shell (pearl layer) obtained by treating a mixture of 9 wt% hydrochloric acid and 35 wt% acetic acid and 9 wt% hydrochloric acid solution alone with the inside of the abalone shell before treatment.
Figure 6 is a graph showing the brightness of the inner surface of the abalone shell inner surface (pearl layer) obtained by treatment of 9wt% hydrochloric acid and 35wt% acetic acid, 9wt% hydrochloric acid solution alone compared with the inside of abalone shell before treatment.
Figure 7 is a photograph taken inside / outside of the abalone shell nacre obtained by treating a mixture of 9wt% hydrochloric acid and 35wt% acetic acid.
FIG. 8 is an enlarged photograph of an inner surface of a horn shell (pearl layer) obtained by treating a mixture of 9 wt% hydrochloric acid and 35 wt% acetic acid and 9 wt% hydrochloric acid solution alone.
FIG. 9 is a photograph taken inside / outside of a horn shell shell nacre obtained by treating a mixed solution of 9 wt% hydrochloric acid and 35 wt% acetic acid.

Hereinafter, a preferred embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, it is provided to fully convey the spirit of the present invention to those skilled in the art so that the contents introduced herein are thoroughly and completely.

<Example 1. Obtaining nacre of the abalone shell>

The abalone shells were treated with an acidic aqueous solution containing various concentrations of hydrochloric acid and acetic acid until the outer surface layer was completely peeled off. The concentrations of aqueous hydrochloric acid solution used were 30 wt%, 20 wt%, 9 wt%, 6 wt%, 3 wt%, and the concentration of acetic acid aqueous solution was 35 wt%. In addition, hydrochloric acid and acetic acid were mixed so that the concentration of hydrochloric acid in the aqueous solution was 30 wt%, 20 wt%, 9 wt%, 6 wt%, 3 wt% and acetic acid 35 wt%.

To this end, the concentration of hydrochloric acid, acetic acid or other acids was adjusted while adjusting the total volume of each aqueous solution to 400 mL, and the abalone shell was added to the final acid solution.

After 10 minutes of treatment, the abalone shell was removed, the outer surface was rubbed with a plastic brush to remove foreign matters attached to the surface, and then retreated in an acid solution to remove foreign substances other than the nacre.

FIG. 1 is a photograph of bubbles generated on the surface of an abalone shell during the acid treatment of the abalone shell. As shown in FIG. 1, when the abalone shell is treated only with hydrochloric acid solution, the calcium carbonate layer is decomposed. While the bubbles of carbon dioxide (CO ₂ ) are large in size, it is confirmed that the bubbles are very small in the form of aerosols when a mixture solution of hydrochloric acid and acetic acid of the same concentration is mixed.

This fact indicates that acetic acid inhibits the reaction strength of strong acids and decomposes the calcium carbonate layer and the conchiolin layer very uniformly throughout the abalone shell surface. That is, it was confirmed that acetic acid molecules promoted the decomposition of conchiolin by increasing wettability through hydrogen bonding with conchiolin molecules having hydrophobic properties.

Next, in order to observe in more detail the effect of different bubble formation on the surface roughness of the abalone shell in 'mixture of hydrochloric acid and acetic acid' compared to 'hydrochloric acid solution' The inner surface of the shell was shown under a microscope.

The shape of the inner surface of the abalone shell (pearl layer) thus obtained was magnified 40 times with a microscope and shown in FIG. 2. As shown in FIG. 2, the inner surface of the abalone shell before acid treatment shows a very flat surface, while the surface after treatment with a high concentration of hydrochloric acid solution (30 wt% and 20 wt%) has a partially very recessed shape. It can be observed that the treatment with a low concentration hydrochloric acid solution has a similar degree of non-uniform surface state, although the degree of fineness is different compared to the treatment with a high concentration hydrochloric acid solution.

Figure 3 shows a picture taken of the inner surface of the abalone shell under the same conditions for the phosphoric acid solution, acetic acid solution, nitric acid solution, a mixture of hydrochloric acid and acetic acid at different concentrations, as shown in Figure 3, a low concentration of hydrochloric acid In the mixed solution of and acetic acid, it was confirmed that the color and the surface state hardly changed compared to before the acid treatment, and maintained the intrinsic nacreous state.

The inner surface of abalone shells treated with only 35 wt% acetic acid showed a similar smooth surface condition compared to before treatment. This is due to the chemical similarity of the carboxyl group (-COOH) to the conchiolin molecule. We have experimentally demonstrated a new fact that insoluble conchiolin is easily degraded by acetic acid.

In addition, the fact that the micrograph after the abalone shell was treated with a mixed solution of low concentration of hydrochloric acid and acetic acid showed almost the same surface condition as the micrograph of the abalone shell before the treatment. The acetic acid molecules are well confirmed by wrapping and dissolving the hydrophilic conchiolin layer.

However, in the acid treatment solution containing hydrochloric acid, the dissolution of the bark components other than the nacre was progressed within 30 to 40 minutes. However, when acetic acid was treated only, it took almost a day until the nacre was exposed at 4 hours and the foreign substances were completely removed. It was judged that it was not preferable condition.

In comparison, the inner surface of abalone shells treated with 18 wt% phosphoric acid (H ₃ PO ₄ ), even with the same weak acid, was subjected to surface roughness due to heterogeneous decomposition of the calcium carbonate layer and the conchiolin layer as in the hydrochloric acid treatment group. Is increased. In addition, the nitric acid treatment can also be seen that the surface condition is not good.

Next, the abalone shell before acid treatment, the abalone shell treated with hydrochloric acid solution alone, and the abalone shell treated with the mixed solution of hydrochloric acid and acetic acid were cut to a constant size (1.5 x 2 cm) to cut the inner surface with the nacre 200 to 800 nm. Reflectance was measured in the wavelength range of and the diffuse reflection spectra results are shown in FIG. 5.

As shown in FIG. 5, when the abalone shell was treated with a mixed solution of 9 wt% hydrochloric acid and 35 wt% acetic acid, the reflectance was almost the same as before the acid treatment, while the reflectance of the specimen treated with hydrochloric acid solution was remarkably high. It is confirmed to decrease. This decrease in reflectance is a phenomenon that occurs when treating only hydrochloric acid, which is a strong acid, and is believed to be due to an increase in surface roughness caused by uneven decomposition of the calcium carbonate layer and the conchiolin layer constituting the surface. This is in good agreement with the micrographs of the inner surface of abalone shell magnified by 40 times, as shown in the illustration of FIG.

The surface brightness of the specimens analyzed in FIG. 5 was analyzed using a brightness meter, and the abalone shell was treated with a mixture of 9 wt% hydrochloric acid and 35 wt% acetic acid. While the brightness of the specimens showed almost similar brightness as compared to before the acid treatment, the brightness of the specimens of the abalone shells treated only with hydrochloric acid solution was significantly reduced.

At this time, before the acid treatment of the abalone shell, the inside of the abalone shell was coated with tallow and acid treatment was carried out with a mixture of 9 wt% hydrochloric acid and 35 wt% acetic acid to check the inside of the shell. As a result, as shown in Fig. 4, it was understood that the surface in the same state as before the acid treatment was maintained. In particular, the surface brightness (surface brightness) was confirmed, but not shown in the graph, only 9 wt% hydrochloric acid and 35 wt% acetic acid mixed solution treated with a coating compared to about 90% compared to the pre-coating It was found that the specimens had a surface brightness of at least 98% very similar to that before coating.

Thus, it can be seen that Uji is suitable as a coating material for protecting the inner surface of the abalone shell from an acidic solution.

From these results, it can be seen that the method of separating the nacre by using only hydrochloric acid, which is a strong acid, impairs the inherent gloss of the nacre of the abalone shell.To prevent this, the acetic acid, a weak acid having a carboxyl group, is mixed with hydrochloric acid to form the nacre. It can be seen that treating the shells with is a preferred method of separating high quality nacres that does not impair the glossiness of the inner surface as well as the outer surface of the abalone shell. Photographs of the abalone shell nacres (treated with a mixture of 9 wt% hydrochloric acid and 35 wt% acetic acid) intact in the form of foreign substances thus obtained were not shown in FIG. 7.

On the other hand, the nacres of the abalone shell obtained according to the mixed liquid conditions of hydrochloric acid and acetic acid of more various concentration conditions are shown in Table 1 below.

Hydrochloric acid concentration in acid treatment liquid (wt%) Acetic acid (wt%) concentration in acid treatment liquid Surface condition Completed foreign material removal within 40 minutes 9 35 Good OK 15 20 Good OK 15 35 Good OK 9 10 Bad OK 20 35 Bad OK

The poor surface condition in Table 1 indicates that the surface roughness is greatly increased as treated with hydrochloric acid only, and the good surface indicates that the state of the inner surface of the abalone shell is very similar to that before the acid treatment.

<Example 2. Obtained nacre of horn shells>

In the same manner as in Example 1, the horn conch shell was subjected to acid treatment until the outer surface layer was completely peeled off to obtain a nacre. The acid treatment solution used was a mixture of 9 wt% hydrochloric acid and 35 wt% acetic acid. 400 mL of this mixed solution was placed in a 500 mL beaker and horned shells were treated for 40 minutes. After 10 minutes from the start of the treatment in the treatment process, the outer surface was removed with a plastic brush to remove foreign matters attached to the surface, and the horn conch shell was added to the mixed solution and reprocessed.

FIG. 8 shows a micrograph of a 40 times magnification of the inner surface of the horn shell shell according to each acid solution treatment method. As in the case where the inner surface of the abalone shell was taken, the specimen was treated with only hydrochloric acid. While the surface roughness was severe, the flat surface similar to that before the acid treatment can be observed in the specimen treated with acidic aqueous solution mixed with hydrochloric acid and acetic acid, or with the Uji coating before acid treatment. Surface brightness was also maintained above 90% in acid treatments and above 98% for tallow coatings (not shown). The intact nacres (treated with a mixture of 9 wt% hydrochloric acid and 35 wt% acetic acid) obtained from the horn conch shell finally obtained in this way are shown in FIG. 9.

Claims (5)

The shell is treated with a mixed solution of hydrochloric acid and acetic acid solution to obtain a nacre. The method of claim 1,
The shell is a separation method of shell shell having a high gloss, characterized in that selected from the group consisting of abalone shell, horn conch shell, oyster shell and pearl shell. The method of claim 1,
Before the shell is treated with a mixed solution of hydrochloric acid solution and acetic acid solution, applying a step of applying a tallow, separation method of shell shell having a high gloss, characterized in that. The method of claim 1,
Separating the shell pearl layer having a high gloss, characterized in that during the treatment of the mixed solution of the hydrochloric acid solution and acetic acid solution to the shell, the step of physically removing the foreign matter attached to the outer surface of the shell. Shell shell layer having a high gloss, characterized in that obtained by the method of any one of claims 1 to 4.

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