KR20220058204A - Protocol for evaluating Oriental Lacquer material and method for providing information of the same - Google Patents

Abstract

The present invention relates to a protocol for evaluating an oriental lacquer material tailored to shape characteristics for the oriental lacquer material and a method for providing information of the oriental lacquer material. By increasing the reliability of evaluating an oriental lacquer material, it is possible to provide objective information about an unknown oriental lacquer material to clients who consume the oriental lacquer material. In addition, based on the information, it is possible for clients to select an oriental lacquer material with desired functionality.

Description

Protocol for evaluating Oriental Lacquer material and method for providing information of the same}

The present invention relates to a lacquer evaluation protocol and a method for providing lacquer information tailored to the shape characteristics in which the lacquer is provided.

Lacquer is a traditional craft technique that represents Korean culture, and it is reported that historically, the use of lacquerware on the Korean Peninsula began around the 1st century BC (Dahori No. 1, Iron Age). What is surprising is that, due to the excellent coating properties of lacquer, such as high strength, heat resistance, high gloss, chemical resistance, waterproofness, and insect repellency, these relics do not decay and remain intact even after 2,000 years have passed. Lacquer is the essence obtained by wounding the lacquer tree, and lipid molecules having a catechol structure are naturally polymerized at room temperature by enzymes to form a very dense network structure.

Lacquer has been used as an adhesive and coating agent since ancient times. Polymer coating materials are essential in almost all products used throughout our lives, and protect products from external optical, physical, and chemical stimuli so that products can maintain their functions for a long time in real life. Recently, as consumers' negative perceptions of environmental hormones and chemical additives are increasing, the need for R&D for the development of eco-friendly coatings is emerging. Accordingly, lacquer (oriental lacquer or Ottchil), which was used as a coating agent in traditional hanok and cultural relics, is receiving new attention as a natural eco-friendly polymer coating material.

The type of catechol fat molecules and the composition of lacquer lacquer may vary depending on the species of lacquer tree and the production environment, and accordingly, the quality of the lacquer coating may vary greatly. However, it is an industry that has not yet established a standard and certification system for the commercialization process, and the reliability of lacquer products is low, which is a problem.

Accordingly, objective evaluation standards and evaluation methods for lacquer are required. Comparative evaluation of the existing lacquer has a problem in that standards for lacquer evaluation have not been secured because most of the non-quantitative evaluations of manual specimens have been limited. Therefore, for the expansion of the lacquer culture industry and the creation of new industries, it is necessary to develop a technology platform for evaluating the qualitative and quantitative characteristics of lacquer based on scientific analysis and molecular level research through convergence research of lacquer craft-polymer material-analytic science. .

The present inventors manufactured lacquer for evaluation that can ensure reliability, analyzed the physical and chemical properties of each type of lacquer, and established and standardized evaluation indicators for lacquer based on the analysis results. This increases the reliability of the evaluation of lacquer, and can provide objective information about unknown lacquer to clients who consume lacquer. In addition, based on the above information, it becomes possible for the client to select a lacquer having the desired functionality.

An object of the present invention is to provide country of origin and catechol molecular mix information by performing a certain evaluation step on the lacquer undiluted solution provided by the client.

Another object of the present invention is to provide a protocol for deriving at least one evaluation item from the group consisting of catechol molecular mixing degree, refining, and coating film characteristics by measuring significant evaluation indicators according to the type of lacquer.

Referring to Figure 1, the first aspect of the present invention is a first step of receiving a lacquer undiluted solution from a client (S100); a second step of determining the form of lacquer (S200); a third step (S300) of preparing a lacquer material having a determined shape of lacquer; a fourth step of selecting the evaluation items of the lacquer material (S400); and a fifth step (S500) of measuring the evaluation index of the lacquer material for determining the evaluation item.

The term “form of lacquer” broadly refers to a form of a lacquer solution or a lacquer-coated coating film. The lacquer solution specifically refers to a raw lacquer form from which impurities are removed by filtering the undiluted solution or the undiluted solution. In addition, the lacquer-coated coating film includes a coating film combined with lacquer, and specifically means that lacquer is applied on the surface of the coating film.

The evaluation item is the country of origin or the degree of catechol molecular mixing.

As used herein, the term 'origin of origin' refers to a region from which lacquer was collected. For example, Korean or domestic may mean that it is collected from a Korean lacquer tree, and a Chinese product may mean that it is collected from a Chinese lacquer tree.

The physical properties of lacquer are different depending on the country of origin, and the client who consumes lacquer wants to purchase lacquer from the country of origin with reliable quality, and the client demands objective and accurate information on the origin of the lacquer.

The term "catechol molecule" of the present invention is a compound represented by the formula (1).

[Formula 1]

Lacquer is to include the catechol molecule as a main component, and catechol is one of the adhesive substances found in nature. Catechol has various types of alkyl chain ('R'), and the main component appears differently depending on the country of origin. Urushiol with 15 alkyl chains ('R') in the Rhus vernicifera species mainly found in Korea, China and Japan; This is the main component.

The "catechol molecular mixing degree" refers to the degree to which the compounds represented by Chemical Formula 1 have different types of alkyl groups are mixed. In the present invention, specifically, it refers to the degree to which urushiol and lactol are mixed.

As described above, since the main components of catechol molecules are different for each country of origin, determining the degree of mixing of catechol molecules is closely related to determining the origin. Commercially available lacquer is often a mixture of urushiol and lactol among catechol molecules. When lacquer is the main component, it is known that it takes a long time to dry and cure, and the drying characteristics of the lacquer coating can vary greatly depending on the mixing ratio. However, there is no standard quantitative and qualitative evaluation method for lacquer components, so a method for evaluating the main components of lacquer is required. Through the standard evaluation method of the main ingredient, it may be possible to provide objective information on whether the lacquer is lacquer with the desired functionality or physical properties by clients who consume it.

The form of lacquer in the second step may be any one selected from the group consisting of lacquer undiluted solution, raw lacquer, and a lacquer-coated film.

Next, when the form of lacquer is determined as the stock solution in the second step (S200), the evaluation item in the fourth step (S400) is the country of origin, and the evaluation index in the fifth step (S500) is viscosity. there is.

The "viscosity" is a value measured with a viscometer, and can be measured using a known viscometer or method, and specifically, it can be measured using DV2TLV (Brookfield), but is not limited thereto.

Next, when the shape of the lacquer is determined to be raw lacquer in the second step (S200), the third step (S300) may include filtering the raw lacquer to remove aggregates. The filtration is to remove aggregates present in the lacquer lacquer. The evaluation item in the fourth step (S400) may be the country of origin or the degree of mixing of catechol molecules.

If the form of lacquer is determined as raw lacquer in the second step (S200), and the evaluation item of the fourth step (S400) is the country of origin, the evaluation index of the fifth step (S500) may be water content and viscosity there is.

The "moisture content" means that when the lacquer is in the form of a solution containing raw lacquer, the weight ratio of moisture in the solution is expressed as a % value.

The "viscosity" is the same as described above.

When the shape of lacquer is determined as raw lacquer in the second step (S200), and the evaluation item in the fourth step (S400) is catechol molecular mixing, the evaluation index of the fifth step (S500) is an infrared absorption spectrum (infrared absorption spectrum) may be.

The "infrared absorption spectrum" refers to an analysis method in which continuously changing infrared rays are irradiated to molecules having a unique vibrational motion, and the absorbed light is displayed as a spectrum.

Through the infrared absorption spectrum, it is possible to calibrate the content of lactol compared to urushiol in raw chil without limiting the saturation concentration, which is determined by creating a calibration curve from the peak shift of the conjugate diene of urushiol and lactol. Among catechol molecules, it is urushiol that the C=C double bond of the alkyl chain can exist in a continuous conjugation state of cis and trans, and the terminal double bond exists. In the case of the lactol, the C = C double bond of the alkyl chain has a main structure of trans, trans conjugation. Accordingly, the main component may be distinguished by identifying a peak in the wavelength range indicating the structural characteristics. Specifically, it can be determined that urushiol is present by the appearance of a peak at 945 cm ^-1 of catechol, and the fraction of urushiol versus lactol can be determined through the conjugated diene peak between approximately 980 cm ^-1 and 990 cm ^-1 . can

Specifically, evaluating the degree of mixing of catechol molecules through the infrared absorption spectrum of saengchil may be performed in the following order.

a) obtaining an infrared absorption spectrum of the raw lacquer; b) monitoring a peak at 980 cm ^-1 to 990 cm ^-1 representing a conjugated diene of carbon in the infrared absorption spectrum; and c) creating a calibration curve based on the peak value of the carbon-conjugated diene of lacquer in which only the catechol molecule is urushiol for the peak, and c) to evaluate the degree of mixing of the catechol molecules.

Next, when the shape of the lacquer is determined as the lacquer-coated film in the second step ( S200 ), a uniform coating method capable of securing the reliability of information provision is required. There was a problem in that thickness uniformity could not be secured because comparative evaluation of the existing lacquer was performed relative to the specimens that were mostly made by hand. Therefore, the coating film was uniformly coated using a brush coater, a dedicated applicator, to ensure the reliability of evaluation information while enabling absolute evaluation of lacquer properties.

The coating film may be glass, wood, metal, ceramics, leather, and bamboo, and specifically glass, metal, and wood.

2 and 3 , the brush of the “brush coater” has a flat shape, and the distance between the brush and the surface of the coating film is about 10 μm, and has a configuration that can be controlled using a nob. The brush can move at a constant speed and repeat coating is possible. If necessary, a UV lamp can be attached to improve the curing speed. The brush is equipped with a separate solution injector, so the lacquer solution is injected at a constant speed as possible during coating.

Accordingly, when the shape of the lacquer is determined as the lacquer-coated film in the second step (S200), the third step (S300) may be performed in the following manner.

i) filtering the raw lacquer to remove aggregates; ii) providing a lacquer solution in which the raw lacquer is mixed with terpine oil; iii) repeating 3 to 8 times at a speed of 10 mm/s to 30 mm/s on the upper surface of the coating film to coat the lacquer solution with a brush coater; and iv) curing the coating film coated with the lacquer solution.

The viscosity of the lacquer solution is about 10 mPa.s to 15 mPa.s, specifically, 10 mPa.s to 13 mPa.s. The coating speed may be from 10 mm/s to 30 mm/s, specifically from 15 mm/s to 25 mm/s, more specifically about 20 mm/s. The number of coatings may be 3 to 8 times, more specifically, about 5 times. During curing, temperature conditions may be 25° C. to 35° C., and relative humidity may be about 70% or more, specifically about 90% or more.

It is characterized in that the coating thickness deviation of the lacquer-coated film manufactured by the manufacturing method of the third step (S300) is 10% or less. The value of 10% or less means a result of calculating the standard deviation of the coating thickness of the coating film samples coated with about 8 to 12 lacquer lacquers manufactured using the manufacturing method of the third step. This indicates that the coating sample has a uniform coating layer, and indicates that the reliability of the absolute evaluation of lacquer is secured.

The coating thickness of the lacquer-coated film may be 2 um to 10 um, specifically 4.5 um to 7.5 um, and more specifically 5 um to 6 um, but is not limited thereto.

Next, in the second step (S200), the shape of the lacquer is determined as a lacquer-coated coating film, and when the coating film is glass, the third step (S300) is performed to prepare the lacquered-coated glass. Thereafter, the evaluation item in the fourth step (S400) is the country of origin, and the evaluation index in the fifth step (S500) may be drying time, curing time, transmittance, cloudiness, glossiness, and hardness.

The term “drying” refers to a phenomenon in which a thin layer of painted lacquer (paint) changes from a liquid to a solid.

The "drying time" means a dry time to the touch. Specifically, the dry to touch refers to a state in which the coating film has adhesiveness when lightly touched with a finger, but the paint does not adhere to the finger.

The “transmittance” refers to the intensity of a wave passing through a material or a boundary layer or an incident intensity of the number of particles. In the present invention, transmittance can be measured using a UV-vis spectrometer.

The "haziness" refers to the amount of light that does not travel in parallel and spreads among the light that has passed through the material. In the present invention, the degree of haze can be measured with a haze meter.

The "glossiness" means a value measured by recognizing the amount of reflection and the amount of light on the surface of the lacquer material having a surface-coated shape, and in the present invention, the glossiness can be measured with a gloss meter.

The "hardness" means the degree of hardness, the degree of hardness and softness. In the present invention, hardness can be measured with a paint film hardness meter or a pencil hardness meter.

The term "hardening" means that the lacquer is hardened. Specifically, the catechol may be hardened through an intermolecular cross-linking reaction.

The "curing time" generally means the time until it is not scratched by a paint film hardness tester, but in the present invention, the peak of =CH group on the FT-IR spectrum gradually decreases as the crosslinking reaction proceeds due to the curing mechanism of the catechol molecule. It means a value measured using the peak as an indicator for a curing reaction or a crosslinking reaction of a catechol molecule.

4 and 5, in the curing of catechol molecules, a curing reaction by laccase and an auto-oxidation reaction by oxygen occur during the curing process according to the curing mechanism of the catechol molecule. As the curing reaction proceeds, the peaks of the -OH group and =CH group gradually decrease. The amount of change in -OH is contained not only in catechol molecules, but also in polysaccharides and glycoproteins, so it is not suitable for use as an indicator for the curing reaction of catechol molecules, but =CH is only seen in catechol molecules. As a peak, it can be used as an indicator for the curing reaction of catechol molecules. Therefore, the present invention provides an evaluation index using the integral value of =CH peak of the infrared absorption spectrum as described above, and allows to determine the curing time of the lacquer material and the degree of curing to be described later.

The curing time measured using an index for the crosslinking reaction of the catechol molecule means specifically measured through the following method.

i) obtaining an infrared absorption spectrum of the lacquer-coated film; ii) monitoring a peak at 2990 cm ^-1 to 3010 cm ^-1 representing =CH in the infrared absorption spectrum; and iii) plotting the integral value of the peak to create a graph.

Referring to FIG. 6 , the second aspect of the present invention is a method for evaluating lacquer, and the evaluation indicators are viscosity, moisture content, infrared absorption spectrum, drying time, curing time, hardness, transmittance, cloudiness, glossiness, and curing degree. And it provides a method for evaluating lacquer that is at least one or more from the group consisting of adhesive strength.

The present invention is characterized by providing a meaningful evaluation index according to the evaluation items of lacquer, providing a quantitative and qualitative measurement method of the evaluation index, as well as providing an evaluation method that is easily accessible to clients who consume lacquer. .

The form of lacquer may be any one selected from the group consisting of lacquer undiluted solution, raw lacquer, and a lacquer-coated coating film.

When the form of the lacquer is lacquer undiluted solution, the evaluation indicators are viscosity and moisture content, and the country of origin can be evaluated by measuring the evaluation indicators.

Next, when the form of the lacquer is raw lacquer, the evaluation index is an infrared absorption spectrum, and by measuring the evaluation index, the country of origin or the degree of mixing of catechol molecules can be evaluated.

Next, when the form of the lacquer is a lacquer-coated film, the evaluation indicators are drying time, curing time, hardness, transmittance, haze, gloss, curing, and adhesion, and the country of origin by measuring the evaluation indicators Or it can be evaluated whether or not to refining.

The origin of lacquer is from Vietnam, China, Korea, and Japan. In particular, in the case of Vietnamese products, it shows distinctive characteristics from other origins in drying time, curing time, and hardness characteristics. As it is known that lacquer is the main ingredient in Vietnamese products, it can be inferred that whether laccol is mixed among the components of lacquer is an important factor in evaluating the origin of lacquer. Accordingly, the present invention can provide a method for evaluating the main component and origin of lacquer by analyzing the physical properties as well as the direct chemical analysis of the lacquer component.

The terms “moisture content”, “infrared absorption spectrum”, “drying time”, “curing time”, “hardness”, “transmittance”, “cloudiness” and “glossy” are the same as described above.

The "adhesion" is a function that can be measured in the case of a coating film coated with lacquer among the forms of lacquer. When the coating film is metal, the adhesive force is measured by a cross-cut test, and specifically, the adhesive force evaluated based on the classification table for the area ratio remaining when the metal specimen surface is scratched in the form of a grid pattern and then removed with a tape. do. When the coating film is wood, the adhesive force is measured using a pull-off adhesion tester, and specifically, the adhesive force is evaluated by attaching a dolly using an adhesive and measuring the tensile force at the time the dolly is separated. do.

The "curing degree" was conventionally evaluated relative to the degree of hardening using the degree of scratching or dryness to the touch of dried lacquer, but in the present invention, as the curing reaction proceeds due to the curing mechanism of the catechol molecule, =CH group on the FT-IR spectrum It is found that the peak of is gradually decreased and means a value measured by using the peak as an indicator for the curing reaction of the catechol molecule. Through this, it is possible to quantitatively determine the degree of hardening of lacquer.

The degree of curing is calculated by the following formula 1 using the integral value of the peak at 2990 cm ^-1 to 3010 cm ^-1 representing =CH,

[Formula 1]

Where i is the integral value of the =CH double bond peak after drying to touch, and f is the integral value of the =CH double bond peak after 3 days have elapsed.

The reason for using the peak value at the 2990 cm ^-1 to 3010 cm ^-1 is the same as described above for the curing time.

The "refined lacquer" means that small and uniform water particles are evenly distributed in the lacquer while evaporating unnecessary moisture by stirring and heating the raw lacquer.

The "purified lacquer or not" means to distinguish between raw lacquer and refined lacquer because there are two types of lacquer coated on the coating film, raw lacquer or refined lacquer.

Whether the refining is performed can be determined by measuring the drying time, curing time, transmittance, glossiness, and adhesive force among the evaluation indicators to determine whether the refining or refining is performed.

The present invention is a platform for evaluation technology of lacquer based on scientific analysis, which standardizes evaluation indicators according to evaluation items of lacquer to secure reliability in the evaluation method, and provides objective information about unknown lacquer to clients who consume lacquer. can provide Through this, the reliability of the lacquer craft industry can be secured, and the expansion of the lacquer culture industry and creation of new industries can be expected.

1 is a flowchart showing the determination step of the method for providing information of lacquer according to the present invention.
2 is an image of a design of a brush coater that is an application of the present invention.
3 is an image of how to use a device for introducing a lacquer solution of a brush coater in an embodiment of the present invention.
4 is a diagram showing a mechanism in which lacquer is cured by a radical reaction by laccase.
5 is a diagram illustrating a mechanism in which lacquer is cured by auto-oxidation.
6 is a schematic diagram summarizing evaluation indicators and evaluation items for each type of lacquer according to the present invention.
7 is a graph showing a photograph of a lacquer coating film using a brush coater and thickness uniformity in an embodiment of the present invention.
8 is a graph showing the transmittance and thickness uniformity deviation of the central portion of 10 lacquer coating film samples of FIG. 6 .
9 is a graph showing changes in -OH and =CH peaks analyzed by infrared spectroscopy (FT-IR) according to the curing time of the lacquer coating film.
10 is an FT-IR graph for each component of urushiol, glycoprotein, and polysaccharide.
11 is a graph showing the change in the =CH peak integral value analyzed by FT-IR according to the curing time of Japanese (E2) raw lacquer in an embodiment of the present invention.
12 is an FT-IR analysis graph according to the curing time of raw lacquer by country of origin.
13 is a photograph of the surface observed with the naked eye of a lacquer coating film (glass specimen) by country of origin in an embodiment of the present invention.
14A is a diagram showing the molecular structure of urushiol.
14b is a diagram showing the molecular structure of lactol.
15 shows the results of FT-IR analysis of each sample mixed with urushiol: lactol mixing molar ratios of 1:0, 1:0.5, 1:1, 1:2, and 0:1 in an embodiment of the present invention; This is the graph shown.
16 is a calibration curve graph for evaluating the degree of catechol molecular mixing prepared based on the conjugated diene peak value (about 981 cm ⁻¹ ) when urushiol: lactol is 1:0.
17 is a graph analyzing the degree of mixing by showing the observed values of the FT-IR peaks of three saengchil samples having an unknown degree of catechol molecular mixing on a calibration curve.
18 is a photograph of the surface observed with the naked eye of a Chinese raw and refined coating film (glass specimen) distributed in Korea in an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail through examples. These Examples are for explaining the present invention in more detail, and the scope of the present invention is not limited by these Examples.

Example 1. Construction of a coating film production test bed to secure evaluation reliability

In the past, the characteristics of the lacquer coating film such as thickness, uniformity, and roughness differ greatly from user to user, such as coating speed, solution concentration, brush pressure, and loading amount of lacquer solution. Due to the change in characteristics, there were uncertainties and low reliability problems in the evaluation of lacquer materials.

As shown in Figure 2, in order to solve the above problem, a brush coater, which is an applicator used for lacquer coating, was manufactured. This made it possible to secure a uniform and constant film thickness even for variously modified lacquer materials by matching the viscosity, making it possible to evaluate the characteristics of each lacquer material.

As shown in FIG. 3 , according to the usage of the lacquer solution introduction device, the flat brush mainly used in lacquer crafts was leveled using a nob so that it could be easily mounted. There is a gap of several tens of um to several mm below the solution injector, and the lacquer solution flows out through it. Agglomerates or particles existing inside the lacquer were filtered through the lacquer paper to form a uniform coating film. The lid was able to minimize the reaction with oxygen in the lacquer solution.

7 shows a solution of a mixture of raw lacquer and terpine oil in a 1:1 volume ratio was injected into the brush coater solution introduction device, and then the speed and number of coatings of the brush coater were adjusted to coat the glass plate with lacquer, and at 30° C., 90% relative humidity. These are photos and graphs showing the results of measuring the lacquer thickness uniformity of the lacquer material produced by curing for one day. In the case of one coat at 10 mm/s, the uniformity decreased according to the distance, but it was confirmed that the uniformity of the thickness of 4 μm was exhibited regardless of the distance when applied at 20 mm/s five times.

For reference, raw lacquer lacquer refers to the product solution itself, and since the viscosity of raw lacquer lacquer is different for each product solution, there is a limit to the thickness of all specimens being different when the specimen is prepared as a product solution itself. In order to achieve a similar viscosity, a terpine oil solvent was added to the raw lacquer lacquer to dilute it. This was expressed as a viscosity at the time of specimen preparation.

8 is a graph showing the results of analyzing the lacquer transmittance and thickness deviation when the brush coater is constantly adjusted at a speed of 20 mm/s and the number of times of lacquering is varied. In the case of one coat, the thickness uniformity deviation was more than 20%, but in the case of five coats, the deviation was 7%, within 10%, confirming that it was possible to secure reliability in the thickness uniformity of each lacquer material sample.

Example 2. Production of a coating film coated with lacquer for evaluation of the same thickness (hereinafter referred to as 'lacquer coating film')

In the same manner as in Example 1 above, the viscosity of a solution obtained by mixing terpine oil in a 1:1 volume ratio with raw chil for each country of origin (China, Korea, Japan, Vietnam) was adjusted to 10 mPa at a shear rate of 100 s ^{-1 .} S to 13 mPa ^. S (using a DV2TLV viscometer (Brockfield, Sindle No. 18), based on a shear rate of 100 s ^-1 ) was set. The surface of the commercial glass was painted 5 times with a brush coater at a speed of 20 mm/s, and cured at 30° C. and 90% relative humidity for 3 days to prepare 10 or more lacquers to have a thickness of about 5 μm to 6 μm.

made in china Made in Korea (from Wonju) made in japan from Vietnam Lacquer raw lacquer viscosity
(Pa ^. s) 1.02 0.47 5.02 0.88 Viscosity when making specimen (mPa.s) 12.58 12.52 14.77 13.79 S1 (um) 5.69 6.59 4.96 5.16 S2 (um) 5.70 6.32 6.38 5.45 S3 (um) 4.83 6.56 4.73 4.70 S4 (um) 5.66 7.35 5.46 4.63 S5 (um) 6.05 6.02 5.00 5.08 S6 (um) 6.21 6.06 5.65 4.81 S7 (um) 5.57 5.74 4.89 6.03 S8 (um) 6.05 6.06 5.65 4.81 S9 (um) 5.51 5.62 5.50 4.50 S10 (um) 6.05 7.07 6.09 4.92 average (um) 5.73 6.34 5.40 5.05 Standard Deviation 0.40 0.56 0.54 0.45

As shown in Table 1, the fact that the standard deviation of the thickness of the glass material lacquer coating film by country of origin is very small, around 0.5, indicates that the reliability of the lacquer evaluation method is secured by producing a uniform lacquer coating film.

Example 3. Lacquer-coated coating film (hereinafter referred to as 'lacquer coating film') characteristics evaluation method

Transmittance: 200 using a UV-Visible spectrometer (Sclerometer hardness tester, Elcometer) to measure the change in transmittance in the visible light region of the lacquer material prepared under various conditions using the brush coater used in Example 1 Transmittance was measured in the range of ~ 800 nm wavelength.

Glossiness: After measuring the glossiness using a gloss meter (60° angle) for several points (each corner part and central part, etc.) of the lacquer film, the dispersion value was calculated.

Degree of curing or catechol molecular mixing (FT-IR, NMR analysis): FT-IR (Spectrum 100, PerkinElmer) and NMR (Avance Ⅲ, Bruker) to obtain data for judging the degree of curing and catechol molecular mixing was used to analyze the chemical structure of lacquer.

Hardness: A pencil for measuring pencil hardness was inserted into a pencil hardness measuring instrument (KS M ISO 15184 ASTM D3360) at an angle of 45°, a 1 kg load was applied, and the degree of scratching was measured by pushing it about 5 times. As the pencil, pencils showing the strength of 9B ~ B, HB, F, H ~ 9H, etc. were used.

Alternatively, when the lacquer film was scratched against the surface of the lacquer film with a hardness meter after curing was completed in the range of 0 to 3N using a K3092 paint film hardness meter (Sclerometer), the strength when not scratched was measured.

Blurness : haze meter　Cloudiness was measured according to ASTM D1003 conditions.

Drying time: The time taken until fingerprints are not left was measured.

Curing time: After setting the lacquer coating film to be measured in the range of 0 to 3 N using a K3092 paint film durometer (Sclerometer), the time until scratched when scratched on the surface was measured. Another measurement method will be described later in Example 4 below.

Adhesion: In the case of a metal specimen, the degree of separation from the coating film was checked after cutting the coated surface of the lacquer film in a rectangular grid pattern using a cross-cut test (ISO 2409, ASTM D3359). Alternatively, for wood specimens, the tensile force at the point when the coating film was separated from the surface by 60% or more was measured by pulling the attached dolly using the adhesive of the F506 Pull-off adhesion tester.

Example 4. Construction of curing degree and curing time evaluation method according to the degree of chemical bonding

As shown in FIG. 9, as a result of analyzing the coated surfaces of Chinese, Korean (Wonju), Vietnamese, and Japanese lacquer films produced in the same manner as in Example 2 by FT-IR (Spectrum 100, PerkinElmer), It was confirmed that the peaks of -OH and =CH groups gradually decreased during the curing reaction of the catechol molecule. It can be seen that the reduction of the -OH group in the curing reaction mechanism of urushiol (FIGS. 4 and 5) is due to the radical reaction by laccase, and the decrease in =CH group is due to the auto-oxidation reaction. could Using these indicators, it is possible to determine the degree of hardening.

However, referring to FIG. 10 , in the case of the -OH group peak, it is also present in glycoprotein and polysaccharide, so it is not suitable for curing degree analysis. On the other hand, the =CH group peak is related to the oxidation reaction of unsaturated carbon inside the urushiol lipid chain, and is evident only in urushiol, so the =CH peak was used as an evaluation index for the completion of the curing reaction.

As shown in FIG. 11, when the area of the =CH peak of FT-IR is plotted with time, it was confirmed that the decrease of =CH became significantly smaller after a certain time, and the characteristics of the lacquer material at this point were Looking at it, it was not scratched even with a force of 1 N or more, so it was possible to determine the time when the coating film was cured, that is, the curing time.

Example 5. Evaluation of lacquer coating film basic properties and establishment of evaluation index

5.1 Glass material lacquer coating (hereinafter 'glass specimen') hardening evaluation and reliability of evaluation

12, the =CH peak at 2990 cm ^-1 to 3010 cm ^-1 in the FT-IR graph of glass specimens made in China, Korea (Wonju), Vietnam, and Japan produced in the same manner as in Example 2 You can see the decrease in time. At this time, it is possible to determine the curing characteristics of the lacquer material by country of origin by using the time for which the =CH peak decreases.

In order to secure reliability when judging the country of origin according to the degree of curing, the degree of curing of 10 or more lacquer material samples by country of origin was analyzed to confirm whether a curing process with a standard deviation of less than 10% was established. The degree of curing was calculated using Equation 1 below.

[Formula 1]

Table 2 shows the degree of curing () calculated after curing the lacquer material for 3 days. The degree of curing variation was about 5% to 8%. The variation in the degree of curing indicates that the reliability of evaluation of the degree of curing is secured by producing a lacquer material having a uniform curing level.

5.2 Evaluation of basic characteristics of lacquer solution and lacquer film and establishment of evaluation index

As shown in FIG. 13 , the lacquer properties of the lacquer coating film and fresh lacquer lacquer solution prepared in the same manner as in Example 2 were evaluated by the evaluation method of Example 3.

fill characteristics How to measure origin made in china Wonjusan made in japan from Vietnam
Solution (fresh coating) characteristics Moisture content (%) 25.32 22.17 13.42 22.17 Viscosity (Pas @ 100 s ^-1 ) 1.02 0.47 5.02 0.88 drying time Dry to touch (h) One 2 0.8 3 curing time FT-IR 6 5 4 72 fill thickness a-step thickness
(a-step thickness) 5.73 (±0.40) 6.34 (±0.56) 5.40 (±0.54) 5.05 (±0.45) permeability UV-Spectrum (T%, @ 600 nm) 37.8 42.6 47.0 42.4 blur Haze Meter (diffuse % @ 550nm) 26.65 14.5 15.1 22.4 glossiness gloss meter (GU) 23 37 38 24 Hardness Paint Sclerometer (N) 6.7 5.55 5.40 0.36 pencil hardness 9H 9H 9H 0.9H adhesion
(copper plate specimen) Cross-cut test 3B 3B 2B 2B

Table 3 shows the results of evaluating the properties of lacquer. In particular, in the case of Vietnamese products, the results are markedly different from those of other origins in drying time, curing time, and hardness characteristics. As it is known that laccol is the main component of Vietnamese products, it can be inferred that determining whether or not laccol is mixed among the lacquer components and the degree of mixing is an important factor in evaluating the characteristics of lacquer materials. Therefore, on the premise that there is information on the mixing ratio of main components of lacquer by country of origin, based on the results of measuring the moisture content and viscosity of the unknown raw lacquer solution and the drying time, curing time and hardness of the unknown lacquer coating film Thus, it is possible to determine the origin classified in the data of Table 3 and determine whether the main component of lacquer lacquer is mixed or not based on this.

Example 6. Analysis method of urushiol and lactol mixing degree of unknown raw chil using FT-IR

14A and 14B, there is a difference in molecular structure between urushiol and lactol (disclosed in R.Lu et al., Polym. Rev. 53 (2013) 153-191). In particular, cis (cis) and trans (trans) conjugation was found in the structure of the carbon-carbon double bond in the lipid chain of urushiol, but not in lactol. In addition, =CH ₂ exists at the end of the lipid chain of urushiol, but was not found in laccol. It is known that the main structure of lactol is a structure in which a carbon-carbon double bond forms trans and trnas conjugation. Therefore, the present invention performed FT-IR analysis based on this information.

In order to establish a calibration curve, each sample mixed with urushiol: lactol mixing molar ratios of 1:0, 1:0.5, 1:1, 1:2, and 0:1 was analyzed by FT-IR.

15 is a graph showing the results of the FT-IR analysis. C = C cis, trans conjugation peak value of urushiol appeared at about 987 cm ^-1 , and the The peak value of C=C trans, trnas conjugation was about 981 cm ^-1 .

As shown in Figure 16, when the calibration curve is prepared, the peak value (about 981 cm ^-1 ) when urushiol: lactol is 1:0 is displayed on the graph according to the shift of the conjugated diene peak, and then the calibration curve can be derived.

As shown in FIG. 17, based on the calibration curve derived in this way, the lacquer filtrate (Pyeonghwa mother-of-pearl 2016, Pyeonghwa mother-of-pearl 2018, Pyeonghwa mother-of-pearl 2019) having an unknown mixing ratio was analyzed by FT-IR. 980 cm ^-1 to 990 As a result of obtaining the peak shift value within the cm ^-1 range and preparing for the calibration curve, it is possible to infer the degree of catechol molecular mixing in Pyeonghwa mother-of-pearl 2016 with a lactol fraction compared to urushiol of 46.7%, Pyeonghwa mother-of-pearl 2018 31.0%, and Peace mother-of-pearl 2019 94.2%. could

Example 7. Evaluation of properties of raw and refined coating films

As shown in FIG. 18, the brush coater operating conditions and external environmental conditions disclosed in Example 2 were the same, and only the lacquer solution was independently different for raw and refined coating. did

fill characteristics How to measure Sample peace mother-of-pearl (B-2) raw refining Solution (fresh coating) characteristics Moisture content (%) 27.62 2.49 Viscosity
(Pas @ 100s ^-1 ) 1.58 9.61 drying time dry to the touch 3 One curing time FT-IR 5 4 fill thickness a-step thickness (um) 8.28 (± 0.49) 7.29 (± 0.38) permeability UV-Spectrum (T%, @600 nm) 30.5 19.1 blur Haze meter (diffuse %, @550 nm) 16.0 16.5 glossiness gloss meter (GU) 25 15 Hardness
Sclerometer (N) 3.3 2.5 pencil hardness 9 8.8 adhesion
(copper) Cross-cut test 2B 1B

Table 4 shows the results of evaluation of the properties of fresh and refined lacquer. It was confirmed that, while the tablet coating had a faster drying time and curing time, the raw coating had superior transmittance, gloss, and adhesion compared to the refined coating. Conversely, using these results, it is possible to determine whether raw or refined coating is applied by evaluating drying time, curing time, transmittance, glossiness, and adhesion characteristics of an unknown lacquer film.

Claims (18)

A first step of receiving a lacquer material from the client;
a second step of determining whether the lacquer material is a raw lacquer solution or a lacquer-coated film;
a third step of selecting an evaluation item of the lacquer material; and
A method for providing lacquer information, comprising a fourth step of measuring an evaluation index of the lacquer material for determining the evaluation item.
According to claim 1,
When the lacquer material is a raw lacquer solution,
The evaluation item of the third step is the country of origin or the degree of mixing of catechol molecules, the method of providing lacquer information.
3. The method of claim 2,
If the evaluation item in step 3 above is the country of origin,
The evaluation indicators of the fourth step are moisture content and viscosity, lacquer information providing method.
3. The method of claim 2,
When the evaluation item of the third step is the degree of catechol molecular mixing,
The evaluation index of the fourth step will be an infrared absorption spectrum (infrared absorption spectrum), lacquer information providing method.
According to claim 1,
The method for providing lacquer information, characterized in that the lacquer-coated coating film is produced using an applicator with a brush for evaluation of the lacquer coating film.
6. The method of claim 5,
The lacquer-coated film is
i) filtering the lacquer lacquer solution to remove aggregates;
ii) providing a lacquer solution in which the raw lacquer is mixed with terpine oil;
iii) repeating 3 to 8 times at a speed of 10 mm/s to 30 mm/s on the upper surface of the coating film to coat the lacquer solution with a brush coater; and
iv) The method for providing lacquer information, which is produced in the step of curing the coating film coated with the lacquer solution.
7. The method of claim 6,
The method for providing lacquer information, characterized in that the coating thickness deviation of the lacquer-coated film is 10% or less.
7. The method of claim 6,
In the lacquer-coated coating film, the coating thickness is from 2 μm to 10 μm, the method for providing lacquer information.
7. The method of claim 6,
The coating film is any one selected from the group consisting of glass, wood and metal, lacquer information providing method.
10. The method of claim 9,
When the coating film is glass,
The evaluation item of the third step is the country of origin, lacquer information providing method.
11. The method of claim 10,
The evaluation index of the fourth step is drying time, curing time, transmittance, haze, gloss and hardness, lacquer information providing method.
12. The method of claim 11,
The curing time is
i) obtaining an infrared absorption spectrum of the lacquer-coated film;
ii) monitoring a peak at 2990 cm ^-1 to 3010 cm ^-1 representing =CH in the infrared absorption spectrum; and
iii) A method for providing lacquer information, which is measured by performing the step of plotting the integral value of the peak to create a graph.
A method for evaluating lacquer materials, comprising:
The evaluation index is at least one or more from the group consisting of viscosity, moisture content, infrared absorption spectrum, drying time, curing time, hardness, transmittance, haze, gloss, curing and adhesive strength, lacquer material evaluation method.
14. The method of claim 13,
When the lacquer material is a raw lacquer solution,
The evaluation index is viscosity, moisture content, or infrared absorption spectrum, the lacquer material evaluation method.
15. The method of claim 14,
The lacquer material evaluation method, which evaluates the country of origin by measuring the evaluation index.
15. The method of claim 14,
A lacquer evaluation method for evaluating the degree of catechol molecular mixing or origin by measuring the evaluation index.
14. The method of claim 13,
When the form of the lacquer is a coating film coated with lacquer,
The evaluation indices are drying time, curing time, hardness, transmittance, haze, gloss, curing and adhesive strength, lacquer evaluation method.
18. The method of claim 17,
A lacquer evaluation method that evaluates whether the country of origin or refining by measuring the evaluation index.

Images