JP3386580B2 - X-ray analysis method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for preparing a calibration curve for determining the amount of coating material adhering to a measurement object immediately after coating in X-ray analysis, and a coating method using the calibration curve. The present invention relates to a method for measuring the amount of paint adhered to obtain the amount of adhered paint.

[0002]

2. Description of the Related Art The amount of paint adhered is important as a factor that determines the color tone and adhesion strength of a coating. Conventionally, the object to be measured immediately after coating, such as a galvanized steel sheet, is irradiated with primary X-rays and is generated from the paint. It is controlled by a measuring method in which the intensity of the secondary X-rays to be obtained is calculated, and the amount of paint adhered per unit area is calculated using a calibration curve prepared in advance. The method of creating the calibration curve used at this time will be described below.

On a section of a galvanized steel sheet having the same composition as the galvanized steel sheet to be analyzed and having a known weight and area,
Apply a paint of the same composition as the analysis target and use it as a standard sample.
Here, the paint is composed of a solvent which is a volatile component and a pigment which is a volatile residue, and the weight ratio between the pigment in the paint to be analyzed and the whole paint is known. After irradiating this standard sample with primary X-rays and measuring the intensity of secondary X-rays generated from the undried paint, the standard sample paint is dried to volatilize the solvent, and the weight after drying is measured. .

[0004] The weight of the standard sample after the drying is subtracted from the weight of the standard sample is the weight of the pigment in the standard sample. From the weight and the weight ratio of the pigment to the entire paint, the weight of the standard sample immediately after coating is measured. Calculate the weight of the paint.
The weight of the paint immediately after coating in this standard sample is divided by the area of the above-mentioned section to obtain the amount of paint adhered per unit area in the standard sample, and the amount of paint adhered per unit area and the secondary generated from the above paint The correlation with the X-ray intensity was obtained from a plurality of standard samples and used as the calibration curve.

[0005]

In the above-mentioned calibration curve producing method, a standard sample is prepared by applying a paint to a section of a galvanized steel sheet, and then the standard sample is set in an X-ray analyzer.
It takes at least 1 minute or more to measure the intensity of the next X-ray, but it is assumed that the solvent does not volatilize from the paint during that time, that is, the measured intensity of the secondary X-ray is applied to a standard sample. A calibration curve is prepared as the intensity of the secondary X-ray generated from the paint immediately after. However, in reality, the volatilization amount of the solvent from the paint immediately after coating is rather large in the entire volatilization process, and the calibration curve created by ignoring the volatilization of the solvent during the working time immediately after the coating described above was actually used immediately after coating. Even if the intensity of the secondary X-ray generated from the coating is applied to the galvanized steel sheet by irradiating it with the primary X-ray, the accurate adhesion amount per unit area cannot be obtained.

The present invention has been made in view of the above-mentioned conventional problems. In X-ray analysis, there is no error due to volatilization of the solvent from the paint, and an accurate paint per unit area of the object to be measured immediately after painting. It is an object of the present invention to provide a method for creating a calibration curve for determining the amount of adhesion, and a method for measuring the amount of coating material that determines the amount of coating by using the calibration curve.

[0007]

In order to achieve the above object, in the method of claim 1, the primary X-rays are irradiated onto a measuring object immediately after coating, in which the coating material is applied to the base substrate, and the measurement object is generated from the coating material. Then, the intensity of the secondary X-ray to be obtained is obtained, and a calibration curve for obtaining the amount of paint adhered per unit area is created from the intensity. Here, a small coating polymer film in which the coating material is dropped on the base polymer film, and the whole area is included in the main shadow area of which the area is known and the linear density in the primary X-ray irradiation region is almost uniform. A standard sample is covered with the dropped paint, the weight of the paint in the standard sample is measured, and the amount of the paint adhered per unit area in the standard sample is calculated from the weight and the area of the coating polymer film. Next, the standard sample is installed so that the entire polymer film for coating constituting the standard sample is in the main shadow portion, and the primary X-ray is irradiated to generate a secondary sample generated from the paint in the standard sample. Obtain the intensity of X-rays.

On the other hand, a large-scale conversion polymer film having an area larger than the irradiation area of the primary X-rays is irradiated with the primary X-rays to obtain 2
The first film strength of the next X-ray is measured, and the entire small polymer film for conversion having the same composition and thickness as the large polymer film for conversion and the same area as the covering polymer film is used as the main shadow. The film is placed in a portion and irradiated with primary X-rays, the second film intensity of the secondary X-rays is measured, and the correlation between the first film intensity and the second film intensity is obtained. Then, based on the correlation, the intensity of the secondary X-rays generated from the paint in the standard sample is set to 1 for the measurement object immediately after coating, in which the amount of paint adhered per unit area is the same as that of the standard sample. When the secondary X-ray is irradiated, it is converted into the intensity of the secondary X-ray generated from the paint on the base substrate, and the converted intensity of the secondary X-ray and the adhesion of the paint per unit area in the standard sample. A calibration curve showing the correlation with the amount is created.

According to the method of claim 2, the primary X-ray is applied to the measurement object immediately after coating, which is obtained by coating the base substrate with the coating material, and the intensity of the secondary X-ray generated from the coating material is obtained.
Determine the amount of paint adhered per unit area using the calibration curve created in.

[0010]

According to the present invention, when the calibration curve is prepared, the paint is covered with the polymer film so that the solvent does not evaporate from the paint in the standard sample, so that the accurate calibration curve can be prepared and the calibration curve can be prepared. It is possible to accurately determine the amount of paint adhered per unit area of the measurement target immediately after coating using the line.

[0011]

【Example】

[Preparation Method of Calibration Curve] An embodiment of the present invention will be described below with reference to the drawings. First, a method of creating a calibration curve will be described. As shown in FIG. 1A, generally, during primary X-ray irradiation, a sample table 4 for primary X-rays generated from an X-ray source 3 is generated due to the positional relationship between the target 1 and the opening of the X-ray tube 2. The irradiation area C above is a main shadow area A at the center and a semi-shadow area B at the outer circumference.
Divided into As shown in FIG. 2, the linear density of the primary X-rays in the irradiation region C is almost uniform in the main shadow part A, and in the penumbra part B at the inner edge that forms a boundary with the main shadow part A. It has the same intensity as the main shadow portion A, and decreases at a constant gradient until it becomes 0 at the outer edge that coincides with the outer edge of the irradiation area C.

On the base polymer film 7 having a larger area than the primary X-ray irradiation region C, a covering polymer film 8 having a smaller area than the main shadow A and a known area S is placed. And the total weight M ₁ is measured, and both of these films are placed on the sample table 4 so that the entire coating polymer film 8 is in the main shadow portion A, as shown in FIG. The secondary X-ray generated from the base polymer film 7 and the coating polymer film 8 , for example, Compton scattered ray intensity i ₁ by being installed and irradiated with the primary X-ray from the X-ray source 3.
Is detected by the detector 6.

Next, the coating polymer film 8 is once removed, a paint 9 having the same composition as the paint to be analyzed is dropped on the base polymer film 7, and the paint 9 is used as the base polymer film 7. The coating 9 is covered with the coating polymer film 8 so as not to spread too much above and the solvent does not evaporate from the coating 9 to obtain a standard sample 10.
At this time, due to the surface tension relationship between the coating 9 and the base polymer film 7 and the coating polymer film 8, the coating 9 does not protrude from the coating polymer film 8 and stays within a range smaller than the area S thereof. . And FIG. 1 (b)
As shown in FIG. 1, the X-ray sources 3 to 1 are installed on the sample table 4 so that the entire coating polymer film 8 is in the main shadow portion A.
The next X-ray is irradiated, and the intensity i ₂ of the Compton scattered ray generated from the standard sample 10 is detected by the detector 6.

[0014] Then, the weight M ₂ measured down the standard sample 10 from the sample stage 4, the weight M ₂ of the standard sample 10
The total weight M ₁ of the base polymer film 7 and the coating polymer film 8 is subtracted from the above to calculate the weight M (g) of the paint 9 in the standard sample 10 (M = M ₂ −
M ₁ ). Further, the paint in the standard sample 10 is obtained by subtracting the intensity i ₁ of the Compton scattering line generated from the base polymer film 7 and the coating polymer film 8 from the intensity i _{2 of} the Compton scattering line generated from the standard sample 10. The intensity i of Compton scattered rays generated from 9 is calculated (i =
i ₂ -i _1).

Here, the intensity i of this Compton scattered ray is
Is the intensity of Compton scattered rays generated when the entire paint 9 enters the main shadow area A where the linear density of the primary X-rays is considered to be uniform, and is proportional to the weight M of the paint 9 in the standard sample 10. However, it has nothing to do with the spread area of the paint 9 and the uniformity of spread. The coating material 9 having a weight M does not necessarily spread evenly and strictly within the range of the coating polymer film 8 and it is difficult to measure the spread area, but for the above reason, in the main shadow portion A. Even if it spreads uniformly over a certain area, the intensity of Compton scattered rays generated regardless of the area is the same intensity i. Therefore, assuming that the certain area is the area S of the coating polymer film 8 for convenience, the weight M of the paint 9 in the standard sample 10 is divided by the area S, and the adhesion amount M of the paint per unit area in the standard sample 10 is M. / S
It can be (g / m ² ).

As described above, the intensity i of the Compton scattered ray is the intensity of the Compton scattered ray generated when the entire paint 9 enters the main shadow area A where the linear density of the primary X-rays is considered to be uniform. The strength is proportional to the weight M of the paint 9 in the standard sample 10. Since the weight of the paint is the product of the amount of paint adhered per unit area and the painted area, if the expression is changed, in the main shadow part A, the intensity of Compton scattered rays generated from the paint is If the amount of paint adhered per area is the same, it is proportional to the painted area.

Therefore, if the coating material on the galvanized steel sheet immediately after coating to be analyzed is contained in the main shadow area A, the area X on which the coating material on the steel sheet is irradiated with the primary X-rays.
From the ratio X / S of the area S of the coating polymer film 8 to
The intensity i of the Compton scattered rays generated from the paint 9 in the standard sample 10 was irradiated with primary X-rays on a galvanized steel sheet immediately after coating having the same amount of paint adhered per unit area as the standard sample 10. In that case, the unit area of the galvanized steel sheet immediately after coating is converted into the intensity I of Compton scattered rays (hereinafter abbreviated as the conversion target intensity I) generated from the paint on the steel sheet (I = i × X / S). It is possible to create a calibration curve for determining the amount of paint adhered per area.

However, when the coating material on the galvanized steel sheet immediately after coating in the coating process to be analyzed is irradiated with the primary X-rays, the coating material has a penumbra with a non-uniform primary X-ray irradiation density. The intensity i of the Compton scattered ray which spreads over the irradiation region C including the portion B and is generated from the paint 9 in the standard sample 10 is the area ratio X / S, that is, C / S in this case.
It cannot be simply converted from S to the conversion target intensity I and cannot be used for creating a calibration curve. Therefore, the intensity i of the Compton scattered rays generated from the paint 9 in the standard sample 10 is converted into the conversion target intensity I by the method described below.

As shown in FIG. 3 (a), the conversion large polymer film 1 having a larger area than the primary X-ray irradiation area C.
1 is placed on the sample table 4, primary X-rays are irradiated from the X-ray source 3, and the intensity I ₀ of the Compton scattered rays generated is detected by the detector 6 to be the first film intensity I ₀ . Next, FIG.
As shown in (b), the conversion base polymer film 12 having a larger area than the primary X-ray irradiation region C is placed on the sample table 4, and the primary X-ray is irradiated from the X-ray source 3. The detector 6 detects the intensity i ₃ of the generated Compton scattered ray.

Subsequently, as shown in FIG. 3 (c), a polymer having the same composition and thickness as the large polymer film for conversion 11 and an area of the covering polymer is formed on the conversion base polymer film 12. The same small polymer film 13 for conversion as the film 8 is placed, the entire small polymer film 13 for conversion is put in the main shadow portion A, and primary X-rays are irradiated from the X-ray source 3 to generate Compton scattered rays. detecting the intensity i ₄ by the detector 6, by subtracting the intensity i ₃ Compton scattered rays generated from the conversion for the base polymer film 12, the second film strength i generated from only terms for small polymer film 13 ₀ is calculated (i ₀ = i ₄ −i ₃ ). Here, the second film strength i ₀ generated only from the conversion small polymer film 13 is not directly measured, but is indirectly measured using the conversion base polymer film 12. This is because 13 has a small diameter of 10 mm, for example, and the intensity of Compton scattered rays generated therefrom is small, and it is difficult to perform X-ray analysis independently without being affected by the surroundings.

In the large conversion polymer film 11 and the small conversion polymer film 13 having the same composition and the same thickness as those of the large conversion polymer film 11, a plurality of different thicknesses are used for the first
The film strength I ₀ and the second film strength i ₀ (i ₀ =
By obtaining i ₄ −i ₃ ), the correlation represented by the following equation (1) can be obtained. I ₀ = a · i ₀ + b (1) where a and b are constants, where the first film strength I ₀ and the second film strength i ₀
The relationship between and corresponds to the relationship between the converted target intensity I and the intensity i of Compton scattered rays generated from the paint 9 in the standard sample 10. Therefore, based on this correlation, that is, by substituting the intensity i of the Compton scattered ray generated from the paint 9 in the standard sample 10 into i ₀ , the converted target intensity I is calculated as I ₀ . The correlation between the calculated conversion target strength I and the amount M / S (g / m ² ) of the paint adhered per unit area in the standard sample 10 is determined by the standard sample 10 containing a plurality of paints of different weights. From
A calibration curve as shown in FIG. 4 can be created.

[Method of Measuring Adhesion Amount of Paint on Measurement Object] Next, a method of measuring an adhesion amount of paint using the calibration curve will be described. An object to be measured immediately after coating, for example, a galvanized steel sheet, is irradiated with primary X-rays, the intensity I ₅ of Compton scattered rays generated from the paint is detected, and fitted to a calibration curve shown in FIG. The coating amount T ₅ per unit area of the galvanized steel sheet is obtained.

[0023]

According to the present invention, when a calibration curve is prepared, the coating material is covered with a polymer film so that the solvent does not evaporate from the coating material in the standard sample, so that an accurate calibration curve can be prepared. Using the calibration curve, it is possible to accurately determine the amount of paint adhered per unit area of the measurement target immediately after coating. Therefore, in the coating process of the object to be measured, a high level of quality control can be performed in terms of the color tone of the coating and the adhesion strength, and the efficiency of the coating work is also improved.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of the present invention.

FIG. 2 is a diagram showing a distribution of linear densities of primary X-rays in a main shadow part and a penumbra part.

FIG. 3 is a side view showing the irradiation state of primary X-rays on the conversion large polymer film, the conversion base polymer film, and the conversion small polymer film in the present invention.

FIG. 4 is a calibration curve showing the correlation between the intensity of Compton scattered rays and the amount of paint adhered per unit area in the present invention.

[Explanation of symbols]

7 ... Polymer film for base, 8 ... Polymer film for coating, 9 ... Paint, 10 ... Standard sample, A ... Main shadow part, C ... 1
Next X-ray irradiation area, S ... Area of coating polymer film.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuuaki Kato 2 Dejima Nishimachi, Sakai City, Osaka Prefecture Igeta Steel Sheet Co., Ltd. (72) Toshiyuki Tanaka 2-31-1 Nihonbashihamacho, Chuo-ku, Tokyo Taiyo Steel Corporation In-house (72) Inventor Yoshiki Koshikawa 11-17 Fuyuki, Koto-ku, Tokyo Kawairon Steel Plate Stock Company (72) Inventor Takeshi Ikeno 4-1-1 Minamihonmachi, Chuo-ku, Osaka-shi, Osaka Yodogawa Steel Co., Ltd. In-house (72) Inventor Seiya Shibata 14-8 Akaoji-cho, Takatsuki-shi, Osaka Inside Rigaku Denki Kogyo Co., Ltd. (56) Reference JP-A-5-180788 (JP, A) JP-A-5-10743 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 23/20-23/207 G01B 15/02

Claims (2)

(57) [Claims] 1. A secondary X generated from the paint by irradiating a measurement target object immediately after painting, in which the paint is applied to the base substrate, with the primary X-ray.
A method for creating a calibration curve for determining the strength of a line and the amount of paint adhered per unit area from the strength, in which the paint is dropped on the base polymer film and the area is known and the primary X A small amount of the coating polymer film, which is entirely contained in the main shadow area where the line density in the line irradiation area is almost uniform, is applied as a standard sample, and the weight of the paint in the standard sample is measured. From the weight and the area of the coating polymer film, calculate the adhesion amount of the paint per unit area in the standard sample, and put the standard sample into the main shadow area where the entire coating polymer film that constitutes the standard sample Installed, the primary X-ray is irradiated, the intensity of the secondary X-ray generated from the paint in the standard sample is determined, and the area is larger than the primary X-ray irradiation area. Secondary X-ray by irradiating primary X-ray In addition to measuring the first film strength, the whole small polymer film for conversion having the same composition and thickness as the large polymer film for conversion and the same area as the polymer film for coating is placed in the main shadow portion. Then, the secondary X-ray is irradiated with primary X-rays, the second film intensity of the secondary X-rays is measured, the correlation between the first film intensity and the second film intensity is obtained, and the standard sample is obtained based on the correlation. The intensity of the secondary X-rays generated from the coating material on the base substrate when the primary X-ray is irradiated to the measurement object immediately after coating, which has the same amount of coating material per unit area as the standard sample. Is converted into the intensity of the secondary X-ray generated from the paint, and a calibration curve showing the correlation between the converted intensity of the secondary X-ray and the amount of the paint adhered per unit area in the standard sample is prepared. How to create a calibration curve. 2. The primary X-ray is applied to a measurement object immediately after coating, in which the coating is applied to the base substrate, and the intensity of the secondary X-ray generated from the coating is determined, and the calibration curve prepared in claim 1 is used. A method for measuring the amount of paint adhered by X-ray analysis to determine the amount of paint adhered per unit area.