JPH05180788A - Method for measuring adherence value of paint film - Google Patents

Abstract

PURPOSE:To measure an adherence value of a paint film accurately by a Compton scattering beam without stopping a painting line by determining a calibration curve with high reliability using a reference sample for a sample to be measured which has the wet painted film on a ground substrate continuing in the direction of flowing. CONSTITUTION:In a process of determining a calibration curve, first, the weight of a ground substrate 2 is measured before the coating of a reference sample 2Pw. After the measurement, the weight of the reference sample 2Pw wet after the coating is measured while the intensity of a Compton scattering beam BC is measured. After the measurement, a deposit quantity of the paint film Pw of the reference sample 2Pw wet is determined from both the weights to obtain a calibration curve based on the deposit quantity and the intensity of the Compton scattering beam Bc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the amount of coating film adhered, and more particularly, to a base substrate continuous in the flow direction,
The present invention relates to a measuring method of irradiating a surface of a sample to be measured having a coating film in a wet state coated with a coating material containing a volatile component with radiation to measure the amount of the coating film attached.

[0002]

2. Description of the Related Art The adhesion amount of a coating film is important as a factor for determining the color tone and adhesion strength of the coating film. Therefore, conventionally, the coating film adhesion amount is controlled by a measuring method using radiation. An example of this measuring method will be described with reference to FIGS.

In FIG. 5, a coating material having a volatile component is applied by an applicator 7 onto a base substrate 1 which is continuous in the flow direction Y, such as a plated steel plate. Immediately after the coating, i.e. the measured sample 1P _W to the coating film P _W wet state, on its surface, the radiation source 3, such as X-ray tube
Then, the primary X-ray (radiation) B is emitted. The irradiated primary X-rays B lose some of their energy in the coating film P _W to become Compton scattered rays B _{C and} enter the X-ray detector 4. The Compton scattered ray B _C is detected by the X-ray detector 4, and the first intensity I _C1 of this Compton scattered ray B _C is measured in a counting circuit section (not shown). Based on the first intensity I _C1 and the calibration curve obtained in advance,
The adhesion amount T _PW of the coating film P _{W in} the wet state is obtained. In this way, by measuring the adhesion amount T _PW of the coating film P _W immediately after coating, the coating machine 7 is controlled in real time, and the adhesion amount T _PW is controlled.
Manage.

The sample 1P _{W to} be measured is dried by passing through the dryer 5. In addition, the radiation source 3
The analyzer including the X-ray detector 4 and the like is a coating machine 7
It is provided immediately downstream of.

Next, how to obtain the calibration curve will be described. In FIG. 6A, first, a section 2 of a plated steel sheet having the same composition as that of the base substrate 1 is prepared, and its weight W ₂
Is weighed by the weighing device 6. Then, as shown in FIG. 6 (b), a coating material is applied onto the base substrate composed of the above-mentioned section 2,
Standard sample 2 with wet coating P _W on section 2
Create P _W. After this, this standard sample 2P _W
The second intensity I _C2 of the Compton scattered ray B _C is measured by the analyzer 10 having the radiation source 3 and the X-ray detector 4 in (c). After this measurement, the standard sample 2P _W is put into the dryer 5A shown in FIG. 6D to dry the coating film P _W, and the coating film P _D in the dry state shown in FIG. _6E is dried. Obtain standard sample 2P _D. After this drying, dry standard sample 2P
Weigh _{D 2} W _PD .

Here, the ratio of the pigment (volatile residue) to the solvent (volatile component) in the paint is constant. Thus, from the weight W _2PD dry standard sample 2P _D, by subtracting the weight W ₂ of section 2 obtains the weight W _PD only dry coating film P _D, the weight W _PD of the dried coating film volatilized residue By dividing by the division ratio k, the weight W _PW of the coating film P _{W in} the wet state can be obtained. The weight W _PW by dividing by the area of section 2 obtains the adhesion amount T _PW of the wet state, the adhesion amount T _PW and the Compton scattered X-ray plurality of standard samples 2 the relationship of the second intensity I _C2 of B _C
P _W was obtained, and thereby a calibration curve was obtained.

[0007]

Here, when preparing the above calibration curve, it takes about 1 minute before the standard sample 2P _W is carried into the analyzer 10 after coating. Inevitable. However, in this conventional method, as shown in FIG.
Since the elapsed time from immediately after the application of (b) to the measurement of Compton scattered radiation B _C of FIG. 6 (c) is not so long as about 1 minute, it is assumed that the volatile content during this period is minute, The calibration curve is created by ignoring it.

However, this volatile content is relatively large immediately after coating as shown in FIG. 7, and therefore, the amount of adhesion T _PW of the coating film P _W immediately after coating and the Compton scattered radiation B _C
Is slightly different from the adhesion amount T _PW when the second strength I _C2 of the above is measured. Therefore, the calibration curve is inaccurate, which causes a measurement error. As a result, the accuracy of analysis is reduced, and depending on the type of paint, 3 g / m ^{2 to} 4 g / m
An error of about ² (for an adhesion amount of 20 g / m ² ) occurs.

On the other hand, using the online device of FIG.
It is also possible to accurately obtain the above-mentioned calibration curve. That is, a part of the measured sample 1P _{D in} the dry state dried by the dryer 5 is taken as a slice, the adhesion amount T _PD of this slice is obtained, and the adhesion amount T _PW in the wet state is obtained from this value. afterwards,
It is also possible to obtain a calibration curve by performing regression calculation by the fundamental parameter method from the measured first strength I _C1 and the adhered amount T _PW .

However, in this method, the coating line must be stopped to create a calibration curve for each type of coated steel sheet for which a calibration curve is to be obtained, and therefore productivity is significantly reduced.

The present invention has been made in order to solve the above-mentioned conventional drawbacks. For a sample to be measured having a coating film in a wet state on a base substrate, a highly reliable calibration curve is obtained using a standard sample. Accordingly, it is an object of the present invention to provide a method for measuring the amount of adhered coating film, which can accurately perform the radiation analysis.

[0012]

In order to achieve the above object, in the invention of claim 1, in the step of obtaining the calibration curve, first, the weight of the base substrate before coating in the standard sample is measured. After this measurement, the weight of the wet standard sample after coating is measured, and at the same time, the intensity of the radiation emitted from the standard sample is measured. On the other hand, the adhered amount of the coating film of the standard sample in the wet state is obtained from the both weights, and the calibration curve is obtained based on the adhered amount and the intensity of the radiation.

According to the second aspect of the present invention, in the step of obtaining the calibration curve, first, the temporal change of the volatile matter content rate of the coating film is first obtained. After this, the intensity of radiation is measured for the standard sample. After this measurement, the volatile content is obtained based on the time from the application of the standard sample to the measurement of the intensity of the radiation and the volatile content rate, and the volatile content is subtracted from the coating film adhesion amount immediately after application of the standard sample. Then, the coating film adhesion amount at the time of measuring the intensity of the radiation is obtained. A calibration curve is obtained based on the amount of coating film adhered and the intensity of the radiation.

According to the third aspect of the invention, the calibration curve constant α ₁ of the volatile component obtained by measuring the volatile component of the coating material and the calibration curve constant α of the volatile residue obtained by measuring the dried coating film are obtained. _{Based on 2} and the volatilization residue ratio k, a calibration constant α for quantifying the adhesion amount of the wet coating film is obtained.

[0015]

According to the invention of claim 1 or 2, the accurate amount of coating film in the wet state when the radiation intensity of the standard sample is measured is obtained, that is, after the application, until the radiation intensity measurement. Since the volatile components of are considered, the amount of coating film adhesion corresponds to the intensity of radiation. Therefore, an accurate calibration curve can be obtained.

According to the third aspect of the invention, the calibration curve constant α for quantifying the amount of coating film in the wet state is determined by the calibration curve constants α ₁ and α ₂ of the volatile residue and the volatile component and the volatilization residue. Since it is obtained based on the ratio k, there is no error caused by volatilization of the volatile component.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, a method of obtaining a calibration curve or a calibration curve constant will be mainly described.

FIG. 1 shows how to obtain a calibration curve according to the first embodiment of the present invention. First, as shown in FIG. 1A, the weight W ₂ of the base substrate before application in the standard sample, that is, the piece ₂ is measured by the measuring device 6. Then, as shown in FIG. 1 (b), a paint is applied to the section 2 with a hand-painted applicator such as a bar coater (not shown) to form a standard sample 2P _W having a wet coating film P _W. obtain. This Figure 1
Up to the step of (b), it is similar to the conventional example of FIGS.

After the above coating, the standard sample 2P _W is carried into the analyzer 10A as shown in FIG. 1 (c). The analyzer 10A has a weighing instrument 6A in addition to the radiation source 3, the X-ray detector 4, and the like.

After the above-mentioned loading, the standard sample 2P in a wet state
The weight W _2PW of _W metered in meter 6A. Simultaneously with this measurement, the primary X-ray B is applied to the standard sample 2P _W from the radiation source 3. The irradiated primary X-rays B generate Compton scattered rays B _C from the coating film P _W and enter the X-ray detector 4.
The second intensity I _C2 of the Compton scattered ray B _C is measured by a counting circuit unit (not shown).

[0021] After the measurement is subtracted the weight W ₂ of section 2 from the weight W _2PW the standard sample 2P _W of the wet state, obtains the weight W _PW of coating P _W wet state, the weight W _PW Is divided by the area of the section 2 to obtain the wet film coating amount T _PW . The relationship between the coating film adhesion amount T _PW and the measured second strength I _C2 is obtained for a plurality of standard samples 2P _W to obtain a calibration curve.

Using this calibration curve, the above-mentioned online measurement of FIG. 5 is carried out to obtain the wet film coating amount T _PW of the sample 1P _{W to} be measured. The method is similar to that of the conventional example shown in FIG. 5, and the description thereof is omitted.

In the measuring method of FIG. 1, the standard sample 2P _W in a wet state is weighed, and at the same time, the second intensity I _C2 of the Compton scattered ray B _C is measured. Therefore, it is possible to measure the second strength I _C2 that accurately corresponds to the adhesion amount T _PW in the wet state. Therefore, even if the second strength I _C2 is not measured at the online position, the standard sample 2P _W having the section 2 as the base substrate is used. Therefore, the calibration curve can be accurately obtained. That is, in the past, the calibration curve shown by the one-dot chain line in FIG. 1 (d) was used, but according to this measurement method, the volatile content rate ΔT from coating to the measurement of the Compton scattering line B _C is taken into consideration. An accurate calibration curve can be obtained. As a result, the measured sample 1P of FIG.
It is possible to accurately measure the coating film deposition amount T _PW of _W.

FIG. 2 shows a method of preparing a calibration curve according to the second embodiment of the present invention. First, as shown in FIG. 2 (a), the weight W _{8 of the} section 8 serving as the sample for measurement is measured by the measuring device 6. Then, a measurement sample 8P _W having a coating film P _W in a wet state in which the paint is applied to the section 8 is obtained. After the coating immediately as shown in FIG. 2 (b), placing the metering sample 8P _W on the weighing device 6, the metering sample 8P _W, the weight W of the weighing sample 8P _W with respect to the elapsed time from immediately after application
_Record the change in _8PW (see Figure 3). Based on this weight W _8PW , the amount of volatile _matter with respect to the elapsed time immediately after coating can be known. After this measurement is performed for about 2 minutes, the measurement sample 8P _W is put into the dryer 5A and dried as shown in FIG. 2 (c). The dried weighing sample 8P _D is placed on the weighing device 6 and weighed.

As described in the above-mentioned conventional example, the weight W _PD of the coating film P _{D in} the dry state is obtained from the measured values shown in FIGS. 2D and 2A, and the weight W _PD and the volatile residue ratio are obtained. The weight W _PW of the coating film P _W immediately after coating is determined from k. On the other hand, FIG. 2 (b)
Since the volatile content is known from the continuous measurement of, the ratio of the volatile content to the coating film weight W _PW immediately after the application, that is, the volatile content rate ΔT can be found. In this way, the change in the volatile matter amount rate ΔT with respect to the elapsed time after coating is obtained as shown in FIG.

After that, a standard sample 2P _W different from the above-mentioned weighing sample 8P _W is used for the above-mentioned FIGS. 5 (a) to 5 (e).
2E to 2H, the section 2 is weighed, applied, the second intensity I _C2 of the Compton scattered ray B _C is measured, and the dried and dried standard sample 2P _D is weighed.

At this time, from the coating of FIG. 2 (f) to the coating of FIG. 2 (g).
The elapsed time t up to the measurement of the second intensity I _C2 of the Compton scattered ray B _C is measured. The volatile content rate ΔT at this elapsed time t is obtained from the graph of FIG. 3, while the volatile content is subtracted from the coating film deposition quantity T _PW of the standard sample 2P _W immediately after coating to obtain the second intensity of the Compton scattered ray B _C. The coating film adhesion amount T _PW (1-ΔT) at the time of measuring I _C2 is determined. The second intensity I _C2 of this Compton scattered ray B _C and the coating film deposition amount T _PW (1-ΔT)
The relationship with the two or more standard samples 2P with different coating amount T _PW
Obtain _W and obtain a calibration curve.

After obtaining the above calibration curve, the above-mentioned measurement in the online state of FIG. 5 is carried out, and the coating amount W _PW in the wet state of the sample 1P _{W to} be measured is determined using the above calibration curve. The method is similar to that of the conventional example shown in FIG. 5, and the description thereof is omitted.

As described above, in the measuring method of FIG. 2, the volatile content rate ΔT with respect to the elapsed time after coating is obtained in advance, and the second intensity I _C2 of the Compton scattered ray B _C in the standard sample 2P _W is obtained.
When this coating adhesion amount at the time of measurement of the second intensity I _C2 T _PW (1-
Since the calibration curve is calculated based on ΔT),
No error occurs due to the amount of volatile matter that has volatilized until the measurement of the intensity I _C2 . Therefore, since the calibration curve can be accurately obtained, the coating film deposition amount T _PW of the measured sample 1P _{W in} FIG. 5 can be accurately measured.

FIG. 4 shows how to obtain a calibration curve according to the third embodiment of the present invention. First, as shown in FIG. 4A, the volatile component P _V of the paint, which is composed only of the solvent, is sealed in the container 9 so as not to volatilize. After this, the volatile component P _V
About the intensity I of the Compton scattered ray B _C using the analyzer 10 including the radiation source 3 and the X-ray detector 4.
Measure _V. This measurement is performed for a plurality of volatile components P _V having different depths to obtain a calibration curve constant α ₁ for the volatile components P _V. The pigment (volatile residue) P in the paint
This calibration curve constant α ₁ is constant because the volatile component P _V does not change even if the component of _D changes.

On the other hand, the calibration curve constant α ₂ of the volatile residue P _D is obtained through the steps shown in FIGS. 4B to 4F, as described below. In order to obtain this calibration curve constant α ₂ , first, the weight W ₂ of the section ₂ is weighed in FIG. 4 (b), the coating material is applied to the section 2 as shown in FIG. 4 (c), and the standard sample 2P _W To get
This standard sample 2P _W is put into the dryer 5A of FIG. 4 (d) to remove the volatile components, and the dry standard sample 2P _D of FIG. 4 (e) is obtained. This dry standard sample 2P _D is put into the analyzer 10 and the intensity I _D of the Compton scattered ray B _C from the coating film P _D in the dry state is measured. After this measurement,
From the weight W _2PD the standard sample 2P _D of the dry state, by subtracting the weight W ₂ of the section 2, which was divided by the area of section 2 a, the coating deposition amount of the dry state T _D = (W _2PD - W ₂ ) /
get a. The coating amount T _{D in the} dry state and the intensity I _D of the Compton scattered ray B _C generated therefrom were measured for a plurality of standard samples 2P _D , and by regression calculation, the coating film P _{D in the} dry state, that is, the volatile residue A calibration curve constant α ₂ of P _D is obtained.

Next, based on the calibration curve constants α ₁ and α _{2 of} the volatile component P _V and the volatile residue P _D thus obtained and the volatile residue ratio k, the coating amount T _PW in the wet state is calculated. An example of how to obtain the calibration curve constant α in the case of quantification will be described.

The intensities I _V and I _D of the Compton scattered ray B _C are expressed by the following equations (1) and (2), respectively. I _V = A ₁ {1-exp (-B ₁ T _V )} (1) I _D = A ₂ {1-exp (-B ₂ T _D )} (2) where A ₁ , A ₂ : constant B _1: the mass absorption coefficient of X-rays by volatile components B _2: mass absorption coefficient of X-rays by volatile residue T _V: deposition amount T _D of the volatile component: wherein deposition amount of the volatile residue, B ₁ T _V << 1, B ₂ T _D <<< 1, so
The equations (1) and (2) are approximately represented by the following equations (11) and (12), respectively. I _V = A ₁ B ₁ T _V (11) I _D = A ₂ B ₂ T _D (12) A ₁ B ₁ = 1 / α ₁ and A ₂ B ₂ = 1 / α ₂ Expressions (11) and (12) are respectively expressed by (21)
It is expressed as in equation (22) and equation (22). T _V = α ₁ I _V (21) T _D = α ₂ I _D (22)

On the other hand, the coating amount T _PW in the wet state and the intensity I _C of the Compton scattered ray thereof are expressed by the following equations (3) and (4), respectively. T _PW = T _V + T _D (3) I _C = I _V + I _D (4) Further, from the volatilization residue ratio k, T _D = kT _PW (5) Further, the coating film deposition amount T _PW , The relationship with the Compton scattered ray I _W is as follows: T _PW = αI _C (6) The above equations (21), (22), (3), (4), (5) and (6) are solved to obtain a wet condition. The calibration curve constant α in the case of quantifying the coating film deposition amount T _PW in the state is obtained by the following equation (7). α = α ₁ α ₂ / {α ₂ (1-k) + α ₁ k)} (7)

The calibration curve constant α thus obtained is shown in FIG.
From the intensity I _C1 of the Compton scattered ray Bc measured in the online state, the coating film adhesion amount T _PW is obtained based on the above equation (6).

As described above, in this embodiment, the calibration curve constant α for quantifying the coating amount T _PW in the wet state is
Calibration curve constants for volatile residue P _D and volatile component P _V α ₁ , α
_Since it is obtained based on ₂ and the volatilization residue ratio k, the error caused by volatilization of the volatile component P _V is eliminated. Therefore, analysis accuracy is improved.

The adhesion amount T _PW was measured using this calibration curve constant α, and when the coating amount was 20 g / m ² ,
While there has been conventionally 3g / m ² ~4g / m ² about a large measurement error of the measurement error was reduced to about 0.6 g / m ^2.

By the way, in each of the above examples, the intensities I _C1 and I _C2 of the Compton scattered rays B _C were measured as the radiation generated from the sample to be measured 1P _W and the standard sample 2P _W.
In the present invention, the intensity of β-ray backscattered rays may be measured.

[0039]

As described above, according to the present invention, a highly reliable calibration curve is obtained by using a standard sample for a sample to be measured having a wet coating film on a base substrate continuous in the flow direction. Since it can be determined, the amount of coating film can be accurately measured by radiation without stopping the coating line for each type of coating material.

[Brief description of drawings]

1A to 1C are process diagrams showing a method for obtaining a calibration curve according to a first embodiment of the present invention, and FIG. 1D is a characteristic diagram showing the calibration curve.

FIG. 2 is a process drawing showing a method for obtaining a calibration curve according to a second embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a temporal transition of a volatile content rate.

4 (a) to 4 (f) are process diagrams showing a method for obtaining calibration curve constants α ₁ and α _{2 according} to the third embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a method for measuring Compton scattered radiation in a coating line.

FIG. 6 is a process chart showing how to obtain a conventional calibration curve.

FIG. 7 is a characteristic diagram showing a temporal transition of the volatile content.

[Explanation of symbols]

1 ... Base substrate continuous in the flow direction, 1P _W ... Measured sample, 2 ... Section (base substrate), 2P _W ... Wet standard sample, B ... Radiation (primary X-ray), Bc ... Radiation (Compton scattered ray) ), P _W ... wet coating, P _D ... dried coating.

 ─────────────────────────────────────────────────── ─── Continued Front Page (71) Applicant 000006910 Yodogawa Steel Works, Ltd. 4-1-1 Minamihonmachi, Chuo-ku, Osaka-shi, Osaka (72) Inventor Naoki Matsuura 14-8 Akaoji-machi, Takatsuki-shi, Osaka Rigaku Denki Kogyo Co., Ltd. (72) Inventor Seiya Shibata 14-8 Akaoji-cho, Takatsuki-shi, Osaka Rigaku Denki Kogyo Co., Ltd. (72) Inventor Tatsuo Fukusaki 14-8 Akaoji-cho, Takatsuki-shi, Osaka Rigaku Denki Industrial Co., Ltd. (72) Inventor Akira Tanaka, 2 Dejima Nishimachi, Sakai City, Osaka Prefecture Igeta Steel Plate Co., Ltd. (72) Inventor Shigeo Fukuda 2-4-1, Shiba Koen, Minato-ku, Tokyo Kawakawa Steel Plate Co., Ltd. (72) Inventor Hiroki Nishiyama 883 Kanesugi-cho, Funabashi-shi, Chiba Taiyo Steel Co., Ltd. 2-231, Sugisha House (72) Inventor Mitsuru Tanaka 4-1-1 Minamihonmachi, Chuo-ku, Osaka-shi, Osaka Inside the Yodogawa Steel Works

Claims (3)

[Claims] 1. The surface of a sample to be measured having a coating film in a wet state in which a paint containing a volatile component is applied on a base substrate continuous in the flow direction is irradiated with radiation immediately after coating, and this radiation is irradiated. The first intensity of the radiation emitted from the sample to be measured that has been received is measured, and on the other hand, the standard sample in a wet state composed of a slice is irradiated with the radiation, and the radiation emitted from the standard sample that has received this radiation is measured. By measuring the second intensity, a calibration curve consisting of the relationship between the second intensity and the amount of the coating film in the wet state is obtained in advance, and based on the first intensity and the calibration curve of the radiation, A method for measuring the amount of coating film in a wet state on a measurement sample, wherein in the step of determining the calibration curve, the weight of the base substrate before coating in the standard sample is weighed, and after this weighing, after coating The second strength is measured at the same time as the weight of the standard sample in the wet state is measured, and the coating amount of the coating film of the standard sample in the wet state is obtained from the both weights. Based on the coating amount and the second strength, A method for measuring the amount of coating film adhered to obtain a calibration curve. 2. The surface of a sample to be measured having a coating film in a wet state in which a coating material containing a volatile component is applied on a base substrate continuous in the flow direction is irradiated with radiation immediately after coating, and this radiation is irradiated. The first intensity of the radiation emitted from the sample to be measured that has been received is measured, and on the other hand, the standard sample in a wet state composed of a slice is irradiated with the radiation, and the radiation emitted from the standard sample that has received this radiation is measured. By measuring the second intensity, a calibration curve consisting of the relationship between the second intensity and the amount of the coating film in the wet state is obtained in advance, and based on the first intensity and the calibration curve of the radiation, A measuring method for determining the amount of a coating film in a wet state on a measurement sample, wherein in the step of determining the above calibration curve, a temporal transition of the volatile matter content rate of the coating film is determined in advance, and then the standard sample The strength is measured, the volatile content is obtained based on the time from the application of the standard sample to the measurement of the second strength and the volatile content rate, and the volatile content is calculated from the amount of coating film immediately after application of the standard sample. A method for measuring the amount of coating film adhered by subtracting the amount of coating film adhered during the second strength measurement to obtain the calibration curve based on the amount of coating film adhesion and the second strength. 3. The surface of a sample to be measured having a coating film in a wet state in which a paint containing a volatile component is applied on a base substrate continuous in the flow direction is irradiated with radiation immediately after coating, and this radiation is irradiated. Based on the calibration curve constant α and the radiation intensity when measuring the intensity of the radiation emitted from the received sample to be measured and quantifying the amount of the coating film in the wet state, the wet state in the sample to be measured A method for determining the amount of adhered coating film, wherein the calibration curve constant α ₁ of the volatile component obtained by measuring the volatile component of the coating and the volatile residue obtained by measuring the dried coating film A method for measuring the adhered amount of a coating film, wherein the calibration curve constant α is obtained based on the calibration curve constant α ₂ and the volatile residue ratio k.