JP2006090892A - Apparatus and method for measuring coated sheet, using x-ray transmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately and easily measure the weight per unit area and/or the thickness of a coating film of the coated sheet in a traveling state, using an X-ray transmission method. <P>SOLUTION: In measuring the coating film of the coated sheet in the traveling state of the coated sheet 10, using an X-ray source 11 and an X-ray detector 12, data in which the amount of transmitted X-ray of the coated sheet is measured and data in which the amount of transmitted X-ray of the uncoated sheet is measured are processed by a computating part 30, and the weight per unit area and/or the thickness of the coating film of the coated sheet 10 are calculated substantially continuously. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus and a method for measuring a coated sheet using an X-ray transmission method, and more particularly to an apparatus and a method for measuring the weight and / or thickness per unit area of a coated film of a coated sheet. For example, a coating sheet in which a single layer or multilayer coating film is formed on a base material sheet such as a polymer film or a metal film, and continuously measured in a running state of a laminate sheet in which two sheets are laminated It is used when doing.

  In a line for producing sheet-like metal foil or steel material, a radiation thickness meter that measures the thickness of a member to be measured by the amount of X-ray radiation transmitted to the member to be measured such as a metal foil is widely used. (See Patent Document 1). This radiation thickness meter has a C-type or O-type frame provided so as to surround a member to be measured that moves at a constant speed in a predetermined direction, and scans the measuring device in a direction perpendicular to the direction of movement of the member to be measured. The thickness is measured by measuring the amount of radiation transmitted at each position of the member to be measured.

  By the way, when measuring the thickness of the coating film of the coating sheet in which the coating film is formed on the base sheet by the above-mentioned conventional radiation thickness meter, the base material before coating is measured. The thickness of the sheet and the thickness of the coated sheet after coating are measured separately with two thickness gauges, and the difference between each measured value is calculated and measured with one thickness gauge. There is a case.

However, since the former two thickness gauges are required, the cost increases. On the other hand, when measuring with the latter one thickness meter, even if the total thickness of the entire coated sheet after coating can be measured, the thickness of the coated film is It is difficult to measure with high accuracy. In addition, when measuring with one thickness meter, even if measuring with the absorption coefficient of the weight or thickness of the total unit area of the base material and the coating film, or measuring with the absorption coefficient of the coating film, Since the measurement was performed using the absorption coefficient and the correction coefficient separately obtained by manual calculation or the like, the measurement process was complicated.
JP-A-11-142128

  The present invention has been made in order to solve the above-mentioned conventional problems, and is a coating using an X-ray transmission method that can easily and accurately measure the weight and / or thickness per unit area of a coating film of a coated sheet. An object of the present invention is to provide a measuring device and a measuring method for a work sheet.

  An apparatus for measuring a coated sheet using the X-ray transmission method of the present invention is to determine the weight and / or thickness per unit area of the coating film of the coating sheet to be measured in which the coating film is formed on the base sheet. An apparatus for measuring a coating sheet that is measured using an X-ray transmission method, wherein an X-ray source and an X-ray detector arranged so as to face each other, and the coating film is formed on the substrate sheet X-ray beams irradiated from the X-ray source pass through the uncoated sheet when there is an uncoated sheet in an unspaced position between the X-ray source and the X-ray detector. Data of the first transmitted X-ray dose detected by the X-ray detector and the X-ray irradiated from the X-ray source when the coating sheet to be measured is present in the opposing space between the X-ray source and the X-ray detector The X-ray detector transmits the transmitted X-ray transmitted through the measured coating sheet. Using the data of the second transmitted X-ray dose and the prescribed value, the weight and / or thickness per unit area of the uncoated sheet and the unit area of the measured coated sheet based on a predetermined calculation formula A calculation unit for calculating a weight and / or thickness per unit area and calculating a weight and / or thickness per unit area of the coating film of the coating sheet to be measured using the calculated values. .

  Here, the X-ray source and the X-ray detector are arranged so as to face each other across the travel path on both sides of the travel path of the coating sheet to be measured, and further, the X-ray source and the X-ray detection A scanning means for maintaining the relative position of the detector, causing the X-ray source and the X-ray detector to scan in the width direction of the traveling path, and to reciprocate in the width direction of the traveling path. The part can repeatedly measure the weight and / or thickness per unit area of the coating film in the running state of the coating sheet to be measured.

The method for measuring a coated sheet using the X-ray transmission method of the present invention includes an X-ray source and an X-ray detector arranged so as to face each other, and X-ray dose data detected by the X-ray detector. Per unit area of the coating film of the coating sheet to be measured in which the coating film is formed on the base sheet using a measuring device having a calculation unit that performs calculation based on a predetermined calculation formula When measuring the weight and / or thickness, an uncoated sheet sample comprising a base material sheet of the same material as the base material sheet of the coating sheet to be measured, as a sample having a known thickness t and / or density ρ A coated sheet sample made of the same material and composition as the coated sheet to be measured is prepared, and when each sample is separately irradiated with X-rays from the X-ray source, the transmitted X is transmitted through the sample. X-ray data of transmitted X-ray detected by X-ray detector Used, the whole of the X-ray absorption coefficient mu _B and / or mass absorption coefficient of the uncoated sheet sample was processing in the calculating portion (μ / ρ) _B and the coated sheet sample based on a predetermined calculation formula A first step of calculating an X-ray absorption coefficient μ and / or a mass absorption coefficient (μ / ρ), and storing the known value and the calculated value in the arithmetic unit as a specified value; The X-ray absorption coefficient μ _B and / or mass absorption coefficient (μ / ρ) _B of the uncoated sheet sample calculated in the step, and the entire X-ray absorption coefficient μ and / or mass absorption of the coated sheet sample Using the coefficient (μ / ρ) and the thickness t _C and / or the weight W _C per unit area of the coated sheet sample, the coating unit computes the coating based on a predetermined formula. Compensation of X-ray absorption coefficient μ _C and thickness t _C of coated film of coated sheet sample A positive value and / or a correction value for the mass absorption coefficient (μ / ρ) _C of the coating film of the coated sheet sample and the weight W _C per unit area are calculated and stored in the calculation unit. Steps,
Data of transmitted X-ray dose detected by the X-ray detector when transmitted X-rays transmitted through the measured coating sheet when the measured coated sheet is irradiated with X-rays from the X-ray source and A third step of calculating the weight and / or thickness per unit area of the coating film of the coating sheet to be measured by using the storage data of the calculation unit and performing calculation processing in the calculation unit based on a predetermined calculation formula; In the present invention, the coating film of the coating sheet is not limited to a single layer structure, and may have a multilayer (two or more layers) structure. In the case of a multilayer structure, the coating film The uppermost layer can be regarded as a single layer structure, and other lower coating films and substrate sheets can be regarded as uncoated sheets.

  According to the measuring apparatus and measuring method of a coated sheet using the X-ray transmission method of the present invention, by measuring a coated sheet and a non-coated sheet (base material sheet) according to a predetermined procedure. The weight or thickness per unit area of the coated portion (coated film) of the coated sheet can be easily and accurately measured.

  Therefore, equipment for continuously producing a coating sheet having a coating film on a base material sheet such as a polymer film or a metal film, or equipment for continuously producing a laminated sheet in which two sheets are laminated, etc. The thickness of the coating film of the coating sheet (the uppermost coating film in the case of a multilayer structure) can be easily and accurately measured in-line.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this description, common parts are denoted by common reference numerals throughout the drawings.

<First Embodiment>
FIG. 1 is a side view showing a basic configuration of a coating sheet measuring apparatus according to the first embodiment of the present invention.

  In FIG. 1, an X-ray source 11 and an X-ray detector 12 are arranged so as to face each other. Note that the X-ray source preferably limits the irradiation area with the collimator 13. When a sheet is present at the opposite interval between the X-ray source and the X-ray detector, the X-ray beam irradiated from the X-ray source passes through the sheet (a part of the X-ray is absorbed by the sheet, but a part of Straight), it enters the X-ray detector 12 and the transmitted X-ray intensity is detected. When there is no sheet at the facing interval between the X-ray source and the X-ray detector, the X-ray beam irradiated from the X-ray source directly enters the X-ray detector 12 and the irradiated X-ray intensity is detected.

  Then, an amplifier (not shown) that appropriately amplifies the detection output of the X-ray detector 12, an analog / digital converter (ADC) 23 that converts the output of this amplifier into current value data, and the ADC 23. A calculation unit 30 is provided that performs data processing on the current value data and calculates based on a predetermined calculation formula.

  For example, a personal computer is used as the arithmetic unit 30, and an example thereof is a CPU (central processing unit) 31 that controls the entire apparatus and executes various arithmetic processes, a ROM 32 for program storage, and a data memory A RAM 33, a parameter storage unit 34, and the like are connected to a parameter setting unit 35, a display unit 36 including a display, and the like. The parameter setting unit 35 has a function of inputting a parameter (specified value) related to a calculation formula, which will be described later, to the calculation unit 30. The parameter storage unit 34 stores parameters input from the parameter setting unit 35 or parameters actually measured using the measurement apparatus of this example in the form of a data table, for example.

  In the arithmetic unit 30, the CPU 31 stores the current value data input from the ADC 23 together with the measurement position data in the RAM 33, performs data processing based on the program stored in the ROM 32, and applies the coating sheet. The weight and / or thickness per unit area of the film is calculated, and the calculation result is stored in the RAM 33 and displayed on the display device 36. Further, a drive mechanism including a motor or the like for reciprocally driving the X-ray source 11 and the X-ray detector 12 at a constant speed in the width direction of the travel path (direction perpendicular to the travel direction of the coating sheet 10) in synchronization with each other. The scanning means 24 using is provided. The scanning unit 24 sets one end of the scanning region so that the X-rays irradiated from the X-ray source 11 protrude to a position slightly shifted outward in the width direction of the traveling path. Here, FIG. 2 shows the relationship between the traveling direction of the coated sheet, the scanning direction of the measuring instrument, and an example of the locus of the measurement position.

  Next, a measurement method and operation using the measurement apparatus of the present embodiment will be briefly described.

  In this measurement method, a substrate sheet having the same material and thickness as the substrate sheet of the measured coating sheet is separated from the measured coating sheet in which a coating film is formed on the substrate sheet. Prepare a coating film with no coating film (reference uncoated sheet). And each is measured using an X-ray transmission method, and by using each measured value, the weight per unit area and / or thickness of the coating film of the coating sheet to be measured is easily and accurately measured, The measurement principle will be described in detail later.

  At this time, the X-ray detector 12 is configured so that the reference X-ray beam irradiated from the X-ray source when the reference uncoated sheet is present in the opposite interval portion of the X-ray source / X-ray detector is not applied for reference. The first transmitted X-ray dose that has passed through the sheet and the X-ray beam irradiated from the X-ray source when the measured coating sheet is present at the opposing distance between the X-ray source and the X-ray detector The transmitted second transmitted X-ray dose is detected.

  In addition, the calculation unit 30 uses the first transmitted X-ray dose data and a specified value (such as an absorption coefficient of the base sheet) based on a predetermined calculation formula to calculate the weight per unit area of the reference uncoated sheet. And / or the thickness, and the weight per unit area and / or the total thickness of the coating sheet to be measured are calculated based on a predetermined calculation formula using the second transmitted X-ray dose data and the prescribed value. Then, the weight and / or thickness per unit area of the coating film of the coating sheet to be measured is calculated using the calculated value of the coating sheet to be measured and the calculated value of the uncoated sheet for reference.

The specified values (such as the absorption coefficient of the base sheet) are collected in advance by actual measurement and stored in the parameter storage unit 34 of the calculation unit 30. In order to collect this specified value, an uncoated sheet sample made of a base material sheet of the same material as the base material sheet of the coating sheet to be measured, as a sample having a known thickness t and / or density ρ, A coated sheet sample having the same material and configuration as the measurement coated sheet is prepared. Then, when each sample is separately irradiated with X-rays from the X-ray source 11, a predetermined calculation formula is used using transmission X-ray dose data obtained by detecting the transmitted X-rays transmitted through the sample with the X-ray detector 12. Based on the X-ray absorption coefficient μ _B and / or mass absorption coefficient (μ / ρ) _B of the uncoated sheet sample and the entire X-ray absorption coefficient μ and / Alternatively, the mass absorption coefficient (μ / ρ) is calculated.

  Next, the measurement principle of the measurement apparatus and measurement method of this example will be described in detail. In general, the basic formula by the X-ray transmission method is expressed as follows.

I = Io exp ^{− {(μ / ρ) × ρ × t}} (1)
= Io exp- ^{(μ / ρ) × W} (2)
= Io exp ^{− (μ × t)} (3)
Where I: intensity of transmitted X-ray (transmitted X-ray dose)
Io: X-ray intensity before transmission (irradiation X-ray dose)
μ: X-ray absorption coefficient of measurement material [1 / cm]
ρ: Density of measurement material [g / cm ³ ]
(Μ / ρ): Mass absorption coefficient of measurement material [cm ² / g]
t: Thickness of measurement material [cm]
W: Weight per unit area of measurement material [g / cm ² ]
It is. The previous formula (2) focuses on the weight W per unit area of the measurement material, and the previous formula (3) focuses on the thickness t of the measurement material. The X-ray absorption coefficient μ changes when the density ρ is different even for the same substance. Therefore, the previous equation (1) uses a mass absorption coefficient (μ / ρ) obtained by dividing the X-ray absorption coefficient μ by the density ρ.

  In addition, when the measurement material is a coating sheet in which a coating film is coated on a base material sheet and each layer (base material sheet and coating film) is handled without distinction, the above formula (1 In () to (3), μ represents the X-ray absorption coefficient of the total thickness of the base sheet and the coating film, and (μ / ρ) represents the mass absorption coefficient of the total thickness of the base sheet and the coating film.

  The measurement material is a coating sheet in which a coating film is coated on a base sheet, and each layer (base sheet and the base sheet) is coated with a single X-ray source and an X-ray detector. In the case of handling separately by coating film), the basic formula by the X-ray transmission method is shown as follows. For convenience of description, the exponent part following the EXP symbol is enclosed in parentheses and written on the same line as the EXP symbol.

I = Io EXP [- {( μ / ρ) C × ρ C × t C + (μ / ρ) B × ρ B × t B}]
(4)
= Io EXP [-{(μ / ρ) _C × W _C + (μ / ρ) _B × W _B }]
= Io EXP [- (μ / ρ) C × {W C + W B × (μ / ρ) B / (μ / ρ) C}]
... (5)
_{= Io EXP [- (μ C} × t C + μ B × t B)]
_{= Io EXP [-μ C × {} t C + (t B × μ B / μ C)}] ... (6)
I: Intensity of transmitted X-ray
Io: X-ray intensity before transmission
(Μ / ρ) _C : Mass absorption coefficient of coating material
(Μ / ρ) _B : Mass absorption coefficient of substrate
μ _C : Absorption coefficient of coating material
μ _B : Absorption coefficient of substrate
ρ _C : Coating material density
ρ _B : Density of substrate
t _C : thickness of coating material
t _B : thickness of substrate
W _C : Weight per unit area of coating material
W _B : Weight per unit area of the substrate. Here, the previous formula (5) focuses on the weight per unit area of the measurement material, and the previous formula (6) focuses on the thickness of the measurement material.

  In the above formulas (1) to (3), if the absorption coefficient of the coating film and the absorption coefficient of the base material are almost the same or different, there is little error in the measured value of the coating film, but the absorption coefficient Are greatly different from each other, the measurement error of the weight or thickness per unit area of the area near the sample where the absorption coefficient of the coated sheet is collected is small, but the measurement error of the weight or thickness per unit area of the different area is large. . That is, when the absorption coefficient of the coating material is larger than the absorption coefficient of the base material, the measured value of the thickness of the coating film appears larger than the actual thickness change. On the contrary, when the absorption coefficient of the coating material is smaller than the absorption coefficient of the substrate, the measured value of the thickness of the coating film appears smaller than the actual change in thickness.

  Therefore, as shown in the previous formulas (4) to (6), the weight or thickness per unit area of the coating film can be accurately obtained by separately handling the coating film and the base sheet. However, since it is difficult to measure by peeling the coating material from the base material sheet, in this embodiment, the measured coating sheet and the uncoated sheet (base material sheet) are respectively measured, Calculations are made using each measured value.

  When manufacturing a coating sheet, it is common to apply the base material sheet using a fixed material (material of weight or thickness per unit area). For this reason, the measurement is often possible by determining the measurement conditions with the substrate sheet regarded as constant. In this case, as described below, the coating film of the coating sheet can be easily and accurately measured.

  When the conditions of the base sheet are constant, the previous formula (5) is as follows.

I = Io EXP [− (μ / ρ) _C × (W _C + b1)] (5a)
b1 = W _B × (μ / ρ) _B / (μ / ρ) _C (5b)
Ln (I / Io) = − (μ / ρ) _C × (W _C + b1) (7)
W _C = {− Ln (I / Io) / (μ / ρ) _C } −b1 (8)
Therefore, if (μ / ρ) _C , W _B , (μ / ρ) _B in the previous equation (8) and the equation (5b) indicating the correction value b1 are known, Io and I are measured. it can be determined accurately weight per unit area W _C of the coating film.

  Similarly to the above, when the condition of the base sheet is constant, the previous formula (6) becomes the following formula.

I = Io EXP [−μ _C × (t _C + b2)] (6a)
b2 = t _B × μ _B / μ _C (6b)
Ln (I / Io) = − μ _C × (t _C + b2) (9)
t _C = {− Ln (I / Io) / μ _C } −b2 (10)
Therefore, if μ _C , t _B and μ _{B in the} formula (10) and the formula (6b) indicating the correction value b2 are known, the thickness t _C of the coating film is measured by measuring Io and I. Can be obtained with high accuracy.

  In the previous equations (8) and (10), Io is a state in which the coating sheet is not running (does not exist) between the X-ray source 11 and the X-ray detector 12, in this example, the X-ray source 11 X-rays irradiated from the X-ray source 11 directly to the opposite X-ray detector 12 in a state where the X-rays irradiated from the X-ray source 11 are scanned at positions shifted to the outside of the travel path The value of the irradiated X-ray that is measured and corrected based on the result is used. On the other hand, I is a value of transmitted X-rays measured when the coating sheet is running (exists) between the X-ray source 11 and the X-ray detector 12.

W _B in the formula (5b) showing a correction value _{b1, (μ / ρ) B} , (μ / ρ) C, and, t _B in the formula (6b) showing a correction value b2, μ _B, μ _C is , Which is a specified value, measured in advance using the measuring apparatus of this example, stored in the parameter storage unit 34 in FIG. 1, and supplied from the parameter storage unit 34 in subsequent calculations. However, when obtaining (μ / ρ) _C or μ _C of the coating film out of the above specified values, it is often difficult to measure by peeling the coating film from the substrate sheet.

Therefore, in order to indirectly determine (μ / ρ) _C or μ _C of the coating film, the same material as the base sheet of the coating sheet to be measured is used as a sample having a known thickness t and / or density ρ in advance. An uncoated sheet sample made of the base material sheet and a coated sheet sample made of the same material and composition as the measured coated sheet are prepared. Then, when each sample is irradiated with X-rays from the X-ray source 11 separately, transmission X-ray data transmitted through the sample is detected by the X-ray detector 12 and predetermined calculation is performed. The X-ray absorption coefficient μ _B and / or the mass absorption coefficient (μ / ρ) _B of the uncoated sheet sample and the entire (total thickness) X-ray of the coated sheet sample are calculated by the calculation unit 30 based on the equation. The absorption coefficient μ and / or the mass absorption coefficient (μ / ρ) are calculated, and these known values and calculated values (actual measurement values) are stored in the computing unit 30 as specified values.

That is, in the case of measuring using the absorption coefficients μ _C and μ _B of the previous formulas (2) and (3) when measuring using the absorption coefficient μ of the total thickness and the coated sheet divided into each layer The following relationship holds between the previous equations (5) and (6) when the same sample is measured.

Since the previous equations (2) and (5) are equal,
(Μ / ρ) × W = (μ / ρ) _C × W _C + (μ / ρ) _B × W _B
(Μ / ρ) _C = {(μ / ρ) × W− (μ / ρ) _B × W _B } / W _C (11)
Therefore, the mass absorption coefficient (μ / ρ) of the total thickness of the coated sheet sample, the weight W per unit area, the mass absorption coefficient (μ / ρ) _{B of} the uncoated sheet sample, the weight W _B per unit area, the coating Using the weight W _C per unit area of the coating film of the sheet sample, the mass absorption coefficient (μ / ρ) _C of the coating film can be obtained by automatic calculation.

Also, since the previous expressions (3) and (6) are equal,
μ × t = μ _C × t _C + μ _B × t _B
μ _C = (μ × t−μ _B × t _B ) / t _C (12)
Therefore, using the absorption coefficient μ and thickness t of the total thickness of the coated sheet sample, the absorption coefficient μ _B and thickness t _{B of} the uncoated sheet sample, and the coating thickness t _C of the coated film of the coated sheet sample, The absorption coefficient μ _C of the coating film can be obtained by automatic calculation.

  That is, according to the measurement method of this example described above, the uncoated sheet sample and the coated sheet sample are sequentially measured, the absorption coefficient is automatically obtained, and the absorption coefficient of the coated film is automatically calculated. The measurement conditions can be obtained and stored.

  Next, a first embodiment of a measurement method using the above-described measurement principle will be described with reference to the flowchart shown in FIG.

  In the measurement method according to the first embodiment, the width direction of the coating sheet is measured while the measuring device (X-ray source and X-ray detector) is moved (scanned) in the lateral direction with respect to the continuous coated sheet in the running state. Measure almost continuously.

  As a sample whose thickness t and / or density ρ is known in advance, an uncoated sheet sample composed of a base material sheet of the same material as the base sheet of the measured coated sheet, and the same material and configuration as the measured coated sheet A coated sheet sample consisting of: An X-ray source 11 and an X-ray detector 21 arranged so as to face each other, and a scanning unit that repeats reciprocating scanning in the width direction of the traveling path while maintaining the relative positions of the X-ray source and the X-ray detector. And an arithmetic unit that processes the X-ray dose detected by the X-ray detector and calculates the weight and / or thickness per unit area of the coating film of the coating sheet to be measured based on a predetermined calculation formula A measuring device shall be used.

First, in the first step S1, the coated sheet sample is set at the absorption coefficient collection position (opposite interval portion between the X-ray source and the X-ray detector), and the coated sheet sample is irradiated with X-rays. The absorption coefficient μ and / or the mass absorption coefficient (μ / ρ) are automatically collected, and the result is stored in the parameter storage unit 35. Next, the base sheet (uncoated sheet) sample is set at the absorption coefficient collection position, and the base sheet absorption coefficient μ _B and / or mass absorption coefficient (μ / ρ) _B when X-rays are irradiated Are automatically collected, and the result is stored in the parameter storage unit 35. In the absorption coefficient sampling process, the order of the coated sheet sample and the uncoated sheet sample may be reversed.

In the second step S2, the mass absorption coefficient (μ / ρ) _{C of the} coating film represented by the previous formula (11) and the correction value b1 represented by the previous formula (5b) and / or the previous formula (12) Then, the absorption coefficient μ _C of the coating film indicated by (2) and the correction value b2 indicated by the previous equation (6b) are calculated, and the respective results are stored in the parameter storage unit.

In the third step S3, when X-rays are irradiated from the X-ray source with respect to the traveling state of the coating sheet to be measured, transmitted X-rays transmitted through the coating sheet to be measured are detected by the X-ray detector. Using the transmitted X-ray dose data and the specified value, the calculation unit calculates the weight W and / or thickness t per unit area of the coating sheet to be measured based on a predetermined calculation formula. At this time, first, in step S31, the X-ray source is irradiated based on the output detected by the X-ray detector when the X-ray irradiated from the X-ray source is in a position shifted to the outside of the traveling path. The X-ray intensity Io is automatically measured. Next, in step S32, the transmitted X-ray intensity I is automatically measured based on the output of the X-ray detector when X-rays are transmitted through the measured coating sheet in the running state. Next, in step S33, the weight W _C per unit area of the coated sheet to be measured is automatically calculated by the calculation unit based on the previous equation (8) using the specified value and the actual measurement value obtained in each of the previous steps. And / or the thickness t _C is automatically calculated by the calculation unit based on the previous equation (10), and the result is recorded and displayed.

  And during the period which continues a measurement, the measurement of the transmitted X-ray intensity I with respect to the to-be-measured coating sheet of a running state is repeated. In the process of the third step S3, the X-ray source is based on the output detected by the X-ray detector when the X-ray emitted from the X-ray source is in a position shifted to the outside of the traveling path. The irradiation X-ray intensity Io is automatically measured, the corrected Io is compared with the previously measured irradiation X-ray intensity Io, and the irradiation X-ray intensity that has changed over time in the above formula is corrected. A fourth step may be added.

  By applying the measuring apparatus and measuring method of the present embodiment as described above to a part of the conveying line of the coating sheet in the manufacturing line for coating the coating material on the base material in an in-line manner, It is possible to easily and accurately measure the thickness of the film.

  FIG. 4 is a perspective view schematically showing a specific example of the measuring apparatus of FIG.

  In FIG. 4, for example, a pair of upper and lower rails 42, 43 are horizontally attached between a pair of left and right frames 41, 41 in an O-shaped frame. Between the pair of upper and lower rails 42 and 43, a belt-like elongate coating sheet 10 is a part of a traveling path along which the traveling in the arrow direction shown in the drawing.

  An X-ray source 11 as shown in FIG. 1 is attached to one rail (in this example, the upper rail 42) so as to be slidable in the rail longitudinal direction. Reciprocal movement is possible. Here, the X-ray source 11 is built in, for example, an X-ray tube cover with the X-ray irradiation port of the X-ray tube facing downward, and a light passage hole through which X-rays pass through the lower portion of the X-ray tube cover. Is formed. The X-ray source 11 generates X-rays by irradiating an anode target with an electron beam from a cathode of an X-ray tube. As this X-ray, an X-ray having energy suitable for measurement by the X-ray transmission method is used, and the energy distribution of the X-ray may be continuous X-ray or specific X-ray. An X-ray detector 12 as shown in FIG. 1 is attached to the other rail (lower rail 43 in this example) so as to be slidable in the rail longitudinal direction. Reciprocal movement in the longitudinal direction is possible. Here, the X-ray detector 12 receives incident X-rays, for example, in an ion chamber and converts them into a current signal proportional to the incident X-ray signals, or receives them in a scintillator and converts them into light. It is converted into a current signal proportional to the incident X-ray signal by a priorer or a photodiode (scintillation detector).

  Further, as shown in FIG. 1, the X-ray source 11 and the X-ray detector 12 are driven to reciprocate at a constant speed in the width direction (rail longitudinal direction) of the travel path in synchronization with each other (while maintaining the relative position). For this purpose, scanning means (not shown) using a drive mechanism including a motor or the like is built in the measuring apparatus. This scanning means scans and drives one end of the scanning region so that the X-rays emitted from the X-ray source 11 are slightly shifted outward in the width direction of the travel path. For example, an operation unit 44 of the apparatus is provided on the front surface of the frame 41.

  With the above configuration, the X-ray emitted from the X-ray source 11 is detected by the X-ray detector 12 regardless of the position of the X-ray source 11 and the X-ray detector 12 in the rail longitudinal direction. The X-ray dose detected by the X-ray detector 12 is converted into a current value, and converted into current value data by the A / D converter 23 as described above with reference to FIG.

<Second Embodiment>
The second embodiment is different from the first embodiment described above in that the weight and / or thickness per unit area of the coating film of the coating sheet in the stopped state is different, and the measurement principle is the same. . The measurement method according to the second embodiment is different from the measurement method according to the first embodiment described above in that the measurement is automatically performed on the non-measurement workpiece sheet that is stopped in the third step S3. Others are the same. According to the second embodiment, the scanning unit 24 can be omitted, or the operation can be stopped even when the scanning unit 24 is not omitted.

  The measuring apparatus using the X-ray transmission method of the present embodiment is made of a synthetic resin film such as a polyester film, a base such as paper or non-ferrous metal foil, a ceramic material, a magnetic material or filler with magnetism, titanium, lead, etc. Various strip-shaped coated sheets coated with powder can be measured. Specific examples include a coating sheet for a magnetic card using iron oxide as a coating film, or a coating sheet for an anode of a lithium ion battery (for example, cobalt acid lithium is coated on an aluminum substrate). It is possible to measure a coating sheet for a negative electrode of a lithium ion battery (for example, carbon is coated on a copper substrate).

[Example 1] A ceramic capacitor is formed as a dielectric for a capacitor by applying a ceramic material (BaTiO ₂ or the like) to a required thickness using a PET film as a base material and firing it. When measuring the weight and / or thickness per unit area of the coating film in the process of applying the ceramic material, the measuring apparatus of the present invention is used.

Usually, the base material (PET film) has a thickness of about 20 to 50 μm, and the coating film (ceramic material) has a thickness of about 2 to 50 μm. It is difficult to peel and handle the coated ceramic of several μm from the substrate, and the sample coated on the substrate and the PET film of the substrate can be easily prepared. In this actual measurement example,
The base sheet is a PET film with a thickness of 38 μm, an absorption coefficient μ _B = 0.002 μm ⁻¹
The coating material (coating film) of the coating sheet (coating sample) is 10 μm,
The total thickness of the coated sheet (coated sample) is 48 μm, the absorption coefficient of the total thickness μ = 0.02 μm ^-1
And

Based on these values and the previous equations (10) and (6b), the absorption coefficient μ _C of the coating material and the correction value b2 are obtained as follows.

μ _C = (0.02 * 48−0.002 * 38) /10=0.0884 μm ⁻¹
b2 = 0.002 * 38 / 0.0884 = 0.86

The side view which shows the basic composition of the measuring apparatus of the coating sheet which concerns on the 1st Embodiment of this invention. The top view which shows the relationship between the running direction of a coating sheet in the measuring apparatus of FIG. 1, the scanning direction of a measuring device, and an example of the locus of a measurement position. The flowchart which shows an example of the measuring method using the measuring apparatus of FIG. FIG. 2 is a perspective view schematically showing a specific example of the measuring apparatus of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Coating sheet, 10a ... Coating film of coating sheet, 10b ... Base sheet of coating sheet, 11 ... X-ray source, 12 ... X-ray detector, 13 ... Collimator, 23 ... A / D converter, 24... Scanning means, 30... Arithmetic unit, 31... CPU, 32... ROM for program storage unit, 33 ... RAM for data memory, 34.

Claims (7)

A coating sheet measuring apparatus for measuring a weight and / or thickness per unit area of a coating film of a coating sheet to be measured in which a coating film is formed on a base sheet using an X-ray transmission method. ,
An X-ray source and an X-ray detector arranged to face each other;
An X-ray beam irradiated from the X-ray source when an uncoated sheet in a state where the coating film is not formed on the base sheet is present in the facing interval portion of the X-ray source and the X-ray detector. Data of the first transmitted X-ray dose obtained by detecting the transmitted X-rays transmitted through the uncoated sheet with the X-ray detector, and the measured coated sheet at the opposing interval portions of the X-ray source and the X-ray detector When the X-ray beam emitted from the X-ray source is transmitted through the measured coating sheet, the X-ray detector detects the second transmitted X-ray dose data and the specified value. Use the weight per unit area and / or thickness of the uncoated sheet and the weight per unit area and / or the total thickness of the coated sheet to be measured based on a predetermined calculation formula, Using the weight per unit area of the coating film of the coating sheet to be measured And / or coated sheet measuring apparatus using the X-ray transmission method which is characterized by comprising an arithmetic unit for calculating the thickness. The X-ray source and the X-ray detector are arranged so as to face each other across the traveling path on both sides of the traveling path of the coating sheet to be measured, and the relative positions of the X-ray source and the X-ray detector are determined. Scanning means for maintaining and scanning the X-ray source and the X-ray detector in the width direction of the traveling path and reciprocatingly scanning in the width direction of the traveling path. The apparatus for measuring a coated sheet using an X-ray transmission method according to claim 1, wherein the weight and / or thickness per unit area of the coated film is repeatedly measured in the running state of the coated sheet. The scanning means scans the X-ray source and the X-ray detector to a position shifted to the outside of the traveling path,
The arithmetic unit receives and detects the X-ray beam emitted from the X-ray source directly with the X-ray detector in a state where the irradiation position of the X-ray source is scanned to a position shifted to the outside of the traveling path. The apparatus for measuring a coated sheet using the X-ray transmission method according to claim 2, wherein data processing is performed so as to correct a change with time of the second transmitted X-ray dose using the irradiated X-ray dose. The X-ray transmission according to any one of claims 1 to 3, wherein the calculation unit calculates a thickness t _C of the coating film of the coating sheet to be measured based on the following calculation formula. Coating sheet measuring device using the method.
t _C = {− Ln (I / Io) / μ _C } −b
b = t _B × μ _B / μ _C
However, I: Transmission X-ray intensity I0: Irradiation X-ray intensity μ _C ; Absorption coefficient of coated film of coated sheet t _B : Uncoated sheet (base material) thickness μ _B ; Uncoated sheet (base material) Absorption coefficient The arithmetic unit, according the any one of claims 1 to 3, characterized in that calculated on the basis of the weight per unit area W _C following calculation formula of the coating film of the measured coated sheet An apparatus for measuring a coated sheet using an X-ray transmission method.
W _C = {− Ln (I / Io) / (μ / ρ) _C } −b
b = W _B × (μ / ρ) _B / (μ / ρ) _C
However I; transmitted X-ray intensity I0; X-ray intensity (μ / ρ) _C; mass absorption coefficient of the coating sheet of the coating film W _B; weight per unit area of the uncoated sheet (base material) (mu / ρ) _B : Mass absorption coefficient of uncoated sheet (base material) An X-ray source and an X-ray detector arranged to face each other;
Using a measurement apparatus having a calculation unit that performs calculation based on a predetermined calculation formula using data of the X-ray dose detected by the X-ray detector, a coating film formed on a substrate sheet When measuring the weight and / or thickness per unit area of the coating film of the measurement coating sheet,
As a sample whose thickness t and / or density ρ is known in advance, an uncoated sheet sample made of a base material sheet made of the same material as the base sheet of the measured coated sheet, and the same material as the measured coated sheet And a coated sheet sample having a configuration, and when each sample was irradiated with X-rays from the X-ray source separately, transmitted X-rays transmitted through the sample were detected by the X-ray detector. Using the data of the transmitted X-ray dose, the calculation unit calculates the X-ray absorption coefficient μ _B and / or the mass absorption coefficient (μ / ρ) _{B of the} uncoated sheet sample based on a predetermined calculation formula and The first step of calculating the X-ray absorption coefficient μ and / or the mass absorption coefficient (μ / ρ) of the entire coated sheet sample and storing these known values and calculated values as specified values in the calculation unit When,
The X-ray absorption coefficient μ _B and / or the mass absorption coefficient (μ / ρ) _B of the uncoated sheet sample calculated in the first step, the X-ray absorption coefficient μ of the whole coated sheet sample, and Using the mass absorption coefficient (μ / ρ) and the coating film thickness t _C and / or the weight W _C per unit area of the coating sheet sample, calculation processing is performed in the calculation unit based on a predetermined calculation formula The X-ray absorption coefficient μ _C of the coated film of the coated sheet sample and the correction value of the thickness t _C and / or the mass absorption coefficient (μ / ρ) _C of the coated film of the coated sheet sample And a second step of calculating a correction value of the weight W _C per unit area and storing the correction value in the calculation unit;
Data of transmitted X-ray dose detected by the X-ray detector when transmitted X-rays transmitted through the measured coating sheet when the measured coated sheet is irradiated with X-rays from the X-ray source and A third step of calculating the weight and / or thickness per unit area of the coating film of the coating sheet to be measured by using the storage data of the calculation unit and performing calculation processing in the calculation unit based on a predetermined calculation formula; ,
The measuring method of the coating sheet using the X-ray transmission method characterized by comprising. As the measuring device, a scanning operation is performed in which the relative positions of the X-ray source and the X-ray detector are maintained, and the coating sheet to be measured is formed on the base sheet and reciprocally scanned in the width direction of the traveling path. Further comprising means,
In the third step, the running state of the measured coating sheet is irradiated with X-rays from the X-ray source, and the weight and / or thickness per unit area of the coating film of the measured coating sheet is determined. It measures repeatedly. The measuring method of the coating sheet using the X-ray transmission method of Claim 6 characterized by the above-mentioned.

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