JP7176356B2 - Measuring device, measuring method, and program - Google Patents

Description

The present invention relates to a measuring device, a measuring method, and a program.

US Pat. No. 6,200,009 discloses an apparatus for inspecting sheet material produced in a production process having a process flow, the central process controller being configured to control at least one aspect of the production process, and sheet material. A source of incident radiation, a conveyor for moving the sheet material in a single plane, and a surface of the sheet material in close proximity so that an image of the surface of the sheet material can be produced at or downstream of the source of the incident radiation. and in communication with a central process controller for receiving and analyzing images from the infrared detectors to determine physical characteristics of the sheet material; to a central process controller, causing the central process controller to adjust at least one aspect of the production process in response to the determined physical characteristic. An apparatus is disclosed that features:

Japanese Patent Publication No. 2002-502968

An object of the present invention is to provide a measuring device, a measuring method, and a program capable of nondestructively and accurately measuring the basis weight of a coating film.

In order to achieve the above object, the measuring device of the present invention provides the above-described Any one of the estimated value of the temperature of the coating film at the first time when heating or cooling is started and the measured value of the temperature of the coating film at the second time immediately after the heating or cooling is started Using an acquisition means for acquiring a specific value, and a predetermined relationship between the temperature of the coating film at a time corresponding to the specific value and the basis weight of the coating film when the specific value is acquired, and an output means for obtaining and outputting a basis weight at a predetermined position of the coating film corresponding to the specific value obtained by the obtaining means.

In the measuring method of the present invention, when the coating film applied to the surface of the plate-shaped member is heated or cooled, the heating or cooling is started at a predetermined position of the coating film. Either one of the estimated value of the temperature of the coating film at time 1 and the measured value of the temperature of the coating film at a second time immediately after the heating or cooling is started is acquired as a specific value, and the specific When a value is acquired, the coating corresponding to the acquired specific value using a predetermined relationship between the temperature of the coating film at the time corresponding to the specific value and the basis weight of the coating film. This measurement method obtains and outputs the basis weight at a predetermined position of the coating film.

The program of the present invention causes the computer to start heating or cooling at a predetermined position of the coating film applied to the surface of the plate-shaped member when the coating film is heated or cooled. Acquisition of acquiring as a specific value either an estimated value of the temperature of the coating film at a first time when the heating or cooling is started, or an actual measurement value of the temperature of the coating film at a second time immediately after the heating or cooling is started Means, when the specific value is acquired, using a predetermined relationship between the temperature of the coating film at the time corresponding to the specific value and the basis weight of the coating film, acquired by the acquisition means A program for functioning as an output means for obtaining and outputting a basis weight at a predetermined position of the coating film corresponding to a specific value.

ADVANTAGE OF THE INVENTION According to this invention, the basis weight of a coating film can be measured nondestructively and accurately.

It is a schematic diagram showing an example of composition of a measuring device concerning an embodiment of the invention. It is a schematic diagram showing an example of composition of a coating film. 1 is a block diagram showing an example of an electrical configuration of a measuring device according to an embodiment of the invention; FIG. It is a graph which shows an example of the time change (measurement data) of the temperature of a coating film. It is a flowchart which shows an example of the flow of a "preparation process." 4 is a table showing examples of known coating films having different combinations of basis weight and density. (A) to (C) are graphs showing an example of temporal change in temperature of each of a plurality of known coating films. 4 is a table showing an example of maximum temperatures for a plurality of known coating films; 2 is a graph plotting the maximum temperature against basis weight for a plurality of known coating films. 4 is a table showing an example of cooling characteristics for a plurality of known coating films; 1 is a graph plotting cooling characteristics against (1/ρw _T0 ) for several known coatings; It is a flowchart which shows an example of the flow of a "measurement process." FIG. 11 is a flow chart showing an example of the flow of “measurement processing” according to the second embodiment; FIG. FIG. 10 is a table showing another example of known coating films having different combinations of basis weight and density; FIG. It is a graph which shows an example of measurement data. 4 is a graph showing the relationship between the temperature rise value _ΔTm at time _tm and the basis weight w. (A) to (E) are images showing an example of the basis weight distribution obtained from the coating film to be measured. It is a graph which shows an example of measurement data. (A) and (B) are graphs showing the relationship between the temperature rise value ΔT ₀ and the basis weight w. (A) is an image showing an example of measurement points superimposed on the basis weight distribution obtained from the temperature distribution of the coating film 0.03 seconds after heating. (B) is a graph showing an example of measurement data measured for each position. (A) to (F) are images showing an example of the basis weight distribution obtained from the coating film to be measured. It is a graph which shows an example of measurement data. (A) and (B) are graphs showing the relationship between the temperature rise value ΔT ₀ and the basis weight w. (A) and (B) are images showing an example of basis weight distribution obtained from a coating film to be measured. It is a graph which shows an example of measurement data. (A) and (B) are graphs showing the relationship between the temperature rise value ΔT ₀ and the basis weight w. (A) to (D) are images showing an example of the basis weight distribution obtained from the coating film to be measured.

An example of an embodiment of the present invention will be described in detail below with reference to the drawings.

-First Embodiment-
In the first embodiment, both the basis weight and density of the coating film are calculated.
<Measuring device>
First, the measuring device will be explained.
FIG. 1 is a schematic diagram showing an example of the configuration of a measuring device according to an embodiment of the present invention. The measuring device 10 includes a temperature adjusting section 20 that adjusts the temperature of the coating film 12, a temperature measuring section 30 that measures the temperature of the coating film 12, and a control section 40 that controls the entire device. When the temperature measuring unit 30 measures the temperature of the coating film 12 using infrared rays, the measuring device 10 is placed inside the darkroom 14 .

As shown in FIG. 2, the coating film 12 is applied to the surface of the plate member 18 . The coated film 12 has unknown basis weight and density. In the present embodiment, the temperature is measured at a predetermined position in the plane of the coating film 12, and finally, the basis weight and density of the coating film 12 at the predetermined position are measured non-destructively. do.

Here, the "weight per unit area" is the weight per unit area, and the "density" is the weight per unit volume. For example, a graphite layer coated on a copper foil of a negative electrode sheet of a lithium ion battery is a suitable coating film in the present embodiment. In the graphite layer, graphite is held by a binder resin.

The temperature adjustment unit 20 adjusts the temperature of the coating film 12 by heating or cooling the coating film 12 from the coating surface side. When the coating film 12 is heated, the amount of heat is applied to the coating film 12 . When cooling the coating film 12 , heat is taken from the coating film 12 .

As a heating method, light heating using light irradiation, convection heating using hot air, radiation heating using an infrared heater or the like, induction heating, or the like may be used. As a cooling method, convective heat transfer using cold air may be used. Light heating shortens the heating time compared to other heating methods. Examples of light heating include a method of irradiating white light with a flash lamp, a method of irradiating infrared rays, and the like.

The temperature measurement unit 30 measures the temperature of the coating film 12 in a non-contact manner. A non-contact temperature sensor such as an infrared camera or a radiation thermometer can be used as the temperature measurement unit 30 that measures temperature in a non-contact manner. For example, an infrared camera detects the amount of infrared rays emitted from a subject according to the temperature of the subject, and measures the temperature of the coating film 12 for each unit area (for example, each pixel). The infrared camera enables temperature measurement at each position of the coating film 12 .

The predetermined position may be one place or a plurality of places. Each position is a region having a unit area in the plane of the coating film. Each of the basis weight and density obtained for each position is a representative value of the basis weight and density within the area. Here, the “representative value” is a value that represents values that can be taken within the region, such as an average value and a median value. In the following, the predetermined position will be described as "one position".

FIG. 3 is a block diagram showing an example of the electrical configuration of the measuring device according to the embodiment of the invention. As shown in FIG. 3, the control unit 40 of the measuring device 10 is configured as a computer that controls each unit and performs various calculations. That is, the control unit 40 includes a CPU (Central Processing Unit) 40A, a ROM (Read Only Memory) 40B, a RAM (Random Access Memory) 40C, a nonvolatile memory 40D, and an input/output unit (I/O). 40E is provided.

Each of CPU40A, ROM40B, RAM40C, memory 40D, and I/O40E is connected via the bus|bath 40F. The CPU 40A reads a program stored in the ROM 40B, for example, and uses the RAM 40C as a work area to execute the program. The I/O 40E of the control unit 40 includes a display unit 42 such as a display, an input unit 44 such as a keyboard and a mouse, a communication unit 46, a storage unit 48, a temperature adjustment unit 20, a temperature measurement unit 30, and a conveyor belt 16. is connected.

The communication unit 46 is an interface for communicating with an external device via a wired or wireless communication line. For example, it functions as an interface for communicating with an external device such as a computer connected to a network such as a LAN (Local Area Network) or the Internet. The storage unit 48 is an external storage device such as a hard disk.

In this embodiment, the ROM 40B stores a program for executing a "measurement process", which will be described later. Further, as will be described later, the “second relational expression” and the “third relational expression” acquired by the “preparation processing” are stored in a storage device such as the storage unit 48 .

Note that the program storage area is not limited to the ROM 40B. Various programs may be stored in other storage devices such as the memory 40</b>D and the storage unit 48 or may be acquired from an external device via the communication unit 46 .

Various drives may be connected to the control unit 40 . Various drives are devices for reading data from and writing data to computer-readable portable recording media such as CD-ROMs and USB (Universal Serial Bus) memories. When various drives are provided, a program may be recorded on a portable recording medium and read and executed by a corresponding drive.

As shown in FIG. 1, the measuring apparatus 10 includes a conveyor belt 16 that conveys a plate-like member 18 having a coating film 12 to a predetermined measurement position. The conveyor belt 16 is driven and controlled by the controller 40 to convey the plate-like member 18 placed on the conveyor belt 16 to a predetermined measurement position. For example, the plate member 18 is placed on the conveyor belt 16 so that the coating surface of the coating film 12 coated on the surface is exposed.

Each of the temperature adjustment unit 20 and the temperature measurement unit 30 is arranged to face a predetermined measurement position. Each of the temperature adjusting section 20 and the temperature measuring section 30 is arranged along the transport direction. In the illustrated example, a plurality of temperature adjustment units 20 are arranged on both sides of the temperature measurement unit 30 .

The temperature adjustment unit 20 is controlled by the control unit 40 to heat or cool the coating film 12 at the designated timing. The temperature measurement unit 30 is controlled by the control unit 40 to measure the temperature at a predetermined position of the coating film 12 only for the specified period. The control unit 40 acquires measurement data from the temperature measurement unit 30 . The acquired measurement data is stored in a storage device such as the RAM 40C and the storage unit 48. FIG. Based on the obtained measurement data, the control unit 40 executes a "measurement process", which will be described later.

<Measurement data>
Here, the "measurement data" obtained by the temperature measurement unit will be described.
The measurement data is data representing temporal changes in the temperature of the coating film. Measurement data is obtained for each sample. FIG. 4 is a graph showing an example of measurement data. The vertical axis represents the temperature _Tt of the coating film at time t. The horizontal axis represents time t. Heating of the coating film is started at time t=0. For example, the irradiation time of the flash lamp is assumed to be 0 seconds.

A measured value of the temperature _Tt of the coating film is obtained at predetermined time intervals. Each measurement point corresponding to each acquired measurement value is represented by O (circle). Temperature measurement is started immediately before the start of heating. Measured data is acquired during the period from immediately before heating until the temperature of the coating film converges to the ambient temperature _T∞ . The measurement period is, for example, a period from immediately before heating to 15 seconds after heating.

Here, the coating film is placed in a medium such as air. The temperature of the coating film before heating is the temperature of the medium surrounding the coating film, that is, the ambient temperature _T∞ . The ambient temperature T _∞ is room temperature, approximately 0° C. in the illustrated example. Here, it is assumed that the temperature of the coating film is uniform within the unit area. In other words, the temperature of the coating film differs for each unit area.

When the coating film is heated, the temperature _Tt of the coating film instantaneously reaches the maximum temperature _T0 and then gradually returns from the maximum temperature _T0 to the ambient temperature _T∞ due to natural cooling. “Maximum temperature T ₀ ” is an estimated value of the temperature of the coating film at time t=0.

The room temperature can be assumed constant for the measurement period of one sample. However, the room temperature cannot be said to be constant during the measurement period of a plurality of samples. Therefore, in order to avoid the influence of room temperature fluctuations, the ambient temperature T _∞ is used as a reference temperature, and the difference between the maximum temperature T ₀ and the ambient temperature T _∞ is defined as a temperature rise value ΔT ₀ (=T ₀ −T _∞ ). do.

Theoretically, the temperature _Tt of the coating film is represented by the following formula (1) in accordance with Newton's law of cooling. The following formula (1) is an example of the "first relational expression". Newton's Law of Cooling is an empirical rule that states that when a substance is cooled by the surrounding medium, the cooling rate of the substance is proportional to the temperature difference between the substance and the medium.

In the above formula (1), t is the time, _T0 is the maximum temperature of the coating film, and _T∞ is the ambient temperature. h is the heat transfer coefficient, A is the surface area of the region through which heat is transferred, and C is the heat capacity. The heat capacity C is the total heat capacity when the plate member 18 and the coating film 12 shown in FIG. 2 are integrated. In this embodiment, for example, a plurality of coating films of the same type are to be measured. Although the heat transfer coefficient h varies depending on (T ₀ −T _∞ ), it is assumed to be a constant value for each coating film. Further, the surface area A is a constant numerical value regardless of the coating film.

The above formula (1) shows that the temperature _Tt of the coating film exponentially decays from the maximum temperature _T0 to the ambient temperature _T∞ . The cooling rate of the coating film is represented by (hA/C). In this embodiment, h is defined as "heat transfer coefficient" and (hA/C) is defined as "cooling characteristic". When the surface area A and the heat capacity C are constant, the cooling characteristic (hA/C) becomes a value proportional to the heat transfer coefficient h.

By approximating the measured data with the above formula (1), the values of the ambient temperature T _∞ , maximum temperature T ₀ , and cooling characteristic (hA/C) are obtained. Specifically, "T _t " and "t" in the above equation (1) are assumed to be variables, and "T _∞ ", "T ₀ " and "hA/C" to be constants. Then, using the method of least squares, etc., so that the curve representing the above formula (1) is closest to the plurality of measurement points (combinations of T _t and t) represented by ○ (circles). Determine the values of "T _∞ ", "T ₀ " and "hA/C".

Curves having constants “T _∞ ”, “T ₀ ”, and “hA/C” are shown in bold in FIG. 4 as “approximation lines”. The number of measurement points should be equal to or greater than the number of constants. For example, to determine the three constants in this example, three or more measurements are required.

<Preparation processing>
Next, the “preparation processing” performed by the user will be described.
FIG. 5 is a flow chart showing an example of the procedure of "preparation processing". As shown in FIG. 5, first, in step 100, a plurality of coating films each having a known basis weight w and density ρ (hereinafter referred to as "known coating films") are prepared. Hereinafter, a coating film having a known basis weight w and density ρ is referred to as a “known coating film” to distinguish it from the coating film to be measured.

The known coating film has the same material for the plate-shaped member to be coated and the material for the coating film as the coating film to be measured. Also, the known coating film and the coating film to be measured have substantially the same coating area. Each of the plurality of known coating films has a different combination of basis weight w and density ρ.

Next, in step 102, each of the plurality of known coating films is heated, temperature changes are measured when the heating is followed by natural cooling, and a plurality of measurement data are obtained for each of the plurality of known coating films. . The temperature measurement is performed at a predetermined position within the plane of the known coating film.

A known coating film is heated or cooled under predetermined conditions to acquire measurement data. The predetermined conditions are the same as those for the coating film to be measured. For example, when irradiating white light with a flash lamp, the amount of power input to the flash lamp is kept constant. By heating or cooling the known coating film and the coating film under the same conditions, the amount of heat imparted to or removed from each film becomes substantially constant.

Next, in step 104, for each of a plurality of known coating films, the measurement data is approximated by the above formula (1) to obtain the maximum temperature _T0 , the ambient temperature _T∞ , and the cooling characteristic hA/C. . The approximate calculation may be performed by the control unit 40 .

Next, at step 106, a "second relational expression" representing the relationship between the temperature rise value _ΔT0 and the basis weight w is acquired. For example, Equation (5), which will be described later, is acquired. As will be described later, in equation (5), the temperature rise value ΔT ₀ is the same value as the maximum temperature T ₀ . Next, in step 108, a "third relational expression" representing the relationship between the cooling characteristic (hA/C) and the product of the basis weight w and the density ρ is acquired. For example, Equation (7), which will be described later, is acquired. The "second relational expression" and the "third relational expression" will be described in a specific example of the preparation process.

Next, at step 110, the second relational expression and the third relational expression are stored in a storage device such as the storage unit 48, and the preparatory process is finished. The above first relational expression is stored in advance in a storage device such as the storage unit 48 . The second relational expression and the third relational expression are stored in a storage device such as the storage unit 48 together with the first relational expression. Note that the order of steps 106 and 108 may be interchanged.

The coating film has a different cooling rate depending on the in-plane position. For example, the ends with side surfaces and a wider heat dissipation surface cool faster than the central portion. Therefore, for each of a plurality of known coating films, the closer the position where the temperature is measured to the "position" measured on the coating film to be measured, the more accurate the "second relational expression" and the "third relational expression". is required.

(Specific example of preparation processing)
A specific example of the preparation process will be described below.
FIG. 6 is a table showing examples of known coating films having different combinations of basis weight and density. In the illustrated example, the known coating is a graphite layer coated on a copper foil. In the illustrated example, nine types of known coating films with different combinations of basis weight w and density ρ are prepared.

The basis weight w of the known coating film changes in three steps, 7 mg/cm ² , 10 mg/cm ² and 13 mg/cm ² . Also, the density ρ of the known coating film changes in three stages for the coating film having the same basis weight by changing the pressing strength in three stages. As the pressing strength increases, the value of the density ρ increases and the thickness d of the known coating film decreases.

The basis weight w of the known coating film is an indicated value indicated as the coating weight. In addition, by cutting out a sample and measuring the weight per unit area (the total of the copper foil and the graphite layer) and subtracting the weight of the copper foil per unit area, the basis weight w of the known coating film (graphite layer) is calculated. you may ask. In this case, the "second relational expression" and the "third relational expression" can be obtained accurately by cutting out a sample of an area close to the "position" to be measured on the coating film to be measured.

The thickness d of the known coating film is a measured value measured by a displacement meter such as a micrometer. The thickness d may be an average value of the entire area to be measured, or may be an average value of arbitrary multiple points in the area to be measured.

The density ρ is obtained by dividing the basis weight w by the thickness d. In the illustrated example, the unit of density ρ is [g/cm ³ ], the unit of basis weight w is [mg/cm ² ], and the unit of thickness d is [μm]. It goes without saying that the density ρ is calculated.

FIGS. 7A to 7C are graphs showing measurement data for each of a plurality of known coating films. FIG. 7(A) shows measurement data of a coating film having a basis weight w of 7 mg/cm ² . FIG. 7(B) shows measurement data of a coating film having a basis weight w of 10 mg/cm ² . FIG. 7(C) shows measurement data of a coating film having a basis weight w of 13 mg/cm ² .

7 mg/cm ² →10 mg/cm ² →13 mg/cm ² , the higher the basis weight w, the lower the maximum temperature _T0 and the lower the cooling rate. Also, the higher the pressing strength and the higher the density ρ, the lower the cooling rate.

As described above, by approximating the measured data with the above equation (1), each value of the maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/C) is obtained for each measured data. In this example, the room temperature is 0° C. (T _∞ =0), and the temperature rise value ΔT ₀ (=T ₀ −T _∞ ) is the same value as the maximum temperature T ₀ .

FIG. 8 is a table showing values of maximum temperature _T0 obtained for a plurality of known coating films shown in FIG. FIG. 9 is a graph plotting the highest temperature _T0 shown in FIG. 8 against the basis weight w of the known coating film. A measurement point for a basis weight of 7 mg/cm ² is indicated by a circle. □ (square) indicates a measurement point for a basis weight of 10 mg/cm ² . The measurement points for the basis weight of 13 mg/cm ² are represented by ◇ (diamonds). As can be seen from FIG. 9, the maximum temperature _T0 correlates with the basis weight w. The change in the maximum temperature _T0 due to the density ρ is slight compared to the change in the maximum temperature _T0 due to the basis weight w.

The correlation between the temperature rise value ΔT ₀ and the basis weight w is also supported by the theoretical formula. For example, when the temperature rise value of a coating film having a heat capacity per unit area of C is _ΔT0 , the amount of heat Q per unit area is given by the following equation (2).

Assuming that the graphite layer coated on the copper foil is the coating film, the heat capacity C is expressed by the following formula (3) from the specific heat c of the graphite layer, the basis weight w of the graphite layer, and the heat capacity D of the copper foil. By adding the term of the heat capacity D of the copper foil, the heat capacity (cw) of the graphite layer and the heat capacity D of the copper foil are separated, and the weight per unit area and the density of only the graphite layer are obtained.

By substituting the above formula (3) into the above formula (2), the following formula (4), which is a theoretical formula, is obtained.

As described above, the room temperature is 0° C. here, and the temperature rise value ΔT ₀ (=T ₀ −T _∞ ) is the same value as the highest temperature T ₀ . When the relationship (measurement result) between the maximum temperature _T0 and the basis weight w shown in FIG. each is required. Specifically, it is assumed that 'ΔT ₀ (=T ₀ )' and 'w' in the above equation (4) are variables, and 'Q', 'c' and 'D' are constants. Then, the constants "Q", " _c ", "D ” value.

When the measurement result shown in FIG. 9 is approximated by the above formula (4), the following formula (5) is obtained as the "second relational formula". Here, it is not necessary to obtain correct values for each of the heat quantity Q, the specific heat c of the graphite layer, and the heat capacity D of the copper foil. A value should be determined. Also, if the heat quantity Q, the specific heat c, and the heat capacity D are known from other measurements, their values may be substituted.

By obtaining in advance the "second relational expression" representing the relationship between the maximum temperature _T0 and the weight per unit area w before executing the measurement process, it is possible to obtain a coating with an unknown weight per area w in the "measurement process". It becomes possible to measure the basis weight w from the maximum temperature _T0 of the film. The above "second relational expression" may be an expression representing the relationship between the temperature rise value ΔT ₀ (=T ₀ -T _∞ ) and the basis weight w. The temperature rise value ΔT ₀ absorbs the influence of the ambient temperature _T∞ .

If the values of the amount of heat Q to be applied, the specific heat c of the graphite layer, and the heat capacity D of the copper foil are known in advance, each value is substituted into the theoretical formula (4) above to obtain the "second A relational expression" may be obtained. In this case, the approximation in the above equation (4) can be omitted.

FIG. 10 is a table showing values of cooling characteristics (hA/C) obtained for a plurality of known coating films shown in FIG. As shown in FIG. 11, the cooling characteristic (hA/C) shows a change different from the maximum temperature _T0 with respect to the basis weight w. For example, unlike the change in the maximum temperature _T0 , the values decrease in the order of no press, weak press, and strong press.

As described above, the maximum temperature _T0 correlates with the weight per unit area w, so the cooling characteristic (hA/C) changes under the influence of factors other than the weight per unit area w. In the plurality of coating films shown in FIG. 6, since the basis weight w and the density ρ are changed, the cooling characteristics (hA/C) are considered to be affected by the density ρ.

FIG. 11 is a graph plotting the cooling characteristics (hA/C) shown in FIG. 10 against (1/ρw _T0 ). w _T0 is the basis weight obtained from the maximum temperature T ₀ of the coating film using the “second relational expression”. A measurement point for a basis weight of 7 mg/cm ² is indicated by a circle. □ (square) indicates a measurement point for a basis weight of 10 mg/cm ² . The measurement points for the basis weight of 13 mg/cm ² are represented by ◇ (diamonds). As can be seen from FIG. 11, the relationship (measurement result) between the cooling characteristic (hA/C) and (1/ρw _T0 ) can be approximated by a straight line represented by the following equation (6). "a" and "b" are constants.

The straight line represented by the above formula (6) is the _constant "a" Determine the value of “b.” By approximating the measurement result shown in Fig. 11 with the above equation (6), the following equation (7) is obtained as the “third relational expression”.

By obtaining in advance the "third relational expression" representing the relationship between the cooling characteristic (hA/C), basis weight w, and density ρ before executing the measurement process, the density ρ It is possible to measure the density ρ of the coating film from the cooling characteristic (hA/C) of the coating film whose Δ is unknown and the basis weight _{wT0 obtained from the maximum temperature T0 .}

<Measurement processing>
Next, the "measurement process" for measuring the coating weight and the like of the coating film will be described.
FIG. 12 is a flowchart showing an example of the flow of "measurement processing". A program for executing the "measurement process" is transferred from the ROM 40B by the CPU 40A of the measuring device when the user instructs the execution of the program while the plate-shaped member having the coating film is placed at the measurement position. read and executed. When measuring a plurality of coating films of the same type, "measurement processing" is executed for each coating film.

First, in step 200, acquisition of measurement data of the coating film is started. In the measurement process, the “coating film” to be measured is a coating film whose basis weight w and density ρ are unknown. The temperature measurement unit starts measuring the temperature of the coating film. The temperature measurement is performed at a predetermined position within the surface of the coating film. The control unit acquires the measured value of the temperature of the coating film at predetermined time intervals.

Next, in step 202, the temperature controller is instructed to heat the coating film. The temperature control unit applies heat to the coating film at once. The temperature of the coating film rises to the maximum temperature.

Next, in step 204, it is determined whether or not the temperature of the coating film has converged. The coating film heated by the temperature control unit is gradually naturally cooled. The temperature of the coating film converges to the ambient temperature over time.

For example, a predetermined temperature range is determined centering on the ambient temperature, such as setting the ambient temperature to 0 ° C (0 ° C ± 3 ° C), and the temperature of the coating film is within the predetermined temperature range. In this case, it may be determined that the temperature of the coating film has converged.

When the temperature of the coating film converges, the process proceeds to step 206 . Subsequently, in step 206, acquisition of the measurement data of the coating film ends. On the other hand, if the temperature of the coating film has not converged, the determination is repeated in step 204 .

Next, in step 208, the first relational expression is read from the storage device, the obtained measurement data is approximated by the first relational expression, and the maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/C ) to get each value.

Next, in step 210, the second relational expression is read from the storage device, and using the second relational expression, from the value of the maximum temperature _T0 obtained in step 208, the value of the basis weight _wT0 of the coating film is calculated. get. If the above "second relational expression" is an expression representing the relationship between the temperature rise value ΔT ₀ (=T ₀ −T _∞ ) and the basis weight w, the maximum temperature T ₀ and the ambient temperature T _∞ From the value of the temperature rise value ΔT ₀ obtained from , the value of the basis weight w _T0 of the coating film is obtained.

Next, in step 212, the third relational expression is read out from the storage device, and the value of the cooling characteristic (hA/C) obtained in step 208 and the basis weight w obtained in step 210 are calculated using the third relational expression. The value of the density ρ of the coating film is acquired from the value of _T0 , and the routine ends.

According to the first embodiment, it is possible to non-destructively measure the basis weight and density of the coating film from the time change of the temperature of the coating film after heating. By using the measurement result in a short time after the start of heating as in the embodiment described later, the measurement accuracy of the basis weight is improved. In addition, when approximating with the "first relational expression" related to Newton's cooling law, which is theoretically backed, the basis weight and density values of the coating film become more reliable.

Further, in the above-described embodiment, the basis weight and density at each position were determined on the assumption that the temperature of the plate-like member and the coating film at a predetermined position (within a unit area) is uniform. If at least one of the plate member and the coating film is thick and a temperature gradient occurs in the thickness direction, thermal diffusion within the substance may be considered.

For example, if a temperature gradient occurs in the thickness direction during heating, cooling is started before the temperature of the coating film becomes constant. Even if each numerical value of D is known, it becomes difficult to apply the theoretical formula (4). In this case, the second relational expression is obtained by changing the theoretical expression to an expression that takes thermal diffusion into account, or by approximating the above expression (4).

Also, if a temperature gradient occurs during cooling, the approximation with the above equation (6) becomes difficult. In this case, assuming that the density in the thickness direction is constant, the above equation (6) may be changed to an equation that considers thermal diffusion.

-Second Embodiment-
The second embodiment differs from the first embodiment in that only the basis weight w is obtained. In addition, in the second embodiment, the method of calculating the basis weight w (preparation processing and measurement processing) is different from that in the first embodiment. In a preparatory process, the relationship between the temperature rise value _{ΔTm at} a specific time tm immediately after heating and the basis weight w is obtained in advance.
In the measurement process, the temperature _Tm of the coating film at a specific time _tm is measured, and the basis weight w corresponding to the measured temperature _Tm is calculated using the previously determined relationship. In the first embodiment, the basis weight w is calculated from the estimated value of the temperature _T0 of the coating film at time _t = 0, but in the second embodiment, the coating film at a specific time tm The basis weight w is calculated from the measured value of the temperature _Tm . Since other parts are the same as those of the first embodiment, description thereof is omitted, and only differences are described.

<Preparation processing>
In the second embodiment, in the preparatory process, each of a plurality of known coating films is heated and the temperature _Tm at time _tm is measured. The temperature _Tm of the coating film obtained in the preparatory process may be an actual value measured at time _tm or an estimated value estimated from measured values before and after time _tm . A more accurate value of the temperature _Tm can be obtained by using an estimated value estimated from a plurality of measured values rather than using one measured value (actual value).
When obtaining an estimated value of the temperature _Tm , for example, as in the first embodiment, by approximating the measurement data with the "first relational expression" according to Newton's law of cooling, the maximum Obtain the temperature T ₀ , the ambient temperature T _∞ , and the like. As in the first embodiment, the measurement period may be the period from immediately before heating until the temperature of the coating film converges to the ambient temperature _T∞ . For example, the period is from immediately before heating until 15 seconds have elapsed.
As will be described later, an estimated value of the temperature _Tm may be obtained using measurement data for a specific period immediately after heating. Further, as will be described later, the measured data may be approximated by a straight line to obtain an estimated value of the temperature _Tm .

In the first embodiment, a "second relational expression" representing the relationship between the temperature rise value ΔT ₀ and the basis weight w is calculated from the obtained maximum temperature T ₀ , the ambient temperature T _∞ and the known basis weight w. Ask. On the other hand, in the second embodiment, for the “ _specific time _{t m} ”, the _{“ fourth} Find the relational expression.

(specific time)
The specific time _tm is the time immediately after heating. The measurement accuracy of the weight per unit area w is improved by using the measurement results in a short time after the start of heating. At least one specific time _tm is set by the user. For example, if the measurement interval by the temperature measurement unit is 0.01 seconds (100 Hz), the specific times _tm are 0.03 seconds, 0.05 seconds, 0.07 seconds, 0.1 seconds, 0.5 seconds Seconds or the like may be used.

Heat transfer, which is a change in the temperature of the coating film, includes (1) heat transfer from the front, back, and side surfaces of the coating film into the air, and (2) heat conduction due to the temperature difference within the coating film. be. For example, consider a case of measuring distribution of basis weight of a coating film. The temperature rise value at the moment when a constant amount of heat is applied is larger in the area with the smaller basis weight than in the area with the larger basis weight. This is because a region with a smaller basis weight has a smaller heat capacity.

Therefore, a temperature difference occurs in the coating film at the moment of heating. After that, the temperature of the coating film decreases due to the behaviors of (1) and (2) above. The temperature difference, which was large at the moment of heating, is reduced by heat transfer inside the coating film due to the above (2). Therefore, if the measurement result for a long period of time until the temperature returns to the ambient temperature is used, the measurement accuracy of the temperature rise value ΔT ₀ and the weight per unit area w decreases.

On the other hand, when measuring the temperature of the coating film without contact, the temperature at the moment of heating cannot be measured accurately. For example, when heating is performed by irradiating a flash lamp, the influence of reflected light and scattered light is great at the moment of heating, and the temperature of the coating film cannot be accurately measured. Therefore, the temperature of the coating film is measured at a specific time t _m (immediately after heating).

Also, when a large value is set as the time _tm , the temperature rise value _ΔTm is greatly affected by the cooling characteristics of the coating film. Since the cooling characteristics change depending on the thickness and density of the coating film, the value of _ΔTm differs even with the same basis weight. If this variation exceeds the permissible range, the relationship between the temperature rise value _ΔTm and the basis weight w will not be determined. Therefore, there is an upper limit at a particular time _tm . For example, the specific time _tm is within 1 second.

Since time tm is just after heating, the temperature rise value _ΔTm is substantially equal to the temperature rise value _ΔT0 at time _t =0. Therefore, if ΔT _m ≈ΔT ₀ in the above equation (4), the correlation between the temperature rise value ΔT _m and the basis weight w is supported by the theoretical equation.

(Preparatory procedure)
The procedure of preparation processing according to the second embodiment will be described using the flowchart shown in FIG. The procedure of the preparation process according to the second embodiment is the same as the procedure of the "preparation process" shown in FIG. 5 up to step 104. FIG. In step 104, for each of a plurality of known coating films, the measured data are approximated by the above equation (1) to obtain the maximum temperature _T0 and ambient temperature _T∞ .

In the second embodiment, in the next step ₁₀₆ , _instead of the above-mentioned "second relational expression", a "fourth relational expression ”. The next step 108 is omitted. Next, in step 110, the obtained "fourth relational expression" is stored in the storage device, and the preparatory process is terminated.

The "second relational expression" is, for example, an expression expressing the relationship between the temperature rise value ΔT ₀ and the weight per unit area w, regardless of time, as shown in the above expression (5). On the other hand, the "fourth relational expression" expresses the relationship between the temperature rise value _{ΔTm at} the time _tm and the basis weight w in association with the specific time tm. If a plurality of specific times _tm are set, such as 0.03 seconds, 0.05 seconds, 0.07 seconds, 0.1 seconds, and 0.5 seconds, for each of the multiple times _tm , " A fourth relational expression" is obtained.

<Measurement processing>
In the second embodiment, in the measurement process, the coating film to be measured is heated and the temperature _Tm of the coating film at time _tm is measured. A temperature rise value _{ΔTm at} time _tm is obtained from the measured temperature _Tm of the coating film at time tm and the ambient temperature _T∞ separately measured. Also, using the "fourth relational expression" obtained in the preparatory process, the basis weight w corresponding to the temperature rise value _{ΔTm at} the time tm is obtained. In the second embodiment, unlike the first embodiment, approximation by the "first relational expression" is not performed in the measurement process.

(Measurement processing procedure)
Next, the "measurement process" for measuring the coating weight and the like of the coating film will be described.
FIG. 13 is a flow chart showing an example of the flow of "measurement processing" according to the second embodiment. A program for executing the "measurement process" is transferred from the ROM 40B by the CPU 40A of the measuring device when the user instructs the execution of the program while the plate-shaped member having the coating film is placed at the measurement position. read and executed. When measuring a plurality of coating films of the same type, "measurement processing" is executed for each coating film.

First, in step 300, acquisition of measurement data of the coating film is started. The “coating film” to be measured is a coating film whose basis weight w and density ρ are unknown. The temperature measurement unit starts measuring the temperature of the coating film. In this embodiment, the temperature distribution of the coating film is acquired by measuring the temperature at a plurality of positions in the surface of the coating film.

Next, in step 302, the temperature controller is instructed to heat the coating film. The temperature control unit applies heat to the coating film at once. The temperature of the coating film rises to the maximum temperature. The coating film heated by the temperature control unit is gradually naturally cooled. Next, in step 304, the control unit acquires the temperature distribution _Tm of the coating film at the set time _tm from the temperature measurement unit, and ends the measurement.

Next, in step 306, the temperature distribution _{Tm at} time tm obtained in step 304 is converted into a basis weight distribution using a fourth relational expression corresponding to time _tm . That is, for each position in the plane of the coating film, the value of the corresponding basis weight _wTm is acquired from the temperature _Tm of the coating film and the ambient temperature _T∞ at time _tm , and the routine ends.

<Specific example>
A specific example will be described below.
(Preparation process)
FIG. 14 is a table showing another example of known coating films having different combinations of basis weight and density. In the illustrated example, the known coating is a graphite layer coated on a copper foil. In the illustrated example, nine types of known coating films with different combinations of basis weight w and density ρ are prepared.

The basis weight w of the known coating film changes in three steps, 7.24 mg/cm ² , 10.59 mg/cm ² and 14.11 mg/cm ² . In addition, the density ρ of the known coating film changes in three stages: no press→weak press→strong press. As the pressing strength increases, the density ρ of the known coating film increases and the thickness d of the known coating film decreases.

FIG. 15 is a graph showing an example of measurement data. This measurement data is measurement data of a known coating film with a weight per unit area w=7.24 mg/cm ² and without pressing. As described above, the maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/C) were obtained for each measurement data by approximating the measurement data with the above equation (1). Curves having constants “T _∞ ”, “T ₀ ”, and “hA/C” are also written as “approximation lines” in FIG. 15 with thick lines.

The approximation line is a curve represented by Equation (8) below. The values of constants α, β, γ are determined from the maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/C). As shown in the following formula (8), the temperature _Tt of the coating film is a function of time t. Therefore, the temperature _Tm corresponding to a particular time _tm is determined. From the temperature T _m , the ambient temperature T _∞ , and the known weight per unit area w, the relationship between the temperature rise value ΔT _m at time t _m and the weight per unit area w is obtained.

FIGS. 16A and 16B are graphs showing the relationship between the temperature rise value _ΔTm at time _tm and the basis weight w. FIG. 16A shows the relationship when the time _tm is 0.03 seconds, and FIG. 16B shows the relationship when the time _tm is 0.5 seconds. A measurement point for a basis weight of 7.24 mg/cm ² is indicated by ◯ (circle). The measurement point for the basis weight of 10.59 mg/cm ² is represented by □ (square). The measurement points for the basis weight of 14.11 mg/cm ² are indicated by ◇ (diamonds).

(measurement processing)
A coating film (measurement target) with unknown basis weight w and density ρ is heated under the same conditions as the known coating film, and the temperature distribution of the coating film at time _tm immediately after heating is obtained. Using the "fourth relational expression" obtained in the preparatory process, the temperature distribution is converted into the basis weight distribution.

FIGS. 17A to 17E are images showing an example of the basis weight distribution obtained from the coating film to be measured. FIG. 17A shows the basis weight distribution when the time _tm is 0.03 seconds. FIG. 17B shows the basis weight distribution when the time _tm is 0.05 seconds. FIG. 17(C) shows the basis weight distribution when the time _tm is 0.07 seconds. FIG. 17D shows the basis weight distribution when the time _tm is 0.1 seconds. FIG. 17(E) shows the basis weight distribution when the time _tm is 0.5 seconds. The whiter the weight, the higher the basis weight, and the blacker the weight, the lower the basis weight.

The sample is the horizontally elongated part in the center of the image. The black areas at the top and bottom of the screen are jigs that fix the sample. A region with a small basis weight exists in the center of the sample. It can be seen that the larger the value of time _tm , the more blurred the basis weight distribution becomes. In the illustrated example, the basis weight distribution at time t _m =0.03 seconds shown in FIG. 17A has the highest resolution and accuracy. The closer to the moment of heating, the more accurately the basis weight is obtained.

By obtaining in advance the relationship (fourth relational expression) between the temperature rise value ΔT _m at a specific time t _m immediately after heating and the basis weight w before executing the measurement process, the basis weight w It becomes possible to measure the basis weight w from the temperature _Tm of the coating film whose is unknown.

According to the second embodiment, it is possible to non-destructively and accurately measure the basis weight of the coating film from the measured value of the temperature of the coating film at a specific time immediately after heating. By using the measurement result in a short time from the start of heating, the measurement accuracy of the basis weight is improved.

Note that the density of the coating film can be determined by other methods such as determination from the separately measured thickness of the coating film.

-Third Embodiment-
In the third embodiment, the calculation method (preparation processing and measurement processing) of the basis weight w is different from those in the first and second embodiments. When curve approximating the measured data in the preparation process and the measurement process, the measured data in a specific period (from time _tm to time _te ) immediately after heating is used. The measurement period may also be up to time _te . Since other parts are the same as those of the first embodiment, description thereof is omitted, and only differences are described.

<Preparation processing>
In the third embodiment, in the preparation process, for each of a plurality of known coating films, the coating film is heated and measurement data for a specific period (t _m - t _e ) is acquired.

The same as the first embodiment except that the period used for curve approximation is shortened. The maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/C) are obtained for each measurement data by approximating with the “first relational expression” according to Newton's law of cooling. “Maximum temperature T ₀ ” is an estimated value of the temperature of the coating film at time t=0.
From the obtained maximum temperature T ₀ , ambient temperature T _∞ and known weight per unit area w, the “second relational expression” representing the relationship between the temperature rise value ΔT ₀ and the per unit weight w, and the cooling characteristic (hA/C) and the product of the weight per unit area w and the density ρ.

(specific period)
The specified time period (t _m - t _e ) is the short period immediately after heating. To improve the measurement accuracy of the basis weight w by using the measurement result in a short period from the start of heating. At least one specific period (t _m - t _e ) is set by the user. The reason why the measurement data after time _tm is used is that the temperature at the moment of heating cannot be measured accurately, as in the first embodiment. A particular time t _m is, for example, 0.03 seconds.

The time _te , which is the end of the period, is set earlier than the time when the temperature _Tt of the coating film converges to the ambient temperature _T∞ . In the first embodiment, measurement data is obtained up to the convergence time. For example, if the convergence time is 15 seconds after the start of heating, the time _te in the third embodiment may be 10 seconds.

For example, when the measurement interval by the temperature measurement unit is 0.01 seconds (100 Hz), the specific period (t _m -t _e ) is 0.03 seconds to 0.1 seconds, 0.03 seconds to 0.2 seconds. seconds, 0.03 seconds to 0.5 seconds, 0.03 seconds to 1 second, 0.03 seconds to 2 seconds, 0.03 seconds to 10 seconds, and the like.

<Measurement processing>
In the third embodiment, in the measurement process, the coating film to be measured is heated, and measurement data for a specific period (t _m - t _e ) is obtained in the same manner as in the preparatory process. The same as the first embodiment except that the period used for curve approximation is shortened. The maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/C) are obtained for each measurement data by approximating with the “first relational expression” according to Newton's law of cooling. A temperature rise value ΔT ₀ is obtained from the obtained maximum temperature T ₀ and the ambient temperature T _∞ .

From the obtained temperature rise value ΔT ₀ , the corresponding basis weight w _T0 is obtained using the “second relational expression”. Further, from the obtained cooling characteristic (hA/C) and basis weight _wT0 , the corresponding density ρ is obtained using the "third relational expression".

<Specific example>
A specific example will be described below.
(Preparation process)
For each of the nine types of known coating films shown in FIG. 14, measurement data was obtained for the period from immediately before heating to 10 seconds after heating. FIG. 18 is a graph showing an example of measurement data. Here, measurement data from immediately before heating to 1 second after heating is illustrated. This measurement data is measurement data of a known coating film with a weight per unit area w=7.24 mg/cm ² and without pressing.

As described above, by approximating the measurement data for a specific period (t _m - t _e ) with the above formula (1), the maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/ Each value of C) was obtained. A temperature rise value ΔT ₀ was obtained from the maximum temperature T ₀ and the ambient temperature T _∞ . A curve having constants “T _∞ ”, “T ₀ ”, and “hA/C” is also shown in FIG. 18 as an “approximation line” with a thick line.

19A and 19B are graphs showing the relationship between the temperature rise value ΔT ₀ and the basis weight w. FIG. 19A shows the relationship when the specific period (t _m −t _e ) is 0.03 seconds to 0.1 seconds, and FIG. 19B shows the specific period (t _m −t _e ) is 0.03 seconds to 10 seconds. A measurement point for a basis weight of 7.24 mg/cm ² is indicated by ◯ (circle). The measurement point for the basis weight of 10.59 mg/cm ² is represented by □ (square). The measurement points for the basis weight of 14.11 mg/cm ² are indicated by ◇ (diamonds).

(measurement processing)
A coating film (measuring target) with unknown basis weight w and density ρ was heated under the same conditions as the known coating film, and measurement data was obtained for a period of 10 seconds from immediately before heating. FIG. 20 shows an example of the difference in temperature change depending on the portion of the coating film. The coating film used in the second embodiment was used as a measurement target. FIG. 20(A) is superimposed on the basis weight distribution (see FIG. 17(A)) obtained from the temperature distribution of the coating film 0.03 seconds after heating, showing an example where the basis weight at the center of the sample is It is an image showing the position of a measurement point α in a small area and the position of a measurement point β in an area with a large basis weight.

FIG. 20B is a graph showing an example of measurement data measured for each position. The vertical axis represents the temperature _Tt of the coating film at time t. The horizontal axis represents time t. Heating of the coating film is started at time t=0. Since the measurement point α has a small basis weight, the value of the maximum temperature _T0 during heating is large.

A temperature rise value ΔT ₀ was obtained from the measurement data for a specific period (t _m - t _e ), and the corresponding basis weight w _T0 was obtained from the obtained temperature rise value ΔT ₀ using the “second relational expression”. Further, from the obtained cooling characteristics (hA/C) and basis weight _wT0 , the corresponding density ρ was obtained using the "third relational expression".

FIGS. 21A to 21F are images showing an example of the basis weight distribution obtained from the coating film to be measured. FIG. 21(A) shows the basis weight distribution when the time _te is 0.1 seconds. FIG. 21B shows the basis weight distribution when the time _te is 0.2 seconds. FIG. 21(C) shows the basis weight distribution when the time _te is 0.5 seconds. FIG. 21(D) shows the basis weight distribution when the time _te is 1 second. FIG. 21( _E ) shows the basis weight distribution when the time te is 2 seconds. FIG. 21(F) shows the basis weight distribution when the time _te is 10 seconds.

It can be seen that the larger the value of time _te , the more unclear the basis weight distribution. In the illustrated example, the basis weight distribution at time t _e =0.1 seconds shown in FIG. 21(A) has the highest resolution and accuracy. The shorter the period used for curve approximation, the more accurately the basis weight is obtained.

According to the third embodiment, it is possible to non-destructively measure the basis weight and density of the coating film from the temporal change in the temperature of the coating film in a specific period immediately after heating. By using the measurement result in a short time after the start of heating, the influence of heat transfer in the coating film due to heat conduction is reduced, and the measurement accuracy of the basis weight is improved.

When curve approximating the measurement data in the preparation process and measurement process, use the measurement data up to the convergence time by using the measurement data for a specific period immediately after heating (for example, the period within 1 second from the start of heating). It is possible to measure the weight per unit area with higher accuracy than in the case of

-Fourth Embodiment-
The fourth embodiment is the same as the third embodiment in that the measurement data for a specific period (t _m - t _e ) immediately after heating is used. The fourth embodiment is different from the third embodiment, which performs curve approximation, in that the measurement data is linearly approximated. The fourth embodiment differs from the third embodiment in that, in principle, only the basis weight w is obtained. Since the other parts are the same as those of the third embodiment, description thereof will be omitted, and only differences will be described.

<Preparation processing>
In the fourth embodiment, in the preparatory process, for each of a plurality of known coating films, the known coating films are heated to obtain measurement data for a specific period (t _m - t _e ). The specific time period (t _m - t _e ) is a short period, for example, from 0.03 seconds to 1 second.

In the fourth embodiment, the measured data are approximated by a straight line represented by the following formula (9). A constant E and a constant F are obtained for each measurement data, and an approximation formula is acquired. Specifically, it is assumed that "T _t " and "t" in the following formula (9) are variables, and "E" and "F" are constants. Then, using the method of least squares, etc., the constants "E" and "F" are used so that the straight line representing the following formula (9) is closest to the plurality of measurement points (combination of T _t and t) of the measurement data. Determine each value of

Substitute t=0 into the obtained approximate expression to obtain the maximum temperature _T0 . “Maximum temperature T ₀ ” is an estimated value of the temperature of the coating film at time t=0. A temperature rise value ΔT ₀ is obtained from the obtained maximum temperature T ₀ and the ambient temperature T _∞ obtained separately. The relationship between the temperature rise value ΔT ₀ and the basis weight w is represented by the above formula (4). A “second relational expression” representing the relationship between the temperature rise value ΔT ₀ and the weight per unit area w is obtained from the value of the temperature rise value ΔT ₀ obtained by linear approximation and the known value of the weight per unit weight w.

<Measurement processing>
In the fourth embodiment, in the measurement process, the coating film to be measured is heated to obtain measurement data for a specific period (t _m - t _e ). Similar to the preparatory process, the straight line represented by the above equation (9) is used for approximation to obtain an approximation formula.

Substitute t=0 into the obtained approximate expression to obtain the maximum temperature _T0 . A temperature rise value ΔT ₀ is obtained from the obtained maximum temperature T ₀ and the ambient temperature T _∞ obtained separately. From the obtained temperature rise value ΔT ₀ , the corresponding basis weight w _T0 is obtained using the “second relational expression”.

<Specific example>
A specific example will be described below.
(Preparation process)
For each of the nine types of known coating films shown in FIG. 14, measurement data was obtained for the period from immediately before heating to 1 second after heating. FIG. 22 is a graph showing an example of measurement data. This measurement data is measurement data of a known coating film with a weight per unit area w=7.24 mg/cm ² and without pressing.

As described above, by approximating the measurement data for a specific period (t _m - t _e ) with the above equation (9), the maximum temperature T ₀ (temperature when t = 0), the temperature rise value ΔT ₀ was determined. A straight line having constants "E" and "F" is also written in bold in FIG. 22 as an "approximation line". If the period used for approximation is short, the change in the temperature of the coating film over time approaches a straight line, and can be approximated by a straight line. Approximating with a straight line reduces the number of constant terms and allows approximate calculation to be performed in a shorter time.

23A and 23B are graphs showing the relationship between the temperature rise value ΔT ₀ and the basis weight w. FIG. 23A shows the relationship when the specific period (t _m −t _e ) is 0.03 seconds to 0.1 seconds, and FIG. 23B shows the specific period (t _m −t _e ) is 0.03 to 0.5 seconds. A measurement point for a basis weight of 7.24 mg/cm ² is indicated by ◯ (circle). The measurement point for the basis weight of 10.59 mg/cm ² is represented by □ (square). The measurement points for the basis weight of 14.11 mg/cm ² are indicated by ◇ (diamonds).

(measurement processing)
A coating film (measuring object) with unknown basis weight w and density ρ was heated under the same conditions as the known coating film, and measurement data for a specific period (t _m - t _e ) was obtained. A temperature rise value ΔT ₀ was obtained from the measurement data, and a corresponding basis weight w _T 0 was obtained from the obtained temperature rise value ΔT ₀ using the “second relational expression”. The time _tm was set to 0.03 seconds.

FIGS. 24A and 24B are images showing an example of the basis weight distribution obtained from the coating film to be measured. FIG. 24A shows the basis weight distribution when the time _te is 0.1 seconds. FIG. 24B shows the basis weight distribution when the time _te is 0.5 seconds. The basis weight distribution can also be obtained by linear approximation.

It can be seen that the larger the value of time _te , the more unclear the basis weight distribution. In the illustrated example, the basis weight distribution at time t _e =0.1 seconds shown in FIG. 24A is higher resolution and more accurate. The shorter the period used for approximation, the more accurately the basis weight is obtained.

According to the fourth embodiment, it is possible to non-destructively measure the basis weight of the coating film from the time change in the temperature of the coating film in a specific period immediately after heating. By using the measurement result in a short time from the start of heating, the measurement accuracy of the basis weight is improved.

When approximating the measurement data in the preparation process and the measurement process, by using the measurement data of a specific period immediately after heating, the basis weight can be measured with higher accuracy than when the measurement data up to the convergence time is used. becomes possible.

In addition, by linearly approximating the measured data, the load of approximation calculation is reduced compared to the case of approximating with an exponential function such as the "first relational expression" according to Newton's law of cooling.

In the fourth embodiment, a case where only the basis weight w is obtained will be described, but the density ρ may be obtained using the constant "E" of the above equation (9) as the cooling characteristic. For example, before executing the measurement process, the relationship between the cooling characteristic E, the basis weight w, and the density ρ is acquired in advance. In the measurement process, the density ρ of the coating film is measured from the cooling characteristic E of the coating film whose density ρ is unknown and the basis weight _{wT0 obtained from the maximum temperature T0 .}

- Fifth Embodiment -
The fifth embodiment differs from the fourth embodiment in that the measurement interval (sampling interval) for acquiring measurement data is lengthened. Since other parts are the same as those of the fourth embodiment, description thereof is omitted, and only differences are described.

<Specific example>
A specific example will be described below.
(Preparation process)
For each of the nine types of known coating films shown in FIG. 14, measurement data was obtained for the period from immediately before heating to 1 second after heating. FIG. 25 is a graph showing an example of measurement data. This measurement data is measurement data of a known coating film with a weight per unit area w=7.24 mg/cm ² and without pressing. In the first to fourth embodiments, measured values are obtained at intervals of 0.01 seconds (100 Hz). In the fifth embodiment, measurement values are obtained at measurement intervals of 0.05 seconds (20 Hz). In the fifth embodiment, the number of measurement points is reduced to (1/5) compared to the other embodiments.

As described above, by approximating the measurement data with the above equation (9), the maximum temperature T ₀ (temperature when t=0) and the temperature rise value ΔT ₀ were obtained for each measurement data. A straight line having constants "E" and "F" is also written in bold in FIG. 25 as an "approximation line".

26(A) and (B) are graphs showing the relationship between the temperature rise value ΔT ₀ and the basis weight w. FIG. 26(A) shows the relationship when the specific period (t _m −t _e ) is 0.05 seconds to 0.15 seconds, and FIG. 26(B) shows the specific period (t _m −t _e ) is 0.05 seconds to 1 second. A measurement point for a basis weight of 7.24 mg/cm ² is indicated by ◯ (circle). The measurement point for the basis weight of 10.59 mg/cm ² is represented by □ (square). The measurement points for the basis weight of 14.11 mg/cm ² are indicated by ◇ (diamonds).

(measurement processing)
A coating film (measuring object) with unknown basis weight w and density ρ was heated under the same conditions as the known coating film, and measurement data for a specific period (t _m - t _e ) was obtained. A maximum temperature _T0 was obtained from the measurement data. “Maximum temperature T ₀ ” is an estimated value of the temperature of the coating film at time t=0. A temperature rise value ΔT ₀ was obtained from the maximum temperature T ₀ and the ambient temperature T _∞ obtained separately. From the obtained temperature rise value ΔT ₀ , the corresponding basis weight w _T0 was obtained using the “second relational expression”. The time _tm was set to 0.05 seconds.

FIGS. 27A to 27D are images showing an example of the basis weight distribution obtained from the coating film to be measured. FIG. 27A shows the basis weight distribution when the time _te is 0.15 seconds. FIG. 27B shows the basis weight distribution when the time _te is 0.2 seconds. FIG. 27(C) shows the basis weight distribution when the time _te is 0.5 seconds. FIG. 27(D) shows the basis weight distribution when the time _te is 1 second. Even if the measurement interval is lengthened, the basis weight distribution can be obtained.

It can be seen that the larger the value of time _te , the more unclear the basis weight distribution. In the illustrated example, the basis weight distribution at time t _e =0.15 seconds shown in FIG. 27A is higher resolution and more accurate. The shorter the period used for approximation, the more accurately the basis weight is obtained.

According to the fifth embodiment, it is possible to non-destructively measure the weight per unit area of the coating film from the temporal change in the temperature of the coating film in a specific period immediately after heating. By using the measurement result in a short time from the start of heating, the measurement accuracy of the basis weight is improved.

When approximating the measurement data in the preparation process and the measurement process, by using the measurement data of a specific period immediately after heating, the basis weight can be measured with higher accuracy than when the measurement data up to the convergence time is used. becomes possible.

In addition, by linearly approximating the measured data, the load of approximation calculation is reduced compared to the case of approximating with an exponential function such as the "first relational expression" according to Newton's law of cooling. Furthermore, when linear approximation is performed, the basis weight can be obtained even if the measurement interval is lengthened and the number of measurement points is reduced.

-Modification-
It goes without saying that the configuration of the measurement device, measurement method, and program described in the above embodiment is an example, and that the configuration may be changed without departing from the gist of the present invention.

In the above embodiment, mainly, the case where the heat is applied to the coating film to heat it and then it is cooled is explained. Since it accompanies change, the basis weight and density can be calculated by the same measuring method.

The maximum temperature _T0 is an example of the "temperature attainment value" when the coating film is heated. When the coating film is cooled, the "temperature attainment value" is the lowest temperature _T01 . After reaching the minimum temperature _T01 , the temperature _Tt of the coating film gradually returns from the minimum temperature _T01 to the ambient temperature _T∞ . In this case, the ambient temperature T _∞ is taken as the reference temperature, and the difference between the lowest temperature T ₀₁ and the ambient temperature T _∞ is taken as the temperature drop value ΔT ₀₁ (=−T ₀₁ −T _∞ ).

10 Measurement device 12 Coating film 14 Dark room 16 Conveyor belt 18 Plate-shaped member 20 Temperature adjustment unit 30 Temperature measurement unit 40 Control unit 42 Display unit 44 Input unit 46 Communication unit 48 Storage unit

Claims (12)

When the coating film applied to the surface of the plate-like member is heated or cooled, the temperature of the coating film at a predetermined position of the coating film at the time when the heating or cooling is started. an acquisition means for acquiring an estimated value of as a specific value ;
When the specific value is obtained, the specific value obtained by the obtaining means using a predetermined relationship between the temperature of the coating film at a time corresponding to the specific value and the basis weight of the coating film. an output means for obtaining and outputting the basis weight at a predetermined position of the coating film corresponding to;
with
The estimated value of the temperature of the coating film at the time is
Obtaining the time change of the temperature of the coating film by approximating it with a curve or straight line,
measuring device. The curve is represented by an exponential formula representing Newton's law of cooling,
The measuring device according to claim 1 . Approximate the time change of the temperature of the coating film for a predetermined period after the start of the heating or cooling and before the temperature of the coating film converges with the curve or the straight line;
The measuring device according to claim 1 or 2 . The predetermined period is a period within 1 second after the start of the heating or cooling,
The measuring device according to claim 3 . The estimated value of the temperature of the coating film at the time is
When obtaining the predetermined relationship, estimate by the same method as when estimating the temperature of the coating film at the time for each of a plurality of coating films with a known basis weight,
The measuring device according to any one of claims 1 to 4 . When the acquisition means further acquires the cooling characteristics of the coating film together with the estimated value of the temperature of the coating film at the time ,
The output means cools the coating film acquired by the acquisition means using a predetermined relationship among the cooling characteristics of the coating film, the basis weight of the coating film, and the density of the coating film. Outputting the density at a predetermined position of the coating film corresponding to the basis weight of the coating film obtained by the characteristics and the output means;
The measuring device according to any one of claims 1 to 5 . 2. The measuring device according to claim 1 , wherein when the time change of the temperature of the coating film is approximated by a straight line, the sampling interval of the time change of the temperature of the coating film is widened. The coating film is a graphite layer coated on a copper foil,
The measuring device according to any one of claims 1 to 7 . there are a plurality of the predetermined positions;
The acquisition means acquires a time change of the temperature distribution of the coating film.
The measuring device according to any one of claims 1 to 8 . The temperature distribution of the coating film is obtained from an infrared camera,
The measuring device according to claim 9 . When the coating film applied to the surface of the plate-like member is heated or cooled, the temperature of the coating film at a predetermined position of the coating film at the time when the heating or cooling is started. Take the estimated value of as a specific value ,
When the specific value is acquired, using a predetermined relationship between the temperature of the coating film at the time corresponding to the specific value and the basis weight of the coating film, corresponding to the acquired specific value, Obtaining and outputting the basis weight at a predetermined position of the coating film,
The estimated value of the temperature of the coating film at the time is
Obtaining the time change of the temperature of the coating film by approximating it with a curve or straight line,
measurement method. the computer,
When the coating film applied to the surface of the plate-like member is heated or cooled, the temperature of the coating film at a predetermined position of the coating film at the time when the heating or cooling is started. Acquisition means for acquiring an estimated value of as a specific value ,
When the specific value is obtained, the specific value obtained by the obtaining means using a predetermined relationship between the temperature of the coating film at a time corresponding to the specific value and the basis weight of the coating film. Output means for obtaining and outputting the basis weight at a predetermined position of the coating film corresponding to,
A program for functioning as
The estimated value of the temperature of the coating film at the time is
It is obtained by approximating the time change of the temperature of the coating film with a curve or straight line,
program.

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