JP7363989B2 - Measuring device, measuring method, and program - Google Patents

Description

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

Patent Document 1 discloses an apparatus for inspecting sheet material produced in a production process having a process flow, including a central process control device configured to control at least one aspect of the production process, and a central process control device corresponding to the sheet material. an incident radiation source and a conveyor for moving this sheet material in a single plane, and in close proximity to the surface of the sheet material such that an image of the surface of the sheet material can be generated at or downstream of the incident radiation source; at least one infrared detector located at the infrared detector and communicating with the central process controller to receive and analyze an image from the infrared detector to determine a physical property of the sheet material, and to receive and analyze an image from the infrared detector to determine a physical property of the sheet material; a computer configured to send the determined physical characteristic to a central process controller, the central process controller adjusting at least one aspect of the production process in response to the determined physical characteristic. An apparatus is disclosed that is characterized by:

Special Publication No. 2002-502968

An object of the present invention is to provide a measuring device, a measuring method, and a program that can non-destructively and accurately measure the basis weight of a coating film.

In order to achieve the above-mentioned object, the measuring device of the present invention provides a measurement device that measures the temperature at a predetermined position of the coating film applied to the surface of a plate-shaped member when the coating film is heated or cooled. Either an estimated value of the temperature of the coating film at a first time when heating or cooling was started, or an actual value of the temperature of the coating film at a second time immediately after the heating or cooling was 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, The measuring device includes an output means for determining and outputting a basis weight at a predetermined position of the coating film corresponding to the specific value acquired by the acquisition means.

The measurement method of the present invention is characterized in that when a coating film applied to the surface of a plate-like member is heated or cooled, the measurement method is performed at a predetermined position of the coating film at a point where the heating or cooling is started. Either one of an estimated value of the temperature of the coating film at one time and an actual 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 value is obtained. When a value is acquired, the coating film corresponding to the acquired specific value is determined using a predetermined relationship between the temperature of the coating film and the basis weight of the coating film at the time corresponding to the specific value. This is a measurement method that calculates and outputs the area weight at a predetermined position on the coating film.

The program of the present invention causes a computer to perform heating or cooling at a predetermined position of the coating film applied to the surface of a plate member when the coating film is heated or cooled. acquiring 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 value of the temperature of the coating film at a second time immediately after the heating or cooling is started, as a specific value; means, when the specific value is acquired, the temperature of the coating film at the time corresponding to the specific value and the basis weight of the coating film are obtained by using a predetermined relationship; This is a program for functioning as an output means for determining and outputting the basis weight at a predetermined position of the coating film, which corresponds to a specific value.

According to the present invention, the basis weight of a coating film can be measured non-destructively and accurately.

1 is a schematic diagram showing an example of the configuration of a measuring device according to an embodiment of the present invention. It is a schematic diagram showing an example of composition of a coating film. FIG. 1 is a block diagram showing an example of the electrical configuration of a measuring device according to an embodiment of the present invention. 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." It is a table showing an example of a plurality of known coating films having different combinations of basis weight and density. (A) to (C) are graphs showing an example of temporal changes in temperature of each of a plurality of known coating films. It is a table showing an example of maximum temperature for a plurality of known coating films. It is a graph plotting maximum temperature against area weight for a plurality of known coating films. It is a table showing an example of cooling characteristics for a plurality of known coating films. It is a graph in which cooling characteristics are plotted against (1/ρw _T0 ) for a plurality of known coating films. It is a flowchart which shows an example of the flow of "measurement processing." It is a flowchart which shows an example of the flow of "measurement processing" concerning a 2nd embodiment. It is a table showing another example of a plurality of known coating films having different combinations of basis weight and density. It is a graph showing an example of measurement data. It is a graph showing the relationship between the temperature increase value ΔT _m at time t _m and the basis weight w. (A) to (E) are images showing an example of the basis weight distribution acquired from the coating film to be measured. It is a graph showing an example of measurement data. (A) and (B) are graphs showing the relationship between the temperature increase 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 at each position. (A) to (F) are images showing an example of the basis weight distribution acquired from the coating film to be measured. It is a graph showing an example of measurement data. (A) and (B) are graphs showing the relationship between the temperature increase value ΔT ₀ and the basis weight w. (A) and (B) are images showing an example of the basis weight distribution acquired from the coating film to be measured. It is a graph showing an example of measurement data. (A) and (B) are graphs showing the relationship between the temperature increase value ΔT ₀ and the basis weight w. (A) to (D) are images showing an example of the basis weight distribution acquired from the coating film to be measured.

Hereinafter, an example of an embodiment of the present invention will be described in detail 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 measurement device 10 includes a temperature adjustment section 20 that adjusts the temperature of the coating film 12, a temperature measurement 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 in the dark room 14 .

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

Here, the "fabric weight" is the weight per unit area, and the "density" is the weight per unit volume. For example, a graphite layer coated on copper foil of a negative electrode sheet of a lithium ion battery is a suitable coating film in this 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 heating the coating film 12, an amount of heat is applied to the coating film 12. When the coating film 12 is cooled, heat is taken from the coating film 12.

As a heating method, optical heating by irradiating light, convection heating by hot air, radiant heating using an infrared heater, induction heating, etc. may be used. Further, as a cooling method, convection heat transfer using cold air or the like may be used. According to optical heating, the heating time is shortened compared to other heating methods. Examples of optical 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. Examples of the temperature measurement unit 30 that measures temperature without contact include a non-contact temperature sensor such as an infrared camera or a radiation thermometer. 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, for each pixel). According to the infrared camera, it is possible to measure the temperature at each position of the coating film 12.

The predetermined position may be one or multiple positions. Each position is a region having a unit area within the plane of the coating film. The basis weight and density determined for each position are representative values of the basis weight and density within the area. Here, the "representative value" is a value representative of possible values within a region, such as an average value or a median value. In the following, the predetermined position will be described as "one location".

FIG. 3 is a block diagram showing an example of the electrical configuration of the measuring device according to the embodiment of the present invention. As shown in FIG. 3, the control section 40 of the measuring device 10 is configured as a computer that controls each section 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). Equipped with 40E.

Each of the CPU 40A, ROM 40B, RAM 40C, memory 40D, and I/O 40E is connected via a bus 40F. The CPU 40A reads a program stored in the ROM 40B, for example, and executes the program using the RAM 40C as a work area. In addition, 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, a program for executing "measurement processing" to be described later is stored in the ROM 40B. Further, as will be described later, the "second relational expression" and "third relational expression" obtained by the "preparation process" 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 40D and the storage section 48, or may be acquired from an external device via the communication section 46.

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

As shown in FIG. 1, the measuring device 10 includes a conveyor belt 16 that conveys a plate member 18 provided with a coating film 12 to a predetermined measurement position. The conveyor belt 16 is drive-controlled by the control unit 40 and conveys the plate 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 coated surface of the coating film 12 coated on the surface is exposed.

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

The temperature adjustment section 20 is controlled by the control section 40 and heats or cools the coating film 12 at an instructed timing. The temperature measurement section 30 is controlled by the control section 40 and measures the temperature at a predetermined position on the coating film 12 only for an instructed 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 or the storage unit 48. The control unit 40 executes a "measurement process" to be described later based on the acquired measurement data.

<Measurement data>
Here, "measurement data" obtained by the temperature measurement section will be explained.
The measurement data is data representing changes in the temperature of the coating film over time. Measurement data is acquired 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 flash lamp irradiation time is set to 0 seconds.

The measured value of the temperature _Tt of the coating film is acquired at predetermined intervals. Each measurement point corresponding to each acquired measurement value is represented by a circle. Measurement of temperature starts immediately before heating starts. Measurement data is acquired for a period from just 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 until 15 seconds have elapsed 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 a unit area. In other words, the temperature of the coating film differs for each unit area.

When the coating film is heated, the temperature T _t of the coating film instantaneously reaches the maximum temperature T ₀ and then gradually returns from the maximum temperature T ₀ 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.

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

When considered theoretically, the temperature _Tt of the coating film is expressed by the following formula (1) in accordance with Newton's law of cooling. The following equation (1) is an example of the "first relational equation". Newton's law of cooling is an empirical law that states that when a substance is cooled by a 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 time, T ₀ 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 where heat is transferred, and C is the heat capacity. The heat capacity C is the entire 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 measured. Although the heat transfer coefficient h changes depending on (T ₀ -T _∞ ), it is a constant value for each coating film. Further, the surface area A is a constant value regardless of the coating film.

The above equation (1) indicates that the temperature T _t of the coating film decays exponentially from the maximum temperature T ₀ to the ambient temperature T _∞ . The cooling rate of the coating film is expressed as (hA/C). In this embodiment, h is defined as a "heat transfer coefficient" and (hA/C) is defined as a "cooling characteristic." When the value of surface area A and the value of heat capacity C are constant, the cooling characteristic (hA/C) has a value proportional to the heat transfer coefficient h.

When the measured data is approximated by the above equation (1), the values of the ambient temperature T _∞ , the maximum temperature T ₀ , and the cooling characteristic (hA/C) are obtained. Specifically, it is assumed that "T _t " and "t" in the above equation (1) are variables, and "T _∞ ", "T ₀ ", and "hA/C" are constants. Then, by using the least squares method _etc. , a constant Define each value of "T _∞ ", "T ₀ ", and "hA/C".

The curves having the constants "T _∞ ", "T ₀ ", and "hA/C" are also shown in thick lines in FIG. 4 as "approximate lines." Note that the number of measurement points is set to be greater than or equal to the number of constants. For example, in order to determine the three constants in this example, three or more measured values are required.

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

In the known coating film, the material of the plate member to be coated and the material of the coating film are the same as the coating film to be measured. Furthermore, the known coating film and the coating film to be measured have approximately 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, and the temperature change when the plurality of known coating films is naturally cooled after heating is measured, thereby obtaining a plurality of measurement data 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 obtain measurement data. The predetermined conditions are the same as those of the coating film to be measured. For example, when emitting 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 applied to or taken away from each film becomes approximately constant.

Next, in step 104, for each of the plurality of known coating films, the measured data is approximated by the above equation (1) to obtain the maximum temperature T ₀ , the surrounding temperature T _∞ , and the cooling characteristic hA/C. . The approximate calculation may be performed by the control unit 40.

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

Next, in 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 preparation process is ended. 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 along with the first relational expression. Note that the order of steps 106 and 108 may be reversed.

The cooling rate of the coating film differs depending on the in-plane position. For example, the cooling rate is faster at the end portion with side surfaces and a wider heat dissipation surface than at the center portion. Therefore, for each of a plurality of known coating films, the closer the temperature measurement position is to the measurement target coating film position, the more accurate the "second relational expression" and "third relational expression" will be. is required.

(Specific example of preparation process)
A specific example of the preparation process will be described below.
FIG. 6 is a table showing an example of a plurality 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 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 weight w of the known coating film changes in three steps: 7 mg/cm ² , 10 mg/cm ² , and 13 mg/cm ² . Further, the density ρ of the known coating film is also changed in three stages by changing the press strength in three stages for a coating film with the same basis weight. No press→weak press→strong press: As the press strength increases, the value of the density ρ increases and the thickness d of the known coating film becomes thinner.

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

The known thickness d of the coating film is a measured value measured with a displacement meter such as a micrometer. The thickness d may be an average value of the entire region to be measured, or may be an average value of any plurality of points in the region 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 the density ρ is [g/cm ³ ], the unit of the basis weight w is [mg/cm ² ], and the unit of the thickness d is [μm]. Needless to say, the density ρ is calculated.

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

As the value of the basis weight w increases (7 mg/cm ² →10 mg/cm ² →13 mg/cm ^{2 )} , the maximum temperature T ₀ decreases and the cooling rate decreases. Moreover, the higher the press strength and the larger the density ρ, the lower the cooling rate.

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

FIG. 8 is a table showing the maximum temperature T ₀ values obtained for the plurality of known coating films shown in FIG. 6. FIG. 9 is a graph in which the maximum temperature T ₀ shown in FIG. 8 is plotted against the area weight w of a known coating film. The measurement points for a basis weight of 7 mg/cm ² are indicated by circles. The measurement points for a basis weight of 10 mg/cm ² are represented by □ (squares). The measurement points for a basis weight of 13 mg/cm ² are represented by ◇ (diamond). As can be seen from FIG. 9, the maximum temperature T ₀ is correlated with the basis weight w. The change in the maximum temperature T ₀ due to the density ρ is small compared to the change in the maximum temperature T ₀ due to the basis weight w.

The theoretical formula also supports that the temperature increase value ΔT ₀ is correlated with the basis weight w. For example, when the temperature increase value of a coating film having a heat capacity per unit area of C is ΔT ₀ , the amount of heat Q per unit area is given by the following formula (2).

When the graphite layer coated on the copper foil is used as a 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 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 basis weight and density are determined for only the graphite layer.

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

As described above, the room temperature is 0° C. here, and the temperature increase value ΔT ₀ (=T ₀ -T _∞ ) is the same value as the maximum temperature T ₀ . Approximating the relationship (measurement result) between the maximum temperature T ₀ 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, using _the method of least squares, etc., the constants "Q", "c", "D ” value.

When the measurement results shown in FIG. 9 are approximated by the above equation (4), the following equation (5) is obtained as the "second relational equation". Here, it is not necessary to find 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, but instead, each of the constants "Q," "c," and "D" is Just set the value. Furthermore, if each of the amount of heat Q, specific heat c, and heat capacity D is known from other measurements, those values may be substituted.

By obtaining in advance the "second relational expression" that expresses the relationship between the maximum temperature T ₀ and the basis weight w before executing the measurement process, it is possible to apply a coating whose basis weight w is unknown in the "measurement process". It becomes possible to measure the basis weight w from the maximum temperature _T0 of the film. Note that the above-mentioned "second relational expression" may be an expression expressing the relationship between the temperature increase value ΔT ₀ (=T ₀ -T _∞ ) and the basis weight w. The temperature increase value ΔT ₀ absorbs the influence of the surrounding temperature T _∞ .

In addition, if each numerical value 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 is known in advance, each numerical value is substituted into the above formula (4), which is the theoretical formula, and the "second You may also find a relational expression. In this case, the approximation in equation (4) above can be omitted.

FIG. 10 is a table showing values of cooling characteristics (hA/C) obtained for the plurality of known coating films shown in FIG. 6. As shown in FIG. 11, the cooling characteristic (hA/C) shows a different change with respect to the basis weight w than with the maximum temperature _T0 . For example, unlike the change in maximum temperature _T0 , the value decreases in the order of no press, weak press, and strong press.

As mentioned above, since the maximum temperature T ₀ is correlated with the basis weight w, the cooling characteristic (hA/C) changes due to the influence of factors other than the basis weight w. In the plurality of coating films shown in FIG. 6, since the basis weight w and the density ρ are changed, it is thought that the cooling characteristic (hA/C) is influenced by the density ρ.

FIG. 11 is a graph in which the cooling characteristic (hA/C) shown in FIG. 10 is plotted 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”. The measurement points for a basis weight of 7 mg/cm ² are indicated by circles. The measurement points for a basis weight of 10 mg/cm ² are represented by □ (squares). The measurement points for a basis weight of 13 mg/cm ² are represented by ◇ (diamond). 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 expressed by the following equation (6). "a" and "b" are constants.

Using the method of least squares, etc., calculate the constant "a" so that the straight line expressed by the above formula (6) approaches the plurality of measurement points (the combination of (hA/C) and (1/ρw _T0 )) Determine the value of "b". When the measurement results shown in FIG. 11 are approximated by the above equation (6), the following equation (7) is obtained as the "third relational equation".

By obtaining in advance the "third relational expression" that expresses the relationship between the cooling characteristic (hA/C), the basis weight w, and the density ρ before executing the measurement process, the density ρ can be calculated in the "measurement process". It becomes possible to measure the density ρ of the coating film from the cooling characteristic (hA/C) of the coating film, which is unknown, and the basis weight w _T0 determined from the maximum temperature T ₀ .

<Measurement processing>
Next, a "measurement process" for measuring the basis weight and the like of the coating film will be explained.
FIG. 12 is a flowchart showing an example of the flow of "measurement processing". The program for executing the "measurement process" is executed from the ROM 40B by the CPU 40A of the measurement device when the user instructs the execution of the program with the plate-shaped member provided with the coating film placed at the measurement position. read and executed. When measuring multiple 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 each unknown. The temperature measuring section starts measuring the temperature of the coating film. The temperature is measured at a predetermined position within the surface of the coating film. The control unit obtains a measured value of the temperature of the coating film at predetermined intervals.

Next, in step 202, the temperature adjustment unit is instructed to heat the coating film. The temperature adjustment section 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 the temperature of the coating film has converged. The coating film heated by the temperature adjustment section is gradually cooled naturally. The temperature of the coating film converges to the ambient temperature over time.

For example, if the ambient temperature is set to 0℃ (0℃±3℃), a predetermined temperature range is determined around the ambient temperature, 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.

If the temperature of the coating film has converged, the process proceeds to step 206. Subsequently, in step 206, the acquisition of measurement data of the coating film is ended. 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, the value of the basis weight w _T0 of the coating film is calculated from the value of the maximum temperature _T0 obtained in step 208. get. In addition, when the above-mentioned "second relational expression" is used as an expression expressing the relationship between the temperature increase value ΔT ₀ (=T ₀ -T _∞ ) and the basis weight w, the maximum temperature T ₀ and the surrounding temperature T _∞ The value of the basis weight w _T0 of the coating film is obtained from the value of the temperature rise value ΔT ₀ obtained from the above.

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

According to the first embodiment, the basis weight and density of the coating film can be measured non-destructively from the temporal change in temperature of the coating film after heating. By using the measurement results within a short time from the start of heating as in the embodiment described later, the accuracy of measuring the basis weight is improved. In addition, when approximating with the "first relational expression" based on Newton's law of cooling, which has theoretical support, the values of the basis weight and density of the coating film become more reliable.

In addition, in the above embodiment, the basis weight and density at each position were calculated assuming that the temperature of the plate member and the coating film at a predetermined position (within a unit area) was uniform. When 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 taken into consideration.

For example, if a temperature gradient occurs in the thickness direction during heating, cooling will start before the temperature of the coating film becomes constant, so the amount of heat applied Q, the specific heat c of the graphite layer, and the heat capacity of the copper foil Even if each numerical value of D is known, it becomes difficult to apply the above-mentioned formula (4), which is a theoretical formula. In this case, the second relational expression is obtained by changing the theoretical equation to one that takes thermal diffusion into consideration, or by approximating it with the above equation (4).

Furthermore, if a temperature gradient occurs during cooling, approximation using 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 takes thermal diffusion into consideration.

-Second embodiment-
The second embodiment differs from the first embodiment in that only the basis weight w is determined. Furthermore, in the second embodiment, the method of calculating the basis weight w (preparation process and measurement process) is different from the first embodiment. In the preparation process, the relationship between the temperature increase value ΔT _m at a specific time t _m immediately after heating and the basis weight w is determined in advance.
In the measurement process, the temperature T _m of the coating film at a specific time t _m is measured, and the basis weight w corresponding to the measured temperature T _m is calculated using a predetermined relationship. In the first embodiment, the basis weight w is calculated from the estimated value of the temperature T ₀ of the coating film at time t = 0, but in the second embodiment, the basis weight w of the coating film at a specific time t _m is calculated. The basis weight w is calculated from the measured value of the temperature _Tm . Since the other parts are the same as those in the first embodiment, their explanation will be omitted, and only the differences will be explained.

<Preparation process>
In the second embodiment, in the preparation process, the coating film is heated for each of the plurality of known coating films, and the temperature T _m at time t _m is measured. The temperature T _m of the coating film determined in the preparation process may be an actual value measured at time t _m or an estimated value estimated from measured values before and after time t _m . Rather than using one measured value (actual measured value), it is possible to obtain a more accurate value of the temperature T _m by using an estimated value estimated from a plurality of measured values.
When calculating the estimated value of the temperature T _m , for example, as in the first embodiment, by approximating the measured data with the "first relational expression" related to Newton's law of cooling, the maximum value for each measured data is calculated. Find the temperature T ₀ , ambient temperature T _∞, etc. Similarly to the first embodiment, the measurement period may be a period from just before heating until the temperature of the coating film converges to the ambient temperature T _∞ . For example, the period is defined as the period from immediately before heating until 15 seconds have elapsed.
Note that, as described later, the estimated value of the temperature T _m may be obtained using measurement data for a specific period immediately after heating. Furthermore, as will be described later, the estimated value of the temperature T _m may be obtained by approximating the measured data with a straight line.

In the first embodiment, a "second relational expression" expressing the relationship between the temperature increase 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. demand. On the other hand, in the _second embodiment, for a "specific time t _m ", _{a " fourth} Find the relational expression.

(specific time)
The specific time t _m is the time immediately after heating. The measurement accuracy of the basis weight w is improved by using the measurement results within a short time from the start of heating. At least one specific time t _m is set by the user. For example, if the measurement interval by the temperature measurement unit is 0.01 seconds (100Hz), the specific times t _m are 0.03 seconds, 0.05 seconds, 0.07 seconds, 0.1 seconds, 0.5 seconds. It may also be seconds, etc.

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

Therefore, a temperature difference occurs within the coating film at the moment of heating. Thereafter, the temperature of the coating film decreases due to the behaviors (1) and (2) above. The temperature difference, which was large at the moment of heating, becomes smaller as heat moves inside the coating film due to (2) above. Therefore, if the measurement results taken over a long period of time until the temperature returns to the ambient temperature are used, the measurement accuracy of the temperature increase value ΔT ₀ and the basis weight w will decrease.

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

Further, when a large value is set as time t _m , the temperature increase value ΔT _m is greatly influenced by the cooling characteristics of the coating film. Since the cooling property changes depending on the thickness and density of the coating film, the value of ΔT _m differs even with the same basis weight. If this variation exceeds the allowable range, the relationship between the temperature rise value ΔT _m and the basis weight w is not determined. Therefore, the specific time t _m has an upper limit. For example, the specific time t _m is within one second.

Since time t _m is immediately after heating, the temperature rise value ΔT _m is approximately equal to the temperature rise value ΔT ₀ at time t=0. Therefore, if ΔT _m ≈ΔT ₀ in the above equation (4), the theoretical equation also supports that the temperature increase value ΔT _m is correlated with the basis weight w.

(Preparation process steps)
The procedure of the preparation process according to the second embodiment will be explained 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. In step 104, for each of the plurality of known coating films, the measured data is approximated by the above equation (1) to obtain the maximum temperature T ₀ and the surrounding temperature T _∞ .

In the second embodiment, in the next step 106, instead of the above-mentioned "second relational expression", a "fourth relational expression" expressing the relationship between the temperature rise value ΔT _m at time t _m and the basis weight w is used. ” The next step 108 is omitted. Next, in step 110, the obtained "fourth relational expression" is stored in the storage device, and the preparation process is ended.

The "second relational expression" is, for example, an expression expressing the relationship between the temperature increase value ΔT ₀ and the basis weight 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 increase value ΔT _m and the basis weight w at time t _m in association with a specific time t _m . If multiple specific times t _m are set such as 0.03 seconds, 0.05 seconds, 0.07 seconds, 0.1 seconds, and 0.5 _seconds , " 4th relational expression" is calculated.

<Measurement processing>
In the second embodiment, in the measurement process, the coating film to be measured is heated, and the temperature T _m of the coating film at time t _m is measured. The temperature increase value ΔT m at time t _m is determined from the measured value of the temperature T _m of the coating film at time t _m and the separately measured ambient temperature _{T ∞} . Furthermore, using the "fourth relational expression" obtained in the preparation process, the basis weight w corresponding to the temperature increase value ΔT _m at time t _m is obtained. In the second embodiment, unlike the first embodiment, approximation using the "first relational expression" is not performed in the measurement process.

(Measurement processing procedure)
Next, a "measurement process" for measuring the basis weight and the like of the coating film will be explained.
FIG. 13 is a flowchart showing an example of the flow of "measurement processing" according to the second embodiment. The program for executing the "measurement process" is executed from the ROM 40B by the CPU 40A of the measurement device when the user instructs the execution of the program with the plate-shaped member provided with the coating film placed at the measurement position. read and executed. When measuring multiple 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 each unknown. The temperature measuring section starts measuring the temperature of the coating film. In this embodiment, the temperature distribution of the coating film is obtained by measuring temperatures at multiple positions within the surface of the coating film.

Next, in step 302, the temperature adjustment section is instructed to heat the coating film. The temperature adjustment section 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 adjustment section is gradually cooled naturally. Next, in step 304, the control unit acquires the temperature distribution T _m of the coating film at the set time t _m from the temperature measurement unit, and ends the measurement.

Next, in step 306, the temperature distribution T _m at time t _m obtained in step 304 is converted into a basis weight distribution using a fourth relational expression corresponding to time t _m . That is, for each position in the plane of the coating film, the value of the corresponding basis weight w _Tm is obtained from the temperature T _m of the coating film at time t _m and the ambient temperature T _∞ , and the routine is ended.

<Specific example>
A specific example will be explained below.
(preparation process)
FIG. 14 is a table showing another example of a plurality 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 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 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 . Furthermore, the density ρ of the known coating film changes in three stages: no press → weak press → strong press. As the press 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 basis weight w=7.24 mg/cm ² and without pressing. As described above, by approximating the measured data using the above formula (1), the values of the maximum temperature T ₀ , ambient temperature T _∞ , and cooling characteristic (hA/C) were determined for each measured data. Curves having the constants "T _∞ ", "T ₀ ", and "hA/C" are also shown as "approximation lines" in thick lines in FIG. 15.

The approximate line is a curve expressed by the following formula (8). The values of the constants α, β, and γ are determined from the maximum temperature T ₀ , the ambient temperature T _∞ , and the cooling characteristic (hA/C). As shown in equation (8) below, the temperature _Tt of the coating film is a function of time t. Therefore, the temperature T _m corresponding to the specific time t _m is determined. The relationship between the temperature increase value ΔT _m at time t _m and the basis weight w is determined from the temperature T _m , the ambient temperature T _∞ , and the known basis weight w.

FIGS. 16A and 16B are graphs showing the relationship between the temperature increase value ΔT _m at time t _m and the basis weight w. FIG. 16(A) shows the relationship when time t _m is 0.03 seconds, and FIG. 16(B) shows the relationship when time t _m is 0.5 seconds. The measurement points for the basis weight of 7.24 mg/cm ² are indicated by circles. The measurement points for the basis weight of 10.59 mg/cm ² are represented by □ (squares). The measurement points for the basis weight of 14.11 mg/cm ² are represented by ◇ (diamond).

(Measurement processing)
A coating film (measurement target) whose basis weight w and density ρ are unknown is heated under the same conditions as the known coating film, and the temperature distribution of the coating film at time t _m immediately after heating is obtained. Using the "fourth relational expression" obtained in the preparation process, the temperature distribution is converted into a 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. 17(A) shows the basis weight distribution when time t _m is 0.03 seconds. FIG. 17(B) shows the basis weight distribution when time t _m is 0.05 seconds. FIG. 17(C) shows the basis weight distribution when time t _m is 0.07 seconds. FIG. 17(D) shows the basis weight distribution when time t _m is 0.1 second. FIG. 17(E) shows the basis weight distribution when time t _m is 0.5 seconds. The whiter the color, the higher the weight, and the darker the color, the lower the weight.

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

By determining 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 can be calculated in advance in the measurement process. It becomes possible to measure the basis weight w from the temperature T _m of the coating film, which is unknown.

According to the second embodiment, the basis weight of the coating film can be measured non-destructively and accurately from the measured value of the temperature of the coating film at a specific time immediately after heating. By using the measurement results within a short time from the start of heating, the accuracy of measuring the basis weight can be improved.

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

-Third embodiment-
In the third embodiment, the method of calculating the basis weight w (preparation process and measurement process) is different from the first and second embodiments. When curve approximating measurement data in the preparation process and measurement process, measurement data for a specific period (from time t _m to time _te ) immediately after heating is used. The measurement period may also end at time _te . Since the other parts are the same as those in the first embodiment, their explanation will be omitted, and only the differences will be explained.

<Preparation process>
In the third embodiment, in the preparation process, the coating film is heated for each of the plurality of known coating films, and measurement data for a specific period (t _{m −te} ) is acquired.

The process is 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 determined for each measurement data by approximating 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 basis weight w, the “second relational expression” expressing the relationship between the temperature rise value ΔT ₀ and the basis weight w, and the cooling characteristic (hA/C) and the product of the basis weight w and the density ρ.

(specific period)
The specific period (t _{m −te} ) is a short period immediately after heating. The measurement accuracy of the basis weight w is improved by using the measurement results within a short period of time from the start of heating. At least one specific period (t _{m −te} ) is set by the user. The reason why measurement data after time t _m is used is because, as in the first embodiment, the temperature at the moment of heating cannot be accurately measured. The specific time t _m is, for example, 0.03 seconds.

The time _te , which is the end of the period, is set to be earlier than the time when the temperature T _t of the coating film converges to the ambient temperature T _∞ . In the first embodiment, measurement data up to the convergence time is acquired. 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, etc.

For example, if the measurement interval by the temperature measurement unit is 0.01 seconds (100Hz), 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, etc.

<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 -te} ) is acquired as in the preparation process. The process is 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 determined for each measurement data by approximating the “first relational expression” according to Newton's law of cooling. A temperature increase value ΔT ₀ is determined from the obtained maximum temperature T ₀ and the ambient temperature T _∞ .

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

<Specific example>
A specific example will be explained below.
(preparation process)
For each of the nine types of known coating films shown in FIG. 14, measurement data was obtained for a period from just before heating to 10 seconds after. 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 basis weight w=7.24 mg/cm ² and without pressing.

As mentioned above, by approximating the measured data for a specific period (t _m - _{t e} ) using the above equation (1), the maximum temperature T ₀ , ambient temperature T _∞ , and cooling characteristic (hA/ Each value of C) was determined. Further, a temperature increase value ΔT ₀ was determined from the maximum temperature T ₀ and the ambient temperature T _∞ . Curves having the constants "T _∞ ", "T ₀ ", and "hA/C" are also shown in thick lines in FIG. 18 as "approximation lines."

FIGS. 19A and 19B are graphs showing the relationship between the temperature increase value ΔT ₀ and the basis weight w. FIG. 19(A) shows the relationship when the specific period (t _m -t _e ) is 0.03 seconds to 0.1 seconds, and FIG. 19(B) shows the relationship when the specific period (t _m -t _e ) This is the relationship when 0.03 seconds to 10 seconds. The measurement points for the basis weight of 7.24 mg/cm ² are indicated by circles. The measurement points for the basis weight of 10.59 mg/cm ² are represented by □ (squares). The measurement points for the basis weight of 14.11 mg/cm ² are represented by ◇ (diamond).

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

FIG. 20(B) is a graph showing an example of measurement data measured at 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 T ₀ during heating is large.

A temperature increase value ΔT ₀ was determined from the measurement data for a specific period (t _{m −te} ), and a corresponding basis weight w _T0 was determined from the obtained temperature increase value ΔT ₀ using the “second relational expression”. Further, the corresponding density ρ was determined from the obtained cooling characteristic (hA/C) and the basis weight w _T0 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 time t _e is 0.1 second. FIG. 21(B) shows the basis weight distribution when time _te is 0.2 seconds. FIG. 21(C) shows the basis weight distribution when time _te is 0.5 seconds. FIG. 21(D) shows the basis weight distribution when time _te is 1 second. FIG. 21(E) shows the basis weight distribution when time _te is 2 seconds. FIG. 21(F) shows the basis weight distribution when time _te is 10 seconds.

It can be seen that the larger the value of time _te becomes, the more unclear the basis weight distribution becomes. In the illustrated example, the basis weight distribution at time t _e =0.1 second 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 can be determined.

According to the third embodiment, the basis weight and density of the coating film can be measured non-destructively from the temporal change in the temperature of the coating film during a specific period immediately after heating. By using the measurement results within a short time from the start of heating, the influence of heat transfer within the coating film due to thermal conduction is reduced, and the measurement accuracy of the basis weight is improved.

By using measurement data from a specific period immediately after heating (for example, within 1 second from the start of heating) when approximating measurement data to a curve in the preparation process and measurement process, measurement data up to the convergence time can be used. It becomes possible to measure the basis weight with higher accuracy than in the case where

-Fourth embodiment-
The fourth embodiment is the same as the third embodiment in that measurement data for a specific period (t _{m −te} ) immediately after heating is used. The fourth embodiment differs from the third embodiment in that the measured data is approximated by a straight line. Furthermore, the fourth embodiment differs from the third embodiment in that, in principle, only the basis weight w is determined. Since the other parts are the same as those in the third embodiment, their explanation will be omitted, and only the differences will be explained.

<Preparation process>
In the fourth embodiment, in the preparation process, each of the plurality of known coating films is heated, and measurement data for a specific period (t _{m −te} ) is acquired. The specific period (t _{m −te} ) is, for example, a short period of time from 0.03 seconds to 1 second.

In the fourth embodiment, measurement data is approximated by a straight line expressed by the following equation (9). A constant E and a constant F are determined for each measurement data, and an approximate expression is obtained. 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 set so that the straight line representing the following equation (9) comes closest to the plurality of measurement points (combination of T and _t ) of the measurement data. Define each value.

By substituting t=0 into the obtained approximate expression, the maximum temperature T ₀ is determined. “Maximum temperature T ₀ ” is an estimated value of the temperature of the coating film at time t=0. A temperature increase value ΔT ₀ is determined from the obtained maximum temperature T ₀ and a separately determined ambient temperature T _∞ . The relationship between the temperature increase value ΔT ₀ and the basis weight w is expressed by the above equation (4). A "second relational expression" representing the relationship between the temperature increase value ΔT ₀ and the basis weight w is determined from the value of the temperature increase value ΔT ₀ obtained by linear approximation and the known value of the basis weight w.

<Measurement processing>
In the fourth embodiment, in the measurement process, the coating film to be measured is heated, and measurement data for a specific period (t _{m -te} ) is acquired. Similar to the preparation process, approximation is performed using the straight line expressed by the above equation (9) to obtain an approximate expression.

By substituting t=0 into the obtained approximate expression, the maximum temperature T ₀ is determined. A temperature increase value ΔT ₀ is determined from the obtained maximum temperature T ₀ and a separately determined ambient temperature T _∞ . From the obtained temperature increase value ΔT ₀ , the corresponding amount w _T0 is determined using the “second relational expression”.

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

As mentioned above, by approximating the measurement data for a specific period (t _m - _{t e} ) using the above formula (9), the maximum temperature T ₀ (temperature when t=0) and temperature increase value are calculated for each measurement data. ΔT ₀ was determined. A straight line having the constants "E" and "F" is also shown as an "approximate line" in thick lines in FIG. If the period used for approximation is short, the change in temperature of the coating film over time approaches a straight line, so it can be approximated by a straight line. Approximation using a straight line reduces the number of constant terms and allows for faster approximation calculations.

FIGS. 23A and 23B are graphs showing the relationship between the temperature increase value ΔT ₀ and the basis weight w. FIG. 23(A) shows the relationship when the specific period (t _m -t _e ) is 0.03 seconds to 0.1 seconds, and FIG. 23(B) shows the relationship when the specific period (t _m -t _e ) This is the relationship when 0.03 seconds to 0.5 seconds. The measurement points for the basis weight of 7.24 mg/cm ² are indicated by circles. The measurement points for the basis weight of 10.59 mg/cm ² are represented by □ (squares). The measurement points for the basis weight of 14.11 mg/cm ² are represented by ◇ (diamond).

(Measurement processing)
A coating film (measurement target) 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 −te} ) was obtained. A temperature increase value ΔT ₀ was determined from the measurement data, and a corresponding basis weight w _T0 was determined from the obtained temperature increase value ΔT ₀ using the “second relational expression”. The time t _m 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. 24(A) shows the basis weight distribution when time _te is 0.1 second. FIG. 24(B) shows the basis weight distribution when time _te is 0.5 seconds. The basis weight distribution can also be determined by linear approximation.

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

According to the fourth embodiment, the basis weight of the coating film can be measured non-destructively from the temporal change in the temperature of the coating film during a specific period immediately after heating. By using the measurement results within a short time from the start of heating, the accuracy of measuring the basis weight can be improved.

By using measurement data from a specific period immediately after heating when approximating measurement data in the preparation process and measurement process, the basis weight can be measured more accurately than when using measurement data up to the time of convergence. becomes possible.

Further, by performing a linear approximation to the measurement data, the load of the approximation calculation is reduced compared to the case of approximation using an exponential function such as the "first relational expression" related to Newton's law of cooling.

In the fourth embodiment, a case will be described in which only the basis weight w is determined, but the density ρ may also be determined using the constant "E" in 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 obtained 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 w _T0 determined from the maximum temperature T ₀ .

-Fifth embodiment-
The fifth embodiment differs from the fourth embodiment in that the measurement interval (sampling interval) when acquiring measurement data is lengthened. Since the other parts are the same as those in the fourth embodiment, the explanation will be omitted and only the differences will be explained.

<Specific example>
A specific example will be explained below.
(preparation process)
For each of the nine types of known coating films shown in FIG. 14, measurement data was obtained for a period from just before heating to 1 second later. FIG. 25 is a graph showing an example of measurement data. This measurement data is measurement data of a known coating film with a basis weight w=7.24 mg/cm ² and without pressing. In the first to fourth embodiments, measured values were acquired at measurement intervals of 0.01 seconds (100 Hz). In the fifth embodiment, measured values are acquired 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, the maximum temperature T ₀ (temperature when t=0) and temperature increase value ΔT ₀ were determined for each measurement data by approximating the measurement data using the above equation (9). A straight line having the constants "E" and "F" is also shown as an "approximation line" in thick lines in FIG.

FIGS. 26A and 26B are graphs showing the relationship between the temperature increase 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 relationship when the specific period (t _m -t _e ) This is the relationship when 0.05 seconds to 1 second. The measurement points for the basis weight of 7.24 mg/cm ² are indicated by circles. The measurement points for the basis weight of 10.59 mg/cm ² are represented by □ (squares). The measurement points for the basis weight of 14.11 mg/cm ² are represented by ◇ (diamond).

(Measurement processing)
A coating film (measurement target) 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 −te} ) was obtained. The maximum temperature T ₀ was determined from the measurement data. “Maximum temperature T ₀ ” is an estimated value of the temperature of the coating film at time t=0. The temperature increase value ΔT ₀ was determined from the maximum temperature T ₀ and the ambient temperature T _∞ obtained separately. From the obtained temperature increase value ΔT ₀ , the corresponding weight w _T0 was determined using the “second relational expression”. The time t _m 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. 27(A) shows the basis weight distribution when time _te is 0.15 seconds. FIG. 27(B) shows the basis weight distribution when time _te is 0.2 seconds. FIG. 27(C) shows the basis weight distribution when time _te is 0.5 seconds. FIG. 27(D) shows the basis weight distribution when 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 becomes, the more unclear the basis weight distribution becomes. In the illustrated example, the basis weight distribution at time t _e =0.15 seconds shown in FIG. 27(A) has higher resolution and is more accurate. The shorter the period used for approximation, the more accurately the basis weight can be determined.

According to the fifth embodiment, the basis weight of the coating film can be measured non-destructively from the temporal change in the temperature of the coating film during a specific period immediately after heating. By using the measurement results within a short time from the start of heating, the accuracy of measuring the basis weight can be improved.

By using measurement data from a specific period immediately after heating when approximating measurement data in the preparation process and measurement process, the basis weight can be measured more accurately than when using measurement data up to the time of convergence. becomes possible.

Further, by performing a linear approximation to the measurement data, the load of the approximation calculation is reduced compared to the case of approximation using an exponential function such as the "first relational expression" related to Newton's law of cooling. Furthermore, when linear approximation is performed, the basis weight can be determined even if the measurement interval is lengthened and the number of measurement points is reduced in this way.

-Modified example-
Note that the configurations of the measuring device, measuring method, and program described in the above embodiments are merely examples, and it goes without saying that the configurations may be changed without departing from the spirit of the present invention.

In the above embodiment, the case was mainly described in which heat is applied to the coating film and the coating film is heated and then cooled. However, when heat is taken away (cooling), the temperature is opposite to that when heat is applied. Since it involves a change, the basis weight and density can be calculated using the same measurement method.

The maximum temperature T ₀ is an example of the "temperature reached value" when the coating film is heated. When the coating film is cooled, the "attained temperature value" is the lowest temperature T ₀₁ . After reaching the minimum temperature T ₀₁ , the temperature T _t of the coating film gradually returns from the minimum temperature T ₀₁ to the ambient temperature T _∞ . In this case, the ambient temperature T _∞ is used as the reference temperature, and the difference between the lowest temperature T ₀₁ and the ambient temperature T _∞ is defined as the temperature drop value ΔT ₀₁ (=-T ₀₁ -T _∞ ).

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

Claims (6)

When the coating film applied to the surface of the plate member is heated or cooled, the coating film at a predetermined position of the coating film at a time immediately after the heating or cooling is started. an acquisition means for acquiring an actual measured value of the temperature of the temperature as a specific value;
When the specific value is obtained, a predetermined relationship between the temperature increase value expressed by the difference between the temperature of the coating film and room temperature at the time corresponding to the specific value and the basis weight of the coating film is determined. output means for determining and outputting the basis weight at a predetermined position of the coating film, which corresponds to the specific value acquired by the acquisition means, using the method;
Equipped with
When determining a predetermined relationship between the temperature rise value of the coating film at the time and the basis weight of the coating film, the time change in temperature of the coating film whose basis weight is known is approximated by a curve or a straight line. and determining the temperature of the coating film at the time,
Measuring device. The coating film is a graphite layer coated on copper foil,
The measuring device according to claim 1. There are a plurality of the predetermined positions,
The acquisition means acquires the temperature distribution of the coating film at the time ,
The measuring device according to claim 1 or claim 2. The temperature distribution of the coating film is obtained from an infrared camera.
The measuring device according to claim 3. When the coating film applied to the surface of the plate member is heated or cooled, the coating film at a predetermined position of the coating film at a time immediately after the heating or cooling is started. Obtain the actual measured value of the temperature as a specific value,
When the specific value is obtained, a predetermined relationship between the temperature increase value expressed by the difference between the temperature of the coating film and room temperature at the time corresponding to the specific value and the basis weight of the coating film is determined. to calculate and output the basis weight at a predetermined position of the coating film corresponding to the acquired specific value,
When determining a predetermined relationship between the temperature rise value of the coating film at the time and the basis weight of the coating film, the time change in temperature of the coating film whose basis weight is known is approximated by a curve or a straight line. and determining the temperature of the coating film at the time,
Measurement method. computer,
When the coating film applied to the surface of the plate member is heated or cooled, the coating film at a predetermined position of the coating film at a time immediately after the heating or cooling is started. acquisition means for acquiring one of the actual measured values of the temperature as a specific value;
When the specific value is obtained, a predetermined relationship between the temperature increase value expressed by the difference between the temperature of the coating film and room temperature at the time corresponding to the specific value and the basis weight of the coating film is determined. output means for determining and outputting the basis weight at a predetermined position of the coating film, which corresponds to the specific value acquired by the acquisition means, using
It is a program to function as
When determining a predetermined relationship between the temperature rise value of the coating film at the time and the basis weight of the coating film, the time change in temperature of the coating film whose basis weight is known is approximated by a curve or a straight line. and the temperature of the coating film at the time is determined.
program.