JP2008267858A - Coated film drying behavior measuring method and instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated film drying behavior measuring method for simultaneously measuring a mass change in drying a coated film formed on a sheet-like base material and a temperature change of a coated film surface, and a measuring instrument used for the measuring method. <P>SOLUTION: An infrared heater of 1.5 to 3.0 μm peak wavelength is used as a heating means. An electronic force balance is used as a mass change measuring means. An infrared radiation thermometer of 8 to 14 μm measurement wavelength is used as a coated film surface temperature measuring means. The radiation thermometer has a minimum measured spot diameter of 1 cm or less and includes a stand for holding a specimen in the air. The stand has a pin receiving member made of silicon rubber or foam silicon rubber and capable of fixing the specimen with a pin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coating film drying behavior measuring method and a coating film drying behavior measuring apparatus capable of simultaneously measuring a mass change when drying a coating film formed on a sheet-like substrate and a temperature change of the coating film surface. About.

  The process of drying the coating layer formed on the sheet-like substrate is widely performed industrially. For example, various coated papers, photographic films, photographic papers, functional films, adhesive sheets and the like are manufactured by this process. As demands for energy saving and resource saving in recent years increase, the production amount of functional sheets in which a coating layer is formed on a sheet-like base material is increasing.

  In order to improve the quality and efficiently manufacture functional sheets with a coating layer formed on a sheet-like substrate, it is necessary to grasp the behavior of the coating film in the drying process, which is the formation process of the coating layer. Very important. In this case, important parameters in the drying process include heating temperature, coating film temperature, substrate temperature, drying progress, and the like. Since these parameters are not necessarily constant throughout the drying process and often change, it is very important to understand changes over time of these parameters as the drying progresses.

  The actual industrial manufacturing process is often performed using large coating and drying equipment, and it is very difficult to observe and grasp the drying behavior of the coating film using these large equipment. Difficult or inefficient. Therefore, it is required to observe and analyze the drying behavior of the coating film with smaller experimental equipment.

  Various small-sized dryers are commercially available as experimental scale coating film drying apparatuses. With these devices, it is possible to examine the influence of drying conditions such as temperature, heating method, heating time, and heating air volume. However, in the examination with such an apparatus, it is possible to change the drying condition itself, but it is difficult to quantitatively evaluate how the progress of the drying has changed with the change. In particular, if it is intended to grasp the state of the coating film during drying, the sample must be taken out of the system and evaluated during the drying process. There was a problem that it did not necessarily match the state inside the drying apparatus.

Several methods have been devised for evaluating the progress of drying in real time. For example, as shown in Non-Patent Document 1, an apparatus has been devised for drying a sample with hot air and detecting a change in its weight with a balance. Alternatively, there is an apparatus that measures mass change while performing infrared heating as shown in Patent Document 1, which is commercially available as an infrared moisture meter.
Ikoma et al., Chemical Engineering Papers 2003, 29, 4, 579-581 Japanese Patent Laid-Open No. 10-267821

  The method of measuring mass change while performing hot air drying described in Non-Patent Document 1 uses hot air widely used in industry as a heating means, and the progress of drying is real time as mass change. It has the advantage that it can be measured easily. However, it is difficult to accurately measure the mass change of the sample receiving hot air because the vibration of the sample due to the hot air is an obstacle. In particular, it is extremely difficult to obtain data with many errors under high wind speed conditions equivalent to that of industrial production equipment. Non-Patent Document 1 states that the limit of mass measurement with such an apparatus is about 0.6 m / sec.

  Compared with the above method, an apparatus for measuring a mass change while performing infrared heating as shown in Patent Document 1 has an advantage that the progress of drying can be accurately measured as a mass change without being influenced by wind. However, the apparatus for measuring mass change while performing infrared heating that is commercially available as a moisture meter shown in Patent Document 1 does not have a function of measuring the temperature of the sample, and the temperature of the temperature sensor provided separately from the sample Is simply displayed instead. Without the temperature change data of the sample, it is difficult to estimate the drying behavior in warm air drying which is more general industrially from the mass change data due to drying by infrared heating.

The reason why such a moisture meter does not have the function of measuring the temperature of the sample is that it does not affect the mass measurement and it is technically difficult to measure the sample temperature. If a contact-type temperature detector such as a thermocouple or a platinum temperature sensor is measured in contact with the sample, the connection cable to these detectors prevents accurate mass change measurement. In addition, when using a contact-type temperature sensor, the sensor must be closely attached to the surface, but sufficient adhesion to the wet coating without affecting the mass measurement and drying of the coating. There is virtually no way to achieve this.

  On the other hand, when measuring the temperature of a sample with a non-contact temperature sensor, for example, an infrared radiation thermometer, it does not interfere with mass measurement, but infrared light from an infrared source as a heating device is reflected. This method is also difficult because light and stray light enter the radiation thermometer and interfere with temperature measurement.

  Further, a non-contact temperature sensor such as a detector of the infrared radiation thermometer is usually required to be kept at 60 ° C. or lower. For this purpose, it is necessary to install the detector away from the hot sample or cool the detector. When the detector is installed away from the sample, the radiation thermometer usually measures a wider range (field of view) of temperature as the distance from the measurement object becomes longer. Therefore, for example, when the radiation thermometer is installed about 15 cm away from the sample, a range of about 5 cm in diameter is measured, and the windshield positioned between the sample and the radiation thermometer is cut in the range beyond the measurement visual field. It must be lacking. When the windshield is notched in such a large size, the function as a windshield is impaired, which not only hinders mass measurement but also affects the temperature distribution of the sample. In addition, if the detector is installed in the windshield or close to the windshield by cooling the detector, it is not only costly to cool the detector, but also because there is a cooling object near the sample, the sample has an effect. There is a risk of receiving.

  Another possible method is to guide the infrared radiation from the sample with a mirror or optical fiber and guide it to a radiation thermometer installed in a place where it is not affected by heat. Will condense and interfere with the measurement. Moreover, since the infrared radiation from a sample at room temperature to 100 ° C. is greatly attenuated in the optical fiber, it is difficult to put it to practical use in this system. For these reasons, an apparatus for simultaneously measuring the sample temperature by a radiation thermometer and changing the mass has been devised, but has not been put into practical use or marketed.

  In addition, a commercially available moisture meter was originally developed to measure the moisture content of a massive solid material, and is not a device for measuring the drying behavior of a coating liquid film applied to a sheet-like substrate. . Therefore, these moisture meters place a sample in a metal sample pan and perform mass measurement while heating. When the sample with the coating solution applied to the sheet-like substrate is set on the sample pan and heated by infrared rays, the coating surface is heated rapidly, whereas the back surface of the substrate in contact with the metal sample pan is heated. The temperature is relatively low. This is not desirable because drying and the state in an industrial process in which the temperature on the base material side often increases due to double-sided heating will be different.

  If the substrate side is kept cold and an attempt is made to obtain the same degree of drying in the same drying time as in an actual industrial process, the heating becomes excessive, and the surface is burnt. In particular, commercially available moisture meters often use a ceramic heater, which is a far infrared source, as the infrared source. Since far-infrared rays have high absorption efficiency, they are strongly absorbed on the sample surface and often scorch the surface.

  Furthermore, these commercially available moisture meters are only considered to place a liquid or lump sample on a sample pan, have an excessive drying capacity, and are not suitable for a coating film sample formed on a sheet-like substrate. Often. These commercially available devices are not particularly equipped with a sample holder. When a sample with a coating film formed on a sheet-like substrate is heated and dried with such an apparatus, the sample curls and the drying proceeds non-uniformly. There was a risk of igniting the change measurement or in contact with the heating device.

  That is, there has been practically no small means and apparatus for accurately measuring the drying behavior of the coating film.

  The present invention has been made in view of the above circumstances, solves the above-described problems of the prior art, changes in mass when drying a coating film formed on a sheet-like substrate, and the temperature of the coating film surface It is an object of the present invention to provide a coating film drying behavior measuring method capable of simultaneously measuring changes and a measuring apparatus used in the measuring method.

  As a means for considering the drying behavior of the coating film formed on the sheet-like base material, the present inventor changed the mass when drying the coating film formed on the sheet-like base material, and the coating film surface. As a result of investigating a method for measuring the drying behavior of a coating film capable of simultaneously measuring the temperature change of the coating film, the inventors have invented the following coating film drying behavior measuring method and coating film drying behavior measuring apparatus.

The present invention is based on the following technologies.
[1] A coating film drying behavior measuring method capable of simultaneously measuring a mass change when drying a coating film formed on a sheet-like substrate and a temperature change of the coating film surface, as a heating means Using an infrared heating apparatus having a peak wavelength of 1.5 to 3.0 μm, using an electronic balance as a mass change measuring means, and using an infrared radiation thermometer having a measurement wavelength of 8 to 14 μm as a coating surface temperature measuring means. Characteristic coating film drying behavior measurement method.
[2] An apparatus used in the coating film drying behavior measuring method according to [1], wherein an infrared heating apparatus having a peak wavelength of 1.5 to 3.0 μm, an electronic balance, and a measuring wavelength of 8 to 14 μm. A coating film drying behavior measuring apparatus comprising an infrared radiation thermometer.
[3] The coating film drying behavior measuring apparatus according to [2], wherein a minimum measurement spot diameter of the infrared radiation thermometer is 1 cm or less.
[4] The coating film drying behavior measuring apparatus according to [2] or [3], further comprising a gantry for holding the sample in the air.
[5] The coating according to [2] to [4], wherein the gantry for holding the sample in the air includes a pin receiving member made of silicon rubber or foamed silicon rubber capable of pinning and fixing the sample. Membrane drying behavior measurement device.

  According to the coating film drying behavior measuring method and the coating film drying behavior measuring apparatus of the present invention, the sheet-like sample on which the coating film is formed is held in the air, and the mass change when the coating is dried, Temperature changes can be measured simultaneously.

  One embodiment of the coating film drying behavior measuring apparatus of the present invention will be described as an example.

  FIG. 1 shows a coating film drying behavior measuring apparatus 10 (hereinafter, abbreviated as measuring apparatus 10) of the present embodiment. This measuring device includes a windshield 11a for measuring the mass of the sample 1, a sample pan 11b, an electronic balance 11 comprising a mass measuring device 11c, a near to mid-infrared heater 12a for heating the sample, an infrared reflector 12b, The light reducing plate 12c, a radiation thermometer 13a for measuring the surface temperature of the sample in a non-contact manner, an infrared window 13b, a fixing pin 14a for holding the sample in the air, and a gantry 14b are provided.

  As shown in FIG. 2, the sample 1 has a coating film 1b formed on a substrate sheet 1a. The method for forming the coating film 1b is not particularly limited, and any method such as printing, coating, impregnation, or transfer can be used. The material which comprises the base material sheet 1a and the coating film 1b can be chosen arbitrarily. The thickness of the base sheet 1a and the coating film 1b can be set arbitrarily.

  The measurement accuracy of the mass measuring device 11c of the electronic balance 11 for measuring the mass change of the sample 1 is preferably 10 mg or less, more preferably 1 mg or less, although it depends on the size of the sample and the mass change amount of the coating film. preferable. If the accuracy is poor, the mass change of a thin coating film cannot be measured accurately. The weighing (maximum mass that can be measured) is preferably 10 g or more, and more preferably 100 g or more. If the weighing is small, the sample amount must be reduced, and the error becomes large. Further, members other than the sample, such as the sample mount 14c, which are mounted on the mass measuring device must be lighter than necessary, and the strength is insufficient, so that the sample cannot be properly held.

  The mass measuring device 11c may use a mass detection method used in an ordinary electronic balance. Those which are not easily affected by the influence of heating are preferred. It is preferable to provide a heat radiating plate, a heat insulating material, a shielding plate or the like between the sample pan and the mass measuring unit to reduce the influence of heat. Further, a mechanism for performing zero point correction and mass calibration at any time during measurement may be provided.

  The mass measurement result in the mass measuring unit is displayed on the mass measuring device 11c or on a mass display unit provided separately. Further, it may be transmitted to an external device such as a personal computer by communication. In particular, it is convenient if the mass measuring unit has a function of measuring mass at regular time intervals and outputting the output together with the time.

  The sample pan is preferably heat resistant and has little mass change upon heating. A sample dish that is chemically stable and hardly static or magnetized is suitable. For example, metal, ceramic, glass, or the like can be used. In particular, aluminum and its alloys are preferred because of its light weight, and stainless steel is preferred for its chemical stability. The sample pan is preferably larger than the sample. If it is smaller, if the paint falls from the sample, the mass measuring device 11c may be affected. The sample pan 11b may be integrated with a sample mount 14c described later or may be a separate part. By providing the sample tray 11b with a function of holding a sample equivalent to the later-described sample mount 14c, the sample tray 11b may also be used as a sample mount, and an independent sample mount may be omitted.

  The windshield not only prevents the sample from vibrating and affects the mass measurement value due to the wind from the surroundings, but also has a role of stabilizing the airflow generated by heating the sample, the heating device, and the device constituent members. The windshield may be integral with the reflective material or may be a separate part. The windshield preferably has an intake hole at the bottom and an exhaust hole at the top. It is convenient if the windshield 11a is provided with a window for observing the internal sample state. The windshield 11a may have a single structure or a double structure. In the case of a multiple structure, a heat-resistant material such as metal can be used inside, and an easily moldable material such as plastic can be used outside. The windshield needs to be able to open and close when setting the sample.

  The gantry 14c is necessary for holding the back surface of the sample substantially floating without substantially contacting the apparatus constituent member. In addition, the sample is prevented from being deformed by heating and coming into contact with the apparatus constituent members to prevent mass change measurement, or from being burnt by contacting the sample with the heating source. The gantry 14c includes a gantry body and a sample holder. The gantry body has a structural strength to maintain the sample holder in an appropriate position. It is preferable that the gantry body is heat resistant and has little mass change due to heating. Further, it is preferable that the gantry body is chemically stable and hardly has static electricity or magnetization. For example, metal, ceramic, glass, heat-resistant plastic, etc. can be used. In particular, aluminum or an alloy thereof is preferably used because of its light weight. It is desirable that the gantry body is reduced in weight as long as it meets the required strength. From the viewpoint of weight reduction, a punching plate or the like in which an aluminum plate is punched into a pattern and has holes is preferable. The size of the gantry needs to be large enough to unfold and hold the measurement sample and be smaller than the size of the sample pan. The gantry may be integrated with the above-described sample pan or may be a separate part. By providing the gantry with the function of the above-described sample plate, the sample plate may also be used, and an independent sample plate may be omitted.

  The sample holder of the gantry 14c has a function of suspending and holding the sample while keeping the back surface of the sample substantially not in contact with the measurement member of the apparatus. That is, it has a function of holding the sample by the minimum necessary contact so as not to affect the progress of drying of the sample and the measurement of the surface temperature.

  Examples of methods for holding the sample in a suspended manner in the sample holding unit include pinching holding, adhesion holding, adhesive holding, screwing holding, pinning holding, and hooking holding. Pin holding is preferable because it can be attached and detached in a short time and the area of contact with the sample is minimal. Pinning and holding is to fix and hold the sample with a pin. Therefore, it is desirable that the tip of the pin is sharp. The shape and material of the pin are not particularly limited, but a metal pin is preferable in terms of strength and less influence by heat. The pin shape is preferably a thumbtack shape or an insect pin shape since it can be easily inserted and removed. The thickness of the pin is not particularly limited, but if it is too thin, the strength is insufficient, and if it is too thick, the sample cannot be stabbed. The length of the pin needs to be long enough to hold the pin tip to a pin receiving member 14b described later. Generally, 3 to 40 mm is preferable. If it is too short, the pin may come off carelessly, and if it is too long, it will be inadequate because it will contact the device.

  When pinning is selected as a method for suspending and holding the sample, the sample holding part is constituted by a pin and a pin receiving member. The pin receiving member needs to have a function of holding the tip of the pin that has penetrated the sample. Examples of the method for holding the pin include stab holding, pinching holding, adhesion holding, adhesion holding, and magnetic force holding. In view of the simplicity of the structure, piercing and holding with a rubber-like elastic body is preferable.

  Various natural rubbers, synthetic rubbers, and the like can be used as the rubber-like elastic body that pierces and holds the pins. In particular, silicon rubber is preferable from the viewpoint of heat resistance and whiteness. Also, foamed rubber is preferable from the viewpoint of reducing the weight of the gantry. Therefore, white foamed silicone rubber is very suitable.

  The length of the pin receiving member (in the direction of piercing the pin) may be a piercing length that holds the pin holding force to such an extent that the pin does not accidentally come off. The appropriate piercing length varies depending on the material of the pin, the thickness of the pin, the shape of the pin tip, etc., but is generally about 3 to 20 mm. The thickness of the pin receiving member (the length in the direction orthogonal to the pin) is not particularly limited as long as it is large enough to stab the pin, but is generally 3 to 20 mm.

  The number of sample holders on the gantry is not particularly limited as long as it is one or more. However, when the sample is a square, about four are preferable so that each sample vertex can be held. If the amount is too small, the sample may be curled or the sample may be deformed due to heat and the sample may not be held properly. If it is too much, the mass of the mount will become heavy.

  An infrared heater is used as the heating heat source of this apparatus. Infrared heaters of various shapes and methods are commercially available, but the so-called infrared wavelength has a main component of the emission wavelength of 0.8 to 4 μm so as not to overlap with the measurement wavelength of the radiation thermometer used for measuring the temperature of the sample. Must be a near to mid-infrared heater.

  The near-to-medium infrared heater having a main component of the radiation wavelength used in this apparatus is 0.8 to 4 μm, and a resistance heating line such as tungsten is not present in a tubular quartz glass tube having a peak wavelength of 1.5 to 3.0 μm. A tubular infrared heater called a halogen heater, a halogen lamp, a quartz heater, a quartz heater, or the like in which an active gas or an inert gas and a small amount of halogen gas are enclosed is preferable. These tubular infrared heaters can greatly reduce the size of the device compared to infrared bulbs and xenon lamps. In addition, since there is less radiation in the visible light region than infrared bulbs and xenon lamps, there is an advantage that there is no difference in heating due to the color of the sample.

  As an infrared heater, such as a ceramic heater that radiates far infrared rays with a wavelength of 4 μm or more to about 1 mm as a main component, the radiation wavelength overlaps with the measurement wavelength of the radiation thermometer, and this device has a problem in temperature measurement. Unsuitable. In addition, these far infrared rays have very high absorption efficiency, and the vicinity of the sample surface is locally heated, and may be burned in the case of a thin coating film sample.

  It is preferable to use a plurality of straight tube heaters or U-curved tube heaters for this apparatus because a visual field for a radiation thermometer can be secured on the center of the sample.

  The infrared heater may be fixedly held inside the windshield or may be held by a dedicated member. The holding portion of the infrared heater needs to be a structure and material that can withstand the heat from the infrared heater.

  A normal temperature control device can be used for the output control of the infrared heater, that is, the temperature adjustment mechanism. However, if the temperature is adjusted by voltage control, the wavelength of the infrared ray radiated is not constant due to a change in the light source temperature, and therefore, duty ratio control (a method for changing the ON-OFF time ratio) is suitable. The control cycle time for duty ratio control is preferably about 0.1 to 10 seconds. If it is too long, the temperature of the sample will not be stable, and if it is too short, the life of the control element will be shortened.

  The infrared output control may be an arbitrary constant output value, and if necessary, feedback control is performed according to the sample surface temperature measured by a radiation thermometer or the temperature of a reference temperature sensor installed near the sample surface. You may go.

  In order to make the radiation from the infrared heater enter the sample uniformly and efficiently, it is preferable to provide a reflector in the windshield. The material of the reflecting plate is not particularly limited as long as it efficiently reflects infrared rays, but a material having a lower infrared emissivity has less influence on the sample temperature measurement by the radiation thermometer. Therefore, a metal or a metal mirror is preferably used. The reflector may be integrated with the windshield, or may be a separate part. Further, a part of the tube of the infrared heater may be integrated with the infrared heater by giving a reflection effect by a vapor deposition film or the like.

  The distance between the infrared heater and the sample is preferably 1 cm to 30 cm. If it is too close, heating of the sample may become uneven or the sample may burn. If it is too far, not only will the efficiency of heating be reduced, but the apparatus will be larger than necessary.

  If necessary, a dimming plate may be installed between the infrared heater and the sample to adjust the heating intensity. As the light reducing plate, a punching metal having a hole in the metal plate at a predetermined interval, a heat-resistant mesh (net), a glass plate, or the like can be used.

<Radiation thermometer>
The sample surface temperature must be measured with a non-contact surface thermometer. With a contact-type thermometer, it is impossible to measure temperature without affecting the sample state or mass change measurement. Non-contact surface thermometers are generally marketed as radiation thermometers. A radiation thermometer is based on the principle that an object emits energy corresponding to its temperature as infrared rays, and the infrared rays emitted from the object are collected and measured by an infrared sensor. After the correction, the temperature of the object to be measured is displayed. Although radiation thermometers in various measurement wavelength regions are commercially available, this device is not easily affected by moisture or carbon dioxide in the air, and does not overlap with the wavelength of the infrared heating source of this device. An infrared radiation thermometer that detects infrared rays of ˜14 μm is desirable.

  The sample surface temperature measured by the radiation thermometer may be displayed on the temperature display section of the radiation thermometer and recorded. Alternatively, it may be recorded as a voltage or current signal by a recording device such as a data logger. Further, it is convenient to transmit to an external device by communication and record in an external device such as a personal computer.

  The installation position of the radiation thermometer must be a place where the radiation thermometer is not affected by heat. Usually, since the usable ambient temperature of the radiation thermometer is 60 ° C. or less, the sample must be installed in a place not exceeding 60 ° C. even when the sample is being heated. However, this does not apply when cooling the radiation thermometer or its surroundings. A radiation thermometer is usually installed outside the draft shield just above the center of the sample. The draft shield is provided with a hole for securing a visual field for the radiation thermometer. However, in order to avoid the direct contact with the hot air from the hole, it is an effective means to deflect the hot air by applying cold air from the side. In addition, in order to avoid hot air, it is possible to set up avoiding directly above the center of the sample and measure the sample surface from an oblique direction. However, when measuring from an oblique direction, it is necessary to secure a wider field of view so that the apparatus constituent members do not block the measurement field of view of the radiation thermometer. In addition, when installed obliquely, it is necessary to prevent radiation light from an object other than the sample from being reflected by the sample surface and entering the radiation thermometer so as not to affect the measurement value.

Rather than providing a hole in the windshield to secure the field of view of the radiation thermometer, a window may be made of a material having a high infrared transmittance, and a radiation thermometer may be installed above the window to measure the temperature. Such a device configuration is desirable because the radiation thermometer is not affected by hot air exhaust and does not cause uneven air flow due to holes provided in the windshield for securing a visual field. In this case, it is necessary to use a material having a high infrared transmittance in the measurement wavelength region of the radiation thermometer as the window material. For example, barium fluoride, calcium fluoride, etc. are preferably used. Although the thickness of a window material is not specifically limited, 1-5 mm is used suitably from the balance with intensity | strength, infrared rays transmittance | permeability, and a price.
In order to reduce temperature measurement errors due to radiation from the window material, it is also effective to cool the window material within a range where no condensation occurs.

  The measurement field of the radiation thermometer is a device-specific value determined by the detector and the optical system in the radiation thermometer. Usually, there are many radiation thermometers whose measurement field of view becomes wider as they move away from the radiation thermometer, but this device has a narrow field of view type where the measurement field of view does not change greatly with distance, or a spot type radiation with a minimum value at a certain distance. A thermometer is desirable. In particular, if a radiation thermometer with a minimum field of view of 1 cm or less is used, the holes for the thermometer and the infrared window can be minimized, minimizing the influence of the radiation thermometer installation. it can. Moreover, in the case of the apparatus structure using the said infrared transmission window, an expensive infrared window material can be made small and it is preferable. Furthermore, when a radiation thermometer having a narrow field of view is used, it is easy to make an arrangement configuration of the apparatus internal members so that there is no obstacle on the field of view. For these reasons, when a radiation thermometer with a narrow field of view is used, it becomes easy to arrange the radiation thermometer immediately above the center of the sample, and a much simpler device configuration than that using a mirror or an optical fiber can be realized. In addition, it is possible to minimize the influence of surface reflection (reflection of radiated light from other objects), compared to the case where the radiation thermometer is arranged obliquely above the sample.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of the present invention.

  A sample 1 shown in FIG. 2 is obtained by applying a paint 1b to a base material 1a. This sample 1 is fixed to a pin receiving member 14b made of foamed silicon rubber provided on a mount 14c by a fixing pin 14a and is held in a floating state. Infrared radiation from the two near to mid-infrared quartz heaters 12a (rated 100V250W) is attenuated by the aluminum punching metal dimming plate 12c having an aperture ratio of 50% to heat the sample 1. Radiant infrared light from the sample 1 passes through a barium fluoride window 13b having a thickness of 2 mm and a diameter of 2 cm, enters a radiation thermometer 13a installed 15 cm directly above the sample, and is measured as the sample temperature.

  FIG. 3 shows the field of view of the radiation thermometer used. The measurement visual field is 40 mm in diameter at the sample position and 8 mm in diameter at the barium fluoride window position.

Temperature when a sample obtained by applying a polyvinyl alcohol solution having a concentration of 10% on a polyethylene terephthalate film having a thickness of 10 cm × 10 cm with a Meyer bar to a coating amount of 156 g / m ² is heated at a heater output of 20%. The graph of change and mass change is shown in FIG.

  The amount of water evaporation per unit time (drying rate) could be obtained by differentiating the graph of mass change in FIG. 4 (FIG. 5).

  According to the coating film drying behavior measuring method and the coating film drying behavior measuring apparatus of the present invention, it is possible to simultaneously measure the mass change when drying the coating film and the temperature change of the coating film surface. And optimization of the drying process. Since this apparatus has a holding member specialized for drying the coating film and can perform drying in a state where the sample is held in the air, a drying experiment in a state close to an industrial drying process can be performed. Moreover, the sample dried by this apparatus can be effectively used for other experiments as a standard coating film sample with a clear drying history.

It is a block diagram of the coating-film drying behavior measuring apparatus of this invention. It is a block diagram of the sample 1 of this invention. It is a visual field figure of the radiation thermometer 13a of this invention. Temperature when a sample obtained by applying a polyvinyl alcohol solution having a concentration of 10% on a polyethylene terephthalate film having a thickness of 10 cm × 10 cm to a coating amount of 200 g / m ² with a Mayer bar is heated at a heater output of 20%. Graph of change with time of mass and value (value converted per 1 m ² ) (drying curve) The graph which differentiated the graph of the mass change of FIG. 4, and calculated | required the water evaporation rate (value converted per 1 m < ² >).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample 1a Base material 1b Coating film 11 Electronic balance 11a Windshield 11b Sample pan 11c Mass measuring device 12a Near to mid-infrared quartz heater 12b Reflector 12c Light reduction plate 13a Radiation thermometer 13b Infrared window made of barium fluoride 14a Sample fixing pin 14b Pin receiving member 14c Sample mount

Claims (5)

  A coating film drying behavior measuring method capable of simultaneously measuring a mass change when drying a coating film formed on a sheet-like substrate and a temperature change of the coating film surface, and having a peak wavelength as a heating means. An infrared heating apparatus of 1.5 to 3.0 μm is used, an electronic balance is used as a mass change measuring means, and an infrared radiation thermometer having a measurement wavelength of 8 to 14 μm is used as a coating film surface temperature measuring means. Method for measuring coating film drying behavior.   It is an apparatus used for the coating-film drying behavior measuring method of Claim 1, Comprising: The infrared heating apparatus whose peak wavelength is 1.5-3.0 micrometers, an electronic balance, and the infrared radiation temperature whose measurement wavelength is 8-14 micrometers A coating film drying behavior measuring device comprising a meter.   3. The coating film drying behavior measuring apparatus according to claim 2, wherein a minimum measurement spot diameter of the infrared radiation thermometer is 1 cm or less.   The coating film drying behavior measuring device according to claim 2 or 3, further comprising a gantry for holding the sample in the air. The coating film drying behavior measuring device according to claim 2, wherein the frame for holding the sample in the air includes a pin receiving member made of silicon rubber or foamed silicon rubber capable of pinning and fixing the sample. .