JP2016193394A - Coated article and method for producing coated article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a coated article by which it is possible, by defoaming and/or degassing a coating using a hollow fiber membrane defoaming apparatus, to form a uniform coating film of good quality in which coating defects are inhibited even in curtain coating, slide coating or slot coating, in spite of a relatively high viscosity as a coating.SOLUTION: Provided are: a method for producing a coated article provided with at least a coating layer on a support, where the method for producing a coated article includes a step for curtain-coating, slide-coating or slot-coating a support with a coating that has a specific viscosity and that has been defoamed and/or degassed using a hollow fiber membrane degassing apparatus; and a coated article provided with at least a coating layer obtained by applying a coating that has a specific viscosity and has little foam or dissolved gas onto a support.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a coated body and a coated body. Specifically, a method for producing a coating body including a step of curtain coating, slide coating, or slot coating of a paint having a specific viscosity that has been defoamed and / or degassed using a hollow fiber membrane defoaming apparatus, and a specific method It is related with the coating body obtained by apply | coating with the foam which has the viscosity of below, and a coating material with little dissolved gas.

  Curtain coating by a curtain coater is a method in which a coating material is freely dropped into a curtain shape, and an object to be coated is applied by passing through the curtain. Such a pre-weighing coating method can increase productivity, reduce energy consumption during manufacturing, increase production yield, and easily adjust the coating amount. From the point of view, it is widely used for producing coated bodies.

  In the paint used for curtain coating, the properties of the contained components and the like greatly affect the curtain film and affect the quality of the final coated body. In Patent Documents 1 and 2, filtration using a membrane filter or a membrane filter is used in order to eliminate a component having a large particle size that causes a coating defect. A uniform coating can be obtained by such filtration, and the use of the coating can be expected to improve coating defects due to curtain coating.

  In recent years, depending on the application of the coated body, there has been a demand for a coating film that is less mixed and has a more uniform and smooth surface. The paint used to obtain such a coating film needs to have a relatively high concentration and high viscosity. However, when a highly viscous paint is used, bubbles and dissolved gas in the paint cannot be sufficiently eliminated. As a result, due to the presence of these bubbles and dissolved gas, bubbles and the like remain in the obtained coating film, and the function of the coating film cannot be fully exhibited, causing a product defect. Further, even during curtain coating, coating defects such as film cracking of the curtain may occur due to bubbles in the paint or bubbles generated from the dissolved gas, resulting in a serious problem that a coated body cannot be obtained.

  Therefore, in Patent Documents 3 and 4, attempts have been made to defoam bubbles in the paint using a centrifugal vacuum deaeration device. Moreover, in patent document 5, the method of defoaming the foam in a coating material is disclosed by using a thin film casting decompression device as a centrifugal separation defoaming system.

  However, in the high-viscosity paint, it is difficult to sufficiently defoam / degas fine bubbles and dissolved gas by the defoaming / degassing methods of Patent Documents 3 to 5. Further, the defoaming devices of Patent Documents 3 to 5 are generally large in size and cannot be easily defoamed / degassed. Furthermore, when the defoaming device of Patent Documents 3 to 5 is installed in the vicinity of the curtain coater due to vibration generated from a motor or the like provided in the device, the vibration of the defoaming device is transmitted to the coating curtain and affects the resulting coating film. There is a problem that a uniform coating cannot be formed.

  Further, the pre-measuring method includes slide coating and slot coating. In these coating methods, as in the curtain coating, since shearing stress that can destroy the mixed bubbles does not act, the presence of bubbles and dissolved gases in the paint causes product defects.

JP 58-11195 A JP 2001-341425 A Special table 2010-504851 gazette Utility Model Gazette No. 3152498 Japanese Patent Laid-Open No. 11-262601

  In the present invention, the coating material is defoamed and / or degassed by a hollow fiber membrane defoaming device, so that it can be applied even in curtain coating, slide coating, or slot coating despite having a relatively high viscosity as the coating material. The main object is to provide a method for producing a coated body, which can form a uniform and high-quality coating film in which work defects are suppressed.

  As a result of intensive studies, the present inventors have defoamed and / or degassed the paint with a hollow fiber membrane defoaming device, so that fine bubbles and dissolved gas can be relatively easily produced even with a highly viscous paint. It was found that a paint suitable for curtain coating, slide coating, or slot coating can be obtained. As a result of further studies, the present inventors have found that the above-mentioned problems can be solved, and have completed the present invention. That is, this invention relates to the manufacturing method of the following coating body, and a coating body.

Item 1. A method for producing a coated body comprising at least a coating layer on a support,
A step of defoaming and / or degassing using a hollow fiber membrane defoaming device and applying a paint having a Brookfield viscosity of 200 to 3000 mPa · s at 25 ° C. onto a support by curtain coating, slide coating or slot coating. The manufacturing method of the coating body containing.

  Item 2. Item 2. The plurality of coating layers that the coating layer has two or more layers, wherein the step of curtain coating, slide coating, or slot coating is a step of simultaneous multilayer coating using at least two layers of paint. The manufacturing method of the coating body of description.

Item 3. A hollow fiber membrane defoaming device having a plurality of hollow fibers having pores on the surface whose inside is decompressed,
In the defoaming and / or degassing step, the paint is passed through a hollow fiber membrane defoaming device so that the paint and the outer wall of the hollow fiber are in contact with each other, and bubbles and / or dissolved gas present in the paint is passed through the hollow fiber. Item 3. The method for producing a coated body according to Item 1 or 2, wherein the method is a step of separating through a surface hole.

  Item 4. Item 4. The method for producing a coated body according to any one of Items 1 to 3, wherein the pressure loss of the hollow fiber membrane defoaming apparatus at the time of defoaming and / or degassing is 6 bar or less.

  Item 5. Item 5. The method for producing a coated body according to any one of Items 1 to 4, wherein the step of obtaining a coating is a step of defoaming and / or degassing using a hollow fiber membrane defoaming apparatus after preparing the coating.

  Item 6. The step of obtaining the coating is a step of mixing and preparing a plurality of dispersions or solutions used for preparing the coating after defoaming and / or degassing using a hollow fiber membrane defoaming device, The manufacturing method of the coating body in any one of claim | item 1 -5.

  Item 7. Item 7. The method for producing a coated body according to Item 5 or 6, wherein the preparation of the paint is a step of mixing using an in-line mixer.

  Item 8. Item 8. The method for producing a coated body according to any one of Items 1 to 7, wherein the defoamed and / or degassed coating has 10 or less bubbles having a diameter of 200 μm or more per liter of the coating.

  Item 9. Item 9. The method for producing a coated body according to any one of Items 1 to 8, wherein the coated body is a thermosensitive recording body, and the coating layer is a thermosensitive coloring layer and / or a protective layer.

  Item 10. The coated body is a heat-sensitive recording material, the coated layer is formed of a plurality of coated layers of two or more layers, and at least two coated layers including at least a thermosensitive coloring layer are simultaneously formed on the support. Item 10. The method for producing a coated body according to any one of Items 2 to 9, which is applied in a multilayer manner.

Item 11. The coated body is a thermal recording body, and the coated layer is (1) a thermal coloring layer / protective layer from the side close to the support.
(2) Undercoat layer / thermosensitive color developing layer / protective layer,
(3) thermosensitive coloring layer / first protective layer / second protective layer,
(4) undercoat layer / thermosensitive color developing layer / first protective layer / second protective layer (5) undercoat layer / first thermosensitive color developing layer / second thermosensitive color developing layer / protective layer, or (6) undercoat layer / first thermosensitive layer. Item 11. The method for producing a coated body according to Item 10, wherein the colored layer / intermediate layer / second thermosensitive coloring layer / protective layer is formed in this order.

  Item 12. Item 12. The defoamed and / or degassed coating material is a coating material that forms an outermost protective layer, and the number of bubbles having a diameter of 200 μm or more is less than 3 per liter of the coating material. Method for producing coated body.

  Item 13. Item 8. The method for producing a coated body according to Item 7, comprising a step of continuously mixing the surfactant and / or the water resistance agent using an in-line mixer.

  Item 14. A coated body having a coating layer obtained by coating a support having a Brookfield viscosity at 25 ° C. of 200 to 3000 mPa · s and a foam of 200 μm or more in diameter of 10 or less paint per liter of paint. .

  Item 15. Item 15. The coated body according to Item 14, wherein the coating is obtained by defoaming and / or degassing using a hollow fiber membrane defoaming apparatus.

Item 16. Using a hollow fiber membrane defoaming device having a plurality of hollow fibers having pores on the surface whose pressure is reduced inside,
A defoaming method in which the paint is passed through a hollow fiber membrane defoaming device so that the paint and the outer wall of the hollow fiber are in contact with each other, and bubbles and / or dissolved gas existing in the paint are separated through pores on the surface of the hollow fiber. Item 16. The coated body according to Item 14 or 15, obtained by coating a paint obtained by performing deaeration.

  Item 17. Item 17. The coated body according to any one of Items 14 to 16, wherein the coated body is a thermosensitive recording body, and the coating layer is a thermosensitive coloring layer and / or a protective layer.

  Item 18. Item 18. The coated body according to any one of Items 14 to 17, wherein the coated layer is formed of a plurality of coated layers of two or more layers, and is provided on the support in the order of a thermosensitive coloring layer and a protective layer.

Item 19. The coated body is a thermal recording body, and the coated layer is (1) a thermal coloring layer / protective layer from the side close to the support.
(2) Undercoat layer / thermosensitive color developing layer / protective layer,
(3) thermosensitive coloring layer / first protective layer / second protective layer,
(4) undercoat layer / thermosensitive color developing layer / first protective layer / second protective layer (5) undercoat layer / first thermosensitive color developing layer / second thermosensitive color developing layer / protective layer, or (6) undercoat layer / first thermosensitive layer. Item 19. The coated body according to Item 17 or 18, which is provided in the order of a coloring layer / intermediate layer / second thermosensitive coloring layer / protective layer.

  Item 20. Item 20. The coated body according to any one of Items 14 to 19, which is a paint obtained by continuously mixing a surfactant and / or a water resistance agent using an in-line mixer.

  Item 2 A paint having a Brookfield viscosity of 200 to 3000 mPa · s at 11.25 ° C. and 10 or less bubbles of 200 μm in diameter per liter of paint.

  Item 22. Item 22. The paint according to Item 21, obtained by defoaming and / or degassing using a hollow fiber membrane defoaming device.

Item 23. Using a hollow fiber membrane defoaming device having a plurality of hollow fibers having pores on the surface whose pressure is reduced inside,
A defoaming method in which the paint is passed through a hollow fiber membrane defoaming device so that the paint and the outer wall of the hollow fiber are in contact with each other, and bubbles and / or dissolved gas existing in the paint are separated through pores on the surface of the hollow fiber. Item 22. The paint according to Item 21 or 22, obtained by performing deaeration.

  Item 24. Item 24. The paint according to any one of Items 21 to 23, which is obtained by continuously mixing a surfactant and / or a waterproofing agent using an in-line mixer.

  Item 25. Item 25. The coating material according to any one of Items 21 to 24, which is used for curtain coating, slide coating, or slot coating.

  According to the method for producing a coated body of the present invention, the coating material is defoamed and / or degassed by the hollow fiber membrane defoaming device. Bubbles and dissolved gas can be removed relatively easily. Therefore, it not only prevents bubbles from being applied to the coated surface, but also does not cause, for example, curtain film cracking that occurs during curtain coating or streak coating defects that occur during bead coating, and it can operate stably continuously. be able to. Further, it is not necessary to reduce the concentration and viscosity of the coating material in order to facilitate defoaming, and the coating layer has excellent barrier functionality. Moreover, since there are few coating defects in manufacture of a coating body, a yield is high and productivity is high. Furthermore, the hollow fiber membrane defoaming device is relatively smaller than other defoaming / degassing devices, and further has no source of vibrations such as a motor. Therefore, it is possible to install in the vicinity of the coater without causing coating defects such as horizontal stripes and chatter marks on the coated surface. Furthermore, the obtained coated body can drastically suppress coating defects caused by bubbles and dissolved gas present in the paint.

  In this specification, the expression “comprising” includes the concepts of “comprising”, “consisting essentially of”, and “consisting solely”.

  The method for producing a coated body of the present invention comprises a step of defoaming and / or degassing a paint on a support using a hollow fiber membrane defoaming device (hereinafter also referred to as step (1)), and a curtain. A step of coating, slide coating, or slot coating (hereinafter also referred to as step (2)).

1. Process (1)
Step (1) is a step of defoaming and / or degassing the paint using a hollow fiber membrane defoaming apparatus.

  The Brookfield viscosity at 25 ° C. of the coating material used in the step (1) is 200 to 3000 mPa · s, preferably about 300 to 3000 mPa · s, more preferably about 300 to 1500 mPa · s, and about 400 to 1000 mPa · s. Further preferred. When the Brookfield viscosity at 25 ° C. is less than 200 mPa · s, the formed curtain film or the bead tends to be unstable, and the paint is mixed at the interface between the upper layer and the lower layer during simultaneous multilayer coating. Tend to occur. On the other hand, when the Brookfield viscosity at 25 ° C. exceeds 3000 mPa · s, it becomes difficult to feed the paint to the curtain coater, and there is a tendency that defoaming and / or degassing by the defoaming device cannot be sufficiently performed. is there.

  When preparing a paint, when mixing a plurality of dispersions or solutions, the viscosity of each dispersion or solution is not particularly limited, so that the paint after mixing is set to the above viscosity. In addition, it may be appropriately prepared.

  As the hollow fiber membrane defoaming device used for defoaming and / or degassing of the paint, a hollow fiber membrane defoaming device having a plurality of hollow fibers having pores on the surface whose inside is depressurized can be used. In the defoaming and / or degassing step, the paint is passed through the hollow fiber membrane defoaming device so that the paint and the outer wall of the hollow fiber come into contact with each other, and bubbles and / or dissolved gas present in the paint are removed. This is done by separating through the pores on the surface of the hollow fiber.

  A hollow fiber membrane defoaming apparatus and a method for defoaming and / or degassing bubbles and dissolved gas in a coating using the hollow fiber membrane defoaming apparatus will be described in detail below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of a hollow fiber membrane defoaming apparatus. As shown in FIG. 1, the hollow fiber membrane defoaming device 1 includes a plurality of hollow fibers 2, support members 3 a and 3 b, and a tube body 4.

  The plurality of hollow fibers 2 are bundled so that a cavity is formed in the center. Both ends of the bundle of hollow fibers 2 are fixed to the support members 3a and 3b.

  The support members 3a and 3b are not particularly limited as long as the support members 3a and 3b can fix the bundle of hollow fibers 2, but they have a ring shape. Holes corresponding to the hollow fibers 2 are formed in the support members 3a and 3b. Each hollow fiber 2 is fixed to the support member by passing one end and the other end through the holes of the support members 3a and 3b.

  The tube body 4 is inserted into a cavity at the center of the bundle of hollow fibers 2, and one end and the other end of the tube body 4 are located in a through hole at the center of the support members 3 a and 3 b.

  A wall 5 is formed inside the other end of the tube body 4. The passage 6 on one end side of the wall 5 is used for flowing the paint 7. The passage 6 on the one end side is formed with a slit 8 for allowing the paint 7 to flow into the bundle of hollow fibers.

  The other end side of the hollow fiber 2 penetrates the support member 3b and is connected to a vacuum pump used for decompressing the inside of the hollow fiber.

  A hole through which one end of the hollow fiber 2 is passed may be formed so as to penetrate the support member 3a, and a vacuum pump may be connected to the hole. In this way, the inside of the hollow fiber 2 can be depressurized from one end side and / or the other end side of the hollow fiber 2.

  FIG. 2 is an enlarged schematic cross-sectional view of the hollow fiber 2 constituting the hollow fiber membrane defoaming device 1 and the vicinity thereof. As shown in FIG. 2, the surface of the membrane of the hollow fiber 2 that comes into contact with the paint 7 does not allow the components in the paint 7 to permeate, and allows the bubbles 9 and dissolved gas 10 present in the paint 7 to permeate. A hole 11 is formed. The inside of the hollow fiber 2 is depressurized by a vacuum pump.

  The number of hollow fibers 2 constituting the hollow fiber membrane defoaming device 1 is not particularly limited, and a sufficient surface area of the outer wall of the hollow fiber 2 in contact with the paint 7 can be secured. What is necessary is just to select suitably so that the magnitude | size of 1 itself can be made compact.

The paint flow rate when the surface of the outer wall in contact with the paint of the hollow fiber 2 is in contact with the paint and defoamed and / or degassed is preferably 1 liter / m ² · min or less, preferably 0.5 liter / m ² · Minutes or less are more preferable. By setting the above paint flow rate to 1 liter / m ² · min or less, it is possible to sufficiently defoam and / or degas the bubbles and dissolved gas in the paint, and the paint between the hollow fibers Can be prevented. In order to further increase the above-described paint flow rate, for example, a plurality of hollow fiber membrane defoaming devices 1 themselves can be used to defoam and / or degas bubbles and / or dissolved gas in the paint. .

  As an internal diameter of the hollow fiber 2, about 50-500 micrometers is preferable and about 150-250 micrometers is more preferable. By setting the inner diameter of the hollow fiber 2 to 50 μm or more, it is possible to efficiently discharge bubbles and dissolved gas degassed and / or degassed from the paint 7. In addition, by setting the inner diameter of the hollow fiber 2 to 500 μm or less, it is possible to ensure sufficient strength so that the inside of the hollow fiber is not crushed by the reduced pressure by the vacuum pump.

  The outer diameter of the hollow fiber 2 is preferably about 200 to 700 μm, more preferably about 300 to 500 μm. By setting the outer diameter of the hollow fiber 2 to 200 μm or more, sufficient strength can be secured so that the inside of the hollow fiber is not crushed. In addition, by setting the outer diameter of the hollow fiber 2 to 700 μm or less, the thickness of the hollow fiber membrane is reduced, and the bubbles and dissolved gas degassed and / or degassed from the paint 7 efficiently. Can do.

  The diameter of the hole 11 formed on the surface of the membrane of the hollow fiber 2 is not particularly limited, and bubbles and dissolved gas in the paint 7 can be efficiently discharged, and the permeation of the paint itself is suppressed, What is necessary is just to select suitably so that clogging can be reduced.

  Although it does not restrict | limit especially as pressure (absolute pressure) at the time of decompressing the hollow inside of the hollow fiber 2, For example, about 0.9 bar or less is preferable and 0.5 bar or less is more preferable. By setting the pressure (absolute pressure) to 0.9 bar or less, bubbles and gas contained in the paint 7 can be efficiently defoamed / degassed.

  As shown in FIG. 1, when the coating material 7 flows into the passage 6 in the direction of the arrow, the coating material 7 passes through the slit 8 and contacts the outer wall of the hollow fiber 2, while the radial direction (outside) ). As shown in FIG. 2, since the inside of the hollow fiber 2 is depressurized by a vacuum pump, the paint 7 in contact with the hollow fiber 2 is separated only from the bubbles 9 and the dissolved gas 10 from the principle of gas-liquid equilibrium. 11 is discharged. By the above mechanism, the defoamed and / or degassed coating 7 finally exudes from the outer peripheral surface of the hollow fiber membrane defoaming device 1.

  The pressure loss until the paint 7 flows to the passage 6 in the direction of the arrow and exudes from the surface of the hollow fiber membrane defoaming device 1 is preferably 6 bar or less, and more preferably 3 bar or less. Thereby, irrespective of the component contained in the coating material 7, generation | occurrence | production of the clogging in the hollow fiber membrane defoaming apparatus 1 can be suppressed, and defoaming and / or deaeration of a coating material can be performed continuously. The “pressure loss” is calculated by subtracting the pressure at which the paint 7 exudes from the hollow fiber membrane deaerator 1 from the pressure at which the paint 7 flows into the hollow fiber membrane deaerator. The

The flow rate when the coating material 7 is allowed to flow into the hollow fiber membrane defoaming device 1 is appropriately set so as to achieve the above pressure loss. Specifically, about 1 liter / minute or less per 1 m ^{2 of the} hollow fiber membrane surface area is preferable, and about 0.5 liter / minute or less is more preferable.

  The hollow fiber membrane deaerator 1 shown in FIG. 1 may have a form of a so-called sealed (cartridge type) hollow fiber membrane deaerator enclosed in a cartridge 12 as shown in FIG. . Since the cartridge 12 is provided with the outlet 13 communicating with the inside of the cartridge 12, the defoamed and / or degassed paint 7 can be collected from the outlet 13 collectively.

  In such a hollow fiber membrane defoaming apparatus, a commercially available one can be used as the sealed type, for example, SuperPhobic (registered trademark) 4 × 13, Liqui-Cel (registered trademark) manufactured by MEMBRANA. ) Industrial8x20, SEPAREL EF-002A-P, SEPARELEF-004P manufactured by Dainippon Ink & Chemicals, Inc. Moreover, the hollow fiber deaeration module described in JP2013-237276A can also be used.

  Further, the hollow fiber membrane defoaming device 1 may be a bare form, a so-called open-type hollow fiber membrane defoaming device. However, if the coating is defoamed and / or degassed while the hollow fiber membrane deaerator 1 is exposed, the defoamed and / or degassed paint oozes out of the hollow fiber membrane deaerator 1. Therefore, as shown in FIG. 4, it is necessary to provide a container 14 for containing the paint outside the hollow fiber membrane defoaming apparatus 1. In the case of the hollow fiber membrane defoaming device enclosed in the cartridge shown in FIG. 3, depending on the components of the paint, there is a risk of clogging of the components in the hollow fiber membrane defoaming device, but the open type shown in FIG. The hollow fiber membrane defoaming device is preferable in that pressure loss can be reduced and clogging of components in the hollow fiber membrane defoaming device can be reduced.

  Regarding the preparation of the paint, a plurality of components may be mixed and prepared, and the prepared paint may be defoamed and / or degassed using the above-described hollow fiber membrane defoaming apparatus (paint preparation 1). A plurality of dispersions or solutions may be defoamed and / or degassed using a hollow fiber membrane defoamer, respectively, and then each dispersion or solution may be mixed to prepare a paint (paint preparation 2). . In the case of the coating preparation 1, it is preferable from a viewpoint that the foam and dissolved gas which generate | occur | produced in the process which mixes a some component can be removed with a hollow fiber membrane defoaming apparatus. Moreover, in the case of the coating preparation 2, since each foam dispersion and / or solution having a low viscosity is defoamed and / or degassed using a hollow fiber membrane defoaming device, bubbles and dissolved gases are relatively easily removed. It is excellent in that it can be used.

  In any paint preparation, conventional vacuum defoaming, for example, defoaming by vacuum centrifugation, foams the gas-liquid interface of the paint when the dissolved gas is degassed under reduced pressure, and does not lead to bubble breakage. There is a risk of mixing in the paint. On the other hand, in this invention, it is excellent at the point which can deaerate and / or deaerate effectively, without mixing a bubble newly.

  Of course, after defoaming and / or degassing a plurality of dispersions or solutions using a hollow fiber membrane defoaming device, the respective dispersions or solutions are mixed to prepare a paint, and the prepared paint is then used as a hollow fiber. You may deaerate and / or deaerate using a membrane deaerator.

  When mixing a plurality of dispersions or solutions described above, they may be mixed separately in a mixing container. However, the apparatus is relatively simple, does not take up space, and the stability of the paint with a short time stability is stable. In view of enabling application, etc., each dispersion liquid or solution can be mixed by providing an in-line mixer at the joining point of the line through which each dispersion liquid or solution flows. In order to further improve the stability over time, an auxiliary agent such as a surfactant and / or a water-resistant agent can be added to the paint by an in-line mixer.

  The step of removing bubbles and dissolved gas in the solution may be performed by using a known deaeration device in addition to the hollow fiber membrane deaeration device. As a known deaeration device, for example, a vacuum centrifugal plate flow-down type deaerator such as a Colma vacuum deaeration device; an ultrasonic deaeration device and the like can be mentioned. As the vacuum centrifugal plate flow-down type defoaming machine, for example, apparatuses described in Japanese Patent No. 5468901, Utility Model Registration No. 3152498, Japanese Patent Laid-Open No. 11-262601, and the like can be used.

  The number of foams with a diameter of 200 μm or more per liter of paint after defoaming and / or degassing is the number of coating defects such as coating streaks due to film cracking or bead formation failure during curtain application, after application From the viewpoints of appearance due to bubble defects and suppression of poor performance, the number is preferably 10 or less, more preferably less than 3, and even more preferably 2 or less. Generally, defoaming can be facilitated and the number of foams can be reduced by lowering the viscosity of the paint by lowering the viscosity. However, the decrease in the viscosity of the paint not only makes the curtain film and bead formation unstable, but also increases the thickness unevenness of the coating layer depending on the support. For this reason, when the viscosity of the coating material is lowered in order to reduce the number of bubbles, the influence is rather large, and there is a possibility that the barrier functionality is impaired. In the present invention, for example, the ethanol barrier property can be improved without reducing the concentration of the paint.

  Note that the lower limit of the number of bubbles is preferably substantially free from bubbles having a diameter of 200 μm or more, that is, zero.

  The bubble measuring method is based on a bubble detection device using ultrasonic waves. This apparatus includes a pipeline through which a liquid for detecting air bubbles flows, ultrasonic transmission means installed so as to oscillate ultrasonic waves in a direction parallel to the traveling direction of the liquid flowing in the pipeline, Ultrasonic wave receiving means for receiving a reflected wave of the ultrasonic wave oscillated by the sound wave transmitting means, and signal processing means for detecting a bubble by processing a signal from the ultrasonic wave receiving means. When bubbles are present in the liquid, the ultrasonic waves are reflected by the bubbles and returned to the ultrasonic transducer, which is detected as a signal. Since the signal received by the ultrasonic transducer is detected at a position approaching the ultrasonic transducer with time, the signal due to reflection from the bubbles can be detected separately from a signal whose position does not change, such as noise. If there is a signal whose detection position has moved, since it is a signal due to bubbles, the number of signals is counted and output as the number of bubbles. On the other hand, the detection limit of bubbles in a liquid is about 1/2 of the wavelength of the ultrasonic wave when the bubbles are considered as a sphere. Therefore, for example, in order to detect bubbles of 100 μm or less, a sound wave having a wavelength of 200 μm is required. In the case of water, if the sound speed is about 1500 m / sec, an oscillation frequency of about 7.5 MHz is required. In the present invention, air bubbles having a diameter of 200 μm or more can be accurately measured with such a transmission frequency. In addition, the said bubble measuring method can be measured based on the procedure described in paragraph [0037] using the apparatus described in paragraph [0025] of patent 4561336.

2. Step (2)
Step (2) is a step of applying the paint obtained in step (1) on the support using curtain coating, slide coating or slot coating using a pre-weighing type coater. The step of applying the curtain is a step of applying the paint by freely dropping it in the form of a curtain using a curtain coater. The step of applying the slide is a step of supplying the coating material from one or a plurality of slots by a slide coater and causing the coating material to flow down on the sliding surface to form a coating film made of the coating material or coating materials on the sliding surface. In slide coating, a bead (liquid reservoir) can be formed and applied (slide bead coating) at the slide coater outlet. The slide coater can be applied as a curtain coater by forming a curtain film at the exit of the slide coater (slide type curtain application). The slot coating process is a process in which a bead is formed by a slot coater having one or a plurality of flow paths inside a die or the like, or a narrow gap that does not form a bead is applied. It is a process of applying a rusion. The slot coater can be applied as a curtain coater by forming a curtain film made of one or a plurality of paints (slot type curtain application). On the other hand, in the post-measuring type bar coating or blade coating, there is a risk that new shearing bubbles may occur at the gas-liquid interface of the paint due to the shear stress due to the bar or blade. In this regard, the present invention can fully exhibit the effects of the present invention in curtain coating, slide coating, and slot coating without shear stress.

  In addition, when a plurality of coating layers are formed on a support to form a coating film having a multilayer structure, it is possible to form a coating film by sequential curtain coating, but simultaneous multilayer curtain coating coating. It is preferable to do. Thereby, interlayer mixing can be prevented and a uniform coating layer can be formed. Moreover, simultaneous multilayer curtain coating is preferable in that productivity can be improved and energy consumption during production can be further reduced. As a specific method for applying the curtain, known methods such as a slide curtain method, a couple curtain method, a twin curtain method, and the like can be adopted, and the method is not particularly limited. Also, as described in Japanese Patent Application Laid-Open No. 2006-247611, paint is ejected downward from the curtain head to form a paint layer on the slope, and a paint curtain is formed from the downwardly directed curtain guide portion of the slope. Then, a method using a multistage curtain coater for transferring the coating layer onto the web surface can also be adopted.

  In simultaneous multi-layer coating by curtain coating, slide coating, or slot coating, after coating each coating, it may be applied and then dried to form each layer, or after applying a lower layer coating that forms the lower layer The upper layer coating surface may be applied to the lower layer coating surface while the lower layer coating surface is in a wet state without drying, and then dried to form each layer.

  In the production method of the present invention, at least one layer or two or more layers of coating films are formed by sequential coating or simultaneous multilayer coating. For the other layers, the above curtain coating, slide coating or slot coating is performed. Besides, for example, air knife method (air knife coating), blade method (for example, varibar blade coating, pure blade coating, rod blade coating, etc.), gravure method, roll coater method, spray method, dip method, bar method (bar Coating) and known application methods such as short dwell coating may be used in combination.

  Further, the smoothing process using a super calendar can be performed in an arbitrary process after the formation of each layer, the formation of a specific layer, or the formation of all layers. Further, for the purpose of curl control or the like, it is possible to further provide a coating layer on the back surface of the support.

  There are no particular restrictions on the type, shape, dimensions, etc. of the support on which the paint is applied to the curtain, slide, or slot. For example, high-quality paper (acidic paper, neutral paper) , Paper (paper support) such as medium-quality paper, coated paper, art paper, cast-coated paper, glassine paper, and resin-laminated paper, polyolefin-based synthetic paper, synthetic fiber paper, non-woven fabric, synthetic resin film, transparent or semi-solid A transparent plastic film, a white plastic film, etc. are mentioned.

  Moreover, as a pulp fiber which comprises a support body, both hardwood pulp and conifer pulp (pulp obtained by KP, SP, AP method etc.) can be used. Examples of such pulp include chemical pulps such as LBKP and NBKP, mechanical pulps such as semi-chemical pulp (SCP), GP and TMP, various high-yield pulps, and waste paper pulps such as DIP. If necessary, glass fiber and various synthetic pulps can be used in combination.

  The support may further contain various pigments as fillers. Examples of the pigment include inorganic pigments such as calcium carbonate, calcined kaolin, kaolin, diatomaceous earth, talc, chlorite, titanium oxide, barium sulfate, aluminum sulfate, and silica. Furthermore, a basic pigment can also be contained. Examples of the basic pigment include calcium carbonate, barium carbonate, aluminum hydroxide, magnesium carbonate, magnesium silicate, and magnesium oxide. Here, the basic pigment is a pigment that brings the pH of the dissolved aqueous solution to the alkali side.

  Although the thickness of a support body is not specifically limited, Usually, it is about 20-500 micrometers.

  The pulp slurry contains internal additives for papermaking such as fillers, paper strength agents, wet strength agents, sizing agents, dyes, fluorescent whitening agents, pH adjusters, antifoaming agents, pitch control agents, slime control agents, etc. An agent can be appropriately added depending on the use of the paper. In addition, starch or the like can be applied to at least one surface of the support by a size press or the like. As the paper machine, a long net paper machine, a twin wire type paper machine, a circular net paper machine, a Yankee dryer paper machine and the like can be used as appropriate.

3. Coated body In the coated body obtained by the method for producing a coated body of the present invention, a uniform and high-quality coated film in which coating defects are suppressed is formed on a support. As such a coated body, for example, it is preferably used for information recording medium applications such as a thermal recording body, an inkjet recording body, and a thermal transfer recording body.

  When producing a heat-sensitive recording material, as a coating layer on the support layer, for example, to form an undercoat layer, a thermosensitive coloring layer, and a protective layer, as a coating layer paint, an undercoat layer paint, A coloring layer coating material and a protective layer coating material are used. Hereinafter, the case where a thermal recording body is manufactured as a coated body will be described in detail.

3-1. As the support in the thermosensitive coloring layer for support thermosensitive recording medium can be used the support listed in "2. Step (2)".

3-2 Undercoat layer An intermediate layer such as an undercoat layer can be provided between the support and the thermosensitive coloring layer. By forming such an undercoat layer, it is possible to suppress a component that inhibits the color development reaction from passing through the support. Further, a uniform coating layer can be formed, and the recording performance is excellent. Furthermore, it is possible to have a multilayer structure between the support and the thermosensitive coloring layer, and it is possible to reduce coloring unevenness due to coating unevenness and to improve the halftone image quality in the single layer structure.

The coating for the undercoat layer is generally prepared by mixing water with a dispersion medium and mixing a pigment and a water-based adhesive, and if necessary, a sizing agent and an auxiliary agent. After the undercoat layer coating material is applied on the support, it is dried to form an undercoat layer on the support. The coating amount of the undercoat layer coating is not particularly limited, but is preferably about 3 to 20 g / m ² , more preferably about 5 to 15 g / m ² in terms of dry weight.

  The undercoat layer coating material may contain a sizing agent. Thereby, the penetration of the coating material into the undercoat layer formed by sequentially applying can be suppressed. Examples of sizing agents include rosin sizing agents, alkyl ketene dimer sizing agents, alkenyl succinic anhydrides, cationic polymer sizing agents, rosin neutral sizing agents, styrene-acrylic sizing agents, olefin sizing agents, and wax sizing sizes. Agents, styrene-maleic acid sizing agents and the like. Generally, it is called a sizing agent for papermaking and has a hydrophilic group and a hydrophobic group in its molecular structure. The form of the sizing agent may be a solution type or an emulsion type. These can be used alone or in combination of two or more. The styrene-acrylic sizing agent is a sizing agent mainly composed of a copolymer of styrene and acrylic.

  In addition to the above sizing agents, alkyl ketene dimer sizing agents, olefin sizing agents, wax sizing agents and the like that are generally used as surface sizing agents are preferred, and styrene-acrylic sizing agents, olefin-maleic acid sizing agents. It is more preferable to use a synthetic resin sizing agent such as a styrene-maleic acid sizing agent. Among these, a sizing agent having a styrene-containing copolymer as a main component is preferable. The styrene-maleic acid sizing agent includes a styrene-maleic anhydride sizing agent. The styrene-acrylic sizing agent includes a styrene-acrylic acid copolymer salt, and the salt includes a sodium salt, a potassium salt, an ammonium salt, or a mixture of these salts. In addition, the styrene-maleic anhydride sizing agent includes styrene-maleic anhydride copolymer salts, which include sodium salts, potassium salts, ammonium salts, or those in which these salts coexist. . Further, the styrene-maleic anhydride sizing agent includes esters of styrene-maleic anhydride copolymer, and butyl ester of styrene-maleic anhydride copolymer is particularly preferable.

  Examples of the water-based adhesive contained in the coating for the undercoat layer include polyvinyl alcohol, modified polyvinyl alcohol, starch, oxidized starch, modified starch, starch-vinyl acetate graft copolymer, casein, gelatin, polyacrylamide, polyamide, and hydroxyethyl cellulose. , Methyl cellulose, carboxymethyl cellulose, styrene-butadiene latex, polyurethane latex, acrylic latex and the like. These aqueous adhesives may be used alone or in combination of two or more. The total content of the aqueous adhesive is not particularly limited, but is preferably about 5 to 30% by mass, more preferably about 8 to 20% by mass, and more preferably about 10 to 20% by mass in the total solid content of the paint for the undercoat layer. Is more preferable.

  As the auxiliary agent, for example, dioctylsulfosuccinic acid sodium salt, dodecylbenzenesulfonic acid sodium salt, lauryl alcohol sulfate sodium salt, fatty acid metal salt, silicon-based surfactant, fluorine-based surfactant, aziridine compound, blocked isocyanate compound, Carboxylic acid dihydrazide compounds such as adipic acid dihydrazide, glyoxal, formalin, glycine, glycidyl ester, glycidyl ether, dimethylol urea, melamine resin, polyamide resin, polyamide polyamine-epichlorohydrin resin, ketone-aldehyde resin, ammonium persulfate, ferric chloride , Magnesium chloride, ammonium zirconium carbonate, borax, boric acid, sodium tetraborate, boric acid triester, boron-based polymer, potassium tetraborate, dicarbonate Benzalkonium ammonium, epoxy compounds, hydrazide compounds, oxazoline group-containing compound, sodium glyoxylate, di (glyoxylic acid) Calcium, waterproofing agent such as glyoxylic acid salts such as ammonium glyoxylic acid, antifoaming agents and the like. In addition, about a waterproofing agent, it is preferable to use in the range of 0.1-10 mass% in the total solid amount of the coating material for undercoat layers, and about 1-5 mass% is more preferable.

  The undercoat layer paint may contain an oil-absorbing pigment. Various oil-absorbing pigments can be used, and specific examples include inorganic pigments such as calcined kaolin, amorphous silica, light calcium carbonate, and talc. Of these, calcined kaolin is preferred from the viewpoint of improving recording performance. The average particle diameter of the primary particles of these oil-absorbing pigments is preferably about 0.01 to 5 μm, particularly preferably about 0.02 to 3 μm. The content of the oil-absorbing pigment is not particularly limited, but is preferably about 2 to 90% by mass, more preferably about 5 to 90% by mass, and further about 30 to 80% by mass in the total solid content of the coating for the undercoat layer. preferable.

  The paint for the undercoat layer may contain plastic hollow particles. Examples of the plastic hollow particles include conventionally known particles, for example, particles having a hollow ratio of about 50 to 99% in which the film material is made of an acrylic resin, a styrene resin, a vinylidene chloride resin, or the like. Here, the hollowness is a value obtained by the following formula (d / D) × 100. In the formula, d represents the inner diameter of the plastic hollow particle, and D represents the outer diameter of the plastic hollow particle. The average particle size of the plastic hollow particles is preferably about 0.5 to 10 μm, more preferably about 1 to 3 μm. The content ratio of the plastic hollow particles is not particularly limited, but is preferably about 2 to 90% by mass, more preferably about 5 to 70% by mass, and about 10 to 50% by mass in the total solid content of the paint for the undercoat layer. Further preferred.

  The mass ratio of the oil-absorbing pigment / plastic hollow particles in the coating for the undercoat layer is preferably in the range of 100/0 to 40/60, more preferably in the range of 90/10 to 60/40, and 85/15 to 60/40. The range of is more preferable. By setting the mass ratio of the oil-absorbing pigment to 100 or less, the cushioning property of the undercoat layer can be improved, and the recording color development property and the recording image quality can be improved. On the other hand, by setting it to 40 or more, the oil absorbency of the undercoat layer can be sufficiently exhibited, and image defects due to head wrinkles and the like can be reduced to improve the recording image quality. Moreover, by setting it as this range, barrier property can be improved further and it can fully endure long-term storage after processing into a thermosensitive recording label.

  As a method for applying the coating for the undercoat layer on the support, the curtain coating, the slide coating, or the slot coating mentioned in the above step (2) can be used. The coating layer is preferably formed by a blade coating method because the coating layer can be formed with a uniform thickness. The blade coating method is not limited to a coating method using a blade represented by a bevel type or a vent type, and includes a rod blade method, a bill blade method, and the like.

  Moreover, as a method for applying the paint for the undercoat layer, pure blade coating, rod blade coating, or the like is preferable from the viewpoint of improving the surface properties of the undercoat layer.

3-3. Thermosensitive coloring layer The thermosensitive coloring layer can be formed by applying a coating for the thermosensitive coloring layer on the support or on the undercoat layer mentioned in “3-2. Undercoat layer”. . The heat-sensitive color-developing layer coating material can contain various known leuco dyes and colorants. In addition, you may contain a sensitizer, a preservability improving agent, a pigment, various adjuvants, etc. as needed.

  Specific examples of leuco dyes include, for example, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-methylphenyl) -3- (4-dimethylamino) Blue coloring dyes such as phenyl) -6-dimethylaminophthalide and fluoran; 3- (N-ethyl-Np-tolyl) amino-7-N-methylanilinofluorane, 3-diethylamino-7-ani Green coloring dyes such as linofluorane, 3-diethylamino-7-dibenzylaminofluorane, rhodamine B-anilinolactam; 3,6-bis (diethylamino) fluorane-γ-anilinolactam, 3-cyclohexylamino- 6-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-chloroph Red chromogenic dyes such as Oran; 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7 -Anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di (n-butyl) amino-6-methyl-7-anilinofluorane, 3-di (n-pentyl) Amino-6-methyl-7-anilinofluorane, 3- (N-ethyl-N-isoamylamino) -6-methyl-7-arininofluorane, 3-diethylamino-7- (m-trifluoromethylani Lino) fluorane, 3- (N-isoamyl-N-ethylamino) -7- (o-chloroanilino) fluorane, 3- (N-ethyl-N-2-tetrahydrofurfurylamino) -6-methyl -7-anilinofluorane, 3- (Nn-hexyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3- [N- (3-ethoxypropyl) -N-ethylamino ] -6-methyl-7-anilinofluorane, 3- [N- (3-ethoxypropyl) -N-methylamino] -6-methyl-7-anilinofluorane, 3-diethylamino-7- (2 -Chloroanilino) fluorane, 3-di (n-butylamino) -7- (2-chloroanilino) fluorane, 4,4'-bis-dimethylaminobenzhydrin benzyl ether, N-2,4,5-trichlorophenylleuco Auramine, 3-diethylamino-7-butylaminofluorane, 3-ethyl-tolylamino-6-methyl-7-anilinofluorane, 3-cyclohexyl-methylaure No-6-methyl-7-anilinofluorane, 3-diethylamino-6-chloro-7- (β-ethoxyethyl) aminofluorane, 3-diethylamino-6-chloro-7- (γ-chloropropyl) amino Fluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N-isoamyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3-dibutylamino-7-chloro Anilinofluorane, 3-diethylamino-7- (o-chlorophenylamino) fluorane, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-p) -Toluidino) -6-methyl-7- (p-toluidino) fluorane, 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-a Linofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-dimethylamino-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3- Piperidino-6-methyl-7-anilinofluorane, 2,2-bis {4- [6 '-(N-cyclohexyl-N-methylamino) -3'-methylspiro [phthalide-3,9'-xanthene- Black coloring dyes such as 2′-ylamino] phenyl} propane and 3-diethylamino-7- (3′-trifluoromethylphenyl) aminofluorane; 3,3-bis [1- (4-methoxyphenyl) -1 -(4-Dimethylaminophenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3,3-bis [1- (4-methoxyphenyl) 1- (4-Pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3-p- (p-dimethylaminoanilino) anilino-6-methyl-7-chloro Fluorane, 3-p- (p-chloroanilino) anilino-6-methyl-7-chlorofluorane, 3,6-bis (dimethylamino) fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide And dyes having an absorption wavelength in the near infrared region. Of course, it is not restricted to these, Moreover, 2 or more types can also be used together as needed. Among these, 3-di (n-butyl) amino-6-methyl-7-anilinofluorane, 3-di (n-pentyl) amino-6-methyl-7-anilinofluorane, and 3- ( N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluorane is preferably used because it is excellent in color development sensitivity and print storage stability. The content ratio of the leuco dye is not particularly limited, and is preferably about 3 to 30% by mass, more preferably about 5 to 25% by mass, and about 7 to 20% by mass in the total solid amount of the heat-sensitive coloring layer coating. Further preferred. By setting the content to 3% by mass or more, it is possible to improve the color developing ability and improve the printing density. Heat resistance can be improved by setting it as 30 mass% or less.

  Specific examples of the colorant include, for example, 4-tert-butylphenol, 4-acetylphenol, 4-tert-octylphenol, 4,4′-sec-butylidene diphenol, 4-phenylphenol, 4,4′-dihydroxy Diphenylmethane, 4,4′-isopropylidene diphenol, 4,4′-cyclohexylidene diphenol, 1,1-bis (4-hydroxyphenyl) -ethane, 1,1-bis (4-hydroxyphenyl) -1- Phenylethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2′-bis [4- (4-hydroxyphenyl) phenoxy] diethyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′- Thiobis (3-methyl-6-tert-butylphenol), 4,4 ' Dihydroxydiphenylsulfone, 2,4′-dihydroxydiphenylsulfone, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,4′-dihydroxydiphenylsulfone, 4-hydroxy-4′-isopropoxydiphenylsulfone 4-hydroxy-4′-n-propoxydiphenylsulfone, 4-hydroxy-4′-allyloxydiphenylsulfone, 4-hydroxy-4′-benzyloxydiphenylsulfone, 3,3′-diallyl-4,4′- Dihydroxydiphenyl sulfone, bis (p-hydroxyphenyl) butyl acetate, methyl bis (p-hydroxyphenyl) acetate, hydroquinone monobenzyl ether, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxy-4'-methyldiphe Phenolic compounds such as sulfone, 4-allyloxy-4′-hydroxydiphenylsulfone, 3,4-dihydroxyphenyl-4′-methylphenylsulfone, 4-hydroxybenzophenone; dimethyl 4-hydroxyphthalate, methyl 4-hydroxybenzoate 4-hydroxybenzoic acid propyl, 4-hydroxybenzoic acid-sec-butyl, 4-hydroxybenzoic acid phenyl, 4-hydroxybenzoic acid benzyl, 4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid tolyl, 4-hydroxy Phenolic compounds such as chlorophenyl benzoate and 4,4′-dihydroxydiphenyl ether; benzoic acid, p-chlorobenzoic acid, p-tert-butylbenzoic acid, trichlorobenzoic acid, terephthalic acid, salicylic acid, 3-tert -Butylsalicylic acid, 3-isopropylsalicylic acid, 3-benzylsalicylic acid, 3- (α-methylbenzyl) salicylic acid, 3,5-di-tert-butylsalicylic acid, 4- [2- (p-methoxyphenoxy) ethyloxy] salicylic acid, 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid, 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] salicylic acid, 4- {3- (p-tolylsulfonyl) propyloxy] salicylic acid, etc. And aromatic carboxylic acids.

In addition, a salt of the above-described phenolic compound or aromatic carboxylic acid and a polyvalent metal such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin, nickel, etc .; further, an antipyrine complex of zinc thiocyanate, terephthalaldehyde Organic acidic substances such as complex zinc salts of acids and other aromatic carboxylic acids; Np-toluenesulfonyl-N′-3- (p-toluenesulfonyloxy) phenylurea, Np-toluenesulfonyl- N′-p-butoxycarbonylphenylurea, Np-tolylsulfonyl-N′-phenylurea, 4,4′-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane, 4,4′-bis [(4- Urethanes such as methyl-3-phenoxycarbonylaminophenyl) ureido] diphenylsulfone Compound; Thiourea compound such as N, N′-di-m-chlorophenylthiourea; N- (p-toluenesulfonyl) carbamoyl acid p-cumylphenyl ester, N- (p-toluenesulfonyl) carbamoyl acid p-benzyloxy Organic compounds having —SO ₂ NH— bond in the molecule such as phenyl ester, N- [2- (3-phenylureido) phenyl] benzenesulfonamide, N- (o-toluoyl) -p-toluenesulfoamide; activity Inorganic acidic substances such as white clay, attapulgite, colloidal silica, and aluminum silicate are listed.

  Furthermore, 4,4′-bis [(4-methyl-3-phenoxycarbonylaminophenyl) ureido] diphenylsulfone represented by the following general formula (1), 4,4′-bis [(2-methyl-5- Urea urethane derivatives such as phenoxycarbonylaminophenyl) ureido] diphenylsulfone, 4- (2-methyl-3-phenoxycarbonylaminophenyl) ureido-4 ′-(4-methyl-5-phenoxycarbonylaminophenyl) ureidodiphenylsulfone; Examples thereof include diphenyl sulfone derivatives represented by the following general formula (2). These colorants can be used alone or in combination of two or more.

(In the formula, n represents an integer of 1 to 6.)
The content of the colorant is not particularly limited, and may be adjusted according to the leuco dye used. Generally, 0.5 part by mass or more is preferable with respect to 1 part by mass of the leuco dye, and 0.8 part by mass. The above is more preferable, 1 mass part or more is still more preferable, 1.2 mass parts or more is still more preferable, and 1.5 mass parts or more is especially preferable. Further, the content of the colorant is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 4 parts by mass or less, and particularly preferably 3.5 parts by mass or less with respect to 1 part by mass of the leuco dye. . By setting the content to 0.5 parts by mass or more, the recording performance can be improved. On the other hand, by setting it as 10 mass parts or less, the background fogging in a high temperature environment can be suppressed effectively.

  If necessary, the heat-sensitive coloring layer coating material may contain a sensitizer. Thereby, the recording sensitivity can be increased. Examples of the sensitizer include myristic acid amide, palmitic acid amide, stearic acid amide, arachidic acid amide, methoxycarbonyl-N-stearic acid benzamide, N-benzoyl stearic acid amide, N-eicosanoic acid amide, and ethylene bistearic acid. Amides, behenic acid amides, methylenebis stearic acid amides, N-methylol stearic acid amides, dibenzyl terephthalate, dimethyl terephthalate, dioctyl terephthalate, benzyl p-benzyloxybenzoate, phenyl 1-hydroxy-2-naphthoate, 2 -Naphthyl benzyl ether, m-terphenyl, oxalate dibenzyl, oxalate-di-p-methylbenzyl, oxalate-di-p-chlorobenzyl, oxalate dibenzyl ester, p-benzylbiphenyl, tolrubi Phenyl ether, p-tolylbiphenyl ether, di (p-methoxyphenoxyethyl) ether, 1,2-di (3-methylphenoxy) ethane, 1,2-di (4-methylphenoxy) ethane, 1,2-di (4-methoxyphenoxy) ethane, 1,2-di (4-chlorophenoxy) ethane, 1,2-diphenoxyethane, 1- (4-methoxyphenoxy) -2- (2-methylphenoxy) ethane, 1- (4-methoxyphenoxy) -2- (3-methylphenoxy) ethane, p-methylthiophenylbenzyl ether, 1,4-di (phenylthio) butane, p-acetoluidide, p-acetophenetide, N-acetoacetyl- p-toluidine, di (β-biphenylethoxy) benzene, p-di (vinyloxyethoxy) benzene, 1-iso Examples thereof include propylphenyl-2-phenylethane, diphenylsulfone, 1,2-diphenoxymethylbenzene and the like. These can be used in combination as long as there is no hindrance. Among them, stearic acid amide, diphenylsulfone, 2-naphthylbenzyl ether, oxalic acid di-p-chlorobenzyl ester, oxalic acid di-p-methylbenzyl ester, 1,2-di (3-methylphenoxy) ethane, 1, 2-Diphenoxyethane is preferably used because of its excellent color sensitivity. The content of such a sensitizer is not particularly limited, but it is generally desirable to adjust the content in the range of about 4 parts by mass or less with respect to 1 part by mass of the colorant, and 2 to 40 in the total solid content of the thermal recording coating material. About mass% is preferable and about 5-25 mass% is more preferable.

  If necessary, the heat-sensitive coloring layer coating material may contain a preservability improver. Thereby, the storage stability of a recording part can be improved. Examples of the preservability improver include 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-ethylenebis (4-methyl-6-tert-butylphenol), 2,2 ′. -Methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4,6-di-tert-butylphenol), 2,2'-ethylidenebis (4,6-di-tert-butylphenol) 2,2′-ethylidenebis (4-methyl-6-tert-butylphenol), 2,2′-ethylidenebis (4-ethyl-6-tert-butylphenol), 2,2 ′-(2,2-propylidene) ) Bis (4,6-di-tert-butylphenol), 2,2'-methylenebis (4-methoxy-6-tert-butylphenol) ), 2,2′-methylenebis (6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (2-methyl-6-tert-butylphenol) ), 4,4′-thiobis (5-methyl-6-tert-butylphenol), 4,4′-thiobis (2-chloro-6-tert-butylphenol), 4,4′-thiobis (2-methoxy-6) -Tert-butylphenol), 4,4'-thiobis (2-ethyl-6-tert-butylphenol), 4,4'-butylidenebis (6-tert-butyl-m-cresol), 1- [α-methyl-α -(4'-hydroxyphenyl) ethyl] -4- [α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene, 1,1,3-to Lis (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 4,4′-thiobis (3 -Methylphenol), 4,4'-dihydroxy-3,3 ', 5,5'-tetrabromodiphenylsulfone, 4,4'-dihydroxy-3,3', 5,5'-tetramethyldiphenylsulfone, 2, , 2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5- Hindered phenolization of dimethylphenyl) propane, tris (2,6-dimethyl-4-tertiarybutyl-3-hydroxybenzyl) isocyanurate, etc. 1,4-diglycidyloxybenzene, 4,4′-diglycidyloxydiphenylsulfone, 4-benzyloxy-4 ′-(2-methylglycidyloxy) diphenylsulfone, diglycidyl terephthalate, cresol novolac type epoxy resin, Epoxy compounds such as phenol novolac type epoxy resin and bisphenol A type epoxy resin, N, N′-di-2-naphthyl-p-phenylenediamine, bis (4-ethyleneiminocarbonylaminophenyl) methane, 2,2′-methylenebis (4,6-di-tert-butylphenyl) sodium phosphate, N, N′-di-2-naphthyl-p-phenylenediamine, 2,2′-methylenebis (4,6-di-tert-butylphenyl) Sodium or polyvalent metal salt of phosphate, bis (4- Ren iminocarbonyl aminophenyl) methane, and the like.

  The content of the preservability improver may be an effective amount for improving the preservability, but is usually preferably about 0.5 to 30% by mass in the total solid content of the heat-sensitive color developing layer coating. About 20% by mass is more preferable.

  Specific examples of pigments contained in the heat-sensitive coloring layer coating include, for example, kaolin, clay, talc, calcined kaolin, calcium carbonate, magnesium carbonate, aluminum oxide, aluminum hydroxide, magnesium hydroxide, magnesia, zinc oxide, and oxidation. Titanium (titanium dioxide), barium carbonate, barium sulfate, finely divided silicic acid, calcium silicate, (synthetic) aluminum silicate, talc, calcined kaolin, titanium oxide, zinc oxide, wax stone, diatomaceous earth, particulate anhydrous silica, amorphous silica, activity White clay, surface treated inorganic pigments such as calcium carbonate and silica, styrene microballs, nylon powder, polyethylene powder, urea-formalin resin filler, phenol resin, epoxy resin, styrene-methacrylic acid copolymer resin, polystyrene resin, raw starch Particle, nai Emissions, a melamine resin, and organic pigments such as benzoguanamine resin. The content of the pigment is preferably 50% by mass or less in an amount that does not decrease the color density, that is, in the total solid content of the heat-sensitive color developing layer coating.

  As the adhesive used for the heat-sensitive coloring layer coating, for example, any water-based adhesive such as a water-soluble adhesive and a water-dispersible adhesive can be used. Examples of water-soluble adhesives include fully saponified or partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol and other modified polyvinyl alcohol, starch and derivatives thereof, methoxycellulose , Cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, methylcellulose, and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, polyamide, diisobutylene-maleic anhydride copolymer salt, styrene-acrylic acid copolymer salt, Styrene-maleic anhydride copolymer salt, ethylene-maleic anhydride copolymer salt, acrylic amide-acrylic acid ester Ether copolymers, acrylic acid amide - acrylic acid ester - methacrylic acid copolymer, polyacrylamide, sodium alginate, gelatin, and casein, gum arabic, and the like. Water dispersible adhesives include polyvinyl acetate, polyurethane, styrene-butadiene copolymer, styrene-butadiene-acrylonitrile copolymer, acrylonitrile-butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride-acetic acid Water such as vinyl copolymer, polybutyl methacrylate, ethylene-vinyl acetate copolymer, silylated urethane, acrylic-silicon composite, and acrylic-silicon-urethane composite, urea resin, melamine resin, amide resin, polyurethane resin, etc. Examples include insoluble polymer latex. These can be used alone or in combination of two or more. At least one of these is preferably blended in the range of about 5 to 50% by mass, more preferably about 10 to 40% by mass in the total solid content of the heat-sensitive color developing layer coating material.

  In the coating for the heat-sensitive coloring layer, surfactants, water-proofing agents, waxes, metal soaps, colored dyes, organic pigments or inorganic pigments (basic inorganic pigments), colored pigments, fluorescent dyes, and oil repellents are included as necessary. Auxiliaries such as antifoaming agents and viscosity modifiers can be included.

  Examples of water-resistant agents include aldehyde compounds such as glyoxal, polyamine compounds such as polyethyleneimine, epoxy compounds, polyamide resins, melamine resins, dimethylol urea compounds, aziridine compounds, blocked isocyanate compounds, and adipic acid dihydrazides. Acid dihydrazide compounds, glyoxylate salts, inorganic compounds such as ammonium persulfate, ferric chloride, magnesium chloride, sodium tetraborate, potassium tetraborate and boric acid, boric acid, boric acid triester, boron polymer, dialdehyde starch, etc. Can be mentioned. These can be used alone or in combination of two or more. These waterproofing agents are preferably used in the range of 0.1 to 10% by mass in the total solid content of the thermosensitive coloring layer.

  Examples of the wax include paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, and higher fatty acid ester wax. Examples of the metal soap include higher fatty acid polyvalent metal salts, that is, zinc stearate, aluminum stearate, calcium stearate, zinc oleate and the like.

  Examples of the surfactant include dioctyl sulfosuccinic acid sodium salt, dodecylbenzene sulfonic acid sodium salt, lauryl alcohol sulfate sodium salt, fatty acid metal salt, silicon-based surfactant, fluorine-based surfactant, and the like. In the present invention, an effect of improving the wettability of the coating material with respect to the hollow fiber can also be obtained by the surfactant.

The heat-sensitive coloring layer coating can be prepared by a known method. For example, water is generally used as a dispersion medium, and leuco dyes and colorants, and if necessary, sensitizers and preservatives are added together or separately, and various types of stirring such as ball mills, coball mills, attritors, vertical and horizontal sand mills, etc. -Disperse with a water-soluble synthetic polymer compound such as polyacrylamide, polyvinyl pyrrolidone, polyvinyl alcohol, methyl cellulose, styrene-maleic anhydride copolymer salt, and other surfactants in a wet pulverizer to obtain a dispersion. Thus, for example, using a dispersion obtained by dispersing so as to have an average particle size of 2 μm or less, a paint for a thermosensitive coloring layer prepared by mixing pigments, adhesives, auxiliaries and the like as necessary is obtained. After the coating, it is dried to form a thermosensitive coloring layer on the support or the undercoat layer. The coating amount of the coating material for heat-sensitive coloring layer is not particularly limited, is preferably about 1~12g / ^{m 2} of the coating amount after drying, more preferably ^{2~10g / m 2, 2.5~8g / m} 2 is Further preferred is 3 to 5.5 g / m ² . The heat-sensitive color developing layer coating can be formed in two or more layers as necessary, and the composition and application amount of each layer may be the same or different.

  As a method for applying the heat-sensitive color developing layer coating on the support or the undercoat layer, it is preferable to apply the curtain coating, the slide coating, or the slot coating mentioned in “2. Step (2)”. The step of using and applying the curtain is more preferable.

  In the case of providing an undercoat layer or a protective layer to be described later, each layer can be formed by sequential coating by curtain coating, slide coating, or slot coating, but at least two layers including a thermosensitive coloring layer are required. Simultaneous multi-layer coating is preferred. Examples of the combination of the layers to be simultaneously applied in multiple layers include an undercoat layer and a thermosensitive color developing layer, a thermosensitive color developing layer and a protective layer, and an undercoat layer, a thermosensitive color developing layer and a protective layer. Furthermore, the thermosensitive coloring layer or the protective layer may have a multilayer structure, and an intermediate layer may be formed between them. As a specific method of curtain coating, slide coating, or slot coating, the method described in the above “2. Step (2)” can be employed.

3-4. If necessary, a protective layer can be formed on the protective layer. The protective layer coating for forming the protective layer preferably contains a pigment and an adhesive. The protective layer may be a single layer or may have a plurality of layers (first protective layer and second protective layer) of two or more layers. Furthermore, the coating material for the protective layer preferably contains a lubricant such as polyolefin wax or zinc stearate for the purpose of preventing sticking to the thermal head, and can also contain an ultraviolet absorber. In addition, the added value of the product can be increased by providing a glossy protective layer.

  The adhesive contained in the protective layer coating is not particularly limited, and any water-based adhesive such as a water-soluble adhesive and a water-dispersible adhesive can be used. The adhesive can be appropriately selected from those that can be used for the heat-sensitive coloring layer coating. The effect of the present invention is obtained by containing polyvinyl alcohol having a polymerization degree of 1000 to 3000 as a water-soluble adhesive in the total solid amount of the coating material for a protective layer, preferably 10 to 50% by mass, more preferably 15 to 50% by mass. Can be further increased. Examples of the polyvinyl alcohol having a polymerization degree of 1000 to 3000 include modified polyvinyl alcohols such as completely saponified or partially saponified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, and silicon-modified polyvinyl alcohol. Among these, acetoacetyl-modified polyvinyl alcohol and diacetone-modified polyvinyl alcohol are preferable because they can improve the barrier property of the surface of the protective layer and improve the storage stability such as chemical resistance. Further, cellulose resins such as hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, alkali salts of ethylene-acrylic acid copolymer, and the like can be given. Examples of the water-dispersible adhesive include latexes such as styrene-butadiene latex, acrylic latex, and urethane latex. Among these, at least one selected from the group consisting of acetoacetyl-modified polyvinyl alcohol and diacetone-modified polyvinyl alcohol is preferably used because it can improve surface barrier properties and improve storage stability such as chemical resistance. . From the viewpoint of improving water resistance and printability, at least one water-dispersible adhesive selected from the group consisting of acrylic resins and polyurethane resins is preferably used.

  The total content of the aqueous adhesive contained in the protective layer coating is preferably about 10 to 80% by mass, more preferably about 20 to 75% by mass, based on the total solid content of the protective layer coating. By setting it as 10 mass% or more, the outstanding barrier property can be obtained, and also generation | occurrence | production of paper dust can be prevented by improving surface strength. On the other hand, by setting it to 80% by mass or less, sticking that is a recording failure can be suppressed.

  Examples of the pigment in the protective layer coating include inorganic pigments such as calcium carbonate, zinc oxide, aluminum oxide, titanium dioxide, amorphous silica, synthetic mica, aluminum hydroxide, barium sulfate, talc, kaolin, clay, and calcined kaolin. Organic pigments such as nylon resin fillers, urea-formalin resin fillers, and raw starch particles. Among these, kaolin and aluminum hydroxide are preferable because they have a small decrease in barrier properties against chemicals such as plasticizers and oils and a small decrease in recording density.

  The content ratio of the pigment in the protective layer coating is preferably about 5 to 80% by mass, and more preferably about 10 to 70% by mass in the total solid content of the protective layer coating. By setting the content to 5% by mass or more, the sliding with the thermal head can be improved, and sticking and head wrinkles can be suppressed. On the other hand, by setting it as 80 mass% or less, barrier property can be improved and the function as a protective layer can be improved significantly.

  Examples of the auxiliary agent used in the protective layer coating include lubricants such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax, ester wax, alkylbenzene sulfonate sodium salt, dioctyl sulfosuccinate sodium salt, sulfonic acid modified Acetylene glycol surfactants such as polyvinyl alcohol and sodium acrylate acetylene glycol compounds, fluorine surfactants, silicon surfactants, phosphate ester surfactants, ether surfactants, or betaines, Surfactants such as amphoteric surfactants such as aminocarboxylates and imidazoline derivatives, glyoxal, boric acid, dialdehyde starch, methylol urea, glyoxylate, epoxy compound, hydrazine compound Of water-proofing agent (crosslinking agent), a hydrophobic polycarboxylic acid copolymer, an ultraviolet absorber, fluorescent dyes, coloring dyes, mold release agents, antioxidants, and the like. The usage-amount of auxiliary agent can be suitably set from a wide range. In the present invention, an effect of improving the wettability of the coating material with respect to the hollow fiber can also be obtained by the surfactant.

The coating material for the protective layer is generally prepared by using water as a dispersion medium and mixing a pigment, an adhesive, and an auxiliary agent if necessary. After coating using the coating material for the protective layer, it is dried and formed as a protective layer on the thermosensitive coloring layer. The coating amount of the protective layer coating is not particularly limited, and is preferably about 0.3 to 15 g / m ² , more preferably about 0.3 to 10 g / m ² in terms of dry weight, and 0.5 to 8 g / m ^2. more preferably the extent, particularly preferably about 1-8 g / ^{m 2,} about 1 to 5 g / ^{m 2} is more preferable. The protective layer coating can be formed in two or more layers as necessary to form a protective layer, and the composition and coating amount of each layer may be the same or different. May be.

  As a method for applying the protective layer coating on the heat-sensitive color developing layer, the curtain coating, slide coating or slot coating mentioned in the above “2. Step (2)” can be used.

  The protective layer can be formed by sequential application after forming the thermosensitive coloring layer, but it is preferable to apply the protective layer simultaneously with the coating for the thermosensitive coloring layer. Thereby, interlayer mixing can be prevented, and a uniform thermosensitive coloring layer and protective layer can be formed. A step of applying a curtain using a curtain coater is more preferable. As a specific method of curtain coating, slide coating, or slot coating, the method described in the above “2. Step (2)” can be employed.

  The coating layer forming the heat-sensitive recording material thus obtained comprises (1) the thermosensitive coloring layer / protective layer, (2) the undercoat layer / thermosensitive coloring layer / protective layer, and (3) the thermosensitive coloring layer / First protective layer / second protective layer, (4) undercoat layer / thermosensitive color developing layer / first protective layer / second protective layer, (5) undercoat layer / first thermosensitive color developing layer / second thermosensitive color developing layer / protective layer Or (6) those formed in the order of undercoat layer / first thermosensitive coloring layer / intermediate layer / second thermosensitive coloring layer / protective layer.

It is a schematic cross section which shows one Embodiment of the hollow fiber membrane defoaming apparatus used in order to manufacture the coating body of this invention. It is the schematic cross section which expanded the hollow fiber which comprises a hollow fiber membrane defoaming apparatus, and its vicinity. It is a schematic diagram which shows one Embodiment of the hollow fiber membrane deaeration apparatus enclosed with the cartridge used in order to manufacture the coating body of this invention. It is a schematic diagram which shows one Embodiment of the hollow fiber membrane defoaming apparatus provided with the container which accommodates the coating material used in order to manufacture the coating body of this invention.

  The heat-sensitive recording material of the present invention will be described more specifically with reference to the following examples, but of course not limited thereto. In the examples, “parts” and “%” represent “parts by mass” and “% by mass”, respectively, unless otherwise specified.

Example 1
-Preparation of paint for undercoat layer 120 parts of plastic hollow particle dispersion (trade name: Ropaque AF-1055, hollow ratio: 55%, average particle size: 1.0 μm, manufactured by Dow Chemical Co., Ltd., solid content concentration 26.5%) , 110 parts of 50% aqueous dispersion (average particle size: 0.6 μm) of calcined kaolin (trade name: Ansilex, manufactured by BASF), styrene-butadiene latex (trade name: DL939, manufactured by TRINSEO, solid content concentration 50%) 32 parts, a composition comprising a 13% aqueous solution 40 of fully saponified polyvinyl alcohol (trade name: PVA110, polymerization degree 1000, saponification degree 98 to 99 mol%, manufactured by Kuraray Co., Ltd.), and mixed and stirred for the undercoat layer A paint was obtained.

-Preparation of liquid A (leuco dye dispersion) 3-di (n-butyl) amino-6-methyl-7-anilinofluorane 100 parts, sulfone-modified polyvinyl alcohol (trade name: Goceran L-3266, Nippon Synthetic Chemical A composition comprising 50 parts of a 20% aqueous solution of a 20% aqueous solution of a natural fat and oil, 10 parts of a 5% emulsion of a natural fat and oil-based antifoaming agent (trade name: NOPCOMASTER 1407KN (manufactured by NOPCOPPERTECHNOLOGY)), and 80 parts of water by a sand mill. A leuco dye dispersion was obtained by pulverizing until a median diameter of 0.5 μm was obtained using a distribution measuring apparatus (MASTERSIZER 2000 (manufactured by MALVERN)).

-Preparation of liquid B (colorant dispersion) 4-hydroxy-4'-isopropoxydiphenylsulfone 100 parts, sulfone-modified polyvinyl alcohol (trade name: Gocelan L-3266, manufactured by Nippon Synthetic Chemical Co., Ltd.) 50% aqueous solution 50 A composition comprising 10 parts of a 5% emulsion of a natural fat and oil-based antifoaming agent (trade name: NOPCOMASTER 1407KN (manufactured by NOPCOPPERTECHNOLOGY)) and 50 parts of water is mixed with a laser diffraction particle size distribution measuring apparatus (MASTERSERZER2000 (MALVERN) The colorant dispersion was obtained by pulverizing so that the median diameter according to the production)) was 1.0 μm.

-Preparation of liquid C (sensitizer dispersion) 100 parts of 1,2-di (3-methylphenoxy) ethane, 50 parts of a 20% aqueous solution of sulfone-modified polyvinyl alcohol (trade name: Gocelan L-3266, supra), A composition comprising 10 parts of a 5% emulsion of a natural fat and oil-based antifoaming agent (trade name: NOPCOMASTER 1407KN (manufactured by NOPCOPAPERTECHNOLOGY)) and 90 parts of water is subjected to a laser diffraction particle size distribution measuring device (MASTERSTERSIZER 2000 (manufactured by MALVERN)) using a sand mill. ) Was pulverized so that the median diameter by 1.0 was 1.0 μm to obtain a sensitizer dispersion.

-Preparation of liquid D (kaolin dispersion) Kaolin (trade name: UW-90, manufactured by BASF) 55 parts, 45% aqueous solution of polyacrylic acid sodium salt (trade name: SOKALANFTCP10 (BASF)) 0.4 parts And a composition comprising 45 parts of water were mixed to obtain a kaolin dispersion.

・ Preparation of paint for thermosensitive coloring layer A part 45 parts, B part 80 parts, C part 60 parts, D part 45 parts, fully saponified polyvinyl alcohol (trade name: PVA110, supra) 90 parts, complete saponification 65 parts of 10% aqueous solution of polyvinyl alcohol (trade name: PVA56-98, polymerization degree 2400, saponification degree 98-99 mol%, manufactured by Kuraray Co., Ltd.), styrene-butadiene latex (trade name: DL939, manufactured by TRINSEO, solid content concentration 50%) 13 parts of dioctyl sulfosuccinic acid sodium salt (trade name: REWOPOLSBDO75, EVONIK) 7% 10% aqueous composition and 45 parts of water were mixed and stirred to form a thermosensitive coloring layer having a solid content of 31%. A paint was obtained.

-Preparation of coating material for protective layer 80 parts of D solution, 125 parts of 13.5% aqueous solution of acetoacetyl-modified polyvinyl alcohol (trade name: Gohsephimer Z-200, degree of polymerization 1000, manufactured by Nippon Synthetic Chemical Industry), stearic acid A composition comprising 7 parts of a zinc aqueous dispersion (trade name: HIDRINEZ-740, solid concentration 40%, manufactured by Chukyo Europe Ltd.) and 0.6 part of a 10% aqueous solution of dioctylsulfosuccinic acid sodium salt was mixed to obtain a solid content. A coating for protective layer having a concentration of 30% was obtained.

-Preparation of thermosensitive recording material After applying a blade coater on a single side of a high-quality paper having a basis weight of 60 g / m ² as a support using a blade coater so that the coating amount after drying the coating material for the undercoat layer is 7 g / m ² And dried to form an undercoat layer. On the other hand, using a hollow-fiber membrane deaerator with a casing sealed in a cartridge (Superphobic (registered trademark) manufactured by MEMBRANA, surface area of the outer wall of the hollow fiber membrane is 16 m ² ), the paint flow rate is an internal pressure of 0.04 bar. The thermal coloring layer coating and the protective layer coating were separately defoamed and / or degassed at 8 liters / minute. Further, the number of bubbles having a diameter of 200 μm or more in the decolored and / or degassed heat-sensitive color developing layer coating material and protective layer coating material was measured. Using this defoamed and / or degassed thermal coloring layer coating and protective layer coating, a simultaneous multilayer curtain was applied onto the undercoat layer by a slide curtain coater, and a thermal coloring layer of 4.0 g / kg in dry weight was applied. m ^2, so that the protective layer 2.8 g / ^{m 2,} to form a thermal color-forming layer and a protective layer in this order by coating and drying the coating speed 350 meters / minute. Thereafter, the surface of the protective layer was supercalendered to obtain a heat-sensitive recording material having a surface smoothness of 1000 to 4000 seconds using a Wangken type smoothness meter.

Example 2
A thermosensitive recording material was obtained in the same manner as in Example 1 except that the hollow fiber membrane defoaming device was used so that the casing was an open tank type in the production of the thermosensitive recording material of Example 1.

Example 3
In the production of the thermal recording material of Example 2, the content of sodium dioctylsulfosuccinate added to the total solid content of 100 parts by mass of the defoamed and / or degassed thermal color developing layer coating was 0.3. Other than adding 2% aqueous solution of dioctyl sulfosuccinate sodium salt to the thermal color developing layer coating continuously with an in-line mixer provided in the line through which the thermal color developing layer coating flows in front of the curtain coater head so as to be part by mass Obtained a heat-sensitive recording material in the same manner as in Example 2.

Comparative Example 1
In the production of the heat-sensitive recording material of Example 1, the absolute pressure of the casing was changed using a vacuum centrifugal plate flow-down type defoamer (VE-6 manufactured by Flymakoruma) instead of the cartridge-sealed hollow fiber membrane defoaming device. A heat-sensitive recording material was obtained in the same manner as in Example 1 except that defoaming and / or degassing treatment was performed at an internal pressure of 0.025 bar.

Comparative Example 2
A thermosensitive recording material was obtained in the same manner as in Comparative Example 1 except that water was added so that the solid content concentration was 22% instead of 31% in the preparation of the thermosensitive coloring layer coating material of Comparative Example 1.

Comparative Example 3
In the production of the thermal recording material of Example 1, the casing was not subjected to defoaming and / or degassing treatment using a cartridge-enclosed hollow fiber membrane defoaming device (SuperPhobic (registered trademark) manufactured by MEMBRANA). Obtained a heat-sensitive recording material by the same method as in Example 1.

  The following evaluation was performed about the coating material and heat-sensitive recording material which were obtained in this way. The results were as shown in Table 1.

(Viscosity of paint)
The paint before defoaming was measured at a liquid temperature of 25 ° C. using a Brookfield B-type viscometer DV3ULTRA.

(Number of bubbles)
For Examples 1 to 3 and Comparative Examples 1 and 2, for the paint after defoaming treatment, for Comparative Example 3 for the undefoamed paint, an ultrasonic bubble detector (Pulsar Receiver: TP manufactured by Genes Co., Ltd.) -1001, and an ultrasonic vibrator manufactured by Kureha Co., Ltd .: KES-19R53F), an ultrasonic wave having a center frequency of about 7.5 MHz is irradiated, and the number of bubbles (pieces / liter) having a diameter of 200 μm or more is disclosed in Japanese Patent No. 4561336. Using the apparatus described in paragraph [0025] of the No. 5, measurement was performed in accordance with the procedure described in paragraph [0037].

(Ethanol barrier property)
Using a commercially available oil-based marker ink (manufactured by Zebra: Zebra Mackie Pen Yellow), the degree of color development on the surface of the thermal recording surface coated with ink was visually observed and evaluated according to the following criteria.
○: No color development.
Δ: Slight point-like color development, but no problem in practical use.
X: Color development is remarkable, which is a practical problem.

(Bubble defect)
Using a hot air dryer, the surface was colored at a temperature of 120 ° C. in the dryer, and the colored surface (baked surface) was visually observed and evaluated according to the following criteria.
○: No bubble defect occurs in defoaming and / or degassing treatment for 12 hours or more continuously.
(Triangle | delta): A bubble defect does not generate | occur | produce in the degassing | defoaming and / or deaeration process for continuous 6 hours or more and less than 12 hours.
X: The occurrence of bubble defects is remarkable from the beginning.

(Curtain film cracking)
The curtain film was visually observed at the time of coating and evaluated by the following criteria by checking with a defect detector.
○: Curtain film cracking does not occur in the defoaming and / or degassing treatment for 24 hours or longer.
(Triangle | delta): Curtain film | membrane crack does not generate | occur | produce in the defoaming and / or deaeration process of continuous 12 hours or more and less than 24 hours.
X: Curtain film cracking frequently occurs from the beginning.

DESCRIPTION OF SYMBOLS 1 Hollow fiber membrane defoaming device 2 Hollow fiber 3a, 3b Support member 4 Tube 5 Wall 6 Passage 7 Paint 8 Slit 9 Foam 10 Dissolved gas 11 Hole 12 Cartridge 13 Exit 14 Container

Claims (12)

A method for producing a coated body comprising at least a coating layer on a support,
A step of defoaming and / or degassing using a hollow fiber membrane defoaming device and applying a paint having a Brookfield viscosity of 200 to 3000 mPa · s at 25 ° C. onto a support by curtain coating, slide coating or slot coating. The manufacturing method of the coating body containing. The plurality of coating layers of the coating layer having two or more coating layers, wherein the step of curtain coating, slide coating, or slot coating is a step of simultaneous multilayer coating using at least two layers of paint. The manufacturing method of the coating body as described in 2 .. A hollow fiber membrane defoaming device having a plurality of hollow fibers having pores on the surface whose inside is decompressed,
In the defoaming and / or degassing step, the paint is passed through a hollow fiber membrane defoaming device so that the paint and the outer wall of the hollow fiber are in contact with each other, and bubbles and / or dissolved gas present in the paint is passed through the hollow fiber. The manufacturing method of the coating body of Claim 1 or 2 which is the process of making it isolate | separate through the hole of the surface of this. The method for producing a coated body according to any one of claims 1 to 3, wherein the pressure loss of the hollow fiber membrane defoaming device at the time of defoaming and / or degassing is 6 bar or less. The method for producing a coated body according to any one of claims 1 to 4, wherein the step of obtaining a paint is a step of defoaming and / or degassing using a hollow fiber membrane defoaming device after preparing the paint. . The step of obtaining the coating is a step of mixing and preparing a plurality of dispersions or solutions used for preparing the coating after defoaming and / or degassing using a hollow fiber membrane defoaming device, The manufacturing method of the coating body in any one of Claims 1-5. The method for producing a coated body according to any one of claims 1 to 6, wherein the defoamed and / or degassed paint has 10 or less bubbles having a diameter of 200 µm or more per liter of paint. The method for producing a coated body according to any one of claims 1 to 7, wherein the coated body is a thermosensitive recording body, and the coating layer is a thermosensitive coloring layer and / or a protective layer. The coated body is a heat-sensitive recording material, the coated layer is formed of a plurality of coated layers of two or more layers, and at least two coated layers including at least a thermosensitive coloring layer are simultaneously formed on the support. The manufacturing method of the coating body in any one of Claims 2-8 apply | coated in multiple layers. The coated body is a thermal recording body, and the coated layer is (1) a thermal coloring layer / protective layer from the side close to the support.
(2) Undercoat layer / thermosensitive color developing layer / protective layer,
(3) thermosensitive coloring layer / first protective layer / second protective layer,
(4) Undercoat layer / thermosensitive color developing layer / first protective layer / second protective layer,
(5) Undercoat layer / first thermosensitive coloring layer / second thermosensitive coloring layer / protective layer, or (6) undercoat layer / first thermosensitive coloring layer / intermediate layer / second thermosensitive coloring layer / protective layer. The manufacturing method of the coating body of Claim 8 or 9. The defoamed and / or degassed coating material is a coating material that forms the outermost protective layer, and the number of bubbles having a diameter of 200 µm or more is less than 3 per liter of the coating material. The manufacturing method of the coating body of description. A coated body having a coating layer obtained by coating a support having a Brookfield viscosity at 25 ° C. of 200 to 3000 mPa · s and a foam of 200 μm or more in diameter of 10 or less paint per liter of paint. .