JP2022055892A - Coating device and ink jet printer - Google Patents

Abstract

To provide a coating device and an ink jet printer which can secure evenness of a coating liquid on a base material from a timing of coating the base material.SOLUTION: A coating device includes: a discharge port (22) which discharges a coating liquid and has a long plane shape in which the length in a first direction is longer than the length in a second direction orthogonal to the first direction; a liquid flow channel (24) which is connected to the discharge port and has a length in the first direction corresponding to the length of the discharge port in the first direction; and a liquid storage part (26) in which the coating liquid is stored and which is connected to the liquid flow channel and has a supply port of the coating liquid formed on a one end side in the first direction. The liquid flow channel has a structure in which flow channel resistance in a position on one end (26A) side in the first direction is larger than flow channel resistance in a position on the other end (26B) side in the first direction.SELECTED DRAWING: Figure 3

Description

The present invention relates to a coating device and an inkjet printing device.

In order to realize high-quality inkjet printing, it is necessary to apply an acidic undercoat liquid to the substrate thinly and evenly for the purpose of fixing the dots of the water-based ink to the substrate for a short period of time. The non-uniformity of the undercoat liquid applied to the substrate can induce uneven density and contribute to the discomfort in the image quality of the printed image.

On the other hand, in recent years, the improvement of productivity has been demanded by users, and the suitability for high-speed application in the application of the undercoat liquid is also important. That is, the application of the undercoat liquid is required to achieve both uniform application of a thin layer and high-speed application. The high-speed coating here means a coating in which a relatively short period is applied and a continuous coating in which a relatively short cycle is applied.

In the gravure method coating such as gravure coater and kiss reverse coater, the excess coating liquid applied to the gravure roll is removed by using a blade or the like, so that the gravure roll immediately before the coating liquid is applied to the substrate is used. , The liquid is present only in the cells, grooves, etc., and the coating liquid is in a discontinuous state. Then, it is difficult to reduce the thickness of the coating liquid applied to the substrate and secure uniform coating.

In the bar coating type coating device, the excess coating liquid of the bar coater is not scraped off, so that the bar coater immediately before the coating liquid is applied to the substrate is in a state where the coating liquid is continuous. Immediately after being applied to the substrate, the coating liquid is rapidly leveled, and a coating film having a certain degree of uniformity can be formed even in high-speed coating.

Patent Document 1 describes a coating device to which the bar coating method is applied. The device described in the same document is provided with a coating bar in which a plurality of spiral grooves are formed on the surface of a cylindrical bar, the web as a member to be coated is continuously run, the coating bar is brought into contact with the web, and the coating liquid is applied. Applied to the web.

Patent Document 2 describes a coating device including a wire bar in which a wire is wound around a core metal. In the device described in the same document, the rotated wire bar is brought into contact with the traveling web, and the coating liquid is applied from the wire bar to the web.

Patent Document 3 describes a coating device for applying an undercoat liquid to an intermediate transfer roller provided in an inkjet printing device. The coating apparatus described in the same document includes a squeeze roller as a member for controlling the thickness of the undercoat liquid applied to the intermediate transfer roller uniformly and with high accuracy.

Japanese Unexamined Patent Publication No. 2009-226371 Japanese Unexamined Patent Publication No. 2006-82059 JP-A-2015-139971

However, in the bar coating method, the coating liquid applied to the bar coater has a certain distribution, and it is difficult to obtain the uniformity of the coating liquid on the base material from the timing when the coating liquid is applied to the base material. The apparatus described in Patent Document 1 and the apparatus described in Patent Document 2 have the problem of the bar coating method described above.

The apparatus described in Patent Document 3 includes a squeeze roller as a member for realizing coating with less uneven coating and a thin film thickness. The document describes that the runout accuracy is preferably 10 micrometers or less because high precision component accuracy is required.

However, when the liquid is applied to a film-like base material having relatively low rigidity, the film thickness of the coating liquid on the base material is, for example, a thin film of several micrometers or less and a constant film thickness uniformity. Securing is not realistic. Further, due to deterioration such as wear of the squeeze roller, the accuracy of the film thickness of the coating film is impaired, and there is a concern about the stability of the coating.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a coating apparatus and an inkjet printing apparatus capable of ensuring the uniformity of a coating liquid on a substrate from the timing of coating on the substrate. ..

In order to achieve the above object, the following aspects of the invention are provided.

The coating apparatus according to the present disclosure is a discharge port for discharging a coating liquid, and has a planar shape whose length in the first direction is longer than the length in the second direction orthogonal to the first direction, and a discharge port. A liquid flow path that is connected and has a length in the first direction corresponding to the length of the discharge port in the first direction, and a liquid storage unit that stores the coating liquid and is connected to the liquid flow path. The liquid flow path is provided with a liquid storage portion in which a coating liquid supply port is formed on the side of one end in the first direction, and the liquid flow path has a flow path resistance at a position on the side of one end in the first direction. Is a coating device having a structure larger than the flow path resistance at the position on the side of the other end in the first direction.

According to the coating apparatus according to the present disclosure, the position on the side of one end of the liquid flow path in the first direction has a larger flow path resistance than the position on the side of the other end in the first direction. As a result, the distribution of the pressure applied to the coating liquid in the first direction is made uniform, and the coating liquid can be uniformly discharged from the discharge port in the first direction. As a result, the uniformity of the coating liquid can be ensured from the timing of application to the substrate.

As an example of changing the flow path resistance of the liquid flow path, the mode of changing the length in the third direction, the mode of changing the cross-sectional area of the surface intersecting the third direction of the liquid flow path, and the surface roughness inside the liquid flow path are described. A mode of change can be mentioned.

In the coating device according to another aspect, a width adjusting device for adjusting the length in the second direction is provided for each of a plurality of regions along the first direction of the discharge port.

According to this aspect, the length in the second direction is adjusted for each region along the first direction in the discharge port. Thereby, the discharge amount of the coating liquid in the first direction can be made uniform.

The coating apparatus according to another aspect includes a thickness measuring apparatus for measuring the thickness of the coating liquid applied to the substrate, and one or more processors, and the processor has a width according to the measurement result of the thickness measuring apparatus. Operate the adjusting device to adjust the length of the discharge port in the second direction.

According to such an embodiment, the length of the discharge port in the second direction can be adjusted for each region of the discharge port according to the measurement result of the thickness of the coating liquid applied to the substrate. As a result, the distribution of the discharge amount in the first direction of the coating liquid discharged from the discharge port can be suppressed.

The coating device according to another aspect includes a coating liquid removing device that removes a part of the coating liquid coated on the substrate.

According to such an embodiment, the excess of the coating liquid applied to the substrate is removed. As a result, it is possible to promote the leveling of the coating liquid applied to the base material in a large amount, and the coating liquid applied to the base material can be thinned.

In the coating device according to another aspect, a recovery device for collecting the coating liquid discharged from the discharge port is provided.

According to this aspect, the surplus of the coating liquid discharged from the discharge port is recovered. As a result, the thickening of the coating liquid applied to the substrate is suppressed.

The coating device according to another aspect includes a transport device for transporting the base material in a base material transport direction parallel to the second direction at the position of the discharge port.

According to this aspect, the coating amount of the coating liquid can be made uniform in the width direction of the substrate orthogonal to the transport direction of the substrate.

In the coating apparatus according to the other aspect, the discharge port has a length in the first direction corresponding to the total length in the first direction of the region to which the coating liquid of the base material is applied.

According to such an aspect, the coating amount of the coating liquid can be made uniform with respect to the total length in the width direction of the base material.

In the coating apparatus according to the other aspect, the coating liquid has a viscosity of 0.5 millipascals or more and 5.0 millipascals or less.

According to such an embodiment, favorable fluidity of the coating liquid applied to the substrate is ensured, and leveling is promoted.

In the coating apparatus according to another aspect, the coating liquid has a surface tension of 30 millinewtons per meter or more and 45 millinewtons per meter or less.

According to such an embodiment, the generation of streaks in the coating liquid on the base material can be suppressed, and a certain wettability of the coating liquid on the base material can be ensured.

In the coating apparatus according to another aspect, the surface of the base material to which the coating liquid is applied has a surface tension of 30 millinewtons per meter or more and 60 millinewtons per meter or less.

According to such an embodiment, the repelling of the coating liquid applied to the substrate can be suppressed, and the variation in the thickness of the coating liquid can be suppressed.

In the coating apparatus according to another embodiment, when the surface tension of the surface of the base material to which the coating liquid is applied is γ _s and the surface tension of the coating liquid is γ _pc , γ _s −γ _pc ≧ 5.0 millinewtons. Fill every meter.

According to such an embodiment, the adhesion between the base material and the coating liquid can be ensured.

The inkjet printing apparatus according to the present disclosure includes a coating device that applies a coating liquid that agglomerates ink to a printing medium, and an inkjet head that ejects ink to a printing medium to which the coating liquid is applied. A discharge port for discharging liquid, a discharge port having a planar shape whose length in the first direction is longer than the length in the second direction orthogonal to the first direction, and a liquid flow path connected to the discharge port. A liquid flow path having a length in the first direction corresponding to the length of the discharge port in the first direction, and a liquid storage unit in which the coating liquid is stored and connected to the liquid flow path, and is one of the first directions. The liquid flow path is provided with a liquid storage portion in which a supply port for a coating liquid is formed on the end side, and the liquid flow path has a flow path resistance at a position on the side of one end in the first direction and the other end in the first direction. It is an ink jet printing apparatus having a structure larger than the flow path resistance at the position on the side of.

According to the inkjet printing apparatus according to the present disclosure, it is possible to obtain the same operation and effect as the coating apparatus according to the present disclosure. The constituent requirements of the coating apparatus according to the other embodiment may be applied to the constituent requirements of the inkjet printing apparatus according to the other embodiment.

According to the present invention, the position on the side of one end of the liquid flow path in the first direction has a greater flow path resistance than the position on the side of the other end in the first direction. As a result, the distribution of the pressure applied to the coating liquid in the first direction is made uniform, and the coating liquid can be uniformly discharged from the discharge port in the first direction. As a result, the uniformity of the coating liquid can be ensured from the timing of application to the substrate.

FIG. 1 is an overall configuration diagram of a coating device according to the first embodiment. FIG. 2 is a perspective view of the die block shown in FIG. FIG. 3 is a schematic diagram showing the internal structure of the die block shown in FIG. FIG. 4 is a functional block diagram of the coating device shown in FIG. FIG. 5 is an overall configuration diagram of the coating device according to the second embodiment. FIG. 6 is a schematic view of a width adjusting device applied to the die block shown in FIG. FIG. 7 is a functional block diagram of the coating device shown in FIG. FIG. 8 is an overall configuration diagram of the coating device according to the third embodiment. FIG. 9 is a functional block diagram of the coating device shown in FIG. FIG. 10 is an overall configuration diagram of the coating device according to the fourth embodiment. FIG. 11 is a table for explaining the difference in effect from other coating methods. FIG. 12 is an explanatory diagram illustrating a difference in performance from other coating methods. FIG. 13 is a table showing the results of the evaluation test of the surface tension of the base material and the coating liquid. FIG. 14 is an overall configuration diagram of an inkjet printing apparatus to which the coating apparatus according to the embodiment is applied.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, the same components are designated by the same reference numerals, and duplicate description will be omitted as appropriate.

[Applying device according to the first embodiment]
〔overall structure〕
FIG. 1 is an overall configuration diagram of a coating device according to the first embodiment. The coating device 10 shown in the figure includes a die coater 12 for discharging the coating liquid and a transport device 14 for transporting the base material S. The coating device 10 supplies the coating liquid from the liquid pool 26 to the slit 22 formed in the die block 20 of the die coater 12 through the slot 24, brings the base material S into contact with the slit 22, and applies the coating liquid to the base material S. Is applied.

The contact between the base material S and the slit 22 includes a state in which the coating liquid is discharged from the slit 22 and the coating liquid is present between the base material S and the slit 22.

[Example of die coater configuration]
The die coater 12 includes a die block 20, a base 40, and a coating liquid supply device 50. The die block 20 is formed with a slit 22, a slot 24, a liquid pool 26, and a liquid supply port 28.

The planar shape of the slit 22 has a rectangular shape in which the length in the first direction is longer than the length in the second direction. The slit 22 is connected to one end of the slot 24. The length of the slot 24 in the first direction corresponds to the length of the slit 22 in the first direction.

The other end of slot 24 is connected to the liquid pool 26. A liquid supply port 28 is formed at one end of the liquid pool 26 in the first direction. The first direction is a direction penetrating the paper surface of FIG. 1 and represents a longitudinal direction of the liquid pool 26. The first direction is shown by using the reference numeral x shown in FIG. 2 and the like.

The coating liquid supplied from the liquid supply port 28 is stored in the liquid pool 26. The coating liquid stored in the liquid pool 26 is supplied to the slit 22 via the slot 24 and discharged from the slit 22.

The bottom surface 20A of the die block 20 is supported by the base 40. The base 40 includes a mechanism for adjusting the levelness representing the angle with respect to the horizontal plane in the substrate transport direction.

The levelness of the base 40 is adjusted, the angle between the base material S and the opening surface of the slit 22 is adjusted, and the slit 22 is brought into contact with the base material S in parallel. Thereby, it is possible to suppress the variation in the lap width and the variation in the pressure generated between the coating liquid and the substrate S due to the uneven contact of the substrate S with respect to the slit 22. The lap width is the length in the second direction of the region where the base material S is in contact with the tip of the die block 20 in which the slit 22 is formed. The reference numeral y is used to indicate the second direction.

Maintenance such as cleaning and parts replacement is regularly carried out on the die block 20. When performing maintenance on the die block 20, the die block 20 is removed from the base 40. Further, the die block 20 that has undergone maintenance is attached to the base 40.

That is, the base 40 is configured so that the die block 20 can be attached and detached. Further, the base 40 adopts a structure having high reproducibility of the installation position of the die block 20. This makes it possible to improve the maintenance efficiency of the die block 20 and maintain the coating performance before and after the maintenance.

The coating liquid supply device 50 includes a coating liquid flow path 52, a liquid feeding pump 54, and a coating liquid tank 56. The coating liquid stored in the coating liquid tank 56 is supplied to the liquid pool 26 of the die block 20 via the liquid feeding pump 54 and the coating liquid flow path 52.

The die coater 12 can control the amount of liquid to be sent to the liquid pool 26 to precisely control the amount of the coating liquid to be discharged from the slit 22. The liquid feed pump 54 preferably has a method in which pulsation during liquid feed is suppressed.

The slit 22 described in the embodiment is an example of a discharge port. The slot 24 described in the embodiment is an example of a liquid flow path. The liquid pool 26 described in the embodiment is an example of a liquid storage unit.

[Configuration example of transport device]
The transport device 14 includes a transport mechanism 60 that transports the base material S in the transport direction of the base material S. In the following description, the transport direction of the base material S may be described as the base material transport direction.

FIG. 1 illustrates, as an example of the base material S, a continuum to which roll-to-roll transfer is applied. In FIG. 1, the roll on the feeding side of the base material S and the roll on the winding side of the base material S are not shown.

The transport mechanism 60 includes a first lift roller 62, a second lift roller 64, and a drive roller 66. A motor is connected to the drive roller 66. The drive roller 66 rotates according to the operation of the motor, supports the base material S, and conveys the base material S.

The transport mechanism 60 includes one or more support rollers. The support roller is arranged at an arbitrary position in the base material transport path in the transport mechanism 60, and supports the base material S in the base material transport path. The illustration of the support roller is omitted.

The first lift roller 62 and the second lift roller 64 support the base material S in the region where the coating liquid is applied from the die block 20 to the base material S, and the large lap angle of the base material S with respect to the slit 22. The distance between the base material S and the slit 22 is adjusted.

The first lift roller 62 and the second lift roller 64 are configured to be individually movable. The arrow line attached to the first lift roller 62 is the moving direction of the first lift roller 62, and represents the direction of the pressing force applied to the base material S by using the first lift roller 62. The first lift roller 62 may move in the second and third directions.

The arrow line attached to the second lift roller 64 is the moving direction of the second lift roller 64, and represents the direction of the pressing force applied to the base material S by using the second lift roller 64. The second lift roller 64 may move in the second and third directions. The reference numeral z is used to indicate the third direction.

The size of the lap angle of the base material S with respect to the slit 22 can be adjusted individually on the primary side and the secondary side. The same applies to the distance between the base material S and the slit 22. Here, the primary side is the upstream side of the slit 22 in the substrate transport direction, and is the left side of the slit 22 in FIG. The secondary side is the downstream side of the slit 22 in the substrate transport direction, and is the right side of the slit 22 in the figure.

The lap angle of the base material S with respect to the slit 22 is preferably in the range of 2 degrees or more and 30 degrees or less. When the lap angle of the base material S with respect to the slit 22 is less than 2 degrees, the contact surface between the slit 22 and the base material S is not stable, and uneven coating of the coating liquid on the base material S may occur.

Further, when the lap angle of the base material S with respect to the slit 22 exceeds 30 degrees, stepwise coating unevenness of the coating liquid in the base material S may occur due to the frictional force generated between the slit 22 and the base material S. .. A more preferable range of the lap angle of the base material S with respect to the slit 22 is 5 degrees or more and 20 degrees or less.

The tension applied to the base material S when the base material S is conveyed is preferably 10 newtons or more and 200 newtons or less per meter. When the tension applied to the base material S is less than 20 Newtons per meter, wrinkles may occur on the base material S, and uneven coating of the coating liquid may occur.

On the other hand, when the tension applied to the base material S exceeds 200 Newtons per meter, step unevenness of the coating liquid due to the frictional force between the tip portion of the die block 20 and the base material S may occur.

The transport device 14 includes an elevating device 68. The elevating device 68 moves the transport mechanism 60 in the third direction to adjust the distance between the base material S and the die block 20 in the third direction. When the first direction and the second direction are parallel to the horizontal plane, the third direction is the vertical vertical direction.

When the coating liquid is applied to the base material S, the elevating device 68 lowers the transport mechanism 60 to press the base material S against the tip of the die block 20. On the other hand, when the coating liquid is not applied to the base material S, the elevating device 68 raises the transport mechanism 60 to separate the base material S from the tip of the die block 20.

[Die block configuration example]
FIG. 2 is a perspective view of the die block shown in FIG. The slot portion 30 shown in FIG. 2 is composed of a first block 32 and a second block 34. The slot portion 30 may adopt a tip lip shape in which a step is provided between the flat portion 32A of the first block 32 and the flat portion 34A of the second block 34.

The slot portion 30 is configured so that the length of the flat portion 32A of the first block 32 in the second direction and the length of the flat portion 34A of the second block 34 in the second direction can be adjusted according to the type of the coating liquid. You may.

The slot portion 30 is configured so that the inclination of the inclined portion 32B of the first block 32 with respect to the third direction and the inclination of the inclined portion 34B of the second block 34 with respect to the third direction can be adjusted according to the type of the coating liquid. You may.

As the material of the die block 20, a metal material such as stainless steel is applied. From the viewpoint of corrosiveness to the coating liquid, SUS304, SUS316L and the like are preferable as the stainless steel. SUS is an abbreviation for Steel Use Stainless.

As the material of the die block 20, it is preferable to use a metal that is harder than stainless steel from the viewpoint of ensuring the accuracy of the tip lip shape. Examples of metals that are harder than stainless steel include cemented carbide in which titanium and tungsten are bonded to carbide crystals.

The liquid pool 26 formed in the die block 20 has a liquid supply port 28 formed at one end in the first direction. The liquid supply port 28 is connected to the coating liquid flow path 52 shown in FIG. Depending on the operation of the liquid feed pump 54, the coating liquid is supplied from the coating liquid tank 56 to the liquid supply port 28 via the liquid feeding pump 54 and the coating liquid flow path 52. In FIG. 2, the reference numeral of the liquid pool 26 is not shown.

The coating liquid supplied to the liquid pool 26 via the liquid supply port 28 is supplied to the slit 22 via the slot 24 according to the operation of the liquid feeding pump 54, and is applied from the slit 22 to the base material S. Since the entire amount of the coating liquid sent to the liquid pool 26 is applied to the base material S, the capacity of the liquid pool 26 can be smaller than that of a method of scraping the coating liquid such as a gravure coating method. The capacity of the liquid pool 26 is synonymous with the volume of the liquid pool 26 and the volume of the liquid pool 26.

Further, the coating liquid supplied to the liquid pool 26 does not come into contact with air other than the slit 22, and there is little need to consider the volatilization of the solvent.

[Slot structure example]
FIG. 3 is a schematic diagram showing the internal structure of the die block shown in FIG. The schematic diagram shown in the figure is a cross section of the die block 20, and represents a cross section that passes through the inside of the slit 22 and the slot 24 and is parallel to the first direction and the third direction. The arrow line shown in the figure indicates the supply direction of the coating liquid.

The slot 24 formed inside the die block 20 has a longer length in the third direction at the position on the liquid supply side in the first direction as compared with the position on the anti-liquid supply side in the first direction. For example, the length LA along the third direction at one end of the slot 24, which is the end 26A on the side of the liquid supply port 28 in the first direction of the slot 24, is the liquid supply port 28 in the first direction of the slot 24. It is longer than the length LB along the third direction at the other end of the slot 24, which is the opposite end 26B.

FIG. 3 has a structure in which the flow path length in the third direction becomes longer from the end on the supply side in the first direction to the end on the non-supply side in the first direction, and the supply is supplied from the non-supply side in the first direction. An example of the structure of the slot 24 in which the flow path resistance in the third direction increases toward the side is shown.

The end of the slot 24 on the supply side in the first direction is the end 26A on the side of the liquid supply port 28 in the first direction. The opposite end of the slot 24 in the first direction is the opposite end 26B of the liquid supply port 28 in the first direction.

When the flow path resistance in the third direction is the same for the entire length of the slot 24 in the first direction, the position on the non-supply side in the first direction causes a large pressure loss as compared with the position on the supply side. Then, the discharge amount of the slit 22 at the position on the non-supply side in the first direction is relatively smaller than the position on the supply side.

On the other hand, in the slot 24 shown in FIG. 3, the generation of a difference in pressure loss in the first direction is suppressed, and the discharge amount of the coating liquid discharged from the slit 22 in the first direction is made uniform.

In the present embodiment, an embodiment in which the flow path resistance in the third direction of the slot 24 is continuously changed in the first direction is exemplified, but the flow path resistance in the third direction of the slot 24 is changed stepwise in the first direction. May be good.

As an embodiment for changing the flow path resistance in the third direction in the slot 24, the cross-sectional area of the cross section of the slot 24 intersecting the third direction, such as the cross section of the slot 24 parallel to the first direction and the second direction, may be changed. ..

Further, as another aspect of changing the flow path resistance in the third direction in the slot 24, the surface roughness of the inner wall surface of the slot 24 may be changed. The surface roughness of the inner wall surface of the slot 24 may be changed by changing the surface treatment or changing the material. The slot 24 may change the flow path resistance value by appropriately using two or more of the flow path length, the cross-sectional area, and the surface roughness. In FIG. 3, the reference numeral y representing the second direction is not shown.

[Functional block of coating device]
FIG. 4 is a functional block diagram of the coating device shown in FIG. The coating device 10 includes one or more processors 100 and one or more memories 102.

The processor 100 includes a transport control unit 110, an elevating control unit 112, and a liquid feed control unit 114. Each part provided in the processor 100 corresponds to the function of the coating device 10 realized by using the processor 100.

The transfer control unit 110 transmits a command signal to the transfer device 14, controls the operation of the transfer device 14, and controls the transfer of the base material S. The transfer control unit 110 controls the operation of the motor connected to the drive roller 66 provided in the transfer device 14. The transport control unit 110 controls the operation of the motor connected to the lift roller moving mechanism that moves the first lift roller 62 and the second lift roller 64. Further, the transport control unit 110 controls the feeding of the base material S and the winding of the base material S.

The elevating control unit 112 transmits a command signal to the elevating device 68 to control the operation of the elevating device 68. The elevating control unit 112 lowers the transport mechanism 60 from the retracted position and moves the transport mechanism 60 to the coating position at the start timing of the coating period of the coating liquid. The elevating control unit 112 raises the transport mechanism 60 from the coating position and moves the transport mechanism 60 to the retracted position at the end timing of the coating period of the coating liquid.

The liquid feed control unit 114 transmits a command signal to the liquid feed pump 54 to control the operation of the liquid feed pump 54. The liquid feed control unit 114 controls the liquid feed amount of the coating liquid sent from the liquid feed pump 54 to the die block 20.

The memory 102 stores various programs executed by the processor 100 and control parameters applied to various controls of the coating device 10. Various types of data may be stored in the memory 102. The memory 102 may be applied to an area of computation performed using the processor 100.

The coating device 10 includes a display device 120 and an input device 130. The display device 120 displays various information applied to the coating device 10 based on the display signal transmitted from the display driver 122.

A keyboard, mouse, and the like are applied to the input device 130. The input device 130 transmits an input signal according to the user's operation to the processor 100. The processor 100 performs various processes according to the input signal.

The coating device 10 includes an input / output interface 140. Various communication standards such as USB (Universal Serial Bus) can be applied to the input / output interface 140. An input / output interface 140 may be provided for each of the plurality of communication standards.

[Hardware configuration of various processing units and various control units]
Various processors can be applied to the hardware of the processing unit that performs various processes. The processing unit may be called a processing unit. Various processors include a CPU (Central Processing Unit), a PLD (Programmable Logic Device), an ASIC (Application Specific Integrated Circuit), and the like.

The CPU is a general-purpose processor that executes a program and functions as various processing units. The PLD is a processor whose circuit configuration can be changed after manufacturing. An example of PLD is FPGA (Field Programmable Gate Array). An ASIC is a dedicated electrical circuit having a circuit configuration specifically designed to perform a particular process.

One processing unit may be composed of one of these various processors, or may be composed of two or more processors of the same type or different types. For example, one processing unit may be configured by using a plurality of FPGAs and the like. One processing unit may be configured by combining one or more FPGAs and one or more CPUs.

Further, a plurality of processing units may be configured by using one processor. As an example of configuring a plurality of processing units using one processor, there is a form in which one processor is configured by combining one or more CPUs and software, and one processor functions as a plurality of processing units. Such a form is represented by a computer such as a client terminal device and a server device.

As another configuration example. An example is a mode in which a processor that realizes the functions of the entire system including a plurality of processing units by using one IC chip is used. Such a form is typified by a system on chip and the like. IC is an abbreviation for Integrated Circuit. Further, the system on chip may be described as SoC by using the abbreviation of System On Chip.

As described above, the various processing units are configured by using one or more of the above-mentioned various processors as a hardware-like structure. Further, the hardware-like structure of various processors is, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

[Operation and effect of the coating device according to the first embodiment]
According to the coating device 10 according to the first embodiment, the following effects can be obtained.

[1]
In the slot 24, the flow path resistance in the third direction is larger at the position on the supply side in the first direction than at the position on the non-supply side in the first direction. As a result, the discharge amount of the coating liquid discharged from the slit 22 in the first direction is made uniform.

[2]
The slot 24 has a longer flow path length in the third direction at the position on the supply side in the first direction than at the position on the non-supply side in the first direction. As a result, the discharge amount of the coating liquid discharged from the slit 22 in the first direction is made uniform.

[3]
In the slot 24, the flow path resistance in the third direction continuously increases from the end on the non-supply side in the first direction to the end on the supply side. As a result, unevenness in the local discharge amount of the coating liquid discharged from the slit 22 is suppressed in the first direction.

[Applying device according to the second embodiment]
〔overall structure〕
FIG. 5 is an overall configuration diagram of the coating device according to the second embodiment. The coating device 200 shown in the figure includes a film thickness meter 202 that detects the thickness of the coating liquid coated on the base material S. The film thickness meter 202 is arranged at a position on the downstream side of the die block 210 in the substrate transport direction.

The film thickness meter 202 measures the thickness of the coating liquid at a plurality of positions of the base material S in the first direction. The coating device 200 can detect the distribution of the thickness of the coating liquid in the first direction according to the measurement result of the film thickness meter 202. The film thickness meter 202 may be a contact method in which the thickness of the coating liquid is measured by contacting the coating liquid, or a non-contact method in which the thickness of the coating liquid is measured in a non-contact manner with the coating liquid. The film thickness meter 202 described in the embodiment is an example of a thickness measuring device.

The die block 210 includes a width adjusting device for adjusting the width of the slit 22, which is the length of the slit 22 in the second direction. Although the width adjusting device is not shown in FIG. 5, the width adjusting device is shown in FIG. 6 using reference numeral 230.

[Die block configuration example]
FIG. 6 is a schematic view of a width adjusting device applied to the die block shown in FIG. The slit 22 defines a plurality of regions 22A in the first direction. The width adjusting device 230 adjusts the width of the slit 22 for each region 22A.

FIG. 6 illustrates an embodiment in which the position of the shielding plate 232 provided for each region 22A is moved in the second direction. The width adjusting device 230 includes a shielding plate moving mechanism connected to the shielding plate 232 and a shielding plate moving motor connected to the shielding plate moving mechanism. It should be noted that the illustration of the shielding plate moving mechanism and the shielding plate moving motor is omitted.

The width adjusting device 230 adjusts the position of the shielding plate 232 based on the measurement result of the film thickness meter 202. Due to the difference in the flow path length in the third direction for each position of the slot 24 in the first direction, there may be a difference in the discharge amount of the coating liquid discharged from the slit 22 in the first direction. The width adjusting device 230 adjusts the width of the slit 22 according to the difference in the discharge amount in the first direction. As a result, the difference in the discharge amount in the first direction is suppressed.

The width adjusting device 230 can acquire information on the thickness of the target coating liquid and adjust the width of the slit 22 based on the information on the thickness of the target coating liquid. The width adjusting device 230 can acquire the physical property value of the coating liquid and adjust the width of the slit 22 based on the physical property value of the coating liquid. The width adjustment range of the slit 22 applied to the width adjusting device 230 may be 5 micrometers or more and 500 micrometers or less.

[Functional block of coating device]
FIG. 7 is a functional block diagram of the coating device shown in FIG. The processor 101 included in the coating device 200 includes a width adjustment control unit 234 and an information acquisition unit 236. The width adjustment control unit 234 controls the width adjustment device 230. The width adjustment control unit 234 acquires the measurement result of the film thickness meter 202, operates the width adjustment device 230 according to the measurement result, and adjusts the width of the slit 22 for each region 22A.

The processor 101 displays the measurement result of the film thickness meter 202 on the display device 120, and the width adjusting device according to the width of the slit 22 input by the user who saw the measurement result of the film thickness meter 202 using the input device 130. 230 may be controlled.

The information acquisition unit 236 acquires information such as information on the thickness of the target coating liquid and information on the physical property values of the coating liquid. The width adjustment control unit 234 controls the width adjustment device 230 based on various information acquired by using the information acquisition unit 236.

[Operation and effect of the coating device according to the second embodiment]
According to the coating device 200 according to the second embodiment, the following effects can be obtained.

[1]
The width of the slit 22 is adjusted for each region 22A defined in the slit 22 in the first direction. Thereby, the distribution of the coating amount in the first direction of the coating liquid applied to the base material S can be suppressed.

[2]
A film thickness meter 202 for measuring the thickness of the coating liquid applied to the base material S is provided, and the film thickness meter 202 measures the thickness of the coating liquid at a plurality of positions in the first direction. The measurement result of the film thickness meter 202 is transmitted to the width adjustment control unit 234. As a result, the width adjustment control unit 234 can adjust the width of the slit 22 based on the measurement result of the film thickness meter 202.

[3]
An information acquisition unit 236 for acquiring information on the thickness of the target coating liquid is provided. As a result, the width adjustment control unit 234 can adjust the width of the slit 22 based on the information on the thickness of the target coating liquid.

[4]
An information acquisition unit 236 for acquiring information on the physical property values of the coating liquid is provided. As a result, the width adjustment control unit 234 can adjust the width of the slit 22 based on the information on the physical property values of the coating liquid.

[Applying device according to the third embodiment]
〔overall structure〕
FIG. 8 is an overall configuration diagram of the coating device according to the third embodiment. The coating device 300 shown in the figure includes a blade 302 that scrapes off the coating liquid applied to the base material S. The blade 302 is a position on the downstream side of the die block 20 in the substrate transport direction, and is arranged at a position on the upstream side of the film thickness meter 202 in the substrate transport direction.

The blade 302 has a length corresponding to the total length of the base material S in the first direction. The blade 302 may adopt a configuration in which a plurality of short blades are arranged side by side in the first direction over a length corresponding to the total length of the base material S.

The blade 302 is supported by using a blade position adjusting device that adjusts the position of the blade 302 in the third direction. In FIG. 8, the blade position adjusting device is not shown. The blade position adjusting device is illustrated in FIG. 9 using reference numeral 310.

The blade position adjusting device includes a blade position adjusting mechanism and a blade position adjusting motor. The blade position adjusting mechanism is connected to the blade position adjusting motor. The blade position adjustment mechanism and the blade position adjustment motor are not shown. The blade described in the embodiment is an example of a component of the coating liquid removing device.

[Functional block of coating device]
FIG. 9 is a functional block diagram of the coating device shown in FIG. The processor 103 provided in the coating device 300 includes a blade position adjustment control unit 312. The blade position adjustment control unit 312 acquires information on the thickness of the target coating liquid via the information acquisition unit 236, controls the operation of the blade position adjustment device 310, and the blade 302 according to the thickness of the target coating liquid. The position of can be adjusted.

The blade position adjustment control unit 312 can control the operation of the blade position adjustment device 310 to adjust the position of the blade 302 according to the thickness of the coating liquid on the base material S measured using the film thickness meter 202. ..

In the present embodiment, the blade is exemplified as a member for scraping the coating liquid applied to the base material S, but instead of the blade, another member such as a bar having a cylindrical shape and rotatably supported by the central axis. May be applied. In the embodiment in which the bar is applied, the rotation speed of the bar may be slower.

[Operation and effect of the coating device according to the third embodiment]
According to the coating device 300 according to the third embodiment, the following effects can be obtained.

[1]
A blade 302 for scraping the coating liquid applied to the base material S is provided. The blade 302 is arranged at a position on the downstream side of the die block 20 in the substrate transport direction. As a result, the coating liquid can be applied to the base material S in a larger amount than the specified coating amount to promote leveling, and then the coating liquid can be thinned according to the specified coating amount.

[2]
A film thickness meter 202 arranged at a position on the downstream side of the blade 302 in the substrate transport direction is provided. The position of the blade 302 in the third direction is adjusted according to the measurement result of the film thickness meter 202. This makes it possible to scrape the coating liquid using the blade 302 according to the information on the thickness of the coating liquid.

[Applying device according to the fourth embodiment]
FIG. 10 is an overall configuration diagram of the coating device according to the fourth embodiment. In FIG. 10, a part of the die block 420 is enlarged and shown. The die block 420 provided in the coating device 400 shown in the figure includes a recovery slit 423 and a recovery flow path 425.

The recovery slit 423 is formed at a position on the downstream side of the slit 22 in the substrate transport direction. One end of the recovery channel 425 is connected to the recovery slit 423. The other end of the recovery channel 425 is connected to the recovery liquid pool. The recovery liquid pool is connected to the recovery tank via a recovery channel and a recovery pump. It should be noted that the illustration of the liquid pool for recovery, the flow path for recovery, the pump for recovery, and the tank for recovery is omitted.

The die block 420 applies a coating liquid larger than the specified amount to the base material S, and recovers the excess coating liquid from the recovery slit 423. As a result, the coating liquid applied to the base material S is thinned. Further, the die block 420 can remove the air accompanying the coating liquid from the coating liquid when collecting the coating liquid. This makes it possible to reduce the thickness of the coating liquid applied to the base material S and eliminate air. The recovery slit 423 and the recovery flow path 425 described in the embodiment are examples of the components of the recovery device.

[Operation and effect of the coating device according to the fourth embodiment]
According to the coating apparatus 400 according to the fourth embodiment, the coating liquid is applied to the base material S in a larger amount than the specified amount, and the excess coating liquid in the base material S is recovered. This makes it possible to reduce the thickness of the coating liquid applied to the base material S and to eliminate the air accompanying the coating liquid.

[Comparison of coating devices with different coating methods]
FIG. 11 is a table for explaining the difference in effect from other coating methods. In FIG. 11, for each of the gravure method, the bar coater method, and the slot die coater method, the cell shape, the presence or absence of a liquid scraping member such as a blade, the liquid film state immediately before the typical transfer, and the liquid film state after the typical transfer are shown. Is shown.

FIG. 11 illustrates a direct method, a kiss reverse method, and an offset method as examples of the gravure method. Further, the slot die coater shown in FIG. 11 corresponds to the die coater method.

In order to achieve homogenization and thinning of the coating liquid applied to the base material S, the state of the liquid film on the coating member forms a three-dimensional continuous film immediately before the coating liquid is transferred to the base material S. Is preferable. In the continuous film immediately before transfer, the film thickness is constant in the width direction of the substrate and constant in the transport direction of the substrate, and the film thickness is high with respect to the coating liquid applied to the substrate S. , The film thickness coating suitability can be imparted uniformly.

Transcription here is synonymous with coating. The liquid film means a coating liquid in a thin film state. The film thickness means the thickness of the coating liquid. Further, the base material width direction is orthogonal to the base material transport direction and parallel to the coating surface of the base material S.

In the gravure method, the excess coating liquid of the measuring roller such as the gravure roll is scraped off by using a scraping member such as a blade, and the coating liquid is applied to the cell and the groove immediately before the coating liquid is applied to the base material S. It exists only inside, and the coating liquid is in a discontinuous state.

In the gravure method, the coating liquid in a discontinuous state is applied to the base material S. When high-speed coating is performed, the leveling of the coating liquid does not proceed sufficiently due to the physical characteristics of the coating liquid, and it is difficult to uniformly apply the coating liquid to the base material S.

Even in the gravure method in which a measuring roller to which a non-isolated diagonal groove is applied is applied, uniform application of the coating liquid to the substrate S is performed as in the embodiment provided with the gravure roll provided with the cell. It is difficult. Further, the gravure method is a method in which the scraping member is brought into contact with the measuring roller, and there is a problem that the coating amount is not stable due to the wear of the measuring roller.

In the bar coater method, a bar coater in which diagonal grooves are formed is used, but since excess coating liquid is not scraped off, the coating liquid is continuously applied immediately before the coating liquid is applied to the base material S. ing. Then, immediately after the coating liquid is applied to the base material S, the coating liquid is immediately leveled, and even when high-speed coating is performed, a certain degree of uniformity of the coating liquid can be ensured. However, it is difficult to ensure the uniformity of thickness in the coating liquid immediately after being applied to the base material S.

On the other hand, the die coater type coating device in which the coating liquid is discharged from the slit 22 and the coating liquid is directly applied to the base material S does not use a measuring roller in which cells, grooves and the like are formed, so that the base material is used. Immediately after the coating liquid is applied to S, the uniformity of the thickness in the coating liquid immediately after being applied to the base material S can be ensured.

In addition, leveling of the coating liquid itself is not required, and the realization of thinning and uniform thickness is due to the physical properties of the coating liquid such as surface tension, viscosity and volatility of the coating liquid, and the wettability of the base material S to the coating liquid. It doesn't depend on it.

FIG. 12 is an explanatory diagram illustrating a difference in performance from other coating methods. FIG. 12 illustrates the difference in performance between the gravure method, the bar coater method, and the die coater method using a graph format.

FIG. 12 shows a graph in which the uniformity of the thickness of the coating liquid is on the vertical axis and the thinning performance of the coating liquid and the suitability for high-speed coating are on the horizontal axis as the performance of each method. In FIG. 12, the uniformity of the thickness of the coating liquid is described as the uniformity of the film thickness. The thick film represents a state in which the thickness of the coating liquid is relatively thick, and the thin film represents a state in which the thickness of the coating liquid is relatively thin. In addition, the gravure coater corresponds to the gravure method, the bar coater corresponds to the bar coater method, and the slot die coater corresponds to the die coater method.

Compared with the bar coater method and the die coater method, it is difficult to secure the uniformity of the thickness of the coating liquid in the gravure method, and the thinning of the coating liquid and the suitability for high-speed coating are also inferior to the bar coater method and the die coater method. The bar coater method is superior to the gravure method in ensuring the uniformity of the thickness of the coating liquid, but the bar coater method is inferior in ensuring the uniformity of the thickness of the coating liquid as compared with the die coater method.

Further, the bar coater method is superior to the gravure method in thinning and high-speed coating suitability of the coating liquid, and the thin-filming and high-speed coating suitability of the coating liquid is about the same as that of the die coater method. On the other hand, the bar coater method is inferior in ensuring the uniformity of the thickness of the coating liquid as compared with the die coater method.

On the other hand, the die coater method is superior to the gravure method and the bar coater method in terms of the uniformity of the thickness of the coating liquid, the thinning of the coating liquid, and the suitability for high-speed coating.

[Coating liquid]
〔viscosity〕
The viscosity of the coating liquid is preferably in the range of 0.5 millipascals or more and 5.0 millipascals or less. If the viscosity of the coating liquid is less than 0.5 millipascals, the fluidity of the coating liquid is too high and the coating liquid may scatter. On the other hand, when the viscosity of the coating liquid exceeds 5.0 millipascal seconds, the fluidity of the coating liquid is too low, leveling becomes difficult, and the surface shape of the coating liquid may deteriorate.

〔surface tension〕
FIG. 13 is a table showing the results of the evaluation test of the surface tension of the base material and the coating liquid. In the evaluation test, the surface tension of the base material S and the surface tension of the coating liquid shown in the figure were evaluated. From the viewpoint of evaluation, the coating liquid repellent and the coating film thickness were uneven.

The surface of the base material S was subjected to a corona discharge treatment, and the surface tension γ _s was adjusted stepwise in the range of 27 millinewtons per meter to 65 millinewtons per meter. The surface tension γ _s of the base material S was measured by applying a measuring method based on the plastic-film and sheet wetting tension test method specified in ISO 8296.

The surface tension γ _pc of the coating liquid was adjusted stepwise in the range of 25 millinewtons per meter to 50 millinewtons per meter by adjusting the type and amount of the surfactant added. The surface tension γ _pc of the coating liquid was measured using a surface tension meter.

In the evaluation test of repellent, the state of repellent of the coating liquid applied to the base material S was visually observed. + In the evaluation result of repellent indicates non-occurrence of repellent. In addition,-in the evaluation result of repellent indicates the occurrence of repellent.

In the evaluation test of coating film thickness unevenness, the coating liquid was applied to the base material S having a length of 580 mm in the width direction, and the evaluation value E was calculated from the measured values _Mi at a plurality of film thickness measurement positions arranged in the width direction. .. The film thickness was measured at nine locations. Note that i is an integer from 1 to 9.

The evaluation value E was calculated by applying the following procedure. The average value _Mave of the measured values _Mi at all the measurement positions is calculated. Of all the measured values _Mi , the absolute value of the difference from the mean value M _ave | M _i -M _ave | is the maximum measured value M _max and the absolute value of the difference from the mean value M _{ave |} Calculate the measured value M _min that minimizes _ave |. The ratio (M _max −M _min ) / _Mave × 100 of the value obtained by subtracting the measured value M _min from the measured value M _max to the average value M _ave was calculated, and this was used as the evaluation value E.

A described in the evaluation column of coating film thickness unevenness shown in FIG. 13 represents a case where the evaluation value E is less than plus or minus 5%. B described in the same column represents a case where the evaluation value E is plus or minus 5% or more and less than 10%. C described in the same column represents a case where the evaluation value E is plus or minus 10% or more and less than 20%. The D described in the same column represents the case where the evaluation value E is plus or minus 20% or more.

Based on the above evaluation viewpoint, the preferable conditions for the surface tension of the base material S and the coating liquid are that the evaluation of the repellent of the coating liquid is + and the evaluation of the coating film thickness unevenness is A or B. Is the range of surface tension.

Specifically, the surface tension of the coating liquid is preferably in the range of 30 millinewtons per meter or more and 45 millinewtons per meter or less. When the surface tension of the coating liquid is less than 30 millinewtons per meter, streak-like coating unevenness may occur in the coating liquid coated on the base material S. On the other hand, when the surface tension of the coating liquid exceeds 45 millinewtons per meter, the wettability to the base material S may be insufficient.

Further, when the surface tension of the coating liquid is in the above range, the surface tension of the base material S is preferably in the range of 30 renewtons per meter or more and 60 millinewtons per meter or less. As a result, the coating liquid wets and spreads on the surface of the base material S, and the leveling of the coating liquid is promoted.

Further, regarding the coating device applied to the inkjet printing device and for applying the treatment liquid that reacts with the ink, the surface tension of the base material S and the surface of the coating liquid are obtained from the viewpoint of the adhesion of the ink to the base material S. Tension was evaluated.

In the evaluation test of the adhesion of the ink to the base material S, the base material S was set to OPP (Oriented Poly Propylene) and the thickness of the base material S was set to 20 micrometers. As a coating liquid, a coagulation treatment liquid that agglomerates the color material particles of the water-based ink was applied. The film thickness of the coating liquid was 1.5 micrometers. The film thickness of the coating liquid was measured using a non-contact film thickness meter.

The print resolution was set to 1200 dots per inch on the surface coated with the coating liquid of the base material, and ink of 6.0 picolitres per pixel on average was dropped to dry the ink to produce a printed matter.

A cellophane tape with an adhesive was attached to the printed film, and one second later, the cellophane tape was peeled off, and the peeled state of the printed film was visually observed. A in the adhesion evaluation column of FIG. 13 indicates that peeling of the printed film has not occurred. B in the same column indicates that peeling of the printing film within an allowable range occurs.

The range of the surface tension γ _s of the coating liquid and the range of the surface tension γ _pc of the substrate S based on the evaluation of the adhesion of the ink to the substrate S are γ _s −γ _pc ≧ 5.0 millinewtons per meter. As a result, the adhesion of the ink to the base material S can be ensured.

The adhesion of the ink to the base material S depends on the adhesion of the coating liquid to the base material S. Therefore, the range of the surface tension γ _s of the coating liquid and the range of the surface tension γ _pc of the base material S described above are conditions for ensuring the adhesion of the coating liquid to the base material S.

[Specific example of coating liquid]
The coating liquid may contain a component that aggregates the color material component of the water-based ink applied to the inkjet printing apparatus. Examples of the component that aggregates the color material component of the water-based ink include organic acids, inorganic acids, polyvalent metal ions, cationic polymers, and the like.

The coating liquid contains a resin component from the viewpoint of ensuring adhesion to the base material S. From the viewpoint of dispersion uniformity in the coating liquid, the resin component is preferably contained as latex particles in the coating liquid. The average particle size of the latex contained in the coating liquid is preferably in the range of 30 nanometers or more and 500 nanometers or less.

When the average particle size of the latex is less than 30 nanometers, it becomes too strong as a continuous film when the coating liquid is formed into a film, and it is difficult to clean the slit 22 and the slot 24 shown in FIG. 1 and the like. .. On the other hand, when the average particle size of the latex exceeds 500 nanometers, the dispersibility of the latex in the coating liquid is insufficient, and clogging due to soft aggregation of the latex may occur.

The solid content concentration of the latex in the coating liquid is preferably in the range of 5.0% or more and 30% or less. When the solid component concentration is less than 5.0%, the adhesion of the coating liquid to the base material S may be insufficient. On the other hand, when the solid component concentration exceeds 30%, the viscosity of the coating liquid becomes too high, and the coating amount of the coating liquid on the base material S may increase.

A surfactant is added to the coating liquid. As a result, the lubricity of the coating liquid is improved, and further, the shearing force when the coating liquid is discharged from the slit 22 is expected to decrease. The amount of the surfactant added is preferably in the range of 0.1% by weight or more and 1.0% by weight or less. When the amount of the surfactant added is less than 0.1% by weight, it is difficult to obtain the above effect.

Examples of preferred types of surfactants applied to acidic coatings include nonionic and anionic properties. The type of surfactant is not limited to the above example.

[Example of application to inkjet printing equipment]
FIG. 14 is an overall configuration diagram of an inkjet printing apparatus to which the coating apparatus according to the embodiment is applied. The printing apparatus 500 includes a precoat portion 530 that applies a precoat liquid that aggregates the color material components of the water-based ink to the base material 512. The coating device according to the embodiment is applied to the precoat portion 530.

The printing device 500 is a roll-to-roll inkjet printing device that prints an image on a substrate 512, which is a continuous medium, by a single-pass method. As the base material 512, a non-penetrating medium such as a transparent film base material used for flexible packaging can be applied. The base material 512 described in the embodiment is an example of a printing medium.

The printing apparatus 500 includes a winding unit 520, a precoat unit 530, a precoat drying unit 532, a first suction drum 540, a second suction drum 542, a jetting unit 550, an image sensor 560, and a winding unit 570.

The transport path of the base material 512 from the unwinding section 520 to the take-up section 570 is referred to as a base material transport path. The base material transporting direction along the base material transport path is called the base material transport direction. Regarding the substrate transport path, the upstream side means the side close to the unwinding portion 520, and the downstream side means the side close to the winding portion 570.

Along the substrate transport path from the unwinding section 520, the precoat section 530, the precoat drying section 532, the first suction drum 540, the second suction drum 542, the jetting section 550, the image sensor 560 and the winding section 570 are Arranged in order.

The base material transfer device 580 that conveys the base material 512 unwound from the unwinding unit 520 to the take-up unit 570 along the base material transfer path is a roll-to-roll device including a first suction drum 540 and a second suction drum 542. It is a roll transfer mechanism. The base material transfer device 580 may be configured to include a winding unit 520 and a winding unit 570.

The unwinding roll 522 is arranged in the unwinding portion 520. The unwinding roll 522 is a roll in which an unprinted base material 512 is wound in a roll shape. The unwinding unit 520 includes an unwinding device that rotatably supports the core 524 of the unwinding roll 522.

A take-up roll 572 is arranged in the take-up portion 570. The take-up roll 572 is a roll in which the printed base material 512 printed using the jetting portion 550 is wound into a roll shape. The take-up unit 570 includes a take-up device. The take-up reel held by the take-up device is connected to one end of the base material 512 unwound from the unwinding portion 520.

In the printing apparatus 500, the precoating liquid is applied to the printing surface 512A of the base material 512 in the precoating section 530 before printing in the jetting section 550. The precoat portion 530 is arranged at a position on the upstream side of the substrate transport path with respect to the jetting portion 550.

The precoat liquid suppresses the occurrence of uneven density when the ink droplets land on the base material 512 and uneven adhesion between the base material 512 and the ink droplets. The printing apparatus 500 realizes high-speed inkjet printing by using a water-based ink and a precoat liquid, and can obtain an image having high density and high resolution drawing performance, for example, reproducibility of fine lines and fine portions even in high-speed printing. ..

The precoat portion 530 is coated with an aqueous primer as a precoat liquid. Aqueous primers include components that aggregate or insolubilize the colorant components in water and water-based inks. As the aqueous primer, an embodiment containing a component that thickens water and ink may be applied.

The precoat drying unit 532 uses the precoating unit 530 to dry the aqueous primer applied to the printed surface 512A of the base material 512. The precoat drying section 532 includes a warm air heater. As an example of the hot air heater, there is an embodiment provided with a slit nozzle over the entire width of the base material 512.

From the viewpoint of promoting the leveling of the precoat liquid, the surface tension of the base material 512 is preferably 30 millinewtons per meter or more and 60 millinewtons per meter or less.

When the surface tension of the base material 512 is γ _s and the surface tension of the precoat liquid is γ _pc , the relationship between the surface tension of the base material 512 is γ _s and the surface tension of the precoat liquid is γ _pc . It is preferable to satisfy _s −γ _pc ≧ 5 millinewtons per meter. Thereby, the adhesion of the ink to the base material 512 can be ensured.

The precoat drying unit 532 blows warm air toward the printed surface 512A of the base material 512 to dry the aqueous primer. As a configuration example of the precoat drying unit 532, there is an embodiment in which warm air is ejected from a slit nozzle of a hot air heater.

The base material 512 on which the precoat liquid has been dried is conveyed to the jetting unit 550 via the first suction drum 540 and the second suction drum 542. The first suction drum 540 and the second suction drum 542 blow out air to the base material 512 to carry out floating transport, and the base material 512 travels in the traveling direction without contacting the printed surface 512A of the base material 512. A non-contact transfer unit that changes the direction of bending toward the printing surface 512A of 512 may be applied.

The jetting unit 550 includes an inkjet head 552K, an inkjet head 552C, an inkjet head 552M, an inkjet head 552Y, and an inkjet head 552W.

Hereinafter, the inkjet head 552K, the inkjet head 552C, the inkjet head 552M, the inkjet head 552Y, and the inkjet head 552W may be collectively referred to as the inkjet head 552.

The inkjet head 552 is a print head that ejects black, cyan, magenta, yellow, and white water-based inks, respectively. The water-based ink refers to an ink in which coloring material components such as dyes and pigments are dissolved or dispersed in water and a solvent soluble in water.

In this embodiment, an embodiment in which a water-based pigment ink is applied as a water-based ink is illustrated. Organic pigments are applied to the pigments of the black, cyan, magenta and yellow water-based inks. Titanium oxide is applied as the pigment of the water-based white ink. The viscosity of each water-based ink is 0.5 millipascals or more and 5.0 millipascals or less. The water-based ink thickens by reacting with the water-based primer.

Water-based ink is supplied to each of the inkjet heads 552 from ink tanks of corresponding colors via a piping path. The illustration of the ink tank and the piping route is omitted.

As the inkjet head 552, a line-type head capable of single-pass printing is applied, in which the substrate 512 transported by the substrate transport device 580 is scanned once and printed. A serial type head may be applied to the inkjet head 552. A plurality of nozzles for ejecting ink are formed on the nozzle surface of the inkjet head 552. Multiple nozzles may apply a two-dimensional arrangement. Further, a water-repellent film is formed on each nozzle surface of the inkjet head 552.

The inkjet head 552 can be configured by connecting a plurality of head modules, respectively, in the width direction of the base material 512. The nozzle surface, the nozzle, and the water-repellent film are not shown. The width direction of the base material 512 is a direction orthogonal to the base material transport direction, and represents a direction parallel to the printing surface 512A of the base material 512. Hereinafter, the width direction of the base material 512 may be described as the base material width direction.

Droplets of ink are ejected from the inkjet head 552 toward the printing surface 512A of the base material 512 to be conveyed by using the base material transfer device 580. Droplets of the ejected ink adhere to the base material 512, and an image is printed on the printing surface 512A of the base material 512. The ink applied to the printed surface 512A of the base material 512 in the jetting portion 550 undergoes a condensation thickening reaction by the aqueous primer applied to the printed surface 512A of the base material 512 in the precoat portion 530.

In the present embodiment, an embodiment in which four color inks of black, cyan, magenta, and yellow and white ink are used is exemplified, but the ink color and the number of colors are not limited to the present embodiment.

For example, an embodiment using light color inks such as light magenta and light cyan, and an embodiment using special color inks such as green, orange, violet, clear ink and metallic ink may be applied. Further, a plurality of inkjet heads 552 that eject ink of the same color may be arranged.

The arrangement order of the inkjet heads 552 of each color is not particularly limited, but since the white ink is used when printing a white background image, the inkjet head 552W is on the downstream side of the inkjet head 552Y or the like that ejects non-white ink. It is preferable to be arranged at the position of. In the embodiment to which the non-transparent base material 512 is applied, the inkjet head 552W may not be provided.

The jetting unit 550 prints a ejection state monitoring pattern for each inkjet head 552 on the printing surface 512A of the base material 512. The printing apparatus 500 may include an ink drying unit that performs a drying process on the printing surface 512A of the substrate 512 at a position downstream of the jetting unit 550 in the substrate transport direction.

The image sensor 560 reads the ejection condition monitoring pattern printed on the base material 512. The printing device 500 analyzes the reading data of the ejection state monitoring pattern and determines the ejection state of the inkjet head 552.

As the image sensor 560, a CCD line sensor in which a plurality of photoelectric conversion elements are arranged in a row may be applied, or a CCD area sensor in which a plurality of photoelectric conversion elements are arranged two-dimensionally may be applied.

The image sensor 560 may apply an embodiment having a length corresponding to the entire width of the image printed on the printed surface 512A of the base material 512, or scan along the base material width direction to scan the base material 512. An embodiment in which the full width of the image printed on the print surface 512A is read may be applied.

Each step in the inkjet printing is carried out, and the base material 512 on which the image based on the print data is printed is collected in the winding unit 570. In the present embodiment, the transfer of the base material 512 of the roll-to-roll method is exemplified, but the base material 512 such as a method of transporting the single-leaf base material 512 by using a base material transfer device provided with a transfer belt, a transfer drum, or the like. Various transport methods can be applied to the transport.

[Example of electrical configuration of inkjet printing equipment]
The printing apparatus 500 executes various programs using a processor to perform various controls and various processes. Various controls include transport control of the base material 512, application control of the precoat liquid, drying control of the precoat liquid, ejection control of the inkjet head 552, scan control of the printed image, and the like. The various processes include a color conversion process, a color separation process, a correction process, a halftone function, a drive voltage generation process, an image process for a scanned image, and the like.

The printing apparatus 500 includes a memory for storing various data, various parameters, and various programs. The processor executes various programs with reference to various data and various parameters.

[Specific example of precoat liquid]
An example of the composition of the precoat applied to the printing apparatus 500 shown in FIG. 14 is as follows.

Malonic acid (manufactured by Fujifilm Wako Junyaku Co., Ltd.): 4.0% by mass Triisopropanolamine (manufactured by Fujifilm Wako Junyaku Co., Ltd.): 0.5% by mass Acrylic resin particles A1: 8.0% by mass as the amount of resin particles 1,2-Propanediol (manufactured by Fujifilm Wako Junyaku Co., Ltd.): 10% by mass Defoamer TSA-739 (product number) (Momentive Performance Materials Japan GK, manufactured by Emulsion Type Silicone Defoamer): 15.0% by mass Percent (0.01% by mass as the solid content of defoamer)
Water: The preparation of the residual precoat solution, which is 100% by mass as a whole, is as follows.

By using the aqueous dispersion of the acrylic resin particles A1, the precoat liquid contained 8% by mass of the acrylic resin particles A1 as the amount of the resin particles (C). The aqueous dispersion of the acrylic resin particles A1 was prepared as follows.

To a 1000 ml three-necked flask equipped with a stirrer and a cooling tube, 3.0 g of a 62 mass percent aqueous solution of sodium dodecylbenzene sulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 376 grams of water were added and heated to 90 ° C. under a nitrogen atmosphere. bottom.

The following solutions A, B and C were simultaneously added dropwise to the mixed solution in the heated three-necked flask over 3 hours. After completion of the dropping, the reaction was further carried out for 3 hours to obtain 500 grams of an aqueous dispersion of acrylic resin particles A1. The aqueous dispersion of the acrylic resin particles A1 has a solid content of 10.1% by mass, which is the amount of the acrylic resin particles A1.

Solution A is a solution in which 11.0 g of a 50 mass% aqueous solution (manufactured by Aldrich) of sodium 2-acrylamide-2-methylpropansulfonate is dissolved in 20 g of water.

Solution B contains 12.5 grams of 2-hydroxyethyl methacrylate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 5.0 grams of 2- (2-ethoxy) ethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), and benzyl acrylate. It is a mixed solution of 17.0 grams (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10.0 grams of styrene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

Solution C is a solution in which 6.0 grams of sodium persulfate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) is dissolved in 40 grams of water. The glass transition temperature of the acrylic resin particles A1 was 26 ° C. The weight average molecular weight of the acrylic resin particles A1 was 69000.

The composition and adjustment of the precoat liquid described above is an example, and the printing apparatus shown in FIG. 14 can apply a precoat liquid having another composition and produced through other preparations.

[Terminology]
The term precoat liquid is synonymous with terms such as pretreatment liquid and treatment liquid, and is a general term for liquids applied before printing. The precoat liquid is an example of a coating liquid.

The term printing device is synonymous with terms such as a printing machine, a printer, a printing device, an image recording device, an image forming device, an image output device, and a drawing device. The image shall be interpreted in a broad sense, and includes a color image, a black-and-white image, a single-color image, a gradation image, a uniform density image, and the like.

The term printing includes the concepts of terms such as image recording, image formation, printing, drawing and printing. The term device can include the concept of a system.

The image is not limited to a photographic image, but is used as a comprehensive term including a pattern, a character, a symbol, a line drawing, a mosaic pattern, a color-coded pattern and various other patterns, and an appropriate combination thereof. Further, the term image may include the meaning of an image signal and image data representing an image.

In the embodiment of the present invention described above, the constituent requirements can be appropriately changed, added, or deleted without departing from the spirit of the present invention. The present invention is not limited to the embodiments described above, and many modifications can be made by a person having ordinary knowledge in the art within the technical idea of the present invention. Further, the embodiments, modifications, and applications may be combined as appropriate.

10 Applying device 12 Die coater 14 Conveying device 20 Die block 20A Bottom 22 Slit 22A Area 24 Slot 26 Liquid pool 26A Supply port side end 26B Supply port opposite end 28 Liquid supply port 30 Slot part 32 First block 32A Flat portion 32B Inclined portion 34 Second block 34A Flat portion 34B Inclined portion 40 Base 50 Coating liquid supply device 52 Coating liquid flow path 54 Liquid feeding pump 56 Coating liquid tank 60 Conveying mechanism 62 First lift roller 64 Second lift roller 66 Drive Roller 68 Elevating device 100 Processor 101 Processor 102 Memory 103 Processor 110 Transfer control unit 112 Elevating control unit 120 Display device 122 Display driver 130 Input device 140 Input / output interface 200 Coating device 202 Film thickness meter 210 Die block 230 Width adjustment device 232 Shielding plate 234 Width adjustment control unit 236 Information acquisition unit 300 Coating device 302 Blade 310 Blade position adjustment device 312 Blade position adjustment control unit 400 Coating device 420 Die block 423 Recovery slit 425 Recovery flow path 500 Printing device 512 Base material 512A Printing surface 520 Unwinding Part 522 Unwinding roll 524 Core 530 Pre-coat part 532 Pre-coat drying part 540 First suction drum 542 Second suction drum 550 Jetting part 552 Inkjet head 552C Inkjet head 552K Inkjet head 552M Inkjet head 552W Inkjet head 552Y Inkjet head 560 Image sensor 570 Winding part 572 Winding roll 580 Base material transfer device

Claims (12)

A discharge port for discharging the coating liquid, which has a planar shape whose length in the first direction is longer than the length in the second direction orthogonal to the first direction.
A liquid flow path connected to the discharge port and having a length in the first direction corresponding to the length of the discharge port in the first direction.
A liquid storage unit in which the coating liquid is stored and connected to the liquid flow path, and a liquid storage unit in which a coating liquid supply port is formed on one end side in the first direction.
Equipped with
The liquid flow path is a coating device having a structure in which the flow path resistance at the position on the side of one end in the first direction is larger than the flow path resistance at the position on the side of the other end in the first direction. The coating device according to claim 1, further comprising a width adjusting device for adjusting the length in the second direction for each of the plurality of regions of the discharge port along the first direction. A thickness measuring device that measures the thickness of the coating liquid applied to the substrate,
With one or more processors
Equipped with
The coating device according to claim 2, wherein the processor operates the width adjusting device to adjust the length of the discharge port in the second direction according to the measurement result of the thickness measuring device. The coating device according to any one of claims 1 to 3, further comprising a coating liquid removing device for removing a part of the coating liquid coated on the substrate. The coating device according to any one of claims 1 to 4, further comprising a recovery device for recovering the coating liquid discharged from the discharge port. The coating device according to any one of claims 1 to 5, further comprising a transport device for transporting the substrate in a substrate transport direction parallel to the second direction at the position of the discharge port. The coating device according to claim 6, wherein the discharge port has a length in the first direction corresponding to a total length in the first direction of a region to which the coating liquid of the base material is applied. The coating apparatus according to any one of claims 1 to 7, wherein the coating liquid has a viscosity of 0.5 millipascals or more and 5.0 millipascals or less. The coating device according to any one of claims 1 to 8, wherein the coating liquid has a surface tension of 30 millinewtons per meter or more and 45 millinewtons per meter or less. The coating device according to any one of claims 1 to 9, wherein the surface of the base material to which the coating liquid is applied has a surface tension of 30 millinewtons per meter or more and 60 millinewtons per meter or less. Claim 1 that satisfies γ _s −γ _pc ≧ 5.0 millinewtons per meter when the surface tension of the surface of the substrate to which the coating liquid is applied is γ _s and the surface tension of the coating liquid is γ _pc . 9. The coating apparatus according to any one of 9. A coating device that applies a coating liquid that aggregates ink on a print medium,
An inkjet head that ejects ink to the print medium to which the coating liquid is applied, and
Equipped with
The coating device is
A discharge port for discharging the coating liquid, which has a planar shape whose length in the first direction is longer than the length in the second direction orthogonal to the first direction.
A liquid flow path connected to the discharge port and having a length in the first direction corresponding to the length of the discharge port in the first direction.
A liquid storage unit in which the coating liquid is stored and connected to the liquid flow path, and a liquid storage unit in which a coating liquid supply port is formed on one end side in the first direction.
Equipped with
The liquid flow path is an inkjet printing apparatus having a structure in which the flow path resistance at a position on the side of one end in the first direction is larger than the flow path resistance at a position on the side of the other end in the first direction.

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