JP4023258B2 - Inkjet recording paper manufacturing method and manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing an inkjet recording paper in which a coating liquid is sprayed as droplets and applied to a substrate.
[0002]
[Prior art]
Various methods for applying a coating solution on a substrate are known. For example, as described in “MODERNCOATING AND DRYING TECHNOLOGY” by Edward Cohen, Edgar Gutoff, as a method of applying a coating liquid with high accuracy onto a long belt-like substrate to be conveyed (hereinafter also simply referred to as a substrate). Various methods have been proposed, for example, dip coating method, blade coating method, air knife coating method, wire bar coating method, gravure coating method, reverse coating method, reverse roll coating method, extrusion coating method, slide bead. A coating method, a curtain coating method, and the like are known. And in these coating methods, in order to obtain a uniform dry film thickness with high accuracy in the width direction of the substrate, pay attention to the coating film thickness accuracy and uniformity during coating (after coating and before drying), Applying.
[0003]
Among these coating methods, in particular, a coating device having a flow rate control die can perform high-speed, thin film, and multilayer simultaneous coating, and coating devices for photographic photosensitive materials, ink jet recording materials, magnetic recording materials, and the like due to their characteristics. Is widely used.
[0004]
As a preferred example, a slide bead coating device or an extrusion coating device proposed by Russell et al. In US Pat. No. 2,761,791 is widely used. The curtain coating device is also a flow regulation type coating device having a die, but is also widely used.
[0005]
For example, in the case of this slide bead coating device, a coating liquid reservoir called a bead is formed between the tip of the coating device and the substrate to be transported, and coating is performed via this bead. In the case of a curtain coating apparatus, the curtain-like coating liquid film is freely dropped from the coating apparatus, and coating is performed by positioning the substrate at the dropping destination. These are very useful for obtaining a uniform dry film thickness with high accuracy.
[0006]
However, the coating by the coating device having these dies, in principle, continuously connects the coating device and the substrate, such as a bead or a curtain film, with the coating liquid. In order to form a coating film having a uniform thickness on the substrate, the flow rate of the coating solution from the coating apparatus is always constant and must not be interrupted. That is, in order to form a coating film continuously and to make the coating film thickness highly accurate and constant, a predetermined amount or more of coating solution is required. Therefore, in these methods, it is difficult to extremely reduce the amount of the coating liquid discharged from the coating apparatus for the purpose of obtaining a uniform film thickness.
[0007]
Therefore, when forming a film having a small dissolved mass per coating layer, that is, a very thin wet film thickness (for example, about 1 to 50 μm) before coating and drying the coating liquid, the solvent amount of the coating liquid is set. It is necessary to increase the total amount of the coating liquid. In particular, when the viscosity of the coating solution is low, it flows on the substrate, so that it is difficult to form a stable coating film, and the amount of the coating solution must be increased.
[0008]
However, if the amount of the solvent is increased, the load (drying load) for drying the solvent after application increases, which is not preferable in terms of production efficiency. In addition, when the amount of solvent is large or drying takes a long time, when another constituent layer is present under the coating layer, the coating layer coating solution excessively penetrates and diffuses into the constituent layer, May have adverse effects.
[0009]
Therefore, there is a demand for a coating method in which a thin film is provided with high accuracy in coating thickness, low drying load, and high productivity.
[0010]
[Problems to be solved by the invention]
An object of the present invention has been made in view of the above problems, and an object of the present invention is to provide a method and an apparatus for manufacturing an ink jet recording paper, which form a thin film with a uniform film thickness with high accuracy on a substrate at high speed. It is. In addition, when a thin film is provided on a component layer that has already been applied and formed, there is no adverse effect on the component layer, and a coating method and a coating apparatus with high total production efficiency are provided. In particular, in the production of ink jet recording paper, when the ink absorbing layer is a constituent layer and a thin overcoat layer is provided thereon, the recording paper has excellent properties, coating film uniformity, and coating solution stability. An object of the present invention is to provide an ink jet recording paper manufacturing method and manufacturing apparatus.
[0011]
[Means for Solving the Problems]
The above object of the present invention is achieved by the following constitution.
[0012]
(1) Inkjet recording paper for transporting a substrate and forming a coating liquid layer on the substrate by spraying droplets of the coating liquid with a spray coating device over a coating width in a direction intersecting the transport direction of the substrate. In this manufacturing method, the spray coating apparatus is disposed in a sealed casing, and the casing is connected to a decompression means and held in a decompressed state, and a coating liquid layer is formed on the substrate by the spray coating apparatus. An ink jet recording paper manufacturing method characterized by the above.
[0013]
(2) Inkjet recording paper for transporting a substrate and forming a coating liquid layer on the substrate by spraying droplets of the coating liquid with a spray coating device over a coating width in a direction intersecting the transport direction of the substrate. In the manufacturing method according to the present invention, the coating liquid layer non-formation portion is formed by shielding the outer edge portion in the width direction of the substrate with a masking plate disposed in the vicinity of the coating liquid discharge portion of the spray coating apparatus. Recording paper manufacturing method.
[0014]
(3) Inkjet recording paper which forms a coating liquid layer on the substrate by transporting the substrate and spraying droplets of the coating solution with a spray coating device over a coating width in a direction crossing the transport direction of the substrate. A housing for housing the spray coating device, a decompression means for maintaining the interior of the housing in a decompressed state, a transport means for transporting the substrate while suctioning the back side of the substrate facing the housing under reduced pressure, An inkjet recording paper manufacturing apparatus comprising:
[0015]
(4) Inkjet recording paper for transporting a substrate and forming a coating liquid layer on the substrate by spraying droplets of the coating liquid with a spray coating device over a coating width in a direction crossing the transport direction of the substrate. A housing for housing the spray coating device, a decompression means for maintaining the interior of the housing in a decompressed state, a transport means for transporting the substrate while suctioning the back side of the substrate facing the housing under reduced pressure, An ink jet recording paper comprising: a masking plate disposed in the vicinity of a coating liquid discharge portion of the spray coating apparatus, and shielding a peripheral edge portion in the width direction of the base to form a coating liquid layer non-forming portion. Manufacturing equipment.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
[Spray coating device]
FIG. 1 is a perspective view of a spray coating apparatus 1 in an inkjet recording paper manufacturing apparatus according to the present invention.
[0018]
In the figure, reference numeral 1 denotes a spray coating device, and S denotes a long base. The base S is transported at a constant speed by a transport means (not shown) in the transport direction indicated by the arrow in the drawing, which is the longitudinal direction of the base S. The coating liquid nozzle 2 and the gas nozzle 3 of the spray coating apparatus 1 have a length in the width direction of the substrate S, which is a direction orthogonal to the transport direction, and are disposed so as to face the coating surface of the substrate S. The coating liquid discharged from the coating liquid discharge part 2 a of the coating liquid nozzle 2 is sprayed in the form of droplets by the pressurized gas discharged from the gas discharge part 3 a of the gas nozzle 3, and the droplets are formed on the substrate S to be transported. Application is performed by landing.
[0019]
FIG. 2 is a schematic cross-sectional view of a coating apparatus including the spray coating apparatus 1 described in FIG.
[0020]
In FIG. 2, the spray coating apparatus 1 has a pair of gas nozzles 3 having gas pockets 3b and a coating liquid nozzle 2 having a coating liquid pocket 2b. The coating solution is formed of, for example, a function-imparting compound-containing solution having a viscosity (preferably 0.1 to 250 mPa · s) that does not form a chain but can form droplets. This coating liquid is put into the preparation tank 4, supplied to the coating liquid pocket 2 b through the pump 5 and the flow meter 6, and introduced into the coating liquid nozzle 2. On the other hand, the pressurized air fed to the gas pocket 3 b is supplied from the pressurized air source 7 to the gas nozzle 3 through the control valve 8.
[0021]
During the coating process, the coating liquid is supplied from the preparation kettle 4 so as to have a prescribed coating amount from the coating liquid nozzle 2, and at the same time, pressurized air is blown from the pair of gas nozzles 3 to make the coating liquid into fine droplets. Then, spray and deposit on the substrate S. By supplying the coating liquid as fine droplets to the surface of the substrate S, a very uniform thin film can be formed at high speed without a drying load.
[0022]
FIG. 3 is an enlarged cross-sectional view for explaining the spray coating apparatus 1 and the formation and flying state of droplets formed on the substrate S. FIG.
[0023]
In FIG. 3, the coating liquid discharged from the coating liquid nozzle 2 is subdivided into droplets by the compressed air supplied from the gas nozzle 3 provided in the vicinity of both sides of the coating liquid nozzle 2, and has a nearly spherical shape. It becomes droplet particles 9 and flies to land uniformly on the surface of the substrate S. In FIG. 3, the substrate S is shown as a model in which the ink absorbing layer Sb is applied as a constituent layer on the support Sa. It is preferable that the area range of the droplets of the coating liquid landing on the substrate S is always uniform, but in particular, the length in the transport direction (denoted as scattering length in the figure) is uniform over the coating width. preferable. Further, it is preferable that the spread angle θ of the droplet group sprayed on the base S with the opening end of the coating liquid nozzle 2 as a base point is uniform over the coating width.
[0024]
FIG. 4 is a bottom view of the spray coating apparatus 1 of FIG. 3 as viewed from the coating liquid discharge unit 2a side, and shows the arrangement of a plurality of coating liquid discharge units 2a arranged in the coating width direction and the gas discharge units 3a. .
[0025]
In the coating liquid discharge section 2a shown in FIG. 4, for example, 23 coating liquid discharge sections 2a each having a circular opening end are arranged in the coating width direction. And the gas discharge part 3a is provided in the vicinity of both sides of each coating liquid discharge part 2a. Each coating liquid discharge part 2a is arranged at equal intervals, respectively. Similarly, the gas discharge portions 3a are also arranged at equal intervals.
[0026]
Here, one coating liquid discharge part 2a and two gas discharge parts 3a corresponding to each other are arranged in a straight line in a direction orthogonal to the application width direction, but the coating liquid discharge part 2a and the gas discharge part 3a are arranged in a straight line. Alternatively, they may be arranged in a staggered pattern. It is preferable that the interval (pitch) between the coating liquid discharge part 2a or the gas discharge part 3a is constant.
[0027]
FIG. 5 is an exploded perspective view of the spray coating apparatus 1. In the figure, reference numerals 1b and 1d denote die blocks for forming a coating liquid slit having a predetermined distance and causing the coating liquid to flow down the slit. One die block 1b has a coating liquid supply pipe 1f that receives a coating liquid supplied from a coating liquid supply source (not shown) and communicates with the coating liquid pocket 2b. The coating liquid staying in the coating liquid pocket 2b flows down through the coating liquid slit formed between the die blocks 1b and 1d. 1c is a shim (padded) sandwiched between the blocks 1b and 1d, and a plurality of coatings are applied in the coating width direction by dividing the coating liquid slit formed in the gap between the two die blocks 1b and 1d in the vertical direction. A liquid nozzle is formed.
[0028]
Reference numerals 1a and 1e denote gas blocks that form gas nozzles through which compressed gas flows in gaps between the die blocks 1b and 1d. The gas nozzle in this case is a slit extending in the coating width direction. Compressed air is supplied from an air supply source (not shown) to the air supply pipe 1g of each gas block, and once accumulated in the coating liquid pocket 2b, it is formed in the gap between the die blocks 1b and 1d and the gas blocks 1a and 1e. Down the gas nozzle with pressure.
[0029]
The coating liquid flowing down between the shims 1c and the compressed air flowing down through the two gas nozzles 3 collide with each other at the coating liquid discharge section 2a, which is the bottom of the spray coating apparatus 1, to form liquid droplets. It flies over the substrate S that is the object.
[0030]
[Example of spray coating apparatus 1]
In the spray coating apparatus 1 used in the present invention, the shape of the coating liquid discharge portion 2a of the coating liquid nozzle 2 may be circular or rectangular, and the size thereof can be used in the range of 50 to 300 μm, and the interval between them. (Pitch) is preferably 100 to 3000 μm.
[0031]
On the other hand, the shape of the gas discharge part 3a of the gas nozzle 3 may be a circle or a slit extending to the coating width, and the diameter or slit interval at this time can be used in a range of approximately 50 to 500 μm. . The angle of the gas nozzle 3 with respect to the coating solution nozzle 2 is preferably in the range of 5 to 50 degrees. Moreover, the distance between the coating liquid discharge part 2a of the spray coating apparatus 1 and the substrate S can be appropriately selected within a range of approximately 2 to 50 mm.
[0032]
Although the supply amount of the coating liquid from the coating liquid nozzle cannot be defined unconditionally depending on the desired coating film thickness, coating liquid concentration, coating speed, etc., the coating amount on the substrate S is generally 1 to 50 g / m. ² The range of is preferable. 1g / m ² Is less than 50 g / m, it is difficult to form a stable and uniform coating film. ² Exceeding this will affect the drying load and the like, making it difficult to effectively exert the effects of the present invention. The wet film thickness of the coating solution is 1 to 50 μm, and preferably 5 to 30 μm.
[0033]
On the other hand, the gas ejected from the gas nozzle 3 may be any gas suitable for application, and generally air (air) is used, but as a gas supply condition, the flow rate per application width is about 1 to 50 cm. ^Three The range of / min is preferable, and the internal pressure at the gas nozzle 3 at that time is preferably 10 kPa or more from the viewpoint of coating uniformity.
[0034]
The viscosity of the coating solution is preferably 0.1 to 250 mPa · s, more preferably 0.1 to 50 mPa · s, and still more preferably 0.1 to 20 mPa · s. By applying to a slot nozzle spray device, it is possible to spray droplets uniformly over the coating width.
[0035]
In order to spray droplets uniformly over the coating width, the surface tension of the coating solution is adjusted to 20 to 70 mN / m, preferably 20 to 50 mN / m, more preferably 20 to 30 mN / m. That is.
[0036]
Further, when the gas internal pressure is 10 kPa or more, preferably 20 kPa or more, more preferably 50 kPa or more when the gas is collided with the coating solution to form a droplet using the spray coating apparatus 1 or the like, uniform spraying is performed. easy. The gas flow rate is 3.5 cm. ^Three / Min or more, preferably 7 cm ^Three / Min or more, more preferably 10 cm ^Three / Min or more.
[0037]
By using the above-mentioned means, the coating liquid can be uniformly supplied onto the substrate S even if the amount of the coating liquid is small. As a result, the coating film thickness can be made uniform. Further, since the discontinuous droplets are supplied onto the substrate S and the amount of the coating liquid is reduced, no drying load is applied.
[0038]
[Coating production line]
FIG. 6 is a schematic diagram showing an example of a coating production line in which the spray coating apparatus 1 as described above is arranged. Here, as the substrate S, a substrate S coated with a constituent layer is used. A plurality of spray coating apparatuses 1 are arranged in the coating and drying process after coating the constituent layers. In this way, the formation of the constituent layers and the application of the overcoat layer (outermost layer) according to the present invention on the same line is referred to as online coating.
[0039]
Porous supplied from the flow-regulating slide bead coating device 30 in the process in which the substrate S passes from the original winding of the substrate S by the conveying means (not shown), passes through the conveying roller 31, and is reversely conveyed at the position of the backup roll 32. A coating solution for forming a quality ink absorbing layer (constituent layer) is applied. Since the coating liquid for the porous ink absorbing layer contains a hydrophilic binder, it is once cooled and fixed in the cooling zone 40.
[0040]
The substrate S having the ink absorbing layer is conveyed to the drying process. In the drying process, the substrate S is transported by alternately providing a reverser 33 that blows air and reversely transports the coating film surface in a non-contact manner and a normal transport roller 34 that contacts and reversely transports the back surface of the substrate S. In this drying step, hot air is blown to dry (the hot air blowing means is not shown). In the middle of this drying process, preferably, the above-described droplet spraying is performed by the two spray coating apparatuses 1 at a position after the rate-decreasing drying. It is preferable that at least one of the two spray coating apparatuses 1 is placed at a position after the drying end point. Here, two spray coating apparatuses 1 are used, but one may be used, and three or more may be used. By performing application by droplet spraying in multiple stages, the drying load is further reduced and the film thickness uniformity is also improved. It is also possible to add a plurality of components that cannot be mixed simultaneously.
[0041]
The coating speed at the time of forming a thin film on the substrate S using the coating method of the present invention varies depending on the type, concentration, solvent content, drying ability, etc. of the coating solution to be used and cannot be generally specified. However, the coating speed is preferably 50 to 300 m / min, and more preferably 100 to 300 m / min.
[0042]
As a coating time when coating is performed on the substrate S having at least one component layer on the substrate using the coating method of the present invention, preferably after the component layer formed on the substrate is reduced-rate drying, After the end of drying. Moreover, it is preferable that the coating process performed by using the slide bead coating and the like and the coating process performed by using the spray coating apparatus 1 of the present invention are continuously performed on the same production line (online coating and To tell).
[0043]
Since the coating method of the present invention has a small drying load, it can be carried out in the drying step of the constituent layers. The coating and drying process is usually controlled to specific temperature and humidity conditions for the purpose of improving the occurrence of cracks in the coating film from the front or back surface while continuously transporting the wet coating film. Dry by blowing dry air.
[0044]
By forming droplets of the coating liquid over the coating width in the direction crossing the transport direction of the substrate S and supplying the coating solution onto the substrate S, a thin film with a uniform drying thickness and a low drying load can be obtained. It can be applied.
[0045]
Here, in the present invention, the substrate S is an object to be coated by applying a coating liquid in the form of droplets using the coating method of the present invention, and the form is not limited. Although it is preferable that the above-described long strip-shaped substrate S and the substrate S already have a constituent layer because the effects of the present invention can be sufficiently obtained, the present invention is not limited to this.
[0046]
Further, in the present invention, the substrate S is moved relative to the coating liquid discharge part 2a of the spray coating apparatus 1 to perform continuous coating manufacture. The coating liquid discharge part 2a has a length corresponding to at least the coating width of the substrate S (refers to the length of the coated portion of the substrate S in the direction intersecting the transport direction of the substrate S). By disposing the substrate so as to cross the transport direction, the coating liquid is applied onto the substrate S simply by transporting the substrate S to the coating apparatus. When the substrate S is long, the substrate S itself is transported in the longitudinal direction of the substrate S, and the coating liquid discharge portion 2a is positioned in the width direction of the substrate S (in a direction perpendicular to the longitudinal direction). preferable. By transporting the substrate S in one direction to the spray coating apparatus 1 and spraying the coating liquid as droplets over the coating width, a very thin coating film can be coated with high film thickness uniformity without drying load.
[0047]
The droplets sprayed from the coating liquid discharge part 2a of the spray coating device 1 are in the coating width direction.
(1) The droplet size distribution is uniform,
(2) The length in the transport direction of the area range in which the droplets fall on the substrate S is uniform,
(3) The angle falling on the substrate S is uniform,
(4) The collision speed falling on the base S is uniform,
By this, it becomes possible to ensure the uniformity of the coating film thickness.
[0048]
That the droplet diameter distribution is uniform in the coating width direction specifically means that the variation of the average droplet diameter is ± 20% or less in the coating width direction. More preferably, it is ± 10% or less.
[0049]
The fluctuation of the average droplet diameter can be measured and calculated using a laser diffraction particle size distribution measuring apparatus (such as RTS5114 (registered trademark) manufactured by MALVERN). Specifically, the following measurement method is used.
[0050]
First, the coating liquid is sprayed from a spray coating device that sprays the coating liquid as droplets, and the spray state is stabilized. Immediately after the start of spraying, the discharge amount of the coating liquid and the gas pressure are not constant, and the spray state is not stable. Therefore, it can be stabilized by continuing spraying for a predetermined time.
[0051]
[Substrate coating and conveying device]
FIG. 7 is a cross-sectional view showing a substrate coating and conveying apparatus for manufacturing inkjet recording paper.
[0052]
The substrate coating / conveying device includes a coating unit 10 having the spray coating device 1 and a conveying unit 20 for conveying the substrate S.
[0053]
Application means 10
The coating unit 10 includes a spray coating device 1, an outer casing 11, an inner casing 12, a waste liquid collection unit 13, a decompression unit 14, and the like. An opening 11a on the right side of the outer casing 11 in the figure forms a gap g1 so as to face the transport path of the substrate S. Openings 11 b and 11 c arranged on the left side of the outer casing 11 are in communication with the decompression means 14 via the intake pipe 15.
[0054]
By driving the decompression means 14, the inside of the outer casing 11 and the inner casing 12 is held in a decompressed state. When the substrate S is transported, the inside of the outer casing 11 and the inner casing 12 is held in a reduced pressure state of −225 Pa, for example.
[0055]
A spray coating device 1 is arranged inside the inner casing 12 supported inside the outer casing 11. The inner housing 12 has a shielding wall in which a mist-like coating liquid sprayed from the coating liquid nozzle 2 of the spray coating apparatus 1 scatters around. The coating liquid adhering to the shielding wall falls along the inclined surface 12a, passes through the waste liquid pipe 13a, and is recovered by the waste liquid recovery means 13.
[0056]
The spray coating apparatus 1 stops the gas ejection by the gas nozzle 3 during the rest period other than the coating liquid processing, rotates the spray coating apparatus 1 to retreat from the transport surface of the substrate S, and moves the coating liquid nozzle 2 downward. In this state, the coating liquid nozzle 2 is discharged to discharge the coating liquid, and the inside of the coating liquid nozzle 2 is cleaned.
[0057]
・ Conveying means 20
On the back side of the substrate S facing the opening 11a of the coating means 10, a transport means 20 is arranged. The conveying means 20 includes a casing 200 that forms a plurality of partitioned decompression chambers 201, 202, and 203, and a first feed roller that is rotatably disposed in the decompression chamber (second decompression chamber) 201 at the base entrance. 21, 22, second feed rollers 24, 25 rotatably arranged in a decompression chamber (third decompression chamber) 203 at the substrate outlet, and a decompression chamber (first pressure chamber) facing the coating liquid nozzle 2 of the spray coating device 1. The decompression chamber) is composed of a plurality of rollers composed of the backup roller 23 rotatably arranged at the position 202.
[0058]
The decompression chambers 201 and 203 are connected to the decompression means 26 and are kept in a decompressed state of −294 Pa, for example, when the substrate S is transported. The decompression chamber 202 is connected to the decompression means 27 and is kept in a decompressed state of, for example, −225 Pa when the substrate S is transported.
[0059]
A gap g1 between the outer peripheral surface of the first feed roller 22 and the tip of the opening 11a of the outer housing 11 is maintained at, for example, 2 mm or less. The gap g2 between the outer peripheral surfaces of the first feed rollers 21 and 22 and the gap g3 between the outer peripheral surfaces of the second feed rollers 24 and 25 are maintained at about 0.2 mm, for example.
[0060]
The gap g4 between the partition wall 204 that partitions the decompression chambers 201 and 202 and the outer peripheral surface of the first feed roller 22, and the gap g5 between the partition wall 205 that partitions the decompression chambers 202 and 203 and the outer peripheral surface of the second feed roller 25 are: For example, it is held at about 0.2 mm.
[0061]
In the decompression chamber 201 at the paper conveyance entrance, the substrate S is conveyed by the rotating first feed rollers 21 and 22 while sucking the substrate S to be carried in, so that the substrate S is held in a flat and stable state. Can be transported to the spray application section.
[0062]
In the spray application part where the opening 11a of the outer casing 11 and the decompression chamber 202 face each other, the base S is in a flat and stable state due to the decompression in the outer casing 11 and the decompression in the decompression chamber 202. And is conveyed by a rotating backup roller 23.
[0063]
In the decompression chamber 203 at the paper conveyance outlet, the substrate S is conveyed by the rotating second feed rollers 24 and 25 while sucking the substrate S to be carried out, so that the substrate S is held in a flat and stable state. The substrate S after spray coating can be carried out.
[0064]
[Masking plate]
FIG. 8 is a front view of the conveying means 20.
[0065]
Masking plates 50 are disposed on both sides in the width direction of the substrate S. The masking plate 50 is disposed in the vicinity of the coating liquid discharge portion 2a of the spray coating apparatus 1, and shields the outer edge portion in the width direction of the substrate S to form a coating liquid layer non-forming portion (see FIGS. 1 and 8). . A broken line shown in FIG. 8 is an arrangement position of the spray coating apparatus 1 facing the backup roller 23 of the conveying unit 20.
[0066]
FIG. 9A is a schematic plan view for explaining the width dimensions of the spray coating device 1, the substrate S, and the masking plate 50, and FIG. 9B is a view as seen from the direction of arrow A in FIG.
[0067]
The spray coating apparatus 1 has a total width W1 in the width direction, a width W2 (for example, 1532 mm) in the width direction of the coating liquid discharge portion 2a of the coating liquid nozzle 2, and a length W3 in the width direction (for example, 1592 mm) of the gas nozzle 3. (See FIG. 4).
[0068]
The substrate S has a total width Ws1 (for example, 1546 mm) of the substrate S and a total width Ws2 (for example, 1538 mm) of the ink absorbing layer Sb.
[0069]
The internal spacing W5 (for example, 1534 mm) of the masking plate 50 is set to be slightly narrower than the entire width Ws2 of the ink absorbing layer Sb and slightly wider than the length W2 in the width direction of the coating liquid discharge portion 2a (Ws2>W5>). W2 ).
[0070]
The droplet particles 9 discharged from the coating liquid discharge unit 2a and sprayed in the form of a mist by the gas nozzle 3 are diffused at the spread angle θ, and are blocked by the masking plates 50 in the vicinity of both ends of the substrate S. A uniform coating solution layer is formed by landing on the surface. On the substrate S, an effective coating width Ws3 (for example, 1538 mm) is formed.
[0071]
【The invention's effect】
As is clear from the above description, the following effects can be achieved by the method and apparatus for manufacturing an inkjet recording paper of the present invention.
[0072]
(1) Uniform application by placing the spray coating device in a sealed housing, connecting the inside of the housing to a decompression means and holding it in a decompressed state, and forming a coating liquid layer on the substrate with the spray coating device A film is formed at high speed.
[0073]
(2) By holding the back side of the substrate facing the spray coating device in a reduced pressure state and transporting it by a plurality of rollers, the substrate is stably transported while maintaining flatness, and uniformly on the substrate by the spray coating device. Can be formed at high speed.
[0074]
(3) By disposing a masking plate that shields the outer edge in the width direction of the substrate to form a coating liquid layer non-forming portion at both ends of the coating solution discharge portion of the spray coating device, within the effective coating width of the substrate. A uniform coating film is formed at high speed.
[Brief description of the drawings]
FIG. 1 is a perspective view of a spray coating apparatus in an inkjet recording paper manufacturing apparatus according to the present invention.
FIG. 2 is a schematic cross-sectional view of a coating apparatus including a spray coating apparatus.
FIG. 3 is an enlarged cross-sectional view for explaining a spray coating apparatus and formation and flight states of droplets formed on a substrate.
FIG. 4 is a bottom view of the spray coating apparatus as viewed from the coating liquid discharge unit side.
FIG. 5 is an exploded perspective view of a spray coating apparatus.
FIG. 6 is a schematic diagram showing an example of a coating production line in which a spray coating device is arranged.
FIG. 7 is a cross-sectional view showing a substrate coating / conveying apparatus for manufacturing inkjet recording paper.
FIG. 8 is a front view of a conveying unit.
9 is a schematic plan view for explaining each width dimension of a spray coating device, a base body, and a masking plate, and a view taken in the direction of arrow A in FIG.
[Explanation of symbols]
1 Spray coating device
2 Coating liquid nozzle
2a Coating liquid discharge part
3 Gas nozzle
3a Gas discharge part
10 Application means
11 Outer housing
12 Inner housing
13 Waste liquid recovery means
14 Pressure reducing means
20 Transport means
200 case
201, 202, 203 decompression chamber
204,205 partition wall
21, 22 First feed roller
23 Backup roller
24, 25 Second feed roller
26, 27 Pressure reducing means
50 Masking plate
S substrate

Claims (10)

A method for producing an ink jet recording sheet, wherein a substrate is transported and a coating liquid layer is formed on the substrate by spraying droplets of the coating liquid with a spray coating device over a coating width in a direction intersecting the substrate transport direction. In
The spray coating apparatus is disposed in a sealed casing, and the casing is connected to a decompression unit and held in a decompressed state, and a coating liquid layer is formed on the substrate by the spray coating apparatus. Ink jet recording paper manufacturing method. A method for producing an ink jet recording sheet, wherein a substrate is transported and a coating liquid layer is formed on the substrate by spraying droplets of the coating liquid with a spray coating device over a coating width in a direction intersecting the substrate transport direction. In
A method for producing an ink jet recording sheet, wherein a coating liquid layer non-formation portion is formed by shielding an outer edge portion in the width direction of the substrate by a masking plate disposed in the vicinity of a coating liquid discharge portion of the spray coating apparatus. . An inkjet recording paper manufacturing apparatus that forms a coating liquid layer on a substrate by transporting the substrate and spraying droplets of the coating liquid with a spray coating device over a coating width in a direction crossing the substrate transport direction. In
A housing for housing the spray application device;
Decompression means for maintaining the inside of the housing in a decompressed state;
Transport means for transporting the base while suctioning the back side of the base facing the housing under reduced pressure;
An inkjet recording paper manufacturing apparatus comprising: An inkjet recording paper manufacturing apparatus that forms a coating liquid layer on a substrate by transporting the substrate and spraying droplets of the coating liquid with a spray coating device over a coating width in a direction crossing the substrate transport direction. In
A housing for housing the spray application device;
Decompression means for maintaining the inside of the housing in a decompressed state;
Transport means for transporting the base while suctioning the back side of the base facing the housing under reduced pressure;
A masking plate that is disposed in the vicinity of the coating liquid discharge portion of the spray coating apparatus and shields the outer edge portion in the width direction of the substrate to form a coating liquid layer non-forming portion;
An inkjet recording paper manufacturing apparatus comprising: 5. The inkjet recording paper manufacturing apparatus according to claim 3, wherein the conveying unit includes a plurality of partitioned decompression chambers and a plurality of rollers rotatably disposed in the decompression chamber. The plurality of decompression chambers are disposed in a first decompression chamber that holds the base so as to face an opening of a housing that houses the spray coating device, and a second inlet that is disposed in a base entrance of the opening of the housing. The inkjet recording paper according to any one of claims 3, 4, and 5, comprising: a decompression chamber; and a third decompression chamber disposed at a base outlet of the opening of the housing. Manufacturing equipment. A backup roller rotatably supported in the first decompression chamber, a first feed roller rotatably supported in the second decompression chamber, and a second feed roller rotatably supported in the third decompression chamber The apparatus for manufacturing an inkjet recording paper according to any one of claims 3 to 6, wherein: The spray coating apparatus includes a plurality of coating liquid nozzles that discharge the coating liquid over the coating width, and a gas nozzle that ejects gas in the vicinity of an opening end from which the coating liquid of the coating liquid nozzle discharges, The apparatus for producing an inkjet recording paper according to any one of claims 3 to 7, wherein the spraying is performed by causing the gas to collide with a coating liquid discharged from a coating liquid nozzle to form droplets. . The spray coating apparatus is configured to evacuate the spray coating apparatus from the surface of the substrate, stop the gas ejection from the gas nozzle, and discharge the coating liquid from the coating liquid nozzle when the coating liquid is not sprayed. The apparatus for producing an inkjet recording paper according to any one of claims 3 to 8, wherein the inside of the coating liquid nozzle is washed. The inkjet recording paper manufacturing apparatus according to any one of claims 3 to 8, further comprising a collecting unit that collects the droplets scattered in a casing that houses the spray coating device.

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