Conveyance device, printer and adhesive coating method

Abstract

To provide a conveyance device, a printer and an adhesive coating method which can form an adhesive layer having non-uniform adhesiveness on a coating surface of a conveyance belt.SOLUTION: A conveyance device includes a conveyance belt for conveying a recording medium, and a coating liquid supply part for supplying a coating liquid of an aqueous adhesive containing water and a resin onto a coating surface on the side of the recording medium of the conveyance belt, wherein the coating liquid supply part has a storage part which includes a discharge port, has such flexibility as to store the coating liquid and has a bag shape, and a pressurization part for pressurizing the storage part, and pushing the coating liquid from the discharge port.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a conveying device, a printing device, and an adhesive application method. [Background technology]

[0002] For example, a printing device that prints by applying ink onto a recording medium is known, as shown in Patent Document 1. The printing device described in Patent Document 1 includes a conveyor belt that conveys the recording medium, and a printing unit that reciprocates in a direction intersecting the conveyance direction of the recording medium and has a large number of nozzles that eject ink onto the recording medium being conveyed.

[0003] An adhesive layer is formed on the surface of the conveyor belt that comes into contact with the recording medium, thereby enabling the recording medium to be stably conveyed while being adhesively held thereon. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-89806 Summary of the Invention [Problem to be solved by the invention]

[0005] However, adhesives obtained using organic solvents are generally used as adhesives constituting adhesive layers. Therefore, sufficient consideration must be given to safety when handling adhesive coating solutions during production and application to conveyor belts, and particularly when applying adhesive coating solutions, there are many restrictions on the surrounding environment, such as the need for sufficient ventilation. Therefore, it is possible to use aqueous adhesives, but simply applying the aqueous adhesive using the same method as before may result in insufficient uniform application of the aqueous adhesive or uneven adhesion. [Means for solving the problem]

[0006] The conveying device of the present invention comprises: a conveying belt for conveying a recording medium; a coating liquid supply unit that supplies a coating liquid of an aqueous adhesive containing water and a resin to a coating surface of the conveyor belt that faces the recording medium, The coating liquid supply unit includes a flexible bag-shaped storage unit having a discharge port for storing the coating liquid, and a pressurizing unit for pressurizing the storage unit to push the coating liquid out of the discharge port.

[0007] The printing device of the present invention comprises: an inkjet head that performs printing by ejecting ink onto the recording medium being transported by the transport belt.

[0008] The adhesive application method of the present invention includes a supplying step of supplying an aqueous adhesive coating solution containing water and a resin to a coating surface of a conveyor belt that conveys a recording medium, the coating surface being on the recording medium side; a drying step of drying the coating liquid applied to the coating surface, In the supplying step, a flexible bag-shaped reservoir portion that has a discharge port and stores the coating liquid is pressurized to push the coating liquid out of the discharge port. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a conveying device and a printing device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a state in which the conveying device shown in FIG. 1 is performing a leveling process. [Figure 3] FIG. 3 is a flowchart illustrating an example of an adhesive application method according to an embodiment of the present invention. [Figure 4] 4 is a cross-sectional view showing a storage unit and a pressurizing unit provided in the conveying device and the printing device shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing a storage unit and a pressurizing unit provided in a conveying device and a printing device according to a second embodiment of the present invention. [Figure 6]FIG. 6 is a cross-sectional view showing a storage unit and a pressurizing unit provided in a conveying device and a printing device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A conveying device, a printing device, and an adhesive application method according to the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

[0011] First Embodiment Fig. 1 is a schematic diagram of a conveying device and a printing device according to an embodiment of the present invention. Fig. 2 is a diagram showing a state in which the conveying device shown in Fig. 1 is performing a leveling process. Fig. 3 is a flowchart for explaining an example of an adhesive application method according to an embodiment of the present invention. Fig. 4 is a cross-sectional view showing a storage unit and a pressurizing unit provided in the conveying device and the printing device shown in Fig. 1.

[0012] For ease of explanation, in the following, in Figures 1 and 2, the x-axis, y-axis, and z-axis are shown as three mutually orthogonal axes. The x-axis is an axis along one of the horizontal directions (the width direction of the conveyor belt), the y-axis is an axis along the horizontal direction and perpendicular to the x-axis (the running direction of the conveyor belt), and the z-axis is an axis along the vertical direction (the up-down direction in the figure). In addition, the tip side of each arrow shown in the figure is referred to as the "positive side (+ side)" and the base side is referred to as the "negative side (- side)." In addition, the upper side of Figures 1, 2, and 4 is referred to as the "top" or "upper side," and the lower side is referred to as the "bottom" or "lower side."

[0013] As shown in Figures 1 and 2, the printing device 1 includes a conveying device 2 having a conveying belt 21 that conveys the recording medium W, a feeding device 3 that feeds out the long recording medium W wound in a roll, a winding device 4 that winds up the printed recording medium W, a printing unit 5 that applies ink to the recording medium W being conveyed by the conveying belt 21 to perform printing, and an ink drying unit 6 that dries the ink on the recording medium W.

[0014] In this embodiment, the direction perpendicular to the transport direction in which the recording medium W is transported is the x-axis direction, the direction parallel to the transport direction is the y-axis direction, and the direction perpendicular to the x-axis and y-axis directions is the z-axis direction.

[0015] A printable material can be used as the recording medium W. The printable material refers to fabrics, clothing, and other clothing products that are the subject of printing. Fabrics include woven fabrics, knitted fabrics, and nonwoven fabrics made from natural fibers such as cotton, silk, and wool, chemical fibers such as nylon, and composite fibers that combine these. Clothing and other clothing products also include sewn items such as T-shirts, handkerchiefs, scarves, towels, carrier bags, cloth bags, curtains, sheets, bedspreads, and other furniture, as well as fabrics that exist as parts before and after cutting and before sewing.

[0016] The recording medium W is not limited to the above-mentioned printing materials, but may also include, for example, paper specifically designed for inkjet printing, such as plain paper, wood-free paper, and glossy paper. The recording medium W may also be, for example, a plastic film that has not been surface-treated for inkjet printing, i.e., that does not have an ink-absorbing layer, or a substrate such as paper coated with plastic or with a plastic film attached. Examples of such plastics include, but are not limited to, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

[0017] The conveying device 2 has a driving roller 22 and a driven roller 23 arranged at a distance from each other in the y-axis direction, a conveying belt 21 stretched between the driving roller 22 and the driven roller 23 and supporting the recording medium W on its upper surface (support surface), and tensioners 24, 25 that apply tension to the recording medium W between the driving roller 22 and the driven roller 23.

[0018] A motor (not shown) is connected to the driving roller 22, and the driving roller 22 can be driven to rotate by the operation of the motor. The rotational force of the driving roller 22 is transmitted to the driven roller 23 via the conveyor belt 21, and the driven roller 23 can rotate in conjunction with the driving roller 22.

[0019] The conveyor belt 21 is an endless belt on whose front surface an adhesive layer having adhesive properties is formed. A portion of the recording medium W is adhesively fixed to this adhesive layer, and the recording medium W is conveyed toward the + side in the y-axis direction. During this conveyance, the desired printing is performed on the recording medium W. After printing, the recording medium W is peeled off from the conveyor belt 21. The adhesive layer is formed by supplying an adhesive coating liquid 100 from a coating liquid supply unit 8, as shown in FIG. 2. The surface of the conveyor belt 21 that comes into contact with the recording medium W is a coating surface 210 on which the coating liquid 100 is applied.

[0020] Similar to the driving roller 22 and the driven roller 23, the tensioners 24 and 25 are also arranged spaced apart from each other in the y-axis direction.

[0021] The tensioner 24 can sandwich the recording medium W together with the conveyor belt 21 between it and the drive roller 22, and the tensioner 25 can sandwich the recording medium W together with the conveyor belt 21 between it and the driven roller 23. As a result, the recording medium W, to which an appropriate tension is applied by the tensioners 24 and 25, is adhesively fixed to the conveyor belt 21 while being tensioned, and is conveyed. In this state, the recording medium W is less likely to develop wrinkles, sagging, etc. during conveyance, and therefore, when printing is performed, the printing is appropriate and of high quality.

[0022] The payout device 3 is disposed upstream of the transport device 2 in the feeding direction of the recording medium W, i.e., on the negative side in the y-axis direction. The payout device 3 has a payout roller (payout reel) 31 around which the recording medium W is wound in a roll and which pays out the recording medium W, and a tensioner 32 which applies tension to the recording medium W between the payout roller 31 and the transport device 2. A motor (not shown) is connected to the payout roller 31, and the payout roller 31 can be driven to rotate by the operation of the motor.

[0023] The winding device 4 is disposed downstream of the driven roller 23 in the feeding direction of the recording medium W, i.e., on the + side in the y-axis direction, relative to the conveying device 2. The winding device 4 has a winding roller 41 that winds the recording medium W into a roll, and tensioners 42, 43, and 44 that apply tension to the recording medium W between the winding roller 41 and the conveying device 2. A motor (not shown) is connected to the winding roller 41, and operation of the motor drives the winding roller 41 to rotate. The tensioners 42, 43, and 44 are disposed in this order at intervals in a direction away from the winding roller 41.

[0024] The printing unit 5 includes a carriage unit 52 having a plurality of inkjet heads 51 that perform recording by ejecting ink toward the recording medium W, and an X-axis table (not shown) that supports the carriage unit 52 so that the carriage unit 52 can move in the x-axis direction. Each inkjet head 51 includes, for example, a head body having an internal flow path formed therein that is filled with ink, and a large number of nozzle groups each having an opening.

[0025] The head body is provided with a piezoelectric element (piezoelectric body) corresponding to each ejection nozzle, and when a voltage is applied to the piezoelectric element, ink is ejected as droplets from the nozzle group.

[0026] When not ejecting ink, the inkjet head 51 waits at a standby position that is positioned away from the recording medium W (conveyor belt 21) in the x-axis direction when viewed from the z-axis direction.

[0027] In the printing device 1, the recording medium W fed by the feeding device 3 is intermittently fed in the positive direction of the y axis while being adhesively fixed by the conveyor belt 21, and ink is ejected from the nozzle group onto the fixed recording medium W while the carriage unit 52 is reciprocated in the x axis direction. In this way, a desired image pattern is formed and printed on the recording medium W. The image pattern may be printed in multiple colors or in a single color.

[0028] The inks contain water as a solvent and dyes or pigments as colorants, and come in four colors, for example, cyan (C), magenta (M), yellow (Y), and black (K). Each color of ink is ejected independently from the inkjet head 51.

[0029] As shown in FIG. 1, the ink drying unit 6 is located downstream of the printing unit 5 in the transport direction of the recording medium W, i.e., on the +y-axis direction side, between the transport device 2 and the winding roller 41 of the winding device 4.

[0030] The ink drying unit 6 has a chamber 61 and a coil 62, which is a heat source (heater), arranged inside the chamber 61. The coil 62 is made of, for example, nichrome wire, and is configured as a heating element that generates heat when power is supplied. The heat generated by the coil 62 can dry the ink on the recording medium W passing through the chamber 61.

[0031] In such a printing apparatus 1, when printing is not being performed, an adhesive is periodically supplied onto the conveyor belt 21 to form an adhesive layer. In the printing apparatus 1, an adhesive layer is formed on the surface of the conveyor belt 21 on the recording medium W side by the coating liquid supply unit 8, the blade 9, and the adhesive drying unit 10 provided in the conveyor device 2.

[0032] Conventionally, adhesives constituting adhesive layers have generally been made by dissolving hydrophobic resins in organic solvents so as to withstand water washing. Recently, however, there has been a demand for water-based adhesives that use less organic solvents in order to reduce environmental impact and improve working environments. However, water-based adhesives have poor durability, and the adhesive strength of the adhesives applied to the surface of the transport member tends to gradually decrease with washing, making it necessary to apply new adhesive after each washing. In the present invention, the pressure-sensitive adhesive is an aqueous pressure-sensitive adhesive composition containing a resin and water.

[0033] 1.1. Resin (Adhesive / Aqueous Adhesive Composition) The resin is not particularly limited, but for example, a (meth)acrylic resin can be used.

[0034] The inclusion of a (meth)acrylic resin can improve the adhesive strength and durability of the adhesive layer. The (meth)acrylic resin may be a water-soluble resin or an emulsion dispersed in an aqueous catalyst. These are collectively referred to as (meth)acrylic resin in this embodiment. The use of a (meth)acrylic resin can reduce the environmental burden caused by organic solvents and also tends to further improve the peelability of the adhesive layer from the recording medium W, particularly fabric.

[0035] The (meth)acrylic resin is not particularly limited as long as it is a polymer obtained by polymerizing a (meth)acrylic monomer such as (meth)acrylic acid or a (meth)acrylic acid ester as one component. Examples include homopolymers obtained from (meth)acrylic monomers and copolymers of (meth)acrylic monomers with other monomers. More specific (meth)acrylic monomers are not particularly limited, but include (meth)acrylic monomers having an aliphatic group with 3 or less carbon atoms, such as methyl methacrylate (MMA), ethyl methacrylate (EMA), and n-propyl methacrylate (PMA); (meth)acrylic monomers having an aliphatic group with 4 or more carbon atoms, such as butyl methacrylate (BMA), butyl acrylate (BA), and 2-ethylhexyl acrylate (2EHA); and (meth)acrylic monomers having an aromatic group, such as styrene (St). Other monomers are not particularly limited, but include acrylamide and acrylonitrile.

[0036] The monomer contained in the (meth)acrylic resin is not particularly limited, but examples thereof include methyl methacrylate (MMA), ethyl methacrylate (EMA), n-propyl methacrylate (PMA), butyl methacrylate (BMA), styrene (St), butyl acrylate (BA), and 2-ethylhexyl acrylate (2EHA).

[0037] The combination of monomers is not particularly limited, but examples thereof include a combination containing at least ethyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, a combination containing at least methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, a combination containing at least n-propyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, and a combination containing at least butyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate.

[0038] The aqueous pressure-sensitive adhesive composition contains at least a first (meth)acrylic resin and a second (meth)acrylic resin as (meth)acrylic resins, and the glass transition temperature Tg1 of the first (meth)acrylic resin is preferably higher than the glass transition temperature Tg2 of the second (meth)acrylic resin. By containing two types of (meth)acrylic resins having such different glass transition temperatures Tg, there is a tendency for the adhesive strength and durability to be improved, and for the effect of suppressing a decrease in adhesive strength during brushing to be further improved.

[0039] The glass transition temperature Tg1 of the first (meth)acrylic resin is not particularly limited, but is preferably −25° C. or higher and 25° C. or lower, and more preferably −20° C. or higher and 20° C. or lower. When the glass transition temperature Tg1 is in the above range, the adhesive strength tends to be further improved.

[0040] The glass transition temperature Tg2 of the second (meth)acrylic resin is not particularly limited, but is preferably −70° C. or higher and −15° C. or lower, and more preferably −65° C. or higher and −20° C. When the glass transition temperature Tg2 is in the above range, the decrease in adhesive strength during brushing tends to be further suppressed.

[0041] The difference |Tg1-Tg2| between the glass transition temperature Tg1 and the glass transition temperature Tg2 is preferably 10° C. or more and 50° C. or less, and more preferably 15° C. or more and 45° C. or less. When the difference |Tg1-Tg2| is in the above range, the adhesive strength and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0042] The glass transition temperature can be adjusted by the homopolymer glass transition temperature of the polymerizable compound used and the weight ratio of the polymerizable compound used. The glass transition temperature can be measured by a conventionally known method.

[0043] The monomer contained in the first (meth)acrylic resin is not particularly limited, but is preferably one containing at least ethyl methacrylate, butyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, one containing at least ethyl methacrylate, styrene, butyl acrylate, and 2-ethylhexyl acrylate, one containing at least methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, or one containing at least butyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate. Use of a first (meth)acrylic resin containing the above monomers tends to further improve adhesive strength and the effect of suppressing adhesive strength loss during brushing.

[0044] The first (meth)acrylic resin preferably contains, as a constituent unit, a (meth)acrylic monomer whose homopolymer has a glass transition temperature of 40° C. or higher. When the first (meth)acrylic resin contains the above-mentioned monomer, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0045] The content of the (meth)acrylic monomer having a homopolymer glass transition temperature of 40° C. or higher is preferably 20% by weight to 70% by weight, and more preferably 25% by weight to 65% by weight, relative to the total amount of the first (meth)acrylic resin. When the content of the (meth)acrylic monomer having a homopolymer glass transition temperature of 40° C. or higher is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0046] The monomer contained in the second (meth)acrylic resin is not particularly limited, but is preferably one containing at least ethyl methacrylate, butyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate, or one containing at least n-propyl methacrylate, butyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate. By using a second (meth)acrylic resin containing the above monomers, the adhesive strength and the effect of suppressing the adhesive strength decrease during brushing tend to be further improved.

[0047] The content of the first (meth)acrylic resin is preferably 50% by weight or more and 85% by weight or less, more preferably 53% by weight or more and 82% by weight or less, based on the total amount of the first (meth)acrylic resin and the second (meth)acrylic resin. When the content of the first (meth)acrylic resin is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing the decrease in adhesive strength during brushing tend to be further improved.

[0048] The content of the second (meth)acrylic resin is preferably less than 50% by weight, more preferably 10% to 48% by weight, of the total amount of the first (meth)acrylic resin and the second (meth)acrylic resin. When the content of the second (meth)acrylic resin is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing the decrease in adhesive strength during brushing tend to be further improved.

[0049] The content of the (meth)acrylic resin is preferably 20% by weight or more and 70% by weight or less, and more preferably 30% by weight or more and 60% by weight or less, relative to the total amount of the aqueous pressure-sensitive adhesive composition. When the content of the (meth)acrylic resin is 20% by weight or more, the adhesive strength and durability of the resulting pressure-sensitive adhesive layer tend to be further improved. Furthermore, when the content of the (meth)acrylic resin is 70% by weight or less, the application property and storage stability of the aqueous pressure-sensitive adhesive composition tend to be further improved. Note that the content relative to the total amount of the aqueous pressure-sensitive adhesive composition refers to the amount of solids.

[0050] The content of the first (meth)acrylic resin is preferably 10% by weight or more and 70% by weight or less, and more preferably 20% by weight or more and 60% by weight or less, based on the total amount of the aqueous pressure-sensitive adhesive composition. When the content of the first (meth)acrylic resin is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing the decrease in adhesive strength during brushing tend to be further improved.

[0051] The content of the second (meth)acrylic resin is preferably 50% by weight or less, and more preferably 1% by weight or more and 40% by weight or less, based on the total amount of the aqueous pressure-sensitive adhesive composition. When the content of the second (meth)acrylic resin is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing the decrease in adhesive strength during brushing tend to be further improved.

[0052] The aqueous pressure-sensitive adhesive composition may contain a resin other than the (meth)acrylic resin. Such other resins are not particularly limited, but examples thereof include urethane resins, silicone resins, and various elastomers (rubber-based materials).

[0053] The resin is not limited to the above-mentioned (meth)acrylic resin or a resin mainly composed of a (meth)acrylic resin, but may also include, for example, urethane resin, silicone resin, and various rubber materials.

[0054] 1.2. Tackifiers The aqueous pressure-sensitive adhesive composition preferably contains no or a small amount of a tackifier. When the aqueous pressure-sensitive adhesive composition contains no or a small amount of a tackifier, the adhesive strength of the adhesive layer and the effect of suppressing the decrease in adhesive strength during brushing tend to be more sustained. Typical examples of such tackifiers include rosin compounds, terpene compounds, and hydrocarbon resins. More specifically, examples of the compound include rosin-based compounds such as natural rosin, modified rosin, glycerol esters of natural rosin, glycerol esters of modified rosin, pentaerythritol esters of natural rosin, and pentaerythritol esters of modified rosin; terpene-based compounds such as copolymers of natural terpene, three-dimensional polymers of natural terpene, aromatic modified terpene resins, hydrogenated derivatives of aromatic modified terpene resins, terpene phenol resins, and terpene resins (monoterpene, diterpene, triterpene, polyperene, etc.); and hydrocarbon resins such as aliphatic petroleum hydrocarbon resins (C5 resins), hydrogenated derivatives of aliphatic petroleum hydrocarbon resins, aromatic petroleum hydrocarbon resins (C9 resins) such as styrene oligomers, and hydrogenated derivatives of aromatic petroleum hydrocarbon resins.

[0055] It is preferable that the composition does not contain a tackifier, or if it does contain one, it contains only a small amount. When a tackifier is contained, its content is not particularly limited, but is preferably 5 wt% or less, more preferably 4 wt% or less, and even more preferably 0.1 wt% to 3.8 wt% based on the total amount of the aqueous pressure-sensitive adhesive composition. When the tackifier content is within the above range, the adhesive strength of the resulting adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be more sustained. From a similar perspective, the total content of compounds selected from the group consisting of rosin-based compounds, terpene-based compounds, and hydrocarbon resins is also preferably within the same range.

[0056] 1.3.Water The water content in the aqueous pressure-sensitive adhesive composition (coating liquid 100) is not particularly limited, but is preferably 30% by weight to 80% by weight, and more preferably 35% by weight to 70% by weight, which makes it easier to level the coating liquid 100 applied to the application surface 210 to a uniform thickness.

[0057] 1.4.Surfactants The aqueous pressure-sensitive adhesive composition may contain a surfactant. The surfactant is not particularly limited, but examples thereof include anionic surfactants, nonionic surfactants, and cationic surfactants.

[0058] Examples of anionic surfactants include alkyl sulfocarboxylates, alkyl diphenyl ether disulfonates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurines, alkyl sulfates such as ammonium lauryl sulfate and sodium lauryl sulfate, alkyl sulfate polyoxyalkyl ether sulfates, alkyl sulfate polyoxyethylene alkyl ether phosphates, rosin acid soap, castor oil sulfate esters, lauryl alcohol sulfate esters, alkylphenol phosphate esters, alkyl phosphate esters, alkylaryl sulfonates, diethyl sulfosuccinate, diethylhexyl cyrsulfosuccinate, and dioctyl sulfosuccinate.

[0059] Examples of nonionic surfactants include acetylene glycol surfactants, silicone surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene hydrogenated castor oil, propylene glycol fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, alkyl polyglycosides, alkyl diethanolamides, and alkylamine oxides.Commercially available nonionic surfactants include, but are not limited to, Emulgen 123P, 430, and 1108 (product names of Kao Corporation), Newcol 1006, 1008, and 1020 (product names of Nippon Nyukazai Co., Ltd.), Noigen DL-0415, ET-116B, ET-106A, DH-0300, YX-400, and EA-160 (product names of Daiichi Kogyo Seiyaku Co., Ltd.).

[0060] Examples of cationic surfactants include alkylamine salts, fatty acid amidoamine salts, monoalkyl quaternary ammonium salts, dialkyl quaternary ammonium salts, trialkyl quaternary ammonium salts, benzalkonium quaternary ammonium salts, benzethonium chloride, and alkylpyridinium salts.

[0061] In this embodiment, among these, nonionic surfactants are preferred, and more specifically, alkyl ether-based nonionic surfactants are preferred. Use of such surfactants tends to maintain durability.

[0062] The content of the surfactant is preferably 1% by weight or more and 7% by weight or less, and more preferably 2% by weight or more and 6% by weight or less, based on the total amount of the aqueous pressure-sensitive adhesive composition.

[0063] 1.5. Organic Solvents From the viewpoint of reducing the environmental load and the influence on the human body, the aqueous pressure-sensitive adhesive composition in this embodiment preferably does not contain an organic solvent, or if it does contain an organic solvent, it contains only a small amount. Furthermore, if an organic solvent is contained, the content of the organic solvent is preferably 5.0 wt% or less, more preferably 2.5 wt% or less, based on the total amount of the aqueous pressure-sensitive adhesive composition. This reduces the environmental load and also reduces VOCs (volatile organic compounds) when the aqueous pressure-sensitive adhesive composition is used, which tends to further improve the working environment.

[0064] 1.6.Colorants The aqueous pressure-sensitive adhesive composition of this embodiment preferably does not contain a colorant, or if it does contain one, it contains only a small amount of colorant. Furthermore, if a colorant is contained, the content of the colorant is preferably 1.0 wt % or less, more preferably 0.5 wt % or less, based on the total amount of the aqueous pressure-sensitive adhesive composition. This clearly distinguishes the aqueous pressure-sensitive adhesive composition of this embodiment from compositions intended for coloring, such as ink compositions, textile printing pastes, and paints.

[0065] 1.7.Storage Modulus The aqueous pressure-sensitive adhesive composition of the present embodiment is intended to form a pressure-sensitive adhesive layer on the surface of a fabric-transporting member of an ink-jet printing apparatus. The pressure-sensitive adhesive layer obtained by the present embodiment has excellent adhesive strength and durability, and also has excellent mechanical properties as described below.

[0066] The storage modulus of the adhesive layer obtained in this embodiment at 23°C is 1.5 × 10 5 Pa or more 5.0×10 5 Pa or less, and 1.6 × 10 5 Pa or more 4.8×10 5 Pa or less is more preferable, and 2.0×10 5 Pa or more 4.5×10 5 It is more preferable that the storage modulus is 1.5×10 Pa or less. 5 By having a storage modulus of 5.0×10 Pa or more, it is possible to prevent the adhesive strength from decreasing when the adhesive surface is washed with water. 5 By ensuring that the viscosity is equal to or less than 100 Pa, the initial adhesive strength can be increased.

[0067] The method for forming the adhesive layer for measuring the storage modulus is not particularly limited. For example, the aqueous adhesive composition was applied to a 25 mm wide slide glass at room temperature to a thickness of 0.2 mm, and then dried under conditions of 50% humidity, 23°C, and 12 hours.

[0068] When an adhesive layer consisting only of the first (meth)acrylic resin (hereinafter referred to as "first acrylic adhesive layer") is formed by the same method as in the case of the aqueous adhesive composition, the storage modulus of the first acrylic adhesive layer at 23°C is, but is not particularly limited to, 1.0 × 10 5 Pa or more 8.0×10 5 Pa or less, and 1.6 × 10 5 Pa or more 7.6×10 5 It is more preferable that the storage modulus is not more than 1 Pa. When the storage modulus of the first acrylic adhesive layer is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0069] When an adhesive layer consisting only of the second (meth)acrylic resin (hereinafter referred to as "second acrylic adhesive layer") is formed by the same method as in the case of the aqueous adhesive composition, the storage modulus of the second acrylic adhesive layer at 23°C is, but is not particularly limited to, 6.0 × 10 5 Over 8.0 x 10 5 Pa or less, and 7.0 × 10 5 Over 7.5 x 10 5 It is more preferably not more than Pa. When the storage modulus of the second acrylic adhesive layer is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0070] 1.8. Adhesive strength The adhesive strength at 23°C of the adhesive layer obtained according to this embodiment is not particularly limited, but is preferably 0.3 N / 50 mm or more and 3.0 N / 50 mm or less, more preferably 0.5 N / 50 mm or more and 2.0 N / 50 mm or less, and even more preferably 0.7 N / 50 mm or more and 1.8 N / 50 mm or less. Having the adhesive strength at 23°C within the above ranges further improves the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing.

[0071] 1.9.Viscosity The viscosity of the coating liquid 100 at room temperature when forming the adhesive layer is not particularly limited, but is preferably 1 cps or more and 500 cps or less, more preferably 5 cps or more and 470 cps or less, even more preferably 100 cps or more and 450 cps or less, and particularly preferably 120 cps or more and 400 cps or less. This makes it easier to level the coating liquid 100 applied to the application surface 210 to a uniform thickness, contributing to uniform film thickness and homogenous surface properties of the resulting adhesive layer.

[0072] Next, the transport device 2 will be described. 1 and 2, the conveying device 2 includes a conveying belt 21, a coating liquid supplying section 8 that supplies a coating liquid 100 of an aqueous pressure-sensitive adhesive composition to a coating surface 210 on the recording medium W side of the conveying belt 21, a blade 9 that levels the coating liquid 100 supplied to the coating surface 210, and a pressure-sensitive adhesive drying section 10 that dries a coating film 105 obtained by passing through the blade 9. The coating liquid supplying section 8, the blade 9, and the pressure-sensitive adhesive drying section 10 may each be incorporated into the conveying device 2, or may be configured to be detachable.

[0073] The coating liquid supply unit 8 includes a storage section 81 that stores the coating liquid 100, a liquid delivery pipe 82 that delivers the coating liquid 100 from the storage section 81 to the vicinity of the coating surface 210, a pressurizing section 83 that pressurizes the storage section 81 to push the coating liquid 100 out of the discharge port 811, and a control section 7 that controls the operation of the pressurizing section 83, and performs the supply step shown in FIG. 3 . In this embodiment, when the coating liquid supply unit 8 supplies the coating liquid 100, the conveyor belt 21 is continuously driven to rotate and run. In this case, the running speed of the conveyor belt 21 is kept constant. This allows the portion on the coating surface 210 to be supplied with the coating liquid 100 to be continuously changed while the coating liquid 100 is being supplied. Furthermore, continuous leveling can also be achieved in the leveling step described below.

[0074] The running speed of the conveyor belt 21 in the supplying step and the leveling step described later, i.e., when supplying and leveling the coating liquid 100, is not particularly limited, but is preferably 250 mm / min to 4000 mm / min, and more preferably 500 mm / min to 2000 mm / min. By setting the running speed at such a speed, the coating liquid 100 can be applied quickly and a more uniform and good coating film 105 can be obtained.

[0075] In the present invention, the conveyor belt 21 may be configured to be rotated intermittently. Furthermore, the conveyor belt 21 may be configured to be rotated at any timing and at any speed.

[0076] The storage unit 81 has a storage space therein for storing the coating liquid 100, and has an outlet 811 for discharging the coating liquid 100 from the storage space. One end 821 of a liquid feed pipe 82 is connected to the outlet 811. The liquid feed pipe 82 transfers the coating liquid 100 to the vicinity of the coating surface 210. The other end 822 of the liquid feed pipe 82 is located above the conveyor belt 21 and upstream of the printing unit 5 (the - side in the y-axis direction). Therefore, the coating liquid 100 discharged from the other end 822 of the liquid feed pipe 82 is dripped onto the coating surface 210 of the conveyor belt 21 at a position offset to the - side in the y-axis direction, i.e., at a position offset to the drive roller 22 side. The configurations of the storage section 81 and the pressurizing section 83 will be described in detail later.

[0077] Although not shown, the other end 822 of the liquid supply pipe 82 branches into multiple branches. The branched flow paths are arranged side by side along the x-axis direction, i.e., the width direction of the conveyor belt 21. The other end 822 of the liquid supply pipe 82 may be provided with a nozzle, an orifice, or the like.

[0078] As described above, the conveying device 2 has the liquid supply pipe 82 connected to the discharge port 811 and transporting the coating liquid 100 to the coating surface 210. This increases the degree of freedom in the installation position of the storage unit 81. Furthermore, by placing the storage unit 81 at a higher position than the coating surface 210, the coating liquid 100 can be supplied more smoothly.

[0079] The liquid supply pipe 82 may be omitted, and the coating liquid 100 may be directly supplied from the discharge port 811 to the coating surface 210 of the conveyor belt 21. In this case, the discharge port 811 is installed facing downward.

[0080] The supply amount per unit time of the coating liquid 100 supplied from the liquid supply pipe 82 onto the coating surface 210, i.e., the total supply amount of each branch flow path (hereinafter simply referred to as "supply amount"), is not particularly limited, but is preferably 10 ml / min to 70 ml / min, and more preferably 20 ml / min to 60 ml / min. By setting the supply amount in this range, the coating liquid 100 can be applied quickly, and the leveling in the leveling step described below can be performed more uniformly and satisfactorily.

[0081] The coating liquid supply unit 8 may be configured to supply the coating liquid 100 continuously or intermittently.

[0082] The blade 9 levels the coating liquid 100 supplied to the coating surface 210 to a uniform thickness. The leveling step shown in Fig. 3 is performed by using the blade 9 to level the coating liquid 100 applied to the coating surface 210. The blade 9 has an elongated shape extending in the width direction of the conveyor belt 21. The blade 9 is fixed in a state in which it is suspended above the conveyor belt 21 by a support part (not shown).

[0083] The blade 9 is provided between the other end 822 of the liquid feed tube 82 and the printing unit 5, that is, downstream of the other end 822 of the liquid feed tube 82 (positive side in the y-axis direction).

[0084] The blade 9 is positioned such that its lower end, i.e., the end on the negative side in the z-axis direction, is spaced a predetermined distance G from the coating surface 210. This distance G is an important factor in determining the thickness of the coating liquid 100, i.e., the coating film 105, after the leveling step, and is particularly important in determining the film thickness of the resulting adhesive layer. The distance G is determined appropriately depending on various conditions, such as the viscosity of the coating liquid 100, the supply amount, and the adhesive strength of the desired adhesive layer, as described above. When at least one, particularly two or three, of the viscosity of the coating liquid 100, the supply amount, and the adhesive strength of the adhesive layer are within the preferred ranges described above, the distance G is preferably 0 mm or more and 0.5 mm or less, more preferably 0 mm or more and 0.3 mm or less, and even more preferably 0 mm or more and 0.2 mm or less.

[0085] In this way, the blade 9 extends in the width direction of the conveyor belt 21, and is spaced a predetermined distance G from the conveyor belt 21 when leveling the coating liquid 100. This allows the coating liquid 100 to be more uniformly leveled across the entire width of the conveyor belt 21 during the leveling process. In addition, because the blade 9 does not come into contact with the coating surface 210 of the conveyor belt 21, damage to the conveyor belt 21 by the blade 9 can be prevented.

[0086] When leveling the coating liquid 100, the blade 9 may be in contact with the conveyor belt 21 all the time or at appropriate times.

[0087] The coating liquid 100 supplied on the coating surface 210 in the supply process is transported to the +y-axis direction by the movement of the conveyor belt 21, and is leveled as it passes through the gap between the coating surface 210 and the blade 9 by the distance G, making the thickness uniform.

[0088] The blade 9 only needs to be installed above the conveyor belt 21 when the smoothing process is being performed, and may be configured to be removable from the conveyor device 2 when the smoothing process is not being performed.

[0089] The length of the blade 9 in the width direction (x-axis direction) of the conveyor belt 21 is not particularly limited, but is preferably 80 cm or more and 250 cm or less, and more preferably 100 cm or more and 200 cm or less. This allows the length of the blade 9 in the width direction of the conveyor belt 21 to be equal to or longer than the width of the conveyor belt 21, regardless of the model of the printing device 1 or the size of the conveyor belt 21. Therefore, the blade 9 can cover the entire area or effective area of ​​the conveyor belt 21 in the width direction and level the coating liquid 100.

[0090] The blade 9 smoothes the coating liquid 100 while driving the conveyor belt 21 to run, and the running speed of the conveyor belt 21 when smoothing the coating liquid 100 is substantially the same as the running speed of the conveyor belt 21 during printing. This makes it easy to control the running speed of the conveyor belt 21.

[0091] Here, "substantially the same" is a concept that includes not only cases where there is no difference between the two traveling speeds, but also cases where there is a slight difference between the two traveling speeds, for example, when the average speed difference is within ±5%.

[0092] In the present invention, the running speed of the conveyor belt 21 during printing may be different from the running speed of the conveyor belt 21 during leveling of the coating liquid 100. In other words, the running speed of the conveyor belt 21 may be appropriately changed between when forming the coating film 105 and when printing.

[0093] As shown in FIG. 1, the adhesive drying section 10 is a section where the drying step shown in FIG.

[0094] The adhesive drying unit 10 has a coil 11, which is a heat source (heater). The coil 11 is made of, for example, nichrome wire, and is a heating element that generates heat when power is supplied. The heat generated by the coil 11 can adequately dry the coating film 105 of the coating liquid 100 that has been applied to the coating surface 210 and leveled by the blade 9. The position of the adhesive drying unit 10 is not limited to the illustrated configuration.

[0095] The adhesive drying unit 10 may also be configured to have a fan with an air blowing function. In this case, the heat source such as the coil 11 may be omitted, or the adhesive drying unit 10 may be configured to have both the heat source and the fan.

[0096] In this embodiment, the adhesive drying unit 10 can forcibly or quickly dry the coating film 105, but is not limited thereto, and the adhesive drying unit 10 may be one that dries at room temperature, or one that dries naturally without applying airflow, etc. Furthermore, the conveying device 2 and the printing device 1 may not have the adhesive drying unit 10.

[0097] In addition, in the present embodiment, the coating liquid 100 is applied once to the coating surface 210 of the conveyor belt 21, but this is not limiting, and the coating may be performed twice or three times. That is, after the supplying step, the leveling step, and the drying step of the coating liquid 100 are performed, these steps may be repeated multiple times.

[0098] Next, the storage unit 81 and the pressurizing unit 83 will be described. 4, storage unit 81 is in the shape of a flexible bag, and is configured as a so-called flexible bag. Storage unit 81 may be configured entirely or partially from a flexible material. The orientation of storage unit 81 is not particularly limited, and storage unit 81 is preferably installed with outlet 811 facing upward.

[0099] The flexible bag serving as reservoir 81 is liquid-tight to coating liquid 100 and has sufficient strength to withstand pressure applied by pressurizing unit 83 when filled with coating liquid 100 .

[0100] The material constituting the flexible portion of storage section 81 is not particularly limited, but can mainly be polymer materials such as those exemplified below. Examples of such polymer materials include polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, modified polyolefins, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyvinyl chloride, polyamides (e.g., nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, and nylon 6-66), various thermoplastic elastomers such as styrenes, polyolefins, polyvinyl chloride, polyurethanes, polyesters, polyamides, polybutadienes, transpolyisoprenes, fluororubbers, and chlorinated polyethylenes, as well as copolymers, blends, and polymer alloys mainly made of these materials, and one or more of these materials can be mixed and used.

[0101] The constituent material of the flexible portion of storage section 81 may be a laminate of two or more layers made of the above polymer material, or a layer made of the above polymer material and a metal layer such as aluminum laminated thereon. Examples of methods for laminating multiple layers include thermocompression bonding, coating and drying, baking, and vapor deposition.

[0102] The constituent material of reservoir 81 may be transparent, semi-transparent, or opaque, but transparent or semi-transparent materials are preferred because they ensure visibility of the coating liquid 100 contained therein.

[0103] 4, pressurizing unit 83 has a casing 831 that houses storage unit 81, and an air supply unit 832 that supplies air to space S between casing 831 and storage unit 81. Casing 831 is a so-called chamber made of a hard material, and forms space S therein, which is a substantially sealed space.

[0104] The air supply unit 832 has an air supply source 833 and an air pipe 834 that connects the air supply source 833 and the casing 831 .

[0105] The air supply source 833 is composed of a pump equipped with a compressor that pressurizes and supplies air, and is electrically connected to the control unit 7. The control unit 7 has a power supply unit 71 that supplies power to the air supply source 833 and the like, and a control circuit 72 that controls the amount of power supplied from the power supply unit 71 to the air supply source 833, the timing of the power supply, etc. The control circuit 72 is composed of a semiconductor integrated circuit and has an arithmetic processing unit and a memory unit. The memory unit of the control circuit 72 stores programs for executing the operation of the air supply source 833 and an on-off valve 836 (described later), information on the operating conditions, etc.

[0106] Casing 831 has a through-hole through which air supply pipe 834 passes. Air is supplied from air supply source 833 via air supply pipe 834 to space S between casing 831 and storage part 81. This supply of air increases the air pressure in space S, and storage part 81 is pressed from the outside. As a result, coating liquid 100 in storage part 81 is pushed out through outlet 811 and discharged.

[0107] In particular, because the storage section 81 has a flexible bag shape, the storage section 81 deforms to be recessed depending on the remaining amount of the coating liquid 100 in the storage section 81. Furthermore, as described above, the storage section 81 is liquid-tight. Therefore, even if the amount of the coating liquid 100 in the storage section 81 decreases, it is possible to prevent air from entering the interior, and to prevent or suppress deterioration of the coating liquid 100 due to contact with air. As a result, the coating liquid 100 can be supplied stably, and an adhesive layer with uniform adhesiveness can be formed on the coating surface 210 of the conveyor belt 21.

[0108] The pressurizing unit 83 has an adjusting unit 837 that adjusts the degree of pressurization of the storage unit 81 to adjust the discharge speed of the coating liquid 100 pushed out from the storage unit 81, i.e., the discharge amount per unit time. The adjusting unit 837 in this embodiment adjusts the air pressure in the space S to adjust the discharge speed of the coating liquid 100.

[0109] The adjustment unit 837 is installed to penetrate the wall of the casing 831 and has an exhaust pipe 835 whose inner cavity communicates with the space S, and an on-off valve 836 that is provided in the exhaust pipe 835 and opens and closes the flow path in the exhaust pipe 835. The on-off valve 836 is formed by a solenoid valve and is electrically connected to the control unit 7. The control unit 7 controls the opening and closing timing, opening degree, etc. of the on-off valve 836. The on-off valve 836 may be a valve that can be selectively opened or closed, or a valve whose opening degree can be adjusted arbitrarily. Although not shown, the coating liquid supply unit 8 may have a pressure sensor (detection unit) that detects the pressure in the space S, and the control unit 7 may be configured to control the opening / closing timing, opening degree, etc. of the on-off valve 836 based on the detected value of the pressure sensor.

[0110] In the adjusting unit 837 configured as described above, by closing the on-off valve 836, the air in the space S is not discharged to the outside of the casing 831 through the exhaust pipe 835, and therefore the air pressure in the space S can be increased by operating the air supply source 833. This increases the amount of coating liquid 100 discharged per unit time from the storage unit 81.

[0111] Conversely, by opening the on-off valve 836, the air in the space S is discharged to the outside of the casing 831 through the exhaust pipe 835, thereby decreasing the air pressure in the space S. This reduces the amount of coating liquid 100 discharged per unit time from the storage part 81.

[0112] As described above, by adjusting the air pressure in the space S, the degree to which the reservoir 81 is pressurized can be adjusted, and the amount of coating liquid 100 discharged from the reservoir 81 per unit time can be adjusted.

[0113] As described above, the pressurizing unit 83 has an adjusting unit 837 that adjusts the amount of coating liquid 100 discharged per unit time from the storage unit 81 by adjusting the degree of pressure applied to the storage unit 81. This makes it possible to supply a desired amount, particularly an appropriate amount, of coating liquid 100 to the conveyor belt 21. This makes it possible to form a coating film 105 having a more uniform and appropriate thickness.

[0114] Adjustment unit 837 is not limited to the above configuration, and may be configured such that an on-off valve similar to on-off valve 836 is provided in air supply pipe 834, or such that exhaust pipe 835 having on-off valve 836 is provided as a branch pipe branching off from the middle of air supply pipe 834. Furthermore, adjustment unit 837 may be configured to have an on-off member that opens and closes a through-hole (not shown) provided in the wall of casing 831. Furthermore, the on-off valve 836 and the like may be opened and closed manually.

[0115] As described above, the conveying device 2 includes the conveying belt 21 that conveys the recording medium W, and the coating liquid supply unit 8 that supplies the coating liquid 100, which is an aqueous adhesive containing water and a resin, to the coating surface 210 of the conveying belt 21 on the recording medium W side. The coating liquid supply unit 8 includes a flexible, bag-shaped storage unit 81 that has a discharge outlet 811 and stores the coating liquid 100, and a pressure unit 83 that pressurizes the storage unit 81 to push the coating liquid 100 out of the discharge outlet 811. This allows the coating liquid 100 in the storage unit 81 to be smoothly and efficiently discharged and supplied. Therefore, the coating liquid 100 can be appropriately and stably supplied to the coating surface 210 of the conveying belt 21, and an adhesive layer with uniform adhesion can be formed on the conveying belt 21.

[0116] Furthermore, the inventors' research has revealed that if an aqueous adhesive is stored in a state where the gas-liquid interface is large and in contact with air, the water contained in the aqueous adhesive evaporates, generating foreign matter (causing the aqueous adhesive to deteriorate), resulting in poor printing. However, due to the structure of the storage section 81, it is possible to prevent or suppress deterioration of the coating liquid 100 inside due to contact with air, which contributes to the formation of an appropriate, high-quality adhesive layer.

[0117] The adhesive application method includes a supplying step of supplying a coating liquid 100 of an aqueous adhesive containing water and a resin to a coating surface 210 on the recording medium W side of a conveyor belt 21 that conveys the recording medium W, and a drying step of drying the coating liquid 100 applied to the coating surface 210. In the supplying step, a flexible, bag-shaped reservoir 81 that has a discharge outlet 811 and stores the coating liquid 100 is pressurized to push the coating liquid 100 out of the discharge outlet 811. This allows the coating liquid 100 in the reservoir 81 to be smoothly and satisfactorily discharged and supplied. Therefore, the coating liquid 100 can be properly and stably supplied to the coating surface 210 of the conveyor belt 21, and an adhesive layer with uniform adhesion can be formed on the conveyor belt 21.

[0118] Furthermore, due to the structure of the reservoir 81, it is possible to prevent or suppress deterioration of the coating liquid 100 inside due to contact with air, which contributes to the formation of an appropriate and high-quality adhesive layer.

[0119] In this embodiment, the smoothing step is performed using the blade 9, but the present invention is not limited to this, and the smoothing step may be performed by an operator using a tool such as a squeegee. Also, the smoothing step itself may be omitted.

[0120] The printing apparatus 1 also includes a conveying device 2 and an inkjet head 51 that performs printing by ejecting ink onto a recording medium W being conveyed by a conveying belt 21. The conveying device 2 also includes the conveying belt 21 that conveys the recording medium W, and a coating liquid supply unit 8 that supplies a coating liquid 100, which is an aqueous adhesive containing water and a resin, to a coating surface 210 of the conveying belt 21 facing the recording medium W. The coating liquid supply unit 8 has a flexible, bag-shaped storage unit 81 that has a discharge port 811 and stores the coating liquid 100, and a pressure unit 83 that pressurizes the storage unit 81 to push the coating liquid 100 out of the discharge port 811. This allows the coating liquid 100 in the storage unit 81 to be smoothly and efficiently discharged and supplied. Therefore, the coating liquid 100 can be appropriately and stably supplied to the coating surface 210 of the conveying belt 21, and an adhesive layer with uniform adhesion can be formed on the conveying belt 21. By carrying out printing using the transport belt 21 having such an adhesive layer, the recording medium can be transported stably, and printing can be carried out properly and satisfactorily.

[0121] Furthermore, due to the structure of the reservoir 81, it is possible to prevent or suppress deterioration of the coating liquid 100 inside due to contact with air, which contributes to the formation of an appropriate and high-quality adhesive layer.

[0122] As described above, pressurizing unit 83 has casing 831 that houses storage unit 81, and air supply unit 832 that supplies air to space S between casing 831 and storage unit 81, and pressurizes storage unit 81 by the air pressure in space S. This makes it possible to pressurize storage unit 81 and discharge coating liquid 100 with a simple configuration of increasing the air pressure in space S.

[0123] Second Embodiment FIG. 5 is a cross-sectional view showing a storage unit and a pressurizing unit provided in a conveying device and a printing device according to a second embodiment of the present invention.

[0124] Below, we will explain the second embodiment of the conveying device, printing device, and adhesive application method of the present invention with reference to Figure 5. However, below we will mainly explain the differences from the first embodiment, and omit explanations of similar points.

[0125] 5, the pressurizing unit 83 has a clamping unit 83A that clamps the storage unit 81. The clamping unit 83A has a pair of clamping plates 830A and a drive mechanism 831A that moves the clamping plates 830A in a direction in which the pair of clamping plates 830A approach each other.

[0126] The pair of clamping plates 830A are each composed of a flat plate and are arranged to face each other across the storage section 81. The clamping plate 830A on the right side in Fig. 5 is fixed to the inner wall of the casing 831, and the clamping plate 830A on the left side in Fig. 5 is supported by a drive mechanism 831A so as to be movable toward and away from the fixed clamping plate 830A.

[0127] When the pair of clamping plates 830A approaches each other, pressure is applied to the reservoir 81 sandwiched therebetween, and coating liquid 100 is discharged. In addition, by adjusting the separation distance, movement direction, transfer speed, etc. of the pair of clamping plates 830A, the discharge speed (amount discharged per unit time) of coating liquid 100 can be adjusted.

[0128] The drive mechanism 831A has a link mechanism 832A and a motor 833A that extends and contracts the link mechanism 832A in the left-right direction in FIG.

[0129] The link mechanism 832A has a so-called pantograph structure in which a plurality of links are rotatably connected to adjacent links by rotary shaft connecting portions (pivots).

[0130] The motor 833A can rotate in either the forward or reverse direction by switching the direction of current flow. The motor 833A is electrically connected to the control unit 7. The control unit 7 controls the operation timing, rotation direction, rotation speed, etc. of the motor 833A.

[0131] Rotating shaft 835A of motor 833A has a helical male thread formed on its outer periphery, while nut 836A has a female thread formed on the inside that screws into the male thread. This allows nut 836A to screw into rotating shaft 835A and move up and down in FIG. 5 as rotating shaft 835A rotates. Nut 836A is fixed to a rotating connector 834A of one of link mechanisms 832A. As a result, as nut 836A moves up and down, rotating connector 834A also moves up and down.

[0132] When motor 833A is driven to rotate rotation shaft 835A in a predetermined direction, nut 836A moves upward in Fig. 5. This causes link mechanism 832A to extend, and clamping plate 830A connected to the right side of link mechanism 832A in Fig. 5 moves to the right, bringing the pair of clamping plates 830A closer to each other, pressurizing storage section 81 sandwiched between them and discharging coating liquid 100.

[0133] When motor 833A is driven to rotate rotation shaft 835A in the opposite direction to the above, nut 836A moves downward in Fig. 5. This causes link mechanism 832A to contract, and clamping plate 830A connected to the right side of link mechanism 832A in Fig. 5 moves leftward, separating the pair of clamping plates 830A, releasing the pressure on storage section 81 sandwiched between them, and stopping the discharge of coating liquid 100. Stopping the driving of motor 833A also stops the discharge of coating liquid 100 from storage section 81.

[0134] As described above, by the extension and contraction of link mechanism 832A in response to the selection of the rotation direction of motor 833A, clamping plate 830A connected to the right side of link mechanism 832A in Figure 5 can be moved left and right, thereby adjusting the discharge of coating liquid 100 from storage section 81 clamped between the pair of clamping plates 830A.

[0135] By controlling the control unit 7 to set the rotation direction, rotation speed, etc. of the motor 833A as desired, the discharge speed (amount discharged per unit time) of the coating liquid 100 from the reservoir 81 can be adjusted.

[0136] According to this embodiment, it is possible to obtain the same effects as in the first embodiment, and it is also possible to apply a stronger force to the storage section 81 than in the first embodiment. This is therefore advantageous for more reliably or quickly discharging the coating liquid 100. In other words, it is possible to more reliably or quickly supply the coating liquid 100.

[0137] As described above, the pressurizing unit 83 has a clamping unit 83A that clamps the storage unit 81, and pressurizes the storage unit 81 by clamping it with the clamping unit 83A. This allows a strong pressure to be applied to the storage unit 81. Therefore, the supply of the coating liquid 100 can be more reliably or quickly performed.

[0138] The clamping portion 83A has at least one clamping plate 830A, and in this embodiment, two clamping plates 830A, which allows the storage portion 81 to be pressurized more reliably and stably.

[0139] In this embodiment, the pair of clamping plates 830A are arranged parallel to each other, but the present invention is not limited to this and they do not have to be parallel to each other. In this case, it is preferable that the distance between the ends of the pair of clamping plates 830A on the outlet 811 side is smaller than the distance between the ends on the opposite side.

[0140] In this embodiment, one clamping plate 830A moves parallel to the other fixed clamping plate 830A to pressurize the storage section 81, but the present invention is not limited to this, and the pair of clamping plates 830A may also be configured to move toward or away from each other.

[0141] In addition, the lower ends (one end) of a pair of clamping plates 830A may be supported rotatably, and the clamping plates 830A may rotate so that the upper ends (other end) of the pair of clamping plates 830A move closer to or farther away from each other, thereby pressurizing the storage section 81 located between each clamping plate 830A.

[0142] In this embodiment, two clamping plates 830A are provided, but the present invention is not limited to this and the number may be one, or three or more. Clamping plates 830A may have a shape other than a flat plate, for example, a curved plate.

[0143] <Third embodiment> FIG. 6 is a cross-sectional view showing a storage unit and a pressurizing unit provided in a conveying device and a printing device according to a third embodiment of the present invention.

[0144] Below, we will explain the third embodiment of the conveying device, printing device, and adhesive application method of the present invention with reference to Figure 6. However, below we will mainly explain the differences from the first embodiment, and omit explanations of similar points.

[0145] 6, the pressurizing unit 83 has a clamping unit 83B that clamps the storage unit 81. The storage unit 81 is pressurized by clamping with the clamping unit 83B, and the coating liquid 100 is discharged.

[0146] The clamping unit 83B has a pair of pressure rollers 831B and a movement mechanism (not shown) that moves the pair of pressure rollers 831B up and down in Fig. 6. The pair of pressure rollers 831B are columnar or cylindrical, and are arranged on opposite sides of the storage unit 81 with their rotation axes oriented horizontally (perpendicular to the paper surface of Fig. 6). The pair of pressure rollers 831B are supported by a support (not shown) so as to be vertically movable while sandwiching the storage unit 81.

[0147] The movement mechanism that moves the pair of pressure rollers 831B up and down has a motor as a drive source, and the motor can rotate in either forward or reverse direction by switching the direction of current flow. The motor is electrically connected to the control unit 7. The control unit 7 controls the operation timing, rotation direction, rotation speed, etc. of the motor.

[0148] With the pair of pressure rollers 831B sandwiching the storage portion 81, the movement mechanism is operated to raise the pair of pressure rollers 831B, i.e., move them toward the discharge port 811. As a result, the flexible storage portion 81 is pressurized so as to be squeezed upward, and the coating liquid 100 in the storage portion 81 is pushed out and discharged. Here, by adjusting the movement speed of the pair of pressure rollers 831B, the discharge speed (amount discharged per unit time) of the coating liquid 100 can be adjusted.

[0149] When the operation of the movement mechanism is stopped and the vertical movement of the pair of pressure rollers 831B is stopped, the discharge of the application liquid 100 from the reservoir 81 is stopped.

[0150] The pair of pressure rollers 831B may be configured to be able to move closer to or farther away from each other. That is, they may be configured to be able to adjust the degree to which they clamp the storage portion 81. In this case, appropriate pressure can be applied depending on the remaining amount of coating liquid 100 in the storage portion 81.

[0151] Thus, the clamping unit 83B has at least one pressure roller 831B. This makes it possible to more accurately adjust the discharge speed of the coating liquid 100, i.e., the amount discharged per unit time. This is particularly suitable for fine adjustment of the discharge speed of the coating liquid 100. Furthermore, even if the remaining amount of the coating liquid 100 in the storage unit 81 becomes small, the coating liquid 100 can be more reliably pushed out.

[0152] Furthermore, the lower end of storage portion 81 is fixed to the bottom of casing 831 by fixing member 832B. In this embodiment, storage portion 81 is provided at its lower end with tab 834B having insertion hole 833B formed therein, through which fixing member 832B is inserted. Furthermore, casing 831 has a bottom portion provided with fixing member 836B having insertion hole 835B formed therein, through which fixing member 832B is inserted. Fixing member 832B is S-shaped, with one end inserted into and hooked on insertion hole 833B and the other end inserted into and hooked on insertion hole 835B. This fixes the lower end of storage portion 81 to the bottom of casing 831.

[0153] With this configuration, the vertical position of the reservoir 81 can be maintained when the pair of pressure rollers 831B moves up and down, and the application liquid 100 can be discharged more accurately and stably.

[0154] The lower end of storage section 81 may be fixed to the bottom of casing 831 by a fixing mechanism of a different configuration. Also, the lower end of storage section 81 may be fixed to a location other than the bottom of casing 831, or may not be fixed to casing 831.

[0155] In this embodiment, the clamping section 83B has a pair of pressure rollers 831B, but is not limited to this and may have two or more pairs of pressure rollers 831B, or may have a single pressure roller 831B.

[0156] Furthermore, pressure unit 83 may be configured to pressurize storage unit 81 using one or more pressure rollers and a clamping plate.

[0157] Furthermore, the pressure applying section 83 may be an appropriate combination of the configurations of the pressure applying section 83 in the first, second and third embodiments.

[0158] Furthermore, the member that presses or applies pressure to the storage portion 81 is not limited to the clamping plate or pressure roller described above, but may be, for example, a rod-shaped, frame-shaped, mesh-shaped, or block-shaped member.

[0159] Although the conveying device, printing device, and adhesive application method of the present invention have been described above with reference to the illustrated embodiments, the present invention is not limited to these. Furthermore, each part and each step of the conveying device, printing device, and adhesive application method can be replaced with any structure or step that can perform the same function. Furthermore, any structure or step may be added. [Explanation of symbols]

[0160] 1...printing device, 2...conveying device, 3...feeding device, 4...winding device, 5...printing unit, 6...ink drying unit, 7...control unit, 8...coating liquid supply unit, 9...blade, 10...adhesive drying unit, 11...coil, 21...conveyor belt, 22...drive roller, 23...driven roller, 24...tensioner, 25...tensioner, 31...feed roller, 32...tensioner, 41...winding roller, 42...tensioner, 43...tensioner, 44...tensioner, 51...inkjet head, 52...carriage unit, 61...chamber, 62...coil, 71...power supply unit, 72...control circuit, 81...storage unit, 82...liquid supply pipe, 83...pressure unit, 83A...clamping unit, 83B...clamping unit, 100...coating liquid, 105...coating film, 210...coated surface, 811...discharge port, 821...one end, 822...other end, 830A...clamping plate, 831...casing, 831A...driving mechanism, 831B...pressure roller, 832...air supply unit, 832A...link mechanism, 832B...fixing member, 833...air supply source, 833A...motor, 833B...insertion hole, 834...air supply pipe, 834A...rotating shaft connection part, 834B...fixing member, 835...exhaust pipe, 835A...rotating shaft, 835B...insertion hole, 836...opening / closing valve, 836A...nut, 836B...fixing member, 837...adjusting part, G...distance, S...space, W...recording medium

Claims

1. a conveyor belt for conveying a recording medium; a coating liquid supply unit that supplies a coating liquid of an aqueous adhesive containing water and a resin to a coating surface of the conveyor belt that faces the recording medium, The coating liquid supply unit is characterized in that it includes a flexible, bag-shaped storage unit having a discharge outlet and storing the coating liquid, and a pressurizing unit that pressurizes the storage unit to push the coating liquid out of the discharge outlet.

2. the pressurizing unit has a casing that houses the storage unit, and an air supply unit that supplies air to a space between the casing and the storage unit, The conveying device according to claim 1 , wherein the storage section is pressurized by air pressure in the space.

3. the pressurizing unit has a clamping unit that clamps the storage unit, The conveying device according to claim 1 , wherein the storage section is pressurized by clamping with the clamping section.

4. The conveying device according to claim 3 , wherein the clamping section has at least one clamping plate.

5. The conveying device according to claim 3 , wherein the clamping unit has at least one pressure roller.

6. The conveying device according to claim 1 , wherein the pressurizing unit includes an adjusting unit that adjusts the amount of the coating liquid extruded from the storage unit per unit time by adjusting the degree of pressure applied to the storage unit.

7. 6. The conveying device according to claim 1, further comprising a liquid supply pipe connected to the outlet for transporting the coating liquid to the coating surface.

8. A conveying device according to any one of claims 1 to 5; an inkjet head that performs printing by ejecting ink onto the recording medium being transported by the transport belt.

9. a supplying step of supplying a coating liquid of an aqueous adhesive containing water and a resin onto a coating surface of a conveying belt that conveys a recording medium, the coating surface being on the recording medium side; a drying step of drying the coating liquid applied to the coating surface, The adhesive application method is characterized in that, in the supplying step, a flexible, bag-shaped storage section that has a discharge outlet and stores the application liquid is pressurized to push the application liquid out of the discharge outlet.

Images