Printing substrate and method for manufacturing the same

Abstract

To provide a novel printing substrate and the like.SOLUTION: A printing substrate has a printed portion thereon, the printed portion including a different color printed portion in which different colors are printed with a clearance therebetween.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a novel printing substrate and the like.

Background Art

[0002] Conventionally, various printing methods (image recording methods) have been known. For example, the inkjet method is a printing method (printing system) that ejects minute ink droplets to perform printing (record or form an image). And, as such inks for inkjet, various types are known depending on printing performance, the type of substrate to be printed, coating film performance, etc. (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a novel printing substrate and a method for manufacturing the same.

[0005] As described above, various printing methods have been known conventionally. However, when printing adjacent (without spacing) different color inks (color inks), the inks may mix at the boundary between these adjacent colors (a portion of different colors), resulting in bleeding (color mixing).

[0006] In particular, according to the study by the present inventor, such bleeding between different colors is likely to occur in a printing method that prints (records an image) the ink in dots like the inkjet method. Among such printing methods, when printing on a substrate with non- or low-absorbency (liquid absorbency) (for example, a plastic film, etc.), when using an aqueous ink, when printing by overlapping a color ink and a clear ink, etc., it could be significantly confirmed.

[0007] Although the inks of different colors are adjacent, they are naturally printed in positions (dots) that do not overlap with each other, making it extremely difficult to solve the problem of ink bleeding. [Means for solving the problem]

[0008] Under these circumstances, the inventors, after diligent research, discovered that when printing inks of different colors adjacent to each other, the bleeding between adjacent colors can be efficiently resolved by printing in such a way that a clearance is created between the different colors. Further research led to the completion of the present invention.

[0009] In other words, the present invention relates to the following inventions, etc. [1] A printing substrate having a printed portion on a substrate, wherein the printed portion includes (at least) a different-color printed portion in which different colors are printed with a clearance between them. [2] A printing substrate having a printed area on a substrate, A printing substrate in which the printed area includes at least two different colored printed areas in which different colors are printed adjacent to each other without bleeding. [3] A printing substrate according to [1] or [2], wherein the wet tensile strength of the printed surface of the substrate is 30 to 50 dyn / cm. [4] A printing substrate according to any one of [1] to [3], wherein the base material is a plastic film. [5] A printing substrate according to any one of [1] to [4], wherein the printing surface of the substrate is composed of a polyester resin. [6] A printing substrate according to any one of [1] to [5], wherein the printed portion is printed by an inkjet method. [7] A printing substrate according to any one of [1] to [6], wherein the printed portion is formed with water-based ink. [8] A printing substrate according to any one of [1] to [7], wherein the printing portion is formed of color ink and clear ink. [9] A printing substrate according to any one of [1] to [8], wherein the printing portion is formed of water-based color ink and water-based clear ink.

[10] A printing substrate according to any one of [1] to [9], wherein the proportion of resin to the total amount of resin and colorant in the printed portion is 20% by mass or more.

[11] A printing substrate as described in any of [1] to

[10] , wherein the clearance width is 10 to 1500 μm.

[12] A printing substrate according to any one of [1] to

[11] , which includes a different-color printing section in which, when the different colors are designated as color 1 and color 2, the width of color 1 or color 2 is A (μm) and the clearance width is B (μm), the value of B / A is 8 or less.

[13] A printing substrate according to any one of [1] to

[12] , which includes a different-color printing area in which the X / Y value is between 20 and 800, where X (dpi) is the printing resolution and Y is the number of pixels corresponding to the clearance width.

[14] A printing substrate according to any one of [1] to

[13] , comprising a different-color printing section 1, wherein when the different colors of the printing section are designated as color 1 and color 2, the width of color 1 or color 2 is 500 μm or less, and when the printing resolution is X (dpi) and the number of pixels corresponding to the clearance width is Y, the value of X / Y is 50 or more.

[15] The printing substrate according to

[14] , wherein in the different-color printing section 1, the width of color 1 or the width of color 2 is 400 μm or less, and the X / Y value is 100 or more.

[16] A printing substrate according to any one of [1] to

[15] , which includes a different-color printing section 2, wherein when the different colors of the printing section are designated as color 1 and color 2, the width of color 1 or color 2 is greater than 500 μm, and when the printing resolution is X (dpi) and the number of pixels corresponding to the clearance width is Y, the value of X / Y is 200 or less.

[17] The printed substrate according to

[16] , wherein in the different-color printing portion 2, the width of color 1 or the width of color 2 is 600 μm or more, and the value of X / Y is 150 or less.

[18] The printed substrate according to any one of [1] to

[17] , wherein the different-color printing portion includes the different-color printing portion 1 according to

[14] or

[15] , and the different-color printing portion 2 according to

[16] or

[17] .

[19] The printed substrate according to any one of [1] to

[18] , wherein the different-color printing portion includes a different-color printing portion in which any one of the different colors is white.

[20] The printed substrate according to any one of [1] to

[19] , wherein the different-color printing portion includes a different-color printing portion in which when different colors are used as color 1 and color 2, color 1 is a pattern and color 2 is a background.

[21] The printed substrate according to any one of [1] to

[20] , wherein the different-color printing portion includes a different-color printing portion that can be recognized as a barcode or a two-dimensional code in which when different colors are used as color 1 and color 2, color 1 is a barcode or a two-dimensional code and color 2 is a background.

[22] The printed substrate according to any one of [1] to

[21] , for forming a medical soft bag (for example, an infusion bag).

[23] A method for manufacturing the printed substrate according to any one of [1] to

[22] , which includes at least a printing step of printing a printing portion on a substrate, and in the printing step, a clearance is provided between different colors to print a different-color printing portion.

[24] A method for suppressing or preventing bleeding between different colors in a different-color printing portion in a printed substrate provided with a printing portion including a different-color printing portion in which different colors are printed adjacent to each other on a substrate, and in the printing step of printing a printing portion on the substrate, a clearance is provided between different colors to print a different-color printing portion.

[25] The method according to

[23] or

[24] , which is printed by an inkjet method.

[26] The method according to any one of

[23] to

[25] , in which in the printing step, color ink and clear ink are ejected for printing.

[27] The method described in any of the following

[23] -

[26] , wherein the clearance width is printed to be between 10 and 1500 μm.

[28] The method according to any one of

[23] to

[27] , wherein, when two different colors are designated as color 1 and color 2, the width of color 1 or color 2 is A (μm), and the width of the clearance is B (μm), the clearance is provided such that the value of B / A is 8 or less.

[29] The method according to any of

[23] to

[28] , wherein the print resolution is X (dpi) and the number of pixels corresponding to the width of the clearance is Y, and the clearance is provided such that the value of X / Y is between 20 and 800.

[30] A molded product made from one of the printed substrates [1] to

[22] .

[31] A molded product as described in

[30] , which is a medical soft bag. [Effects of the Invention]

[0010] The present invention provides a novel printing substrate and a novel method for manufacturing the printing substrate. Such a printing substrate and manufacturing method can efficiently prevent (or suppress) bleeding between different colors. Such a printing substrate and method are preferable because, even when different colors (different colored inks) are printed adjacent to each other, the visibility and design are not impaired due to bleeding. In particular, when the printing substrate is used as packaging material for pharmaceuticals, preventing a decrease in visibility due to bleeding can prevent medical accidents such as the misidentification of pharmaceuticals. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a close-up photograph of the different-colored printed section 1 of the printed substrate obtained in Example 1. [Figure 2] Figure 2 is a micrograph of the different-colored printed section 1 of the printed substrate obtained in Example 1. [Figure 3] Figure 3 is a close-up photograph of the different-colored printed area 2 of the printing substrate obtained in Example 1. [Figure 4] Figure 4 is a micrograph of the different-colored printed area 2 of the printed substrate obtained in Example 1. [Figure 5] Figure 5 is a close-up photograph of the different-colored printed section 3 of the printing substrate obtained in Example 1. [Figure 6] Figure 6 is a micrograph of the different-colored printed area 3 of the printed substrate obtained in Example 1. [Modes for carrying out the invention]

[0012] <Printing base material> A printing substrate has a printed portion (coating, film) on the substrate. In other words, a printing substrate has a substrate and a printed portion formed (provided) on this substrate.

[0013] Furthermore, this printed section has a printed section (a section printed in a different color) in which at least a different color is printed, and the present invention is characterized by this section printed in a different color.

[0014] In other words, in the first aspect of the present invention, different colors are printed adjacent to each other (without separation) in the different-color printing section without bleeding. As described above, when different colors are printed adjacent to each other, bleeding may occur between adjacent different colors, but in the first aspect, different colors are printed adjacent to each other without such bleeding occurring.

[0015] Furthermore, in a second aspect of the present invention, in this different-color printing section, different colors are printed with a clearance (gap) between them (there is a clearance between the different colors).

[0016] In this second embodiment, since there is clearance between different colors, bleeding (color mixing) does not usually occur between different colors, just as in the first embodiment.

[0017] Furthermore, as will be described later, the printing substrates according to the first and second embodiments of the present invention can usually be efficiently obtained by printing in such a way that clearance is created between different colors.

[0018] After this printing process, when the clearance set during printing is reflected in the different-colored printing area, a different-colored printing area (a second type of different-colored printing area) with a clearance between different colors is formed.

[0019] On the other hand, even if printing is done in a way that creates clearance (by setting it to create clearance), depending on the type of substrate, the type of ink, and the printing method, different colored inks may spread slightly towards each other.

[0020] In such cases, by adjusting the size of the clearance and matching the size (width) of the clearance with the size (width) of the spread, different colored inks spread out close to each other without bleeding, and a mixed-color printed area is formed where (apparently) there is no clearance between the different colors (mixed-color printed area in the first embodiment).

[0021] Therefore, the first embodiment can also be described as a special embodiment of the second embodiment (an embodiment in which the clearance set during printing is not (apparently) reflected in the different color printing area, and no bleeding occurs).

[0022] Further details are provided below.

[0023] [Base material] Examples of substrates (recording media, printing medium) include plastic, metal, wood, paper, etc., and may also be substrates made by combining these materials.

[0024] Examples of plastics include polyester resins (e.g., polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate resins, olefin resins (e.g., polyethylene, polypropylene, cyclic olefin resins), halogen resins (e.g., polyvinyl chloride), acrylic resins, styrene resins, and polyamide resins.

[0025] The type of base material (material) can be selected according to the application, handling, productivity, printability, etc. For example, polyester resins may be suitably used from the viewpoint of printability and high-speed bag making (high-speed sealing).

[0026] The shape of the substrate may be one-dimensional (e.g., rod-shaped), two-dimensional (e.g., film (or sheet)-shaped), or three-dimensional (e.g., various molded products), and is typically a film (sheet) shape.

[0027] The film-like substrate may be a stretched film. Furthermore, the film-like substrate may be a laminated film, or it may be in the form of a bag (tube, tube film, inflation film), etc.

[0028] The substrate may be a coated substrate (e.g., coated paper) or a surface-treated substrate (e.g., corona discharge treatment, plasma treatment).

[0029] Furthermore, such processing may be performed on at least the printing area of ​​the substrate (the recording area, the area forming the printed part, for example, the printed surface of a film-like substrate) (the same applies hereinafter to the characteristics and physical properties of the substrate).

[0030] The base material may be transparent, depending on its properties.

[0031] Typical substrates include plastic films (especially transparent plastic films).

[0032] Furthermore, the base material may be colored or colorless.

[0033] The substrate (the printed surface of the substrate, the part that forms the printed area) may be particularly low in liquid absorption or non-absorbent (particularly low in water absorption or non-absorbent). In the present invention, even with such a substrate, it is possible to efficiently form different color printed areas without bleeding (or with clearance) between different colors.

[0034] The wetting tension of the substrate (the printed surface of the substrate, the part that forms the different color printed area) may be, for example, 25 to 55 dyn / cm, preferably 28 to 52 dyn / cm, and more preferably 30 to 50 dyn / cm (for example, 32 to 45 dyn / cm, 33 to 42 dyn / cm).

[0035] Wetting tension can be measured, for example, according to JIS K6768. As wetting reagents, for example, a wettability test mixture (manufactured by Fujifilm Wako Pure Chemical Industries, etc.) or a wettability check pen (enerdyne series, manufactured by enercon, etc.) can be used. Specific methods include dipping the tip of a cotton swab or similar object into a wettability test mixture and wetting the surface of the printed material with the swab. The areas where the liquid spreads to some extent after about 2 seconds, and areas where the liquid is repelled, are then examined using mixtures of different grades.

[0036] Wetting tension can be related to the wettability of the ink used for printing, and consequently, the ease of printing (recording). However, the greater the wettability, the easier it is for adjacent colors to mix (bleed). This invention efficiently achieves both sufficient printability (appropriate wettability) and prevention (suppression) of bleeding.

[0037] [ink] The printed area (the area with different color printing) is usually formed by ink (ink composition).

[0038] Furthermore, if the ink contains volatile components (solvent components), the printed area (the area printed in a different color) will be composed of the solid components of the ink that have evaporated from the volatile components, i.e., the solid components of the ink (colorants, resins, etc., as described later).

[0039] The ink only needs to consist of at least colored inks, and may be combined with other inks (such as clear ink) as needed.

[0040] (Color ink) The colorants (colorants) included in the colored inks can be either white-based colorants or non-white-based colorants (yellow, cyan, magenta, black, gray, red, orange, green, etc.).

[0041] In particular, the colors constituting the different-colored printed area may contain at least a white-based coloring agent. When the different colors constituting the different-colored printed area include white (and especially when the substrate is transparent), the clearance provided in the different-colored printed area tends to be difficult to see (less noticeable), and bleeding can be prevented in a natural way without making the clearance noticeable.

[0042] As colorants, for example, dyes and pigments can be used, and preferably pigments may be preferred. Both inorganic and organic pigments can be used.

[0043] Examples of inorganic pigments include metal compounds (e.g., titanium dioxide, basic lead carbonate, zinc sulfide, iron oxide, red iron oxide, chromium oxide, etc.) and carbon black (e.g., furnace black, acetylene black, channel black, etc.).

[0044] Examples of organic pigments include azo pigments (e.g., azo lake pigments), phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindlinone pigments, and diketopyrrolopyrrole pigments.

[0045] The color index (CI) of colorants is not particularly limited. For example, examples of color indices for white pigments include CIPigment White 1 (basic lead carbonate), 4 (zinc oxide), 5 (mixture of zinc sulfide and barium sulfate), 6 (titanium dioxide), 6:1 (titanium dioxide containing other metal oxides), 7 (zinc sulfide), 18 (calcium carbonate), 19 (clay), 20 (titanium mica), 21 (barium sulfate), 22 (natural barium sulfate), 23 (gloss white), 24 (alumina white), 25 (gypsum), 26 (magnesium oxide / silicon oxide), 27 (silica), and 28 (anhydrous calcium silicate).

[0046] Furthermore, the coloring agent (pigment) may be surface-treated (even if it is a self-dispersing pigment), or it may be in the form of dispersed in a dispersant (surfactant, resin, etc.) (dispersed pigment).

[0047] Color inks may typically contain resin (resin components). Resin can be used for purposes such as improving the abrasion resistance and adhesion of the coating.

[0048] Examples of resins include acrylic resins, styrene-acrylic resins, styrene resins, vinyl carboxylate ester resins (e.g., vinyl acetate resins), olefin resins, rosin-modified resins, terpene resins, diene resins (e.g., butadiene resins), halogen resins (e.g., vinyl chloride resins), polyester resins, urethane resins (polyurethane resins), polyamide resins, epoxy resins, and the like.

[0049] Furthermore, if a resin can be formed in the coating film [for example, by reacting (polymerization, condensation, etc.) as the coating film dries to polymerize or crosslink], then components that serve as precursors to resins or prepolymers (for example, polyisocyanate compounds, polyol compounds, etc.) can also be used as resins (resin components).

[0050] The resin may be used alone or in combination of two or more types.

[0051] The resin may have functional groups (reactive groups). Examples of functional groups include acid groups (e.g., carboxyl groups), amino groups, hydroxyl groups, mercapto groups, epoxy groups, isocyanate groups, carbodiimide groups, oxazoline groups, and the like.

[0052] The resin may have one or more functional groups.

[0053] Such functional groups can contribute to crosslinking of printed inks (coating films).

[0054] The form of the resin is not limited, but it may be particulate (resin particles), and typically, it may be such resin emulsion particles (resin particles constituting an emulsion). Such emulsion particles may contain a dispersant (surfactant).

[0055] The color ink may have crosslinking properties. Crosslinking properties allow for the formation of an even stronger coating (printed film).

[0056] Such crosslinking properties can be imparted to color inks, for example, by using a resin that has at least functional groups and including a component (crosslinking agent) that can crosslink by reacting with these functional groups in the color ink, or by including a crosslinking agent that reacts with the resin constituting the clear ink described later in the color ink.

[0057] The crosslinking agent (crosslinkable component) can be appropriately selected depending on the type of functional groups present in the resin constituting the color ink and / or the resin constituting the clear ink.

[0058] For example, if the functional group is a carboxyl group, a crosslinking agent having a reactive group for the carboxyl group (e.g., an isocyanate group, epoxy group, carboidimide group, oxazoline group, etc.) can be used.

[0059] Furthermore, functional groups and reactive groups (and even crosslinking agents) only need to be crosslinkable in the coating; they may be protected (blocked) in the ink (ink before printing). In such cases, deprotection and crosslinking occur in the coating.

[0060] In the printing section (different color printing section), the crosslinking agent (crosslinkable component) crosslinks the resin, meaning it is a component of the resin.

[0061] Color inks may contain, for example, dispersants, surfactants, defoamers, solubilizers, viscosity modifiers, pH adjusters, antioxidants, preservatives, fungicides, corrosion inhibitors, etc. These may be included in the color inks individually or in combination of two or more.

[0062] The color ink may be oil-based, water-based, or otherwise, but water-based ink may be preferably used considering environmental factors. Water-based ink tends to have a longer drying time, which can lead to bleeding between different colors (particularly noticeable bleeding when printing on substrates such as plastic films). However, in this invention, bleeding between different colors can be efficiently suppressed even when using water-based ink.

[0063] The solvent contained in the color ink can be appropriately selected according to its classification as oil-based or water-based.

[0064] For example, the solvent contained in water-based ink may consist of at least water, and may also contain an organic solvent (water-soluble organic solvent) as needed.

[0065] Examples of such organic solvents include alcohol-based solvents, ether-based solvents, nitrogen-based solvents (e.g., linear amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; cyclic amide solvents such as 2-pyrrolidone, N-methyl-2-pyrrolidone, and 2-oxazolidone; urea derivatives such as 1,3-dimethyl-2-imidazolidinone and 1,1,3,3-tetramethylurea), and sulfur-based solvents (e.g., dimethyl sulfoxide and sulfolane).

[0066] Examples of alcohol-based solvents include monools (e.g., methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, 2-butanol, t-butanol, isobutanol, n-pentanol, 2-pentanol, 3-pentanol, t-pentanol, and other alkanols), and polyols (e.g., ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and other alkanediols; polyalkanediols such as diethylene glycol, dipropylene glycol, and triethylene glycol; and aliphatic polyols such as glycerin, which have three or more hydroxyl groups).

[0067] Examples of ether-based solvents include mono- to polyethers of polyols (e.g., the polyols exemplified above) [e.g., ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-butyl ether, etc., alkanediolic monoalkyl ethers; diethylene glycol mono-n-propyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monobutyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-butyl ether, diethylene glycol mono-butyl ether, diethylene glycol mono-nisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, Examples include polyalkanediol monoalkyl ethers such as ethylene glycol mono-t-butyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol mono-n-propyl ether, and dipropylene glycol monoisopropyl ether; and polyol polyalkyl ethers (e.g., polyalkanediol dialkyl ethers) such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether.

[0068] Organic solvents may be used individually or in combination of two or more.

[0069] In color inks, the proportion of each component can be appropriately selected depending on the printing method (e.g., ejection properties in inkjet printing), ink viscosity, etc.

[0070] For example, in a colored ink, the proportion of the colorant may be, for example, 0.1% by mass or more (e.g., 0.5 to 30% by mass), preferably 1% by mass or more (e.g., 1.5 to 20% by mass), and more preferably 2% by mass or more (e.g., 3 to 15% by mass).

[0071] Furthermore, in the color ink, the proportion of resin (resin component) may be, for example, 0.1% by mass or more (e.g., 0.5 to 30% by mass), preferably 1% by mass or more (e.g., 1.5 to 20% by mass), and more preferably 2% by mass or more (e.g., 3 to 15% by mass).

[0072] If the color ink contains a crosslinking agent, the proportion of the crosslinking agent may be, for example, 0.01% by mass or more (e.g., 0.05 to 10% by mass), preferably 1% by mass or more (e.g., 0.1 to 5% by mass), and more preferably 0.3% by mass or more (e.g., 0.5 to 3% by mass), depending on the type of crosslinking agent and the amount of resin, etc.

[0073] In colored inks, the proportion of solvent can be selected according to the ink's viscosity, composition, and other factors. For example, in an aqueous ink, the proportion of water may be, for example, 20% by mass or more (e.g., 30-90% by mass), preferably 40% by mass or more (e.g., 45-80% by mass), and more preferably 50% by mass or more (e.g., 50-75% by mass).

[0074] When the water-based ink contains an organic solvent (water-soluble organic solvent), the proportion of the water-soluble organic solvent may be, for example, 1% by mass or more (e.g., 3 to 60% by mass), preferably 5% by mass or more (e.g., 8 to 50% by mass), and more preferably 10% by mass or more (e.g., 15 to 40% by mass).

[0075] The viscosity of the color ink may be, for example, 1 to 80 mPa·s, preferably 2 to 50 mPa·s, and more preferably 3 to 30 mPa·s at 32°C.

[0076] Viscosity can be measured using, for example, a viscometer (Type E viscometer, Type B viscometer, Ubbelohde viscometer, etc.) or a capillary rheometer.

[0077] (Clear ink) Color ink may be combined with clear ink. This combination forms a printed area (a different colored printed area) using the color ink and the clear ink (an ink set of color ink and clear ink).

[0078] The purpose of using clear ink is not particularly limited, but one purpose may be to increase the proportion of resin in the total ink (or printed area) (or the proportion of resin to the colorant). In particular, when printing on a substrate such as plastic film, increasing the amount of resin makes it easier to efficiently form a printed area with superior scratch resistance, adhesion, etc.

[0079] Here, simply increasing the resin content would suffice; this would involve increasing the amount of resin in the color ink. However, doing so would increase the viscosity of the ink, potentially leading to problems such as impaired ejection performance in the inkjet method.

[0080] Therefore, from the standpoint of achieving efficient printing, clear ink may be suitably used.

[0081] Clear ink typically contains a resin (resin component). Examples of such resins include the resins described above (e.g., acrylic resins, styrene-acrylic resins, urethane resins, etc.), which may have the same functional groups as described above.

[0082] Furthermore, the clear ink may also be crosslinkable, and its embodiment is the same as described above. For example, the clear ink may contain a crosslinking agent (such as the components exemplified above), and the crosslinking agent may react with the resin contained in the clear ink (for example, a resin having functional groups) and / or the resin (a resin having functional groups) that constitutes the color ink.

[0083] Clear ink does not necessarily need to contain colorants.

[0084] Clear ink may also contain dispersants, surfactants, defoamers, solubilizers, viscosity modifiers, pH adjusters, antioxidants, preservatives, fungicides, corrosion inhibitors, etc.

[0085] The clear ink may be oil-based or water-based, but water-based ink is preferable. In particular, it is good to use the same oil-based / water-based ink for both the color ink and the clear ink, and typically, both the color ink and the clear ink may be water-based.

[0086] As mentioned above, using clear ink (and even more so using water-based ink) results in a relatively larger amount of solvent (especially water) during printing compared to using only colored ink (and consequently, a longer drying time), which makes bleeding between different colors more pronounced. However, in this invention, bleeding can be efficiently suppressed even when using clear ink (and even more so when using water-based ink).

[0087] The solvent contained in the clear ink can be appropriately selected according to its classification as oil-based or water-based. For example, the solvent contained in water-based ink may consist of at least water, and may also contain an organic solvent (water-soluble organic solvent) as needed.

[0088] Examples of water-soluble organic solvents include those exemplified above (alcohols, ethers).

[0089] In the clear ink, the proportion of resin (resin component) may be, for example, 0.1% by mass or more (e.g., 0.5 to 30% by mass), preferably 1% by mass or more (e.g., 1.5 to 20% by mass), and more preferably 2% by mass or more (e.g., 3 to 15% by mass).

[0090] If the clear ink contains a crosslinking agent, the proportion of the crosslinking agent may be, for example, 0.01% by mass or more (e.g., 0.05 to 10% by mass), preferably 1% by mass or more (e.g., 0.1 to 5% by mass), and more preferably 0.3% by mass or more (e.g., 0.5 to 3% by mass), depending on the type of crosslinking agent and the amount of resin, etc.

[0091] In clear inks, the proportion of solvent can be selected according to the ink's viscosity, composition, and other factors. For example, in an aqueous ink, the proportion of water may be, for example, 20% by mass or more (e.g., 30-90% by mass), preferably 40% by mass or more (e.g., 45-80% by mass), and more preferably 50% by mass or more (e.g., 50-75% by mass).

[0092] When the water-based ink contains an organic solvent (water-soluble organic solvent), the proportion of the water-soluble organic solvent may be, for example, 1% by mass or more (e.g., 3 to 60% by mass), preferably 5% by mass or more (e.g., 8 to 50% by mass), and more preferably 10% by mass or more (e.g., 15 to 40% by mass).

[0093] The viscosity of the clear ink may be, for example, 1 to 80 mPa·s, preferably 2 to 50 mPa·s, and more preferably 3 to 30 mPa·s at 32°C.

[0094] Viscosity can be measured using, for example, a viscometer (Type E viscometer, Type B viscometer, Ubbelohde viscometer, etc.) or a capillary rheometer.

[0095] [Printing Department and Special Printing Department] As described above, the printing substrate has a printing area on the substrate, and this printing area includes at least a different color printing area.

[0096] In the printed section (different color printed section), the ratio of resin (resin component) to the total amount of resin (resin component) and colorant can be selected according to the type of substrate, coating performance, etc., but for example, it may be 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and especially 50% by mass or more. The upper limit of the ratio of resin to the total amount of resin and colorant may be, for example, 95% by mass, 90% by mass, 85% by mass, 80% by mass, 75% by mass, 70% by mass, etc. Examples of specific ratios of resin (resin components) to the total amount of resin (resin components) and colorants include 10-95% by mass, 30-90% by mass, and 50-80% by mass.

[0097] Furthermore, since crosslinking agents are components that react with resins, etc., when a crosslinking agent is used to form a printed area, the crosslinking agent also constitutes part of the resin in the printed area.

[0098] By ensuring a sufficient amount of resin in the printing area, a strong coating (printed area) can be efficiently formed even on substrates such as plastic films, as described above. Furthermore, as mentioned above, using clear ink is advantageous for increasing the amount of resin, but in the present invention, even when using such clear ink, bleeding between different colors can be efficiently suppressed as described above.

[0099] The printed area can be formed using a printing method, and may, in particular, be printed in a dot pattern. Such printed areas can typically be formed by inkjet printing.

[0100] Furthermore, when printing in a dot pattern using an inkjet method or the like, the dots may be reflected in the printed area (different color printed area) [the printed area (different color printed area) may be formed in a dot pattern (the printed area may be composed of dots)], and some or all of the dots may be crushed.

[0101] Depending on the type of ink used (for example, whether clear ink or water-based ink is used) and the resolution, even when printing in a dot pattern, adjacent dots (or the ink ejected on top of them) may mix, causing the dots to become significantly blurred (for example, the dots to appear to disappear). In this invention, even in cases where bleeding is likely to occur, bleeding between different colors can be efficiently suppressed.

[0102] The dot density (resolution) can be appropriately selected to match the desired printing area, but it may be selected from a range such as 50 dpi or higher, or it may be 100 dpi or higher, preferably 200 dpi or higher, and even more preferably 300 dpi or higher. The upper limit of the resolution may be, for example, 1200 dpi, 1000 dpi, 800 dpi, 600 dpi, etc. Specific resolutions include, for example, 50-1200 dpi, 200-1000 dpi, and 300-800 dpi.

[0103] As mentioned above, blurring tends to occur as the resolution increases, but the present invention can efficiently suppress blurring between different colors even at relatively high resolutions.

[0104] The resolution may or may not be the same across the entire printed area. For example, the resolution in the printing direction (vertical direction) and the direction perpendicular to the printing direction (horizontal direction) may or may not be the same.

[0105] Furthermore, when using clear ink, as long as it is printed (ejected) in the same position (dot) as the color ink, the dots of the color ink and the dots of the clear ink may be the same or different (for example, at least the dots of the clear ink may overlap the dots of the color ink).

[0106] In the multi-color printing section, different colors are printed adjacent to each other (or separated by a clearance).

[0107] For different colors, the width (size) of each color can be selected from a variety of sizes, from small to large, depending on the desired printing area. For example, the widths (lengths) in different color directions may be, for example, greater than 500 μm (colors with relatively large widths, e.g., 550 μm or more, 600 μm or more, 800 μm or more, 1000 μm or more, 2000 μm or more, 10000 μm or more, etc.) or 500 μm or less (colors with relatively small widths, e.g., 480 μm or less, 450 μm or less, 400 μm or less, 350 μm or less, 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, etc.). The upper limit of the color range is not particularly limited and can be appropriately selected depending on the intended use of the printing substrate, etc., but for example, it may be 50,000 μm, 30,000 μm, 10,000 μm, 8,000 μm, 5,000 μm, 4,000 μm, 3,000 μm, etc. Similarly, the lower limit of the color range can be appropriately selected according to the intended use of the printing substrate, for example, 10 μm, 20 μm, 30 μm, 50 μm, 80 μm, 100 μm, etc. The specific range of color is determined by appropriately combining the above lower and upper limits, for example, 100 to 10000 μm.

[0108] The widths of different colors may be the same or different. To illustrate with a specific example, let's call adjacent different colors Color 1 and Color 2, the widths of Color 1 and Color 2 may be the same or different (for example, if the widths of both Color 1 and Color 2 are either greater than or less than 500 μm, but different, then Color 1 may have a width greater than 500 μm and Color 2 may have a width of 500 μm or less).

[0109] As will be discussed later, if one of the different colors (e.g., color 1) is a pattern and the other (e.g., color 2) is the background, it may be difficult to clearly define the width of the colors, or the width of the other color may be considerably larger than the width of the other color. In such cases, the width of the smaller color (e.g., color 1) or the width of the colors that make up the pattern may be used (and various adjustments may be made using this), considering factors such as the width of the clear color (e.g., color 1) and how easily the clearance is noticeable. Also, when the width of the colors fluctuates (e.g., when the pattern is not of a constant width, or when the color is the background), the narrowest width may be used as the width of the color.

[0110] In the different-color printing section of the second embodiment, the clearance width (width in the different color direction) may be selected from a range of, for example, about 2000 μm or less, preferably 1500 μm or less, preferably 1000 μm or less, more preferably 800 μm or less (for example, 700 μm or less), or 600 μm or less (for example, 500 μm or less, 400 μm or less, 350 μm or less).

[0111] The lower limit of the clearance width may be, for example, 3 μm, 5 μm, 7 μm, 10 μm, 15 μm, 20 μm, 30 μm, 50 μm, etc. Specific clearance ranges include, for example, 3-2000 μm, 10-1000 μm, 20-500 μm, 30-400 μm, 50-300 μm, and 100-200 μm.

[0112] Since the presence or absence of clearance is noticeable, it is preferable that the clearance width not be too large. On the other hand, to make the clearance less noticeable, it is considered best if the clearance width is as close to zero as possible. However, printing in a way that makes the clearance virtually invisible across all multiple different-colored printed areas, as in the first embodiment, would require complicated printing settings, and there is a possibility of color mixing (bleeding) in some of the different-colored printed areas. Furthermore, even if the clearance width is a somewhat finite value, the presence of the clearance may not be noticeable (for example, it may be almost impossible to detect the presence or absence of the clearance, at least to the naked eye). Therefore, it is practical for the clearance width to be a finite value within a range that is not too large.

[0113] Note that the clearance width may be the same as or different from the clearance set during printing (corresponding to the setting clearance described later). For example, even if the print settings are configured to create a clearance of a predetermined width X, the clearance width in the mixed-color printed area may be smaller than X due to slight spreading of the color inks between different colors.

[0114] When the clearance becomes this small, the width of the clearance between different colored printed areas (the clearance that can actually be confirmed on the printing substrate) depends on the width actually set and the width of the colors, etc. For example, if the clearance width set in printing is 1, it may be 0.99 or less, 0.98 or less, 0.97 or less, 0.96 or less, 0.95 or less, 0.9 or less, 0.85 or less, 0.8 or less, 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less, 0.55 or less, 0.5 or less, etc., and the lower limit may be, for example, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, etc. Specific clearance widths for different colored printed areas include, for example, 0.1-0.99, 0.2-0.98, 0.3-0.97, 0.4-0.96, etc., when the clearance width set during printing is considered as 1.

[0115] The clearance size in the mixed-color printing area may be selected according to the width of the different colors and the printing resolution.

[0116] For example, when two different colors are designated as color 1 and color 2, and the width of color 1 or color 2 (for example, the smaller of the two widths, the width of the color forming the pattern) is A (μm), and the clearance width is B (μm), the value of B / A can be selected from a range of approximately 10 or less (for example, 9.5 or less, 9 or less), preferably 8 or less (for example, 7.5 or less), preferably 7 or less (for example, 6 or less), even more preferably 5 or less (for example, 4 or less), and especially 3 or less (for example, 2.5 or less), and may also be 2 or less (for example, 1 or less, 0.8 or less, 0.5 or less, 0.3 or less, 0.1 or less), etc. Examples of lower limits for the B / A ratio include 0.005, 0.01, 0.015, 0.02, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2, 0.3, 0.4, and 0.5. Specific B / A ratios include, for example, 0.005-7, 0.01-5, 0.15-3, and 0.2-2.

[0117] The visibility of the clearance also seems to be influenced by the width of the colors (if the widths of the different colors are different, the narrower width), and within the range described above, it is possible to suppress bleeding effectively while keeping the visibility of the clearance down.

[0118] Furthermore, when the print resolution is X (dpi) and the number of pixels corresponding to the clearance width is Y, the value of X / Y[dpi / number (number of pixels)] may be, for example, around 20 to 800 (e.g., 22 to 700, 25 to 650, 28 to 600, 30 to 550, 40 to 500, 45 to 450).

[0119] For example, if the resolution is 600 dpi and the number of pixels corresponding to the clearance width is 2 pixels, the clearance width is 2 pixels [approximately 85 μm (2.54 cm ÷ 600 × 2)], the X / Y value is 300, and it falls within the range of the above X / Y values ​​(20 to 800).

[0120] The visibility of the clearance also seems to affect the resolution, and by setting the clearance in relation to the resolution as described above, it is possible to suppress blurring efficiently while minimizing the visibility of the clearance.

[0121] Furthermore, these X / Y values ​​may be selected according to the range of different colors.

[0122] For example, in a section printed with different colors, if the width of color 1 or color 2 (for example, the smaller of the two widths, the width of the color forming the pattern) is relatively small (for example, 500 μm or less, 300 μm or less, 200 μm or less), the X / Y value may be set so as not to be too small (for example, 50 or more, 80 or more, 100 or more, 120 or more, greater than 120, 125 or more, etc.).

[0123] On the other hand, in the section printed with different colors, if the width of color 1 or color 2 (for example, the smaller of the two widths, the width of the color forming the pattern) is relatively large (for example, greater than 500 μm, 600 μm or more), the X / Y value may be kept from being too large (for example, 200 or less, 150 or less, 120 or less).

[0124] By selecting X / Y values ​​according to the color range in this way, it becomes easier to more effectively suppress the visibility of the clearance.

[0125] The printed area (the area printed in a different color) may be plain, or it may have a pattern. The patterns are not particularly limited and can be selected according to the use of the substrate (printing substrate) and its display purpose. Examples include characters (e.g., hiragana, katakana, kanji, alphabet, etc.), numbers (e.g., Arabic numerals, Roman numerals, etc.), and figures. The shapes may be patterns (graphic patterns) such as barcodes or 2D codes.

[0126] By the way, barcodes become difficult to recognize or even unrecognizable (difficult to read or unreadable) if they are smudged or if the clearance is too large, making it challenging to print recognizable barcodes.

[0127] However, in the present invention, as described above, by adjusting the clearance width using a specific indicator, it is possible to print (record) a barcode that can be efficiently recognized (read).

[0128] Furthermore, the readability of the barcode can be confirmed using a barcode reader (for example, the method described later).

[0129] Specific examples of different color printing areas include, for example, (i) cases where color 1 is the pattern and color 2 is the background, and (ii) cases where the combination of colors 1 and 2 forms a pattern (for example, when colors 1 and 2 alternate adjacently to form stripes, or when color 1 forms a wave pattern and color 2 forms a wave pattern along the wave pattern of color 1). A typical example of a different color printing area is the different color printing area in (i).

[0130] As described above, the printing section may have one or more different-color printing sections, and may in particular have two or more (multiple) different-color printing sections.

[0131] When there are multiple areas with different color printing, the multiple areas with different color printing may be the same area, or they may be different areas with different color printing (for example, different in at least one of the following selected from the types of colors, color combinations, color ranges, clearance ranges, patterns, etc.).

[0132] For example, multiple different-color printing areas may have a combination of wide areas (e.g., over 500 μm) and narrow areas (e.g., 500 μm or less). For convenience, let's consider a printing area having two different different-color printing areas, referred to as different-color printing area 1 and 2, respectively. A concrete example would be a case where the width of at least one of the different colors constituting different-color printing area 1 (e.g., the smaller of the two widths, the width of the color forming the pattern) is over 500 μm, and the width of at least one of the different colors constituting different-color printing area 2 (e.g., the smaller of the two widths, the width of the color forming the pattern) is 500 μm or less.

[0133] As mentioned above, the visibility of the different-colored printed areas in the second embodiment (how inconspicuous the clearance is) can be adjusted according to the width of the color. Therefore, even when combining different-colored printed areas with wide-width colors and different-colored printed areas with narrow-width colors, it is possible to efficiently form multiple easily visible different-colored printed areas on the entire printing substrate.

[0134] Multiple areas with different colors typically include at least one area with a different color. In order to efficiently and comprehensively suppress color bleeding and minimize the visibility of clearances in such areas with different colors, it is preferable to select the clearance of each area with different colors based on specific indicators (such as color range or resolution) (selected according to the area with different colors).

[0135] Furthermore, the printed section only needs to have at least different color printed sections (in particular, multiple different color printed sections), and may also have non-different color printed sections (for example, a blank (single-color blank) printed section, or a printed section with a single-color pattern).

[0136] [Manufacturing method] A printing substrate is obtained by forming (recording) a printed area on the substrate.

[0137] In this invention, when printing the different-color printing section (a printing section in which different colors are printed adjacent to each other) within the printed section, the printing is performed such that a clearance is created between the different colors (or a clearance is provided between the different colors).

[0138] By printing in this manner, the aforementioned printing substrate can be efficiently obtained. In other words, bleeding in the areas where different colors are printed can be suppressed or prevented. Therefore, this method can also be called a method for suppressing or preventing bleeding in areas where different colors are printed. Furthermore, as described above, even if printing is done in such a way that a clearance is created (by setting the printer to provide a clearance), different colored inks may spread slightly towards each other. In such cases, if the size (width) of the clearance and the size (width) of the spread are the same, the different colored inks will spread towards each other without bleeding, and a mixed-color printed area will be formed where (apparently) there is no clearance between the different colors (mixed-color printed area in the first embodiment).

[0139] The printing method is not limited, but inkjet printing is particularly acceptable.

[0140] In inkjet technology, inkjet methods include continuous type and on-demand type (e.g., piezo type, thermal type, bulb type, etc.). The most representative is the on-demand type (e.g., piezo type).

[0141] The printing device can be selected according to the printing method; for example, an inkjet printer may be used for the inkjet method.

[0142] When using clear ink in combination, a printer head equipped with an ink chamber for ejecting color ink and an ink chamber for ejecting clear ink may be used.

[0143] Printing (such as ink ejection) may be performed while the substrate is being transported. In such cases, the transport speed can be appropriately selected depending on the type of substrate, etc., and may be, for example, 1 to 20 m / min (e.g., 2 to 15 m / min, 3 to 12 m / min), etc.

[0144] In printing (inkjet), the ink, resolution, and other aspects are as described above.

[0145] The ink discharge volume may be, for example, 1 pL or more (e.g., 3 pL or more), preferably 5 pL or more (e.g., 7 pL or more), and more preferably 8 pL or more (e.g., 9 pL or more) per drop (dot). The upper limit of the ink ejection volume may be, for example, 50 pL, 30 pL, 20 pL, 15 pL, etc., per drop (dot).

[0146] Furthermore, this discharge rate is applicable to both colored and clear inks.

[0147] In particular, when clear ink is used in combination, the total amount of color ink and clear ink ejected [amount ejected per drop (dot)] may be 1.1 or more, preferably 1.3 or more, and more preferably 1.5 or more (for example, 1.8 or more) when the amount ejected of color ink is set to 1, and may also be 10 or less, 8 or less, 5 or less, 3 or less, etc.

[0148] When clear ink is used in combination with color ink, the amount of ink dispensed (and therefore the amount of solvent in the printed area) becomes larger compared to using color ink alone. However, even with this increased solvent volume, bleeding can be effectively suppressed by maintaining a clearance during printing.

[0149] Ink ejection may be performed in conjunction with the scanning (movement) of the carriage (a carriage having a head). In such cases, the scanning direction may be, for example, perpendicular to the transport direction of the substrate. The scanning speed may be, for example, 30 m / min or more (e.g., 40 to 500 m / min), preferably 50 m / min or more (e.g., 80 to 300 m / min), and more preferably 100 m / min or more (e.g., 120 to 200 m / min).

[0150] As described above, when printing in different colored sections, the printing process (setting the printing device) is performed so that a clearance is created between the different colors. The form of the clearance is as described above, and the clearance set during such printing (sometimes called the set clearance, etc.) may also be the same.

[0151] For example, the width of the clearance (set clearance, hereinafter the same applies to the clearance set during printing) may be selected from a range of, for example, 2000 μm or less, preferably 1500 μm or less, preferably 1000 μm or less, and even more preferably 800 μm or less (for example, 700 μm or less), or it may be printed to be 600 μm or less (for example, 500 μm or less, 400 μm or less, 350 μm or less). The lower limit of the set clearance range may be, for example, 3 μm, 5 μm, 7 μm, 10 μm, 15 μm, 20 μm, 30 μm, 50 μm, etc.

[0152] Specific clearance ranges include, for example, 3-2000 μm, 10-1000 μm, 20-500 μm, 30-400 μm, 50-300 μm, and 100-200 μm.

[0153] Furthermore, as mentioned above, the clearance in the different-colored printed area formed by the spread of ink, etc., may be smaller than the set clearance (sometimes referred to as the actual clearance, etc.). Therefore, the set clearance width may be the same as the actual clearance width, or it may be larger than the actual clearance (desired clearance) width. When it is made larger in this way, the degree to which it is made can be selected according to the expected ink spread, the desired clearance width, etc., and is not particularly limited.

[0154] In such cases, the set clearance width may be larger than the actual clearance width by, for example, 1 μm or more [for example, 1.5 μm or more (e.g., 2-300 μm), 2.5 μm or more (e.g., 3-250 μm), 3.5 μm or more (e.g., 4-200 μm), 4.5 μm or more (e.g., 5-150 μm)]. In addition, the set clearance width may be set to more than 1 times the actual clearance width [for example, 1.001 times or more (for example, 1.005 times or more), 1.01 times or more (for example, 1.02 times or more), 1.05 times or more (for example, 1.07 times or more), 1.08 times or more, 1.1 times or more, etc.], or to 5 times or less the actual clearance width (for example, 4 times or less, 3.5 times or less, 3 times or less, 2.5 times or less, 2 times or less, 1.8 times or less, 1.5 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, etc.].

[0155] As mentioned above, the clearance size can be selected depending on the width of different colors and the printing resolution.

[0156] For example, when two different colors are designated as color 1 and color 2, and the width of color 1 or color 2 (for example, the smaller of the two widths, the width of the color forming the pattern) is A (μm), and the clearance width is B (μm), the value of B / A can be selected from a range of approximately 10 or less (for example, 9.5 or less, 9 or less), preferably 8 or less (for example, 7.5 or less), preferably 7 or less (for example, 6 or less), even more preferably 5 or less (for example, 4 or less), and especially 3 or less (for example, 2.5 or less), and may also be set to 2 or less (for example, 1 or less, 0.8 or less, 0.5 or less, 0.3 or less, 0.1 or less), etc. Examples of lower limits for the B / A ratio include 0.005, 0.01, 0.015, 0.02, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2, 0.3, 0.4, and 0.5. Specific B / A ratios include, for example, 0.005-7, 0.01-5, 0.15-3, and 0.2-2.

[0157] Furthermore, the clearance width can be adjusted so that the value of X / Y[dpi / number (number of pixels)] is approximately 20 to 800 (for example, 22 to 700, 25 to 650, 28 to 600, 30 to 550, 40 to 500, 45 to 450), where X is the print resolution (dpi) and Y is the number of pixels corresponding to the clearance width.

[0158] Furthermore, these X / Y values ​​may be selected according to the range of different colors.

[0159] For example, when the width of color 1 or color 2 (for example, the smaller of the two widths, the width of the color forming the pattern) is relatively small (for example, 500 μm or less, 300 μm or less, 200 μm or less), the X / Y value may be set so as not to be too small (for example, 50 or more, 80 or more, 100 or more, 120 or more, greater than 120, 125 or more, etc.).

[0160] On the other hand, when the width of color 1 or color 2 (for example, the smaller of the two widths, the width of the color forming the pattern) is relatively large (for example, greater than 500 μm, 600 μm or more), the X / Y values ​​may be kept from being too large (for example, 200 or less, 150 or less, 120 or less).

[0161] In this way, by selecting (adjusting) the clearance according to conditions such as the color range and resolution, it is possible to efficiently create natural-looking areas of different colors where the clearance is not noticeable, while suppressing the bleeding between colors in the different-colored printed areas.

[0162] As mentioned above, the printing conditions described above (such as clearance characteristics) may be reflected in exactly the same manner in the printed area (different color printed area) or in a different manner.

[0163] For example, even when printing by inkjet, the dots may be crushed in the printed area, and the clearance width in the different color printed area may be smaller than the clearance width set during printing. As described above, when at least one of the different colored inks (especially both inks) spreads toward each other, the width of the color set during printing [for example, the width (length) corresponding to the number of pixels] becomes larger in the printed area. This leads to the actual clearance becoming smaller than the set clearance. In such cases, when the color range set during printing (hereinafter sometimes referred to as the set color range, etc.) is C1, and the color range in the different color printing section (hereinafter sometimes referred to as the actual color range, etc., in relation to the set color range) is C2, the difference between these two [C2 (actual color range C2) - C1 (set color range C1)] may be, for example, 0.5 μm or more (for example, 0.8 μm or more, 1 μm or more, 1.5 μm or more, 2 μm or more, 2.5 μm or more, 3 μm or more, 3.5 μm or more, 4 μm or more, 4.5 μm or more, 5 μm or more), or 300 μm or less (for example, 280 μm or less, 250 μm or less, 200 μm or less, 180 μm or less, 150 μm or less, 120 μm or less, 100 μm or less, 80 μm or less, 70 μm or less, 50 μm or less, etc.).

[0164] After printing, heat treatment (drying) may be performed as needed. Heat treatment can remove the solvent from the printed area. In addition, if the ink contains a crosslinking agent, crosslinking may be promoted along with heating (drying).

[0165] [Applications of printing substrates, etc.] Printing substrates can be used as is for various applications depending on the type and form of the substrate, or they can be further molded (processed) as needed to obtain the desired molded product.

[0166] For example, a printing substrate whose base material is a plastic film (such as an inflation film) can be molded into a soft bag (medical soft bag) through processes such as heat sealing, cutting, and port (filling port) attachment.

[0167] Furthermore, the soft bag can be further processed, for example, by filling it with contents (such as intravenous fluids), performing high-pressure sterilization (high-pressure shower sterilization), and so on, to become a soft bag (intravenous fluid bag) filled with contents.

[0168] As described above, during the molding process after printing, various loads are applied to the printed substrate, and if the printed area (the area printed in a different color) is not sufficiently fixed (recorded), it may fall off. For example, in the case of processing into the aforementioned infusion bag, the printed area (the area printed in a different color) becomes more prone to peeling off after high-pressure sterilization or similar processes. Furthermore, if the printed area is not sufficiently secured, it is more likely to detach due to contact with chemicals (such as alcohol like ethanol).

[0169] To effectively prevent such shedding, it is advantageous to use clear ink in combination with other inks to ensure sufficient resin in the printed area (different color printed area), as mentioned above. However, using clear ink tends to result in significant bleeding (mixing) between colors in the different color printed area, and consequently, a loss of visibility and appearance in the printed area.

[0170] However, according to the present invention, as described above, even when using clear ink, bleeding in the different colored printed area can be efficiently suppressed, and it is possible to efficiently achieve both the strong printing (recording) required for medical soft bags, etc. (for example, having abrasion resistance, excellent adhesion, chemical resistance, etc.) and the suppression of bleeding (and furthermore, making the clearance less noticeable). [Examples]

[0171] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0172] The materials used are as follows:

[0173] Ink (color ink and clear ink) Inks 1-4 and 8 described in the examples of Japanese Patent Publication No. 2020-19180 were prepared and used as color inks. In addition, ink 9 described in the examples of Japanese Patent Publication No. 2020-19180 was prepared and used as a clear ink. The composition of each ink is as follows. In the table below, "parts" refers to parts by mass.

[0174] [Table 1]

[0175] <Antifoaming agent> • DF110D: Product name "Surfinol DF110D", acetylenediol-based surfactant, manufactured by Nisshin Kagaku Kogyo Co., Ltd. <Surfactants> • BYK348: Product name, silicone-based surfactant, manufactured by Bic Chemie Japan Co., Ltd. <Pigments> • Black pigment: Carbon black • Cyan pigment: CI Pigment Blue 15:3 • Magenta pigment: CI Pigment Red 122 • Yellow pigment: CI Pigment Yellow 150 • White pigment: CI Pigment White 6 <Resin> • Joncryl 62J (product name, styrene-acrylic resin, manufactured by BASF Japan Ltd.) • AQUACER539 (product name, water-based modified paraffin wax emulsion, manufactured by BIC CHEMI Japan Co., Ltd.)

[0176] Furthermore, various measurements and analyses were performed as follows.

[0177] viscosity A rheometer (product name "MCR300," manufactured by Anton Paar) was used, with a measurement temperature of 32°C and a shear rate of 200 s. -1 Measured at [location / location].

[0178] Wetting tension A wettability test mixture (manufactured by Fujifilm Wako Pure Chemical Industries, etc.) was used as the wetting reagent. A cotton swab was immersed in wettability test mixture No. 35, and the liquid on the cotton swab was applied to the material to be printed. If the material remained wet after 2 seconds, the wettability was considered to be that value. A new cotton swab was immersed in the No. 45 wetting tension test mixture, and the same procedure was performed. If it repelled within 2 seconds, it was determined that the wetting tension was 45 or less. Assuming that the wetting tension of the substrate is between 35 and 45, the maximum value of the substrate that remained wet for 2 seconds using a solution with an appropriate wetting tension was taken as the wetting tension of the substrate.

[0179] Barcode recognition capability A Keyence SR2000 was placed approximately 20 cm above the printed substrate (barcode area) for imaging and reading. The SR2000 was adjusted to produce the closest possible verification values ​​(modulation, decodeability, and defect) to those obtained on the calibration sheet's verification machine. Recognition was considered successful when the modulation was 25% or higher, the decodeability was 37% or higher, and the defect was less than 30%.

[0180] Visual inspection The paint was visually observed from a distance of approximately 40 cm, and the amount of paint seepage and clearance were judged according to the following criteria. A: It cannot be confirmed at all. B: Almost impossible to confirm C: It can be seen, but it's not very noticeable. D: Easily noticeable The aforementioned judgment was performed by 30 people, and the judgment with the most frequent response was used as the visual judgment result.

[0181] [Example 1] (Manufacturing of printing substrates) From a raw material roll, a tubular film (a laminated film of polybutylene terephthalate and olefin resin) formed by inflation molding, with the air removed from its inner surface and wound up, was fed onto a buffer roll as a plain, transparent strip of film with the printed side (the polybutylene terephthalate side of the laminated film (wetting tension 38 dyn / cm)) facing upwards. While the film was being transported, the printed area was formed using an inkjet method.

[0182] In other words, the tubular film was intended for use in medical soft bags, and ink was ejected and printed onto the film under the conditions shown in the table below, so that multiple areas with different colors were formed.

[0183] [Table 2]

[0184] Furthermore, the colors (patterns and their backgrounds) of the different-colored printed sections were all printed along the horizontal direction of the film (that is, in different-colored printed section 1, the words "glucose-containing electrolyte solution (maintenance solution)," in different-colored printed section 2, "infusion," in different-colored printed section 3, "1000mL," and in different-colored printed section 4, the bars constituting the barcode, were all aligned along the horizontal direction of the film).

[0185] The ink ejection head of the inkjet printer moves perpendicular to the film's direction of travel (vertical direction, film transport speed 8 m / min) (i.e., horizontal direction) (head scanning speed 152 m / min), ejecting ink from the nozzles during this movement. Ink is ejected on both the forward and return journeys of the ink ejection head. On the forward journey, clear ink is ejected immediately after (almost simultaneously with) the ejection of color ink, and on the return journey, color ink is applied immediately after the ejection of clear ink. This is due to the structure of the ejection head, where the nozzles are arranged in the order of ejecting color ink nozzles followed by ejecting clear ink nozzles in the direction of travel on the forward journey. Furthermore, the clear ink is ejected to the color ink ejection section during the outward journey (and to the ejection section during the return journey), and is not ejected to the entire film (clear ink is not ejected where color ink is not ejected).

[0186] After ink ejection, the film was further dried by conveying it while blowing hot air into it, thereby obtaining the desired product (a film with printed areas including multiple areas of different colors).

[0187] (Evaluation of printing substrates) Unconventional Printing Department 1 Figure 1 shows a close-up photograph of the different-colored printed section 1 of the obtained film, and Figure 2 shows a microscopic photograph (20x magnification, black background).

[0188] In the color-shifted printing section 1, relatively small characters (i.e., the width of each character in the string "sugar-added electrolyte solution (maintenance solution)") are used as color 1. Visually, no bleeding was observed between color 1 and the background (Judgment A), and no clearance could be confirmed (Judgment A). This was also evident from Figure 1, which can be considered a close-up view, and Figure 2, a magnified photograph.

[0189] In the non-colored printed section 1, as described above, the clearance set during printing is not noticeable at all. However, when observed with a higher magnification microscope image, the presence of a slight clearance (a gap between the text and its background) could be confirmed [approximately 78 μm in the vertical direction (approximately 0.92 times the clearance set during printing (1.8 pixels), width 1 (350 μm), width 2 (175 μm), width B / width 1 = 0.22, width B / width 2 = 0.45, X / Y = 333), approximately 42 μm in the horizontal direction (0.50 times the clearance set during printing (0.99 pixels), width 1 (350 μm), width 2 (175 μm), width B / width 1 = 0.12, width B / width 2 = 0.24, X / Y = 606)].

[0190] Since color 1 is white, it was suggested that the white color also contributes to the inconspicuousness of the clearance.

[0191] Unique Printing Department 2 Similarly, Figure 3 shows a close-up photograph of the different-colored printing section 2, and Figure 4 shows a microscope image (20x magnification, black background).

[0192] In the color-shifted printing section 2, characters of medium width (i.e., the width of each character in the string "infusion") were used as color 1. However, visually, no bleeding was observed between color 1 and the background (Judgment A), and virtually no clearance could be confirmed (Judgment B). In other words, even in the close-up photograph Figure 3, no clear clearance could be confirmed between color 1 (the string) and the background, and a clear clearance was only finally apparent in the enlarged photograph Figure 4.

[0193] In addition, in the non-colored printing section 2, as described above, the clearance set during printing is almost invisible to the naked eye, but its existence was confirmed by microscopic observation [approximately 159 μm in the vertical direction (approximately 0.94 times the clearance set during printing (3.8 pixels), width 1 (1636 μm), width 2 (630 μm), width B / width 1 = 0.097, width B / width 2 = 0.25, X / Y = 158), approximately 116 μm in the horizontal direction (0.69 times the clearance set during printing (2.7 pixels), width 1 (1636 μm), width 2 (630 μm), width B / width 1 = 0.071, width B / width 2 = 0.18, X / Y = 222)].

[0194] Unique Printing Department 3 Similarly, Figure 5 shows a close-up photograph of the different-colored printed section 3, and Figure 6 shows a microscopic photograph (20x magnification, white background).

[0195] In the color-shifted printing section 3, the characters with a relatively large width [i.e., the width of each character (numbers, letters) in the string "1000mL"] were colored as color 1. However, visually, no bleeding was observed between color 1 and the background (Judgment A), and almost no clearance could be confirmed (Judgment B). In other words, even in the close-up photograph Figure 5, only slight clearance could be confirmed in some places between color 1 (the string) and the background, and a clear clearance was only noticeable in the enlarged photograph Figure 6.

[0196] In addition, in the different-color printing section 3, as described above, the clearance set during printing is almost invisible to the naked eye, but its existence was confirmed by microscopic observation [approximately 226 μm in the vertical direction (approximately 0.89 times the clearance set during printing (5.3 pixels), width 1 (2388 μm), width 2 (2802 μm), width B / width 1 = 0.095, width B / width 2 = 0.081, X / Y = 113), approximately 144 μm in the horizontal direction (0.57 times the clearance set during printing (3.4 pixels), width 1 (2388 μm), width 2 (2802 μm), width B / width 1 = 0.060, width B / width 2 = 0.051, X / Y = 176)].

[0197] Unconventional Printing Department 4 Regarding the non-colored printing section 4 (barcode), no bleeding was observed visually between color 1 (barcode bars) and the background (Judgment A), and no clearance could be confirmed (Judgment A). The fact that no clearance could be confirmed visually is thought to be related to the fact that the background color was white.

[0198] Regarding the different-colored printed section 4, we confirmed, using the method described above, whether or not it could be recognized as a barcode, and it was found to be recognizable.

[0199] Furthermore, when we took magnified photographs of the different-colored printed section 4 and observed them, we were able to confirm the existence of clearance [approximately 154 μm in the vertical direction (approximately 0.91 times the clearance set during printing (3.6 pixels), width 1 (367 μm), width 2 (350 μm), width B / width 1 = 0.42, width B / width 2 = 0.44, X / Y = 167), approximately 118 μm in the horizontal direction (approximately 0.7 times the clearance set during printing (2.8 pixels), width 1 (367 μm), width 2 (350 μm), width B / width 1 = 0.32, width B / width 2 = 0.34, X / Y = 214)].

[0200] (Formation and evaluation of IV bags) On the resulting printed film, the four sides that would form the infusion bag were heat-sealed (however, the port attachment positions were not heat-sealed). After the heat-sealing process, the film was cut to form the infusion bag, and resin ports were attached to the port attachment positions by heat-sealing.

[0201] After the port installation process, the contents (infusion fluid) were filled into the port, a rubber stopper was attached to the port, and a protective film was heat-sealed to the port to protect the surface of the rubber stopper. Finally, the bag was sterilized using a high-pressure shower to obtain the infusion fluid bag.

[0202] Furthermore, the process up to high-pressure shower sterilization was performed in-line.

[0203] During the molding process of the IV bag, no detachment of the differently colored printed sections 1-4 occurred. Furthermore, when the different colored printed areas 1-4 of the infusion bag were rubbed vigorously with a finger after high-pressure shower sterilization, no peeling occurred. Furthermore, when we wiped the different colored printed areas 1-4 with a cloth soaked in ethanol, no peeling occurred. Thus, it was confirmed that the different-colored printed areas 1-4 on the IV bag were firmly printed.

[0204] [Reference example 1] In Example 1, printing was performed in the same manner as in Example 1, except that no clearance was taken between the different colored printing areas (color 1 and color 2 (background)) during printing, and a printing substrate was obtained. In the obtained film, a clear blurring of color 1 and its background was already visible in all of the different-color printed sections 1 to 4 (Judgment D).

[0205] [Reference example 2] In Example 1, printing was performed in the same manner as in Example 1, except that clear ink was not used and no clearance was set between the different colored printing areas (color 1 and color 2 (background)), to obtain a printing substrate.

[0206] In the different color printing sections 1-4, although the amount was slightly less than in Reference Example 1, bleeding between colors was visible to the naked eye in all of them (Judgment C).

[0207] Furthermore, when an infusion bag was formed using a printed substrate in the same manner as in Example 1, the different-colored printed areas 1-4 were observed to peel off in places. When wiped with a cloth soaked in ethanol, almost all of the different-colored printed areas peeled off.

[0208] [Example 2] In Example 1, a printing substrate was obtained at each clearance width in the same manner as in Example 1, except that the width of the vertical clearance of the different-color printing section 1 was changed to the values ​​shown in the table below. Then, the different colored printed areas 1 of each obtained printing substrate were evaluated visually in the same manner as in Example 1. The results are shown in the table below.

[0209] [Table 3]

[0210] [Example 3] In Example 1, the width of the lateral clearance of the different-color printing section 3 was changed to the values ​​shown in the table below, but otherwise, a printing substrate was obtained at each clearance width in the same manner as in Example 1.

[0211] Then, the different colored printed areas 3 of each obtained printing substrate were evaluated visually in the same manner as in Example 1. The results are shown in the table below.

[0212] [Table 4]

[0213] As is clear from the results in the table above, it was found that even with a relatively wide color width, by adjusting the X / Y values, it is possible to create a contrasting color print area where the clearance is less noticeable, even if the clearance width is somewhat increased.

[0214] [Example 4] A printing substrate was obtained in the same manner as in Example 1, except that a single-layer polyethylene film (wetting tension of the printed surface of 35 dyn / cm) was used as the tubular film. The obtained film showed similar trends to those in Example 1 in the different-colored printed sections 1-4, the molding of the infusion bag, and its evaluation.

[0215] [Example 5] A printing substrate was obtained in the same manner as in Example 1, except that a single-layer film of a mixed resin of polyethylene and polypropylene (wetting tension of the printed surface: 45 dyn / cm) was used as the tubular film. The obtained film showed similar trends to those in Example 1 in the different-colored printed sections 1-4, the molding of the infusion bag, and its evaluation.

[0216] [Example 6] The ink described in Example 1 of Japanese Patent Publication No. 2018-141066 was prepared. Then, a printing substrate was obtained in the same manner as in Example 1, except that the obtained ink (cyan) was used in place of ink 2. The obtained film showed similar trends to those in Example 1 in the different-color printed sections 1-4 (especially different-color printed sections 2 and 4), the molding of the infusion bag, and its evaluation.

[0217] [Example 7] A printing substrate was obtained in the same manner as in Example 1, except that inks 1-4 were replaced with Roland DG Corporation's black (FPG-BK), cyan (FPG-CY), magenta (FPG-MG), and yellow (FPG-YE) inks, respectively. The obtained film showed similar trends to those in Example 1 in the different-colored printed sections 1-4, the molding of the infusion bag, and its evaluation.

[0218] [Example 8] In Example 1, a printing substrate was obtained in the same manner as in Example 1, except that the vertical resolution was changed to 400 dpi. The obtained film showed similar trends to those in Example 1 in the different-colored printed sections 1-4, the molding of the infusion bag, and its evaluation.

[0219] [Example 9] In Example 1, a printing substrate was obtained in the same manner as in Example 1, except that the horizontal resolution was changed to 200 dpi. The obtained film showed similar trends to those in Example 1 in the different-colored printed sections 1-4, the molding of the infusion bag, and its evaluation.

[0220] [Example 10] A printing substrate was obtained in the same manner as in Example 1, except that the vertical resolution and horizontal resolution were changed to 300 dpi. The obtained film showed similar trends to those in Example 1 in the different-colored printed sections 1-4, the molding of the infusion bag, and its evaluation. [Industrial applicability]

[0221] According to the present invention, a novel printing substrate and a method for manufacturing the same can be provided.

Claims

1. A printing substrate having a printed area on a substrate, wherein the printed area includes a different color printed area with a clearance between the printed areas, The printed area is printed using the inkjet method. The different-colored printing area is formed with ink composed of at least color inks. The clearance width of the different colored printing area is 0.1 to 0.99, when the clearance width set during printing is defined as 1. A printing substrate that includes a multi-color printing section in which, when the multi-color printing section uses two different colors, namely color 1 and color 2, the width of color 1 or color 2 is A (μm), and the clearance width is B (μm), and the value of B / A is 8 or less.

2. A printing substrate having a printed area on a substrate, The printed area includes at least a section of different colors printed with a clearance between them without bleeding, The printed area is printed using the inkjet method. The different-colored printing area is formed with ink composed of at least color inks. The clearance width of the different colored printing area is 0.1 to 0.99, when the clearance width set during printing is defined as 1. A printing substrate that includes a multi-color printing section in which, when the multi-color printing section uses two different colors, namely color 1 and color 2, the width of color 1 or color 2 is A (μm), and the clearance width is B (μm), and the value of B / A is 8 or less.

3. A printing substrate according to claim 1 or 2, wherein the wet tensile strength of the printed surface of the substrate is 30 to 50 dyn / cm.

4. A printing substrate according to any one of claims 1 to 3, wherein the substrate is a plastic film.

5. A printing substrate according to any one of claims 1 to 4, wherein the printing surface of the substrate is made of a polyester resin.

6. A printing substrate according to any one of claims 1 to 5, wherein the printed portion is formed with water-based ink.

7. A printing substrate according to any one of claims 1 to 6, wherein the printed portion is formed of color ink and clear ink.

8. A printing substrate according to any one of claims 1 to 7, wherein the printed portion is formed of water-based color ink and water-based clear ink.

9. A printing substrate according to any one of claims 1 to 8, wherein the ratio of resin to the total amount of resin and colorant in the printed portion is 20% by mass or more.

10. A printing substrate according to any one of claims 1 to 9, wherein the clearance width is 10 to 1500 μm.

11. A printing substrate according to any one of claims 1 to 10, wherein the different-color printing area includes a different-color printing area where, when the different colors are designated as color 1 and color 2, the width of color 1 or color 2 is A (μm) and the clearance width is B (μm), and the value of B / A is 5 or less.

12. A printing substrate according to any one of claims 1 to 11, wherein the different-color printing area includes a different-color printing area where the X / Y value is 20 to 800, with X (dpi) being the printing resolution and Y being the number of pixels corresponding to the clearance width.

13. A printing substrate according to any one of claims 1 to 12, comprising a different-color printing section 1, wherein when the different colors of the different-color printing section are designated as color 1 and color 2, the width of color 1 or color 2 is 500 μm or less, and when the printing resolution is X (dpi) and the number of pixels corresponding to the clearance width is Y, the value of X / Y is 50 or more.

14. The printing substrate according to claim 13, wherein in the different-color printing section 1, the width of color 1 or the width of color 2 is 400 μm or less, and the X / Y value is 100 or more.

15. A printing substrate according to any one of claims 1 to 14, comprising a different-color printing section 2, wherein when the different colors of the different-color printing section are designated as color 1 and color 2, the width of color 1 or color 2 is greater than 500 μm, and when the printing resolution is X (dpi) and the number of pixels corresponding to the clearance width is Y, the value of X / Y is 200 or less.

16. The printing substrate according to claim 15, wherein in the different-color printing section 2, the width of color 1 or the width of color 2 is 600 μm or more, and the X / Y value is 150 or less.

17. A printing substrate according to any one of claims 1 to 16, wherein the different-color printing section includes the different-color printing section 1 according to claim 13 or 14 and the different-color printing section 2 according to claim 15 or 16.

18. A printing substrate according to any one of claims 1 to 17, wherein the different-color printing area includes a different-color printing area in which one of the different colors is white.

19. A printing substrate according to any one of claims 1 to 18, comprising a different-color printing section in which, when the different colors are designated as color 1 and color 2, color 1 is the pattern and color 2 is the background.

20. A printing substrate according to any one of claims 1 to 19, comprising a different-color printing section in which, when the different colors are designated as color 1 and color 2, color 1 is a barcode or two-dimensional code and color 2 is the background, the different-color printing section is recognizable as a barcode or two-dimensional code.

21. A printing substrate according to any one of claims 1 to 20 for forming a medical soft bag.

22. A method for manufacturing a printed substrate according to any one of claims 1 to 21, comprising at least a printing step of printing a printed portion on a substrate by an inkjet method, wherein in the printing step, clearances are provided between different colors to print the printed portions of different colors.

23. A method for suppressing or preventing bleeding between different colors in a printing substrate having a printing section that includes a different-color printing section in which different colors are printed with a clearance between them, wherein in a printing process in which the printing section is printed on the substrate by an inkjet method, when the different colors are called color 1 and color 2, and the width of color 1 or color 2 is A (μm), and the width of the clearance is B (μm), a clearance is provided between the different colors such that the value of B / A is 8 or less, and the different-color printing section is printed by ejecting ink composed of at least color ink.

24. The method according to claim 22 or 23, wherein in the printing process, color ink and clear ink are ejected so that at least the dots of color ink overlap the dots of clear ink.

25. The method according to any one of claims 22 to 24, wherein the clearance width is printed to be 10 to 1500 μm.

26. The method according to any one of claims 22 to 25, wherein, when the printing resolution is X (dpi) and the number of pixels corresponding to the width of the clearance is Y, a clearance is provided such that the value of X / Y is between 20 and 800.

27. A molded article of a printing substrate according to any one of claims 1 to 21.

28. A molded article according to claim 27, which is a medical soft bag.

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