Inkjet treatment liquid, ink set using the same, and printing method

Abstract

One aspect of the present invention relates to an inkjet treatment liquid containing a cationic polymer and lactic acid, wherein the halogen ion concentration is 5 g / L or less and the pH is 7 to 9.5.

Description

Technical Field

[0001] The present invention relates to an inkjet processing liquid and an ink set and a printing method using the processing liquid. Background Art

[0002] In inkjet recording, it is known to apply a pre-treatment liquid before applying ink. For example, a method has been proposed that uses a treatment liquid containing fine particles as a component that forms aggregates with the color material in the ink.

[0003] Patent Document 1 discloses an inkjet recording method in which a colorless liquid containing silica particles is applied to a recording medium, followed by a non-aqueous recording liquid containing black ink. Furthermore, Patent Document 2 discloses the use of a solution containing particles, or particles and a binder polymer, as a processing liquid.

[0004] Because liquids containing these particles contain the reactive particles in a dispersed state, a large number of reactive components can be added. However, during the manufacturing process of the components, liquid compositions containing these reactive particles inevitably contain corrosive ions. To ensure the dispersion stability of the components that react with the colorant, corrosive particles such as chloride ions and acids are added as secondary ions. For these reasons, the liquid composition contains high concentrations of corrosive ions. Therefore, when this liquid composition is used directly as a raw material for the treatment liquid, liquid contact problems caused by these corrosive ions often occur, which may cause the metal material of the head component used to eject the treatment liquid to dissolve.

[0005] To address the issue of liquid contact caused by corrosive ions, a proposal has been made to improve liquid contact by limiting the chloride ion concentration in a treatment liquid containing a cationic polymer to 3000 ppm or less (Patent Document 3). Furthermore, a method has been proposed for producing a treatment liquid containing one or more components that react with a colorant by replacing corrosive ions (halogen ions) with less corrosive ions during the production process (Patent Document 4).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 4-259590

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 6-92010

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 10-237372

[0011] Patent Document 4: Japanese Patent Publication No. 2004-90456 Summary of the Invention

[0012] An inkjet treatment liquid according to one aspect of the present invention contains a cationic polymer and lactic acid, has a halogen ion concentration of 5 g / L or less, and has a pH of 7 to 9.5. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an example of inkjet recording performed using the inkjet processing liquid of this embodiment. DETAILED DESCRIPTION

[0014] According to Patent Document 3, cationic polymers and cationic surfactants are used as cationic substances in liquid compositions. However, these substances contain some chloride ions, such as hydrochloride, generated by acid treatment during their synthesis and purification (paragraph 0008). Therefore, it is believed that if the chloride concentration is not lowered to 3000 ppm or less, the amount of cationic polymer added, which is a reactive component with the color material, cannot be increased, and the aggregation effect with the color material cannot be fully achieved.

[0015] Furthermore, it is known that, as in the technique described in Patent Document 4, when halogen ions are removed by ion exchange, the cationic polymer becomes unstable to heat, and thus there is a problem in that the portion where the treatment liquid is applied turns yellow due to heating.

[0016] Meanwhile, Patent Documents 1 to 4 above all describe inkjet processing fluids for printing on paper media such as plain paper, and do not contemplate their use in textile printing. Inkjet printing typically involves pre-treatment with a processing fluid containing a binder resin. This binder resin penetrates the gaps between fibers and bonds them together, causing the fabric to become stiff and impairing the texture and feel of the fabric. This also presents unique problems associated with textile printing.

[0017] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited thereto.

[0018] [Inkjet treatment liquid]

[0019] An inkjet treatment liquid (hereinafter sometimes simply referred to as "treatment liquid") according to one embodiment of the present invention contains a cationic polymer and lactic acid, has a halogen ion concentration of 5 g / L or less, and has a pH of 7 to 9.5.

[0020] The treatment liquid of this embodiment is a pre-treatment liquid applied to the recording object before ink application. The cationic polymer contained in the treatment liquid reacts with the pigment contained in the ink applied later and aggregates, thereby ensuring excellent coloring properties.

[0021] Since the treatment liquid of this embodiment has a low halogen ion concentration, corrosion of inkjet head components caused by halogen ions can be suppressed. In addition, the inclusion of lactic acid and the pH within the above range can reduce yellowing of cationic polymers with low halogen concentrations.

[0022] That is, the inkjet processing liquid of this embodiment can suppress corrosion of inkjet head components and yellowing of recording media during inkjet recording, thereby achieving excellent colorability (image density). Furthermore, when the inkjet processing liquid of this embodiment is used for printing, it has the advantage of also improving the texture of the fabric.

[0023] The cationic polymer contained in the inkjet treatment liquid of this embodiment is not particularly limited as long as it is a positively charged cationic polymer. Examples thereof include ammonium-containing polymers, amine-containing polymers, polyacrylamine, polyvinylamine, polyimine, polyvinylpyrrolidone, polyethyleneimine, polyvinylpyridine, aminoacetalized polyvinyl alcohol, ionene polymers, polyvinylimidazole, polyvinylbenzylphosphonium, polyalkylallylammonium, polyamidine, and polyaminesulfone. Among these, quaternary ammonium-containing polymers, diallyldimethylammonium sulfur dioxide copolymers, diallyldimethylammonium chloride acrylamide copolymers, diallyldimethylammonium chloride polymers, dimethylamine-epichlorohydrin polycondensates, and dimethylamine-ammonia-epichlorohydrin polycondensates are particularly preferred from the perspective of achieving superior colorability. These may be used alone or in combination of two or more.

[0024] The weight average molecular weight of the cationic polymer used in this embodiment is not particularly limited, but is preferably about 1000 to 10000. It is believed that when the molecular weight is within this range, the ejection properties from the inkjet head will be better.

[0025] The content of the cationic polymer is preferably 0.3% by weight or more and 35% by weight or less relative to the total amount of the treatment liquid. It is believed that by adjusting the content of the cationic polymer within this range, colorability (image density) is further improved, and yellowing of the recording medium can be further suppressed. A more preferred lower limit of the content of the cationic polymer is 0.5% by weight or more, and more preferably 1% by weight or more. Furthermore, a more preferred upper limit is 29.5% by weight or less, and more preferably 20% by weight or less.

[0026] The treatment liquid of this embodiment further contains lactic acid, and the lactic acid may be contained in the form of lactate ions.

[0027] The lactic acid content is preferably 20% by weight or less relative to the total amount of the treatment liquid. It is believed that by adjusting the lactic acid content within this range, colorability (image density) is further improved and yellowing of the recording medium can be further suppressed. A more preferred upper limit for the cationic polymer content is 17.5% by weight or less, and further preferably 15% by weight or less.

[0028] The lower limit of the lactic acid content is not particularly limited, but is preferably 0.2% by weight or more, and more preferably 0.3% by weight or more, from the viewpoint of achieving the effect of stabilizing the cationic polymer.

[0029] In the treatment liquid of the present embodiment, the balance other than the above-mentioned components is usually water or an aqueous solvent composed of water and an organic solvent.

[0030] Examples of organic solvents that may be contained in the treatment liquid include glycols, alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, and vegetable oils. Examples of water-soluble organic solvents include polyols, ether compounds of polyols, nitrogen-containing compounds, alcohol compounds, sulfur-containing compounds, propylene carbonate, and ethylene carbonate.

[0031] Examples of the polyol include a first diol compound having 5 to 8 carbon atoms, a second diol compound having 2 to 4 carbon atoms, 1,2,6-hexanetriol, glycerol, trimethylolpropane, sugar alcohols (e.g., xylitol), and sugars (e.g., xylose, glucose, and galactose).

[0032] Examples of the first diol compound include 2-methylpentane-2,4-diol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol, and 1,2-hexanediol.

[0033] Examples of the second diol compound include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butanediol, and diethylene glycol.

[0034] Examples of the polyol ether compound include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and ethylene oxide adducts of diglycerin.

[0035] Examples of the nitrogen-containing compound include pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, and triethanolamine.

[0036] Examples of the alcohol compound include ethanol, isopropyl alcohol, butanol, and benzyl alcohol.

[0037] Examples of the sulfur-containing compound include thiodiethanol, thiodiglycerol, sulfolane, and dimethyl sulfoxide.

[0038] Among the above-mentioned organic solvents, glycols such as propylene glycol are preferably used. These may be used alone or in combination of two or more.

[0039] When the treatment liquid contains an organic solvent, its content is preferably 3% by weight or more and 50% by weight or less relative to the total amount of the treatment liquid. By containing the organic solvent within the above range, there is an advantage of providing a treatment liquid with a viscosity that allows for stable discharge and reducing drying of the treatment liquid.

[0040] Furthermore, the treatment liquid of this embodiment may contain a surfactant for the purpose of adjusting the surface tension to an appropriate level. The surfactant that can be used is not particularly limited, and examples thereof include nonionic surfactants, cationic surfactants, and anionic surfactants.

[0041] When the treatment liquid contains a surfactant, its content is preferably 0.1 wt% or more and 5 wt% or less relative to the total amount of the treatment liquid. By containing the surfactant within the above range, there is an advantage of providing a treatment liquid with a surface tension that allows stable discharge.

[0042] The treatment liquid of this embodiment may contain other additives within a range that does not impair the effects of this embodiment. Examples of additives include dissolution stabilizers, anti-drying agents, antioxidants, viscosity modifiers, pH modifiers, and antifungal agents.

[0043] As described above, in the treatment liquid of this embodiment, the halogen ion concentration is 5 g / L or less and the pH is 7 to 9.5. As described below, the halogen ion concentration can be adjusted by obtaining a cationic polymer after adjusting the halogen ion concentration using an ion exchange resin.

[0044] Furthermore, the pH of the treatment liquid can be adjusted by, for example, adjusting the amount of lactic acid added.

[0045] The halogen ion concentration of the treatment liquid is more preferably 3 g / L or less. Furthermore, the pH range of the treatment liquid is more preferably 7-9.

[0046] [Method for producing treatment liquid]

[0047] The method for producing the treatment liquid of this embodiment is not particularly limited, and an example is described below: First, a basic ion exchange resin is filled in a column, and a cationic polymer is passed through the column to obtain a regulated cationic polymer having a reduced halogen ion concentration.

[0048] The treatment liquid of the present embodiment can be obtained by mixing the obtained adjusting cationic polymer, lactic acid, an aqueous solvent, and components added as needed (for example, a surfactant, etc.).

[0049] [Inkjet Recording Method Using Treatment Liquid]

[0050] Next, the method of using the treatment liquid of this embodiment is described. Figure 1 The inkjet recording apparatus 10 shown can be used as a pre-treatment liquid.

[0051] Specifically, Figure 1 The illustrated inkjet recording apparatus 10 includes a processing head 1 and a recording head 2 . The recording head 2 may include a first recording head 2 a , a second recording head 2 b , a third recording head 2 c , and a fourth recording head 2 d .

[0052] The processing head 1 ejects a processing liquid toward at least the image forming area of ​​the recording object P. The processing liquid used here is the above-mentioned processing liquid. The processing head 1 is not particularly limited, and examples thereof include a piezoelectric head and a thermal inkjet head.

[0053] The recording head 2 ejects ink toward the image forming area of ​​the recording object P. The first, second, third, and fourth recording heads 2a, 2b, 2c, and 2d recording heads 2 eject inks of different colors (e.g., yellow, magenta, cyan, and black). The number of recording heads is not limited to four; the number of recording heads can be one to three, or five or more. The recording heads 2 are not particularly limited, and examples thereof include piezoelectric heads and thermal inkjet heads.

[0054] The recording object P is placed on the stage 3. A processing head 1 and a recording head 2 are arranged above the stage 3 so as to eject the processing liquid and ink onto the recording object P. The stage 3 is driven by a motor (not shown) to move in a direction from the processing head 1 toward the recording head 2 (for example, Figure 1 By the horizontal movement of the mounting table 3, the recording object P on the mounting table 3 is transported.

[0055] In this embodiment, the recording object P is not particularly limited and may be a medium such as plain paper, but the processing liquid of this embodiment can be more effective when used for printing. Therefore, the recording object P is preferably a medium that can be used for printing.

[0056] During inkjet printing, the stage 3, carrying the object P, is first moved horizontally to transport the object P to a position facing the processing head 1. A processing liquid is then ejected from the processing head 1 toward the object P. The processing head 1 may eject the processing liquid only toward the image-forming area of ​​the object P, toward an area wider than the image-forming area of ​​the object P, or toward the entire surface of the object P. To reduce the amount of processing liquid used and thereby suppress deterioration in the tactile feel of the printed material, it is preferred that the processing head 1 eject the processing liquid only toward the image-forming area of ​​the object P.

[0057] After the processing liquid is ejected from the processing head 1, the mounting table 3, on which the recording object P is mounted, further moves horizontally, and the recording object P is transported to a position facing the recording head 2. Then, the recording head 2 ejects ink toward the image formation area of ​​the recording object P. In this manner, an image is formed in the image formation area of ​​the recording object P using the ink.

[0058] Although not shown, after the recording head 2 ejects ink, the mounting table 3, which carries the recording object P, can further move horizontally to eject a post-treatment liquid from another processing head. This post-treatment liquid is also a non-coloring treatment liquid that does not stain the recording object P even if it adheres to it. It functions to improve the fixability and durability (resistance to friction and scratches) of the ink image printed on the recording object P using the recording head 2. Silicone-based treatment liquids, for example, can be used as this post-treatment liquid. In this manner, the post-treatment liquid forms a treatment film on the image formed in the image formation area of ​​the recording object P.

[0059] After the post-treatment liquid is ejected, the stage 3 holding the recording object P is further moved horizontally, and the recording object P is transported to a position facing a heating unit (not shown). The heating unit heats the recording object P, drying the ink and the treatment liquid. The heating temperature is, for example, between 120°C and 180°C. The heating time is, for example, between 1 minute and 10 minutes. The heating dries the volatile components contained in the ink and the treatment liquid, accelerating the fixing of the ink and treatment liquid on the recording object P. As a result, the recording object P, after the image has been formed using the ink and treated with the treatment liquid, is formed.

[0060] In addition, the treatment liquid of this embodiment is not limited to use in the above-mentioned inkjet recording device 10, and can be modified as shown in the following modified example. For example, the inkjet recording device 10 can also be provided with a sprayer for spraying the treatment liquid instead of the treatment head 1 that sprays the treatment liquid. Alternatively, the treatment using the treatment liquid can also be implemented by immersing the recording object P in a tank storing the treatment liquid. In addition, in the above-mentioned inkjet recording device 10, the stage 3 moves horizontally, but the treatment head 1 and the recording head 2 can also be moved horizontally in a state where the stage 3 is fixed. Alternatively, the stage 3 can be moved horizontally along the conveying direction of the recording object P, or the treatment head 1 and the recording head 2 can be moved horizontally, and the treatment head 1 and the recording head 2 can be moved horizontally in a direction perpendicular to the conveying direction of the recording object P.

[0061] That is, as long as the processing head 1 and the recording head 2 are provided, the effects of using the processing liquid of this embodiment can be obtained regardless of the type of inkjet recording apparatus.

[0062] [ink]

[0063] The ink used for inkjet recording with the treatment liquid of this embodiment is not particularly limited, and for example, an ink containing a pigment and an aqueous medium can be used. If necessary, the ink may further contain at least one selected from the group consisting of a surfactant, a polyol, and binder resin particles.

[0064] For example, a dispersible pigment dispersed in an aqueous medium can be used. From the perspective of obtaining an ink having excellent image density, hue, and color stability, the volume median particle size (D 50 ) is preferably 30 nm or more and 250 nm or less, more preferably 70 nm or more and 160 nm or less. In this specification, the volume median particle size (D 50 ) is a median diameter measured using a laser diffraction / scattering particle size distribution measuring apparatus ("LA-950" manufactured by Horiba, Ltd.).

[0065] Examples of pigments include yellow pigments, orange pigments, red pigments, blue pigments, violet pigments, and black pigments. Examples of yellow pigments include CI Pigment Yellow (74, 93, 95, 109, 110, 120, 128, 138, 139, 151, 154, 155, 173, 180, 185, and 193). Examples of orange pigments include CI Pigment Orange (34, 36, 43, 61, 63, and 71). Examples of red pigments include CI Pigment Red (122 and 202). Examples of blue pigments include CI Pigment Blue (15, more specifically 15:3). Examples of violet pigments include CI Pigment Violet (19, 23, and 33). Examples of black pigments include CI Pigment Black (7).

[0066] The pigment content relative to the total weight of the ink is preferably 1% to 12% by weight, more preferably 1% to 7% by weight. A pigment content of 1% to 1% by weight improves the image density of the resulting recorded material. Furthermore, a pigment content of 12% to 12% by weight results in an ink with high fluidity.

[0067] In particular, the ink of this embodiment preferably contains anionic pigments. This allows the cationic polymer and anionic pigment contained in the treatment liquid to electrically react and aggregate on the surface of the recording medium, thereby suppressing the binding resin (described later as the adhesive resin) contained in the ink from penetrating into the recording medium. In the case of fabric, this reduces the chances of the binding resin penetrating into the interfiber spaces and bonding the fibers together. This improves the texture (such as the feel) of the printed fabric.

[0068] Specifically, as the anionic pigment, an anionic pigment having an anionic group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, a benzenesulfonic acid group, or a phenylcarboxyl group is more preferred.

[0069] The aqueous medium contained in the ink of this embodiment is a medium with water as the main component. The aqueous medium can function as a solvent or as a dispersion medium. Specific examples of the aqueous medium include water or a mixture of water and a polar solvent. Examples of polar solvents contained in the aqueous medium include methanol, ethanol, isopropanol, butanol, and methyl ethyl ketone. The water content in the aqueous medium is preferably 90% by weight or more, particularly preferably 100% by weight. The content of the aqueous medium relative to the weight of the entire ink is preferably 5% by weight or more and 70% by weight or less, more preferably 40% by weight or more and 60% by weight or less.

[0070] In addition, the ink contains a surfactant, thereby improving the wettability of the ink to the recording object. As surfactants, for example, anionic surfactants, cationic surfactants, nonionic surfactants and amphoteric surfactants can be listed. The surfactant contained in the ink is preferably a nonionic surfactant. The nonionic surfactant is preferably a surfactant having an acetylene glycol structure, more preferably an acetylene glycol ethylene oxide adduct. The HLB value of the surfactant is preferably 3 or more and 20 or less, more preferably 6 or more and 16 or less, and further preferably 7 or more and 10 or less. The HLB value of the surfactant is calculated, for example, by the Griffin method and according to the formula "HLB value = 20 × (the sum of the formula weights of the hydrophilic part) / molecular weight". In order to improve the image concentration while suppressing image offset, the content of the surfactant is preferably 0.1 weight % or more and 5.0 weight % or less, more preferably 0.5 weight % or more and 2.0 weight % or less, relative to the weight of the entire ink.

[0071] Furthermore, by incorporating a polyol into the ink, the viscosity of the ink can be appropriately adjusted. Polyols contained in the ink are preferably diols or triols. Examples of diols include glycol compounds, more specifically ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol. Examples of triols include glycerol. When the ink contains a polyol, in order to appropriately adjust the viscosity of the ink, the polyol content relative to the total weight of the ink is preferably 5% by weight or more and 60% by weight or less, and more preferably 20% by weight or more and 50% by weight or less.

[0072] The binder resin particles contained in the ink of this embodiment are dispersed in an aqueous medium. These binder resin particles function as a binder, bonding the printed object and the pigment. Therefore, by incorporating binder resin particles into the ink, it is possible to produce a printed object with excellent pigment fixability.

[0073] Examples of the resin contained in the binder resin particles include polyurethane resins, (meth)acrylate resins, styrene-(meth)acrylate resins, styrene-maleic acid copolymers, vinylnaphthalene-(meth)acrylate copolymers, and vinylnaphthalene-maleic acid copolymers. The resin contained in the binder resin particles is preferably a polyurethane resin. The content of the polyurethane resin in the binder resin particles is preferably 80% by weight or more, more preferably 100% by weight.

[0074] The binder resin content relative to the total weight of the ink is preferably from 1% to 20% by weight, more preferably from 2% to 10% by weight. A binder resin particle content of 1% or more by weight yields a recording object with excellent pigment fixability. On the other hand, a binder resin particle content of 20% or less by weight enables stable ink ejection onto the recording object.

[0075] Furthermore, the ink of this embodiment may further contain known additives (more specifically, a dissolution stabilizer, an anti-drying agent, an antioxidant, a viscosity adjuster, a pH adjuster, an antifungal agent, etc.) as needed.

[0076] The ink used in this embodiment is produced by mixing a pigment, an aqueous medium, and optionally added components (eg, a surfactant, a polyol, and binder resin particles) using a blender, for example, for a mixing time of 1 minute to 30 minutes.

[0077] [Ink Set]

[0078] This embodiment also includes an ink set including the above-mentioned inkjet processing liquid and inkjet ink.

[0079] As the inkjet ink, an ink containing an anionic pigment is preferred, and an ink containing an anionic pigment and a binder resin is more preferred.

[0080] In particular, when the ink set of this embodiment is used for printing, it exhibits an excellent effect of improving the texture of the printed object, and is therefore preferably an ink set for printing.

[0081] [Printing method]

[0082] This embodiment also includes a printing method using the above-mentioned inkjet processing liquid and inkjet ink.

[0083] When using pigment inks that can print on a variety of fabrics, the pigment must be fixed to the fabric surface. Failure to do so results in poor frictional fastness. On the other hand, if the pigment and binder resin do not remain on the fabric surface but penetrate deeply, not only will colorability deteriorate, but the ink and binder resin will penetrate between fibers, resulting in a hard feel and a poor texture.

[0084] According to the printing method of this embodiment, the above-mentioned problem can be improved by using the above-mentioned processing liquid.

[0085] The specific method can be performed in substantially the same manner as the recording method described in the aforementioned "Inkjet Recording Method Using a Processing Liquid," except that the recording target is changed to a printing target. Printing targets include all types of fabrics, specifically woven fabrics, knitted fabrics, and non-woven fabrics. Examples include cotton, silk, linen, acetate, rayon, nylon, polyurethane, and polyester.

[0086] As the inkjet ink for printing, among the above-mentioned inks, it is preferable to use an ink containing an anionic pigment, and it is more preferable to use an ink containing an anionic pigment and a binder resin.

[0087] According to the printing method of this embodiment, excellent colorability can be obtained while suppressing corrosion of inkjet head components and yellowing of the printed object, and deterioration of the texture of the printed fabric can also be suppressed. Therefore, it is very useful in industrial applications.

[0088] In this embodiment, the processing liquid does not need to be processed by padding and drying the cloth in advance. By placing the processing liquid on the cloth using an inkjet system, there is also an advantage that the trouble of adjusting the cloth can be greatly reduced.

[0089] Example

[0090] Hereinafter, the present invention will be further described in detail with reference to examples, but the present invention is not limited to these examples.

[0091] (Example 1)

[0092] Adjustment of cationic polymers

[0093] The column was filled with 0.5 L of a strongly basic ion exchange resin (OH form), and 1 L of "PAS-A5" (manufactured by Nittobo Medical Co., Ltd.) was passed through it at a flow rate of 50 ml / min to obtain an adjusted cationic polymer liquid 1. PAS-A5 is a quaternary ammonium salt cationic polymer (diallyldimethylammonium chloride-sulfur dioxide copolymer). The solid content of the obtained adjusted cationic polymer liquid 1 was 40%.

[0094] Preparation of treatment solution

[0095] The adjusted cationic polymer liquid 1 obtained above was mixed with 3 parts by weight (solid content), 2 parts by weight of lactic acid, 1 part by weight of a nonionic surfactant "surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene glycol, and the remainder of water, and then filtered with a 5 μm filter to obtain a treated liquid 1 (pH 8.5, chloride ion concentration 4.6 g / L).

[0096] (Example 2)

[0097] Adjustment of cationic polymers

[0098] The adjusted cationic polymer liquid 1 obtained in Example 1 was passed through the column again at a flow rate of 50 ml / min to obtain an adjusted cationic polymer liquid 2. The solid content of the obtained adjusted cationic polymer liquid 2 was 40%.

[0099] Preparation of treatment solution

[0100] The adjusted cationic polymer liquid 2 obtained above was mixed with 3 parts by weight (solid content), lactic acid: 2 parts by weight, nonionic surfactant "surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.): 1 part by weight, propylene glycol: 10 parts by weight, and the balance: water, and then filtered with a 5 μm filter to obtain a treated liquid 2 (pH 9.0, chloride ion concentration 0.5 g / L).

[0101] (Example 3)

[0102] A treatment liquid 3 (pH 7.8, chloride ion concentration 1.1 g / L) was obtained in the same manner as in Example 1 except that the adjusted cationic polymer liquid 1 in Example 1 was changed from 3 parts by weight to 0.5 parts by weight.

[0103] (Example 4)

[0104] Except for changing the adjusted cationic polymer liquid 2 of Example 2 from 3 parts by weight to 30 parts by weight, changing the lactic acid from 2 parts by weight to 18 parts by weight, and changing the propylene glycol to 5 parts by weight, the same method as Example 2 was used to obtain a treatment liquid 4 (pH 9.0, chloride ion concentration 5.0 g / L).

[0105] (Example 5)

[0106] Adjustment of cationic polymers

[0107] The column was filled with 0.5 L of a strongly basic ion exchange resin (OH form), and 1 L of "PAS-21" (manufactured by Nittobo Medical Co., Ltd.) was passed through it at a flow rate of 50 ml / min to obtain an adjusted cationic polymer liquid 3. PAS-21 is a cationic polymer of a secondary amine (diallylamine polymer). The solid content of the obtained adjusted cationic polymer liquid 3 was 15%.

[0108] Preparation of treatment solution

[0109] The adjusted cationic polymer liquid 3 obtained above was mixed with 3 parts by weight (solid content), lactic acid: 2 parts by weight, nonionic surfactant "surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.): 1 part by weight, propylene glycol: 10 parts by weight, and the balance: water, and then filtered with a 5 μm filter to obtain a treated liquid 5 (pH 8.4, chloride ion concentration 3.1 g / L).

[0110] (Example 6)

[0111] Adjustment of cationic polymers

[0112] The column was filled with 0.5 L of a strongly basic ion exchange resin (OH form), and 1 L of "PAS-2201CL" (manufactured by Nittobo Medical Co., Ltd.) was passed through at a flow rate of 50 ml / min to obtain a conditioned cationic polymer liquid 4. "PAS-21" is a cationic polymer of a tertiary amine (methyldiallylamine hydrochloride-sulfur dioxide copolymer). The solids content of the resulting conditioned cationic polymer liquid 4 was 25%.

[0113] Preparation of treatment solution

[0114] The adjusted cationic polymer liquid 4 obtained above was mixed with 3 parts by weight (solid content), 2 parts by weight of lactic acid, 1 part by weight of a nonionic surfactant "surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene glycol, and the remainder of water, and then filtered through a 5 μm filter to obtain a treated liquid 6 (pH 8.2, chloride ion concentration 3.3 g / L).

[0115] (Example 7)

[0116] A treatment liquid 7 (pH 7.3, chloride ion concentration 1.0 g / L) was obtained in the same manner as in Example 1 except that the adjusted cationic polymer liquid 1 in Example 1 was changed from 3 parts by weight (solid content) to 0.4 parts by weight (solid content).

[0117] (Comparative Example 1)

[0118] 3 parts by weight (solid content) of "PAS-A5" (manufactured by Nittobo Medical Co., Ltd.), 1% of 1N sodium hydroxide, 1 part by weight of a nonionic surfactant "surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene glycol, and the remainder of water were mixed and filtered through a 5 μm filter to obtain a treatment liquid 8 (pH 7.3, chloride ion concentration 5.6 g / L).

[0119] (Comparative Example 2)

[0120] After mixing 1:3 parts by weight (solid content) of the adjusted cationic polymer liquid, 0.5 parts by weight of lactic acid, 1 part by weight of the nonionic surfactant "surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene glycol, and the remainder of water, the mixture was filtered through a 5 μm filter to obtain a treated liquid 9 (pH 10.0, chloride ion concentration 4.6 g / L).

[0121] (Comparative Example 3)

[0122] The adjusted cationic polymer liquid 1:3 parts by weight (solid content), the nonionic surfactant "surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.): 1 part by weight, propylene glycol: 10 parts by weight, and the balance: water were mixed and filtered through a 5 μm filter to obtain a treated liquid 10 (pH 10.9, chloride ion concentration 4.6 g / L).

[0123] (Comparative Example 5)

[0124] A mixture of 3 parts by weight (solid content) of the adjusted cationic polymer liquid 1, 0.8 parts by weight of acetic acid, 1 part by weight of the nonionic surfactant "Surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene glycol, and the balance of water was mixed and filtered through a 5 μm filter to obtain a treated liquid 11 (pH 8.4, chloride ion concentration 4.6 g / L).

[0125] (Ink Preparation)

[0126] The ink was prepared using an anionic pigment dispersion "AE-2078F" with a pigment concentration of 20% (manufactured by Sanyo Pigment Co., Ltd.), a polyurethane dispersion liquid "SUPERFLEX 470" with a solid content of 38% (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), a nonionic surfactant "Surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.), propylene glycol, and water.

[0127] The specific mixing ratio of the ink was: pigment: 4 wt %, polyurethane: 8 wt %, propylene glycol: 30 wt %, surfactant: 1 wt %, and the balance: water. After mixing in the above ratios, the mixture was filtered through a 5 μm filter to obtain an ink.

[0128] (Preparation of post-treatment solution)

[0129] A post-treatment liquid was prepared using a silicone oil emulsion called "POLON-MF-51" (manufactured by Shin-Etsu Chemical Co., Ltd.) with a silicone oil content of 39%, propylene glycol, and water. The specific mixing ratio was 10% by weight silicone oil, 30% by weight propylene glycol, and the balance water. After mixing in this ratio, the mixture was filtered through a 5 μm filter to obtain a post-treatment liquid.

[0130] <Print>

[0131] Inkjet printing was performed using a flatbed printing jig with Kyocera Corporation's KJ4B heads arranged along the feed direction. Pretreatment liquid was applied to the first head, ink to the second head, and post-treatment liquid to the third head. Inkjet printing was performed under the following conditions. Only Comparative Example 4 was printed without pretreatment liquid.

[0132] Fabric used: Polyester Tropical

[0133] Cloth / head distance: 3mm, head temperature: 25℃

[0134] Drying: 150℃ for 3 minutes (oven)

[0135] <Evaluation Test>

[0136] (Image density)

[0137] The color was measured using a fluorescent spectrophotometer FD-5 (manufactured by Konica Minolta, Inc.). The evaluation criteria are as follows.

[0138] Image density (OD) 1.3 or above "◎" Very good colorability

[0139] Image density (OD) 1.25 or more and less than 1.3 "○" Good colorability

[0140] Image density (OD) less than 1.25 "×" poor colorability

[0141] (Yellowing of fabric)

[0142] The density of the cloth itself and the density (yellow) of the area where the pretreatment liquid was applied were measured using a fluorescence spectrophotometer FD-5 (manufactured by Konica Minolta, Inc.), and the difference between the two was defined as ΔOD. The evaluation criteria are as follows.

[0143] ΔOD: less than 0.05 "◎" No yellowing is visible, very good

[0144] ΔOD: 0.05 or more and less than 0.10 “○” Slightly yellowed, good

[0145] AOD: 0.10 or above "×" yellowing

[0146] (texture)

[0147] An unused printing object was folded in half along the warp (length direction) and the distance (loop height) between the lower fabric and the upper fabric of the crease was measured. The measured loop height of the unused printing object was set as the loop height before printing. Next, the area where the solid image of the evaluation print was formed was folded in half along the warp (length direction) and the loop height was measured. The measured loop height of the evaluation print was set as the loop height after printing. The loop height change rate before and after printing (unit: %) was calculated according to the formula "loop height change rate = 100 × loop height after printing / loop height before printing". The lower the loop height change rate, the less hardened and expanded the printed object is after printing, which means that the deterioration of the touch of the print is suppressed. The evaluation criteria are as follows.

[0148] Less than 130% "○" Texture change is small and good

[0149] 130% or more "×" means the texture becomes hard and poor

[0150] (Corrosion of metal parts)

[0151] A piece of SUS430 (approximately 0.1 g) was accurately weighed and immersed in a 50 ml glass bottle containing 50 g of the treatment solution. The bottle was capped and left at 60°C for one month. After one month, the SUS430 piece was removed, rinsed with ion-exchanged water, dried, and weighed. The weight change rate was calculated using the following formula.

[0152] Weight after placement / weight before placement × 100 = weight change rate (%)

[0153] The evaluation criteria are as follows.

[0154] Weight change rate (%): 98-100% "○" No corrosion, minimal weight change

[0155] Weight change rate (%): less than 98% "×" corrosion progress, large weight loss

[0156] The results of the above evaluation tests are summarized in Table 1.

[0157]

[0158] (Inspection)

[0159] The results in Table 1 confirm that the treatment liquid of the present invention can inhibit corrosion of metal parts. Furthermore, it is shown that printing using the treatment liquid of the present invention can produce printed products with excellent colorability (image density), suppressed yellowing of fabrics, and excellent texture. In particular, a comparison of Examples 1 to 3 with Example 4 shows that yellowing of fabrics can be further suppressed by setting the amounts of cationic polymer and lactic acid within appropriate ranges. Furthermore, a comparison of Examples 1 to 3 with Examples 5 to 7 shows that using an appropriate amount of the quaternary ammonium-containing cationic polymer results in even better image density.

[0160] On the other hand, in Comparative Example 1, which used a treatment solution containing no lactic acid and a halogen ion (chloride ion) concentration exceeding 5 g / L, corrosion of metal parts occurred. Furthermore, in Comparative Example 2, which used a treatment solution with a pH exceeding 9, and in Comparative Example 3, which used a treatment solution containing no lactic acid and a pH exceeding 9, yellowing of the fabric occurred. In Comparative Example 4, which did not use a pre-treatment solution, image density decreased and texture was poor. Furthermore, yellowing also occurred in Comparative Example 5, which used a treatment solution containing acetic acid instead of lactic acid.

[0161] Explanation of symbols

[0162] 1 processing head

[0163] 2 recording heads

[0164] 2a First recording head

[0165] 2b Second recording head

[0166] 2c third recording head

[0167] 2d fourth recording head

[0168] 3 loading platform

[0169] 10Inkjet recording device

[0170] P record object

Claims

1. An inkjet treatment liquid, characterized in that contain: Cationic polymers; and Lactic acid, among which Halogen ion concentration is 5g / L or less and pH is 7-9.5, The content of the lactic acid is 20% by weight or less relative to the total amount of the treatment liquid. The content of the cationic polymer is 0.3% by weight or more and 35% by weight or less relative to the total amount of the treatment liquid. The cationic polymer is selected from quaternary ammonium polymers, diallylamine polymers, and methyldiallylamine hydrochloride-sulfur dioxide copolymers.

2. The inkjet treatment liquid according to claim 1, wherein The quaternary ammonium-containing polymer is selected from diallyldimethylammonium sulfur dioxide copolymer, diallyldimethylammonium chloride acrylamide copolymer, diallyldimethylammonium chloride polymer, and dimethylamine-ammonia-epichlorohydrin condensation polymer.

3. The inkjet treatment liquid according to claim 1 or 2, wherein Used for printing.

4. The inkjet treatment liquid according to claim 3, wherein The printing uses an inkjet ink containing an anionic pigment.

5. An ink set, characterized in that have: The inkjet treatment liquid according to any one of claims 1 to 4; and Inkjet ink containing anionic pigments.

6. A printing method, characterized in that The following steps are involved: applying the inkjet treatment liquid according to any one of claims 1 to 4 to a printing object; Then, an inkjet ink containing an anionic pigment is applied to the area where the inkjet treatment liquid has been applied.

Images