Inkjet processing liquid, inkjet printing device, and inkjet printing method

Abstract

One aspect of the present invention relates to a treatment liquid for inkjet, comprising: emulsified particles containing a silicone oil; a surfactant; the present invention relates to a treatment liquid for treating a silicone oil, the treatment liquid containing a surfactant, and an aqueous medium in which the content of the silicone oil is 5-15% by mass (inclusive) with respect to the total amount of the treatment liquid, and the surfactant contains: a first surfactant containing an alkyl group having 12-14 carbon atoms, and a second surfactant containing an alkyl group having 12-14 carbon atoms; and a second surfactant containing an alkyl group having 16 to 18 carbon atoms.

Description

[0001] This application is a divisional application of PCT / JP2023 / 015859 application with application number: 202380013821.6, application date: 2023.4.21, and invention name: "Inkjet processing liquid, inkjet printing device and inkjet printing method". Technical Field

[0002] The present invention relates to an inkjet processing liquid and further to an inkjet printing device and an inkjet printing method using the same. Background Art

[0003] In the inkjet recording method, it is known that after the ink is applied, a treatment liquid is applied in order to suppress deformation of the recording medium or to improve image fixability.

[0004] For example, Patent Document 1 discloses that feathering, bleeding, and paper deformation can be suppressed by using a processing liquid containing a surfactant. This document also reports that it is particularly preferable to use a processing liquid containing two surfactants.

[0005] Furthermore, it has been reported that the inclusion of a surfactant in an inkjet recording liquid can achieve ink drying properties, optical density, feathering, and image fixability at the same time (Patent Document 2).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2016-16556 Patent Document 2: Japanese Patent Application Publication No. 2001-226616 Summary of the invention

[0009] An aspect of the present invention relates to an inkjet treatment liquid comprising: emulsified particles containing silicone oil; a surfactant; and an aqueous medium, wherein the content of the silicone oil is 5% by mass or more and 15% by mass or less relative to the total treatment liquid, and the surfactant comprises: a first surfactant containing an alkyl group having 12 to 14 carbon atoms; and a second surfactant containing an alkyl group having 16 to 18 carbon atoms. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram showing one embodiment of an inkjet printing apparatus using the inkjet processing liquid of this embodiment. DETAILED DESCRIPTION

[0011] The treatment liquid described in Patent Document 1 contains a surfactant, but the purpose is to improve image quality and suppress paper deformation, and no research has been conducted on the storage stability of the treatment liquid. In addition, the invention described in Patent Document 2 is not a treatment liquid, but an invention related to the inkjet recording liquid itself, and there is no description in the document on improving the storage stability of the inkjet recording liquid.

[0012] On the other hand, in the printing technology using inkjet, in order to ensure the color fastness to friction of the printed material, a post-treatment liquid containing silicone oil is sometimes used. According to the research of the present inventors, in the post-treatment liquid containing silicone oil ejected by inkjet, in order to ensure the ejection stability, it is necessary to control the particle size of the silicone oil. It is also known that this can be adjusted by adding a surfactant to the post-treatment liquid.

[0013] However, it is known that if the post-treatment liquid containing silicone oil and surfactant is stored for a long time, the surfactant will be separated from the silicone oil surface, and it is difficult to maintain the desired particle size. If the particle size of the silicone oil cannot be maintained in an appropriate range, it is difficult to ensure the problem of ejection stability.

[0014] In addition, the technologies described in the above-mentioned Patent Documents 1 and 2 are mainly related to inkjet image forming methods for printing on paper media such as ordinary paper or low liquid absorption recording media such as film sheets, and the purpose is to form a good image with suppressed bleeding, and it is almost not envisioned to be used for printing on cloth, etc. However, when inkjet recording is used for printing, in addition to image quality, printing-specific characteristics such as rubbing fastness are also required.

[0015] The following specifically describes the embodiments of the present invention, but the present invention is not limited thereto. In addition, in this specification, unless otherwise specified, the volume median particle size (D 50 ) is the median particle size measured using a laser diffraction / scattering particle size distribution measuring device ("LA-950" manufactured by Horiba, Ltd.). 50 ". Unless otherwise specified, the "main component" of a material means the component that is contained in the largest amount by mass. Unless otherwise specified, the "specific gravity" means the specific gravity at 25°C. Acrylic acid and methacrylic acid are sometimes collectively referred to as "(meth)acrylic acid". Each component described in this specification may be used alone or in combination of two or more.

[0016] [Inkjet processing liquid]

[0017] An embodiment of the present invention relates to an inkjet treatment liquid (hereinafter also referred to as "treatment liquid"), which is characterized in that it comprises: emulsified particles containing silicone oil; a surfactant; an aqueous medium, wherein the content of the silicone oil is greater than 5% by mass and less than 15% by mass relative to the total treatment liquid, and the surfactant contains: a first surfactant containing an alkyl group with a carbon number of 12 to 14; and a second surfactant containing an alkyl group with a carbon number of 16 to 18.

[0018] According to the above configuration, the treatment liquid of the present embodiment is stably ejected from the inkjet head component and has excellent storage stability. That is, according to the present invention, it is possible to provide an inkjet treatment liquid that can be stably ejected from the inkjet head component and has excellent storage stability. In addition, when the inkjet treatment liquid of the present invention is used for printing, it also has the advantage of excellent color fastness to rubbing.

[0019] The processing liquid of this embodiment is applicable, for example, to the inkjet printing device and the inkjet printing method described later. The processing liquid of this embodiment is a processing liquid for post-processing. In other words, after the image is formed in the image forming area of ​​the printing object using ink, the processing liquid of this embodiment performs post-processing on the image forming area.

[0020] When the treatment liquid of the present embodiment is used for printing, in addition to the above advantages, there is an advantage that the color fastness to rubbing can be improved.

[0021] The following describes the composition of the inkjet treatment liquid involved in this embodiment. The treatment liquid involved in this embodiment contains: emulsified particles containing silicone oil; a surfactant; and an aqueous medium. In other words, the treatment liquid of this embodiment is an emulsion in which emulsified particles are dispersed in an aqueous medium, more specifically, an oil-in-water (O / W) emulsion.

[0022] (Emulsified particles)

[0023] The emulsified particles contained in the treatment liquid contain silicone oil. The silicone oil contained in the emulsified particles is not particularly limited, but preferably contains at least unmodified silicone oil. By containing unmodified silicone oil, it is possible to produce a printed material with better color fastness to rubbing, especially better color fastness to wet rubbing when used for printing.

[0024] Specific examples of the unmodified silicone oil include dimethylpolysiloxane, methylphenylsilicone oil, methyl hydrogen silicone oil, etc. Among them, dimethylpolysiloxane and the like are preferably used.

[0025] In addition, the silicone oil may be silicone oil other than unmodified silicone oil, or may contain both unmodified silicone oil and other silicone oil. In this case, both unmodified silicone oil and other silicone oil may be contained in one emulsified particle. Alternatively, the treatment liquid may contain two or more emulsified particles, for example, unmodified silicone oil may be contained in the first emulsified particle, and other silicone oil may be contained in the second emulsified particle. As other silicone oils, for example, ionic group-containing silicone oils may be cited.

[0026] When the treatment liquid of this embodiment is used for printing, the viscosity of the silicone oil is preferably 500 mm 2 / s (i.e., mm 2 / sec) or more. If the viscosity of silicone oil is 500mm 2 / s or more, it is believed that silicone oil is unlikely to be separated from the printed material due to friction, and a printed material with better dry and wet friction fastness can be produced. In addition, as mentioned above, the treatment liquid involved in this embodiment has excellent ejection properties from the treatment head of the inkjet printing device. When the treatment liquid is ejected from the treatment head, the amount of treatment liquid used is reduced compared to the case where the printed material is immersed in the treatment liquid. Therefore, even if 500mm 2 When a high viscosity silicone oil of 1000 g / s or more is used as the treatment liquid, it is less likely to cause the printed object to harden, and the deterioration of the touch of the printed object can be further suppressed.

[0027] The upper limit of the viscosity of the silicone oil is not particularly limited. For example, the viscosity of the silicone oil is preferably 100,000 mm 2 / s or less, more preferably 6000mm 2 / s or less. The viscosity of silicone oil, for example, can be from 500mm 2 / s、700mm 2 / s、900mm 2 / s、1000mm 2 / s、1100mm 2 / s、1200mm 2 / s、1500mm 2 / s、1700mm 2 / s、1800mm 2 / s、2000mm 2 / s、3000mm 2 / s、5700mm 2 / s and 6000mm 2 / s is within the range of two values ​​selected from the group consisting of.

[0028] In this embodiment, the viscosity of the silicone oil means the kinematic viscosity at 25° C. When the emulsified particles contain two or more silicone oils (for example, ionic group-containing silicone oil and other silicone oil), the viscosity of the silicone oil means the viscosity of the mixture of the two or more silicone oils.

[0029] The viscosity of the silicone oil is a value measured according to the method described in JIS (Japanese Industrial Standards) Z8803:2011 (Method for measuring viscosity of liquids). Specifically, for example, the silicone oil is extracted from the treatment liquid with toluene, washed and dried, thereby separating the silicone oil from the treatment liquid, and the viscosity of the silicone oil can be measured.

[0030] The content of silicone oil in the treatment liquid of the present embodiment is 5% by mass or more and 15% by mass or less. By making the content percentage of silicone oil in the above range, the ejection property of the treatment liquid can be made more stable, and the color fastness to rubbing when used for printing purposes can be improved. The content percentage of silicone oil in the treatment liquid is preferably 7% by mass or more. In addition, the content percentage of silicone oil in the treatment liquid is preferably 13% by mass or less.

[0031] In this embodiment, the content percentage of silicone oil in the treatment liquid means the percentage of the mass of silicone oil relative to the total mass of the treatment liquid. When the emulsified particles contain two or more silicone oils (for example, unmodified silicone oil and other silicone oils), the content percentage of silicone oil means the percentage of the total mass of the two or more silicone oils relative to the mass of the treatment liquid.

[0032] The emulsified particles may further contain ingredients other than silicone oil. However, from the viewpoint of producing printed matter with excellent color fastness to rubbing, the emulsified particles preferably contain only silicone oil.

[0033] The average particle size of the emulsified particles (dispersed particle size in the aqueous medium) is preferably greater than 100 nm and less than 250 nm. By having the average particle size of the emulsified particles in the above range, the processing liquid of this embodiment has the advantage of better ejection properties from the processing head of the inkjet device. In addition, the color fastness to friction when used for printing purposes can be more reliably obtained. The more preferred range of the average particle size of the emulsified particles is greater than 120 nm and less than 220 nm, and further preferably greater than 150 nm and less than 200 nm. Alternatively, the average particle size of the emulsified particles, for example, may also be within the range of 2 values ​​selected from the group consisting of 100 nm, 120 nm, 135 nm, 150 nm, 155 nm, 160 nm, 180 nm, 200 nm, 210 nm, 220 nm and 250 nm.

[0034] In this embodiment, the average particle size refers to the harmonic mean particle size based on the scattered light intensity calculated by the cumulant method (also referred to as the cumulant average particle size). In other words, the average particle size of the emulsified particles is a value measured by the method described in ISO 13321:1996 (Particle size analysis-Photon correlation spectroscopy).

[0035] In addition, in this embodiment, when the inkjet processing liquid is stored at 60° C. for 30 days, the average particle size X of the emulsified particles in the processing liquid before storage and the average particle size Y of the emulsified particles in the processing liquid after storage preferably satisfy the following formula: 1.0≤Y / X≤1.05

[0036] When the average particle size X and the average particle size Y satisfy the above formula, the average particle size of the emulsified particles does not significantly change even when the treatment liquid is stored for a long period of time, and it is considered that a treatment liquid having excellent storage stability can be obtained more reliably.

[0037] The formula is more preferably 1.0≤Y / X≤1.03.

[0038] In this specification, the "processing liquid before storage" is preferably a processing liquid immediately after production, but may be a processing liquid stored for a predetermined period after production unless stored in a particularly severe environment.

[0039] (Surfactant)

[0040] The treatment liquid of the present embodiment, as a surfactant, contains: a first surfactant containing an alkyl group with a carbon number of 12 to 14; a second surfactant containing an alkyl group with a carbon number of 16 to 18. By containing such a surfactant, the treatment liquid can ensure spraying stability. This is because, by including two surfactants with carbon numbers in the above range in the treatment liquid, the above-mentioned emulsified particles dispersed in the treatment liquid can be inhibited from merging with each other, and the emulsified particles can be inhibited from becoming excessively large. In other words, the treatment liquid of the present embodiment, by containing the above-mentioned surfactant, can maintain the size (average particle size) of the emulsified particles dispersed in the treatment liquid within an appropriate range.

[0041] If only one type of surfactant is contained instead of two types as described above, the surfactant is separated from the surface of the silicone oil forming the emulsified particles, so that the average particle size of the emulsified particles cannot be maintained.

[0042] In addition, when the carbon number of the alkyl group of the first surfactant is less than 11, the surfactant is easily released from the silicone oil in a relatively high temperature region (about 60°C). Therefore, in order to ensure the dispersion stability in the temperature region, it is necessary to increase the amount of the first surfactant. However, if the first surfactant is increased, thixotropy is manifested, so the carbon number of the alkyl group of the first surfactant is 12 to 14. In a preferred embodiment, the carbon number of the alkyl group of the first surfactant is 12 and / or 14.

[0043] On the other hand, if the carbon number of the alkyl group of the second surfactant is 19 or more, the free components that are not attached to the silicone oil (not integrated) increase, resulting in excessive viscosity of the treatment liquid or thixotropy. Therefore, the carbon number of the alkyl group of the second surfactant is 16 to 18. In a preferred embodiment, the carbon number of the alkyl group of the second surfactant is 16 and / or 18.

[0044] As the first surfactant, any surfactant having an alkyl group with a carbon number of 12 to 14 can be used without particular limitation. Polyoxyethylene alkyl ethers can be preferably used. More specifically, for example, polyoxyethylene lauryl ether (C12), polyoxyethylene tridecyl ether (C13), polyoxyethylene myristyl ether (C14), etc. can be used. The first surfactant may further contain two or more compounds having alkyl groups with different carbon numbers.

[0045] In addition, as the second surfactant, any surfactant having an alkyl group with a carbon number of 16 to 18 can be used without particular limitation. Polyoxyethylene alkyl ethers can be preferably used. More specifically, for example, polyoxyethylene cetyl ether (C16), polyoxyethylene octadecyl ether (C18), etc. can be used. The second surfactant may further contain two or more compounds having alkyl groups with different carbon numbers.

[0046] In addition, surfactants other than those described above may be added to the treatment liquid of the present embodiment within a range not impairing the effects of the present invention.

[0047] In the treatment liquid of this embodiment, the content of the second surfactant is preferably less than the content of the first surfactant. It is believed that this can obtain a treatment liquid with better ejection properties and storage stability. It is also believed that a printed material with better color fastness to rubbing, especially color fastness to moisture and rubbing, can be obtained when used for printing.

[0048] In addition, it is preferred that the content of the first surfactant and the content of the second surfactant satisfy the following formula: content of the second surfactant / (content of the first surfactant+content of the second surfactant)=0.15-0.25 (mass %). If the content of the second surfactant is within the above range relative to the total content of the first surfactant and the second surfactant, it is believed that the ejection property and storage stability can be obtained more reliably. This is because if the content of the second surfactant is too much, thixotropy is exhibited, which may lead to deterioration of ejection property and storage stability.

[0049] The total content of the first surfactant and the second surfactant in the treatment liquid of this embodiment is preferably 0.5% by mass or more and 4.0% by mass or less relative to the total treatment liquid. In particular, in order to obtain more excellent storage stability and ejection properties, the lower limit of the total content relative to the total treatment liquid is preferably 1.0% by mass or more, and more preferably 1.5% by mass or more. In addition, the upper limit of the total content is preferably 2.5% by mass or less, and more preferably 2.0% by mass or less.

[0050] In addition, in the treatment liquid of this embodiment, the total content of the first surfactant and the second surfactant is preferably 9.0 mass % or more and 40.0 mass % or less relative to the content of the silicone oil. In particular, from the viewpoint of obtaining a more excellent ejection property and color fastness to friction when used for printing, the lower limit of the total content of the surfactants relative to the content of the silicone oil is preferably 10.0 mass % or more, and more preferably 15 mass % or more. In addition, the upper limit of the total content is preferably 35.0 mass % or less.

[0051] (Aqueous medium)

[0052] The aqueous medium contained in the treatment liquid of the present embodiment is a medium with water as the main component. The aqueous medium can act as a solvent or as a dispersion medium. As a specific example of the aqueous medium, water or a mixed solution of water and a polar solvent can be listed. As examples of polar solvents contained in the aqueous medium, methanol, ethanol, isopropanol, butanol and methyl ethyl ketone can be listed. The percentage content of water in the aqueous medium is preferably 90% by mass or more, and particularly preferably 100% by mass. Relative to the mass of the treatment liquid, the percentage content of the aqueous medium is preferably 50% by mass or more and 90% by mass or less, and more preferably 55% by mass or more and 70% by mass or less.

[0053] (Other ingredients)

[0054] The treatment liquid of the present embodiment may also contain a polyol as needed. The treatment liquid can appropriately adjust the viscosity of the treatment liquid by containing a polyol. As the polyol, a diol or a triol is preferred. As the diol, for example, diol compounds can be listed, more specifically, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol and tetraethylene glycol can be listed. As the triol, for example, glycerol can be listed. When the treatment liquid contains a polyol, the content percentage of the polyol relative to the mass of the treatment liquid is preferably 10 mass % or more and 40 mass % or less, more preferably 15 mass % or more and 35 mass % or less.

[0055] In addition, other additives may be contained in the treatment liquid as long as they do not hinder the effects of the present invention. Examples of additives include dispersants, dissolution stabilizers, anti-drying agents, antioxidants, viscosity modifiers, pH modifiers, and antifungal agents.

[0056] (Method for producing treatment liquid)

[0057] The method for producing the treatment liquid of the present embodiment is not particularly limited, but an example thereof is described. For example, silicone oil, a surfactant, an aqueous medium, and components added as needed (e.g., polyols, etc.) are mixed and emulsified using a homogenizer. In this way, emulsified particles containing silicone oil can be dispersed in the aqueous medium to obtain a treatment liquid.

[0058] (use)

[0059] The treatment liquid of this embodiment is particularly suitable for inkjet printing. When using pigment ink that can be printed on most types of fabrics, the pigment needs to be fixed on the surface of the fabric. If it cannot be fixed on the surface of the fabric, there is a problem of poor color fastness to friction.

[0060] By using the treatment liquid of this embodiment, the above-mentioned problem can be solved. That is, according to the treatment liquid of this embodiment, the color fastness to wet friction and dry friction can be improved in the production of printed materials, so it is very useful in industrial use.

[0061] [Inkjet printing device]

[0062] Next, the inkjet printing device according to this embodiment will be described.

[0063] The inkjet printing device 10 involved in this embodiment is characterized by at least comprising: a recording head 1, which ejects ink to the image forming area of ​​the printing object; a processing head 2, which ejects a processing liquid to at least the image forming area of ​​the printing object; a mounting table 3, which is used to transport the printing object, and the processing liquid ejected from the processing head is the above-mentioned inkjet processing liquid. In addition, for ease of understanding, Figure 1The components are schematically shown in the main body, and the size, number, etc. of each component shown in the figure can be changed as appropriate. Figure 1 It is a side view showing the main part of an inkjet printing apparatus 10 as an example of the inkjet printing apparatus according to the present embodiment. Figure 1 The inkjet printing device 10 shown is a flat-bed inkjet printing device.

[0064] The inkjet printing device 10 according to this embodiment uses the treatment liquid of this embodiment to treat the printing object P. Since the treatment liquid of this embodiment is used, the inkjet printing device 10 can obtain a printed product with excellent color fastness to wet rubbing and color fastness to dry rubbing.

[0065] Figure 1 The inkjet printing device 10 shown in the figure includes a recording head 1, a processing head 2, and a mounting table 3. The recording head 1 includes a first recording head 1a, a second recording head 1b, a third recording head 1c, and a fourth recording head 1d.

[0066] The recording head 1 ejects ink toward an image forming area of ​​the printing object P. The first recording head 1a, the second recording head 1b, the third recording head 1c, and the fourth recording head 1d of the recording head 1 eject inks of different colors (for example, yellow ink, magenta ink, cyan ink, and black ink). The recording head 1 is not particularly limited, but examples thereof include a piezoelectric head and a thermal inkjet head.

[0067] The processing head 2 ejects a processing liquid for post-processing toward at least the image forming area of ​​the printing object P. The processing liquid is the processing liquid involved in the first embodiment. The processing head 2 is not particularly limited, but examples thereof include a piezoelectric head and a thermal inkjet head. The inkjet printing device 10 of this embodiment may further include one or more processing liquid tanks (not shown) for containing the processing liquid. In this case, the processing liquid is supplied from the processing liquid tank to the processing head 2.

[0068] The printing object P is placed on the stage 3. The recording head 1 and the processing head 2 are arranged above the stage 3 so as to eject ink and processing liquid onto the printing object P. The stage 3 is driven by a motor (not shown) to move in a direction from the recording head 1 toward the processing head 2 (for example, Figure 1 The printing object P on the mounting table 3 is transported by the horizontal movement of the mounting table 3.

[0069] The printing object P may be a woven fabric or a knitted fabric. Examples of the printing object P include cotton fabric, silk fabric, linen fabric, acetate fabric, rayon fabric, nylon fabric, polyurethane fabric, and polyester fabric.

[0070] In the production of printed articles, first, the stage 3 on which the printing object P is placed moves horizontally, and the printing object P is transported to a position facing the recording head 1. Ink is ejected from the recording head 1 to the image forming area of ​​the printing object P. In this way, an image is formed in the image forming area of ​​the printing object P by the ink. After the ink is ejected, the stage 3 on which the printing object P is placed moves further horizontally, and the printing object P is transported to a position facing the processing head 2. The processing liquid is ejected from the processing head 2 to at least the image forming area of ​​the printing object P. In this way, a processing film is formed on the image formed in the image forming area of ​​the printing object P by the processing liquid.

[0071] The processing head 2 may spray the processing liquid only to the image forming area of ​​the printing object P, or may spray the processing liquid to an area wider than the image forming area of ​​the printing object P, or may spray the processing liquid to the entire surface of the printing object P. In order to reduce the amount of processing liquid used and suppress the deterioration of the touch of the printed object, it is preferred that the processing head 2 sprays the processing liquid only to the image forming area of ​​the printing object P, and it is more preferred that the processing liquid is sprayed only to the area in the image forming area where the ink is sprayed by the recording head 1. Because the processing head 2 can accurately control the position of spraying the processing liquid, the processing liquid can be sprayed only to the area where the ink has been sprayed. In order to accurately control the position of spraying the processing liquid, the distance between the processing head 2 and the printing object P is preferably greater than 1 mm and less than 5 mm. In addition, in order to efficiently perform post-processing using the processing liquid, it is preferred that only the processing liquid is sprayed from the processing head 2.

[0072] After the treatment liquid is ejected from the treatment head 2 toward the printing object P, the mounting table 3 on which the printing object P is mounted is further moved horizontally to transport the printing object P to a position facing the heating unit (not shown). The printing object P is heated by the heating unit, and the ink and the treatment liquid are dried. The heating temperature is, for example, not less than 120°C and not more than 180°C. The heating time is, for example, not less than 1 minute and not more than 10 minutes. By heating, the volatile components contained in the ink and the treatment liquid evaporate, thereby promoting the fixation of the ink and the treatment liquid on the printing object P. As a result, a printed object, that is, a printing object P on which an image is formed by ink and treated by the treatment liquid, can be produced.

[0073] The inkjet printing apparatus 10 according to the second embodiment has been described above. However, the inkjet printing apparatus of the present invention is not limited to the above-described inkjet printing apparatus 10, and may be modified as shown in the following modified examples, for example.

[0074] Regarding the first modified example, the inkjet printing apparatus 10 may include a sprayer for spraying the processing liquid instead of the processing head 2 for ejecting the processing liquid.

[0075] Regarding the second modification, the treatment with the treatment liquid may be performed by immersing the printing object P in a tank storing the treatment liquid. In the case of immersion, the discharge amount of the treatment liquid described later in the third embodiment corresponds to the application amount of the treatment liquid.

[0076] Regarding the third modification, in the inkjet printing apparatus 10, the stage 3 is moved horizontally, but the recording head 1 and the processing head 2 may be moved horizontally in a state where the stage 3 is fixed.

[0077] Regarding the fourth variant, the stage 3 may be moved horizontally along the conveying direction of the printing object P, or the recording head 1 and the processing head 2 may be moved horizontally, and the recording head 1 and the processing head 2 may be moved horizontally in a direction parallel to the conveying direction of the printing object P.

[0078] Regarding the fifth modification, the number of the recording heads 1 may be 1 to 3 or 5 or more.

[0079] The sixth modification may be a flatbed inkjet printing apparatus. As long as the recording head 1 and the processing head 2 are provided, the effect of using the processing liquid according to the first embodiment can be obtained regardless of the type of the inkjet printing apparatus.

[0080] [Inkjet printing method]

[0081] Next, continue to refer to Figure 1 The inkjet printing method involved in the present embodiment is described. The inkjet printing method of the present embodiment is a method of forming an image in the image forming area of ​​the printing object P using the above-mentioned treatment liquid. Alternatively, the inkjet printing method of the present embodiment is also a method of forming an image in the image forming area of ​​the printing object P using the above-mentioned inkjet printing device 10. The inkjet printing method of the present embodiment can produce printed materials with excellent color fastness to friction because the above-mentioned treatment liquid is used. In addition, since the treatment liquid of the present embodiment has excellent ejection properties from the treatment head, these effects can be reliably exerted in the inkjet printing method.

[0082] The inkjet printing method of this embodiment includes an inkjet process and a treatment process. In the inkjet process, ink is ejected from the recording head 1 to the image forming area of ​​the printing object P. In the treatment process, a treatment liquid is ejected from the treatment head 2 to at least the image forming area of ​​the printing object P. The treatment liquid is the treatment liquid involved in the first embodiment. The treatment process is preferably a post-treatment process performed after the inkjet process. The inkjet printing method may also include a heating process as needed.

[0083] In the inkjet process, the amount of ink ejected to the printing object P is, for example, 5 g / m 2 Above and 40g / m 2 the following.

[0084] In the treatment process, the amount of treatment liquid ejected to the printing object P is, for example, 10 g / m 2 Above and 120g / m 2 In order to improve the color fastness to dryness and rubbing, the spraying amount of the treatment liquid is preferably 15 g / m 2 Above and 30g / m 2 In order to improve the color fastness to wet rubbing in addition to the color fastness to dry rubbing, the spraying amount of the treatment liquid is more preferably 17 g / m 2 Above and 25g / m 2 the following.

[0085] [Ink]

[0086] The ink used for inkjet recording together with the treatment liquid of the present embodiment, and the ink used in the printing device or the printing method are not particularly limited, and for example, an ink containing a pigment and an aqueous medium can be used. The ink may further contain at least one selected from the group consisting of a surfactant, a polyol, and binder resin particles as needed.

[0087] For example, a dispersible pigment dispersed in an aqueous medium can be used. From the viewpoint of obtaining an ink having excellent image density, hue, and color stability, the D 50 The diameter is preferably 30 nm to 250 nm, and more preferably 70 nm to 160 nm.

[0088] 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).

[0089] The content percentage of the pigment relative to the total weight of the ink is preferably 1% by weight or more and 12% by weight or less, and more preferably 1% by weight or more and 7% by weight or less. When the content percentage of the pigment is 1% by weight or more, the image density of the formed recorded object can be increased. In addition, when the content percentage of the pigment is 12% by weight or less, an ink with high fluidity can be obtained.

[0090] In particular, it is preferred that the ink of this embodiment contains anionic pigments. As a result, the cationic polymers and anionic pigments contained in the above-mentioned treatment liquid react and condense on the surface of the recording object, thereby preventing the binding resin (binder resin described later) contained in the ink from penetrating into the recording medium. This is particularly important when the recording medium is cloth, and can prevent the binding resin from penetrating into the gaps between fibers and causing the fibers to adhere to each other. As a result, the feel (touch, etc.) of the cloth to be printed can be improved.

[0091] Specifically, as the anionic pigment, anionic pigments 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 are more preferred.

[0092] The aqueous medium contained in the ink of the present embodiment is a medium with water as the main component. The aqueous medium can function as a solvent or as a dispersion medium. As specific examples of the aqueous medium, water or a mixture of water and a polar solvent can be cited. As examples of polar solvents contained in the aqueous medium, methanol, ethanol, isopropanol, butanol and methyl ethyl ketone can be cited. The percentage of water in the aqueous medium is preferably 90% by weight or more, particularly preferably 100% by weight. Relative to the total weight of the ink, the percentage of the aqueous medium content 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.

[0093] In addition, by making the ink contain a surfactant, the wettability of the ink for the recording object is improved. 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, and more preferably an acetylene glycol ethylene oxide adduct. The HLB value of the surfactant is preferably greater than 3 and less than 20, more preferably greater than 6 and less than 16, and further preferably greater than 7 and less than 10. The HLB value of the surfactant is, for example, calculated by the Griffin method and according to the formula "HLB value = 20×(sum of the formula weights of the hydrophilic part) / molecular weight". In order to suppress the offset of the image while increasing the image concentration, the content percentage of the surfactant relative to the total weight of the ink is preferably greater than 0.1% by weight and less than 5.0% by weight, and more preferably greater than 0.5% by weight and less than 2.0% by weight.

[0094] In addition, the viscosity of the ink is appropriately adjusted by the ink containing a polyol. As the polyol contained in the ink, a diol or a triol is preferred. As the diol, for example, a diol compound can be cited, and more specifically, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol can be cited. As the triol, for example, glycerol can be cited.

[0095] When the ink contains a polyol, in order to appropriately adjust the viscosity of the ink, the content percentage of the polyol is preferably 5 to 60 wt %, more preferably 20 to 50 wt %, based on the total weight of the ink.

[0096] The binder resin particles contained in the ink of this embodiment exist in a state of being dispersed in an aqueous medium. The binder resin particles function as a binder that binds the printing object to the pigment. Therefore, by containing the binder resin particles in the ink, a printed object with excellent pigment fixability can be obtained.

[0097] As the resin contained in the binder resin particles, polyurethane resin, (meth) acrylic resin, styrene-(meth) acrylic resin, styrene-maleic acid copolymer, vinyl naphthalene-(meth) acrylic acid copolymer and vinyl naphthalene-maleic acid copolymer can be mentioned. As the resin contained in the binder resin particles, polyurethane resin is preferred. The content percentage of the polyurethane resin in the binder resin particles is preferably 80% by weight or more, and more preferably 100% by weight.

[0098] The content percentage of the binder resin relative to the total weight of the ink is preferably 1% by weight or more and 20% by weight or less, and more preferably 2% by weight or more and 10% by weight or less. If the content percentage of the binder resin particles is 1% by weight or more, a recording object with excellent pigment fixability can be obtained. On the other hand, if the content percentage of the binder resin particles is 20% by weight or less, the ink can be stably ejected onto the recording object.

[0099] Furthermore, the ink of the present 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 necessary.

[0100] The ink used in this embodiment is produced by, for example, mixing a pigment, an aqueous medium, and components added as needed (for example, a surfactant, a polyol, and binder resin particles) using a stirrer for a mixing time of, for example, 1 minute to 30 minutes.

[0101] Example

[0102] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the examples at all.

[0103] In the examples described below, the average particle size of each emulsified particle is a value measured by the method described below.

[0104] <Method for measuring the average particle size of emulsified particles>

[0105] The average particle size of the emulsified particles was measured using a laser diffraction particle size distribution measuring device ("ZETASIZER NANO ZS" manufactured by Malvern Instruments Ltd.) in accordance with the method described in ISO 13321:1996 (Particle size analysis-Photon correlation spectroscopy). In the measurement of the average particle size of the emulsified particles, a measurement sample prepared by diluting the treatment liquid 1000 times with water was used.

[0106] In addition, the first surfactant and the second surfactant used in this example are as follows.

[0107] (First surfactant)

[0108] ・Surfactant 1 (polyoxyethylene lauryl ether, alkyl group: C12)

[0109] ・Surfactant 2 (polyoxyethylene tridecyl ether, alkyl group: C13)

[0110] ・Surfactant 3 (polyoxyethylene myristyl ether, alkyl group: C14)

[0111] (Second surfactant)

[0112] ・Surfactant 4 (polyoxyethylene cetyl ether, alkyl group: C16)

[0113] ・Surfactant 5 (polyoxyethylene stearyl ether, alkyl group: C18).

[0114] (Example 1)

[0115] 5 g of unmodified silicone oil (“KF96-3000cs” manufactured by Shin-Etsu Chemical Co., Ltd., dimethyl polysiloxane, viscosity: 3,000 mm 2 / s, specific gravity: 0.97), 63.37g of ion exchange water, 30g of propylene glycol, 1.3g of the first surfactant (surfactant 1: C=12) and 0.33g of the second surfactant (surfactant 4: C=16) were placed in a beaker. Using a homogenizer ("ULTRA-TURRAX T25" manufactured by IKA), the contents of the beaker were stirred at 10,000 rpm for 15 minutes and allowed to stand for 30 minutes. Next, the contents of the beaker were filtered through a 120-mesh stainless steel filter to obtain treatment liquid 1. Emulsified particles containing unmodified silicone oil are dispersed in treatment liquid 1. The average particle size (X) of the emulsified particles is 115nm.

[0116] (Example 2)

[0117] 10 g of unmodified silicone oil (“KF96-3000cs” manufactured by Shin-Etsu Chemical Co., Ltd., dimethyl polysiloxane, viscosity: 3,000 mm 2 / s, specific gravity: 0.97), 58.37g of ion exchange water, 30g of propylene glycol, 1.3g of the first surfactant (surfactant 1: C = 12) and 0.33g of the second surfactant (surfactant 4: C = 16) were placed in a beaker. The contents of the beaker were stirred at a speed of 10000rpm for 15 minutes using a homogenizer ("ULTRA-TURRAX T25" manufactured by IKA) and allowed to stand for 30 minutes. Next, the contents of the beaker were filtered using a 120-mesh stainless steel filter to obtain treatment liquid 1. Emulsified particles containing unmodified silicone oil were dispersed in treatment liquid 2. The average particle size (X) of the emulsified particles was 138nm.

[0118] (Examples 3 to 14 and Comparative Examples 1 to 3)

[0119] The unmodified silicone oil, the first surfactant, and the second surfactant were changed to the blending amounts (weight %) shown in Table 1, and the ion exchange water was adjusted so that the above components were combined with 30 g of propylene glycol (fixed) to 100 g. The treatment liquids of Examples 3 to 14 and Comparative Examples 1 to 3 (treatment liquids 3 to 17) were obtained by the same method as in Example 1. Emulsified particles containing unmodified silicone oil were dispersed in each of the obtained treatment liquids. The average particle size (X) of the emulsified particles in each treatment liquid is shown in Table 2 described below.

[0120] [Table 1]

[0121]

[0122] [Evaluation method]

[0123] <Storage stability>

[0124] 400 g of each of the treatment solutions 1 to 17 obtained in each of the examples and comparative examples was placed in a 500 mL plastic container and stored in a thermostat at 60° C. for 30 days. After 30 days, the plastic container stored in the thermostat was taken out, and after the treatment solution cooled to room temperature, the average particle size (Y) of the emulsified particles in each treatment solution was measured and the ejection property test described below was performed.

[0125] <Ejection properties>

[0126] The discharge property of the treatment liquid was evaluated using a discharge evaluation machine (KJ4B, manufactured by Kyocera Corporation) that can confirm the discharge of the treatment liquid drop by drop from the nozzle based on a camera image. The discharge property was evaluated for both the treatment liquid before storage (immediately after the treatment liquid was prepared) and the treatment liquid after storage for 30 days as described in the storage stability.

[0127] The conditions of the discharge evaluation machine were set as follows.

[0128] Conditions of the ejection evaluation machine:

[0129] Nozzle temperature: 32°C

[0130] The amount of treatment liquid sprayed from the nozzle: 10g / m 2

[0131] Drive frequency: 30kHz

[0132] The specific method for evaluating the spraying property is as follows. First, using the spraying evaluation machine, adjust the camera position in a way that three nozzles are visible in one field of view. Secondly, start the spraying of the processing liquid and continue for 1 minute, visually confirming whether the processing liquid is sprayed normally through the camera image. After 1 minute, count the number of nozzles that normally spray the processing liquid. Here, the so-called nozzles that normally spray the processing liquid are nozzles other than nozzles that cannot normally spray the processing liquid (nozzles that cannot spray the processing liquid straightly, nozzles that cannot spray the processing liquid, nozzles with overflowing processing liquid, etc.). In addition, move the camera position, take another nozzle as the object, and repeat the confirmation of the spraying property of the processing liquid within 1 minute through the camera image. A total of 36 nozzles were confirmed in a total of 12 places. Finally. The nozzles that normally spray the processing liquid are counted, and the spraying property of the processing liquid is evaluated according to the following judgment criteria.

[0133] (Judgment criteria)

[0134] A: 36

[0135] B: 34-35

[0136] C: 33 or less

[0137] <Color fastness to rubbing>

[0138] Printed articles were prepared using the treatment solutions obtained in Examples and Comparative Examples, and the color fastness to rubbing (color fastness to wet rubbing and color fastness to dry rubbing) of each printed article was evaluated.

[0139] (Preparation of ink) First, prepare the ink for printing. In a 1L three-necked flask equipped with a stirring blade, place 125g of ion exchange water and 2g of a nonionic surfactant ("SURFYNOL (registered trademark) 440" manufactured by Nissin Chemical Industry Co., Ltd., content: acetylene glycol ethylene oxide adduct). While stirring the contents of the flask, add 165g of propylene glycol, 100g of a black pigment dispersion ("AE2078F" manufactured by Sanyo Pigment Co., Ltd., content: CI pigment ink 7, solid content concentration: 20% by mass), and 108g of a binder resin particle dispersion ("SUPERFLEX 470" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., content: polyurethane dispersion, solid content concentration: 38% by mass) into the flask in sequence. Stir the contents of the flask for 10 minutes to obtain the ink.

[0140] (Production of printed materials for evaluation)

[0141] Using the ink and treatment solutions 1 to 17, printed materials for evaluation were produced.

[0142] As the printing object, a broad-width cotton fabric (manufactured by Seisen Co., Ltd., size: A4 size, warp and weft cotton yarn number: 40 / 1, warp yarn density: 130 strands / inch, weft yarn density: 75 strands / inch, unit area weight: 122 g / m 2 ). An inkjet printer ("Colorio (registered trademark) PX-045A" manufactured by Seiko Epson Corporation) was used to prepare the print for evaluation. The first ink chamber of the first ink cartridge was filled with ink, and the second ink chamber of the second ink cartridge was filled with a treatment liquid. Next, the first ink cartridge and the second ink cartridge were installed in the inkjet printer. Ink filled in the first ink chamber was ejected from the recording head of the inkjet printer, and the treatment liquid filled in the second ink chamber was ejected from the treatment head of the inkjet printer.

[0143] Use an inkjet printer to eject ink from the recording head onto the printed object, with the ink ejection amount being 20 g / m 2 Next, an inkjet printer is used to eject the treatment liquid from the treatment head toward the printing object, so that the ejection amount of the treatment liquid is 20 g / m 2In this way, a treatment film having the same size as the solid image is formed on the solid image of the ink by the treatment liquid. Next, the printed object is heated at 160° C. for 3 minutes to dry the ink and the treatment liquid, thereby obtaining a printed object for evaluation.

[0144] (Evaluation method for color fastness to rubbing)

[0145] The solid image formed on the evaluation printed material was rubbed with a rubbing white cotton cloth in accordance with the dry test and wet test of the friction tester II type (Gakushin type) method described in JIS L-0849:2013 (Test method for color fastness to rubbing). The coloring degree of the rubbing white cotton cloth after rubbing was evaluated in accordance with the "Criteria for determination of color change and fading" described in Article 10 (Determination of color fastness) of JIS L-0801:2011 (General rules for color fastness test methods). The coloring degree of the rubbing white cotton cloth was determined in 9 levels (level 1, level 1 to 2, level 2, level 2 to 3, level 3, level 3 to 4, level 4, level 4 to 5, and level 5 in descending order of the degree of contamination). The smaller the coloring degree of the rubbing white cotton cloth (closer to level 5), the better the color fastness to rubbing. According to the following standards, the color fastness to dry rubbing and the color fastness to wet rubbing were evaluated based on the coloring degree of the rubbing white cotton cloth after the rubbing test. The dry test result was taken as the dry rubbing color fastness, and the wet test result was taken as the wet rubbing color fastness. A and B were considered acceptable, and C was considered unacceptable. The determined rubbing color fastness and its evaluation results are summarized in Table 2 described below.

[0146] (Evaluation standard for color fastness to dryness and rubbing)

[0147] Evaluation A: The color fastness to dryness and rubbing is grade 4 or above.

[0148] Evaluation B: The color fastness to dryness and rubbing is level 3 to 4.

[0149] Evaluation C: The color fastness to dryness and rubbing is grade 3 or less.

[0150] (Evaluation standard for color fastness to moisture and rubbing)

[0151] Evaluation A: The color fastness to moisture and rubbing is grade 3 or higher.

[0152] Evaluation B: Color fastness to moisture and rubbing is level 2 to 3.

[0153] Evaluation C: Color fastness to moisture and rubbing was grade 2 or less.

[0154] The results of the above evaluation tests are summarized in Table 2.

[0155] [Table 2]

[0156]

[0157] (Inspection)

[0158] The results in Table 2 show that the treatment liquid of the present invention has excellent inkjet ejection properties, and when used for printing purposes, the obtained printed material also has excellent rubbing color fastness. In addition, even after being stored at 60° C. for 30 days, the average particle size of the emulsified particles in the treatment liquid does not change much, and the ejection properties do not deteriorate.

[0159] In addition, if the results of Examples 11 to 14 are considered, it can be seen that if the total content of the surfactants is within a more suitable range, a treatment liquid with better storage stability and ejection properties can be obtained. In other words, Examples 11 to 14 show that if the total content of the surfactants is small, the ejection properties tend to be poor, and if it is large, in addition to the deterioration of the ejection properties, the color fastness to moisture and rubbing also tends to be slightly deteriorated. In addition, from the results of Examples 11 to 12, it can be seen that if the content of the second surfactant / (the content of the first surfactant + the second surfactant) is within the specified range, the storage stability and ejection properties are more excellent.

[0160] On the other hand, in Comparative Example 1 using the treatment liquid containing only the first surfactant, the average particle size of the emulsified particles after storage for 30 days became larger, and the ejection properties after storage deteriorated. In other words, Comparative Example 1 was inferior in storage stability.

[0161] In the treatment liquid of Comparative Example 2, in which the content of silicone oil is too small, the ejection property and the color fastness to rubbing (especially the color fastness to wet rubbing) are poor. In the treatment liquid of Comparative Example 3, in which the content of silicone oil is too large, the storage stability, ejection property, and the color fastness to rubbing (especially the color fastness to wet rubbing) are all poor.

[0162] Description of Reference Numerals

[0163] 1: Record header

[0164] 1a: First record header

[0165] 1b: Second recording head

[0166] 1c: Third record header

[0167] 1d: Fourth record header

[0168] 2: Processing header

[0169] 3: Loading table

[0170] 10: Inkjet printing device

[0171] P: Printing object

Claims

1. An inkjet treatment liquid comprising: emulsified particles containing silicone oil; a surfactant; an aqueous medium, wherein: The content of the silicone oil is 5 mass % or more and 15 mass % or less relative to the total amount of the treatment liquid. The surfactant comprises: a first surfactant comprising an alkyl group having 12 to 14 carbon atoms; and a second surfactant comprising an alkyl group having 16 to 18 carbon atoms.

2. The inkjet treatment liquid according to claim 1, wherein The surfactant is polyoxyethylene alkyl ether.

3. The inkjet treatment liquid according to claim 1, wherein The first surfactant includes two or more compounds having alkyl groups having different carbon numbers.

4. The inkjet treatment liquid according to claim 1, wherein The second surfactant includes two or more compounds having alkyl groups having different carbon numbers.

5. The inkjet treatment liquid according to claim 1, wherein The content of the second surfactant is less than that of the first surfactant.

6. The inkjet treatment liquid according to claim 1, wherein The content of the first surfactant and the content of the second surfactant satisfy the following formula: Content of the second surfactant / (content of the first surfactant+content of the second surfactant)=0.15 to 0.25 mass %.

7. The inkjet treatment liquid according to claim 6, wherein The total content of the first surfactant and the second surfactant is 0.5 mass % or more and 4.0 mass % or less relative to the entire treatment liquid.

8. The inkjet treatment liquid according to claim 6, wherein The total content of the first surfactant and the second surfactant is 9.0 mass % or more and 40.0 mass % or less relative to the content of the silicone oil.

9. The inkjet treatment liquid according to claim 1, wherein The average particle size of the emulsified particles is 100 nm or more and 250 nm or less.

10. The inkjet treatment liquid according to claim 9, wherein When the inkjet processing liquid is stored at 60° C. for 30 days, the average particle size X of the emulsified particles in the processing liquid before storage and the average particle size Y of the emulsified particles in the processing liquid after storage satisfy the following formula: 1.0≤Y / X≤1.

05.

11. The inkjet processing liquid according to any one of claims 1 to 10, wherein For printing.

12. An inkjet printing device, wherein: The printing head comprises: a recording head for ejecting ink to an image forming area of ​​a printing object; and a processing head for ejecting a processing liquid to at least the image forming area of ​​the printing object. The treatment liquid is the inkjet treatment liquid according to any one of claims 1 to 10.

13. An inkjet printing method, wherein: The method comprises the following steps: an ink jetting step of jetting ink from a recording head to an image forming area of ​​a printing object; a processing step of jetting a processing liquid from a processing head to at least the image forming area of ​​the printing object; The treatment liquid is the inkjet treatment liquid according to any one of claims 1 to 10.

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