Pretreatment agent, pretreatment apparatus, and pretreatment method

Abstract

The present invention provides a pretreatment agent that can suppress discoloration caused by pretreatment while reducing the possibility of aggregate formation. [Solution] The pretreatment agent of the present disclosure is a pretreatment agent applied to a fabric in a region including the ink discharge region before the ink containing the pigment is discharged, and contains a polyvalent metal salt, and has an electrical conductivity of 32 mS / cm or more and 49 mS / cm or less.

Description

[Technical Field]

[0001] This disclosure relates to a pretreatment agent, a pretreatment apparatus, and a pretreatment method. [Background technology]

[0002] A pretreatment agent (treatment liquid composition) that is dispensed onto the fabric before the pigment ink is dispensed is known (Patent Document 1). The pretreatment agent contains amino acids. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-011527 [Overview of the project] [Problems that the invention aims to solve]

[0004] The pretreatment agent described in Patent Document 1 contains amino acids, and therefore can suppress discoloration of the pretreatment agent when it is dispensed onto the fabric. On the other hand, the pretreatment agent containing amino acids may cause aggregates to form.

[0005] Therefore, the present disclosure aims to provide a pretreatment agent, a pretreatment apparatus, and a pretreatment method that can reduce the possibility of aggregate formation while suppressing discoloration caused by pretreatment. [Means for solving the problem]

[0006] To achieve the aforementioned objective, the pretreatment agent of the present disclosure is A pretreatment agent applied to a fabric in a region including the ink discharge area before the pigment-containing ink is discharged, Contains polyvalent metal salts, The conductivity is 32 mS / cm or higher and 49 mS / cm or lower. It is characterized by the following:

[0007] The pretreatment device of the present disclosure is a pretreatment device that applies a pretreatment agent to a fabric in a region including the ink ejection region before ejecting ink containing a pigment, including a pretreatment unit that applies the pretreatment agent to the fabric, where the pretreatment agent contains a polyvalent metal salt, and has a conductivity of 32 mS / cm or more and 49 mS / cm or less, characterized by this.

[0008] The pretreatment method of the present disclosure is a pretreatment method that applies a pretreatment agent to a fabric in a region including the ink ejection region before ejecting ink containing a pigment, including a pretreatment step of applying the pretreatment agent to the fabric, where the pretreatment agent contains a polyvalent metal salt, and has a conductivity of 32 mS / cm or more and 49 mS / cm or less, characterized by this.

Advantages of the Invention

[0009] According to the present disclosure, it is possible to reduce the possibility of the generation of aggregates while suppressing discoloration caused by pretreatment.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of the pretreatment device of the present disclosure. [Figure 2] FIG. 2 is a flowchart showing an example of the steps in the pretreatment method of the present disclosure. [Figure 3] FIG. 3 is a diagram showing an example of the application of the pretreatment agent in the pretreatment method of the present disclosure. [Figure 4] FIG. 4 is a diagram showing another example of the application of the pretreatment agent in the pretreatment method of the present disclosure.

Embodiments for Carrying Out the Invention

[0011] Embodiments of this disclosure will now be described. However, this disclosure is not limited to the embodiments described below. In the following figures, the same parts are denoted by the same reference numerals. Furthermore, unless otherwise specified, the descriptions of each embodiment can be used interchangeably. In addition, unless otherwise specified, the configurations of each embodiment can be combined.

[0012] First, the pretreatment agent of the present disclosure will be described. The pretreatment agent of the present disclosure is a pretreatment agent applied to a fabric in a region including the ink discharge region before the ink containing the pigment is discharged, and contains a polyvalent metal salt, and has an electrical conductivity of 32 mS / cm or more and 49 mS / cm or less.

[0013] Examples of the polyvalent metal salts include calcium salts, magnesium salts, and aluminum salts. Examples of the calcium salts include calcium chloride, calcium bromide, calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, calcium lactate, calcium fumarate, calcium citrate, and their hydrates. Examples of the magnesium salts include magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, magnesium nitrate, and their hydrates. Examples of the aluminum salts include aluminum chloride, aluminum bromide, aluminum sulfate, aluminum nitrate, aluminum acetate, and their hydrates. One type of polyvalent metal salt may be used, or two or more types of polyvalent metal salts may be used. It is preferable that the polyvalent metal salts include at least one of calcium salts and magnesium salts, for example, from the viewpoint of suppressing discoloration of the fabric caused by pretreatment. It is also preferable that the polyvalent metal salts include calcium salts, for example, from the viewpoint of color development of the formed image and cost.

[0014] The amount of polyvalent metal ions in the polyvalent metal salt in the total amount of the pretreatment agent may be, for example, 1.5% by weight or more, 2% by weight or more, 2.5% by weight or more, or 3% by weight or more, or for example, 4.5% by weight or less, 4% by weight or less, 3.5% by weight or less, or 3.1% by weight or less, or for example, 1.5% to 4.5% by weight, 2% to 4% by weight, 2.5% to 3.5% by weight, 3% to 3.5% by weight, or 3% to 3.1% by weight. Examples of the polyvalent metal ions include calcium ions, magnesium ions, or aluminum ions. The higher the amount of polyvalent metal ions, the better the color development of the image after formation, and the lower the amount of polyvalent metal ions, the more the discoloration of the fabric caused by the pretreatment is suppressed. Therefore, the content of polyvalent metal ions in the polyvalent metal salt is preferably, for example, 3% by weight or more and 3.5% by weight or less, from the viewpoint of color development of the formed image and suppression of discoloration of the fabric due to pretreatment.

[0015] The content of the polyvalent metal salt in the total amount of the pretreatment agent is, for example, 1% to 50% by weight, 5% to 30% by weight, or 10% to 25% by weight.

[0016] The conductivity of the pretreatment agent is 32 mS / cm or more and 49 mS / cm or less. The conductivity of the pretreatment agent may be, for example, 33 mS / cm or more, 34 mS / cm or more, or 35 mS / cm or more, or for example, 45 mS / cm or less, 43 mS / cm or less, or 40 mS / cm or less, or for example, 33 mS / cm to 45 mS / cm, 34 mS / cm to 43 mS / cm, or 35 mS / cm to 40 mS / cm. The conductivity can be measured, for example, by the measurement method described in the examples below.

[0017] Here, the conductivity of the pretreatment agent and its effect in suppressing discoloration will be explained. The degree of discoloration of the fabric due to pretreatment is thought to depend on the amount of polyvalent metal ions in the pretreatment agent. When the amount of polyvalent metal ions dissolved in the pretreatment agent is large, the conductivity of the pretreatment agent tends to be high. That is, a high conductivity of the pretreatment agent means that there is a large amount of polyvalent metal ions dissolved in the pretreatment agent, and therefore the amount of polyvalent metal ions applied to the fabric also tends to be large. Therefore, when the conductivity of the pretreatment agent is high, the fabric is more likely to discolor due to pretreatment. On the other hand, when the conductivity of the pretreatment agent is low, it means that there is a small amount of polyvalent metal ions dissolved in the pretreatment agent, and therefore the amount of polyvalent metal ions applied to the fabric also tends to be small. Therefore, when the conductivity of the pretreatment agent is low, discoloration due to pretreatment can be suppressed.

[0018] Furthermore, the conductivity of the pretreatment agent is not determined solely by the amount of polyvalent metal salt contained in the pretreatment agent, but is also thought to change due to the effects of organic solvents and other components contained in the pretreatment agent, as described later. For example, if the organic solvent effectively captures the polyvalent metal ions, the conductivity of the pretreatment agent is thought to be low even if the amount of polyvalent metal contained in the pretreatment agent is large. As for the organic solvent, having either a hydroxyl group, an ether chain, or both in its molecular structure exhibits a particularly pronounced effect of effectively capturing the polyvalent metal salt. However, the above effects are merely illustrative, and the effects of this disclosure are not limited to the above principles.

[0019] The rate of decrease in conductivity of a pretreatment agent after 3-fold dilution with water (hereinafter sometimes simply referred to as "pretreatment agent after dilution") relative to the conductivity of a pretreatment agent having an conductivity of 32 mS / cm or more and 49 mS / cm or less (hereinafter sometimes simply referred to as "pretreatment agent before dilution") may be, for example, 3% or more, 5% or more, 7% or more, 9% or more, or 10% or more, and may also be, for example, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, or 29% or less, and may also be, for example, 3% to 50%, 5% to 45%, 7% to 40%, 9% to 35%, 9% to 30%, 9% to 29%, or 10% to 29%. The water is not particularly limited, but for example, the water described later may be used. The dilution means, for example, dilution by volume. Furthermore, when the amount of polyvalent metal salt in the pretreatment agent before dilution is small, the rate of decrease in the conductivity of the pretreatment agent tends to be large. When the amount of polyvalent metal salt is small, for example, the wash fastness after image formation tends to improve. Therefore, from the viewpoint of wash fastness, the rate of decrease in the conductivity of the pretreatment agent is preferably 9% or more. On the other hand, when the amount of polyvalent metal salt in the pretreatment agent before dilution is large, the rate of decrease in the conductivity of the pretreatment agent tends to be small. That is, when the amount of polyvalent metal salt is large, even if the pretreatment agent is diluted at a different dilution ratio than the recommended dilution ratio, the fluctuation in the rate of decrease in the conductivity of the pretreatment agent tends to be small. Therefore, when the amount of polyvalent metal salt is large, it is easier to obtain the color development effect of the pretreatment agent even after dilution compared to when the amount of polyvalent metal salt is small. Therefore, from the viewpoint of color development after image formation, the rate of decrease in the conductivity of the pretreatment agent is preferably 29% or less.

[0020] Furthermore, if the undiluted solution is sold undiluted and diluted between the time of sale and the time of printing, in this disclosure, the undiluted solution is an example of the "pre-treatment agent before dilution," and the pre-treatment agent diluted between the time of sale and the time of printing is an example of the "pre-treatment agent after dilution." Also, if the undiluted solution is diluted before the time of sale and diluted again between the time of sale and the time of printing, in this disclosure, the pre-treatment agent at the time of sale is an example of the "pre-treatment agent before dilution," and the pre-treatment agent diluted between the time of sale and the time of printing is an example of the "pre-treatment agent after dilution." Furthermore, if the undiluted solution is sold undiluted and not diluted between the time of sale and the time of printing, in this disclosure, the undiluted solution is an example of the "pre-treatment agent before dilution." Also, if the undiluted solution is diluted before the time of sale and not diluted again between the time of sale and the time of printing, in this disclosure, the pre-treatment agent at the time of sale is an example of the "pre-treatment agent before dilution."

[0021] The rate of decrease in conductivity may be calculated, for example, by the following formula (1). The rate of decrease in conductivity = (Conductivity of the pretreatment agent before dilution - Conductivity of the pretreatment agent after dilution with water three times) / Conductivity of the pretreatment agent before dilution (1)

[0022] The pretreatment agents of this disclosure further include, for example, an organic solvent, a polymer, a surfactant, and water.

[0023] The organic solvent is, for example, an organic solvent that exhibits liquid properties at 25°C and whose weight loss rate after heating at 160°C for 5 minutes relative to its weight at 25°C is 2% or less. Examples of organic solvents with a weight loss rate of 2% or less include glycerin, polyalkylene glycol, and their derivatives. Examples of polyalkylene glycols include polyethylene glycol, polypropylene glycol, polybutylene glycol, and polyoxyethylene polyoxypropylene glycol. Examples of derivatives include diglycerin, polyglycerin, polyoxyethylene glycerin, polyethylene glycol monolauryl ether, polyethylene glycol monododecyl ether, and polyethylene glycol monomethyl ether. The organic solvent may also be, for example, an organic solvent with a boiling point of 280°C or higher. Examples of organic solvents with a boiling point of 280°C or higher include diglycerin, glycerin, polyalkylene glycol, and polyethylene glycol.

[0024] The content of the organic solvent in the total amount of the pretreatment agent may be, for example, 15 to 25% by weight or 15 to 20% by weight. From the viewpoint of wash fastness after image formation, the content of the organic solvent is preferably, for example, 15% by weight or more. Furthermore, from the viewpoint of drying efficiency, the content of the organic solvent is preferably, for example, 20% by weight or less.

[0025] The pretreatment agent of this disclosure may contain solvents other than the organic solvent. Examples of such other solvents include polyhydric alcohols, polyhydric alcohol derivatives, alcohols, amides, ketones, keto alcohols, ethers, nitrogen-containing solvents, sulfur-containing solvents, propylene carbonate, ethylene carbonate, 1,3-dimethyl-2-imidazolidinone, and the like.

[0026] The polymer may, for example, be one contained in a polymer emulsion. The polymer emulsion is composed of, for example, the polymer and a dispersion medium (for example, water). The polymer is not dissolved in the dispersion medium, but is dispersed with a specific particle size.

[0027] Examples of the polymers include acrylic acid resins, maleic acid ester resins, vinyl acetate resins, carbonate-type resins, polycarbonate-type resins, styrene-type resins, ethylene-type resins, polyethylene-type resins, propylene-type resins, polypropylene-type resins, urethane-type resins, polyurethane-type resins, and copolymer resins thereof. For example, acrylic acid resins and urethane-type resins are preferred polymers. One type of polymer may be used, or two or more types of polymers may be used.

[0028] For example, a commercially available polymer emulsion may be used. Examples of such commercially available products include "Movinyl® 6770", "Movinyl® 7320", "Movinyl® 966A", "Movinyl® 6963", and "Movinyl® 6960" manufactured by Japan Coating Resin Co., Ltd., "Vinibran® GV-6181" and "Vinibran® GV-1002" manufactured by Nisshin Chemical Industry Co., Ltd., and "Boncoat® SFC-55" and "Boncoat® SFC-571" manufactured by DIC Corporation.

[0029] The polymer content in the total amount of the pretreatment agent is, for example, 0.1% to 30% by weight, 0.5% to 20% by weight, or 1% to 10% by weight.

[0030] The surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the surfactant include nonionic surfactants. Examples of the nonionic surfactant include acetylene glycol-based surfactants. Commercially available nonionic surfactants may also be used. Examples of commercially available products include "Orphin® E1004", "Orphin® E1006", "Orphin® E1010", "Orphin® E1020", "Orphin® EXP4001", "Orphin® EXP4200", "Orphin® EXP4123", "Orphin® EXP4300", "Orphin® PD-001", "Orphin® PD-002W", "Orphin® PD-005", "Surfinol® 420", "Surfinol® 440", "Surfinol® 465", and "Surfinol® 485", all manufactured by Nisshin Chemical Industry Co., Ltd.

[0031] The surfactant may further include surfactants other than nonionic surfactants (for example, anionic surfactants, cationic surfactants, amphoteric surfactants, etc.).

[0032] The amount of the surfactant in the total amount of the pretreatment agent is, for example, 0.1% to 2% by weight, 0.3% to 1.5% by weight, 0.5% to 1% by weight, or 0.5% to 0.8% by weight.

[0033] Examples of the aforementioned water include ion-exchanged water and pure water.

[0034] The water content in the total amount of the pretreatment agent is, for example, 10% to 90% by weight, or 20% to 80% by weight. The water content may be, for example, the remainder of the other components.

[0035] The pigments contained in the ink are not particularly limited and include, for example, carbon black, inorganic pigments, and organic pigments. Examples of carbon black include furnace black, lamp black, acetylene black, and channel black. Examples of inorganic pigments include titanium dioxide, iron oxide-based inorganic pigments, and carbon black-based inorganic pigments. Examples of organic pigments include azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments; polycyclic pigments such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments; dye lake pigments such as basic dye-type lake pigments and acid dye-type lake pigments; nitro pigments; nitroso pigments; aniline black daylight fluorescent pigments; and others. In addition, other pigments can be used as long as they are dispersible in the aqueous phase. Specific examples of these pigments include, for example, CI Pigment White 1, 4, 5, 6, 7, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, and 28; CI Pigment Black 1, 6, and 7; CI Pigment Yellow 1, 2, 3, 12, 13, 14, 15, 16, 17, 55, 74, 78, 150, 151, 154, 180, 185, and 194; CI Pigment Orange 31 and 43; CI Pigment Red 2, 3, 5, 6, 7, 12, 15, 16, 48, and 48: Examples include 1, 53:1, 57, 57:1, 112, 122, 123, 139, 144, 146, 149, 150, 166, 168, 175, 176, 177, 178, 184, 185, 190, 202, 209, 221, 222, 224 and 238; CI Pigment Violet 19 and 196; CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 16, 22 and 60; CI Pigment Green 7 and 36; and solid solutions of these pigments.

[0036] The pigment may be dispersed in a solvent by a resin dispersant (also called a resin-dispersed pigment). The resin dispersant may be, for example, a general polymer dispersant (also called a pigment dispersion resin or resin dispersant, etc.), and may be prepared in-house. In addition, in the pretreatment agent of this disclosure, the pigment may be encapsulated by a polymer. The resin dispersant may be, for example, one containing at least one of methacrylic acid and acrylic acid as a monomer, and commercially available products may be used. The resin dispersant may be, for example, a hydrophobic monomer such as styrene, styrene derivatives, vinylnaphthalene, vinylnaphthalene derivatives, or aliphatic alcohol esters of α,β-ethylenically unsaturated carboxylic acids, or a block copolymer, graft copolymer, or random copolymer or a salt thereof, consisting of two or more monomers selected from the group consisting of acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, or fumaric acid derivatives. Examples of the aforementioned commercially available products include "Johncryl® 611", "Johncryl® 60", "Johncryl® 586", "Johncryl® 687", "Johncryl® 63", and "Johncryl® HPD296" manufactured by Johnson Polymer Co., Ltd.; "Disperbyk190" and "Disperbyk191" manufactured by Bic Chemie; and "Solspers 20000" and "Solspers 27000" manufactured by Zeneca.

[0037] A method for dispersing the pigment using the aforementioned pigment dispersion resin includes, for example, a method of dispersing the pigment using a dispersion apparatus. The dispersion apparatus used for dispersing the pigment is not particularly limited as long as it is a general-purpose dispersion machine, but examples include ball mills, roll mills, sand mills (e.g., high-speed type), etc.

[0038] The pigment may be a self-dispersing pigment. The self-dispersing pigment is such that, for example, at least one of a hydrophilic functional group such as a carbonyl group, hydroxyl group, carboxylic acid group, sulfonic acid group, or phosphate group, and salts thereof, is introduced into the pigment particles by chemical bonding, either directly or via other groups, so that it can be dispersed in water without the use of a dispersant. The self-dispersing pigment can be one in which the pigment has been treated by the method described in, for example, Japanese Patent Publication No. 8-3498, Japanese Patent Publication No. 2000-513396, Japanese Patent Publication No. 2008-524400, Japanese Patent Publication No. 2009-515007, Japanese Patent Publication No. 2011-515535, etc. The raw material for the self-dispersing pigment can be either an inorganic pigment or an organic pigment. Examples of pigments suitable for the above treatment include carbon black such as "MA8" and "MA100" manufactured by Mitsubishi Chemical Corporation. The self-dispersing pigment can be a commercially available product, for example. Examples of the aforementioned commercially available products include "CAB-O-JET(registered trademark) 200", "CAB-O-JET(registered trademark) 250C", "CAB-O-JET(registered trademark) 260M", "CAB-O-JET(registered trademark) 270Y", "CAB-O-JET(registered trademark) 300", "CAB-O-JET(registered trademark) 400", "CAB-O-JET(registered trademark) 450C", "CAB-O-JET(registered trademark) 465M", and "CAB-O-JET(registered trademark) 470Y" manufactured by Cabot Corporation; "BONJET(registered trademark) BLACK CW-2" and "BONJET(registered trademark) BLACK CW-3" manufactured by Orient Chemical Industry Co., Ltd.; and "LIOJET(registered trademark) WD BLACK 002C" manufactured by Toyo Ink Manufacturing Co., Ltd.

[0039] The aforementioned pigment may consist of one type of pigment or two or more types of pigments.

[0040] Examples of the fabric include knitted fabrics and woven fabrics. The material of the fabric may be natural fibers or synthetic fibers. Examples of natural fibers include cotton and silk. Examples of synthetic fibers include polyester, acrylic, rayon, urethane, and nylon. The material of the fabric may be a blend spun by mixing multiple types of the fibers, such as cotton / polyester = 50% / 50%.

[0041] The pretreatment agent disclosed herein may further include, if necessary, additives such as crosslinking agents, pH adjusters, viscosity adjusters, preservatives, and fungicides.

[0042] Next, a pre-processing apparatus of the present disclosure will be described. Figure 1 shows an example of the configuration of the pre-processing apparatus of the present disclosure. As shown in Figure 1, the pre-processing apparatus 10 of the present disclosure is a pre-processing apparatus that applies a pre-treatment agent to a region including the ink discharge region to the fabric before discharging the ink containing the pigment, and is characterized by including a pre-processing unit 11 that applies the pre-treatment agent to the fabric.

[0043] Examples of pre-processing devices 11 include liquid dispensing means such as a liquid dispensing head, sprayers, stamps, brushes, rollers, etc.

[0044] The pretreatment agent in the pretreatment apparatus 10 of this disclosure is the same as the pretreatment agent of this disclosure described above, and the description thereof can be applied by reference.

[0045] Next, a pretreatment method of the present disclosure will be described. Figure 2 is a flowchart showing an example of the steps in the pretreatment method of the present disclosure. The pretreatment method of the present disclosure is a pretreatment method that includes a pretreatment step of applying a pretreatment agent to the fabric to a region including the ink discharge region before the ink containing the pigment is discharged.

[0046] The pretreatment step (S11) involves applying the pretreatment agent to the fabric. The pretreatment step may be performed, for example, by the pretreatment unit 11 of the pretreatment apparatus 10 of the present disclosure. In the pretreatment step, the application of the pretreatment agent can be carried out by methods such as inkjet, spray, stamp application, brush application, roller application, or padding.

[0047] In the pretreatment step described above, the pretreatment agent may be applied to the entire image-forming surface of the fabric or to a part of it. When applied to a part, for example, the area of ​​the image-forming surface of the fabric that is roughly the same as the ink discharge area may be designated as the pretreatment agent application area. When applied to a part, the size of the pretreatment agent application area should be larger than the printed area. Figure 3 is a diagram showing an example of pretreatment agent application in the pretreatment method of the present disclosure. For example, as shown in Figure 3, when printing the character (X) on the fabric (T-shirt in this example) 100, it is preferable to apply the pretreatment agent so as to form a pretreatment agent application area 110 with a line width larger than the line width of the character. Figure 4 is a diagram showing another example of pretreatment agent application in the pretreatment method of the present disclosure. As shown in Figure 4, when printing a design on the fabric (T-shirt) 100, it is preferable to apply the pretreatment agent so as to form a pretreatment agent application area 120 larger than the design.

[0048] The pretreatment method disclosed herein may include, after the pretreatment step, at least one of the following steps: a pretreatment fixing step and a heat fixing step. The pretreatment fixing step may be carried out using, for example, a commercially available heat press. The temperature of the pretreatment fixing step is not particularly limited, but is, for example, 160°C to 185°C. The heat fixing step may be carried out using, for example, a commercially available oven. The temperature of the heat fixing step is not particularly limited, but is, for example, 140°C to 180°C. [Examples]

[0049] Next, embodiments of this disclosure will be described together with comparative examples. However, this disclosure is not limited to or restricted by the embodiments and comparative examples described below.

[0050] [Examples 1-19, Comparative Examples 1-3, and Reference Example 1] By stirring and mixing each component in the pretreatment agent composition (Table 1), the pretreatment agents for Examples 1-19, Comparative Examples 2-3, and Reference Example 1 shown in Table 1 were obtained. Specifically, the polyvalent metal salts and water shown in Table 1 were pre-mixed. Next, the surfactant, organic solvent, resin emulsion, and preservative were added in order to obtain the pretreatment agents listed in Table 1. Comparative Example 1 is a commercially available pretreatment agent containing trimethylglycine (betaine), and the type and content of the polyvalent metal salts are known. Note that the amounts of each component in Table 1 all represent the amount of active ingredient.

[0051] Using the pretreatment agents of Examples 1-19, Comparative Examples 1-3, and Reference Example 1, images were formed on a red T-shirt (manufactured by Toms Co., Ltd., product number: 00085-CVT, material: 100% cotton) by the following process.

[0052] (Pre-treatment process) The pretreatment agents prepared as shown in Table 1 were diluted three times with water. The diluted pretreatment agents were applied to the image-forming surface of the T-shirt using an automated pretreatment coating device (PRINTSYSTEM Co., Ltd., product name: The Cube). The amount of pretreatment agent applied was 25 mg / cm². 2 ~30 mg / cm³ 2 That's what I decided.

[0053] (Pretreatment and fixing process) After the aforementioned pretreatment process, the pretreatment agent was applied to the pretreatment area of ​​the T-shirt using a heat press (STAHLS' Hotronix "AIR FUSION IQ®" registered trademark). The heat treatment was performed for 35 seconds at a set temperature of 185°C and a set pressure of 31 psi.

[0054] (Image printing process) The image was printed by dispensing ink onto a T-shirt that had been treated with a pre-treatment agent.

[0055] (Heat fixing process) After the image printing process, the ink was thermally fixed to the printed portion of the T-shirt using a dryer set at 160°C (manufactured by ADELCO, product name: Drawer Drying Cabinet, product number: DDC-3A). The heating time for the thermal fixing was 3.5 minutes.

[0056] In this example, evaluation samples were created in each process, but this is merely an example and is not limited to the above creation method. For example, the order of each process may be appropriately changed. The evaluation results described later will not change due to changes in the method of creating evaluation samples.

[0057] Regarding the pretreatment agents of Examples 1 to 19, Comparative Examples 1 to 3, and Reference Example 1, (a) evaluation of conductivity, (b) discoloration evaluation, and (c) dischargeability evaluation were performed by the following methods.

[0058] (a) Evaluation of conductivity Using a glass electrode type hydrogen ion concentration indicator (manufactured by Horiba, Ltd., product number: F-54), the conductivity of the pretreatment agents of Examples 1 to 19, Comparative Examples 1 to 3, and Reference Example 1, and the pretreatment agents after diluting them three times with water was measured. Based on the measured values, the reduction rate of conductivity was determined by the following formula (1). Reduction rate of conductivity = (Conductivity of the pretreatment agent before dilution - Conductivity of the pretreatment agent after diluting three times with water) / Conductivity of the pretreatment agent before dilution (1)

[0059] (b) Discoloration evaluation The T-shirt on which the image was formed as described above was used as an evaluation sample. The L * , a * , b * values of the applied and non-applied portions of the pretreatment agent of the evaluation sample were measured using a CIE1976L * a * b * color space scale colorimeter (manufactured by X-Rite, product name: X-Rite eXact). From the measured values, the color difference ΔE * ab was calculated. Note that ΔE *The smaller the ab value, the less discoloration there is in areas where the pretreatment agent was not applied. This means that the marks from the pretreatment agent are less noticeable, resulting in a superior appearance. ΔE * ab={(L1 * -L2 * ) 2 +(a1 * -a2 * ) 2 +(b1 * -b2 * ) 2} 1 / 2 (2) L1 * : L of the pretreatment agent application section * value a1 * a of the pretreatment agent application section * value b1 * : pre-treatment agent application section b * value L2 * : L of the part where the pretreatment agent was not applied * value a2 * : a of the part where the pretreatment agent is not applied * value b2 * : b of the part where the pretreatment agent was not applied * value

[0060] (c) Evaluation of discharge performance After applying the pretreatment agent, the surface coated with the pretreatment agent was visually inspected, and the dispensing performance was evaluated based on the following evaluation criteria.

[0061] Evaluation of output performance: Evaluation criteria ○: No aggregates with a diameter of 1 mm or more are present on the surface where the pretreatment agent was applied. ×: Aggregates with a diameter of 1 mm or more are present on the surface where the pretreatment agent was applied.

[0062] Table 1 shows the composition and evaluation results of the pretreatment agents used in Examples 1-19, Comparative Examples 1-3, and Reference Example 1.

[0063] [Table 1]

[0064] Table 2 shows the percentage decrease in weight of each organic solvent included in Examples 1-19 and Comparative Examples 2-3 after heating at 160°C for 5 minutes, relative to the weight at 25°C. The heating procedure was as follows: First, each organic solvent was added to a glass container (inner diameter 57 mm, height 33 mm). Then, heating was performed using a drawer-type drying unit (ADELCO, product name: Drawer Drying Cabinet, model number: DDC-3A).

[0065] [Table 2]

[0066] As shown in Table 1, in Examples 1 to 19, ΔE * All values ​​of ab were 2.5 or less. In other words, there was little discoloration of the fabric due to the pretreatment. Furthermore, Examples 1 to 19 showed good discharge performance as no aggregates were formed. On the other hand, Comparative Example 1 had poorer discharge performance compared to Examples 1 to 19. Comparative Examples 2 and 3 showed discoloration of the fabric due to the pretreatment agent compared to Examples 1 to 19. As shown in Reference Example 1, the sample using only polyvalent metal salts had high conductivity and showed discoloration of the fabric due to the pretreatment agent. Thus, it was found that the effect of suppressing discoloration of the fabric by the pretreatment agent depends on the conductivity of the pretreatment agent in the presence of polyvalent metal salts. From Examples 1, 4, and 18, it was found that organic solvents containing both hydroxyl groups and ether chains had a greater effect in suppressing discoloration of the fabric compared to organic solvents containing only hydroxyl groups.

[0067] This disclosure may also be described in part or in whole as follows, but is not limited to the following: (Note 1) A pretreatment agent applied to a fabric in a region including the ink discharge area before the pigment-containing ink is discharged, Contains polyvalent metal salts, The conductivity is 32 mS / cm or higher and 49 mS / cm or lower. A pretreatment agent characterized by the following features. (Note 2) Furthermore, the pretreatment agent described in Appendix 1 comprises an organic solvent, a polymer, a surfactant, and water. (Note 3) The aforementioned organic solvent exhibits liquid properties at 25°C. The weight loss rate after heating at 160°C for 5 minutes, compared to the weight at 25°C, is 2% or less. The pretreatment agent described in Appendix 2. (Note 4) The aforementioned organic solvent exhibits liquid properties at 25°C and has a boiling point of 280°C or higher. The pretreatment agent described in Appendix 2 or 3. (Note 5) The pretreatment agent according to any one of the appendices 2 to 4, wherein the organic solvent is diglycerin. (Note 6) A pretreatment agent according to any one of the appendices 1 to 5, wherein, with respect to a pretreatment agent having an electrical conductivity of 32 mS / cm or more and 49 mS / cm or less, the rate of decrease in the electrical conductivity of the pretreatment agent after being diluted three times with water is 9% or more and 29% or less. (Note 7) The pretreatment agent according to any one of the appendices 1 to 6, wherein the polyvalent metal salt comprises at least one selected from the group consisting of calcium salts, magnesium salts, and aluminum salts. (Note 8) The pretreatment agent according to any one of the appendices 1 to 7, wherein the content of polyvalent metal ions in the polyvalent metal salt in the total amount of the pretreatment agent is 3% by weight or more and 3.5% by weight or less. (Note 9) A pretreatment apparatus for applying a pretreatment agent to a fabric in a region including the ink discharge region before discharging the ink containing the pigment, The pretreatment process includes applying the pretreatment agent to the fabric, The aforementioned pretreatment agent Contains polyvalent metal salts, The conductivity is 32 mS / cm or higher and 49 mS / cm or lower. A preprocessing apparatus characterized by the following: (Note 10) A pretreatment method comprising applying a pretreatment agent to a fabric in a region including the ink discharge area before dispensing the ink containing the pigment, The process includes a pretreatment step of applying the pretreatment agent to the fabric, The aforementioned pretreatment agent Contains polyvalent metal salts, The conductivity is 32 mS / cm or higher and 49 mS / cm or lower. A pretreatment method characterized by the following: [Industrial applicability]

[0068] As described above, the pretreatment agent of this disclosure can suppress discoloration caused by pretreatment while reducing the possibility of aggregation. The applications of the pretreatment agent of this disclosure are not particularly limited and can be widely applied to pretreatment of various fabrics before image formation. [Explanation of symbols]

[0069] 10 Pre-treatment device 11 Pre-processing section

Claims

1. A pretreatment agent applied to a fabric in a region including the ink discharge area before the pigment-containing ink is discharged, Contains polyvalent metal salts, The conductivity is 32 mS / cm or higher and 49 mS / cm or lower. A pretreatment agent characterized by the following features.

2. Furthermore, the pretreatment agent according to claim 1 comprises an organic solvent, a polymer, a surfactant, and water.

3. The pretreatment agent according to claim 1, wherein, with respect to a pretreatment agent having an conductivity of 32 mS / cm or more and 49 mS / cm or less, the rate of decrease in conductivity of the pretreatment agent after being diluted three times with water is 9% or more and 29% or less.

4. The pretreatment agent according to claim 1, wherein the polyvalent metal salt comprises at least one selected from the group consisting of calcium salts, magnesium salts, and aluminum salts.

5. The pretreatment agent according to claim 1, wherein the content of polyvalent metal ions in the polyvalent metal salt in the total amount of the pretreatment agent is 3% by weight or more and 3.5% by weight or less.

6. The aforementioned organic solvent exhibits liquid properties at 25°C. The weight loss rate after heating at 160°C for 5 minutes, compared to the weight at 25°C, is 2% or less. The pretreatment agent according to claim 2.

7. The aforementioned organic solvent exhibits liquid properties at 25°C and has a boiling point of 280°C or higher. The pretreatment agent according to claim 2.

8. The pretreatment agent according to claim 2, wherein the organic solvent has a hydroxyl group and an ether structure.

9. The pretreatment agent according to claim 2, wherein the organic solvent is any one of diglycerin, polyalkylene glycol, and a derivative thereof.

10. A pretreatment apparatus for applying a pretreatment agent to a fabric in a region including the ink discharge region before discharging the ink containing the pigment, The pretreatment process includes applying the pretreatment agent to the fabric, The aforementioned pretreatment agent Contains polyvalent metal salts, The conductivity is 32 mS / cm or higher and 49 mS / cm or lower. A preprocessing apparatus characterized by the following:

11. A pretreatment method comprising applying a pretreatment agent to a fabric in a region including the ink discharge area before dispensing the ink containing the pigment, The process includes a pretreatment step of applying the pretreatment agent to the fabric, The aforementioned pretreatment agent Contains polyvalent metal salts, The conductivity is 32 mS / cm or higher and 49 mS / cm or lower. A pretreatment method characterized by the following:

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