WO2025204728A1 - Adhesive liquid, image forming system, and image forming method - Google Patents

Abstract

Provided is an adhesive liquid that has good transferability of a printing layer and good washing fastness of a printing medium after image transfer.　The adhesive liquid of the present disclosure is characterized by containing water, resin particles, an organic solvent, a crosslinking agent, and a surfactant, the weight change rate X before and after drying satisfying formula (1) or formula (2), and the storage elastic modulus E' at 110°C of a film obtained by drying the adhesive liquid before applying the heat and the pressure being 5.4 × 106 Pa or less. A is a weight ratio of the water in the total amount of the adhesive liquid, and B is a weight ratio of the water and the organic solvent in the total amount of the adhesive liquid.　X < A (1) A ≤ X < B (2)

Description

Adhesive liquid, image forming system, and image forming method

This disclosure relates to an adhesive liquid, an image forming system, and an image forming method.

Patent Document 1 discloses an image forming method in which an image is formed on a transfer medium (print medium) using an intermediate transfer recording medium in which a printing layer and an adhesive layer are formed on the transfer medium.

JP 2009-066789 A

It is conceivable that an inkjet printer forms a printing layer, such as a color print or white print, on a transfer medium, and then a powder adhesive is applied to the printing layer using a device separate from the inkjet printer. The applied powder is heated and melted to create an intermediate transfer recording medium. In this case, heat and pressure are applied while the intermediate transfer recording medium and the printing medium are superimposed, and the transfer medium is peeled off, transferring the printing layer formed on the transfer medium to the printing medium. Alternatively, it is conceivable that the powder adhesive is replaced with a liquid adhesive (adhesive liquid). In this case, ink and adhesive liquid are ejected onto the intermediate transfer recording medium using an inkjet printer, and then dried, creating an intermediate transfer recording medium with an adhesive layer formed on top of the printing layer.

If the adhesive layer formed from the adhesive is hard after drying, there is a risk that the printing layer will not transfer properly to the printing medium when the transfer medium is peeled off from the printing medium. Furthermore, the printing layer transferred to the printing medium may not be able to withstand the bending and folding forces that occur during washing, which could cause the image formed on the printing medium to crack.

The present disclosure therefore aims to provide an adhesive liquid, an image forming system, and an image forming method that provide good transferability of the printing layer and good washing fastness of the print medium after image transfer.

In order to achieve the above object, the adhesive liquid of the present disclosure comprises:
An adhesive liquid that is ejected from an ejection head onto ink on a transfer medium having an ink-receiving layer, and that adheres an image formed by the ink to the print medium by applying heat and pressure after drying,
The composition includes water, resin particles, an organic solvent, a crosslinking agent, and a surfactant,
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
The storage modulus E' of the coating obtained by drying the adhesive liquid at 110°C before the application of the heat and pressure is 5.4 x 106 Pa or less.

X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid.

The image forming system of the present disclosure includes:
an ink storage section;
an ink ejection unit that ejects the ink stored in the ink storage unit onto a transfer medium by an inkjet method;
an adhesive liquid storage section;
an adhesive liquid ejection unit that ejects the adhesive liquid stored in the adhesive liquid storage unit onto the ink on the transfer medium by an inkjet method;
a drying unit that dries the transfer medium onto which the adhesive liquid has been ejected;
a contact heating section that applies heat and pressure to adhere the image formed by the ink to a print medium after the drying;
Equipped with
the adhesive liquid contains water, resin particles, an organic solvent, a crosslinking agent, and a surfactant;
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
The storage modulus E' of the coating obtained by drying the adhesive liquid at 110°C before the application of the heat and pressure is 5.4 x 106 Pa or less.

X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid.

The image forming method of the present disclosure includes:
The method includes an ink ejection step, an adhesive liquid ejection step, a drying step, and a contact heating step,
the ink ejection step includes a step of ejecting ink onto a transfer medium by an inkjet method;
the adhesive liquid ejection step includes a step of ejecting adhesive liquid onto the ink on the transfer medium by an inkjet method;
the drying step includes a step of drying the transfer medium onto which the adhesive liquid has been ejected,
the contact heating step includes applying heat and pressure to adhere the image formed by the ink to a print medium after the drying step;
the adhesive liquid contains water, resin particles, an organic solvent, a crosslinking agent, and a surfactant;
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
The storage modulus E' of the coating obtained by drying the adhesive liquid at 110°C before the application of the heat and pressure is 5.4 x 106 Pa or less.

X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid.

The adhesive liquid, image forming system, and image forming method disclosed herein provide good transferability of the printed layer and good washing durability of the printed medium after image transfer.

FIG. 1 is a schematic perspective view showing a configuration of an example of an image forming system according to the present disclosure. FIG. 2 is a perspective plan view showing the internal structure of the image forming apparatus in the image forming system of the present disclosure. FIG. 3 is a block diagram showing a schematic configuration of the image forming system of the present disclosure. FIG. 4 is a block diagram showing an example of the configuration of the control unit of the image forming apparatus in the image forming system of the present disclosure. FIG. 5 is a flowchart showing an example of steps in the image forming method of the present disclosure.

Embodiments of the present disclosure will be described. However, the present disclosure is not limited to the following embodiments. In the following drawings, identical parts are designated by the same reference numerals. Furthermore, the descriptions of each embodiment can be used interchangeably unless otherwise specified. Furthermore, the configurations of each embodiment can be combined unless otherwise specified.

First, we will explain the water, resin particles, organic solvent, crosslinking agent, and surfactant used in this disclosure.

Examples of the water include ion-exchanged water and pure water. The content of the water relative to the total amount of the adhesive liquid (water ratio) is determined appropriately depending on the desired properties, etc. The water ratio may be, for example, the remainder of the other components. The water content is, for example, 5% to 50% by weight, 5% to 45% by weight, or 8% to 40% by weight.

The resin particles may be contained in, for example, a resin emulsion. The resin emulsion is composed of, for example, the resin particles and a dispersion medium (for example, water, etc.), and the resin particles are not dissolved in the dispersion medium but are dispersed with a specific particle diameter. The resin particles may be, for example, commercially available products. Examples of the resin particles include resin particles whose main component is polyurethane, polyacrylic acid, or polyacrylic acid ester. One type of resin particle may be used, or two or more types of resin particles may be used.

Commercially available resin particles include, for example, "Takelac (registered trademark) WS6021" and "Takelac (registered trademark) W6110" manufactured by Mitsui Chemicals, Inc.; and "Movinyl (registered trademark) W6761" manufactured by Japan Coating Resins Co., Ltd.

In the adhesive liquid, the solid content of the resin particles (also known as the amount of active ingredient) relative to the total amount of the adhesive liquid is, for example, 20% to 90% by weight, 30% to 80% by weight, or 50% to 70% by weight. Note that, for example, when a resin emulsion containing the resin particles is used, the "amount of active ingredient" refers to the amount of the resin particles themselves excluding the dispersion medium such as water.

Examples of the organic solvent include a wetting agent that prevents the adhesive liquid from drying on the nozzle surface of the ejection head, and a penetrating agent that adjusts the drying speed on the print medium.

The wetting agent is not particularly limited and examples include lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones such as acetone; ketoalcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethers such as polyalkylene glycols; polyhydric alcohols such as alkylene glycol, glycerin, trimethylolpropane, and trimethylolethane; 2-pyrrolidone; N-methyl-2-pyrrolidone; and 1,3-dimethyl-2-imidazolidinone. Examples of the polyalkylene glycol include polyethylene glycol and polypropylene glycol. Examples of the alkylene glycol include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, thiodiglycol, and hexylene glycol. One type of wetting agent may be used, or two or more types of wetting agents may be used.

The content of the wetting agent in the total amount of the adhesive liquid is, for example, 0% to 50% by weight, 3% to 50% by weight, or 3% to 20% by weight.

Examples of the penetrating agent include alkylene diols, glycol ether compounds, etc. Examples of the alkylene diols include 1,2-hexanediol, 1,2-heptanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, and 3-methyl-1,5-pentanediol. Examples of the glycol ether-based compound include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol-n-propyl ether, diethylene glycol-n-butyl ether, diethylene glycol-n-hexyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol-n-propyl ether, triethylene glycol-n-butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol-n-propyl ether, propylene glycol-n-butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol-n-propyl ether, and tripropylene glycol-n-butyl ether. One type of penetrating agent may be used, or two or more types of penetrating agents may be used.

The content of the penetrant relative to the total amount of the adhesive liquid is, for example, 0% to 20% by weight, 1% to 20% by weight, or 1% to 15% by weight.

Examples of the crosslinking agent include oxazoline group-containing compounds, carbodiimide group-containing compounds, isocyanate group-containing compounds, aziridine group-containing compounds, epoxy group-containing compounds, and aqueous crosslinking agents in which hydrophilic segments are added to polycarbodiimide resins.

The crosslinking agent may be, for example, a commercially available product. Examples of commercially available products include "Epocross (registered trademark) WS-700" manufactured by Nippon Shokubai Co., Ltd., which is an oxazoline group-containing water-soluble polymer; and "SU-268A" manufactured by Meisei Chemical Industry Co., Ltd., which is an aqueous crosslinking agent in which the isocyanate group is masked with a blocking agent.

As the surfactant, for example, a commercially available product may be used. Specific examples of the surfactant include silicone-based surfactants and acetylene-based surfactants.

Commercially available silicone surfactants include, for example, "Silface (registered trademark) SAG002," "Silface (registered trademark) SAG005," and "Silface (registered trademark) SAG503A," manufactured by Nissin Chemical Industry Co., Ltd.

Commercially available acetylene surfactants include, for example, "Olfine (registered trademark) E1004," "Olfine (registered trademark) E1008," and "Olfine (registered trademark) E1010" manufactured by Nissin Chemical Industry Co., Ltd.; "Surfynol (registered trademark) 440," "Surfynol (registered trademark) 465," and "Surfynol (registered trademark) 485" manufactured by Air Products and Chemicals Co., Ltd.; and "Acetylenol (registered trademark) E40" and "Acetylenol (registered trademark) E100" manufactured by Kawaken Fine Chemicals Co., Ltd.

The surfactant may further include other surfactants in addition to or instead of the silicone-based surfactant and the acetylene-based surfactant. Examples of such other surfactants include nonionic surfactants, anionic surfactants, and cationic surfactants. One type of surfactant may be used, or two or more types of wetting agents may be used.

The content of the surfactant in the total amount of the adhesive liquid is, for example, 0.1% to 2% by mass, 0.3% to 1.5% by mass, or 0.3% to 0.5% by mass.

The adhesive liquid of the present disclosure may further contain conventionally known additives as needed. Examples of such additives include pH adjusters, viscosity adjusters, surface tension adjusters, and anti-mold agents.

Next, the adhesive liquid of the present disclosure will be described in detail.

The weight change rate X of the adhesive liquid before and after drying in the present disclosure satisfies the following formula (1) or the following formula (2).

X<A (1)
A≦X<B (2)

In the formulas (1) and (2), A represents the weight ratio of water to the total amount of the adhesive liquid. That is, when the adhesive liquid of the present disclosure contains only water, resin particles, organic solvent, crosslinking agent, and surfactant, A in the formulas (1) and (2) represents the weight ratio of water to the total weight of water, resin particles, organic solvent, crosslinking agent, and surfactant. Therefore, when the adhesive liquid of the present disclosure further contains the additives, etc., A in the formulas (1) and (2) represents the weight ratio of water to the total weight of water, resin particles, organic solvent, crosslinking agent, surfactant, and the additives, etc.

Satisfying formula (1) above means that even after the drying process in the image forming method of the present disclosure, described below, the water and the high-boiling point solvent contained in the organic solvent remain in the coating formed by drying the adhesive liquid (the coating is in a semi-dried state). For example, if the print medium to which an image formed with ink is to be adhered is fabric or the like, a semi-dried coating will facilitate penetration between the fibers of the fabric. This improves the adhesion between the image and the print medium after the contact heating process, described below. Therefore, when transferring the image to the print medium, even if the transfer medium, described below, is peeled off from the print medium, transfer defects are less likely to occur.

In the formula (2), B represents the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid. In other words, when the adhesive liquid of the present disclosure contains only water, resin particles, an organic solvent, a crosslinking agent, and a surfactant, B in the formula (2) represents the weight ratio of the water and the organic solvent to the total weight of the water, resin particles, the organic solvent, the crosslinking agent, and the surfactant. Therefore, when the adhesive liquid of the present disclosure further contains the additives, etc., B in the formula (2) represents the weight ratio of the water and the organic solvent to the total weight of the water, resin particles, the organic solvent, the crosslinking agent, the surfactant, and the additives, etc.

Satisfying formula (2) above means that the high-boiling point solvent contained in the organic solvent remains in the coating (is semi-dried) even after the drying process in the image forming method of the present disclosure, which will be described later. It also means that the water contained in the adhesive liquid is in a sufficiently dried state. When the print medium is a fabric or the like, a semi-dried coating facilitates penetration between the fibers of the fabric. This improves the adhesion between the image and the print medium after the contact heating process, which will be described later. Furthermore, the coating is less likely to strike through the print medium than when formula (1) above is satisfied. In other words, because the amount of penetration of the coating into the print medium is small, the coating is less likely to penetrate to the side of the print medium opposite the printed surface. Therefore, when the image is transferred to the print medium, the coating does not strike through the print medium, and transfer defects are less likely to occur even if the transfer medium is peeled off from the print medium.

As described above, the adhesive liquid of the present disclosure has a storage modulus E' at 110°C of 5.4×10 Pa or less of the coating formed by drying the adhesive liquid before the application of heat and pressure. That is, the storage modulus E' at 110°C of the coating after the drying step and before the contact heating step is 5.4×10 Pa or less. The upper limit of the storage modulus E' at 110°C may be, for example, 5.0×10 Pa or less, 4.0×10 Pa or less, 3.5×10 Pa or less, or 3.0×10 Pa or less, and the lower limit may be, for example, 7.0×10 Pa or more, 8.0×10 Pa or more, 9.0×10 Pa or more, 1.0×10 Pa or less, or 2.0×10 Pa or less.
0.06 Pa or more, or 1.5×106 Pa or more.

By satisfying the storage modulus E' at 110°C, for example, when the print medium is fabric, the coating can easily penetrate between the fibers of the fabric. This improves adhesion between the image and the print medium after the contact heating process described below. Furthermore, even when the fabric on which the image is formed is washed, the formed image is less likely to crack, improving washing durability.

In the adhesive liquid of the present disclosure, for example, the storage modulus E' at 25°C of the coating obtained by drying the adhesive liquid before the application of heat and pressure is 8.1 x 10 Pa or less. That is, the storage modulus E' at 25°C of the coating after the drying step and before the contact heating step is 8.1 x 10 Pa or less. The upper limit of the storage modulus E' at 25°C is, for example, 8.0 x 10 Pa or less, 7.0 x 10 Pa or less, or 6.5 x 10 Pa or less.
The lower limit may be, for example, 2.0×10 Pa or more, 2.5×10
The pressure may be 3.0×10 Pa or more, 3.0×10 Pa or more, or 4.0×10 Pa or more.

By satisfying the storage modulus E' at 25°C, the formed image is less likely to crack, even when the fabric on which the image is formed is washed, thereby further improving washing fastness.

The ink used to form the image contains, for example, a coloring material. The coloring material may contain, for example, a pigment, a dye, etc.

The pigment is not particularly limited, and examples thereof include 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 oxide, iron oxide-based inorganic pigments, and carbon black-based inorganic pigments. Examples of organic pigments include azo pigments such as azo lake, insoluble azo pigment, condensed azo pigment, and chelate azo pigment; 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 lake pigments and acid dye lake pigments; nitro pigments; nitroso pigments; and aniline black daylight fluorescent pigments. Furthermore, the ink is not limited to these pigments, and pigments dispersible in the aqueous phase may also be included. Specific examples of these pigments include C.I. C.I. Pigment White 1, 4, 5, 6, 7, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, and 28; C.I. Pigment Black 1, 6, and 7; C.I. Pigment Yellow 1, 2, 3, 12, 13, 14, 15, 16, 17, 55, 74, 78, 150, 151, 154, 180, 185, and 194; C.I. Pigment Orange 31 and 43; C.I. Examples of suitable pigments include C.I. Pigment Red 2, 3, 5, 6, 7, 12, 15, 16, 48, 48:1, 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; C.I. Pigment Violet 19 and 196; C.I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 16, 22, and 60; C.I. Pigment Green 7 and 36; and solid solutions of these pigments.

The pigment may be dispersed in a solvent using a resin dispersant (also referred to as a resin-dispersed pigment). The resin dispersant may be, for example, a general polymer dispersant (also referred to as a pigment-dispersing resin or resin dispersant). Furthermore, in the adhesive liquid of the present disclosure, the pigment may be encapsulated in a polymer. The resin dispersant may contain, for example, 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, a styrene derivative, vinyl naphthalene, a vinyl naphthalene derivative, or an aliphatic alcohol ester of an α,β-ethylenically unsaturated carboxylic acid; or a block copolymer, graft copolymer, or random copolymer composed of two or more monomers selected from the group consisting of acrylic acid, an acrylic acid derivative, maleic acid, a maleic acid derivative, itaconic acid, an itaconic acid derivative, fumaric acid, or a fumaric acid derivative, or a salt thereof. Examples of commercially available products include "Joncryl (registered trademark) 611," "Joncryl (registered trademark) 60," "Joncryl (registered trademark) 586," "Joncryl (registered trademark) 687," "Joncryl (registered trademark) 63," and "Joncryl (registered trademark) HPD296" manufactured by Johnson Polymer Co., Ltd.; "Disperbyk 190" and "Disperbyk 191" manufactured by BYK-Chemie; and "Solsperse 20000" and "Solsperse 27000" manufactured by Zeneca Chemicals.

The method for dispersing the pigment using the pigment dispersing resin may involve, for example, dispersing the pigment using a dispersing device. This dispersing device is not particularly limited as long as it is a general dispersing machine, but examples include a ball mill, a roll mill, and a sand mill (e.g., a high-speed type).

The pigment may be a self-dispersing pigment. Such self-dispersing pigments are capable of being dispersed in water without the use of a dispersant, for example, by chemically bonding at least one hydrophilic functional group, such as a carbonyl group, a hydroxyl group, a carboxylic acid group, a sulfonic acid group, or a phosphate group, to the pigment particles, either directly or via another group. Examples of such self-dispersing pigments include those treated by methods described in JP-A-8-3498, JP-T-2000-513396, JP-T-2008-524400, JP-T-2009-515007, and JP-T-2011-515535. Both inorganic and organic pigments can be used as raw materials for the self-dispersing pigment. Examples of pigments suitable for such treatment include carbon blacks such as "MA8" and "MA100" manufactured by Mitsubishi Chemical Corporation. The self-dispersing pigment may be, for example, a commercially available product. Examples of the commercially available product 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," and "CAB-O-JET (registered trademark) 500Y," all manufactured by Cabot Corporation. (registered trademark) 450C, CAB-O-JET (registered trademark) 465M, and CAB-O-JET (registered trademark) 470Y; Orient Chemical Industry Co., Ltd.'s "BONJET (registered trademark) BLACK CW-2" and "BONJET (registered trademark) BLACK CW-3"; and Toyo Ink Mfg. Co., Ltd.'s "LIOJET (registered trademark) WD BLACK 002C."

The pigment may be one type of pigment, or two or more types of pigments.

The dye is not particularly limited, and examples thereof include direct dyes, acid dyes, basic dyes, and reactive dyes. Specific examples of the dye include C.I. Direct Black, C.I. Direct Blue, C.I. Direct Red, C.I. Direct Yellow, C.I. Direct Orange, C.I. Direct Violet, C.I. Direct Brown, C.I. Direct Green, C.I. Acid Black, C.I. Acid Blue, C.I. Acid Red, C.I. Acid Yellow, C.I. Acid Orange, C.I. Acid Violet, C.I. Basic Black, C.I. Basic Blue, C.I. Basic Red, C.I. Basic Violet, and C.I. Food Black. Examples of the C.I. Direct Black include C.I. Examples of the C.I. Direct Black include Direct Black 17, 19, 32, 51, 71, 108, 146, 154, and 168. Examples of the C.I. Direct Blue include Direct Blue 6, 22, 25, 71, 86, 90, 106, and 199. Examples of the C.I. Direct Red include Direct Red 1, 4, 17, 28, 83, and 227. Examples of the C.I. Direct Yellow include Direct Yellow 12, 24, 26, 86, 98, 132, 142, and 173. Examples of the C.I. Direct Orange include Direct Orange 34, 39, 44, 46, and 60. Examples of the C.I. Direct Violet ... Examples of the C.I. Direct Violet 47 and 48 include C.I. Direct Brown 109 and the like. Examples of the C.I. Direct Green include C.I. Direct Green 59 and the like. Examples of the C.I. Acid Black include C.I. Acid Black 2, 7, 24, 26, 31, 52, 63, 112 and 118 and the like. Examples of the C.I. Acid Blue include C.I. Acid Blue 9, 22, 40, 59, 90, 93, 102, 104, 117, 120, 167, 229 and 234 and the like. Examples of the C.I. Acid Red include C.I. Examples of the C.I. Acid Red include C.I. Acid Red 1, 6, 32, 37, 51, 52, 80, 85, 87, 92, 94, 115, 180, 256, 289, 315, and 317. Examples of the C.I. Acid Yellow include C.I. Acid Yellow 11, 17, 23, 25, 29, 42, 61, and 71. Examples of the C.I. Acid Orange include C.I. Acid Orange 7 and 19. Examples of the C.I. Acid Violet include C.I. Acid Violet 49. Examples of the C.I. Basic Black include C.I. Basic Black 2. Examples of the C.I. Basic Blue include C.I. Examples of the C.I. Basic Red include C.I. Basic Red 1, 2, 9, 12, 13, 14, and 37. Examples of the C.I. Basic Violet include C.I. Basic Violet 7, 14, and 27. Examples of the C.I. Food Black include C.I. Food Black 1 and 2.

The dye may be one type of dye, or two or more types of dyes.

The ink may further contain conventionally known additives as needed. Examples of such additives include the resin particles, organic solvents, water, crosslinking agents, surfactants, pH adjusters, viscosity adjusters, surface tension adjusters, and mildew inhibitors.

The adhesive liquid is, for example, different from the ink and is used for purposes other than those of the ink. As mentioned above, the ink contains, for example, the coloring material and is used to color the image. The adhesive liquid is ejected onto the ink ejected onto the transfer medium and is used to adhere the print medium and the image.

Next, the image forming system of the present disclosure will be described. The image forming system of the present disclosure may be a system that includes separate and independent ink storage units, ink ejection units, adhesive liquid storage units, adhesive liquid ejection units, drying units (drying devices), and contact heating units (heating and bonding devices), or it may be an integrated system that includes the ink storage unit, ink ejection units, adhesive liquid storage units, adhesive liquid ejection units, drying units, and contact heating units within a single housing.

FIG. 1 shows the configuration of an example of an image forming system according to the present disclosure. FIG. 2 is a perspective plan view showing the internal structure of the image forming apparatus 1 shown in FIG. 1. In FIG. 1 and FIG. 2, which will be described later, the front, rear, left, and right directions are as indicated by arrows in FIGS. 1 and 2. The directions relating to the front and rear are the sub-scanning direction (transfer medium transport direction), and the directions relating to the left and right are the main scanning direction (head movement direction).

As shown in FIG. 1, the image forming system 100 includes an image forming apparatus 1 including a discharge liquid storage unit 10, a control unit 30, an operation panel 40, and a discharge mechanism 60, a drying device 70, and a contact heating device 80. The image forming apparatus 1 also includes a discharge unit 20 inside its housing. The discharge mechanism 60 discharges a roll of transfer medium F having an ink-receiving layer in the sub-scanning direction. The roll of transfer medium F is, for example, a roll of film formed by winding a long film several meters or more into a roll. The configuration of transfer medium F is not limited to this. For example, cut film cut to a predetermined size, such as A4 size or A3 size, may also be used as transfer medium F. The ink-receiving layer of transfer medium F is not particularly limited and may be one commonly used in the technical field of the present disclosure.

The image forming device 1 is an inkjet printing device that ejects droplets of the ink and adhesive liquid from an ejection unit 20 onto a transfer medium F. The ejection unit 20 is a line head or serial head inkjet head. In the image forming device 1, the droplets are ejected onto the transfer medium F based on image data to form an image.

The ejection liquid storage section 10 is capable of storing the ejection liquid. Examples of the ejection liquid include the ink and the adhesive liquid. However, the ejection liquid storage section 10 includes an ink storage section capable of storing the ink ejection liquid, and an adhesive liquid storage section capable of storing the adhesive ejection liquid, each of which is a separate component.

As shown in FIG. 2, the image forming device 1 includes, for example, multiple serial head ejection units 20, a platen 22, multiple tanks 11, a conveying unit 51, and a scanning unit 52. The ejection units 20, platen 22, tanks 11, conveying unit 51, and scanning unit 52 are housed within the image forming device 1.

The ejection unit 20 includes an ink ejection unit (first head) 20a and an adhesive ejection unit (second head) 20b. The ink ejection unit 20a ejects the ink contained in the ink storage unit onto a transfer medium F having an ink-receiving layer using an inkjet system. The ink ejection unit 20a may include a color head that ejects color inks and a white head that ejects white ink onto the color inks. The adhesive ejection unit 20b ejects the adhesive contained in the adhesive storage unit onto the ink on the transfer medium F using an inkjet system. However, the ejection unit 20 in the image forming apparatus 1 is not limited to ejecting the ink from the ink ejection unit 20a and the adhesive from the adhesive ejection unit 20b. The ejection unit 20 in the image forming apparatus 1 may, for example, eject the ink from at least one nozzle provided in one head and eject the adhesive from another nozzle; that is, the ink and the adhesive may be ejected from a single ejection unit.

In Figure 2, for example, the ink ejection unit 20a located at the front of the image forming device 1 is the color head, and the ink ejection unit 20a located at the rear of the image forming device 1 is the white head. When the ink ejection unit 20a is equipped with the white head, for example, the white head is arranged in the sub-scanning direction relative to the color head. Furthermore, the white head is arranged in the main scanning direction relative to the adhesive liquid ejection unit 20b, but it may also be arranged in the sub-scanning direction relative to the adhesive liquid ejection unit 20b. Furthermore, the color head may be arranged in the sub-scanning direction relative to the white head and the adhesive liquid ejection unit 20b. Furthermore, the ink ejection unit 20a may be arranged in the main scanning direction relative to the adhesive liquid ejection unit 20b. When the ink discharge unit 20a is arranged in the main scanning direction relative to the adhesive liquid discharge unit 20b, for example, the color head, the white head, and the adhesive liquid discharge unit 20b may all be arranged in the main scanning direction, or the color head may be arranged in the main scanning direction relative to the adhesive liquid discharge unit 20b, and the white head may be arranged in the sub-scanning direction relative to the color head and adhesive liquid discharge unit 20b.

The platen 22 supports the transfer medium F. The platen 22 determines the distance between the transfer medium F placed on the upper surface of the platen 22 and the ejection unit 20 placed opposite the transfer medium F. The tanks 11 are containers that store the ink or adhesive liquid, and the number of tanks 11 may be the same as the number of types of ink and adhesive liquid. For example, the tanks 11 may have a first tank 11a that stores each of the color inks and white ink as the ink, and multiple second tanks 11b that store the adhesive liquid.

Examples of the color ink include cyan ink, yellow ink, magenta ink, black ink, red ink, green ink, and blue ink. Example of the white ink is white ink.

The first tank 11a stores the ink and is connected to the ink discharge unit 20a via the first flow path 12a. The ink is supplied from the first tank 11a to the ink discharge unit 20a via the first flow path 12a. The second tank 11b stores the adhesive liquid and is connected to the adhesive liquid discharge unit 20b via the second flow path 12b. The adhesive liquid is supplied from the second tank 11b to the adhesive liquid discharge unit 20b via the second flow path 12b. The first flow path 12a and the second flow path 12b are made of, for example, rubber tubes or plastic tubes.

The transfer medium F discharged by the discharge mechanism 60 is transported, for example, backward in the sub-scanning direction by the transport unit 51. The transport unit 51 has, for example, two pairs of transport rollers 54, as well as a pair of pressure members 53 and a transport motor (not shown). One set of transport rollers 54 and the other set of transport rollers 54 are arranged to sandwich the platen 22 in the sub-scanning direction. The transport rollers 54 of each set are arranged to sandwich the transfer medium F. A transport motor is connected to one of the transport rollers 54 of each set. The transport motor drives the transport rollers 54 to rotate around their axes, thereby transporting the transfer medium F supported by the platen 22 backward in the sub-scanning direction. Note that the transfer medium F may also be transported forward in the sub-scanning direction. When discharging the transfer medium F forward, the discharge mechanism 60 may, for example, return the transfer medium F discharged by the discharge mechanism 60 to the forward direction in the sub-scanning direction.

The scanning unit 52 has, for example, a carriage 71, a pair of guide rails 72, a scanning motor 73, an endless belt 74, and a pulley 75. The pair of guide rails 72 extend along the main scanning direction above the platen 22. The carriage 71 supports the ejection unit 20 and is supported on the guide rails 72 so as to be movable in the main scanning direction. The endless belt 74 is connected to the carriage 71 while extending in the main scanning direction, and is also connected to the scanning motor 73 via a pulley 75. When the scanning motor 73 is driven, the endless belt 74 operates, causing the carriage 71 to move back and forth in the main scanning direction along the guide rails 72. Therefore, the ejection unit 20 supported by the carriage 71 can move back and forth in the main scanning direction.

As shown in FIG. 1, an operation panel 40 having buttons 41 and a display unit 42 is provided at the front right end of the image forming apparatus 1. The display unit 42 is, for example, an LCD display. The buttons are used to input an image formation start signal to the control unit 30. In addition to, or instead of, the buttons, the display unit 42, which is, for example, a touch panel, may accept user input and input the image formation start signal to the control unit 30. The front wall of the housing of the discharge unit 20 is provided with a discharge mechanism 60 and an opening 50 through which the roll-shaped transfer medium F discharged from the discharge mechanism 60 enters and leaves.

Figure 3 is a block diagram showing a schematic configuration of the image forming system 100 of the present disclosure. First, a layered liquid layer L1 made of the ink ejected from the ink ejection unit 20a is formed on the transfer medium F. Next, a layered liquid layer L2 made of the adhesive liquid ejected from the adhesive liquid ejection unit 20b is formed on the liquid layer L1. The liquid layers L1 and L2 are then dried by the drying device 70, and an image is formed on the transfer medium F. The drying device 70 performs the drying process by, for example, heat drying, air drying, or a combination of these. The drying process performed by the drying device 70 forms an image on the transfer medium F. The image is transferred to the printing medium M by the contact heating device 80, and an image is formed on the printing medium M. After the drying, the contact heating device 80 applies heat and pressure to adhere the image formed by the ink to the printing medium. Specifically, the contact heating device 80 applies heat and pressure to transfer the image S1 on the transfer medium F, to which the dried adhesive liquid (hereinafter sometimes referred to as "adhesive S2") has been applied, to the print medium M. To this end, the contact heating device 80 includes, for example, a lower iron 101, an upper iron 102, and a heater mounted within the upper iron 102. The print medium M is placed on the lower iron 101, and the transfer medium F is placed at a desired position on the print medium M. At this time, the transfer medium F is placed with the main surface on which the image has been formed facing downward (i.e., the main surface faces the print medium M). An example of the contact heating device 80 is a heat press device. In this state, the upper iron 102 descends, and the print medium M and transfer medium F are sandwiched between the lower iron 101 and the upper iron 102. The heater is then activated to heat the print medium M and transfer medium F. This melts the adhesive S2, and the image S1 on the transfer medium F is transferred to the print medium M. The print medium M can be, for example, fabric or paper, and is particularly required to be wash-resistant after image formation.

Figure 4 is a block diagram showing an example of the configuration of the control unit of the image forming apparatus 1 of the present disclosure. The control unit 30 is electrically connected via a bus 31 to a central processing unit (e.g., CPU (Central Processing Unit)) 37, a ROM (Read Only Memory) 38, a RAM (Random Access Memory) 39, an input interface 35, and an output interface 30. Buttons 41 and the like are electrically connected to the input interface 35. The output interface 42 is electrically connected to the ejection unit 20, a conveyance unit 51, a scanning unit 52, a display unit 42, and the like via drive circuits 81 to 84, respectively.

The CPU 37 performs various calculations and processes based on signals input by the button 41 and the various programs and data stored in the ROM 38 and RAM 39. It then transmits data, etc. to each component of the discharge unit 20 via the output interface 36. The RAM 39 is a readable/writable volatile storage device, and stores the results of various calculations performed by the CPU 37.

The control unit 30 causes the ink to be ejected from the ink ejection unit 20a. The control unit 30 also causes the adhesive liquid to be ejected from the adhesive liquid ejection unit 20b.

When the control unit 30 acquires information about the transfer medium F, it may control the timing of ejecting the ink and the adhesive liquid according to the acquired information.

The ink and adhesive liquid can be ejected onto the transfer medium F using the image forming apparatus 1 of the present disclosure, for example, as follows. First, the ink is applied (ejected) onto the transfer medium F from the ink ejection unit 20a. Specifically, while the platen 22 and ejection unit 20 are transported by the transport unit 51 and scanning unit 52, the ink ejection unit 20a prints an image using the ink at the image formation location on the transfer medium F. At least one of the ROM 38 and RAM 39 of the control unit 30 of the image forming apparatus 1 stores, for example, various image data created by software and various data for each type of transfer medium F. When the operator instructs printing, the image data is sent to the ink ejection unit 20a via the output interface 36, and the ink ejection unit 20a ejects the ink based on the image data to print onto the transfer medium F held on the platen 22. Furthermore, the adhesive liquid ejection unit 20b ejects the adhesive liquid onto the ink on the transfer medium F held on the platen 22 based on the image data.

The image forming device 1 may further include a storage unit (not shown). The storage unit is memory accessible from the control unit 30 and includes RAM and ROM. The RAM temporarily stores various data, such as image data created by the control unit 30. The ROM stores the image forming program, printing program, and specified data. The image forming program may be downloaded, for example, via a specified communications network and stored in the storage unit. Alternatively, the image forming program stored on a storage medium such as a CD-ROM or USB flash memory may be stored in the storage unit via a reading unit.

The image forming device 1 is equipped with a communication interface (not shown), and receives image data sent from other devices via this communication interface.

In this state, the upper iron 102 descends, and the print medium M and transfer medium F are sandwiched between the lower iron 101 and upper iron 102. The heater is then activated to heat the print medium M and transfer medium F. This melts the adhesive S2, and the image S1 on the transfer medium F is transferred to the print medium M.

Next, the image forming method of the present disclosure will be described with reference to Figure 5. Figure 5 is a flowchart showing an example of the steps in the image forming method of the present disclosure. As mentioned above, this method includes an ink ejection step, an adhesive liquid ejection step, a drying step, and a contact heating step.

The ink ejection step (S11) includes ejecting the ink onto the transfer medium using an inkjet method. The ink ejection step (S11) is performed, for example, by the ink ejection unit 20a described above.

The adhesive liquid ejection step (S12) includes ejecting the adhesive liquid onto the ink on the transfer medium using an inkjet method. The adhesive liquid ejection step (S12) is performed, for example, by the adhesive liquid ejection unit 20b described above. The amount of adhesive liquid ejected is not particularly limited, but for example, if the printing medium is fabric, it is an amount that can sufficiently fill in the unevenness of the fabric. By ejecting an amount of adhesive liquid that can sufficiently fill in the unevenness of the fabric, transfer defects are less likely to occur when the transfer medium is peeled off.

The drying step (S13) includes drying the transfer medium onto which the adhesive liquid has been ejected. The drying step (S13) is performed, for example, by the drying section (drying device) 70 described above. The drying temperature in the drying step (S13) may be, for example, 100°C or less, 80°C or less, or 60°C or less. The drying time in the drying step (S13) may be, for example, 3.5 minutes or less, or 2 minutes or less. By setting the drying temperature and drying time to these values, excessive progress of the crosslinking reaction between the crosslinking agent and the resin particles is suppressed.

The contact heating step (S14) includes a step of applying heat and pressure after the drying to adhere the image formed by the ink to the print medium. The contact heating step (S14) is performed, for example, by the contact heating unit (contact heating device) 80 described above. The heating temperature in the contact heating step (S14) may be changed as appropriate depending on, for example, the type of print medium. If the print medium is a cotton fabric, the heating temperature may be, for example, 185°C or less. If the print medium is a polyester fabric, the heating temperature may be, for example, 130°C or less. Setting the heating temperature depending on the type of print medium can avoid heat damage to the fibers that make up the fabric and detachment of the dye (sublimation transfer) that occurs due to the heating.

The image forming method of the present disclosure can be implemented, for example, using the image forming system described above. However, the image forming method of the present disclosure is not limited to use with the image forming system described above.

Next, examples of the present disclosure will be described in conjunction with comparative examples. Note that the present disclosure is not limited or restricted by the following examples and comparative examples.

[Examples 1 to 9 and Comparative Examples 1 to 5]
The components in Tables 1 and 2 were charged into a stirring vessel while rotating a stirrer and mixed together, thereby obtaining adhesive solutions of Examples 1 to 9 and Comparative Examples 1 to 5 containing the components in Tables 1 and 2.

For the adhesive solutions of Examples 1 to 9 and Comparative Examples 1 to 5, (a) measurement of storage modulus E', (b) evaluation of transferability, and (c) evaluation of washing fastness were carried out using the following methods.

(a) Measurement of storage modulus E' The adhesive solution was dropped onto a Teflon (registered trademark) petri dish and dried in a thermostatic chamber at 100°C for 6 hours to obtain a coating having an average thickness of 0.4 mm. The obtained coating was further cut into a rectangular shape with a width of 10 mm to prepare a test piece for measuring the storage modulus E'.

The prepared test specimen was set in a dynamic viscoelasticity measuring device (TA Instruments "RSA-G2") at 20°C and then cooled to -60°C. After reaching -60°C, the dynamic viscoelasticity was measured under the following measurement conditions. The obtained measurement data were designated as "storage modulus E' at 110°C and "storage modulus E' at 25°C."
・Measurement temperature range: -60℃ to 180℃
Temperature rise rate: 2.5°C/min
・Frequency: 1 Hz
・Initial strain: 0.1%
・Clamp distance: 10mm

(b) Transferability Evaluation Using a printer (Brother Industries, Ltd., "GTX Pro B"), inks (Brother Industries, Ltd., "GCX-4C02-1, GCX-4M02-1, GCX-4Y02-1, GCX-4K02-1, GCX-4W02") and adhesive solutions of the Examples and Comparative Examples were ejected onto a transfer medium (Schultz, "DTF Premium Film") using a printer (Brother Industries, Ltd., "GTX Pro B"). After ejecting the ink and adhesive solution, the adhesive solution was dried so that its weight change rate X satisfied condition 1 (the aforementioned formula (1)) or condition 2 (the aforementioned formula (2)), yielding an intermediate transfer recording medium. The intermediate transfer recording medium was then heat-pressed onto a cotton T-shirt (COTTON HERITAGE, Inc., "MC1082") at 185°C, 65 psi, and 300 seconds. After the cotton T-shirt and transfer medium had sufficiently cooled, the transfer medium was peeled off, and the image was transferred onto the cotton T-shirt. The transfer state after peeling off the transfer medium was judged according to the following criteria to evaluate the transferability: The weight change rate X was calculated based on the following formula (3).
X=(Wb-Wc)/(Wb-Wa)×100 (3)

In the formula (3),
Wa is the weight of the transfer medium,
Wb is the weight of the transfer medium to which the ink and adhesive liquid have been applied before drying,
Wc is the weight of the transfer medium to which the ink and adhesive liquid have been applied and after drying.

Transferability evaluation Evaluation criteria A: The image was transferred from the transfer medium to the T-shirt and there was no bleed-through to the back of the T-shirt. B: The image was transferred from the transfer medium to the T-shirt, but there was bleed-through to the back of the T-shirt. C: The image was not transferred from the transfer medium to the T-shirt, or image defects occurred due to poor transfer.

(c) Evaluation of Washing Fastness A washing test was carried out on a cotton T-shirt to which an image had been transferred in the same manner as in "(b) Evaluation of Transferability." The washing test was carried out for one cycle in accordance with the American standard AATCC 61 II A method. The image after washing was evaluated for washing fastness according to the following criteria.

Evaluation of washing fastness Evaluation criteria A: The image was not peeled off and was not cracked.
B: The image was not peeled off, but it was cracked.
C: The image was peeled off or cracked.

The compositions and evaluation results of the adhesive solutions for Examples 1 to 9 and Comparative Examples 1 to 5 are shown in Tables 1 and 2.

As shown in Table 1, in Examples 1 to 9, the transferability was good, earning a grade of "B" when condition 1 was met, and an grade of "A" when condition 2 was met. The washing fastness was also good, earning a grade of "B" or higher. Furthermore, under conditions where the storage modulus E' at 25°C was 8.1 x 106 Pa or less, the washing fastness was all particularly good, earning an grade of "A."

On the other hand, as shown in Table 2, in Comparative Examples 1 to 5, the transferability was rated "C" under both Condition 1 and Condition 2. Furthermore, the washing fastness was also rated "C" in all cases.

A part or all of the present disclosure may be described as, but is not limited to, the following supplementary notes.
(Appendix 1)
An adhesive liquid that is ejected from an ejection head onto ink on a transfer medium having an ink-receiving layer, and that adheres an image formed by the ink to the print medium by applying heat and pressure after drying,
The composition includes water, resin particles, an organic solvent, a crosslinking agent, and a surfactant,
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
An adhesive liquid, characterized in that a coating obtained by drying the adhesive liquid has a storage modulus E' at 110°C of 5.4 x 106 Pa or less before the application of the heat and the pressure.

X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid. (Appendix 2)
2. The adhesive liquid according to claim 1, wherein the weight change rate X satisfies the formula (2).
(Appendix 3)
3. The adhesive according to claim 1, wherein a storage modulus E' at 25°C of a coating obtained by drying the adhesive solution before the application of heat and pressure is 8.1 x 10 Pa or less.
(Appendix 4)
an ink storage section;
an ink ejection unit that ejects the ink stored in the ink storage unit onto a transfer medium by an inkjet method;
an adhesive liquid storage section;
an adhesive liquid ejection unit that ejects the adhesive liquid stored in the adhesive liquid storage unit onto the ink on the transfer medium by an inkjet method;
a drying unit that dries the transfer medium onto which the adhesive liquid has been ejected;
a contact heating section that applies heat and pressure to adhere the image formed by the ink to a print medium after the drying;
Equipped with
the adhesive liquid contains water, resin particles, an organic solvent, a crosslinking agent, and a surfactant;
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
an image forming system, characterized in that the storage modulus E' of the coating obtained by drying the adhesive liquid at 110°C before the application of the heat and the pressure is 5.4 x 106 Pa or less.

X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid. (Appendix 5)
The method includes an ink ejection step, an adhesive liquid ejection step, a drying step, and a contact heating step,
the ink ejection step includes a step of ejecting ink onto a transfer medium by an inkjet method;
the adhesive liquid ejection step includes a step of ejecting adhesive liquid onto the ink on the transfer medium by an inkjet method;
the drying step includes a step of drying the transfer medium onto which the adhesive liquid has been ejected,
the contact heating step includes applying heat and pressure to adhere the image formed by the ink to a print medium after the drying step;
the adhesive liquid contains water, resin particles, an organic solvent, a crosslinking agent, and a surfactant;
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
an image forming method, characterized in that the storage modulus E' of the coating obtained by drying the adhesive liquid at 110°C before the application of the heat and the pressure is 5.4 x 106 Pa or less.
X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid.

As described above, the adhesive liquid, image forming system, and image forming method disclosed herein provide good transferability of the printing layer and good washing durability of the printing medium after image transfer, even when an intermediate transfer recording medium is produced using the adhesive liquid.

100 Image forming system 1 Image forming apparatus 10 Discharge liquid storage section 20 Discharge section 30 Control section 40 Operation panel 50 Opening 60 Discharge mechanism F Transfer medium

Claims (5)

An adhesive liquid that is ejected from an ejection head onto ink on a transfer medium having an ink-receiving layer, and that adheres an image formed by the ink to the print medium by applying heat and pressure after drying,
The composition includes water, resin particles, an organic solvent, a crosslinking agent, and a surfactant,
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
An adhesive liquid, characterized in that a coating obtained by drying the adhesive liquid has a storage modulus E' at 110°C of 5.4 x 106 Pa or less before the application of the heat and the pressure.

X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid. The adhesive liquid according to claim 1, wherein the weight change rate X satisfies formula (2). The adhesive liquid according to claim 1 or 2, wherein the storage modulus E' of the coating obtained by drying the adhesive liquid at 25°C before the application of heat and pressure is 8.1 x 106 Pa or less. an ink storage section;
an ink ejection unit that ejects the ink stored in the ink storage unit onto a transfer medium by an inkjet method;
an adhesive liquid storage section;
an adhesive liquid ejection unit that ejects the adhesive liquid stored in the adhesive liquid storage unit onto the ink on the transfer medium by an inkjet method;
a drying unit that dries the transfer medium onto which the adhesive liquid has been ejected;
a contact heating section that applies heat and pressure to adhere the image formed by the ink to a print medium after the drying;
Equipped with
the adhesive liquid contains water, resin particles, an organic solvent, a crosslinking agent, and a surfactant;
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
an image forming system, characterized in that the storage modulus E' of the coating obtained by drying the adhesive liquid at 110°C before the application of the heat and the pressure is 5.4 x 106 Pa or less.

X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid. The method includes an ink ejection step, an adhesive liquid ejection step, a drying step, and a contact heating step,
the ink ejection step includes a step of ejecting ink onto a transfer medium by an inkjet method;
the adhesive liquid ejection step includes a step of ejecting adhesive liquid onto the ink on the transfer medium by an inkjet method;
the drying step includes a step of drying the transfer medium onto which the adhesive liquid has been ejected,
the contact heating step includes applying heat and pressure to adhere the image formed by the ink to a print medium after the drying step;
the adhesive liquid contains water, resin particles, an organic solvent, a crosslinking agent, and a surfactant;
The weight change rate X before and after drying satisfies the following formula (1) or the following formula (2),
an image forming method, characterized in that the storage modulus E' of the coating obtained by drying the adhesive liquid at 110°C before the application of the heat and the pressure is 5.4 x 106 Pa or less.
X<A (1)
A≦X<B (2)

In the formulas (1) and (2),
A is the weight ratio of the water to the total amount of the adhesive liquid,
In the formula (2),
B is the weight ratio of the water and the organic solvent to the total amount of the adhesive liquid.