JP7775715B2 - Image forming method - Google Patents

Description

The present invention relates to an image forming method.

Electrophotography is a well-known image formation method, in which an electrostatic latent image is developed with a developer to form a visible image. In electrophotography, an electrostatic latent image is formed on an electrostatic latent image carrier (also called a photoreceptor) containing a photoconductive material, and then developed with a developer containing toner to form a toner image. The toner image is then transferred to a transfer material such as paper, and fixed by applying heat and pressure to form a fixed image. To form a full-color image using electrophotography, a toner set combining cyan, magenta, yellow, and black toners, also known as process colors, is typically used.

In recent years, as electrophotographic color image forming devices have become more widespread, the applications of these printed materials have expanded dramatically. Particularly in the area of custom-made consumer goods, there is a growing need for electrophotographic printing on materials that cannot be printed (fixed) with conventional electrophotographic toners intended for printing on paper media. Specifically, there is a growing need for printing on fabric media such as sports team uniforms, shoes, and bags.

Patent Document 1 discloses forming a full-color toner image on an image transfer sheet and transferring the full-color toner image to a retroreflective substrate. Examples of materials that can be used to form the retroreflective substrate include woven fabrics, knitted fabrics, and nonwoven fabrics. Patent Document 1 also discloses applying a silicone resin or the like to the image transfer sheet to improve release properties. It also discloses forming a thermoplastic resin layer on the image transfer sheet and transferring the full-color toner image to the substrate together with the thermoplastic resin.

Printed images on fabric media must be able to adhere to uneven fabric fibers, have strong adhesion so that they do not peel off during washing, and must not impair the color of the image even on fabrics of various colors. In particular, when printing on dark fabrics, it is necessary to conceal the color of the dark fabric and not impair the color of the image. To achieve an ideal state that overcomes these challenges, the selection of the image layer structure, type of media, imaging method, and other factors is extremely important. However, prior art has yet to achieve a practical method for forming images on fabric that overcomes these challenges without complicating the manufacturing process, and no product of sufficient quality for practical use has been provided.

The present invention aims to provide an image forming method that can fix toner images on fabric media, achieve good washability, and achieve sufficient color saturation even on dark-colored fabrics.

In order to solve the above-mentioned problems, the image forming method of the present invention includes a water-repellent layer forming step of forming a water-repellent layer containing a water-repellent component on an image-receiving substrate, a toner image forming step of forming a toner image on a transfer medium, and a thermal transfer step of thermally transferring the toner image onto the surface of the image-receiving substrate on which the water-repellent layer has been formed , wherein the water-repellent component includes at least one selected from a silicone resin and a fluororesin .

The present invention provides an image forming method that can fix toner images on fabric media, achieve good washability, and achieve sufficient color saturation even on dark-colored fabrics.

FIG. 10 is a diagram showing stroke displacement in flow tester measurement. 1 is a schematic diagram illustrating an example of an image forming method according to the present invention. 10A and 10B are schematic diagrams illustrating another example of an image forming method according to the present invention.

The image forming method according to the present invention will now be described with reference to the drawings. Note that the present invention is not limited to the embodiments shown below, and other modifications, additions, corrections, deletions, and other changes may be made within the scope of what one skilled in the art could conceive. Any aspect that achieves the effects and advantages of the present invention is within the scope of the present invention.

(Image forming method)
The image forming method of the present invention is characterized by comprising a water-repellent layer forming step of forming a water-repellent layer containing a water-repellent component on an image receiving substrate, a toner image forming step of forming a toner image on a transfer medium, and a thermal transfer step of thermally transferring the toner image onto the surface of the image receiving substrate on which the water-repellent layer has been formed.

In the present invention, a toner image formed on a transfer medium is thermally transferred to an image receiving substrate on which a water-repellent layer containing a water-repellent component has been formed, so the toner image can also be fixed on a fabric medium. Furthermore, even if the image receiving substrate contains fibers, for example, the toner does not penetrate into the fibers, preventing bleeding and enabling high-resolution image formation. In the image forming method of the present invention, the toner image can be prevented from penetrating into the fibers, so image bleeding can be reduced compared to when an image is formed on a fabric medium using, for example, an inkjet method.

When fixing toner to an image-receiving substrate such as cloth, the surface of the cloth has unevenness due to the fibers, making it difficult for the toner to wet and spread. With conventional technology, the toner was unable to wet and spread on the cloth, resulting in areas that were not covered, resulting in insufficient hiding power for the image and making it impossible to form a high-resolution toner image on the cloth. Furthermore, with conventional technology, the toner was unable to wet and spread on the cloth, resulting in an image that was not robust, and the toner image easily peeled off, for example, when washed.

On the other hand, the present invention allows for the formation of a toner image on an image-receiving substrate such as fabric, while also providing good washability. Furthermore, the present invention allows for the toner to be wetted and spread over the fabric, thereby minimizing areas of the fabric that are not covered by the toner, improving the fabric's hiding power and providing sufficient saturation even on dark-colored fabrics.

<Water-repellent layer forming process>
In the water-repellent layer forming step, a water-repellent layer containing a water-repellent component is formed on the image-receiving substrate.
The method for forming the water-repellent layer is not particularly limited and can be selected appropriately. For example, a method of applying a water-repellent component can be used. The area where the water-repellent layer is formed can be changed appropriately, and may be the entire surface or a part of the image-receiving substrate.

The image receiving substrate can be selected appropriately, and for example, any so-called fabric made from artificial and natural fibers such as cotton, polyester, silk, etc. can be used. The image receiving substrate of the present invention includes any so-called fabric made from artificial and natural fibers such as cotton, polyester, silk, etc.

The image-receiving substrate is preferably made of fibers, preferably selected from polyester fibers and cotton fibers. These fibers have the advantages of high affinity with toner and high heat resistance to the heat applied during thermal fixing.

The water-repellent component can be selected appropriately, and for example, a water-repellent agent that can be applied to fabric can be used. For example, water-repellent agents that contain silicone resin as the main component, or water-repellent agents that contain fluororesin as the main component, can be used. Generally, commercially available waterproof sprays such as "waterproof spray for clothing" and "waterproof spray for shoes" can be purchased and used.

Silicone resins and fluororesins are preferably used as water-repellent components. In this case, they have a high affinity for fibers, promoting the wetting and spreading of heat-melted toner on the fibers.

The inventors repeatedly conducted trials of forming toner images on cloth, and from the results of observing the toner images, they discovered that applying a water-repellent component to an image-receiving substrate such as cloth can impart uniform toner wettability to the image-receiving substrate. They found that applying a water-repellent component significantly reduces uneven toner adhesion and the occurrence of image defects, even with the same amount of toner adhesion. They also found that applying a water-repellent component significantly reduces exposed fibers when cloth is used as the image-receiving substrate, increasing the degree to which the toner conceals the surface of the image-receiving substrate.

The amount of water-repellent component to be applied can be selected as appropriate, for example, an amount that will provide the desired water-repellent effect. The method for applying the water-repellent component can also be selected as appropriate, for example, by spraying the component evenly over the surface of the image-receiving substrate from a distance of approximately 10 cm for approximately 10 seconds.

<Toner Image Forming Process>
In the toner image forming process, a toner image is formed on a transfer medium. The method for forming the toner image is not particularly limited and can be selected appropriately. For example, a method can be used in which a toner layer is transferred to a transfer medium, followed by thermal fixing to form a toner image on the transfer medium. The toner layer may be a single layer or multiple layers. The toner used in the toner image forming process will be described in detail later.

In the present invention, an undercoat layer may be formed when forming a toner image on a transfer medium. The undercoat layer can conceal the background color of the image-receiving substrate and improve the saturation of the image formed on the image-receiving substrate. Furthermore, by forming a water-repellent layer on the image-receiving substrate and then forming an undercoat layer, it is possible to improve washability. The toner for the undercoat layer can be selected appropriately, and for example, white toner can be used. The undercoat layer may also be referred to as a concealing layer, etc.

In the present invention, it is preferable to form, for example, a white toner layer as the uppermost layer on the transfer medium. In this case, when the toner image is thermally transferred onto the image receiving substrate in the thermal transfer process, it is preferable to perform the thermal transfer so that the white toner layer is the lowermost layer of the toner image on the image receiving substrate. In this way, a white toner image is formed below the color toner image on the image receiving substrate, and the white toner image can function as an undercoat layer. By providing an undercoat layer, hiding power is improved, and even higher resolution images can be obtained.

The ability of white toner to conceal background color is affected by the amount of toner adhered and the wetting and spreading properties of the toner. In this invention, a water-repellent layer is formed on the image-receiving substrate, so when a toner layer such as white toner is formed, concealment is improved and even higher-resolution images can be obtained. This is thought to be because the toner wets and spreads evenly over the image-receiving substrate. For this reason, this invention can improve image quality (increase saturation) without increasing the amount of toner adhered.

The device used to form the toner image can be selected as appropriate, and any known image forming device (which may also be called a printer, recorder, copier, etc.) can be used. For example, a device equipped with an electrostatic latent image carrier, exposure means, charging means, developing means, transfer means, fixing means, etc. can be used. For example, a RICOH Pro C7200S manufactured by Ricoh Co., Ltd. can be used. The device used to form the toner image can be modified, for example, so that the undercoat layer toner and developer can be loaded into one of the color stations.

The transfer medium can be selected as appropriate, and examples include transfer paper or release paper that has been surface-treated to have appropriate fixability and releasability suitable for the toner image formation process and thermal transfer process. For example, Piotec's WOW Light 8.0, WOWi Sheet 7A, and WOWm Sheet 7, and Europort's CLAPp-MULT can be used.

<Thermal transfer process>
In the thermal transfer process, a toner image is thermally transferred onto the surface of an image receiving substrate on which a water-repellent layer has been formed.
The thermal transfer step can be appropriately selected, and examples thereof include a method in which the image receiving substrate and the transfer medium are overlapped so that the surface of the image receiving substrate on which the water-repellent layer is formed faces the surface of the transfer medium on which the toner image is formed, and then heat and pressure are applied, and the transfer medium is peeled off.

In the thermal transfer step, for example, a heat press fixing machine is used to perform the thermal transfer.
The heat press fixing machine can be appropriately selected, and may be any machine capable of applying the temperature and pressure required to fix the toner to the image receiving substrate. For example, Model HTP234PS1, Model 728, and Model 201 manufactured by Piotec Corporation, and Hercules PH-4634, Hercules Wide PH-5040, Gaia PGA-5040, and Zeus PZ-130110D manufactured by Europort, etc. may be used. An iron may also be used instead of the heat press machine.

The thermal transfer temperature _PT in the thermal transfer step can be selected appropriately.
For example, when a toner for an undercoat layer is used, it is preferable that P _T satisfies the following formula (1): In this case, for example, the toner for the undercoat layer does not penetrate too far into the interior of the image receiving substrate, but remains on the surface, and good hiding power and adhesiveness can be exhibited.
UT _fb <P _T ≦UT _1/2 ... Formula (1)

In the above formula (1), UT _fb represents the temperature at which the toner forming the undercoat layer begins to flow. UT _1/2 represents the half-flow temperature of the toner forming the undercoat layer. Note that "U" is used for convenience to indicate the undercoat layer, and has the meaning of "under."

The outflow start temperature and half outflow temperature are measured, for example, as follows.
Using a flow tester (Shimadzu CFT-500D), a 1.0 g sample was heated at a temperature increase rate of 6°C/min while a load of 1.96 MPa was applied by the plunger, and the sample was extruded from a nozzle with a diameter of 1.0 mm and a length of 1.0 mm. This produced a plot of the plunger stroke of the flow tester versus temperature. An example of the plot is shown in Figure 1. From this plot, two points shown in Figure 1 were designated the outflow start temperature T _fb and the 1/2 outflow temperature T _1/2 , respectively. Note that the example shown in Figure 1 is an example of measurement of a toner for an undercoat layer, and the outflow start temperature T _fb is indicated as UT _fb , and the 1/2 outflow temperature T _1/2 is indicated as UT _1/2 .

FIG. 1 will be explained in more detail. In the obtained plot, the inflection point where the change in plunger depression (stroke) shifts from a stable region of zero to an increase is defined as the outflow start temperature T _fb . In the example shown in the figure, the change in stroke is zero between approximately 65°C and approximately 105°C, and the stroke begins to increase around 105°C. Therefore, in this example, the outflow start temperature T _fb can be said to be approximately 105°C. Furthermore, in the obtained plot, the temperature at which half of the sample has flowed out is defined as the 1/2 outflow temperature. In the example shown in the figure, the 1/2 outflow temperature T _1/2 can be said to be approximately 145°C.

In the thermal transfer process, for example, the image receiving substrate and the transfer medium are overlapped, and then heated and pressurized. The conditions for heating and pressurization are not particularly limited and can be selected appropriately. For example, taking into consideration the thermal conductivity, thickness, surface roughness, etc. of the image receiving substrate, the pressure is preferably 100 g/cm ² to 800 g/cm ² and the time is preferably 5 to 60 seconds.

<Example of image formation>
An example of the present invention will now be described with reference to FIG.
2A, a color toner layer 12 is formed on the transfer medium 10. Next, the transfer medium 10 is subjected to thermal fixing, and the color toner layer 12 is fixed to the transfer medium 10.
In Fig. 2(B), a water-repellent component is applied to the image receiving substrate 20 to form a water-repellent layer 22. The order in which Fig. 2(B) is performed can be changed as appropriate, and it may be performed after Fig. 2(A) or before Fig. 2(A).
2(C), the image receiving substrate 20 and the transfer medium 10 are overlapped so that the surface of the image receiving substrate 20 on which the water-repellent layer 22 is formed faces the surface of the transfer medium 10 on which the toner image is formed, and then heat and pressure are applied. Next, the transfer medium 10 is peeled off. As a result, a toner image can be formed on the image receiving substrate 20 as shown in FIG. 2(D).

In the present invention, the toner image may be made up of multiple layers; for example, an image made of color toners and an image made of toner for an undercoat layer may be formed. For example, white toner can be used as the toner for the undercoat layer.

Another example of the present invention will be described with reference to Fig. 3. The example shown in Fig. 3 is an example in which a white toner layer (undercoat layer) is formed. By forming an undercoat layer, the hiding power of the image receiving substrate can be improved, and the saturation of the image on the image receiving substrate can be improved.
In FIG. 3A, a color toner layer 12 is formed on a transfer medium 10 .
In FIG. 3B, a white toner layer 14 is formed on the color toner layer 12 .
Next, the transfer medium 10 is subjected to thermal fixing, and the color toner layer 12 and the white toner layer 14 are fixed to the transfer medium 10 .
In Fig. 3(C), a water-repellent component is applied to the image receiving substrate 20 to form a water-repellent layer 22. The order in which Fig. 3(C) is performed can be changed as appropriate, and it may be performed after Fig. 3(A) or Fig. 3(B), or before Fig. 3(A) or Fig. 3(B).
3(D), the image receiving substrate 20 and the transfer medium 10 are overlapped so that the surface of the image receiving substrate 20 on which the water-repellent layer 22 is formed faces the surface of the transfer medium 10 on which the toner image is formed, and then heat and pressure are applied. Next, the transfer medium 10 is peeled off. As a result, a toner image can be formed on the image receiving substrate 20 as shown in FIG. 3(E).

<Toner>
The toner used in the toner image forming process is not particularly limited and can be selected appropriately. In the toner image forming process, a toner layer is transferred to a transfer medium and fixed to the transfer medium, thereby forming a toner image on the transfer medium. The toner layer can be selected appropriately, and for example, a layer of color toner and an undercoat layer on the color toner layer can be provided.

The color toner used in the toner image formation process is not particularly limited, and for example, process color toner used in electrophotographic printers can be used. Furthermore, one color or multiple colors may be used. Color toner is sometimes referred to as process color toner.

The toner used in the undercoat layer is not particularly limited and can be selected as appropriate. Toner used in the undercoat layer is sometimes referred to as undercoat layer toner. The reason it is called an undercoat layer is because it is expected that the undercoat layer will be formed as the top layer on the transfer medium, and that when the toner image on the transfer medium is thermally transferred to the image receiving substrate, the undercoat layer will be below the layer of color toner.

The toner for the undercoat layer can be made of the same materials as the color toner. The color of the toner for the undercoat layer can be any color, but a colorless, transparent toner that does not contain a coloring agent such as a pigment is preferred, or a white toner that uses a white pigment as a coloring agent is preferred. The use of white toner is particularly preferred, as the use of white toner can conceal the color of the image-receiving substrate when the image-receiving substrate is a dark color such as black or navy blue, preventing the color of the color toner from being impaired.

The half-flow temperature of the undercoat layer toner is preferably higher than the half-flow temperature of the color toners. In this case, the undercoat layer toner adheres well to the color toners and color mixing between the undercoat layer toner and the color toners can be prevented.

Next, we will discuss the materials that make up the toner. Unless otherwise noted, the following explanation applies to both the undercoat layer toner and the color toner.

<<Binder resin>>
The binder resin (which may also be referred to as a fixing resin) used in the toner may be a conventionally known resin. Examples include styrene-based resins (homopolymers or copolymers containing styrene or styrene substitutes) such as styrene, poly-α-styrenestyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-methyl chloroacrylate copolymer, and styrene-acrylonitrile-acrylate copolymer; epoxy resins, vinyl chloride resins, rosin-modified maleic acid resins, phenolic resins, polyethylene resins, polypropylene resins, petroleum resins, polyurethane resins, ketone resins, ethylene-ethyl acrylate copolymers, xylene resins, and polyvinyl butyrate resins. The method for producing these resins is not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.

In the present invention, it is preferable that the binder resin (fixing resin) contains a polyester resin, and it is particularly preferable that the binder resin be polyester resin as the main component. Compared to other resins, polyester resins generally allow for low-temperature fixing while maintaining heat-resistant storage stability, making them an appropriate binder resin for the present invention.

The polyester resin used in the present invention is obtained by condensation polymerization of an alcohol and a carboxylic acid. Examples of alcohols that can be used include glycols such as ethylene glycol, diene glycol, triethylene glycol, and propylene glycol, etherified bisphenols such as 1,4-bis(hydroxymeta)cyclohexane and bisphenol A, other dihydric alcohol monomers, and trihydric or higher polyhydric alcohol monomers.

Furthermore, examples of carboxylic acids include divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and malonic acid, and trivalent or higher polyvalent carboxylic acid monomers such as 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, and 1,2,7,8-octanetetracarboxylic acid.

<<Release Agent>>
The release agent used in the toner is not particularly limited and can be appropriately selected depending on the purpose. In addition, one type may be used alone, or two or more types may be used in combination.

Examples of release agents that can be used include liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, polyolefin wax, and their partial oxides, as well as aliphatic hydrocarbons such as fluorides and chlorides; animal oils such as beef tallow and fish oil; vegetable oils such as coconut oil, soybean oil, rapeseed oil, rice bran wax, and carnauba wax; higher aliphatic alcohols and higher fatty acids such as montan wax; fatty acid amides, fatty acid bisamides; metal soaps such as zinc stearate, calcium stearate, magnesium stearate, aluminum stearate, zinc oleate, zinc palmitate, magnesium palmitate, zinc myristate, zinc laurate, and zinc behenate; fatty acid esters; and polyvinylidene fluoride.

<<Coloring Agents>>
The colorant used in the toner is not particularly limited, and any commonly used colorant can be appropriately selected and used.

Preferred black toner is, for example, carbon black alone or a mixture of carbon black as the main component and copper phthalocyanine or the like, with the hue and brightness adjusted.

For cyan toner, for example, copper phthalocyanine pigment blue 15:3 or a mixture of aluminum phthalocyanine and the colorant is preferred.

For example, pigment red 53:1, pigment red 81, pigment red 122, and pigment red 269 can be used alone or in combination as magenta toner.

For example, Pigment Yellow 74, Pigment Yellow 155, Pigment Yellow 180, and Pigment Yellow 185 can be used alone or in combination as yellow toner. From the standpoints of saturation and storage stability, Pigment Yellow 185 alone or a mixture of Pigment Yellow 185 and Pigment Yellow 74 is preferred.

The white pigment used in white toner can be selected appropriately, and examples include titanium dioxide that has been surface-treated with silicon, zirconia, aluminum, polyol, etc.

For example, Pigment Green 7 can be used as green toner, but safety precautions must be taken.

Examples of blue toners include Pigment Blue 15:1 and Pigment Violet 23.

<<Charge control agent>>
The toner may contain a charge control agent (CCA).
Examples of charge control agents include nigrosine and fatty acid metal salts modified with phosphonium salts and their lake pigments, triphenylmethane dyes and their lake pigments, metal salts of higher fatty acids, diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, and dicyclohexyltin oxide, diorganotinborates such as dibutyltin borate, dioctyltin borate, and dicyclohexyltin borate, organometallic complexes, chelate compounds, monoazometal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, metal complexes of aromatic dicarboxylic acids, and quaternary ammonium salts. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenols. While not limited to these, zirconium salicylate is preferred. These can be used alone or in combination.

<<External additives>>
An external additive may be used in the toner, and examples of the external additive include inorganic fine particles. Examples of inorganic fine particles for external addition include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Silica, alumina, and titanium oxide are particularly preferred.

Furthermore, inorganic fine particles may be surface-treated with a hydrophobic treatment agent. Examples of preferred hydrophobic treatment agents include silane coupling agents, silylating agents, silane coupling agents with fluorinated alkyl groups, organic titanate coupling agents, and aluminum coupling agents. Furthermore, sufficient effects can be obtained by using silicone oil as a hydrophobic treatment agent.

<Developer>
In the toner image forming process, either a one-component development system in which toner is used as a developer or a two-component development system in which toner is mixed with a carrier and used as a two-component developer can be used.

When using a two-component developer system, magnetic particles used in the magnetic carrier can be, for example, magnetite, spinel ferrites such as gamma iron oxide, spinel ferrites containing one or more metals other than iron (Mn, Ni, Zn, Mg, Cu, etc.), magnetoplumbite ferrites such as barium ferrite, or iron or alloy particles with an oxide layer on their surface. Their shape may be granular, spherical, or acicular. When particularly high magnetization is required, it is preferable to use ferromagnetic particles such as iron. Furthermore, considering chemical stability, it is preferable to use magnetite, spinel ferrites containing gamma iron oxide, or magnetoplumbite ferrites such as barium ferrite.

By selecting the type and content of ferromagnetic particles, it is possible to use a resin carrier with the desired magnetization. In this case, the carrier's magnetic properties should preferably be, for example, a magnetization strength of 30 to 150 emu/g at 1,000 oersteds.

The carrier used in the present invention may be produced, for example, by spraying a melt-kneaded mixture of magnetic fine particles and an insulating binder resin using a spray dryer. Alternatively, a carrier in which magnetic fine particles are dispersed in a condensation binder may be produced by reacting and curing a monomer or prepolymer in an aqueous medium in the presence of magnetic fine particles. Furthermore, the chargeability may be controlled by adhering positively or negatively charged fine particles or conductive fine particles to the surface of the magnetic carrier, or by coating it with a resin.

Examples of the coating material (resin) that can be used on the surface of the magnetic microparticles include silicone resin, acrylic resin, epoxy resin, and fluorine-based resin. Positively or negatively charged microparticles or conductive microparticles can also be included in the coating. In this case, silicone resin and acrylic resin are preferred resins.

<Toner manufacturing method>
The method for producing the toner used in the present invention is not particularly limited and can be appropriately selected. An example will be described below.
First, a binder resin, a colorant, a release agent, and optionally a charge control agent are combined and thoroughly mixed in a mixer such as a Henschel mixer or a super mixer, and then the materials are melt-kneaded using a heat melt kneader such as a heating roll, a kneader, or an extruder to thoroughly mix the materials.The mixture is then cooled and solidified, and then finely pulverized and classified to obtain a toner.

Examples of the pulverization method used here include the jet mill method, in which the toner is entrained in a high-speed airflow and collided with a collision plate, resulting in pulverization using the resulting energy. Other methods include the inter-particle collision method, in which toner particles collide with each other in an airflow. Furthermore, other methods can be used, such as mechanical pulverization, in which the toner is supplied between a narrow gap and a rotor rotating at high speed, and pulverized.

The method for producing toner is not limited to the above. A solution suspension method is also possible, in which toner materials are dissolved or dispersed in an organic solvent phase, and the resulting oil phase is dispersed in an aqueous medium phase. After the resin reaction has occurred, the solvent is removed, and the resulting mixture is filtered, washed, and dried to produce toner base particles.

(Toner storage unit)
In the toner image forming process, a toner storage unit may be used. In the present invention, the toner storage unit refers to a unit having a function of storing toner and storing the toner. Here, examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge.
The toner container refers to a container that stores toner.
The developing device is a device that contains toner and has means for developing.
A process cartridge is a device that integrates at least an image carrier and a developing unit, contains toner, and is detachably mountable to an image forming apparatus. The process cartridge may further include at least one selected from a charging unit, an exposure unit, and a cleaning unit. The use of a toner storage unit enables good image formation.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" in the following descriptions represent "parts by mass" and "%" represents "% by mass."

(Toner Production)
<Production Example of White Toner 1>
[Toner raw materials]
Polyester resin RN-290 (manufactured by Kao Corporation) 94.7 parts by weight Carnauba wax WA-05 (manufactured by Cerarica Noda Co., Ltd.) 5.3 parts by weight Zirconium salicylate (CCA) TN-105 (manufactured by Hodogaya Chemical Co., Ltd.) 0.5 parts by weight Titanium oxide white pigment PF-739 (manufactured by Ishihara Sangyo Kaisha) 60 parts by weight

The above toner raw materials were premixed using a Henschel mixer (FM20B, manufactured by Nippon Coke and Engineering Co., Ltd.) and then melted and kneaded at a temperature of 100-130°C in a single-screw kneader (Ko-Kneader kneader, manufactured by Buss). The resulting kneaded mixture was cooled to room temperature and coarsely pulverized to 200-300 μm using a Rotoplex. It was then finely pulverized using a counter jet mill (100AFG, manufactured by Hosokawa Micron Corporation) while adjusting the pulverization air pressure appropriately to achieve the desired number-average particle size distribution. The mixture was then classified using an air classifier (EJ-LABO, manufactured by Matsubo Corporation) while adjusting the louver opening appropriately to achieve the desired number-average particle size distribution, yielding toner base particles. Next, 3.0 parts of an additive (HDK-2000, manufactured by Clariant) were added to 100 parts of the toner base particles and mixed with them in a Henschel mixer to produce [White Toner 1].

<Production Example of Color Toner 1>
[Toner raw materials]
Polyester resin RN-290 (manufactured by Kao Corporation) 94.7 parts by weight Carnauba wax WA-05 (manufactured by Cerarica Noda Co., Ltd.) 5.3 parts by weight Zirconium salicylate (CCA) TN-105 (manufactured by Hodogaya Chemical Co., Ltd.) 0.1 parts by weight Copper phthalocyanine cyan pigment FG-7351 (manufactured by Toyo Ink Co., Ltd.) 10 parts by weight

[Color Toner 1] was produced in the same manner as [White Toner 1], except for changing the toner raw materials to those listed above.

<Production Example of Color Toner 2>
[Toner raw materials]
Polyester resin RN-290 (manufactured by Kao Corporation) 94.7 parts by weight Carnauba wax WA-05 (manufactured by Cerarica Noda Co., Ltd.) 5.3 parts by weight Zirconium salicylate (CCA) TN-105 (manufactured by Hodogaya Chemical Co., Ltd.) 0.5 parts by weight Copper phthalocyanine cyan pigment FG-7351 (manufactured by Toyo Ink Co., Ltd.) 10 parts by weight

[Color Toner 2] was produced in the same manner as [White Toner 1], except for changing the toner raw materials to those listed above.

(Example of manufacturing a two-component developer)
<Preparation of carrier>
Silicone resin (organostraight silicone) 100 parts by weight Toluene 100 parts by weight γ-(2-aminoethyl)aminopropyltrimethoxysilane 5 parts by weight Carbon black 10 parts by weight

The above mixture was dispersed in a homomixer for 20 minutes to prepare a coating layer forming solution. This coating layer forming solution was applied and dried using a fluidized bed coating device, with the temperature in the fluidized bed controlled to 70°C, using Mn ferrite particles with a weight-average particle size of 35 μm as the core material, so that the average film thickness on the core material surface was 0.20 μm. The resulting carrier was fired in an electric furnace at 180°C for 2 hours to obtain [Carrier A].

<Preparation of Two-Component Developer>
The prepared [White Toner 1], [Color Toner 1], [Color Toner 2], and [Carrier A] were mixed uniformly for 5 minutes at 48 rpm in a Turbler mixer (manufactured by Willy & Bachofen (WAB)) and charged to prepare two-component developers. The mixing ratio of the toner and carrier was adjusted to match the toner concentration (7% by mass) of the initial developer for the evaluation machine.

(measurement)
The toner thus produced was measured for flow-out start temperature and half flow-out temperature as follows.
Using a flow tester (Shimadzu CFT-500D), 1.0 g of sample was heated at a temperature increase rate of 6°C/min while applying a load of 1.96 MPa with the plunger, and extruded from a nozzle 1.0 mm in diameter and 1.0 mm in length. This resulted in a plot of the plunger depression (stroke) of the flow tester versus temperature, as shown in Figure 1. From this plot, the outflow start temperature _Tfb and half outflow temperature T1/ ₂ of the white toner and color toner were determined.
The measurement results are shown in Table 1. In Table 1, the following are represented:
UT _1/2 : 1/2 flow-out temperature of white toner (toner for undercoat layer) UT _fb : flow-out start temperature of white toner (toner for undercoat layer) CT _1/2 : 1/2 flow-out temperature of color toner CT _fb : flow-out start temperature of color toner

(evaluation)
The resulting developer was used to form an image and was evaluated. The evaluation results are shown in Table 2. The evaluation methods and conditions were as follows.

<Creating evaluation images>
<<Example 1>>
A developer using [Color Toner 1] was set in the cyan station of a RICOH Pro C7200S (manufactured by Ricoh Co., Ltd.). The development and transfer conditions were adjusted using a process controller so that the toner adhesion amount was 0.40 mg/ ^cm2 , and an unfixed solid cyan image was output on transfer paper (WOW Light 8.0 manufactured by Piotec Corporation).
A developer using [White Toner 1] was set at the fifth station of a RICOH Pro C7200S (manufactured by Ricoh Co., Ltd.). The development and transfer conditions were adjusted using a process controller so that the toner adhesion amount was 1.0 mg/ ^cm² , and an unfixed solid image was output as an undercoat layer, superimposed on the unfixed cyan solid image on the transfer paper.
The transfer paper was then heat-fixed to form a toner image on the transfer paper.
The toner image on the transfer paper was then placed on a 100% polyester cloth (black T-shirt) as an image-receiving substrate and placed in a heat press (Model HTP234PS1 manufactured by Piotec Corp.) After applying heat and pressure at a thermal fixing temperature ( _PT) of 140°C and a pressure of 600 g/ ^cm² for 20 seconds, the transfer paper was peeled off and the toner image was thermally fixed onto the T-shirt.
Here, a black 100% polyester fabric (T-shirt) was sprayed with Konishi's "Bond Long-lasting Waterproof Spray," which contains silicone resin and fluororesin components, from a distance of 10 cm from the T-shirt for 10 seconds, and then allowed to dry.
In this manner, an evaluation image of Example 1 was prepared.

<<Example 2>>
An evaluation image was prepared in the same manner as in Example 1, except that [Color Toner 1] in Example 1 was changed to [Color Toner 2].

<<Comparative Example 1>>
An evaluation image was prepared in the same manner as in Example 1, except that no water-repellent component was applied to the image-receiving substrate. That is, in Comparative Example 1, Bond Waterproof Spray Long-lasting was not applied to a black 100% polyester fabric (T-shirt).

<<Example 3>>
An evaluation image was prepared in the same manner as in Example 1, except that the image receiving substrate was changed from "black 100% polyester fabric" to "black cotton fabric."

<<Example 4>>
An evaluation image was prepared in the same manner as in Example 2, except that the image receiving substrate was changed from "black 100% polyester fabric" to "black cotton fabric."

<<Comparative Example 2>>
An evaluation image was prepared in the same manner as in Comparative Example 1, except that the image receiving substrate was changed from "black 100% polyester fabric" to "black cotton fabric."

<<Example 5>>
An evaluation image was prepared in the same manner as in Example 1, except that the image receiving substrate was changed from "black 100% polyester fabric" to "white 100% polyester fabric."

<<Example 6>>
An evaluation image was prepared in the same manner as in Example 5, except that the white toner was not used.

<<Comparative Example 3>>
An evaluation image was prepared in the same manner as in Example 6, except that no water-repellent component was added to the image-receiving substrate.

<Image color evaluation>
The saturation of the obtained evaluation image was visually evaluated according to the following criteria.
[Evaluation criteria]
◎: The image color is vivid. 〇: The image color is vivid, but only the yellow image part has △ rank parts. △: There are some parts of the image that are slightly darker (only when using a black T-shirt) or some parts where the image color is slightly lighter (common to both black and white T-shirts).
×: Dark areas in the image (only when using a black T-shirt) or lighter areas in the image due to unevenness of the fabric fibers are clearly visible (common to both black and white T-shirts)

<Washing durability evaluation>
The obtained evaluation images were subjected to a washing fastness test according to the test method of JIS0844:2011, and were evaluated according to the following criteria.
[Evaluation criteria]
◎: JIS0844 discoloration grayscale rank 5
○: JIS0844 discoloration grayscale rank 4
△: JIS0844 discoloration grayscale rank 3
×: JIS0844 discoloration grayscale rank 2 to 1

The formulations and evaluation results are shown in Tables 1 and 2.
As can be seen from the evaluation results, according to the present invention, it is possible to form a toner image even on fabric, and to form an image with good wash resistance and good saturation.
Moreover, the reason why Examples 1 and 3 have better results than Examples 2 and 4 is that the half outflow temperature UT _1/2 of the white toner is higher than the half outflow temperature CT _1/2 of the color toners.

10 Transfer medium 12 Color toner layer 14 White toner layer 20 Image receiving substrate 22 Water-repellent layer

Japanese Patent Application Laid-Open No. 2002-006747

Claims (7)

a water-repellent layer forming step of forming a water-repellent layer containing a water-repellent component on an image-receiving substrate;
a toner image forming step of forming a toner image on a transfer medium;
a thermal transfer step of thermally transferring the toner image onto the surface of the image receiving substrate on which the water-repellent layer is formed ,
The image forming method according to claim 1, wherein the water-repellent component contains at least one material selected from the group consisting of silicone resins and fluorine resins . The image forming method described in claim 1, characterized in that the thermal transfer process involves overlapping the image receiving substrate and the transfer medium so that the surface of the image receiving substrate on which the water-repellent layer is formed faces the surface of the transfer medium on which the toner image is formed, applying heat and pressure, and peeling off the transfer medium. The image forming method according to claim 1 or 2, characterized in that the toner image forming process involves transferring a toner layer to the transfer medium, followed by thermal fixing to form a toner image on the transfer medium. 4. The image forming method according to claim 1 , wherein the image receiving substrate is made of fiber. 5. The image forming method according to claim 1, wherein the image receiving substrate contains at least one fiber selected from the group consisting of polyester fiber and cotton fiber. The toner image forming step includes forming a white toner layer on the transfer medium as a top layer,
The image forming method according to any one of claims 1 to 5, wherein the thermal transfer step is performed such that when the toner image is thermally transferred onto the image receiving substrate, the white toner layer is the bottom layer in the toner image on the image receiving substrate. The toner image forming step includes forming a layer of color toner and a layer of white toner on the color toner layer,
7. The image forming method according to claim 1 , wherein the half outflow temperature UT _1/2 of the white toner is higher than the half outflow temperature CT _1/2 of the color toners.