Toner, toner set, image formation method, image formation apparatus and process cartridge

Abstract

To provide toner excellent in fixability to a body to be transferred, excellent in the washing fastness of the body to be transferred having an image and excellent in the reproducibility of a color image even when the body to be transferred is dark color.SOLUTION: Toner is used for an electrophotographic image formation apparatus and used for forming a heat transfer print sheet. The heat transfer print sheet obtained by forming an image on a transfer sheet using the toner is used for transferring the image on the body to be transferred by heat transfer; and the toner having a transmissivity of less than 5% in the total visible light wavelength when forming a solid image having an adhesion thickness of 30 μm on an OHP base material includes polyester, a polyurethane elastomer, wax and white pigment or black pigment.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a toner, a toner set, an image forming method, an image forming apparatus, and a process cartridge. [Background technology]

[0002] In the electrophotographic method, an electrostatic latent image is developed with a developer to form a visible image. This involves forming an electrostatic latent image on an electrostatic latent image carrier (also called a photoreceptor) containing a photoconductive material, developing the electrostatic latent image with a developer containing toner to form a toner image, transferring the toner image to a transfer material such as paper, and then fixing the toner image by applying heat and pressure to form a fixed image.

[0003] To form a full-color image by electrophotography, a toner set is generally used that combines three process color toners (sometimes simply called process colors) - cyan, magenta, and yellow - with black toner.

[0004] In recent years, as electrophotographic color image forming devices have become more widespread, the applications of these printed materials have expanded to a wide variety of uses. Particularly in the field 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 and leather media, such as sports team uniforms, shoes, and bags.

[0005] As a method for printing desired images, logos, and other designs on fabric products such as T-shirts, sweatshirts, and work clothes, as well as on wood and metal plates, methods and devices have been proposed that use inkjet printers to print designs directly onto the printing object (Patent Documents 1 and 2). Also, a device has been proposed that uses a thermal transfer printer to print directly onto fabrics such as clothing (Patent Document 3). Also, methods and devices have been proposed in which an image is printed on transfer paper and then thermally transferred onto a printing medium using an iron or the like (Patent Documents 4 and 5). In addition, a pulverized toner for thermal transfer print sheets and a thermal transfer print sheet have been proposed, which include a release sheet having a release surface, a print image formed on the release sheet that can be thermally transferred to a transfer medium, and a special white toner printed on the print image, making it possible to print on dark-colored transfer materials (Patent Document 6). Summary of the Invention [Problem to be solved by the invention]

[0006] Direct printing methods using inkjet printers or thermal transfer printers, such as those described in Patent Documents 1 to 3, are considered effective when producing a large number of items of the same shape or when producing large items. However, when producing small quantities of a wide variety of small print objects (such as clothing) with different shapes, the method of transporting the print objects to the printer is different for each item, making production time-consuming. Furthermore, when printing on dark-colored print materials, a large amount of white ink must be used, which significantly reduces maintenance due to white pigment settling and head clogging. Furthermore, applying a thick white concealing layer slows down the printing speed for white and light-colored print materials.

[0007] The method of printing an image on transfer paper and then thermally transferring it to the printing object, as in Patent Document 4, is thought to avoid the problems of the above-mentioned methods in that it does not require selection of the shape of the printing object. However, because the size of the transfer paper is standard (for example, A4 or A3 is common), the shape to be transferred to the printing object must be prepared separately.

[0008] Patent Document 5 describes a method of thermally transferring an image onto a print target using two sheets of transfer paper, which is thought to solve the problems of Patent Document 4. However, it is troublesome because it requires using two sheets of transfer paper and performing the thermal transfer process twice. In addition, in practice, the temperature and pressure during transfer vary for each sample produced, requiring skill in the process.

[0009] The printing method of Patent Document 6 is thought to solve the above problems, but it has low productivity for the white toner, does not provide sufficient hiding power for dark-colored transfer objects (transfer media), and the white toner hiding power is insufficient, resulting in exposed transfer objects and reduced saturation and brightness of color images. Furthermore, when repeated printing is performed to thicken the white hiding layer in order to achieve sufficient hiding power, productivity decreases with multiple printings, and furthermore, the transfer object is more likely to curl with each printing. This causes transport problems and misalignment within the device, making reproducible printing difficult.

[0010] Furthermore, in conventional image formation methods using transfer printing, the toner has a high transmittance, making it necessary to improve the accuracy and quality of the image formation. Furthermore, the toner components and amount of adhesion can affect image quality, making it difficult to form consistent images. Furthermore, not only is there a need for good fixability to the transfer target material, such as fabric, but when the transfer target material is a T-shirt, good wash fastness is also required.

[0011] Therefore, an object of the present invention is to provide a toner that has excellent fixability to a transfer medium, has good washing fastness to the transfer medium on which an image is formed, and can provide good color image reproducibility even when the transfer medium is a dark color. [Means for solving the problem]

[0012] In order to solve the above problems, the toner of the present invention is a toner used in an electrophotographic image forming apparatus and also used to form a thermal transfer print sheet, the thermal transfer print sheet being a transfer sheet on which an image is formed using the toner, and being used to transfer the image to a transfer target by thermal transfer, the toner having a transmittance of less than 5% for all visible light wavelengths when forming a solid image with an adhesion thickness of 30 μm on an OHP substrate, and comprising polyester, polyurethane elastomer, wax, and a white pigment or a black pigment. [Effects of the Invention]

[0013] According to the present invention, a toner can be provided which has excellent fixing properties to a transfer medium, has good washing fastness to the transfer medium on which an image is formed, and can provide good color image reproducibility even when the transfer medium is a dark color. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus. [Figure 2] FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus. [Figure 3] FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus. [Figure 4] FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus. [Figure 5] FIG. 2 is a schematic view illustrating an example of a process cartridge. [Figure 6] FIG. 10 is a diagram illustrating an example of an evaluation image. DETAILED DESCRIPTION OF THE INVENTION

[0015] The toner, toner set, image forming method, image forming apparatus, and process cartridge according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and other modifications, additions, corrections, deletions, and other changes can be made within the scope of what a person skilled in the art can conceive. Any embodiment is within the scope of the present invention as long as it achieves the functions and effects of the present invention.

[0016] (Toner and toner set) The toner of the present invention is a toner used in an electrophotographic image forming apparatus and also used to form a thermal transfer print sheet, the thermal transfer print sheet being a transfer sheet on which an image is formed using the toner, and being used to transfer the image to a transfer target by thermal transfer, the toner having a transmittance of less than 5% for all visible light wavelengths when forming a solid image with a deposition thickness of 30 μm on an OHP substrate, and containing polyester, polyurethane elastomer, wax, and a white pigment or a black pigment.

[0017] The toner set of the present invention is used in an electrophotographic image forming apparatus and includes a plurality of toners used to form a thermal transfer print sheet, the thermal transfer print sheet being a transfer sheet on which an image is formed using the toners, and is used to transfer the image to a transfer target by thermal transfer, and all of the toners included in the toner set have a transmittance of less than 1% for all visible light wavelengths when a solid image having an adhesion thickness of 30 μm is formed on the transfer sheet, and the toner set is characterized by including at least the following toner (A), toner (B), and toner (C): (A) A toner containing a white pigment, a polyester, a polyurethane elastomer, and a wax. (B) A toner containing a black pigment, a polyester, a polyurethane elastomer, and a wax. (C) A toner containing a white pigment, a colorant other than the white pigment and the black pigment, a polyester, a polyurethane elastomer, and a wax.

[0018] According to the present invention, the fixing property to the transfer medium is excellent, the transfer medium on which the image is formed has good washing fastness, and the color image can be reproduced well even if the transfer medium is a dark color. Furthermore, the present invention can reduce the cost of producing the thermal transfer print sheet.

[0019] The toner of the present invention is a toner used in an electrophotographic image forming apparatus and also used to form a thermal transfer print sheet, and may be referred to as a toner for a thermal transfer print sheet, etc. The toner set of the present invention is a toner set used in an electrophotographic image forming apparatus and also used to form a thermal transfer print sheet, and may be referred to as a toner set for a thermal transfer print sheet, etc.

[0020] The toner of the present invention has a transmittance of less than 5%, preferably less than 1%, across all visible wavelengths when a solid image having a thickness of 30 μm is formed on an OHP substrate. The amount of adhesion can be increased by repeatedly printing and overlapping images. In this specification, the transmittance across all visible wavelengths when a solid image having a thickness of 30 μm is formed on an OHP substrate may be referred to as the above-mentioned transmittance.

[0021] The transmittance in the present invention refers to the maximum transmittance within the visible light wavelength range (380 to 780 nm). Measurement is performed by measuring a 30 μm thick solid image formed on an OHP substrate with a spectrophotometer, for example, an ultraviolet-visible-near-infrared spectrophotometer (Shimadzu UV-3600) using a film holder under the following conditions: Wavelength range: 380nm to 780nm Scan speed: Medium Sampling pitch: 0.5nm Slit width: 5.0 nm When measuring the transmittance, whether the toner adhesion thickness was 30 μm was confirmed by three-dimensional measurement using a confocal microscope OPTELICS H1200 (manufactured by Lasertec Corporation).

[0022] To achieve a transmittance of less than 5%, the toner must contain a white pigment that totally reflects or scatters visible light, or a black pigment that totally absorbs wavelengths in the visible light region. The transmittance can also be adjusted by changing the type and content of the white or black pigment. The above transmittance is a physical property that allows the toner color to be expressed without being affected by the color of the transfer medium when an image to be transferred is transferred onto a dark-colored transfer medium to form an image. In the present invention, this is a parameter used to distinguish this toner from ordinary color toners. Ordinary color toners do not have a transmittance of less than 5% in some wavelength ranges, even when the thickness is increased. By using a toner with the above transmittance of less than 5%, it is possible to form a color image that is not affected by the transfer medium.

[0023] <White pigment> In one embodiment of the toner of the present invention, the toner contains a white pigment, a polyester, a polyurethane elastomer, and a wax. Such a toner may be referred to as toner (A). Toner (A) corresponds to the toner (A) included in the toner set of the present invention.

[0024] The white pigment used in the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, titanium dioxide, white lead, talc, kaolin, zinc sulfide, barium sulfate, calcium carbonate, zinc oxide, hollow silica, etc. can be used. Furthermore, the surface of the white pigment can be treated with silicon, zirconia, aluminum, an organic substance such as polyol, etc. Preferably, titanium dioxide is surface-treated with aluminum and an organic substance such as polyol. It is presumed that the surface treatment allows the release agent in the toner to wet the white pigment, thereby reducing the hardness of the toner layer and resulting in a white concealing layer that is less susceptible to cracking.

[0025] The optimum content of the white pigment in the toner varies depending on the type of pigment, but is preferably 20% by mass to 50% by mass, and more preferably 30% by mass to 40% by mass. By making the content of the white pigment equal to or greater than the lower limit, a decrease in hiding power can be prevented, and the design on the transfer object can be prevented from showing through, thereby reducing the saturation and brightness of the image. Furthermore, by making the content of the white pigment equal to or less than the upper limit, flexibility can be ensured, and cracking of the toner layer can be prevented even on a flexible transfer object.

[0026] <Black pigment> In one embodiment of the toner of the present invention, the toner contains a black pigment, a polyester, a polyurethane elastomer, and a wax. Such a toner may be referred to as toner (B). Toner (B) corresponds to the toner (B) included in the toner set of the present invention.

[0027] The black pigment used in the present invention is not particularly limited and can be appropriately selected depending on the purpose. 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, is preferred.

[0028] The content of the black pigment in the toner can be selected as appropriate. For example, when carbon black is used, it is preferably contained in the toner in an amount of 6% by mass or more and 10% by mass or less. By making the content of the black pigment equal to or greater than the lower limit, it is possible to prevent a decrease in hiding power and prevent the design of the transfer object from showing through, while by making the content of the black pigment equal to or less than the upper limit, it is possible to prevent a decrease in the volume resistivity of the toner and stabilize the charging characteristics.

[0029] <Coloring agent> In one embodiment of the toner of the present invention, the toner contains a white pigment or a black pigment, a polyester, a polyurethane elastomer, and a wax, and further contains a colorant other than the white pigment and the black pigment. Such a toner may be referred to as toner (C), etc. Toner (C) corresponds to the toner (C) contained in the toner set of the present invention. Hereinafter, unless otherwise specified, the term "colorant" refers to a colorant excluding the white pigment and the black pigment. There are no particular limitations on the colorant contained in the toner, and a commonly used colorant can be appropriately selected and used. The inclusion of a colorant broadens the range of colors that can be expressed.

[0030] The toner (C) contained in the toner set of the present invention contains a white pigment or a black pigment, a colorant other than the white pigment and the black pigment, a polyester, a polyurethane elastomer, and a wax. The toner (C) may contain either a white pigment or a black pigment, and preferably contains both a white pigment and a black pigment. When the toner contains both a white pigment and a black pigment, the range of colors that can be expressed is expanded.

[0031] As the colorant, those having small absorption at wavelengths of 800 nm or more are preferred, and examples thereof include naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, isoindolinone yellow, red iron oxide, red lead, Cinnabar, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Faise Red, Parachlor Orthonitroaniline Red, Lithol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belcan Fast Rubin B, Brilliant Scarlet G, Lithol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Rhodamine 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake Metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo, dioxane violet, anthraquinone violet, chrome green, zinc green, pyridian, emerald green, pigment green B, naphthol green B, green gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithopone, perylene black, perinone black, and mixtures thereof.These may be used alone or in combination of two or more.

[0032] The content of the colorant in the toner is preferably, for example, 1% by mass or more and 12% by mass or less, which allows color expression that makes use of the absorption wavelength specific to the colorant.

[0033] When the toner of the present invention contains a white pigment and a colorant, its low transmittance (the transmittance is less than 5%) makes it difficult to achieve full-color reproduction using a subtractive color method, as is the case with conventional electrophotographic color toners. Therefore, it is preferable to express a specific color by pre-mixing and incorporating colorants into the toner according to the purpose, design, etc. While the toner of the present invention does not exclude the method of expressing colors by overlapping toner layers, it is preferable to pre-mix the colorants and incorporate them into the toner, forming each toner layer as a single layer. In other words, it is preferable that the toner image on the thermal transfer print sheet is a single-layer toner image that does not overlap with other toner images. By forming a single toner layer, not only can the process be simplified but costs can also be reduced.

[0034] <Polyester> The polyester (which may also be referred to as polyester resin) used in the toner is preferably obtained by condensation polymerization of an alcohol and a carboxylic acid. The alcohol used is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof 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.

[0035] The carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof 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.

[0036] The polyester content in the toner is preferably 20% by mass or more and 60% by mass or less. When it is 20% by mass or more, it is possible to prevent a decrease in grindability and a decrease in charging characteristics, thereby improving the stability of the toner. When it is 60% by mass or less, it is possible to ensure flexibility on the transfer medium, and to prevent cracking of the toner layer formed on the flexible transfer medium.

[0037] The softening temperature and glass transition temperature of the polyester are both preferably 55° C. or higher. When the softening temperature and glass transition temperature are 55° C. or higher, the heat-resistant storage stability of the toner image can be ensured.

[0038] <Polyurethane elastomer> The polyurethane elastomer used in the toner is a binder resin suitable for the present invention because it generally has excellent tensile strength, abrasion resistance, elasticity, and oil resistance.

[0039] In terms of polyurethane composition, it is preferable to use a polyurethane elastomer composed of 1,4-butanediol (1,6-hexanediol), adipic acid, diphenylmethane diisocyanate, and the like. Furthermore, the specific trade name of the polyurethane elastomer used is not particularly limited and can be appropriately selected depending on the purpose. Examples include hot melt powder ECOFREEN POWDER (manufactured by ECOFREEN), T8175N, T5102S (manufactured by DIC Covestro Polymers), E780M128, P22MBRNAT, E360MSXW (manufactured by Nippon Miractoran), and 571F (manufactured by BASF).

[0040] The softening temperature and glass transition temperature of the polyurethane elastomer are both preferably 45°C or lower, and more preferably 20°C or lower. The glass transition temperature of the polyurethane elastomer is more preferably -60°C or higher and 0°C or lower, and even more preferably -50°C or higher and -10°C or lower. If the softening temperature and glass transition temperature of the polyurethane elastomer are within these ranges, the flexibility of the toner layer after fixing can be ensured.

[0041] The softening point of the polyurethane elastomer is preferably 90°C or higher and 130°C or lower, and more preferably 100°C or higher and 120°C or lower. When the softening point of the polyurethane elastomer is within this range, offset during fixing and thermal transfer can be prevented and durability can be maintained. The softening temperature and the softening point are different, and the methods for measuring them will be described later.

[0042] When a polyester and a polyurethane elastomer are used in combination, an incompatible sea-island structure can be formed. The polyurethane elastomer is used in combination with a polyester. The toner of the present invention contains a polyurethane elastomer and a polyester. The domains of the sea-island structure in the cross section of the toner contain a polyurethane elastomer, and the matrix contains a polyester resin, and it is preferred that the domains and the matrix in the cross section of the toner are incompatible.

[0043] The weight-average molecular weight of the polyurethane elastomer is preferably 20,000 to 100,000, more preferably 20,000 to 80,000, and even more preferably 20,000 to 60,000. If the weight-average molecular weight is 20,000 or more, there is no risk of the fixed image melting when ironed, and if the weight-average molecular weight is 100,000 or less, other toner components and adhesives can be easily melted and kneaded when forming the toner.

[0044] The content of polyurethane elastomer is not particularly limited and can be appropriately selected depending on the purpose. It is preferably 40% by mass to 70% by mass, and more preferably 50% by mass to 60% by mass in the toner. When it is 40% by mass or more, the toner can be sufficiently fixed to flexible media such as cloth, and the toner layer can be flexible after fixing. When it is 70% by mass or less, the thermal storage stability of the toner is not deteriorated, and there is no risk of aggregation of toner particles. Furthermore, if the toner for thermal transfer print sheets does not contain polyurethane elastomer, cracking occurs, making it impossible to maintain the image.

[0045] In addition, all or part of the polyurethane elastomer can be substituted with any of polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, polybutylene isophthalate, and styrene butadiene rubber, which have the same properties as the polyurethane elastomer.

[0046] <Wax (mold release agent)> The wax (mold release agent) is not particularly limited and can be appropriately selected depending on the purpose. One type may be used alone, or two or more types may be used in combination.

[0047] The release agent that can be used in the present invention is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, polyolefin wax, and their partial oxides, or 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. Of these, it is preferable to contain at least an ester wax such as a fatty acid ester.

[0048] The toner of the present invention preferably contains a wax dispersant. The dispersant is preferably a copolymer composition containing at least styrene, butyl acrylate, and acrylonitrile as monomers, or a polyethylene adduct of the copolymer composition. The content of the wax dispersant is preferably 7 parts by mass or less per 100 parts by mass of the toner.

[0049] The wax content in the toner is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 0.1% by mass to 8.0% by mass, and more preferably 1.0% by mass to 6.0% by mass. If the content is 0.1% by mass or more, the toner and the fixing roller (or fixing belt) separate during fixing, preventing waste paper jams. Also, if the content is 8.0% by mass or less, the toner can be sufficiently fixed to the plastic film.

[0050] <Charge control agent> The toner may contain a charge control agent. The charge control agent can be selected appropriately depending on the purpose as long as it is white or colorless. Examples include onium salts such as 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. These can be used alone or in combination of two or more.

[0051] When the charge control agent is added internally to the toner, the content is not particularly limited and can be set appropriately depending on the purpose, but it is preferable to add 0.1 to 10% by mass based on the total amount of the binder resin.

[0052] <External additives> The toner of the present invention may contain inorganic fine particles as an external additive. The inorganic fine particles to be externally added in the present invention are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof 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, silicon nitride, etc. Among these, silica, alumina, and titanium oxide are preferred.

[0053] In addition, inorganic fine particles may be used that are surface-treated with hydrophobic treatment agent.Hydrophobic treatment agent is not particularly limited, and can be appropriately selected according to purpose, for example, silane coupling agent, silylating agent, silane coupling agent with fluorinated alkyl group, organic titanate coupling agent, aluminum coupling agent, etc. can be listed as preferred surface treatment agent.In addition, silicone oil can also be used as hydrophobic treatment agent, and sufficient effect can be obtained.

[0054] The average particle size of the primary particles of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 to 500 nm, more preferably 5 to 200 nm. If it is 5 nm or more, aggregation of the inorganic fine particles is suppressed, and the inorganic fine particles can be uniformly dispersed in the toner. If it is 500 nm or less, the heat-resistant storage stability can be improved due to the filler effect. The average particle size here refers to a value obtained by directly determining the particle size from photographs obtained by a transmission electron microscope, and it is preferable to observe at least 100 particles and use the average value of the major axes.

[0055] <Flow improver> The toner may contain a flowability improver as an additive. The flowability improver is not particularly limited and can be appropriately selected depending on the purpose as long as it is capable of performing a surface treatment to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity conditions. Examples include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. It is preferable that the silica and titanium oxide used as the external additives are surface-treated with such a flowability improver and used as hydrophobic silica and hydrophobic titanium oxide.

[0056] <Cleaning improver> The toner may contain a cleaning property improver as an additive. The cleaning property improver is not particularly limited as long as it can be added to the toner according to an embodiment of the present invention to remove developer remaining on the photoreceptor or primary transfer medium after transfer, and can be appropriately selected depending on the purpose. Examples of the cleaning property improver include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, and polymer particles produced by soap-free emulsion polymerization, such as polymethyl methacrylate particles and polystyrene particles. The polymer particles preferably have a relatively narrow particle size distribution, and preferably have a volume average particle size of 0.01 μm or more and 1 μm or less.

[0057] <Measurement> <<Measuring method for particle size and particle size distribution based on volume percentage of toner>> The particle size distribution and particle size of the toner based on volume percentage can be measured, for example, using a particle size analyzer (Multisizer III, manufactured by Beckman Coulter) with an aperture diameter of 100 μm, and analysis can be performed using analysis software (Beckman Coulter Multisizer 3 Version 3.51). An example is shown below.

[0058] 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a 100 ml glass beaker, 0.5 g of each toner was added, and the mixture was stirred with a microspatula. 80 ml of ion-exchanged water was then added to obtain a dispersion. The resulting dispersion was dispersed for 10 minutes using an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.) to obtain a toner sample dispersion. The toner sample dispersion was measured using the Multisizer III and an Isoton III (manufactured by Beckman Coulter) as the measurement solution. To ensure measurement reproducibility, the toner sample dispersion was added dropwise so that there was no error in particle size and the concentration indicated by the instrument was 8±2%, and the volume average particle size of the toner was measured.

[0059] <<Toner particle size distribution and volume average particle size>> The toner has no particular limitation in terms of the particle size distribution based on volume percentage and can be appropriately selected according to the purpose. There is also no particular limitation on the volume average particle size of the toner, which can be appropriately selected according to the purpose, but it is preferably 10 to 25 μm, more preferably 12 to 20 μm.

[0060] For a toner as described above, by increasing the toner particle size, the developing ability can be improved, the toner development amount in one development can be increased, the pile height of the toner layer can be increased, and it can be easier to fill the irregularities on the surface of a flexible medium such as cloth. Also, considering the balance with the trade-off transferability, as the toner, those having a particle size distribution with a peak in the range of 10 to 25 μm in terms of the particle size distribution based on volume percentage are more preferable. For the same reason, those with a volume average particle size of the toner being 12 to 20 μm are more preferable. Also, it is preferable that the toner with a particle size of 5 μm or less is 10% by number or less.

[0061] <<Confirmation and Quantification of the Presence of Resin in Toner>> Regarding the resin contained in the toner of the present invention, the presence can be confirmed and quantified preferably by a gas chromatograph mass spectrometer (GC-MS) or NMR (Nuclear Magnetic Resonance). Specifically, it can be carried out according to the following procedures, apparatus, and conditions.

[0062] <<Component Analysis by GC-MS>> - Sample Preparation - Disperse the toner in chloroform and stir it for a whole day and night to obtain a dispersion. Subsequently, centrifuge this dispersion and collect only the supernatant. The collected supernatant dried by evaporation is subjected to composition analysis by a gas chromatograph mass spectrometer (GC-MS). An example of the measurement conditions by GC-MS is shown below. Note that a mixture obtained by dropping about 1 μL of a methylating agent (tetramethylammonium hydroxide 20% methanol solution: TMAH) into a sample of about 1 mg is used as the sample. Sample.

[0063] - Measurement Conditions - · Thermogravimetric analysis - Gas chromatography mass spectrometry (Py-GCMS) analyzer: QP2010 (manufactured by Shimadzu Corporation) · Heating furnace: Py2020D (manufactured by Frontier Lab Co., Ltd.) · Heating temperature: 320 °C · Column: Ultra ALLOY-5 (L = 30 m, I.D = 0.25 mm, Film = 0.25 μm, manufactured by GL Sciences Inc.) · Column temperature: 50 °C (holding time: 1 minute) ~ temperature increase (10 °C / min) ~ 340 °C (holding time: 7 minutes) · Split ratio: 1:100 · Column flow rate: 1.0 ml / min · Ionization method: EI method (70 eV) · Measurement mode: Scan mode · Data for search: NIST 20 MASS SPECTRAL LIB.

[0064] <<Component analysis by NMR>> - Preparation of sample - Disperse the toner in chloroform and stir it for one day and night to obtain a dispersion. Subsequently, centrifuge this dispersion and collect only the supernatant. The evaporated and dried product of the collected supernatant is used as a sample for 1H-NMR and 13C-NMR, and the composition is analyzed by NMR. An example of the preparation method of the sample for 1H-NMR, the preparation method of the sample for 13C-NMR, and the measurement conditions are shown below.

[0065] (1) Preparation method of sample for 1H-NMR Add 1 mL of d8-toluene (manufactured by FUJIFILM Wako Pure Chemical Corporation) to 100 mg of the sample, warm it with a dryer to dissolve it, and prepare a sample for 1H-NMR. (2) Preparation method of sample for 13C-NMR Add 1 mL of deuterated 1,2-dichlorotoluene (manufactured by FUJIFILM Wako Pure Chemical Corporation) to 100 mg of the sample, warm it with a dryer to dissolve it, and prepare a sample for 13C-NMR.

[0066] - Measurement conditions - NMR device: ECX-500 (manufactured by JEOL Ltd.) Measurement nucleus = 1H (500MHz), Measurement pulse file = single pulse dec.jxp (1H), 45℃ pulse, 20,000 accumulations, Relaxation Delay - 4 seconds, Data points 32K, Offset 100ppm, Observation width = 250ppm, Measurement temperature 70℃ Measurement nucleus = 13C (125MHz), measurement pulse file = single pulsedec.jxp (13C), 45℃ pulse, 64 integrations, Relaxation Delay 5 seconds, 32K data points, observation width = 15ppm, measurement temperature 65℃

[0067] <<Weight average molecular weight measurement>> The weight average molecular weight of the resin used in the toner can be obtained by measuring the molecular weight distribution of the THF (tetrahydrofuran) soluble portion using a gel permeation chromatography (GPC) measuring device. The GPC measuring device is not particularly limited and can be appropriately selected depending on the purpose. For example, a product name such as GPC-150C (manufactured by Waters Corporation) can be used.

[0068] The column used for measuring the weight-average molecular weight is not particularly limited and can be appropriately selected depending on the purpose. Examples of the column include, by trade name, KF801 (organic solvent SEC (GPC) column), KF802 (organic solvent SEC (GPC) column), KF803 (organic solvent SEC (GPC) column), KF804 (organic solvent SEC (GPC) column), KF805 (organic solvent SEC (GPC) column), KF806 (organic solvent SEC (GPC) column), and KF807 (organic solvent SEC (GPC) column) (all manufactured by Showa Denko K.K.).

[0069] The method for measuring the weight average molecular weight of the resin used in the toner is not particularly limited and can be appropriately selected depending on the purpose. For example, the method can be as follows. The column is stabilized in a heat chamber at 40°C, and THF is passed through the column at a flow rate of 1 mL / min. Next, 0.05 g of sample is thoroughly dissolved in 5 g of THF and filtered through a pretreatment filter (e.g., Chromatodisc, 0.45 μm pore size, manufactured by Kurabo Industries, Ltd.) to adjust the final sample concentration to 0.05% to 0.6% by mass. After the sample concentration is adjusted, 50 μL to 200 μL of the THF sample solution is injected into the column. The THF-soluble fraction contained in the THF sample solution is separated, and the weight-average molecular weight (Mw) of the THF-soluble fraction in the THF sample solution is measured by converting the data into molecular weight using a detector (e.g., a differential refractive index (RI) detector (GPC-150C, manufactured by Waters Corporation)).

[0070] The weight-average molecular weight Mw and number-average molecular weight Mn of the THF-soluble fraction contained in the sample are measured by calculating the molecular weight distribution of the sample from the relationship between the logarithm of the calibration curve prepared using several monodisperse polystyrene standard samples and the count number. The standard polystyrene sample for preparing the calibration curve is, for example, a polystyrene having a molecular weight of 6 × 10 manufactured by Pressure Chemical Co. or Toyo Soda Kogyo Co., Ltd. 2 , 2.1×10 2 , 4×10 2 , 1.75×10 4 , 5.1×10 4 , 1.1×10 5 , 3.9 × 10 5 , 8.6×10 5 , 2 × 10 6 , and 4.48 × 10 6 It is preferable to use at least about 10 standard polystyrene samples. It is also preferable to use an RI (refractive index) detector as the detector.

[0071] <<Method for measuring softening temperature>> The softening temperature can be measured using a flow tester (Shimadzu Corporation, CFT-500D). Specifically, a 1.0 g sample is heated at a temperature increase rate of 6°C / min, while a load of 1.96 MPa is applied by the plunger, and the sample is extruded through a nozzle 1.0 mm in diameter and 1.0 mm in length. The plunger depression of the flow tester is plotted against the temperature to obtain an S-shaped curve of temperature (°C) / stroke (mm). The temperature at which the sample first begins to deform (i.e., the temperature at which the sample begins to deform as it changes from a solid state to a rubbery state) can be determined as the softening temperature.

[0072] <<Softening point measurement method>> The softening point can be measured using a flow tester (Shimadzu Corporation, CFT-500D). Specifically, 1.0 g of sample is heated at a temperature increase rate of 6°C / min, while a load of 1.96 MPa is applied by the plunger, and the sample is extruded through a nozzle with a diameter of 1.0 mm and a length of 1.0 mm. The plunger depression of the flow tester is plotted against the temperature to obtain an S-shaped curve of temperature (°C) / stroke (mm). Tm is read from the obtained S-shaped curve. Specifically, the maximum stroke value in the S-shaped curve is defined as S1, and the stroke value of the baseline on the low-temperature side is defined as S2. The temperature at which the stroke value in the S-shaped curve becomes (S1 + S2) / 2 is defined as the softening point Tm of the measurement sample.

[0073] <<Method for measuring glass transition temperature>> The glass transition temperature (Tg) can be measured using, for example, a differential scanning calorimeter (DSC210, manufactured by Seiko Instruments Inc.). Specifically, using the differential scanning calorimeter, 0.01 to 0.02 g of a sample is weighed into an aluminum pan at room temperature and cooled to -20°C at a rate of 10°C / min. The sample is then heated to 200°C at a rate of 10°C / min, and Tg can be determined as the temperature at the intersection of an extension of the baseline and a tangent line showing the maximum slope from the rising part of the peak to the peak.

[0074] <Toner manufacturing method> The method for producing the toner of the present invention is not particularly limited and can be appropriately selected depending on the purpose. An example of the method for producing the toner of the present invention will be described below.

[0075] The melt-kneading pulverization method is preferred as the method for producing the toner of the present invention. This is because the white pigment has a higher specific gravity than other toner constituent materials, making it difficult to granulate it using chemical methods such as the dissolution suspension method, and because forming domains requires a step of cooling and rolling the molten mixture of toner components. In contrast, chemical methods such as the dissolution suspension method can internally disperse the white pigment, and can be used in the present invention as long as they employ toner material construction and processes that can form domains.

[0076] The shape and size of the domains are determined by the compatibility between the domain material and the matrix material (determined by the molecular weight and composition of each material) and the stretching force applied when the molten mixture is cooled and rolled. Therefore, the easiest method for controlling the domain diameter and shape is to use incompatible materials, determine in advance the relationship between the domain size and shape and the rolled thickness, and then thin the thickness of the molten mixture of toner materials to an appropriate thickness, preferably 1 mm or less. By thinning the thickness in this way, domains of the appropriate size can be obtained.

[0077] In one embodiment, the toner manufacturing method of the present invention includes, for example, a mixing step, a melting and kneading step, a solidification step, a pulverization step, and a classification step. The mixing step is a step of obtaining a binder resin mixture. The melting and kneading step is a step of obtaining a kneaded product of the mixture. The solidification step is a step of obtaining a solid product of the kneaded product. The pulverization step is a step of obtaining a pulverized product of the solid product. The classification step is a step of classifying and recovering the pulverized product.

[0078] -Process for obtaining a binder resin mixture (mixing process)- First, a binder resin, a colorant, a release agent, and, if necessary, a charge control agent, etc. are mixed in a mixer to obtain a mixture (mixing step). The mixer is not particularly limited and can be appropriately selected depending on the purpose. Examples include a Henschel mixer (product name: FM20B, manufactured by Nippon Coke and Engineering Co., Ltd.) and a Super Mixer (SMV-20Ba, manufactured by Kawata Corporation).

[0079] -Process for obtaining a kneaded mixture (melt-kneading process)- Next, the resulting mixture is melt-kneaded using a thermal melt kneader to obtain a kneaded product (melt-kneading step). The hot melt kneader is not particularly limited and can be appropriately selected depending on the purpose. Examples of the kneader include, by trade name, twin-screw extruder PCM series (manufactured by Ikegai Corporation), TEM-type extruder (manufactured by Shibaura Machine Co., Ltd.), twin-screw extruder PCM Co-Kneader (manufactured by Buss Co., Ltd.), and open-roll type continuous kneader Kneadex (manufactured by Nippon Coke and Engineering Co., Ltd.).

[0080] -Process for obtaining a solidified product from the kneaded material (solidification process)- Next, the obtained kneaded product is cooled and solidified to obtain a solid product (solidification step). The cooling method and the solidification method are not particularly limited and can be appropriately selected depending on the purpose. For example, any appropriate method can be used. However, in order to efficiently pulverize the material in the subsequent pulverization step, it is preferable to reduce the material to a certain particle size in the solidification step.

[0081] A suitable method is to pelletize the kneaded product in a solidification step after the kneading step. The pelletizing process can be performed by a strand cutting method, a water-cooled hot cutting method, an underwater cutting method, etc. For example, in the strand cutting method, the kneaded molten material immediately after the kneading process is extruded through a die with a diameter of about 3 mm to form a strand, which is then cooled in a cooling device such as a water bath, and after cooling, is cut into pellets by a pelletizer.

[0082] The particle size of the pellets can be adjusted by adjusting the feed rate of the melt kneader and the feed rate of the pelletizer to adjust the strand thickness, and by adjusting the cutting width, it is possible to process the material into pellets of an appropriate particle size.

[0083] The pellet size is preferably 0.5 mm to 3 mm in diameter, more preferably 1 mm to 2 mm in diameter. The smaller the particles, even when coarsely pulverized before the pulverization process, the more efficient the pulverization. However, the smaller the strand diameter, the more likely the strand is to break during the process, making it difficult to maintain process stability. Therefore, processing with a diameter of 1 mm or more is preferred.

[0084] -Process for obtaining pulverized solid material (fine pulverization process)- Next, the obtained solid matter is finely pulverized to obtain a pulverized matter (fine pulverization step). The solid matter can be pulverized using a known pulverization method, such as a jet mill method in which toner is contained in a high-speed airflow and the solid matter is pulverized by the energy generated when the toner collides with a collision plate; an inter-particle collision method in which toner particles collide with each other in an airflow; or a mechanical pulverization method in which toner is supplied between a narrow gap and a rotor rotating at high speed to pulverize the toner.

[0085] It is preferred to use a cryogenic grinding method to grind the toner of the present invention. Some materials have the property of becoming brittle suddenly when they fall below a certain temperature, a property known as "low-temperature brittleness." By utilizing this property, it is possible to crush materials such as rubber and plastics, which are difficult to crush at room temperature. Low-temperature crushing, which uses the extremely low temperature of liquid nitrogen at -196°C, is also called cryogenic crushing or freeze crushing.

[0086] The freeze-pulverization method significantly improves pulverizability and stabilizes the shape of the pulverized particles, making it possible to obtain finely pulverized material more suitable for toner. In this freeze-pulverization method, it is preferable to use the mechanical pulverization method described above, in which the toner is supplied between a rotor rotating at high speed and a narrow gap to be pulverized. Specifically, the coarsely pulverized kneaded material is placed in a cooler, cooled with liquid nitrogen, processed in a pulverizer, and sieved to obtain particles with a target particle size or smaller. The coarse particles remaining on the sieve after sieving are returned to the cooler and pulverized again.

[0087] A cooling device such as a chiller can be used as the cooling means. The product temperature of the coarse particles to be finely pulverized is the glass transition point (Tg) of the coarse particles minus 5°C or less, more preferably the glass transition point (Tg) of the coarse particles minus 20°C or less.

[0088] -The process of classifying and recovering the crushed material (classification process)- The pulverized material is then classified to recover pulverized material having a predetermined volume average particle size, thereby obtaining a toner (classification step). There are no particular limitations on the classification method, and an airflow method, a rotary rotor method, or the like can be appropriately selected depending on the purpose. Examples of airflow classifiers include an elbow jet classifier (manufactured by Matsubo Corporation), and examples of rotary rotor classifiers include a TSP separator and a TTSP separator (manufactured by Hosokawa Micron Corporation).

[0089] The toner according to one embodiment of the present invention can also be produced using a solution suspension method. When producing the toner using the solution suspension method, an oil phase in which toner materials such as a binder resin, a colorant, a release agent, and, if necessary, a charge control agent are dissolved or dispersed in an organic solvent is dispersed in an aqueous medium (aqueous phase), and the binder resin is reacted. This produces a dispersion containing a dispersion (oil droplets) containing a prepolymer in which the toner materials are emulsified or dispersed. The organic solvent is then removed from the dispersion, and the resulting mixture is filtered, washed, and dried. Further, classification, etc., is performed as necessary to produce toner base particles. The toner according to one embodiment of the present invention can be obtained by granulating the base particles obtained using the solution suspension method.

[0090] The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, but an organic solvent having a boiling point of less than 150° C. is preferred in terms of ease of removal. The organic solvent having a boiling point of less than 150°C is not particularly limited and can be appropriately selected depending on the purpose. Examples include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, and methyl isobutyl ketone. These may be used alone or in combination of two or more. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferred, and ethyl acetate is more preferred.

[0091] The aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. Examples include water, a solvent miscible with water, and a mixture thereof. These may be used alone or in combination of two or more. Among these, water is preferred.

[0092] The water-miscible solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include alcohols, lower ketones, dimethylformamide, tetrahydrofuran, and cellosolves.

[0093] The alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples include methanol, isopropanol, and ethylene glycol. The lower ketones are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include acetone and methyl ethyl ketone.

[0094] The method for removing the organic solvent from the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method in which the temperature of the entire reaction system is gradually increased to evaporate the organic solvent in the oil droplets, and a method in which the dispersion is sprayed into a dry atmosphere to remove the organic solvent in the oil droplets.

[0095] The classification in the dissolution suspension method may be carried out by removing fine particles in the liquid using a cyclone, decanter, centrifugal separation or the like, or the classification operation may be carried out after drying. In this manner, the toner base of the toner of the present invention is prepared.

[0096] -Process of mixing external additives and sieving aggregates (mixing / sieving process)- To adjust the powder characteristics and charging characteristics required for the toner, fine particles (external additives) such as silica dioxide and titanium oxide are mixed with the obtained toner base, and any aggregates that may occur during mixing are sieved off and removed. As the external additive mixer, an agitator mixer is preferably used, and examples thereof include a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), a Super Mixer (manufactured by Kawata Co., Ltd.), and a TSK mixer (manufactured by Tsukishima Kikai Co., Ltd.).

[0097] (developer) The toner of the present invention can be mixed with a carrier or the like and used as a developer. In other words, the developer contains the toner according to one embodiment of the present invention and may contain other components, such as a carrier, that are appropriately selected as necessary. By using this developer, a base layer with excellent fixability can be formed on the surface of fabric.

[0098] The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer or the like that corresponds to the recent improvement in information processing speed, a two-component developer is preferable from the viewpoint of improving the developer life.

[0099] When the toner according to one embodiment of the present invention is used as a one-component developer, even if the toner is balanced, there is little fluctuation in the particle size of the toner, there is little toner filming on the developing roller, and there is little toner fusion to components such as blades that thin the toner layer, and good and stable developability and images can be obtained even with long-term stirring in the developing device.

[0100] The toner according to one embodiment of the present invention can be mixed with a carrier to form a two-component developer, which can be used in a two-component development electrophotographic image forming method. When the toner according to one embodiment of the present invention is used as a two-component developer, even if the toner is balanced over a long period of time, there is little fluctuation in the particle size of the toner, and good and stable developability and images can be obtained even with long-term stirring in a developing device.

[0101] The development method may be a premix development method, in which a premix developer in which toner and carrier are mixed in advance is replenished. In the premix development method, the excess carrier in the developing device is discharged as excess developer. This gradually refreshes the developer in the developing device. This can extend the replacement cycle due to developer deterioration and eliminate the effort required for developer replacement.

[0102] <Magnetic materials> When using a two-component development method, the magnetic fine particles used in the magnetic carrier are not particularly limited and can be selected appropriately depending on the purpose. Examples include spinel ferrites such as iron powder, magnetite, and 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, and iron or alloy particles having an oxide layer on their surface. Among these, white particles are preferred in terms of color tone. The shape of the magnetic fine particles may be granular, spherical, or acicular. In particular, when high magnetization is required for the magnetic carrier, it is preferable to use ferromagnetic fine particles such as iron.

[0103] In addition, in consideration of chemical stability, it is preferable to use magnetite, spinel ferrite containing gamma iron oxide, or magnetoplumbite ferrite such as barium ferrite, etc. Specifically, MFL-35S, MFL-35HS (manufactured by Powder Tech Co., Ltd.), DFC-400M, DFC-410M, SM-350NV (manufactured by Dowa Iron Powder Co., Ltd.), etc.

[0104] By selecting the type and content of ferromagnetic fine particles (carriers), a resin carrier having the desired magnetization can be used. For example, the magnetic properties of the resin carrier preferably have a magnetization strength of 30 to 150 emu / g at 1,000 oersteds. Such a resin carrier can be produced by spraying a melt-kneaded mixture of magnetic fine particles and an insulating binder resin using a spray dryer, or by reacting and curing a monomer or prepolymer in an aqueous medium in the presence of magnetic fine particles, thereby producing a resin carrier in which magnetic fine particles (carriers) are dispersed in a condensation binder.

[0105] The chargeability can be controlled by adhering positively or negatively chargeable particles or conductive particles to the surface of the magnetic carrier, or by coating the surface with a resin. Examples of surface coating materials (resins) that can be used include silicone resins, acrylic resins, epoxy resins, and fluorine-based resins, and the coating can further include positively or negatively charged particles or conductive particles, but among these, silicone resins and acrylic resins are preferred.

[0106] In the present invention, the mass ratio of the carrier in the developer contained in the developing device is preferably 85% by mass or more and less than 98% by mass. When the mass ratio of the carrier in the developer is 85% by mass or more, toner scattering from the developing device is less likely to occur, and the occurrence of defective images can be reduced. When the mass ratio of the carrier in the developer is less than 98% by mass, an excessive increase in the charge amount of the electrophotographic toner and an insufficient supply of the electrophotographic toner can be suppressed, thereby reducing the occurrence of defective images due to a decrease in image density.

[0107] The volume average particle diameter of the magnetic carrier is preferably 50 μm or more and 80 μm or less. In the image forming method of the present invention, it is preferable to use a toner with a larger particle diameter for development in one pass. When the volume average particle diameter of the magnetic carrier is 50 μm or more, carrier adhesion, in which the magnetic carrier is developed together with the toner, can be suppressed. When the volume average particle diameter is 80 μm or less, the surface area of ​​the magnetic carrier is prevented from becoming smaller, a sufficient amount of toner can be retained on the magnetic carrier surface, and a decrease in the development amount, toner scattering, and background smearing can be suppressed.

[0108] (Transfer sheet) The toner and toner set of the present invention are toner and toner set used to form a thermal transfer print sheet, which is formed by forming an image on a transfer sheet using a toner or toner set, and is used to transfer the image to a receiving material by thermal transfer.

[0109] The transfer sheet may also be referred to as a transfer substrate, a substrate for transfer, etc. Thermal transfer may also be referred to as a thermal transfer print, etc. The thermal transfer print sheet may also be referred to as a color image medium, etc., and the color image medium is a transfer sheet on which a color image is printed. The image formed on the transfer sheet may also be referred to as an image for transfer, etc. The image for transfer may also be referred to as a color toner layer, a toner layer adhesive to the transfer material, etc.

[0110] The transfer sheet can be appropriately selected as long as it can transfer an image when made into a thermal transfer print sheet and thermally transferred to a transfer recipient. The transfer sheet is preferably one that allows good releasability of the image to be transferred.

[0111] The transfer sheet is preferably, for example, one in which a transfer layer containing at least a thermoplastic elastomer and a higher fatty acid is formed on a substrate such as paper or a heat-resistant plastic film sheet. Forming a release layer of a thermoplastic elastomer on the top layer of the image improves the durability of the image on the transferee. Furthermore, by including a higher fatty acid, the higher fatty acid melts during thermal transfer and diffuses into the color toner layer and the transferee-adhesive toner layer that are simultaneously formed, further improving the flexibility of the layer.

[0112] The color image formed on the transfer sheet (transfer substrate) is a mirror image of the original, inverted left and right. After being thermally transferred and printed on the receiving material, it is again inverted left and right to complete the desired image. Similarly, when an additional image is superimposed on the thermal transfer print sheet, a mirror image is superimposed that is inverted left and right to the original.

[0113] A mirror image that has been flipped left and right is formed by printing mirror image information that has been flipped left and right in advance on a PC, etc. In the case of an image forming device with a scanner function, the original image may be scanned and then a flipped image may be output, or an already flipped mirror image may be scanned.

[0114] (Transferred object) The image forming method of the present invention is an image forming method that can print on a wider range of materials and shapes of transfer recipients than direct printing on a transfer recipient. The image forming method of the present invention may also be called a thermal transfer print sheet image forming method, etc. The transfer recipient may also be called a transfer material, transfer substrate, recording medium, etc.

[0115] The material to be transferred can be selected appropriately, and it is preferable that it is not a thermoplastic material that is excessively deformed by heat and pressure transfer. Examples of the material to be transferred include various materials such as paper, plastic, cloth, leather, ceramic, glass, metal, and painted surfaces such as paint.

[0116] In particular, the thermal transfer print sheet obtained by the present invention is suitable for use in the field of garment printing. Examples of garments include those made of cotton, polyester, polyurethane, nylon, rayon, silk, wool, or a mixture of these fibers. The present invention makes it possible to form high-quality, high-saturation images on flexible and stretchable transfer media while maintaining resistance to cracking and washability. Furthermore, since the transfer medium can follow the deformation of a highly flexible transfer medium such as leather, it is possible to obtain a highly durable image.

[0117] For the above reasons, fabric is preferred as the transfer target. The present invention is suitable for use with fabrics such as T-shirts, and can form images on the fabric that have good washing fastness and good image quality. The fabric is preferably made of cotton, polyester, nylon, rayon, or silk fibers, or a blend of these fibers. In this case, the above-mentioned effects can be obtained.

[0118] The toner of the present invention contains a polyurethane elastomer, which enables the formation of high-strength images and provides sufficient image durability even when forming images on coated surfaces such as metal, ceramic, glass, and paint. Furthermore, when the toner of the present invention contains a sufficient proportion of polyurethane elastomer, the effects of strength and image durability are improved. Furthermore, the present invention facilitates custom design and labeling of tableware such as mugs, cups, and plates, accessories, various tools, automobile parts, machine tool parts, furniture, signs, and the like.

[0119] (Image forming method, image forming apparatus, and process cartridge) Next, an embodiment of the image forming method, image forming apparatus, and process cartridge of the present invention will be described.

[0120] The image forming method of the present invention is an image forming method using the toner of the present invention or the toner set of the present invention, and is characterized in that it includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier of the image forming device, a developing step of developing the electrostatic latent image to form a toner image, a transfer step of transferring the toner image to the transfer sheet, and a fixing step of fixing the toner image to the transfer sheet, and that the thermal transfer print sheet is produced through the fixing step.

[0121] The image forming apparatus of the present invention is an image forming apparatus having the toner of the present invention or the toner set of the present invention, and is characterized by comprising an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image to form a toner image, transfer means for transferring the toner image to the transfer sheet, and fixing means for fixing the toner image to the transfer sheet, and producing the thermal transfer print sheet after fixing by the fixing means.

[0122] The process cartridge of the present invention is a process cartridge that contains the toner of the present invention and is detachable from the image forming apparatus, and is equipped with an electrostatic latent image carrier, an electrostatic latent image forming means that forms an electrostatic latent image on the electrostatic latent image carrier, a developing means that develops the electrostatic latent image to form a toner image, and a transfer means that transfers the toner image to the transfer sheet, and the image forming apparatus is equipped with a fixing means that fixes the toner image to the transfer sheet, and the process cartridge is attached to the image forming apparatus, and the thermal transfer print sheet is produced after being fixed by the fixing means.

[0123] The image forming method of the present invention may be called a printing method, a printing method, an image output method, an electrophotographic output method, etc. The image forming apparatus of the present invention may be called a printing apparatus, a printer, an image output apparatus, an electrophotographic output apparatus, etc. The image forming method can be suitably performed by an image forming apparatus, the electrostatic latent image forming step can be suitably performed by an electrostatic latent image forming means, the developing step can be suitably performed by a developing means, and the other steps can be suitably performed by other means.

[0124] The image forming method of the present invention may also include a thermal transfer step of thermally transferring the image on the thermal transfer print sheet to the transfer recipient, and the thermal transfer step preferably involves contacting the thermal transfer print sheet with the transfer recipient and applying heat and pressure. Applying heat and pressure can improve fixation to the transfer recipient and improve image durability.

[0125] In the image forming method of the present invention, it is preferable to form a single-layer toner image on a thermal transfer print sheet, where the toner image does not overlap with other toner images. Forming a single toner layer is expected to simplify the process and reduce costs. As mentioned above, when the toner of the present invention is a toner containing a white pigment and a colorant (the above-mentioned (C)), the toner of the present invention has low transmittance (the transmittance is less than 5%), making it difficult to achieve full-color expression using a subtractive color method, as with general electrophotographic color toners. Therefore, it is preferable to premix the colorant and incorporate it into the toner, and form each toner layer as a single layer. In this case, there is no need to overlap the toner layers, and the above-mentioned effects can be achieved.

[0126] The image forming apparatus of the present invention is, for example, an apparatus having a plurality of developing stations and is equipped with the toner or toner set of the present invention. At each developing station, it is preferable to form a toner layer having a thickness of 15 μm or more in one pass. However, if a sufficient amount of adhesion cannot be obtained, the same toner may be used at the plurality of developing stations or the number of printing passes may be increased to form an image.

[0127] The required amount of toner adhesion varies depending on the material and brightness of the transfer recipient (which may also be referred to as the transfer substrate, transfer material, etc.). If the transfer recipient is smooth, a toner layer thickness of 15 μm or more can suppress the decrease in color saturation of the color image, even when forming an image on a dark (low brightness) transfer recipient, resulting in a vivid image. Furthermore, a toner layer thickness of 30 μm or more can produce an even clearer color image. The toner layer thickness can be selected appropriately; if it is 100 μm or less, it is possible to prevent difficulty in setting fixing conditions that suppress hot offset and cold offset, making it easier to obtain stable quality. In the image formation of the present invention, there is no need to layer different toners, so the desired design can be printed without the need to layer toners to the extent that excessive adhesion occurs.

[0128] The multiple developing stations may all use different color toners, or the same color toner may be used in multiple developing stations. The combination is selected based on the purpose. When multi-color printing is the objective, using different color toners reduces the frequency of color changes and increases efficiency. When printing with two or fewer colors, a single color toner may be used in multiple developing stations, such as using a first color toner in the first and second developing stations and a second color toner in the third and fourth developing stations. This allows for a sufficient amount of toner deposition for each color to be printed with fewer print runs. Furthermore, a single color toner may be used in all developing stations, allowing for a sufficient amount of each color to be deposited in a single print run. This also eliminates the need for color toner changes, further increasing efficiency. However, due to the increased equipment costs and installation space, it is preferable to select a combination based on the intended use.

[0129] <Example of image forming apparatus and image forming method> An example of the image forming apparatus and image forming method of the present invention will be described below.

[0130] <Electrostatic latent image carrier> The electrostatic latent image carrier is not particularly limited in structure, size, etc., and can be appropriately selected from known ones. The shape of the electrostatic latent image carrier is not particularly limited, and can be appropriately selected depending on the purpose, and examples thereof include a drum shape and a belt shape. The material of the electrostatic latent image carrier is not particularly limited, and can be appropriately selected depending on the purpose, and examples thereof include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors (OPCs) such as polysilane and phthalopolymethine.

[0131] Examples of the organic photoreceptor include a laminated photoreceptor having a laminated structure in which a layer (charge generation layer) in which a charge generation material such as metal-free phthalocyanine or titanyl phthalocyanine is dispersed in a binder resin and a layer (charge transport layer) in which a charge transport material is dispersed in a binder resin are stacked on a support such as an aluminum drum, and a single-layer photoreceptor having a single-layer photosensitive layer in which both a charge generation material and a charge transport material are dispersed in a binder resin on a support. In the single-layer type photoreceptor, a hole transport material and an electron transport material can be added to the photosensitive layer as charge transport materials. An undercoat layer may be provided between the support and the multilayer charge generating layer or the single-layer photosensitive layer.

[0132] The shape of the electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but a cylindrical shape is preferred.The outer diameter of the cylindrical electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 mm to 100 mm, and particularly preferably 20 mm to 50 mm.

[0133] <Electrostatic latent image forming means and electrostatic latent image forming process> The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on an electrostatic latent image carrier, and can be appropriately selected depending on the purpose. For example, it may be a means having at least a charging member for charging the surface of the electrostatic latent image carrier and an exposing member for exposing the surface of the electrostatic latent image carrier to light in an imagewise manner. The electrostatic latent image forming step is not particularly limited as long as it is a step of forming an electrostatic latent image on an electrostatic latent image bearing member, and can be appropriately selected depending on the purpose. For example, it can be performed by charging the surface of an electrostatic latent image bearing member and then exposing it to light in an imagewise manner, and can be performed using an electrostatic latent image forming means.

[0134] -Charging materials and charging- The charging means has, for example, a charging member that charges the electrostatic latent image carrier. The charging member is not particularly limited and can be appropriately selected depending on the purpose. Examples include a known contact charger equipped with a conductive or semiconductive roller, brush, film, rubber blade, etc., and a non-contact charger utilizing corona discharge such as a corotron or scorotron. Charging (charging step) can be carried out, for example, by applying a voltage to the surface of the electrostatic latent image bearing member using a charging member.

[0135] The shape of the charging member may be a roller, a magnetic brush, a fur brush, or any other shape, and can be selected according to the specifications and shape of the image forming apparatus. The charging member is not limited to a contact-type charging member, but it is preferable to use a contact-type charging member because it allows an image forming apparatus to be obtained in which the amount of ozone generated from the charging member is reduced.

[0136] - Exposure material and exposure - The exposure unit has, for example, an exposure member that exposes the electrostatic latent image carrier. The exposing member is not particularly limited and can be appropriately selected depending on the purpose as long as it can expose the surface of the electrostatic latent image carrier charged by the charging member in the form of an image to be formed. Examples of the exposing member include various exposing members such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.

[0137] The light source used in the exposure member is not particularly limited and can be appropriately selected depending on the purpose. Examples include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescence (EL), and other light-emitting materials. In order to irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used.

[0138] The exposure (exposure step) can be carried out, for example, by exposing the surface of the electrostatic latent image bearing member to light in an imagewise manner using an exposure member. In the present invention, a backlight system may be employed in which exposure is performed imagewise from the back side of the electrostatic latent image bearing member.

[0139] <Developing means and developing process> The developing means is not particularly limited as long as it is a developing means equipped with toner and forms a toner image by developing an electrostatic latent image formed on an electrostatic latent image carrier, and can be appropriately selected depending on the purpose. The toner image is an image to be transferred to a transferee, so it may also be called a transferee material-adhered image or the like. Furthermore, from the viewpoint that the toner is used to form a transferee material-adhered image, it may also be called a transferee material-adhered toner or the like. The toner image may also be called a transferee material-adhered image or the like.

[0140] The developing step is not particularly limited as long as it is a step of developing an electrostatic latent image formed on an electrostatic latent image carrier with a toner to form a visible image, and can be appropriately selected depending on the purpose. For example, the developing step can be carried out by the developing means described above.

[0141] As the developing means, a developing device having an agitator that charges the toner by friction agitation, a magnetic field generating means fixed inside, and a rotatable developer carrier that carries a developer containing the toner on its surface is preferred.

[0142] In the developing unit, for example, toner and carrier are mixed and stirred, and the toner becomes charged by friction during this process and is held in a standing state on the surface of a rotating magnet roller, forming a magnetic brush. The magnet roller is located near an electrostatic latent image carrier. As a result, a portion of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrostatic latent image carrier by electrical attraction. As a result, the electrostatic latent image is developed with toner, and a visible toner image (toner image) is formed on the surface of the electrostatic latent image carrier.

[0143] <Transfer means and transfer process> The transfer means is not particularly limited as long as it is a means capable of performing transfer, and can be appropriately selected depending on the purpose. It may be a primary transfer method in which a toner image is transferred to a transfer receiving material, or a secondary transfer method in which a toner image is transferred to an intermediate transfer member and then transferred to a transfer receiving material. As the transfer means, for example, a preferred embodiment has a primary transfer means that transfers a toner image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means that transfers the composite transfer image onto a transfer receiving material.

[0144] The transfer step is not particularly limited as long as it is a step that can perform transfer, and can be appropriately selected depending on the purpose. It may be a primary transfer method in which a toner image is transferred to a transfer-receiving material, or a secondary transfer method in which a toner image is transferred to an intermediate transfer material and then transferred to a transfer-receiving material. As the transfer step, for example, an intermediate transfer material is used, and the toner image is primarily transferred onto the intermediate transfer material, and then the toner image is secondarily transferred onto the transfer-receiving material, which is preferred. The transfer step can be carried out, for example, by charging the electrostatic latent image carrier with the toner image using a transfer charger, and can be carried out by the transfer means.

[0145] When the image to be secondarily transferred onto the transfer receiving body is an image made of two types of toner, a clear toner and a white toner, the following method may be used: Toner images may be sequentially superimposed on an intermediate transfer body to form an image to be transferred, and the images on the intermediate transfer body may be secondarily transferred to the transfer receiving body all at once. The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members depending on the purpose, and a suitable example is a transfer belt.

[0146] The transfer means (the primary transfer means, the secondary transfer means) preferably has at least a transfer device that peels and charges the visible image (toner image) formed on the electrostatic latent image carrier onto the transfer sheet.

[0147] Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

[0148] The transfer sheet is not particularly limited and can be appropriately selected depending on the purpose as long as it can transfer the developed toner image and can transfer the image on the transfer sheet to a receiving material. For example, transfer paper having a transfer layer, release paper release film having a release layer, etc. can be used as the transfer sheet.

[0149] <Fixing means and fixing process> After the toner image is transferred onto the transfer sheet, a fixing step is carried out to prepare a thermal transfer print sheet. The fixing step can be carried out by a fixing means. The fixing means is not particularly limited as long as it can fix the toner image transferred to the transfer sheet, and can be appropriately selected depending on the purpose, and a known heating and pressing member is preferred. Examples of the heating and pressing member include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller, and an endless belt.

[0150] The fixing step is not particularly limited as long as it is a step of fixing a toner image transferred onto a transfer sheet, and can be appropriately selected depending on the purpose. The fixing step is characterized by being performed simultaneously at one time in a stacked state on the developing means for each color.

[0151] The heating temperature in the heating and pressing member is preferably 80°C to 200°C. In the present invention, depending on the purpose, for example, a known optical fixing device may be used together with or instead of the fixing means. The surface pressure in the fixing step is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably 10 N / cm 2 ~80N / cm 2 It is preferable that:

[0152] <Other means and other steps> Examples of other means include cleaning means, discharging means, recycling means, and control means. Examples of other processes include a cleaning process, a charge removal process, a recycling process, and a control process.

[0153] -Cleaning means and cleaning process- The cleaning means is not particularly limited as long as it can remove the toner remaining on the photosensitive member, and can be appropriately selected depending on the purpose. Examples of the cleaning means include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner. The cleaning step is not particularly limited as long as it can remove the toner remaining on the photoreceptor, and can be appropriately selected depending on the purpose. For example, the cleaning step can be performed by the cleaning unit.

[0154] -Static removal means and static removal process- The discharging means is not particularly limited as long as it is a means for discharging the photosensitive member by applying a discharging bias to the photosensitive member, and can be appropriately selected depending on the purpose. For example, a discharging lamp can be used. The charge-eliminating step is not particularly limited as long as it is a step of applying a charge-eliminating bias to the photosensitive member to eliminate charges, and can be appropriately selected depending on the purpose. For example, it can be performed by the charge-eliminating unit.

[0155] -Recycling methods and processes- The recycling means is not particularly limited as long as it is a means for recycling the toner removed by the cleaning step into the developing device, and can be appropriately selected depending on the purpose. For example, known conveying means can be used. The recycling step is not particularly limited as long as it is a step of recycling the toner removed by the cleaning step into the developing device, and can be appropriately selected depending on the purpose. For example, it can be performed by the recycling means.

[0156] -Control means and control process- The control means is not particularly limited as long as it is a means capable of controlling the movement of each of the means, and can be appropriately selected depending on the purpose. Examples thereof include devices such as a sequencer and a computer. The control step is not particularly limited as long as it is a step that can control the movement of each step, and can be appropriately selected depending on the purpose, and can be performed, for example, by the control means.

[0157] <Detailed Examples of Image Forming Apparatus and Image Forming Method> Next, an example of an image forming apparatus and an image forming method will be described with reference to FIG. The image forming apparatus 100A shown in FIG. 1 includes a photosensitive drum 10 (hereinafter sometimes referred to as "photosensitive drum 10") as the electrostatic latent image carrier, a charging roller 20 as the charging means, an exposure device 30 as the exposure means, a developing device 40 as the developing means, an intermediate transfer body 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a discharging lamp 70 as the discharging means.

[0158] The intermediate transfer body 50 is an endless belt that is designed to move in the direction of the arrow by three rollers 51 arranged inside and tensioning it. Some of the three rollers 51 also function as transfer bias rollers that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50. A cleaning device 90 having a cleaning blade is arranged near the intermediate transfer body 50. Also, a transfer roller 80 serving as transfer means that can apply a transfer bias for transferring (secondary transfer) the toner image to a transfer sheet 95 serving as a recording medium is arranged near the intermediate transfer body 50, facing the intermediate transfer body 50. A corona charger 58 for applying an electric charge to the toner image on the intermediate transfer body 50 is arranged around the intermediate transfer body 50, between the contact point between the photoreceptor 10 and the intermediate transfer body 50 and the contact point between the intermediate transfer body 50 and the transfer paper 95, in the direction of rotation of the intermediate transfer body 50.

[0159] In this embodiment, an elastic intermediate transfer belt can also be used as the intermediate transfer body 50. As the elastic intermediate transfer belt, for example, one in which a flexible elastic layer is laminated on a rigid base layer that is relatively flexible can be used. In order to prevent the intermediate transfer body 50 from meandering, a guide member for preventing deviation may be provided on the inner peripheral surface of the intermediate transfer body 50 .

[0160] Below, we will explain an example where black (K) is the first color, yellow (Y) is the second color, magenta (M) is the third color, and cyan (C) is the fourth color, but the colors are not limited to these.

[0161] The developing device 40 is composed of a developing belt 41 as the developer carrier, and developing units 45K, 45Y, 45M, and 45C arranged around the developing belt 41. For example, the developing unit 45K includes a developer container 42K, a developer supply roller 43K, and a developing roller 44K. The developing units 45Y, 45M, and 45C are similarly configured. The developing belt 41 is an endless belt that is rotatably stretched around a plurality of belt rollers, and a portion of the developing belt 41 is in contact with the photosensitive member 10.

[0162] In the image forming apparatus 100A shown in FIG. 1, for example, a charging roller 20 uniformly charges the photosensitive drum 10. An exposure device 30 exposes the photosensitive drum 10 to light in an imagewise manner to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from a developing device 40 to form a toner image. The toner image is transferred (primary transfer) onto an intermediate transfer body 50 by a voltage applied from a roller 51, and is further transferred (secondary transfer) onto a transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. Any remaining toner on the photosensitive drum 10 is removed by a cleaning device 60, and the charge on the photosensitive drum 10 is temporarily removed by a discharging lamp 70.

[0163] Another example of the image forming apparatus of the present invention is shown in Figure 2. Image forming apparatus 100B has the same configuration as image forming apparatus 100A shown in Figure 1, except that it does not have developing belt 41 and developing units 45K, 45Y, 45M, and 45C are arranged directly opposite each other around photosensitive drum 10.

[0164] Another example of the image forming apparatus of the present invention is shown in Fig. 3. The image forming apparatus shown in Fig. 3 includes a copying machine main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

[0165] An endless belt-like intermediate transfer member 50 is provided in the center of the copying machine main body 150. Intermediate transfer body 50 is stretched over support rollers 14, 15, and 16 and is rotatable clockwise in FIG. 3. An intermediate transfer body cleaning device 17 for removing residual toner on intermediate transfer body 50 is disposed near support roller 15. A tandem developing device 120 is disposed on intermediate transfer body 50 stretched over support rollers 14 and 15 along the transport direction of intermediate transfer body 50, and includes first, second, third, and fourth image forming means 18 arranged side by side and facing each other. An exposure device 21, which is the exposure member, is disposed near tandem developing device 120.

[0166] A secondary transfer device 22 is disposed on the side of the intermediate transfer body 50 opposite to the side where the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched over a pair of rollers 23, and the transfer paper transported on the secondary transfer belt 24 and the intermediate transfer body 50 can come into contact with each other. A fixing device 25, which is the fixing means, is disposed near the secondary transfer device 22. The fixing device 25 includes a fixing belt 26, which is an endless belt, and a pressure roller 27 that is disposed so as to be pressed against the fixing belt 26.

[0167] In the tandem image forming apparatus, a sheet reversing device 28 is disposed near the secondary transfer device 22 and the fixing device 25 for reversing the transfer paper in order to form images on both sides of the transfer paper.

[0168] Next, we will explain how to form an image on a transfer material using the tandem developing device 120. First, an original is set on the platen 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the original is set on the contact glass 32 of the scanner 300, and then the automatic document feeder 400 is closed.

[0169] When a start switch (not shown) is pressed, the scanner 300 is driven after the original is transported and moved onto the contact glass 32 when an original is set on the automatic document feeder 400, or immediately when an original is set on the contact glass 32. Then, the first travelling body 33 and the second travelling body 34 travel. At this time, light from a light source is irradiated by the first travelling body 33, and the light reflected from the original surface is reflected by a mirror on the second travelling body 34 and received by a reading sensor 36 through an imaging lens 35, whereby the color original (color image) is read and converted into image information of the first color, second color, third color, and fourth color, and further converted into a solid image with uniform deposition amounts of all colors.

[0170] The solid image information is then transmitted to each image forming means 18 in the tandem developing device 120. Then, in each image forming means, an image consistent with the previous image forming means is formed by the respective image forming means. In this example, the image forming means 18 are provided corresponding to each of K, Y, M, and C.

[0171] FIG. 4 is a diagram illustrating each image forming means 18 in the tandem developing device 120. As shown in FIG. As shown in FIG. 4, the image forming means 18 includes an electrostatic latent image carrier 10, a charging device 160, a developing device 61, a transfer charger 62, a cleaning device 63, and a static eliminator 64 for each of K, Y, M, and C.

[0172] The charging device 160 is the charging means for uniformly charging the photoreceptor 10. The exposure device exposes the photoreceptor 10 to light (L) in the form of an image corresponding to a solid image, for example, based on solid image information, and forms an electrostatic latent image corresponding to the image on the electrostatic latent image carrier. The developing device 61 is a developing means for developing the electrostatic latent image with various toners to form a toner image. The transfer charger 62 transfers the toner image onto the intermediate transfer body 50. The cleaning device 63 cleans the photoreceptor 10. The static eliminator 64 neutralizes the photoreceptor 10.

[0173] The image forming means 18 may be referred to as first to fourth image forming means, etc., corresponding to K, Y, M, and C. Similarly, the photoreceptors 10 may be referred to as first to fourth photoreceptors 10, etc., corresponding to K, Y, M, and C.

[0174] Then, each image forming means 18 forms a single color image (first to fourth color images) based on the image information of the corresponding color. The first to fourth color images thus formed are sequentially transferred (primary transfer) onto the intermediate transfer body 50, which is rotated by support rollers 14, 15, and 16. In this way, a color image is synthesized on the intermediate transfer body 50.

[0175] Meanwhile, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed a transfer sheet from one of the paper feed cassettes 144 provided in multiple stages in a paper bank 143. The transfer sheets are separated one by one by a separation roller 145 and sent to a paper feed path 146, then transported by a transport roller 147 and guided to a paper feed path 148 inside the copier body 150, where they are stopped by striking against a registration roller 49. Alternatively, the paper feed roller 142 is rotated to feed out a transfer sheet on the manual feed tray 54, and the sheets are separated one by one by a separation roller 52 and placed in the manual feed path 53, where they are also stopped by striking against a registration roller 49.

[0176] The registration roller 49 is generally grounded when used, but may be used with a bias applied to it in order to remove paper dust from the transfer sheet.

[0177] Then, the registration rollers 49 are rotated in time with the color image synthesized on the intermediate transfer body 50, and a transfer sheet is fed between the intermediate transfer body 50 and the secondary transfer device 22, and the color image is transferred (secondary transfer) onto the transfer sheet by the secondary transfer device 22. In this way, a color image is transferred and formed on the transfer sheet. Note that any residual toner remaining on the intermediate transfer body 50 after image transfer is cleaned by the intermediate transfer body cleaning device 17. A collecting means may also be provided to receive the toner and the like removed by the intermediate transfer body cleaning device 17. A dish-shaped tray or the like can be used as the collecting means.

[0178] The transfer sheet onto which the color image has been transferred is transported by secondary transfer device 22 and sent to fixing device 25, where the color image (adhesive transfer image on the transfer material) is fixed onto the transfer sheet by heat and pressure. Thereafter, the transfer sheet is switched by switching claw 55, discharged by discharge rollers 56, and stacked on paper output tray 57. Alternatively, the sheet is switched by switching claw 55, inverted by sheet inverting device 28, and guided to the transfer position again, an image is recorded on the back side as well, and then discharged by discharge rollers 56 and stacked on paper output tray 57.

[0179] <Example of a process cartridge> The process cartridge according to the present invention is molded to be detachably mountable to various image forming apparatuses, and includes at least an electrostatic latent image carrier that carries an electrostatic latent image, and developing means that develops the electrostatic latent image carried on the electrostatic latent image carrier with a developer to form a toner image. The process cartridge according to the present invention may further include other means, if necessary.

[0180] The developing unit includes, for example, a developer container that contains developer, and a developer carrier that carries and transports the developer contained in the developer container. The developing unit may further include a regulating member for regulating the thickness of the developer carried.

[0181] 5 shows an example of a process cartridge according to the present invention. The process cartridge 110 includes the photosensitive drum 10, a corona charger 52, a developing device 40, a transfer roller 80, and a cleaning device 90.

[0182] The photosensitive drum 10 is an example of an electrostatic latent image carrier. The corona charger 52 is an example of a charging means and charges the photosensitive drum 10. Exposure light L is irradiated onto the photosensitive drum 10 to form an electrostatic latent image on the photosensitive drum 10. The developing device 40 is an example of a developing means and performs development. The transfer roller 80 is an example of a transfer means and transfers the toner image to a transfer sheet. The cleaning device 90 is an example of a cleaning means and cleans the photosensitive drum 10.

[0183] (Thermal transfer device) The transfer step of transferring the image to be transferred formed on the thermal transfer print sheet to a transfer-receiving material by thermal transfer can be carried out by, for example, a thermal transfer device. A thermal transfer device is a device that thermally transfers a thermal transfer print sheet onto a receiving material such as cloth or leather, and is capable of applying heat with uniform pressure on the press surface for a certain period of time. It is also called an iron press or heat press.

[0184] The thermal transfer device used in the present invention can be any commercially available device. When transferring to a transfer target such as a T-shirt, it is preferable that the area of ​​the press surface be larger than the area of ​​the transfer target. By applying uniform heat and pressure to the front surface of the transfer target, a transferred image can be obtained without leaving any press marks on the transfer target. Specific examples of thermal transfer devices include the GFH-380, GHP-300 (all from System Graphy Co., Ltd.), HPT234PS1, HSP-5400, HP-4536A-12, HP-54A, HP-84A, HSP-1513PV-AT, and HSP-1010 (all from HASHIMA), TS-ONE (Sister), TP630M, and TP700A (Horison).

[0185] The temperature for thermal transfer can be appropriately selected depending on the material and thickness of the transfer-receiving body, and is preferably higher than the softening point Ts of the toner and 20° C. below the heat-resistant temperature Th of the transfer-receiving body. The pressure for thermal transfer is preferably low if transfer is possible, for example, 1000 g / cm 2 Preferably less than 600 g / cm 2 Less than 300 g / cm is more preferable. 2 The following is even more preferred:

[0186] It is also possible to use a commercially available iron. However, from the viewpoint of applying heat uniformly and with a constant pressure, it is preferable to use the thermal transfer device described above. In addition, the present invention may be an image forming system having the image forming device of the present invention described above and a thermal transfer device. [Example]

[0187] The present invention will be explained in more detail below by showing examples, but the present invention is not limited to these examples.

[0188] (Manufacturing toner for thermal transfer print sheets) A toner (toner for thermal transfer print sheets) was produced as follows. The formulation is shown in Table 1.

[0189] <Toner 1 manufacturing example> -Raw materials for Toner 1- Polyurethane elastomer ECOFREEN POWDER (manufactured by ECOFREEN, softening point 120°C, glass transition temperature -29°C) 50% by mass Polyester resin RN-306SF (Kao Corporation, softening point 100°C, glass transition temperature 60°C) 20% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Titanium dioxide white pigment (PF-739, manufactured by Ishihara Sangyo Kaisha) 25% by mass

[0190] The above raw materials for Toner 1 were premixed using a Henschel mixer (FM20B, manufactured by Nippon Coke and Engineering Co., Ltd.), and then melted and kneaded at a temperature set to 90°C in a batch kneader (Wonder Kneader "WDS7-30", manufactured by Moriyama Corporation). The resulting kneaded mixture was extruded through a 3 mm diameter die using a feeder ruder to form strands, which were cooled in a water bath with a water temperature of 15°C or less, and the solidified strands were cut using a pelletizer. This yielded Toner Pellets 1 with a diameter of 2 mm and a length of 2 mm. These pellets are the coarsely crushed product of the melted and kneaded toner components. The pellets were then placed in a cooler, cooled with liquid nitrogen, and pulverized in a mechanical pulverizer (Rinrex Mill LX, manufactured by Hosokawa Micron Corporation). The pulverized material discharged from the pulverizer was sieved through a 25 μm mesh, and the non-passing portion was re-introduced into the pulverizer to obtain fine particles that passed through the 25 mesh. The fine particles that passed through the 25 mesh were returned to room temperature and then finely classified in an air classifier (EJ-LABO, manufactured by Matsubo Corporation) while appropriately adjusting the louver opening so that particles of 5 μm or less constituted 10% or less by number, thereby obtaining toner base particles.

[0191] Next, 100 parts by mass of the obtained toner base particles were mixed with 1.0 part by mass of additive 1 (HDK-2000, manufactured by Clariant Co., Ltd., substance name: silica) and 1.0 part by mass of additive 2 (H05TD, manufactured by Clariant Co., Ltd., substance name: silica) by stirring in a Henschel mixer to prepare toner 1 (toner 1 for thermal transfer print sheets).

[0192] <Toner 2 manufacturing example> -Raw materials for Toner 2- Polyurethane elastomer (E780M128, manufactured by Nippon Miractoran Co., Ltd., softening point 118°C, glass transition temperature -24°C) 60% by mass Polyester resin RN-306SF (Kao Corporation, softening point 100°C, glass transition temperature 60°C) 25% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Carbon black (#44, manufactured by Mitsubishi Chemical Corporation) 10% by mass

[0193] The above raw materials for Toner 2 were processed in the same manner as Toner 1 to produce Toner 2.

[0194] <Toner 3 manufacturing example> -Raw materials for Toner 3- Polyurethane elastomer (57F, manufactured by BASF, softening point 116°C, glass transition temperature -26.5°C) 45% by mass Polyester resin RN-306SF (Kao Corporation, softening point 100°C, glass transition temperature 60°C) 20% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Titanium dioxide white pigment (PF-739, manufactured by Ishihara Sangyo Kaisha) 20% by mass Pigment Blue 15:3 (7919, manufactured by Toyochem Co., Ltd.) 9.5% by mass Carbon black (#44, manufactured by Mitsubishi Chemical Corporation) 0.5% by mass

[0195] The raw materials for Toner 3 were processed in the same manner as Toner 1 to produce Toner 3.

[0196] <Toner 4 manufacturing example> -Raw materials for Toner 4- Polyurethane elastomer (E780M128, manufactured by Nippon Miractoran Co., Ltd., softening point 118°C, glass transition temperature -24°C) 45% by mass Polyester resin RN-306SF (Kao Corporation, softening point 100°C, glass transition temperature 60°C) 20.72% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Titanium dioxide white pigment (PF-739, manufactured by Ishihara Sangyo Kaisha) 20% by mass Pigment Red 254 (Irgazin Red D 3656 HD, manufactured by DIC Corporation) 9.1% by mass Carbon black (#44, manufactured by Mitsubishi Chemical Corporation) 0.18% by mass

[0197] The raw materials for Toner 4 were processed in the same manner as Toner 1 to produce Toner 4.

[0198] <Toner 5 manufacturing example> -Raw materials for Toner 5- Polyurethane elastomer (57F, manufactured by BASF, softening point 116°C, glass transition temperature -26.5°C) 49% by mass Polyester resin RN-306SF (Kao Corporation, softening point 100°C, glass transition temperature 60°C) 20% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Titanium dioxide white pigment (PF-739, manufactured by Ishihara Sangyo Kaisha) 25% by mass Carbon black (#44, manufactured by Mitsubishi Chemical Corporation) 1.0% by mass

[0199] The raw materials for Toner 5 were processed in the same manner as Toner 1 to produce Toner 5.

[0200] <Toner 6 manufacturing example> -Raw materials for Toner 6- Polyurethane elastomer (57F, manufactured by BASF, softening point 116°C, glass transition temperature -26.5°C) 55% by mass Polyester resin RN-306SF (Kao Corporation, softening point 100°C, glass transition temperature 60°C) 30% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Pigment Blue 15:3 (7919, manufactured by Toyochem Co., Ltd.) 9.5% by mass Carbon black (#44, manufactured by Mitsubishi Chemical Corporation) 0.5% by mass

[0201] The raw materials for Toner 6 were processed in the same manner as Toner 1 to produce Toner 6.

[0202] <Toner 7 manufacturing example> - Toner 7 raw materials - Polyurethane elastomer (E780M128, manufactured by Nippon Miractoran Co., Ltd., softening point 118°C, glass transition temperature -24°C) 55% by mass Polyester resin RN-306SF (Kao Corporation, softening point 100°C, glass transition temperature 60°C) 30.72% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Pigment Red 254 (Irgazin Red D 3656 HD, manufactured by DIC Corporation) 9.1% by mass Carbon black (#44, manufactured by Mitsubishi Chemical Corporation) 0.18% by mass

[0203] The raw materials for Toner 7 were processed in the same manner as Toner 1 to produce Toner 7.

[0204] <Toner 8 manufacturing example> - Toner 8 raw materials - Polyurethane elastomer (57F, manufactured by BASF, softening point 116°C, glass transition temperature -26.5°C) 69% by mass Wax dispersant (EXD-001, manufactured by Sanyo Chemical Co., Ltd.) 2.5% by mass Ester wax (LW-13, manufactured by Sanyo Chemical Industries, Ltd.) 2.5% by mass Titanium dioxide white pigment (PF-739, manufactured by Ishihara Sangyo Kaisha) 25% by mass Carbon black (#44, manufactured by Mitsubishi Chemical Corporation) 1.0% by mass

[0205] The raw materials for Toner 8 were processed in the same manner as Toner 1 to produce Toner 8.

[0206] (Carrier production) -Raw materials for carriers- IP solvent 710 parts by weight ECF-800 (Titanium Industries Co., Ltd. aluminum oxide, tin oxide, phosphorus pentoxide mixed fine particles) 220 parts by mass R5T (Toray Dow Coatings silicone / acrylic resin / toluene solution) 40 parts by mass 400 parts by weight of RCF-2130 (Toray Dow Coatings Co., Ltd. polyalkenylsiloxane toluene solution) CTC-754 (Titanium isopropoxybis(ethyl acetate) manufactured by Matsumoto Fine Chemical Co., Ltd.) 45 parts by mass RSH-602 (Toray Dow Coating Co., Ltd., r-(2-aminoethyl)aminopropyltrimethoxysilane) 5 parts by mass

[0207] The above raw materials were dispersed in a homomixer for 20 minutes to prepare a resin layer coating solution. Using a fluidized bed coating device, the resin layer coating solution was applied to the surface of 7,200 parts by mass of spherical manganese-magnesium ferrite with an average particle size of 70 μm to prepare a carrier.

[0208] (Preparation of developer) Using a ball mill, 7 parts by mass of each of the toners 1 to 8 and 93 parts by mass of the carrier were mixed to prepare a developer. Images were formed on a transfer sheet using each of the prepared developers as follows.

[0209] Example 1 Color images were output as follows: A Ricoh Pro C7200S production printer manufactured by Ricoh Co., Ltd. was used to output color images. This device has five stations for placing special color toners and stations for each process color. Toner 1 and its developer were loaded into the five stations where the special color toner was placed. The black station was loaded with Toner 2 and its developer. The cyan station was loaded with toner 3 and its developer. The magenta station was loaded with Toner 4 and its developer. The yellow station was loaded with toner 5 and its developer.

[0210] Figure 6 shows the output color image, which features the Ricoh logo and the New Zealand flag. We chose this flag because we thought it would be appropriate for evaluating colors. Using the above device, a mirror image of the design shown in Figure 6 was printed on a transfer sheet (QuickArt Force-in Paper A3 sheet). When printing the image, each color in Figure 6 was printed individually onto the transfer sheet. In other words, the toner layer was a single layer. The white part of the flag was an image expressed with white toner. In this way, thermal transfer print sheet 1 was produced. The standard adhesion amount of each toner to the transfer sheet is 26 mg / cm 2 The toner layer thickness was set to 15 μm. Because the toner particle size was large, it was possible to set these reference adhesion amounts and toner layer thicknesses.

[0211] Table 1 shows the transmittance of all visible light wavelengths when a solid image of 30 μm thickness was formed on a transfer sheet using Toner 1. In Table 1, <1 indicates that the transmittance is less than 1%. The transmittance in this invention refers to the maximum transmittance within the visible light wavelength range (380 to 780 nm). The transmittance was measured using a film holder on an ultraviolet-visible-near-infrared spectrophotometer (Shimadzu UV-3600) for a 30 μm thick solid image formed on an OHP substrate under the following conditions: Wavelength range: 380nm to 780nm Scan speed: Medium Sampling pitch: 0.5nm Slit width: 5.0 nm

[0212] Example 2 Image formation was carried out under the same conditions as for the thermal transfer print sheet in Example 1, and the standard adhesion amount of each toner was 52 mg / cm 2 A thermal transfer print sheet 2 having an image with a toner layer thickness of 30 μm was prepared.

[0213] Example 3 In the production of the thermal transfer print sheet of Example 1, the output thermal transfer print sheet was returned to the paper stocker and the same design was printed again. This operation was repeated four times to form an image, and the standard adhesion amount of each toner was 104 mg / cm 2 A thermal transfer print sheet 3 having an image with a toner layer thickness of 60 μm was prepared.

[0214] (Comparative Example 1) Using the same device and transfer sheet as in Example 1, an evaluation image (FIG. 6) similar to that in Example 1 was output. In Comparative Example 1, RICOH Pro Toner White C7100 (genuine white toner) was installed in the five stations where the spot color toner was placed, and RICOH Pro Toner C7200 series (genuine color toner) was installed in each process color station. The white part of the national flag is an image expressed with genuine white toner. The standard adhesion amount of each color toner is 0.45 mg / cm 2The standard amount of white toner adhered was set to 1.70 mg / cm 2 In this way, a thermal transfer print sheet 4 having an image with a toner layer thickness of 10 μm was prepared.

[0215] The above-mentioned RICOH Pro Toner C7200 series (genuine color toner) is a toner containing polyester, thermoplastic elastomer (polyurethane elastomer), and wax. In addition, the above-mentioned RICOH Pro Toner White C7100 (genuine white toner) does not contain thermoplastic elastomer (polyurethane elastomer). For genuine color toners, the transmittance of all visible light wavelengths in a solid image with a deposition thickness of 30 μm was 20% for cyan toner, 70% for magenta toner, and 80% for yellow toner. The genuine white toner had a transmittance of less than 1% for all visible light wavelengths in a solid image with a deposition thickness of 30 μm.

[0216] (Comparative Example 2) In Comparative Example 1, after forming the image shown in Figure 6 on a transfer sheet, a masked image was printed from above with genuine white toner to produce thermal transfer print sheet 5 having an image with a white toner layer thickness of 20 μm.

[0217] (Comparative Example 3) In Comparative Example 2, after masking with genuine white toner, printing was further repeated to form a layer of genuine white toner with a toner layer thickness of 35 μm, and thermal transfer print sheet 6 was produced.

[0218] Comparative Example 4 In Example 1, the toner was loaded as follows: Toner 1 and its developer were loaded into the five stations where the special color toner was placed. The black station was loaded with Toner 2 and its developer. The cyan station was loaded with toner 6 and its developer. The magenta station was loaded with Toner 7 and its developer. The yellow station was loaded with toner 8 and its developer. A thermal transfer print sheet 7 was produced in the same manner as in Example 1, except for the above-mentioned changes.

[0219] (Comparative Example 5) A thermal transfer print sheet 8 was produced in the same manner as in Example 2, except that toner was loaded in the same manner as in Comparative Example 4.

[0220] (Comparative Example 6) A thermal transfer print sheet 9 was produced in the same manner as in Example 3, except that toner was loaded in the same manner as in Comparative Example 4.

[0221] (evaluation) An image was formed on a transfer medium as follows, and evaluation was carried out. The results are shown in Table 2.

[0222] <Image formation on a transfer target (white T-shirt)> Using the thermal transfer print sheet prepared above, an image was formed on a white T-shirt (5.6 oz. high quality T-shirt, low bleed, manufactured by United Athle Co., Ltd.) as a transfer substrate in the following manner. The thermal transfer print sheet was placed on the T-shirt and placed in a heat press (Piotec Model HTP234PS1) at a temperature of 130°C and a pressure of 300g / cm. 2 Heat and pressure were applied for 20 seconds at 100°C. After that, the transfer sheet was peeled off and the image on the thermal transfer print sheet was thermally transferred onto the T-shirt. Next, a release paper was placed on the image transferred to the T-shirt, and the image was again printed at a temperature of 130°C and a pressure of 300 g / cm 2 After heating and pressing for 20 seconds, the release paper was peeled off to complete the printed T-shirt.

[0223] <Image formation on the receiving material (black T-shirt)> A printed T-shirt was produced in the same manner as in the above image formation on a white T-shirt, except that a black T-shirt (4.7 oz. Dry Silky Touch T-shirt, Low Bleed, manufactured by United Athle Co., Ltd.) was used as the transfer medium instead of the white T-shirt.

[0224] <Evaluation of fixation> The two printed T-shirts obtained in the examples and comparative examples were evaluated for fixation according to the following criteria: Fixation was evaluated by visually checking the printed T-shirts for color loss, peeling, and image cracking.

[0225] [Evaluation criteria] ○: No color fading, peeling, or cracking on the printed T-shirt ×: The printed T-shirt has some discoloration, peeling, or cracks.

[0226] There were no problems with fixation on both printed T-shirts in Examples 1 to 3 and Comparative Examples 1 and 2. On the other hand, peeling or cracking occurred in the white area in Comparative Example 3. In Comparative Examples 4 to 6, some voids occurred in the gray character area.

[0227] <Evaluation of washing fastness> The washing fastness (which may also be referred to as washing and drying durability) was evaluated as follows. The two printed T-shirts obtained in the Example and Comparative Examples were washed and spun using a vertical fully automatic washing machine (AW-425M manufactured by Toshiba Corporation) and a neutral detergent (Super Nanox manufactured by Lion Corporation).The printed T-shirts were then placed in a dryer (NH-D402P manufactured by Panasonic Corporation) and the automatic drying cycle was repeated five times. The evaluation was carried out according to the following evaluation criteria: ⊚ (excellent) and ○ (good) are acceptable, and × (poor) is unacceptable.

[0228] [Evaluation criteria] ◎: No deterioration of image quality even after 5 wash and dry cycles ○: After washing and drying five times, there are some cracks and cracks in the image, but no peeling. ×: After washing and drying five times, some peeling occurs.

[0229] In Example 1, cracks were observed in some areas, but no peeling occurred. In Examples 2 and 3 and Comparative Examples 5 and 6, there was no deterioration and the results were excellent. In Comparative Examples 1 and 4, cracks were observed in some areas, but no peeling occurred. In Comparative Examples 2 and 3, peeling or cracking occurred in the white paper area. In garment printing where an image is formed using the thermal transfer sheet of the present invention, no fading occurred, and all deterioration was damage to the image such as cracking, cracking or peeling.

[0230] <Evaluation of color image reproducibility> The image of the white T-shirt obtained above was compared with the image of the black T-shirt to evaluate the reproducibility of color images depending on the brightness of the object to be transferred. The evaluation was as follows: Let a be the saturation of the red part of the image of the white T-shirt, and b be the saturation of the blue part of the image of the white T-shirt. Let c be the saturation of the red part of the image of the black T-shirt, and d be the saturation of the blue part of the image of the black T-shirt. Evaluate the difference in saturation of the red part (ac) and the difference in saturation of the blue part (bd). The evaluation criteria are as follows, with ◎ and ○ being acceptable. In the cases of ◎ and ○, it can be said that the image of the white T-shirt has been reproduced on the black T-shirt.

[0231] [Evaluation criteria] ◎: The difference in saturation between the red and blue parts is less than 3. ○: The difference in saturation of the red part and the difference in saturation of the blue part are both less than 5, and at least one of the difference in saturation of the red part and the difference in saturation of the blue part is 3 or more and less than 5. ×: The difference in saturation between the red and blue parts is 5 or more.

[0232] In Example 1, the difference in saturation of the red portion was 3 or more and less than 5. In Examples 2 and 3, the difference in saturation of the red portion and the difference in saturation of the blue portion were both less than 3. In Comparative Examples 1, 2, and 4 to 6, the difference in saturation of the red portion and the difference in saturation of the blue portion were both 5 or more. In Comparative Example 3, the difference in saturation of the red portion and the difference in saturation of the blue portion were both 3 or more and less than 5.

[0233] <Overall rating> In the above evaluation, a sample that did not have any x (fail) was judged to be pass. Examples 1 to 3 passed, while Comparative Examples 1 to 6 had evaluation results that were x and failed.

[0234] [Table 1]

[0235] [Table 2]

[0236] For example, aspects of the present invention are as follows. <1> A toner used in an electrophotographic image forming apparatus and for forming a thermal transfer print sheet, The thermal transfer print sheet is a transfer sheet on which an image is formed using the toner, and is used to transfer the image to a transfer target by thermal transfer; The toner has a transmittance of less than 5% for all visible light wavelengths when a solid image having a deposition thickness of 30 μm is formed on an OHP substrate, and contains polyester, polyurethane elastomer, wax, and a white pigment or a black pigment. A toner characterized by: <2> The toner contains a colorant other than a white pigment and a black pigment. Characterized by <1> The toner according to claim 1. <3> A toner set including a plurality of toners used in an electrophotographic image forming apparatus and for forming a thermal transfer print sheet, The thermal transfer print sheet is a transfer sheet on which an image is formed using the toner, and is used to transfer the image to a transfer target by thermal transfer; The toners in the toner set all have a transmittance of less than 5% for all visible light wavelengths when a solid image having a deposition thickness of 30 μm is formed on an OHP substrate, The toner set includes at least the following toner (A), the following toner (B), and the following toner (C): A toner set characterized by: (A) A toner containing a white pigment, a polyester, a polyurethane elastomer, and a wax. (B) A toner containing a black pigment, a polyester, a polyurethane elastomer, and a wax. (C) A toner containing a white pigment or a black pigment, a colorant other than the white pigment or the black pigment, a polyester, a polyurethane elastomer, and a wax. <4> The toner (C) contains a white pigment and a black pigment. Characterized by <3> The toner set according to claim 1. <5> <1> or <2> or the toner according to <3> or <4> An image forming method using the toner set according to claim 1, an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier of the image forming device; a developing step of developing the electrostatic latent image to form a toner image; a transfer step of transferring the toner image onto the transfer sheet; a fixing step of fixing the toner image on the transfer sheet, The thermal transfer print sheet is prepared through the fixing step. An image forming method comprising: <6> The toner image on the thermal transfer print sheet is a single-layer toner image that does not overlap with other toner images. Characterized by <5> The image forming method according to claim 1. <7> a thermal transfer step of thermally transferring an image on the thermal transfer print sheet to the transfer-receiving material, In the thermal transfer step, the thermal transfer print sheet is brought into contact with the object to be transferred and heated and pressed. Characterized by <5> or <6> The image forming method according to claim 1. <8> The object is a fabric. Characterized by <5> from <7> 10. The image forming method according to claim 9, wherein <9> The fabric is made of cotton, polyester, nylon, rayon or silk fibers or a mixture thereof. Characterized by <8> The image forming method according to claim 1. <10> <1> or <2> or the toner according to <3> or <4> An image forming apparatus having the toner set according to an electrostatic latent image carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier; a developing means for developing the electrostatic latent image to form a toner image; a transfer means for transferring the toner image onto the transfer sheet; a fixing unit for fixing the toner image on the transfer sheet, The thermal transfer print sheet is prepared by fixing the image by the fixing means. An image forming apparatus characterized by: <11> <1> or <2> a process cartridge detachably mountable to the image forming apparatus, the process cartridge having the toner according to claim 1, the process cartridge comprises an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image to form a toner image, and transfer means for transferring the toner image to the transfer sheet; the image forming apparatus includes a fixing unit that fixes the toner image on the transfer sheet; The process cartridge is mounted in the image forming apparatus, and the thermal transfer print sheet is produced through fixing by the fixing means. A process cartridge characterized by: [Explanation of symbols]

[0237] 10 Photosensitive drum 18 Image forming means 20 Charging roller 30 Exposure equipment 40 Developer 41 Developing belt 45 Development unit 50 Intermediate transfer body 60 Cleaning Device 70 Static elimination lamp [Prior art documents] [Patent documents]

[0238] [Patent Document 1] Japanese Patent Application Publication No. 07-336466 [Patent Document 2] Japanese Patent Application Publication No. 08-207263 [Patent Document 3] Japanese Patent Application Publication No. 11-157139 [Patent Document 4] Japanese Patent Application Publication No. 05-077557 [Patent Document 5] Japanese Patent Application Publication No. 09-087980 [Patent Document 6] Japanese Patent Application Laid-Open No. 2014-59486

Claims

1. A toner used in an electrophotographic image forming apparatus and for forming a thermal transfer print sheet, The thermal transfer print sheet is a transfer sheet on which an image is formed using the toner, and is used to transfer the image to a transfer target by thermal transfer; The toner has a transmittance of less than 5% for all visible light wavelengths when a solid image having a deposition thickness of 30 μm is formed on an OHP substrate, and contains polyester, polyurethane elastomer, wax, and a white pigment or a black pigment. A toner characterized by:

2. The toner contains a colorant other than a white pigment and a black pigment.

2. The toner according to claim 1.

3. A toner set including a plurality of toners used in an electrophotographic image forming apparatus and for forming a thermal transfer print sheet, The thermal transfer print sheet is a transfer sheet on which an image is formed using the toner, and is used to transfer the image to a transfer target by thermal transfer; Each of the toners in the toner set has a transmittance of less than 5% for all visible light wavelengths when a solid image having a deposition thickness of 30 μm is formed on an OHP substrate, The toner set includes at least the following toner (A), the following toner (B), and the following toner (C): A toner set characterized by: (A) A toner containing a white pigment, a polyester, a polyurethane elastomer, and a wax. (B) A toner containing a black pigment, a polyester, a polyurethane elastomer, and a wax. (C) A toner containing a white pigment or a black pigment, a colorant other than the white pigment and the black pigment, a polyester, a polyurethane elastomer, and a wax.

4. The toner (C) contains a white pigment and a black pigment.

4. The toner set according to claim 3.

5. An image forming method using the toner according to claim 1 or the toner set according to claim 3, an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier of the image forming device; a developing step of developing the electrostatic latent image to form a toner image; a transfer step of transferring the toner image onto the transfer sheet; a fixing step of fixing the toner image on the transfer sheet, The thermal transfer print sheet is prepared through the fixing step. An image forming method comprising:

6. The toner image on the thermal transfer print sheet is a single-layer toner image that does not overlap with other toner images.

6. The image forming method according to claim 5.

7. a thermal transfer step of thermally transferring an image on the thermal transfer print sheet to the transfer-receiving material, In the thermal transfer step, the thermal transfer print sheet is brought into contact with the object to be transferred and heated and pressed.

6. The image forming method according to claim 5.

8. The object is a fabric.

6. The image forming method according to claim 5.

9. The fabric is made of cotton, polyester, nylon, rayon or silk fibers or a mixture thereof.

9. The image forming method according to claim 8.

10. An image forming apparatus comprising the toner according to claim 1 or the toner set according to claim 3, an electrostatic latent image carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier; a developing means for developing the electrostatic latent image to form a toner image; a transfer means for transferring the toner image onto the transfer sheet; a fixing unit for fixing the toner image on the transfer sheet, The thermal transfer print sheet is prepared by fixing the image by the fixing means. An image forming apparatus characterized by:

11. A process cartridge detachably mountable to the image forming apparatus, the process cartridge having the toner according to claim 1, the process cartridge comprises an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image to form a toner image, and transfer means for transferring the toner image to the transfer sheet; the image forming apparatus includes a fixing unit that fixes the toner image on the transfer sheet; The process cartridge is mounted in the image forming apparatus, and the thermal transfer print sheet is produced through fixing by the fixing means. A process cartridge characterized by:

Images