Image forming method

Abstract

To provide means that can form an image having good color development and having neither bleeding nor irregularities, on a non-penetrant substrate using thermal transfer.SOLUTION: The image forming method includes: a resin layer forming step of allowing a dispersion liquid containing resin particles to adhere to a non-permeable substrate by ejecting the dispersion liquid from an inkjet head, and fixing the resin particles as a resin layer on the non-permeable substrate; and a transfer step of allowing a transfer sheet having a sublimable dye ink layer to adhere to the resin layer and transferring a sublimable dye ink in the sublimable dye ink layer to the resin layer by heating.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an imaging method for forming an image on a non-porous substrate using thermal transfer. [Background technology]

[0002] Patent Document 1 discloses a method of printing a blended fiber containing polyester fiber with a disperse dye ink. Patent Document 1 discloses that the blended fiber is pretreated with a printing pretreatment agent containing at least polyester resin particles and a styrene-butadiene resin emulsion, and then the disperse dye ink is sublimation transferred. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-90150 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for full-color printing on three-dimensional objects such as cups. Three-dimensional objects are made of a variety of materials, but it is particularly desirable to print images with good color development and no bleeding or unevenness on non-permeable substrates that are impermeable to water, such as inorganic materials and resins with high glass transition points.

[0005] An object of the present invention is to provide a means for forming images on a non-permeable substrate using thermal transfer, which images have good color development and are free of bleeding and unevenness. [Means for solving the problem]

[0006] (1) The present invention relates to an image forming method for forming an image on a non-permeable substrate that is impermeable to water, the image forming method comprising a resin layer forming step of adhering a dispersion liquid containing resin particles to the non-permeable substrate by ejecting the dispersion liquid from an inkjet head and fixing the resin particles to the non-permeable substrate as a resin layer, and a transfer step of adhering a transfer sheet having a sublimation dye ink layer to the resin layer and transferring the sublimation dye ink of the sublimation dye ink layer to the resin layer by heating.

[0007] It is possible to form an image on a non-permeable substrate with good color development and no bleeding or unevenness. In addition, a resin layer can be formed on a part of the non-permeable substrate. In addition, the transfer sheet has excellent peelability. In addition, the formed image has few irregularities. In addition, it has excellent hiding ability of the color of the non-permeable substrate.

[0008] (2) The impermeable substrate may contain an inorganic material or a resin material having a glass transition point of 90° C. or higher.

[0009] As a result, the peelability of the transfer sheet is further improved.

[0010] (3) The resin layer may contain volatile components in an amount of 20% by weight or less.

[0011] As a result of the above, image unevenness is further reduced.

[0012] (4) In the resin layer forming step, the amount of the dispersion liquid discharged onto the non-permeable substrate is 0.1 mg / cm 2 to 10 mg / cm 2 may be in the range.

[0013] As a result, the image has better color development and less unevenness, and the transfer sheet has better peelability.

[0014] (5) The heating temperature in the transfer step may be within the range of 100°C to 240°C.

[0015] (6) The resin particles may contain at least one of a urethane resin, a polyester resin, and an acrylic resin.

[0016] (7) The resin particles may contain at least one of a polyester resin and an acrylic resin.

[0017] As a result, the image has better color development and the transfer sheet has better peelability.

[0018] (8) The polyester resin or the acrylic resin may have a glass transition point of 40° C. or higher.

[0019] As a result, the peelability of the transfer sheet is further improved.

[0020] (9) The dispersion may further contain a crosslinking agent.

[0021] As a result, the image has better color development and the transfer sheet has better peelability.

[0022] (10) The dispersion liquid may include a first dispersion liquid containing a colorant and a second dispersion liquid not containing a colorant, and the resin layer forming step may include a first step of adhering the first dispersion liquid to the non-permeable substrate by ejecting it from an inkjet head and fixing the resin particles to the non-permeable substrate as a first resin layer, and a second step of adhering the second dispersion liquid to the first resin layer by ejecting it from an inkjet head and laminating the resin particles on the first resin layer as a second resin layer.

[0023] As a result, the image has better color development and is more excellent in hiding the color of the non-permeable substrate. Effect of the Invention

[0024] According to the present invention, images with good color development and no bleeding or unevenness are formed on a non-permeable substrate by thermal transfer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, a preferred embodiment of the present invention will be described. Note that this embodiment is merely one embodiment of the present invention, and it goes without saying that the embodiment can be changed without departing from the gist of the present invention.

[0026] The image forming method for forming an image on a non-permeable substrate includes a resin layer forming step and a transfer step. According to this image forming method, an image with good color development and no bleeding or unevenness is formed on the non-permeable substrate. In addition, a resin layer is formed on a part of the non-permeable substrate. In addition, the transfer sheet has excellent peelability. In addition, the formed image has few irregularities. In addition, the non-permeable substrate has excellent color hiding ability.

[0027] The non-permeable substrate is not particularly limited as long as the liquid does not permeate therethrough, and examples thereof include those made of glass, metal, resin, and the like. The non-permeable substrate may also be made of a plurality of materials. The shape of the non-permeable substrate is not particularly limited, and may be a sheet or a flat plate, or may be a three-dimensional object of various shapes. If the surface of the non-permeable substrate on which the image is formed is made of an inorganic material or a resin material having a glass transition point of 90° C. or higher, it is preferable because it has excellent peelability of the transfer sheet. Examples of inorganic materials include glass and metal. Examples of resin materials having a glass transition point (Tg) of 90° C. or higher include polymethyl methacrylate (Tg=90° C.), polystyrene (Tg=100° C.), polyacrylonitrile (Tg=104° C.), polyacrylic acid (Tg=106° C.), polycarbonate (Tg=150° C.), polymethacrylic acid (Tg=185° C.), and copolymers thereof. Substrates with low glass transition points, such as synthetic resins such as vinyl chloride, may be deformed when heated for transfer. In addition, since the transfer sheet and the resin layer containing the sublimation dye ink are incorporated into the substrate, color development is poor and the peelability of the transfer sheet is also thought to be poor.

[0028] In the resin layer forming step, a dispersion liquid containing resin particles is discharged from an inkjet head to adhere to the non-permeable substrate, and the resin particles are fixed to the substrate as a resin layer.

[0029] The resin particles form a film on the non-permeable substrate when the dispersion dries. Examples of the resin particles include acrylic acid resins, maleic acid ester resins, vinyl acetate resins, carbonate resins, polycarbonate resins, styrene resins, ethylene resins, polyethylene resins, propylene resins, polypropylene resins, urethane resins, polyurethane resins, polyester resins, and copolymer resins thereof. The resin particles contain at least one of polyester resins or acrylic resins, which provides good color development of the image and excellent peelability of the transfer sheet. The glass transition point of the polyester resin or acrylic resin is 40° C. or higher, which provides even better peelability of the transfer sheet.

[0030] The dispersion may contain a solvent. Examples of the solvent include tripropylene glycol, propylene glycol, 1,5-pentanediol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 3-methyl-1,5-pentanediol. The solvent is contained as a volatile component in the resin layer. The volatile component in the resin layer is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably 5% by weight or less. When the volatile component in the resin layer satisfies the above range, unevenness in the image is reduced. The volatile component in the resin layer has the function of causing the sublimation dye ink to flow after transfer, so if a large amount of the volatile component remains in the resin layer, blurring and unevenness are likely to occur at the color boundary, and image quality is considered to be poor.

[0031] The dispersion may further contain a crosslinking agent. Examples of the crosslinking agent include a blocked isocyanate compound, a carbodiimide compound, and an oxazoline compound. The crosslinking agent is preferably 5% by weight or less. When the dispersion contains a crosslinking agent, the crosslinking agent crosslinks the polymer chains of the resin, so that the glass transition point of the crosslinked resin layer becomes higher than the original glass transition point of the resin, and therefore the transfer sheet is less likely to adhere to the resin layer, resulting in excellent peelability. In addition, the sublimation dye ink is more likely to be held in the crosslinked structure of the resin layer, resulting in improved color development of the image.

[0032] The dispersion may be a first dispersion containing a coloring material and a second dispersion not containing a coloring material. The coloring material is, for example, a pigment dispersible in water. Examples of the coloring material include white inorganic pigments and organic pigments. Examples of the inorganic pigment include titanium oxide and iron oxide inorganic pigments. Examples of the organic pigment include azo pigments such as azo lake, insoluble azo pigment, condensed azo pigment, and chelate azo pigment; polycyclic pigments such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments; dye lake pigments such as basic dye lake pigments and acid dye lake pigments; nitro pigments; nitroso pigments; aniline black daylight fluorescent pigments; and the like.

[0033] The weight percent of the colorant in the dispersion is not particularly limited and can be appropriately determined, for example, depending on the desired optical density or saturation. The weight percent of the colorant is, for example, preferably in the range of 0.1% by weight to 20.0% by weight, more preferably in the range of 1.0% by weight to 15.0% by weight. The colorant may be used alone or in combination of two or more kinds.

[0034] When the first dispersion and the second dispersion are used as the dispersion, the resin layer forming step may include a first step of adhering the first dispersion to the non-permeable substrate by ejecting it from an inkjet head, and fixing the resin particles to the non-permeable substrate as a first resin layer, and a second step of adhering the second dispersion to the first resin layer by ejecting it from an inkjet head, and laminating the resin particles to the first resin layer as a second resin layer. This provides good color development of the image and excellent hiding power for the color of the non-permeable substrate. The dispersion may be three or more dispersions, and the resin layer may be three or more layers.

[0035] Examples of white pigments include zinc oxide, which is CI Pigment White (hereinafter also referred to as "CIPW") 4, titanium oxide, which is CIPW6, zinc sulfide, which is CIPW7, zirconium oxide (zirconium white), which is CIPW12, calcium carbonate, which is CIPW18, aluminum oxide / silicon oxide (kaolin clay), which is CIPW19, barium sulfate, which is CIPW21 or 22, aluminum hydroxide (alumina white), which is CIPW23, silicon oxide, which is CIPW27, and calcium silicate, which is CIPW28. The inorganic particles used for the white pigment may be a single particle, or may be a composite particle with an oxide of silicon, aluminum, zirconium, titanium, or the like, an organic metal compound, or an organic compound. Among them, titanium oxide has a smaller specific gravity and a larger refractive index than other white pigments, and therefore has excellent hiding power and coloring properties for the substrate, and is also excellent in durability against acids, alkalis, and other environments, and is therefore preferably used. In addition to titanium oxide, other white pigments (which may be other than the above-mentioned white pigments) may be used in combination.

[0036] The dispersion may further contain a surfactant, water, and conventionally known additives, such as a pH adjuster, a viscosity adjuster, a surface tension adjuster, a preservative, an antifungal agent, a leveling agent, an antifoaming agent, a light stabilizer, an antioxidant, a nozzle drying inhibitor, a polymer component such as an emulsion, and a dye.

[0037] The dispersion liquid is discharged from the inkjet head toward the non-permeable substrate, and is attached to the non-permeable substrate or the already formed resin layer. The inkjet head is a known type that discharges minute droplets from a nozzle. The dispersion liquid may be applied so as to cover the entire non-permeable substrate or the resin layer, or may be applied only to a part of the non-permeable substrate or the resin layer. Then, the resin liquid is heated after being applied to the non-permeable substrate or the resin layer, and the resin component melts to form a resin layer. When multiple resin layers are formed, for example, the discharge and heating of the resin liquid by the inkjet head is repeated in sequence for the base layer and the surface layer.

[0038] In the resin layer forming step, the amount of the dispersion applied to the non-permeable substrate is 0.1 mg / cm 2 to 10 mg / cm 2 and more preferably within the range of 0.5 mg / cm 2 to 10 mg / cm 2 and particularly preferably 1.0 mg / cm 2 to 10 mg / cm 2 The amount of the dispersion liquid is within the above range, so that the image has good color development and little unevenness. In addition, the transfer sheet has excellent peelability. It is considered that the more the amount of the dispersion liquid applied is increased and the thicker the resin layer is, the poorer the peelability is because the transfer sheet adheres to the resin layer during transfer. On the other hand, it is considered that the less the amount of the dispersion liquid applied is and the thinner the resin layer is, the poorer the color development is because the resin layer that holds the sublimation dye ink is reduced.

[0039] In the transfer step, a transfer sheet having a sublimation dye ink layer is attached to the resin layer, and the sublimation dye ink of the sublimation dye ink layer is transferred to the resin layer by heating. After the transfer, the transfer sheet is peeled off from the resin layer.

[0040] The transfer sheet having a sublimation dye ink layer is formed by a known method. Examples of the substrate of the transfer sheet include paper and resin. The sublimation dye ink is ejected onto the substrate sheet by an inkjet head or the like to form a sublimation dye ink layer of a desired image. The sublimation dye ink contains a disperse dye that sublimes when heated, and multiple colors of sublimation dye ink may be used.

[0041] The heating temperature when transferring the sublimation dye ink to the resin layer is preferably within the range of 120°C to 240°C. If the heating temperature is lower than the above range, the transfer effect will be poor. If the heating temperature is higher than the above range, the image will be blurred or the resin layer will be altered, affecting the image. The transfer time is not particularly limited, but is, for example, within the range of 30 seconds to 120 seconds.

[0042] The sublimation dye ink contains water, a water-soluble organic solvent, and a sublimation dye. The sublimation dye is also called a disperse dye. Examples of the sublimation dye include CI Disperse Red 60; CI Disperse Yellow 3, 7, 8, 23, 39, 51, 54, 60, 71, 86; CI Disperse Orange 1, 1:1, 5, 20, 25, 25:1, 33, 56, 76; CI Disperse Brown 2; CI Disperse Red 11, 50, 53, 55, 55:1, 59, 60, 65, 70, 75, 93, 146, 158, 190, 190 :1, 207, 239, 240; CI Bat Red 41; CI Disperse Violet 8, 17, 23, 27, 28, 29, 36, 57; CI Disperse Blue 19, 26, 26:1, 35, 55, 56, 58, 64, 64:1, 72, 72:1, 81, 81:1, 91, 95, 108, 131, 141, 145, 359; CI Solvent Blue 36, 63, 105, 111; and the like. These may be used alone or in combination of two or more. The dye ink may also contain components (other components) other than those described above. Examples of other components include dispersants, antiseptics and fungicides, pH adjusters, chelating agents, rust inhibitors, ultraviolet absorbers, defoamers, and surface tension adjusters. EXAMPLES

[0043] Examples of the present invention will now be described.

[0044] Example 1 A dispersion containing 15% by weight of at least one urethane resin (Tg<40°C) selected from Superflex 860 and Superflex 150HS manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and Hydran AP10, Hydran AP-20, and Hydran AP-201 manufactured by DIC Corporation, and 20% by weight of 1,3-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) was applied to a flat glass plate at a rate of 1.8 mg / cm using an inkjet printer (GTXpro manufactured by Brother Industries, Ltd.). 2 A resin layer was formed by spraying the ink onto a 50 mm x 25 mm rectangle in an amount of 100 g / m² and heating at 150°C for 180 seconds. The volatile components remaining in the resin layer were less than 5%. A transfer sheet, consisting of a paper sheet with a sublimation dye ink laminated thereon, was placed on top of the formed resin layer and heated at 160°C for 120 seconds using a Kabuto PCA-3233 manual small iron press machine. After cooling naturally, the transfer sheet was peeled off from the resin layer to form a rectangular fill-in image on the substrate.

[0045] Example 2 An image was formed in the same manner as in Example 1, except that a vinyl chloride sheet (manufactured by TP Giken Co., Ltd., polyvinyl chloride sheet, Tg=87° C.) was used as the impermeable substrate.

[0046] Example 3 An image was formed in the same manner as in Example 1, except that the solvent in the dispersion was 40% by weight and the amount of volatile components remaining in the resin layer was 25% by weight.

[0047] Example 4 The coating amount of the dispersion was 12 mg / cm 2 An image was formed in the same manner as in Example 1 except for the above.

[0048] Example 5 The coating amount of the dispersion was 0.4 mg / cm 2 An image was formed in the same manner as in Example 1 except for the above.

[0049] Example 6 An image was formed in the same manner as in Example 1, except that the transfer sheet was heated at 220° C. for 60 seconds.

[0050] Example 7 An image was formed in the same manner as in Example 1, except that the transfer sheet was heated at 90° C. for 60 seconds.

[0051] Example 8 An image was formed in the same manner as in Example 1, except that polycarbonate (manufactured by TP Giken Co., Ltd., polycarbonate plate, Tg=150° C.) was used as the non-permeable substrate.

[0052] Example 9 An image was formed in the same manner as in Example 1, except that the dispersion contained 15% by weight of at least one polyester resin (Tg<40°C) selected from PESRESIN A-110F and PESRESIN A-680 manufactured by Takamatsu Oil Co., Ltd., and ELITEL KT-0507, ELITEL KT-8701, and ELITEL KT-9204 manufactured by Unitika Ltd., instead of the urethane resin.

[0053] Example 10 An image was formed in the same manner as in Example 1, except that the dispersion contained 15% by weight of at least one acrylic resin A (Tg<40°C) selected from MOWINYL 6820, MOWINYL 7523, and MOWINYL 6763 manufactured by Japan Coating Resins, and BONCOAT R-3380-E and BONCOAT H-5 manufactured by DIC Corporation, instead of the urethane resin.

[0054] Example 11 An image was formed in the same manner as in Example 1, except that the dispersion contained 5% by weight of a urethane resin and 15% by weight of a polyester resin.

[0055] Example 12 An image was formed in the same manner as in Example 1, except that the dispersion contained 5% by weight of urethane resin and 15% by weight of acrylic resin A.

[0056] Example 13 An image was formed in the same manner as in Example 1, except that the dispersion contained 15% by weight of at least one acrylic resin B (Tg≧40°C) selected from MOWINYL 6899D and MOWINYL 6800 manufactured by Japan Coating Resins, and BONCOAT AN-1170 and BONCOAT SK-105E manufactured by DIC Corporation, instead of the urethane resin.

[0057] Example 14 An image was formed in the same manner as in Example 1, except that the dispersion contained 15% by weight of at least one polyester resin (Tg≧40°C) selected from PESRESIN A-520, PESRESIN A-647GEX, and PESRESIN A-684G manufactured by Takamatsu Oil Co., Ltd., and Elitel KA-5034 and Elitel KT-8803 manufactured by Unitika Ltd., instead of the urethane resin.

[0058] Example 15 An image was formed in the same manner as in Example 1, except that the dispersion contained 15% by weight of acrylic resin B instead of the urethane resin, and further contained 5% by weight of at least one blocked isocyanate crosslinking agent selected from Meisei Chemical Industry Co., Ltd.'s Meikanate TP-10 and NBP-211, and Dai-ichi Kogyo Seiyaku Co., Ltd.'s Elastron E-37 and Elastron H-15 as a crosslinking agent.

[0059] Example 16 A dispersion containing 15% by weight of acrylic resin B, 10% by weight of titanium oxide particles, and 20% by weight of 1,3-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) was applied to a flat glass plate using an inkjet printer (GTXpro manufactured by Brother Industries, Ltd.) at a rate of 1.8 mg / cm. 2A white resin layer was formed by spraying the ink on a 50 mm x 25 mm rectangle in an amount of 150°C for 180 seconds. A dispersion containing 15% by weight of acrylic resin B and 20% by weight of 1,3-propanediol (Tokyo Chemical Industry Co., Ltd.) and not containing a white pigment was sprayed on the white resin layer using an inkjet head and heated at 150°C for 180 seconds to laminate a transparent resin layer on the white resin layer. The volatile components remaining in the resin layer were less than 5%. A transfer sheet in which a sublimation dye ink was laminated on a paper sheet was placed on the formed resin layer and heated at 160°C for 120 seconds using a manual small iron press machine Kabuto PCA-3233. After natural cooling, the transfer sheet was peeled off from the resin layer to form a rectangular fill-in image on the substrate.

[0060] (Example 17) An image was formed in the same manner as in Example 15, except that the dispersion liquid for forming the white resin layer contained 5% by weight of a crosslinking agent.

[0061] Comparative Example 1 An ultraviolet-curable ink was sprayed onto a glass plate using an inkjet printer (GTXpro, manufactured by Brother Industries, Ltd.) in a rectangular shape of 20 mm x 50 mm to form a solid image.

[0062] Comparative Example 2 An image was formed in the same manner as in Comparative Example 1, except that a white pigment-containing ultraviolet-curable ink was used.

[0063] Comparative Example 3 A dispersion containing a pigment as a coloring material component and 15% by weight of at least one urethane resin selected from Daiichi Kogyo Seiyaku's Superflex 860 and Superflex 150HS, and DIC's Hydran AP10, Hydran AP-20, and Hydran AP-201 as a resin component was sprayed onto a flat glass plate in a rectangle of 50 mm x 25 mm using an inkjet printer (Brother Industries, GTXpro), and heated to form a rectangular filled-in image.

[0064] Comparative Example 4 The same ink as the above-mentioned sublimation dye ink was sprayed onto a flat glass plate in a rectangle of 50 mm x 25 mm using an inkjet printer (GTXpro, manufactured by Brother Industries, Ltd.) to form a solid image. The transfer conditions in the printer were 160°C and 120 seconds.

[0065] Comparative Example 5 A dispersion containing 15% by weight of urethane resin was sprayed onto a flat glass plate in a rectangle of 50 mm x 25 mm using an inkjet printer (GTXpro, manufactured by Brother Industries, Ltd.), and heated to form a resin layer. A solid image of 50 mm x 25 mm was formed on the resin layer using an inkjet printer (GTXpro, manufactured by Brother Industries, Ltd.) with the same ink as the sublimation dye ink described above. The transfer conditions for the printer were 160°C and 120 seconds.

[0066] [Color development test] The optical density (OD value) of three points in the formed image was measured using a spectrophotometer SpectoroEye manufactured by X-Rite (light source: D50, viewing angle: 2°, ANSI-T), the average value was calculated, and the image was evaluated according to the following evaluation criteria. 5:2.0 or more 4:1.5 or more and less than 2.0 3:1.0 or more and less than 1.5 2:0.5 or more and less than 1.0 1: Less than 0.5 or no color development

[0067] [Peeling test] When an image was formed using the transfer sheet, the peelability of the transfer sheet was evaluated according to the following criteria. 5:Easy to peel off 4: Some peeling marks remain on the resin layer 3: Many peeling marks remain on the resin layer 2: The transfer sheet remains on the resin layer 1: Cannot be peeled off

[0068] [Image quality test] The image quality of the formed image was visually evaluated according to the following criteria. 5: Printing is consistent 4: There are some uneven spots in the print 3: The print is uneven throughout 2: The print is uneven throughout, and dye has moved. 1: Unable to transfer

[0069] [Bleeding test] The formed image was visually observed to determine whether it bleeds or not, and was evaluated according to the following criteria. ○: No bleeding ×: There is bleeding

[0070] [Printed part unevenness test] The presence or absence of unevenness in the formed image was visually observed and judged according to the following evaluation criteria. ○: No unevenness ×: Uneven

[0071] [Substrate color concealment test] The color of the non-permeable substrate on which the image was formed was then visually determined to be hidden. ○: The base color is hidden ×: The base color is not concealed.

[0072] The results of each test are shown in Tables 1 to 3. [Table 1] [Table 2] [Table 3]

[0073] [Color development test evaluation] It can be seen that Examples 1 to 17 have superior color development compared to Comparative Examples 4 and 5. In particular, Examples 9 to 17 in which the dispersion liquid contains at least one of a polyester resin and an acrylic resin have an evaluation of 4 or more and have superior color development.

[0074] [Peeling test evaluation] It can be seen that Examples 1, 3 to 17, in which the impermeable substrate is flat glass or polycarbonate, have excellent releasability of the transfer sheet compared to Example 2, in which the impermeable substrate is vinyl chloride. Also, Examples 9 to 17, in which the dispersion contains at least one of polyester resin and acrylic resin, are rated 3 or higher and have excellent releasability. In particular, Examples 13, 15, and 16, in which the dispersion contains acrylic resin B having a glass transition point of 40°C or higher, are rated 4 or higher and have particularly excellent releasability.

[0075] [Image quality test evaluation] It can be seen that Examples 1 to 2 and 4 to 17, in which the amount of volatile components remaining in the resin layer is less than 5% by weight, are superior in image quality to Example 3, in which the amount of volatile components remaining in the resin layer is 25% by weight. 2 In Examples 1 to 2 and 5 to 17, the coating amount of the dispersion was 12 mg / cm 2 It can be seen that the image quality is superior to that of Example 4. From these, it is presumed that the image quality improves as the amount of volatile components remaining in the resin layer decreases.

[0076] [Bleeding test evaluation] It can be seen that in Examples 1 to 17, images without bleeding were formed.

[0077] [Printed part unevenness test evaluation] It can be seen that in Examples 1 to 16, images without unevenness in the printed portion were formed.

[0078] [Concealment test evaluation of substrate color] It can be seen that Examples 16 and 17, in which the dispersion contains a white pigment, hide the base material color better than Examples 1 to 15, in which the dispersion does not contain a white pigment.

[0079] [comprehensive evaluation] In Examples 1 to 17, the transfer sheet has good peelability, and an image with good color development and no bleeding or unevenness is formed on the non-permeable substrate. In addition, since the separation liquid is ejected from the inkjet head onto the non-permeable substrate, a resin layer is formed on a part of the non-permeable substrate. In addition, the transfer sheet has excellent peelability. In addition, the formed image has no unevenness.

[0080] In particular, in Examples 1, 3 to 17 in which the non-permeable substrate is flat glass or polycarbonate, the transfer sheet has good peelability, and the color is well developed and an image without bleeding or unevenness is formed, compared to Example 2 in which the non-permeable substrate is vinyl chloride. It can be seen that Examples 1 to 2 and 4 to 17 in which the amount of volatile components remaining in the resin layer is less than 5% by weight are more excellent in image quality than Example 3 in which the amount of volatile components remaining in the resin layer is 25% by weight. It can also be seen that Examples 9 to 17 in which the dispersion contains at least one of a polyester resin and an acrylic resin are more excellent in color development and transfer sheet peelability than the other Examples. In particular, Examples 13, 15, and 16 in which the dispersion contains an acrylic resin B having a glass transition point of 40°C or more are more excellent in color development and transfer sheet peelability than the other Examples.

Claims

1. 1. An image forming method for forming an image on a water-impermeable substrate, comprising: a resin layer forming step of depositing a dispersion liquid containing resin particles onto the non-permeable substrate by ejecting the dispersion liquid from an inkjet head, and fixing the resin particles to the non-permeable substrate as a resin layer; a transfer step of adhering a transfer sheet having a sublimation dye ink layer to the resin layer and transferring the sublimation dye ink of the sublimation dye ink layer to the resin layer by heating.

2. 2. The image forming method according to claim 1, wherein the non-permeable substrate comprises an inorganic material or a resin material having a glass transition point of 90[deg.] C. or higher.

3. 3. The image forming method according to claim 1, wherein the resin layer contains a volatile component of 20% by weight or less.

4. In the resin layer forming step, the amount of the dispersion liquid discharged onto the non-permeable substrate is 0.1 mg / cm ２ to 10 mg / cm ２ 4. The image forming method according to claim 3, wherein the color density is within the range of

5. 5. The image forming method according to claim 4, wherein the heating temperature in the transfer step is within the range of 100[deg.] C. to 240[deg.] C.

6. 6. The image forming method according to claim 5, wherein the resin particles contain at least one of a urethane resin, a polyester resin, and an acrylic resin.

7. 6. The image forming method according to claim 5, wherein the resin particles contain at least one of a polyester resin and an acrylic resin.

8. 8. The image forming method according to claim 7, wherein the glass transition point of the polyester resin or the acrylic resin is 40[deg.] C. or higher.

9. The image forming method according to claim 8 , wherein the dispersion further comprises a crosslinking agent.

10. The dispersion includes a first dispersion including a colorant and a second dispersion not including a colorant, The resin layer forming step includes: a first step of depositing the first dispersion onto the non-permeable substrate by ejecting it from an inkjet head, and fixing the resin particles to the non-permeable substrate as a first resin layer by heating; and a second step of depositing the second dispersion liquid onto the first resin layer by ejecting the second dispersion liquid from an inkjet head, thereby laminating the resin particles onto the first resin layer as a second resin layer.

Images