Method for manufacturing a transfer sheet, transfer sheet, and transfer product

Abstract

To provide a manufacturing method of a transfer sheet which is excellent in fastness of an image transferred from a transfer sheet in a transferred material.SOLUTION: A manufacturing method of a transfer sheet includes discharging aqueous ink to a detachable support by an inkjet method, and forming an image, and discharging an aqueous adhesive liquid by the inkjet method so as to at least partially overlap the image, wherein the aqueous adhesive liquid contains a resin A and a resin B having a glass transition temperature higher than that of the resin A by 80°C or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a transfer sheet and an aqueous adhesive used in the method for manufacturing a transfer sheet.

Background Art

[0002] A method is known in which a transfer sheet having an image layer formed on a releasable support is overlaid on a transfer object, and heat treatment or the like is performed to transfer the image to the transfer object. Specifically, an image layer is formed on a releasable support, and an adhesive is applied on the image layer. When transferring to a transfer object, the image layer adheres to the transfer object by the adhesive, and the image is peeled off from the releasable support and transferred to the transfer object.

[0003] By the way, if an adhesive is also applied to a place other than the image formation area on such a releasable support, when transferring an image from the releasable support to the transfer object, the adhesive also adheres to a place other than the transferred image formation area on the transfer object, resulting in problems that the transfer object becomes sticky at that place and the appearance is impaired.

[0004] In order to reduce the occurrence of such problems, there is a method of applying an adhesive only on the image formed on the releasable support. Patent Documents 1 and 2 disclose a method in which ink is adhered onto a sheet by an inkjet method to form a pattern, and then an adhesive is applied only on the pattern by an inkjet method.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] While Patent Documents 1 and 2 disclose transferability, adhesion, and blocking resistance, they do not disclose robustness, and therefore their performance is insufficient.

[0007] One objective of the present invention is to provide a method for manufacturing a transfer sheet that exhibits excellent image fastness on the transferred image, and an aqueous adhesive used in the manufacturing method. [Means for solving the problem]

[0008] Some embodiments of the present invention are shown below. (1) A method for manufacturing a transfer sheet, comprising: ejecting an aqueous ink onto a release support in an inkjet manner to form an image; and ejecting an aqueous adhesive in an inkjet manner so as to partially overlap the image, wherein the aqueous adhesive comprises resin A and resin B having a glass transition temperature 80°C or higher than that of resin A.

[0009] (2) The method for manufacturing a transfer sheet according to (1), wherein the glass transition temperature of resin A is less than 0°C, or the glass transition temperature of resin B is greater than 95°C. (3) The method for manufacturing a transfer sheet according to (1), wherein the glass transition temperature of resin A is less than 0°C and the glass transition temperature of resin B is greater than 95°C. (4) The method for manufacturing a transfer sheet according to any one of (1) to (3), wherein resin A and resin B are each independently a urethane resin or a (meth)acrylic resin. (5) A method for manufacturing a transfer sheet according to any one of (1) to (4), wherein the mass ratio of resin A to resin B is 50:50 to 90:10.

[0010] (6) An aqueous adhesive used in a method for manufacturing a transfer sheet, comprising: ejecting an aqueous ink onto a releaseable support in an inkjet manner to form an image; and applying an aqueous adhesive in an inkjet manner so as to at least partially overlap the image, the aqueous adhesive comprising resin A and resin B having a glass transition temperature 80°C or higher than that of resin A.

[0011] (7) A transfer sheet comprising a release support and a laminate formed on the release support, the laminate comprising an image layer and an adhesive layer, wherein the adhesive layer comprises resin A and resin B having a glass transition temperature 80°C or higher than that of resin A. (8) The transfer sheet according to (7), wherein the peelable support comprises a substrate and a protective layer formed peelably on the substrate, and the laminate is formed on the protective layer. (9) A transfer object comprising a transfer object and an image transferred from the transfer sheet to the transfer object using the transfer sheet described in (7) or (8). [Effects of the Invention]

[0012] According to one embodiment of the present invention, it is possible to provide a method for manufacturing a transfer sheet that exhibits excellent robustness of the image transferred from the transfer sheet in a transfer product, and an aqueous adhesive used in the manufacturing method. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic cross-sectional view showing a transfer sheet and a transfer product according to one embodiment at each stage of the manufacturing method. [Modes for carrying out the invention]

[0014] The present invention will be described below using one embodiment. The present invention is not limited to the examples given in the following embodiments.

[0015] A method for manufacturing a transfer sheet according to one embodiment includes ejecting aqueous ink onto a release support using an inkjet method to form an image, and ejecting an aqueous adhesive solution using an inkjet method so as to at least partially overlap the image, wherein the aqueous adhesive solution comprises resin A and resin B having a glass transition temperature 80°C or higher than that of resin A. This manufacturing method provides a method for manufacturing a transfer sheet that exhibits excellent fastness of the image transferred from the transfer sheet on the transferred material.

[0016] The aqueous adhesive contains resin A, which has a low glass transition temperature (Tg), and resin B, which has a high glass transition temperature. By ensuring that the difference between the glass transition temperatures of resin A and resin B is 80°C or more, it is possible to achieve a good balance between adhesion to the transfer target and the strength of the adhesive layer on the transferred object. Specifically, by including resin A, which has a low glass transition temperature, in the aqueous adhesive, the adhesion of the resulting transfer sheet to the transfer target can be improved. Furthermore, by including resin B, which has a high glass transition temperature, in the aqueous adhesive, the strength of the adhesive layer on the transferred object from the resulting transfer sheet can be improved. As a result, it is possible to obtain a transferred object with excellent transferability and durability for various materials, from soft and stretchable materials like cloth to hard materials such as wood, metal, glass, plastic, and ceramics.

[0017] Regarding the effects described above, it is believed that resin A, with its low glass transition temperature, fits well to the uneven surface shape of the object being transferred, creating a wedge effect and thus improving adhesion. Furthermore, when the water-based adhesive is applied to the transfer sheet, resin B, with its high glass transition temperature, exists in an island-like manner within the matrix of resin A. When external force is applied, it plastically deforms and absorbs energy, thus suppressing cohesive failure of the adhesive layer. Here, it is important to design the interfacial strength so that interfacial delamination between the matrix of resin A (with its low glass transition temperature) and resin B (with its high glass transition temperature) does not occur until resin B (with its high glass transition temperature) undergoes plastic deformation.

[0018] In a preferred embodiment, a resin having a glass transition temperature of less than 0°C as Resin A can have a better adhesion effect. Also, a resin having a glass transition temperature exceeding 95°C as Resin B can have a better strength of the adhesive layer. In a more preferred embodiment, when Resin B having a glass transition temperature exceeding 95°C is used in combination with the matrix of Resin A having a glass transition temperature of less than 0°C, the interfacial strength is maintained high, the toughness of the adhesive layer in the transfer product is increased, and the effect of increasing the adhesive strength can be obtained.

[0019] "Transfer sheet" An embodiment of the transfer sheet will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a transfer sheet and a transfer product according to an embodiment at each stage of the manufacturing method. In FIG. 1, 10 is a transfer sheet, 20 is a transfer product, 1 is a peelable support, 2 is an image layer formed on the peelable support, 3 is an adhesive layer formed on the image layer, and 4 is a transfer target on which an image is transferred from the transfer sheet. The peelable support 1 includes a base material 1a and a protective layer 1b formed on the base material 1a.

[0020] In the example shown in FIG. 1, the manufacturing method of the transfer sheet 10 includes preparing the peelable support 1 (a), and forming the image layer 2 and the adhesive layer 3 on the peelable support 1 (b). Also, in the example shown in FIG. 1, the manufacturing method of the transfer product 20 includes attaching the transfer sheet to the surface of the transfer target 4 (d), and peeling off the peelable support 1 (d).

[0021] "Water-based adhesive liquid" In one embodiment, in a method of ejecting an aqueous ink and an aqueous adhesive liquid onto a peelable support by an inkjet method, the aqueous adhesive liquid contains resin A and resin B whose glass transition temperature (Tg) is 80°C or more higher than that of resin A. In the aqueous adhesive liquid, the difference in the glass transition temperatures of resin A and resin B, "(glass transition temperature of resin B) - (glass transition temperature of resin A)", is 80°C or more, thereby improving the transferability of the image from the transfer sheet to the object to be transferred, and further improving the fastness of the image in the transferred object. The difference in the glass transition temperatures of resin A and resin B is more preferably 90°C or more, 100°C or more, 110°C or more, or 120°C or more.

[0022] In the aqueous adhesive liquid, the difference in the glass transition temperatures of resin A and resin B is not particularly limited, but from the viewpoints of reducing the stickiness of the resin and adhesiveness in the transfer sheet, it is preferably 200°C or less, 150°C or less, or 130°C or less.

[0023] In the aqueous adhesive liquid, the glass transition temperature of resin A is preferably less than 0°C, and may be -5°C or lower, -10°C or lower, -15°C or lower, or -20°C or lower. Within these ranges, the adhesion of the transfer sheet to the object to be transferred can be further improved. In the aqueous adhesive liquid, the glass transition temperature of resin B is preferably more than 95°C, and may be 98°C or more, or 100°C or more. Within these ranges, the strength of the adhesive layer in the transferred object onto which the image is transferred from the transfer sheet can be further improved.

[0024] In the aqueous adhesive liquid, it is preferable that the glass transition temperature of resin A is less than 0°C, or the glass transition temperature of resin B is more than 95°C. More preferably, in the aqueous adhesive liquid, it is preferable that the glass transition temperature of resin A is less than 0°C and the glass transition temperature of resin B is more than 95°C. Thereby, as described above, the toughness of the adhesive layer in the transferred object is increased, and the effect of increasing the adhesive strength can be obtained more.

[0025] In this specification, the glass transition temperature (Tg) is measured by differential scanning calorimetry (DSC). More specifically, it can be measured by the method described below. For differential scanning calorimetry (DSC), a thermal analyzer manufactured by Rigaku Corporation (ThermoplusEVO2DSC8231), etc., can be used. The measurement conditions are as follows: The sample for measurement is prepared by heating from room temperature to 200°C at a heating rate of 10°C / min, and then cooling from 200°C to -50°C at a cooling rate of 10°C / min. After that, the temperature is raised at a heating rate of 10°C / min, and the temperature at the intersection of the extension of the baseline below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rising part of the peak to the peak apex is defined as the glass transition temperature.

[0026] Furthermore, for resins where it is difficult to measure the glass transition temperature using differential scanning calorimetry (DSC), the glass transition temperature measured by dynamic viscoelasticity measurement may be used. For dynamic viscoelasticity measurement, a dynamic viscoelasticity measuring device (Rheogel-E4000) manufactured by UBM Co., Ltd. can be used. The measurement conditions are a frequency of 10 Hz and a heating rate of 2 °C per minute, and the temperature at which the loss modulus of elasticity (E'') in dynamic viscoelasticity is maximized is defined as the glass transition temperature.

[0027] The resin contained in the aqueous adhesive may consist of two types of resins, resin A and resin B, or it may be three or more types of resins containing resins A and B, plus one or two or more additional resins. For example, if the aqueous adhesive contains three types of resins, and the resin with the lowest glass transition temperature is designated as resin A, and the resin with a glass transition temperature 80°C or more higher than resin A is designated as resin B, then the glass transition temperature of the third resin may be in the range between the glass transition temperatures of resins A and B, in a range higher than the glass transition temperature of resin B, or it may be the same as the glass transition temperature of resin A or resin B.

[0028] The reduction of stickiness depends on the resin with the highest glass transition temperature, and the adhesion depends on the resin with the lowest glass transition temperature. Therefore, the glass transition temperature of the resin with the lowest glass transition temperature is preferably less than 0°C, and may be -5°C or lower, -10°C or lower, -15°C or lower, or -20°C or lower. Within these ranges, the adhesion of the transfer sheet to the object to be transferred can be further improved. The glass transition temperature of the resin with the highest glass transition temperature is preferably greater than 95°C, and may be 98°C or higher, or 100°C or higher. Within these ranges, the strength of the adhesive layer in the transfer object onto which the image has been transferred from the transfer sheet can be further improved.

[0029] In the aqueous adhesive, resins A and B are preferably adhesive resins, and more specifically, thermoplastic resins. Resins A and B may be either water-dispersible resins or water-soluble resins, but they are preferably water-dispersible resins because they have low viscosity, good storage stability, and excellent adhesion in the aqueous adhesive. Resins A and B may be anionic resins, cationic resins, amphoteric resins, and nonionic resins, and these may be used in combination. Resins A and B are preferably resins that form a transparent coating film on a releaseable support. This reduces the influence of the aqueous ink on the color development of the transfer product from which the image has been transferred from the transfer sheet.

[0030] Water-dispersible resins are preferably those that can be dispersed in aqueous adhesives in the form of resin particles and can be added to aqueous adhesives in the form of a resin emulsion. Water-dispersible resins may be self-emulsifying types with hydrophilic groups and / or hydrophilic segments introduced to ensure stable dispersion in water, or they may become water-dispersible through the use of an external emulsifier.

[0031] When a water-dispersible resin forms resin particles in an aqueous adhesive solution, the average particle diameter of the resin particles is preferably 500 nm or less, more preferably 300 nm or less, and even more preferably 150 nm or less, from the viewpoint of inkjet ejection performance. For example, the average particle diameter of the resin particles is preferably in the range of 10 nm to 500 nm. Furthermore, it is preferable that the average particle diameter of the resin particles in the resin emulsion added to the aqueous adhesive solution meets these ranges. In this specification, the average particle diameter of the resin particles is the average particle diameter based on volume and is a value measured by dynamic light scattering.

[0032] Examples of water-dispersible resins include conjugated diene resins such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, and vinyl chloride-vinyl acetate copolymer; (meth)acrylic resins; vinyl resins such as ethylene-vinyl acetate copolymer; urethane resins; melamine resins, urea resins, polyester resins, polyolefin resins, silicone resins, polyvinyl butyral resins, alkyd resins; or functional group-modified resins of these resins using monomers containing functional groups such as carboxyl groups. Hydrophilic functional groups may be introduced into these resins, or the surface may be treated with a dispersant to form an oil-in-water resin emulsion, which may then be added to an aqueous adhesive.

[0033] Examples of water-soluble resins include polyvinyl alcohol, poly(meth)acrylic acid, poly(meth)acrylic acid neutralized product, (meth)acrylic acid / maleic acid copolymer, (meth)acrylic acid / sulfonic acid copolymer, and styrene / maleic acid copolymer.

[0034] The weight-average molecular weight (Mw) of the water-dispersible resin is not particularly limited, but is preferably 3,000 to 1,000,000, more preferably 5,000 to 500,000, and even more preferably 10,000 to 300,000. However, if the molecule has a cross-linked structure, measurement may be difficult, and the upper limit is not particularly limited. In this specification, the weight-average molecular weight of the resin is the value obtained by gel permeation (GPC) and converted to polystyrene equivalent.

[0035] Resins A and B are preferably urethane-based resins or (meth)acrylic-based resins, respectively, from the viewpoint of coating properties and adhesion to aqueous adhesives. Furthermore, urethane-based resins and (meth)acrylic-based resins can further improve the coating strength and flexibility of the laminate of the image layer and adhesive layer in the transferred product from the transfer sheet. Also, resins A and B are preferably water-dispersible resins, respectively, from the viewpoint of coating properties and adhesion. Furthermore, water-dispersible resins can suppress viscosity increase in aqueous adhesives and further improve storage stability. In particular, resins A and B are preferably water-dispersible urethane-based resins or water-dispersible (meth)acrylic-based resins, respectively.

[0036] The urethane resin is a resin having a urethane skeleton, and it is preferable that, in addition to the urethane skeleton, it is a polyether-type urethane resin containing ether bonds in the main chain, a polyester-type urethane resin containing ester bonds in the main chain, a polycarbonate-type urethane resin containing carbonate bonds in the main chain, or a polyester-ether-type urethane resin containing both ester and ether bonds in the main chain.

[0037] As the urethane resin, a reaction product of polyisocyanate and polyol can be used. The reaction can be carried out according to a conventional method. The urethane resin can be used individually or in combination of two or more types. The polyisocyanate is not particularly limited as long as it is a compound having at least two isocyanate groups in its molecule.

[0038] Polyisocyanates include, for example, aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and aromatic aliphatic polyisocyanates. Each type of polyisocyanate can be used individually or in combination of two or more types. In addition, dimers, trimers, reaction products, modified products, or polymers of the above-mentioned polyisocyanates can also be used.

[0039] Examples of the polyols mentioned above include low molecular weight polyols; long-chain polyols such as polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, and polyacrylic polyols. Low molecular weight polyols and long-chain polyols can be used individually or in combination of two or more types.

[0040] Furthermore, the above-mentioned urethane resin can be used in combination with chain extenders and reaction inhibitors. There are no particular restrictions on the chain extender, as long as it has two or more active groups that react with isocyanate groups; generally, polyols and polyamines can be used. Monoalcohols and monoamines can be used as reaction inhibitors.

[0041] As an example of a urethane resin, (meth)acrylic urethane resin may be used. In this specification, (meth)acrylic urethane resin is classified as a urethane resin, not a (meth)acrylic resin.

[0042] Examples of (meth)acrylic urethane resins include copolymers of (meth)acrylic resins and urethane resins. One example is a copolymer obtained by polymerizing a urethane prepolymer and (meth)acrylate, in which (meth)acrylate units or poly(meth)acrylic side chains are introduced into the urethane backbone. Examples of urethane prepolymers include those synthesized using the polyisocyanates and polyols mentioned above. Examples of (meth)acrylates include those described later in the section on (meth)acrylic resins. Another example is a copolymer obtained by reacting a polyol and polyisocyanate with a (meth)acrylic resin having a hydroxyl group, in which a polyurethane backbone is introduced into the (meth)acrylate resin. Examples of (meth)acrylic resins having a hydroxyl group include those described later in the section on (meth)acrylic resins. Examples of polyols and polyisocyanates include the polyisocyanates and polyols mentioned above.

[0043] It is preferable to use an emulsion-type urethane resin as the urethane resin. The emulsion-type urethane resin may be either a forced-emulsification type urethane resin that uses a surfactant as an emulsifier, or a self-emulsifying type urethane resin in which hydrophilic groups are introduced into the resin. Among these, the self-emulsifying type urethane resin is particularly preferred as the emulsion-type urethane resin. Examples of hydrophilic groups in the self-emulsifying type urethane resin include sulfonic acid groups, carboxyl groups, hydroxyl groups, polyethyleneoxy groups, amino groups, mono- or disubstituted amino groups, etc. Among these, sulfonic acid groups, carboxyl groups, hydroxyl groups, and polyethyleneoxy groups are preferred as the hydrophilic groups.

[0044] As the (meth)acrylic resin, in addition to homopolymers or copolymers having methacrylic units and / or acrylic units, copolymers (ethylenically unsaturated monomers) having methacrylic units and / or acrylic units along with other units can be used. The (meth)acrylic resin can be obtained by polymerization using (meth)acrylic monomers. Polymerization can be carried out according to conventional methods.

[0045] Examples of (meth)acrylic monomers include alkyl (meth)acrylates, cycloalkyl (meth)acrylates, alkoxyalkyl (meth)acrylates, aralkyl (meth)acrylates, aryl (meth)acrylates, and hydroxyl group-containing (meth)acrylates, as well as other (meth)acrylic esters such as polyalkylene glycol (meth)acrylates, alkyl (meth)acrylates having halogen atoms, (meth)acrylic esters having amino groups, (meth)acrylic esters having epoxy groups and their derivatives, (meth)acrylates having sulfonic acid groups, (meth)acrylates having phosphate groups, (meth)acrylates having isocyanate groups, (meth)acrylates having heterocyclic structures, alkyl or aryl group-terminated polyalkylene glycol mono(meth)acrylates, etc. These can be used individually or in combination of two or more types in the synthesis of (meth)acrylic resins.

[0046] Furthermore, monomers other than (meth)acrylic monomers (hereinafter referred to as "other monomers") can be used in combination. Other monomers are not particularly limited as long as they are copolymerizable with (meth)acrylic monomers, but examples include unsaturated carboxylic acid monomers, styrene monomers, unsaturated monomers containing nitrogen atoms, vinyl monomers, unsaturated alcohols, vinyl ether monomers, vinyl ester monomers, unsaturated monomers containing epoxy groups, and unsaturated monomers containing sulfonic acid groups, as well as ethylenically unsaturated monomers containing alkoxysilyl groups. In addition, monomers having two or more polymerizable double bonds (polyfunctional monomers) can also be used. These can be used individually or in combination of two or more in the synthesis of (meth)acrylic resins.

[0047] As an example of a (meth)acrylic resin, styrene (meth)acrylic resin may be used. Examples of styrene (meth)acrylic resins include copolymers of styrene and (meth)acrylate. As the (meth)acrylate, one or more types from those described above can be used in combination.

[0048] The (meth)acrylic resin is preferably a water-dispersible (meth)acrylic resin, and is preferably added to the aqueous adhesive in the form of an oil-in-water resin emulsion.

[0049] Examples of commercially available resins with a glass transition temperature (Tg) of less than 0°C are listed below. As urethane resins, "Superflex 300 (anionic, Tg: -42°C), Superflex 420 (anionic, Tg: -10°C), Superflex 420NS (anionic, Tg: -10°C), Superflex 460 (anionic, Tg: -21°C), Superflex 460S (anionic, Tg: -28°C), Superflex 470 (anionic, Tg: -31°C), Superflex" are examples of urethane resins manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Examples include "Flex 500M (nonionic, Tg: -39℃), Superflex 650 (cationic, Tg: -17℃), Superflex 740 (anionic, Tg: -34℃), Superflex E-2000 (nonionic, Tg: -38℃), Superflex E-4800 (nonionic, Tg: -65℃)", and "Takelac W-6110 (anionic, Tg: -20℃)" manufactured by Mitsui Chemicals, Inc. (all are product names).

[0050] As (meth)acrylic resins, Japan Coating Resin Co., Ltd. offers "Movinyl 702 (anionic, Tg: -19℃), Movinyl 7525 (anionic, Tg: -16℃), Movinyl LDM7522 (anionic, Tg: -15℃), Movinyl LDM7010 (anionic, Tg: -22℃), Movinyl 461 (anionic, Tg: -48℃), Movinyl 462 (anionic, Tg: -48℃), Movinyl 490 (anionic Examples include Movinyl 987B (anionic, Tg: -2℃), Movinyl S-71 (anionic, Tg: -53℃), Movinyl 718A (anionic, Tg: -6℃), Movinyl 730L (nonionic, Tg: -13℃), Movinyl 7320 (anionic, Tg: -20℃), Movinyl 7400 (anionic, Tg: -41℃), Movinyl 7420 (anionic, Tg: -26℃), etc. (all are trade names).

[0051] Examples of styrene-acrylic resins include "NeoCryl A-1120 (anionic, Tg: -9℃)" from DSM, and "Movinyl 6730 (anionic, Tg: -2℃), Movinyl 7502 (anionic, Tg: -35℃), Movinyl VDM7410 (anionic, Tg: -4℃), and Movinyl 6960 (anionic, Tg: -23℃)" from Japan Coating Resin Co., Ltd. (all are trade names).

[0052] Examples of commercially available resins with a glass transition temperature (Tg) exceeding 95°C are listed below. Examples of urethane resins include "Superflex 130 (anionic, Tg: 101°C)" from Daiichi Kogyo Seiyaku Co., Ltd., "Takelac W-405 (anionic, Tg: 135°C), Takelac W-605 (anionic, Tg: 100°C), Takelac WS-4000 (anionic, Tg: 136°C), Takelac WS-4022 (anionic, Tg: 115°C), Takelac WS-5100 (anionic, Tg: 120°C)" from Mitsui Chemicals, Inc., and "DAOTANTW6493 (anionic, Tg: 100°C)" from Daicelallnex (all are trade names).

[0053] Examples of (meth)acrylic resins include "NeoCryl XK-52 (anionic, Tg: 108℃)" manufactured by DSM Corporation (product name). Examples of styrene-acrylic resins include "Movinyl 972 (anionic, Tg: 101℃)" manufactured by Japan Coating Resin Co., Ltd. (product name).

[0054] Examples of commercially available resins with a glass transition temperature (Tg) of 0°C to 95°C are given below. As urethane resins, Daiichi Kogyo Seiyaku Co., Ltd. has the following products: Superflex 126 (anionic, Tg: 72°C), Superflex 150 (anionic, Tg: 40°C), Superflex 150HS (anionic, Tg: 32°C), Superflex 170 (anionic, Tg: 75°C), Superflex 210 (anionic, Tg: 41°C), Superflex 620 (anionic, Tg: 43°C), Superflex 820 (anionic, Tg: 46°C), Superflex 830HS (anionic, Tg: 68°C), and Superflex 8 Examples include "60 (anionic, Tg: 36℃), Superflex 870 (anionic, Tg: 78℃)", and "Takelac W-5030 (anionic, Tg: 85℃), Takelac W-5661 (anionic, Tg: 70℃), Takelac W-6010 (anionic, Tg: 90℃), Takelac W-6020 (anionic, Tg: 90℃), Takelac W-6061 (anionic, Tg: 25℃), Takelac W-635 (anionic, Tg: 70℃), Takelac WS-5984 (anionic, Tg: 70℃)" from Mitsui Chemicals, Inc. (all are product names).

[0055] As (meth)acrylic resins, Japan Coating Resin Co., Ltd. offers "Movinyl 727 (anionic, Tg: 5℃), Movinyl 742A (anionic, Tg: 45℃), Movinyl 743N (anionic, Tg: 37℃), Movinyl 745 (anionic, Tg: 21℃), Movinyl 1711 (anionic, Tg: 30℃), Movinyl 6520 (anionic, Tg: 41℃), Movinyl 6530 (anionic, Tg: 30℃), Movinyl 7180 (anionic, Tg: 53℃), Movinyl 7470 (nonionic, Tg: 42℃), Movinyl 7720 (nonionic, Tg: 4℃), Movinyl 7820 (cationic, Tg: "NeoCryl" manufactured by DSM, with Tg: 6°C, Movinyl DM772 (anionic, Tg: 6°C), Movinyl DM774 (anionic, Tg: 13°C), Movinyl LDM7156 (anionic, Tg: 37°C), Movinyl LDM7520 (anionic, Tg: 4°C), Movinyl 7980 (anionic, Tg: 55°C), Movinyl 735 (anionic, Tg: 14°C), Movinyl 742A (nonionic, Tg: 39°C), Movinyl 747 (nonionic, Tg: 42°C), Movinyl LDM7582 (nonionic, Tg: 26°C), Movinyl 710A (anionic, Tg: 9°C), Movinyl 731A (nonionic, Tg: 0°C) Examples include "A1105 (anionic, Tg: 93℃)" (all are trade names).

[0056] Examples of styrene-acrylic resins include "Movinyl 749E (anionic, Tg: 25℃), Movinyl 752 (anionic, Tg: 15℃), Movinyl 880 (anionic, Tg: 3℃), Movinyl 940 (anionic, Tg: 3℃), Movinyl 1752 (anionic, Tg: 16℃), Movinyl 1760 (anionic, Tg: 7℃), Movinyl 6720 (anionic, Tg: 34℃), Movinyl DM60 (anionic, Tg: 3℃), and Movinyl 975N (anionic, Tg: 27℃)" manufactured by Japan Coating Resin Co., Ltd. (all are trade names).

[0057] Examples of commercially available water-dispersible (meth)acrylic urethane resins include "DAOTAN TW6462," "DAOTANVTW6463," "DAOTANVTW6464," "DAOTANVTW6471," "DAOTANVTW6473," "DAOTANVTW6474," "DAOTANVTW1262," and "DAOTANVTW1265" manufactured by Daicel Ornex Corporation (all are product names).

[0058] Furthermore, examples of commercially available resins that can be added to aqueous adhesives as oil-in-water resin emulsions are given below. Examples of ethylene-vinyl acetate copolymers include the Sumikaflex series from Sumitomo Chemical Co., Ltd. ("201HQ, 305HQ, 355HQ, 400HQ, 401HQ, 408HQ, 410HQ, 450HQ, 455HQ, 456HQ, 460HQ, 465HQ, 467HQ, 470HQ, 510HQ, 520HQ, 752, 755"), the Vinibran series from Nisshin Chemical Industry Co., Ltd. ("3483Y, 4018, 4495L, 4495H"), and the Polysol series from Showa Denko K.K. ("EVA AD-2, EVA AD-10, EVA AD-13, EVA AD-17, EVA AD-70, EVA AD-96, EVA EL-851") (all are product names).

[0059] Examples of water-dispersible polyolefin resins include the Arrowbase series from Unitika Ltd. ("SB-1010, SE-1010, DC1010," etc.), the Hardlen series from Toyobo Co., Ltd. ("NZ1004, EW5250, EH801J," etc.), and the AQUACER series from Big Chemie Inc. ("272, 497, 515, 531, 537," etc.) (all are product names).

[0060] Resins A and B can be used in combination with various other resins such that the difference in glass transition temperatures is 80°C or more. For example, they can be used in combination from the resins exemplified above. It is preferable that either one of resins A or B is a urethane-based resin or a (meth)acrylic-based resin. It is also preferable that resins A and B are each a urethane-based resin or a (meth)acrylic resin. Resins A and B may be the same type of resin, or they may be different types of resins. For example, it is preferable that both resins A and B are urethane-based resins, or that both resins A and B are (meth)acrylic resins.

[0061] In aqueous adhesives, the mass ratio of resin A to resin B is preferably 50:50 to 90:10, more preferably 55:45 to 80:20, and even more preferably 60:40 to 70:30. A higher proportion of resin A within these ranges can further enhance the durability of transfers using soft substrates such as cloth. On the other hand, a higher proportion of resin B within these ranges can further enhance the durability of transfers using hard substrates such as plastic.

[0062] From the viewpoint of further improving the robustness of transfers using various materials and further improving inkjet ejection performance, the amount of resin A is preferably 1 to 20% by mass, more preferably 5 to 15% by mass, and more preferably 8 to 10% by mass, relative to the total mass of the aqueous adhesive. From the viewpoint of further improving the robustness of transfers using various materials and further improving inkjet ejection performance, the amount of resin B is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass, and more preferably 4 to 6% by mass, relative to the total mass of the aqueous adhesive.

[0063] The total amount of all types of resins contained in the aqueous adhesive is preferably 1.5 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 15% by mass, relative to the total mass of the aqueous adhesive. Within these ranges, inkjet ejection performance can be further improved, and the adhesion of the transfer sheet can be further improved.

[0064] The aqueous adhesive solution is preferably an aqueous composition containing water, and the main solvent may be water. There are no particular restrictions on the type of water, but it is preferable to use water that contains as few ionic components as possible. For example, deionized water, distilled water, pure water, or ultrapure water may be used. From the viewpoint of viscosity and polarity adjustment, the amount of water is preferably 20 to 90% by mass, more preferably 40 to 80% by mass, and even more preferably 50 to 70% by mass, based on the total mass of the aqueous adhesive solution.

[0065] Aqueous adhesives may contain a water-soluble organic solvent in addition to, or instead of, water. From the viewpoint of wettability and moisture retention, it is preferable to use a water-soluble organic solvent that is liquid at room temperature (25°C), is soluble in or miscible with water, and mixes uniformly with the same volume of water at 1 atmosphere and 20°C.

[0066] Examples of water-soluble organic solvents include lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and 2-methyl-2-propanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, and 1,2-butanediol; glycerins such as glycerin, diglycerin, triglycerin, and polyglycerin; acetins such as monoacetin and diacetin; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol Glycol ethers such as monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether can be used; triethanolamine, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, β-thiodiglycol, sulfolane, etc. can be used. The water-soluble organic solvent may be used alone or mixed in groups of two or more, as long as they form a single phase. The boiling point of the water-soluble organic solvent is preferably 100°C or higher, and more preferably 150°C or higher.

[0067] From the viewpoint of wettability, moisturizing effect, viscosity adjustment, etc., the water-soluble organic solvent can be included in an amount of 1 to 80% by mass relative to the total mass of the aqueous adhesive, more preferably 5 to 50% by mass, and even more preferably 10 to 20% by mass. When two or more water-soluble organic solvents are used, it is preferable that the total amount of the two or more water-soluble organic solvents is within these ranges. The total amount of water-soluble organic solvent and water is preferably in the range of 20 to 90% by mass, 40 to 80% by mass, or 60 to 75% by mass relative to the total mass of the aqueous adhesive.

[0068] The aqueous adhesive may further contain a surfactant. Any of the following surfactants may be used: anionic surfactants, cationic surfactants, amphoteric surfactants, or nonionic surfactants, but nonionic surfactants are more preferred. In addition, either low molecular weight surfactants or high molecular weight surfactants may be used. The HLB value of the surfactant is preferably 5 to 20, and more preferably 10 to 18.

[0069] Examples of nonionic surfactants include ester-type surfactants such as glycerin fatty acid esters and fatty acid sorbitan esters; ether-type surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxypropylene alkyl ethers; ether ester-type surfactants such as polyoxyethylene sorbitan fatty acid esters; acetylene-based surfactants; silicone-based surfactants; and fluorine-based surfactants. Among these, acetylene-based surfactants, silicone-based surfactants, and fluorine-based surfactants can be preferably used, and acetylene-based surfactants are more preferable.

[0070] Examples of acetylene-based surfactants include acetylene glycol-based surfactants, acetylene alcohol-based surfactants, and surfactants having an acetylene group. Acetylene glycol-based surfactants are glycols having an acetylene group, preferably having a symmetrical structure with the acetylene group located in the center, and may also have a structure in which ethylene oxide is added to the acetylene glycol.

[0071] Examples of commercially available acetylene-based surfactants include the Surfinol series from Evonik Industries, such as "Surfinol 104E," "Surfinol 104H," "Surfinol 420," "Surfinol 440," "Surfinol 465," and "Surfinol 485," and the Orfin series from Nisshin Chemical Industry Co., Ltd., such as "Orfin E1004," "Orfin E1010," and "Orfin E1020" (all are product names).

[0072] Examples of silicone-based surfactants include polyether-modified silicone-based surfactants, alkyl-aralkyl copolymerized silicone-based surfactants, and acrylic silicone-based surfactants. Examples of commercially available silicone-based surfactants include "Sylface SAG002" and "Sylface 503A" manufactured by Nisshin Chemical Industry Co., Ltd. (both are product names).

[0073] Other nonionic surfactants include, for example, polyoxyethylene alkyl ether-based surfactants such as the Emulgen series manufactured by Kao Corporation, including "Emulgen 102KG," "Emulgen 103," "Emulgen 104P," "Emulgen 105," "Emulgen 106," "Emulgen 108," "Emulgen 120," "Emulgen 147," "Emulgen 150," "Emulgen 220," "Emulgen 350," "Emulgen 404," "Emulgen 420," "Emulgen 705," "Emulgen 707," "Emulgen 709," "Emulgen 1108," "Emulgen 4085," and "Emulgen 2025G" (all are product names).

[0074] Examples of anionic surfactants include the Emal series manufactured by Kao Corporation, such as "Emal 0," "Emal 10," "Emal 2F," "Emal 40," and "Emal 20C"; the Neoperex series, such as "Neoperex GS," "Neoperex G-15," "Neoperex G-25," and "Neoperex G-65"; the Perex series, such as "Perex OT-P," "Perex TR," "Perex CS," "Perex TA," "Perex SS-L," and "Perex SS-H"; and the Demol series, such as "Demol N," "Demol NL," "Demol RN," and "Demol MS" (all are product names).

[0075] Examples of cationic surfactants include the Acetamine series "Acetamine 24" and "Acetamine 86" manufactured by Kao Corporation, the Cortamine series "Cortamine 24P", "Cortamine 86P", "Cortamine 60W", and "Cortamine 86W", and the Sanizol series "Sanizol C" and "Sanizol B-50" (all are product names).

[0076] Examples of amphoteric surfactants include the Anchitol series manufactured by Kao Corporation, such as "Anchitol 20BS," "Anchitol 24B," "Anchitol 86B," "Anchitol 20YB," and "Anchitol 20N" (all are product names).

[0077] The surfactant may be used alone or in combination of two or more types. The surfactant content is preferably 0.1 to 5% by mass, and more preferably 0.2 to 2% by mass, based on the total mass of the aqueous adhesive.

[0078] The aqueous adhesive may optionally contain various additives in addition to the above-mentioned components, as long as it does not impair the effects of the present invention, such as rust inhibitors, preservatives, antioxidants, UV absorbers, infrared absorbers, crosslinking agents, pH adjusters, defoamers, wetting agents (moisturizers), surface tension adjusters (penetrating agents), and fixing agents. The total amount of these additives relative to the total mass of the aqueous adhesive is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less.

[0079] The viscosity of the aqueous adhesive is preferably 1 to 30 mPa·s, more preferably 2 to 20 mPa·s, and even more preferably 3 to 15 mPa·s at 23°C to obtain ejection properties suitable for inkjet printing. In this specification, the viscosity of the aqueous adhesive is the value measured at 23°C using a rotational viscometer. For example, the "Rheometer MCR302" manufactured by Anton Paar Japan Co., Ltd. can be used as the viscosity measuring device.

[0080] The surface tension of the aqueous adhesive is preferably 20 mN / m to 40 mN / m at 23°C. In this specification, the surface tension of the aqueous adhesive can be determined according to the bubble pressure method (maximum bubble pressure method). For example, the surface tension can be measured using the "SITA Messtechnik GmbH science line t60" manufactured by SITA Process Solutions.

[0081] The method for producing the aqueous adhesive is not particularly limited, and the desired aqueous adhesive can be obtained by appropriately mixing each component. The obtained composition may be filtered using a filter or the like. Various additives may also be added as appropriate.

[0082] "Water-based ink" Next, we will describe the aqueous ink used in the manufacturing method of the transfer sheet. The aqueous ink is an aqueous composition containing a colorant.

[0083] The coloring material may include pigments, dyes, or combinations thereof. When the image is formed on the transfer sheet, and further when the image is transferred to the transfer material, pigments are preferably used from the viewpoint of weather resistance and water resistance of the image.

[0084] Pigments can be preferably incorporated into inks as pigment dispersions. Any pigment dispersion that allows the pigment to disperse in a solvent and become dispersed in the ink is acceptable. For example, a dispersion of pigment in water with a pigment dispersant, a dispersion of self-dispersible pigment in water, or a dispersion of microencapsulated pigment coated with resin in water can be used.

[0085] As pigments, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, and blue-green lake pigments, and inorganic pigments such as carbon black and metal oxides can be used. Examples of azo pigments include soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments. Examples of phthalocyanine pigments include metallic phthalocyanine pigments and metal-free phthalocyanine pigments. Examples of polycyclic pigments include quinacridone pigments, perylene pigments, perinone pigments, isoindoline pigments, isoindolinone pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, metal complex pigments, and diketopyrrolopyrrole (DPP). Examples of carbon black include furnace carbon black, lamp black, acetylene black, and channel black. Examples of metal oxides include titanium dioxide and zinc oxide. These pigments may be used individually or in combination of two or more types.

[0086] The average particle size of the pigment is preferably 10 to 500 nm, and more preferably 10 to 200 nm. From the viewpoint of color development, the average particle size of these pigments is preferably 10 nm or more, and from the viewpoint of dispersion stability, it is preferably 500 nm or less. In the case of inkjet inks, it is preferably 500 nm or less from the viewpoint of ejection performance. In this specification, the average particle size of the pigment is the average particle size based on volume, and is a value measured by dynamic light scattering.

[0087] To stably disperse pigments in ink, pigment dispersants such as polymer dispersants and surfactants can be preferably used. Examples of commercially available polymer dispersants include the TEGO Disperse series "TEGO Disperse 740W, 750W, 755W, 760W" from Evonik Japan Co., Ltd., the Solsperse series "Solsperse 20000, 27000, 41000, 43000, 44000, 46000" from Lubrizol Nippon Co., Ltd., the Joncryl series "Joncryl 57J, 60J, 63J" from BASF Japan Ltd., and "DISPERBYK-102, 185, 190, 193, 199" and "BYKJET-9152" from BIC Chemie Japan Co., Ltd. (all are product names).

[0088] For surfactant-type dispersants, nonionic surfactants can be used, taking into consideration the dispersion stability of the pigment in the ink. Examples of commercially available surfactant-type dispersants include nonionic surfactants such as Kao Corporation's Emulgen series "Emulgen A-60, A-90, A-500, 420" (all are product names).

[0089] Pigment dispersants can be used individually or in combination of two or more types. When using a pigment dispersant, the content of the pigment dispersant varies depending on its type and is not particularly limited. For example, the content of the pigment dispersant is preferably 0.005 to 2.0, more preferably 0.01 to 1.0, and even more preferably 0.1 to 0.5, in terms of the mass ratio of the active ingredient to the pigment.

[0090] Self-dispersing pigments may be used as pigments. Self-dispersing pigments are pigments in which hydrophilic functional groups are introduced to the surface of the pigment by chemical or physical treatment. The hydrophilic functional groups introduced into the self-dispersing pigment are preferably ionic, and by charging the pigment surface anionic or cationic, the pigment particles can be stably dispersed in water by electrostatic repulsion. Preferred anionic functional groups include carboxyl groups, sulfo groups, and phosphate groups. Preferred cationic functional groups include quaternary ammonium groups and quaternary phosphonium groups.

[0091] These hydrophilic functional groups may be directly bonded to the pigment surface or bonded via other atomic groups. Examples of other atomic groups include, but are not limited to, alkylene groups, phenylene groups, and naphthylene groups. Examples of pigment surface treatment methods include diazotization, sulfonation, hypochlorite treatment, humic acid treatment, and vacuum plasma treatment.

[0092] As self-dispersing pigments, for example, the CAB-O-JET series from Cabot Corporation, such as "CAB-O-JET200," "CAB-O-JET300," "CAB-O-JET250C," "CAB-O-JET260M," "CAB-O-JET270," and "CAB-O-JET450C," and from Orient Chemical Industries, Ltd., such as "BONJET BLACK CW-1," "BONJET BLACK CW-2," "BONJET BLACK CW-3," and "BONJET BLACK CW-4," can be preferably used (all are product names).

[0093] Pigment dispersions in which the pigment is pre-dispersed with a pigment dispersant may be used. Examples of commercially available pigment dispersions dispersed with a pigment dispersant include the HOSTAJET series from Clariant and the FUJI SP series from Fuji Pigment Co., Ltd. (all are trade names). Microencapsulated pigments in which the pigment is coated with resin may also be used as the pigment.

[0094] Dyes may be incorporated as colorants. The dyes used are those commonly used in the field of printing, and are not particularly limited. Specifically, examples include basic dyes, acid dyes, direct dyes, soluble vat dyes, acid mordant dyes, mordant dyes, reactive dyes, vat dyes, sulfur dyes, etc. Of these, those that are water-soluble or become water-soluble through reduction, etc., are preferably used. More specifically, examples include azo dyes, rhodamine dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, triphenylmethane dyes, diphenylmethane dyes, methylene blue, etc.

[0095] The colorants can be used individually or in combination of two or more. The amount of colorant is preferably 0.1 to 20% by mass, more preferably 1 to 10% by mass, and even more preferably 2 to 5% by mass, relative to the total amount of ink. When a white pigment is used as the base color layer in the aqueous ink, in order to improve the opacity of the transferred object, the amount of white pigment is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 15% by mass, relative to the total amount of ink.

[0096] Water-based inks may further contain surfactants. Surfactants can further enhance the penetration or wettability of the ink into a releaseable support, thereby improving the coating properties of the ink.

[0097] As surfactants, nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, or combinations thereof can be preferably used, and it is more preferable that a nonionic surfactant is included. As surfactants, one or more types from those described above for aqueous adhesives may be used in combination. The amount of surfactant as an active ingredient is preferably 0.1 to 5% by mass, and more preferably 0.2 to 2% by mass, based on the total mass of the aqueous ink.

[0098] The water-based ink may further contain a binder resin. Examples of binder resins include water-dispersible resins, water-soluble resins, and combinations thereof. By using a water-based ink containing a binder resin, a resin coating can be formed on a releaseable support, further improving image fixation and coating strength. When using a transfer sheet with an image formed in this way, even after the image has been transferred to the object to be transferred, the image fixation and coating strength of the transferred object are further improved, resulting in improved robustness.

[0099] Examples of water-dispersible resins include conjugated diene resins such as styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, and vinyl chloride-vinyl acetate copolymer; (meth)acrylic resins; vinyl resins such as ethylene-vinyl acetate copolymer; or functionally modified resins using monomers containing functional groups such as carboxyl groups of these resins; urethane resins; melamine resins, urea resins, polyester resins, polyolefin resins, silicone resins, polyvinyl butyral resins, and alkyd resins. Hydrophilic functional groups may be introduced into these resins, or the surface may be treated with a dispersant to form an oil-in-water resin emulsion, which can then be added to an aqueous adhesive. From the viewpoint of inkjet ejection performance, the average particle size of the water-dispersible resin should be in the range of 10 to 300 nm, preferably 50 to 150 nm. Furthermore, it is preferable that the average particle size of the resin particles in the resin emulsion added to the aqueous ink meets these ranges.

[0100] Examples of water-soluble resins include polyvinyl alcohol, poly(meth)acrylic acid, poly(meth)acrylic acid neutralized product, (meth)acrylic acid / maleic acid copolymer, (meth)acrylic acid / sulfonic acid copolymer, and styrene / maleic acid copolymer.

[0101] The binder resin is preferably 1 to 20% by mass, and more preferably 5 to 10% by mass, relative to the total mass of the aqueous ink. When a white pigment is used as the aqueous ink to form the base color layer, it is preferable to increase the content of the white pigment in order to improve the opacity of the transferred object, and it is also preferable to increase the content of the binder resin in accordance with the content of the white pigment. From this viewpoint, in the case of an aqueous ink containing a white pigment, the binder resin is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 15% by mass, relative to the total mass of the aqueous ink.

[0102] Water-based inks preferably contain water, and the main solvent may be water. Details regarding water are as described above for water-based adhesives. From the viewpoint of viscosity adjustment, the amount of water is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, and even more preferably 40 to 80% by mass, relative to the total amount of ink.

[0103] The water-based ink may further contain a water-soluble organic solvent in addition to or instead of water. The water-soluble organic solvent may be one of those described above for the water-based adhesive, or a combination of two or more. From the viewpoint of wettability, moisturizing effect, and viscosity adjustment, the water-soluble organic solvent is preferably included in an amount of 1 to 80% by mass, more preferably 10 to 50% by mass, and even more preferably 20 to 40% by mass, relative to the total amount of ink. The total amount of the water-soluble organic solvent and water is preferably in the range of 50 to 98% by mass, 60 to 95% by mass, or 70 to 95% by mass relative to the total mass of the water-based adhesive.

[0104] In addition to the components described above, the water-based ink may optionally contain various additives such as rust inhibitors, preservatives, antioxidants, UV absorbers, infrared absorbers, crosslinking agents, pH adjusters, defoamers, wetting agents (moisturizers), surface tension adjusters (penetrating agents), and fixing agents. The total amount of these additives relative to the total mass of the water-based ink is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less.

[0105] The viscosity of the water-based ink is preferably 1 to 40 mPa·s, more preferably 4 to 20 mPa·s, and even more preferably 3 to 15 mPa·s at 23°C to obtain suitable ejection properties for inkjet ink. The viscosity of the water-based ink can be measured in accordance with the method for measuring the viscosity of the water-based adhesive solution described above.

[0106] The surface tension of the water-based ink is preferably 20 to 40 mN / m at 23°C. The surface tension of the water-based ink can be measured in accordance with the viscosity measurement method for the water-based adhesive solution described above.

[0107] The method for preparing aqueous ink is not particularly limited, but the desired ink can be obtained by appropriately mixing each component. For example, a disperser such as a bead mill may be used to improve the dispersibility of the pigment. The obtained composition may also be filtered using a filter or the like. Various additives may also be added as appropriate.

[0108] "Removable support structure" Next, a release support for use in a method for manufacturing a transfer sheet will be described. The release support is such that, after a laminate containing an image layer and an adhesive layer is formed on its surface, the laminate can be peeled off the release support. The release support has a release surface, and examples include a configuration in which the surface has an uneven shape, a configuration in which the surface is release-able, or a combination thereof.

[0109] One form of a release support comprises a substrate and a protective layer formed on the substrate in a releaseable manner. The substrate is not particularly limited as long as it is releaseable from the protective layer, and opaque, translucent, or transparent substrates can be used. The substrate may be either a rigid or flexible substrate, but a flexible substrate is preferred so as to be able to conform to the surface shape of the object to be transferred. As the substrate, release-resistant substrates, such as release-treated paper or release-treated plastic films, are preferably used. As the plastic film, there are no particular limitations, but polyesters are preferred in terms of mechanical strength, heat resistance, and workability, and polyethylene terephthalate is particularly preferred. Release properties can be imparted by conventional methods, for example, by treating the substrate with a release agent. Examples of release agents include waxes, higher fatty acid salts, fatty acid esters, higher fatty acid amides, silicone oils, and silicone resins. The protective layer is releaseable from the substrate and protects the image when transferred to the object, and various thermoplastic resins, thermosetting resins, elastomers, etc. can be used as long as they do not significantly impair the image quality.

[0110] Another form of a release support comprises a substrate, a protective layer formed on the substrate in a releaseable manner, and an ink-receiving layer formed on the protective layer. The ink-receiving layer can be made of a material capable of absorbing and retaining ink, and can consist of inorganic particles, cationic polymers, hydrophilic polymers, thermoplastic resin particles, thermosetting resin particles, elastomers, and the like.

[0111] Examples of commercially available release supports include transfer films from companies such as Eastman Kodak (USA), McLaud Technology (USA), and ecofreen (South Korea).

[0112] "Method for manufacturing transfer sheets" The following describes a method for preparing a transfer sheet using water-based ink and water-based adhesive.

[0113] First, we will explain how to form an image by ejecting water-based ink onto a releaseable support using an inkjet method.

[0114] The inkjet method is a printing method that allows for easy and flexible image formation on demand without contact with the substrate. The inkjet method is not particularly limited and may be any of the following: piezo, electrostatic, thermal, etc. When using an inkjet printing apparatus, it is preferable to eject aqueous ink from the inkjet head based on a digital signal and to adhere the ejected aqueous ink droplets to the substrate.

[0115] The water-based ink may be a single-color ink or a multi-color ink. In the case of a multi-color ink, it is preferable to sequentially apply multiple inks to a release support to form a color image, and then apply a water-based adhesive solution. In a multi-color ink, it is preferable that each of the multiple inks is a water-based ink.

[0116] From the viewpoint of obtaining opacity of the surface of the object to be transferred, an image may be formed on a release support using an aqueous ink, and then a base color layer may be formed on top of the image using an ink with a highly opaque tone, such as a white pigment ink. When forming a base color layer, it is preferable to form the image on the release support, form the base color layer on top of the image, and then apply an aqueous adhesive. It is preferable that the inks used to form the image and the base color layer are both aqueous inks.

[0117] Next, we will explain how to eject an aqueous adhesive solution using an inkjet method so that it at least partially overlaps the image.

[0118] The inkjet method is not particularly limited and can be as described above for water-based inks. The water-based ink and water-based adhesive may be printed inline using the same inkjet printing device, or they may be printed using separate inkjet printing devices.

[0119] In a release support on which an image has been formed, an aqueous adhesive is applied so as to at least partially overlap the area where the image has been formed. In order to selectively transfer the image from the transfer sheet to the object to be transferred, it is preferable to apply the aqueous adhesive so as to overlap the shape of the image. That is, in the release support, it is preferable that the aqueous adhesive is applied to the area where the image has been formed and not to the area where the image has not been formed. As a result, when transferred to the object to be transferred, the image layer is formed on top of the area where the adhesive layer is formed, preventing the exposure of the adhesive layer on the surface of the object to be transferred and further preventing stickiness due to the adhesive. However, it is not necessary to completely eliminate the application of some aqueous adhesive outside the image at the contour of the image.

[0120] The aqueous adhesive may be applied to the release support on which the image has been formed in one application, or it may be applied in two or more applications. Even if the aqueous adhesive is applied in one application and a single adhesive layer is formed on the release support on which the image has been formed, sufficient transferability and robustness can be obtained. When the aqueous adhesive is applied in two or more applications, the aqueous adhesives may be the same or different, but it is preferable that at least one application of the aqueous adhesive contains resin A and resin B.

[0121] After the water-based ink and water-based adhesive solution are applied to the release support, a further process to remove moisture from the release support may be provided. For example, the release support can be dried by heat treatment, blowing air, dehumidification, etc. Heat treatment should be performed within a range that does not affect the adhesion of the water-based adhesive solution, and is preferably performed at 40°C to 140°C for 1 minute to 1 hour.

[0122] Furthermore, a process to remove moisture from the release support coated with water-based ink may be added after applying the water-based ink to the release support but before applying the water-based adhesive. This suppresses the spreading of water-based ink dots and further prevents image blurring. Moreover, from the viewpoint of further improving the adhesion of the image to the transfer target by mixing the water-based ink and water-based adhesive on the release support, a drying step is not required between applying the water-based ink and water-based adhesive to the release support. In other words, it is preferable to apply the water-based adhesive to the release support coated with water-based ink using a wet-on-wet method.

[0123] "Water-based adhesive liquid and preparation kit for transfer sheets" An aqueous adhesive for transfer sheets according to one embodiment is an aqueous adhesive used in a method for manufacturing a transfer sheet, in which an image is formed on a releaseable support by an inkjet method, and the aqueous adhesive is applied by an inkjet method so as to at least partially overlap the image, and comprises resin A and resin B having a glass transition temperature 80°C or higher than resin A. Details of the aqueous adhesive are as described above.

[0124] According to one embodiment, a transfer sheet preparation kit can be provided, consisting of the aqueous ink and aqueous adhesive according to the above embodiment. According to another embodiment, a transfer sheet preparation kit can be provided, consisting of the aqueous ink, aqueous adhesive, and a release support according to the above embodiment.

[0125] "Transfer sheet" A transfer sheet according to one embodiment comprises a release support and a laminate formed on the release support, including an image layer and an adhesive layer, wherein the adhesive layer includes resin A and resin B having a glass transition temperature 80°C or higher than resin A. This transfer sheet can be obtained using the aqueous ink, aqueous adhesive, and release support according to the above embodiment and the manufacturing method described above.

[0126] By including resin A and resin B, which has a glass transition temperature 80°C or more higher than resin A, the transferability of the laminate containing the image layer and adhesive layer from the transfer sheet to the object to be transferred can be improved, and the robustness of the transferred object can be improved. In the transfer sheet, the image layer and adhesive layer may be separate laminates, or they may be laminates in which the image layer and adhesive layer are mixed in a release support with a gradient of their components, or they may be laminates in which the image layer and adhesive layer are mixed with each other and their components are dispersed.

[0127] The details of the release support are as described above, for example, comprising a substrate and a protective layer formed on the substrate, with a laminate formed on the protective layer. Furthermore, an ink-receiving layer may be formed on the surface of the release support on which the image is formed.

[0128] "Method for manufacturing a transfer" One embodiment of the transfer material comprises an object to be transferred and an image transferred from a transfer sheet to the object to be transferred. This transfer material can be obtained using the transfer sheet according to the above embodiment.

[0129] A transfer obtained using a transfer sheet according to one embodiment is a laminate containing an image layer and an adhesive layer transferred from the transfer sheet, and it is preferable that the adhesive layer contains resin A and resin B according to the above-described embodiment. This makes it possible to improve the robustness of the image transferred to the transfer.

[0130] The following describes a method for manufacturing a transfer. The method for manufacturing a transfer is not particularly limited and can be carried out according to conventional methods. For example, a transfer can be obtained by attaching a transfer sheet to the surface of the object to be transferred, performing a heat treatment as necessary, and peeling off the release support from the transfer sheet, thereby transferring the image from the transfer sheet to the surface of the object to be transferred.

[0131] Examples of materials to be transferred include metal substrates such as aluminum, iron, copper, titanium, tin, chromium, cadmium, and alloys (e.g., stainless steel, steel); glass substrates such as borosilicate glass, quartz glass, and soda-lime glass; resin substrates such as polyethylene terephthalate (PET), polypropylene (PP), polyester (PE), (meth)acrylic resins, and vinyl chloride resins; and ceramic substrates such as alumina, zirconia, steatite, silicon nitride, and ceramics. The shape of these substrates is not particularly limited and may be in the form of films, sheets, plates, molded bodies, structures, etc. These substrates may have a plating layer, a metal oxide layer, a resin layer, etc. formed on them, or may be surface-treated using corona treatment or the like.

[0132] Furthermore, examples of materials to be transferred include printing papers such as plain paper, coated paper, and specialty paper; fabrics or fabric products such as woven fabrics, knitted fabrics, and nonwoven fabrics; porous building materials for humidity control, sound absorption, and heat insulation; and wood, concrete, and other porous materials. Here, plain paper is paper that does not have an ink-receiving layer or film layer formed on top of ordinary paper. Examples of plain paper include fine paper, medium-quality paper, PPC paper, newsprint, and recycled paper. As for coated paper, inkjet coated paper such as matte paper, glossy paper, and semi-glossy paper, or so-called coated printing paper, can be preferably used.

[0133] The fibers that make up the fabric include, for example, inorganic fibers such as metal fibers, glass fibers, rock fibers, and mineral fiber; regenerated fibers such as cellulose-based and protein-based fibers; semi-synthetic fibers such as cellulose-based fibers; synthetic fibers such as polyamide, polyester, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, polyurethane, polyethylene, polypropylene, polystyrene, and polyfluoroethylene; and natural fibers such as cotton, linen, silk, and wool.

[0134] The material to be transferred may be either a soft substrate or a hard substrate. By using the transfer sheet according to one embodiment, sufficient image transferability and durability can be obtained even on soft substrates that stretch and contract, such as cloth. Furthermore, by using the transfer sheet according to one embodiment, sufficient image transferability and durability can be obtained on hard substrates such as plastics.

[0135] A transfer temperature of 50 to 200°C is preferred. The heating device used for the transfer is preferably one that applies pressure simultaneously with thermal energy, such as a heat roller device or a heat press device. [Examples]

[0136] The present invention will be described in detail below with reference to examples. The present invention is not limited to the following examples. In the following description, unless otherwise specified, "%" indicates "mass%".

[0137] "Preparation of water-based ink" Table 1 shows the aqueous ink formulation. According to the formulation shown in the table, pigment, dispersant, and 20g of water were placed in a polypropylene (PP) bottle and dispersed using a rocking mill RM-05 (manufactured by Seiwa Giken Co., Ltd.) to obtain a dispersion. The rocking mill conditions were φ0.5mm zirconia beads, 60Hz, and 3 hours. After filtering the beads through a #120 mesh filter, resin, water-soluble solvent, surfactant, and the remaining water were added. The mixture was stirred at 100rpm for 20 minutes using a mixing rotor, and then filtered through a 3μm filter to obtain aqueous ink. The content of each component shown in the table is indicated as the amount of active ingredient.

[0138] "Preparation of water-based adhesive" Table 2 shows the aqueous adhesive formulations. The raw materials were mixed according to the formulations shown in the table, stirred at 100 rpm for 20 minutes using a mixing rotor, and filtered through a 3 μm filter to obtain the aqueous adhesive. The content of each component shown in the table is indicated as the amount of active ingredient.

[0139] "Method for measuring the glass transition temperature of resins" The glass transition temperature (Tg) of the resin was measured by differential scanning calorimetry (DSC). Specifically, differential scanning calorimetry (DSC) was performed using a Rigaku Corporation thermal analyzer (ThermoplusEVO2DSC8231). The measurement conditions were as follows: the sample was heated from room temperature to 200°C at a heating rate of 10°C / min, and then cooled from 200°C to -50°C at a cooling rate of 10°C / min to prepare the sample for measurement. Subsequently, the temperature was increased at a heating rate of 10°C / min, and the temperature at the intersection of the extension of the baseline below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rise of the peak to the peak apex was defined as the glass transition temperature.

[0140] Furthermore, for resins where measuring the glass transition temperature by differential scanning calorimetry (DSC) is difficult, the glass transition temperature measured by dynamic viscoelasticity measurement was used. Specifically, dynamic viscoelasticity measurements were performed using a dynamic viscoelasticity measuring device (Rheogel-E4000) manufactured by UBM Co., Ltd. The measurement conditions were a frequency of 10 Hz and a heating rate of 2°C per minute, and the temperature at which the loss modulus of elasticity (E'') in dynamic viscoelasticity reached its maximum was defined as the glass transition temperature.

[0141] The ingredients used are as follows: Color pigment: Carbon black "MOGUL L" (product name), manufactured by Cabot Corporation. Color pigment: Cyan pigment "Blue No. 4", manufactured by Dainichi Seika Kogyo Co., Ltd. White pigment: Titanium dioxide "CR-80" (product name), manufactured by Ishihara Sangyo Co., Ltd. Dispersant "DISPERBYK-190" (product name): Active ingredient content 40%, manufactured by Big Chemie Japan Co., Ltd. Water-soluble solvent: Glycerin, bp = 290°C. Water-soluble solvent: Propylene glycol, bp = 188°C. Surfactant: Acetylene glycol-based surfactant "Surfinol 485" (product name), 100% active ingredient, manufactured by Nisshin Chemical Industry Co., Ltd.

[0142] The ingredients used are as follows: (resin) Urethane resin (Superflex 460) (product name): Manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Acrylic resin (Movinyl 702) (product name): Manufactured by Japan Coating Resin Co., Ltd. Urethane resin (Superflex 420) (product name): Manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Ethylene-vinyl acetate copolymer (Polysol EVA AD-18) (product name): Manufactured by Showa Denko Corporation. Styrene-acrylic resin (NeoCryl A-1120) (product name): Manufactured by Kusumoto Kasei Co., Ltd. Acrylic resin (Movinyl 727) (product name): Manufactured by Japan Coating Resin Co., Ltd. Styrene acrylic resin (Movinyl 1760) (product name): Manufactured by Japan Coating Resin Co., Ltd. Urethane resin (Superflex 870) (product name): Manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Urethane resin (Takelac W-6020) (product name): Manufactured by Mitsui Chemicals, Inc. Urethane acrylic resin (DAOTAN TW6462) (product name): Acrylic resin (NeoCryl A1105) (product name): Manufactured by Daicel Ornex Corporation. Urethane resin (Takelac W-605) (product name): Manufactured by Mitsui Chemicals, Inc. Urethane resin (Takelac WS-4022) (product name): Manufactured by Mitsui Chemicals, Inc. Acrylic resin (NeoCryl XK-52) (product name): Manufactured by Kusumoto Kasei Co., Ltd. Styrene acrylic resin (Movinyl 972) (product name): Manufactured by Japan Coating Resin Co., Ltd.

[0143] Transfer sheets were prepared using the combinations of aqueous ink and aqueous adhesive obtained as shown in Table 3, following the procedure below. Aqueous ink and aqueous adhesive were introduced into a Mastermind flatbed printer "MMP8130" in the combinations shown in Table 3. An image pattern was printed by ejecting aqueous ink onto a transfer film (Kodak; DTF Kodak Transfer Film A3+ 13'' x 19'' COLD Peel), and then the aqueous adhesive was ejected onto the image pattern. The image patterns of the aqueous ink and aqueous adhesive were made identical in shape and printed at the same position on the transfer film, so that the coated areas of the aqueous ink and aqueous adhesive overlapped. The resulting prints were heat-treated in an oven at 140°C for 10 minutes.

[0144] The dried transfer sheet was cut, placed on top of the material to be transferred, and heat-treated in a heat press machine at 160°C for 30 seconds to transfer the image pattern to the material. The release support of the transfer film was then peeled off to obtain the transferred material. The materials used for the transfer were cotton fabric (compliant with JIS L0803, attached white cloth for testing, cotton (Kanakin No. 3)) and polycarbonate sheet (AGC Inc.'s "Carboglass C110C").

[0145] In Example 12, the transfer material was prepared in the same manner as described above, except that water-based ink No. 1, water-based ink No. 3, and water-based adhesive No. 4 were dispensed in that order, and the resulting printed material was heat-treated in an oven.

[0146] "Transferability" The transferability of images from the transfer sheet to each substrate was evaluated according to the following criteria. The printed characters were in MS Gothic font and full-width hiragana. A: I was able to perfectly transcribe text smaller than 5 points. B: The transcription of characters smaller than 5 points was incomplete. Characters smaller than 6 points were transcribed perfectly. The transcription of the C:6 point font was incomplete.

[0147] "Robustness" For each transfer from the transfer sheet, the dry friction fastness was evaluated according to the following criteria. Dry friction fastness was tested using a Type I testing machine in accordance with the drying test specified in JIS L0849, and evaluated using a stain grayscale. A: Level 4 or higher B: Grade 3~3-4 C: 2nd grade ~ 2nd-3rd grade D: Level 1-2 or lower

[0148] [Table 1]

[0149] [Table 2]

[0150] [Table 3]

[0151] As shown in the table, the combinations of aqueous ink and aqueous adhesive in each example yielded excellent fastness on various substrates. Furthermore, the transferability on various substrates was also excellent.

[0152] Examples 1-15 are examples of using various resins in combination with aqueous adhesives, and all yielded good results. In Examples 1-6 and 9-12, the Tg of one resin A was below 0°C, or the Tg of the other resin B was above 95°C, resulting in even better results. In Examples 1-6 and 11, the Tg of one resin A was below 0°C and the Tg of the other resin B was above 95°C, resulting in even better results. From Examples 1-3, it can be seen that when the ratio of resin A with a low Tg to resin B with a high Tg is large in the aqueous adhesive, the rigidity of the soft substrate is further improved, and when this ratio is small, the rigidity of the hard substrate is further improved.

[0153] Good results were also obtained in the printing of white ink in Example 11, the overprinting of black and white ink in Example 12, and the printing of cyan ink in Example 13. Good results were also obtained when using the resin-free water-based ink in Example 15.

[0154] Comparative Examples 1-3 are examples where the aqueous adhesive contains only one type of resin, or where the difference in Tg between the two types of resins in the aqueous adhesive is small, resulting in reduced durability. [Explanation of Symbols]

[0155] 1. Peelable support 1a Base material 1b Protective layer 2 Image Layers 3 Adhesive layer 4 Transferred object

Claims

1. Forming an image by ejecting aqueous ink onto a releaseable support using an inkjet method, and This includes ejecting an aqueous adhesive liquid using an inkjet method so as to at least partially overlap the aforementioned image, A method for manufacturing a transfer sheet, wherein the aqueous adhesive solution comprises resin A and resin B having a glass transition temperature 80°C or higher than that of resin A.

2. The method for manufacturing a transfer sheet according to claim 1, wherein the glass transition temperature of resin A is less than 0°C, or the glass transition temperature of resin B is greater than 95°C.

3. The method for manufacturing a transfer sheet according to claim 1, wherein the glass transition temperature of resin A is less than 0°C and the glass transition temperature of resin B is greater than 95°C.

4. The method for manufacturing a transfer sheet according to claim 1, wherein resin A and resin B are each independently a urethane resin or a (meth)acrylic resin.

5. A method for manufacturing a transfer sheet according to claim 1, wherein the mass ratio of resin A to resin B is 50:50 to 90:

10.

6. Peelable support, and The laminate is formed on the aforementioned peelable support and includes an image layer and an adhesive layer, The adhesive layer is a transfer sheet comprising resin A and resin B having a glass transition temperature 80°C or higher than that of resin A.

7. The transfer sheet according to claim 6, wherein the peelable support comprises a base material and a protective layer formed peelably on the base material, and the laminate is formed on the protective layer.

8. The object to be transferred, and A transfer object comprising an image transferred from a transfer sheet to an object to be transferred using the transfer sheet described in claim 6.

Images