JP2017136810A - Transfer printing method using adhesive ink for inkjet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that in conventional image transfer, a hot melt layer may adhere to an image and also a blank space other than the image and heating is required during the transfer, and the problem that there is no ink which can form a final strong adhesive layer between a transferred image and a print object by an inkjet printing method.SOLUTION: By printing and forming an adhesive layer on an image on a transfer sheet, using, as adhesive ink, an organic solvent containing an organic/inorganic hybrid composition which can obtain a silica hybrid hardened film after being dried and hardened, only the image can be transferred and also a strong adhesive layer can be obtained. Further, by using as a transfer sheet a water transfer sheet, non-thermal transfer is made possible as well.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method in which an adhesive layer is formed on an image by ink jet printing and can be transferred without heating.

  As a conventional image transfer method to a fiber like a T-shirt, a method is known in which a toner image is formed on a release sheet coated with hot melt on the entire surface, and the image side is heated and pressed onto a substrate to be transferred. ing. The hot melt layer moves to the base material together with the image and functions as a fixing material to the printed material side of the image. In this method, a hot melt layer is also attached to a blank portion other than the image. The texture of the fiber changes and is hated. Avoiding foreign matters on the margin is a major theme of transfer printing. An example of a countermeasure is proposed in Patent Document 1. In this method, at least two types of layers are applied to the peeling sheet, and the transfer conditions are devised so that the hot melt layer does not migrate to the blank portion. Many of these hot melt layers for fibers are urethane-based and soft, so they are suitable for following textile products, but are not used for hard materials due to insufficient strength.

  On the other hand, a toner image transfer sheet that transfers an image to a hard material other than fibers is generally a transfer sheet that does not transfer anything to the margin. This is because it is considered that the adhesive strength of the polyester resin hot melt constituting the toner is sufficient. A toner image is directly formed on the release layer, and the adhesive force at the time of transfer is obtained by thermal softening of the hot melt resin at the time of heating and pressing. In order to obtain the final strength, it is common to put a substrate to be printed in a heating furnace and heat it for several tens of minutes. All of these conventional transfer methods are the same in that they require heating and pressing at the time of transfer.

  There is also a hard material transfer method in which an adhesive is selectively applied to the image portion of the toner image formed on the release sheet by hand, such as a brush, for the purpose of transferring nothing to the blank portion by image transfer to the fiber. This is proposed in Patent Document 2. Depending on the type of adhesive, this technique can provide a higher adhesive strength by transfer to a hard material, and can be a technique that enables non-heat transfer. However, the application of the adhesive is a manual operation.

  Patent Document 3 is known as an ink-jet printing ink having adhesiveness. This is a technique in which a layer is formed with this adhesive ink on an image, and a fired pigment powder is sprinkled on it to be fired and fixed. The fired pigment referred to here is a mixture of an inorganic pigment and glass frit. By firing, the adhesive ink component evaporates, and the inorganic pigment powder is fused and fixed to the glass frit. The adhesive ink here functions as a temporary adhesive ink for powder, and a complete image is fixed to the substrate by a glass component. The same inventor has proposed a method for attaching a heat-adhesive powder to a printed image portion using this adhesive ink in Patent Document 4, and this also serves as a temporary adhesion, and the final role is the ink. In order to fix an image, a heat-adhesive powder is required.

  As a conventional technique related to the adhesive ink of the present invention, there is a paint containing inorganic fine particles whose size is crushed to the nano level (see, for example, Patent Documents 5 and 6). Solvents are water-based and solvent-based, fine particles are 100% inorganic or hybrid of organic and inorganic mixed, but many of these cured coatings have mechanical strength, heat resistance, weather resistance, stain resistance, and transparency. It has excellent characteristics such as chemical resistance.

Japanese Patent Laid-Open No. 9-52497 JP-A-2005-125292 JP 2010-51940 A JP 2014-162226 A JP 2013-130593 A JP 2008/035669 A

  All of the conventional transfer methods described above require heating and pressing during transfer. Although there was a method to obtain a higher final adhesive force by manually applying adhesive powder or adhesive liquid to the image, a method of printing an adhesive with final adhesive force by digital printing without requiring manual work There was no. Further, although there was a temporary adhesive ink for inkjet printing, the ink alone did not give a final adhesive force between the transferred image and the substrate.

  Although the present invention can deal with hand-drawn images, a series of operations from image printing to applying an adhesive to a transfer image can be performed by digital printing, and can be transferred even without heating, for a wide range of printed materials. The purpose is to obtain a sufficient final adhesive strength.

  In order to achieve the above-mentioned object, the present invention uses an organic solvent containing an organic / inorganic hybrid composition capable of obtaining a silica hybrid cured film after drying and curing as an adhesive ink, and is used for the top of an image formed on a water transfer sheet. In addition, after the adhesive film layer is formed by printing with an ink jet printer, the adhesive film layer is non-heat-pressed or heated and attached to the printing material, and moisture is applied to the water transfer sheet to remove the base sheet. And a step of forming a transfer image on the substrate via the adhesive film layer.

  In addition, the second problem-solving means uses an organic solvent containing an organic / inorganic hybrid composition capable of obtaining a silica hybrid cured film after drying and curing as an ink, and an ink jet printer on an image formed on a release sheet. After the adhesive film layer is formed by printing, the step of attaching the adhesive film layer to the printed material by heating and pressing, and the step of peeling and removing the base sheet of the release sheet via the adhesive film layer are provided. Thus, a method for forming a transfer image is employed.

  The third problem-solving means is that the concentration of silica dispersed in the silica hybrid cured film is 5 wt% to 80 wt%, and the single particle diameter is in the range of 1 to 100 nm. An adhesive ink for ink jet printing used as a problem solving means is provided.

  A fourth problem solving means provides an adhesive ink for ink jet printing as a third problem solving means containing a tackifier and / or a plasticizer.

  A fifth problem solving means provides a printed matter produced by the first and second problem solving means using the ink according to the third problem solving means.

  The operation of the first problem solving means is as follows. The adhesive strength of the adhesive ink will be described in two parts. The force required to transfer the image at the time of transfer is the initial adhesive force, and the force required for the use of the printed material is the final adhesive force. When water is applied to the image formed on the water transfer sheet from the front surface and / or the back surface of the water transfer sheet, the water-soluble layer such as dextrin applied on the surface of the sheet is dissolved, so that the image is released from the base sheet. Therefore, even if the initial adhesive force of the adhesive layer formed on the image is weak, it is easy to receive the image and press-transfer it to the substrate side without heating. It is sufficient to push the pressing force with a finger. Another role at the time of transfer of the adhesive layer is to hold the water transfer sheet so that there is no displacement. In general, an operation is performed by placing a transfer sheet on a substrate with the image on the bottom and the base sheet on the top. Accordingly, the weight of the base sheet acts in the direction in which the image is pressed and does not affect the horizontal displacement. Here, it can be understood that the purpose can be achieved even if the initial adhesive strength is weak. In the transfer onto the curved surface, the water transfer sheet is easily peeled off when the base sheet is warped. Therefore, when the base sheet is paper, a thin paper of 120 μm or less is preferable. However, the paper warping force can be removed by applying moisture before spraying. Furthermore, when the substrate is a cylinder or the like, it can be considered that the transfer work is performed by rolling on the water transfer sheet. In this case, the image is easily transferred to the cylindrical object by applying moisture in advance to make the image free and rolling the cylindrical object at a low speed on the image. From the above, it can be said that the initial adhesive force of the adhesive layer for realizing the non-heat transfer may be as weak as the adhesive ink provided in the present invention. In the adhesive ink of the present invention, if the solid image layer printed is left for several minutes, the viscosity increases due to evaporation of the solvent. The actual transfer procedure includes image formation on the water transfer sheet, inkjet printing of the adhesive layer, leaving the wet ink on the image for a few minutes until it dries a little, pressing the image, applying moisture from the back of the water transfer sheet, The base sheet is peeled off. Water may be applied from the front and / or back of the water transfer sheet before the image is pressed and transferred.

  The adhesive ink of the present invention is not a temporary adhesive ink that newly attaches a bonding powder in order to obtain a final adhesive force. A strong final adhesive force can be obtained by the adhesive layer itself formed by printing. This is because the silica hybrid cured film is excellent in various properties such as transparency, high hardness, chemical resistance, water resistance, heat resistance and adhesion. The solvent containing the organic / inorganic hybrid composition includes an aqueous solvent, but the organic solvent is selected in the present invention. On a laser printer print image made of toner, water-based ink is bounced and scattered in a polka dot shape. This is because the solvent-based ink can cleanly cover the entire surface of the image and can firmly bond the entire surface of the image. The reason why the inorganic fine particle 100% dispersion solvent was not used in the adhesive ink of the present invention was that a wider base material range to be bonded was obtained. The organic / inorganic hybrid type, which has an affinity for both organic polymers and inorganic materials, adheres to a wide range of materials. The substrate to be printed extends to various plastics, glass, metal, leather, wood, paper, ceramics, rubber, non-woven fabrics and the like. If an appropriate resin such as polyurethane or acrylic is selected as the hybrid organic polymer, the adhesive layer can be flexible and can be transferred not only to hard materials but also to flexible materials such as rubber.

  The operation of the second problem solving means is as follows. If the image formed on the release sheet is not heated and pressed, the image cannot be released from the base sheet. This is because the force with which the image adheres to the release layer of the release sheet is much greater than when the water-soluble layer dissolves and the image floats. When heated and pressed, the adhesion force of the layer formed with the adhesive ink of the present invention to the substrate is superior and enables transfer. The adhesive ink of the present invention forms a strong adhesive layer by itself after being dried at room temperature or after being cured by heating and drying. Therefore, in order to obtain the final adhesive force, it is necessary to newly attach an adhesive powder. The same is true. Of course, the adhesion force is stronger than the adhesion force of the toner image itself without the adhesive ink layer of the conventional method to the printing material, and the adhesion to a wide range of materials is the same as in the case of the first problem solving means.

  The operation of the third problem solving means is as follows. The cured film after drying and curing is required to have a strong adhesion to both the image and the printing material. If the ratio of silica generated in the cured film is too low, the effect of the present invention cannot be obtained. If it is too high, cracks are likely to occur. Considering these, the silica concentration in the adhesive film layer was set to 5 wt% to 80 wt%. The standard pigment ink particle size on the market is said to be 200-300 nm. If it is too large, the inkjet printing ejection stability will be poor, and if it is too small, the color will be light. For the purpose of the invention, it is not necessary to consider the color density, and the silica single particle diameter dispersed and formed in the cured film is in the range of 1 to 100 nm. Although it is said that transparency exceeds 50 nm for coating applications, there is no problem even in this range because it is not attached to glass and seen through for the purpose of the present invention.

  The action of the fourth problem solving means is enhancement of the initial adhesive force of the adhesive layer provided by the present invention. The final adhesion does not change. That is, the initial adhesive force provided by the ink according to the third problem solving means utilizes the increase in viscosity due to evaporation of the solvent, and achieves the purpose but is weak. If a tackifier, a plasticizer or the like is added to the adhesive ink, a new tack can be imparted. As a result, even if the level is the same, the initial adhesive force is increased, so that the transfer operation is facilitated.

  Although toner images to be printed by a laser printer have been mainly described, even hand-drawn images using screen printing, oil-based magic pens, etc., which are conventional techniques, can be transferred by the technique of the present invention. An inkjet printer can transfer images formed with water-based ink, UV ink, latex ink, and the like. The condition is that an image is formed on the water-soluble layer or the release layer. As the resin to be combined with the inorganic fine particles of the organic / inorganic hybrid composition, any of thermosetting or thermoplastic organic resins such as acrylic resins, ester resins, ketone resins, polyurethane resins, and the like can be used. The organic solvent is not particularly limited as long as it is a solvent that dissolves the organic / inorganic hybrid composition contained in the adhesive ink, but alcohol-based use is preferable. This is because the safety of handling, the working environment, the relatively low solubility and the low risk of dissolving the resin parts of the printer. Low boiling alcohols, medium boiling alcohols, and high boiling alcohols can be mixed, and it is easy to obtain the required evaporation rate. Adhesive inks are organic, inorganic, such as viscosity modifiers, leveling agents, antifoaming agents, colorants, stabilizers, solvents for preparing solubility, etc., depending on various purposes within the range not impairing the effects of the present invention. Various additives may be added as necessary. There is a method of forming the white layer of the image back using a white toner, but it is also possible to form a white adhesive layer by including a white pigment such as titanium oxide in the adhesive ink of the present invention.

  As described above, according to the present invention, an adhesive layer can be formed by printing on an image formed on a transfer sheet, and can be easily transferred to a printing material even without heating, and sufficient adhesion to a wide range of printing substrates. It is possible to provide a transfer printing method capable of obtaining strength and an adhesive ink for inkjet printing.

It is sectional drawing in which the adhesive ink layer is riding on the image on the transfer sheet which shows embodiment of this invention. FIG. 6 is a cross-sectional view in which the transferred image is transferred to a printing material through an adhesive ink layer.

  In FIG. 1A, reference numeral 1 denotes a transfer sheet base, on which a water-soluble layer or a release layer 2 is applied. The adhesive ink layer 4 covering the image 3 formed on the water-soluble layer or the release layer 2 is formed by printing slightly larger than the image 3 by inkjet. FIG. 1B shows the substrate 5 after image transfer. Since it is after transfer, the vertical relationship between the water-soluble layer or release layer 2 and the image 3 is opposite to that shown in FIG. Common products used in the examples are as follows. The laser printer used was C-841dn (trademark, Oki Data), and the inkjet printer used was PX-1004 (trademark, Seiko Epson). As the water transfer sheet, 110 μm-thick “water transfer paper B” (trademark, sold by Sanryu Co., Ltd.) having a dextrin water-soluble layer 2 coated on one side of the transfer sheet base 1 was used. It is a common water transfer paper used for transferring inorganic pigment images to earthenware. As the release sheet, 120 μm-thick transfer paper for laser printers TP (trademark, sold by Sanryu Co., Ltd.) having a silicon-impregnated release layer 2 formed on one side of the transfer sheet base 1 was used. It is a general transfer paper that transfers toner images to earthenware or metal hard materials other than cloth. There is no hot melt coating layer that transfers together with the images, and it is a type of transfer paper on which only the toner images are transferred. As the tackifier, alcohol-soluble YS Polyster T100 (trademark, sold by Yasuhara Chemical Co., Ltd.) was used.

  Juliano U201 (trademark, Arakawa Chemical Industries, Ltd.), a combination of polyurethane resin and inorganic fine particles, in which silica fine particles of several nm are dispersed and formed in a cured film by 21% by weight, is selected as the organic-inorganic hybrid composition. 20 cc of 2-ethoxyethanol and 2-propanol were added at a ratio of 40 cc to produce a total of 100 cc of adhesive ink. This ink was mounted on the PX-1004, and an image (adhesive layer 4) that was 1 mm larger than the image was printed on the image 3 printed with C-841dn on the water-soluble layer 2 of the water transfer sheet. This was allowed to stand for 3 minutes, and then the image side was pressed against a glass plate (printed material 5), wiped with a sponge soaked with water from the back, and allowed to stand for another 3 minutes. When the base sheet 1 of the water transfer paper B was slowly turned, the image was clearly transferred. In order to obtain the final strength, after performing the heat curing treatment at 130 ° C. for 1 hour, it passed a scratch test with a nail and a peel test with an adhesive tape. Furthermore, the image that was transferred to a flexible polyurethane resin plate and heat-cured was adhered to the image without causing cracks because the image flexibly followed the deformation of the substrate.

  In the case of Example 1, what was left for 10 minutes after printing the adhesive layer 4 was too dry to transfer. The adhesive layer 4 printed by adding 7% by weight of YS polyster T100 to the ink prepared in Example 1 maintains the adhesive strength even after being left for 10 minutes. The adhesive strength higher than that of the adhesive layer 4 was shown. If you want to leave it for a longer time, you can add a high-boiling point alcohol that slows evaporation. There was no effect on the ink ejection stability during ink jet printing, and it was effective in enhancing the initial adhesive strength. The final adhesion was the same as in Example 1.

Solvent-based Glasca HPC7506A (trademark, JSR), which is a combination of an inorganic resin and an acrylic resin in which 70 to 80% by weight of silica fine particles of several nm to several tens of nm are dispersedly formed, is selected as an organic / inorganic hybrid composition. In addition, isopropyl alcohol and 2-ethoxyethanol were added in a ratio of 33 cc to 33 cc of Grasca to produce a total of 99 cc of adhesive ink. In order to obtain the final strength by performing printing and transfer in the same manner as in Example 1, a heat curing treatment was performed at 120 ° C. for 30 minutes. Similar good results were obtained.

Comparative example

  Instead of the organic / inorganic hybrid composition, a super glass barrier (trademark, sketch company) stock solution in which 100% of inorganic fine particles in which 90% by weight or more of silica is formed in the cured layer is dispersed in an organic solvent is used as an adhesive ink. An attempt was made to perform printing and transfer in the same manner as in Example 1, but transfer was not possible. If an organic polymer is present, a certain amount of adhesive strength is obtained by solvent evaporation, but the initial adhesive strength cannot be obtained with only inorganic fine particles and a solvent. In order to confirm the final adhesive strength, printing and transfer were performed by adding 15% by weight of a tackifier. Even after natural drying and after heat curing at 200 ° C. for 1 hour, it adhered to the glass substrate, but what was transferred to the flexible polyurethane resin plate was easily broken and easily dropped off by scratching the nails. It was judged that it did not meet the purpose of the present invention to finally obtain a sufficient adhesive force for a wide range of printed materials.

  With the spread of digital printing in the world, design expressions have become diversified and individualized, and printing has been performed from mass production to single-use items. The present invention is a low-priced technology that eliminates the need for expensive transfer equipment, and can be used by a general store in the town to exchange various gifts from package printing to exchange of gifts between individuals. In addition, if a system capable of printing by transferring an ink jet printer to the site, it can be used for on-site transfer of wall materials of existing buildings.

DESCRIPTION OF SYMBOLS 1 Transfer sheet base sheet 2 Water-soluble layer or release layer 3 Image 4 Adhesive ink layer 5 Printed material

(A) is a cross-sectional view in which an adhesive ink layer is placed on an image on a transfer sheet showing an embodiment of the present invention. (B) is a cross-sectional view in which the transferred image is transferred to the printing material via the adhesive ink layer.

Claims (5)

  Using an organic solvent containing an organic / inorganic hybrid composition that yields a silica hybrid cured film after drying and curing as an adhesive ink, an adhesive film layer was printed on an image formed on a water transfer sheet by an inkjet printer. The adhesion is performed on the printed material, including a step of applying the adhesive film layer to the printed material without heating or adhering to the printed material, and a step of peeling off the base sheet by applying moisture to the water transfer sheet. A transfer printing method, comprising forming a transfer image through a film layer.   An organic solvent containing an organic / inorganic hybrid composition that yields a silica hybrid cured film after drying and curing is used as an adhesive ink, and an adhesive film layer is printed on an image formed on a release sheet by an inkjet printer. A transfer image is formed on the printed material via the adhesive film layer, the method comprising a step of heating and pressing the adhesive film layer to the printed material, and a step of peeling and removing the base sheet of the release sheet. And transfer printing method.   The inkjet printing used for transfer printing according to claim 1 or 2, wherein the silica dispersed in the silica hybrid cured film has a concentration of 5 wt% to 80 wt% and a single particle diameter in the range of 1 to 100 nm. Adhesive ink.   The adhesive ink for inkjet printing according to claim 3, further comprising a tackifier and / or a plasticizer.   A printed matter produced using the transfer printing method according to claim 1.

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