JP2007111867A - Ink jet transfer printing method, transfer sheet and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer sheet for ink jet transfer printing for transferring a digital image onto the surface of a leather. <P>SOLUTION: This transfer sheet is formed by forming a dry water urethane base resin emulsion film on the front surface side of a transparent or semi-transparent flexible polyurethane rubber film peelably pasted onto a plastic film and then by forming a dry water color ink accepting layer forming agent film on the front surface of the dry water urethane base resin emulsion film. A water color ink accepting layer forming agent is formed by dissolving a water soluble polycation in a water-based medium of a weakly acidic water emulsion type acrylic self-adhesive obtained through a copolymerization between one or more kinds of (meth)acrylates with a 4-12C alkyl group and a vinyl base monomer. By transferring the transfer sheet, on which inkjet printing has been performed with water dye ink or water pigment ink, onto the leather or the like, dyeing with no mottling and excellent color developing can be realized onto the leather or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is an inkjet that can firmly transfer a digital image formed with an aqueous dye ink or an aqueous pigment ink to the surface of leather (including natural leather, synthetic leather, artificial leather, recycled leather, etc.) by an inkjet printing method. The present invention relates to a transfer printing method, a transfer sheet used in the inkjet transfer printing method, and a method for manufacturing the transfer sheet.

  In recent years, the performance of ink-jet color printers has improved dramatically, and in ink-jet printing intended for printing with paper, especially by using special paper with an ink-receiving layer containing a pigment or binder on the surface, It has become possible to easily obtain high-quality color prints that approach photographic quality.

  On the other hand, various attempts have been made to apply inkjet printing technology to leather (see Patent Document 1), but it has the following problems.

  That is, solvent ink is generally used when printing leather by an ink jet method. Since the solvent ink has a high viscosity and has an adhesive force itself, the leather and all the materials to be colored can be colored without bleeding. Further, after coloring, a thick film is formed on the material to be colored, and it is strong and fast, and the color is difficult to peel off. A general printing method uses a transfer sheet having an ink receiving layer forming agent suitable for solvent ink as a receiving layer. Ink-jet printing is performed on the transfer sheet using solvent ink, which is then transferred to the leather to be colored using water or heat.

  However, when solvent ink is used for leather, ink jet printers that can handle solvent ink are expensive and are for business use, and ink jet printing on leather is not widespread. For this reason, printing of leather products is not popular in the market, and printed leather products are regarded as expensive leather products. In addition, the printing environment using solvent ink is very bad due to a strange odor and it is difficult to print leather products easily at home.

  Originally, natural leather has characteristics for each type of animal, and even the same animal has characteristics depending on the part, so it is processed using a wide variety of solutions. It is difficult to print all the leathers with the same ink-receptive layer forming agent without causing blurring and vivid inkjet printing. Even if ink jet printing can be performed, the water resistance is weak in print quality.

  For this reason, it is difficult to print leather etc. easily by an inkjet system at home.

Special table 2003-512958

  Therefore, the present invention is not a conventional business ink-jet ink jet printer that requires a large amount of capital investment, but a digital image formed using a water-based dye ink or water-based pigment ink and ink-jet printer that are widely used in the home. Can be firmly transferred onto the surface of leather (including natural leather, synthetic leather, artificial leather, recycled leather, or composite materials thereof), and the print quality is multicolored, good color development, and less ink bleeding Another object of the present invention is to provide an ink-jet transfer printing method capable of obtaining an image transfer printed material that does not deteriorate the texture and is difficult to peel off, a transfer sheet used in the ink-jet transfer printing method, and a method for producing the same.

  In order to achieve the above object, the present invention forms a dry film of an aqueous urethane resin emulsion on the surface side of a transparent or translucent stretchable polyurethane rubber film that is releasably attached on a plastic film. , A transfer sheet for inkjet transfer printing in which a dry film of an aqueous ink receptive layer forming agent is formed on the surface of the dry film of the aqueous urethane resin emulsion, wherein the aqueous ink receptive layer forming agent has 4 to 12 carbon atoms. Dissolve water-soluble polycations in an aqueous medium of a weakly acidic aqueous emulsion acrylic adhesive obtained by copolymerizing one or more (meth) acrylic acid ester having an alkyl group and a vinyl monomer. A transfer sheet for inkjet printing is provided.

  The present invention also provides a dry film of an aqueous urethane resin emulsion on the surface side of a transparent or translucent non-stretchable urethane film that is releasably attached on a release paper, and the aqueous urethane resin emulsion A transfer sheet for inkjet transfer printing in which a dry film of a water-based ink receptive layer forming agent is formed on the surface of the dry film, wherein the water-based ink receptive layer forming agent has one or more alkyl groups having 4 to 12 carbon atoms. A water-soluble polycation is dissolved in an aqueous medium of a weakly acidic aqueous emulsion type acrylic pressure-sensitive adhesive obtained by copolymerizing two or more kinds of (meth) acrylic acid esters and a vinyl monomer. A transfer sheet for ink jet printing is provided.

  Furthermore, the present invention provides an aqueous urethane resin by applying an aqueous urethane resin emulsion on the surface side of a transparent or translucent stretchable urethane rubber film that is detachably pasted on a plastic film, and drying it. A step of forming an emulsion dry film, and a step of applying a water-based ink-receiving layer forming agent to the surface of the dry film of the water-based urethane resin emulsion and drying to form a dry film of the water-based ink-receiving layer forming agent. The water-based ink receiving layer forming agent is a weakly acidic aqueous solution obtained by copolymerizing one or two or more (meth) acrylic acid esters having an alkyl group having 4 to 12 carbon atoms and a vinyl monomer. A water-soluble polycation is dissolved in an aqueous medium of an emulsion-type acrylic pressure-sensitive adhesive. A method for producing a copy sheet is provided.

  Furthermore, the present invention provides an aqueous urethane resin emulsion dried by applying and drying an aqueous urethane resin emulsion on the surface side of a transparent or translucent non-stretchable urethane film affixed releasably on a release paper. Forming a film; and applying a water-based ink-receiving layer forming agent on the surface of the dry film of the water-based urethane resin emulsion and drying to form a dry film of the water-based ink-receiving layer forming agent, The water-based ink receiving layer forming agent is a weakly acidic aqueous emulsion type obtained by copolymerizing one or more (meth) acrylic acid ester having 4 to 12 carbon atoms and a vinyl monomer. Provided is a method for producing a transfer sheet for ink jet printing, wherein a water-soluble polycation is dissolved in an aqueous medium of an acrylic adhesive. To do.

  Furthermore, the present invention provides a step of forming a transfer image with an aqueous ink on the dry film surface of the aqueous ink receiving layer forming agent in the transfer sheet for ink jet printing according to claim 1, and the aqueous ink receiving layer forming agent. Heating and pressing the transfer sheet for inkjet printing from above the plastic film with the transferred image on the surface of the dry film in contact with the leather surface, and removing the plastic film of the transfer sheet from the urethane film And an inkjet transfer printing method characterized by comprising the steps of:

  Furthermore, the present invention provides a step of forming a transfer image with an aqueous ink on the dry film surface of the aqueous ink receiving layer forming agent in the transfer sheet for ink jet printing according to claim 2, and the aqueous ink receiving layer forming agent. The transfer image on the surface of the dried film is brought into contact with the leather surface and the leather surface and the transfer sheet are immersed in water, and the transfer sheet is peeled off and removed; and the transfer sheet is removed from the urethane sheet. There is provided an ink jet transfer printing method comprising a step of heating and pressurizing from the top of a system film.

  In the transfer sheet for ink jet printing having the above-described configuration, preferably, the water-based emulsion-type acrylic pressure-sensitive adhesive of the ink-receiving layer forming agent has a viscosity of 4000 to 20000 mPa · s / 30 ° C. in an emulsion state with a solid content of about 50%. And the pattern glass transition temperature (Tg) of the dried film is in the range of −10 to −50 ° C.

The ink receiving layer forming agent is preliminarily applied to the ink receiving surface of the substrate to be colored that is colored with ink (for example, dyeing, printing, painting, etc.), so that the ink receiving surface of the substrate to be colored is applied. A transparent dry film is formed on the base material, and it is possible to impart coloration excellent in image sharpness, water resistance, weather resistance and color development to various substrates regardless of whether the ink is pigment type or dye type. it can. In addition, a soft base material can be imparted with coloring suitability excellent in image sharpness, water resistance, weather resistance, and color developability while maintaining its texture and suppleness.

  The water-soluble cationic polymer in the ink receiving layer forming agent plays a role of increasing the adsorption force of the emulsion particles of the acrylic adhesive to the substrate to be colored in the presence of moisture, and onto the dry film of the acrylic adhesive. It is thought that it plays a role of increasing the adsorptive power of the anionic colorant. The dry film of the ink-receiving layer forming agent is effective even when the ink containing the anionic colorant is a water-based ink or when printing with a laser printer, a color copier or the like. .

  The water-based emulsion-type acrylic pressure-sensitive adhesive has a solid content of about 50% in an emulsion state when the viscosity is less than 4000 mPa · s / 30 ° C. and when the viscosity is more than 20000 mPa · s / 30 ° C. The adsorptive power of the substrate to be colored and the ink to the anionic colorant is lowered, and the adhesive strength or adhesive strength is insufficient. Furthermore, when the viscosity in an emulsion state having a solid content of about 50% is larger than 20000 mPa · s / 30 ° C., the permeability to leather and the like is lowered, and the flexibility of the leather and the like is impaired. Therefore, more preferably, the viscosity of the aqueous emulsion-type acrylic pressure-sensitive adhesive in an emulsion state having a solid content of about 50% is 10,000 to 15000 mPa · s / 30 ° C.

The water-based emulsion-type acrylic pressure-sensitive adhesive is a base material and an ink to be colored even when the glass transition temperature (Tg) of the dry film is higher than −10 ° C. or lower than −50 ° C. The adsorbing power with respect to the anionic colorant is reduced, and the adhesive force or adhesive force becomes insufficient. Further, when the glass transition temperature (Tg) of the dry film is higher than −10 ° C., the dry film formed on the fiber surface impairs the texture of the cloth when the cloth is used as the substrate to be colored. Cause. Further, when the glass transition temperature (Tg) of the dry film is lower than −50 ° C., the dry film formed on the substrate to be colored is uncomfortable when touched by hand in a temperature environment of 5 to 30 ° C. Will be produced. Therefore, more preferably, the water-based emulsion-type acrylic pressure-sensitive adhesive has a glass transition temperature (Tg) of the dry film in the range of −10 ° C. to −50 ° C.

  Preferably, the water-based emulsion type acrylic pressure-sensitive adhesive has an alkyl group having 4 to 12 carbon atoms in the presence of a nonionic surfactant or in the presence of a nonionic surfactant and an anionic surfactant. One or two or more (meth) acrylic acid esters and a vinyl monomer are copolymerized. Even if the water-based emulsion type acrylic pressure-sensitive adhesive is emulsion-polymerized in the presence of a nonionic surfactant, the water-based emulsion type acrylic pressure-sensitive adhesive also has a nonionic surfactant and an anionic surfactant. Even when emulsion polymerization is carried out in the presence of an agent, a mixture of the aqueous emulsion-type acrylic pressure-sensitive adhesive and the water-soluble cationic polymer is practically used in a weakly acidic (pH 4 to 6) aqueous medium. Aggregates that do not cause a hindrance are not produced, and the aqueous emulsion acrylic pressure-sensitive adhesive can maintain practically sufficient dispersibility for a long period of time.

  Preferably, the content of the solid content of the water-based emulsion-type acrylic pressure-sensitive adhesive is 0.5 to 5 wt%, the content of the water-soluble cationic polymer is 0.1 to 3 wt%, and the rest is an aqueous medium. is there. When the content of the solid content of the water-based emulsion-type acrylic pressure-sensitive adhesive is more than 5 wt%, the permeability of the emulsion particles particularly between the fibers of the fabric is deteriorated. When the solid content of the water-based emulsion-type acrylic pressure-sensitive adhesive is less than 0.5 wt%, the ink-receiving layer-forming agent on the substrate to be colored can be secured in order to secure the coloring concentration by ink. It becomes necessary to increase the number of repetitions of the application, which becomes inefficient. When the content of the water-soluble cationic polymer is less than 0.1 wt%, the adsorptive power or adhesive strength with respect to the colorant contained in the ink is reduced, which causes deterioration in fastness to washing and fastness to washing. On the other hand, when the content of the water-soluble cationic polymer is more than 3 wt%, the content is excessive with respect to the solid content of the water-based emulsion type acrylic pressure-sensitive adhesive, and coloring (dyeing, printing, painting, etc.) is performed. When the substrate to be colored is subsequently wetted with water, excess water-soluble cationic polymer flows out and causes the surroundings to be contaminated.

  Preferably, the water-based emulsion-type acrylic pressure-sensitive adhesive has a number average molecular weight (Mn) in the range of 3000 to 20000 and a weight average molecular weight (Mw) in the range of 10,000 to 100,000.

  Preferably, the average particle diameter of the water-based emulsion type acrylic pressure-sensitive adhesive is in the range of 0.1 to 3 μm as measured by a laser diffusion method.

  Preferably, the water-based emulsion type acrylic pressure-sensitive adhesive has a minimum film-forming temperature (MFT) of a dry film of 0 ° C. or less.

  Preferably, the aqueous emulsion-type acrylic pressure-sensitive adhesive is obtained by copolymerizing 2-ethylhexyl acrylate, butyl acrylate, and vinyl acetate with an emulsion.

  Preferably, the content of vinyl acetate with respect to the entire copolymer in the water-based emulsion type acrylic pressure-sensitive adhesive is 20 to 30 wt%.

  Preferably, the water-soluble cationic polymer is a quaternary ammonium salt polymer.

Preferably, the water-soluble cationic polymer has the general formula:
CH2 = CH-CH2-NHR
(Wherein R represents hydrogen or an alkyl group having 1 to 18 carbon atoms, a substituted alkyl group, an aralkyl group, or a cycloalkyl group)
Or a salt of the monoallylamine derivative or a salt thereof, or a copolymer of the above-mentioned monoallylamine derivative or a salt thereof and a monomer having an unsaturated double bond copolymerizable therewith.

  Preferably, the water-soluble cationic polymer is polyallylamine hydrochloride having a weight average molecular weight (Mw) in the range of 1000 to 5000.

  According to the present invention, a digital image formed by using a water-based dye ink or a water-based pigment ink and an ink-jet printer that are widely used in the home rather than a conventional solvent-type ink-jet printer that requires a large amount of capital investment for business use Can be firmly transferred onto the surface of leather (including natural leather, synthetic leather, artificial leather, recycled leather, or composite materials thereof), and the print quality is multicolored, good color development, and less ink bleeding In addition, it is possible to provide an ink jet transfer printing method capable of obtaining an image transfer printed material which does not deteriorate the texture and hardly peels off.

  Furthermore, according to the invention, it is possible to provide a transfer sheet that can be used for the above-described inkjet transfer printing method to obtain a transfer printed material with good quality.

  Furthermore, according to this invention, the manufacturing method of the transfer sheet which can manufacture the said transfer sheet efficiently and economically can be provided.

  A film printed vividly on the surface of leather has water resistance and friction fastness, and a polyurethane film has flexibility, so the texture of leather to be colored remains unchanged. Furthermore, since the polyurethane film coats the surface of the leather to be colored, the waterproof property is also high.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of a transfer sheet for inkjet printing according to the present invention. In the figure, 1 is a plastic film, 2 is a urethane rubber film, 3 is a dry film of an aqueous polyurethane emulsion, and 4 is a dry film of an aqueous ink receiving layer forming agent.

  This transfer sheet is obtained by applying an aqueous urethane resin emulsion to the surface side of a translucent urethane rubber film 2 that is detachably attached to the plastic film 1 and drying the aqueous urethane resin emulsion. After the film 3 is formed, a water-based ink receptive layer forming agent is applied to the surface of the dry film 3 of the water-based urethane resin emulsion and dried to form a dry film 4 of the water-based ink receptive layer forming agent. Although the plastic film 1 is not specifically limited, For example, a polypropylene (PP) film can be used. The urethane rubber film 2 having a thickness of several μm to several 100 μm can be used, but a thinner one is preferable so as not to reduce the flexibility of the leather. The water-based ink-receiving layer-forming agent is used in an aqueous medium of a weakly acidic aqueous emulsion type acrylic pressure-sensitive adhesive obtained by copolymerizing an emulsion of 2-ethylhexyl acrylate, butyl acrylate, and vinyl acetate. Polyallylamine hydrochloride having the structural formula (Danfix-723 from Nitto Boseki Co., Ltd.) is dissolved.

  The water-based emulsion-type acrylic pressure-sensitive adhesive used has a viscosity of 4000 to 20000 mPa · s / 30 ° C. in an emulsion state having a solid content of about 50%, and the handle glass transition temperature (Tg) of the dried film is −10. It is in the range of -50 ° C. Further, the solid content of the aqueous emulsion acrylic pressure-sensitive adhesive is 0.5 to 5 wt%, the content of the water-soluble cationic polymer is 0.1 to 3 wt%, and the rest is an aqueous medium. Furthermore, the water-based emulsion type acrylic pressure-sensitive adhesive used has a number average molecular weight (Mn) in the range of 3000 to 20000 and a weight average molecular weight (Mw) in the range of 10,000 to 100,000. . Moreover, the used water-based emulsion type acrylic pressure-sensitive adhesive has an average particle diameter in the range of 0.1 to 3 μm as measured by a laser diffusion method. Furthermore, the water-based emulsion type acrylic pressure-sensitive adhesive used has a dry film with a minimum film-forming temperature (MFT) of 0 ° C. or lower.

  FIG. 2 shows an embodiment of an ink jet transfer printing method using the transfer sheet. Referring to the drawing, according to the ink jet transfer printing method of the present invention, first, transfer with aqueous ink is performed on the surface of the dry film 4 of the aqueous ink receiving layer forming agent in the transfer sheet shown in FIG. 1 by an ink jet printer (not shown). An image (for example, a multicolor digital image) 15 is formed (see FIG. 2A). Next, the transfer sheet is heated and pressed (ironed) from above the plastic film 11 in a state where the transfer image 15 on the surface of the dry film 4 of the water-based ink receiving layer forming agent is in contact with the surface of the leather 16. (See FIG. 2 (b)). Next, the plastic film 11 of the transfer sheet is peeled off and removed from the urethane rubber film 12 (see FIGS. 2C and 2D). In addition, as a heating and pressing treatment method, a roller type heating and pressing apparatus may be used.

  In this way, the film printed vividly on the surface of the leather is water resistant and resistant to friction, and the polyurethane film is flexible, so the texture of the leather to be colored remains unchanged. . Furthermore, since the polyurethane film coats the surface of the leather to be colored, the waterproof property is also high.

  Next, examples of the transfer sheet and the inkjet transfer printing method of the above embodiment will be described together with comparative examples.

Example 1
(1) Transfer sheet A water-based urethane resin emulsion is coated on a surface of a stretchable polyurethane rubber film (protective film) releasably pasted on a plastic film (separator) and dried. After forming a dry film, a water-based ink receiving layer forming agent was applied to the surface of the dry film of the aqueous urethane resin emulsion and dried to form a dry film of the water-based ink receiving layer forming agent. At this time, as the water-based ink receiving layer forming agent, a water-soluble polycation dissolved in an aqueous medium of an aqueous emulsion of a copolymer containing an acrylic resin and vinyl acetate as monomer components was used.

(2) Inkjet printing Using a water-based dye ink, a multicolor image was printed on the surface of the dry film of the aqueous ink-receiving layer forming agent of the transfer sheet using an inkjet printer. As the aqueous dye inkjet printer, PIXUSiP4100 manufactured by Canon Inc. and PM-G720 manufactured by Epson Corporation were used. Moreover, Canon W8400 and Epson PX-9000 were used as the aqueous pigment ink jet printer.

(3) Transfer processing Natural leather, artificial leather, and rigid leather were used as transfer objects. The printing surface side of the transfer sheet was brought into close contact with the surface side of each leather, and was heated and pressed (ironed) for several minutes at a temperature of about 100 to 150 ° C. from the top of the plastic film (separator).

  After the heat and pressure treatment, natural leather, artificial leather and rigid leather were naturally cooled to room temperature, and then the plastic film (separator) was peeled off from the surface of the polyurethane rubber film to complete image transfer.

Example 2
Ink jet printing was carried out in the same manner as in Example 1 using the same transfer sheet as in Example 1. Further, transfer was performed in the same manner as in Example 1. However, the heat and pressure treatment is performed at a temperature of about 100 to 150 ° C. for several minutes from the top of the plastic film (separator), and then at a temperature of about 150 to 200 ° C. Ironed for 10 seconds.

Example 3
The same transfer sheet as in Example 1 was used. In addition, inkjet printing and transfer treatment were performed in the same manner as in Example 1 except that pigment-based aqueous ink was used for inkjet printing.

Example 4
The same transfer sheet as in Example 1 was used. In addition, inkjet printing and transfer treatment were performed in the same manner as in Example 2 except that pigment-based aqueous ink was used for inkjet printing.

Comparative Example 1
As a transfer sheet, a plastic film (separator) on which a stretchable polyurethane rubber film was detachably attached was used. Ink jet printing was performed on the surface of the polyurethane rubber film of this transfer sheet in the same manner as in Example 1 to attempt transfer to natural leather, artificial leather, and rigid leather.

Comparative Example 2
As a transfer sheet, an aqueous urethane resin emulsion was applied to the surface side of a stretchable polyurethane rubber film releasably pasted on a plastic film (separator) and dried to form the aqueous urethane resin emulsion dry film. A thing was used. Ink jet printing was performed on the surface of the aqueous urethane resin emulsion dry film of this transfer sheet in the same manner as in Example 1 to attempt transfer to natural leather, artificial leather, and rigid leather.

Comparative Example 3
As a transfer sheet, a water-based ink-receiving layer-forming agent is applied to the surface side of a stretchable polyurethane rubber film that is releasably affixed to a plastic film (separator) and dried to dry the water-based ink-receiving layer-forming agent. What formed was used. At this time, the water-based ink receiving layer forming agent was prepared by dissolving a water-soluble polycation in an aqueous medium of a copolymer aqueous emulsion containing an acrylic resin and vinyl acetate as monomer components. The transfer sheet was subjected to ink jet printing on the surface of the water-based ink receptive layer forming agent dried film in the same manner as in Example 1 to attempt transfer to natural leather, artificial leather, and rigid leather.

Comparative Example 4
The same transfer sheet as in Example 1 was used, and inkjet printing and transfer were performed in the same manner as in Example 1. However, the heat and pressure treatment (ironing) after the transfer was not performed, and the film was naturally dried at room temperature.

  The following evaluation confirmation test was performed about Examples 1-4 and Comparative Examples 1-4. Each of the evaluations was made into a four-level evaluation of “◎: extremely excellent”, “◯: excellent”, “Δ: slightly inferior”, and “×: inferior”. In addition, "-" in a table | surface shows that the evaluation confirmation test was not able to be performed.

1. Fixability of water-based ink to transfer sheet The fixability of water-based ink to the transfer sheet immediately after inkjet printing was visually confirmed and evaluated.

2. Ink Dot Bleeding on Transfer Sheet After ink jet printing, the presence / absence and degree of occurrence of bleeding on the ink dots on the transfer sheet were visually confirmed and evaluated.

3. Adhesiveness of transferred image to leather The adhesiveness (hardness of peeling) of the transferred image to the surface of natural leather, artificial leather and synthetic leather was confirmed and evaluated.

4). Visibility of transferred image Visibility of transferred images transferred to the surfaces of natural leather, artificial leather and synthetic leather was visually confirmed and evaluated.

5. Water resistance after transfer Natural leather, artificial leather and synthetic leather to which an image was transferred were exposed to running water for 10 hours, and the adhesion (hardness to peel off) of the transferred image and the protective film was confirmed and evaluated.

6). Weather resistance after transfer Natural leather, artificial leather, and synthetic leather to which images have been transferred are exposed to the outdoors for 30 days, and the degree of deterioration in adhesion (hardness to peeling) and color development of the transferred image and protective film was confirmed and evaluated. .

The above evaluation test results are shown in Table 1.

As shown in the said table | surface, in Examples 1-4, it confirmed that a favorable result was obtained in any evaluation test. In particular, after performing a heat and pressure treatment (ironing) at a temperature of about 100 to 150 ° C. for several minutes from the top of the protective film during transfer, the heat and pressure treatment (ironing) is further performed at a temperature of about 150 to 200 ° C. for several tens of seconds. ), The adhesion of the transferred image to leather, the water resistance after transfer and the weather resistance after transfer will be better, and the plastic film (separator) will be a polyurethane rubber film (protective film) It was confirmed that it would be easy to peel off from the surface.

  FIG. 3 is a cross-sectional view showing another embodiment of the transfer sheet for inkjet printing according to the present invention. In the figure, 11 is a release paper, 12 is a water-soluble glue (PVA), 13 is a polyurethane film sheet, 14 is a dry film of an aqueous polyurethane emulsion, and 15 is a dry film of an aqueous ink receiving layer forming agent.

  In this transfer sheet, a water-based urethane resin emulsion is applied to the surface side of a transparent non-stretchable polyurethane film sheet 13 detachably attached to a release surface of a release paper 11 via a water-soluble glue layer 12. After drying to form the water-based urethane resin emulsion dry film 14, a water-based ink-receiving layer forming agent is applied to the surface of the dry film 14 of the water-based urethane resin emulsion and dried to form the water-based ink-receiving layer forming agent. A dry film 15 is formed. Although the plastic film 1 is not specifically limited, For example, a polypropylene (PP) film can be used. The urethane rubber film 2 having a thickness of several μm to several 100 μm can be used, but a thinner one is preferable so as not to reduce the flexibility of the leather. The water-based ink receiving layer forming agent is prepared by mixing polyallylamine in an aqueous medium of a weakly acidic aqueous emulsion type acrylic pressure-sensitive adhesive obtained by copolymerizing 2-ethylhexyl acrylate, butyl acrylate, and vinyl acetate with an emulsion. Hydrochloride (Danfix-723 from Nitto Boseki Co., Ltd.) is dissolved.

  The water-based emulsion-type acrylic pressure-sensitive adhesive used has a viscosity of 4000 to 20000 mPa · s / 30 ° C. in an emulsion state having a solid content of about 50%, and the handle glass transition temperature (Tg) of the dried film is −10. It is in the range of -50 ° C. Further, the solid content of the aqueous emulsion acrylic pressure-sensitive adhesive is 0.5 to 5 wt%, the content of the water-soluble cationic polymer is 0.1 to 3 wt%, and the rest is an aqueous medium. Furthermore, the water-based emulsion type acrylic pressure-sensitive adhesive used has a number average molecular weight (Mn) in the range of 3000 to 20000 and a weight average molecular weight (Mw) in the range of 10,000 to 100,000. . Moreover, the used water-based emulsion type acrylic pressure-sensitive adhesive has an average particle diameter in the range of 0.1 to 3 μm as measured by a laser diffusion method. Furthermore, the water-based emulsion type acrylic pressure-sensitive adhesive used has a dry film with a minimum film-forming temperature (MFT) of 0 ° C. or lower.

  FIG. 4 shows an embodiment of an ink jet transfer printing method using the transfer sheet shown in FIG. Referring to the figure, according to the ink jet transfer printing method of the present invention, first, transfer with water-based ink is performed on the surface of the dry film 15 of the water-based ink receiving layer forming agent in the transfer sheet shown in FIG. An image (for example, a multicolor digital image) 16 is formed (see FIG. 4A). Next, when the transfer image 16 on the surface of the dry film 15 of the water-based ink receptive layer forming agent is brought into contact with the surface of the leather 17 and the surface of the leather 17 and the transfer sheet are immersed in water from above the release paper 11, The adhesive paste (PVA) 12 is melted and the release paper 11 is removed by sliding on the polyurethane film 13 (see FIGS. 4B and 4C). Furthermore, the water-soluble glue 12 remaining on the polyurethane film 13 of the transfer sheet is wiped off cleanly (see FIGS. 4D and 4E). After the leather 17 and the transfer sheet are naturally dried, the transfer sheet is heated and pressed (ironed) from above the polyurethane film 13.

  A film printed vividly on the surface of leather has water resistance and friction fastness, and a polyurethane film has flexibility, so the texture of leather to be colored remains unchanged. Furthermore, since the polyurethane film coats the surface of the leather to be colored, the waterproof property is also high.

  In particular, when the transfer sheet (water transfer type) shown in FIG. 3 is ink-jet printed with the aqueous dye ink 16, the image is stored inside the polyurethane film 13, and the color development unique to the dye can be maintained. In addition, it has excellent fastness to friction, water and light.

  Any film material such as polyester, polyethylene, polylactic acid or the like can be used in place of the polyurethane film 13 of the transfer sheet, but the polyurethane film is suitable under the condition that it is resistant to heat and flexible.

  When the transfer sheet is subjected to heat and pressure treatment (ironing), it is preferable to cover the polyurethane film sheet 13 with a silicon sheet and heat and pressure treatment (ironing) from the top. This is because the silicon sheet is slippery, and even when the polyurethane film is heat-treated from above the silicon sheet, the water-soluble glue (PVA) does not stick to the silicon sheet.

  Next, examples of the transfer sheet and the inkjet transfer printing method of the above embodiment will be described together with comparative examples.

Example 5
(1) Transfer sheet Water-based urethane on the surface side of a transparent non-stretchable polyurethane film (protective film) that is peelably attached to the release surface side of a release paper (separator) via a water-soluble paste (PVA) A water-based resin emulsion is applied and dried to form a dry film of the water-based urethane resin emulsion, and then a water-based ink receptive layer forming agent is applied to the surface of the dry film of the water-based urethane resin emulsion and dried. A dry film of the layer forming agent was formed. At this time, as the water-based ink receiving layer forming agent, a water-soluble polycation dissolved in an aqueous medium of an aqueous emulsion of a copolymer containing an acrylic resin and vinyl acetate as monomer components was used.

(2) Inkjet printing Using a water-based dye ink, a multicolor image was printed on the surface of the dry film of the aqueous ink-receiving layer forming agent of the transfer sheet using an inkjet printer. As the aqueous dye inkjet printer, PIXUSiP4100 manufactured by Canon Inc. and PM-G720 manufactured by Epson Corporation were used. Moreover, Canon W8400 and Epson PX-9000 were used as the aqueous pigment ink jet printer.

(3) Transfer processing Natural leather, artificial leather, and rigid leather were used as transfer objects. With the surface of each leather wet with water, the printing surface of the transfer sheet is in close contact with the surface of the leather, and the release sheet of the transfer sheet is immersed in water from the back to dissolve the water-soluble glue. The release paper was slid sideways and removed from the top of the protective film. Then, the water-soluble paste remaining on the protective film was wiped off. Thereby, the transfer image by which the outer surface was coat | covered with the protective film on the surface of each leather was obtained.

(4) Post-treatment Each leather was naturally dried at room temperature, and then heated and pressurized (ironed) for several minutes at a temperature of about 100 to 150 ° C. from above the protective film.

Example 6
The same transfer sheet as in Example 5 was used. Inkjet printing and transfer were performed in the same manner as in Example 5. Furthermore, as post-processing, after ironing for several minutes from the top of the protective film at the same temperature as in Example 5, ironing was further performed at a temperature of about 150 to 200 ° C. for several tens of seconds.

Example 7
The same transfer sheet as in Example 5 was used. In addition, inkjet printing, transfer, and post-treatment were performed in the same manner as in Example 5 except that pigment-based aqueous ink was used for inkjet printing.

Example 8
The same transfer sheet as in Example 5 was used. Inkjet printing, transfer, and post-treatment were each performed in the same manner as in Example 6 except that pigment-based aqueous ink was used for inkjet printing.

Comparative Example 5
As the transfer sheet, a sheet in which a transparent non-stretchable polyurethane film was attached to the release surface side of the release paper via a water-soluble paste (PVA) was used. Ink jet printing was carried out on the polyurethane film surface of this transfer sheet in the same manner as in Example 1 to attempt transfer to natural leather, artificial leather and rigid leather.

Comparative Example 6
As a transfer sheet, an aqueous urethane resin emulsion is applied to the surface side of a transparent non-stretchable polyurethane film attached to the release surface side of the release paper via a water-soluble paste (PVA), and dried. What formed the urethane-type resin emulsion dry film was used. Ink jet printing was performed on the surface of the aqueous urethane resin emulsion dry film of this transfer sheet in the same manner as in Example 1 to attempt transfer to natural leather, artificial leather, and rigid leather.

Comparative Example 7
As a transfer sheet, a water-based ink-receiving layer forming agent is applied to the surface side of a transparent non-stretchable polyurethane film attached to the release surface side of the release paper via a water-soluble paste (PVA) and dried. A water-based ink receiving layer forming agent having a dry film formed thereon was used. At this time, the water-based ink receiving layer forming agent was prepared by dissolving a water-soluble polycation in an aqueous medium of a copolymer aqueous emulsion containing an acrylic resin and vinyl acetate as monomer components. Ink-jet printing was performed on the surface of the dry sheet of the aqueous ink receptive layer forming agent of this transfer sheet in the same manner as in Example 5 to attempt transfer to natural leather, artificial leather and rigid leather.

Comparative Example 8
The same transfer sheet as in Example 5 was used, and inkjet printing and transfer were performed in the same manner as in Example 5. However, the heat and pressure treatment (ironing) after transfer was not performed, and only natural drying was performed at room temperature.

  The following evaluation confirmation test was performed about Examples 5-8 and Comparative Examples 5-8. Each of the evaluations was made into a four-level evaluation of “◎: extremely excellent”, “◯: excellent”, “Δ: slightly inferior”, and “×: inferior”. In addition, "-" in a table | surface shows that the evaluation confirmation test was not able to be performed.

1. Fixability of water-based ink to transfer sheet The fixability of water-based ink to the transfer sheet immediately after inkjet printing was visually confirmed and evaluated.

2. Ink Dot Bleeding on Transfer Sheet After ink jet printing, the presence / absence and degree of occurrence of bleeding on the ink dots on the transfer sheet were visually confirmed and evaluated.

3. Adhesiveness of transferred image to leather The adhesiveness (hardness of peeling) of the transferred image to the surface of natural leather, artificial leather and synthetic leather was confirmed and evaluated.

4). Visibility of transferred image Visibility of transferred images transferred to the surfaces of natural leather, artificial leather and synthetic leather was visually confirmed and evaluated.

5. Adhesiveness of protective film The adhesiveness (hardness of peeling) of the protective film covering the front side of the transferred image transferred to the surface of natural leather, artificial leather and synthetic leather was evaluated and evaluated.

6). Water resistance after transfer Natural leather, artificial leather and synthetic leather to which an image was transferred were exposed to running water for 10 hours, and the adhesion (hardness to peel off) of the transferred image and the protective film was confirmed and evaluated.

7). Weather resistance after transfer Natural leather, artificial leather, and synthetic leather to which images have been transferred are exposed to the outdoors for 30 days, and the degree of deterioration in adhesion (hardness to peeling) and color development of the transferred image and protective film was confirmed and evaluated. .

The above evaluation test results are shown in Table 2.

  As shown in the above table, in Examples 5 to 8, it was confirmed that good results were obtained in any of the evaluation tests. In particular, as a post-treatment after the transfer, after heating and pressing (ironing) for several minutes at a temperature of about 100 to 150 ° C. from the top of the protective film, heating is further performed at a temperature of about 150 to 200 ° C. for several tens of seconds. It was confirmed that when pressure treatment (ironing) was performed, the adhesion of the transferred image to leather, the adhesion of the protective film, the water resistance after transfer, and the weather resistance after transfer were improved.

  The inkjet transfer printing method according to the present invention can be suitably applied to natural leather, synthetic leather, artificial leather, recycled leather, or composite materials thereof.

It is sectional drawing which shows one Embodiment of the transfer sheet for inkjet printing by this invention. (A)-(d) is sectional drawing which shows one Embodiment of the inkjet transfer printing method using the transfer sheet shown in FIG. It is sectional drawing which shows other embodiment of the transfer sheet for inkjet printing by this invention. (A)-(e) is sectional drawing which shows one Embodiment of the inkjet transfer printing method using the transfer sheet shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plastic film 2 Polyurethane rubber film 3 Dry film of water-based polyurethane emulsion 4 Dry film of water-based ink receiving layer forming agent 5 Water-based ink 6 Leather 11 Release paper 12 Water-soluble glue layer 13 Polyurethane film sheet 14 Dry film 15 of water-based polyurethane emulsion Water-based Ink-receiving layer forming agent dry film 16 Water-based ink 17 Leather

Claims (18)

A dry film of a water-based urethane resin emulsion is formed on the surface side of a transparent or translucent stretchable polyurethane rubber film that is detachably pasted on a plastic film, and the surface of the dry film of the water-based urethane resin emulsion A transfer sheet for inkjet transfer printing in which a dry film of a water-based ink receptive layer forming agent is formed, wherein the water-based ink receptive layer forming agent is one or more kinds having a C 4-12 alkyl group ( Inkjet printing characterized by dissolving a water-soluble polycation in an aqueous medium of a weakly acidic aqueous emulsion type acrylic pressure-sensitive adhesive obtained by copolymerizing a (meth) acrylate ester and a vinyl monomer. Transfer sheet. A dry film of a water-based urethane resin emulsion is formed on the surface side of a transparent or translucent non-stretchable urethane film that is releasably pasted on a release paper, and the surface of the dry film of the water-based urethane resin emulsion is formed. A transfer sheet for inkjet transfer printing in which a dry film of a water-based ink receptive layer forming agent is formed, wherein the water-based ink receptive layer forming agent has one or more (meta) having an alkyl group having 4 to 12 carbon atoms. ) Ink jet printing characterized by dissolving a water-soluble polycation in an aqueous medium of a weakly acidic aqueous emulsion type acrylic pressure-sensitive adhesive obtained by copolymerizing an acrylic ester and a vinyl monomer Transfer sheet. The water-based emulsion-type acrylic pressure-sensitive adhesive has a viscosity in the emulsion state of about 50% solid content of 4000 to 20000 mPa · s / 30 ° C., and a glass transition temperature of the dry film of −10 to −50 ° C. The ink-jet printing transfer sheet according to claim 1 or 2, wherein the ink falls within a range. The water-based emulsion type acrylic pressure-sensitive adhesive is a copolymer of one or more (meth) acrylic acid ester having a C 4-12 alkyl group and a vinyl monomer in the presence of a nonionic surfactant. The transfer sheet for ink jet printing according to claim 1, wherein the transfer sheet is used. The water-based emulsion-type acrylic pressure-sensitive adhesive is composed of one or more (meth) acrylic acid esters and vinyl having an alkyl group having 4 to 12 carbon atoms in the presence of a nonionic surfactant and an anionic surfactant. The transfer sheet for ink-jet printing according to claim 1 or 2, wherein the monomer is copolymerized. The solid content of the water-based emulsion type acrylic pressure-sensitive adhesive is 0.5 to 5 wt%, the content of the water-soluble cationic polymer is 0.1 to 3 wt%, and the rest is an aqueous medium. The transfer sheet for ink jet printing according to claim 1 or 2, characterized in that: The water-based emulsion type acrylic pressure-sensitive adhesive has a number average molecular weight in the range of 3000 to 20000 and a weight average molecular weight in the range of 10,000 to 100,000. Transfer sheet for inkjet printing. The transfer sheet for inkjet printing according to claim 1 or 2, wherein an average particle size of the water-based emulsion type acrylic pressure-sensitive adhesive is in a range of 0.1 to 3 µm. The transfer sheet for ink-jet printing according to claim 1 or 2, wherein the water-based emulsion type acrylic pressure-sensitive adhesive has a minimum film forming temperature of a dry film of 0 ° C or lower. 3. The ink jet printing according to claim 1, wherein the water-based emulsion type acrylic pressure-sensitive adhesive is obtained by copolymerizing 2-ethylhexyl acrylate, butyl acrylate, and vinyl acetate with an emulsion. Transfer sheet. 9. The ink receiving layer forming agent according to claim 8, wherein the content of vinyl acetate in the aqueous emulsion acrylic pressure-sensitive adhesive is 20 to 30 wt% with respect to the entire copolymer. 2. The ink receiving layer forming agent according to claim 1, wherein the water-soluble cationic polymer is a polymer of a quaternary ammonium salt. The water-soluble cationic polymer has the general formula:
CH2 = CH-CH2-NHR
(Wherein R represents hydrogen or an alkyl group having 1 to 18 carbon atoms, a substituted alkyl group, an aralkyl group, or a cycloalkyl group)
A polymer of a monoallylamine derivative or a salt thereof, or a polymer of the monoallylamine derivative or a salt thereof and a monomer having an unsaturated double bond copolymerizable therewith. The transfer sheet for ink jet printing according to claim 1 or 2, characterized in that: The transfer sheet for inkjet printing according to claim 1 or 2, wherein the water-soluble cationic polymer is polyallylamine hydrochloride having a weight average molecular weight in a range of 1000 to 5000. An aqueous urethane resin emulsion is coated on the surface side of a transparent or translucent urethane rubber film that is detachably attached to a plastic film and dried to form the aqueous urethane resin emulsion dry film. And a step of applying a water-based ink receptive layer forming agent to the surface of the dry film of the water-based urethane resin emulsion and drying to form a dry film of the water-based ink receptive layer forming agent. The layer forming agent is a weakly acidic aqueous emulsion acrylic pressure-sensitive adhesive obtained by copolymerizing one or more (meth) acrylic acid esters having 4 to 12 carbon atoms and a vinyl monomer. A method for producing a transfer sheet for ink-jet printing, comprising a water-soluble polycation dissolved in an aqueous medium . Applying a water-based urethane resin emulsion to the surface side of a transparent or translucent non-stretchable urethane film releasably pasted on a release paper and drying to form the water-based urethane resin emulsion dry film; Forming a water-based ink-receiving layer forming agent on the surface of the dry film of the water-based urethane-based resin emulsion, and drying to form a water-based ink-receiving layer-forming agent. The agent is an aqueous solution of a weakly acidic aqueous emulsion acrylic pressure-sensitive adhesive obtained by copolymerizing one or more (meth) acrylic acid ester having 4 to 12 carbon atoms and a vinyl monomer. A method for producing a transfer sheet for ink jet printing, wherein a water-soluble polycation is dissolved in a medium. A step of forming a transfer image with an aqueous ink by an ink jet printer on the surface of the dry film of the aqueous ink receiving layer forming agent in the transfer sheet for ink jet printing according to claim 1; Heating and pressurizing the transfer sheet for inkjet printing from above the plastic film in a state where the transfer image is in contact with the surface of the leather, and removing the plastic film of the transfer sheet from the urethane film. An inkjet transfer printing method characterized by A step of forming a transfer image with an aqueous ink by an ink jet printer on the dry film surface of the water-based ink receiving layer forming agent in the transfer sheet for ink jet printing according to claim 2; The transfer image is brought into contact with the surface of the leather and the leather surface and the transfer sheet are immersed in water, and the transfer sheet is peeled off and heated, and the transfer sheet is heated from above the urethane film. And pressurizing the ink jet transfer printing method.

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