JP2006328285A - Sublimation transfer printed leather product and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leather product which can be applied with a heat sublimation transfer method to natural leather, thereby giving a beautiful and robust print without impairing the original texture of the leather.
SOLUTION: On the surface of leather in which an undercoat layer containing a single layer or multiple layers of a general leather coating resin, an overcoat layer containing a dyeing resin and a crosslinking agent, and a release layer made of a peelable resin as required, are sequentially formed. A method for producing sublimation transfer print coated leather by transferring an image onto the surface of leather by a sublimation transfer print coated leather obtained by transferring an image containing a sublimation dye and a heat sublimation transfer method.
[Selection figure] None

Description

  The present invention relates to a coated leather product obtained by printing an image on leather, particularly natural leather, by a heat sublimation transfer method, and a method for producing the same.

  As a method for printing a variety of small quantities of images on a substrate such as leather, fiber cloth or earthenware for personal use, there is a method of transferring the image by heat-pressing a transfer paper pre-printed with an image onto the surface of the substrate. It is known (see Patent Documents 1 to 3). This thermal transfer method includes a thermal melt transfer method and a thermal sublimation transfer method. In the latter, the sublimation dye in the image on the transfer paper is sublimated by heating and soaks into the substrate as a gas molecule. Therefore, there are great advantages in that the transferred image is beautiful, has high gradation, and is excellent in wear resistance.

However, since dyes exhibiting sublimation properties are almost limited to disperse dyes, it is necessary that the base material be dyed by disperse dyes and be able to withstand high sublimation temperatures. For this reason, the base material to which this method is applied is limited to polyester cloth and the like, and has not been applied to leather as well as natural fiber cloth such as cotton.
No. 6-38009 Japanese Patent No. 3069064 JP-A-4-57538

  It is an object of the present invention to provide a leather product that has been subjected to a heat sublimation transfer method for leather such as natural leather, and has a beautiful and robust print, in particular, a leather product that has been printed with a small amount of various varieties and a method for producing the same. Is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have succeeded in developing a leather coating film capable of dyeing a sublimation dye on the leather surface by a thermal sublimation transfer method, Thus, the present invention has been completed by establishing a technique capable of thermally transferring an image of a sublimation dye to leather while preventing the leather from being modified and maintaining the inherent flexibility of the leather.

That is, the present invention according to claim 1 is a sublimation dye on the surface of leather on which an undercoat layer containing a single-layer or multiple-layer general leather coating resin and an overcoat layer containing a dyeable resin and a crosslinking agent are formed. It is a sublimation transfer printed paint leather formed by transferring an image containing.
The invention according to claim 2 is a leather in which an undercoat layer containing a single-layer or multiple-layer general leather coating resin, an overcoat layer containing a dyeing resin and a crosslinking agent, and a release layer comprising a release resin are sequentially formed. Is a sublimation transfer print coated leather obtained by transferring an image containing a sublimation dye to the surface of
Next, the present invention described in claim 3 is the sublimation transfer printed paint leather according to claim 1 or 2, wherein the general leather coating resin layer of the undercoat layer contains an acrylic resin and / or a polyurethane resin. is there.
The present invention described in claim 4 is the sublimation transfer print coated leather according to any one of claims 1 to 3, wherein the dyeing resin of the overcoat layer contains a polyester resin.
The present invention according to claim 5 is the sublimation transfer print coated leather according to any one of claims 2 to 4, wherein the peelable resin of the release layer contains a fluorine resin or a polyamideimide resin.

The present invention described in claim 6 is a step of forming at least one general leather coating resin layer on the leather surface to form an undercoat layer, and a step of forming an overcoat layer containing a dyeing resin and a crosslinking agent. A method for producing sublimation transfer print coated leather, comprising a step of placing a transfer sheet on which an image containing a sublimation dye is printed on the upper surface of the overcoat layer, and transferring the image by thermocompression bonding. .
Further, in the present invention according to claim 7, after forming an undercoat layer by providing at least one general leather coating resin layer on the leather surface, an overcoat layer containing a dyeing resin and a crosslinking agent is formed. Forming a release layer by providing a release resin layer on the top surface of the overcoat layer, placing a transfer sheet on which an image containing a sublimation dye is printed on the top surface of the release layer, and thermocompression bonding A method for producing a sublimation transfer print-coated leather comprising a step of transferring an image.

The present invention described in claim 8 is the method for producing sublimation transfer printed paint leather according to claim 6 or 7, wherein the resin layer for general leather coating of the undercoat layer contains an acrylic resin and / or a polyurethane resin. is there.
The present invention described in claim 9 is the method for producing sublimation transfer printed leather according to any one of claims 6 to 8, wherein the dyeing resin of the topcoat layer is a polyester resin.
Furthermore, the present invention according to claim 10 is the method for producing a sublimation transfer print coated leather according to any one of claims 7 to 9, wherein the peelable resin of the release layer contains a fluorine resin or a polyamideimide resin. It is.

  According to the present invention, a beautiful and robust print can be applied to leather such as natural leather by a heat sublimation transfer method. Moreover, the leather products printed by the method of the present invention sufficiently maintain the texture and texture inherent to natural leather, and provide consumers with various leather products that have been printed in a variety of small quantities. Can fully meet the needs.

Hereinafter, the present invention will be described in detail.
The leather to which the present invention is applied may be either natural leather or synthetic leather, but natural leather is particularly preferable. Examples of natural leather include cowhide, horseskin, sheepskin, goatskin, pigskin and the like, although not particularly limited, those having a smooth surface such as cowskin and horseskin are preferred. Further, when these leathers are used, necessary pretreatments such as heat resistance and a tanning process can be performed.

  In the present invention, the undercoat layer formed on the leather surface is a single layer or multiple layers based on a general leather coating resin layer. As an example, there can be mentioned a subbing layer comprising a general leather coating resin layer having a thickness of 10 μm in contact with the leather surface and a general leather coating resin layer having a thickness of 10 μm as an upper layer.

The undercoat layer is usually composed of 1 to 3 layers, and the total thickness is 10 to 80 μm, preferably 15 to 40 μm. For leather with a rough surface such as floor leather, several layers may be formed by several coatings in order to obtain smoothness.
Here, various resins such as acrylic resins, polyurethane resins, polyvinyl acetate resins, and thermoplastic elastomers can be used as general leather coating resins. From the standpoint of heat resistance stability, a combination of an acrylic resin and a polyurethane resin is preferable. Furthermore, it is preferable to use a resin having a secondary transition point (Tg) of −20 ° C. or lower.
These resins are applied in the form of an aqueous emulsion, an organic solvent solution or the like, but the undercoat layer is desirably used as an aqueous emulsion for reasons of cost and environmental problems. The coating method is arbitrary and may be any known method such as a roll coater method or a spray method. In the undercoat layer, pigments, thickeners, fillers, waxes and the like can be appropriately blended as necessary.

Next, the overcoat layer is a layer containing a dyeable resin and a crosslinking agent, and is formed on the undercoat layer. The topcoat layer mainly composed of a dyeable resin is used for dyeing a sublimation dye and forming a beautiful print during the transfer described later. Therefore, it is desirable to increase the dyeable resin as much as possible and effectively capture the dye sublimated in the transfer step described later.
As the dyeing resin, polyester resins, epoxy resins, alkyd resins, cellulose ester resins and the like can be used, and these resins can be used alone or in combination of two or more. Polyester resins are particularly preferable. Polyester resins that can be used for coating include various copolymers, but those having an aromatic ring in the molecule are preferred from the viewpoint of dyeability.
The dyeing resin such as polyester resin preferably has a low secondary transition point (Tg), and is preferably -10 ° C or lower, more preferably -15 ° C or lower. The reason is that a resin having a temperature of −10 ° C. or higher may be hard and brittle within the environment of use, which may damage the texture or break when bent.
The form of the resin liquid can be used in the form of an aqueous emulsion, an organic solvent solution, etc. as in the case of the undercoat layer, and is not particularly limited. However, when it is desired to form a transparent layer, It should be in the form of a solvent solution.
In addition to the above, an ultraviolet absorber, a drying accelerator and the like can be added to the topcoat layer as necessary.

Next, the crosslinking agent reacts with the functional group in the dyeing resin to restrain the molecular movement of the resin, that is, to cure, and is used to improve the dyeing property. Becomes hard.
As the crosslinking agent, for example, isocyanate compounds, aziridines, epoxy compounds, and the like can be used. In the case where a polyester resin is used as the dyeing resin, it is preferable to use an isocyanate compound as a crosslinking agent because the texture of the coating film is hardly impaired. In this case, if the proportion of the isocyanate compound is increased, bleeding and blurring of the transferred image are suppressed, the image is stabilized, and heat resistance is also improved. Therefore, even when a release layer is not provided on the overcoat layer, the transfer sheet can be easily peeled off during transfer processing. However, when there are too many ratios of an isocyanate compound, a coating film will become hard and a texture will be impaired. This phenomenon is the same when other cross-linking agents are used. Therefore, the blending ratio of the polyester resin and the isocyanate compound is preferably set so that the isocyanate compound is 60 to 75% by weight. Further, as an effect of the cross-linking agent, there is an action of withstanding the heating temperature at the time of transfer processing and suppressing sticking to the transfer sheet.

  The thickness of the top coat layer is preferably as long as the sublimable dye can be sufficiently absorbed by the dyeable resin. However, if a single layer does not provide a sufficient effect, it may be overcoated with two or more layers. May be. Usually, the thickness of the overcoat layer is 10 to 30 μ, preferably about 20 μ. In addition, as described above, the topcoat layer mainly composed of a dyeable resin is a layer that forms a print by dyeing a sublimation dye, and therefore, by selecting a transparent material, It is preferable that the contrast enhances the transferred image and provides a clear and beautiful feeling.

As described above, the cross-linking agent for the overcoat layer provides the effect of stabilizing the transferred image and improving the heat resistance, but the dyeing resin such as a polyester resin used for the overcoat layer has a strong thermoplasticity. The transfer sheet surface on which is printed is easy to stick.
Therefore, by providing a release layer on the top surface of the topcoat layer, such a problem can be prevented by eliminating direct contact between the topcoat layer and the transfer sheet. If this is seen from the other side, the merit which raises the freedom degree with respect to the mixing | blending selection of resin of an overcoat layer will be acquired.
The release layer is required to have heat resistance and peelability that can withstand the temperature during transfer. On the other hand, it also has the effect of protecting the transfer print of the sublimable resin. As the release layer, a heat-resistant resin such as a fluororesin, a silicon-based resin, a polyamide-imide resin, or a polyethersulfone resin is used. In particular, a fluororesin or a polyamide that maintains a good balance between heat resistance and peelability. Imide resins are preferred. In addition, what is necessary is just to form a peeling layer thinly, and about 0.1-0.01 micrometer is suitable for the thickness normally.

  As a coating method for each of the above layers, any conventional method can be applied without particular limitation. Specific examples include a roll coating method, a flow coating method, a spray coating method, a knife coating method, and a hand coating method. Usually, a roll coating method, a flow coating method, and a spray coating method are preferable. The release layer is particularly preferably a spray coating method.

  The sublimation transfer print coated leather of the present invention is obtained by thermally sublimating the image of the transfer sheet described below on the coated surface of the coated leather (hereinafter referred to as transferred coated leather) obtained by coating each layer described above on the leather surface. It can be produced by transferring to the coated leather by a transfer method.

The transfer sheet in the present invention is one in which an image containing a sublimation dye is printed on the surface of a transfer substrate, and the image is transferred to the coating surface.
The transfer substrate may be any material that accepts a sublimation dye and can be applied to the thermal sublimation transfer method, such as paper, synthetic paper, polyolefin resin such as polypropylene and polyethylene, and polyamide resin such as nylon. Examples thereof include a film made of a synthetic resin, and a paper sheet is preferable. A transfer sheet that strongly adsorbs ink containing a sublimable dye tends to lack image transfer, while a transfer sheet that is too weakly adsorbed may cause the sublimable dye to scatter. Therefore, an appropriate product should be selected in consideration of the product object and production conditions.

As the sublimation dye in the present invention, any dye having a sublimation property can be arbitrarily used, but disperse dyes having good light resistance have been generally used so far.
In order to print an image containing a sublimation dye on the surface of the transfer substrate, a known method may be used. For example, any method such as an inkjet method, a screen method, an offset method, a gravure method, or a flexo method may be employed. it can. Among these, the ink jet method is a preferable method because it is suitable for printing a small amount of various types of images.
The above image may be any image, for example, an achromatic line drawing, a color photograph, a television screen, or the like.
In addition, the thickness (or coating amount) of the printing layer is usually 1 to 10 μm.

Next, the thermal sublimation transfer method will be described.
First, the printed surface of the transfer sheet is applied to the coated surface (top coat layer or release layer) of the transfer coated leather, and then heated and pressed from the back surface of the transfer sheet. Then, the sublimable dye is sublimated by heating, and is dyed as a gas molecule on the dyeable resin layer of the top coat layer of the paint surface, and the image is transferred.

In the present invention, as the heating and pressure bonding means at the time of transfer, it can be performed using a press machine that is usually used in a thermal sublimation transfer method such as a hot roll press or a hot plate press. Although it may be determined in consideration of the sublimation dye used for the image and the type of the transfer sheet, the temperature is usually 130 to 200 ° C., preferably 150 to 190 ° C., time: 10 to 120 seconds, and preferably 30 to 90 seconds, the pressure: 0.1~60kg / cm ^2, and preferably is 1-5 kg / cm ² suitable. The high pressure shortens the time or allows the temperature to be lowered, and can be appropriately adjusted according to the use of the leather.
If the heating temperature exceeds the upper limit, the leather may be deteriorated. Moreover, if it is less than a minimum, the sublimation property of dye will worsen and the dyeing amount to the coating surface falls, and is not preferable.
If the pressure exceeds the upper limit, the leather may be crushed or hardened. On the other hand, if it is less than the lower limit, the sublimation property of the dye is deteriorated, and the penetrability to the coating surface and the dyeing amount are lowered, which is not preferable. When the upper limit is exceeded, the transfer time is the same as when the pressure exceeds the upper limit, and when it is less than the lower limit, the pressure is less than the lower limit, which is not preferable.

  EXAMPLES The present invention will be specifically described below with reference to examples and the like, but the present invention is not limited to these.

Example 1
(1) Production of transfer-coated leather The cowhide (chrome tanned leather, 10 cm × 10 cm) was sequentially coated with (a) and (b) layers having the following composition as an undercoat layer. The (a) layer was applied once by roll coating, the (b) layer was applied by spray coating 4 times, and the thickness of each layer after drying was (a) 10 μm and (b) 10 μm.

(A) Layer Acrylic emulsion (made by IS Paint Co., Ltd., resin content 38%) 40 parts by weight Polyurethane emulsion (trade name: Urecoat Bright 70) 5 parts by weight Pigment paste 28 parts by weight Auxiliary agent 10 parts by weight Water 11 parts by weight Part (b) Layer Acrylic emulsion (made by IS Paint Co., Ltd., resin content 38%) 40 parts by weight Polyurethane emulsion (trade name: Urecoat Bright 70) 5 parts by weight Pigment paste 28 parts by weight Auxiliary agent 10 parts by weight Water 41 Parts by weight

Next, as an overcoat layer, the following composition was applied once by roll coating on the (b) layer of the undercoat layer. The layer thickness after drying was 20μ.
Polyester solution (Toyobo Co., Ltd., resin 30%) 40 parts by weight Isocyanate compound (Ais Paint Co., Ltd., resin 45%) 20 parts by weight Urethane thinner (Ais Paint Co., Ltd.) 20 Part by weight Auxiliary agent (including UV absorber) 7 parts by weight

(2) Production of image transfer sheet An image containing a sublimation dye printed on a paper transfer sheet by an inkjet method was prepared.

(3) Thermal sublimation transfer of image The image transfer sheet is superimposed on the surface of the coated leather produced in (1) above, and heat-pressed for 90 seconds under the conditions of a temperature of 190 ° C. and a pressure of 2 kg / cm ² using a press machine. The image was transferred. Thereafter, when the transfer sheet was carefully peeled off, a coated leather having a beautiful transfer image was obtained.
After standing at room temperature for 24 hours and judging visually, the image was stable and almost no blur or fading was observed.

(Example 2)
A release layer having the following composition was formed by spraying (thickness: 0.1 μm) on the top coat layer of coated leather produced in the same manner as in Example 1.
Polyamideimide resin (Toyobo Co., Ltd., 25% resin content) 5 parts by weight Thinner 95 parts by weight

Thereafter, the same image transfer sheet prepared in Example 1 was superposed on the release layer, and the image was subjected to thermal sublimation transfer in the same manner as in Example 1.
As a result, the transfer sheet was easily peeled off, and a stable transfer image free from bleeding and inferiority was obtained.

(Comparative Example 1)
A coated leather having a transfer image was produced in the same manner as in Example 1 except that the topcoat layer was omitted in Example 1.
This leather product had a blurred transfer image.

  ADVANTAGE OF THE INVENTION According to this invention, the leather product which gave the beautiful and robust print, and its manufacturing method can be provided. Further, the leather product printed by the method of the present invention sufficiently maintains the texture inherent to natural leather and the like. The present invention is particularly suitable for providing a leather product that has been subjected to a variety of small-volume printing for personal use.

It is sectional drawing which shows an example of the to-be-transferred coated leather (type of Example 2) used for preparation of the sublimation transfer printed painted leather of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leather fabric 2 (a) layer of undercoat layer 3 (b) layer of undercoat layer 4 Top coat layer 5 Peeling layer

Claims (10)

  Sublimation transfer print coating by transferring an image containing a sublimation dye onto the surface of leather with a single-layer or multiple-layer general leather coating resin and an overcoat layer containing a dyeable resin and a crosslinking agent. leather.   An image containing a sublimation dye on the surface of a leather in which an undercoat layer containing a single layer or multiple layers of a general leather coating resin, an overcoat layer containing a dyeable resin and a crosslinking agent, and a release layer made of a release resin are sequentially formed. Sublimation transfer print paint leather made by transferring.   The sublimation transfer printed coated leather according to claim 1 or 2, wherein the resin layer for general leather coating of the undercoat layer contains an acrylic resin and / or a polyurethane resin.   The sublimation transfer printed leather according to any one of claims 1 to 3, wherein the dyeing resin of the topcoat layer contains a polyester resin.   The sublimation transfer printed coated leather according to any one of claims 2 to 4, wherein the release resin of the release layer contains a fluorine resin or a polyamideimide resin.   A step of forming at least one general leather coating resin layer on the leather surface to form an undercoat layer, a step of forming an overcoat layer containing a dyeing resin and a crosslinking agent, and a sublimation dye on the upper surface of the topcoat layer A method for producing a sublimation transfer print-coated leather, comprising a step of placing a transfer sheet on which an image containing an image is printed and heat-pressing to transfer the image.   A step of forming an undercoat layer by providing at least one general leather coating resin layer on the surface of the leather, and then forming an overcoat layer containing a dyeing resin and a crosslinking agent, a release resin on the upper surface of the overcoat layer A step of forming a release layer by applying a layer, and a step of placing a transfer sheet on which an image containing a sublimation dye is printed on the upper surface of the release layer and transferring the image by thermocompression bonding. Sublimation transfer printed leather manufacturing method.   The method for producing a sublimation transfer printed coated leather according to claim 6 or 7, wherein the general leather coating resin layer of the undercoat layer contains an acrylic resin and / or a polyurethane resin.   The method for producing sublimation transfer printed leather according to any one of claims 6 to 8, wherein the dyeing resin of the topcoat layer is a polyester resin. The method for producing a sublimation transfer print-coated leather according to any one of claims 7 to 9, wherein the release resin of the release layer contains a fluorine resin or a polyamideimide resin.

Images