JP3818813B2 - Inkjet recording sheet for electric display and electric display - Google Patents

Description

【００２５】
【発明の効果】
表１から明らかなように、本発明のインクジェット記録用シートは、樹脂板に貼り付けたときに硬質の支持体を有さないため、樹脂板の変形によく追従し、浮きやワレが発生せず、美感に優れる表示体をもたらすという従来品にはない効果を有する。更に、本発明のインクジェット記録用シートはインク乾燥性、発色性、解像力に優れている。
【図面の簡単な説明】
【図１】インクジェット記録用シートの断面図である。
【図２】電飾表示体の製法を断面により示す概略図である。
【図３】別の電飾表示体の製法を断面により示す概略図である。
【符号の説明】
１ インク透過層
２ インク吸収層
３ 支持体
４ 画像部
５ 透明又は半透明の樹脂板
６ 保護フィルム[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording sheet suitable for an ink jet system using water-based ink, an electric display body (electric signboard) using the same, and a manufacturing method thereof.
[0002]
[Prior art]
There is a backprint recording sheet on which an image (mirror image) is printed by an inkjet method on an electric display used for the purpose of advertisement, map, facility guidance, etc., and viewed from the opposite side. The sheet is required to have good image quality by the transmitted light from the illumination light on the back of the film, and good image quality is required even from the reflected light in a time zone or place where there is a lot of outside light such as the sun or indoor lighting.
[0003]
The following characteristics are required for the backprint print recording sheet.
First, some ink jet printers have a back print mode. However, since this print mode usually has a larger amount of ink than other print modes, the back print ink jet recording sheet is required to have high ink absorbability. It is done.
Next, in outdoor use, good image quality is required by the transmitted light from the back lighting at night, but it is reflected by reflected light in daytime and places where there is a lot of outside light from indoor lighting. In addition, since good image quality is required, it is necessary to achieve both color developability in transmitted light and reflected light.
Furthermore, it is necessary that the image quality and color developability of the electric display body are not deteriorated due to deformation of the resin plate due to heat and stress over the course of manufacturing or over time.
[0004]
Japanese Patent Publication No. 7-2428 and Japanese Patent Laid-Open No. 9-207499 are disclosed as an ink jet recording sheet for back print. Japanese Examined Patent Publication No. 7-2428 discloses a recording material in which an ink holding layer and an ink permeable layer are sequentially laminated on a translucent substrate such as polyester, and effects such as excellent sharpness and image optical density are disclosed. It is described to give. Japanese Patent Laid-Open No. 9-207499 discloses a transfer sheet in which a hydrophilic resin layer having a transfer image formed on a hydrophobic resin sheet such as polyester and a double-sided adhesive sheet are laminated. It is described that there is an effect that properties, colorability, water resistance and the like are improved.
[0005]
However, these recording sheets are used with a support such as a hard film attached to the printed ink receiving layer. That is, after these ink jet recording sheets are printed, the sheet is adhered to a resin plate placed in front of the light for illumination using an adhesive, but the resin plate is removed by heat and stress applied after the display body is constructed. The recording sheet is deformed and the recording sheet does not follow the deformation. In addition, when the resin plate repeatedly expands and contracts due to the thermal history, the bonded recording sheet does not follow the deformation of the resin plate when the strained deformation occurs in the three-dimensional direction, so that floating occurs between the recording sheet and the resin plate. There is a problem that unevenness occurs on the surface of the sheet. Furthermore, even if a substrate that follows the deformation of the resin plate is used as a support for the recording sheet, the support itself is deformed by the heat and tension necessary for coating the ink receiving layer on the support. There is a problem of end. When such a deformation problem occurs, the image quality and color developability of the electrical display body are significantly impaired.
[0006]
[Problems to be solved by the invention]
The present invention does not impair the aesthetics of the electric display body even if the resin plate is deformed by heat or stress, and the ink drying at the time of printing is fast, the coloration by transmitted light and reflected light is sufficient, and the resolving power An ink jet recording sheet excellent in quality is provided. More specifically, there is provided an ink jet recording sheet that provides an electric display with good image quality and color development without causing any blur on the surface of the sheet even when the resin plate is deformed by light heat or other stress. provide.
[0007]
[Means for Solving the Problems]
The subject of the present invention is an ink jet recording sheet comprising a support and an ink receiving layer having a release layer on at least one side or made of a releasable material, wherein the ink receiving layer is separated from the support. It consists of an ink absorbing layer mainly composed of a water-soluble resin and an ink permeable layer mainly composed of a pigment and a water-insoluble resin, which are laminated in order on the mold surface, and the reaction force (tensile strength) of the ink receiving layer is 500 g. / 15 mm or less is an inkjet recording sheet for an electric display.
Another subject of the present invention is a process of printing an image on the ink receiving layer of the above-mentioned ink jet recording sheet by an ink jet method, the ink of the ink jet recording sheet on one side of a transparent or translucent resin plate using an adhesive means. It is a manufacturing method of the electrical display body which consists of the process of affixing the permeable layer side, and the process of peeling the said support body of the said sheet | seat for inkjet recording after that.
Another subject of the present invention is a step of printing an image on an ink receiving layer of the above-mentioned ink jet recording sheet by an ink jet method, a step of attaching a protective film to the ink permeable layer side of the ink jet recording sheet, and then the ink jet It is a manufacturing method of the electrical display body which consists of the process of peeling the said support body of a recording sheet, and the process of sticking the ink absorption layer side which the support body peeled and exposed to a transparent or translucent resin board.
Still another subject matter of the present invention is an electrode in which a transparent or translucent resin plate is laminated with an ink absorbing layer mainly composed of a water-soluble resin and an ink permeable layer mainly composed of a pigment and a water-insoluble resin. A decorative display body, which is an electrical display body in which an image is printed on the ink absorption layer by an ink jet method.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The ink jet recording sheet of the present invention comprises an ink absorbing layer, an ink receiving layer comprising an ink and a transmissive layer, and a support, which can be peeled after printing (FIG. 1). Water-based dye ink or water-based pigment ink can be used as ink for an inkjet plotter for printing. The light transmittance of the ink receiving layer is suitably from 30 to 50%. When the printed image is viewed from the side of the support to be peeled off, an appropriate contrast can be obtained with the transmitted light.
[0009]
The ink absorbing layer of the present invention contains a resin as the main component in consideration of the color developability of the image, but it is preferable to use a water-soluble resin. Examples of the water-soluble resin include starches such as polyvinyl alcohol, polyvinylyl pyrrolidone, oxidized starch and etherified starch, water-soluble celluloses such as methyl cellulose and carboxymethyl cellulose, proteins such as gelatin, casein and soy protein. These can be used alone or in combination. In particular, polyvinyl alcohol having a polymerization degree in the range of 1500 to 2200 and a saponification degree of 75 to 85 mol% is preferable. When polyvinyl alcohol having a polymerization degree of less than 1500 or a saponification degree of less than 75 mol% is used, the surface of the ink permeable layer dries quickly when printing a solid part with a large amount of ink, but the ink absorbs ink. Since the layer dissolves, the coating strength of the ink receiving layer as a whole cannot be obtained, and polyvinyl alcohol dissolves locally, and uniform color development cannot be obtained. Further, since the ink absorbing layer is sticky when the support is peeled off, there is a problem that a trouble that does not peel off at the interface between the support and the ink absorbing layer occurs. In addition, when polyvinyl alcohol having a polymerization degree of 2300 or more or a saponification degree of 85 mol% or more is used, the speed of ink absorption becomes slow, so that the drying of the ink permeable layer surface becomes slow, As the ink diffuses, the resolving power decreases. Polyvinyl alcohol can be appropriately crosslinked according to the permeability of the ink to be printed. However, if it is excessively cross-linked, the speed of absorbing ink becomes slow.
[0010]
In addition, when the thickness of the ink absorbing layer is thin, the amount of ink to be absorbed per unit volume increases. Therefore, polyvinyl alcohol having a polymerization degree of less than 1500 or a saponification degree of less than 75 mol% is used. It is easy to produce the same result as the case. Therefore, from the viewpoint of ink drying properties, it is better that the ink absorbing layer is thicker, but in that case, when the support is peeled off and adhered to the resin plate, the coating film stretches when the resin plate is deformed. no longer follow the Nikuku deformation, large floating or cracking in the ink-receiving layer in some cases compromise the aesthetics of the display body occurs.
[0011]
In order to follow the deformation without impairing the aesthetics, the ink receiving layer consisting of the ink absorbing layer and the ink permeable layer described below is the reaction when pulling 30% from the reference length (100 mm, width 15 mm) (130 mm). The force (tensile strength) may be 500 g or less. The thickness of the ink absorbing layer is preferably 8 to 14 μm.
An appropriate amount of a plasticizer may be added to the ink receiving layer to facilitate elongation. Further, a small amount of a porous pigment may be added in order to accelerate the ink drying time, but if added in a large amount, the whitishness of the pigment that did not absorb the ink is noticeable, so 10% or less is preferable. Further, a fluorescent agent may be added to increase whiteness, an ultraviolet absorber may be added to prevent ink fading, or a cationic resin may be added as an ink fixing agent. In addition, various auxiliary agents such as known antifoaming agents and leveling agents may be added to such an extent that the effects of the present invention are not impaired.
[0012]
The ink permeable layer of the present invention contains a pigment and a water-insoluble resin as main components. As the pigment, a white pigment is preferable. For this white pigment, an appropriate oil absorption amount is selected in accordance with the type of ink to be printed so that the ink quickly reaches the ink absorbing layer. As a result, the image quality was excellent when you watch from the support side is Ru obtained. When sufficient ink to Lee ink absorbing layer does not reach the reflection color density is low, the image is whitish, ie, at the time of viewing only by transmitted light inconspicuous the difference, when viewing in reflected light, images Looks whitish.
When a pigment ink is used as the ink, since the permeability is low, it is preferable to use a pigment with a small oil absorption. In order to prevent the ink from staying in the ink transmission layer, JIS-K5101-19 is used as the main white pigment. It is preferable to use a plastic pigment having an oil absorption amount of less than 100 ml / 100 g, surface-treated silica, or the like. When a dye ink is used as the ink, since it has high penetrability and is likely to cause bleeding, a pigment having a large oil absorption amount may be used, and silica having an oil absorption amount of 100 ml / 100 g or more as defined above is particularly preferable.
[0013]
The binder used in the ink permeable layer is dissolved in an aqueous ink, the ink when swelling ing difficult to pass, using a water-insoluble resin. Examples of the non-aqueous resin include polyester resins such as polyethylene terephthalate, various olefin resins, styrene resins, vinyl naphthalene resins, and vinylidene fluoride resins. In the case of using a white pigment having a large oil absorption, in consideration of the dispersibility of the white pigment, a water-soluble resin may be used for the binder, and it may be cross-linked in the drying step to make it water-insoluble or water-dispersed. May be used. The glass transition temperature of the binder is preferably 20 ° C. or lower in order to obtain the cohesive force of the ink transmission layer and not to prevent the elongation of the ink absorption layer. In the ratio of white pigment to binder, if there are many white pigments, the cohesive force of the coating film will decrease, causing problems such as powder falling.If there are many binders, the binder will occupy the gaps between the pigments and the ink will It becomes difficult to pass through, causing problems such as ink stagnating on the surface layer and slow drying. Therefore, the ratio of the binder to the pigment (binder / pigment) is suitably in the range of 60/40 to 20/80.
In addition, an auxiliary agent such as a fluorescent agent, an ultraviolet absorber, a cationic resin, or a surfactant may be added to the ink transmission layer.
[0014]
The support of the present invention is resistant to the heat and tension received in the step of coating the ink receiving layer, has the necessary rigidity when printing, and is transparent enough to confirm the image from the support side after printing the mirror image. Use the one that has the characteristics. For example, a transparent acrylic resin film and a polyester film are preferable, and the thickness is preferably 50 to 125 μm. A release layer is provided on the support so that the ink absorbing layer and the support can be peeled off. This release layer may be formed by, for example, applying a wax, a higher fatty acid, an olefin resin, a fluororesin, a silicone resin or the like on a support. Alternatively, the support may be made of a releasable material. This releasable material is, for example, an olefin resin, a fluororesin, a silicone resin, or the like.
Although the resin board of this invention will not be specifically limited if there exists the intensity | strength and rigidity which comprise an electrical decoration display body, It is preferable that it is transparent or translucent. Examples of the resin plate include acrylic resins such as polymethacrylic acid esters, polycarbonate resins, polyethylene resins, polyester resins, and polystyrene resins.
[0015]
In order to produce the electric display of the present invention, first, after the image 4 is printed on the ink receiving layer of the recording sheet by the ink jet method, for example, the following method is used.
As shown in FIG. 2, the first method is to peel the support 3 and the step of adhering to the transparent or translucent resin plate 5 using an adhesive means such as an adhesive or a double-sided adhesive film on the ink permeable layer 1 side. Process. After the support 3 is peeled off, a protective film (not shown in FIG. 2) can be adhered to the exposed ink absorbing layer 2, in which case the ink permeable layer 1 and the resin plate are adhered. In combination with the use of a double-sided adhesive film for adhesion to 5, firstly only one side of the double-sided adhesive film is adhered to the ink transmission layer 1, and the support 3 is peeled off before the other side is adhered to the resin plate 5, A protective film is overlaid on the exposed ink absorbing layer 2. Thereafter, the other side of the double-sided adhesive film is adhered to the resin plate 5 to produce a display body. In the above embodiment, the display body is arranged so that the ink absorbing layer 2 exposed by peeling off the support 3 is on the viewing side.
[0016]
As shown in FIG. 3, the second method includes a step of adhering the protective film 6 to the ink permeable layer 1 side of the recording sheet, a step of peeling the support 3, and the exposed ink absorbing layer 2 is transparent or translucent. It consists of the process of adhering to the resin plate 5. In this usage pattern, the display body is arranged so that the resin plate 5 side is the viewing side.
In these two methods, it is preferable to use a polyvinyl chloride film, an acrylic film, or the like, which is more easily thermally deformed than the polyester film, as the support for the double-sided adhesive film and the protective film.
Further, heat, pressure, a reactive adhesive, or a film on which these are already applied may be used for bonding each film. In order to follow the deformation of the resin plate, it is preferable to use acrylic, rubber, ethylene-vinyl acetate copolymer system, ethylene-acrylic ester system, etc. as the adhesive.
[0017]
【Example】
Example 1
Using a transparent polyethylene terephthalate sheet with a thickness of 75 μm coated with a silicone resin as a release agent (250 × 350 mm) as a support (250 × 350 mm), after drying the ink absorbing layer coating liquid prepared as follows on the release agent surface The recording sheet is coated and dried so as to have a thickness of 12 μm, and the coating liquid for ink permeable layer prepared as described below is coated and dried so that the thickness after drying becomes 20 μm, and then the recording sheet. Was made. Here, “part” represents “part by weight”.
Ink absorbing layer coating solution: 8 parts of polyvinyl alcohol (degree of polymerization 2000, degree of saponification 79%), 46 parts of water, 46 parts of methanol.
Coating liquid for ink permeable layer: 5 parts of polyester (Byron 500: manufactured by Toyobo Co., Ltd.), 15 parts of organic pigment (Epester M30: manufactured by Nippon Shokubai Co., Ltd., oil absorption 80 ml / 100 g), 50 parts of toluene, 30 parts of methyl ethyl ketone Department.
[0018]
Example 2
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the ink absorbing layer of Example 1 was applied to be 14 μm and dried.
Example 3
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the ink absorbing layer of Example 1 was applied to be 10 μm and dried.
Example 4
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the ink absorbing layer of Example 1 was applied to be 8 μm and dried.
Example 5
An ink jet recording sheet was prepared in the same manner as in Example 1 except that polyethylene glycol was added as a plasticizer to the coating solution for the ink absorbing layer of Example 1 and changed to the following.
Coating liquid for ink absorbing layer: 7.6 parts of polyvinyl alcohol (polymerization degree 2000, saponification degree 79%), polyethylene glycol (polymerization degree 400) 0.4 part water 46 parts, methanol 46 parts.
[0019]
Comparative Example 1
A transparent polyethylene terephthalate sheet with a thickness of 75 μm and no release layer was used as the support, and an inkjet recording sheet was prepared in the same manner as in Example 1 without peeling off the support.
Comparative Example 2
In Example 1, an ink-absorbing layer was not provided, and an ink-permeable layer was provided directly on the support to produce an inkjet recording sheet.
Comparative Example 3
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the coating liquid for ink permeable layer in Example 1 was changed to the following. That is, this ink transmission layer becomes water-soluble.
Coating liquid for ink permeable layer: 5 parts of polyvinyl alcohol (polymerization degree 2000, saponification degree 79%), 15 parts of organic pigment (Eposter M30: manufactured by Nippon Shokubai Co., Ltd.), 40 parts of water, 40 parts of methanol.
Comparative Example 4
An ink jet recording sheet was prepared in the same manner as in Example 1 except that the ink absorbing layer of Example 1 was applied to be 16 μm and dried.
[0020]
A test pattern is printed on the recording sheet thus prepared using an ink-jet plotter and a Roland CAMM JET (CJ-70) using water-soluble ink, and ink drying properties and color development in transmission and reflection are performed by the following methods. The resolution was evaluated. Moreover, the ink permeable layer side was adhered to a resin plate (250 × 350 × 2 mm) using a double-sided adhesive film, and the following property was evaluated by the following method. Each evaluation was performed according to the following criteria.
[0021]
Ink dryness : Black, red, blue, and green solid print portions were pressed strongly with fingers, and ink transfer and film strength were evaluated. Less than 10 seconds from the end of printing, no ink transfer, and no ink receiving layer collapsed were evaluated as ◯ (good), and those requiring 30 seconds or more as x (bad). The middle one was marked with Δ.
Color developability : Light was irradiated from the support side, and the color developability of the solid print portion of yellow, magenta, cyan, and black was evaluated. ○ (good) when the white color of the background is not left and the color is uniform and sufficient, and x (bad) when the white color clearly remains or the color is not uniform. .
[0022]
Resolving power : Observe the unprinted 300 μm fine line in the black solid printing part, ○ (good) if the fine line can be confirmed clearly, and x (bad) that can not be confirmed due to smearing, The middle one was marked with Δ.
Followability : After the ink permeable layer side was adhered to the resin plate, the support was peeled off. However, the sheet | seat of the comparative example 1 did not peel a support body but performed the following evaluation like other films as it was. Leave it in an oven at 100 ° C for 1 hour, apply the force from both ends with the adhesive surface of the resin plate as the top surface, and forcibly deform the center of the resin plate so that the center of the resin plate is lifted about 3 cm from both ends, and about 1 minute The operation of holding and then releasing the force and allowing to cool to room temperature was repeated 5 cycles. Those that did not generate floating or cracking that followed the deformation of the resin plate and impaired the aesthetics of the display body were evaluated as “good”, and those that did not were evaluated as “poor”.
[0023]
Reaction force : According to the tensile test method of JISK7127, the reaction force (strength) when an ink receiving layer having a width of 15 mm was pulled 30% (ie, 130 mm) from the reference length (100 mm) at a tensile speed of 300 mm / min. ) (G / 15 mm).
Table 1 shows the above evaluation and measurement results. The overall evaluation in the table is X (overall bad) if there is at least one x (bad) for each evaluation, ◯ (overall good) when up to one △, and △ otherwise.
[0024]
[Table 1]

[0025]
【The invention's effect】
As is apparent from Table 1, the ink jet recording sheet of the present invention does not have a hard support when attached to a resin plate, and therefore follows the deformation of the resin plate well, and does not float or crack. In addition, it has an effect not found in conventional products in that it provides a display body with excellent aesthetics. Furthermore, the ink jet recording sheet of the present invention is excellent in ink drying property, color developability and resolving power.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an inkjet recording sheet.
FIG. 2 is a schematic view showing a method for producing an electrical decoration display body in cross section.
FIG. 3 is a schematic view showing another method for producing an electric decoration display body in section.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ink transmission layer 2 Ink absorption layer 3 Support body 4 Image part 5 Transparent or translucent resin board 6 Protective film

Claims (6)

An ink jet recording sheet comprising a support and an ink-receiving layer having a release layer on at least one surface or made of a release material, wherein the ink-receiving layer is sequentially laminated on the release surface of the support Ink absorbing layer mainly composed of water-soluble resin and ink having pigment and water-insoluble resin as main components, and weight ratio of the water-insoluble resin and the pigment being 60/40 to 20/80 According to the tensile test method of JISK7127, the ink receiving layer when the ink receiving layer having a width of 15 mm is pulled 30% from the reference length (100 mm) at a pulling speed of 300 mm / min. An ink jet recording sheet for an electric display body having a reaction force (tensile strength) of 500 g / 15 mm or less. The inkjet recording sheet for an electrical display according to claim 1, wherein the pigment is a pigment having an oil absorption amount of less than 100 ml / 100 g according to JIS-K5101-19 standard.   A step of printing an image on an ink receiving layer of an ink jet recording sheet according to claim 1 or 2 by an ink jet method, an ink transmitting layer of the ink jet recording sheet on one side of a transparent or translucent resin plate using an adhesive means. A process for producing an electric display comprising a step of attaching a side, and a step of peeling off the support of the ink jet recording sheet.   A step of printing an image on an ink receiving layer of the ink jet recording sheet according to claim 1 or 2 by an ink jet method, a step of attaching a protective film to the ink transmission layer side of the ink jet recording sheet, and then the ink jet recording sheet A method for producing an electric display comprising: a step of peeling the support, and a step of attaching the exposed ink absorbing layer side to the transparent or translucent resin plate. An ink receiving layer is provided on a transparent or translucent resin plate, and the ink receiving layer is mainly composed of an ink absorbing layer mainly composed of a water-soluble resin and a pigment and a water-insoluble resin. An ink permeable layer having a weight ratio of the resin to the pigment of 60/40 to 20/80 is laminated. According to the tensile test method of JIS K7127, the ink receiving layer having a width of 15 mm The display element has a reaction force (tensile strength) of the ink receiving layer of 500 g / 15 mm or less when a 30% portion is pulled from a reference length (100 mm) in minutes, and an ink jet recording is applied to the ink absorbing layer. An illuminated display with images printed on it. The electric display according to claim 5, wherein the pigment is a pigment having an oil absorption of less than 100 ml / 100 g according to JIS-K5101-19 standard.

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