JP2012171314A - Decorative adhesive sheet and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative adhesive sheet allowing display of a high-quality image and excellent in transparency.SOLUTION: The decorative adhesive sheet 1 are made by dispersing pigment 4 to the inside of a decoration area 3 of a heat-weld resin sheet 2 made from hydrophobic resin and having thickness of 12-100 μm. The pigment 4 has particles with average particle diameter of 0.5 μm or smaller in volume equivalent, and exists in all of locations in a thickness direction of the heat-weld resin sheet 2. A front surface 1a and a back surface 1b including the decoration area 3 in the thickness direction have adhesiveness.

Description

  The present invention relates to a decorative adhesive sheet decorated on an adhesive sheet and a method for producing the same.

  As one of methods for decorating an article having a curved surface or an uneven surface, there is a method of sticking a resin sheet with a desired decoration on the curved surface or the uneven surface. An example of a decorative sheet used in such a method is a laminated sheet in which an adhesive layer, a base material layer, and a temporary base material layer are laminated in that order. An adhesive material having a property layer is known (for example, see Patent Document 1). In addition, cosmetics in which a pattern is printed by an oil-based inkjet method on a heat-sensitive adhesive layer of a printing sheet obtained by laminating a base material sheet made of a thermoplastic resin and a heat-sensitive adhesive layer containing a vinyl chloride-vinyl acetate copolymer. Sheets are also known (see, for example, Patent Document 2).

JP 2008-007637 A JP 2005-125651 A

  Since the sheet such as the above-mentioned conventionally known adhesive material or decorative sheet is decorated on the adhesive layer having heat-sensitive adhesiveness, it is only necessary to heat and adhere the adherend to the adherend. Can be decorated. However, such a sheet has the following problems.

  When a conventional sheet is attached to the curved surface or uneven surface of the adherend, the sheet is partially or entirely stretched. At this time, a gap is formed in the image, and a small unevenness is generated in the ridge line that becomes the boundary of the image, so that the resolution of the image is lowered. In addition, fine cracks occurred in the image, and the image quality was degraded. Moreover, as seen in the technique disclosed in Patent Document 2, when a hot melt resin (hydrophobic resin) is mixed with a hydrophilic resin for imparting ink receptivity, the sheet has a sea-island structure. As a result, the transparency of the sheet is lowered, and it becomes difficult to produce the original color of the image, and it is difficult to produce the original color and pattern of the adherend even at a location where the image does not exist.

  The present invention has been made to solve the above-described problem, and an object thereof is to provide a decorative adhesive sheet that can display an image with high quality and is excellent in transparency.

  One form of the present invention for solving the above object is a decorative adhesive sheet in which a pigment is dispersed inside a decorative area of a heat-welding resin sheet having a thickness of 12 to 100 μm made of a hydrophobic resin. The pigment is made into particles having an average particle size of 0.5 μm or less in terms of volume, and is present at all positions in the thickness direction of the heat-welding resin sheet, and the surface on the front side and the back side of the thickness direction including the decoration area It is a decorative adhesive sheet having adhesiveness on both sides of the surface.

  In another embodiment of the present invention, the heat-welding resin sheet is further selected from the group consisting of a urethane resin, an acrylic resin, a polyester resin, an epoxy resin, a polyamide resin, and an ethylene vinyl acetate copolymer resin. Or it is a decorating adhesive sheet made into the sheet | seat which consists of 2 or more resin.

  Another embodiment of the present invention is a decorative adhesive sheet in which the average particle size of the pigment is 0.15 μm or less.

  In one embodiment of the present invention, a pigment is dispersed inside a decoration area of a heat-welding resin sheet having a thickness of 12 to 100 μm made of a hydrophobic resin, and the average particle diameter in terms of volume is 0.5 μm or less. Of the heat-adhesive resin sheet at all positions in the thickness direction, and the production of a decorative adhesive sheet having adhesiveness on both the front and back surfaces in the thickness direction including the decorative area A method wherein an ink formed by mixing at least 80 to 95 parts by weight of an organic solvent and 1 to 10 parts by weight of a pigment is formed on the other side of a heat-welding resin sheet having a release sheet on one side. It is a manufacturing method of a decorative adhesive sheet including a printing step of supplying and printing by an inkjet method, and a separation step of separating the release sheet and the decorative adhesive sheet after the ink reaches the release sheet.

  ADVANTAGE OF THE INVENTION According to this invention, an image can be displayed with high quality and the decorating adhesive sheet excellent in transparency can be provided.

FIG. 1 is a perspective view of a decorative adhesive sheet according to an embodiment of the present invention. 2 is an AA line cross-sectional view of the decorative adhesive sheet shown in FIG. 1 and an enlarged view of a part X thereof. FIG. 3 is a diagram schematically showing a manufacturing process of the decorative adhesive sheet shown in FIG. 4 is an optical micrograph (magnification: 150 times) showing a cross section of the decorative adhesive sheet with release paper in Example 1. FIG. FIG. 5 is an optical micrograph (magnification: 150 times) showing a cross section of the decorative adhesive sheet with release paper in Example 2.

  Next, preferred embodiments of the decorative adhesive sheet and the manufacturing method thereof according to the present invention will be described.

<1. Composition of decorative adhesive sheet>
FIG. 1 is a perspective view of a decorative adhesive sheet according to an embodiment of the present invention. 2 is an AA line cross-sectional view of the decorative adhesive sheet shown in FIG. 1 and an enlarged view of a part X thereof.

  The decorative adhesive sheet 1 according to this embodiment is obtained by dispersing the pigment 4 inside the decorative area 3 of the heat-welding resin sheet 2.

(1) Heat-weldable resin sheet The heat-weldable resin sheet 2 is a resin-made sheet that is welded to an adherend by heating itself without using an adhesive. The heat-weldable resin sheet 2 according to this embodiment is made of a hydrophobic resin, and preferably contains sufficient thermoplastic resin that can exhibit heat-weldability. “Hydrophobic” means a property that is more stable in a phase separated from water than in a compatible state in a system that coexists with water. If defined in terms of the contact angle, in general, hydrophobicity is a property in which the contact angle is in the range of 50 to 180 degrees, preferably 90 to 180 degrees, more preferably 135 to 180 degrees. Say. Further, in terms of the proportion of polar groups, in general, a hydrophobic resin has polar groups containing any atom of oxygen, nitrogen, or sulfur (for example, —OH, —COOH, —NH ₂ groups). , —SO ₃ H group) and the ratio (Pn / Mw) of the average total number per molecule (Pn) and the weight average molecular weight (Mw) of the resin is 0.01 or less, preferably 0.005 or less. is there. In the present specification, a resin exhibiting hydrophobicity means a resin satisfying at least one of “contact angle of 50 ° to 180 °” and “(Pn / Mw) of 0.01 or less”.

  The resin material constituting the heat-welding resin sheet 2 is not particularly limited as long as it is a sheet made of a hydrophobic resin, but is preferably a urethane resin, an acrylic resin, or a polyester resin. , An epoxy resin, a polyamide resin, and an ethylene vinyl acetate copolymer resin (EVA resin). Among them, an acrylic resin is particularly preferable from the viewpoint of being hardly yellowed by sunlight or the like, and an acrylic modified epoxy polymer is more preferable. Moreover, as a resin material, the thing which does not contain chlorine from a viewpoint which does not have a bad influence on an environment is more preferable. The resin material constituting the heat-welding resin sheet 2 does not include a hydrophilic resin (a resin having a property that deviates from the definition of hydrophobicity).

  The thickness of the heat-welding resin sheet 2 is in the range of 12 to 100 μm, preferably 20 to 100 μm, more preferably 30 to 50 μm. When the thickness is less than 12 μm, during the process of manufacturing the decorative adhesive sheet 1, the ink containing the pigment 4 is discharged onto the heat-weldable resin sheet 2 during printing or after the heat-weldable resin sheet. 2 swells and the decoration area 3 and its vicinity protrude. In order to reliably prevent swelling, the thickness is preferably 20 μm or more, and more preferably 30 μm or more. On the other hand, when the thickness is greater than 100 μm, air bubbles are likely to enter during the manufacturing process of the decorative adhesive sheet 1, and one or more sheets such as a base sheet are laminated on the decorative adhesive sheet 1 to form a three-dimensional shape. In this case, the total thickness becomes too large and the rigidity becomes high, so that molding becomes difficult. In order to further increase the degree of freedom in forming a three-dimensional shape, the thickness is preferably 50 μm or less.

(2) Pigment As the pigment 4, one or more of organic pigments or inorganic pigments can be used depending on the color scheme to the decoration area 3. Examples of organic pigments include azo, azomethine, polyazo, phthalocyanine, quinacridone, anthraquinone, indigo, thioindigo, quinophthalone, benzimidazolone, isoindoline, isoindolinone, diazo A pigment such as acetoacetoallylide can be suitably used. Examples of inorganic pigments include titanium oxide, zinc oxide, zinc oxide, lithopone, iron oxide, aluminum oxide, silicon dioxide, kaolinite, montmorillonite, talc, barium sulfate, calcium carbonate, silica, alumina, cadmium red, and red rose. , Molybdenum red, chrome vermilion, molybdate orange, yellow lead, chrome yellow, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, pyridiane, cobalt green, titanium cobalt green, cobalt chrome green, ultramarine blue, ultramarine blue, Pigments such as bitumen, cobalt blue, cerulean blue, manganese violet, cobalt violet and mica can be suitably used. These organic pigments or inorganic pigments may be used alone or in combination.

  As the black pigment, for example, pigment black 7, 26, and 28 can be used as color index numbers. Examples of the red or magenta pigment include color index numbers. For example, pigment red 3, 5, 19, 22, 31, 38, 43, 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49: 1, 53: 1, 57: 1, 57: 2, 58: 4, 63: 1, 81, 81: 1, 81: 2, 81: 3, 81: 4, 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, pigment violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13, 16, 20, 36 can be used. Examples of blue or cyan pigments include color index numbers, for example, pigment blue 1,15,15: 1,15: 2,15: 3,15: 4,15: 6,16,17-1,22. 27, 28, 29, 36, 60 can be used. Examples of the yellow pigment include color yellow, pigment yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193 can be used. Examples of the white pigment include, for example, pigment white 1, 2, 4, 5, 6, 7, 11, 12, 18, 19, 21, 22, 23, 24, 26, 27, 28. Available

  The average particle diameter calculated | required by the volume conversion of the pigment 4 is 0.5 micrometer or less, Preferably it is 0.15 micrometer or less. Here, the average particle diameter means a particle diameter measured by the Coulter method. For the measurement of the particle size, for example, an apparatus (model number: N4PLUS) manufactured by Beckman Coulter can be suitably used. When the average particle diameter exceeds 0.5 μm, when the ink in which the pigment 4 is dispersed in an organic solvent is supplied from one surface (front surface) 1a of the heat-welding resin sheet 2, the pigment 4 is in the sheet. 2, it becomes difficult to easily reach the back surface 1b when the thickness of the heat-weldable resin sheet 2 is close to 100 μm. For this reason, the average particle diameter of the pigment 4 needs to be 0.5 μm or less. Furthermore, even when the heat-welding resin sheet 2 is close to 12 μm, in order for the pigment 4 to reach the surface 1 b on the back side of the sheet 2, the average particle diameter is particularly preferably 0.15 μm or less. The optimum combination of the average particle diameter of the pigment 4 and the thickness of the above-mentioned heat-welding resin sheet 2 is an average particle diameter of 0.15 μm or less and a thickness of 30 to 50 μm.

(3) Decorative Adhesive Sheet The decorative adhesive sheet 1 itself has adhesiveness on both the front side surface 1a and the back side surface 1b, and also in the decorative area 3 in which the pigment 4 is dispersed. Adhesive. The thickness direction of the pigment 4 is such that the pigment 4 is not unevenly distributed on one surface of the heat-welding resin sheet 2 on the side to which the ink having the pigment 4 is supplied, but is cut on any surface in the thickness direction of the sheet 2. Move to. For this reason, adhesiveness is not lost also in the decoration area 3 of the said single side | surface.

<2. Manufacturing method of decorative adhesive sheet>
FIG. 3 is a diagram schematically showing a manufacturing process of the decorative adhesive sheet shown in FIG.

  A release sheet 5 is provided on one surface (referred to as the back side surface) 1b of the heat weldable resin sheet 2, and the decorative surface 3 of the other surface (referred to as the front side surface) 1a of the heat weldable resin sheet 2 is provided. In the position, printing is performed by an inkjet method using an ink 6 formed by mixing at least 80 to 95 parts by mass of an organic solvent and 1 to 10 parts by mass of a pigment (printing process). The release sheet 5 may be a biaxially oriented polypropylene (OPP), a resin sheet made of polyethylene terephthalate subjected to a release treatment, or a paper sheet such as a release paper.

  As the organic solvent constituting the ink 6, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent, a hydrocarbon solvent, a higher fatty acid solvent, or the like can be preferably used, and only one of them can be used. Or a plurality of them may be used. Examples of the organic solvent include ether solvents such as diethyl ether, tetrahydrofuran and dioxane; ester solvents such as lactone, ethyl acetate, butyl acetate and isopropyl acetate; and methanol, ethanol, 2-propanol, 1-propanol, 1- One or a combination of two or more selected from the group of alcohol solvents such as butanol and tert-butanol is preferred. The organic solvent is preferably in the range of 80/10 to 95/1 by mass ratio with respect to the pigment 4, and more preferably in the range of 85/5 to 93/3. The ink 6 includes at least the pigment 4 and an organic solvent, and may further include a surfactant, a resin, a film property modifier, and the like in addition to the dispersant for improving the dispersibility of the pigment 4.

  When the ink 6 reaches the release sheet 5 after the printing process, the release sheet 5 and the decorative adhesive sheet 1 are separated (separation process). As a result, it is possible to obtain the decorative adhesive sheet 1 that maintains the adhesiveness on the entire surface including the decorative area 3 on both the front surface 1a and the back surface 1b.

  Next, examples of the present invention will be described.

<Example 1>
Model No .: YT-452 manufactured by Hitachi Chemical Co., Ltd. having a length of 300 mm and a width of 240 mm was used as the heat-welding resin sheet serving as a base material for the decorative adhesive sheet. This heat-weldable resin sheet is a sheet made of an acrylic resin having a thickness of about 50 μm, having release paper having a thickness of about 150 μm on one side, and having a heat-welding function on both sides. As the ink, a magenta pigment ink containing at least 3 parts by mass of a quinacridone pigment having an average particle diameter of 0.1 μm and 93 parts by mass of an organic solvent was prepared. The organic solvent in the ink is a mixture of 55 to 60 parts by mass of diethylene glycol diethyl ether, 10 to 20 parts by mass of γ-butyrolactone, 10 to 20 parts by mass of tetraethylene glycol dimethyl ether, and 1 to 5 parts by mass of tetraethylene glycol monobutyl ether. It consists of Set the heat-weldable resin sheet with release paper on one side to a printer (Seiko Epson Corporation, model number: GS6000), and the opposite side of the heat-weldable resin sheet from the release paper by the inkjet method using the ink. Printed on the surface. After drying the ink, the cross section of the decorative adhesive sheet with the release paper attached was observed with an optical microscope, and the pigment distribution in the thickness direction was examined.

  4 is an optical micrograph (magnification: 150 times) showing a cross section of the decorative adhesive sheet with release paper in Example 1. FIG.

  As shown in the photograph of FIG. 4, the pigment contained in the ink was present almost uniformly in the thickness direction so as to reach from the one surface of the heat-welding resin sheet to the application surface of the release paper. The image formed with the pigment was extremely high quality, and even when the decorative adhesive sheet was expanded or contracted, no gaps were observed in the image, and no cracks were observed in the image. This is because the pigment is densely filled in the thickness direction of the heat-weldable resin sheet and does not form an unevenly distributed layer on the surface of the sheet. Furthermore, since the heat-welding resin sheet does not contain a hydrophilic resin, it is superior in transparency as compared with those containing it. As a result, the color of the ink could be expressed almost on the decorative adhesive sheet.

<Example 2>
The same sheet as in Example 1 was used as the heat-welding resin sheet. As the ink, a white pigment ink containing at least 3 parts by mass of a titanium oxide pigment having an average particle size of 0.17 μm and 93 parts by mass of an organic solvent was prepared. The organic solvent in the ink is the same as in Example 1. Using this ink, printing was performed under the same conditions as in Example 1. After drying the ink, the cross-section of the decorative adhesive sheet with the release paper was observed with an optical microscope, and the thickness direction of the decorative adhesive sheet was observed. The pigment distribution was examined.

  FIG. 5 is an optical micrograph (magnification: 150 times) showing a cross section of the decorative adhesive sheet with release paper in Example 2.

  As shown in the photograph of FIG. 5, the pigment contained in the ink reached from the one surface of the heat-welding resin sheet to the sticking surface of the release paper. However, some unevenness occurred in the thickness direction, and the amount of pigment on the side closer to the release paper was less than that on the side closer to the printing surface. As a result of comparison with Example 1, it is considered that the difference in pigment distribution between Examples 1 and 2 is mainly due to the difference in the average particle diameter of the pigment. However, the image formed with the pigment was extremely high quality, and even when the decorative adhesive sheet was expanded and contracted, no gaps were observed in the image, and no cracks or the like were observed in the image. This is because the pigment is relatively densely packed in the thickness direction of the heat-welding resin sheet and does not form an unevenly distributed layer on the surface of the sheet. Furthermore, since the heat-welding resin sheet does not contain a hydrophilic resin, it is superior in transparency as compared with those containing it. As a result, the color of the ink could be expressed almost on the decorative adhesive sheet.

  INDUSTRIAL APPLICATION This invention can be utilized for the decoration of the molded object which has a curved surface or an uneven surface.

DESCRIPTION OF SYMBOLS 1 Decorating adhesive sheet 1a Front side surface 1b Back side surface 2 Heat-welding resin sheet 3 Decorating area 4 Pigment 5 Release sheet 6 Ink

Claims (4)

A decorative adhesive sheet in which a pigment is dispersed inside a decorative area of a heat-welding resin sheet having a thickness of 12 to 100 μm made of a hydrophobic resin,
The pigment is a particle having an average particle size of 0.5 μm or less in terms of volume, and is present at all positions in the thickness direction of the heat-welding resin sheet,
A decorative adhesive sheet characterized by having adhesiveness on both the front surface and the back surface in the thickness direction including the decorative area.   The heat-welding resin sheet is made of one or more resins selected from the group consisting of urethane resins, acrylic resins, polyester resins, epoxy resins, polyamide resins, and ethylene vinyl acetate copolymer resins. The decorative adhesive sheet according to claim 1, wherein   The decorative adhesive sheet according to claim 1, wherein the average particle diameter of the pigment is 0.15 μm or less. A pigment is dispersed inside a decoration area of a heat-welding resin sheet having a thickness of 12 to 100 μm made of hydrophobic resin, and the pigment is converted into a particle having an average particle diameter of 0.5 μm or less in terms of volume, and the above-mentioned heat welding It is present in all positions in the thickness direction of the adhesive resin sheet, and is a method for producing a decorative adhesive sheet having adhesiveness on both the front surface and the back surface in the thickness direction including the decorative area,
An ink comprising at least a mixture of 80 to 95 parts by mass of an organic solvent and 1 to 10 parts by mass of the pigment is supplied to the other side of the heat-welding resin sheet having a release sheet on one side. A printing process for printing by an inkjet method;
A separation step of separating the release sheet and the decorative adhesive sheet after the ink reaches the release sheet;
The manufacturing method of the decorating adhesive sheet characterized by including.