JP2019111730A - Transfer sheet - Google Patents

Abstract

To provide a transfer sheet capable of thinning a transfer layer compared to conventional ones, in which a color of the transfer layer is less likely to be affected by a color of an article to be transferred even though it is thin.SOLUTION: There is provided a transfer sheet by laminating at least a coloring layer 3, a light scattering layer 4, and an adhesive layer 5 on a single surface of a substrate sheet 2 in this order, in which a color of the coloring layer 3 is white-based, and the light scattering layer 4 is formed by aggregating hollow fine particles. There is provided a transfer sheet in which 2 sets of layers consisting of the coloring layer 3 and the light scattering layer 4 are laminated, and a hiding layer patterned between the light scattering layer 4 and the adhesive layer 5 are further laminated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transfer sheet.

  The transfer sheet is for transferring a transfer layer having a colored layer to a transfer target such as a molded product to obtain a decorated product. For example, Patent Document 1 discloses a transfer sheet 20 in which a white layer 22 is laminated on one side of a base sheet 21 (see FIG. 7A). In the transfer sheet 20, by transferring the white layer to the transferred material, the transferred material can be decorated in white. However, since the film thickness is small when the white layer is one layer as described above, the color of the transferred object is visually recognized through the white layer 22, and there is a problem that the color of the white layer 22 is changed.

  The following two transfer sheets were available to solve this problem. One is a transfer sheet in which a plurality of white layers 22 are stacked to increase the thickness of the white layer 22. When such a transfer sheet is transferred to a transfer target (see FIG. 7B), light incident from the white layer 22 side hardly reaches the transfer target, and as a result, it becomes difficult to visually recognize the color of the transfer target . The other is a transfer sheet in which a reflective layer 24 formed by metal deposition is laminated on a white layer 22 (see FIG. 8A). When such a transfer sheet is transferred onto a transfer target (see FIG. 8B), the light transmitted through the white layer 22 is reflected by the reflective layer 24 so that the light is less likely to reach the transfer target. It becomes difficult to visually recognize the color of the transferred material.

JP 2007-290300 A

However, in the transfer sheet in which the film thickness of the white layer 22 is increased by laminating a plurality of white layers 22, the total film thickness of the white layer is increased, and therefore, there are the following three problems. (1) A crack is generated in the transfer layer at the time of transfer, (2) an extra transfer layer remains around the transferred object after transfer, a so-called foil burr is generated, and (3) the white layer is not transferred firmly to the transferred object In addition, in the transfer sheet in which the reflection layer 24 formed by metal deposition is laminated on the white layer 22, light is reflected by the metal deposition layer, so that the metallic color is visually recognized, and the color tone of the white layer There was a problem that would change.

  The present invention has been made to solve the problems as described above, and it is possible to make the transfer layer thinner than in the prior art, and despite the thinness, the transfer sheet is less affected by the color of the transferred material. Intended to provide.

  Below, a plurality of modes are explained as a means to solve a subject. These aspects can be arbitrarily combined as needed.

  In the transfer sheet of the present invention, at least a colored layer, a light scattering layer containing hollow fine particles, and an adhesive layer are sequentially laminated on one surface of a substrate sheet.

  The color of the colored layer may be white.

  The light scattering layer may be formed of densely packed hollow particles.

  Two or more sets of layers formed of a colored layer and a light scattering layer may be laminated.

  A patterned masking layer may be further laminated between the light scattering layer and the adhesive layer.

  The transfer sheet of the present invention was configured such that at least a colored layer, a light scattering layer, and an adhesive layer were sequentially laminated on one side of the substrate sheet. Therefore, in the transfer sheet of the present invention, the transfer layer can be thinner than in the prior art, and the color of the transfer layer is hardly affected by the color of the transferred material despite being thin.

It is a typical sectional view showing an example of the embodiment of the transfer sheet of the present invention. (A) It is typical sectional drawing which shows an example of the behavior of the light in the transfer sheet of this invention. (B) It is typical sectional drawing which shows an example of the behavior of the light in the transfer sheet of this invention. It is a schematic cross section which shows an example of the behavior of the light in the conventional transfer sheet. It is a typical sectional view showing an example of the embodiment of the decoration goods which transferred the transfer sheet of the present invention. It is a typical sectional view showing an example of the embodiment of the transfer sheet of the present invention. It is a typical sectional view showing an example of the embodiment of the decoration goods which transferred the transfer sheet of the present invention. (A) It is a typical sectional view showing an example of the conventional transfer sheet. (B) It is a schematic cross section which shows an example of the decoration goods which transcribe | transferred the conventional transfer sheet to the material being transferred. (A) It is a typical sectional view showing other examples of the conventional transfer sheet. (B) It is a schematic cross section which shows an example of the decoration goods which transcribe | transferred the conventional transfer sheet to the material being transferred.

  Hereinafter, an example of an embodiment of the transfer sheet of the present invention will be described with reference to the drawings.

  In the transfer sheet 1 of the present invention, at least a colored layer 3, a light scattering layer 4 containing hollow fine particles, and an adhesive layer 5 are sequentially laminated on one surface of a substrate sheet 2 (see FIG. 1).

  The base sheet 2 is to be separated from the transferred material after transferring the transfer sheet 1 to the transferred material. Examples of the material of the base sheet 2 include thermoplastic resins such as polypropylene resins, polyethylene resins, polyamide resins, acrylic resins, olefin resins, polyester resins, polyvinyl chloride resins, polycarbonate resins, and ABS resins. And laminates of these.

  Examples of the method for transferring the transfer sheet 1 of the present invention to the transferred object 9 include known methods such as a thermal transfer method and a molding simultaneous transfer method.

  A release layer (not shown) may be laminated on the base sheet 2 in order to further improve the release property of the base sheet 2. The release layer is peeled off together with the base sheet 2 when the base sheet 2 is peeled off.

  The colored layer 3 may be formed on the entire surface, or may be formed in an arbitrary pattern. The decorative layer of a material to be transferred can be improved by the colored layer 3. The material of the colored layer 3 is, for example, a binder resin such as an acrylic resin, a vinyl chloride vinyl acetate copolymer resin, a thermoplastic or thermosetting urethane resin, or a polyester resin, and a pigment or dye added to the binder resin. It is included. The color of the colored layer 3 may be white. The white type is a pale color that contains a coloring material other than a white pigment in addition to pure white, and as such a color, for example, milky white, ivory, natural color, pink flower color, pea flour, lead white, gray white Etc.

In the case of a white type, as the pigment added to the binder resin, an opaque white pigment having no specific absorption in the visible light region and having a large refractive index is used. Examples of such pigments include titanium dioxide, magnesium oxide, barium sulfate, zirconium oxide, zinc oxide, lead white and the like. Among them, titanium dioxide (TiO ₂ ) is preferable. In addition to the large refractive index of 2.7, it has excellent visible light reflectivity, high chemical stability, and easy industrial use.

  The method for forming the colored layer 3 may be a usual printing method such as a gravure printing method, a screen printing method or an offset printing method, a roll coating method, a die coating method, an air doctor coating method, a blade coating method, a rod coating method, a bar coating method Coating methods such as a method, curtain coating method, knife coating method, squeeze coating method, impregnation coating method, kiss coating method, spray coating method, calendar coating method, extrusion coating method and the like can be used.

  The thickness of the colored layer 3 can be, for example, 1 μm to 20 μm. Preferably, it is 3 μm to 10 μm. If it is less than 3 μm, it is difficult to express the desired lightness, and if it exceeds 10 μm, defects such as cracks in the white layer, foil burrs and sticking defects occur at the time of simultaneous molding transfer, for example.

  The light scattering layer 4 contains hollow fine particles 6 (see FIG. 2A). The hollow particle 6 is a particle having a cavity, that is, an air layer inside. The refractive index of air is 1.0, and when the hollow fine particles 6 are included in the light scattering layer 4, a large number of fine voids are formed inside the light scattering layer 4. It can be reduced to about three.

  As the hollow particles 6, hollow particles using silica as a raw material, acrylic resin, urethane resin (polyurethane), polyethylene resin, polypropylene resin, polycarbonate resin, polyvinyl chloride resin, melamine resin, nylon resin (polyamide resin), polystyrene resin , Styrene-acrylic copolymer resin, polyester resin, polybutadiene resin, polyisobutylene resin, polyacrylamide resin, polyvinyl alcohol resin, polyvinylidene chloride resin, polymaleic anhydride resin, polyvinylidene fluoride resin, polyacrylonitrile resin, polyvinyl acetate Organic hollow fine particles (resin hollow fine particles) formed of resin, resin such as polyethylene terephthalate resin, or copolymer resin; silica (silicic acid) soda glass, aluminosilicate glass, boroke Glass hollow particles such as acid soda glass and soda lime borosilicate glass; hollow particles made from natural volcanic glass such as shirasu and obsidian; hollow particles formed from inorganic compounds such as inorganic hollow particles (inorganic hollow particles) Be Among them, hollow particles made of silica as a raw material are preferable.

  The light scattering layer 4 may be formed by a common printing method such as gravure printing, screen printing or offset printing, roll coating, die coating, air doctor coating, blade coating, rod coating, bar coating Coating methods such as coating method, curtain coating method, knife coating method, squeeze coating method, impregnation coating method, kiss coating method, spray coating method, calendar coating method, and extrusion coating method can be used. The thickness of the light scattering layer 4 can be, for example, 50 nm to 100 nm.

  In the decorative product 10 in which the conventional transfer sheet containing the white pigment 8 is transferred to the transferred object 9, the light that has reached the surface of the transferred object 9 among the light incident on the white layer (see FIG. 3) Part of the arrow a) is absorbed by the material to be transferred 9 (arrow b), and the remainder is reflected on the surface of the material to be transferred 9 (arrow c). At this time, when the color of the transferred material 9 is, for example, black, incident light is reflected by the white pigment 8 and most of the light (arrow a) that has reached the transferred material is absorbed by the transferred material 9. (Arrow b) A slight reflection occurs on the surface of the transferred object 9 (Arrow c). Therefore, the color of the decorative article 10 that is visible appears to be a mixture of the white of the white layer and the black of the transferred object 9. That is, the whiteness of the white layer is affected by the black color of the transferred material and becomes dull.

  On the other hand, in the decorative product 10 in which the transfer sheet of the present invention is transferred to the transferred object 9, referring to FIG. 2A, the light (arrow d) incident on the white layer is the binder resin of the colored layer 3 and the light. While being reflected at the interface between the colored layer 3 and the light scattering layer 4 due to the difference in refractive index with the scattering layer 4 (arrow e), the hollow fine particles 6 scatter inside the light scattering layer 4 (of the light scattering layer 4 Internal arrow). This makes it difficult for the incident light (arrow d) to reach the surface of the transferred object 9. That is, since the incident light (arrow d) is less likely to be absorbed by the transferred material 9 and the reflected light from the transferred material 9 is also reduced, the color of the transferred material 9 becomes less visible. Therefore, the color of the decorative article 10 that is visible becomes the original color of the white layer, because the whiteness of the white layer is less affected by the black color of the transferred material.

  The hollow particles may be formed densely (see FIG. 2 (b)). As shown, the hollow fine particles 6 are disposed in the light scattering layer 4 without gaps. In this case, the number of hollow particles is larger than in the case of FIG. 2A, so the air layer inside the hollow particles also increases. That is, since the refractive index of the light scattering layer 4 decreases and the refractive index difference between the colored layer 3 and the binder resin also increases accordingly, the light scattering layer 4 is more reflected at the interface with the light scattering layer 4 than in FIG. The amount of light increases. Further, the incident light (arrow d) is reflected at the interface of the light scattering layer 4 by the hollow fine particles 6 formed densely (arrow e), and as shown in FIG. It is also scattered inside (not shown) and it becomes difficult to reach the surface of the transferred object 9. Therefore, most of the incident light (arrow d) is reflected and scattered by the light scattering layer, and thus hardly reaches the surface of the transferred object 9. Therefore, the white color of the white layer is less affected by the black color of the transferred material.

  The hollow fine particles are blended in the binder resin of the light scattering layer so as to maximize the above-mentioned scattering effect. Depending on the kind of the hollow fine particles and the binder resin of the light scattering layer, it is appropriately blended to meet the purpose. If the content of the hollow particles is too small, the scattering effect of the incident light is not sufficient. If the content is too large, cohesive failure of the scattering layer is likely to occur, which causes a problem in the reliability of the quality of the final product. The hollow fine particles often have an apparent specific gravity of about 0.01 to 0.50 because the hollow fine particles are hollow inside, and a considerable amount of hollow fine particles is to be blended in volume.

  The adhesive layer 5 is a layer for firmly adhering the transfer sheet 1 to the surface of the material to be transferred 9. As the material of the adhesive layer 5, a heat-sensitive or pressure-sensitive resin can be appropriately selected and used. For example, acrylic resin, polystyrene resin, polyamide resin, chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, coumarone indene resin and the like. These resins are appropriately selected according to the material of the material to be transferred. The thickness of the adhesive layer can be 0.1 μm to 50 μm.

  The transfer sheet 1 may contain other layers. Other layers include, for example, a protective layer and a metal thin film layer. The protective layer is a layer which becomes the outermost surface of the material to be transferred 9 after peeling off the substrate sheet 2. As a material of the protective layer, thermoplastic resin such as acrylic resin, polystyrene resin, polyamide resin, chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, coumarone indene resin, etc. is used. be able to. When the protective layer is formed of such a thermoplastic resin, it is possible to impart chemical resistance and the like to the transferred material. In addition, as another material, it can be formed including any of a photocurable resin such as an ultraviolet curable resin, a radiation curable resin such as an electron beam curable resin, and a thermosetting resin. Examples of such resins include urethane acrylate resins, cyanoacrylate resins, epoxy acrylate resins, polyester acrylate resins, and resins obtained by adding an additive such as isocyanate to these resins. When the protective layer is formed of the above-described curable resin, physical properties such as durability and abrasion resistance can be imparted to the transferred material. The thickness of the protective layer 5 can be 0.5 μm to 10 μm. The metal thin film layer is formed between the base sheet 2 and the colored layer 3 in an arbitrary pattern. The formation method includes, for example, a method of depositing metal using a vacuum deposition method or a sputtering method.

  In the above embodiment, only one set of the colored layer 3 and the light scattering layer 4 is provided, but two or more sets may be provided (see FIG. 4). In this case, for example, when the colored layer 3 is a white layer containing the white pigment 8, light (arrow f) incident on the white layer 3 is reflected and scattered by the light scattering layer 4 (arrow g). Even if part of the incident light is transmitted to the lower white layer 3 (arrow h), the light reaches the surface of the transferred object 9 because it is reflected and scattered by the other light scattering layer 4 (arrow i) It is difficult to do. Therefore, even if there are two sets of layers consisting of a white layer and a light scattering layer, the light scattering layer 4 is formed under each white layer, so the color of the white layer depends on the color of the transferred object 9 It is hard to be affected. In addition, since two white layers are laminated, the whiteness can be increased more than in the case of one layer.

  The transfer sheet 1 of the present invention may be one in which a patterned shielding layer 7 is further laminated between the light scattering layer 4 and the adhesive layer 5 (see FIG. 5). When such a transfer sheet 1 is transferred to the transferred object 9 and the light source 11 is disposed on the back side of the transferred object 9, for example, a decorative article 10 as shown in FIG. 6 is obtained. In order to prevent the light from the light source 11 from leaking, the concealing layer 7 is preferably black in color. The black type is a color including black, gray and the like in addition to black.

  The concealing layer 7 is formed in an arbitrary pattern. As a result, a portion where the concealing layer 7 is not formed and a portion where it is formed can be obtained. The arbitrary pattern is, for example, characters, symbols, figures, and combinations of these. The portion from which the shielding layer 7 is not formed transmits light from the light source 11, and the portion from which the shielding layer 7 is formed shields the light from the light source 11. Therefore, when the light source 11 is turned on, light is transmitted from the portion where the shielding layer 7 is not formed, and it appears that an arbitrary pattern appears on the decorative article 10. The light source 11 may be embedded inside the transferred object 9.

  In addition, also for such a decorative article 10, light incident from the surface of the decorative article 10 is reflected and scattered by the light scattering layer 4 and hardly reaches the surface of the transferred object 9. Therefore, the color of the colored layer 3 is less susceptible to the color of the transferred material 9.

Example 1
Using a PET film as a substrate sheet, a white layer, a light scattering layer, and an adhesive layer were sequentially formed on one side by a printing method to obtain a transfer sheet. For the white layer, one obtained by dispersing titanium dioxide as a white pigment in an acrylic resin was used. The following composition was used for the light scattering layer. For the adhesive layer, a mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin was used. The thickness of each layer is as follows.
(Light scattering layer)
Vinyl chloride-vinyl acetate copolymer resin paint (solid content 30%) 15% by weight
Hollow silica fine particles (particle size 25 nm) 5% by weight
Diluted solvent (methyl ethyl ketone: toluene = 1: 1) 80% by weight
(Thickness of each layer)
Substrate sheet 38 μm
White layer 2 μm
Light scattering layer 80 nm
Adhesive layer 1.5 μm

(Comparative example 1)
A PET film was used as a base sheet, and two white layers, a light scattering layer, and an adhesive layer were formed in this order on one side by a printing method to obtain a transfer sheet. The material of each layer was the same as in Example 1. The total thickness of the two white layers is 4 μm, and the thicknesses of the other layers are the same as in Example 1.

(Comparative example 2)
A transfer sheet was obtained in the same manner as in Comparative Example 1 except that the white layer was changed to three layers. The total thickness of the three white layers is 6 μm, and the thicknesses of the other layers are the same as in Example 1.

(Comparative example 3)
A transfer sheet was obtained in the same manner as in Comparative Example 1 except that the white layer was changed to four layers. The total thickness of the three white layers is 8 μm, and the thicknesses of the other layers are the same as in Example 1.

(Comparative example 4)
A PET film was used as a base sheet, and a white layer and an adhesive layer were sequentially formed on one side by a printing method to obtain a transfer sheet. The material of each layer was the same as in Example 1. The thickness of each layer is the same as in Example 1.

(Comparative example 5)
A transfer sheet was obtained in the same manner as in Comparative Example 4 except that the white layer was changed to two layers. The total thickness of the two white layers is 4 μm, and the thicknesses of the other layers are the same as in Example 1.

(Comparative example 6)
A transfer sheet was obtained in the same manner as in Comparative Example 4 except that the white layer was changed to three layers. The total thickness of the three white layers is 6 μm, and the thicknesses of the other layers are the same as in Example 1.

(Comparative example 7)
A transfer sheet was obtained in the same manner as in Comparative Example 4 except that the white layer was changed to four layers. The total thickness of the four white layers is 8 μm, and the thicknesses of the other layers are the same as in Example 1.

  The transfer sheets of Example 1 and Comparative Examples 1 to 7 were disposed between a pair of molds, and the molds were clamped for molding, and the base sheet was peeled off to obtain a decorated molded article. The color of the molding resin was bluish.

  The reflected chromaticity of the decorative molded article was measured by the following method. Here, the reflection chromaticity is a value under the measurement conditions of standard light source D65, viewing angle 2 ° (CIE 1976), atmospheric pressure and 20 ° C., and is represented by L *, a *, b *. Among them, the larger the value of L * (lower limit value 0, upper limit value 100) which is a coordinate indicating brightness, the higher the brightness.

Standard light source D65 (color temperature 6504 K), viewing angle 2 ° (CIE 1976), atmospheric pressure using a spectrocolorimeter (CM-2600 d, manufactured by Konica Minolta) calibrated with a white calibration plate (CM-A145, manufactured by Konica Minolta) Below, total reflection chromaticity (SCI) with respect to the light which injected from the white layer side of the decoration molding under measurement conditions of 20 degreeC was measured, and L * value was evaluated.
The results are shown in Table 1.

  When Example 1 and Comparative Examples 1 to 3 are compared, a light scattering layer is formed in each of these decorative molded articles, and only the number of white layers is different. As described above, when only the number of white layers is increased, incident light is reflected by the white pigment, so the L * value becomes large. However, these L * values are substantially the same as the L * values of the decorative molded product having no light scattering layer shown in Comparative Examples 5 to 7. From this result, it can be seen that even if only the white layer is laminated on the light scattering layer and the white layer, the influence of the color of the molded article can not be obtained.

  Comparing Example 1 and Comparative Example 4, the L * value of Example 1 in which the light scattering layer is formed is larger than the L * value of Comparative Example 4 in which the light scattering layer is not formed. I understand. From this result, it can be seen that when the light scattering layer is formed, the light incident on the white layer hardly reaches the surface of the resin molded article, and therefore the white color of the white layer is less susceptible to the blue color of the molded article.

1: Transfer sheet 2: Substrate sheet 3: Colored layer 4: Light scattering layer 5: Adhesive layer 6: Hollow fine particles 7: Concealing layer 8: White pigment 9: Transferred material 10: Decoration goods 11: Light source 20: Transfer sheet 21 : Substrate sheet 22: White layer 23: Material transferred 24: Reflective layer

Claims (5)

  A transfer sheet in which at least a colored layer, a light scattering layer containing hollow fine particles, and an adhesive layer are sequentially laminated on one side of a substrate sheet.   The transfer sheet according to claim 1, wherein the color of the colored layer is white.   The transfer sheet according to claim 1, wherein the light scattering layer is formed by densely forming the hollow fine particles.   The transfer sheet according to any one of claims 1 to 3, wherein two or more sets of layers comprising the colored layer and the light scattering layer are laminated.   The transfer sheet according to any one of claims 1 to 4, wherein a patterned shielding layer is further laminated between the light scattering layer and the adhesive layer.

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