JPH07137498A - Transfer sheet - Google Patents

Abstract

PURPOSE:To let the title sheet have high ultraviolet ray blocking capability, deodrizing properties and antibacterial properties, by a method wherein a specific quantity of zinc oxide powder having specific mean particla diameter is compounded with at least one side out of a mold release layer adjoining to a peeling film and a protective layer adjoining to a mold release surface. CONSTITUTION:A transfer sheet is constituted of a peeling film, peeling layer and adhesive layer and a protective layer and pattern which are formed by a demand. Zinc oxide powder is compounded with a mold rlease layer and/or the protective layer. On this occasion, since the degrees of ultraviolet ray blocking capability and antibacteria properties depends on the particle diameter of zinc oxide, powder having mean particle diameter of not exceeding 0.1mum is used. Then the quantity of zinc oxide powder is 50-90wt.% based on weight of a layer with which the zinc oxide is mixed. Hereby, since the zinc oxide powder which can be compounded with at a high additive rate even in the case of a thin layer, the sufficient ultraviolet ray blocking capability can be displayed, and there is neither dissolution by ultraviolet rays nor bleedout from an additive layer, deterioration does not happen in adhession between layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer sheet, and more particularly, to a transfer sheet having at least a release layer and an adhesive layer formed on a release film, in the release layer, and / or in the release layer. The present invention relates to a transfer sheet having a UV-shielding property and an antibacterial property, in which zinc oxide powder is mixed in a protective layer optionally formed on the surface of a mold layer.

[0002]

2. Description of the Related Art A transfer sheet has a release film (a) and at least a release layer (b) and an adhesive layer (e) formed thereon. Further, in addition to these layers, an optional layer The protective layer (c) and / or the pattern layer (d) is formed as the. As the layer arrangement in the transfer sheet, generally, there are the following four types. Type 1: a / b / c / d / e, Type 2: a / b / d
/ E, type 3: a / b / c / e, type 4: a / b /
e

A transfer sheet having the above-mentioned layer arrangement is prepared by adhering the adhesive layer (e) side of the transfer sheet to a base material and then peeling off the release film (a), depending on the purpose. Stick a design on the surface of the substrate (Type 1,
It is used for attaching type 2), a protective layer (type 1, type 3) or attaching only a release layer (type 4). Then, depending on the application of the base material to which the transfer sheet is attached, for example, a benzophenone-based or benzotriazole-based organic ultraviolet ray in a release layer, a protective layer or a pattern layer in the transfer sheet for the purpose of imparting an ultraviolet shielding ability. It is practiced to blend an absorbent.

However, in a normal transfer sheet, since the release layer, the protective layer and the pattern layer are as thin as several μm, the addition amount is several% by weight due to the solubility of the organic UV absorber in the resin. There is a limit and it is not possible to provide sufficient UV shielding ability. Further, the organic ultraviolet absorber is more likely to bleed out than the added layer, which adversely affects the adhesiveness between the layers, and the concentration of the organic ultraviolet absorber is reduced due to the disappearance of the organic ultraviolet absorber to further deteriorate the ultraviolet shielding property. Therefore, the ultraviolet ray shielding function with respect to the base material is not sufficient, or a problem occurs in the fading resistance of the design.

[0005]

The object of the present invention is to provide a high layer-blocking ability because a thin layer can be blended at a high addition rate and there is no decomposition by ultraviolet rays.
It is an object of the present invention to provide a transfer sheet which does not bleed out from an additive layer, does not have a decrease in adhesiveness between layers, and can impart antibacterial properties, particularly antibacterial properties against Staphylococcus aureus, etc., and deodorant properties. .

[0006]

The above object is to provide a protective layer formed in a release layer formed on the surface of a release film of a transfer sheet and / or a protective layer formed on the surface of the release layer. This is achieved by a transfer sheet having an ultraviolet shielding property and an antibacterial property, characterized in that zinc oxide powder having an average particle diameter of 0.1 μm or less is mixed therein in an amount of 50 to 90% by weight.

The transfer sheet of the present invention comprises a release film, a release layer, an adhesive layer, and optionally a protective layer and a pattern layer, and the release layer adjacent to the release film and the protection adjacent to the release surface. Zinc oxide powder is incorporated in at least one of the layers.

The layers constituting the transfer sheet may be the same as those in the conventional transfer sheet except that zinc oxide powder is added. Each constituent layer of the transfer sheet is generally formed to have a film thickness of about 1 to 3 μm due to requirements such as workability. Examples of the release film include polyester, acrylic resin, polypropylene and other various plastic films, metal foil, paper, cellophane and the like.

The zinc oxide powder used in the present invention is 0.1 μm.
It has an average particle diameter of m or less, preferably 0.05 μm or less. If the average particle diameter exceeds 0.1 μm, the scattering of visible light becomes large, and the transparency of the coating layer containing ZnO powder is impaired, so that the design layer of the design layer or the base material may be used as a release layer.
You will not be able to see clearly through the protective layer. The strength of the ultraviolet shielding property and antibacterial property depends on the particle size, and when the average particle size exceeds 0.1 μm, the ultraviolet shielding function and the antibacterial property remarkably decrease. The ZnO powder having an average particle size of 0.1 μm or less can be produced, for example, by the method described in Japanese Patent Application No. 130422 of 1991.

The amount of zinc oxide powder is 50 to 90% by weight, preferably 60 to 80% by weight, based on the weight of the layer in which zinc oxide is incorporated (ie the release layer and / or the protective layer). If the amount of zinc oxide powder is less than 50% by weight, a coating layer thickness of 4 μm or more is required to obtain sufficient UV shielding performance, but such a thick film cannot be formed due to the design of the thermal transfer sheet, and thus is insufficient. However, the anti-fading property is deteriorated. In addition, the antibacterial property is insufficient. If the addition rate is 90% by weight or more, the relative amount of the binder component becomes too small, and the mechanical strength of the coating film decreases.

In order to form the zinc oxide powder mixed layer, the zinc oxide powder, the matrix resin and the solvent of the matrix resin are kneaded according to a conventional method, and the dry film thickness is 1 to 3 μm using a roll coater or other coating device. It may be applied so that the degree is about the same.

[0012]

EXAMPLES The present invention will be described below with reference to Comparative Examples based on Examples. Example 1 A release layer (b) of a polymethylmethacrylate resin was printed on one surface of a polyethylene terephthalate release film (a) having a thickness of 16 μm by a roll coater so as to have a thickness of 2 μm and has the following composition. The ink was produced by kneading and dispersing for 5 hours using a sand mill, and the film was dried with a roll coater on the release layer (b) to have a dry film thickness of 1 μm.
To form a protective layer (c) containing ZnO powder. ZnO powder (average particle size 0.02 μm) 32 parts by weight Polyester resin 8 parts by weight Toluene 48 parts by weight Methyl ethyl ketone 12 parts by weight

The spectral curve of this sheet is shown in FIG. 1 (curve a). Subsequently, a red-based color pattern layer (d) was printed on the print layer of the ZnO-containing ink with an ink in which a dye was dissolved in an acrylic polyol resin. Further, an adhesive layer (e) made of an acrylic adhesive was applied on the pattern layer (d) in a dry film thickness of 2 μm, and the type 1 (a / b / c /
A transfer sheet of d / e) was obtained. Further, this transfer sheet was transferred to a synthetic paper substrate by a flat plate press heat treatment at 150 ° C. for 20 seconds. Next, the release film (a) was peeled off and removed.

[0014] JIS-
A fading test was carried out with an indoor fading mercury lamp specified by KS5400. The degree of fading was evaluated by visual inspection according to the following four-step method. A: No fading B: Slight fading C: Fading D: Remarkably fading The results are shown in Table 1.

Example-2 On the same release film (a) as in Example-1, Example-
Ink having the following composition produced in the same manner as in No. 1 was applied by a gravure coater to give a dry film thickness of 3 μm.
A release layer (c) containing nO powder was formed. The spectral curve of this sheet is shown in FIG. 1 (curve a). Then, as in Example-1, a pattern layer (d) and an adhesive layer (e) were formed on the release layer (c).
To form a transfer sheet of the type 2 ((a / b / d / e). ZnO powder (average particle size 0.02 μm) 24 parts by weight polyester resin 16 parts by weight toluene 48 parts by weight methyl ethyl ketone 12 parts by weight Department

The transfer sheet thus obtained was thermocompression bonded to synthetic paper in the same manner as in Example-1, the release film was peeled off, and then a fading test was conducted in the same manner as in Example-1. . The results are shown in Table 1.

[0017]

[Table 1]

The antibacterial properties of the synthetic paper with a transfer sheet thus obtained were evaluated by the following test methods. The results are shown in Table-2. Test bacterium: Staphylococcus aureus Medium: Normal agar medium, Normal broth medium, Phosphate physiological buffer Test method: Bacteria solution is cultured in normal broth medium for 24 hours,
A test bacterial solution was prepared by diluting with a phosphate physiological buffer solution. A synthetic paper 4 × 4 cm sample piece with a transfer sheet prepared in this example was put in an Eiken screw cup, and 0.1 ml of the test bacterial solution was dropped on the sheet piece. 2 immediately after dropping and at 37 ° C
After storing for 4 hours, it was washed out with sterile physiological saline and the viable cell count was measured.

First, the sterilization rate was calculated from the following formula. * Sterilization rate (%) = [(ab) / a] x 100 a: Log control viable cell count b: Log sample viable cell count Effectiveness> 26%

[0020]

[Table 2]

Comparative Example-1 On the same release film (a) as in Example-1, an organic UV absorber-containing ink having the following composition was prepared in the same manner as in Example-1, and this ink was printed to obtain a poly A methyl methacrylate (MMA) resin-based release layer (b) was formed with a film thickness of 3 μm. The spectral curve of this sheet is shown in FIG. 1 (curve b). Subsequently, as in Example-1, a pattern layer (d) and an adhesive layer (e)
Were sequentially formed to obtain a type 2 (a / b / d / e) transfer sheet. The amount of the benzophenone-based ultraviolet absorber added to the MMA resin here is an amount substantially equivalent to the saturated dissolution amount. 2-4-dihydroxybenzophenone 3 parts by weight MMA resin 30 parts by weight toluene 55 parts by weight methyl ethyl ketone 12 parts by weight

The transfer sheet thus obtained was thermocompression-bonded to synthetic paper in the same manner as in Example-1 to peel off the release film, and then a fading test was conducted in the same manner as in Example-1. . The results are shown in Table 1.

As shown in Table 1 and FIGS. 1 and 2, the transfer sheet of the present invention containing a release layer or a protective layer containing ZnO powder having an average particle size of 0.1 μm or less significantly blocks ultraviolet rays. Therefore, fading of the pattern layer can be effectively suppressed, and the sheet shows a remarkable sterilization rate of 68%, which exceeds the sterilization rate of 26% which is generally considered to be effective in the antibacterial test, and is sufficient. It also has antibacterial properties.

[0024]

INDUSTRIAL APPLICABILITY The zinc oxide powder used in the present invention can be blended at a high addition rate even in a thin layer, so that it can exhibit a sufficient UV shielding property, and there is no decomposition by UV rays or bleed-out from the addition layer. Therefore, there is no decrease in the ultraviolet shielding property or the adhesion between the layers. Moreover, since zinc oxide exhibits antibacterial properties against both Gram-positive and Gram-negative bacteria such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella, and Klebsiella pneumoniae, and also exhibits deodorant properties, the transfer sheet is antibacterial and deodorant. It exhibits its properties, and by sticking it to a substrate, it is possible to impart antibacterial and deodorant properties to the substrate.
In view of the above characteristics, the transfer sheet of the present invention can be used for various packaging films, duvet bags and the like.

[Brief description of drawings]

FIG. 1 is a spectral curve showing the ultraviolet shielding rate of a sheet of the present invention (curve a) and a comparative example sheet (curve b) having a zinc oxide powder mixed layer.

Claims (1)

[Claims] 1. A transfer sheet having a release film, a release layer and an adhesive layer, optionally formed in the release layer formed on the surface of the release film and / or on the surface of the release layer. A transfer sheet having an ultraviolet shielding property and an antibacterial property, characterized in that 50 to 90% by weight of zinc oxide powder having an average particle diameter of 0.1 μm or less is blended in the protective layer.