JP2002155247A - Pressure-sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive sheet capable of preventing aluminum particles from being oriented in a specific direction, even when a coloring base material layer containing the aluminum particles is formed by roll coating, and therefore capable of developing a feeling of metallic gloss when observed in every direction. SOLUTION: This pressure-sensitive adhesive sheet is formed by laminating a pressure-sensitive adhesive layer on one of both the surfaces of the coloring base material layer composed of a resin sheet which contains scaly aluminum particles (I) having a aspect ratio of >=5, wherein the aluminum particles (I) to be used satisfy the following requisites: the average particle diameter (d50) is not larger than 60% of the thickness of the coloring base material layer; and undersized particles which are sieved by using a sieve having a pore size of 2/3 time the average particle diameter (d50) are contained in an amount of >=30 wt.% based on the total amount of the aluminum particles (I).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive sheet used for outdoor and indoor advertising stickers, display stickers used for vehicles, and the like. To a pressure-sensitive adhesive sheet having

2. Description of the Related Art Conventionally, in coatings and marking films, aluminum vapor deposition or the like has been used to impart a specular property, and in order to impart a brilliant metallic feeling, generally, an aluminum powder rolled from an aspect is used. Mica or the like, in which a scale-like metal powder having a ratio of about 5 to 200 is dispersed in a resin, or surface-treated, is used.

[0002] In the above-mentioned coating for imparting a metallic feeling, spray coating is generally performed in many cases. In this case, as described in Asahi Kasei's “Coating Hourly Report” (NO. 152), a scale-like metal is used. Since powder is used and the metallic reflection is given by its specular reflection surface, the metal powder is 3
If it can be dispersed in the dimensional direction, almost the same brilliant metallic luster can be obtained from any direction. On the other hand, in the formation of a colored layer by a coating method such as a marking film, by arranging the metal powder in the same direction and two-dimensionally, the brilliant metallic luster is reduced and Therefore, there is a problem that it is difficult to obtain a desired metallic luster due to the property.

[0003]

When the colored layer is formed by roll coating, the scale-like metal particles are oriented in a certain direction by the flow during coating and the pressure due to the roll gap, and a metallic luster is imparted. Since the direction in which the light is applied is deviated to a specific direction, the metallic gloss in all directions is reduced.

[0004] The present invention solves the above problems, and even if a colored substrate layer containing aluminum particles is formed by roll coating, the aluminum particles are not oriented in a specific direction.
An object of the present invention is to provide a pressure-sensitive adhesive tape that exhibits a metallic luster such as spray coating from any direction.

[0005]

The pressure-sensitive adhesive sheet of the invention described in claim 1 (hereinafter referred to as the first invention) comprises a resin sheet containing scale-like aluminum particles (I) having an aspect ratio of 5 or more. A pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is laminated on one side of a colored base material layer, wherein the aluminum particles (I) have an average particle diameter (d ₅₀ ) at which ₅₀ % by weight is sieved by sieving. Is less than 60% of the thickness of the aluminum particles (I) and 30% by weight or more of the total amount of the aluminum particles (I) by sieving with a pore diameter of ／ of the average particle diameter (d ₅₀ ). .

The pressure-sensitive adhesive tape according to the invention described in claim 2 (hereinafter referred to as the second invention) has a single-sided surface of a colored base layer made of a resin sheet containing scale-like aluminum particles (I) having an aspect ratio of 5 or more. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer laminated thereon, wherein the colored base material layer has particles having an aspect ratio of 2 or less and a particle diameter of 1/30 to 1/2 of the thickness of the colored base material layer (II ) Is blended in an amount of 10 to 50 parts by weight based on 100 parts by weight of the aluminum particles (I).

Hereinafter, the present invention will be described in detail. The pressure-sensitive adhesive sheet of the present invention is formed from a color substrate layer containing scale-like aluminum particles (I) in which a pressure-sensitive adhesive layer is laminated on one surface.

In the first invention, the colored base material layer is formed from a resin sheet containing scale-like aluminum particles (I). As the aluminum particles (I), flake-like particles having a large reflection area are used instead of particles in order to express metallic luster in the colored base material layer. The aluminum particles (I) have the advantage of being superior in cost, durability, productivity, and the like, as compared with other metal particles.

In order to exhibit good metallic luster by using the aluminum particles (I), the aspect ratio of the aluminum particles (I) is limited to 5 or more.

The aluminum particles (I) have an average particle size (d ₅₀ ) at which ₅₀ % by weight is sieved by sieving and is 60% or less of the thickness of the colored base material layer, and the average particle size is 50% or less. (D ₅₀ ) A sieve having a pore size of 2/3 of the sieve under sieving of 30% by weight or more of the total amount of the aluminum particles (I) is used.

When the average particle diameter (d ₅₀ ) is 60% or less of the thickness of the colored base material layer, the orientation of the aluminum particles (I) itself is suppressed. Furthermore, 2/3 of the average particle diameter (d ₅₀ )
By using 30% by weight or more of the sieve obtained by sieving the pore diameter of, the aluminum particles (I) are prevented from being oriented two-dimensionally. On the other hand, the average particle diameter (d ₅₀ )
When the sieving by sieving with a 2/3 pore size is less than 30% by weight, the effect of suppressing two-dimensional orientation becomes insufficient, and the average particle diameter (d ₅₀ ) is 60% of the thickness of the colored base material layer. %, The orientation of the aluminum particles (I) becomes very large due to the coating pressure during roll coating. When the average particle size (d ₅₀ ) is less than 10 μm, the orientation decreases, but the metallic luster is reduced, so that it is preferably 10 μm or more.

In the first invention, by using the aluminum particles (I) having a particle size satisfying the above two conditions, it is possible to impart a metallic luster with reduced orientation and no directivity.

The above-mentioned aluminum particles (I) are usually rolled and pulverized in a high-boiling solvent such as solvent naphtha or mineral spirit and, if necessary, are subjected to solvent substitution or drying. Generally, it is often supplied as a paste dispersed in a solvent during pulverization. In addition, although there are those that have been surface-treated to improve the appearance and weather resistance, etc., in this application, the type, shape, and surface treatment of the solvent may be selected according to the required function. It can be used regardless.

[0014] In the second invention, in order to further develop a good metallic luster, flake-like aluminum particles (I) having an aspect ratio of 5 or more and particles (II) having an aspect ratio of 2 or less as in the first invention are used. Are used together. By using particles (II) having an aspect ratio of 2 or less in combination, the orientation of the particles (II) is physically suppressed, so that a more excellent metallic luster is exhibited. When the aspect ratio of the particles (II) exceeds 2, a sufficient orientation suppressing effect cannot be obtained.

When the particle diameter of the particles (II) increases,
Although the effect of suppressing the physical orientation of the particles (II) is obtained,
Since the surface smoothness of the colored base material layer is impaired, and if the particle diameter is reduced, a sufficient effect of suppressing the orientation cannot be obtained, the thickness is set in the range of 1/30 to 1/2 of the thickness of the colored base material layer.

When the amount of the particles (II) is small, the effect of suppressing the physical orientation is insufficient, and when the amount is large, the metallic luster is reduced. Therefore, 10 to 50 parts by weight based on 100 parts by weight of the aluminum particles (I). Department is limited.

The size of each filling material is effective as long as it is described in the claims. However, if the particle diameter of the particles (II) having an aspect ratio of 2 or less exceeds 100 μm, the unevenness on the surface becomes large and the external appearance becomes large. The particle size of the particles (II) is preferably 100 μm or less, since the quality is apt to deteriorate. If the thickness of the entire colored base material layer is less than 30 μm, the surface appearance is likely to be reduced due to the unevenness of the aluminum particles (I).
It is preferable to make the above.

For the colored substrate layer used in the present invention, various materials generally used for a marking sheet and the like are used. For example, soft vinyl chloride resin, acrylic resin, urethane resin, polyethylene terephthalate (PE)
T) and resin films or sheets of various olefin-based resins. Various additives such as a light stabilizer, a dispersant, and a pigment may be added to these resin films or sheets. The method for forming these resin films is not particularly limited, and a molding method such as solution casting or extrusion is used. Among these, solution cast molding is preferably used for the pressure-sensitive adhesive sheet of the present invention because the orientation of aluminum particles is reduced.

The pressure-sensitive adhesive used in the present invention is not particularly limited, and examples thereof include acrylic and rubber-based pressure-sensitive adhesives. The method of applying the pressure-sensitive adhesive may be directly applied to the colored base material layer and dried, or may be applied to release paper once, dried and then transferred and laminated on the colored base material layer.

In the pressure-sensitive adhesive tape of the present invention, a release paper is laminated on the pressure-sensitive adhesive layer and stored as a roll. If necessary, various printings or clear coats may be applied to the colored base material layer.

[0021]

Embodiments of the present invention will be described below.

(Example 1) Acrylic resin ("Hitaloid 8083" manufactured by Hitachi Chemical Co., Ltd., hydroxyl value 60 mg / g,
100 parts by weight of solid content concentration: 60 parts by weight, 14 parts by weight of aluminum paste (7 parts by weight of "M-801" manufactured by Asahi Kasei Kogyo Co., Ltd. as Al content and 7 parts by weight of "MG21" as Al content), pigment (Ciba Special) 1 part by weight of "DPP Red BP" manufactured by Chemicals, 0.4 part by weight of a light stabilizer ("Tinuvin 622LD" manufactured by Ciba Special Chemicals), and "Dysper-byk" manufactured by BYK-CHEMIE
140 ") 0.5 part by weight, 20 parts by weight of an isocyanate-based curing agent (" Duranate E402 "manufactured by Asahi Kasei Corporation)
Further, 20 parts by weight of MIBK was blended as a diluting solvent to obtain a coating liquid. The obtained coating liquid is coated on a PET release paper (“HP2” manufactured by Toyo Metallizing Co., Ltd.) to a thickness of 50 μm after drying.
m and dried at 110 ° C. for 7 minutes to obtain a colored base material layer. Separately, an acrylic pressure-sensitive adhesive was separately applied to silicone release paper (“SLK100” manufactured by Kite Chemical Industry Co., Ltd.), dried and laminated on a colored base material layer, cured at 40 ° C. for 72 hours, and then PET-peeled. The paper was peeled off to obtain an adhesive sheet.

(Example 2, Comparative Examples 1 to 6) Table 1 shows the types and amounts of aluminum paste and the amounts of additives (calcium carbonate particles and fibers) with respect to 100 parts by weight of Al. Example 1 except for changing to
In the same manner as in the above, an adhesive sheet was produced.

Table 1 shows the properties of the aluminum paste and additives used in the examples and comparative examples.

[0025]

[Table 1]

The pressure-sensitive adhesive sheets of the above Examples and Comparative Examples were evaluated for appearance by the following methods, and the results are shown in Table 2. Irradiation was performed from a D65 light source so that both the incident angle and the reflection angle were 45 degrees, and the presence or absence of anisotropy, metallic glossiness, and surface smoothness in the coating direction and the vertical direction were evaluated by visual observation.

[0027]

[Table 2]

[0028]

The pressure-sensitive adhesive sheet of the present invention has the above-mentioned constitution, and even if a colored base material layer containing aluminum particles is formed by roll coating, the aluminum particles do not orient in a specific direction. From any direction, it produces a metallic glitter with a “glitter” like spray paint.
Therefore, it is suitably used as a decorative marking film for outdoor and indoor advertising stickers, display stickers used in vehicles, and the like.

Claims (2)

[Claims] 1. A pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is laminated on one side of a colored base material layer composed of a resin sheet containing scale-like aluminum particles (I) having an aspect ratio of 5 or more, wherein said aluminum particles (I ) Means that the average particle diameter (d ₅₀ ) at which ₅₀ % by weight is on the sieve by sieving is 60% or less of the thickness of the colored base material layer, and is 2/3 of the average particle diameter (d ₅₀ ). A pressure-sensitive adhesive sheet, characterized in that the size of the pores sieved by sieving is 30% by weight or more of the total amount of the aluminum particles (I). 2. A pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is laminated on one side of a colored base material layer composed of a resin sheet containing scale-like aluminum particles (I) having an aspect ratio of 5 or more, wherein the colored base material layer Particles (II) having an aspect ratio of 2 or less and a particle diameter of 1/30 to 1/2 of the thickness of the colored base material layer,
10 to 50 parts by weight per 100 parts by weight of the aluminum particles (I)
An adhesive tape characterized by being blended in parts by weight.