JP2002301789A - Decorative film and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative film made of a resin having metallic appearance and also showing a good metal feeling and good concealability not only before molding but also after deep drawing, and a method for manufacturing the same. SOLUTION: The decorative film is manufactured by forming two or more resin layers, each of which contains metal thin pieces obtained by grinding a vapor deposition metal and has a thickness of 0.2-3.0 μm, on a film base material comprising a thermoplastic resin. The content of metal thin pieces is set to 30-80 wt.% and the metal thin pieces are arranged so as to become almost parallel to the surface of the resin layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative film having a metallic appearance and used, for example, for packaging various kinds of articles and decorations, and a method for producing the same.

[0002]

2. Description of the Related Art As an alternative technique to metal plating or metal deposition, for example, as disclosed in Japanese Patent No. 2957560, a paint or ink using a metal film piece obtained by pulverizing a metal film as a glittering material is disclosed. Is being developed.

At this time, in order to obtain an excellent metallic appearance, the vapor-deposited metal film pieces are oriented on a resin film so as to form a smooth surface, and a gap is formed between adjacent vapor-deposited metal film pieces. It is necessary to overlap so that it does not occur. For this reason, when using these paints and inks, it is common to apply as thinly as possible and to form a thin coating layer as thin as possible.

[0004]

However, in the case of such a conventional metal-decorative decorative film, it is used for packaging as it is, or when it is applied to the surface of an article as it is without molding. Although there is no particular problem, for example, when the shape is imparted by vacuum pressure molding or the like and then attached to the article, or when the film and the article are simultaneously molded as in insert molding, that is, post-molding When elongation occurs in the film due to the fact that the coating layer containing the deposited metal film pieces is extremely thin, the metallic feeling is reduced, uneven, and the shielding property is insufficient, and the appearance is particularly good when deep drawing is performed. The problem may be worsened, and the elimination of such a problem has been a problem in the conventional decorative metal film.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in a conventional decorative film having a metallic appearance, and has a good metallic feeling not only before forming but also after deep drawing. It is an object of the present invention to provide a decorative film having a hiding property and a method for manufacturing such a decorative film.

[0006]

According to the present invention, a decorative film according to the present invention comprises a film substrate made of a thermoplastic resin and a film having a thickness of 0.2 to 3.0 μm made of a metal flake obtained by crushing at least the resin and a vapor-deposited metal film. Two or more resin layers are formed, the metal flakes are arranged substantially parallel to the surface of the resin layer, and the content of the metal flakes in the resin layer is 30%.
It is characterized in that it has a configuration in the range of up to 80% by weight, and such a configuration in the decorative film is a means for solving the above-mentioned conventional problems.

[0007] The preferred form of the decorative film according to the present invention is that it is formed, and more preferably, the decorative film is substantially parallel to the surface of the resin layer even when the metal flake is in a formed state. It is characterized by having been arranged in the.

In the method of manufacturing a decorative film according to the present invention, at least two components of a resin constituting the resin layer and a metal flake obtained by pulverizing the vapor-deposited metal film have an absolute value of a difference in solubility parameter SP between the resin and the resin. Repeat the operation of applying a mixed solution dissolved in a solvent in the range of 1 to 3 to a film substrate made of a thermoplastic resin, followed by drying and evaporating the solvent to form a resin layer composed of at least the resin and metal flakes. In this case, two or more resin layers are laminated, and such a structure in the method for manufacturing a decorative film is used as means for solving the above-mentioned conventional problems.

[0009]

FIG. 1 shows a typical structure of a decorative film according to the present invention. The decorative film 1 is obtained by pulverizing at least a resin and a vapor-deposited metal film on a film substrate 2 made of a thermoplastic resin. , 3a, 3b,..., 3c.

At this time, at least two or more resin layers 3 are laminated to each other even when the molding is performed severely such that the area after the molding exceeds 180% with respect to the initial area. This is for maintaining the metallic feeling and the concealing property of the metal. That is, as described above, in order to obtain a good metallic feeling, the layer containing the metal flakes is extremely thin, and the metal flakes are oriented so as to form a smooth surface,
Further, it is necessary to arrange the adjacent metal flakes so as to overlap each other. In the case of a single layer, when this layer is stretched by molding, a gap is formed between the metal flakes, and the metallic appearance and the concealment property are greatly reduced. In order to avoid this, if the thickness of the layer is increased and the concentration of the metal flakes contained per unit area is increased, the orientation of the metal flakes tends to be disordered,
Although the concealing property can be secured, the metallic feeling is remarkably reduced. Although the thickness of the resin layer 3 will be described later, in the present invention, by maintaining an extremely thin resin layer 3 (at least two layers), it is possible to maintain both the concealing property after molding and a good metallic appearance. .

The film substrate 2 is not particularly limited as long as it contains a thermoplastic resin as a main component, but a transparent resin such as an acrylic resin represented by polymethyl methacrylate or a polycarbonate is desirable. Further, it is not necessary to be completely colorless and transparent, and it may be colored with a pigment, a dye, or the like, or may be mixed with a matting agent such as silica particles in accordance with a desired design property and metallic feeling. In addition, similarly, according to the desired design properties and metallic properties, as shown in FIG. 2, a colored layer, a pattern layer, a layer provided with a shape such as unevenness,
It is also possible to provide an arbitrary design layer 4 such as between the film substrate 2 and the resin layer 3.

The resin constituting the resin layer 3 is not particularly limited as long as it is a thermoplastic resin, and may be appropriately selected from those used in general lacquer paints and sun-crosslinkable inks. it can. As a typical one,
Examples thereof include a urethane resin, an acrylic resin, a butyral resin, and a vinyl chloride resin.

The metal flakes are not particularly limited as long as they are obtained by pulverizing a vapor-deposited metal film. Generally, a metal film is vapor-deposited on a resin film, and then the resin film is peeled and ground. It can be obtained by, for example, dissolving only the resin component after pulverization. The material of the metal to be vapor-deposited is not particularly limited, but aluminum is preferable in terms of good metallic feeling, cost, and ease of handling, and a resin film is further coated to suppress metal oxidation. Is desirable. The thickness of the metal flake is not particularly limited, but is preferably 0.4 μm or less, and 0.1 μm
It is particularly preferred to use: That is,
When the thickness exceeds 0.4 μm, the obtained metallic feeling is reduced.

The thickness of each of the layers 3a, 3b... 3c of the resin layer 3 must be in the range of 0.2 to 3.0 μm. That is, if it is less than 0.2 μm, the absolute amount of the metal flakes contained per unit area is insufficient, so that a sufficient metallic feeling cannot be obtained, and it is difficult to form a uniform layer. vice versa,
If it exceeds 3.0 μm, the orientation of the metal flakes is disturbed and the metallic appearance is reduced. The thickness is more preferably 0.5 to 1.5 μm. The thickness of each of the laminated resin layers 3a, 3b... 3c may be different as long as it is within the above range.

The weight concentration of the metal flakes contained in each of the resin layers 3a, 3b... 3c needs to be 30 to 80%.
That is, if the content is less than 30 wt%, a sufficient metallic feeling cannot be obtained, and if the content exceeds 80 wt%, the absolute amount of the resin is insufficient, the followability of the metal flake to molding is reduced, and the metallic feeling after molding is reduced. The weight concentration of the metal flakes is more preferably in the range of 40 to 60%.

The metal flakes 5 contained in the resin layer 3 are shown in FIG.
As shown in (a), it is necessary that the thin piece 5 be disposed so as to be substantially parallel to the surface of the resin layer 3, that is, the plane portion of the thin piece 5 is substantially parallel to the surface direction of the resin layer 3. That is,
As shown in FIG. 3 (b), when the metal flakes 5 whose angle between the plane portion and the surface direction of the resin layer 3 exceeds 20 ° increase, the metallic appearance gradually decreases. 20
° or less. The resin layer 3 contains at least two components of a resin and a metal flake, but may also contain other components such as a coloring agent such as a pigment or a dye, and an additive such as a wax, a medium, and a varnish. Good.

Since the decorative film 1 according to the present invention has a good metallic appearance even after molding, it is desirable to use it by molding it by, for example, vacuum pressure molding, and a molded product having a good metallic appearance is obtained. Can be Needless to say, it can be used in an unformed state, but it can be said that using in a molded state makes use of the features of the present invention. Moreover, in the decorative film 1 according to the present invention, even after molding, the metal flakes 5 included in the resin layer 3 are arranged such that the plane portions thereof are substantially parallel to the surface direction of the resin layer 3.

Such a decorative film 1 is prepared by dissolving at least two of the resin and the metal flake 5 in a solvent in which the absolute value of the difference in the solubility parameter (SP value) with the resin constituting the resin layer 3 is in the range of 1 to 3. The mixed solution in which the components are dissolved is applied to a film substrate made of a thermoplastic resin, and then dried, and the solvent is evaporated to form a resin phase 3 composed of at least the resin and the metal flakes 5.
Are formed, and this is sequentially repeated to form at least two or more resin layers 3a, 3b... 3c.

The solvent is not particularly limited as long as it satisfies the relationship of the solubility parameter, and may be a solvent of a single component or a mixed solvent obtained by mixing a plurality of types of solvents. Here, the reason why the absolute value of the difference between the solubility parameter and the resin is in the range of 1 to 3 is that when the absolute value of the difference is less than 1, the ability to dissolve the resin is too high and the resin layer 3 formed earlier is not used. Is affected by the mixed solution applied later, the orientation of the contained metal flakes 5 is disturbed, and a desired metallic feeling cannot be obtained. On the other hand, if the absolute value of the difference exceeds 3, the dissolving ability of the resin is too low and the dissolution of the resin becomes insufficient, so that a uniform mixed solution cannot be obtained and the thin resin layer 3 cannot be formed uniformly. by.

In the present invention, the solubility parameter (SP
For the general compounds, the known values (edited by the Society of Polymer Science, Basic Polymer Data Handbook, p. 591) are quoted, but for other compounds, the following formula (the above-mentioned Polymer Data Handbook) is used. Use the value calculated in (Basic section). δ = dΣG / M where δ: solubility parameter (SP value) [(cal /
cm ³ ) ^1/2 ] d: density [(g / cm ³ )] G: molar index constant (Hoy set by vapor pressure measurement)
Value) [(cal / cm ³ ) ^1/2 / mol] M: molecular weight [(g / mol)]

For the copolymer, the solubility parameter of each constituent unit constituting the copolymer as a homopolymer is calculated by the above formula, and the value is calculated by multiplying the solubility parameter by the mole fraction of each constituent unit. Is calculated by summing The mixed solvent is calculated by summing the values obtained by multiplying the solubility parameter of each solvent component constituting the mixed solvent by the volume fraction.

The method for applying the mixed solution to the film substrate 2 made of a thermoplastic resin is not particularly limited.
For example, printing method using gravure, screen, etc., painting method using spray, etc., bar coat, applicator,
It can be appropriately selected from methods such as extrusion and used. However, it is desirable to set a sufficient drying temperature and a sufficient drying time so that wet-on-dry is performed in the process of repeatedly applying.

[0023]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to only these examples.

EXAMPLE 1 An aluminum vapor-deposited film was pulverized in 100 parts by weight of a mixed solvent (δ = 11.9) obtained by mixing methyl ethyl ketone and methanol at a volume ratio of 1: 1.
m, 50 parts by weight of a metal flake having an average particle diameter of 10 μm, and a thermoplastic polyurethane resin (manufactured by Nippon Polyurethane Industry: DN-
(5980, δ = 10.0) 50 parts by weight, stirred and dissolved to obtain a mixed solution.

Next, a 250 μm thick polymethyl methacrylate film (manufactured by Sumitomo Chemical Co., Ltd.)
The layer thickness after drying was about 1.0 μm on Technoroy HG).
Was applied using a simple gravure printing machine, dried with warm air, and then applied again to have the same thickness, and two resin layers containing metal flakes were provided. A film was obtained. This is a 300 μm thick gray A
The BS sheet was laminated using a urethane-based one-component adhesive to obtain a decorative film.

Example 2 Methyl ethyl ketone and n-hexane were mixed at a volume fraction of 1: 2.
100 parts by weight of a mixed solvent (δ = 8.0) mixed with a thickness of 0.08 to 0.1 μ
m, 50 parts by weight of a metal flake having an average particle diameter of 10 μm, and a thermoplastic polyurethane resin (manufactured by Nippon Polyurethane Industry: DN-
(5980, δ = 10.0) 50 parts by weight, stirred and dissolved to obtain a mixed solution.

Next, this mixed solution was placed on a 250 μm-thick polymethyl methacrylate film (Technoloy HG, manufactured by Sumitomo Chemical Co., Ltd.) so that the layer thickness after drying was about 0.5 μm, and a simple gravure printing machine was used. Apply using
After drying with warm air, the coating was performed in the same manner so as to have the same thickness again, and this was repeated twice to obtain a film provided with three resin layers containing metal flakes. Thickness 30
A gray ABS sheet of 0 μm was laminated using a urethane-based one-component adhesive to obtain a decorative film.

COMPARATIVE EXAMPLE 1 An aluminum vapor-deposited film was pulverized in 100 parts by weight of a mixed solvent (δ = 11.9) in which methyl ethyl ketone and methanol were mixed at a volume ratio of 1: 1.
m, 50 parts by weight of a metal flake having an average particle diameter of 10 μm, and a thermoplastic polyurethane resin (manufactured by Nippon Polyurethane Industry: DN-
(5980, δ = 10.0) 50 parts by weight, stirred and dissolved to obtain a mixed solution.

Then, the mixed solution is applied to a 250 μm-thick polymethyl methacrylate film (Technoloy HG, manufactured by Sumitomo Chemical Co., Ltd.) to a thickness of about 1.0 after drying.
It was applied using a simple gravure printing machine to a thickness of μm and dried with warm air to obtain a film having one resin layer containing metal flakes. A gray ABS sheet having a thickness of 300 μm was laminated thereon using a urethane-based one-component adhesive to obtain a decorative film.

COMPARATIVE EXAMPLE 2 100 parts by weight of a mixed solvent (δ = 11.9) in which methyl ethyl ketone and methanol were mixed at a volume ratio of 1: 1 was ground to a thickness of 0.08 to 0.1 μm by pulverizing a vapor-deposited aluminum film.
m, 50 parts by weight of a metal flake having an average particle diameter of 10 μm, and a thermoplastic polyurethane resin (manufactured by Nippon Polyurethane Industry: DN-
(5980, δ = 10.0) 50 parts by weight, stirred and dissolved to obtain a mixed solution.

Next, a 250 μm-thick polymethyl methacrylate film (manufactured by Sumitomo Chemical Co., Ltd .:
The layer thickness after drying was about 5.0 μm on Technoroy HG).
Is applied using a simple gravure printing machine, dried with warm air, and the resin layer containing the metal flakes is
A film having a layer was obtained. A gray ABS sheet having a thickness of 300 μm was laminated thereon using a urethane-based one-component adhesive to obtain a decorative film.

Comparative Example 3 A general aluminum powder for coating (thickness: 0.6 to 1.0 μm) was added to 100 parts by weight of a mixed solvent (δ = 11.9) in which methyl ethyl ketone and methanol were mixed at a volume ratio of 1: 1.
m, average particle size 13 μm) and 50 parts by weight of a thermoplastic polyurethane resin (manufactured by Nippon Polyurethane Industry: DN-598).
(0, δ = 10.0) 50 parts by weight, stirred and dissolved to obtain a mixed solution.

Next, this mixed solution was applied to a 250 μm-thick polymethyl methacrylate film (Technoloy HG, manufactured by Sumitomo Chemical Co., Ltd.) to a thickness of about 1.5 after drying.
μm, using a simple gravure printing machine, dried with hot air, and then applied again to have the same layer thickness. Two layers of resin containing metal powder A film was obtained. A gray ABS sheet having a thickness of 300 μm was laminated thereon using a urethane-based one-component adhesive to obtain a decorative film.

COMPARATIVE EXAMPLE 4 An aluminum vapor-deposited film was pulverized in 100 parts by weight of a mixed solvent (δ = 10.0) in which methyl ethyl ketone and isopropyl alcohol were mixed at a volume ratio of 2: 1 to a thickness of 0.08.
To 0.1 μm, 50 parts by weight of a metal flake having an average particle size of 10 μm, and 50 parts by weight of a thermoplastic polyurethane resin (manufactured by Nippon Polyurethane Industry: DN-5980, δ = 10.0), followed by stirring and dissolving to obtain a mixed solution I got

A simple gravure printer was used to apply this mixed solution to a 250 μm-thick polymethyl methacrylate film (Technoloy HG, manufactured by Sumitomo Chemical Co., Ltd.) so that the layer thickness after drying was about 1.0 μm. After drying with hot air, coating was performed again to have the same layer thickness to obtain a film having two resin layers containing metal flakes. A gray ABS sheet having a thickness of 300 μm was laminated thereon using a urethane-based one-component adhesive to obtain a decorative film.

Evaluation The decorative film obtained as described above was evaluated as follows.

First, the initial (before forming) metal interval of each decorative film was evaluated. For evaluation of the metallic feeling, the Y value of the specularly reflected light area and the shade area with respect to the incident light at an incident angle of 60 ° was measured using a gonio colorimeter, and the metallic feeling index value was calculated based on this ratio. Then, when the metal feeling index value was 1.0 or more, it was determined that there was a metal feeling, and when it was less than 1.0, it was determined that there was no metal feeling.

Next, each decorative film was formed using a vacuum forming machine, and the metal feeling index value after forming was calculated in the same manner as described above. A mold having a portion in which the area of the film after molding is twice as large as that before molding is used.
The doubled portion was cut out and measured with a gonio colorimeter.
Further, the ratio of the index value before and after the molding was taken to be the metal feeling retention rate. That is, when the metal feeling index value after molding does not change at all from that before molding, the metal feeling holding ratio becomes 100%. When this value is 80% or more, it is determined that substantially no (visually) appearance problem (decrease in metal feeling, unevenness) occurs.

The above evaluation results are shown in Table 1 together with the structure of the decorative film.

[0040]

[Table 1]

As is clear from the results shown in Table 1, in the decorative films according to Examples 1 and 2, the metal feeling index value exceeded 1.0 before and after molding.
In addition, the metal feeling retention rate exceeded 80%, and it was confirmed that the metal feeling was excellent before and after molding. When the cross sections of these decorative films were examined by microscopic observation, the metal flakes were arranged almost parallel to the surface of the resin layer before and after molding, and no metal flake having an angle of more than 15 ° with respect to the resin layer surface was observed.

On the other hand, in the decorative film according to Comparative Example 1, since there is only one resin layer containing metal flakes, the metallic feeling before molding is good, but the metallic feeling after molding is large. It has been found that it is not suitable for molding applications because of its lowering and the lower metal feeling retention rate.

In Comparative Example 2 having only one resin layer containing metal flakes and having a large thickness,
Although a layer is formed, the metal film for coating according to Comparative Example 3 using a normal metal powder for painting is not ground but a metal film retention ratio is high, but this is a stage before molding. , The desired metallic feeling could not be obtained. Furthermore, in the decorative film according to Comparative Example 4 using a solvent having no difference in solubility parameter from the resin constituting the resin layer, the orientation of the metal flakes in the resin layer is disturbed, so that the metal feeling before and after molding and the In the retention rate,
It was confirmed that the film was significantly inferior to the decorative films according to Examples 1 and 2 of the present invention.

[0044]

As described above, the decorative film according to the present invention can be used on a film base made of a thermoplastic resin.
2. A film thickness including metal flakes obtained by pulverizing the deposited metal film.
Since two or more resin layers each having a thickness of 0 μm are formed, the metal flakes are contained in the resin layer in an amount of 30 to 80% by weight, and are arranged substantially parallel to the surface of the resin layer. A good metallic feeling can be obtained, and even if partial elongation occurs due to the forming process, the parallel state with the resin layer surface of the metal flake is maintained, and a good metallic feeling before and after molding is obtained. This is a very excellent effect that can be achieved.

In the method of manufacturing a decorative film according to the present invention, the resin and the vapor-deposited metal film are pulverized into a solvent having an absolute value of a difference between a solubility parameter SP value and a resin constituting the resin layer in a range of 1 to 3. A mixed solution in which at least two components of the metal flakes are dissolved is prepared, and the mixed solution is applied to a film substrate made of a thermoplastic resin and dried, and a solvent is evaporated to form a resin layer composed of at least the resin and the metal flakes. Since the above operation is repeated to laminate two or more resin layers, an excellent effect that the decorative film according to the present invention can be easily obtained is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of a decorative film according to the present invention.

FIG. 2 is an explanatory sectional view showing another embodiment of the decorative film according to the present invention.

FIG. 3A is an explanatory cross-sectional view showing an orientation state of metal flakes in a resin layer in a decorative film according to the present invention. (B) It is sectional explanatory drawing which shows the undesired orientation state of the metal flake in a resin layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Decorative film 2 Film base material 3 (3a, 3b, 3c) Resin layer 5 Metal flake

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B32B 27/20 B32B 27/20 A F-term (Reference) 4D075 AC25 AE03 AE15 AE16 BB24Y BB24Z CB07 CB13 DA04 DB31 DB43 DB48 DC36 DC38 EA05 EA17 EB13 EB15 EB22 EB38 EC01 EC23 EC30 EC51 EC54 4F100 AB01B AB01C AB01H AK01A AK01B AK01C BA02 BA03 BA07 BA23 CA13B CA13C DE01B DE01C DE02B DE02C DE02H EH462 EH66Y EH66Y EH66B EH66Y

Claims (4)

[Claims] 1. A film base comprising a thermoplastic resin,
At least two resin layers having a thickness of 0.2 to 3.0 [mu] m, each of which is made of a metal flake obtained by crushing a resin and a vapor-deposited metal film, are formed, and the metal flakes are arranged substantially parallel to the surface of the resin layer. A decorative film, wherein the content of metal flakes in the resin layer is in the range of 30 to 80% by weight. 2. The decorative film according to claim 1, wherein the decorative film is formed. 3. The decorative film according to claim 2, wherein the metal flakes are arranged substantially parallel to a surface of the resin layer in a molded state. 4. A mixture in which at least two components of a resin constituting a resin layer and a metal flake obtained by pulverizing a vapor-deposited metal film are dissolved in a solvent having an absolute value of a difference in a solubility parameter SP value between the resin and the resin in a range of 1 to 3. Applying the solution to a film substrate made of a thermoplastic resin, drying it, and repeating the operation of evaporating the solvent and forming a resin layer composed of at least the resin and metal flakes to laminate two or more resin layers. A method for producing a decorative film, comprising: