JPH0919984A - Metal thin film transfer sheet - Google Patents

Abstract

PURPOSE: To obtain a metal thin film transfer sheet in which a metal thin film is hardly hurt and which is excellent in wettability by forming a silicon oxide vapor deposition layer and next a metal vapor deposition layer on one side of a plastic film. CONSTITUTION: A transfer sheet fed by rewinding from a roll 1 is passed through an adhesive application part 2 to be coated with an adhesive on the side of the metal vapor deposition layer of the transfer sheet, and paper fed from a roll 3 is pressed on the adhesive application surface to be joined. Next, the laminate is passed through a dryer 4 to cure the adhesive, and then the sheet and the paper are peeled off from each other. The film of the transfer sheet is wound up onto a roll 5, while the metallized paper protected by a silicon oxide vapor deposition layer is taken up onto a roll 6. In another process, the press-joined laminate is wound up directly and, after the adhesive being cured completely, delaminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal thin film transfer sheet used when a metal thin film is provided on the surface of a substrate such as paper or paperboard, and a method for producing metallized paper using the same.

[0002]

2. Description of the Related Art Metallized paper such as that found on labels attached to beer bottles can be manufactured by providing a metal thin film on the surface of a substrate such as paper or paperboard. However, it is technically difficult to directly provide a metal thin film on the surface of a base material such as paper. Therefore, a transfer method has been developed as a method for more easily producing metallized paper. The transfer method is basically a method of depositing a metal thin film on the surface of a plastic film by a vacuum deposition method and transferring the metal thin film to a substrate such as paper. Specifically, the following transfer method is known. Has been.

In the method described in Japanese Patent Publication No. 35-4775, a release agent layer is first provided on the surface of a plastic film, and a metal thin film is vapor-deposited on the release agent layer to produce a metal thin film transfer sheet. The transfer sheet and the base material are pressure-bonded via an agent, and then the two are separated from each other. At this time, the metal thin film is separated from the release agent layer of the transfer sheet and transferred to the surface of the base material. In this case, it is taught that the release agent layer provided on the surface of the plastic film can use silicone or a metal oxide film. In this transfer method, the metal thin film is easily transferred from the transfer sheet to the substrate due to the release agent layer provided on the plastic film, but the strength of the metal thin film is weakened, and the transfer sheet is wound and rewound. There is a drawback that the metal thin film is scratched or cracked due to the strain generated at the time of, the friction with the roll, and the like. When silicone is used as the release agent,
Since a part thereof is transferred to the surface of the base material together with the metal thin film, there is a drawback that the printability or coating suitability of the metal thin film surface is impaired.

In Japanese Patent Publication No. 63-20703, a transfer sheet is prepared by forming a metal vapor deposition film on a biaxially oriented polypropylene film (hereinafter referred to as OPP), and a metal on the transfer sheet is prepared by using an adhesive. A method for transferring a thin film to the surface of a substrate such as paper is described. in this way,
It is stated that it is not necessary to subject the OPP to special pretreatment for vapor deposition of the metal thin film, and the OPP after transfer can be reused. This transfer method uses a metal thin film
Since it is vapor-deposited on PP, there is an advantage that the metal thin film is easily peeled off from OPP without providing a release agent layer. However, the metal thin film itself has a drawback that it is poor in strength, as in the above case.

As a technique for increasing the strength of a metal thin film obtained by a vacuum vapor deposition method, Japanese Patent Publication No. 63-39425 teaches that the surface of OPP is previously subjected to corona discharge treatment. However, it is not easy to appropriately and uniformly perform the corona discharge treatment, and if this treatment is excessive, the metal thin film is less likely to be peeled from the OPP during transfer. OP
There is a drawback that a part that cannot be transferred from P to the substrate occurs. In addition to the above-mentioned drawbacks, each of the three conventional methods introduced above has the drawback that the metal thin film after transfer is still exposed, so that (a) the metal thin film is easily scratched. B)
When OPP is used, the additive contained therein bleeds and adheres to the metal surface, resulting in extremely low wettability and poor printability.

As a means for improving this problem, Japanese Patent Laid-Open No. 55-71725 discloses that a transparent resin layer is formed on the surface of a plastic film before vapor deposition of a metal thin film, and the transparent resin layer is formed on the transparent resin layer. When a transfer sheet is prepared by vapor-depositing a metal thin film, and the metal thin film is transferred to a base material such as paper, the transfer sheet and the base material are pressure-bonded via an adhesive, and then both are peeled off to remove the metal thin film. Is disclosed together with the transparent resin layer. That is, in this method, peeling at the time of transfer occurs between the plastic film and the transparent resin layer, and after the transfer, the transparent resin layer exists as a protective layer on the metal thin film. ), (B) no problem.

[0007]

However, in the method taught by Japanese Patent Laid-Open No. 55-71725, the transparent resin layer formed on the surface of the plastic film has (a) good releasability from the plastic film, (b) The selection of the resin is limited to an extremely narrow range because it is necessary to have the properties that the metal vapor deposition film can be easily formed and (c) the printability is excellent. For example, when a polyethylene terephthalate film that has heat resistance and is optimal for repeated reuse is selected as the plastic film, the resin forming the transparent resin layer is practically a part of the acrylic resin and the cellulose resin. Can only be used. Further, in this method, in order to form the transparent resin layer on the plastic film, a step of applying the transparent resin to the plastic film and drying it is indispensable prior to the metal deposition. This is a very serious drawback because it complicates the manufacturing process of the metal thin film transfer sheet. The main object of the present invention is to solve the above-mentioned disadvantages (a) and (b) of the conventional method, to eliminate the need for a transparent resin layer as disclosed in JP-A-55-71725, and to provide after transfer. Another object of the present invention is to provide a metal thin film transfer sheet which has good wettability on the metal surface.

[0008]

The metal thin film transfer sheet according to the present invention basically has a structure in which a silicon oxide vapor deposition layer and then a metal vapor deposition layer are provided on one surface of a plastic film. The plastic film used in the present invention is a polyolefin-based film, a polyester-based film or a polyamide-based film, and the polyolefin-based film includes a polyethylene film, an ethylene-based copolymer film, a polypropylene film, and a propylene-based film. A copolymer film, poly-4-methylpentane film, or the like can be used. Above all,
Biaxially oriented polypropylene film (OPP) is one of the most preferable plastic films used in the present invention because it has excellent smoothness and elasticity. Typical examples of the polyester film are a polyethylene terephthalate film and a polybutylene terephthalate film. A biaxially stretched polyethylene terephthalate film is particularly preferable.

When a polyester film is used in the production of a transfer sheet, it is preferable that a release agent layer is provided in advance before the silicon oxide vapor deposition layer is provided on the film. A silicone resin or a fluororesin is used. A silicone resin or a fluororesin can form a mold release agent layer made of a silicone resin or a fluororesin by applying a solution or dispersion of the silicone resin or the fluororesin to a polyester film and drying it.

When a biaxially stretched polypropylene film is used for producing a transfer sheet, it is not necessary to subject it to corona discharge treatment, but the film itself contains 0.2 to 1.0% by weight of an antistatic agent. Preferably, it is contained in an amount of about 0.3 to 1.0% by weight. The biaxially stretched polypropylene film containing no antistatic agent generates static electricity when it comes into contact with a roll or the like during the production of a transfer sheet, and the wettability of the film locally changes due to partial discharge. The releasability of the sheet varies. The antistatic agent contained in the biaxially oriented polypropylene film may be any of anionic type, cationic type, amphoteric type and nonionic type. By the way, typical examples of the antistatic agent that can be blended in the biaxially oriented polypropylene film include anion type antistatic agents such as alkyl sulfonates, alkylbenzene sulfonates, alkyl sulfates, and alkyl phosphates. . Examples of the cationic antistatic agent include alkyltrimethylammonium salt and allyloylamidopropyltrimethylammonium methosulfate, and examples of the amphoteric antistatic agent include alkylbetaine type, imidazoline type, and alanine type. Examples of the nonionic antistatic agent include fatty acid glycerin ester, polyoxyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkylamine, di- (2-hydroxyethyl) alkylamine, and fatty acid alkylolamide. Can be mentioned.

According to the present invention, a silicon oxide layer is first vapor-deposited on one surface of the plastic film (if a release agent layer is provided, that surface). The deposition of the silicon oxide layer is 10 ^-4 To
In a vacuum vapor deposition apparatus maintained at a pressure not higher than the order of rr, for example, at a pressure of about 2 × 10 ⁻⁴ Torr, one selected from silicon, silicon monoxide, silicon dioxide and a mixture thereof is subjected to resistance heating. And / or it is heated by an electron beam system to be vaporized, and this can be carried out by depositing it on the film (in the case where a film provided with a release agent layer is used, on the release agent layer). The thickness of the silicon oxide layer is 5 to 30.
A range of 0 Å is suitable. 5
When the film thickness is less than angstrom, the effect of providing the silicon oxide layer is insufficiently expressed, and when the film thickness exceeds 300 angstrom, the silicon oxide layer may not only be colored but the adhesion with the silicon oxide layer may be insufficient. This is because it becomes stronger and the releasability decreases.

On the silicon oxide vapor deposition layer formed on one surface of the plastic film, a metal thin film is laminated by a vacuum vapor deposition method. Aluminum, zinc, gold, silver, copper, nickel, chromium or the like can be used as the metal forming the metal vapor deposition layer. A normal vacuum vapor deposition method can be adopted for vapor deposition of a metal, and a desired metal is vaporized by heating it at a melting point or higher in a vacuum vapor deposition apparatus maintained at a pressure of 10 ^-2 to 10 ^-6 Torr. A metal vapor deposition layer can be formed by condensing and depositing the generated metal vapor on the silicon oxide layer. The film thickness of the metal vapor deposition film is preferably adjusted within the range of 100 to 700 angstrom. The step of forming a metal thin film by vacuum vapor deposition can be continuously performed in the same vapor deposition apparatus as that for forming the silicon oxide layer. In this way, by forming the metal vapor deposition layer on the silicon oxide vapor deposition layer formed on one surface of the plastic film, the production of the metal thin film transfer sheet of the present invention is completed.

Next, a method for producing metallized paper using the above-mentioned metal thin film transfer sheet will be described. The transfer sheet and the paper are pressure-bonded by interposing an adhesive layer between the metal vapor deposition layer side of the transfer sheet and the paper, and then both are peeled off, and the film of the transfer sheet and the oxidation are formed. Peeling occurs between the silicon vapor deposition layer (when the film has a release agent layer and the release agent layer and the silicon oxide vapor deposition layer), and the metal vapor deposition layer is transferred together with the silicon oxide layer for transfer. Transferred from sheet to paper. That is, by using the metal thin film transfer sheet of the present invention, it is possible to obtain metallized paper in which the metal vapor deposition layer is protected by the silicon oxide layer. When manufacturing metallized paper, a thermoplastic resin can be used to bond the metal deposition layer of the transfer sheet to the paper, and a thermosetting adhesive or a radiation curable adhesive can be used. Absent. As the thermoplastic resin, polyvinyl acetate-based, acrylic ester-based, nitrocellulose-based, polyamide-based, or other thermoplastic resins can be used as the adhesive, and as the thermosetting adhesive, epoxy-based or polyurethane is used. It is possible to use adhesives of melamine type, melamine type, melamine alkyd type and phenol type. As the radiation curable adhesive, an ultraviolet curable adhesive or an electron beam curable adhesive can be used, and an epoxy or acrylic radiation curable adhesive can be used.

As a method for adhering the transfer sheet and the paper, both a dry lamination method and a wet lamination method can be adopted, and the combination of the above-mentioned adhesive and the adhering method can be arbitrarily selected. FIG. 1 exemplifies a conceptual diagram of a wet lamination method in which an aqueous dispersion of a thermoplastic resin is used as an adhesive. The transfer sheet unwound from the roll (1) and pulled out,
The adhesive is applied to the metal vapor deposition layer side of the transfer sheet through the adhesive applying section (2), and the paper pulled out from the roll (3) is pressure-bonded and joined to the applied surface. Then, after passing the laminate through a dryer (4) to cure the adhesive,
After peeling them off, the film of the transfer sheet is wound on a roll (5) and the metallized paper protected by the silicon oxide vapor deposition layer is wound on a roll (6). In the example shown in the figure, the transfer sheet and the paper are pressure-bonded and the resulting laminate is peeled off in a series of steps. Alternatively, the laminate can be peeled off after the adhesive is sufficiently cured. FIG. 2 exemplifies a conceptual diagram of a dry lamination method using a solvent-type thermosetting resin as an adhesive. In this example, a transfer sheet unwound from a roll (1) is pulled out by an adhesive. The adhesive is applied to the metal vapor deposition layer side of the transfer sheet through the application part (2). Next, this sheet is passed through a dryer (4) to volatilize the solvent contained in the adhesive, and then the paper drawn from the roll (3) is pressure-bonded and joined. Then, the laminate was peeled off, and the transfer sheet film was rolled (5).
Then, the metallized papers protected by the silicon oxide vapor deposition layer are wound up on rolls (6), respectively. In the example shown in FIG.
It is possible to wind the pressure-bonded laminate of the transfer sheet and the paper as it is, and peel it off after the bonding with the direct-bonding agent has sufficiently progressed.

[0015]

In the sheet for metal thin film transfer of the present invention, the silicon oxide vapor deposition layer formed on the surface of the plastic film (the surface of the release agent layer when the release agent layer is provided), and the plastic film Peelability (if the film is provided with a release agent layer, the peelability between the silicon oxide vapor deposition layer and the release agent layer) is in an appropriate range, and the adhesive strength between the silicon oxide vapor deposition layer and the metal vapor deposition layer is Is high. Therefore, the vapor-deposited metal thin film adheres to the film surface relatively firmly, and the metal thin film is less likely to be scratched or wrinkled in the subsequent steps. Also, when transferring the metal vapor deposition layer from the transfer sheet to the paper,
The metal deposition layer can be transferred smoothly. Moreover, since the metal vapor deposition layer transferred to the paper is protected by the silicon oxide layer,
No cracks or scratches are formed on the metal vapor deposition layer during the winding operation or the rewinding operation of the metallized paper. In addition, when producing metallized paper having a thin film of aluminum, when aluminum is directly vapor-deposited on a plastic film and the vapor-deposited film is transferred to the paper, the aluminum thin film exposed on the surface of the metallized paper has poor wettability. It is customary to have troubles when printing on the surface of the. It is considered that this trouble is caused by the additives and the like compounded in the plastic film adhering to the aluminum surface during transfer. However, the metallized paper obtained by using the transfer sheet of the present invention has the silicon oxide vapor-deposited layer as the outermost surface thereof, so that the wettability does not decrease. In addition, in the method for producing metallized paper described in JP-A-55-71725, as shown in FIG. 3, a step of forming a transparent resin layer on a plastic film, a step of vapor-depositing a metal thin film, and a step of bonding with paper are performed. The metallized paper is manufactured through the peeling process and the peeling process, but since the transparent resin layer is transferred to the paper together with the metal deposition layer in the peeling process, the plastic film after the peeling process is reused for manufacturing the transfer sheet. In this case, it is necessary to apply a transparent resin to the plastic film and dry each time. On the other hand, in the method for producing metallized paper using the transfer sheet of the present invention, as shown in FIG. 4, even when the release agent layer is formed on the plastic film, the release agent layer is not formed in the release step. It remains on the plastic film and does not transfer to paper together with the silicon oxide vapor deposition layer and the metal vapor deposition layer. Therefore, even when the plastic film after the peeling step is reused in the production of the transfer sheet, it is not necessary to newly form the release agent layer on the plastic film.

[0016]

【Example】

Example 1 A biaxially stretched polypropylene film (antistatic agent content: 0.6% by weight) having a thickness of 200 μm was formed by a vacuum deposition method using silicon monoxide as an evaporation material at a degree of vacuum of 2 × 10 ⁻⁴ Torr to give 30%. An angstrom vapor-deposited film is formed, and then a silicon oxide vapor-deposited layer is formed to a thickness of
An aluminum deposition layer of 00 Å was formed to obtain a metal thin film transfer sheet. On the metal vapor deposition surface of this transfer sheet, an adhesive for urethane dry lamination
After coating so as to have a coating amount of 4 g / m ² at the time of drying and drying, a paperboard having a basis weight of 250 g / m ² is overlaid, and the temperature is 80 ° C.
It was pressure-bonded at 00 kg / cm, left to stand overnight for curing the adhesive, and then the polypropylene film was peeled off to obtain a metallized paper. Then, the transferability of the metal vapor deposition layer when obtaining the metallized paper is evaluated by the presence or absence of cracks in the metal vapor deposition layer, the presence or absence of an untransferred portion, and the ease of peeling, and the surface of the metallized paper obtained. The wettability was measured according to JIS K-6768. The results are shown in Table 1.

Example 2 A metallized paper was produced in the same manner as in Example 1 except that a mixture of 25 parts by weight of silicon and 75 parts by weight of silicon dioxide was used as an evaporation material for forming a silicon oxide layer. The transferability of the vapor deposition layer and the surface wettability of the metallized paper were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 3 A biaxially stretched polyethylene terephthalate film having a thickness of 16 μm was coated with a silicone resin in an amount of 1.0 when dried.
It was coated so as to be g / m ² and dried to form a release agent layer. Next, a silicon oxide vapor-deposited layer and a metal vapor-deposited layer were formed on the release agent layer in the same manner as in Example 1 to prepare a metal thin film transfer sheet, which was used in the same manner as in Example 1. To obtain metallized paper. Then, the transferability of the metal vapor deposition layer when obtaining the metallized paper and the surface wettability of the obtained metallized paper were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 4 A metal was prepared in the same manner as in Example 1 except that a biaxially stretched polypropylene film containing no antistatic agent was used in place of the biaxially stretched polypropylene film containing an antistatic agent. Manufacture synthetic paper, transferability of metal vapor deposition layer,
The surface wettability of the metallized paper was measured in the same manner as in Example 1. The results are shown in Table 1.

Example 5 Example 1 except that a biaxially oriented polypropylene film containing 0.3% by weight of an antistatic agent was used in place of the biaxially oriented polypropylene film containing 0.6% by weight of an antistatic agent. A metallized paper was produced in exactly the same manner as above, and the transferability of the metal vapor deposition layer and the surface wettability of the metallized paper were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 A metallized paper was produced in exactly the same manner as in Example 1 except that the formation of the silicon oxide vapor deposition layer was omitted.
The surface wettability of the metallized paper was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 A metallized paper was produced in the same manner as in Example 3 except that the formation of the silicon oxide vapor deposition layer was omitted.
The surface wettability of the metallized paper was measured in the same manner as in Example 3. The results are shown in Table 1.

[0023]

TABLE 1 whether peelable surface wettability of whether untransferred portion of the crack (dyne / cm ²⁾ Example 1 ○ ○ ○ 50 2 ○ ○ ○ 50 3 ○ ○ ○ 52 4 ○ ○ △ 50 5 ○ ○ ○ 50 Comparative Example 1 × ○ ○ 31 2 × ○ ○ 31 ──────────────────────────────────── Remark Crack ○: No cracks at all ×: Partially cracked presence of untransferred area ○: No untransferred area ×: Untransferred area Removability ○: Peeling is relatively light, transfer is not problematic △: Peeling is heavy However, it can be peeled off from the transfer sheet. ×: Peeling is very heavy and cannot be peeled off from the transfer sheet.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram when a metallized paper is manufactured by a wet lamination method using the metal thin film transfer sheet of the present invention.

FIG. 2 is a conceptual diagram when a metallized paper is produced by a dry lamination method using the metal thin film transfer sheet of the present invention.

FIG. 3 is an explanatory view of a process for producing metallized paper by the method described in JP-A-55-71725.

FIG. 4 is an explanatory view of a manufacturing process of metallized paper according to the present invention.

[Explanation of symbols]

1 Transfer Sheet Roll 2 Adhesive Application Section 3 Paper Roll 4 Dryer 5 Film Winding Roll 6 Metallized Paper Winding Roll

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[Procedure amendment]

[Submission date] February 24, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

[0016]

Example 1 A 20-micron- thick biaxially oriented polypropylene film (content of antistatic agent: 0.1%) was obtained by a vacuum deposition method using silicon monoxide as an evaporation material at a vacuum degree of 2 × 10 ⁻⁴ Torr.
6 wt%), a vapor deposition film of 30 Å is formed, and subsequently on the silicon oxide vapor deposition layer in the same vacuum,
An aluminum vapor deposition layer having a thickness of 300 Å was formed to obtain a metal thin film transfer sheet. A urethane-based dry laminating adhesive was applied to the metal deposition surface of this transfer sheet so as to have a coating amount of 4 g / m ² at the time of drying and dried, and then a paperboard having a basis weight of 250 g / m ² was overlaid. 80 ℃,
A pressure was applied at a linear pressure of 100 kg / cm, and the adhesive was cured by leaving it for a whole day and night, and then the polypropylene film was peeled off to obtain a metallized paper. Then, the transferability of the metal vapor deposition layer when obtaining the metallized paper is evaluated by the presence or absence of cracks in the metal vapor deposition layer, the presence or absence of an untransferred portion, and the ease of peeling, and the surface of the metallized paper obtained. The wettability was measured according to JIS K-6768. The results are shown in Table 1.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

[0023]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Saburo Takeyama 2-3-2 Higashishinozaki, Edogawa-ku, Tokyo Honshu Paper Co., Ltd.

Claims (6)

[Claims] 1. A sheet for metal thin film transfer, which comprises a vapor-deposited silicon oxide layer and a vapor-deposited metal layer provided on one surface of a plastic film. 2. The sheet for metal thin film transfer according to claim 1, wherein the plastic film is a polyolefin film. 3. The sheet for metal thin film transfer according to claim 2, wherein the polyolefin film is an untreated biaxially oriented polypropylene film containing an antistatic agent. 4. A sheet for metal thin film transfer, wherein the plastic film is a polyester film, and a release agent layer, a silicon oxide vapor deposition layer, and a metal vapor deposition layer are provided in this order on one surface of the polyester film. 5. The sheet for metal thin film transfer according to claim 4, wherein the release agent layer is composed of a silicone resin or a fluororesin. 6. A metal vapor deposition layer side of the sheet for metal thin film transfer according to any one of claims 1 to 5 is pressure-bonded to a paper via an adhesive layer, and then both are peeled off. A method for producing a metallized paper in which the adhesive layer, the metal vapor deposition layer, and the silicon oxide vapor deposition layer are laminated on the paper surface in this order by.