JP3074493B2 - Method for producing composite sheet of film and paper having metal deposited layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite sheet of a film and a paper having a metal-deposited layer, which is subjected to secondary processing into, for example, a cosmetic packaging box or a paper bag.

[0002]

2. Description of the Related Art As a packaging material using paper that realizes a high-grade metallic feeling, a composite sheet in which aluminum foil or an aluminum vapor-deposited film is laminated on paper, or a metal vapor-deposited layer in which paper is directly subjected to aluminum vapor deposition and paper And the like.

[0003]

In the above-mentioned conventional method for producing a packaging material which embodies a metallic appearance, the method of laminating paper and aluminum foil has a high production cost. Since the irregularities appear on the surface of the aluminum foil, there is a disadvantage that sufficient metallic luster is not provided. In addition, in the method of laminating a paper and an aluminum vapor-deposited film, the metallic luster of the aluminum vapor-deposited film is not sufficient, and the adhesive strength between the aluminum vapor-deposited layer and the film is not sufficient. When the secondary processing is performed, there is a defect that the metal deposition layer is peeled off. Further, in the method of directly performing aluminum vapor deposition on paper, the metal vapor deposition process is performed almost in batches, so that the metal vapor deposition process on cardboard is expensive, and the moisture content of the paper subjected to metal vapor deposition is low. There is also a problem that the adjustment is complicated, and that the metallic luster is reduced because irregularities on the paper surface are exposed on the surface of the aluminum vapor-deposited layer.

[0004] On the other hand, in the method for producing a composite sheet of a film having a metal-deposited layer and paper according to the present invention,
Provided is a method in which a sufficient metallic luster is exhibited and a strong adhesive strength is obtained between a metal deposition layer and a film.

[0005]

According to the present invention, there is provided a method for producing a composite sheet of a film having a metal-deposited layer and paper, comprising the steps of: providing a thermoplastic polyester film uniaxially stretched in the machine direction in a thermoplastic film; After forming an undercoating layer of a mixture of a polyester resin and a compound having an isocyanate group, the first step of stretching the thermoplastic polyester film in the transverse direction (perpendicular to the machine direction) has a haze of 1. 2 below 0
An axially stretched thermoplastic polyester film is obtained.

Next, in the second step of forming a metal deposition layer on the undercoat layer surface of the biaxially stretched thermoplastic polyester film obtained in the first step, "metal deposition layer / undercoating layer / biaxially stretched thermoplastic film" A biaxially-stretched thermoplastic polyester film having a metal-deposited layer composed of "polyester film" is obtained.

After that, at least one surface of the biaxially stretched thermoplastic polyester film surface (nonmetallic vapor deposition layer surface) of the biaxially stretched thermoplastic polyester film having the metal deposition layer obtained in the second step is centered. A third step of attaching the smooth surface of the paper having a smooth surface having an average roughness of 1.0 μ or less using an adhesive to obtain a composite sheet of a film and a paper having an intended metal-deposited layer. Things.

In the method for producing a composite sheet of a film having a metal-deposited layer and paper according to the present invention, the thermoplastic polyester film comprises an aromatic dibasic acid or an ester derivative thereof and a diol or an ester derivative thereof. For example, a resin film of polyethylene terephthalate, a copolymer thereof, or a mixture of a small amount of another resin with them, or the like is used.

The step of uniaxially stretching the thermoplastic polyester film in the longitudinal direction is performed in the same manner as the step of stretching the thermoplastic polyester film in the longitudinal direction in the step of obtaining the thermoplastic polyester film by the successive biaxial stretching method.

[0010] An undercoat layer is formed on the thermoplastic polyester film after uniaxial stretching in the machine direction by using a coating agent of a mixture of a thermoplastic polyester resin and a compound having an isocyanate group. The thermoplastic polyester resin in the undercoating layer includes polycarboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, and sebacine. Acids, trimellitic acid, pyromellitic acid, dimer acid, itaconic acid, etc., and polyhydric alcohols such as
Ethylene glycol, 1,4-butanediol, dipropylene glycol, 1,6-hexanediol, 1,4
A known condensation polymer with cyclohexanedimethanol, glycerin, trimethylolpropane, etc. is used.
Compounds having an isocyanate group include 1,4-
Isocyanate-based compounds such as tetramethylylene isocyanate, 1,6-hexamethylene diisocyanate, 1,8-octamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, toluene diisocyanate, 1,3-phenylene diisocyanate, or
These and ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-
Butylene glycol, 1,4-butylene glycol,
2,2-dimethyl-1,3-propylene glycol,
1,6-hexanediol, 2,2,4-trimethyl-
Aliphatic diols such as 1,3-pentanediol, 1,3-cyclopentanediol, 1,4-cyclohexanediol, 1,4-methylene-bis (cyclohexanol), polyether polyols, polyester polyols, polyurethane polyols, etc. Are utilized.

A coating agent used for forming an undercoating layer with a mixture of a thermoplastic polyester resin and a compound having an isocyanate group is prepared as a solvent-based or aqueous dispersion-based coating agent. When adjusting this coating agent as an aqueous dispersion,
For example, phenol, cresol, t-butylphenol, t-aminophenol, t-butanol, ε-
It is necessary to block with a blocking agent such as caprolactam. In addition, in the coating agent used for forming the undercoating layer, for example, inorganic compounds such as silicon dioxide, aluminum trioxide, magnesium carbonate, calcium oxide, and magnesium oxide and heat-resistant resins are used in order to impart lubrication. Powders or beads having a particle size of 10 μm or less made of an organic compound may be added.

An undercoating layer made of a mixture of a thermoplastic polyester resin and a compound having an isocyanate group is prepared by applying a coating agent prepared using a thermoplastic polyester resin and a compound having an isocyanate group by a roll coating method or a gravure coating method. It is formed as a coating layer by a known coating method such as a spray coating method, an air knife coating method, and a curtain coating method.

[0013] After the coating agent of the mixture of the thermoplastic polyester resin and the compound having an isocyanate group is applied to the surface of the thermoplastic polyester film that is uniaxially stretched in the longitudinal direction, the coating layer is dried. It is preferable that the stretching is performed in a heating furnace in a transverse stretching zone of the film, and the transverse stretching of the thermoplastic polyester film is performed in a continuous step following drying of the coating layer.

The thermoplastic polyester film is subjected to a conventional heat-setting treatment after the transverse stretching step to obtain a biaxially stretched film having a haze of 1.0 or less.

Subsequently, a metal vapor-deposited layer is formed on the undercoating layer surface of the biaxially stretched thermoplastic film obtained in the preceding step by using a mixture of a thermoplastic polyester resin and a compound having an isocyanate group. The formation of the metal vapor deposition layer is performed by a batch type or continuous type metal vapor deposition apparatus. For example, a metal vapor deposition layer of about 100 to 5000 ° is formed of aluminum, nickel, copper or the like. If the thickness of the metal vapor-deposited layer formed on the biaxially stretched film is less than 100 °, the obtained metallic gloss is not sufficient, and if it exceeds 5000 °, it becomes uneconomical.

In the final step, paper is laminated on the non-metal-deposited layer surface of the metal-deposited film obtained by the above steps by using an adhesive. In this step, at least one surface of the paper to be laminated on the metal vapor-deposited film is a smooth surface having a center line average roughness of 1.0 μ or less, and the smooth surface of the paper is adhered to the metal vapor-deposited layer surface. . A known laminating method such as wet lamination or dry lamination is used for the sticking method. In addition, paper having at least one surface formed of a smooth surface having a center line average roughness of 1.0 μm or less is formed on the surface of the paper by, for example, a styrene-butadiene copolymer resin, an acrylic resin, a vinyl acetate-acryl copolymer resin, After coating latex such as vinyl acetate resin, starches, casein, polyvinyl alcohol, etc., the coated surface is subjected to calendering, or low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, It is obtained by forming an extruded laminate layer of a thermoplastic resin such as polypropylene.

The composite sheet of a film having a metal-deposited layer and paper obtained by the method of the present invention is usually subjected to a primer treatment on the surface of the metal-deposited layer in order to protect the surface of the metal-deposited layer. When the surface of the metal deposition layer is subjected to surface processing such as application of decorative printing or embossing, the primer treatment on the surface of the metal deposition layer also serves to improve the adhesion of the decorative printing.

[0018]

According to the method of the present invention for producing a composite sheet of a film having a metal vapor-deposited layer and paper, a thermoplastic polyester resin and a compound having an isocyanate group are formed on the surface of a thermoplastic polyester film uniaxially stretched in the machine direction. After forming the undercoating layer by the mixture, by stretching the thermoplastic polyester film in the transverse direction,
A first step of obtaining a biaxially stretched thermoplastic polyester film having a haze of 1.0 or less, and a second step of forming a metal deposition layer on the undercoating layer surface of the biaxially stretched thermoplastic polyester film obtained in the first step And the second
The biaxially stretched thermoplastic polyester film having a metal-deposited layer obtained by the step has a smooth surface on the biaxially stretched thermoplastic polyester film surface, at least one surface of which has a smooth surface having a center line average roughness of 1.0 μ or less. And a third step of attaching the surface.

The composite sheet of a film having a metal-deposited layer and a paper obtained by the above method has the following features. (1) A thermoplastic polyester resin and an isocyanate group are provided on the surface of a thermoplastic polyester film uniaxially stretched in the machine direction. After forming the undercoating layer by the mixture with the compound, the step of stretching the thermoplastic polyester film in the lateral direction is adopted, so that the undercoating layer is formed into a uniform and thin film, and the thermoplastic polyester film having high transparency Therefore, the brightness of the metallic luster in the biaxially stretched thermoplastic polyester film having a metal deposited layer is high. (2) The metal deposited layer formed on the surface of the thermoplastic polyester film has a thermoplastic polyester resin and an isocyanate group. Undercoat layer by a mixture with a compound having Because it is formed, the adhesion between the thermoplastic polyester film and the metal deposition layer becomes extremely good, and the printing ink formed on the metal deposition layer surface of the composite sheet does not shrink, etc., and Even when the obtained composite sheet is subjected to secondary processing into a cosmetic packaging box or the like, the metal deposition layer does not peel off. (3) Also, biaxially stretched thermoplastic polyester having a metal deposition layer The adhesive surface of the paper to be attached to the film has a center line average roughness of 1.
Since it has a smooth surface of 0μ or less, the brightness of the metal deposition layer formed on the biaxially stretched thermoplastic polyester film does not decrease due to the adhesion of paper, and exhibits a high degree of metallic luster. And the like.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The specific structure of the method for producing a composite sheet of a film having a metal vapor-deposited layer and paper according to the present invention will be described based on examples.

Example 1 A polyethylene terephthalate resin having an intrinsic viscosity of 0.65 was extruded with a T-die to obtain an original film having a thickness of 300 μm. The film was stretched to 1.5 times, and a uniaxially stretched polyethylene terephthalate film was obtained.

Subsequently, an undercoating agent made of a mixture of a thermoplastic polyester resin and a compound having an isocyanate group is applied to the surface of the uniaxially stretched polyethylene terephthalate film by a kiss coating method, and then passed through a preheating zone at 100 ° C. And then 105
Biaxially oriented polyester having a thickness of 25.2μ with a thickness of 0.1 g (dry) / m ² with an average coating amount of 0.1 g (dry) / m ^2. A resin film (hazing degree 0.8) was obtained.
In addition, ethylene glycol, terephthalic acid (80 mol%) and isophthalic acid (2
0 mol%) (molecular weight 620)
0) A compound obtained by reacting 100 parts by weight, 100 parts by weight of polyethylene glycol having an average molecular weight of 6000, and 12 parts by weight of toluene diisocyanate at 95 ° C. for 5 hours, and a compound having a terminal isocyanate group blocked with ε-caprolactam. In an aqueous dispersion with 60 parts by weight,
A mixture of 20 parts by weight of silicon dioxide having an average particle size of 2 μ was used.

Next, a 400 ° -thick aluminum vapor-deposited layer was formed on the undercoat layer surface of the biaxially stretched polyester film having the undercoat layer by a metal vapor deposition machine.

Thereafter, a styrene-butadiene copolymer latex was applied on one side, and then calendered on this side to obtain a paper having a basis weight of 210 g / m ² (center line average roughness of 0.1 g / m ² ).
1μ) a calendered surface is adhered to the aluminum vapor-deposited layer of the biaxially stretched polyester film having the aluminum vapor-deposited layer by a dry lamination method,
The desired composite paper was obtained. The obtained composite paper had a gloss of 830 and was excellent in metallic glossiness.

[0025]

According to the method for producing a composite sheet of a film having a metal-deposited layer and paper according to the present invention, a metal-deposited film having excellent metallic luster and strong adhesion between the metal-deposited layer and the film can be obtained. As a result, a high quality product can be obtained.

Therefore, for example, a gift box for a gift or the like,
It has a great value as a packaging material for high value-added products such as outer boxes for cosmetics and outer boxes for various drinks.

Claims (1)

(57) [Claims] 1. An undercoating layer made of a mixture of a thermoplastic polyester resin and a compound having an isocyanate group is formed on the surface of a thermoplastic polyester film uniaxially stretched in a longitudinal direction, and then the thermoplastic polyester film is placed in a transverse direction. A first step of obtaining a biaxially stretched thermoplastic polyester film having a haze of 1.0 or less, and forming a metal deposition layer on the undercoating layer surface of the biaxially stretched thermoplastic polyester film obtained by the first step. A smooth surface having a center line average roughness of 1.0 μm or less on at least one surface on a thermoplastic polyester film surface of a biaxially stretched thermoplastic polyester film having a metal deposition layer obtained in the second process and the second process. And a third step of attaching the smooth surface of the paper. Method of producing a composite sheet of film and paper having a metal deposition layer.