JPH0569698B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a print lamination method. [Prior Art] Print lamination methods for thermocompression bonding films on which heat-sealing polymer layers are laminated include a two-stage thermocompression bonding method (Japanese Patent Application Laid-Open No. 60-236727), an endless belt method (Japanese Patent Application Laid-Open No. 60-236727). Publication No. 68594, Japanese Unexamined Patent Publication No. 1996
-141029) are known. [Problems to be Solved by the Invention] However, although the above-mentioned conventional print laminating method has a satisfactory adhesive strength, it does not have a good gloss. It had a poor gloss. It is an object of the present invention to provide a method for solving these problems and obtaining a printed laminate with excellent adhesive strength and gloss. [Means for Solving the Problems] The print laminating method of the present invention includes a print laminating film and a printed body comprising a base film layer and a heat melting polymer layer, and a heat melting polymer layer surface of the print laminating film. In a print laminating method in which the printed surfaces of the printed material face each other and are pressure fused using a fusing device, the printed laminating film and the printed material are heated to 80°C or above.
After pressure welding at a temperature of 140℃ or less, 100℃ of 60℃ or higher
Firstly cooled to a temperature of ℃ or less, then further cooled to a temperature of 5℃ or more to 60℃
It is characterized in that it is separated from the crimping surface of the fusion device after being secondarily cooled to a temperature below 100 mL. The heat-fusible polymer in the present invention may be any polymer that has heat-fusibility, and is not particularly limited to polyethylene, ethylene copolymers (e.g., ethylene acrylic acid copolymer, ethylene ethyl acrylate), etc. copolymer, ethylene methacrylic acid copolymer, ethylene methyl methacrylate copolymer,
Ethylene acrylic acid copolymers such as ethylene methyl methacrylate maleic anhydride terpolymer,
Examples include ethylene vinyl acetate copolymer, ethylene propylene copolymer, ethylene butene copolymer), propylene butene copolymer, and methyl methacrylate copolymer, and mixtures thereof may also be used. . Further, petroleum resins, terpene resins, rosins, waxes, etc. may be added, and the preferred amount added is 5 to 35% by weight. Furthermore, particularly preferred are the above copolymers or mixtures whose main melting point peak is between 50 and 110°C. The thickness of the heat-sealable polymer layer is 1 to 30 μm, preferably 4 to 18 μm. The base film layer refers to a film made of polyolefin, polyester, polyamide, etc., of which polyolefin is preferred, and examples of the polyolefin film include films made of polypropylene, copolymers of propylene and other olefins, and the like. Particularly preferred is a biaxially stretched film mainly composed of polypropylene (propylene component: 85% by weight or more). Further, the base film layer may be a laminate of two or more layers, and the surface base layer preferably has lower rigidity or melting point than the inner base layer. The thickness of the base film layer is not particularly limited, but
It is 5 to 100 μm, preferably 10 to 25 μm. Heat stabilizers, antioxidants, antistatic agents, antiblocking agents, lubricants (organic and inorganic), UV inhibitors, nucleating agents, etc. are added to the heat-adhesive polymer layer and base film layer to improve adhesive strength and gloss. It may be added within a range (for example, 0.01 to 5% by weight) that does not reduce the texture. The method of laminating the heat-sealable polymer layer on the base film layer is not particularly limited, but may include a coating method, an extrusion lamination method, a method of laminating and then stretching (co-extrusion method, a method of uniaxial stretching, then laminating and stretching). ), etc., and an example is shown next. A polyolefin and a heat-sealable polymer are fed to one extruder and a heat-sealing polymer to another extruder, respectively, as resins to form the base film layer. Heat it, stretch it 3 to 7 times in the machine direction (in the method of laminating and stretching after uniaxial stretching, extrusion laminate the heat-sealing layer polymer at this point), heat it again and stretch it 5 to 15 times in the transverse direction. It is stretched, heat treated, and if necessary thermally relaxed to form a laminated film. It is preferable to perform corona discharge treatment on both sides of the heat-sealable polymer layer and the polyolefin in-film layer. The term "printed material" refers to material printed on art paper, coated paper, high-quality paper, Japanese paper, synthetic paper, film, etc., and it may be either a single material or a laminate. Also, printing is not particularly limited, and may include gravure printing, offset printing, letterpress printing, intaglio printing, flexo printing, etc.
Either is fine. The fusing device used in the present invention is a device that pressure-fuses the heat-fusing polymer layer laminated on one side of the base film layer and the printed surface of the printed material using two rolls. There are devices such as pressure welding and pressure welding using metal endless belts and rolls. A glazed film may be used instead of the metal endless belt. The roll is preferably made of metal (for example, hard chrome plating, stainless steel), ceramic, rubber, or the like.
When pressure fusing is performed using two rolls, both rolls are metal rolls, only one roll is metal roll or ceramic (on the base film layer side), and the other roll is a rubber roll. Among these, a method using an endless metal belt is preferred. When pressure fusing the print laminating film and the printing material, the temperature should be 80℃ or higher from one or both sides.
Excellent gloss, etc. can be obtained by heating and pressing at a temperature of 140°C or lower, preferably 90°C or higher and 130°C or lower. The temperature of this pressure fusion is preferably 10°C or more, more preferably 20°C or more higher than the melting point of the heat-sealing polymer layer, and preferably 30°C or more lower than the melting point of the base film layer. Pressure is usually
A linear pressure of 20 to 120 kg/cm is recommended. If the temperature of this pressure fusion is below 80℃, the adhesion is insufficient;
If the temperature exceeds 140℃, the printed laminate may undergo thermal deformation such as curling. In the present invention, after pressure fusion, 60℃ or higher
First cooling to a temperature of 100℃ or less, then further cooling to a temperature of 5℃ or more
Secondary cooling to a temperature below 60°C. The primary cooling temperature is
If the temperature exceeds 100℃, the printed material and the print lamination film may separate or become partially lifted, and if the temperature falls below 60℃, internal flickering remains and the product becomes less glossy. Furthermore, if the secondary cooling temperature is 60°C or higher, the printed laminate tends to curl, making it difficult to separate from the fusing device, causing uneven gloss, and generating a large amount of static electricity when removed. It becomes an obstacle to sorting things out. On the other hand, if the secondary cooling temperature is below 5° C., dew condensation is likely to occur, causing problems such as wetting of the printed laminate. The secondary cooling temperature is preferably 10°C or more and less than 40°C, and the secondary cooling temperature is preferably 20°C or more lower than the primary cooling temperature, more preferably 30°C or more lower. After pressure fusion, to primary cool to a temperature of 60°C or higher and 100°C or lower, bring hot water, heat medium, hot air, etc. into direct contact with the cooling position of the fusion device to perform primary cooling to that temperature. Alternatively, a method may include a method in which a roll controlled by a heat medium or a heater is brought into contact with a cooling position of a fusing device. The cooling method may be from the side of the film in contact with the fusing device, from the side of the printed material, or from both sides. It is best to use the same method for secondary cooling to a temperature of 5°C or higher and lower than 60°C.
Ice water, dry ice, freon, etc. can be used as the refrigerant. Hereinafter, the method of the present invention will be explained based on the drawings, but the method of the present invention is not limited to the following method. FIG. 1 is a schematic side view of an example of a metal endless belt type fusion device that can be used in the method of the present invention. The metal belt 3 has a heating roll 4 and a roll 6
The metal belt 3 rotates counterclockwise by the rotation of both rolls, and the heating roll 4 is held at a temperature of 80℃ or more.
The temperature is set to 140℃ or less. The printed laminating film 1 and the printed body 2 are fed between the metal endless belt 3 and the pressure roll 5 such that the heat-sealable polymer layer surface of the printed laminated film 1 and the printed surface of the printed body 2 face each other, The laminate is pressure-fused at a temperature of 80° C. or more and 140° C. or less, and the pressure-fused laminate moves while the base film layer surface is in contact with the metal endless belt 3. metal belt 3
Before reaching the roll 6, it is cooled secondarily by a hot water shower 7 and then cooled secondarily by a cold water shower 8. At position A, the laminate is separated from the metal endless belt 3 (crimping surface of the fusing device). The methods for measuring and evaluating physical property values used in the present invention are as follows. (1) Melting point Using a differential scanning calorimeter (DSC), the temperature is raised to 280°C at a rate of 20°C/min, held for 5 minutes, cooled at the same rate, and then raised again. The peak point of the melting curve of the orchid is taken as the melting point. When there are two or more peak points, the melting point is the peak with the largest melting area drawn from the base line and the curve. (2) Adhesive strength The printed material is printed from the obtained printed laminate.
Peel in a 180 degree direction, and reduce the force required for peeling to 1 cm.
Calculate it by converting it into units. (3) Surface gloss The surface gloss of the obtained printed laminate was evaluated according to the following criteria. 〇: There are no minute lumps on the surface, there is no uneven gloss, and the surface is smooth and has excellent gloss. Δ: There are some fine bumps on the surface. ×: There are many fine bumps, uneven gloss is observed, and the gloss is poor. (4) Internal gloss Inside of the obtained printed laminate (near the interface between the printed laminate film and the printed material)
The following criteria were used to evaluate the presence or absence of flickering. 〇: The inside is transparent and the internal gloss is excellent. △: There is some internal flickering. ×: There is a lot of internal flickering, and the internal gloss is poor. (5) Workability The workability of stacking and aligning the obtained printed laminates was evaluated based on the following criteria. 〇: There is little curling, and there is no problem with static electricity, and alignment can be done smoothly. ×: Curling is observed, static electricity is generated, and alignment is difficult. [Example] Example 1 Polypropylene (melt index: 2.0)
was fed to one extruder, and the ethylene propylene copolymer was fed to another extruder, coextruded into a sheet at 260℃, wrapped around a drum, cooled, and then heated to 120℃.
The polypropylene layer was extruded and laminated with ethylene vinyl acetate copolymer (melting point 80°C) from another extruder, and then introduced into a tenter heated to 170°C. Stretched twice in the transverse direction, heat-treated at 165℃, and then corona discharge treated on the surface of the heat-sealable polymer layer (ethylene vinyl acetate copolymer layer) to reduce the thickness of the heat-sealable polymer layer.
A print laminating film having a thickness of 15 μm and a polypropylene layer of 20 μm was obtained. Next, using the fusing device shown in FIG. 1, the print lamination film is laminated onto the printed body at a pressure fusing temperature of 105°C, a primary cooling temperature of 85°C, and a secondary cooling temperature of 30°C, and the printed laminated body is Obtained. The resulting printed laminate was evaluated for adhesive strength, surface gloss, internal gloss, and workability. The results are shown in Table 1. Example 2 The same procedure as in Example 1 was carried out except that the primary cooling temperature was changed to 65°C and the secondary cooling temperature was changed to 20°C. Comparative Example 1 The same procedure as in Example 1 was carried out except that the primary cooling temperature was changed to 65°C and secondary cooling was not performed. Comparative example 2 Primary cooling temperature is 100℃, secondary cooling temperature is 80℃
The procedure was carried out in the same manner as in Example 1, except that the procedure was changed to . Example 3 Polypropylene (melt index: 2.0)
extruded into a sheet at 260℃ and longitudinally heated at 120℃
A uniaxially stretched polypropylene film obtained by stretching 4.5 times was extrusion laminated with ethylene methyl methictalate copolymer (melting point: 85°C) as a heat-sealing polymer, and was stretched in a tenter at 170°C in the transverse direction for 11 minutes.
The film was stretched twice, heat-treated at 165°C, and the surface of the heat-fusible polymer layer was subjected to corona discharge treatment to obtain a film for print lamination having a heat-fusible polymer layer thickness of 8 μm and a polypropylene layer thickness of 20 μm. Next, using the fusing device shown in FIG. 1, the print laminating film is laminated onto the printed body at a pressure fusing temperature of 115°C, a primary cooling temperature of 95°C, and a secondary cooling temperature of 15°C,
A printed laminate was obtained. The resulting printed laminate was evaluated for adhesive strength, surface gloss, internal gloss, and workability. The results are shown in Table 1. Example 4 The same procedure as in Example 3 was carried out except that the primary cooling temperature was changed to 85°C and the secondary cooling temperature was changed to 50°C. Comparative Example 3 The same procedure as in Example 3 was carried out except that the primary cooling temperature was changed to 45°C and the secondary cooling temperature was changed to 70°C.

〔Effect of the invention〕

The present invention has the following excellent effects. (1) Since the heat fusing temperature is set to 80°C or higher and 140°C or lower, a printed laminate with sufficient adhesive strength can be obtained. (2) Since the primary cooling temperature is 60°C or more and 100°C or less and the secondary cooling temperature is 5°C or more and less than 60°C, a printed laminate with no internal flickering, excellent gloss, and excellent workability can be obtained. It will be done.

[Brief explanation of drawings]

FIG. 1 illustrates a fusing device that can be used in the method of the invention. 1...Film for print lamination, 2...
Printed body, 3... Metal endless belt, 4... Heating roll, 5... Pressure roll, 6... Roll, 7
... Shower for primary cooling, 8 ... Shower for secondary cooling, 9 ... Roll, 10 ... Roll, 11 ...
Drainer roll, 12...Drainer roll, 13...Printed laminate body, A...Removal position.

Claims (1)

[Claims] 1. A printed laminating film and a printed body consisting of a base film layer and a heat-fusible polymer layer are processed by a fusing device, with the heat-fusible polymer layer surface of the printed laminating film and the printed surface of the printed body facing each other. In a print lamination method that involves pressure fusing, after pressure fusing the print laminating film and the printed body at a temperature of 80°C or higher and 140°C or lower,
A print laminating method characterized by first cooling to a temperature of 60° C. or higher and 100° C. or lower, and then secondary cooling to a temperature of 5° C. or higher and lower than 60° C., and then separating the print from the pressure bonding surface of the fusing device.