JPH06179250A - Manufacture of laminated steel sheet of image clarity - Google Patents

Abstract

PURPOSE:To provide a method improving the image clarity in a manufacture of a laminated steel plate of image clarity by laminating a laminated film of a plasticized polyvinyl chloride resin film and polyethylene terephthalate film to the steel sheet. CONSTITUTION:At the time of lamination, a steel plate temperature and laminating roll temperature are decided so that melt viscosity of plasticized polyvinyl chloride resin becomes 1X10<3>-5m10<4>Pa.S, lamination is performed by a mirror face metallic roll, the steel plate temperature is kept at the same temperature after the lamination and pressurized again by the mirror face metallic roll heated at the same temperature.

Description

Detailed Description of the Invention

[001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated steel sheet suitable for use in the exterior of home electric appliances requiring high image clarity and design, such as refrigerator doors and fan heater outer panels. Manufacturing method.

[002]

2. Description of the Related Art In the field of home electric appliances, a pre-coated steel sheet or a laminated steel sheet is used for the exterior to save labor during manufacturing. In recent years, these steel sheets have high image clarity and high image clarity. There is an increasing demand for design-oriented products.
At present, the high-visibility design steel sheet is roughly classified into two types, that is, a laminated film of a plasticized polyvinyl chloride resin film subjected to gravure printing and a polyethylene terephthalate film, with an adhesive layer interposed therebetween. It is manufactured by a method of laminating a steel sheet and a method of performing gravure printing on the steel sheet and then applying clear coating on it.
The latter method requires printing equipment in the painting line, so the former method has become the mainstream.

By the way, in the production of the high image clarity design steel sheet by the former method, after the adhesive layer is provided on the surface of the steel sheet and the adhesive layer is heated, when the steel sheet temperature is 170 to 180 ° C. -A laminated film of a plasticized polyvinyl chloride resin film (hereinafter referred to as a PVC film) and a polyethylene terephthalate film (hereinafter referred to as a PET film) is laminated on a troll so that the PVC film side is in contact with the adhesive layer. Was there. However, with this method, PV
Since the C film does not melt, the unevenness of the PVC film appears on the surface of the PET film, resulting in a dull skin, and a high-visibility appearance cannot be obtained.

Therefore, in order to improve the yuzu skin, the laminated film is laminated, and then the laminated film is pressed with a heated mirror-finish metal finishing roll to melt only the PVC film having a low melting point, thereby making the PET film surface. Has been proposed (Japanese Patent Laid-Open No. 63-280627).
issue). However, in this method, it is difficult to completely eliminate the unevenness because the pressure applied to the laminated film by the heating mirror finishing roll is short and the PVC film is not melted so much. In addition, there is also a problem that a uniform appearance cannot be obtained because the sharpness of the image varies depending on the pressure applied to the roll.

[0095]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a clear laminated steel sheet in which the effect of unevenness of a PVC film does not appear on the surface so much and a uniform appearance can be obtained. .

[0096]

SUMMARY OF THE INVENTION In the present invention, the laminer roll is a mirror-finished metal roll having a surface roughness of 1 μm or less,
The melting temperature of the plasticized polyvinyl chloride resin is 1 × 10 ^{3 to} 5 depending on the temperature of the steel plate and the temperature of the lamine roll during lamination.
Together so as × becomes 10 ⁴ Pa · s, specular metallic pressure Russia - the steel sheet temperature to pressurization at Le keeping the same temperature, the specular metal heated surface roughness following 1μm at the same temperature pressure B - Le It was made to pressurize.

[0097]

When the laminated film is laminated, the melt viscosity of the plasticized polyvinyl chloride resin is 1 × with the steel plate and the mirror-finished metal roll.
When it is heated to 10 ^{3 to} 5 × 10 ⁴ Pa · s, it will be in a sufficiently molten state, so that it can be smoothed when pressed down by a mirror-finished metal roll. Melt viscosity is 1 × 10 ³
When it is less than Pa · s, the melt viscosity is too low, so that a part of the plasticized polyvinyl chloride resin flows out from the interface with the adhesive layer or the PET film, and the yuzu feeling becomes large. On the other hand, if it exceeds 5 × 10 ⁴ Pa · s, the melting becomes insufficient, so that even if it is pressed down by the mirror surface metal roll, the citrus feeling does not disappear.

The reason why the laminated film is heated by both the steel plate and the mirror-finished metal roll is that the amount of heat supplied to the laminated film is insufficient and the laminated film cannot be melted in a short time with only the steel plate. Is. When the mirror-finished metal roll is heated, the plasticized polyvinyl chloride resin is practically melted while the PET film retains the film form and is laminated on the steel sheet, so that the PVC film becomes smooth.
Unless the surface roughness of the laminae-roll is 1 μm or less,
Sufficient smoothness cannot be obtained and the image clarity is deteriorated.

Since sufficient sharpness cannot be obtained only by laminating by the above method, a mirror surface metal rolling roll is arranged at the rear of the laminating roll, and this roll is rolled. Until the pressurization, the temperature of the steel sheet is kept so that the melt viscosity of the plasticized polyvinyl chloride resin is 1 × 10 ^{3 to} 5 × 10 ⁴ Pa · s, and the roll is heated to the same temperature to press the laminated film. . The surface is corrected by this pressurization, resulting in high image clarity.
For the same reason, the temperature and surface roughness of the mirror surface metal rolling roll at the time of pressurizing with the roll are the same as those of the laminate.

In the production of a laminated steel sheet, the steel sheet is usually subjected to pretreatment such as degreasing treatment or chemical conversion treatment before the formation of the adhesive layer, but the pretreatment may be omitted depending on the surface state of the steel sheet. If the adhesive of the adhesive layer requires a primer layer to secure the adhesiveness to the steel sheet, the primer layer may be formed before the adhesive layer is formed. If desired, a rust preventive pigment, a coloring pigment, an extender pigment or the like may be added to this primer layer. The steel plate is not particularly limited, and may be, for example, a cold rolled steel plate, a galvanized steel plate, an aluminum plated steel plate, a composite plated steel plate, a stainless steel plate, or the like.

As the adhesive for forming the adhesive layer, PVC on steel plate is used.
A film laminate can be used, and a plasticized polyvinyl chloride resin having a melt viscosity of 1 liquid type or 2 liquid type can be used.
The adhesive is not particularly limited as long as it can be adhered within a range of × 10 ^{3 to} 5 × 10 ⁴ Pa · s, and for example, an acrylic adhesive, a polyester adhesive, or a polyurethane adhesive can be used. If necessary, a rust preventive pigment, a coloring pigment, an extender pigment or the like may be added to this adhesive layer.

For the PVC film of the laminated film, a vinyl chloride resin composition comprising a polyvinyl chloride resin, a plasticizer, a stabilizer, a pigment, and other additives (for example, an ultraviolet absorber) is calendered or extruded. The polyvinyl chloride resin contains a homopolymer of vinyl chloride, a copolymer of a vinyl chloride monomer such as vinyl acetate and ethylene, and a copolymerizable monomer. There is no particular limitation on the stabilizer and the pigment. On the other hand, the PET film is biaxially stretched and transparent. The thickness of these films is about 50 to 200 μm in the case of PVC film and 10 in the case of PET film.
It is preferably about 50 μm.

As the laminated film, a film on which a pattern is printed may be used in order to improve the design. This film has a pattern pattern formed by gravure printing on one of a PVC film and a PET film, and the printed surface is laminated on the other film with an adhesive so that the pattern pattern exists in the laminated film. Acrylic printing ink
A base resin such as polyester or polyurethane may be mixed with a pigment or various additives.

[0142]

【Example】

(1) Preparation of laminated film Ba-Zn was added to 100 parts by weight of polyvinyl chloride resin.
3 parts by weight of system stabilizer, 2 parts by weight of epoxidized soybean oil, 5 parts by weight of TiO ₂ (predetermined colorant) and plasticizer (D
OP) was mixed in a predetermined amount shown in Table 1 and then kneaded with a test roll at a predetermined temperature shown in Table 1 for 10 minutes to produce PVC films having various thicknesses. Next, a two-component polyester adhesive was applied to PET films of various thicknesses shown in Table 1 so that the dry thickness would be 3 μm, and 1
The PVC film was laminated by baking at 80 ° C. In Table 1, the laminated films Nos. 1, 3 and 5 were patterned by gravure printing on the adhesive side before lamination, and the laminated films Nos. 2, 4 and 6 were reversely gravure printed on the PET film before lamination. I gave it a pattern. Table 2 shows that the plasticized polyvinyl chloride resin has a melt viscosity of 1 × 10 ^{3 to} 5 × 10 ⁴ Pa.
・ Indicates the range of s.

[0115]

[Table 1]

[0163]

[Table 2]

(2) Manufacture of laminated steel sheet Electrogalvanized steel sheet (weight per unit surface: 20 g / m ² , plate thickness: 0.
4 mm) is applied with a coating type chromate treatment to apply a phenoxy type primer to a dry thickness of 5 μm, and then a two-pack type polyester adhesive is applied to the primer layer to a dry thickness of 5 μm.
The laminated film shown in Table 1 was coated with a mirror-finished metal laminator (surface roughness: 0.3 μm), which was applied at a temperature of the steel plate shown in Table 3 immediately after the coating and baking. Were laminated. The laminated steel sheets were heated and maintained at the temperature for baking, and pressed by a mirror surface metal rolling roll (surface roughness 0.5 μm) heated at the temperature for baking.

The laminated steel sheet thus obtained was subjected to surface NSIC and NS using a mapping sharpness measuring device.
IC * was measured. The measured values are shown in Table 4. In addition,
NSIC shows a citrus sensation and NSIC * shows a blurring sensation, and the larger the value in%, the higher the sharpness. Also, high image clarity is about 70 or more in NSIC, NS
IC * is about 60 or more.

[0119]

[Table 3]

[0204]

[Table 4]

[0211]

[Comparative Example] In the Examples, a process in which the temperature of the steel plate during laminating and the temperature of the mirror-finished metal laminae roll are outside the scope of the present invention, or in the Examples, the mirror-finished metal laminator roll and the mirror-finished metal rolling roll are used. Of the laminated steel sheet manufactured by a process different in the material, surface roughness, and the presence / absence of pressurization from the examples, and the NSIC and NSIC * of the surface of the obtained laminated steel sheet are measured by the image clarity measuring device. did. The results are shown in Table 6.

[0222]

[Table 5] (Note) When the material of the roll is metal, the unit of surface roughness in parentheses is μm.

[0233]

[Table 6]

[0242]

As described above, in the method of the present invention, the PVC film is sufficiently melted and laminated with a mirror-finished metal roll to smooth the surface, and then the PVC film is kept in a molten state. The surface is straightened by pressing again with a mirror-finished metal roll, so that a high-visibility laminated steel sheet can be manufactured. Further, when the surface is straightened with a mirror-finished metal roll, the PVC film is kept in a molten state, so that the degree of fusion does not change due to the applied pressure, and the image clarity is uniform.

Claims (2)

[Claims] 1. A plasticized polyvinyl chloride resin film and a polyethylene terephthalate film on the surface of a steel sheet through an adhesive layer.
Laminated film made of rubber with laminated film
In the method for producing a laminated steel sheet, which comprises laminating the plasticized polyvinyl chloride resin film side with a roll so as to contact the adhesive layer, and then pressing the laminated film with a mirror surface metal rolling roll. As a mirror-finished metal roll having a surface roughness of 1 μm or less, and the melt viscosity of the plasticized polyvinyl chloride resin was 1 × 10 ^{3 to} 5 × 10 ^{4 for} the steel plate temperature and the laminator roll temperature during lamination. In addition to the pressure of Pa · s, the steel plate temperature is kept at the same temperature until pressure is applied by the mirror surface metal reduction roll, and pressure is applied by the mirror surface metal reduction roll heated to the same temperature and having a surface roughness of 1 μm or less. A method for producing a clear image-forming laminated steel sheet, comprising: 2. The vividness laminae according to claim 1, wherein one of the film surfaces is gravure-printed and the other surface of the film is laminated with an adhesive as the laminated film. -A method for manufacturing a steel sheet.