JP2014141695A - Method of manufacturing steel foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of preventing the occurrence of folded wrinkles due to directly contacting a steel foil with a transportation roll in manufacturing the steel foil accompanied by heating and cooling.SOLUTION: A steel foil (laminate 14) of which transportation direction is changed by heating an arrival temperature at T°C and directly contacting with a transportation roll 6 at a temperature T°C, where T<T-120°C is precooled by supplying a cooling liquid to the steel foil by a curtain nozzle 8 so that a temperature of the laminate 14 when directly contacting with the transportation roll 6 becomes T°C, where T≤T+120°C. The occurrence of folded wrinkles of the laminate 14 when cooling the laminate 14 to the temperature T°C is prevented by the precooling.

Description

  The present invention relates to a method for producing a steel foil.

  Steel foil is usually used in various applications because it has both corrosion resistance and strength. For example, the steel foil is used as a material for an inner bag of a container that requires corrosion resistance by using a resin-coated steel foil having a resin layer formed thereon. In general, the steel foil may be heated to a temperature of, for example, 140 ° C. or higher in order to form a layer such as the above-described resin layer or chemical conversion coating on the surface thereof. The heated steel foil is usually cooled under certain conditions in order to stably realize the desired state of the above-mentioned layer and steel foil.

  The steel foil is cooled by supporting the steel foil transported in a substantially horizontal direction flatly by a roll that abuts the lower surface of the steel foil, or supporting the steel foil being transported slightly upward by the roll. A method of cooling the steel foil by increasing the flatness of the steel foil and spraying a refrigerant on both surfaces of the supported steel foil is known (for example, see Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 10-088249 Japanese Patent Laid-Open No. 07-008883

  On the other hand, from the viewpoint of productivity and product quality maintenance, the steel foil may be rapidly cooled. In this case, a sufficient cooling rate may not be obtained only with a spray-type cooler such as a spray nozzle or a curtain nozzle that blows the refrigerant onto the steel foil, which is disadvantageous for rapid cooling of the steel foil. For rapid cooling of the steel foil, it is effective to cool the steel foil by immersing it in a coolant.

  However, for example, when a resin-coated austenitic stainless steel foil having a width of 320 mm is heated to 180 ° C., the width of the steel foil becomes 320.89 mm, and when cooled to room temperature, it becomes 320 mm. Thus, the steel foil expands and contracts by heating and cooling. For this reason, as shown in FIG. 1, when a transport roll 6 for changing the transport direction of the steel foil is arranged at the outlet of the heating furnace so as to guide the steel foil into the coolant, the steel foil is transported by the transport roll 6. The crease wrinkles 7 along the conveyance direction of the steel foil 14 may be generated. This is because tension is applied to the steel foil that abuts the transport roll, and the steel foil does not shrink in the direction of transport of the steel foil, but contracts mainly in the axial direction of the transport roll (the width direction of the steel foil). Conceivable.

  The present invention has been made in view of the above points, and in the production of a steel foil accompanied by heating and cooling, a method capable of preventing the occurrence of folding wrinkles caused by bringing the steel foil into contact with a transport roll. The purpose is to provide.

  By cooling the steel foil to a specific temperature before the heated steel foil comes into contact with the transport roll, the inventors have confirmed that the above-described folding wrinkle does not occur even when the steel foil is rapidly cooled. The headline and the present invention were completed.

That is, this invention relates to the manufacturing method of the following steel foil.
[1] A steel foil whose ultimate temperature is heated to T ₁ ° C. and then abutting on a conveyance roll at a temperature T ₃ ° C. (however, T ₃ <T ₁ −120 ° C.) and whose conveyance direction should be changed, wherein the transport rollers such that the temperature of the steel foil when in contact becomes T _{3 +} 120 ° C. or less, comprising the step of pre-cooled by supplying a coolant to the steel foil by the cooling device, a manufacturing method of the steel foil.
[2] The method for producing a steel foil according to [1], wherein the transport roll is disposed so as to be partially immersed in a cooling liquid having a temperature T ₃ ° C in a cooling bath.

  According to the present invention, it is possible to produce a steel foil that does not have creases.

It is a figure which shows typically the wrinkle which arises in steel foil at the time of manufacture. FIG. 2A is a diagram schematically showing an example of the configuration of the manufacturing apparatus used in the present invention, and FIG. 2B is a diagram schematically showing another example of the configuration of the manufacturing apparatus used in the present invention. It is a figure which expands and shows the cooling part of the manufacturing apparatus shown by FIG.

In the method for producing a steel foil according to the present invention, a steel foil whose ultimate temperature is heated to T ₁ ° C. and then abuts on a T ₃ ° C. conveyance roll and whose conveyance direction is to be changed is applied to the conveyance roll. It includes a step (hereinafter, also referred to as “pre-cooling step”) of supplying a refrigerant to the steel foil by a cooling device and pre-cooling so that the temperature of the steel foil at the time of contact becomes T ₂ ° C. or less. However, _{T 2 is} a T 3 +120 or less, _{T 3} is less than _T 1 -120. In addition, ultimate temperature is the highest temperature among the temperatures which the steel foil heated reaches.

  The steel foil is a steel plate having a thickness of 200 μm or less. Examples of the material of the steel foil include a cold rolled steel plate, a galvanized steel plate, a Zn—Al alloy plated steel plate, a Zn—Al—Mg alloy plated steel plate, an aluminum plated steel plate, and a stainless steel plate. The stainless steel plate may be any of austenitic, ferritic and martensitic stainless steel plates. From the viewpoint of corrosion resistance, the steel foil is preferably various plated steel plates or stainless steel plates. The thickness of the steel foil is preferably 15 μm or more from the viewpoint of strength, workability, and manufacturing cost.

  From the viewpoint of improving corrosion resistance and adhesion to the resin layer, a chemical conversion treatment film may be formed on the surface of the steel foil. The type of chemical conversion treatment is not particularly limited. Examples of the chemical conversion treatment include chromate treatment (chromic acid type), chromium-free treatment (silane type, organic titanium type, organic aluminum type, etc.), and phosphate treatment (chromium phosphate, zinc phosphate, etc.).

The adhesion amount of the chemical conversion treatment film formed by chemical conversion treatment is not particularly limited as long as it is within a range effective for improving corrosion resistance and adhesion to the resin layer. For example, in the case of a chromate film, the adhesion amount may be adjusted so that the total Cr conversion adhesion amount is 5 to 100 mg / m ² . Further, in the case of a chromium-free coating, the Ti-Mo composite coating has a range of 10 to 500 mg / m ² , and the fluoroacid-based coating has a fluorine equivalent or total metal element equivalent deposit of 3 to 100 mg / m ^2. The adhesion amount may be adjusted. Moreover, what is necessary is just to adjust the adhesion amount so that it may become 5-500 mg / m < ² > in the case of a phosphate membrane | film | coat.

  The chemical conversion film can be formed by a known method. For example, the chemical conversion treatment liquid may be applied to the surface of the steel foil by a method such as a roll coating method, a spin coating method, or a spray method, and dried without washing with water. The drying temperature and drying time are not particularly limited as long as moisture can be evaporated. From the viewpoint of productivity, the drying temperature is preferably in the range of 60 to 150 ° C. at the ultimate temperature, and the drying time is preferably in the range of 2 to 10 seconds.

  Moreover, the resin layer may be formed in the surface from steel foil from a viewpoint of improvement of functions, such as improvement of corrosion resistance. The resin contained in the resin layer may be one type or two or more types. The resin layer may be a single layer or multiple layers. Examples of resin types include polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyamides such as nylon 6, fluororesins such as polyvinylidene fluoride, acrylic resins, and acid-modified resins thereof. , And the like are included.

  The acid-modified resin is a resin in which an acidic group is introduced into the above resin. The acidic group can be introduced into the resin by, for example, graft modification with an unsaturated carboxylic acid or an anhydride thereof, radical polymerization containing an unsaturated carboxylic acid as a monomer, or the like. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, citraconic acid and itaconic acid. The acid-modified resin is preferably used from the viewpoint of improving the adhesion between the steel foil and the resin layer.

  The thickness of the resin layer is preferably 10 to 200 μm from the viewpoint of sufficiently expressing both the function of each layer and the workability of the resulting resin-coated steel foil. When the resin layer is a multilayer, the thickness of each layer is preferably 10 to 100 μm from the above viewpoint.

The said conveyance roll makes steel foil contact | abut on the surrounding surface, and changes the conveyance direction of steel foil. The transport roll 6 may be a roll that is driven to rotate, or may be a roll that rotates following the transported steel foil. A well-known roll used for conveyance of steel foil can be used for a conveyance roll. Since the transport roll is always in contact with the heated steel foil, the temperature of the transport roll tends to rise. Therefore, the temperature of the transport roll can be maintained at T ₃ ° C by appropriately cooling the transport roll. For example, the temperature of the transfer roll, a method arranged to use while immersed in T ₃ ° C. a liquid with a sufficient amount of the conveying rolls, or, in the T ₃ ° C. The method of circulating T ₃ ° C. of liquid inside the transport rolls Can be adjusted. When the temperature T ₁ ° C of the steel foil during heating is high, the transport roll can be heated as necessary.

  As the cooling device, a known device for supplying a coolant to the steel foil can be used. For example, the cooling device may be a device that blows a cooling gas onto a steel foil, or may be a device that supplies a coolant to the steel foil. From the viewpoints of productivity, shortening of the production line, and maintaining a sufficiently high cooling rate, the cooling device is preferably a device that supplies a cooling liquid to the steel foil. The coolant is water, for example. Examples of more preferred cooling devices include spray nozzles and curtain nozzles. Among them, a curtain nozzle is more preferable because it has a higher cooling capacity. The curtain nozzle is a nozzle having a slit-like opening for discharging the cooling liquid, and allows the cooling liquid to flow in a curtain shape on the steel foil.

  The production method according to the present invention may further include other steps than the above-described precooling step within a range where the effects of the present invention can be obtained. Examples of such other steps include a step of preparing a steel foil, a step of forming a resin material layer on the surface of the steel foil, a step of heating the steel foil, and a step of further cooling the precooled steel foil, Is included.

  Examples of the step of preparing the steel foil include known steps such as a step of pickling the steel foil and a step of forming a chemical conversion coating on the surface of the steel foil.

  The step of forming the resin material layer on the surface of the steel foil is performed by a known method corresponding to the resin material layer. For example, the resin material layer can be formed by bonding the resin film to a steel foil. Alternatively, the resin material layer can be formed by applying the resin paint to the surface of the steel foil. The paint is, for example, a resin composition melted by heating or a resin solution in which a resin is dissolved in a solvent. Examples of the coating method include a method of coating the steel foil with a T-die extruder, a bar coater, a roll coater or a spin coater. When the resin material layer is a multilayer, each layer may be formed sequentially or simultaneously.

  The step of heating the steel foil is performed using a heating furnace usually used for manufacturing the steel foil. In the present invention, as described above, since the wrinkle does not occur even when the conveyance roll comes into contact, a horizontally disposed heating furnace in which the conveyance roll is usually used for cooling the steel foil after heating is suitable. Used. The horizontally disposed heating furnace is a heating furnace configured to be heated while the steel foil to be heated is conveyed in the horizontal direction. The heating of the steel foil may be performed by a member that contacts the steel foil, may be performed by a non-contact member, or both.

The step of further cooling the pre-cooled steel foil can be performed, for example, by conveying the pre-cooled steel foil into a cooling liquid in a cooling tank. At this time, when the temperature of the cooling liquid is set to T ₃ ° C and the conveying roll is arranged so as to be partially immersed in a sufficient amount of cooling liquid, the temperature of the conveying roll can be maintained at T ₃ ° C, and the steel foil is made of T It becomes possible to rapidly cool to ₃ ° C. The kind of the cooling liquid in the cooling tank may be the same as or different from the kind of the cooling liquid in the pre-cooling step. The temperature of the cooling liquid can be adjusted by a known method such as adjusting the temperature of the cooling liquid in the cooling tank using a thermostat or circulating the cooling liquid in the cooling tank between the cooling tank and the temperature adjusting device. It is.

In the case where the resin material layer is formed on the surface of the steel foil, the ultimate temperature T ₁ ° C of the steel foil before pre-cooling can be set to a temperature equal to or higher than the melting point of the resin. When the resin material layer contains a plurality of types of resins, the “melting point of the resin” is the melting point of the resin having the highest melting point among the resins in the resin material layer. The temperature of the steel foil after the cooling step in the above case is, for example, 65 ° C. or less when the resin is polypropylene, 30 ° C. or less when the resin is polyethylene, 80 ° C. or less when the polyester is used, nylon 6, etc. It is preferable that the temperature is 85 ° C. or lower in the case of polyamide, and 70 ° C. or lower in the case of a fluororesin such as polyvinylidene fluoride.

In the manufacturing method according to the present invention, the steel foil is pre-cooled so that the temperature difference between the steel foil and the transport roll when contacting the transport roll is 120 ° C. or less. A certain amount of tension is applied to the steel foil in contact with the transport roll to transport the steel foil into the cooling liquid, and wrinkles are likely to occur along the transport direction, which is the direction of this tension. However, since the temperature difference between the temperature T ₂ ° C of the steel foil and the temperature T ₃ ° C of the transport roll when in contact with the transport roll is 120 ° C or less, the steel foil on the transport roll due to this temperature difference. The shrinkage can be made sufficiently small. For this reason, generation | occurrence | production of the wrinkle along a conveyance direction can be prevented.
Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 2 is a diagram schematically showing a configuration of an example of a manufacturing apparatus capable of performing the manufacturing method according to the present invention. The apparatus shown in FIG. 2A includes a pair of rolls 1 for bonding resin films 12 and 13 to steel foil 11, and a steel foil 11 (hereinafter also referred to as “laminated body 14”) in which resin films 12 and 13 are bonded. To the cooling tank 3, the roll 4 which guides horizontally, the heating furnace 2 which heats the laminated body 14 arrange | positioned horizontally, the curtain nozzle 8 which precools the laminated body 14 carried out from the heating furnace 2, and having a transport roll 6 for guiding the laminate 14 downwards, the laminate 14 is guided, a cooling bath 3 containing the temperature T ₃ ° C. cooling water, the. The transport roll 6 is partially immersed in the cooling water in the cooling tank 3.

The laminated body 14 is heated to T ₁ ° C. by the heating furnace 2 during the pre-cooling step. T ₁ can be, for example, the temperature of the laminate 14 immediately below the curtain nozzle 8. T ₁ may be a temperature higher than 120 ° C. with respect to the temperature T ₃ of the cooling water in the cooling bath 3. For example, when T ₃ is 20 ° C., T ₁ is, for example, greater than 140 ° C. When T ₃ is a T ₁ -120 ° C. or less, shrinkage becomes larger steel foil when in contact with the conveyor roll, it may wrinkle folded along the conveying direction in the steel foil is generated. T ₁ can be appropriately determined within a range in which a steel foil or a film or layer formed on the surface thereof is maintained in an intended state.

In the pre-cooling step, the laminated body 14 before coming into contact with the transport roll 6 is cooled so that the temperature at the position in contact with the transport roll 6 (first position P1 in FIG. 3) is T ₂ ° C. or lower. T ₂ is T ₃ + 120 ° C. The position of the curtain nozzle 8 is not particularly limited as long as it is a position on the upstream side of the first position P1 that can cool the laminated body 14 of T ₁ ° C to T ₂ ° C or less at the first position P1.

  The angle of the curtain nozzle 8 is preferably 30 degrees or less. The angle of the curtain nozzle 8 is the upstream side in the transport direction of the laminated body 14 among the angles formed when the axis of the curtain nozzle 8 intersects the laminated body 14 when the curtain nozzle nozzle 8 and the laminated body 14 are viewed from the side. Is an angle (θ in FIG. 3). By setting the angle of the curtain nozzle 8 as described above, it is possible to prevent the cooling liquid from flowing back to the upstream side in the transport direction of the laminate 14 during precooling, thereby preventing excessive cooling of the laminate 14 in the precooling step. Is done. In addition, it is also preferable to incline the conveyance direction of the laminated body 14 so that the laminated body 14 is conveyed further downward from the viewpoint of preventing excessive cooling of the laminated body 14 due to the backflow of the coolant.

The temperature of the transport roll 6 is adjusted to T ₃ ° C., the stacked body 14 is brought into contact with the peripheral surface thereof, and the transport direction of the stacked body 14 is changed downward. FIG. 3 is a diagram schematically showing the vicinity of the transport roll of the manufacturing apparatus shown in FIG. As shown in FIG. 3, the stacked body 14 being transported is from the first position P1 to the second position P2 on the outer peripheral surface of the transport roll 6 when the stack 14 and the transport roll 6 are viewed from the side. Is separated from the second position P2 on the outer peripheral surface in the tangential direction at the second position P2.

The laminated body 14 in contact with the transport roll 6 is transported to the cooling tank 3 containing cooling water having a temperature of T ₃ ° C, guided into the cooling water, and rapidly cooled to T ₃ ° C. Since the temperature difference between T ₂ ° C. and T ₃ ° C. is 120 ° C. or less, the occurrence of folding wrinkles along the transport direction of the laminate 14 can be prevented. The pre-cooling step described above can be performed not only by cooling with a cooling device such as the curtain nozzle 8 but also by air cooling of the laminate 14 carried out from the heating furnace 2. Here, using a cooling device such as the curtain nozzle 8 to lower the temperature of the laminated body 14 to T ₂ ° C is more advantageous when T ₃ is relatively low or from the viewpoint of suppressing the extension of the production line. It is. From such a viewpoint, T ₃ is preferably 85 ° C. or lower, more preferably 65 ° C. or lower, and further preferably 40 ° C. or lower.

  The manufacturing method according to the present invention can also be implemented by the apparatus shown in FIG. 2B. The apparatus shown in FIG. 2B has a roll coater 9 that applies a resin layer coating to the surface of the steel foil instead of the pair of rolls 1 and 4. According to this apparatus, the laminated body which has the resin material layer formed by application | coating of a coating material is obtained.

In addition, in the manufacturing method which concerns on this invention, when arrange | positioning two or more conveyance rolls, in each conveyance roll, the temperature difference of the temperature of the steel foil contact | abutted to a conveyance roll and the temperature of a conveyance roll shall be 120 degrees C or less. From the viewpoint of preventing the occurrence of the above-described folding wrinkles. In the case where the steel foil has no resin layer, T ₁ may be a high temperature such as the resin layer is modified (e.g., 400 ° C. or higher).

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not limited by these Examples.

[Manufacture of steel foil 1]
The surface of a stainless steel foil (SUS304: thickness 0.1 mm) is degreased and washed, and then dried, and a commercially available coating-type phosphoric acid chromate treatment solution (ZMR1320; Nippon Parkerizing Co., Ltd.) has a total Cr equivalent adhesion amount of 25 mg / m. ² was applied with a roll coater. The steel foil coated with the chromate treatment solution was heated for 10 seconds so that the ultimate plate temperature was 120 ° C. to form a chemical conversion treatment film.

  Next, a resin material layer was produced on the surface of the steel foil using an apparatus as shown in FIG. 2A. First, while carrying the chemical conversion treated stainless steel foil at 10 m / min, a 30 μm-thick maleic anhydride-modified polypropylene film (QE-060; Mitsui Chemicals, Inc., melting point 139 ° C.) is laminated on the surface. Next, an unstretched polypropylene film (CP-S; Mitsui Chemicals, Inc., melting point 163 ° C.) having a film thickness of 30 μm is further laminated on the surface of the maleic anhydride-modified polypropylene film, and heated with a heating laminate roll heated to 140 ° C. Crimped. Then, while conveying the laminate in a heating furnace, the laminate was heated for 50 seconds so that the ultimate temperature of the stainless steel foil was 185 ° C., and the acid-modified polypropylene film and the polypropylene film were thermally welded to the stainless steel foil. .

After thermal welding, pre-cooled resin material layer by supplying the water from the curtain nozzle on the resin material layer is at a temperature T ₁ is 181 ° C.. Temperatures T ₁ was set to a temperature of the steel foil at a position immediately below the curtain nozzle. Thus, the temperature T ₂ of the steel foil when the steel foil is in contact with the transport rollers are immersed part in the cooling liquid of the cooling bath so that 140 ° C., and cooled steel foil. Then, the contact with the steel foil the transport rollers are accommodated in the cooling vessel and transported into a cooling liquid temperature T _{3 (20} ℃) _(water), and cooled by submerged. Thus, a steel foil 1 having a resin layer was obtained.

In this embodiment, T ₁ is the output of the heating furnace, T ₂ is the position in the conveyance direction of the curtain nozzle and the temperature of the water supplied from the curtain nozzle, and T ₃ is between the cooling tank and the temperature adjusting device. Each was adjusted by circulating water in the cooling bath. A data logger (Memory Hi Logger 8430; Hioki Electric Co., Ltd.) was used for measuring the temperatures T ₁ and T ₂ . Moreover, the cooling rate of the resin material layer during submergence from when the steel foil contacted the transport roll was 100 ° C./second or more.

[Manufacture of steel foils 2-7]
The steel foil was heated in a heating furnace so that T ₁ would be 180, 182, 180, 179, 156 and 155 ° C., respectively, T ₂ would be 140, 151, 150, 149, 140 and 143 ° C. respectively, and T ₃ would be Steel foils 2 to 7 having resin layers were produced in the same manner as steel foil 1 except that the temperatures were 32, 20, 31, 18, 20 and 13 ° C, respectively.

[Manufacture of steel foils 8-9]
In place of the polypropylene film, a polyethylene film having a film thickness of 30 μm (a polyethylene film containing Modic (registered trademark of Mitsubishi Chemical Corporation) HDPE H503 (Mitsubishi Chemical Corporation), melting point 128 ° C.) is used, and T ₁ is 141,140 respectively. ° C. become so heated steel foil in a heating furnace, and the T ₂ respectively 125, 135 ° C., except that the T ₃ and 20,10 ° C., respectively, in the same manner as a steel foil 1, a steel having a resin layer Foil 8-9 was produced, respectively.

[Production of steel foils 10 to 16]
Instead of polypropylene film, a polyester film with a film thickness of 16 μm (Lumirror F865; Toray Industries, Inc., 213 ° C.) is used, and the steel foil is adjusted so that T ₁ is 250, 250, 252, 251, 252, 201 and 200 ° C., respectively. except that the heating in a heating furnace, and the _{T 2} respectively 180,181,180,190,191,180 and 180 ° C., and the _{T 3} respectively 61,70,55,72,59,60 and 54 ° C. are In the same manner as the steel foil 1, steel foils 10 to 16 each having a resin layer were produced.

[Manufacture of steel foils 17 to 23]
Instead of the polypropylene film, a nylon 6 film having a film thickness of 30 μm (Reyfan NO 1401; Toray Industries, Inc., melting point 267 ° C.) is used, and T ₁ becomes 280, 280, 281, 281, 281, 280, 250 and 251 ° C., respectively. the steel foil was heated in a heating furnace, and the _{T 2} respectively 190,190,192,200,201,190 and 191 ° C., and the _{T 3} respectively 70,81,65,80,72,71 and 66 ° C. Except for the above, steel foils 17 to 23 each having a resin layer were produced in the same manner as steel foil 1.

[Manufacture of steel foils 24 to 30]
Using an apparatus as shown in FIG. 2B, instead of laminating a maleic anhydride-modified polypropylene film and a polypropylene film, polyvinylidene fluoride (Kyner (registered trademark of Arkema Co., Ltd.) is used so that the resin material layer has a thickness of 30 μm. ) 720; the ARKEMA) paint containing coated on the surface of the stainless steel foil with a roll coater, heating furnace steel foil as _{T 1} is the respective 190,193,191,190,192,160 and 161 ° C. Steel foil 1 except that T ₂ was 140, 141, 140, 149, 150, 139 and 140 ° C., and T ₃ was 20, ₃₀ , 14, 29, 19, 20 and 15 ° C. respectively. In the same manner, steel foils 24 to 30 each having a resin layer were produced. The melting point of the resin composition of the obtained resin material layer was 170 ° C.

[Manufacture of steel foils 31 to 37]
Using an apparatus as shown in FIG. 2B, instead of laminating a maleic anhydride-modified polypropylene film and a polypropylene film, polyester (Byron (registered trademark of Toyobo Co., Ltd.) is used so that the resin material layer has a thickness of 30 μm. GM925; a paint containing Toyobo Co., Ltd.) was applied to the surface of the stainless steel foil with a roll coater, heating furnace steel foil as _{T 1} is the respective 242,241,240,240,241,201 and 200 ° C. in heating to a _{T 2} respectively 180,182,180,190,190,180 and 181 ° C., except that the _{T 3} respectively 61,71,50,72,65,60 and 53 ° C., the steel foil 1 In the same manner, steel foils 31 to 37 having a resin layer were produced. The melting point of the resin composition of the obtained resin material layer was 216 ° C.

[Evaluation]
Each steel foil was visually observed to confirm the presence or absence of creases formed along the longitudinal direction (conveying direction) of the steel foil, and evaluated according to the following criteria.
○: No wrinkles were confirmed ×: Wrinkles were confirmed

  The production conditions and evaluation results of each steel foil are shown in Table 1 and Table 2. In the table, “PP” means polypropylene, “PE” means polyethylene, “PA” means nylon 6, “PVdF” means polyvinylidene fluoride, and “Polyester” means polyester. In the table, “HL” means thermal lamination, and “C” means painting.

As is apparent from the steel foil 1, 2, 4 and 6, the temperature difference between the temperature T ₃ of the cooling water in the cooling bath and the temperature T ₂ of the transport roll contact time of the resin material layer is 120 ° C. or less A steel foil having no wrinkles along the conveying direction of the steel foil was obtained. Further, as is clear from Tables 1 and 2, the same characteristics as above were confirmed even when the types of resins were different.

  In the present invention, it is possible to produce a steel foil that does not have wrinkles even in a horizontal production line. Therefore, according to the present invention, further spread of steel foil and further expansion of applications are expected.

DESCRIPTION OF SYMBOLS 1 Pair of rolls 2 Heating furnace 3 Cooling tank 4 Roll 6 Carrying roll 7 Folding wrinkle 8 Curtain nozzle 9 Roll coater 11 Steel foil 12, 13 Resin film 14 Laminate

Claims (2)

A steel foil whose ultimate temperature is heated to T ₁ ° C. and thereafter abuts on a transport roll at a temperature T ₃ ° C. (where T ₃ <T ₁ −120 ° C.) and whose transport direction is to be changed is those temperature of the steel foil when in contact are formed so that T _{3 +} 120 ° C. or less, comprising the step of pre-cooled by supplying a coolant to the steel foil by the cooling device, a manufacturing method of the steel foil. The transport roll is arranged to be immersed part to the coolant temperature T ₃ ° C. in the cooling bath, the production method of the steel foil according to claim 1.

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