JP2005146388A - Stripe laminated steel sheet for welded can and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stripe laminated steel sheet for a welded can used for a welded can (such as a beverage can, a food can, an aerosol can, a paint can, an 18L can and a pail can), in which the phenomenon that smudge as the powder of tin oxide produced on the surface is scraped by friction with a winding roll at the time of lamination and is transferred to the steel sheet can be prevented, and to provide its production method. <P>SOLUTION: In the stripe laminated steel sheet for a welded can, a plurality of stripes of a thermoplastic resin film are formed in the longitudinal direction of one side of a surface treated steel sheet. Regarding the surface treated steel sheet, the front and back surfaces are provided with a tinned layer having a tin content of 0.7 to 2.0 g/ m<SP>2</SP>and a free tin content of 0.2 to 0.8 g/m<SP>2</SP>, and a chromate-treated layer having a metal chromium content of 5 to 15 mg/m<SP>2</SP>and a chromium oxide content of 5 to 15 mg/m<SP>2</SP>, and the back surface side of the laminated face in which the thermoplastic resin film is formed is provided with an oil-applied layer having an oil content of 0.1 to 10 mg/m<SP>2</SP>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a striped laminated steel sheet for a welding can in which a plurality of strips of a thermoplastic resin film are formed in the longitudinal direction of one surface of a surface-treated steel sheet, and a method for producing the same.

In recent years, steel sheets laminated with thermoplastic resin such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc. instead of painted steel sheets as electrical steel sheets, TFS, and other surface-treated steel sheets as container steel sheets ( Hereinafter referred to as a laminated steel plate).
When making can materials using this laminated steel sheet, there are those that can adhere to the can by utilizing the self-bonding property of the resin, and those that fuse the laminate layers using an adhesive. In order to apply a steel plate as a material for a welding can, it is necessary to secure a plurality of non-laminate portions in the longitudinal direction of the laminated steel plate in order to weld and join by energization heating.

In particular, small-diameter cans such as beverage cans, food cans, air-sol cans, paint cans, etc., and large-diameter cans such as 18-liter cans and pail cans are strip-laminated steel plates having a plurality of non-laminated parts in the width direction of the surface-treated steel plate, After cutting out a blank corresponding to one can with a 1-5mm non-laminate part at both ends, the steel sheet is formed into a cylindrical shape, the non-laminate parts are welded together, and the welded non-laminate part It is manufactured by melting or heat-sealing a resin or resin film for repair.
As a method for producing a laminated steel plate, a high-temperature thermoplastic resin is used between a heat-laminated method in which a pre-formed thermoplastic resin film is bonded to a surface-treated steel plate by thermocompression bonding, and a preheated surface-treated steel plate and a pressure contact roll. There is a T-die laminating method in which a film is flowed down from a T-die and laminated.

Using this T-die laminating method, after laminating a film between a preheated surface-treated steel sheet and a high-temperature thermoplastic resin film, the film is laminated with the thermoplastic resin film before or after cooling the laminated steel sheet. For example, Japanese Patent Laid-Open No. 10-16132 discloses a conventional technique related to a method of forming a non-laminated portion by peeling, without using an expensive device, in addition to both ends in the width direction of the steel plate, in addition to the inner side of the steel plate. A method of forming a non-laminate portion in a laminate unnecessary portion is disclosed.
However, when a surface-treated steel sheet having a tin plating layer is preheated to, for example, about 160 ° C. using the method disclosed in Japanese Patent Laid-Open No. 10-16132, tin oxide powder called smudge is generated on the steel sheet surface, When performing, the smudge is scraped off by friction with the winding roll, and further transferred to the steel plate, thereby deteriorating the appearance of the laminated steel plate.
Moreover, when forming the lump removal part of the blank of the steel plate end side using the method disclosed by Unexamined-Japanese-Patent No. 10-16132, there existed the following problems.
FIG. 6 is a cross-sectional view in the steel plate width direction showing a conventional method of manufacturing a laminated steel plate.
In FIG. 6, 1 is a steel plate, 2 is a thermoplastic resin film, 3 is a narrow film, 4 is a wide film, and 6 is a resin mustache.
As shown in the upper part of FIG. 6, by inserting a plurality of narrow films 3 between the steel sheet 1 and the thermoplastic resin film 2 and peeling them off, the length of the steel sheet as shown in the lower part of FIG. A strip-laminated steel sheet having a plurality of thermoplastic resin films formed in the direction is manufactured.

At this time, as shown in the upper part of FIG. 6, the wide laminate film 4 for removing the overcoat is inserted into both ends of the steel plate, and then peeled off to remove the blank laminate portions at both ends of the steel plate 1. While removing the laminate, it prevents the thermoplastic resin from adhering to the winding roll around which the steel plate is wound.
However, if the wide film 4 is peeled off after the laminated steel plate is cooled, the wide film 4 is not fixed except for the wrapping allowance with the steel plate, and may be folded due to flapping in the through plate or external force in the forced cooling process. Even if it is made to peel, the operation trouble which a film will sometimes break will generate | occur | produce. For this reason, it was not possible to stably form a laminated portion of the blank at the end of the steel plate. On the other hand, if it is performed before cooling the laminated steel plate, it can be peeled off without any trouble. However, when the wide film 4 is peeled off, the resin is stretched as shown in the lower part of FIG. In some cases, a beard-like resin residue (hereinafter referred to as “resin beard 6”) is formed. In particular, when the thermoplastic resin is polyethylene terephthalate, the resin mustache 6 is easily formed.

Since this resin mustache 6 does not protrude outside the end of the steel plate, the resin is scraped when the steel plate is pressed against the guide roll in the printing process in the can making process as shown in FIG. There is no problem that the steel plate surface is contaminated by being mixed into the paint pan or directly adhering to the steel plate surface.
However, as shown in FIG. 8, in order to ensure the corrosion resistance of the welded portion, the laminated steel sheet after printing is formed by cutting the non-laminated portion and welding the end portion for each blank to form a can body portion. The welded portion is repaired or baked with powder or resin tape. If the resin beard 6 protrudes from the end of the blank, air is engaged with the lower surface of the resin beard 6 as shown in FIG. When repairing and baking, the air expands and the repair film is ruptured, resulting in a pinhole.
Japanese Patent Laid-Open No. 4-325251 discloses a method of applying oil to the winding roll in order to prevent the overcoat resin from adhering to the winding roll.
However, the technical idea of providing an oil coating layer on a striped laminated steel sheet in order to prevent smudge scraping and transfer, which is a problem of the present invention, is not disclosed at all.
Japanese Patent Laid-Open No. 10-16132 JP-A-4-325251

  The present invention solves the problems of the prior art as described above, and is produced on the surface of a laminated steel sheet used for welded cans (drinks cans, food cans, air cans, paint cans, 18 liter cans, hail cans, etc.) Smudge, which is tin oxide powder, is scraped off by friction with the winding roll when laminating, and is prevented from being transferred to the steel plate, and pinholes are generated in the welding part repair process of the welding can barrel It is an object of the present invention to provide a striped laminated steel sheet for a welding can that can be prevented and a method for producing the same.

As a result of intensive studies to solve the above-mentioned problems, the present invention provides an oil coating layer having a certain range of thickness on the back surface of the laminate surface, and further does not generate resin whiskers, so that a welding can (a beverage can, Smudge, a tin oxide powder produced on the surface of laminated steel plates used in food cans, air cans, paint cans, 18-liter cans, hail cans, etc.) is scraped off by friction with winding rolls when laminating. The present invention provides a striped laminated steel sheet for welded cans and a method for producing the same, which can prevent transfer to a steel sheet and prevent pinholes in the welded part repair process of the welded can body. The gist of the present invention is as follows, as described in the claims.
(1) A stripe laminated steel sheet in which a plurality of thermoplastic resin films are formed in the longitudinal direction of one surface of a surface-treated steel sheet,
The surface-treated steel sheet has a tin plating layer having a tin content of 0.7 to 2.0 g / m2, a free tin content of 0.2 to 0.8 g / m2, a metal chromium content of 5 to 15 mg / m2, and a chromium oxide content of 5 to 5 on the front and back surfaces of the steel plate. Having a chromate treatment layer of 15 mg / m2,
A striped laminated steel sheet for welded cans having high corrosion resistance and high workability, having an oil layer having an oil amount of 0.1 to 10 mg / m2 on the back side of the laminate surface on which the plastic resin film is formed.
(2) The resin whiskers generated on the outer end surface of the thermoplastic resin film in the edge scrap portions formed at both ends in the width direction of the surface-treated steel sheet do not protrude from the end surface in the width direction of the steel sheet, and The striped laminated steel sheet for welding cans according to (1), wherein there is no resin whiskers on both end faces of the thermoplastic resin film in the product part at the center in the width direction.
(3) The method for producing a strip-laminated steel sheet according to (1) or (2), wherein a rubber wrapping roll around which the surface-treated steel sheet is wound when being laminated on one side of the surface-treated steel sheet A method for producing a striped laminated steel sheet for a welding can, characterized in that an oil coating layer is formed on the back side of the laminate surface by impregnating rust oil.

  According to the present invention, an oil coating layer having a certain range of thickness is provided on the back surface of the laminate surface, and further, by not generating resin whiskers, weld cans (beverage cans, food cans, air sole cans, paint cans, 18 liters) Prevents smudge, which is tin oxide powder formed on the surface of laminated steel plates used in cans, hail cans, etc., being scraped off by friction with the winding roll during lamination and transferred to the steel plate. At the same time, there are provided industrially significant effects, such as the provision of a striped laminated steel sheet for welded cans and a method for producing the same that can prevent the occurrence of pinholes in the welded part repair process of the welded can body.

The best mode for carrying out the present invention will be described in detail with reference to FIGS.
<First Embodiment>
FIG. 1 is a diagram illustrating a first embodiment of the present invention.
In FIG. 1, 2 indicates a thermoplastic resin film, 5 indicates ear dust, and 6 indicates a resin mustache.
In the present embodiment, as the surface-treated steel sheet as the base of the striped laminated steel sheet, the front and back surfaces of a low carbon steel having a carbon content of about 0.1% by mass or a very low carbon steel sheet having a carbon content of 0.04% by mass or less, Tin-plated steel sheet (hereinafter referred to as thin tin) having a tin-plated layer with 2.0g / m2, free tin content of 0.2-0.8g / m2, a chromium-treated layer with metal chromium content of 5-15mg / m2, and chromium oxide content of 5-15mg / m2. By using a plated steel sheet, a striped laminated steel sheet for a welding can that is inexpensive and has excellent weldability can be obtained.
In addition, for example, in a state where the smudge that is tin oxide powder generated on the surface of the steel plate due to preheating at about 160 ° C. is increased, the smudge scraped off by friction with the winding roll is transferred to the steel plate and used as the outer surface of the can. As a solution to the problem of impairing the appearance of the laminate, by forming an oil coating layer of 0.1 to 10 mg / m2 made of rust preventive oil on the back side of the laminate surface, the friction resistance with the winding roll is reduced, and smudge is scraped. In addition to preventing removal and transfer, it is possible to prevent the occurrence of dirt due to smudge in the can manufacturing process.

If the amount of oil on the surface of the steel sheet is small, the frictional resistance is too large, so 0.1 mg / m2 or more is necessary to sufficiently reduce the frictional resistance so that smudge is not scraped off. Since it will repel paint printing in the can manufacturing process, it is necessary to set the upper limit to 10 mg / m2.
In the present invention, there is no limitation on the method of applying oil to the steel sheet surface, but a rubber roll infiltrated with rust preventive oil as the winding roll, for example, a silicon rubber winding roll, is used on the entire surface of the steel sheet contact portion of the winding roll. There are a method of impregnating oil in advance and a method of forming an oil film only on the non-laminate surface side of the steel sheet before lamination by roll coater method, electrostatic method, direct coating method, etc. The method of applying the oil to the rotating roll made of silicon rubber by pressing it onto the winding roll so that the rust preventive oil is infiltrated into the winding roll is simple and preferable without requiring a special device.
At this time, by repeating the same operation at regular intervals, the amount of oil applied to the steel sheet can be adjusted to a range of 0.1 to 10 mg / m2.
In the present invention, the type of rust preventive oil is not limited, but mineral oil (DOS), cottonseed oil (CSO), and synthetic oil (ATBC) are preferred from the viewpoint of rust preventive performance and availability.
<Second Embodiment>
2 to 4 are diagrams illustrating a second embodiment of the present invention.
2 to 4, 1 is a thin tin-plated steel sheet, 2 is a thermoplastic resin film, 3 is a narrow film, 4 is a wide film, 5 is ear dust, and 6 is a resin mustache.
As shown in the upper part of FIG. 2, a plurality of narrow films 3 are inserted and laminated between a preheated steel sheet 1 and a high-temperature thermoplastic resin film 2, and then the narrow films 3 are peeled off. Thus, as shown in the lower part of FIG. 2, it is possible to manufacture a stripe laminated steel sheet in which a plurality of thermoplastic resin films are formed in the longitudinal direction of the steel sheet 1.
Here, the thermoplastic resin film refers to a thin film made of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) or the like.

In the present embodiment, the narrow film 3 is inserted on the laminate surface side, the wide film 4 is inserted on both ends of the steel plate on the laminate surface side, the wide film 4 is peeled off before cooling the steel plate, The narrow film 3 is characterized by being peeled off after cooling the steel sheet.
In the above-described conventional method shown in FIG. 6, the laminating of the steel plate end portion is performed with the wide film 4 and is peeled off after cooling the laminated steel plate or before cooling, so the former is fixed except for the lapping cost with the steel plate. In the latter case, the film may break due to flapping in the plate and external force in the forced cooling process, causing an operation trouble that sometimes causes the film to break. In the latter case, the thermoplastic resin is particularly polyethylene. In the case of terephthalate, the resin is stretched and resin whiskers are generated at the end of the blank used as a product. In the present invention, the end of the steel plate is removed with a thin film 3 and pulled after cooling. Since the resin is not easily stretched because it is peeled off, it is possible to form a beautiful laminating section even in the blank at the end of the steel plate as shown in the lower part of FIG.

Further, the wide film 4 for removing the overcoat is inserted into both ends of the steel plate on the laminated surface as shown in the upper part of FIG. 2, and is peeled off before cooling the steel plate, thereby flapping in the through plate and forced cooling process. There is no fold due to the external force, and film breakage at the time of peeling due to this fold can be prevented.
By peeling off the narrow film 3 and the wide film 4, as shown in the lower part of FIG. 2 and FIG. 4, the resin whiskers generated on the end surfaces of the thermoplastic resin film in the ear dust part are outward from the end surfaces of both ends of the steel plate. It does not protrude, and the end of the thermoplastic resin film of all blanks in the product part can be made into a beautiful shape without resin whiskers, thus preventing the occurrence of pinholes in the welded part repair process of the welded can body can do.
In addition, as shown in the lower part of FIG. 2 and FIG. 4, ear dust 5 with resin mustache is formed at both ends of the steel plate 1, but this part is trimmed and discarded in a can-making process.

FIG. 3 is a diagram illustrating an embodiment when the present invention is applied to an 18 L can.
In the case of an 18 L can, a laminated steel sheet having a beautiful laminated end face can be produced by using two narrow films 3 and two wide films 4.
In these embodiments, in order to reduce the ear dust portion, it is preferable to insert the narrow film 3 and the wide film 4 at both ends of the steel plate close to each other on the laminate surface side.

FIG. 5 is a diagram showing an embodiment of the present invention.
The steel sheet 1 is supplied between a winding roll 8 made of silicon rubber and a pressure contact roll 9 via a turn-down roll 7 and laminated with a high-temperature thermoplastic resin film 2 supplied from an extruder 10 and a T-die 11. The
In this embodiment, both the narrow film 3 and the wide film 4 are inserted into the laminate surface, and the narrow film 3 and the wide film 4 are close to each other at the end of the thin tin-plated steel sheet 1.
In this embodiment, the oil coating 22 in which the wrapping oil 8 is impregnated with the rust preventive oil is pressed about once a day, and the silicon rubber roll is impregnated with the rust preventive oil, so that the amount of oil on the surface of the steel sheet Can be adjusted in the range of 0.1 to 10 mg / m2. As a result, the frictional resistance with the winding roll can be reduced, scraping and transferring of the smudge can be prevented, and contamination caused by the smudge in the can making process can be prevented.
In this example, both the narrow film 3 and the wide film 4 are inserted into the laminate surface, and the narrow film 3 and the wide film 4 are close to each other at the end of the steel plate 1, Ear waste can be made smaller. Moreover, the resin mustache which generate | occur | produces in the end surface of the thermoplastic resin film in an ear waste part does not protrude outside from the end surface of both ends of a steel plate, and the end part of the thermoplastic resin film of all the blanks in a product part does not have resin beard. Since it can be made into a beautiful shape, it is possible to prevent the occurrence of pinholes in the weld repair process of the weld can body.

As the resin of the thermoplastic resin film 2, polyethylene terephthalate is used, and a thin film 3 made of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm, a width of 4 mm, and a tensile strength of 22 kgf / mm 2 is used. 2 and the steel plate 1 were inserted at substantially equal intervals in the steel plate width direction.
Furthermore, the ear dust part was newly provided by inserting the narrow film 3 also in the steel plate width direction edge vicinity.
In addition, between the high-temperature thermoplastic resin film 2 and the steel plate 1, the width direction end of this film and the width direction end of the steel plate are wrapped by 5 mm, and the width and width of the same material and thickness are 100 mm. A wide film 4 was inserted. Between the wide film 4 and the adjacent narrow film 3, it was set to 4 mm in order to reduce the ear dust portion.

The narrow film 3 was peeled off together with the laminate resin at a constant speed after the cooling device 12 (position of the table roll 19). The temperature of the laminated steel sheet at the peeling position was 50 ° C.
Since the wide film 4 only wraps 5 mm with the steel plate, it may flutter in the plate and may fold due to the pressure of the water spray / dryer in the cooling device 8, and even if you try to peel it off at the position of the table roll 19 The film breaks. For this reason, the wide film 4 was wound up by the winder 18 via the guide roll 17 installed in the front stage of the cooling device 12.
In the case of the present embodiment, even if the resin mustache 6 is generated, the resin mustache corresponds to the ear dust portion, and no resin mustache 6 is generated in the product portion, so that it is possible to prevent the occurrence of pinholes during repair of the welded portion.

It is sectional drawing of the steel plate width direction which illustrates 1st Embodiment in this invention. It is sectional drawing of the steel plate width direction which illustrates 2nd Embodiment in this invention. It is a figure which illustrates embodiment at the time of applying this invention to an 18L can. It is detail drawing of the steel plate edge part which illustrates 2nd Embodiment in this invention. It is a figure which illustrates the Example of this invention. It is a figure which shows the manufacturing method of the conventional laminated steel plate. It is a figure which illustrates the printing process of a laminated steel plate. It is a figure which illustrates the can manufacturing process using a laminated steel plate. It is a figure which illustrates the repair method in the can manufacturing process using a laminated steel plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel plate 2 Thermoplastic resin film 3 Narrow film 4 Wide film 5 Ear dust 6 Resin mustache 7 Turn-down roll 8 Winding roll 9 Pressing roll 10 Extruder 11 T die 12 Cooling device 13 Delivery reel 14 Delivery reel 17 Film guide roll 18 Take-up reel 19 Table roll 20 Film guide roll 21 Take-up reel 22 Oiled cloth

Claims (3)

Striped laminated steel sheet in which a plurality of thermoplastic resin films are formed in the longitudinal direction of one surface of the surface-treated steel sheet,
The surface-treated steel sheet has a tin plating layer having a tin content of 0.7 to 2.0 g / m2, a free tin content of 0.2 to 0.8 g / m2, a metal chromium content of 5 to 15 mg / m2, and a chromium oxide content of 5 to 5 on the front and back surfaces of the steel plate. Having a chromate treatment layer of 15 mg / m2,
A striped laminated steel sheet for welding cans, comprising an oil coating layer having an oil amount of 0.1 to 10 mg / m2 on the back side of the laminate surface on which the plastic resin film is formed.   The resin whiskers generated on the outer end surface of the thermoplastic resin film in the edge scrap portions formed at both ends in the width direction of the surface-treated steel plate do not protrude from the end surface in the width direction of the steel plate, and the width direction center of the steel plate The striped laminated steel sheet for a welding can according to claim 1, wherein there is no resin whiskers on both end faces of the thermoplastic resin film in the product part. It is a manufacturing method of the stripe lamination steel plate according to claim 1 or 2,
Forming an oil coating layer on the back side of the laminated surface by impregnating a rust preventive oil into a rubber wrapping roll that winds the surface-treated steel plate when laminating on one side of the surface-treated steel plate A method for producing a striped laminated steel sheet for a welding can, which is characterized.

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