US-12623439-B2 - Resin film-laminated metal sheet and method for manufacturing same

Abstract

A resin film-laminated metal sheet includes a metal sheet and thermoplastic resin films that are fused to both surfaces of the metal sheet, the metal sheet is a steel sheet having a thickness of 0.08 mm or more or an aluminum sheet having a thickness of 0.15 mm or more, and, when a surface of the thermoplastic resin film opposite to a surface that is fused to the metal sheet is defined as a first surface, the surface tension on the first surface in at least one of the thermoplastic resin films is 50 mN/m or less, the surface tension on the surface that is fused to the metal sheet is 36 mN/m or more, and the amount of a wax attached to the first surface is more than 0 mg/m 2 and 5.00 mg/m 2 or less.

Inventors

• Nobuo Kadowaki
• Kazushi IWAKIRI
• Tomohiro Mizutani
• Daisuke YASUFUKU
• Tomoya Hara
• Satoshi Kato
• Yuta TAJIMA
• Yuki Nagai

Assignees

• NIPPON STEEL CORPORATION

Dates

Publication Date

20260512

Application Date

20200623

Priority Date

20190705

Claims (8)

1. 1 . A resin film-laminated metal sheet comprising: a metal sheet; and thermoplastic resin films that are fused to both surfaces of the metal sheet, wherein the metal sheet is a steel sheet having a thickness of 0.08 mm or more, and, when a surface of the thermoplastic resin film opposite to a surface that is fused to the metal sheet is defined as a first surface, a surface tension on the first surface in at least one of the thermoplastic resin films is 50 mN/m or less and 36 mN/m or more, a surface tension on the surface that is fused to the metal sheet is 36 mN/m or more, an amount of a wax present on the first surface is more than 0 mg/m 2 and 5.00 mg/m 2 or less, and wax is not present within or inside the thermoplastic resin films.
2. 2 . A laminated panel, comprising: a pair of the resin film-laminated metal sheets according to claim 1 , wherein, when the resin film-laminated metal sheets are set on an upper surface side and a lower surface side of an injection mold, the mold is filled with a foaming raw material containing a polyisocyanate and a polyol through an injection opening on a lateral side of the mold within 30 seconds while mixing the foaming raw material, and the foaming raw material is held at a pressure of 20 kN/m 2 for approximately 30 seconds, thereby forming a foam polyurethane resin between the resin film-laminated metal sheets, an adhesion strength between the thermoplastic resin film and the metal sheet is higher than an adhesion strength between the foam polyurethane resin and the thermoplastic resin film.
3. 3 . A method for manufacturing a resin film-laminated metal sheet that is a method for manufacturing the resin film-laminated metal sheet according to claim 2 , wherein, after film lamination, a wax is applied in a range of 0.1 mg/m 2 or more and 2.0 mg/m 2 or less, and then a resin film-laminated metal sheet is threaded using a threading roll having a surface tension of 36 mN/m or more on a surface of the threading roll.
4. 4 . The method for manufacturing a resin film-laminated metal sheet according to claim 3 , wherein, before the threading of the resin film-laminated metal sheet, a non-lubricated steel sheet is threaded through 1000 m or more at a rate of 50 m/minute or faster without laminating a film, and then the resin film-laminated metal sheet is manufactured and threaded.
5. 5 . A method for manufacturing a resin film-laminated metal sheet that is a method for manufacturing the resin film-laminated metal sheet according to claim 1 , wherein, after film lamination, a wax is applied in a range of 0.1 mg/m 2 or more and 2.0 mg/m 2 or less, and then a resin film-laminated metal sheet is threaded using a threading roll having a surface tension of 36 mN/m or more on a surface of the threading roll.
6. 6 . The method for manufacturing a resin film-laminated metal sheet according to claim 5 , wherein, before the threading of the resin film-laminated metal sheet, a non-lubricated steel sheet is threaded through 1000 m or more at a rate of 50 m/minute or faster without laminating a film, and then the resin film-laminated metal sheet is manufactured and threaded.
7. 7 . A laminated panel comprising: a core layer; and a resin film-laminated metal sheet, wherein the resin film-laminated metal sheet includes a metal sheet; and thermoplastic resin films that are fused to both surfaces of the metal sheet, the metal sheet is a steel sheet having a thickness of 0.08 mm or more, and when a surface of the thermoplastic resin film that is fused to the core layer is defined as a first surface, a surface tension on the first surface in at least one of the thermoplastic resin films is 50 mN/m or less and 36 mN/m or more, a surface tension on a surface that is fused to the metal sheet is 36 mN/m or more, an amount of a wax present on the first surface is more than 0 mg/m 2 and 5.00 mg/m 2 or less, and wax is not present within or inside the thermoplastic resin films.
8. 8 . The laminated panel according to claim 7 , wherein an adhesion strength between the thermoplastic resin film and the metal sheet is higher than an adhesion strength between the core layer and the thermoplastic resin film.

Description

TECHNICAL FIELD The present invention relates to a material for a laminated panel that is used as a measure for reduction in the weights of floors and wall materials of building materials, ships and vehicles and particularly to a resin film-laminated metal sheet that is used for a laminated panel having a foam resin core layer between two metal sheets. Priority is claimed on Japanese Patent Application No. 2019-125682, filed in Japan on Jul. 5, 2019, the content of which is incorporated herein by reference. BACKGROUND ART As a measure for reduction in the weights of floors and wall materials of building materials, ships and vehicles, a laminated lightweight panel having, as a core layer, a foam resin layer or an aluminum honeycomb or paper honeycomb layer laminated and attached between two metal sheets has been proposed and put into practical use. As a laminated panel in which a foam resin is used for the core layer, an example of a laminated panel having an adhesive layer and a non-foaming resin layer provided between a metal sheet and a foam resin sequentially from the metal sheet side, which is described in Patent Document 1, is an exemplary example, and, as a laminated panel in which a honeycomb is used for the core layer, Patent Document 2 describes an example of a method for manufacturing a sandwich panel having sheet-like prepregs cured on both surfaces of a sheet-like core layer having a honeycomb structure. In addition, Patent Document 3 describes an example of a resin sheet-laminated metal sheet having at least a resin sheet (b) in which a metal sheet is embedded and a steel sheet that is positioned on a surface of the resin sheet (b) opposite to the other surface in contact with a resin sheet (a) sequentially laminated on both surfaces of the resin sheet (a), in which, in the metal sheet that is embedded in the resin sheet (b), a micropore portion is formed at a volume fraction of 30% by volume or more with respect to the entire volume of the metal sheet. CITATION LIST Patent Document [Patent Document 1] Japanese Patent No. 4326001 [Patent Document 2] Japanese Unexamined Patent Application, First Publication No. 2018-187939 [Patent Document 3] Japanese Patent No. 5553542 Incidentally, in a laminated panel as described in Patent Document 1, a non-foaming resin layer is stuck with an adhesive and laminated between a metal sheet and a foam resin in order to suppress the peeling of a foam resin layer and the metal sheet, and there is a need for a number of steps of sticking the non-foaming resin with the adhesive and a separate foaming step, which increases the manufacturing costs. In addition, Patent Document 2 describes a method for manufacturing a sandwich panel by heating and pressurizing the sheet-like core layer having a honeycomb structure and the sheet-like prepregs while pressing the sheet-like core layer and the sheet-like prepregs from the upper surface and the lower surface of the core layer, but a honeycomb material in the core layer of the sandwich panel and the prepregs in cover materials are expensive, and the heating time is also long, which increases both the material costs and the manufacturing costs. In addition, the laminated panel described in Patent Document 3 is a resin sheet-laminated metal sheet having at least the resin sheet (b) in which a metal sheet is embedded and the steel sheet that is positioned on a surface of the resin sheet (b) opposite to the other surface in contact with the resin sheet (a) sequentially laminated on both surfaces of the resin sheet (a), but there is a need for a step of processing micropores in advance in the metal sheet that is embedded in the resin sheet (b) at a volume fraction of 30% by volume or more with respect to the entire volume of the metal sheet, which makes it difficult to attain the cost reduction of the laminated panel since the cost of the resin sheet (b) that occupies the laminated panel is high. In addition, the resin sheet-laminated metal sheet of the patent is intended to be applied to automobile external sheets, housings of home electrical appliances, furniture and OA equipment components and thus needs to be strong enough to withstand a bending process or deep drawing process. Therefore, the resin sheet (a), which is the core layer, is flexible and preferably as relatively thin as 0.2 to 1.5 mm in thickness, and the total thickness of the panel is also approximately 3 mm or less. Therefore, this laminated panel is not suitable for applications of laminated panels for building materials, ships and vehicles in which a high load bearing property is required and the thickness of the core layer needs to be at least approximately 5 mm. SUMMARY OF THE INVENTION Problems to be Solved by the Invention The present invention is an invention made in consideration of the above-described problems, and an object of the present invention is to provide a resin film-laminated metal sheet that has a high adhesion strength to core layers of