Toyo Kohan Co., Ltd.

Tetsuhiro Hanabusa

Tsuneo Inui

Atsuo Tanaka

Harunori Kojo

Harunori Kubota

A method for producing a copolyester resin film laminated metal sheet having an excellent heat resistance which comprises laminated a biaxially oriented copolyester resin film having specified characteristics on one or both sides of a metal sheet coated with a single layer of hydrated chromium oxide or a double layer consisting of a lower layer of metallic chromium and an upper layer to hydrated chromium oxide which has been heated to a temperature of Tm-50.degree. C. to Tm, where Tm represents the melting temperature of said copolyester resin film. This copolyester resin film laminated metal sheet is suitable for the materials for can stock which is reheated for curing the coated lacquer or treated with hot steam for sterilization of food after packing food in the cans, such as deeply drawn cans, drawn and redrawn cans, can ends, screwed caps and crown caps.

Method for production of a copolyester resin film laminated metal sheet

A copolyester resin film laminated metal sheet having excellent formability and a method for its production is disclosed. This disclosure comprises laminating a biaxially oriented copolyester resin film having specified characteristics, to one or both sides of a surface treated metal sheet, which has been heated to the melting point of the copolyester resin film .+-.50.degree. C., just before the lamination of the copolyester resin film. This film has been precoated with a resin composite containing in its molecular structure at least one radical, such as epoxy radical and hydroxyl radical. The side of the copolyester resin film pre-coated with resin composite is in contact with the surface treated metal sheet. This copolyester resin film laminated metal sheet is suitable for some applications in which severe formability is required, such as deeply drawn cans formed by multiple drawings, drawn and partially ironed cans, drawn and stretch formed cans, can ends wherein a tab for easy opening is attached, screwed caps and crown caps.

Copolyester resin film laminated metal sheet

A method for the production of a metal sheet covered with polyester resin film which comprises laminating a biaxially oriented polyester resin film which has been precoated uniformly with a small amount of an epoxy resin containing a curing agent of epoxy resin to a metal sheet covered with double layer consisting of an upper layer of hydrated chromium oxide and a lower layer of metallic chromium, which metal sheet has been heated to a temperature of 220.degree. C. to below the melting point of polyester resin film, in the condition wherein the surface of said polyester resin film precoated with an epoxy resin containing the curing agent of epoxy resin contacts the metal sheet. This metal sheet covered with polyester resin film is excellent in corrosion resistance and adhesion of polyester resin film to the metal sheet after any severe forming.

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Tokuyama, Japan

Tetsuhiro Hanabusa