Laminated metal sheet for metal container lid and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-11518144-B2
Application number	US-201716307316-A
Country	US
Kind code	B2
Filing date	May 15, 2017
Priority date	Jun 17, 2016
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A laminated metal sheet for a metal container lid includes a polyester resin layer formed on a metal sheet. The polyester resin layer is composed of an A and a B layer, wherein the melting point of the A layer is lower than the melting point of the B layer by 20° C. or more, the A layer includes a molten layer where the value of the ratio of a peak intensity I 0° to a peak intensity I 90° is 1.5 or less, the B layer includes an orientation layer where the value of the ratio of the peak intensity I 0° to the peak intensity I 90° is 3.0 or more, the thickness of the A layer is within the range from 5 μm or more to less than 30 μm, and the thickness of the B layer is within the range from 0.5 μm or more to less than 6.0 μm.

First claim

The invention claimed is:

1. A laminated metal sheet for a metal container lid, comprising a polyester resin layer formed on a surface of a metal sheet, the surface of the metal sheet being located on the inner-surface side of a metal container after forming, wherein:
the polyester resin layer is composed of an A layer located so as to abut on the metal sheet, and a B layer disposed over the A layer,
the melting point of the A layer is lower than the melting point of the B layer by 20° C. or more,
the A layer includes a molten layer, where a value of a peak intensity ratio A of a peak intensity I 0° to a peak intensity I 90° is 1.5 or less, disposed over the metal sheet,
the B layer includes an orientation layer, where a value of a peak intensity ratio B of a peak intensity I 0° to a peak intensity I 90° is 3.0 or more,
the peak intensity I 0° being attributed to C═O stretching vibration in the vicinity of Raman shift of 1730 cm −1 obtained from a laser Raman spectroscopy method using a linearly polarized laser beam whose polarization plane is parallel to the surfaces of the A layer and the B layer, the peak intensity I 90° being attributed to C═O stretching vibration in the vicinity of Raman shift of 1730 cm −1 obtained from the laser Raman spectroscopy method using a linearly polarized laser beam whose polarization plane is perpendicular to the surface of the A layer and the B layer,
the thickness of the A layer is within the range from 5 μm or more to less than 30 μm,the thickness of the B layer is within the range from 0.5 μm or more to less than 6.0 μm, and
the polyester resin layer has a thickness of a transition region from the molten layer having a peak intensity ratio A, in the layer A to the orientation layer, having the peak intensity ratio B, in the B layer, within a range from 1 μm to 4 μm.

2. The laminated metal sheet for the metal container lid according to claim 1 , wherein the A layer is composed of polyester resin containing polyethylene terephthalate as a main component, and copolymerized with 10 to 20% isophthalic acid as an acid component, and the B layer is composed of polyester resin containing 93% or more of polyethylene terephthalate.

3. A method for manufacturing the laminated metal sheet for the metal container lid according to claim 1 , the method comprising:
a step of controlling the orientation property in the thickness direction of the polyester resin layer by controlling at least one of the temperature of the metal sheet, the temperature of a laminating roll, and the pressing pressures of the laminating roll, when the polyester resin layer is laminated to the metal sheet.

4. A method for manufacturing the laminated metal sheet for the metal container lid according to claim 2 , the method comprising:
a step of controlling the orientation property in the thickness direction of the polyester resin layer by controlling at least one of the temperature of the metal sheet, the temperature of a laminating roll, and the pressing pressures of the laminating roll, when the polyester resin layer is laminated to the metal sheet.

Assignees

• Jfe Steel Corp

Inventors

• Hiraguchi Tomonari
• Oshima Yasuhide
• Kojima Katsumi

Classifications

• B32B2439/66

  Cans, tins · CPC title

• B32B2270/00

  Resin or rubber layer containing a blend of at least two different polymers · CPC title

• B32B2307/738

  Thermoformability · CPC title

• B32B2309/12

  Pressure · CPC title

• B29K2067/00

  Use of polyesters {or derivatives thereof}, as moulding material · CPC title