JPH09216312A - Resin composite metal plate for metal vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated metal plate for a vessel having excellent processability and corrosion resistance. SOLUTION: The resin composite metal plate for a metal vessel is obtained by forming the metal plated film of Sn, Cr or Ni or chrome hydrated oxide film only on one side surface or both side surfaces, or forming the metal plated film of Sn, Cr or Ni on one side surface and chrome hydrated oxide film on the other side surface as the different type films on both the surfaces, and then coating the one side surface of the metal plated or chrome hydrated oxide film with thermoplastic amorphous polyester resin composition as a lower layer and thermoplastic crystalline polyamide resin as an upper layer of the two layers. Further, the metal plate for the vessel is coated on the side not coated with the resin with thermosetting resin or thermoplastic resin to provide excellent content physical property resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated metal plate used as a container material. More specifically, the structure of the coating resin is such that the lower layer is an amorphous polyester resin and the upper layer is a crystalline polyamide resin. The present invention relates to a resin composite metal plate for a metal container having scratch resistance and adhesion at the time of processing, and rust resistance after processing, particularly when used as the outer surface side of a can. .

[0002]

2. Description of the Related Art Conventionally, a resin-coated metal plate used as a material for a container has been used for the purpose of improving the corrosion resistance of the inner surface of a can container, as disclosed in JP-A-52-65579. Most of the time, but recently, JP-A-3
A double-sided polyester laminated steel sheet disclosed in JP-A-101930 and a biaxially stretched polyethylene terephthalate film disclosed in JP-B-5-34063 have been proposed for use on the outer surface of an aerosol can.

As described above, the portion where the resin-coated steel plate is used on the outer surface of the can, for example, the can lid and the can bottom, is generally in direct contact with the winding roll when the winding process is performed. In the present situation, a biaxially stretched polyethylene terephthalate film is frequently used because a resin excellent in the above is required.

[0004]

Generally, a biaxially stretched polyethylene terephthalate film has poor adhesion to a metal plate, and when an attempt is made to cover the metal plate, an adhesive layer should be provided between the film and the metal plate. Alternatively, under the present circumstances, the metal plate is heated up to near the melting point of the polyethylene terephthalate film to melt the extremely thin resin layer in the portion in contact with the metal plate to secure the adhesion. Further, as another resin coating method, there is an extrusion melting laminating method using a T-die. In this method, the molten resin is directly solidified on the metal plate, so that the resin structure is in an amorphous state and the adhesiveness with the metal plate is sufficient. However, since the hardness and slipperiness are inferior to those of the biaxially stretched structure, flaws may become a problem when the processing conditions are severe.

According to the present invention, a metal plate coated with such a polyethylene terephthalate resin having an amorphous structure has a two-layer structure of an upper layer polyamide resin and a lower layer amorphous polyester resin, so that the outer surface of the can is scratch-resistant. It is an object of the present invention to provide a resin composite metal plate for a metal container, which has excellent sticking property, and has good adhesion and rust resistance.

[0006]

That is, the gist of the present invention is as follows. (1) After a metal plating of Sn, Cr, Ni or the like or a chemical conversion treatment film of chromium hydrate oxide is applied to one surface of the metal plate, a thermoplastic amorphous polyester resin composition is further formed as a lower layer A single-sided resin composite metal plate for a metal container, characterized by being coated with two layers of thermoplastic crystalline polyamide resin as an upper layer.

(2) Sn, Cr, N on both surfaces of the metal plate
After applying a metal plating such as i or a chromium hydrate oxide chemical conversion treatment film, a thermoplastic amorphous polyester resin composition is further formed as a lower layer on one surface to form a thermoplastic crystalline polyamide resin. A single-sided resin composite metal plate for a metal container, which is coated with two layers as an upper layer. (3) After plating one surface of the metal plate with a metal such as Sn, Cr, Ni, etc., and coating the other surface with different kinds of chromium hydrate oxide-based chemical conversion coatings on the front and back, the above metal plating is applied. As a lower layer of a thermoplastic amorphous polyester resin composition,
A single-sided resin composite metal plate for a metal container, characterized by being coated with two layers of thermoplastic crystalline polyamide resin as an upper layer.

(4) In the resin composite metal plate of the above (1), (2) and (3), the amorphous polyester resin / crystalline polyamide resin two-layer coated side is the outer surface of the can, and the other side is bare. Double-sided resin composite metal for metal container used as an inner surface of a can by coating a thermosetting resin composition on the metal plate of Sn, Cr, Ni, etc. metal plating or chromium hydrate oxide chemical conversion treatment film Board.

(5) In the resin composite metal plate according to the above (1), (2) and (3), the amorphous polyester resin / crystalline polyamide resin double layer coating side is the outer surface of the can and the other side is bare. Double-sided resin composite metal plate for use as an inner surface of a can, which is used as an inner surface of a can by coating the thermoplastic resin composition on the metal plate of Sn, Cr, Ni, etc. .

(6) In the resin composite metal plate of the above (1), (2) and (3), the amorphous polyester resin / crystalline polyamide resin double layer coating side is the outer surface of the can and the other side is bare. First, the thermosetting resin composition is coated on the metal plate of Sn, Cr, Ni, etc. metal plating or the chromium hydrate oxide chemical conversion treatment film, and then the thermoplastic resin composition is coated in two layers. Then, a double-sided resin composite metal plate for a metal container used as an inner surface of a can.

The present invention will be described in detail below. The present invention, for the structure of the laminate resin film used as the outer surface of the can, the upper layer is a crystalline polyamide resin excellent in scratch resistance and slipperiness, the lower layer is an amorphous amorphous excellent in adhesion and rust resistance. It is characterized by using polyester resin. Examples of the metal plate used in the present invention include aluminum, iron, and alloys containing these as a main component, but are not particularly limited thereto, and are applicable to all metal materials generally used as a material for a container. . These metal plates are coated with Sn, Ni, Cr, Zn, Al, etc., and their alloys, as well as chromium or phosphorus hydrate oxides, in order to impart corrosion resistance and adhesion according to their applications. A chemical conversion treatment such as Typical examples of these coating methods include general electroplating, hot-dip plating, chemical plating, and simple application. Also, the thickness of these metal plates varies depending on the size of the container, the application, etc.
Generally, those having a range of 0.10 to 1.5 mm are used.

A resin is coated on the surface-treated metal plate. As a coating method, it is possible to use a non-stretched film even in a film lamination method in which a film is heat-bonded, which is a general method, but in the extrusion lamination method in which a resin is melt-extruded by a T-die and directly coated. From the viewpoint of the adhesion between the upper layer and the lower layer, the method of simultaneously extruding the upper and lower two layers is more preferable.

Next, regarding a resin coating, the present invention is characterized in that the resin structure is an upper layer polyamide resin and a lower layer amorphous polyester resin. Polyamide resins have excellent scratch resistance and slipperiness, but have problems with adhesion and water absorption, and it is common to use an adhesive for adhesion to a metal plate. Further, when the polyamide resin is directly coated on the steel sheet, there is a problem that rust occurs due to water absorption. On the other hand, the amorphous polyester resin has excellent adhesiveness and has almost no water absorption, so problems such as polyamide resin do not occur, but on the contrary, inferior in scratch resistance and slipperiness, when producing a metal container. Defects are generated by processing, and corrosion resistance becomes a problem. Thus, the polyamide resin and the amorphous polyester resin having contradictory performance, in order to express their respective characteristics, in the present invention, the polyamide resin excellent in flaw resistance is the upper layer, the adhesion and the resistance. The problem was solved by adopting a two-layer structure in which an amorphous polyester resin having excellent rust properties is used as a lower layer.

As the upper layer polyamide resin composition, there are nylon 6, nylon 66, nylon 12 and the like, which are generally called, and in these resin compositions, polyolefin etc. are added for the purpose of improving impact resistance. Addition of additives and addition of various additives such as colorants and lubricants are carried out by a general method, if necessary.

The lower layer amorphous polyester resin composition includes polyethylene isophthalate, cyclohexane.
Examples include, but are not limited to, polyethylene terephthalate copolyester containing 30 mol% of dimethal, polyethylene terephthalate containing 20 mol% or more of isophthalic acid, polyarylate, polyester polycarbonate, and the like, but are not limited thereto and have a glass transition temperature of 20 ° C. or higher, preferably 40 ° C. or higher. Of amorphous polyester. Also,
These amorphous polyester resins may also be blended with known compounding agents such as antioxidants, impact resistance agents, pigments, and viscosity improvers, if necessary. Further, although it is defined as amorphous, it means a resin having no peak of crystallization energy in a general differential thermal analysis.

The total thickness of these polyamide resin and amorphous polyester resin coatings varies depending on the type of metal can and the application, but it is generally in the range of 5 to 200 microns, and particularly preferably in the range of 10 to 50 microns. In this case, the lower limit is determined by corrosion resistance, and the upper limit is determined by workability and cost issues. The ratio of the upper polyamide resin to the lower amorphous polyester resin is 1: 1 to 1:
A range of 10 is preferred.

Regarding the inner surface side of the metal can, the required level of corrosion resistance differs depending on the contents of the can. For the one having the least corrosiveness, the bare metal plate shown in claim 1 or claim 2, The Sn, Ni, Cr plating or the chemical conversion treatment on the single-sided resin-coated metal sheet shown in No. 3 does not cause any particular problem, but if the corrosion resistance is required, Sn, Ni, , 0.5% of thermosetting water-soluble resin on Cr plating film or chemical conversion film
For those coated with 10 to 10 μm, and those requiring further corrosion resistance, those coated with a resin such as polyethylene, polypropylene, polyester, nylon, or polycarbonate as the thermoplastic resin shown in claim 5 to about 10 to 200 μm, As shown in claim 6,
By providing a double-sided resin-coated composite metal plate having a two-layer structure by coating a thermosetting resin as described in claim 4 on the underlayer of these thermoplastic resins, one having good corrosion resistance can be obtained.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described based on embodiments. [Example 1-1] A low carbon cold-rolled steel sheet cold-rolled and annealed by a usual method was degreased and pickled by a usual method, and then a normal Sn plating (Sn = 2.8 to 11) was performed. 0.2 g / m
² ) is applied and a normal reflow treatment is performed to form a Sn-Fe alloy layer, and chromate treatment is applied to one surface side of the tin material, 20 μm of amorphous polyester as the lower layer and 10 μm of polyamide resin as the upper layer. It was coated with micron and subjected to various evaluation tests.

[Example 1-2] After degreasing and chromating treatment by a conventional method on one surface of an aluminum plate cold-rolled and annealed by a conventional method, a lower layer is further formed thereon. 20 micron of amorphous polyester and 10 micron of polyamide resin as the upper layer,
It was subjected to various evaluation tests.

Example 2 In Example 1, the lower layer of amorphous polyester was coated with 30 μm and the upper layer of polyamide resin was coated with 10 μm, and subjected to various evaluation tests. [Example 3] In Example 1, the lower layer amorphous polyester was coated with 10 µm and the upper layer polyamide resin was coated with 10 µm and subjected to various evaluation tests. [Example 4] In Example 1, C was used instead of the tin plate material.
A tin-free material having r-plated at 50 to 200 mg / m ² was coated on one surface thereof with an amorphous polyester of 20 μm as a lower layer and a polyamide resin of 10 μm as an upper layer, and subjected to various evaluation tests. [Embodiment 5] In Embodiment 1, N is used instead of the tin plate material.
i-plated 0.1 to 10 g / m ^{2 is used as} a material, and one side thereof is coated with 20 μm of amorphous polyester as a lower layer and 10 μm of a polyamide resin as an upper layer,
It was subjected to various evaluation tests. [Example 6] In Example 1, a thermosetting water-soluble epoxy resin was applied to the other side of the tin plate by 5 microns,
It was subjected to an evaluation test on the inner surface side. [Example 7] In Example 1, the other side of the tin plate was coated with 30 μm of a thermoplastic polyester resin,
It was subjected to an evaluation test on the inner surface side. Example 8 In Example 1, 30 μm of a thermoplastic polypropylene resin was applied to the other side of the tin plate material and subjected to an evaluation test on the inner side.

[Example 9] In Example 1, a thermosetting water-soluble epoxy resin was applied to the other side of the tinplate material in an amount of 5 μm, and a thermoplastic polyester resin was applied in two layers of 30 μm. , And subjected to an evaluation test on the inner surface side. [Comparative Example 1] In Example 1, the resin coating layer was a single layer of the lower amorphous polyester resin. Other items are the same as those in the first embodiment.

[Comparative Example 2] A resin coating layer in Example 1 which is a single layer of only an upper polyamide resin. All other conditions are the same as in Example 1. The above-described inventive examples and comparative examples were subjected to the evaluation tests (a) to (c) shown below to compare the characteristics.

(A) Evaluation of flaws during winding The scratches of the resin during winding are evaluated by making a φ211 size can lid so that the resin side is the outer surface of the can, and performing normal double winding. Then, the surface appearance of the resin after tightening was observed with a magnifying glass. When there were no flaws, the mark was ◯, when only the extreme surface had shallow marks, the mark was Δ, and when the flaw reached the base metal plate was marked with x.

(B) Evaluation of rust resistance after winding The rust resistance after winding was evaluated by rust generation and discoloration on the surface after soaking in tap water for 1 month. At the same time, 60 ℃ × 9
It was aged for 1 month under the condition of 0% RH, and the generation of rust on the surface was evaluated. In the evaluation, those without rust were rated as ◯, and those with rust were rated as x. (C) Corrosion resistance evaluation on inner surface side Erichsen extrusion processing 4 mm was performed so that the surface which becomes the inner surface of the can became convex, and it was immersed in the water-soluble content for 1 month for aging to evaluate the occurrence of rust. In the evaluation, ⊚ indicates that no rust was generated, ∘ indicates discoloration, Δ indicates minute rust formation, and x indicates completely rust formation.

The test results are summarized in Table 1 above.

[0026]

[Table 1]

[0027]

INDUSTRIAL APPLICABILITY As described above, the present invention is applied to the container material, especially to the outer surface side of the can, for the scratch resistance and adhesion at the time of processing, and the rust resistance after processing. This is solved by coating a resin having a two-layer structure of an upper layer polyamide resin and a lower layer amorphous polyester resin, and it contributes greatly to extending the life of the container by improving the corrosion resistance of the container material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahisa Ohno 1 Fuji-machi, Hirohata-ku, Himeji City Nippon Steel Corporation Stock company Hirohata Works

Claims (6)

[Claims] 1. A thermoplastic amorphous polyester resin composition, which is obtained by applying a metal plating of Sn, Cr, Ni or the like or a chemical conversion treatment film of chromium hydrate oxide on one surface of a metal plate, and further coating the film. As a lower layer, and a thermoplastic crystalline polyamide resin as an upper layer are coated in two layers to form a single-sided resin composite metal plate for a metal container. 2. A thermoplastic amorphous polyester is further coated on one surface after metal plating of Sn, Cr, Ni or the like or a chemical conversion coating of chromium hydrate oxide is applied on both surfaces of the metal plate. A single-sided resin composite metal plate for a metal container, characterized in that the resin composition is used as a lower layer, and a thermoplastic crystalline polyamide resin is applied as an upper layer in two layers. 3. One side of the metal plate surface is Sn, Cr, Ni
Metal plating such as, after applying the different surface of the chromium hydrate oxide-based chemical conversion coating on the other side, the thermoplastic amorphous polyester resin composition as the lower layer on the metal plating, A single-sided resin composite metal plate for a metal container, characterized by being coated with two layers of a plastic crystalline polyamide resin as an upper layer. 4. The resin composite metal plate according to any one of claims 1, 2 and 3, wherein the amorphous polyester resin / crystalline polyamide resin two-layer coated side is the outer surface of the can, and the other side is a bare metal plate or Sn, A double-sided resin composite metal plate for a metal container, which is used as an inner surface of a can by coating a thermosetting resin composition on a metal plating of Cr, Ni or the like or a hydrated chromium oxide conversion coating. 5. The resin composite metal plate according to any one of claims 1, 2 and 3, wherein the amorphous polyester resin / crystalline polyamide resin two-layer coating side is the outer surface of the can, and the other side is a bare metal plate or Sn, A double-sided resin composite metal plate for a metal container, which is used as an inner surface of a can by coating a thermoplastic resin composition on a metal plating of Cr, Ni or the like or a hydrated chromium oxide type chemical conversion treatment film. 6. The resin composite metal plate according to any one of claims 1, 2 and 3, wherein the amorphous polyester resin / crystalline polyamide resin two-layer coating side is the outer surface of the can, and the other side is a bare metal plate or Sn, A thermosetting resin composition is first coated on a metal plating of Cr, Ni or the like or a hydrated chromium oxide type chemical conversion treatment film, and then a thermoplastic resin composition is further coated in two layers to form an inner surface of a can. Double-sided resin composite metal plate for metal containers used.