WO2000023329A9

WO2000023329A9 - Corrosion inhibiting labels for container exteriors

Info

Publication number: WO2000023329A9
Application number: PCT/US1999/024786
Authority: WO
Inventors: Goerge B Diamond
Original assignee: Dispensing Containers Corp
Priority date: 1998-10-21
Filing date: 1999-10-21
Publication date: 2000-11-02
Also published as: WO2000023329A1; AU1450000A

Abstract

A corrosion inhibiting label (1) for a container (2) includes a shrinkable film (4) containing a corrosion inhibitor in the film or in the printing (3) on the inside of the film or in both the film and the printing.

Description

CORROSION INHIBITING LABELS FOR CONTAINER EXTERIORS

BACKGROUND OF THE INVENTION

The present invention relates to container labels and, in particular, to a corrosion inhibiting label for metal containers .

Metal containers for food, beverage, aerosol, industrial products and the like are usually made from steel or tin plated steel . The interior of the container is protected from corrosive products by being lined

(spray, electrocoat, rolled on etc.) with a resin which is then baked on, or by inserting an anticorrosive packet. Excess air is usually removed by flushing, vacuum, etc. The exterior of the can is however exposed to the atmosphere and tends to oxidize. Even tin coated steel has only a short life span before it oxidizes.

These containers are then printed or labeled. If the container is printed then the base printing coat protects it from corrosion. If it is labeled, then oxygen permeates the label and oxidizes the metal. In order to prevent the corrosion of the container, the container exterior is usually "wash coated", i.e., a thin coat of resin is applied and then baked on.

Many labels are now made from a shrinkable film ("shrink film") which is wrapped around the container and then shrunk on by heat. This shrink film is printed on the inside so that the printing inks and/or base coat inks are in contact with the can. If an additional adhesive coat is applied to the inside of the film then the adhesive coat is in contact with the can.

The addition of anticorrosive chemicals into film is well known and is used for film which is used to wrap objects requiring corrosion protection while the objects are in storage or in transport. It is then removed before the product is used or further processed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a corrosion inhibiting label and, in particular, to provide such a label for use with metal containers.

It is another object of the invention to eliminate the wash coating process in the manufacture of cans.

These and other objects are achieved in accordance with the present invention by a corrosion inhibiting label comprising a shrinkable film and printing on the label, wherein a corrosion inhibitor is included in the film or the printing or in both the film and the printing . One of the advantages of the invention is elimination of the wash coat. This is a major improvement in can making. It saves the wash coating step and the environmental problems of pollutant mist from the wash coat sprayer and the effluent water containing the wash coat . It also saves the necessity of periodic cleaning of the conveyor which takes the cans through the wash coat process .

Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

Fig. 1 is an exploded view of a can and a heat shrinkable film label in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT (S) Referring to Fig. 1, this invention utilizes a shrinkable film label 1, which contains corrosion inhibitors and which is heat shrunk onto a container 2, such as a metal can. The label 1, which as is typical, includes printing 3 thereon identifying the product contained in the container and containing related information, stays on the container 1 throughout the product's useful life (e.g., a label on a soup can). The heat shrinkable film may be polyethylene, polypropylene, or polyvinyl chloride and contain a corrosion inhibitor such as an amine.

Another way of making a shrink label is to put the corrosion inhibitors into the base coat ink if a base coat ink, such as is generally used for printing on film, is used. Labels are sometimes partly transparent and therefore a transparent base coat is needed or the film itself will have a corrosion inhibitor. If the label has an adhesive coat, such as thermoplastic on the interior of the label, the anticorrosive inhibitor can be added to the adhesive coat. The shrink film label 1 covers the entire surface of the container 2 (except the ends) . The top end of the container 4 is usually made separately and is pre-coated. If the bottom end 6 is separate it is also precoated. If the bottom end 6 is integral it is easily protected by a spray coat or a coat applied by other means, which may be ultraviolet and/or heat cured.

The bottom chime 6 (the edge that contacts a surface when the container 2 is on that surface) can be doubly protected by folding the shrink film around it using a method such as that disclosed in copending Application Serial No. 09/182,546, filed October 29, 1998 and entitled "A METHOD OF APPLYING A HEAT SHRINK FILM TO CONTAINERS AND CONTAINERS FORMED THEREBY" , the entire disclosure of which is incorporated by reference herein. This is useful for very corrosive contact such as on wash basins, bathtubs etc.

Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims .

Claims

WHAT IS CLAIMED IS:

1. A corrosion inhibiting label comprising: a shrinkable film containing a corrosion inhibitor; and printing on the label.

2. A corrosion inhibiting label for a container, comprising: a shrinkable film; and printing on the film on a side thereof to be placed in contact with a surface of the container, the printing including a corrosion inhibitor.

3. A labeled container comprising: a container; a heat shrunk film on the container in contact with an exterior surface thereof; printing on the heat shrunk film on the side thereof in contact with the exterior surface of the container; and a corrosion inhibitor in the heat shrunk film, or in the printing or in both the heat shrunk film and the printing.

4. A labeled container in accordance with claim 3, wherein the corrosion inhibitor is in the heat shrunk film.

5. A labeled container in accordance with claim 3, wherein the corrosion inhibitor is in the printing.

6. A labeled container in accordance with claim 3, wherein the corrosion inhibitor is in the heat shrunk film and the printing.

7. A corrosion inhibiting label comprising: a shrinkable film; and an adhesive on one side of the film, the adhesive containing a corrosion inhibitor.