Title of Invention	"ANTI CORROSION PLASTIC FILM"
Abstract	This invention relates to anti-corrosion plastic film involving use of vapour corrosion inhibitors in a plastic film. The anti-corrosion plastic film of present invention comprises of a single layer film preferably, a co-extruded multiplayer film containing two or more layers of plastic. The monolayer film is extruded with vapor corrosion inhibitors which bleed towards the surface of the package, evaporate and deposit on the packaged metallic product and provide rust inhibition. The co-extruded film contains one or more inner layers of low density polyethylene containing vapour phase corrosion inhibitors (VCIs) and/or one or more of outer layer of low density material or high density polyethylene preferably high density polyethylene which constitutes the barrier layer. The outer layer retains VCIs within the package and does not allow permeation into the package, of atmospheric contaminants like moisture, sulphur dioxide, hydrogen sulphide etc.

Title of Invention

"ANTI CORROSION PLASTIC FILM"

Abstract

This invention relates to anti-corrosion plastic film involving use of vapour corrosion inhibitors in a plastic film. The anti-corrosion plastic film of present invention comprises of a single layer film preferably, a co-extruded multiplayer film containing two or more layers of plastic. The monolayer film is extruded with vapor corrosion inhibitors which bleed towards the surface of the package, evaporate and deposit on the packaged metallic product and provide rust inhibition. The co-extruded film contains one or more inner layers of low density polyethylene containing vapour phase corrosion inhibitors (VCIs) and/or one or more of outer layer of low density material or high density polyethylene preferably high density polyethylene which constitutes the barrier layer. The outer layer retains VCIs within the package and does not allow permeation into the package, of atmospheric contaminants like moisture, sulphur dioxide, hydrogen sulphide etc.

Full Text	FIELD OF INVENTION This invention relates to anti corrosion plastic film wherein vapour corrosion inhibitors (VCIs) are extruded with the plastic, which may advantageously be employed as plastic packaging material to provide protection to metallic surfaces from corrosion and oxidation from corrosive gases as well as water vapour and oxygen during their storage and transportation. BACKGROUND OF THE INVENTION The corrosion of metallic products is a recognized problem, which is present during manufacturing, storage or transportation of such products. Such products also undergo rigorous temperature and humidity changes during their transportation and are also subjected to highly corrosive acidic environments. Several methods are known for inhibiting corrosion of metallic articles during storage or transportation. One such method employs the use of vapour phase corrosion inhibitors supported or provided on a paper substrate as a carrier therefor. Thus vapours of corrosion inhibiting chemicals are released into the inside atmosphere of the packaged product which then deposit themselves onto the metallic article and prevent it from oxidation. The life of the packaging depends upon the type of chemicals used, their concentration and vapour pressure. The combination of chemicals used for the VCI packaging can be altered according to the desired shelf life of the article being packed in the VCI packaging. However, the use of vapour corrosion inhibitor provided on paper as a carrier, has several advantages. A disadvantage of vapour corrosion inhibitor on paper as carrier is that paper has porous characteristics. It allows water, moisture and corrosive gases to pass through which get deposited on the metallic surfaces and cause corrosion. Another disadvantage of vapour corrosion inhibitor on paper is low resistance to puncture and tear, due to which, a product wrapped in VCI paper is packaged within a plastic bag. This leads to increase in end costs and further cannot be conveniently employed in a packaging machine. Still another disadvantage of VCI paper is that there is variation on corrosion inhibiting quality from one batch to another batch. Further disadvantage of VCI paper undergoes changes in corrosion inhibiting properties with the change in temperature or humidity. Still further disadvantage of VCI paper is that paper being non-transparent is not suitable for packaging components which require inspection as package has to the opened for inspection. Even further disadvantage of VCI paper is that it is suitable only for small sized metallic spares/components but it is not suitable for huge size products. Another method known in the art for inhibiting corrosion of metallic articles is brushing the articles with anti-rust oil. A drawback of the above method is that applying and removing oil is costly, messy and labour intensive. Another drawback of the above method is that oil is not suitable for components having rubber or other non-metallic parts. Still another drawback of the above method is that the application of oil requires additional packaging materials like jute, plastic etc. Further drawback of the above method is that application of oil leaves hazardous cloud around the work environment. Still further drawback of the above method is that wastage of oil occurs during application of oil. OBJECT OF THE INVNETION An object of this invention is to propose an anti-corrosion plastic film comprising VCIs supported on a carrier which obviates the aforesaid disadvantages of the previously used substrates. Another object of this invention is to propose an anti-corrosion plastic film, which prevents the seepage of water. Still another object of this invention is to propose an anti-corrosion plastic film and which substantially reduces the flow of moisture or corrosive gases from flowing there through. Yet another object of this invention is to propose an anti-corrosion plastic film which has suitable strength properties. Further object of this invention is to propose an anti-corrosion plastic film which can conveniently be used on a packaging machine. Yet further object of this invention is to propose an anti-corrosion plastic film which avoids the use of a outer wrap. Still further object of this invention is to propose an anti-corrosion plastic film which can be used for small as well as large size products. Even further object of this invention is to propose an anti-corrosion plastic film which can be on a transparent carrier so that the contents of the package can be readily inspected or identified there by obviating the need for opening the package. The VCI can also be supported on translucent and opaque carriers. Still further object of the present invention is to provide an anti-corrosion plastic film which minimizes cost. Yet further object of the present invention is to provide an anti-corrosion plastic film which can be applied to metallic articles in safe working environment. Even further object of the present invention is to provide an anti-corrosion plastic film which eliminates the coating step from the manufacturing process as packaging in the film of the present invention takes care of corrosion problem. Still further object of the present invention is to also provide a multi layered anti-corrosion plastic film, which provides better puncture and tear resistance for packaging of sharp edged products. Even further object of the present invention is to provide an anti-corrosion plastic film, which does not allow atmospheric contaminants like moisture, sulphur dioxide, hydrogen sulphide etc to permeate into the package. STATEMENT OF INVENTION According to this invention, there is provided an anti-corrosion plastic film comprising monolayer film extruded with vapour corrosion inhibitors, preferably co-extruded multi layer film comprising one or more of outer layer as barrier layer selected from low density material or high density polyethylene, preferably high density polyethylene, with or without vapour phase corrosion inhibitors; and one or more of inner layers of linear low density polyethylene containing vapour phase corrosion inhibitors. This invention provides a cost-effective vapour phase corrosion inhibitor on a plastic film as a carrier. The anti-corrosion plastic film of present invention, can be applied on small and large size products. The film being transparent, enables inspection/identification of contents of package without opening it. The multi layered film has exceptionally high barrier characteristics against moisture, sulphur dioxide and hydrogen sulphide, while the VCI is retained by the inner layer of film. The VCIs volatilise from the inner film into the air within the package, condensing on all exposed metal surfaces, even the most remote areas. After condensation, a thin molecular protective layer is formed on the metallic surfaces which prevents corrosion. DESCRIPTION OF THE INVENTION According to this invention there is provided an anti corrosion plastic film containing vapour phase corrosion inhibitor for the wrapping of metallic articles to protect them from corrosion during storage and transportation. The anti corrosion plastic film of present invention comprises a single layer extruded with vapour corrosion inhibitor, preferably co-extruded multi-layer film containing outer layer as barrier layer selected from low density material and high density polyethylene, preferably high density polyethylene, with or without corrosion inhibitor and one or more inner layers of linear low density polyethylene (LLDPE) containing vapour phase corrosion inhibitors. The incorporation of the anti-corrosive chemicals into the film causes the migration of the vapour corrosion inhibitors to the surface; both outer and inner surface in case of monolayer/single-layer film and controlled migration towards the inner surface in case of a multilayer film. The migrated chemicals evaporate into the packaged atmosphere and also attach themselves to the water vapours present. Such vapours of the anti-corrosive substance form an anti-corrosive atmosphere inside the packaging. These vapours also deposit on the surface of the metal to form a thin moleculer layer by condensation, which protects the surface of the metal from corrosion. In accordance with this invention, the anti-corrosion plastic film of the present invention is prepared by using a DGP Windsor 3 layer co-extrusion line where one or more layers of plastic can be extruded simultaneously. The anti corrosion chemicals are blended with the polymer granules using an ordinary ribbon blender or a mixer in the desired quantities varying from 0.1% to 25% depending on the end use requirement and functionality of the film. The processing parameters are also adjusted accordingly to prevent the decomposition of the chemicals during the processing. The temperature profile selected for the one or more extruders used to manufacture film is as following: (Table Removed) In case of a monolayer film only one extruder out of the three is used. However, in case a multilayer film is required two or more extruders may be used with the inner surface of the film containing anti-corrosion chemicals and the outer may or maynot contain the VCI chemicals. The outer may contain a High Density Polyethylene Film to control the migration of the chemicals. However, the outer can also be formed from Lower Density Materials. It is to be noted that the present invention is susceptible to modifications, changes and adaptations by those skilled in the art. Such variant embodiments incorporating the concepts and features of the present invention, are intended to be within the scope of the present invention, which is further set forth under the following claims:- I CLAIM; 1. An anti-corrosion plastic film comprising monolayer film extruded with vapour corrosion inhibitors, preferably co-extruded multi layer film comprising one or more of outer layer as barrier layer selected from low density material or high density polyethylene, preferably high density polyethylene, with or without vapour phase corrosion inhibitors; and one or more of inner layers of linear low density polyethylene containing vapour phase corrosion inhibitors. 2. An anti-corrosion plastic film as claimed in claim 1 wherein anti-corrosion chemicals used vary from 0.1% to 25% of the weight of polymer granules, depending on the end use requirement and functionally of the film. 3. An anti-corrosion plastic film as substantially described and illustrated herein.

Full Text

FIELD OF INVENTION
This invention relates to anti corrosion plastic film wherein vapour corrosion inhibitors (VCIs) are extruded with the plastic, which may advantageously be employed as plastic packaging material to provide protection to metallic surfaces from corrosion and oxidation from corrosive gases as well as water vapour and oxygen during their storage and transportation.
BACKGROUND OF THE INVENTION
The corrosion of metallic products is a recognized problem, which is present during manufacturing, storage or transportation of such products. Such products also undergo rigorous temperature and humidity changes during their transportation and are also subjected to highly corrosive acidic environments.
Several methods are known for inhibiting corrosion of metallic articles during storage or transportation. One such method employs the use of vapour phase corrosion inhibitors supported or provided on a paper substrate as a carrier therefor. Thus vapours of corrosion inhibiting chemicals are released into the inside atmosphere of the packaged product which then deposit themselves onto the metallic article and prevent it from oxidation.
The life of the packaging depends upon the type of chemicals used, their concentration and vapour pressure. The combination of chemicals used for the VCI packaging can be
altered according to the desired shelf life of the article being packed in the VCI packaging.
However, the use of vapour corrosion inhibitor provided on paper as a carrier, has several advantages.
A disadvantage of vapour corrosion inhibitor on paper as carrier is that paper has porous characteristics. It allows water, moisture and corrosive gases to pass through which get deposited on the metallic surfaces and cause corrosion.
Another disadvantage of vapour corrosion inhibitor on paper is low resistance to puncture and tear, due to which, a product wrapped in VCI paper is packaged within a plastic bag. This leads to increase in end costs and further cannot be conveniently employed in a packaging machine.
Still another disadvantage of VCI paper is that there is variation on corrosion inhibiting quality from one batch to another batch.
Further disadvantage of VCI paper undergoes changes in corrosion inhibiting properties with the change in temperature or humidity.
Still further disadvantage of VCI paper is that paper being non-transparent is not suitable for packaging components which require inspection as package has to the opened for inspection.
Even further disadvantage of VCI paper is that it is suitable only for small sized metallic spares/components but it is not suitable for huge size products.
Another method known in the art for inhibiting corrosion of metallic articles is brushing the articles with anti-rust oil.
A drawback of the above method is that applying and removing oil is costly, messy and labour intensive.
Another drawback of the above method is that oil is not suitable for components having rubber or other non-metallic parts.
Still another drawback of the above method is that the application of oil requires additional packaging materials like jute, plastic etc.
Further drawback of the above method is that application of oil leaves hazardous cloud around the work environment.
Still further drawback of the above method is that wastage of oil occurs during application of oil.
OBJECT OF THE INVNETION
An object of this invention is to propose an anti-corrosion plastic film comprising VCIs supported on a carrier which obviates the aforesaid disadvantages of the previously used substrates.
Another object of this invention is to propose an anti-corrosion plastic film, which prevents the seepage of water.
Still another object of this invention is to propose an anti-corrosion plastic film and which substantially reduces the flow of moisture or corrosive gases from flowing there through.
Yet another object of this invention is to propose an anti-corrosion plastic film which has suitable strength properties.
Further object of this invention is to propose an anti-corrosion plastic film which can conveniently be used on a packaging machine.
Yet further object of this invention is to propose an anti-corrosion plastic film which avoids the use of a outer wrap.
Still further object of this invention is to propose an anti-corrosion plastic film which can be used for small as well as large size products.
Even further object of this invention is to propose an anti-corrosion plastic film which can be on a transparent carrier so that the contents of the package can be readily inspected or identified there by obviating the need for opening the package. The VCI can also be supported on translucent and opaque carriers.
Still further object of the present invention is to provide an anti-corrosion plastic film which minimizes cost.
Yet further object of the present invention is to provide an anti-corrosion plastic film which can be applied to metallic articles in safe working environment.
Even further object of the present invention is to provide an anti-corrosion plastic film which eliminates the coating step from the manufacturing process as packaging in the film of the present invention takes care of corrosion problem.
Still further object of the present invention is to also provide a multi layered anti-corrosion plastic film, which provides better puncture and tear resistance for packaging of sharp edged products.
Even further object of the present invention is to provide an anti-corrosion plastic film, which does not allow atmospheric contaminants like moisture, sulphur dioxide, hydrogen sulphide etc to permeate into the package.

STATEMENT OF INVENTION
According to this invention, there is provided an anti-corrosion plastic film comprising monolayer film extruded with vapour corrosion inhibitors, preferably co-extruded multi layer film comprising one or more of outer layer as barrier layer selected from low density material or high density polyethylene, preferably high density polyethylene, with or without vapour phase corrosion inhibitors; and one or more of inner layers of linear low density polyethylene containing vapour phase corrosion inhibitors.
This invention provides a cost-effective vapour phase corrosion inhibitor on a plastic film as a carrier. The anti-corrosion plastic film of present invention, can be applied on small and large size products. The film being transparent, enables inspection/identification of contents of package without opening it. The multi layered film has exceptionally high barrier characteristics against moisture, sulphur dioxide and hydrogen sulphide, while the VCI is retained by the inner layer of film. The VCIs volatilise from the inner film into the air within the package, condensing on all exposed metal surfaces, even the most remote areas. After condensation, a thin molecular protective layer is formed on the metallic surfaces which prevents corrosion.
DESCRIPTION OF THE INVENTION
According to this invention there is provided an anti corrosion plastic film containing vapour phase corrosion inhibitor for the wrapping of metallic articles to protect them from corrosion during storage and transportation. The anti corrosion plastic film of present invention comprises a single layer extruded with vapour corrosion inhibitor, preferably co-extruded multi-layer film containing outer layer as barrier layer selected from low density material and high density polyethylene, preferably high density polyethylene, with or without corrosion inhibitor and one or more inner layers of linear low density polyethylene (LLDPE) containing vapour phase corrosion inhibitors.
The incorporation of the anti-corrosive chemicals into the film causes the migration of the vapour corrosion inhibitors to the surface; both outer and inner surface in case of monolayer/single-layer film and controlled migration towards the inner surface in case of a multilayer film. The migrated chemicals evaporate into the packaged atmosphere and also attach themselves to the water vapours present. Such vapours of the anti-corrosive substance form an anti-corrosive atmosphere inside the packaging. These vapours also deposit on the surface of the metal to form a thin moleculer layer by condensation, which protects the surface of the metal from corrosion.
In accordance with this invention, the anti-corrosion plastic film of the present invention is prepared by using a DGP Windsor 3 layer co-extrusion line where one or more layers of plastic can be extruded simultaneously. The anti corrosion chemicals are blended with the polymer granules using an ordinary ribbon blender or a mixer in the desired quantities varying from 0.1% to 25% depending on the end use requirement and functionality of the film. The processing parameters are also adjusted accordingly to prevent the decomposition of the chemicals during the processing. The temperature profile selected for the one or more extruders used to manufacture film is as following:

(Table Removed)
In case of a monolayer film only one extruder out of the three is used. However, in case a multilayer film is required two or more extruders may be used with the inner surface of the film containing anti-corrosion chemicals and the outer may or maynot contain the VCI chemicals. The outer may contain a High Density Polyethylene Film to control the migration of the chemicals. However, the outer can also be formed from Lower Density Materials.
It is to be noted that the present invention is susceptible to modifications, changes and adaptations by those skilled in the art. Such variant embodiments incorporating the concepts and features of the present invention, are intended to be within the scope of the present invention, which is further set forth under the following claims:-

I CLAIM;
1. An anti-corrosion plastic film comprising monolayer film extruded with
vapour corrosion inhibitors, preferably co-extruded multi layer film
comprising one or more of outer layer as barrier layer selected from low
density material or high density polyethylene, preferably high density
polyethylene, with or without vapour phase corrosion inhibitors; and one or
more of inner layers of linear low density polyethylene containing vapour
phase corrosion inhibitors.
2. An anti-corrosion plastic film as claimed in claim 1 wherein anti-corrosion
chemicals used vary from 0.1% to 25% of the weight of polymer granules,
depending on the end use requirement and functionally of the film.
3. An anti-corrosion plastic film as substantially described and illustrated herein.

Documents:

291-DEL-2002-Abstract-(11-02-2008).pdf

291-del-2002-abstract.pdf

291-DEL-2002-Claims-(11-02-2008).pdf

291-del-2002-claims.pdf

291-DEL-2002-Correspondence-Others-(11-02-2008).pdf

291-DEL-2002-Correspondence-Others-(31-03-2010).pdf

291-del-2002-correspondence-others.pdf

291-del-2002-correspondence-po.pdf

291-DEL-2002-Description (Complete)-(11-02-2008).pdf

291-del-2002-description (complete).pdf

291-DEL-2002-Form-1-(11-02-2008).pdf

291-del-2002-form-1.pdf

291-DEL-2002-Form-15-(31-03-2010).pdf

291-del-2002-form-18.pdf

291-DEL-2002-Form-2-(11-02-2008).pdf

291-del-2002-form-2.pdf

291-DEL-2002-Form-3-(11-02-2008).pdf

291-del-2002-form-3.pdf

291-del-2002-form-4.pdf

291-del-2002-form-5.pdf

291-del-2002-gpa.pdf

291-del-2002-petition-138.pdf

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Patent Number

220998

Indian Patent Application Number

291/DEL/2002

PG Journal Number

31/2008

Publication Date

01-Aug-2008

Grant Date

11-Jun-2008

Date of Filing

22-Mar-2002

Name of Patentee

SAREEN SIDHARTH

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	SAREEN SIDHARTH.

PCT International Classification Number

B32B 5/06

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA