Adhesive composition and method

Abstract

An adhesive composition contains a block copolymer hot melt adhesive and a vapor releasing vapor corrosion inhibitor mixed with the block copolymer hot melt adhesive, the vapor corrosion inhibitor being in the form of particles suspended in the adhesive composition, the particles preferably having a maximum dimension of less than about 30 microns. One improvement results from inclusion in the adhesive mixture of a titanium and / or zirconium containing coupling agent, either separately or as part of the VCI particles. Another improvement results from blending the adhesive mixture in a continuous process using for example a twin screw extruder. As a result, the adhesive mixture has better uniformity and superior viscosity properties during use.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a National Stage of International Application No. PCT / US2009 / 044686, filed May 20, 2009, which is a continuation of PCT International Application No. PCT / US2009 / 030541, filed Jan. 9, 2009, now withdrawn, which claims the benefit of U.S. Provisional Application No. 61 / 054,728, filed on May 20, 2008. The entire disclosures of each of the above applications are incorporated herein by reference.INTRODUCTION[0002]This invention relates to an adhesive containing a corrosion protective additive and a wrap material for wrapping products which uses the adhesive. The adhesive may include, for example, a vapor corrosion inhibitor (VCI) that reacts with moisture enclosed within the wrapping material to protect the products from corrosion.[0003]Corrosion is a natural occurring process that causes metals to react with their environment to form more stable compounds. The cost of corrosion on metals has been estimated as about 4.9% of...

AI Technical Summary

Benefits of technology

[0005]To reduce corrosion and its attendant costs, vapor corrosion inhibitors (VCI's) have been studied since early 1900's, and their popularity in use increased during WWII. The commercial formulations of VCI's tend to be held as proprietary by VCI suppliers, but they generally contain low molecular weight amines or mixtures of amines. In many applications of VCI's the amines are volatile enough to vaporize from their carrier and create a protective layer of film, only a few molecules thick, on metal surfaces. The protective layer of film blocks or retards the amount of electron activity on the metallic surface from reaction with water molecules and helps protect the surface. When VCI's are contained in a closed environment, as a box or room, they build a relatively low vapor pressure around the articles enclosed.

[0016]A material for shrink wrapping an article contains a shrinkable, stretchable film outer layer having a predetermined shrink response to energy such as heat energy applied to the film, and a fabric inner layer, for example a nonwoven fabric. A hot melt adhesive secures the fabric inner layer to the outer layer, and contains a protective vapor releasing additive. When an article is wrapped with the fabric side toward the article, the additive releases a protective vapor, passes through the nonwoven fabric for treating the article and preventing corrosion.

Problems solved by technology

In the military and in the transportation industry, vehicles used on ground, on air or in the sea, and the equipment placed on these vehicles are subject to corrosion as a consequence of their operational, storage or shipping environments.

Automobiles, automobile parts and other metallic industrial articles being shipped or stored are also subject to corrosion due to their environment.

Any force applying over a void can cause the cover to sag, or deform.

Dew and condensation are undesirable from a corrosion standpoint and the nonwoven, by its wicking properties, helps remove the condensation away from the surface and pulls it towards the film.

At these levels, the nonwoven tends to release from the shrink film, and this release creates small air bubbles between the nonwoven and the shrink film when the covers are being shrunk.

This is a safety issue for other vehicles on the road as well as the owner of the product being covered.

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