Adhesive composition and method
AssigneeTranshield, Inc.
InventorsGregory L. Todt, Seckin Ozol
Life of this patent
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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.
Claims23
A method of manufacturing a corrosion inhibiting hot melt adhesive composition in multiple stages, the method comprising
- in a first stage at a first shear rate, melting an adhesive at a first temperature above 120° C.;
- in a second stage, feeding the adhesive into an extruder on-demand and increasing the shear to a second shear rate and reducing the temperature below 120° C.;
- and
- in a third stage, adding a vapor corrosion inhibiting powder to the adhesive in the extruder while maintaining a sufficient shear to maintain the temperature below 120° C. while providing melt flow for a sufficient time to disperse the powder in the adhesive, the powder comprising a carrier, a vapor phase corrosion inhibitor, and a coupling agent selected from the group consisting of organotitanates and organozirconates.
A method of compounding an adhesive composition in an extrusion apparatus, comprising
- melting an adhesive comprising a block copolymer;
- introducing the molten hot melt adhesive into the barrel of the extruder;
- cooling the melt below 90° C. while increasing shear in the barrel to maintain sufficient melt flow;
- adding a titanate coupling agent and/or a zirconate coupling agent to the melt at a temperature of 90° C. or below;
- adding a vapor corrosion inhibitor in particulate form to the melt;
- and
- blending the hot melt adhesive, VCI, and titanate and/or zirconate coupling agent at 90° C. or less until the particles are dispersed in the hot melt adhesive.
Dependencies are inferred from the claim text.