Laminating adhesives containing microencapsulated catalysts
OwnerBalasubramaniam Ramalingaminventor
Life of this patent
Estimating the term…
Abstract
The curing rate of a two component laminating adhesive is effectively accelerated by incorporating in at least one component a microencapsulated catalyst. When the laminating adhesive is subjected to an effective amount of pressure (for example, the pressure applied when laminating flexible films together using nip rollers), the catalyst (which may be, for example, a dialkyl tin dicarboxylate) is released from encapsulation and is made available to catalyze the polyurethane-forming reaction between the isocyanate groups and the active hydrogen-functionalized groups in the adhesive mixture.
Claims16
A two component laminating adhesive comprising Component A and Component B, wherein Component A comprises an isocyanate-functionalized compound and Component B comprises an active hydrogen-functionalized compound and at least one of either Component A or Component B additionally comprises a microencapsulated catalyst, wherein the catalyst encapsulated therein is capable of accelerating reaction of the isocyanate groups of the isocyanate-functionalized compound with the active hydrogen groups of the active hydrogen-functionalized compound but is at least substantially isolated from contact with the isocyanate-functionalized compound and the active hydrogen-functionalized compound until sufficient pressure is applied to the microencapsulated catalyst to release the catalyst encapsulated therein.
A method of making a flexible film laminate, said method comprising a) combining Component A and Component B to form an adhesive mixture, wherein Component A comprises an isocyanate-functionalized compound and Component B comprises an active hydrogen-functionalized compound and at least one of either Component A or Component B additionally comprises a microencapsulated catalyst, wherein the catalyst encapsulated therein is capable of accelerating reaction of the isocyanate groups of the isocyanate-functionalized component with the active hydrogen groups of the active hydrogen-functionalized component and is at least substantially isolated from contact with the isocyanate-functionalized compound, b) joining a first flexible film and a second flexible film using the adhesive mixture interposed between the first flexible film and the second flexible film, c) applying sufficient pressure to the adhesive mixture interposed between the first flexible film and the second flexible film to release the catalyst from the microencapsulated catalyst, and d) curing the adhesive mixture.
Dependencies are inferred from the claim text.