Bi-layer adhesive for lens lamination

Abstract

A method for laminating a film on to an optical article and a bi-layer adhesive for use in the method. The bi-layer adhesive includes a latex adhesive layer or a specific silane adhesive and an HMA layer sequentially disposed on the film and dried to form a solid layer of uniform thinness throughout to provide optical quality. Various types of films may be employed to provide an optical function. Following optional pre-treatment steps, the adhesives are coated on to the film. An optical hot press technique is used to deliver heat and pressure over a short period of time to form a functionally-enhanced optical article with high adhesive strength.

1 . A functionalized optical element comprising:
 an optical base element; and   a functionalized layered structure incorporating at least one functional layer which is glued directly to the optical base element to form a functionalized optical element,   wherein the optical element further includes a bi-layer adhesive structure which comprises a layer of latex adhesive or gamma-aminopropyltriethoxysilane adhesive disposed on a surface of said functionalized layered structure and a layer of hot melt adhesive (HMA) disposed between the latex layer or the gamma-aminopropyltriethoxysilane layer and the optical base element to form a bi-layer adhesive that permanently retains the functionalized layered structure on the optical base element while maintaining optical quality.   
     
     
         2 . The functionalized optical element of  claim 1 , wherein said latex adhesive layer comprises a material selected from the group consisting of an acrylic latex, a (meth)acrylic latex, a polyurethane latex, a core/shell latex, and combinations thereof. 
     
     
         3 . The functionalized optical element of  claim 2 , wherein said latex layer comprises a dry, solid layer of between 0.5 microns and 10 microns thick with a uniform thickness throughout to provide optical quality. 
     
     
         4 . The functionalized optical element of  claim 2 , wherein said latex layer comprises a dry, solid layer of between 1.0 microns and 5.0 microns thick with a uniform thickness varying by less than 0.5 microns throughout to provide optical quality 
     
     
         5 . The functionalized optical element of  claim 1 , wherein said hot melt adhesive layer includes one or more of a UV curable HMA, a UV curable monomer, a thermal curable HMA, and a thermal curable monomer. 
     
     
         6 . The functionalized optical element of  claim 1 , wherein said hot melt adhesive layer includes one or more of a polymer HMA, thermoplastic polymer HMA, and a colloid. 
     
     
         7 . The functionalized optical element of  claim 1 , wherein said hot melt adhesive layer includes a heat-activatable polyurethane adhesive. 
     
     
         8 . The functionalized optical element of  claim 7 , wherein the HMA layer comprises a dry, solid layer between 1.0 microns and 20 microns with a uniform thickness throughout to provide optical quality. 
     
     
         9 . The functionalized optical element of  claim 8 , wherein the HMA layer comprises a dry, solid layer between 1.5 microns and 10 microns with a uniform thickness varying by less than 0.5 microns throughout to provide optical quality. 
     
     
         10 . The functionalized optical element of  claim 1 , wherein the functionalized layered structure includes one or more layers selected from the group consisting of:
 an optical function layer;   an optical structured layer;   a Fresnel lens structure;   a polarizing layer;   a photochromic layer;   a hard coat layer;   a top coat layer;   an anti-fog layer;   an anti-smudge layer;   an anti-reflective layer; and   an antistatic layer.   
     
     
         11 . The functionalized optical element of  claim 1 , wherein the functionalized layered structure includes one of a polarizing film, a TAC/PVA/TAC polarizing film and a PET polarizing film. 
     
     
         12 . The functionalized optical element of  claim 1 , wherein the optical base element is a thermoplastic optical base element selected from the group consisting of a finished lens, a semi-finished lens, a PAL lens, an afocal lens, a plano lens, a unifocal lens, and a multifocal lens. 
     
     
         13 . The functionalized optical element of  claim 1 , wherein the optical base element is a thermoset optical base element selected from the group consisting of a finished lens, a semi-finished lens, a PAL lens, an afocal lens, a plano lens, a unifocal lens and a multifocal lens. 
     
     
         14 . The functionalized optical element of  claim 1 , wherein the optical base element is a polycarbonate lens, and wherein the functionalized layered structure includes a polarizing film and wherein the latex adhesive is a polyurethane latex adhesive, and wherein the HMA is a heat-activatable polyurethane adhesive which collectively form a laminated polarized ophthalmic lens. 
     
     
         15 . The functionalized optical element of  claim 1 , wherein the optical base element is a high refractive index lens comprising a polyurethane polymer formed from polyisocyanate and polythiol, and wherein the functionalized layered structure includes a polarizing film and wherein the latex adhesive is a polyurethane adhesive, and wherein the HMA is a heat-activatable polyurethane adhesive, which collectively form a laminated polarized ophthalmic lens. 
     
     
         16 . A method for manufacturing a functionalized optical element comprising the following steps:
 providing ( 10 ) an optical base element;   providing ( 10 ) a functionalized layered structure that includes at least one functional layer;   first coating ( 16   a ) a layer of latex adhesive or a layer of gamma-aminopropyltriethoxysilane adhesive onto one surface of said functionalized layered structure;   second coating ( 18   a ) a layer of hot-melt adhesive onto the dried latex adhesive layer or the dried gamma-aminopropyltriethoxysilane adhesive layer to form a uniformly thin bi-layer adhesive lamina of optical quality; and   hot pressing ( 20 ) the functionalized layered structure against the optical base element with the second HMA coating layer in contact with a surface of the optical base element to form a functionalized optical element with high adhesive strength.   
     
     
         17 . The method of  claim 16 , wherein the optical base element has a base curve, and prior to said first coating step, the method further includes the step of:
 thermoforming the functionalized layered structure to a curve that is close to the base curve.   
     
     
         18 . The method of  claim 16 , wherein prior to said first coating step, the method further includes the step of:
 surface treating ( 13 ) the functionalized layered structure with a corona discharge and/or a caustic treatment.   
     
     
         19 . The method of  claim 16 , wherein said first coating step comprises spin coating a liquid polyurethane latex adhesive to a final dry thickness of between 0.5 microns and 10 microns. 
     
     
         20 . The method of  claim 16 , wherein said second coating step comprises spin coating a liquid polyurethane HMA to a final dry thickness of between 1 micron and 20 microns. 
     
     
         21 . The method of  claim 16 , further including the following step:
 exposing the functionalized optical element to UV radiation.   
     
     
         22 . The method of  claim 16 , wherein said first coating step comprises spin coating a liquid polyurethane latex adhesive to a final dry thickness of between 1.0 microns and 5.0 microns; and wherein said second coating step comprises spin coating a liquid polyurethane HMA to a final dry thickness of between 1.5 microns and 10 microns to provide a bi-layer adhesive lamina at optical quality with a uniform thickness varying by less than 0.5 microns across the surface. 
     
     
         23 . The method of  claim 22 , wherein the functionalized layered structure includes one or more layers selected from the group consisting of:
 an optical function layer;   an optical structured layer;   a Fresnel lens structure;   a polarizing layer;   a photochromic layer;   a hard coat layer;   a top coat layer;   an anti-fog layer;   an anti-smudge layer;   an anti-reflective layer; and   an anti-static layer.   
     
     
         24 . The method of  claim 22 , wherein the functionalized layered structure includes a polarizing film. 
     
     
         25 . The method of  claim 22 , wherein the optical base element is a thermoplastic optical base element selected from the group consisting of a finished lens, a semi-finished lens, a PAL lens, an afocal lens, a plano lens, a unifocal lens, and a multifocal lens. 
     
     
         26 . The method of  claim 22 , wherein the optical base element is a thermoset optical base element selected from the group consisting of a finished lens, a semi-finished lens, a PAL lens, an afocal lens, a plano lens, a unifocal lens, and a multifocal lens. 
     
     
         27 . The method of  claim 22 , wherein the optical base element is a polycarbonate lens, and wherein the functionalized layered structure includes a polarizing film which collectively form a laminated polarized ophthalmic lens. 
     
     
         28 . The method of  claim 22 , wherein the optical base element is a high refractive index lens comprising a polyurethane based polymer formed from polyisocyanate and polythiol, and wherein the functionalized layered structure includes a polarizing film which collectively form a laminated polarized ophthalmic lens.