Surface Modification of Pressure-Sensitive Adhesives with Nanoparticles
Adhesive articles having surface-modified nanoparticles located on or near at least one surface of a layer of pressure sensitive adhesive are described. Methods of making such adhesive articles are also described.
1 . An adhesive article comprising a layer of a pressure sensitive adhesive comprising a first surface and a second surface, and a plurality of surface modified nanoparticles having an average diameter of Davg as measured by the TEM method, wherein at least 80% by weight of the surface modified nanoparticles are located within at least one of a first region extending from on the first surface to a depth of five times Davg from the first surface and a second region extending from on the second surface to a depth of five times Davg from the second surface.
2 . The adhesive article of claim 1 , wherein at least 80% by weight of the surface modified nanoparticles are located within a first region extending from on the first surface to a depth of five times Davg from the first surface.
3 . An adhesive article comprising a layer of a pressure sensitive adhesive comprising a first surface and a second surface, and a plurality of surface modified nanoparticles having an average diameter of Davg, wherein at least 80% by weight of the surface modified nanoparticles are located within at least one of a first region extending from on the first surface to a depth 500 nm from the first surface and a second region extending from on the second surface to a depth of 500 nm from the second surface.
4 . The adhesive article of claim 3 , wherein at least 80% by weight of the surface modified nanoparticles are located within a first region extending from on the first surface to a depth of 500 nm from the first surface.
5 . The adhesive article according to claim 1 , wherein the surface modified nanoparticles comprise a silica core.
6 . The adhesive article of claim 5 , wherein the surface modified nanoparticles further comprises a surface modifying agent comprising a binding group attached to the surface of the core and a compatiblizing group.
7 . The adhesive article of claim 6 , wherein the difference between the solubility parameters of the pressure sensitive adhesive and the solubility parameter of the compatiblizing group is no more than 4 J 1/2 cm −3/2 as determined by the Additive Group Contribution Method.
8 . The adhesive article according to claim 1 , wherein the adhesive is crosslinked.
9 . The adhesive article according to claim 1 , wherein Davg is no greater than 250 nm.
10 . The adhesive article of claim 9 , wherein Davg is at least 10 nm.
11 . The adhesive article of claim 10 , wherein Davg is between 20 and 100 nm, inclusive.
12 . A method of preparing an adhesive article comprising a layer of a pressure sensitive adhesive comprising a first surface and a second surface, the method comprising applying a solution comprising surface-modified nanoparticles having an average diameter of Davg as measured by the TEM method dispersed in a solvent system to at least one of the first and second surfaces of the layer and drying the applied solution.
13 . The method of claim 12 , wherein at least 80% by weight of the surface modified nanoparticles are located within at least one of a first region extending from on the first surface to a depth of five times Davg from the first surface and a second region extending from on the second surface to a depth of five times Davg from the second surface.
14 . The method of claim 13 , wherein at least 80% by weight of the surface modified nanoparticles are located within a first region extending from on the first surface to a depth of five times Davg from the first surface.
15 . The method of claim 12 , wherein at least 80% by weight of the surface modified nanoparticles are located within at least one of a first region extending from on the first surface to a depth 500 nm from the first surface and a second region extending from on the second surface to a depth of 500 nm from the second surface.
16 . The method of claim 15 , wherein at least 80% by weight of the surface modified nanoparticles are located within a first region extending from on the first surface to a depth of 500 nm from the first surface.
17 . The method according to claim 12 , wherein the surface modified nanoparticles comprise a silica core.
18 . The method of claim 17 , wherein the surface modified nanoparticles further comprises a surface modifying agent comprising a binding group attached to the surface of the core and a compatiblizing group.
19 . The method of claim 18 , wherein the difference between the solubility parameters of the pressure sensitive adhesive and the solubility parameter of the compatiblizing group is no more than 4 J 1/2 cm −3/2 as determined by the Additive Group Contribution Method.
20 . The method according to claim 12 , wherein the adhesive is crosslinked.
21 . The method according to claim 12 , wherein Davg is no greater than 250 nm.
22 . The method of claim 21 , wherein Davg is at least 10 nm.
23 . The method of claim 22 , wherein Davg is between 20 and 100 nm, inclusive.
24 . The method according to claim 12 , wherein the solution comprises between 0.5 and 2 wt. % surface-modified nanoparticles.
25 . The method according to claim 12 , wherein the solubility parameter of the solvent is selected such that the solvent swells but does not dissolve the pressure sensitive adhesive.