METHOD TO MODIFY AND APPLY EDGE SEAL MATERIALS IN LAMINATED MEDIA
An article with a pair of substrates made from a thermoplastic and each having an outer edge; a holographic storage medium positioned between the substrates such that the holographic storage medium has an exposed outer edge area proximate the outer edges of the substrates; and an environmental barrier seal protecting the exposed outer edge area; wherein (1) the environmental barrier seal includes a temperature-responsive stress-relieving structure; or (2) the substrates, holographic storage medium, and environmental barrier seal have materials with compatible coefficients of thermal expansion. Also a process which forms a temperature-responsive stress-relieving structure in a portion of the environmental barrier seal for relieving such temperature induced stress.
1 . An article comprising:
a pair of substrates each comprising a thermoplastic and each having an outer edge;
a holographic storage medium positioned between the substrates such that the holographic storage medium has an exposed outer edge area proximate the outer edges of the substrates; and
an environmental barrier seal protecting the exposed outer edge area from environmental degradants;
wherein the environmental barrier seal comprises:
an inner layer adhered to at least one of the substrates and comprising a thermally meltable adhesive;
an outer layer comprising a moisture impervious material;
an intermediate layer positioned between the inner and outer layers and comprising a moisture and oxygen impervious material; and
an edge covering portion which covers the exposed outer edge area of the holographic storage medium and the outer edges of the substrates, wherein the edge covering portion includes a temperature-responsive stress-relieving structure and wherein the edge covering portion is adhered to the outer edge of each of the substrates.
2 . The article of claim 1 , wherein the environmental barrier seal further comprises a tie layer positioned between the outer layer and the intermediate layer that adheres the outer layer to the intermediate layer.
3 . The article of claim 1 , wherein the intermediate layer comprises metallic foil.
4 . The article of claim 3 , wherein the metallic foil comprises aluminum foil.
5 . The article of claim 1 , wherein the moisture impervious material comprises one or more of: polyesters, copolyesters, polypropylene, polytetrafluoroethylene, nylon, polystyrene, a polycarbonate, an acrylonitrile, polyvinyl chloride, polyvinyl dichloride, ethylene vinyl alcohol, polyvinylidene chloride, ionomer-based polymers, and polyethylene.
6 . The article of claim 1 , wherein the thermally meltable adhesive comprises a thermoplastic film.
7 . The article of claim 1 , wherein each substrate and the holographic recording medium are generally circular-shaped.
8 . The article of claim 1 , wherein the article has a thickness of from about 0.2 to about 2 mm.
9 . The article of claim 1 , wherein a coefficient of thermal expansion (CTE) compensating interface is positioned between the holographic recording medium and at least one of the substrates.
10 . The article of claim 1 , wherein the environmental barrier seal has a thickness of from about 3 to about 10 mils.
11 . An article comprising:
a pair of substrates each comprising a thermoplastic and each having an outer edge;
a holographic storage medium positioned between the substrates such that the holographic storage medium has an exposed outer edge area proximate the outer edges of the substrates; and
an environmental barrier seal protecting the exposed outer edge area from environmental degradants;
wherein the environmental barrier seal comprises:
an inner layer adhered to at least one of the substrates and comprising a thermally meltable adhesive;
an outer layer comprising a moisture impervious plastic; and
an intermediate layer positioned between the inner and outer layers and comprising a moisture and oxygen impervious metallic foil;
wherein a portion of the environmental barrier seal comprises a temperature-responsive stress-relieving structure to thereby relieve stresses in the environmental barrier seal which may be caused by temperature changes.
12 . The article of claim 11 , wherein the environmental barrier seal further comprises a tie layer positioned between the outer layer and the intermediate layer that adheres the outer layer to the intermediate layer.
13 . The article of claim 11 , wherein the metallic foil comprises aluminum foil.
14 . The article of claim 11 , wherein the moisture impervious plastic comprises one or more of: polyesters, copolyesters, polypropylene, polytetrafluoroethylene, nylon, polystyrene, a polycarbonate, an acrylonitrile, polyvinyl chloride, polyvinyl dichloride, ethylene vinyl alcohol, polyvinylidene chloride, ionomer-based polymers, and polyethylene.
15 . The article of claim 11 , wherein the thermally meltable adhesive comprises a thermoplastic film.
16 . The article of claim 11 , wherein each substrate and the holographic recording medium are generally circular-shaped.
17 . The article of claim 11 , wherein the article has a thickness of from about 0.2 to about 2 mm.
18 . The article of claim 11 , wherein a coefficient of thermal expansion (CTE) compensating interface is positioned between the holographic recording medium and at least one of the substrates.
19 . The article of claim 11 , wherein the environmental barrier seal has a thickness of from about 3 to about 10 mils.
20 . A process comprising the following steps of:
(a) providing an article comprising:
a pair of substrates each comprising a thermoplastic and each having an outer edge;
a holographic storage medium positioned between the substrates such that the holographic storage medium has an exposed edge area; and
an environmental barrier seal to protect the edge exposed area from environmental degradants, wherein the environmental barrier seal comprises:
an inner layer adhered to at least one of the substrates and comprising a thermally meltable adhesive;
an outer layer comprising a moisture impervious plastic; and
an intermediate layer positioned between the inner and outer layers and comprising a moisture and oxygen impervious metallic foil; and
(b) forming in a portion of the environmental barrier seal a temperature-responsive stress-relieving structure to thereby relieve stresses in the environmental barrier seal which may be caused by temperature changes.
21 . The process of claim 20 , further comprising the following step:
(c) adhering the environmental barrier seal to the outer edge of each substrate.
22 . An article comprising:
a pair of substrates each comprising a thermoplastic and each having an outer edge;
a holographic storage medium positioned between the substrates such that the holographic storage medium has an exposed outer edge area proximate the outer edges of the substrates; and
an environmental barrier seal protecting the exposed outer edge area from environmental degradants;
wherein the environmental barrier seal comprises:
an inner layer adhered to at least one of the substrates and comprising a thermally meltable adhesive;
an outer layer comprising a moisture impervious plastic; and
an intermediate layer positioned between the inner and outer layers and comprising a moisture and oxygen impervious metallic foil;
wherein the substrates, holographic storage medium, and environmental barrier seal comprise materials which have compatible coefficients of thermal expansion.
23 . The article of claim 22 , wherein the environmental barrier seal further comprises a tie layer positioned between the outer layer and the intermediate layer that adheres the outer layer to the intermediate layer.
24 . The article of claim 22 , wherein the metallic foil comprises aluminum foil.
25 . The article of claim 22 , wherein the moisture impervious plastic comprises one or more of: polyesters, copolyesters, polypropylene, polytetrafluoroethylene, nylon, polystyrene, a polycarbonate, an acrylonitrile, polyvinyl chloride, polyvinyl dichloride, ethylene vinyl alcohol, polyvinylidene chloride, ionomer-based polymers, and polyethylene.
26 . The article of claim 22 , wherein the thermally meltable adhesive comprises a thermoplastic film.
27 . The article of claim 22 , wherein each substrate and the holographic recording medium are generally circular-shaped.
28 . The article of claim 22 , wherein the article has a thickness of from about 0.2 to about 2 mm.
29 . The article of claim 22 , wherein a coefficient of thermal expansion (CTE) compensating interface is positioned between the holographic recording medium and at least one of the substrates.
30 . The article of claim 22 , wherein the environmental barrier seal has a thickness of from about 3 to about 10 mils.