Protective layers for optical coatings
An optical coating on a transparent substrate is provided with a temporary layer of carbon as protection during manufacturing against scratches and corrosive environments. When the optical coating and/or substrate are tempered in an atmosphere reactive to carbon, such as air, the layer of carbon is removed as a carbon-containing gas. For an optical coating with a brittle, glassy, outermost layer furthest from the substrate, additional protection is provided by a scratch propagation blocker layer between the outermost layer and the carbon protective layer.
1 - 40 . (canceled)
41 . A transparent article comprising
a substrate;
an optical coating comprising one or more layers on the substrate, where the one or more layers include furthest from the substrate a homogeneous outermost layer comprising amorphous silicon nitride; and
a protective coating on the outermost layer, wherein
the protective coating consists of
a scratch propagation blocker layer on the outermost layer, and
a layer consisting essentially of carbon on the scratch propagation blocker layer; and
the scratch propagation blocker layer is a homogeneous layer comprising a material selected from the group consisting of
Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
oxides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
nitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
oxynitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W; and
mixtures thereof.
42 . The transparent article according to claim 41 , wherein the substrate comprises a glass.
43 . The transparent article according to claim 42 , wherein the substrate comprises a tempered glass.
44 . The transparent article according to claim 41 , wherein the optical coating is a low-emissivity coating.
45 . The transparent article according to claim 41 , wherein the optical coating is a tempered coating.
46 . The transparent article according to claim 41 , wherein the optical coating contains at least one layer comprising Ag.
47 . The transparent article according to claim 41 , wherein the fracture toughness of the scratch propagation blocker layer is higher than the fracture toughness of the outermost layer.
48 . The transparent article according to claim 41 , wherein the scratch propagation blocker layer is from 2 to 8 nm thick.
49 . The transparent article according to claim 48 , wherein the scratch propagation blocker layer comprises a material selected from the group consisting of oxides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W.
50 . The transparent article according to claim 48 , wherein the scratch propagation blocker layer comprises a material selected from the group consisting of oxynitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W.
51 . The transparent article according to claim 41 , wherein the layer consisting essentially of carbon is doped with nitrogen.
52 . The transparent article according to claim 41 , wherein the layer consisting essentially of carbon consists of carbon and unavoidable impurities.
53 . The transparent article according to claim 41 , wherein the carbon in the layer consisting essentially of carbon comprises at least one form of carbon selected from the group consisting of diamond-like carbon and graphite.
54 . The transparent article according to claim 41 , wherein the layer consisting essentially of carbon is from 1 to 10 nm thick.
55 . A transparent article comprising
a substrate;
an optical coating comprising one or more layers on the substrate, where the one or more layers include furthest from the substrate a homogeneous outermost layer comprising silicon nitride; and
a protective coating on the outermost layer, wherein
the protective coating consists of
a scratch propagation blocker layer on the outermost layer, and
a layer consisting essentially of carbon on the scratch propagation blocker layer; and
the scratch propagation blocker layer is a homogeneous layer 2 to 8 nm thick comprising a material selected from the group consisting of
Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
oxides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
nitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
oxynitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W; and
mixtures thereof.
56 . The transparent article according to claim 55 , wherein the substrate comprises a glass.
57 . The transparent article according to claim 56 , wherein the substrate comprises a tempered glass.
58 . The transparent article according to claim 55 , wherein the optical coating is a low-emissivity coating.
59 . The transparent article according to claim 55 , wherein the optical coating is a tempered coating.
60 . The transparent article according to claim 55 , wherein the optical coating contains at least one layer comprising Ag.
61 . The transparent article according to claim 55 , wherein the fracture toughness of the scratch propagation blocker layer is higher than the fracture toughness of the outermost layer.
62 . The transparent article according to claim 55 , wherein the scratch propagation blocker layer comprises a material selected from the group consisting of oxides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W.
63 . The transparent article according to claim 55 , wherein the scratch propagation blocker layer comprises a material selected from the group consisting of oxynitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W.
64 . The transparent article according to claim 55 , wherein the layer consisting essentially of carbon is doped with nitrogen.
65 . The transparent article according to claim 55 , wherein the layer consisting essentially of carbon consists of carbon and unavoidable impurities.
66 . The transparent article according to claim 55 , wherein the carbon in the layer consisting essentially of carbon comprises at least one form of carbon selected from the group consisting of diamond-like carbon and graphite.
67 . The transparent article according to claim 55 , wherein the layer consisting essentially of carbon is from 1 to 10 nm thick.
68 . A transparent article comprising
a substrate;
an optical coating comprising one or more layers on the substrate, where the one or more layers include furthest from the substrate a homogeneous outermost layer comprising silicon nitride; and
a protective coating on the outermost layer, wherein
the protective coating consists of a scratch propagation blocker layer on the outermost layer; and
the scratch propagation blocker layer is a homogeneous layer comprising a material selected from the group consisting of
Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
oxides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
nitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W;
oxynitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W; and
mixtures thereof.
69 . The transparent article according to claim 68 , wherein the substrate comprises a glass.
70 . The transparent article according to claim 69 , wherein the substrate comprises a tempered glass.
71 . The transparent article according to claim 68 , wherein the optical coating is a low-emissivity coating.
72 . The transparent article according to claim 68 , wherein the optical coating is a tempered coating.
73 . The transparent article according to claim 68 , wherein the optical coating contains at least one layer comprising Ag.
74 . The transparent article according to claim 68 , wherein the outermost layer comprises amorphous silicon nitride.
75 . The transparent article according to claim 68 , wherein the fracture toughness of the scratch propagation blocker layer is higher than the fracture toughness of the outermost layer.
76 . The transparent article according to claim 68 , wherein the scratch propagation blocker layer is from 2 to 8 nm thick.
77 . The transparent article according to claim 76 , wherein the scratch propagation blocker layer comprises a material selected from the group consisting of oxides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W.
78 . The transparent article according to claim 76 , wherein the scratch propagation blocker layer comprises a material selected from the group consisting of oxynitrides of Ti, Si, Zn, Sn, In, Zr, Al, Cr, Nb, Mo, Hf, Ta and W.
79 . The transparent article according to claim 68 , wherein the scratch propagation blocker layer is in contact with air.