Anti-reflective lenses and methods for manufacturing the same

Abstract

The invention relates to a method of applying an anti-reflective coating to an optical surface of a mold, including providing a lens mold having an optical surface, forming a deposition layer of a fluoride or oxide material to the optical surface of the lens mold, forming a layer of a hydrophobic material over the deposition layer, wherein the hydrophobic material contains an amount of dipodal silane that is a relative percentage of the hydrophobic material, forming a first layer of SiO.sub.2 with a thickness of 5-40 nm over the layer of the hydrophobic material, forming an anti-reflective coating layered structure over the first layer of SiO.sub.2, and forming a layer of a silane coupling agent that is deposited with a monolayer thickness to the anti-reflective coating layered structure using vapor deposition under aprotic conditions or by dip coating using a solution of silane coupling agent in an aprotic solvent.

Claims

1. A method for applying an anti-reflective coating to an optical surface of a mold, comprising the steps of: (a) providing a lens mold having an optical surface; (b) forming a deposition layer of a fluoride or oxide material to the optical surface of the lens mold; (c) forming a layer of a hydrophobic material over the deposition layer, wherein the hydrophobic material contains an amount of dipodal silane that is a relative percentage of the hydrophobic material; (d) forming a first layer of SiO.sub.2 with a thickness of about 5 to 40 nm over the layer of the hydrophobic material; (e) forming an anti-reflective coating layered structure over the first layer of SiO.sub.2; (f) forming a layer of a silane coupling agent that is deposited with a monolayer thickness to the anti-reflective coating layered structure using vapor deposition under aprotic conditions or by dip coating using a solution of silane coupling agent in an aprotic solvent; and (g) forming a scratch resistant hard coating on the layer of the silane coupling agent, wherein the amount of the dipodal silane is effective to prevent the anti-reflective coating layered structure from crazing.

2. The method of claim 1, wherein the deposition layer is adapted to provide temporary adhesion between the mold surface and the hydrophobic layer such that all subsequent layers remain adherent to one another.

3. The method of claim 1, wherein the deposition layer is formed of LiF, MgF.sub.2, CaF.sub.2, SrF.sub.2, BaF.sub.2, LaF.sub.3, CeF.sub.3, HfF.sub.4, NdF.sub.4, SiO.sub.2, ZrO.sub.2, Al.sub.2O.sub.3, Cr.sub.2O.sub.3, HfO.sub.2, In.sub.2O3, Ta.sub.2O.sub.5, TiO.sub.2, Y.sub.2O.sub.3, or a combination of them.

4. The method of claim 3, wherein the deposition layer is formed of MgF.sub.2 using ion assist and has a thickness of about 45 nm.

5. The method of claim 1, wherein the hydrophobic layer is a super hydrophobic layer with a thickness of about 30 to 40 nm and the amount of the dipodal silane is about 1.7-8.3% of said super hydrophobic material by weight.

6. The method of claim 1, wherein the step of forming an anti-reflective coating layered structure to the first layer of SiO.sub.2 further comprises the steps of: (a) forming a second layer of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 100 nm to the first layer of SiO.sub.2; (b) forming a first layer of ZrO.sub.2 with a thickness of about 40 to 50 nm to the second layer of SiO.sub.2; (c) forming a third layer of SiO.sub.2 that is deposited using ion assist and with a thickness of about 10 to 20 nm to the first layer of ZrO.sub.2; (d) forming a second layer of ZrO.sub.2 with a thickness of about 50 to 70 nm to the third layer of SiO.sub.2; (e) forming a fourth layer of SiO.sub.2 that is deposited using ion assist and with a thickness of about 25 to 40 nm to the second layer of ZrO.sub.2; (f) forming a third layer of ZrO.sub.2 with a thickness of about 10 to 25 nm to the fourth layer of SiO.sub.2; and (g) forming a fifth layer of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 15 nm to the third layer of ZrO.sub.2.

7. The method of claim 1, wherein the dipodal silane comprises bis(trimethoxysilylpropyl)amine.

8. The method of claim 1, wherein the layer of the silane coupling agent is formed of a composition that comprises cyclic azasilanes.

9. The method of claim 8, wherein the layer of the silane coupling agent is formed of N-n-butyl-aza-2,2-dimethoxy-silacyclopentane.

10. The method of claim 1, wherein the step of forming an anti-reflective coating layered structure to the first layer of SiO.sub.2 further comprises the steps of: (a) forming a first layer of a first material with a first index of refraction, which is deposited using ion assist and with a thickness of about 5 to 100 nm, to the first layer of SiO.sub.2; (b) forming a second layer of a second material with a second index of refraction, with a thickness of about 40 to 50 nm, to the first layer of the first material; (c) forming a third layer of the first material with the first index of refraction, which is deposited using ion assist and with a thickness of about 10 to 20 nm, to the second layer of the second material; (d) forming a fourth layer of the second material with the second index of refraction, with a thickness of about 50 to 70 nm, to the third layer; (d) forming a fifth layer of the first material with the first index of refraction, which is deposited using ion assist and with a thickness of about 25 to 40 nm, to the fourth layer; (f) forming a sixth layer of the second material with the second index of refraction, with a thickness of about 10 to 25 nm, to the fifth layer; and (g) forming a seventh layer of the first material with the first index of refraction, which is deposited using ion assist and with a thickness of about 5 to 15 nm, to the sixth layer.

11. The method of claim 10, wherein the first index of refraction L and the second index of refraction H satisfy a ratio of H/L>1.

12. The method of claim 11, wherein the first material with the first index of refraction comprises SiO.sub.2, and the second material with the second index of refraction comprises ZrO.sub.2.

13. A method for applying an anti-reflective coating to an optical surface of a mold, comprising the steps of: (a) providing a lens mold having an optical surface; (b) forming a layer of a hydrophobic material over the optical surface, wherein the hydrophobic material contains an amount of dipodal silane that is a relative percentage of the hydrophobic material; (c) forming an anti-reflective coating layered structure over the layer of the hydrophobic material; (a) forming a layer of a coupling agent deposited with a monolayer thickness to the anti-reflective coating layered structure using vapor deposition under aprotic conditions or by dip coating using a solution of a coupling agent in an aprotic solvent; and (g) forming a scratch resistant hard coating on the layer of the coupling agent, wherein the amount of the dipodal silane is effective to prevent the anti-reflective coating layered structure from crazing.

14. The method of claim 13, wherein the hydrophobic layer is a super hydrophobic layer, and the amount of the dipodal silane is about 1.7-8.3% of said super hydrophobic material by weight.

15. The method of claim 13, wherein the step of forming an anti-reflective coating layered structure over the layer further comprises the steps of: (a) forming a first layer of a first material with a first index of refraction and a thickness of about 5 to 100 nm over the layer of the super hydrophobic material; (b) forming a second layer of a second material with a second index of refraction and a thickness of about 40 to 50 nm, to the first layer; (c) forming a third layer of the first material with the first index of refraction and a thickness of about 10 to 20 nm, to the second layer; (d) forming a fourth layer of the second material with the second index of refraction and a thickness of about 50 to 70 nm, to the third layer; (e) forming a fifth layer of the first material with the first index of refraction and a thickness of about 25 to 40 nm, to the fourth layer; (f) forming a sixth layer of the second material with the second index of refraction and a thickness of about 10 to 25 nm, to the fifth layer; and (g) forming a seventh layer of the first material with the first index of refraction and a thickness of about 5 to 15 nm, to the sixth layer.

16. The method of claim 15, wherein the first index of refraction L and the second index of refraction H satisfy a ratio of H/L>1.

17. The method of claim 16, wherein the first material with the first index of refraction is SiO.sub.2, and the second material with the second index of refraction is ZrO.sub.2.

18. The method of claim 17, prior to the step of forming the anti-reflective coating layered structure over the layer of the hydrophobic material, further comprising a step of forming an eighth layer of SiO.sub.2 that is deposited without ion assist and with a thickness of 5 to 40 nm over the layer of the hydrophobic material such that the eighth layer of SiO.sub.2 is formed between the layer of the hydrophobic material and the first layer of the first material.

19. The method of claim 17, wherein each layer of SiO.sub.2 is deposited using ion assist or without using ion assist.

20. The method of claim 13, prior to the step of forming the layer of the hydrophobic material over the optical surface, further comprising a step of forming a deposition layer of a fluoride or oxide material to the optical surface of the lens mold.

21. The method of claim 20, wherein the deposition layer is formed of LiF, MgF.sub.2, CaF.sub.2, SrF.sub.2, BaF.sub.2, LaF.sub.3, CeF.sub.3, HfF.sub.4, NdF.sub.4, SiO.sub.2, ZrO.sub.2, Al.sub.2O.sub.3, Cr.sub.2O.sub.3, HfO.sub.2, In.sub.2O3, Ta.sub.2O.sub.5, TiO.sub.2, Y.sub.2O.sub.3, or a combination of them.

22. The method of claim 13, wherein the dipodal silane comprises bis(trimethoxysilylpropyl)amine.

23. The method of claim 13, wherein the layer of coupling agent is formed of a composition that comprises cyclic azasilanes.

24. The method of claim 23, wherein the layer of coupling agent is formed of N-n-butyl-aza-2,2-dimethoxy-silacyclopentane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows chemical reactions related to coupling agents utilized in related art for manufacturing an anti-reflective coated lens.

(2) FIG. 2 shows chemical reactions related to coupling agents utilized for manufacturing an anti-reflective coated lens according to one embodiment of the present invention.

(3) FIG. 3 shows preparation of an anti-reflective coated lens mold according to one embodiment of the present invention.

(4) FIG. 4 shows preparation of an anti-reflective coated lens mold according to one embodiment of the present invention.

(5) FIG. 5 shows preparation of an anti-reflective coated lens mold according to one embodiment of the present invention.

(6) FIG. 6 shows preparation of an anti-reflective coated lens mold according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) The present invention is more particularly described in the following examples, which are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Various embodiments of the invention are now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. As used in the description herein and throughout the claims that follow, the meaning of a, an, and the includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of in includes in and on unless the context clearly dictates otherwise.

(8) The terms used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where each term is used. Certain terms that are used to describe the invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the invention. The use of examples anywhere in this specification, including examples of any terms discussed herein, is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification.

(9) As used herein, around, about or approximately shall generally mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning that the term around, about or approximately can be inferred if not expressly stated.

OVERVIEW OF THE INVENTION

(10) The description will be made as to the embodiments of the present invention in conjunction with the accompanying drawings in FIGS. 1-6. In accordance with the purposes of this invention, as embodied and broadly described herein, this invention relates to AR-coated spectacle lenses, compositions and methods of making AR lenses.

(11) According to various embodiments of the present invention, a layer of MgF.sub.2 is applied using ion assist to a clean optical surface of a plastic mold, preferably with a thickness of about 45 nm. A coating layer of a super hydrophobic material is then applied. The super hydrophobic material contains about 1.7-8.3% of dipodal silane by weight relative to the super hydrophobic material. Subsequent to the super hydrophobic coating, an anti-reflective (AR) coating is applied. The AR coating is a layered structure with multiple layers of dielectric materials (4 to 7 layers or even more) that are applied by vacuum deposition such that the first and last layer are ion-assisted SiO.sub.2. Preferably, the anti-reflective coating is a layered structure with multiple layers of three or more dielectric materials having alternating high and low refractive indexes.

(12) Dipodal silanes are available from Gelest, Inc. A preferred dipodal silane can be bis(trimethoxysilylpropyl)amine having the formula:

(13) ##STR00001##

(14) A layer of cyclic azasilane as a silane coupling agent is applied to the AR-coated mold to promote adhesion of the hard coating. The coupling agent layer must be applied under aprotic conditions. This can be done using methods commonly practiced in the lens industry today (such as spin, spray, dip, vacuum coating). The silane from the coupling agent will bond to the anti-reflective coating and the functional group will bond with the organic hard coat, respectively. The coupling agent layer is applied at room temperature.

(15) The next coating layer applied to the mold is the scratch-resistant (hard) coating. The hard coat can be applied by conventional methods used in the lens industry, including spin, spray, or dip coating followed by curing.

(16) The exemplary process illustrated above can be repeatedly applied to different optical surfaces of an optical mold assembly containing a front mold and a back mold. Following the applications of the coating to both of the front and back molds, the molds are assembled with a spacer ring to form the optical mold assembly. The cavity of the assembly is then filled with lens material formulation and cured. After the cure is complete, the lens is removed from the assembly. All coatings except MgF.sub.2 are transferred to the lens so that the lens has super hydrophobic, anti-reflective, and scratch resistance coatings applied. This process may also be used to make polarized and photochromic lenses.

(17) Thus, in one aspect, more specifically, the invention relates to a method for making an AR-coated plastic substrate having good adhesion of the AR coating. The plastic substrate in one embodiment is a plastic ophthalmic spectacle lens.

(18) In another aspect, the invention relates to a method of making AR coated plastic ophthalmic spectacle lenses on-site.

(19) An AR coating is commonly applied to the surface of lenses to reduce reflection. Often, the AR coating is made of multiple layers of high index and low index materials such as ZrO.sub.2 and SiO.sub.2. One problem with inorganic silica AR coatings is that they do not readily adhere to plastic organic lenses. The present invention successfully solves the problem by, among other things, using a coupling layer between the inorganic silica AR coating and the lens. In one embodiment of the present invention, the coupling layer is formed by utilizing cyclic azasilane.

(20) In general, the method for forming an ophthalmic lens having an AR coating thereon is comprised of the steps of preparing first and second molds having optical surfaces facing each other. In a preferred embodiment, molds and a gasket such as described in U.S. Pat. No. 7,114,696 are used. Various desired coatings are applied to the interior of one or both molds. The molds with the coatings thereon are placed in a gasket assembly which provides a space between the molds. A liquid monomer is placed in the space and is cured to provide a lens.

(21) The molds can be formed of any suitable material which is capable of withstanding the processing temperatures hereinafter utilized and which can provide surfaces of the type required for the optical elements being prepared.

(22) In one embodiment of the present invention, as a first step, a coating is applied by electron beam deposition directly onto the plastic mold optical surface. Subsequent to the first coating, a second coating may be applied before a multilayer AR coating is applied in reverse order. In one embodiment of the present invention, an AR coating is a multilayer structure with alternating layers formed with two different materials, a high index material and a low index material. In one preferred embodiment of the present invention, an AR coating is a multilayer structure with 7 alternating layers formed with two different materials, a high index material H and a low index material L with a ratio H/L>1. Materials found to be suitable for practicing the present invention are zirconium dioxide (referred as ZrO.sub.2) as a high index material and silicon dioxide as a low index material, having an index of refraction of approximately 1.46.

(23) In one embodiment of the present invention, the layers are applied by vacuum deposition such that the first and last layers are silicon dioxide (SiO.sub.2). It is preferred that the AR chamber be humidified during application of the last layer of silicon oxide.

(24) Following the AR coating application, a layer or film of the coupling agent cyclic azasilane is applied by vapor phase deposition. The cyclic azasilane will bond to surface hydroxyls on the silicon dioxide layer, opening the ring and resulting in an organic molecule on the surface. This can be done under vacuum, at room temperature, and does not require water as a catalyst.

(25) Next, a scratch resistant (hard) coating is applied. The hard coat can be applied as either an extension of the AR coating process by vacuum deposition or by the more conventional methods of spin, spray, or dip coating, with the coating application followed by curing.

(26) Following the application of the various coatings to the mold, a front and back mold are assembled. The cavity of the assembly is then filled with lens material formulation which is then cured and bonds to the hard coat. After the cure is complete, the lens is removed from the assembly. All coatings are transferred to the lens so that the lens has hydrophobic, anti-reflective, and scratch resistance coatings applied.

(27) Cyclic azasilanes are available from Gelest, Inc. Generic formulas include azasilacyclopentanes having the formula:

(28) ##STR00002##
where R.sup.1 and R.sup.2 are independently selected from the group consisting of branched and linear, substituted and unsubstituted alkyl, alkenyl and alkoxy groups, and where R.sup.3 is selected from the group consisting of substituted and unsubstituted, saturated and unsaturated, branched and linear aliphatic hydrocarbon groups; substituted and unsubstituted, branched and linear aralkyl groups; substituted and unsubstituted aryl groups; and hydrogen. Cyclic azasilanes also include diazasilacyclic compounds having the formula:

(29) ##STR00003##
where R.sup.3 is selected from the group consisting of substituted and unsubstituted, saturated and unsaturated, branched and linear aliphatic hydrocarbon groups; substituted and unsubstituted, branched and linear aralkyl groups; substituted and unsubstituted aryl groups; and hydrogen; and wherein R.sub.4 and R.sub.5 are independently selected from the group consisting of substituted and unsubstituted, branched and linear alkyl and alkoxy groups.

(30) A preferred super hydrophobic compound is Optool DSX available from Daikin. This hydrophobic compound does not contain additives that are typically included in commercial super hydrophobic preparations to increase sticking of the super hydrophobic material to a plastic lens.

(31) These and other aspects of the present invention are more specifically described below.

IMPLEMENTATIONS AND EXAMPLES OF THE INVENTION

(32) Without intent to limit the scope of the invention, additional exemplary embodiments and their related results according to the embodiments of the present invention are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the invention. Moreover, certain theories are proposed and disclosed herein; however, in no way should they, whether they are right or wrong, limit the scope of the invention so long as the invention is practiced according to the invention without regard for any particular theory or scheme of action.

Example 1

Cyclic Azasilanes

(33) Various types of cyclic azasilanes can be used to practice the present invention, including:

(34) (a) SIB1932.4 or N-n-BUTYL-AZA-2,2-DIMETHOXYSILACYCLOPENTANE, C9H21NO2Si, with the following formula:

(35) ##STR00004##

(36) (b) SID3543.0 or 2,2-DIMETHOXY-1,6-DIAZA-2-SILACCTANE, C7H18N2O2Si, with the following formula:

(37) ##STR00005##
(c) SIA0592.0 or N-AMINOETHYL-AZA-2,2,4-TRIMETHYLSILACYCLOPENTANE, C8H21NSi, with the following formula:

(38) ##STR00006##

(39) (d) SIA0380.0 or N-ALLYL-AZA-2,2-DIMETHOXYSILACYCLOPENTANE C8H17NO2Si, with the following formula:

(40) ##STR00007##

Example 2

Coating Bonding Tests

(41) This example shows various tests utilized for the bonding of coatings produced according to various embodiments of the present invention.

(42) Cross-Hatch Test.

(43) In the cross-hatch test, a series of 10 lines spaced 1 mm apart is cut into the coating with a razor blade. A second series of 10 lines spaced 1 mm apart at right angles to and overlaying the first is cut into the coating. A piece of cellophane tape is then applied over the crosshatch pattern and pulled quickly away from the coating.

(44) Crazing Test.

(45) In the crazing test, a lens is de-molded then annealed at 80 C. for 20 minutes. The lens is quickly transferred to room temperature water and it is checked for crazing. If no crazing is apparent, then the AR/coupling agent system is acceptable.

(46) Boiling Salt Water Test.

(47) In the boiling salt water test, the lens is first immersed for two minutes in a boiling salt solution containing 4.5% NaCl and 0.8% NaH.sub.2PO.sub.4.2H.sub.2O. Next, the lens is quickly transferred to room temperature (18-24 C.) deionized water. If no crazing or delamination in the coating is noted, then the AR/coupling agent system is acceptable.

Example 3

Preparation of an AR Coating that is Applied to a Disposable Mold

(48) In this Example, among other things, a process of preparation of applying an AR coating to a disposable mold is provided according to one embodiment of the present invention. It is noted that in this Example, SiO.sub.2 layers are formed or deposited with or without ion assist.

(49) Referring now to FIG. 3, the processes described below are performed with a standard box coater and an electron beam for evaporation in connection with a mold 302 having an optical surface 304. The processes are done by using well known vacuum practices.

(50) Procedure:

(51) (1) Cleaning the optical surface 304 of the mold 302. In one embodiment of the present invention, a plasma cleaning is performed on the mold surface for about 2 min.

(52) (2) Forming a layer 305 of MgF.sub.2 with a thickness of about 45 nm to the optical surface 304.

(53) (3) Forming a layer 306 of a super hydrophobic material with a thickness of about 30 to 40 nm over the layer 305, where the super hydrophobic material contains about 1.7-8.3% of dipodal silane by weight relative to the super hydrophobic material.

(54) (4) Forming a layer 310 of SiO.sub.2 that is deposited without using ion assist and with a thickness of about 5 to 40 nm to the layer 306.

(55) (5) Forming a layer 312 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 100 nm to the layer 310.

(56) (6) Forming a layer 314 of ZrO.sub.2 with a thickness of about 40 to 50 nm to the layer 312.

(57) (7) Forming a layer 316 of SiO.sub.2 that is deposited using ion assist and with a thickness about 10 to 20 nm to the layer 314.

(58) (8) Forming a layer 318 of ZrO.sub.2 with a thickness of about 50 to 70 nm to the layer 316.

(59) (9) Forming a layer 320 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 25 to 40 nm to the layer 318.

(60) (10) Forming a layer 322 of ZrO.sub.2 with a thickness of about 10 to 25 nm to the layer 320.

(61) (11) Forming a layer 324 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 15 nm to the layer 322.

(62) (12) Forming a layer 326 of a coupling agent that is deposited using dip coating or vapor deposition and with a monolayer of thickness to the layer 324.

(63) It is noted that in this embodiment, the layer 306 of the super hydrophobic material contains about 1.7-8.3% of dipodal silane by weight relative to the super hydrophobic material so that the AR coating can be stable. An example of the concentration of dipodal silane in the super hydrophobic is that every 0.6 g of super hydrophobic material contains about 0.01 g to 0.05 g of dipodal silane. If no or too little dipodal silane is used in the super hydrophobic material, the AR coating crazes and separates from the mold. Moreover, layer 310 of SiO.sub.2 functions as a protective seal to the AR layered structure 311 and also as natural bonding surface or a link between the AR layered structure 311 and the layer 306 of a super hydrophobic material. Likewise, layer 324 of SiO.sub.2 provides a natural bonding surface or link between the AR layered structure 311 and the layer 326 of coupling agent. It is noted that although layer 310 and layer 312 both are formed of SiO.sub.2, they are formed with different processes such that they adhere to each other but function differently.

Example 4

Preparation of an AR Coating that is Applied to a Disposable Mold

(64) In this Example, among other things, a process of preparation of applying an AR coating to a disposable mold is provided according to another embodiment of the present invention. It is noted that in this Example, SiO.sub.2 layers are formed or deposited with ion assist.

(65) Referring now to FIG. 4, the processes described below are performed with a standard box coater and an electron beam for evaporation in connection with a mold 402 having an optical surface 404. The processes are done using well known vacuum practices.

(66) Procedure:

(67) (1) Cleaning the optical surface 404 of the mold 402. In one embodiment of the present invention, a plasma cleaning is performed on the mold surface for about 2 min.

(68) (2) Forming a layer 406 of a super hydrophobic material with a thickness of about 30 to 40 nm over the optical surface 404, where the super hydrophobic material contains about 1.7-8.3% of dipodal silane by weight relative to the super hydrophobic material.

(69) (3) Forming a layer 412 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 60 to 120 nm to the layer 406.

(70) (4) Forming a layer 414 of ZrO.sub.2 with a thickness of about 40 to 50 nm to the layer 412.

(71) (5) Forming a layer 416 of SiO.sub.2 that is deposited using ion assist and with a thickness about 10 to 20 nm to the layer 414.

(72) (6) Forming a layer 418 of ZrO.sub.2 with a thickness of about 50 to 70 nm to the layer 416.

(73) (7) Forming a layer 420 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 25 to 40 nm to the layer 418.

(74) (8) Forming a layer 422 of ZrO.sub.2 with a thickness of about 10 to 25 nm to the layer 420.

(75) (9) Forming a layer 424 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 15 nm to the layer 422.

(76) (10) Forming a layer 426 of a coupling agent that is deposited using dip coating or vapor deposition and with a monolayer thickness to the layer 424.

Example 5

Preparation of an AR Coating that is Applied to a Disposable Mold

(77) In this Example, among other things, a process of preparation of applying an AR coating to a disposable mold is provided according to yet another embodiment of the present invention. It is noted that in this Example, SiO.sub.2 layers are formed or deposited with or without ion assist.

(78) Referring now to FIG. 5, the processes described below are performed with a standard box coater and an electron beam for evaporation in connection with a mold 502 having an optical surface 504. The processes are done using well known vacuum practices.

(79) Procedure:

(80) (1) Cleaning the optical surface 504 of the mold 502. In one embodiment of the present invention, plasma cleaning is performed on the mold surface for about 2 min.

(81) (2) Forming a layer 506 of a super hydrophobic material with a thickness of about 30 to 40 nm over the optical surface 504, where the super hydrophobic material contains about 1.7-8.3% of dipodal silane by weight.

(82) (3) Forming a layer 510 of SiO.sub.2 that is deposited without using ion assist and with a thickness of about 5 to 40 nm to the layer 506.

(83) (4) Forming a layer 512 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 100 nm to the layer 510.

(84) (5) Forming a layer 514 of ZrO.sub.2 with a thickness of about 40 to 50 nm to the layer 512.

(85) (6) Forming a layer 516 of SiO.sub.2 that is deposited without using ion assist and with a thickness about 10 to 20 nm to the layer 514.

(86) (7) Forming a layer 518 of ZrO.sub.2 with a thickness of about 50 to 70 nm to the layer 516.

(87) (8) Forming a layer 520 of SiO.sub.2 that is deposited without using ion assist and with a thickness of about 25 to 40 nm to the layer 518.

(88) (9) Forming a layer 522 of ZrO.sub.2 with a thickness of about 10 to 25 nm to the layer 520.

(89) (10) Forming a layer 524 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 15 nm to the layer 522.

(90) (11) Forming a layer 526 of a coupling agent that is deposited using dip coating or vapor deposition and with a monolayer thickness to the layer 524.

Example 6

Preparation of an AR Coating that is Applied to a Disposable Mold

(91) In this Example, among other things, a process of preparation of applying an AR coating to a disposable mold is provided according to a further embodiment of the present invention. It is noted that in this Example, SiO.sub.2 layers are formed or deposited with or without ion assist.

(92) Referring now to FIG. 6, the processes described below are performed with a standard box coater and an electron beam for evaporation in connection with a mold 602 having an optical surface 604. The processes are done using well known vacuum practices.

(93) Procedure:

(94) (1) Cleaning the optical surface 604 of the mold 602. In one embodiment of the present invention, plasma cleaning is performed on the mold surface for about 2 min.

(95) (2) Forming a layer 606 of a super hydrophobic material with a thickness of about 30 to 40 nm over the optical surface 604, where the super hydrophobic material contains about 1.7-8.3% of dipodal silane by weight relative to the super hydrophobic material.

(96) (3) Forming a layer 610 of SiO.sub.2 that is deposited without using ion assist and with a thickness of about 5 to 40 nm to the layer 606.

(97) (4) Forming a layer 612 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 100 nm to the layer 610.

(98) (5) Forming a layer 614 of ZrO.sub.2 with a thickness of about 40 to 50 nm to the layer 612.

(99) (6) Forming a layer 616 of SiO.sub.2 that is deposited using ion assist and with a thickness about 10 to 20 nm to the layer 614.

(100) (7) Forming a layer 618 of ZrO.sub.2 with a thickness of about 50 to 70 nm to the layer 616.

(101) (8) Forming a layer 620 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 25 to 40 nm to the layer 618.

(102) (9) Forming a layer 622 of ZrO.sub.2 with a thickness of about 10 to 25 nm to the layer 620.

(103) (10) Forming a layer 624 of SiO.sub.2 that is deposited using ion assist and with a thickness of about 5 to 15 nm to the layer 622.

(104) (11) Forming a layer 626 of a coupling agent that is deposited using vapor deposition and with a monolayer thickness to the layer 624.

Example 7

Preparation and Application of Coupling Agent

(105) In Examples 3-6, among other things, the present invention is practiced with a layer of a coupling agent that is applied to the AR-coated mold to promote adhesion of the hard coating.

(106) Material-wise, the coupling agents are functional silanes in which the silane bonds to the anti-reflective coating and the functional group bonds with the organic hard coat. According to one embodiment of the present invention, cyclic azasilanes are particularly well suited for the application, as they will form silane bonds at room temperature via a ring-opening reaction. This results in a monolayer with functional groups that readily attach to the hard coat, forming a strong AR to hard-coat bond. It is believed that it is the first time in the industry and only by the inventive discovery of the present invention, that cyclic azasilanes are utilized in an optical lens forming process as coupling agents. For embodiments as shown in FIGS. 3-6, where SiO.sub.2 is used as the first material with first index of refraction, utilizing N-n-butyl-aza-2,2-dimethoxy-silacyclopentane as a silane coupling agent allows a surface bonding ring opening reaction without requiring water or heat, as shown in FIG. 2, resulting in much better bonding and making on-site AR lens formation a reality.

(107) Procedure-wise, the coupling agent must be applied under aprotic conditions and can be done using many of the methods commonly practiced in the lens industry today, such as spin, spray, dip, and vacuum coating. Two specific examples of coupling agent application are provided below.

(108) A. Vacuum coatingProcedure: (1) A pair of optical molds comprising a front mold and a back mold, where corresponding optical surfaces of the molds are AR-coated molds according to one of various embodiments of the present invention as illustrated in Examples 3-6, is placed in a vacuum chamber, which is evacuated to create an aprotic environment with a predetermined pressure, in which a coupling agent will vaporize when introduced into the chamber. (2) The coupling agent is introduced into the sealed chamber and allowed to coat and react with each AR coating for a minimum of 10 minutes. (3) The chamber is evacuated to the original (pre-coupling agent), predetermined pressure to remove excess coupling agent. (4) The vacuum is released and the optical mold assembly is removed from the chamber. Afterwards, a hard coat can be applied.

(109) B. Dip coatingProcedure: (1) A solution of coupling agent in an aprotic solvent is prepared (0.05% minimum). Examples of aprotic solvents include toluene, benzene, petroleum ether, or other hydrocarbon solvents. (2) An AR-coated mold, prepared according to one of various embodiments of the present invention as illustrated in Examples 3-6, is exposed to (or treated with) the solution for a minimum of 5 minutes at room temperature. (3) The treated mold is removed from the solution and rinsed with ethanol or a similar solvent. (4) The mold is then air-dried and afterwards a hard coat can be applied.

Example 8