METHOD FOR TINTING GLASS LENSES AND RELATED GLASS LENSES

Abstract

A method for tinting glass lenses, comprising the immersion of a glass lens in a bath comprising at least one salt constituted by a cation selected from the group constituted by a transition metal, a metal of the p block of the periodic table, a rare earth metal, and by an anion selected from the group constituted by a halide, a sulfate, a nitrate; the tinting salt is mixed with another salt constituted by a cation selected from the group constituted by an alkaline metal, an alkaline earth metal, and by an anion selected from the group constituted by a halide, a sulfate, a nitrate.

Claims

1-23. (canceled)

24. A method for tinting glass lenses, comprising the immersion of a glass lens in a bath comprising at least one salt constituted by a cation selected from the group constituted by an alkaline metal, an alkaline earth metal, a transition metal, a metal of the p block of the periodic table, a rare earth metal, and by an anion selected from the group constituted by a halide, a sulfate, a nitrate, the temperature of said bath being selected in an interval comprised between 350 C. and 650 C., the duration of the immersion of said lens in said bath being selected in a time interval comprised between 1 minute and 20 hours, the concentration of said at least one salt being selected in an interval comprised between 0.1% and 70% by weight with respect to the total weight of said bath, the selection of said temperature, of said duration of the immersion and of said composition determining the intensity of the tinting of said lens.

25. The method for tinting glass lenses according to claim 24, wherein said at least one salt is silver nitrate.

26. The method for tinting glass lenses according to claim 24, wherein said at least one salt is copper sulfate.

27. The method for tinting glass lenses according to claim 24, wherein the temperature of said bath is selected in an interval comprised between 400 C. and 500 C.

28. The method for tinting glass lenses according to claim 24, wherein the temperature of said bath is selected in an interval comprised between 500 C. and 600 C.

29. The method for tinting glass lenses according to claim 24, wherein the concentration of said at least one salt is selected in an interval comprised between 1% and 10% by weight with respect to the total weight of said bath.

30. The method for tinting glass lenses according to claim 24, wherein the concentration of said at least one salt is selected in an interval comprised between 30% and 70% by weight with respect to the total weight of said bath.

31. The method for tinting glass lenses according to claim 24, wherein the duration of the immersion in said bath is selected in a time interval comprised between 1 minute and 20 hours.

32. The method for tinting glass lenses according to claim 24, wherein said bath further comprises sodium nitrate or potassium nitrate or sodium sulfate.

33. The method for tinting glass lenses according to claim 24, further comprising the immersion of said glass lens in a tempering bath that comprises at least potassium nitrate.

34. The method for tinting glass lenses according to claim 33, wherein the temperature of said tempering bath is selected in an interval comprised between 400 C. and 500 C., and wherein the duration of the immersion in said tempering bath is selected in a time interval comprised between 8 hours and 18 hours.

35. The method for tinting glass lenses according to claim 24, wherein said bath further comprises potassium nitrate, the immersion of said lens in said bath comprising said at least one salt and said potassium nitrate achieving a tempering and tinting effect on said lens.

36. The method for tinting glass lenses according to claim 35, wherein the duration of the immersion in said bath is selected in a time interval comprised between 8 hours and 18 hours.

37. The method for tinting glass lenses according to claim 35, wherein the duration of the immersion in said bath is selected in a time interval comprised between 12 hours and 16 hours.

38. The method for tinting glass lenses according to claim 24, wherein the concentration of said at least one salt is selected in an interval comprised between 0.1% and 2% by weight with respect to the total weight of said bath.

39. The method for tinting glass lenses according to claim 24, wherein the concentration of said at least one salt is selected in an interval comprised between 0.2% and 0.5% by weight with respect to the total weight of said bath.

40. The method for tinting glass lenses according to claim 24, wherein the concentration of said at least one salt is 0.4% by weight with respect to the total weight of said bath.

41. The method for tinting glass lenses according to claim 24, wherein the temperature of said bath is selected in an interval comprised between 410 C. and 550 C.

42. The method for tinting glass lenses according to claim 35, wherein after the tinting process a thermal treatment in an oxidizing or reducing atmosphere is performed.

43. The method for tinting glass lenses according to claim 42, wherein tinting with silver nitrate, tinting with copper sulfate and thermal treatment in an oxidizing or reducing atmosphere are combined at will.

44. The method for tinting glass lenses according to claim 24, wherein said bath is kept under agitation.

45. The method for tinting glass lenses according to claim 24, wherein said immersion of said glass lens in said bath comprises the introduction and extraction of said lens in and from said bath in a gradual manner in order to obtain a lens with graduated tinting.

46. A glass lens, wherein it is tinted by means of a method for tinting glass lenses according to claim 24.

Description

EXAMPLE 1

[0056] A UV400 glass lens is tempered for 9 hours at 450 C. in a potassium nitrate bath and is then tinted by immersion in a bath with 48% copper sulfate in sodium sulfate for 30 minutes at 530 C. in order to obtain a lens with a solid tinting that is different from the original one.

EXAMPLE 2

[0057] A UV400 glass lens is tempered for 9 hours at 450 C. in a potassium nitrate bath and is then tinted by immersion in a bath with 1.7% silver nitrate in potassium nitrate for 2 hours at 410 C. to obtain a lens with a solid tinting that is different from the original one.

EXAMPLE 3

[0058] A UV400 glass lens is tinted by immersion in an agitated bath with 1% silver nitrate in sodium nitrate for 1 hour at 400 C. and is then tempered for 16 hours at 450 C. in a potassium nitrate bath, in order to obtain a lens with a solid tinting that is different from the original one. A hydro- or oleophobic finishing treatment is applied to the lens.

EXAMPLE 4

[0059] A glass lens with UV400 protection is tempered for 16 hours at 450 C. in a potassium nitrate bath and is then tinted by gradual immersion in (or immersion and gradual extraction from) a bath with 4% silver nitrate in potassium nitrate for 2 hours at 400 C. in order to obtain a lens with graduated tinting.

EXAMPLE 5

[0060] A glass lens with UV400 protection is immersed and kept in motion for 16 hours at 420 C. in a bath with 0.2% silver nitrate in potassium nitrate, undergoing tempering and tinting simultaneously; a graduated treatment is applied by PVD to the concave side of the resulting lens.

EXAMPLE 6

[0061] A UV400 glass lens is lapped to 1 mm in order to constitute a wafer, is tempered for 16 hours at 450 C. in a bath of potassium nitrate and is then tinted by immersion in a bath with 4% silver nitrate in potassium nitrate for 2 hours at 420 C. The resulting wafer is used to produce a laminated lens by adhesive bonding with a second wafer optionally provided with further characteristics (IR protection, contrast enhancement, photochromic treatment).

EXAMPLE 7

[0062] A UV 400 glass lens is lapped to 1 mm to constitute a wafer and is immersed for 12 hours at 420 C. in a bath with 0.5% silver nitrate in potassium nitrate, undergoing tempering and tinting simultaneously. The resulting wafer is coupled by adhesive bonding with a photochromic front wafer.

EXAMPLE 8

[0063] A glass lens is lapped to 1 mm to constitute a wafer, is tempered for 16 hours at 450 C. in a potassium nitrate bath and is tinted by immersion in a bath with 6% silver nitrate in sodium nitrate for 1 hour at 400 C. The resulting wafer is coupled to a second UV400 wafer with an acrylic adhesive after the interposition of a functional film (for example a polarizing one). An antiglare treatment is optionally applied to the rear surface by PVD.

EXAMPLE 9

[0064] A glass lens is lapped to 1 mm to constitute a wafer, is tempered for 16 hours at 450 C. in a potassium nitrate bath and is tinted by immersion in a bath with 6% silver nitrate in potassium nitrate for 2 hours at 400 C. The resulting wafer is coupled to a second wafer by means of a polyurethane adhesive by including a UV absorbing agent in the adhesive.

EXAMPLE 10

[0065] A UV400 glass lens is lapped to 1 mm in order to constitute a wafer, is tinted by immersion in a bath with 1% silver nitrate in potassium nitrate for one hour at 400 C. and is then tempered for 16 hours at 450 C. in a potassium nitrate bath. The resulting wafer is coupled to a second wafer with a polyurethane adhesive modified by including in the adhesive pigments/colors adapted to give the lens desired optical properties.

EXAMPLE 11

[0066] A UV400 glass lens is lapped to 1 mm in order to constitute a wafer, is tinted by immersion in a bath with 4% silver nitrate in potassium nitrate for 2 hours at 420 C. The resulting wafer is coupled to a second wafer by means of an epoxy adhesive after the interposition of a functional film (e.g., a polarizing one); before or after coupling, a solid or graduated treatment is applied to one or more surfaces of the wafers by PVD.

[0067] In practice it has been found that the method for tinting glass lenses according to the present invention achieves the intended aim and objects, since it allows to tint glass lenses in a manner that is various, controllable, simple, reliable and cheap.

[0068] Another advantage of the method for tinting glass lenses according to the invention resides in that it is possible to perform simultaneously tempering and tinting of the lenses in a single tinting and tempering bath.

[0069] A further advantage of the method according to the invention resides in that it is possible to obtain a wide variety of tints of the glass lens by selecting appropriately the temperature and duration parameters of the tinting bath and of the concentration of the tinting salt.

[0070] The method for tinting glass lenses thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

[0071] All the details may further be replaced with other technically equivalent elements.

[0072] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements.

[0073] The disclosures in Italian Patent Application No. 102016000043786 (UA2016A002996) from which this application claims priority are incorporated herein by reference.