Neutral color antireflective glass substrate and method for manufacturing the same

Abstract

A method for manufacturing neutral color antireflective glass substrates by ion implantation, the method including ionizing a N.sub.2 source gas so as to form a mixture of single charge and multicharge ions of N, forming a beam of single charge and multicharge ions of N by accelerating with an acceleration voltage A between 20 kV and 25 kV and setting the ion dosage at a value between 6×10.sup.16 ions/cm.sup.2 and −5.00×10.sup.15×A/kV+2.00×10.sup.17 ions/cm.sup.2. A neutral color antireflective glass substrates including an area treated by ion implantation with a mixture of simple charge and multicharge ions according to the method.

Claims

1. A method for producing a neutral color antireflective glass substrate, the method comprising: a) providing a N2 source gas; b) ionizing the N2 source gas so as to form a mixture of single charge ions and multicharge ions of N; c) accelerating the mixture of single charge ions and multicharge ions of N with an acceleration voltage A so as to form a beam of single charge ions and multicharge ions, wherein the acceleration voltage A is comprised between 20 kV and 25 kV and an ion dosage D is comprised between 7.5×10.sup.16 ions/cm.sup.2 and −5.00×10.sup.15×A/kV+2.00×10.sup.17 ions/cm.sup.2; d) providing a glass substrate; and e) positioning the glass substrate in a trajectory of the beam of single charge and multicharge ions of N, wherein the glass substrate has a neutral color reflectance such that the reflectance is −1≤a*≤1 and −1≤b≤1 as measured under illuminant D65 using 10° observer angle on a side of the substrate that is treated as specified by the International Commission on Illumination after the mixture of single charge ions and multicharge ions of N has been implanted in the glass substrate.

2. The method for producing a neutral color antireflective glass substrate according to claim 1, wherein the glass substrate comprises the following composition ranges expressed as weight percentage of the total weight of the glass: TABLE-US-00005 SiO.sub.2 35-85%,  Al.sub.2O.sub.3 0-30%, P.sub.2O.sub.5 0-20%, B.sub.2O.sub.3 0-20%, Na.sub.2O 0-25%, CaO 0-20%, MgO 0-20%, K.sub.2O  .sup.   0-20%, and BaO 0-20%.

3. The method for producing a neutral color antireflective glass substrate according to claim 2, wherein the glass substrate is selected from the group consisting of a soda-lime glass sheet, a borosilicate glass sheet and an aluminosilicate glass sheet.

4. A method, comprising employing a mixture of single charge and multicharge ions of N to decrease the reflectance of a glass substrate and at the same time keep a color in reflectance neutral, the mixture of single charge and multicharge ions being implanted in the glass substrate with an ion dosage D and an acceleration voltage A effective to reduce the reflectance of the glass substrate and at the same time keep the color in reflectance neutral, wherein the acceleration voltage A is between 20 kV and 25 kV and the ion dosage D is between 7.5×10.sup.16 ions/cm.sup.2 and −5.00×10.sup.15×A/kV+2.00×10.sup.17 ions/cm.sup.2 wherein the glass substrate has a neutral color in reflectance such that the reflectance is −1<a*<1 and −1<b*<1 as measured under illuminant D65 using 10° observer angle on a side of the substrate that is treated as specified by the International Commission on Illumination after the mixture of single charge ions and multicharge ions of N has been implanted in the glass substrate.

5. The method according to claim 4, wherein the mixture of single charge and multicharge ions is being implanted in the glass substrate with an ion dosage and an acceleration voltage effective to reduce the reflectance of the glass substrate to at most 6.5%.

6. The method according to claim 5, wherein the mixture of single charge and multicharge ions is being implanted in the glass substrate with an ion dosage and an acceleration voltage effective to reduce the reflectance of the glass substrate to at most 6.5% and at the same time keep the color in reflectance neutral such that −0.3≤a*≤0.3 and −0.3≤b*≤0.3.

7. The method of claim 1, wherein said antireflective glass substrate is frosted, printed or screen process printed.

8. The method of claim 1, wherein said substrate is tinted, tempered, reinforced, bent, folded or ultraviolet filtering.

9. The method for producing a neutral color antireflective glass substrate according to claim 3, wherein the glass substrate is a soda-lime glass sheet.

10. The method for producing a neutral color antireflective glass substrate according to claim 1, wherein the ions are implanted to an implantation depth of from 01. μm to 1 μm.

11. The method for producing a neutral color antireflective glass substrate according to claim 1, wherein the glass substrate has a neutral color in reflectance such that −0.3≤a*≤0.3 and −0.3≤b*≤0.3 after the mixture of single charge ions and multicharge ions of N has been implanted in the glass substrate.

12. The method for producing a neutral color antireflective glass substrate according to claim 4, wherein the glass substrate comprises the following composition ranges expressed as weight percentage of the total weight of the glass: TABLE-US-00006 SiO.sub.2 35-85%, Al.sub.2O.sub.2  0-30%, P.sub.2O.sub.5  0-20%, B.sub.2O.sub.3  0-20%, Na.sub.2O  0-25%, CaO  0-20%, MgO  0-20%, K.sub.2O  0-20%, and BaO  0-20%.

13. The method for producing a neutral color antireflective glass substrate according to claim 12, wherein the glass substrate is a soda-lime glass sheet.

14. The method for producing a neutral color antireflective glass substrate according to claim 4, wherein the ions are implanted to an implantation depth of from 01. μm to 1 μm.

15. The method for producing a neutral color antireflective glass substrate according to claim 1, wherein the acceleration voltage A is between 20 kV and 25 kV and the dosage D is between 8×10.sup.16 ions/cm.sup.2 and −5.00×10.sup.15×A/kV+2.00×10.sup.17 ions/cm.sup.2.

16. The method for producing a neutral color antireflective glass substrate according to claim 1, wherein the acceleration voltage A is between 20 kV and 25 kV and the dosage D is between 1×10.sup.17 ions/cm.sup.2 and −5.00×10.sup.15×A/kV+2.00×10.sup.17 ions/cm.sup.2.

Description

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

(1) The ion implantation examples were prepared according to the various parameters detailed in the tables below using an RCE ion source for generating a beam of single charge and multicharge ions. The ion source used was a Hardion+ RCE ion source from Quertech Ingénierie S.A.

(2) All samples had a size of 10×10 cm.sup.2 and were treated on the entire surface by displacing the glass substrate through the ion beam at a speed between 20 and 30 mm/s.

(3) The temperature of the area of the glass substrate being treated was kept at a temperature less than or equal to the glass transition temperature of the glass substrate.

(4) For all examples the implantation was performed in a vacuum chamber at a pressure of 10.sup.−6 mbar.

(5) Ions of N were implanted in 4 mm regular clear soda-lime glass and alumino-silicate glass substrates. Before being implanted with the ion implantation method of the present invention the reflectance of the glass substrates was about 8%. The key implantation parameters and optical measurements can be found in the table below.

(6) TABLE-US-00004 TABLE 4 a* b* acceleration ion Light reflectance reflectance Source glass voltage dosage reflectance [CIELAB, [CIELAB, reference gas substrate [kV] [ions/cm.sup.2] [%, D65, 2°] D65, 10°] D65, 10°] E1 N.sub.2 Sodalime 25 6 × 10.sup.16 6.50 −0.14 −0.57 E2 N.sub.2 Sodalime 20 6 × 10.sup.16 6.14 −0.22 0.40 E3 N.sub.2 Sodalime 20 8 × 10.sup.16 5.67 −0.01 −0.07 E4 N.sub.2 Sodalime 20 1 × 10.sup.17 6.50 −0.25 −0.03 E5 N.sub.2 Sodalime 25 7.5 × 10.sup.16  5.25 0.20 0.02 E6 N.sub.2 Alumino- 20 6 × 10.sup.16 5.85 0.17 −0.96 silicate C1 N.sub.2 Sodalime 7.90 −0.53 −0.56 C2 N.sub.2 Sodalime 25 9 × 10.sup.16 5.15 0.33 −1.19 C3 N.sub.2 Sodalime 25 2.5 × 10.sup.17  5.76 −0.93 −4.84 C4 N.sub.2 Sodalime 35 1 × 10.sup.17 6.37 −1.12 −5.16

(7) As can be seen from examples E1 to E6 of the present invention, the chosen key parameters used for the ion implantation, where acceleration voltage A is comprised between 20 kV and 25 kV and the dosage D is comprised between 6×10.sup.16 ions/cm.sup.2 and −5.00×10.sup.15×A/kV+2.00×10.sup.17 ions/cm.sup.2, lead on one hand to a reduced reflectance of at most 6.5%, at most 6.0% or even at most 5.5% and on the other hand the color in reflectance of these examples is neutral, that is −1≤a*≤1 and −1≤b*≤1. The key implantation parameters chosen for examples E3, E4, and E5 lead to a very neutral color in reflectance, that is −0.3≤a*≤0.3 and −0.3≤b*≤0.3.

(8) Furthermore XPS measurements were made on the examples E1 to E6 of the present invention and it was found that the atomic concentration of implanted ions of N is below 8 atomic % throughout the implantation depth.