CS205067B2 - Photochromic aluminophosphoric glass - Google Patents

Abstract

Fast-response alumino-phosphate photochromic glasses having silver halide crystals dispersed throughout the glass comprise, in weight percentages: SiO2 8.5 to 25% Al2O3 13 to 36.5% P2O5 7.5 to 33.5% B2O3 7 to 28% R2O 7 to 20.5% where R2O represents at least one of Na2O, K2O and Li2O, the maximum content of Li2O being 5%; the amount of SiO2 is not less than 16% when the B2O3 content is less than 8%; and the silver content of the glass, expressed as Ag2O, is not less than 0.05% by weight. Such glasses in which Al2O3 is the largest constituent are preferred for ophthalmic purposes, but it is also possible for either B2O3 or P2O5 to be the largest constituent. The glass can also contain 1% to 21% by weight R'O where R'O represents MgO, CaO, SrO or BaO. The refractive index can be corrected by nD = 1.523.

Description

The invention relates to photochromic aluminophosphorus glass with silver halide crystals dispersed in the glass.

As is known, photochromic glass. there are glasses that darken when exposed. and will illuminate to its original normal colorless state when they are no longer exposed to this radiation.

In the British patent specification no. No. 1,367,903 discloses photochronic glasses containing at least 17% by weight of P2O5 phosphorus pentoxide with silver halide crystals dispersed in the glass, the total silver content in the glass being at least 0.05% by weight.

The special glasses mentioned in this patent are aluminophosphoric glasses containing at most. 40 wt.% SiO 2 and up to 9 to 34 wt.% Al 2 O 3 as other non-photochromic components, and at least 10 wt.% R 2 O, wherein R is potassium K, sodium Na or lithium Li. These glasses may also contain up to 19% by weight. % of the boron oxide B2O3, although most of said glasses contain no more than 3 to 7% by weight of boron oxide B2O3.

Lenses falling within the scope of the invention of said British Patent Specification No. 1,367,903. are currently used in. production. spectacle lenses for both solar and goggles. These - aluminophosphorus - glasses as well as photochromic borosilicate - - glasses, - which are also on the market, ... have, with the required photochromic properties, - relatively slow responses to exposure and removal of actinic radiation, - to - means they have low darkening and - lightning speeds.

For glasses, it is especially important to have glasses with faster - responses, especially - with a higher light speed. Fast illumination is needed to achieve a sudden drop in the - available - light, such as when the wearer of photochromic lens lenses enters a dimly lit room.

SUMMARY OF THE INVENTION It is an object of the invention to provide photochromic glasses having better properties, in particular glasses having a better photochromic effect, measured as induced - optical density or - change in light transmittance · when irradiated with - actinic radiation, and a greater response speed. irradiation or elimination of radiation.

SUMMARY OF THE INVENTION The present invention is based on the object of providing photochromic aluminophosphoric glass with silver halide crystals dispersed in the glass, the principle of which is to contain non-photochromic components.

8 to 5% by weight of SiO2, 5 to 25% by weight of SiO2, up to 36.5% by weight of Al2O3,

7.5 to 33.5% by weight of phosphorus pentoxide P2O5, up to 28% by weight of boron oxide B2O3, and up to 20.5% by weight of R 2 O, wherein R yO represents at least one of the oxides of sodium oxide Na 2 O, potassium K 2 O , and lithium oxide L12O, wherein the maximum content of lithium oxide L12O is 5% by weight, the amount of SiO2 is at least 16% by weight when the content of B2O3 is less than 8% by weight, and as photochromic components, expressed as% by weight over 100% by weight of the total amount of non-photochromic components, contains silver expressed as silver content of Ag2O in an amount of 0.05 to 0.6% w / w, chlorine and bromine from 0.2 to 2.0% by weight and copper oxide trace % to 1.0% by weight.

It has been found that these glasses have a good combination of the induced optical density under actinic light irradiation and rapid darkening during irradiation and rapid illumination when irradiation ceases to act.

As a basic rule, darkening and illumination times are longer when the induced optical density is greater.

With these glasses, it is possible for Al2O3, boron oxide B2O3 or phosphorus pentoxide P2O5 to be the largest components. A preferred range of compositions for these glasses is that in which the largest component is Al2O3, which is present in an amount of at least 22% by weight, wherein the P2O5 content does not exceed 25.5% by weight and the B2O3 content does not exceed 24.5% by weight. %.

Lenses of this composition may be assembled to have a rapid response to or elimination of irradiation associated with physical properties that make them suitable for scale production and for use on spectacle lenses. For example, the temperature of the Iikoid and the viscosity of the sicumin may be chosen to suit the molding processes used, the glass hardness being suitable for the grinding and polishing processes used. The refractive index can be set to a standard value of 1.523, which is used in ophthalmic optics, and the glass can have good chemical resistance or durability.

Usually, both Al2O3 and SiO2 contents can only be selected at the upper limits of the above ranges when high viscosity is desired at an iicoid temperature that is not too high by itself, for example when the glass is to be shaped of flat glass.

A second composition of glasses within the scope of the invention is that in which the largest component is boron oxide B2O3, which is present in an amount of at least 25% w / w, the Al2O3 content not exceeding 20% by weight and the P2O5 content not exceeding 20% by weight.

Another type of glasses according to the invention are those in which the largest component is P2O5, which is present in an amount of at least 21.5% by weight, the Al2O3 content not exceeding 26% by weight and the B2O3 content not exceeding 17.5% by weight.

If the temperature of the Iikoid is relatively low, for example due to the use of a relatively large amount of B2O3 boron oxide and a relatively small amount of SiO2, it is important to ensure that the resistance of the glass, for example tested in acidic or alkaline solutions, is still acceptable. The degree of resistance that is acceptable will, of course, vary with the intended use of the glass. Thus, glass having insufficient resistance for optics but good photochromic properties may be suitable for use in instrumentation or elsewhere where it is not exposed to attack.

When the B2O3 content of the boron trioxide approaches the lower limit, i.e. less than 8% by weight, it is necessary that the SiO2 content is at least 16% by weight to ensure both the desired rapid response and adequate durability for ocular purposes optics. If the content of boron oxide B2O3 is less than 7% by weight, the phosphorus pentoxide content must be kept below 17% by weight.

The component R2O may consist only of potassium K2O or a combination of two or three oxides from the group comprising potassium oxide K2O, oxide, sodium Na2O and lithium oxide Li2O, or sodium oxide Na2O alone. When R20 is Na2 O alone, its content should not exceed 14% by weight in order to avoid problems with glass forming and glass resistance.

In glasses intended for use in ophthalmic optics, it is preferable that the glasses can be strengthened by a conventional ion exchange process in which larger metal ions are exchanged for smaller metal ions in the surface layer of the glass, thereby creating a compressive stress in the surface layer. The ion exchange is performed by immersing the glass in a bath of molten salts. Typically, potassium ions are exchanged for sodium and / or lithium ions in a molten potassium nitrate bath of KNO3 or sodium ions are exchanged for lithium ions in a molten sodium nitrate bath of NaNO3.

If the glass is to be chemically strengthened in this way, it is preferred that the component

R20 contained sodium oxide Na2O and / or 205067 or lithium oxide L10O. Preference is given to using a mixture of alkali oxides, potassium K2O being present and sodium Na2O and lithium oxide L12O being kept below 5% by weight.

The penetration depth of the exchanged ions and the pressure stresses generated can be varied by varying the temperature of the molten salt bath. Usually, the greater the penetration, the lower the compressive stress and vice versa, so that the advantageous compromise must be found experimentally.

As mentioned above, the silver content of the glass according to the invention, expressed as 1 content of Ag2O silver, is at least 0.05% by weight, since at lower amounts of Ag2O silver it may be difficult to achieve the desired darkening _{t of the} glass. Preferably, the silver oxide content of Ag2O is at least 0.06% by weight.

According to a preferred embodiment of the invention, the photochromic glass further comprises from 1 to 21% by weight of R'O, wherein R'O represents at least one oxide from the group of oxides comprising magnesium oxide MgO, calcium oxide CaO, strontium oxide SrO and barium oxide BaO. up to 4 wt.% MgO, traces up to 6.5 wt.% calcium CaO, traces up to 10 wt.% strontium oxide and traces up to 21 wt.% barium oxide.

According to another preferred embodiment of the invention in the presence of potassium oxide K2O and lithium oxide Li2O, the sodium oxide content of Na2O is at most 5% by weight.

According to a further preferred embodiment of the invention, in the presence of only Na 2 O 2, the amount of R 2 O is 7 to 14% by weight.

According to a further preferred embodiment of the invention, the photochromic glass according to the invention further comprises titanium dioxide TiO2 in a trace amount of up to 6% by weight.

According to a further preferred embodiment of the invention, the photochromic glass according to the invention further comprises zirconium oxide Ζ1Ο2 in a trace amount of up to 10% by weight.

According to a further preferred embodiment of the invention, the photochromic glass according to the invention further comprises lead oxide PbO in a trace amount of up to 8% by weight.

For the purposes of ophthalmic optics, it is suitable that the glass according to the invention have a refractive index nD, measured for light of the wavelength of the sodium spectrum, as close as possible to the standard value of 1.523. The abovementioned additions of titanium dioxide T1O2, zirconium oxide ZrO2 and / or lead oxide PbO in the above ranges are used to adjust the refractive index to this value in order to avoid the risk of crystallization and undesirable coloring of the glass using zirconium oxide when using titanium dioxide · TiO2 ZrO2 to an undesirable increase in liquidus temperature.

Small amounts of other additives, such as hafnium oxide up to 3% by weight and zinc oxide ZriO up to 6% by weight, can also be used for the same purposes.

Tinting agents can also be added in a known manner, thereby creating a stable shade in addition to the variable photochromic coloring.

As is known, the photochromic effect is caused by the silver halide crystals as mentioned above. Smaller amounts of copper oxide help to develop the photcchromic effect and to ensure a stable. larger amounts can be used. Preferred amounts of photochromic components, in particular silver, expressed as silver oxide Ag2O, copper oxide CuO and halides (Cl and Br), expressed in accordance with normal practice, such as amounts above 100% by weight of the total amount of all components the glass is as follows:

silver oxide AgzO 0.06 to 0.60 wt% copper oxide CuO 0.005 to 1.0 wt% chlorine + bromine Cl + Br 0.20 to 2.0 wt% chlorine Cl trace to 1.0 wt% bromine Br · 0 08 to 1.0% by weight

In most cases, the photochromic effect may be enhanced by heat treatment of the glass, the appropriate heat treatment program being primarily determined on the basis of the viscosity-thermal relationships of the respective glass. Typically, the heat treatment temperature lies between the lower cooling temperature and the glass softening point, with the desired heat treatment time being a few hours at a lower temperature but only a few minutes at a higher temperature.

However, at a higher temperature, deformation and clouding of the glass may occur, so it is usually advantageous to use temperatures of 20 to 100 ° C above the upper cooling temperature and a processing time of 10 to 60 minutes.

The heat treatment of the glass may be carried out immediately after being formed or the glass may be cooled and cooled to room temperature prior to the heat treatment. The cooling rate at which the glass cools after heat treatment sometimes affects the photochromic properties of the final product. However, this is not a general rule, but it must be determined by testing individual glasses.

The temperature versus time curve of the glass being processed is determined by the concentrations of the photochromic agents in the glass and the requirements for the photochromic properties of the final product. In general, the higher the contents of the components contributing to photochromism, the shorter the heat treatment, and in some cases photochromism may develop during melt cooling or glass cooling. Too long heat treatments should be avoided as they can lead to the glass becoming cloudy.

The invention will now be described, by way of example only, with reference to the following table, which illustrates examples of glass compositions according to the invention, showing the oxide-based compositions and the photochromic effect achieved in terms of induced optical density (ODd) and time in seconds. it is necessary to illuminate to the state of half the total induced optical density (1/2 OD FT), measured on standard 2 mm glass samples under standard simulated solar conditions in air mass 2 (see Parry Moon, J. Frankliin Inlsit. 230 (1940) , Pp. 583–617). The developed optical density is the difference between the optical density of the glass in the fully darkened state and the optical density in the fully lit state, the optical density being defined in the usual manner as logio -γ • 4 where

I, is the intensity of incident light and I _t is the intensity of transmitted light.

The developed optical density is thus a true measure of the photochromic effect and is in fact proportional to the number of photochromically activated silver atoms in a given volume of glass. The time required to illuminate from a fully darkened state to a half-induced optical density (1/2 OD FT) is thus an effective measure for comparing the illumination times of glasses having different light transmittance values in a bleached or illuminated state.

The table also contains the temperature (HT ° C) at which each of the glasses was heat treated. In all cases the heat treatment time was 20 minutes, for comparative purposes only.

The final table also contains the refractive index n _{D of} most of the glasses.

The content of silver oxide Ag2O, cuprous oxide CuO, chlorine Cl and bromine Br is expressed in the table above 100% w / w and the content of all other glass components.

Table I

wt. % glass no. 1 2 3 4 5 S1O2 23.1 23.1 21.7 20.4 21.2 AI2O3 19.8 13.9 19.0 23.5 25.6 P2O5 12.8 19.4 26.5 32.8 25.9 B2O3 27.5 26.8 .17.1 8.4 11.9 Ы2О NasO K2O 0.1 15.4 15.2 14.3 13.5 14.0 MgO 1.3 1.5 1.4 1,3 ·· .. 1.4. cao SrO BaO PbO TiOž 2θ2 HÍO2 ZnO AgaO 0.27 0.17 0,0’8 0.09 0.12 CuO 0.013 0,029 0,031 0,035 0,035 Cl. 0.13 0.37 0.22 0.17 0.13 Br 0.39 0.40 0.28 0.22 0.17 ODd 0,307 0.334 0.283 0.202 0.261 2 OD FT 3 20 May 20 May 20 May 10 HT ° C 525 520 620 550 660 n _D 1,480 1,478 1,482 1,484 1,483

2050 67

Weight % glass no.

6 7 8 9 10 SiO'2 17.9 17.0 17.0 17.0 22.2 A12-O3 15.6 19.6 19.6 19.6 27.4 P2O5 21.8 27.3 27.3 27.3 17.8 B2O3 14.1 7.0 7.0 7.0 16.6 L12O NazO K2O ·. 9.8 9.3 9.3 9.3 14.6 MgO CaO SrO PbO BaO 20.8 19.8 19.8 19.8 1.4 T1O2 ΖΓΟ2 HfOz ZnO AgžO 0.12 0.12 0.12 0.11 0.10 CuO 0,036 0,033 0,045 0.040 0,029 Cl 0.35 0.40 0.49 0.48 0.18 Br 0.44 0.41 0.49 0.40 0.22 ODd 0.184 0.223 0.226 0.33 0.071 2 OD FT 7 8.5 12 20 May 2 HT ° C 635 640 630 630 705 nD 1,519 1,519 1,519 1,519 1,482 Weight % 11 12 glass no. 13 14 15 Dec

SiO2 22.5 21.5 21.2 20.4 19.9 AI2O3 30.7 29.5 25.6 23.5 22.9 P2O5 22.3 21.3 25.9 32.7 31.9 B2O3 12.6 12.0 11.9 8.4 8.2 LižO NazO 8.2 13.6 13.1 K2O 2.3 14.2 14.0 3.9 MgO 1.5 1.4 1.4 1.3 CaO SrO BaO PbO T1O2 Zl’O'2 HfOz ZnO AgaO 0.12 0.18 0.16 0.08 0.07 CuO 0,038 0.030 0,035 0,045 0,043 Cl 0.17 0; 27 0.29 0.34 0.17 Br 0.27 0.26 0.24 0.45 0.21 ODd 0,066 0,094 0.308 0.100 0.281 ~ —OF FT .2 1 12 24 30 HT 9C 705 750 640 610 . 665 nD 1,487 1,482 1,483 1,478

Weight % 16 17 glass no. 18 19 Dec 20 May S102 20.0 20.0 20.0 19.6 19.4 AI2O3 23.0 23.0 23.0 22.6 22.3 P2O5 32.0 32.0 32.0 31.4 31.1 B2O3 L120 Νβ2θ 8.2 8.2 8.2 8.1 8.0 Θ2θ MgO 13.2 13.2 13.2 12.9 12.8 CaO SrO BaO PbO ТЮ2 ZrO2 HÍO2 ZnO 3.6 3.6 3.6 5.3 6.5 AgzO 0.08 0.08 0.07 0.07 0.07 CuO 0,043 0,045 0,036 0,045 0,041 Cl 0 _; 24 0.41 0.40 0.34 0.27 Br 0.27 0.46 0.28 0.33 0.34 ODd 0.217 0.283 0.243 0.200 0.187 --OD FT 13.5 15 Dec 10 16 10 HT ° C 645 645 645 630 610 n _D 1,491 1,491 1,491 1,491 1,499

Weight % glass no. 21 22nd 2'3 24 25

SIO2 18.8 18.8 18.0 20.0 20.8 AI2O3 31.6 21.6 30.7 23.0 23.9 P2O5 30.1 30.1 38.8 32.0 33.3 В2О3 7.7 7.7 7.4 8.2 8.5 Li2O NaaO 4.8 KaO 12.4 12.4 11.8 13.2 7.4 MgO 1.3 CaO 3.6 SrO 9.4 3.6 BaO 9.3 13.3 PbO T1O2 ZrO2 HÍO2 ZnO Ag2O 0.07 0.08 0.07 0.09 0.15 CuO 0.040 0,043 0,043 0,047 0,036 Cl 0.25 0.30 0.31 0.28 0.30 Br 0.35 0.32 0.34 0.181 0.34 0.35 ODd 0.190 0.146 0.294 0,203 -i — OD FT 18 12 33 15 Dec 18 HT ° C Θ15 610 680 670 550 n _D 1,494 1,498 1,507 1,491 1,485

Weight % 205067 26 27 Mar: glass no. 28 29 30 S1O2 20.4 20.1 19.7 20.3 20.6 A12O3 23.5 23.1 22.7 23.3 23.7 P2O5 32.7 32.1 31.6 32.5 32.9 B2O3 8.4 8.3 8.1 8.3 8.5 L12O NazO 5.4 6.0 6.6 4.0 6.9 K2O 8.3 9.1 10.0 10.3 6.2 MgO 1.3 1.3 1.3 1.3 1.3 CaO SrO BaO PbO T1O2 Zr02 HfO ₂ ZnO AgžO 0.09 0.07 0.09 0.06 0.08 CuO 0,041 0,038 0,039 0,044 0,044 Cl 0.25 0.30 0.29 0.54 0.36 Br 0.35 0.35 0.38 0.33 0.24 ODd 0.231 0.238 0.214 0.271 0.226 * OD FT 18 33 24 10 12 2 HT ° c 610 610 610 610 555 Пр 1,485 1,486 1,486 1,485 1,487 Weight % 31 32 glass no. 33 34 35 S1O2 20.7 19.9 20.2 20.6 23.4 A12O3 23.8 22.9 23.3 23.7 19.2 P2O5 33.2 31.9 32.4 33.0 12.5 B2OJ 8.5 8.2 8.3 8.5 27.0 L12O ИагО 8.4 4.6 0.6 7.5 4.9 15.4 K2O 4.1 11.2 7.1 7.4 MgO 1.3 1.3 1.3 1.4 1.5 CaO SrO BaO PbO T1O2 1.0 ΖΓΟ2 ШО2 ZnO Ag2O 0.08 0.07 0.06 0.08 0.15 CuO 0,042 0,039 0,036 0,042 0,026 Cl 0.28 0.24 0.27 0.26 0.34 Br 0.40 0.24 0.32 0.33 0.33 ODd 0.170 0.279 0.275 0.172 0,127 -OD _FT 15 Dec 15 Dec 15 Dec 8 3 HT ° c 555 600 510 600 560 n _D 1,486 1,486 1,487 1,489 1,4865

Weight % 36 37 glass no. · 38 39 40 S1O2 23.1 23.2 22.9 23.1 23.0 A12O3 19.0 19.1 18.8 19.0 18.9 P2O5 12.3 12.4 12.2 12.3 12.3 B2O3 26.8 26.9 26.5 26.8 26.6 L12O Na2O K2O 15.2 15.3 15.1 15.2 15.1 MgO 1.5 1.5 1.5 1.5 1.5 CaO SrO BaO PbO T1O2 2,0 Ζ1Ό2 1.54 HfO2 3.0 2.6 ZnO 2,0 AgaO 0.15 0.12 0.10 0.13 0.12 CuO 0,026 0,026 0,026 0,033 0,031 Cl 0.31 0.35 0.31 0.37 0.30 Br 0.29 0.33 0.29 0.29 0.24 ODd 0,118 0,041 0,043 0.142 0.051 --OD FT 3 1 1 6 1 HT ° C 560 630 630 630 630 n _D 1.4915 1.4860 1,4905 1.4855 1.4850 Weight % glass no. 41 42 43 44 45

SiO2 23.5 17.0 17.0 17.0 17.0 AI2O3 19.3 19.6 19.6 19.6 19.6 27.3 P2O5 12.5 27.3 27.3 27.3 B2O3 27.2 7.0 7.0 7.0 7.0 Ы2О 0.38 K2O 15.5 9.3 9.3 9.3 9.3 MgO 1.5 CaO SrO BaO 19.8 19.8 19.8 19.8 PbO TIO2 ZrO HÍO2 ZnO 0.26 Ag2O 0.15 0.76 0.09 0.24 CuO 0,0¾) 0.014 0.040 0,044 0,046 Cl 0.57 0.30 0.33 0.19 0.19 Br 0.32 0.35 0.30 0.41 0.40 ODd 0.175 0.143 0.130 0.416 0.389 —OD FT 10 18 20 May 25 20 May HT ° c 520 630 630 630 630 Пв 1,5005 1,519 1,519 1,519 1,519

Weight % 46 47 glass number 48 49 50 S1O2 17.0 17.0 17.0 17.0 21.5 AI2O3 19.6 19.6 19.6 19.6 29.5 P2O5 27.3 27.3 27.3 27.3 21.3 B2O3 7.0 7.0 7.0 7.0 12.0 Li2O Na2O K2O 9.3 9.3 9.3 9.3 14.2 MgO CaO SrO BaO 19.8 19.8 19.8 19.8 1.4 PbO ТЮ2 ZrO2 НЮ2 ZnO AgžO 0.32 0.35 0.16 0.10 0.37 CuO. 0,038 0,041 0.16 0.16 0.38 Cl 0.48 0.50 0.44 0.44 0.26 Br 0.18 0.49 0.10 0.09 0.18 ODd 0.531 0.215 0.44 0.18 0.212 -4 — OD FT 80 35 24 15 Dec 2 HT ° c 630 630 630 630 662 11D 1,519 1,519 1,519 1,519 1,482

Weight % 51 ’ 52 glass no. 53 54 55 Network ° 2 31.5 21.5 21.5 31.5 21.5 AI2O3 29.5 29.5 29.5 29.5 29.4 P2O5 21.3 21.3 31.3 21.3 21.3 B2O3 12.0 12.0 12.0 12.0 12.0 L12O Na2O K2O 14.2 14.2 14.2 14.2 14.2 MgO 1.4 1.4 1.4 1.4 1.4 CaO SrO BaO PbO T1O2 0.35 Ζ1Ό2 ШО2 ZnO AgžO 0.56 0.31 0.24 0.29 0.27 CuO 0,036 0.38 0,039 0.19 0,038 Cl 0.21 0.35 0.12 0.25 0.22 Br 0.18 0.09 0.23 0.16 0.19 ODd 0.308 0.232 0.131 0.05 0,616 1 2 OD FT 2 2 1 1 18 HT ° c 685 685 705 705 725 n _D 1,482 1,482 1,482 1,482 1,486

Weight ° / o

SiOz

AI2O3

P2O5

B2O3

Ы2О

N820

K2O

MgO

CaO

SrO

BaO

PbO

TlOz

ZrO2

Hf0'2

ZnO

Ag2O

CuO

Cl

Br

ODd

-2 — OD FT

HT C n _D

Weight %

SiOz

AI2O3

P2O5

B2O3

Ы2О

NazO

K2O

MgO

CaO

SrO

BaO

PbO

T1O2

ZrO2

HfO2

ZnO

AgzO

CuO

Cl

Br

ODd — OD FT

HT ° C

По ....

glass no.

56 57 58 59 60 21.4 17.0 17.0 21.4 21.4 29.3 19.6 19.6 29.3 29.3 21.2 27.3 27.3 21.2 21.2 12.0 7.0 7.0 12.0 12.0 14.2 9.3 9.3 14.2 14.2 1.4 1.4 1.4 19.6 19.8 0.5 0.5 0.5 0.31 0.36 0.35 0.25 0.27 0,044 0.16 0.18 0,035 0j0f7i5 0.10 0.53 0.33 0.12 0.28 0.18 0.08 0.09 0.26 0.17 0,817 0,636 0.579 0.372 0.390 14 63 24 10 8 720 640 640 745 735 1,49'1 1,519 1,519 1,491 1,491 glass no. 61 82 63 64 65 21.4 22.9 32.3 21.8 21.4 29.3 18.9 18.4 17.9 18.8 21.2 12.2 11.9 11.6 26.1 12.0 26.6 25.9 25.2 16.8 14.2 15.1 14.7 14.3 14.1 1.4 1.5 1.4 1.4 2.8 0.5 2.8 5.4 7.8 0.36 0.13 0.10 0.18 0,095 0,038 0.030 0,032 0.030 0,038 0.19 0.28 0.22 0.21 0.23 0.15 0.22 0.14 0.17 0.25 0,861 1.17 0.90 1.09 0.196 24 400 140 840 8 720 580 570 600 645 1,491 1,4815 1.4915 1,497 1,483

0 50 67

Weight ° / o

SiOž

AI2O3

P2O5

B2O3

L12O

Na2O

K2O

MgO

CaO

SrO

BaO

PbÓ

TiOž

ZtO'2

HfÓ2

ZnO

Ag2O

CuO

G1

Br

ODd

-OD FT

HT T n _L1 glass no.

66 67 68 69 70 21.2 18.6 25.8 16.6 20.5 18.0 25.0 16.1 19.9 17.4 24.2 15.6 22.0 19.3 26.8 17.3 22.5 30.7 22.3 12.7 H, 7 9.8 13.9 13.5 13.1 2.9 1.47 3.8 6.85 9.8 0.5

HípOt. %

0,099 0,036 0.23. 0.36 0.183 0.12 0,044 0.34 0.34 0.234 0.13 0,039 0.38 0.39 0.26 0.13 0,048 0.32 0.34 0.10 0.32 0,041 0.21 0.23 0.184 8 8 15 Dec 6 5 645 1,488 645 1,496 615 1,499 630 1,487 745 1,487 71 72 glass no. 73 74 75

SjOz

AJ2O3

P2O5

B2O3

L12O

Na? O

K2O

MgO

CaO

Si’0

BaO

PbO

T1O2

ZrOž

HfO2

ZnO

Ag2O

CuO

Cl

Br

ODd

-i - OD FT

HT C n _D

22.2 30.3 22.0 12.5 21.6 29.5 21.4 12.1 21.2 28.9 21.0 11.8 30.8 28.4 20.6 11.6 17.5 32.9 22.8 11.7 11.1 5.4 6.0 6.6 8.1 9.2 10.1 13.7 1.45 1.41 1.38 1.36 1.36

0,5 0,5

0,5 0,5

0.31 0,048 0.25 0.25 0.228 0.29 0,037 0.24 0.26 0.319 0.27 0,037 0.28 0.23 0.336 0.26 0,037 0.32 0.25 0.453 0.26 0,036 0.31 0,2'5 0.152 4 12 12 30 2 745 1,489 720 1,487 710 1,488 710 1,490 720 1,484

0 5067 glass no.

Weight %

SiO ₂

AI2O3

P2O5

B2O3

L12O

NazO

K2O

MgO

CaO SrO BaO PbO T1O2

ZrO2

НЮ2

ZnO

AgzO

CuO

Cl

Br ODd ~ —O FT

FIT ° C n _D

76 77 78 79 80 13.7 35.5 24.7 11.4 18.0 29.3 21.2 16.0 14.4 29.2 21.1 19.9 10.9 29.0 21.0 23.8 17.7 31.6 22.0 13.4 13.3 1.32 14.1 1.39 14.0 1.38 13.9 1.38 13.9 1.37;

Weight %

SiOž '

AI2O3

P2O5 ^:

B2O3

Ы2О

NazO

K2O

MgO

CaO

SrO

BaO

PbO

T1O2

ZrO ₂

HfO2

ZnO

AgzO

CuO

Cl

Br ODd '

-g - OD FT

HT ^q C n _D

0.28 0,036 0.27 0.23 0.199 0.24 0,036 0.33 0.22 0,115 0.25 0,037 0.30 0.28 0.13 0.25 0,037 0.31 0.28 0.144 0.24: 0,036 0.30 0.24 0,119. : 3 2 2 2 1 ...... 720 1,484 720 1,483 720 1,483 710 1,483 725 1,484 81 82 glass no. 83 84 85 ..... 14.0 33.2 23.2 14.7 10.5 34.7 24.3 15.9 11.2 29.7 21.5 24.3 10,7 ....... 28.4 20.5 23.3 10.5 27.7 20.1 22.7 13.6 1.34 13.3 1.32 4.7 7.1 1.41 13.6 13.3 0.94 1.53 2.56 4.17

0.29 0.33 0.26 0.27 0.135 0.28 0,036 0.28 0.29 0,122 0.28 0,038 0.26 0.32 0.10 0.26 0,038 0,4'0 0.43 0.188 0.26 0,038 0.44 0.37 0.144 2 1 2 5 3 725 725 640 640 640 1,485 1,486 1,454 1,491

Weight ° / o glass no.

88 88 89 90

SiOž 10.2 9.9 10.4 10.2 9.7 A12Os  27.1 26.2 27.6 26.8 25.6 P2O5 19.6 19.0 20.0 19.4 18.7 B2O3 22.2 21.5 22.6 22.0 21.0 L12O NazO 13.5 K2O 13.1 12.6 13.6 13.5 MgO CaO 2.09 2.89 1.56 2.17 3.08 SrO BaO 5.71 7.89 4.25 5.93 8.42 PbO- TiOž ZrOz ZnO AgzO 0.27 0.21 0.23 0.21 0.21 CuO 0,038 0,038 0,038 0,038 0,038 Cl 0.32 0.37 0.38 0.34 0.39 Br 0.39 0.32 0.37 0.33 0.35 ODd 0.208 0.311 0.167 0.24 0.418 1 -—OD FT 4 7 4 4 10 Ca HT ° C 640 640 640 640 620 Πϋ 1,496 1,515 1,491 1,496 1,505 Weight % glass no. 91 92 93 94 95 S1O2 9.3 9.4 9.1 9.4 9.7 A12O5 24.5 24.8 24.0 25.0 25.7 P2O5 17.8 18.1 17.5 18.1 18.6 B2O3 20.1 30., 3 19.7 20.5 21.0 LizO Na2O 12.3 K2O 11.8 13.1 12.6 12.0 MgO 1., 63 CaO 4.43 3.87 4.61 SrO BaO 12.1 10.6 12.61 15.1 11.1 PbO TiOz ZrOz ZnO AgzO 0.2.7 0.22 0.23 0.27 0.22 CuO 0.38 0.46 0.38 0.38 0.38 0.38 Cl 0.60 0.52 0.46 0.34 Br 0.33 0.38 0.33 0.35 0.37 ODd 0.383 0,727 0.549 0.52 0.382 --OD FT 11 18 17 22nd 12 °Т ° c 605 660 635 615 615 n _D 1,519 1,514 1,519 1.51 1,507 ·

Weight % 96 97 glass 6. 98 99 100 ALIGN! S1O2 10.1 10.4 9.9 9.9 9.9 AI2O3 26.8 27.6 26.2 26.2 26.2 P2O5 19.4 20.0 19.0 19.0 19.0 B2O3 22.0 22.6 21.5 21.5 21.5 LízO NazO K2O 12.9 13.3 12.6 12.6 12.6 MgO CaO 4.23 6.11 2.59 2.89 2.89 SrO BaO 4.66 7.89 7.89 7.89 PbO T1O2 ZrO2 ZnO AgzO 0.23 0.28 0.27 0.20 0.17 CuO 0,038 0,038 0,038 0,038 0,038 Cl 0.36 0.40 0.38 0.50 0.29 Br 0.38 0.34 0.31 0.32 0.31 ODd ~ —OF FT 0.280 0,203 0.36 0.396 0.255 5 4 8 8 5 нт? c 640 640 640 640 649 n _D 1,502 1,499 1,505 1,505 1,505 Weight % 101 102 glass no. 103 104 105 S1O2 9.9 9.9 10.35 9.68 10.12 AI2O3 26.2 26.3 27.47 25.69 26.85 P2O5 19.0 19.0 19.89 18.60 19.44 B2O3 21.5 21.5 22.51 21.05 22,00 Ы2О ЫагО КгО 12.6 2.05 10,04 7,8'5 14.43 4.19 6.47 MgO CaO 2.69 2.89 3.0 2.82 2.95 SrO BaO 7.89 7.89 8.2 7.72 8Л57 PbO TIO2 ΖΓθ2 ZnO AgaO 0.21 0.26 0.29 0.22 0.26 CuO 0,038 0,035 0,037 0,037 0,037 Cl 0.38 0.60 0.43 0.39 0.49 Br 0.31 0.37 0.32 0.28 0.39 ODd 0.321 0.376 0.547 0.452 0.226 1 ' ——OD FT 9 7 12 12 20 May HT ° C 640 640 680 610 660 n _D 1,505 1,506 1,513 1,505 1,509

Weight % glass no.

108

106 107

109 110

S1O2 A12O3 P2O5 B2O3 10.21 10.30 10.43 9.38 9.08 27.09 19.61 22,00 27.33 19.79 22.39 27.67 20.03 22.67 24.80 18.09 20.33 24.02 17.52 19.68 Lizo NažO 3.88 3.56 7.85 13.01 K2O 5.89 5.40 13.01 MgO CaO 2.98 3.01 3.04 2.98 2.98 SrO BaO 8.14 8.22 8.32 11.41 14.2.1 PbO TiOz ZrOž ZnO 0.22 Ag2O 0.26 0.29 0.26 0.26 CuO 0,037 0,037 0,037 0,037 0,037 Cl 0.49 0.55 0.34 0.65 0.47 Br 0.39 0.30 0.36 0.51 0.31 ODd 0.421 0.556 0.451 0.445 0.498 4 — OD FT 33 15 Dec 21 16 18 1 HT ^Q C 6 & 0 680 Θ8Ο 625 640 n _D 1,508 1,509 1,511 1,513 1,519 Weight % glass no. 115 ¹¹¹ 112 ¹¹³ 114

S1O2 8.81 9.61 9.53 10.6 10.2 A12O3 23.28 25.41 25.19 33.6 34.0 P2O5 16.98 18.54 18.38 24.9 23.8 B2O3 19.08 20.83 20.65 16.1 15.6 L12O NazO 13.22 13.5 13.1 K2O 12.21 13.33 MgO CaO 2.80 3.05 3.03 1.33 0.9 SrO 2.45 BaO 16,8'3 8.35 8.28 PbO TiOz 0.87 1.73 ZrOz ZnO 0.36 AgzO 0/25 0.23 0.23 0.30 CuO 0,037 0,037 0,037 0,038 0,038 Cl 0.44 0.53 0.43 0.2 0.33 Br 0.36 0.38 0.26 0.37 0.36 ODd 0.638 0.402 0.277 0.214 0.193 —OD FT HT ° C 21 10 9 3 4 595 617 617 690 695 n _D 1,524 1,511 1,518 1,481 1,494

Weight % 2 0 5 0 7 7 116 117 glass no. 118 119 120 SiO2 10.0 9.8 9.5 10.0 9.1 AI2O3 33.3 32.6 31.6 33.2 30.1 P2O5 23.2 22.7 22.0 23.2 21.0 B2O5 15.2 14.9 14.5 15.2 13.8 Ы2О МагО КгО 12.8 12.5 12.1 13.0 11.5 MgO CaO 1.46 2.00 2.8 1.46 SrO BaO 4.00 5.48 7.58 4.0 14.5 PbO TiO2 ZrOž ZnO AgžO 0.36 0.26 0.25 0.27 0.24 CuO 0,038 0,038 0,038 0,038 0,038 Cl 0.30 0.31 0.36 0.30 0.41 Br 0.34 0.32 0.31 0.28 0.31 ODd 0.225 0.270 0.403 0.234 0.572 —OD FT 3 8 15 Dec 6 70 HT ° c 695 695 Θ8Ο 690 615 n _D 1,494 1,498 1,506 1,493 1.51 Weight % glass no. 121 122 123 124 125 SiO2 10.0 9.5 9.5 9.5 9.5 A12O3 33.1 31.6 31.6 31.6 31.6 P2O5 23.1 22.0 22.0 22.0 22.0 B2O3 15.2 14.5 14.8 14.5 14.5 Ы2О Na2O 1.97 K2O 12.7 12.1 12.1 12.1 9.98 MgO 5.86 CaO 2.8 2.8 2.8 2.78 SrO BaO 7.58 7.58 7.58 7.59. PbO 0.05 T102 ZrO2 ZnO AgaO 0.24 0.22 0.21 0.21 0.24 CuO 0,038 0,038 0,038 0,038 0.37 Cl 0.36 0.39 0.38 0.38 0.40 Br 0.25 0.24 0.31 0.31 0.30 ODd 1 0.293 0.492 0.321 0.403 0.335 -g - OD FT 4 24 9 15 Dec 12 HT ° c 660 680 640 640 626 n _D 1,501 1,505 1,505 1,505 1,508

2050 67

Weight %

126 127 glass no.

S1O2

AI2O3

P2O5

B2O3

Ы2О

NazO

K2O

MgO CaO SrO

BaO

PbO

TiOz

ZrO2

ZnO

AgzO

CuO

Cl

Br

ODd —-- OD FT

HT C n _D

9.75

32.4

22.6

14.8

6.73

6.73

2.84

7.78

9.31

30.92

21.5 = 9

14.17

13.87

2.72

7.43

0.22 0Д37 0.27 0.35 0.167 0.22 0.03 = 7 0.39 0.29 0.545 14 45 627 617 1,513 1,506

Weight %

S1O2

AI2O3

P2O5

B2O3

L12O

NazO

K2O

MgO

CaO

SrO

BaO

PbO

TiOz

Ζ1Ό2

ШО2

ZnO

AgzO

CuO

Cl

Br

ODd -1 — OD FT

HT ° c

Πϋ

128 129 glass no. 130 131 132 17.6 17.2 - ......... 9,6 13.6 . 16.5 29.3 28.6 32.0 28.7 26.7 11.1 10.8 18.5 13.7 7.9 17.1 1.5 16.7 i, ⁵ 21.0 3.3 16.1 19.5 10.5 12.5 5.1 13.3 14.1 3.5 3.4 2.8 3.1 3.2 9.5 9.3 7.7 8.3 8.8

1.26

1.95

0.33 0,035 0.46 0.26 0.53 0.33 0,035 0.45 0.25 0.90 0.31 0,033 0.48 0.38 0.208 0.40 0,029 0.45 0.27 1.07 0.29 0,036 0.44 0.26 0.71 15 Dec 27 Mar: 27 Mar: 36 24 620 620 700 670 660 1,523 1,522 1,511 1,524 1,528

Weight % 133 134 glass no. 136 136 137 S1O2 10.1 1'6,1 21.1 18.4 17.0 AI2O3 30.3 27.1 28.8 28.5 27.9 P2O5 14.6 14.2 20.9 13.6 14.6 B2O3 21.9 14.2 11.8 13.4 13.9 Ы2О 1.4 1.4 NazO 5.7 K2O 5.4 13.7 13.9 9.7 9.7 MgO CaO 3.2 3.1 0.96 3.2 SrO BaO 8.8 8.6 2.6 14.1 12.3 PbO TIO2 1,23 ΖΓΟ2 1.89 HfO2 ZnO AgzO 0.33 0.26 0.20 0.26 0.25 CuO 0,037 0.03 0,038 0.03 0.03 Cl 0.47 0.49 0.48 0.57 0.58 Br 0.39 0.30 0.27 0.28 0.26 ODd 0.57 0.96 0.4 0.51 0,7'62 -i — OD FT 18 60 14 24 18 HT ° C 680 660 670 630 630 n _D 1,517 1,524 1,518 1,518 1,524

Weight % 138 139 glass no. 140 141 142 SiO2 ' 16.6 18.7 13.1 15.9 '17, 3 AI2O3 32.8 22.1 32.4 28.3 '38, 3 P2O5 ^: 22.9 18.6 22.6 20.8 '14, 9 B2O3 7.0 10.5 11.0 9.8 '14, 1 L12O 0.66 3.0 1.3 ‘1,4 NazO ' 3.73 K2O 5.69 12.3 5.1 10.1 11.0 MgO CaO 2.9 4,5 2.8 '3,3 SrO BaO 7.8 12.3 7.8 11.9 8.9 PbO ^; ПО2. 0.91 0.89 0.92 ZrOz 1.36 HfO2 ZnO AgaO 0.22 0.25 0.26 0.26 0.24 CuO 0,037 0.035 0,036 0,032 0,032 Cl 0.43 0.6 0.37 0.42 0.46 Br 0.32 0.29 0.30 0.29 0.26 ODd 0.26 0,642 0.232 0,622 0,646 -a — OD FT 30 '54 6 '27 27 Mar: HT ° C '640 '610 650 '640 580 По 1,519 1,522 1,530 1,521 '1,523

Weight ^c / e '143 144 glass no. 145 146 147 Si02 8.5 17.91 18.5 13.57 13.20 A12O3 '27, 8 13.03 36.5 33.61 29.46 P2O5 '16, 5 21.76 25.5 23.48 14.24 B2O3 L12O Na ₂ O '18, 7 16.68 8.0 2.2 11.40 3.79 17.46 3.04 4 K2O MgO CaO SrO BaO PbO TiO _ZrO2 HfO2 ZnO 4-5,0 • 2.6 16.0 9,82 20.08 9.3 3.22 2.85 8.08 4.07 3.13 15.40 AgzO 0.24 0.12 0.29 0.35 0.31 CuO 0.032 0.03 0,037 0.03 0.03 Cl 6.58 0.43 0.213 0.44 0.44 Br 0.48 0.41 0.19 0.36 0.34 ODd 0,959 0.315 0.11 0,108 0.403 ₂ OD FT HT ° C n _D 1185 18 4 3 12 585 1,521 680 700 1,492 660 680

Weight % 148 149 glass no. 150 151 152 Si.02 9.2 22.21 8.8 9.36 8.5 A12O3 24.5 27.36 28.0 33.98 29.4 P2O5 17.7 15.77 17.0 17.98 20.5 B2O3 L’2O КагО 20.1 18.60 19.0 20.35 3.23 13.5 K2O MgO CaO BaO SrO T1O2 ZrO2 ШО2 ZnO 18.5 2.7 7.4 14.61 1.44 12.1 2.2 16.7 4.91 2.73 7.46 12.2 4.24 11.6 Ag2O 0.27 0.12 0.23 0,025 0.19 CuO 0,035 0.03 0,035 0.03 0,038 Cl 0.62 0.38 0.79 0.24 0.49 . Br 0.55 0.31 0.44 0.32 0.29 ODd 0,721 0.09 0.83 0.08 0,621 —OD FT 72 3 21 2 210 HT ° C Πβ 610 1,505 690 1,482 660 1,525 660 700 1,520

Weight ° / o 153 154 glass no. 155 156 157 S1O2 20.8 9.5 17.3 17.1 16.3 А1'20з 28.4 26.1 30.7 30.4 29.0 P2O5 20.6 16.7 14.9 14.7 14.0 B2O3 11.6 20.5 14.2 14.0 13.3 L'i-20 2.1 2.1 1.3 NaaO 6.6 K2O 11.4 13.1 8.8 9.8 9.3 MgO CaO 3.0 3.3 3.2 SrO BaO 8.2 8.9 8.8 16.8 PbO T1O2 0.5 3.0 ZrO2 ZnO AgzO 0.26 0.39 0.28 0.25 0.25 CuO 0,037 0,034 0,036 0,037 0,033 Cl 0, -312 0.51 0.55 0.44 0.38 Br 0.25 0.53 0.32 0.26 0.26 ODd 0.453 0.62 0.403 0.581 0,7'36 --OD FT 30 18 12 24 114 HT ° C 710 660 610 590 610 n _D 1,490 1.52: 3 1,523 1,523 1,523. Weight % glass no. 158 159 160 161 162

SiO'2 A12O3 P2O5 B2O3 LizO NazO K2O MgO CaO SrO BaO PbO T1O2 Ζ1Ό2 HfO'2 ZnO AgžO CuO Cl Br ODd 1

HT ° C

OD FT

14.1 14.4 9.4 12.0 13.3 27.3 27.5 26.0 26.4 27.4 12.2 19.9 16.7 19.1 17.6 19.8 17.8 20.4 19.3 17.6 3.6 2.1 2.8 13.2 5.4 13.1 10.4 9.5 3.1 3.0 3.0 2.9 3.2 8.4 8.3 8.2 7.9 8.6

2.54

0.08

0.27 0.25 0.30 0.26 0.35 0,034 0,037 0,035 0,039 0,037 0.60 0.47 0.43 0.40 0.53 0.32 0.40 0.25 0.36 0.29 0,037 0.12 0,687 0.29 0.55 30 5 12 12 21 665 040 670 640 670 1,524 1,509 1,5 * 22- 1,508 1,512

Weight ° / o glass c. 163 164 105 166 167 Si0'2 ..... 17,3 ....... , .. .17.2 13.6 13.1 13.8 A12O3 28.4 27.0 28.7 32.5 30.9 P2O5 14.9 14.8 13.7 22.7 14.9 B2O3 14.2 14.1 16.1 11.1 18.3 L12O 1.7 1.4 0.66 2.1 NazO 3.71 K2O 9.9 9.8 13.3 5.64 7.7 MgO CaO 3.3 3.1 2.9 3.3 SrO BaO 12.5 12.5 8.3 7.8 8.97 PbO С T1O2 0.95 1.20 Ζ1Ό2 1.84 HfOz ZnO Ag2O 0.27 0.30 0.59 0.23 0.26 and CuO 0.030 0,033 0,029 0,037 0.04 Cl 0.40 0.50 0.40 0.49 0.45 Br 0.24 0.30 0.25 0.40 0.29 ODd 0.568 0.551 1.0 0.437 0.371 3 - OD FT 18 24 36 10 8 HT ° C 585 655 Θ20 585 690 Bd 1,520 1,520 1,52'4 1,514 1,524

Weight % 168 '169 glass no. 170 171 172 SíO‘2 21.4 9.57 9.91 9.5 8.9 A12O3 29.3 25.30 31.94 26.3 25.5 P2O5 21.2 18.46 11.15 16.7 14.3 B2O3 12.0 20.74 21.48 21.6 19.2 L12O NazO 0.7 K2O 14.0 13.27 13.69 16.5 12.3 MgO 1.4 1.31 CaO 3.04 3.14 2.8 2.8 SrO BaO 8.32 8.58 7.6 16.97 PbO T1O2 Ζ1Ο2 HfO2 Z11O Ag2O 0.24 0.24 0.32 0.25 0.20 CuO 0,037 0,037 0,037 0,035 0,032 > Cl 0.26 0.53 0.48 0.40 0.54 Br 0.18 0.33 0.28 0.31 0.33 ODd 0,651 0.378 0,928 0.89 0.903 --OD FT 36 12 24 14 38 HT ° C 630 633 640 635 650 n u 1,486 1,507 1,515 1,505 1,526

glass no.

Weight %

17i3

S1O2 8.9 A12O3 19.2 P2O5 17.2 B2O3 32.3 L12O NazO K2O 12.4 MgO CaO 2.8 SrO BaO 17.1 PbO ТЮ2 ΖΓΟ2 HfO2 ZnO AgzO 0.29. CuO 0,035 Cl 0.43 Br 0.40 ODd 0.545 --OD FT 18 HT ° c Θ00 Hd 1.5212

The following Table II summarizes a series of photochromic glass compositions according to the invention which can be chemically strengthened by ion exchange as described above, with compressive stresses in MN.m ^-2 and penetration depth in micrometers achieved when ion exchange was performed by immersion for 18 hours. hours into a bath of molten potassium nitrate KNO3 at 470 ° C, as well as the photochromic properties of reinforced glasses. In the case of glasses 174, 175 and 178, this involves the exchange of potassium ions with sodium ions. In glass 176, potassium ions are exchanged for sodium and lithium ions.

In glasses 177 and 179, potassium ions were exchanged for lithium ions. Obviously, the chemical strengthening process does not affect the photochromic properties, for example by comparing the properties of glass 174 with a very similar glass 71 in Table I.

Table II

Weight % glass no.

174 175 176

SIO2 22.3 10.7 12.0 AI2O3 '30, 5 35.6 32.1 P2O5 22.1 24.8 21.7 B2O3 12.5 16.3 14.3 LlzO 1.83 NažO 11.1 4,5 1.4 K2O 6.8 5.8 MgO 1.45 1.35 CaO 2.9 SrO BaO 8.0 PbO 0.5 ZrO'2 TIO2 AgžO 0.31 0.28 0.25 CuO 0,048 0,036 0,0-37 Cl 0.25 0.38 0.45 Br 0.25 0.29 0.34 Stress (MPa) 165.5 147.0 326.0 Penetration depth (μΐη) 55 8'5 28 ODd 0.228 0.135 0.14 -4 — OD FT 4 4 4

Weight % glass c. 17: 7,178 179 S1O2 13.1 15.0 15.5 UpOs 32.4 28.1 27.5 P2O5 22.6 17.6 20.2 B2O3 11.0 11.6 9.5 LižO 2,0 1,3 ' NažO 6.1 K2O 8.3 9.3 9.8 MgO CaO 2.9 2.7 SrO BaO 7.8 7.4 16.2 PbO Z1O2 1.29 T1O2 0.84 Ag2O 0.20 0.28 0.27 CuO 0,037 0,037 0,035 Cl 0.38 0.52 0.50 Br 0.34 0.35 0.28 Stress (MPa) 163.5 305.5 233.0 Penetration depth (um) 76 60 65 ODd 0.334 1.1 0.536 - ⁴ —OF FT 15 Dec 20 May 35

and.

The glasses of the compositions shown in the table can be produced as follows. The batch is melted under oxidizing or neutral conditions at a temperature in the range of 1200 ° C to 1600 degrees Celsius and, after cooling, cooled at temperatures between 450 ° C to 6'50 ° C.

The final heat treatment can be carried out at temperatures between 20 ° C and 100 ° C above the upper cooling temperature for 10 to 60 minutes. The optimum heat treatment temperature range for a particular glass can be determined using a drop furnace. In some cases, it may prove necessary to underlay the glass during heat treatment to avoid sagging of the glass.

The batch can be made from conventional glass raw materials such as carbonates, methane or ortho-phosphates, nitrates and oxides. The silver and halide components may be added to the batch in the form of finely ground silver salts and potassium or sodium halides.

Care should be taken during melting to minimize volatilization losses of the batch components, as up to hmotnostních0% by weight of halide components and up to 30% by weight of silver can be lost in this way, so that additions are required during batch preparation.

The glasses listed in the table above have a suitable co-combination of photochriomic effect, measured as the induced optical density with a rate of response to exposure or removal of actinic radiation. Although it is apparent in some glasses that the induced optical density is not high, the response speed of these glasses is particularly high. Said glasses may be used for optics as well as for other applications where transient protection from actinic radiation such as sunlight is required, returning to normal transmittance when actinic radiation is absent.

These glasses may therefore be used in certain circumstances for glazing buildings or motor vehicles.

The formation of photochromic properties in glass is associated with the formation of silver halide crystals in the mass of glass in a form in which they are sensitive to actinic radiation. Thus, the glass manufacturer not only encounters problems of glass composition selection that can be safely melted and shaped in a suitable manufacturing process, but also the problem of achieving this in glass in which silver halide crystals will be formed in a sensitive form irradiation so that the glass obtains sufficient photochromic properties.

Many hypotheses regarding the behavior of the silver halide crystals in the glass mass have been explained, and British Patent Specification 1,428,880 even states that in some cases and in certain phosphor glasses, a silver halide may be present in the glass mass in non-crystalline segregation phases.

Due to the large number of components that can be incorporated into the glass according to the invention, it is virtually impossible to test all possibilities even from the selected area of glass composition defined in the application for simple glass composition without including the behavior of other additives. The problem will increase in the case of glass compositions, where additional physical effect is created by the addition of other additives, such as the additives of the invention.

During the research carried out by the inventor of the invention, a large number of glasses having a composition within the scope of the invention have been produced.

In the examples selected from this work and listed above in the table to illustrate the invention, a wide variety of compositions is shown in part. glasses which are possible in the defined area of composition with respect to the main components, namely alumina Al2O3, boron oxide B2O3 and phosphorus pentoxide P2O5. It is shown how, with this wide variety, glasses with a good combination of the induced optical density under actinic radiation can be obtained in conjunction with fast darkening during irradiation and fast lighting upon irradiation.

As mentioned above, it is preferred to select Al 2 O 3 as the main glass component. Examples of glasses for varying proportions of the amount of boron oxide B2O3 to the amount of P2O5, i.e., from a content of B2O3 greater than that of P2O5 to a content of B2O3, are shown. equal to the content of P2O5 phosphorus pentoxide, up to the content of P2O5 phosphorus pentoxide greater than the content of boron oxide B2O3.

Examples are also given to show that it is possible to produce suitable glasses with either B2O3 boron oxide or P2O5 as the main constituent of the glass. The examples further show that variations in the content of the individual components in these regions are possible, i.e. B.2O3> A12O3> P2O5 and BzO3>> θ2θ5> ^ 12θ3 and Ρ2θ5> Α12θ3> Β2θ3 and PzO5>> Βζθ3> Α1ζθ3.

The silica content of SiO 2 in the glass has little or no effect on the photochromatic properties of the glass, but makes it possible to adjust the forming properties of the glass and may be important, for example, to obtain glass which can be easily solidified by chemical means.

The choice of the SiO2 content for altering the content of the other major components of the glass, i.e., Al2O3, P2O5, and B2O3, is therefore a matter of normal skill of the glass manufacturer and knowledge of the known effects of these changes on the glass.

The table shows examples of glass compositions to show the limits of the permissible contents of the main components of glass, but also contains examples of glasses in which the main components of glass are not within the content limits to help glass manufacturers in those areas where the most useful glasses can be obtained. and has shown that there is a large number of glass and that it has been tried to determine and verify the valuable range of glass compositions underlying the invention.

The examples are by no means intended to be determined. separate regions within this wide range in which the advantages of the invention reside, but to demonstrate that glass composition can be selected throughout the region, with particular attention to the choice of glasses in which Al 2 O 3 aluminum oxide is the main component.

The choice of a suitable base glass composition must also be accompanied by the selection of appropriate amounts of photochromic additives, Ag 2 O silver, Cu 2 Cu 3, Br 1 and Br 2. The possibility of varying the amount of these additives in the same basic glass composition is shown, for example, in Examples 43 to 49. Other changes in this composition are given in Examples 7, 8, 9, 57 and 58. _t

Generally, as the silver content of Ag 2 O increases, the induced optical density increases. It is therefore important, when selecting the basic composition of the glass, also to try to adjust the content of the photochromic additives in order to obtain the desired induced optical density in any suitable glass.

As mentioned above, the final heat treatment of the glass may be carried out, and in this case, it is necessary to investigate changes in both the time and temperature of the glass heat treatment to separate the silver halide crystals in the glass mass in order to achieve optimum performance. for certain glass. This can suitably be accomplished by means of a rod sample of glass poured into the downcomer.

Examples showing a change in the heat treatment temperature of a glass with some variations in photochromic additives with almost the same basic glass composition are examples 12, 50 to -56, -59 to -61 and 72 to 74.

Further adjustments to the content of photochromic additives as well as to the heat treatment conditions of the glass may be necessary if the glass composition is further adjusted to obtain the desired refractive index of 1.523. Adjusting the glass to a standard refractive index of 1.523 + 0.001 is achievable with the ⁴ glasses according to the invention.

Most examples of glasses in the table where the refractive index of -glass is or has been corrected to 1.523 + + 0.001 are in the area where alumina ♦

AI2O3 is the main constituent of glass because it is the area where the most advantageous combination of properties - glass for the manufacture of glasses - for glasses has been found, but it is clear that the glass according to Example 173 also has this refractive index, which is its main constituent - boron B2O3.

BEFORE THE INVENTION

Claims (7)

205067 15 18 F R E D I I 1. A photochromic aluminophosphoric glass having a silver halide dispersed therein, characterized in that it contains 8.5 to 26% by weight SiO2, from 13 to 36.5% by weight of Al2O3, 7.5 to 33, as non-alpha-chochromic components. 5 wt% of phosphorus pentoxide P2O5, 7 to 28 himoithoisitins of boron oxide B2O3 and 7 to 20.5 wt% of R2O, wherein R2O represents at least one oxide of the oxide group comprising sodium oxides of sodium, potassium oxide K2O, and lithium oxide LizO wherein the maximum lithium LizO content is 5 wt. The% SiO2 is at least 16% by weight when the content of boron oxide B2O3 is less than 8% by weight, and as the photochromic component expressed as weight% above 100% by weight of the total amount of non-photochromic components is expressed as silver oxide content Ag 2 O in an amount of from 0.06 to 0.6% by weight, chlorine bromine from 0.2 to 2.0% by weight, and copper (I) oxide trace up to 1.0% by weight. 2. The photochromic glass of claim 1, further comprising from about 1% to about 21% by weight of R10, wherein R10 represents at least one oxide from the group consisting of magnesium oxide MgO, calcium oxide CaO, strontium oxideSrO and barium oxide BaO, containing traces of up to 4% by weight of magnesium oxide MgO, traces up to 6.5% by weight of calcium oxide CaO, traces up to 10% by weight strontium oxide SrO and traces up to 21% by weight barium oxide BaO. 3. The photochromic glass of claim 1, wherein in the presence of K2O and lithium oxide, the Na2 O content is at most 5% by weight. 4. Photochromic glass according to claim 1, characterized in that in the presence of Na2 O3 from R2O, its amount is 7 to 14% by weight. Photochromic glass according to any one of Claims 1 to 4, characterized in that it further comprises titanium dioxide T1O2 in an amount of up to 6% w / w. 6. A photochromic glass according to any one of claims 1 to 5, characterized in that it further comprises zirconium oxide ZrO2 in a quantity of up to 10% by weight. 7. Photochromic glass according to any one of Claims 1 to 6, characterized in that it further comprises lead oxide PbO in an amount of up to 8% by weight. Severografia, n. P., Plant 7, Most