CS202876B1 - Colour dioptric photochromic glass - Google Patents

Description

The invention relates to colored dioptric photochromic glasses, in particular for use in ophthalmic optics, based on silver halides, colored by ionic dyes prior to activation by sunlight or other ultraviolet radiation source.

Colored photochromic lenses used, for example, for the production of sun glasses are known. For example, according to MS. However, the glass and other known glasses are less suitable for some eye protection purposes due to the significant absorption in the wavelength range of 500 to 600 nm. Particularly to protect the eyesight from the effects of sunlight, it is advantageous to continuously increase the absorption over the entire visible range of the spectrum. These requirements are fulfilled by color dioptric photochromic glass according to the invention whose principle consists in content in weight from, 30 to 70 of silicon dioxide Si0 _2, ^2-50 boron oxide B2O3, 3-27 aluminum oxide Al ^ -j, 1-12 sodium oxide Na ₂ 0, 0.001 to 0.1 CuO, at least one halogen element in the abovementioned amount from the group consisting of 0.5 to 2 fluorine F, 0.1 to 1.0 chlorine Cl, 0.1 to 2 bromine Br and traces of up to 1.0 iodine 1, 0.1 to 1.0 silver Ag, 0.001 to 0.1 silver sulfide Ag ₉ S and / or 0.001 to 0.1 silver selenide, at least one oxide in said amount from the group comprising 0.05 to 0.5 of MnO ₂ , 0.001 to 0.1 of CoO, 0.001 to 0.2 of Cr ₂ O 3, and 0.1 to 0.5 of NiO. To improve photochromic properties or to affect physical properties, such as viscosity temperature profile, refractive index, etc., the glass may further comprise 1 to 12 harium oxide BaO and / or lead oxide PbO, 0.5 to 3 arsenic oxide As ₂ O ₃ and / or or antimony trioxide Sb ₂ 03 and 1 to 12 of at least one oxide selected from the group consisting of lithium oxide Li ₂ 0, potassium oxide K ₂ 0 and zirconia ZrO ₂ ·

The glass of this composition is characterized by good photochromic properties while satisfying the requirements for sun-protection glasses. The color of the lenses is yellowish-brown to smoky before activation and brownish-brown after activation by sunlight or ultraviolet radiation.

The following table shows exemplary glass compositions according to the invention.

Component R 2 weight. R 3 silicon dioxide SiOg 53.3 53.3 aluminum oxide Al2O3 8.9 8.9 boron oxide B2O3 15.8 15.8 sodium oxide Na2O 2.9 2.9 K2O 1.4 1.4 lead oxide PbO 4.2 4.2 barium oxide BaO 6.5 6.5 lithium oxide L12O 2.3 2.3 Zirconia ZrOj 1 .8 1,8 ' CuO 0,029 0,026 silver Ag 0.24 0.25 chlorine Cl 0.5 0.5 bromine Br 0.5 0.5 fluorine F 0.99 0.99 silver sulphide Ag2S 0.005 0.005 cobalt oxide CoO - 0.01 manganese dioxide MnOj 0.24 0.35 nickel oxide NiO 0.2 0.2 chromium oxide CrjO3 0.01 0.01

The spectral characteristics of the glasses R2 and R3 prior to irradiation are shown in Figure 1, as compared to colorless photochromic glass and photochromic glass stained with Nd2O4.

Fig. 2 shows the photochromic properties of the glasses R2 and R3, i.e. the differences in optical densities with respect to the activation time and after it has been interrupted. Activation was performed with a HBO 200 W mercury lamp.

Glass R3 was melted from a batch containing, in parts by weight, 53.6 ground sand, 13.6 aluminum hydrate Al / OH / g, 11.4 barium nitrate Ba / NO 2, 28.5 boric acid H 3 BO 3, 2.4 potassium nitrate KNO3, 5.5 'sodium nitrate NaNO3, 4.4 sulphate, 1.7 sodium fluorosilicate Na2SiFg, 0.03 CuO, 0.39 silver nitrate AgNO4, 0.82 sodium chloride NaCl, 5.7 carbonate lithium Li2CO3, 1.95 zirconium dioxide ZrOj, 0.75 potassium bromide KBr, 0.005 silver sulfides Ag2S, 0.21 nickel oxide NiO, 0.019 potassium dichromate KgCl4, 0.43 manganese dioxide MnO2 and 0.011 cobalt oxide CoO. The glass was melted at 1450 ° C and the glass was homogenized by a propeller stirrer. The shaped spectacle pieces were heat treated to eliminate the microcrystalline phase of the silver halides at 600 ° C for 1 hour in support plates made of a suitable refractory material.

Color dioptric photochromic alo can also be used to optically record information, in memory device structures, etc.

Claims (4)

SUBJECT OF THE INVENTION 1. Silver halide color photochromic dioptric glass, characterized in that it contains, by weight, 30 to 70 silica, 2 to 50 boron oxide, 3 to 27 alumina, 1 to 12 sodium oxide, 0.001 to 0, At least one halogen element in said amount selected from the group consisting of 0.5 to 2 fluorine, 0.1 to 1 chlorine, 0.1 to 2 bromine and traces to 1.0 iodine, 0.1 to 1.0 silver, 0.001 to 0.1 silver sulfides and / or 0.001 to 0.1 silver selenide, at least one oxide in said 202876 gives us an amount of from 0.05 to 0.5 manganese dioxide, 0.001 to 0.1 cobalt oxide, 0.001 to 0.1 0.2 chromium trioxide and 0.1-0.5 nickel oxide. 2. Colored dioptre phato chromium glass according to claim 1, characterized in that it contains, by weight, 1 to 12 lead and / or barium oxide. 3. The colored dioptric photochromic glass according to claims 1 and 2, characterized in that it contains, by weight, 0.5 to 3 of arsenic trioxide and / or antimony trioxide. 4. The colored dioptric photochromic glass according to claim 1, 2 and 3, characterized in that it contains, by weight, 1 to 12 of at least one oxide selected from the group consisting of lithium oxide, potassium oxide and zirconium oxide.