CRYSTALLIZABLE LITHIUM ALUMINUM SILICATE GLASS AND GLASS CERAMIC PRODUCED THEREFROM

Abstract

A lithium aluminum silicate glass ceramic, which, apart from unavoidable impurities, is As2O3-free and Sb2O3-free. The lithium aluminum silicate glass ceramic has keatite as primary crystal phase and a keatite peak temperature TP of the keatite solid solution formation in the range of 980° C. to 1090° C., and the keatite peak temperature TP is determined by dynamic differential calorimetry (DSC) in accordance with DIN 51007:2019-04 at a heating rate of 5 K/min. A ceramization method is also described.

Claims

1. A lithium aluminum silicate glass ceramic, which, is free from As2O3 and Sb2O3, with keatite as a primary crystal phase, comprising: a keatite peak temperature (TP) of a keatite solid solution formation in the range of 980° C. to 1090° C.; wherein the keatite TP is determined by dynamic differential calorimetry (DSC) in accordance with DIN 51007:2019-04 at a heating rate of 5 K.Math.min.sup.−1.

2. The glass ceramic according to claim 1, comprising the following components in the following proportions (in wt % based on oxide): TABLE-US-00010 Li2O  3-5 Al2O3 18-25 SiO2 60-70 SnO2  0-0.5.

3. The glass ceramic according to claim 1, wherein the glass ceramic has a perceptual lightness L* in the color space L*, a*, b* of 60 to 97 and a brightness Y of 0.1% to 25%; wherein L* and Y are determined using the standard illuminant D65 at an angle of 2° for a 4 mm thickness of the glass ceramic.

4. The glass ceramic according to claim 1, wherein the glass ceramic is opaque and has a keatite TP in the range of 980° C. to 1070° C. as well as the following values: L*=85 to 97 a*=−1.5 to 0.5 b*=−6 to 0.5 and Y=0.1% to 2%.

5. The glass ceramic according to claim 1, wherein the glass ceramic is translucent and has a keatite TP in the range of 980° C. to 1070° C. as well as the following values: L*=72 to 93 a*=−5.5 to 0 b*=−7 to 0.5 and Y=>2% to 10%.

6. The glass ceramic according to claim 1, wherein the glass ceramic is translucent and has a keatite peak temperature TP in the range of 980° C. to 1070° C. as well as the following values: L*=60 to 82 a*=−7.5 to −2 b*=−19 to −4.5 and Y=>10% to 25%.

7. The glass ceramic according to claim 1, wherein the glass ceramic has a coefficient of mean linear thermal expansion α(20° C.; 700° C.) of 0 to 2.0×10.sup.−6/K.

8. The glass ceramic according to claim 1, further comprising 0.01 to <1 wt % MgO.

9. The glass ceramic according to claim 1, further comprising 0.5 to 3 wt % ZnO.

10. The glass ceramic according to claim 1, wherein the glass ceramic contains no more than 0.065 wt % Nd2O3.

11. The glass ceramic according to claim 1, wherein the glass ceramic contains 0 to 2 wt % P2O5.

12. The glass ceramic according to claim 1, wherein the glass ceramic contains the following components (in wt % based on oxide): TABLE-US-00011 Li2O  3.2-<4.5 Al2O3   19-23 SiO2   62-68 Na2O  0.05-1 K2O    0-1 Na2O + K2O  0.15-1.2 MgO  0.1-0.8 CaO  0.05-1 SrO    0-1.5 BaO    0-2.5 SrO + BaO  0.5-2.5 ZnO    1-2.9 B2O3    0-1 TiO2  1.8-2.8 ZrO2    1-<2.2 SnO2  0.01-<0.25 TiO2 + ZrO2 + SnO2  3.6-4.8 P2O5    0-2 Fe2O3 0.008-0.05 with 0.005 < MgO × SnO2 < 0.1 (condition B3a)

13. The glass ceramic according to claim 5, wherein the glass ceramic has a quotient (PvK−PiP)/PiP of 20 for light of wavelength 630 nm.

14. A method for producing a glass ceramic according to claim 1, comprising a crystallizable As2O3-free and Sb2O3-free lithium aluminum silicate glass, and wherein the ceramization is carried out with the following method steps in the following sequence: a) increasing the temperature of the crystallizable glass from room temperature TRT to a temperature Ta in the range of 660 to 730° C. within 3 to 60 minutes; b) increasing the temperature of the crystallizable glass from Ta to a temperature up to at most 800° C. over a time period of 5 to 100 minutes; c) increasing the temperature of the glass containing crystallization seeds within 5 to 80 minutes duration in the temperature range Tb of beginning HQ solid solution formation of 780 to 850° C.; d) residence in the temperature range Tb over a time period of 5 to 120 minutes; e) increasing the temperature of the glass containing HQ-solid solution within 5 to 80 minutes duration in the temperature range TC of high crystal growth rate from 900° C. to 950° C.; f) increasing the temperature of the glass containing HQ-solid solution within 5 to 80 minutes duration in the temperature range TD from 950° C. to 1250° C.; g) residence in the temperature range TD over a residence time tV>0 to 60 minutes; and h) rapid cooling of the obtained glass ceramic to room temperature in less than 150 minutes; wherein the ceramization of the glass comprises a total time of less than 300 min.

15. The method according to claim 14, for producing a glass ceramic that has a keatite TP≤1005° C., wherein in the method step g), the following method step is carried out: g11) residence at a temperature TD in the range of 1120° C. to 1180° C., over a residence time tV of 5 minutes to 20 minutes.

16. The method according to claim 14, for producing a glass ceramic that has a keatite TP≤1005° C., wherein in the method step g), the following method step is carried out: g12) residence at a temperature TD in the range of 1060° C. to 1120° C., over a residence time tV of 5 minutes to 20 minutes.

17. The method according to claim 14, for producing a glass ceramic that has a keatite TP≤1005° C., wherein in the method step g), the following method step is carried out: g13) residence at a temperature TD in the range of 1035° C. to 1080° C., over a residence time tV of 5 minutes to 20 minutes.

18. The method according to claim 14, for producing a glass ceramic that has a keatite TP>1005° C., wherein in the method step g), the following method step is carried out: g21) residence at a temperature TD in the range of 1145° C. to 1180° C., over a residence time tV of 5 minutes to 20 minutes.

19. The method according to claim 14, for producing a glass ceramic that has a keatite peak temperature TP>1005° C., wherein in the method step g), the following method step is carried out: g22) residence at a temperature TD in the range of 1100° C. to 1150° C., over a residence time tV of 5 minutes to 20 minutes.

20. The method according to claim 14, for producing a glass ceramic that has a keatite TP>1005° C., wherein in the method step g), the following method step is carried out: g23) residence at a temperature TD in the range of 1050° C. to 1100° C., over a residence time tV of 5 minutes to 20 minutes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0182] Next, the present disclosure will be described in detail with reference to the appended drawing, wherein:

[0183] FIG. 1 is a schematic temperature/time diagram of a ceramization program, and drawn on the time axis t are the different method steps a) to h).

DETAILED DESCRIPTION

[0184] Exemplary embodiments will be explained below on the basis of FIG. 1 and from tables.

[0185] In the method step a), the green glass is heated from an initial temperature TRT with TRT=20° C. within 3 to 60 minutes to the temperature Ta. In the subsequent method step b), in which the nucleation takes place, there occurs a continuous increase in the temperature from Ta to a temperature of at most 800° C.

[0186] In the following step c), the temperature is increased to a temperature in the temperature range Tb. In this exemplary embodiment, the residence in the temperature range Tb in accordance with step d) is associated with a continuous temperature increase within this temperature range.

[0187] Afterwards, in accordance with step e), the temperature is raised within 5 to 80 minutes to a temperature in the temperature range TC. In the step f), a further increase in temperature is carried out from the temperature TC to a temperature in the temperature range TD, which extends from 950° C. to 1250° C.

[0188] When the temperature range TD is reached, the temperature in accordance with method step g) is held constant over a residence time tV. Which temperature TD and which residence time tV are preferably to be chosen in order to optimize the properties of the glass ceramics are described in connection with the various embodiments with the preferred method steps g11 to g43. Finally, in the method step h), there occurs a rapid cooling to room temperature.

[0189] Presented in Table 1 are preferred glass compositions that underwent the different ceramization methods 1, which are identified by the labels g11) to g13) or g21) to g23) in Tables 2 to 4. The ceramization methods 2, which are identified by g31 to g33 or g41 to g43, refer to special embodiments of the ceramization method 1. Which alternative of the respective ceramization method 2 is employed ensues from the specified TD and tv values.

[0190] Table1 shows the compositions of the crystallizable starting glasses according to the invention in wt % and the associated glass properties, such as the glass transition temperature Tg and the keatite peak temperature TP. The glass 14 here serves as a Comparative Example. The glass ceramics have the same compositions as the starting glasses.

[0191] The glasses were melted as follows: [0192] a) preparation of a batch recipe from technical raw materials; [0193] b) melting and refinement of the batch recipe on a laboratory scale in a silica glass crucible at 1620° C. with a subsequent holding time of 2 h, stirring at 1600° C. for 1 h for homogenization, increase of the temperature to 1640° C., and holding for 3 h; [0194] c) production of a cast block; and [0195] d) cooling in a stress relief oven to room temperature, whereby undesired stresses in the glass are eliminated.

[0196] Table 2 shows the optical properties of the glass ceramics according to the invention produced by means of a suitable ceramization method 1 (for example, g11 or g21) and of the comparative example of the variant A with Y≤2% (opaque glass ceramic) for a thickness of approximately 4 mm as well as the coefficients of mean linear thermal expansion.

[0197] The data show that the first embodiment, in comparison to the second embodiment, has higher perceptual lightness values L*, measured in reflection, for the same or similar brightness Y, measured in transmission, for the same ceramization method. This is clear, in particular, at lower maximum temperatures TD and shorter residence times tV. Furthermore, it can be seen that the comparative example, in comparison to the glass ceramics according to the invention, has a higher perceptual lightness L* at the same or similar brightness Y for the same ceramization method, in particular at high maximum temperatures TD as well as lower maximum temperatures TD and shorter residence times tV. It is assumed that this is associated with the As2O3 as refining agent, which acts in this glass ceramic as a “whitener.” At lower maximum temperatures TD and long residence times, however, embodiment 1, in comparison to embodiment 2 as well as in comparison to the comparative example, shows higher perceptual lightness L* at the same or similar brightness Y.

[0198] The glass ceramics according to the invention have the advantage that, in comparison to the comparative example, they have a lower coefficient of mean linear thermal expansion α(20° C.; 700° C.). This contributes to the thermoshock resistance of the glass ceramics.

[0199] Furthermore, it is noticeable that the two color values a* and b* as well as c* become smaller in absolute value with increasing perceptual lightness L* within an embodiment; that is, a* goes towards 0 and b* goes towards 0 and c* goes towards 0. The Nd2O3-containing examples here form within embodiment 2 for the color values b* as well as c* a separate group in the relationship between these color values and the perceptual lightness L*. In addition, it is especially noticeable that, in comparison to embodiment 2, embodiment 1 achieves, in terms of absolute value, lower color values b* as well as lower c* values at higher perceptual lightness values L*.

[0200] It becomes clear that Fe2O3 shifts the color value a* into the positive range, that is, towards red. It is to be noted here that, in regard to a*, this glass system appears to be insensitive to an increased Fe2O3 content, since, even in comparison to the comparative examples 26 to 28, it shows the same or even a smaller color value a* in terms of absolute value for the same ceramization method. In contrast to the color value a*, it is shown that, depending on the ceramization, the color value b* can be improved for the Fe2O3-rich glass ceramic or it can even be worsened. Thus, it can be ascertained that, for compositions with a higher Fe2O3 proportion, lower maximum temperatures TD and shorter residence times tV are to be favored in order to adjust both a* and b* in an optimal manner. However, attention needs to be paid here to the perceptual lightness L*, which drops at lower maximum temperatures TD and shorter residence times tV, in order to ensure a good white impression.

[0201] The addition of Nd2O3 in the glasses according to the invention, in contrast to the comparative examples that likewise contain Nd2O3, leads to an increase in absolute value of the color values a* and b* for the same ceramization method. In comparison to the other examples of embodiment 2 as well as in comparison to embodiment 1, the addition of Nd2O3 leads to a marked reduction in the color value b*, regardless of the ceramization method, for the same or similar color value a*.

[0202] In contrast to this, the increase in the SnO2 proportion, in particular in embodiment 1, results in the fact that the color values a* and b* become more distant from the so-called neutral point with a*=0 and b*=0.

[0203] Viewed overall, embodiment 1, in comparison to embodiment 2 and in comparison to the comparative examples, shows better color values a* and b* as well as c* for low SnO2 contents and for the absence of Nd2O3.

[0204] When the transmission values at 700 nm are regarded, it becomes clear that, in particular, the values of embodiment 2, in comparison to embodiment 1 as well as in comparison to the comparative examples, have higher values for the same ceramization method. The transmission at 700 nm is proportional to the brightness Y and therefore affords an indication for the brightness Y. The advantage here is that this value is directly measured.

[0205] It becomes especially clear for the glass ceramics according to the invention shown here that the infrared transmission at 1600 nm is markedly higher for both embodiments, apart from a few exceptions, in comparison to the comparative example for the same ceramization method.

[0206] The examples further show clearly that the addition of MgO leads to an increase in the perceptual lightness L* for comparable color values a* and b*. This lies in the fact that MgO helps to shift the keatite peak temperature to lower values (see Table 1) and accordingly a high perceptual lightness L* is more easily achieved. In addition, the addition of MgO leads to an increase in the transmission at 1600 nm.

[0207] Table 3 shows the optical properties of the glass ceramic according to the invention that was produced by means of a suitable ceramization method (g12 or g22) and of the comparative examples 64 and 65 of the variant B with Y>2% to 10% (translucent glass ceramic without display capability) for a thickness of approximately 4 mm as well as the coefficients of mean linear thermal expansion. The data reveal that, in this variant, too, higher perceptual lightness L* is achieved at the same or similar brightness Y for embodiment 1 in comparison to embodiment 2 for the same ceramization methods. In comparison to embodiment 1, the comparative examples achieve here, too, a higher perceptual lightness L* when the same ceramization methods are used. In addition, embodiment 1, in comparison to embodiment 2, already achieves a very good perceptual lightness L* at lower maximum temperatures TD, that is, even at 1120° C. instead of 1145° C.

[0208] The glass ceramics of this variant do not, in general, have a display capability. This is supported by the high quotient (PvK−PiP)/PiP at 630 nm, which is greater than 39. The examples 48 and 71 constitute an exception and were evaluated as “weak.” This optical impression obtained by visual inspection is confirmed by the low quotient (PvK−PiP)/PiP at 630 nm, namely, below 10.

[0209] The glass ceramics according to the invention have the advantage that, in comparison to the comparative examples, they have a lower coefficient of mean linear thermal expansion. This contributes to the thermoshock resistance of the glass ceramics.

[0210] In contrast to the variant A, variant B shows no clear relationship between the color values a* and b* as well as c* and the perceptual lightness L* within an embodiment, as described in connection with Table 2. However, this relationship is clearly shown within a composition. Thus, the color values a* and b* as well as c* decrease in absolute value with increasing L*. Furthermore, it can be ascertained that the addition of SnO2 in embodiment 1 leads to a marked increase in absolute value in the color values a* and b* as well as c* for the same or similar perceptual lightness L* for the same ceramization. When Fe2O3 is added, the perceptual lightness L* shifts clearly to lower values for the same or similar color values a* and c*.

[0211] As already described for the variant A, the variant B reveals that an increased Fe2O3 content in the glass ceramics according to the invention, in comparison to the comparative example 64, results in a lower color value a* in absolute value for the same ceramization method.

[0212] In the variant B, embodiment 1, in comparison to embodiment 2, has the advantage, regardless of the ceramization method, even at lower maximum temperatures TD, that the b* value for the same or similar a* value can be markedly increased. The color values a* and b* as well as c*, in comparison to the comparative examples for the same ceramization method, in particular at TD=1100° C., can be reduced in absolute value in the glass ceramics according to the invention, by reducing the coloring components SnO2 and Fe2O3. Thus, in comparison to the comparative examples, markedly improved (lower in terms of absolute amount) color values a* and b* as well as c* are achieved. On the basis of glass 12, it becomes clear that an increase in the maximum temperature TD and/or a prolongation of the residence time tV leads to the fact that the color values a* and b* as well as c* can be reduced in absolute value. This can be explained within this composition by an increasing perceptual lightness L* with an increase in the maximum temperature TD and/or with a prolongation of the residence time tV.

[0213] For the same ceramization method, both embodiments show higher transmission values at 700 nm and/or at 1600 nm in comparison to the comparative examples. For the same composition of the glass ceramic, the transmission values increase at 700 and 1600 nm with a dropping maximum temperature TD for the same residence time tv. On the basis of the glass 12, it could be shown that, for a prolongation of the residence time tV, the maximum temperature TD can be lowered, so that the same transmission values are produced for a comparable perceptual lightness L*.

[0214] Table 4 shows the optical properties of the glass ceramics according to the invention that were produced by means of a suitable ceramization method (g13 or g23) and of the comparative examples 95 and 96 of the variant C with Y>10% to 25% (translucent glass ceramic with display capability) for a thickness of approximately 4 mm as well as the coefficients of mean linear thermal expansion. As already shown for the other two variants A and B, embodiment 1 shows, in comparison to embodiment 2, higher perceptual lightness values L* at the same or similar brightness Y for the same ceramization method. In particular, it becomes clear here that, for embodiment 1, lower maximum temperatures TD are sufficient, in comparison to embodiment 2, to achieve comparable perceptual lightness values L*. However, higher brightnesses Y are achieved here, which favor a better display capability for red. Also, for this variant, the comparative example shows higher perceptual lightness values L* in comparison to both embodiments when the same ceramization methods are used.

[0215] In comparison to the comparative example, however, many examples show, for the same or higher perceptual lightness values L*, a better (good) display capability. This can be explained by the smaller quotient (PvK−PiP)/PiP at 630 nm, namely, 2.2 to 4.0, of the embodiments in comparison to 7.3 of the comparative example 96. In comparison to the comparative examples, both embodiment 1 and embodiment 2 show, for a very good display capability, higher perceptual lightness values L* for higher maximum temperatures TD and/or longer residence times tV. This improves the white impression in comparison to the comparative examples, whereas, although the comparative example shows a higher perceptual lightness L* at higher maximum temperatures TD, it still has only a weak display capability.

[0216] Higher brightnesses Y, but lower perceptual lightness values L* favor a very good display capability. Also in this display capability category, many examples show higher perceptual lightness values L* in comparison to the comparative examples, thereby favoring an improved white impression.

[0217] In the variant C as well, there is, within a glass composition, a clear relation between the color values a* and b* as well as c* and the perceptual lightness L*. The higher the latter is, the higher is the maximum temperature TD for same residence times tV, or the longer the residence time tV is for lower maximum temperatures TD, the lower in absolute value are also the color values a* and b* as well as c*.

[0218] As in the case of the other two variants A and B, it becomes clear here, too, that a reduction in the SnO2 content leads to an improvement (that is, a reduction in absolute value) of the color values a* and b* as well as c* for the same ceramization method.

[0219] In comparison to the comparative examples, embodiment 1 shows, for the same ceramization method and for a reduction in the SnO2 content, markedly better color values a* and b* as well as c*, even though the perceptual lightness L* is markedly smaller in comparison to the comparative examples for the same ceramization method. This means that a further improvement in the color values a* and b* as well as c* is possible for a marked increase in the perceptual lightness values L* with an increase in the maximum temperature TD or a prolongation of the residence time tV for the same maximum temperature TD. This example highlights the fact that, with a suitable composition, no impairment in the color values a* and b* as well as c* occurs through the use of SnO2 as refining agent.

[0220] Similar or even better color values a* and b* as well as c*, in comparison to embodiment 1, can also be achieved with embodiment 2. To this end, however, higher maximum temperatures TD and/or longer residence times tV are needed.

[0221] In contrast to the comparative examples, for the same ceramization method, a comparable or even better display capability is achieved in embodiment 1.

[0222] In comparison to embodiment 1, embodiment 2 enables a good display capability to be achieved even at higher maximum temperatures TD. However, it is possible with embodiment 1, in comparison to embodiment 2, to achieve comparable or even higher perceptual lightness values L* for an equally good display capability even at lower maximum temperatures TD and/or longer residence times tV, as a result of which the white impression of embodiment 1, in comparison to embodiment 2, can be adjusted in a more energy-efficient manner.

[0223] Furthermore, the variant C, as also in the case of the other two variants A and B, shows within a composition an increasing transmission at 700 and/or 1600 nm at lower maximum temperatures TD and the same residence time tV. For the same ceramization method, the comparative examples, in comparison to embodiment 1, have a higher transmission at 700 and/or 1600 nm. However, both examples of embodiment 1 and embodiment 2 show, at higher maximum temperatures TD and/or longer residence times tV, an increased transmission at 700 and/or 1600 nm in comparison to the comparative examples.

[0224] In addition, the examples show that the removal of MgO from the composition in the variant C leads to a markedly color-neutral glass ceramic (color values a*, b*, and c* reduced in absolute value) for a comparable perceptual lightness L*. As already shown for the examples of variant A, the addition of MgO also leads in variant C to an increase in the transmission at 1600 nm, but also at 630 as well as at 700 nm.

[0225] The increase in SnO2 for a better refinement of the glass melt, in comparison to a lower SnO2 content in a suitable composition, leads to comparable color values a*, b*, and c* for a comparable perceptual lightness L*.

[0226] Table 5 shows that an annealing of the glass ceramics according to the invention with a thickness of approximately 4 mm of the variants A (embodiment 1) and B (embodiment 2) at 700° C. over an annealing time of 10 h causes no shift or only a negligible shift in the brightness Y, in the perceptual lightness L*, and in the color values a* and b*. Accordingly, in comparison to the comparative example, there is no drawback due to the use of SnO2 as a refining agent.

TABLE-US-00005 TABLE 1 Composition 1 2 3 4 5 6 Glass Li2O wt. % 3.69 3.70 3.74 3.72 3.70 3.68 Na2O wt. % 0.14 0.14 0.14 0.14 0.14 0.14 K2O wt. % 0.33 0.33 0.33 0.33 0.33 0.33 MgO wt. % 0.32 0.32 0.32 0.32 0.50 0.32 CaO wt. % 0.31 0.31 0.31 0.31 0.31 0.31 SrO wt. % 0.051 0.062 0.045 0.051 0.050 0.050 BaO wt. % 1.00 0.99 0.99 0.99 0.98 0.99 ZnO wt. % 1.86 1.84 1.84 1.87 1.85 2.07 Al2O3 wt. % 21.40 21.42 21.34 20.41 20.39 21.41 SiO2 wt. % 66.50 66.40 66.50 67.50 67.60 66.50 TiO2 wt. % 2.43 2.43 2.42 2.43 2.21 2.22 ZrO2 wt. % 1.85 1.85 1.84 1.85 1.84 1.86 P2O5 wt. % 0.038 0.034 0.031 0.032 0.030 0.031 SnO2 wt. % 0.07 0.07 0.07 0.07 0.09 0.07 Fe2O3 wt. % 0.014 0.05 0.014 0.014 0.014 0.014 Nd2O3 wt. % 0.056 As2O3 wt. % Σ wt. % 100.00 99.95 99.99 100.04 100.03 100.0 MgO × SnO2 wt. 0.02 0.02 0.02 0.02 0.04 0.02 TiO2/SnO2 34.23 33.75 34.08 33.75 25.11 31.27 TiO2 + ZrO2 + wt. % 4.35 4.35 4.33 4.35 4.14 4.15 Na2O + K2O wt. % 0.47 0.48 0.47 0.47 0.47 0.47 Na2O/K2O 0.42 0.43 0.42 0.42 0.42 0.42 SrO + BaO wt. % 1.05 1.05 1.04 1.04 1.03 1.04 SiO2/Al2O3 3.11 3.10 3.12 3.31 3.32 3.11 Al2O3/(Li2O + 3.65 3.66 3.62 3.45 3.37 3.53 MgO + ZnO) Glass Tg ° C. 687 686 680 687 686 686 Keatite peak ° C. 1043 1044 1044 1030 1032 1048 7 8 9 10 11 12 Glass Li2O wt. % 3.71 3.75 3.73 3.72 3.72 4.22 Na2O wt. % 0.14 0.13 0.14 0.14 0.13 0.22 K2O wt. % 0.33 0.33 0.33 0.33 0.33 MaO wt. % 0.31 0.31 0.49 0.31 0.49 0.40 CaO wt. % 0.31 0.31 0.31 0.31 0.31 0.43 SrO wt. % 0.051 0.050 0.050 0.050 0.050 0.010 BaO wt. % 0.98 0.99 0.99 0.99 0.99 1.02 ZnO wt. % 2.26 2.16 1.87 2.05 2.05 2.71 Al2O3 wt. % 21.34 21.42 21.41 20.40 20.40 22.48 SiO2 wt. % 66.60 66.60 67.00 67.50 67.50 64.60 TiO2 wt. % 2.02 1.92 1.92 2.23 2.01 1.92 ZrO2 wt. % 1.85 1.84 1.65 1.86 1.86 1.84 P2O5 wt. % 0.030 0.029 0.029 0.031 0.028 0.028 SnO2 wt. % 0.07 0.07 0.07 0.07 0.07 0.09 Fe2O3 wt. % 0.014 0.014 0.014 0.014 0.014 0.015 Nd2O3 wt. % As2O3 wt. % Σ wt. % 100.02 99.93 100.00 100.00 99.95 99.98 MgO × SnO2 wt. %.sup.2 0.02 0.02 0.03 0.02 0.03 0.04 TiO2/SnO2 29.28 27.47 28.24 31.80 28.32 20.68 Ti02 + ZrO2 wt. % 3.94 3.83 3.64 4.16 3.94 3.86 Na2O + K2O wt. % 0.47 0.46 0.47 0.47 0.46 0.22 Na2O/K2O 0.42 0.40 0.41 0.43 0.39 — SrO + BaO wt. % 1.03 1.04 1.04 1.04 1.04 1.03 SiO2/Al2O3 3.12 3.11 3.13 3.31 3.31 2.87 Al2O3/ 3.40 3.44 3.51 3.36 3.26 3.07 (Li2O + MgO Glass Tg ° C. 685 690 689 684 685 679 Keatite peak ° C. 1041 1040 1037 1031 1036 996 13 14 15 16 17 18 Glass Li2O wt. % 3.88 3.71 3.91 3.64 3.81 3.66 Na2O wt. % 0.12 0.15 0.15 0.15 0.14 0.17 K2O wt. % 0.20 0.20 0.33 0.32 0.42 0.31 MgO wt. % 0.40 1.07 0.32 0.32 0.33 0.29 CaO wt. % 0.33 0.02 0.31 0.25 0.25 0.41 SrO wt. % 0.009 0.008 0.050 0.500 0.300 0.055 BaO wt. % 1.03 0.83 0.99 0.55 1.01 0.95 ZnO wt. % 2.14 1.61 2.06 1.94 2.04 2.04 Al2O3 wt. % 21.55 20.13 20.47 21.70 21.66 21.73 SiO2 wt. % 66.40 67.10 67.50 66.40 66.10 66.30 TiO2 wt. % 1.94 2.38 1.92 2.20 1.92 2.07 ZrO2 wt. % 1.86 1.80 1.85 1.85 1.85 1.84 P2O5 wt. % 0.029 0.029 0.029 0.030 0.028 0.029 SnO2 wt. % 0.09 0.07 0.07 0.07 0.07 Fe2O3 wt. % 0.015 0.018 0.014 0.015 0.015 0.013 Nd2O3 wt. % 0.060 0.047 0.059 0.048 As2O3 wt. % 0.820 Σ wt. % 99.99 99.94 99.97 99.99 100.00 99.98 MgO × SnO2 wt. %.sup.2 0.04 0.00 0.02 0.02 0.02 0.02 TiO2/SnO2 21.56 — 25.89 31.94 27.04 30.90 TiO2 + ZrO2 wt. % 3.89 4.18 3.84 4.12 3.84 3.98 Na2O + K2O wt. % 0.32 0.35 0.48 0.48 0.57 0.48 Na2O/K2O 0.59 0.76 0.45 0.48 0.34 0.53 SrO + BaO wt. % 1.04 0.84 1.04 1.05 1.31 1.01 SiO2/Al2O3 3.08 3.33 3.30 3.06 3.05 3.05 Al2O3/ 3.36 3.15 3.26 3.68 3.51 3.63 (Li2O + MgO Glass Tg ° C. 687 682 684 689 684 688 Keatite peak ° C. 1030 1021 1024 1052 1029 104 19 20 21 22 Glass Li2O wt. % 3.98 4.00 4.12 3.82 Na2O wt. % 0.08 0.08 0.15 0.16 K2O wt. % 0.42 0.52 0.32 0.33 MgO wt. % 0.34 0.39 0.34 0.43 CaO wt. % 0.37 0.37 0.37 0.37 SrO wt. % 0.050 0.150 0.053 0.051 BaO wt. % 1.10 1.09 1.10 1.19 ZnO wt. % 2.18 1.99 2.12 2.16 Al2O3 wt. % 20.00 20.44 20.52 20.51 SiO2 wt. % 67.40 67.00 66.90 67.00 TiO2 wt. % 1.93 1.92 1.90 1.94 ZrO2 wt. % 1.91 1.91 1.86 1.91 P2O5 wt. % 0.028 0.029 0.029 0.028 SnO2 wt. % 0.22 0.07 0.17 0.12 Fe2O3 wt. % 0.014 0.014 0.014 0.014 Nd2O3 wt. % As2O3 wt. % Σ wt. % 100.01 99.97 99.97 100.02 MgO × wt. %.sup.2 0.08 0.03 0.06 0.05 TiO2/ 8.68 25.95 10.94 15.74 TiO2 + wt. % 4.06 3.90 3.94 3.97 Na2O + wt. % 0.49 0.60 0.48 0.48 Na2O/ 0.19 0.15 0.47 0.48 SrO + BaO wt. % 1.15 1.24 1.15 1.24 SiO2/ 3.37 3.28 3.26 3.27 Al2O3/ 3.08 3.21 3.12 3.20 (Li2O + Glass Tg ° C. 676 679 676 682 Keatite ° C. 1002 1008 995 1019 23 24 25 26 Glass Li2O wt. % 4.04 4.15 3.70 4.18 Na2O wt. % 0.13 0.14 0.14 0.15 K2O wt. % 0.33 0.32 0.33 0.33 MgO wt. % 0.32 0.33 0.32 0.33 CaO wt. % 0.31 0.37 0.31 0.37 SrO wt. % 0.052 0.051 0.052 0.052 BaO wt. % 0.99 1.10 0.99 1.10 ZnO wt. % 1.91 2.05 1.85 2.11 Al2O3 wt. % 21.49 21.54 20.29 20.39 SiO2 wt. % 66.40 66.10 67.60 67.10 TiO2 wt. % 2.03 1.91 2.43 1.90 ZrO2 wt. % 1.85 1.86 1.85 1.85 P2O5 wt. % 0.028 0.027 0.030 0.027 SnO2 wt. % 0.07 0.07 0.08 0.07 Fe2O3 wt. % 0.015 0.015 0.014 0.015 Nd2O3 wt. % 0.021 As2O3 wt. % Σ wt. % 99.96 100.04 100.01 99.97 MgO × wt. % 0.02 0.02 0.03 0.02 SnO2 TiO2/ 29.03 28.49 31.15 26.82 SnO2 TiO2 + wt. % 3.95 3.84 4.36 3.83 ZrO2 + SnO2 Na2O + wt. % 0.46 0.47 0.47 0.47 K2O Na2O/ 0.40 0.44 0.41 0.45 K2O SrO + BaO wt. % 1.04 1.15 1.04 1.15 SiO2/ 3.09 3.07 3.33 3.29 Al2O3 Al2O3/ 3.43 3.30 3.46 3.08 (Li2O + MgO + ZnO) Glass properties Tg ° C. 684 676 Keatite ° C. 1022 1012 >1005 ≤1005 solid solution peak temperature 27 28 29 30 31 Glass Li2O wt. % 4.15 4.17 4.18 4.01 4.15 Na2O wt. % 0.24 0.14 0.14 0.12 0.13 K2O wt. % 0.32 0.32 0.33 0.33 0.32 MgO wt. % 0.33 0.32 0.33 CaO wt. % 0.37 0.36 0.36 0.31 0.36 SrO wt. % 0.050 0.067 0.237 0.050 0.051 BaO wt. % 1.09 1.38 1.21 1.00 1.11 ZnO wt. % 2.13 2.14 2.16 2.03 2.14 Al2O3 wt. % 20.36 20.44 20.49 20.39 20.52 SiO2 wt. % 67.00 67.00 66.90 67.50 66.90 TiO2 wt. % 1.91 1.90 1.91 1.93 1.90 ZrO2 wt. % 1.85 1.86 1.86 1.87 1.86 P2O5 wt. % 0.027 0.027 0.027 0.030 0.027 SnO2 wt. % 0.17 0.17 0.17 0.07 0.17 Fe2O3 wt. % 0.014 0.014 0.014 0.014 0.014 Nd2O3 wt. % 0.023 0.015 0.023 As2O3 wt. % Σ wt. % 100.02 100.01 99.98 99.99 100.01 MgO × wt. % 0.06 0.00 0.00 0.02 0.06 TiO2/ 11.16 11.18 11.10 27.13 11.25 TiO2 + wt. % 3.93 3.93 3.94 3.87 3.93 Na2O + wt. % 0.57 0.46 0.46 0.45 0.45 Na2O/ 0.76 0.43 0.43 0.38 0.40 SrO + BaO wt. % 1.14 1.45 1.45 1.05 1.16 SiO2/ 3.29 3.28 3.27 3.31 3.26 Al2O3/ 3.08 3.24 3.23 3.20 3.10 (Li2O + Glass properties Tg ° C. Keatite ° C. <1005 >1005 >1005 >1005 <1005 solid 32 33 34 35 36 37 Glass Li2O wt. % 4.17 3.84 3.83 3.79 3.81 3.65 Na2O wt. % 0.13 0.26 0.25 0.06 0.26 0.25 K2O wt. % 0.32 0.23 0.24 0.23 0.24 0.24 MaO wt. % 0.34 0.32 0.33 0.32 0.32 0.32 CaO wt. % 0.37 0.31 0.31 0.31 0.31 0.31 SrO wt. % 0.23 0.251 0.252 0.251 0.250 0.24 BaO wt. % 0.94 0.80 0.80 0.80 0.80 0.80 ZnO wt. % 2.16 1.87 1.87 1.84 1.87 1.84 Al2O3 wt. % 20.4 20.45 20.53 20.31 20.38 20.4 SiO2 wt. % 66.8 67.30 67.10 67.20 67.30 67.4 TiO2 wt. % 1.91 2.41 2.40 2.41 2.42 2.43 ZrO2 wt. % 1.86 1.86 1.86 2.24 1.86 1.86 P2O5 wt. % 0.02 0.029 0.029 0.029 0.031 0.03 SnO2 wt. % 0.17 0.07 0.12 0.07 0.11 0.07 Fe2O3 wt. % 0.01 0.015 0.014 0.014 0.014 0.01 Nd2O3 wt. % 0.022 0.025 0.053 0.050 0.02 As2O3 wt. % Σ wt. % 99.9 100.03 99.95 99.92 100.02 99.9 MgO × wt. % 0.06 0.02 0.04 0.02 0.04 0.02 TiO2/ 11.0 37.08 20.34 35.44 — 35.7 TiO2 + wt. % 3.94 4.34 4.38 4.72 4.39 4.36 Na2O + wt. % 0.45 0.49 0.49 0.29 0.49 0.49 Na2O/ 0.40 1.09 — 0.24 1.07 1.06 SrO + wt. % 1.17 1.05 1.05 1.05 1.05 1.05 SiO2/ 3.26 3.29 3.27 3.31 3.30 3.29 Al2O3 / 3.07 3.39 3.41 3.41 3.40 3.53 (Li2O + Glass properties Tg ° C. 682 Keatite ° C. ≤1005 1029 1027 >1005 >1005 1051 solid 38 39 40 41 42 Glass Li2O wt. % 3.66 3.81 3.85 3.85 3.79 Na2O wt. % 0.24 0.25 0.25 0.25 0.24 K2O wt. % 0.24 0.24 0.23 0.24 0.23 MgO wt. % 0.32 0.32 0.32 0.32 0.32 CaO wt. % 0.31 0.31 0.31 0.30 0.31 SrO wt. % 0.252 0.252 0.250 0.251 0.248 BaO wt. % 0.80 0.81 0.81 0.80 0.80 ZnO wt. % 1.84 2.24 2.24 2.22 2.23 Al2O3 wt. % 20.43 21.49 21.41 21.45 21.40 SiO2 wt. % 67.40 66.30 66.20 66.20 66.30 TiO2 wt. % 2.43 2.02 2.02 2.04 2.01 ZrO2 wt. % 1.86 1.85 1.85 1.85 1.86 P2O5 wt. % 0.029 0.026 0.027 0.027 0.027 SnO2 wt. % 0.09 0.07 0.12 0.07 0.12 Fe2O3 wt. % 0.014 0.014 0.014 0.014 0.014 Nd2O3 wt. % 0.024 0.025 0.026 0.054 0.052 As2O3 wt. % Σ wt. % 99.94 100.02 99.93 99.92 99.95 MgO × wt. % 0.03 0.02 0.04 0.02 0.04 TiO2/ 26.70 28.84 16.97 30.85 17.07 TiO2 + wt. % 4.38 3.94 3.99 3.95 3.99 Na2O + wt. % 0.48 0.48 0.48 0.48 0.47 Na2O/ 1.03 1.03 1.06 1.06 1.01 SrO + wt. % 1.05 1.06 1.06 1.05 1.05 SiO2/ 3.30 3.09 3.09 3.09 3.10 Al2O3/ 3.51 3.37 3.34 3.36 3.38 (Li2O + Glass properties Tg ° C. 691 687 Keatite ° C. 1049 1032 1031 >1005 >1005 solid 43 44 45 46 47 Glass Li2O wt. % 3.84 3.87 3.84 3.85 3.73 Na2O wt. % 0.24 0.25 0.25 0.24 0.24 K2O wt. % 0.32 0.32 0.32 0.31 0.23 MgO wt. % 0.33 0.33 0.33 0.33 0.31 CaO wt. % 0.25 0.25 0.24 0.25 0.31 SrO wt. % 0.290 0.293 0.291 0.291 0.252 BaO wt. % 1.02 1.02 1.02 1.03 0.80 ZnO wt. % 2.03 2.05 2.00 2.01 1.84 Al2O3 wt. % 21.68 21.68 21.66 21.66 20.49 SiO2 wt. % 66.10 65.90 66.10 66.00 67.30 TiO2 wt. % 1.91 1.92 1.91 1.92 2.41 ZrO2 wt. % 1.85 1.86 1.85 1.85 1.86 P2O5 wt. % 0.027 0.027 0.027 0.026 0.029 SnO2 wt. % 0.07 0.12 0.07 0.12 0.07 Fe2O3 wt. % 0.015 0.015 0.015 0.015 0.014 Nd2O3 wt. % 0.023 0.019 0.053 0.053 0.051 As2O3 wt. % Σ wt. % 99.99 99.93 99.97 99.95 99.94 MgO × wt. % 0.02 0.04 0.02 0.04 0.02 TiO2/ 26.49 15.61 27.34 16.38 36.52 TiO2 + wt. % 3.83 3.90 3.83 3.88 4.34 Na20 + wt. % 0.56 0.57 0.56 0.56 0.48 Na2O/ 0.75 0.78 0.78 0.78 1.04 SrO + wt. % 1.31 1.31 1.31 1.32 1.05 SiO2/ 3.05 3.04 3.05 3.05 3.28 Al2O3/ 3.50 3.47 3.51 3.50 3.48 (Li2O + Glass properties Tg ° C. 684 Keatite ° C. 1029 1027 >1005 >1005 >1005 solid indicates data missing or illegible when filed

TABLE-US-00006 TABLE 2 Variant A Glass 2 2 2 3 3 3 4 Example 1 2 3 4 5 6 7 Comparative example Properties of glass ceramic Variant A A A A A A A Embodiment 2 2 2 2 2 2 2 Ceramization g21 g21 g21 g21 g21 g21 g21 methods 1 Ceramization g41 g41 g41 g41 g41 methods 2 T D ° C. 1145 1170 1145 1170 1145 1145 1170 tV min 6.5 6.5 15 6.5 6.5 15 6.5 Transmission mm 3.95 3.98 3.90 3.96 3.95 3.96 3.89 (D65/2°), Thickness Y % 1.4 0.3 0.6 0.5 1.7 0.5 1.3 (PvK-PiP)/PiP at 100.5 104.8 119.8 103.7 104.3 120.0 106.6 630 nm Transmission at % 8.1 3.4 4.8 3.7 8.3 3.9 6.2 700 nm (PvK) Transmission at % 63.6 40.7 46.0 44.6 67.5 46.5 44.9 1600 nm (PvK) Reflection mm 3.95 3.98 3.90 3.96 3.95 3.96 3.89 (D65/2°), Thickness L* 85.0 92.2 91.3 92.5 89.0 92.1 93.1 a* 0.2 0.3 0.3 −0.4 0.9 −0.5 −0.3 b* −0.6 −1.9 −2.2 −3.8 −5.5 −4.1 −2.5 c* 0.6 1.9 2.2 3.8 5.5 4.1 2.5 α(20° C.; 700° C.) ppm/K 0.97 Glass 4 5 6 6 7 7 8 Example 8 9 10 11 12 13 14 Comparative Example Glass ceramic properties Variant A A A A A A A Embodiment 2 2 2 2 2 2 2 Ceramization methods g21 g21 g21 g21 g21 g21 g21 1 Ceramization methods g41 g41 g41 g41 g41 g41 g41 2 T.sub.D ° C. 1145 1170 1170 1145 1170 1145 1170 tV min 15 6.5 6.5 15 6.5 15 6.5 Transmission mm 3.88 3.96 3.86 3.84 3.93 3.90 3.96 (D65/2°), Thickness Y % 0.8 1.6 1.3 1.8 1.4 1.9 1.9 (PvK-PiP)/PiP at 630 103.9 93.5 105.0 101.3 101.3 96.1 100.7 nm Transmission at 700 nm % 4.4 6.5 6.1 7.4 6.1 7.7 7.3 (PvK) Transmission at 1600 % 50.6 39.8 53.4 59.2 51.6 59.6 54.9 nm (PvK) Reflection (D65/2°), mm 3.88 3.96 3.86 3.84 3.93 3.90 3.96 Thickness L* 93.9 92.7 93.1 92.5 93.1 92.1 93.2 a* −0.1 −0.3 −0.3 −0.5 −0.3 −0.6 −0.5 b* −2.3 −2.1 −2.3 −2.6 −2.4 −2.7 −2.2 c* 2.3 2.2 2.3 2.6 2.5 2.7 2.2 α(20° C.; 700° C.) ppm/K Glass 9 9 10 10 11 11 12 Example 15 16 17 18 19 20 21 Comparative Example Glass ceramic properties Variant A A A A A A A Embodiment 2 2 2 2 2 2 1 Ceramization g21 g21 g21 g21 g21 g21 g11 methods 1 Ceramization g41 g41 g41 g41 g41 g41 g31 methods 2 TD ° C. 1170 1145 1170 1145 1170 1145 1145 tV min 6.5 15 6.5 15 6.5 15 6.5 Transmission mm 3.92 3.97 3.90 3.99 3.94 3.95 3.94 (D65/2°), Thickness Y % 2.0 1.6 2.0 1.3 1.6 1.9 0.6 (PvK-PiP)/PiP at 630 99.0 97.0 102.3 107.1 99.5 101.3 106.4 nm Transmission at 700 % 7.2 6.7 7.3 5.4 6.1 6.6 3.3 nm (PvK) Transmission at 1600 % 41.9 6.7 41.2 5.4 35.3 38.4 26.9 nm (PvK) Reflection (D65/2°), mm 3.92 3.97 3.90 3.99 3.94 3.95 3.94 Thickness L* 93.1 92.7 92.8 93.3 93.8 92.9 94.5 a* −0.3 −0.4 −0.4 −0.2 −0.2 −0.2 0.2 b* −2.4 −2.3 −2.3 −1.9 −1.9 −1.6 −0.9 c* 2.5 2.3 2.3 1.9 1.9 1.7 0.9 α(20° C.; 700° C.) ppm/K 0.91 Glass 12 12 13 13 14 14 14 Example 22 23 24 25 Comparative 26 27 28 Example Glass ceramic properties Variant A A A A A A A Embodiment 1 1 2 2 Ceramization g11 g11 g21 g21 g21 g21 g21 methods 1 Ceramization g31 g31 g41 g41 g41 g41 methods 2 TD ° C. 1170 1145 1170 1145 1145 1170 1145 tV min 6.5 15 6.5 15 6.5 6.5 15 Transmission mm 4.05 3.99 4.01 3.98 3.94 3.91 3.91 (D65/2°), Thickness Y % 0.2 0.3 1.1 1.9 1.5 0.7 0.8 (PvK-PiP)/PiP at 630 202.3 812.0 109. 893.9 109.3 114.1 129.6 nm Transmission at 700 % 1.5 1.8 5.3 6.9 6.2 3.7 4.1 nm (PvK) Transmission at 1600 % 17.0 18.3 45.1 45.6 29.2 20.5 21.3 nm (PvK) Reflection (D65/2°), mm 4.05 3.99 4.01 3.98 3.94 3.91 3.91 Thickness L* 95.5 95.8 94.0 92.3 95.0 96.7 94.4 a* −0.1 −0.2 −0.3 −0.6 −0.7 −0.3 −0.4 b* 1.2 −0.8 −1.6 −1.7 −1.9 −1.5 −0.8 c* 1.2 0.9 1.6 1.8 2.0 1.5 0.9 α(20° C.; 700° C.) ppm/K 0.99 Glass 15 15 16 16 17 17 18 Example 29 30 31 32 33 34 35 Comparative Example Glass ceramic properties Variant A A A A A A A Embodiment 2 2 2 2 2 2 2 Ceramization g21 g21 g21 g21 g21 g21 g21 methods 1 Ceramization g41 g41 g41 g41 g41 g41 g41 methods 2 TD ° C. 1170 1145 1170 1145 1170 1145 1170 tV min 6.5 15 6.5 15 6.5 15 6.5 Transmission mm 4.00 4.00 4.00 3.99 3.92 3.91 3.91 (D65/2°), Thickness Y % 1.6 1.6 0.8 1.1 1.2 1.7 0.9 (PvK-PiP)/PiP at 630 111.6 99.5 102.1 102.7 91.7 102.8 nm Transmission at 700 % 6.1 6.0 4.9 5.8 6.2 7.4 5.2 nm (PvK) Transmission at 1600 % 38.1 39.7 47.9 50.4 44.7 51.2 49.2 nm (PvK) Reflection (D65/2°), mm 4.00 4.00 4.00 3.99 3.92 3.91 3.91 Thickness L* 93.8 93.6 92.8 91.6 93.1 92.4 93.3 a* −0.2 −0.2 −0.3 −0.6 −0.4 −0.5 −0.4 b* −1.7 −1.3 −3.4 −3.8 −3.8 −3.9 −3.4 c* 1.7 1.3 3.4 3.8 3.8 3.9 3.4 α(20° C.; 700° C.) ppm/K Glass 18 19 19 19 20 20 21 Example 36 37 38 39 40 41 42 Comparative Example Properties of glass ceramic Variant A A A A A A A Embodiment 2 1 1 1 2 2 1 Ceramization g21 g11 g11 g11 g21 g21 g11 methods 1 Ceramization g41 g31 g31 g31 g41 g41 g31 methods 2 TD ° C. 1145 1145 1170 1145 1170 1145 1145 tV min 15 6.5 6.5 15 6.5 15 6.5 Transmission mm 3.91 4.00 3.97 4.00 4.00 3.98 3.98 (D65/2°), Thickness Y % 1.3 1.7 0.6 0.6 1.3 1.2 1.4 (PvK-PiP)/PiP at 630 95.1 100.4 90.5 93.9 nm Transmission at 700 % 6.7 7.4 3.9 3.8 5.8 5.4 6.0 nm (PvK) Transmission at 1600 % 56.6 68.9 50.2 54.4 61.4 62.4 64.5 nm (PvK) Reflection (D65/2°), mm 3.91 4.00 3.97 4.00 4.00 3.98 3.98 Thickness L* 92.4 93.3 94.8 95.5 95.4 95.5 94.2 a* −0.6 −1.1 −0.4 −0.4 −0.5 −0.5 −0.8 b* −3.9 −1.1 −0.9 −1.2 −1.5 −1.8 −1.5 c* 3.9 1.5 1.0 1.3 1.6 1.9 1.7 α(20° C.; 700° C.) ppm/K 0.62 0.66 Glass 21 21 22 22 Example 43 44 45 46 Comparative Example Properties of glass ceramic Variant A A A A Embodiment 1 1 2 2 Ceramization g11 g11 g21 g21 methods 1 Ceramization g31 g31 g41 g41 methods 2 TD ° C. 1170 1145 1170 1145 tV min 6.5 15 6.5 15 Transmission mm 4.01 4.01 4.03 3.96 (D65/2°) Thickness, Y % 0.4 0.6 0.8 0.6 (PvK-PiP)/PiP at 630 83.2 115.6 nm Transmission at 700 % 3.0 3.3 4.5 3.6 nm (PvK) Transmission at 1600 % 43.9 47.2 35.1 29.5 nm (PvK) Reflection (D65/2°), mm 4.01 4.01 4.03 3.96 Thickness L* 95.9 95.9 93.5 94.4 a* −0.3 −0.3 −0.2 −0.1 b* −1.2 −1.3 −1.9 −1.6 c* 1.3 1.3 2.0 1.6 α(20° C.; 700° C.) ppm/K Glass 23 25 27 28 Example 47 48 49 50 Comparative Example Properties of glass ceramic Variant A A A A Embodiment 2 2 1 2 Ceramization g21 g21 g11 g21 methods 1 Ceramization g41 g41 methods 2 T.sub.D ° C. 1145 1145 1145 1145 t.sub.V min 15 15 6.5 6.5 Transmission mm 3.96 3.94 3.98 3.98 (D65/2°), Thickness Y % 1.9 0.8 1.6 2.0 Transmission @ 630 % 4.3 2.4 4.0 5.1 nm (PvK) Transmission @ 630 % nm (PiP) PvK-PiP @ 630 nm % (PvK-PiP)/PiP @ 630 nm Transmission @ 700 % 7.1 4.9 7.3 8.7 nm (PvK) Transmission @ 1600 % 41.8 52.2 67.2 55.9 nm (PvK) Reflection (D65/2°), mm 3.96 3.94 3.98 3.98 Thickness L* 91.0 91.6 92.2 89.5 a* −0.3 −0.3 −0.7 −0.7 b* −0.4 −1.7 −0.2 −1.1 c* 0.5 1.7 0.7 1.3 α(20° C.; 700° C.) ppm/K 0.68 Glass 29 30 31 33 34 Example 51 52 53 54 55 Comparative Example Properties of glass ceramic Variant A A A A A Embodiment 2 2 1 2 2 Ceramization g21 g21 g11 g21 g21 methods 1 Ceramization g41 g41 g41 methods 2 T.sub.D ° C. 1145 1145 1145 1145 1145 t.sub.V min 6.5 15 6.5 15 15 Transmission(D65/2), mm 3.98 3.96 3.96 3.94 3.92 Thickness Y % 1.7 1.5 1.8 0.5 0.4 Transmission @ 630 % 4.2 3.7 4.7 1.6 1.4 nm (PvK) Transmission @ 630 % nm (PiP) PvK-PiP @ 630 nm % (PvK-PiP)/PiP @ 630 nm Transmission @ 700 % 7.7 6.2 8.2 3.5 3.2 nm (PvK) Transmission @ 160 % 53.3 40.4 66.7 48.0 45.3 nm (PvK) Reflection (D65/2°), mm 3.98 3.96 3.96 3.94 3.92 Thickness L* 90.2 92.3 91.5 92.1 92.6 a* −0.4 −0.1 −0.8 −0.2 −0.3 b* −0.4 −0.4 −1.1 −1.5 −1.0 c* 0.5 0.4 1.4 1.5 1.1 α(20° C.; 700° C.) 0.90 0.91 ppm/K Glass 35 36 37 38 39 40 Example 56 57 58 59 60 61 Comparative Example Properties of glass ceramic Variant A A A A A A Embodiment 2 2 2 2 2 2 Ceramization g21 g21 g21 g21 g21 g21 methods 1 Ceramization g41 g41 g41 g41 g41 g41 methods 2 T.sub.D ° C. 1145 1145 1145 1145 1145 1145 t.sub.V min 15 15 15 15 15 15 Transmission(D65/2°), mm 3.93 4.05 3.86 3.97 3.89 3.98 Thickness Y % 0.3 0.3 1.0 0.8 1.8 1.3 Transmission @ 630 % 1.1 1.1 2.9 2.5 4.5 3.6 nm (PvK) Transmission @ 630 % nm (PiP) PvK-PiP @ 630 nm % (PvK-PiP)/PiP @ 630 nm Transmission @ 700 % 2.7 2.7 5.7 5.1 7.7 6.5 nm (PvK) Transmission @ 1600 % 52.3 44.9 54.0 52.8 55.8 52.8 nm (PvK) Reflection (D65/2°), mm 3.93 4.05 3.86 3.97 3.89 3.98 Thickness L* 90.5 92.7 90.8 90.7 91.1 91.3 a* −0.3 −0.3 −0.5 −0.5 −0.5 −0.6 b* −2.8 −1.5 −2.4 −2.1 −1.4 −1.1 c* 2.8 1.6 2.4 2.2 1.5 1.3 ppm/K 0.82 0.87 0.93 0.93 0.92 0.91 Glass 41 42 44 45 46 47 Example 62 63 64 65 66 67 Comparative Example Properties of glass ceramic Variant A A A A A A Embodiment 2 2 2 2 2 2 Ceramization g21 g21 g21 g21 g21 g21 methods 1 Ceramization g41 g41 g41 g41 g41 g41 methods 2 T.sub.D ° C. 1145 1145 1145 1145 1145 1145 t.sub.V min 15 15 15 15 15 15 Transmission mm 3.97 3.97 3.94 3.85 3.86 4.10 (D65/2°), Thickness Y % 1.6 1.2 1.8 2.0 1.7 0.3 Transmission @ 630 % 4.3 3.6 4.5 5.1 4.7 1.1 nm (PvK) Transmission @ 630 % nm (PiP) PvK-PiP @ 630 nm % (PvK-PiP)/PiP @ 630 nm Transmission @ 700 % 7.5 6.5 7.6 8.3 7.9 2.6 nm (PvK) Transmission @ 1600 % 55.3 52.6 49.2 52.9 53.7 45.6 nm (PvK) Reflection (D65/2°), mm 3.97 3.97 3.94 3.85 3.86 4.10 Thickness L* 90.8 90.7 91.5 90.7 90.8 92.1 a* −0.5 −0.6 −0.6 −0.5 −0.6 −0.4 b* −2.3 −1.7 −0.9 −2.4 −2.0 −2.4 c* 2.3 1.8 1.0 2.4 2.1 2.4 α(20° C.; 700° C.) ppm/K 0.93 0.91 1.01 1.02 1.00 0.91 PVK = specimen in front of the sphere; PiP = specimen in the specimen chamber - Translator's note

TABLE-US-00007 TABLE 3 Variant B Glass 1 2 4 5 6 7 Example 68 69 70 71 72 73 Comparative Example Properties of glass ceramic Variant B B B B B B Embodiment 2 2 2 2 2 2 Ceramization g22 g22 g22 g22 g22 g22 methods 1 Ceramization g42 g42 g42 g42 g42 methods 2 T.sub.D ° C. 1145 1100 1145 1145 1145 1145 t.sub.V min 6.5 6.5 6.5 6.5 6.5 Transmission mm 3.98 4.01 3.92 3.97 3.96 3.92 (D65/2°), Thickness Y % 2.3 8.2 4.0 4.7 3.3 3.2 Transmission at % 5.2 16.2 7.9 8.6 6.9 7.4 630 nm (PvK) Transmission at % 0.1 3.1 0.1 0.1 0.1 0.1 630 nm (PiP) (PvK-PiP)/PiP 103.6 4.2 99.3 94.3 99.0 96.2 at 630 nm Transmission at % 9.1 26.2 11.9 12.1 10.9 11.3 700 nm (PvK) Transmission at % 68.5 77.8 65.5 60.5 72.2 71.1 1600 nm (PvK) Display capability poor for red Reflection (D65/2°), mm 3.98 4.01 3.92 3.97 3.96 3.92 Thickness L* 87.5 72.3 89.0 85.4 89.7 89.6 a* −0.8 −2.0 −1.1 −1.4 −1.1 −1.0 b* −0.8 −6.3 −4.1 −1.3 −3.9 −3.6 c* 1.1 6.6 4.3 1.9 4.0 3.8 α(20° C.; 700° C.) ppm/K 0.96 0.95 Glass 8 8 9 10 11 12 Example 74 75 76 77 78 79 Comparative Example Properties of glass ceramic Variant B B B B B B Embodiment 2 2 2 2 2 1 Ceramization g22 g22 g22 g22 g22 g12 methods 1 Ceramization g42 g42 g42 g42 g42 g32 methods 2 T.sub.D ° C. 1145 1145 1145 1145 1145 1100 t.sub.V min 6.5 15 6.5 6.5 6.5 6.5 Transmission mm 3.90 3.93 3.93 3.99 3.96 4.00 (D65/2°), Thickness Y % 5.2 3.0 5.7 5.1 4.5 4.6 Transmission at % 9.5 6.1 9.8 9.0 8.1 8.4 630 nm (PvK) Transmission at % 0.1 0.1 0.1 0.1 0.1 0.1 630 nm (PiP) (PvK-PiP)/PiP at 91.8 105.6 94.3 91.0 94.5 96.3 630 nm Transmission at % 13.5 9.4 13.4 12.5 11.4 11.9 700 nm (PvK) Transmission at % 73.5 60.1 62.1 61.8 54.5 60.7 1600 nm (PvK) Display capability poor for red Reflection (D65/2°), mm 3.90 3.93 3.93 3.99 3.96 4.00 Thickness L* 89.1 92.3 88.7 88.4 89.7 85.4 a* −1.4 −0.8 −1.4 −1.2 −0.9 −1.1 b* −3.8 −2.6 −4.2 −3.7 −2.9 −1.3 c* 4.1 2.8 4.5 3.9 3.0 1.7 α(20° C.; 700° C.) ppm/K 0.85 Glass 12 12 12 13 13 14 Example 80 81 82 83 84 Comparative Example Properties of glass 85 ceramic Variant B B B B B B Embodiment 1 1 1 2 2 Ceramization g12 g12 g12 g22 g22 g22 methods 1 Ceramization g32 g42 g42 methods 2 T.sub.D ° C. 1120 1080 1065 1145 1120 1100 t.sub.V min 6.5 6.5 15 6.5 6.5 6.5 Transmission mm 3.99 3.95 3.93 4.00 3.98 3.92 (D65/2°), Thickness Y % 2.2 8.6 8.5 3.1 7.4 5.9 Transmission at % 4.6 13.2 13.1 6.5 12.5 10.9 630 nm (PvK) Transmission at % 0.2 0.2 0.1 0.3 0.1 630 nm (PiP) (PvK-PiP)/PiP at 68.3 65.3 105.4 39.7 97.6 630 nm Transmission at % 7.3 16.8 16.7 10.1 17.3 14.2 700 nm (PvK) Transmission at % 45.7 69.0 69.1 64.4 76.9 58.5 1600 nm (PvK) Display capability none none none for red Reflection (D65/2°), mm 3.99 3.95 3.93 4.00 3.98 3.92 Thickness L* 91.5 82.4 82.0 90.4 83.2 89.1 a* −0.6 −2.6 −2.6 −1.0 −2.6 −2.3 b* −1.0 −3.3 −3.2 −2.4 −5.2 −4.1 c* 1.2 4.2 4.1 2.6 5.8 4.7 α(20° C.; 700° C.) ppm/K 0.84 0.97 Glass 14 15 15 16 17 18 Example 87 88 89 90 91 Comparative 86 Example Properties of glass ceramic Variant B B B B B B Embodiment 2 2 2 2 2 Ceramization g22 g22 g22 g22 g22 g22 methods 1 Ceramization g42 g42 g42 g42 g42 g42 methods 2 T.sub.D ° C. 1120 1145 1120 1145 1145 1145 t.sub.V min 6.5 6.5 6.5 6.5 6.5 6.5 Transmission mm 3.92 3.99 3.99 3.99 3.91 3.92 (D65/2°), Thickness Y % 3.3 3.9 8.0 2.6 3.7 2.7 Transmission at % 7.3 7.3 12.5 6.3 8.0 6.5 630 nm (PvK) Transmission at % 0.1 0.2 0.1 630 nm (PiP) (PvK-PiP)/PiP at 96.9 78.9 99.3 630 nm Transmission at % 10.2 10.8 16.1 10.3 11.7 10.4 700 nm (PvK) Transmission at % 44.5 58.6 72.2 70.9 66.0 71.1 1600 nm (PvK) Display capability none for red Reflection (D65/2°), mm 3.92 3.99 3.99 3.99 3.91 3.92 Thickness L* 92.4 90.4 84.6 89.3 89.7 90.0 a* −1.4 −0.8 −1.9 −1.0 −1.2 −1.1 b* −2.8 −2.9 −4.4 −5.3 −5.5 −5.2 c* 3.1 3.0 4.8 5.4 5.6 5.3 α(20° C.; 700° C.) ppm/K 0.79 Glass 19 19 20 20 21 21 Example 92 93 94 95 96 97 Comparative Example Properties of glass ceramic Variant B B B B B B Embodiment 1 1 2 2 1 1 Ceramization g12 g12 g22 g22 g12 g12 methods 1 Ceramization g32 g32 g42 g42 g32 g32 methods 2 T.sub.D ° C. 1100 1120 1145 1120 1100 1120 t.sub.V min 6.5 6.5 6.5 6.5 6.5 6.5 Transmission mm 4.00 3.98 4.00 3.96 4.02 3.99 (D65/2°), Thickness Y % 9.4 4.9 3.7 7.4 7.3 3.7 Transmission at % 15.6 9.5 7.3 12.5 12.6 7.6 630 nm (PvK) Transmission at % 1.4 0.1 0.2 0.3 630 nm (PiP) (PvK-PiP)/PiP at 9.9 89.6 56.9 40.9 630 nm Transmission at % 22.7 14.0 11.2 17.3 17.9 11.6 700 nm (PvK) Transmission at % 83.8 80.2 76.0 81.9 84.0 79.0 1600 nm (PvK) Display capability for poor none none red Reflection (D65/2°), mm 4.00 3.98 4.00 3.96 4.02 3.99 Thickness L* 83.3 89.0 92.3 88.0 86.1 90.9 a* −5.0 −2.8 −1.4 −3.0 −4.0 −1.9 b* −5.1 −2.1 −3.0 −5.6 −4.8 −2.0 c* 7.1 3.5 3.3 6.4 6.3 2.8 α(20° C.; 700° C.) ppm/K 0.62 0.76 0.66 Glass 22 22 22 Example 98 99 100 Comparative Example Properties of glass ceramic Variant B B B Embodiment 2 2 2 Ceramization g22 g22 g22 methods 1 Ceramization g42 g42 methods 2 T.sub.D ° C. 1145 1100 1120 t.sub.V min 6.5 6.5 6.5 Transmission mm 3.98 4.00 3.99 (D65/2°), Thickness Y % 2.3 9.1 5.3 Transmission at % 5.1 14.0 9.5 630 nm (PvK) Transmission at % 0.1 0.3 630 nm (PiP) (PvK-PiP)/PiP at 95.0 45.8 630 nm Transmission at % 8.4 18.2 13.3 700 nm (PvK) Transmission at % 49.9 74.4 65.4 1600 nm (PvK) Display capability none for red Reflection (D65/2°), mm 3.98 4.00 3.99 Thickness L* 90.6 81.1 86.7 a* −0.5 −2.5 −1.5 b* −2.3 −4.8 −3.2 c* 2.3 5.4 3.5 α(20° C.; 700° C.) ppm/K 0.87 0.86 Glass 24 43 Example 101 102 Comparative Example Properties of glass ceramic Variant B B Embodiment 2 2 Ceramization g22 g22 methods 1 Ceramization g42 g42 methods 2 T.sub.D ° C. 1145 1145 t.sub.V min 6.5 15 Transmission mm 3.95 3.97 (D65/2°), Thickness Y % 2.5 2.1 Transmission @ % 5.3 5.0 630 nm (PvK) Transmission @ % 630 nm (PiP) PvK-PiP @ % 630 nm (PvK-PiP)/PiP @ 630 nm Transmission @ % 8.2 8.2 700 nm (PvK) Transmission @ % 46.5 50.8 1600 nm (PvK) Display none none capability for red Reflection mm 3.95 3.97 (D65/2°), Thickness L* 90.6 91.1 a* −0.3 −0.5 b* −0.5 −1.6 c* 0.6 1.6 α(20° C.; 700° C.) ppm/K 1.01

TABLE-US-00008 TABLE 4 Variant C Glass 1 3 4 5 6 7 Example 103 104 105 106 107 108 Comparative Example Properties of glass ceramic Variant C C C C C C Embodiment 2 2 2 2 2 2 Ceramization g23 g23 g23 g23 g23 g23 methods 1 Ceramization g43 g43 g43 g43 g43 g43 methods 2 T.sub.D ° C. 1100 1100 1100 1100 1100 1100 t.sub.V min 6.5 6.5 6.5 6.5 6.5 6.5 Transmission mm 3.92 3.91 4.02 4.01 3.97 3.95 (D65/2°), Thickness Y % 11.5 11.6 14.7 14.1 12.5 13.3 Transmission at 630 % 19.3 20.2 22.3 20.1 20.8 21.6 nm (PvK) Transmission at 630 % 4.4 5.4 6.5 3.6 4.8 5.7 nm (PiP) (PvK-PiP)/PiP at 630 3.3 2.8 2.4 4.6 3.4 2.8 nm Transmission at 700 % 29.1 30.3 30.8 26.6 31.3 31.8 nm (PvK) Transmission at 1600 % 84.6 84.5 81.6 80.7 83.8 84.0 nm (PvK) Display capability for good good very poor good very red good good Reflection (D65/2°), mm 3.92 3.91 4.02 4.01 3.97 3.95 Thickness L* 74.3 71.9 69.6 71.5 73.6 72.9 a* −4.0 −4.0 −3.4 −3.1 −4.2 −4.1 b* −8.1 −10.2 −8.3 −5.4 −8.3 −8.4 c* 9.0 10.9 9.0 6.3 9.3 9.3 α(20° C.; 700° C.) ppm/K 1 0.99 0.89 0.92 0.9 0.86 Glass 8 9 10 11 12 12 Example 109 110 111 112 113 114 Comparative Example Properties of glass ceramic Variant C C C C C C Embodiment 2 2 2 2 1 1 Ceramization g23 g23 g23 g23 g13 g13 methods Ceramization g43 g43 g43 g43 methods 2 T.sub.D ° C. 1100 1100 1100 1100 1035 1055 t.sub.V min 6.5 6.5 6.5 6.5 13 13 Transmission(D65/2°), mm 3.97 3.89 3.94 3.97 3.95 3.9 Thickness Y % 15.4 15.2 14.5 13.5 22.3 16.7 Transmission at 630 % 23.8 21.7 20.5 18.6 29.2 22.5 nm (PvK) Transmission at 630 % 7.9 4.2 3.5 2.1 8.5 3.7 nm (PiP) (PvK-PiP)/PiP at 630 2.0 4.2 4.8 8.1 2.4 5.1 nm Transmission at 700 % 33.9 28.7 27.0 23.8 35.9 28.4 nm (PvK) Transmission at 1600 % 84.0 80.9 80.9 79.0 78.7 76.4 nm (PvK) Display capability for very good poor poor very good red good good Reflection (D65/2°), mm 3.97 3.89 3.94 3.97 3.95 3.9 Thickness L* 72.0 72.4 72.5 74.1 62.7 68.5 a* −4.3 −3.5 −3.2 −2.7 −3.1 −3.1 b* −8.4 −8.0 −6.3 −5.3 −7.1 −5.9 c* 9.5 8.7 7.1 5.9 7.8 6.6 α(20° C.; 700° C.) ppm/K 0.9 0.99 0.87 0.87 Glass 12 13 13 14 14 15 Example 115 116 117 120 Comparative Example 118 119 Properties of glass ceramic Variant C C C C C C Embodiment 1 2 2 2 Ceramization g13 g23 g23 g23 g23 g23 methods 1 Ceramization g43 g43 methods 2 T.sub.D ° C. 1065 1100 1080 1035 1055 1100 t.sub.V min 6.5 6.5 6.5 13 13 6.5 Transmission(D65/2°), mm 3.90 3.97 3.92 3.91 3.91 4.01 Thickness Y % 12.5 12.0 19.0 21.2 15.7 12.6 Transmission at 630 % 17.5 18.7 29.2 29.7 22.0 17.7 nm (PvK) Transmission at 630 % 1.0 3.0 12.5 9.3 2.7 1.7 nm (PiP) (PvK-PiP)/PiP at 630 17.3 5.3 1.3 2.2 7.3 9.7 nm Transmission at 700 % 22.0 26.3 40.0 37.5 27.3 22.6 nm (PvK) Transmission at 1600 % 73.6 82.2 84.3 81.9 78.7 79.3 nm (PvK) Display capability for poor poor very very poor poor red good good Reflection (D65/2°), mm 3.90 3.97 3.92 3.91 3.91 4.01 Thickness L* 76.4 77.4 70.1 69.8 76.3 78.0 a* −3.1 −3.9 −4.4 −4.0 −3.8 −2.8 b* −5.1 −8.3 −11.9 −14.0 −11.4 −7.3 c* 6.0 9.2 12.7 14.6 12.0 7.8 α(20° C.; 700° C.) ppm/K 0.82 0.78 Glass 15 15 16 17 18 19 Example 121 122 123 124 125 126 Comparative Example Properties of glass ceramic Variant C C C C C C Embodiment 2 2 2 2 2 1 Ceramization g23 g23 g23 g23 g23 g13 methods 1 Ceramization g43 g43 g43 g33 methods 2 T.sub.D ° C. 1080 1065 1100 1100 1100 1080 t.sub.V min 6.5 15 6.5 6.5 6.5 6.5 Transmission(D65/2°), mm 3.97 3.93 4.00 3.93 3.94 3.97 Thickness Y % 18.6 19.1 11.3 15.1 12.4 18.5 Transmission at 630 % 26.1 27.0 19.9 23.4 21.2 30.3 nm (PvK) Transmission at 630 % 9.9 10.5 4.0 7.2 5.5 14.4 nm (PiP) (PvK-PiP)/PiP at 630 1.6 1.6 4.0 2.2 2.8 1.1 nm Transmission at 700 % 34.2 35.4 30.2 32.0 31.4 43.0 nm (PvK) Transmission at 1600 % 83.4 83.2 83.5 82.7 84.3 86.0 nm (PvK) Display capability for very very good very good very red good good good good Reflection (D65/2°), mm 3.97 3.93 4.00 3.93 3.94 3.97 Thickness L* 70.2 69.7 76.6 73.7 76.3 72.6 a* −3.3 −3.3 −3.9 −3.7 −4.1 −7.3 b* −10.1 −9.8 −12.2 −13.3 −12.6 −10.8 c* 10.6 10.4 12.8 13.8 13.3 13.0 α(20° C.; 700° C.) ppm/K 0.92 1 0.95 Glass 19 20 20 21 21 22 Example 127 128 129 130 131 132 Comparative Example Properties of glass ceramic Variant C C C C C C Embodiment 1 2 2 1 1 2 Ceramization g13 g23 g23 g13 g13 g23 methods 1 Ceramization g33 g43 g33 g33 methods 2 T.sub.D ° C. 1065 1100 1080 1080 1065 1080 t.sub.V min 15 6.5 6.5 6.5 15 6.5 Transmission(D65/2°), mm 3.99 4.00 3.93 3.93 3.87 3.89 Thickness Y % 17.7 12.8 24.3 14.0 14.1 14.6 Transmission at 630 % 28.9 20.0 37.9 22.0 22.2 20.5 nm (PvK) Transmission at 630 nm (PiP) % 13.0 4.0 21.7 6.8 5.8 3.3 (PvK-PiP)/PiP at 630 1.2 4.0 0.7 2.2 2.8 5.3 nm Transmission at 700 % 41.6 29.0 50.5 32.1 32.4 26.6 nm (PvK) Transmission at 1600 % 86.2 84.6 85.6 86.1 86.1 79.9 nm (PvK) Display capability for very poor very good good poor red good good Reflection (D65/2°), mm 3.99 4.00 3.93 3.93 3.87 3.89 Thickness L* 74.1 80.1 68.8 78.5 79.6 75.1 a* −7.3 −4.8 −5.5 −5.9 −5.9 −3.5 b* −9.9 −10.8 −18.5 −9.1 −8.3 −7.5 c* 12.3 11.8 19.3 10.9 10.1 8.3 α(20° C.; 700° C.) ppm/K 0.76 Glass 22 22 Example 133 134 Comparative Example Properties of glass ceramic Variant C C Embodiment 2 2 Ceramization g23 g23 methods 1 Ceramization methods 2 T.sub.D ° C. 1065 1065 t.sub.V min 6.5 15 Transmission(D65/2°), mm 3.90 3.90 Thickness Y % 21.0 13.7 Transmission at 630 % 29.5 19.0 nm (PvK) Transmission at 630 nm (PiP) % 11.6 2.2 (PvK-PiP)/PiP at 630 1.5 7.6 nm Transmission at 700 % 38.2 24.4 nm (PvK) Transmission at 1600 % 82.5 79.1 nm (PvK) Display capability for very good poor red Reflection (D65/2°), mm 3.90 3.90 Thickness L* 67.7 75.5 a* −3.8 −3.2 b* −10.1 −5.9 c* 10.8 6.7 α(20° C.; 700° C.) ppm/K Glass 23 24 24 25 Example 135 136 137 138 Comparative Example Properties of glass ceramic Variant C C C C Embodiment 2 2 2 2 Ceramization g23 g23 g23 g23 methods 1 Ceramization g43 g43 methods 2 T.sub.D ° C. 1100 1080 1090 1100 t.sub.V min 6.5 6.5 6.5 6.5 Transmission mm 3.96 3.94 4.00 3.94 (D65/2°), Thickness Y % 15.5 16.5 13.8 15.9 Transmission @ 630 % 21.9 22.9 19.3 24.8 nm (PvK) Transmission @ 630 % 4.4 5.7 1.9 7.7 nm (PiP) PvK-PiP @ 630 nm % 17.5 17.2 17.4 17.1 (PvK-PiP)/PiP @ 630 3.9 3.0 9.3 2.2 nm Transmission @ 700 % 28.7 29.7 24.4 33.7 nm (PvK) Transmission @ 1600 % 80.0 81.0 79.0 82.0 nm(PvK) Display capability for good very good poor very good red Reflection (D65/2°), mm 3.96 3.94 4.00 3.94 Thickness L* 73.1 69.9 76.4 70.8 a* −3.4 −2.8 −2.7 −3.7 b* −7.7 −7.6 −5.6 −10.6 c* 8.4 8.1 6.2 11.2 α(20° C.; 700° C.) ppm/K Glass 26 27 28 29 30 31 Example 139 140 141 142 143 144 Comparative Example Properties of glass ceramic Variant C C C C C C Embodiment 1 1 2 2 2 1 Ceramization g13 g13 g23 g23 g23 g13 methods 1 Ceramization g33 g33 g33 methods 2 T.sub.D ° C. 1080 1080 1080 1080 1080 1080 t.sub.V min 6.5 6.5 6.5 6.5 6.5 6.5 Transmission mm 3.92 3.96 3.99 3.98 3.93 3.95 (D65/2°), Thickness Y % 21.6 16.9 15.4 14.1 20.1 18.0 Transmission @ 630 % 33.4 27.0 22.6 20.9 28.2 28.5 nm (PvK) Transmission @ 630 % 17.7 11.6 5.3 4.1 10.2 12.4 nm (PiP) PvK-PiP @ 630 nm % 15.7 15.5 17.4 16.7 18.1 16.2 (PvK-PiP)/PiP @ 630 0.9 1.3 3.3 4.1 1.8 1.3 nm Transmission @ 700 % 45.7 38.7 29.9 28.1 36.5 40.2 nm (PvK) Transmission @ 1600 % 85.9 85.8 82.8 82.5 82.9 85.1 nm (PvK) Display capability for very very good good very very red good good good good Reflection(D65/2°), mm 3.92 3.96 3.99 3.98 3.93 3.95 Thickness L* 71.4 74.1 73.1 75.1 68.5 73.5 a* −5.4 −6.3 −4.6 −4.6 −3.5 −6.2 b* −14.0 −9.1 −6.8 −6.0 −9.0 −11.6 c* 15.0 11.0 8.2 7.5 9.7 13.2 α(20° C.; 700° C.) ppm/K 0.7 Glass 32 33 34 35 36 37 Example 145 146 147 148 149 150 Comparative Example Properties of glass ceramic Variant C C C C C C Embodiment 1 2 2 2 2 2 Ceramization g13 g23 g23 g23 g23 g23 methods 1 Ceramization g33 g43 g43 g43 g43 g43 methods 2 T.sub.D ° C. 1080 1100 1100 1100 1100 1100 t.sub.V min 6.5 6.5 6.5 6.5 6.5 6.5 Transmission mm 3.94 3.96 3.93 3.92 4.20 4.01 (D65/2°), Thickness Y % 17.0 13.3 12.6 10.4 10.7 13.7 Transmission @ 630 % 26.5 20.6 19.7 17.2 17.2 23.1 nm (PvK) Transmission© 630 % 10.5 4.6 3.7 3.2 2.2 7.2 nm (PiP) PvK-PiP @ 630 nm % 16.0 16.0 16.0 14.0 15.0 15.9 (PvK-PiP)/PiP @ 630 1.5 3.5 4.3 4.4 6.9 2.2 nm Transmission @ 700 % 37.7 28.2 26.9 24.1 23.3 33.9 nm (PvK) Transmission @ 1600 % 84.7 80.6 80.2 83.4 79.1 84.0 nm (PvK) Display capability for very good good good poor very red good good Reflection (D65/2°), mm 3.94 3.96 3.93 3.92 4.20 4.01 Thickness L* 74.8 72.3 73.4 72.2 74.0 72.4 a* −6.2 −3.0 −3.8 −2.7 −3.4 −4.0 b* −9.6 −9.9 −8.0 −8.6 −8.0 −11.8 c* 11.4 10.3 8.8 9.0 8.7 12.5 α(20° C.; 700° C.) ppm/K 0.90 0.91 0.82 0.88 0.92 Glass 38 39 40 41 42 43 Example 151 152 153 154 155 156 Comparative Example Properties of glass ceramic Variant C C C C C C Embodiment 2 2 2 2 2 2 Ceramization g23 g23 g23 g23 g23 g23 methods 1 Ceramization g43 g43 g43 g43 g43 g43 methods 2 T.sub.D ° C. 1100 1100 1100 1100 1100 1100 t.sub.V min 6.5 6.5 6.5 6.5 6.5 6.5 Transmission mm 3.90 3.91 3.93 3.96 3.96 3.83 (D65/2°), Thickness Y % 14.8 12.8 11.3 12.5 11.3 16.0 Transmission @ 630 % 24.9 20.7 18.9 21.0 19.3 23.8 nm (PvK) Transmission @ 630 % 9.3 4.4 3.4 4.7 3.6 6.1 nm (PiP) PvK-PiP @ 630 nm % 15.6 16.3 15.5 16.3 15.7 17.7 (PvK-PiP)/PiP @ 630 1.7 3.7 4.6 3.5 4.4 2.9 nm Transmission @ 700 % 35.9 29.3 27.4 30.4 27.9 31.8 nm (PvK) Transmission @ 1600 % 83.7 83.3 83.0 83.1 83.3 81.6 nm (PvK) Display capability for very good good good good good red good Reflection (D65/2°), mm 3.90 3.91 3.93 3.96 3.96 3.83 Thickness L* 69.9 76.0 76.0 75.0 75.7 73.5 a* −4.1 −3.8 −4.1 −3.9 −4.2 −3.5 b* −11.9 −9.3 −8.1 −11.0 −9.0 −10.1 c* 12.6 10.1 9.1 11.7 10.0 10.7 α(20° C.; 700° C.) ppm/K 0.92 0.90 0.89 0.91 0.89 1.00 Glass 44 45 46 47 Example 157 158 159 160 Comparative Example Properties of glass ceramic Variant C C C C Embodiment 2 2 2 2 Ceramization g23 g23 g23 g23 methods 1 Ceramization g43 g43 g43 g43 methods 2 T.sub.D ° C. 1100 1100 1100 1100 t.sub.V min 6.5 6.5 6.5 6.5 Transmission(D65/2°), mm 3.94 3.94 3.92 4.06 Thickness Y % 14.4 14.4 13.7 11.2 Transmission @ 630 % 21.6 22.4 21.8 18.0 nm (PvK) Transmission @ 630 % 4.5 5.5 5.2 3.2 nm (PiP) PvK-PiP @ 630 nm % 17.1 16.9 16.6 14.8 (PvK-PiP)/PiP @ 630 3.8 3.1 3.2 4.6 nm Transmission @ 700 % 29.1 30.4 29.9 24.8 nm (PvK) Transmission @ 1600 % 81.4 82.2 81.5 80.3 nm (PvK) Display capability for good good good good red Reflection (D65/2°), mm 3.94 3.94 3.92 4.06 Thickness L* 74.5 73.4 73.5 72.5 a* −4.0 −3.5 −4.0 −2.9 b* −8.4 −10.8 −9.9 −9.6 c* 9.3 11.3 10.7 10.0 α(20° C.; 700° C.) ppm/K 1.00 1.01 0.99 0.91

TABLE-US-00009 TABLE 5 Long-duration annealing Glass 11 12 13 Example 161 162 163 Comparative Example Base example 78 21 83 Properties of glass ceramic Variant B A B Embodiment 2 1 2 Ceramization g22 + g11 + g22 + methods 700° C., 700° C., 700° C., 10 h 10 h 10 h T.sub.D ° C. 1145 1145 1145 t.sub.v min 6.5 6.5 6.5 Transmission mm 3.95 3.95 3.98 (D65/2°), Thickness Y % 4.4 0.6 3.0 ΔY % −0.1 0.0 -0.1 Transmission at 630 % 8.0 1.6 6.3 nm (PvK) Transmission at 700 % 11.3 3.2 10.0 nm (PvK) Transmission at 1600 % 54.5 26.9 64.4 nm (PvK) Reflection (D65/2°), mm 3.95 3.95 3.98 Thickness L* 89.2 94.3 90.3 ΔL* −0.5 −0.3 −0.2 a* −0.9 −0.3 −1.0 Δa* 0.1 0.0 0.0 b* −2.8 −0.9 −2.5 Δb* 0.1 0.0 −0.1 c* 2.9 1.0 2.7 Glass 14 15 19 Example 165 166 Comparative 164 Example Base Example 26 87 37 Properties of glass ceramic Variant A B A Embodiment 2 1 Ceramization g21 + g22 + g11 + methods 700° C., 700° C., 700° C., 10 h 10 h 10 h T.sub.D ° C. 1145 1145 1145 t.sub.v min 6.5 6.5 6.5 Transmission mm 3.95 3.97 4.00 (D65/2°), Thickness Y % 1.5 3.7 1.6 ΔY % 0.0 −0.1 −0.1 Transmission at 630 % 4.0 7.2 4.0 nm (PvK) Transmission at 700 % 6.2 10.7 7.3 nm (PvK) Transmission at 1600 % 29.0 58.4 68.8 nm (PvK) Reflection (D65/2°), mm 3.95 3.97 4.00 Thickness L* 95.2 90.3 93.0 ΔL* 0.2 −0.1 −0.3 a* −0.7 −0.8 −1.1 Δa* 0.0 0.1 0.0 b* −2.0 −2.6 −1.2 Δb* −0.1 0.2 −0.2 c* 2.1 2.8 1.7 Glass 20 21 22 Example 167 168 169 Comparative Example Base Example 94 42 98 Properties of glass ceramic Variant B A B Embodiment 2 1 2 Ceramization g22 + g11 + g22 + methods 700° C., 700° C., 700° C., 10 h 10 h 10 h T.sub.D ° C. 1145 1145 1145 t.sub.v min 6.5 6.5 6.5 Transmission (D65/2°), Thickness mm 4.01 3.99 3.99 Y % 3.5 1.5 2.2 ΔY % −0.1 0.1 −0.1 Transmission at 630 % 7.2 3.6 5.0 nm (PvK) Transmission at 700 % 11.0 6.5 8.3 nm (PvK) Transmission at 1600 % 75.4 66.1 50.1 nm (PvK) Reflection (D65/2°), mm 4.01 3.99 3.99 Thickness L* 92.0 94.2 90.1 ΔL* −0.3 0.0 −0.5 a* −1.4 −0.6 −0.5 Δa* 0.0 0.1 0.0 b* −3.4 −1.7 −2.6 Δb* −0.4 −0.2 −0.3 c* 3.6 1.8 2.6