Siclicium-sodium-calcium glass compositions and their application

The present invention relates to a glass composition, an emission screen substrate and fire protection glazing. The glass composition according to the invention can be transformed into a glass ribbon that can be cut into panels, which in turn have good heat resistance. Such plates can be used to make fire glazing or they can be used as a substrate for the production of emission screens, plasma screens, electroluminescent screens and for cold cathode shields.

The glass currently used to make such substrates is a glass belonging to the group of silico-soda-lime glasses, commonly used for the production of glass for building and glazing of motor vehicles. While this type of glass is generally satisfactory when it comes to chemical resistance, flatness and defects, its temperature resistance is sometimes unsatisfactory.

During the production of emission screens, the substrate undergoes several heat treatments, which aims to stabilize the dimensions of said substrate and bind a series of layers of various compounds, such as enamels, deposited on its surface. Binding of these layers of smaller or larger thickness requires the substrate to be exposed to a temperature higher than 550 ° C. While the expansion coefficient of the used silico-soda-lime glass is of the same order as the expansion coefficients of the compounds deposited on its surface, its temperature resistance is insufficient and during heat treatment it must be placed on a ground plate to avoid deformation.

Glasses used for the production of fire-resistant glass usually belong to the group of borosilicate glasses. These glasses, which show very good heat and thermal shock resistance, are usually characterized by a low expansion coefficient. The latter property does not allow high stress to be induced in these glasses by heat toughening, and thus increasing their mechanical resistance by this method is limited.

The present invention overcomes the above limitations.

According to the invention, the glass composition intended for the production of a thermally stable substrate or plate is characterized in that it comprises the following components in the following weight proportions:

<td>SiO2</td><td>45 to 68%</td>

<td>Al2O;</td><td>0 to 22%</td>

<td>ZrO2</td><td>0 to 22%</td>

<td>B2O3</td><td>0.5 to 4%</td>

<td>Na 2 O</td><td>2 to 12%</td>

<td>K2O</td><td>3.5 to 9%</td>

<td>CaO</td><td>1 to 113%</td>

<td>MgO</td><td>0 to 8%</td>

the sum of the oxides SiO2, A ^ O ;; and ZrO2 remains equal to or less than 70%, the sum of the content of oxides AĘO ;, and ZrO2 is equal to or greater than 2%, the sum of the content of alkali oxides Na2O and K2O is equal to or greater than 8%, the composition optionally containing BaO oxides and / or SrO in the following proportions:

% &lt;MgO + CaO + BaO + SrO &lt;24% and in addition this composition has a lower stress decay temperature equal to or higher than about 530 ° C and a dilatation coefficient (a25-3oo ° C) of 80 to 95 x 10 '⁷/ ° C.

Preferably, this composition contains the following ingredients in the following weight proportions:

SiO2 45 to 68%

AKO₃ 2 to 20%

ZrO2 0 to 20%

B2O3 0.5 to 4%

Na2O 4 to 11%

K2O 3.5 to 7%

CaO 1 to 133 / o

MgO 1 dd 8%.

187 002

Preferably, the sum of the content of oxides Al2O3 and ZrO2 which it contains is equal to or greater than 5%; the S1O2 weight content ranges from 45 to 59%.

Preferably the glass composition comprises the following ingredients in the following proportions

<td>weight: SiO2</td><td>45 to 59%</td>

<td>Al2O3</td><td>5 to 18%</td>

<td>ZrO2</td><td>Odo 17%</td>

<td>B2O3</td><td>0.5 to 4%</td>

<td>Na 2 O</td><td>4 to 10%</td>

<td>K2O</td><td>3.5 to 7%</td>

<td>CaO</td><td>1 to 122 / o</td>

<td>MgO</td><td>0 0o 7%</td>

wherein the sum of the alkali oxides content remains equal to or greater than 10%, the composition may also contain BaO and / or SrO oxides in the following proportions:

14% &lt;CaO + MgO + BaO + SrO &lt;22% and in addition this composition has a lower stress decay temperature equal to or higher than about 550 ° C and a dilatation coefficient (ct25-3oo ° C) of 85 to 95 x 10 '⁷/ ° C.

Preferably, the sum of the content of oxides A ^ tO and ZrO2 that it contains ranges from 8 to 22%.

This composition has a viscosity corresponding to the logo = 1.6 at a temperature equal to or lower than 1630 ° C, preferably 1590 ° C. More preferably the glass composition has a viscosity corresponding to the logo = 3.5 at a temperature equal to or lower than 1220 ° C, preferably 1T70 ° C.

The glass composition according to the invention has a liquidus temperature equal to or lower than the temperature corresponding to the viscosity with the logo = 3.5.

According to the invention, the substrate for the emission screen obtained from a glass pane cut from a glass ribbon obtained by flowing the glass in a molten metal bath is characterized in that the glass composition contains the following components in the following proportions

<td colspan="2">weight:</td>

<td>SiO2</td><td>45 to 68?%</td>

<td>Al2O3</td><td>0 to 20%</td>

<td>ZrO2</td><td>0 to 20%</td>

<td>B2O3</td><td>0.5 to 41%</td>

<td>Na 2 O</td><td>2 to H%</td>

<td>K2O</td><td>3.5 to 9%</td>

<td>CaO</td><td>1 to 11%</td>

<td>MgO</td><td>0 0o by%</td>

where the sum of the SiO2, AĘO3 and ZrO2 oxides remains equal to or less than 70%, the sum of the ALO ;, and ZrO2 oxides is equal to or greater than 2%, the sum of the content of Na2O and K2O alkali oxides is equal to or greater than 8%, with which composition optionally contains BaO and / or SrO oxides in the following proportions:

11% &lt;MgO + CaO + BaO + SrO &lt;24% and in addition this composition has a lower stress decay temperature equal to or higher than about 530 ° C and a dilatation factor (a25-3oo^c'C) between 80 and 95 x 10'7 / ° C.

According to the invention, fire-resistant glazing made of a plate or sheet of glass cut from a glass ribbon obtained by flowing glass in a molten metal bath is characterized in that the composition of the glass contains the following components in the following weight proportions:

<td>SiO2</td><td>45 to 68%</td>

<td>Al2O3</td><td>0 to 22%</td>

<td>ZrO2</td><td>0 2o 22%</td>

<td>B2O3</td><td>0.5 to 5%</td>

<td>Na 2 O</td><td>2 to U%</td>

<td>K2O</td><td>3.5 to 9%</td>

187 002

CaO 1 to 14%

MgO 0 to 8% where the sum of the content of S1O2, Al2O3 and ZrO2 oxides remains equal to or less than 7d%, the sum of the content of AfO3 and ZrO2 oxides is equal to or greater than 2%, the sum of the content of alkali oxides Na2O and K2O is equal to or greater than 8 %, wherein the composition optionally contains BaO and / or SrO oxides in the following proportions:

11% &lt;MgO + CaO + BaO + SrO &lt;24% and in addition this composition has a lower stress decay temperature equal to or higher than about 53d ° C and a dilatation coefficient (a25-3dd ° C) of 8d to 95 x 1d'7 / ° C.

Thus, the glass composition of the invention allows the production of plates or a substrate whose deformation is virtually no when subjected to a temperature of 55d-6dd ° C.

The preferred glass composition according to the invention makes it possible to produce a plate inside which thermal stress can be created which is at least as high as that which forms in the plate of ordinary silico-soda-lime glass.

The glass composition according to the invention makes it possible to produce a substrate in which the surface loss of alkali ions is less than in a substrate made of ordinary silico-soda-lime glass.

This glass composition is suitable for melting and transforming into a glass ribbon floating in a metal bath under temperature conditions similar to those of ordinary silico-soda-lime glass.

It is usually assumed that the glass no longer has any sticky properties below the characteristic temperature called the lower annealing temperature, which corresponds to a viscosity of ld^14,5 poise. For this reason, this temperature is a control point that allows you to assess the temperature resistance of glass. Due to the combination of components, such as follows from the definition of the invention, glasses corresponding to this definition have a lower annealing temperature about 25 ° C higher than the temperature for classic silico-soda-lime glass. For most types of glass according to the invention, this difference is at least 45-5d ° C.

This combination of ingredients also allows obtaining glasses in which the expansion ratio is of the same order as the expansion ratio of traditional silico-soda-lime glass.

The glasses according to the invention also show an advantageous ability to melt and transform into a glass ribbon at a temperature close to that adopted in the production of classic silico-soda-lime glass.

For this reason, S1O2 plays a central role. In the context of the invention, the SiO2 content should not exceed about 68%; above this value, the melting of the glassmaking mixture and the clarification of the glass require a high temperature, which causes accelerated consumption of refractory materials in furnaces. In addition, it was noted that increasing the SiO2 content is not conducive to raising the lower annealing temperature. Below 45% by weight of S1O2, the stability of the glasses according to the invention is insufficient. The glasses according to the invention, which melt the easiest, whose viscosities are best suited to the flow of glass in a molten metal bath and which exhibit the highest lower annealing temperatures, contain 45-59% S1O2.

Aluminum oxide plays the role of a stabilizer. This oxide to some extent increases the chemical resistance of glass and promotes an increase in the lower annealing temperature.

The AfOs content should not exceed 2d% under the threat of too difficult melting and unacceptable increase of glass viscosity at high temperature.

ZrO2 also plays the role of a stabilizer. This oxide to some extent increases the chemical resistance of glass and promotes an increase in the lower annealing temperature.

ZrO2 content should not exceed 2d% under threat of too difficult melting. Although this oxide is difficult to melt, it has the advantage of not increasing the viscosity of the glasses of the invention at high temperatures. This avoids the introduction of oxides such as B2O3 into these glasses, which inter alia reduce the viscosity of the glass, or increase the content of alkali oxides having the same effect.

187 002

In general, the melting of the glasses according to the invention occurs within acceptable temperature limits, with the proviso that the sum of the oxides SiO2, A ^ Oj and ZrO2 remains equal to or less than 70%. Acceptable limits should be understood as glass temperature, corresponding to logn = 1.6, not exceeding approximately 1630 ° C, preferably 1590 ° C.

Of these glasses, some contain alumina and / or zirconia, others contain zirconia and / or alumina. To distinguish them further in the description, the first will qualify as glasses with aluminum oxide and the second glass with zirconia.

Glasses known as alumina glasses contain the following ingredients in the following weight ratios:

<td>SiO2</td><td>45 to 680%</td>

<td>Ahoy</td><td>2 to 200%</td>

<td>ZrO2</td><td>0 to 20%</td>

<td>B2O3</td><td>0.5 to 4%</td>

<td>Na 2 O</td><td>4 to 11%</td>

<td>K2O</td><td>3.5 to 7%</td>

<td>CaO</td><td>1 to 11%</td>

<td>MgO</td><td>1 to 8%</td>

wherein the sum of the SiO2, AfOj and ZrO2 oxides content is equal to or lower than 70%, the sum of the Na2O and K2O alkali oxides content is equal to or higher than 8%, and said composition optionally comprises BaO and / or SrO oxides in a ratio such that % &lt;MgO + CaO + BaO + SrO &lt;24%

This group of glasses is distinguished in particular by the systematic presence of B2O3. Indeed, this oxide, as the lattice oxide, can be added or replaced with SiO2. It reduces the melting temperature of the glass making mixture as well as the viscosity of the glass at high temperatures. It also reduces the glass's ability to glazing, and in particular avoids raising the liquidus temperature. This reduction in viscosity action allows a sufficient interval between the glass formation temperature and its liquidus temperature to be maintained. Especially in the floating glass method, it is important that the liquidus temperature of the glass remains equal to or lower than the temperature corresponding to logn = 3.5, which is the case with this type of glass. More specifically, glasses of this type exhibit a temperature, corresponding to logn = 3.5, equal to or lower than about 1220 ° C, preferably 1170 ° C.

In this type of glass, the B2O3 content does not exceed about 4%, because above this value boron volatilization in the presence of alkali oxides during the melting of the glass may not be negligible. In this group of glasses, the sum of the content of Al2O3 and ZrO2 oxides is preferably equal to or higher than 5%. The sum of these oxides is preferably 8-22%.

Preferred alumina glass compositions contain the following ingredients in the following weight proportions:

<td>Si02</td><td>45 to 59%</td>

<td>Al2O3</td><td>5 dd) 11%</td>

<td>ZrO2</td><td>0 to 17%</td>

<td>B2O3</td><td>0.5 to 4%</td>

<td>Na 2 O</td><td>4 to 10%</td>

<td>K2O</td><td>3.5 to 70%</td>

<td>CaO</td><td>1 to 12%</td>

<td>MgO</td><td>1 to%</td>

wherein the sum of the SiO2, AĘO3 and Z1O2 oxides content remains equal to or lower than 70%, the sum of the alkali oxides content is equal to or higher than 10%, said compositions optionally comprise BaO and / or SrO oxides in such a ratio that

14% &lt;MgO + CaO + BaO + SrO &lt;22% said glass compositions have a lower annealing temperature equal to or higher than 550 ° C and their expansion ratio (ct25-300 ° C) is 85-95 10 * '/ ° C.

187 002

Glasses referred to as zirconia glasses contain the following ingredients in the following weight proportions:

<td>SiO2</td><td>45 to 63%</td>

<td>ABO3</td><td>6.5 to 20%</td>

<td>ZrO2</td><td>0 to 18%</td>

<td>Na 2 O</td><td>4 to 12%</td>

<td>K2O</td><td>3.3 to o57</td>

<td>CaO</td><td>1 to 13%</td>

<td>MgO</td><td>1 to 8%</td>

wherein the sum of the content of SiO2, Al2O3 and ZrO2 oxides remains equal to or lower than 70%, the sum of the content of alkali oxides Na2O and K2O is equal to or higher than 8%, said composition optionally comprises BaO and / or SrO oxides in such a ratio that

11% &lt;MgO + CaO + BaO + SrO &lt;24% said glass composition has a lower annealing temperature equal to or higher than about 530 ° C and its expansion ratio (a25-300 ° C) is 80-95 x 10'7 / ° C.

In this group of glasses, the SiO2 content depends on the presence of other oxides, also difficult to melt, such as ZrO2 and possibly AĘO3. Thus, the maximum SiO2 content should not exceed about 63%; above this value, the melting of the glassmaking mixture and the clarification of the glass require high temperatures, which results in accelerated consumption of refractory materials in furnaces. In addition, it was noted in the context of the invention that increasing the SiO2 content is not conducive to increasing the lower annealing temperature. Less than 45% SiO by weight? this type of glass stability is insufficient.

Zirconium oxide glasses that melt the easiest, whose viscosities are best suited to the flow of glass in a molten metal bath, and which exhibit the highest lower annealing temperatures, contain 45-59% SiO2.

As with alumina glasses, it has been found that the melting of zirconia glasses occurs within acceptable temperature limits, provided that the sum of SiO oxides₂, Al₂O3 and ZrO₂ remains equal to or less than 70%. Acceptable limits are understood to mean the glass temperature corresponding to logn = 1.6 and not exceeding approximately 1630 ° C, preferably 1590 ° C.

In zirconium oxide glasses, the sum of the Al / O and ZrO2 oxides is preferably equal to or higher than 8%, and preferably 8-22%. The content of Z1O2 is preferably 8-15%.

Zirconia glasses are particularly distinguished from alumina glasses by the absence of boron oxide because, unlike Al₂ABOUT₂ the presence of even a high ZrO2 content in this type of glass does not increase their viscosity at high temperatures.

Zirconium oxide glasses also have the advantage of being easily adapted to the melting methods associated with the method of flowing glass in a bath of molten metal. Indeed, it turns out that these glasses cause low corrosion of AZS-type refractory materials (alumina-zirconia-silicon oxide) usually used in this type of furnace. In this way, the glasses optimize the life of the furnace.

Preferred zirconia glass compositions contain the following ingredients in the following weight proportions:

<td>SiO2</td><td>4o to 59%</td>

<td>ZrO2</td><td>8 to 155 / ο</td>

<td>N O3</td><td>Odd 51%</td>

<td>Na 2 O</td><td>4dd 510%</td>

<td>K2O</td><td>3.5 to 7%</td>

<td>CaO</td><td>1 dd 512%</td>

<td>MgO</td><td>1 to 7%</td>

the sum of the SiO2, Al oxides content₂O3 and ZrO2 remain equal to or less than 70%, the sum of the alkali oxides is equal to or greater than 10%, said compositions optionally contain oxides of BaO and / or SrO in such a ratio that

14% &lt;MgO + CaO + BaO + SrO &lt;22%

187 002 said glass compositions have a lower annealing temperature equal to or higher than 550 ° C and their expansion ratio (a25-300 ° C) is 82-95 x 10'7 ° C.

In general, the effect of other oxides on the ability of glasses to melt and flow in a metal bath as well as on their properties is as follows.

The Na2O and K2O oxides allow the melting temperature of the glasses according to the invention and their viscosity to be maintained at high temperatures within the limits previously defined. To do this, the sum of these oxides remains equal to or greater than about 8%. Compared to ordinary silico-soda-lime glass, the simultaneous presence of these two oxides in glasses of this type sometimes in similar proportions allows for a significant increase in their chemical resistance, and more specifically in their hydrolytic resistance as well as their specific resistance. Increasing the specific resistance of glasses is interesting in some applications, more precisely, when they serve as a substrate for making cold cathode shields. These screens create surface electric fields that cause local electron clusters. Such clusters can cause unwanted migration of alkaline compounds in the reaction when the specific resistance of the glass is insufficient, as is the case with ordinary silico-soda-lime glass.

Alkaline earth oxides incorporated into the glasses of the invention generally have an effect of increasing the lower annealing temperature and this is the reason why the sum of their weight content should be at least 11%. Above about 30%, the glazing ability of the glasses may increase to a degree that does not correspond to the method of flowing in a metal bath. To maintain glass glazing within acceptable limits, the CaO and MgO content should not exceed 13 and 8% respectively. The MgO content is preferably equal to or lower than 5%.

MgO, CaO and, to a lesser extent, SrO allow an increase in the lower annealing temperature; BaO and SrO allow increasing the chemical resistance of the glasses according to the invention as well as increasing the specific resistance. BaO also affects the melting temperature as well as the viscosity of the glasses at high temperatures.

The benefits presented by the glass compositions of the invention can be better assessed by the examples shown in the attached tables 1 and 2.

Glass No. 1 corresponds to a composition of classic silicon-soda-lime glass used for the production of glass tape according to the method of floating glass in a molten metal bath; Glass No. 2 corresponds to the known borosilicate glass. Glasses 3 to 13 explain the glass compositions of the invention. The lower annealing temperature Tj, dilatation coefficient, viscosity and liquidus temperature as well as hydrolytic resistance (DGG) and specific resistance were measured by known methods.

As the examples show, the viscosity and liquidus characteristics in the glasses according to the invention are similar to those of the reference glass in order to be able to melt and transform it into a strip in virtually the same conditions as the latter.

Thus, the glasses according to the invention are obtained by the method of floating glass in the form of a tape with a precisely adjustable thickness, which can vary from 0.5 mm to 10 mm. Said tape is cut into boards of the desired format before undergoing thermal treatment, designed to stabilize the dimensions of the listed boards. These boards are ready to serve as a substrate that withstands the application of various layers and the thermal treatment required for their binding.

These sheets or panels after thermal toughening can be combined to obtain insulating glazing or multilayer glazing. Insulating glazing is created from boards joined in two by means of an inserted glued profile. The method of their installation in the boxes supporting them is such that when exposed to flames, the edge of the plate from the side of fire is immediately exposed or in each case with a short delay to thermal radiation or the flames themselves, which reduces the thermal stress that usually arises in the plate, when it heats up more inside than at the edges. The combination of good-quality thermal toughening and the assembly in question allows such glazing to be kept in place long enough to meet applicable standards.

187 002

Multilayer glazing is made by joining panels with inserted plastic film; commonly used glass plates are also thermally toughened.

Table 4

<td></td><td>No. 4</td><td>No. 2</td><td>No. 3</td><td>No. 4</td><td>No. 5</td><td>No. 6</td><td>No. 7</td><td>No. 8</td>

<td>SiO₂</td><td> 71,7</td><td> 81,0</td><td> 60,9</td><td> 66,6</td><td> 53,6</td><td> 46,9</td><td> 51,1</td><td> 48,5</td>

<td>Al2O3</td><td> 0,6</td><td> 2,2</td><td> 5,7</td><td> 3,0</td><td> 10,0</td><td> 18,0</td><td> 12,0</td><td> 14,8</td>

<td>ZrO₂</td><td></td><td></td><td></td><td></td><td> 2,0</td><td></td><td> 1,9</td><td> 2,0</td>

<td>b₂about₃</td><td></td><td> 13</td><td> 3,5</td><td> 3,4</td><td> 2,2</td><td> 3,5</td><td> 1,7</td><td> 2,3</td>

<td>Na 2 O</td><td> 13,9</td><td> 3,6</td><td> 5,5</td><td> 9,6</td><td> 5,2</td><td> 4,7</td><td> 4,7</td><td> 5,3</td>

<td>K2O</td><td></td><td> 0,2</td><td> 6,2</td><td> 4,1</td><td> 6,2</td><td> 6,2</td><td> 6,8</td><td> 6,5</td>

<td>MgO</td><td> 4,1</td><td></td><td> 4,2</td><td> 6,7</td><td> 4,2</td><td> 3,0</td><td> 3,7</td><td> 3,8</td>

<td>CaO</td><td> 9,5</td><td></td><td> 6,8</td><td> 6,6</td><td> 6,8</td><td> 7,5</td><td> 6,8</td><td> 6,6</td>

<td>SrO</td><td></td><td></td><td> 4,4</td><td></td><td> 7,0</td><td> 7,2</td><td> 7,6</td><td> 7,0</td>

<td>BaO</td><td></td><td></td><td> 2,8</td><td></td><td> 2,8</td><td> 3,0</td><td> 3,7</td><td> 3,2</td>

<td>T (° C)</td><td> 507</td><td> 510</td><td> 540</td><td> 531</td><td> 580</td><td> 579</td><td> 577</td><td> 582</td>

<td>T (logη = 7.6) (° C)</td><td> 725</td><td> 821</td><td></td><td></td><td></td><td></td><td></td><td> 830</td>

<td>a (x10'7 ° C)</td><td> 88,5</td><td> 32</td><td> 84,5</td><td> 80,5</td><td> 84,0</td><td> 86,0</td><td> 88,5</td><td> 88,0</td>

<td>Logp (Q.cm) (at 250 ° C)</td><td> 6,6</td><td></td><td></td><td></td><td></td><td></td><td></td><td> 8,7</td>

<td>DGG (mg)</td><td> 30</td><td></td><td></td><td></td><td> 7</td><td></td><td></td><td></td>

<td>T (log η =, 6) (° C)</td><td> 1550</td><td> &gt;1800</td><td> 1566</td><td> 1579</td><td> 1584</td><td> 1559</td><td> 1554</td><td> 1546</td>

<td>T (logn = 3.5) (° C)</td><td> 1085</td><td></td><td> 1113</td><td> 1119</td><td> 1156</td><td> 1160</td><td> 1159</td><td> 1162</td>

<td>^Tliquidus (° C)</td><td> 1020</td><td></td><td> 1060</td><td> 1110</td><td> 1120</td><td> 1100</td><td> 1120</td><td> 1120</td>

187 002

Table 2

<td></td><td>No. 1</td><td>No. 2</td><td>No. 9</td><td>No. 10 *</td><td>No. 11 *</td><td>No. 12 *</td><td>No. 13 *</td>

<td>SiO2</td><td> 71,7</td><td> 81,0</td><td> 54,6</td><td> 52,0</td><td> 53,05</td><td> 52</td><td> 52</td>

<td>Al2O3</td><td> 0,6</td><td> 2,2</td><td> 3,0</td><td> 4,0</td><td> 3,25</td><td> 2</td><td> 5,0</td>

<td>ZrO2</td><td></td><td></td><td> 10,0</td><td> 11,0</td><td> 9,25</td><td> 5</td><td> 4</td>

<td>B2O3</td><td></td><td> 13</td><td></td><td></td><td></td><td></td><td></td>

<td>Na 2 O</td><td> 13,9</td><td> 3,6</td><td> 6,0</td><td> 7,0</td><td> 4,25</td><td> 4,0</td><td> 5,0</td>

<td>K2O</td><td></td><td> 0,2</td><td> 6,9</td><td> 5,0</td><td> 6,05</td><td> 8,0</td><td> 6,0</td>

<td>MgO</td><td> 4,1</td><td></td><td> 4,2</td><td> 7,0</td><td> 2,05</td><td> 4,0</td><td> 5,0</td>

<td>CaO</td><td> 9,5</td><td></td><td> 3,5</td><td> 9,0</td><td> 7,2</td><td> 8,0</td><td> 10,0</td>

<td>SrO</td><td></td><td></td><td> 8,0</td><td> 3,0</td><td> 9,15</td><td> 9,0</td><td> 7,0</td>

<td>BaO</td><td></td><td></td><td> 3,8</td><td> 2,0</td><td> 5,75</td><td> 8,0</td><td> 6,0</td>

<td>Ti (° C)</td><td> 507</td><td> 510</td><td> 606</td><td> 600</td><td> 612</td><td> 574</td><td> 575</td>

<td>T (logn = 7.6) (° C)</td><td> 725</td><td> 821</td><td></td><td></td><td></td><td></td><td></td>

<td>n (x10'7 /^aboutC)</td><td> 88,5</td><td> 32</td><td> 81,5</td><td> 84</td><td> 81,5</td><td> 93,5</td><td> 91,3</td>

<td>L8ge (Ω · cm) (at 250 ° C)</td><td> 6,6</td><td></td><td> 9,7</td><td> 9,65</td><td> 10,7</td><td> 11,3</td><td> 10,7</td>

<td>DGG (mg)</td><td> 30</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>t (logn = 1.6) (° C)</td><td> 1550</td><td> &gt;1800</td><td> 1554</td><td> 1450</td><td> 1539</td><td> 1413</td><td> 1415</td>

<td>T (^ η = 3.5) (° C)</td><td> 1085</td><td></td><td> 1192</td><td> 1120</td><td> 1172</td><td> 1078</td><td> 1072</td>

<td>Tlikwidus (° C)</td><td> 1020</td><td></td><td></td><td> 1360</td><td> 1120</td><td></td><td></td>

No. 10-13 - theoretical compositions.

187 002

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