阅读说明：本技术 减少静电的由玻璃制成的元件 (Element made of glass for reducing static electricity ) 是由 J·戴默 M·策特尔 于 2020-01-07 设计创作，主要内容包括：本发明涉及一种由玻璃制成的元件,特别是一种用于电子元件和/或可植入人体或动物体内的元件的壳体部件和/或特别是一种用于磁簧开关或应答器和/或植入体的玻璃管,该由玻璃制成的元件包含至少一种碱金属和/或碱金属氧化物并包括至少一个表面,其中,至少一种碱金属和/或碱金属氧化物的浓度从表面向由玻璃制成的元件内部的方向递增,以使这种碱金属和/或碱金属氧化物在由玻璃制成的元件中的最大浓度位于自表面垂直测量的至多60纳米的距离处。(The invention relates to a component made of glass, in particular a housing part for an electronic component and/or a component that can be implanted in a human or animal body and/or in particular a glass tube for a reed switch or a transponder and/or an implant, comprising at least one alkali metal and/or alkali metal oxide and comprising at least one surface, wherein the concentration of the at least one alkali metal and/or alkali metal oxide increases from the surface in the direction of the interior of the component made of glass, such that the maximum concentration of the alkali metal and/or alkali metal oxide in the component made of glass is located at a distance of at most 60 nm measured perpendicularly from the surface.)

1. An element made of glass, comprising at least one alkali metal and/or alkali metal oxide and comprising at least one surface,

wherein the concentration of said at least one alkali metal and/or alkali metal oxide increases from said surface in a direction towards the interior of said glass-made element such that the maximum concentration of such alkali metal and/or alkali metal oxide in said glass-made element is located at a distance of at most 60 nanometers measured perpendicularly from said surface.

2. Element according to claim 1, wherein the maximum concentration of the alkali metal and/or alkali metal oxide in the element made of glass is located at a distance of at most 40nm, preferably at most 30nm, particularly preferably at most 20nm, measured perpendicularly from the surface.

3. Element according to claim 1 or 2, wherein the concentration of the alkali metal and/or alkali metal oxide at the element surface is at least 2%, in particular at least 4%, preferably at least 6%, more preferably at least 8%, even more preferably at least 10% of the aforementioned maximum concentration of the at least one alkali metal and/or alkali metal oxide in the element made of glass.

4. The element according to any one of the preceding claims, wherein the average of the aforementioned maximum concentration of the alkali metal and/or alkali metal oxide and the concentration of the alkali metal and/or alkali metal oxide at the surface is located at a distance of at least 1 nm, preferably at least 5nm and at most 50 nm, preferably at most 25nm, measured perpendicularly from the surface.

5. Element according to any one of the preceding claims, wherein the concentration of the at least one alkali metal and/or alkali metal oxide at the element surface is at most 90%, preferably at most 75%, particularly preferably at most 60% of the aforementioned maximum concentration of the at least one alkali metal and/or alkali metal oxide in the element made of glass.

6. According to any of the preceding claimsThe element of one of the preceding claims, wherein the glass comprises at least 0.5 wt% sodium oxide (Na)₂O)，

And wherein the concentration of sodium oxide increases from a minimum at or near the at least one surface in a direction towards the interior of the element,

and wherein the concentration of sodium oxide has a substantially constant plateau value inside the element from a distance of at most 50 nm, preferably at most 40nm, particularly preferably at most 30nm from at least one surface,

and wherein in particular the minimum value of the concentration of sodium oxide is at least 1%, preferably at least 2%, particularly preferably at least 5%, even more preferably at most 10% of the plateau value.

7. The element according to any one of the preceding claims, wherein the glass comprises at least 0.5 wt% lithium oxide (L i)₂O)，

And wherein the concentration of lithium oxide increases from a minimum at or near the at least one surface in a direction toward the inside of the element,

and wherein the concentration of the lithium oxide has a substantially constant plateau value within the element from a distance of at most 50 nm, preferably at most 40nm, particularly preferably at most 30nm from at least one surface,

and wherein in particular the minimum value of the concentration of the lithium oxide is at least 1.5%, preferably at least 3%, particularly preferably at least 5% of the plateau value.

8. The element according to any one of the preceding claims, wherein the glass comprises at least 0.5 wt% potassium oxide (K)₂O)，

And wherein the concentration of potassium oxide increases from a minimum at or near the at least one surface in a direction toward the interior of the element,

and wherein the potassium oxide concentration has a substantially constant plateau value within the element from a distance of at most 50 nm, preferably at most 35 nm, particularly preferably at most 20nm from at least one surface,

and wherein in particular the minimum value of the concentration of potassium oxide is at least 1%, preferably at least 2%, particularly preferably at least 5% of the plateau value.

9. The element according to any one of the preceding claims, wherein the glass measured at a distance of at least 50 nm measured perpendicularly from the surface comprises the following oxides in weight percent:

-silicon dioxide (SiO)₂): 50% to 77%;

alumina (Al)₂O₃): 0 to 10%;

boron oxide (B)₂O₃): 0 to 10%;

iron (III) oxide₂O₃): 0 to 10%;

sodium oxide (Na)₂O): 0 to 18%;

-potassium oxide (K)₂O): 0 to 17%;

lithium oxide (L i)₂O): 0% to 6%;

-the sum of the oxides of Ca, Mg, Ba, Sr and/or Zn: 1 percent to 15 percent of the total weight of the composition,

and wherein also preferably fluorine (F) is comprised between 0 and 4%, preferably between 0 and 3.5%.

10. Element according to any one of the preceding claims, comprising Na₂O and K₂O, wherein, Na₂O and K₂The weight percentage ratio of O is more than 0.1; preferably greater than 0.3; particularly preferably greater than 1.0; and particularly preferably greater than 1.4.

11. Housing component for an electronic component and/or a component implantable in a human or animal body, comprising a component made of glass according to any of the preceding claims.

12. Glass tube (10) for a reed switch or a transponder and/or an implant, formed by or at least comprising an element made of glass according to any one of the preceding claims.

13. Glass tube (10) according to claim 12, wherein the glass tube is configured as a cylindrical tube having an outer surface (11) and an inner surface (12) and a substantially uniform wall thickness.

14. Glass tube (10) according to claim 12 or 13, wherein the outer diameter (13) of the glass tube is less than 6 mm, preferably less than 3 mm, particularly preferably less than 2.5 mm.

15. Glass tube (10) according to any of claims 12 to 14, wherein the ratio of the wall thickness (15) to the outer diameter (13) of the glass tube is less than 1/3, preferably less than 1/5.

16. Glass tube (10) according to any of claims 12 to 15, wherein the ratio of the length (16) to the outer diameter (13) of the glass tube is less than 50, preferably less than 20.

17. A reed switch (20) or a transponder (30) or an implant comprising a glass tube (10) according to any one of claims 12 to 16.

Technical Field

The invention relates to a component made of glass, containing at least one alkali metal and/or alkali metal oxide, and to a housing part for encapsulating electronic components and/or for encapsulating components that can be implanted in the human or animal body (implants for short), comprising at least said component made of glass.

Background

Due to their high electrical resistance, components made of glass accumulate charge carriers during their processing, in particular at their surface, and thus have an electrostatic potential, which is also referred to as electrostatic charging.

If such electrostatically charged components are used in electrical applications, the electrical or electronic switching process may be impeded or even triggered independently. During the processing of electrostatically charged components made of glass, faults can also be triggered as a result, in particular when these components come into contact with other electrical components or a corresponding circuit structure is established therewith.

The glass component designed as a glass tube is used in particular for producing a reed switch or an RFID transponder. In the case of reed switches, ferromagnetic contact pieces are usually fused into the glass tube so that they overlap in the longitudinal direction of the glass tube and are generally only a short distance apart in the transverse direction. When a magnetic field is applied from outside the glass tube, the switch reed contacts and closes the switch. The reed switch can be used under almost all environmental conditions because the contact pieces inside the glass tube are hermetically closed and therefore can be protected from dust or moisture. In the case of RFID transponders, many applications also require the realization of a gas-tight encapsulation, in particular when the transponder is implanted in a living being. Such applications also typically use glass elements that may be configured as glass tubes.

In the manufacture of glass tubes for such or similar purposes, it is common to cut an initial tube of desired inner and outer diameters, sometimes drawn directly from a melt, into glass tube sections of desired length. For example, it may be divided into shorter segments by scoring and snapping. Depending on the application, the cut glass element can be further processed in various ways and then hermetically closed. Thus, the quality of the cut edge is typically improved by fire polishing.

US 2013/0287977 a1 describes a glass tube for a reed switch capable of preventing possible chipping and tearing of its end portion by forming a compressive stress layer having a length in the range of 0.1 to 0.6 mm from one end face on the outer peripheral surface of the end portion thereof.

Conventionally, glass elements are produced by a thermoforming process as described above and optionally cleaned. Due to the manufacturing process of the glass element, in particular the hot forming, component losses in the surface area of the glass element may result. Generally, if the electrical conductivity of the glass element is reduced (e.g., within the surface area), the glass element may be more electrostatically charged.

If the glass components are processed on an industrial scale, especially in large-scale production, too much electrostatic charge can lead to failure of the production process. In particular, the individual elements may adhere to one another and/or to machine parts, in particular to the conveying device, thus hindering and/or at least disturbing the process flow.

The glass is also particularly disadvantageous for use as reed glass or transponder glass because this may lead to electrical and/or magnetic influences on the function of the reed switch or RFID transponder. Furthermore, the tubular glass element may attract undesired particles, such as dust. If such components are incorporated into an electronic device, damage to the device may result from excessive static charge.

On the other hand, a certain electrostatic charging may facilitate further processing of the glass element, e.g. the glass element adheres better to the transport equipment and is less prone to slip due to e.g. vibrations or shocks.

Disclosure of Invention

Against this background, it is an object of the present invention to provide an element made of glass, in which the charging properties are optimized, and a housing part at least comprising such an element made of glass. This means, in particular, that the electrostatic properties are balanced between avoiding too strong charging and not charging.

The object of the invention is achieved by the subject matter of the independent claims. Advantageous developments of the invention are furthermore the subject matter of the respective dependent claims.

The invention provides a component made of glass, which contains at least one alkali metal and/or alkali metal oxide. Alkali metals or alkali metal oxides are also used as components of the glass to reduce the viscosity of the glass and facilitate melting and/or subsequent thermoforming of the glass.

If the electrostatic charging of the elements made of glass according to the invention is reduced, they can also advantageously reduce the attraction of particles as described previously, which makes it possible to improve the yield (yield) during their further processing and to reduce subsequent failures within the electrical structure.

The glass component according to the invention has at least one surface and the concentration of the at least one alkali metal and/or alkali metal oxide increases from the surface in the direction of the interior of the glass component. Accordingly, the concentration of the alkali metal and/or alkali metal oxide has a minimum at or near the surface. The concentration increases with increasing distance from the surface towards the inside of the element made of glass. Thus, the concentration of the alkali metal and/or alkali metal oxide at the surface of the element made of glass is lower than that in the internal direction thereof, and thus has electrostatic charging properties in principle.

According to the invention, the concentration of the at least one alkali metal and/or alkali metal oxide increases in the direction of the interior of the element made of glass, so that the maximum concentration of the at least one alkali metal and/or alkali metal oxide in the element made of glass is at a distance of at most 60 nm, advantageously at most 50 nm, more advantageously at most 40nm, still more advantageously at most 30nm, still more advantageously at most 20nm, measured perpendicularly from the surface.

It has been found that components made of glass having the abovementioned alkali metal and/or alkali metal oxide concentration profiles are charged electrostatically only to a small extent and are suitable, for example, for further processing. The electrostatic charging can be reduced in an advantageous manner by reaching a maximum concentration of alkali metal and/or alkali metal oxide within a distance of at most 60 nm, advantageously at most 50 nm, more advantageously at most 40nm, still more advantageously at most 30nm, even more advantageously at most 20nm from the surface.

In a development of the invention, the concentration of the at least one alkali metal and/or alkali metal oxide at the surface of the component is at least 2%, in particular at least 4%, preferentially at least 6%, preferably at least 8%, more preferably at least 10%, optionally particularly preferably at least 15%, optionally even more preferably at least 60% of the aforementioned maximum concentration of the at least one alkali metal and/or alkali metal oxide in the component made of glass.

A sample of an element made of glass having the aforementioned minimum concentration of alkali metal and/or alkali metal oxide at or near the surface is characterized by an increased surface conductivity when compared to a different concentration profile.

Preferably, the average of the aforementioned maximum concentration of the at least one alkali metal and/or alkali metal oxide and the concentration of the at least one alkali metal and/or alkali metal oxide at the surface is located at a distance of at least 1 nm, preferably at least 5nm and at most 50 nm, preferably at most 25nm, measured perpendicularly from the surface.

In this way, it is generally possible to define, at least in the region close to the surface, a large continuous increase in concentration towards the inside of the element made of glass.

In a development of the invention, the concentration of the at least one alkali metal and/or alkali metal oxide at the surface of the component is at most 60%, preferably at most 75%, particularly preferably at most 90%, more preferably at most 95%, even more preferably at most 99% of the aforementioned maximum concentration of the at least one alkali metal and/or alkali metal oxide in the component made of glass.

The values at the surface may, in addition to their actual meaning, have the meaning of an average value in the depth range of 0 to 5nm, or may also have the meaning of a minimum value in the depth range of 0 to 5 nm. As far as the values at the surface are mentioned, this applies in general.

The glass element samples having the aforementioned maximum concentration of alkali metal and/or alkali metal oxide at or near the surface no longer exhibit any significant increase in surface conductivity when compared to a different concentration profile.

The advantage of the aforementioned maximum concentration is, precisely, that elements made of glass, such as glass tubes, have a suitable electrostatic charging, i.e. a charging that is present but not too strong, during their reprocessing, so that they are optimized.

In a development of the invention, the glass contains at least a proportion of alkali metals which is at least 18 wt.%, advantageously at least 16 wt.%, advantageously at least 15 wt.%, advantageously at least 12 wt.%, advantageously at least 10 wt.%, particularly advantageously at least 8 wt.%.

A particularly suitable alkali metal oxide is sodium oxide (Na)₂O). Sodium oxide is commonly used to make glass more easily meltable. Advantageously, the glass comprises at least 15 wt.%, advantageously at least 13 wt.%, advantageously also at least 10 wt.%, advantageously also at least 8 wt.%, advantageously also at least 4 wt.%, particularly advantageously at least 2 wt.% of Na₂O。

Other particularly suitable alkali metals are K₂O and/or L i₂And O. Advantageously, the glass comprises at least 10 wt.%, advantageously at least 8 wt.%, advantageously at least 6 wt.%, advantageously at least 5 wt.%, advantageously at least 0.7 wt.% of K₂O。

Advantageously, the glass may also contain L i₂O as mandatory component.

The alkali metal oxides can in particular also be used in any combination with one another. Accordingly, the above minimum contents may be used in any combination.

The electrostatic properties of the glass element can be influenced by this combination. In particular, the total concentration of alkali metal oxides is advantageously at most 20% by weight, likewise advantageously at most 17% by weight, and likewise advantageously at most 13% by weight.

It can be provided that the concentration of sodium oxide increases from a minimum at or near at least one surface in the direction of the interior of the element. Furthermore, the concentration of sodium oxide has a substantially constant plateau value inside the element from a distance of at most 50 nm, advantageously at most 30nm, more advantageously at most 25nm from at least one surface.

In particular, it is further provided that the minimum value of the concentration of sodium oxide is at least 1%, preferably at least 2%, particularly preferably at least 5%, of the plateau value.

It has been shown that the minimum value of the concentration of these sodium oxides is a good compromise for optimizing the electrostatic charging.

However, it can optionally also be provided that the minimum value of the concentration of sodium oxide is at least 7.5%, preferably at least 10%, particularly preferably at least 15%, even more preferably at least 20% of the plateau value.

It can be provided that the concentration of lithium oxide increases from a minimum at or near at least one surface in the direction of the interior of the element. Furthermore, the concentration of lithium oxide has a substantially constant plateau value within the element from a distance of at most 50 nm, advantageously at most 30nm, from at least one surface.

In particular, it is further provided that the minimum value of the concentration of lithium oxide is at least 1.5%, preferably at least 3%, particularly preferably at least 5%, of the plateau value.

It has been found that a minimum of these lithium oxide concentrations is also a good compromise for optimizing the electrostatic charging.

It can be provided that the concentration of potassium oxide increases from a minimum at or near at least one surface in the direction of the interior of the element. Furthermore, the concentration of potassium oxide has a substantially constant plateau value within the element from a distance of at most 30nm, preferably at most 50 nm, from at least one surface.

In particular, it is further provided that the minimum value of the concentration of potassium oxide is at least 1%, preferably at least 2%, particularly preferably at least 5%, of the plateau value.

It has been found that a minimum of these potassium oxide concentrations is also a good compromise for optimizing the electrostatic charging.

Preferably, the glass measured at a distance of at least 50 nanometers measured perpendicularly from the surface comprises the following oxides in weight percent:

-silicon dioxide (SiO)₂): 50% to 77%;

alumina (Al)₂O₃): 0 to 10%, in particular 0.5% to 7%, in particular 1% to 7%;

-oxygenBoron (B)₂O₃): 0 to 10%;

iron (III) oxide₂O₃): 0 to 10%;

sodium oxide (Na)₂O): 0 to 18%, in particular 1% to 15%;

-potassium oxide (K)₂O): 0 to 17%;

lithium oxide (L i)₂O): 0 to 6%, in particular 0 to 5%;

-the sum of the oxides of Ca, Mg, Ba, Sr and/or Zn: 1% to 15%.

There may also be provided a composition in the above proportions, additionally comprising from 0 to 4% (wt%), preferably from 0 to 3.5% (wt%) of fluorine (F).

A composition in the above-mentioned proportions may also be provided, in addition to Na₂O、Li₂O and K₂The sum of O is a value of 8% to 24% (wt%).

A composition of the above proportions may also be provided wherein 0 to 1% (wt%) TiO is also provided₂. May also contain Sb₂O₃In particular in the amounts conventionally used for refining agents.

In a preferred variant, the following percentages by weight may also be present:

-silicon dioxide (SiO)₂): 50% to 77%;

alumina (Al)₂O₃): 0.5% to 7%;

boron oxide (B)₂O₃): 0.1% to 8%;

iron (III) oxide₂O₃): 0 to 8%;

sodium oxide (Na)₂O): 0 to 18%;

-potassium oxide (K)₂O): 0 to 17%;

lithium oxide (L i)₂O): 0% to 6%;

-the sum of the oxides of Ca, Mg, Ba and Sr: 0 to 15%.

There may also be provided a composition in the above proportions, additionally comprising 0 to 4% (wt%) fluorine (F).

A composition in the above-mentioned proportions may also be provided, in addition to Na₂O、Li₂O and K₂The sum of O is a value of 8% to 24% (wt%).

A composition of the above proportions may also be provided wherein 0 to 1% (wt%) TiO is also provided₂. May also contain Sb₂O₃In particular in the amounts conventionally used for refining agents.

In a further preferred variant, the following percentages by weight can also be present:

-silicon dioxide (SiO)₂): 50% to 77%;

alumina (Al)₂O₃): 0.5% to 7%;

boron oxide (B)₂O₃): 0.1% to 8%;

iron (III) oxide₂O₃): 0 to 8%;

sodium oxide (Na)₂O): 0 to 18%;

-potassium oxide (K)₂O): 0 to 17%;

lithium oxide (L i)₂O): 0 to 6%;

-the sum of the oxides of Ca, Mg, Ba, Sr and Zn: 3.5 to 17 percent.

There may also be provided a composition in the above proportions, additionally comprising 0 to 4% (wt%) fluorine (F).

A composition in the above-mentioned proportions may also be provided, in addition to Na₂O、Li₂O and K₂The sum of O is a value of 8% to 24% (wt%).

A composition of the above proportions may also be provided wherein 0 to 1% (wt%) TiO is also provided₂. May also contain Sb₂O₃In particular in the conventional content of refining agents.

Can extract Na₂O/K₂O>0.1; preferably, Na₂O/K₂O>0.3; preferably, Na₂O/K₂O>1; particularly preferably, Na₂O/K₂O>1.4。

Fe₂O₃The minimum proportion of (B) is 1 wt%This is advantageous, in particular, when infrared radiation can be used to melt the material.

As previously mentioned, the electrostatic charging may be related to the electrical conductivity of the glass element. For example, it can be seen that, at the surface conductivity mentioned above, the electrostatic charging can be reduced to such an extent that, in particular, the adhesion of particles to the glass elements and/or the adhesion of the glass elements to one another can be largely avoided.

According to the invention, a glass tube for a reed switch or transponder is also provided, which glass tube is formed from the aforementioned element made of glass or comprises at least one such element made of glass. The glass element configured as a glass tube is particularly advantageous for the production of a reed switch or an RFID transponder.

Preferably, the glass tube is configured as a cylindrical tube having an outer surface and an inner surface and a uniform wall thickness.

Preferably, the outer diameter of the glass tube is less than 6 mm, preferably less than 3 mm, particularly preferably less than 2.5 mm.

Further, the ratio of the wall thickness to the outer diameter of the glass tube is less than 1/3, preferably less than 1/5.

The ratio of the length of the glass tube to the outer diameter is preferably less than 20, preferably less than 10, advantageously less than 5.

According to the invention, a reed switch or transponder is also provided, which comprises the above-mentioned glass tube, wherein the glass tube in particular forms a housing.

Drawings

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1a and 1b show the depth profiles of lithium ions on four reed glass tubes generated by TOF-SIMS;

FIGS. 2a and 2b show potassium ion depth profiles on four reed glass tubes generated by TOF-SIMS;

FIGS. 3a and 3b show the sodium ion depth profiles on four reed glass tubes generated by TOF-SIMS;

FIGS. 4a and 4b show the depth profiles of silicon ions on four reed glass tubes generated by TOF-SIMS;

FIGS. 5a and 5b show Na on four reed glass tubes generated by ToF-SIMS₂O depth profile; and

FIG. 6 shows depth profiles of different glass compositions of a magnetic reed glass tube produced by TOF-SIMS.

Fig. 7 shows a glass tube.

Fig. 8 shows a transponder.

Fig. 9 shows a reed switch.

Detailed Description

The measured depth profiles of the different glass compositions shown in fig. 1a and 1b to fig. 5a and 5b and fig. 6 were determined on the outer surface of four different reed glass tubes by means of time-of-flight secondary ion mass spectrometry (ToF-SIMS). Here, the four glass tubes of fig. 1a are of the same type as the four glass tubes of fig. 1 b. The same applies to the glass tubes of fig. 2a and 2b, fig. 3a and 3b, fig. 4a and 4b and fig. 5a and 5 b.

In this ToF-SIMS method, a surface is bombarded with a primary ion beam of high energy, thereby emitting neutral particles, electrons and secondary ions from the surface. In a time-of-flight mass spectrometer (ToF spectrometer), secondary ions are separated according to their mass and their relative number to each other is detected. The relative numbers represent a measure of the concentration of various secondary ions as a function of glass depth.

Fig. 1a and 1b show the lithium ion concentration determined in this way in the y-axis direction. The concentration is plotted as a function of depth in the x-axis direction, which is referred to as a function of distance from the outer surface of the glass element in the direction of the interior of the glass element. For this reason, the removal rate of the surface material by the primary ion beam was determined, while the depth in nanometers was calculated from the irradiation time. The x-axis and y-axis labels refer to a conventional two-dimensional cartesian coordinate system with the x-axis extending horizontally and the y-axis extending vertically, both axes intersecting at respective zero values.

Four measured lithium ion concentration curves 10, 12, 14 and 16 as a function of depth were determined on four different reed glass tubes with a diameter of 2.06 mm (fig. 1 a). The same applies to the curves 10', 12', 14', 16' of the same type of glass tube (fig. 1 b).

It should be noted that the absolute concentration cannot be determined by the ToF-SIMS method. To improve comparability, these curves were normalized to the silicon strength at the end of the measurement. Accordingly, the concentration (y-axis) is plotted in arbitrary units. The respective concentration curves 10, 12, 14 and 16 (and 10', 12', 14 'and 16') along the y-axis represent relative values.

Based on the ToF-SIMS method, the measured lithium ion concentration curves 10, 12, 14 and 16 (and 10', 12', 14 'and 16') as a function of depth represent only an approximation of the concentration curve actually present in the material. In particular, fluctuations in the shown concentration profile are common errors of such measurement methods.

The determination of the concentration as a function of the glass depth in this way is shown in fig. 1a and 1 b. Here, curves 10, 12, 14 and 16 (and 10', 12', 14 'and 16') as a function of depth were determined for four different mag-glass tubes each having a diameter of 2.06 mm.

Concentration curves 10, 20, 30 and 40 are for the same sample. Likewise, concentration curves 12, 22, 32, and 42 can be assigned to one sample, while concentration curves 14, 24, 34, and 44 can be assigned to another sample. The same applies to the concentration curves 16, 26, 36 and 46. The same applies to the concentration curves 10', 20', 30 'and 40', etc.

The lithium oxide concentration curve 10 measured on the first glass tube takes a minimum value in the region near the surface. This value increases towards the inside of the glass tube. A substantially constant plateau value is reached inside the element from a distance of about 45nm from the surface. At this point, the minimum value is about 2% of the plateau value.

The lithium oxide concentration curve 12 measured on the second glass tube shows a distinctly different behavior. Reaching a minimum at or near the surface; a plateau value representing a maximum value is reached from a depth of about 25 nm. At this point, the minimum value is about 6% of the plateau value.

The lithium oxide concentration curve 14 measured on the third glass tube shows again a behavior similar to curve 10. Reaching a minimum at or near the surface. A plateau value representing a maximum value is reached from a depth of about 45 nm. At this point, the minimum value is about 2% of the plateau value.

In the concentration curve 16 of the fourth glass, a similar behavior to that of the second glass tube can also be observed. Here, the lithium ion concentration at or near the surface also begins to drop sharply and then reaches a plateau at a depth of about 25 nanometers. At this point, the minimum value is about 3.5% of the plateau value.

The curve shown in fig. 1b substantially corresponds to the curve in fig. 1 a.

The potassium concentration determined in a similar manner is shown in fig. 2a and 2 b. Again, four concentration curves 20, 22, 24 and 26 (and 20', 22', 24 'and 26') as a function of depth were determined on four different reed glass tubes each 2.06 mm in diameter.

The potassium concentration curve 20 measured on the first glass tube takes a minimum value in the region near the surface. This value increases towards the inside of the glass tube. Reaching a maximum at a distance of about 10 nanometers. A substantially constant plateau value is reached inside the element from a distance of about 40nm from the surface. The minimum value of potassium concentration is about 0.5% of the plateau or maximum value.

The potassium concentration curve 22 measured on the second glass tube shows slightly different properties. Reaching a minimum at or near the surface. Reaching a maximum at a depth of about 6 nm. Plateau values are reached from a depth of about 25 nm. The minimum value of potassium concentration is about 6% of the plateau or maximum value.

The potassium concentration curve 24 measured on the third glass tube shows similar performance to curve 20. Reaching a minimum at or near the surface. Reaching a maximum at a depth of about 10 nanometers. A substantially constant plateau value is reached from a depth of about 40 nanometers. The minimum value of potassium concentration is about 2% of the plateau or maximum value.

The curve 22 also applies to the concentration curve 26 of the fourth glass. Here, a maximum is reached at a depth of about 6 nm. A plateau value is reached from a depth of about 25 nm. The minimum value of potassium concentration is about 2% of the plateau or maximum value.

The curve shown in fig. 2b substantially corresponds to the curve in fig. 2 a.

Fig. 3a and 3b show sodium ion concentrations determined in a similar manner. Here, the sodium ion concentration in the near-surface region was the lowest in all samples. The concentration curves 30 and 34 exhibit plateau values representing maxima from a depth of about 45 nm. In samples 32 and 36, a plateau value was reached at a depth of about 30 nm. In this case, the minimum value for sample 30 is about 0.2% of the plateau value, the minimum value for sample 32 is about 11% of the plateau value, the minimum value for sample 34 is about 1.3% of the plateau value, and the minimum value for sample 36 is about 5% of the plateau value.

The curve shown in fig. 3b substantially corresponds to the curve in fig. 3 a.

FIGS. 4a and 4b show Na determined in a similar manner₂The O concentration. Here, the sodium concentration in the near-surface region began to decrease in all samples. The concentration curves 40 and 44 exhibit plateau values representing maxima from a depth of about 40 nm. In samples 42 and 46, a plateau value was reached at a depth of about 25 nm.

The curve shown in fig. 4b substantially corresponds to the curve in fig. 4 a.

Fig. 5a and 5b show concentration curves of silicon ions as a function of glass depth determined in a similar manner. Here, all of the samples 50, 52, 54, and 56 had a maximum value in the near-surface region of the glass, and then the value was decreased by about 30nm to 40nm to become a plateau value, which simultaneously represents a minimum value.

The curve shown in fig. 5b substantially corresponds to the curve in fig. 5 a.

In general, the samples belonging to the concentration curves 12, 16, 22, 26, 32, 36, 42, 46, 52, 56 exhibit characteristics that are more favorable for the purposes of the present invention than the samples belonging to the concentration curves 10, 14, 20, 24, 30, 34, 40, 44, 50, 54.

It is also related to the following chemical resistance: in particular, glass elements with low minimum values of sodium, potassium, lithium at or near the surface have a SiO-rich content₂Of (2) is provided. Thus, such glass elements are chemically more stable, but capable of carrying higher electrostatic charges.

Surprisingly, glass elements having a higher minimum at or near the surface have good chemical resistance despite reduced electrostatic charge.

Figure 6 shows concentration curves for different ions in a sample determined in a similar manner. In the concentration curves of the alkali ions sodium and lithium, the sample also showed a decrease in concentration in the near-surface region, followed by an increase in concentration into a plateau. The potassium ion concentration curve begins to decrease in the near surface region, then takes a maximum at a depth of about 10nm, and then enters a plateau of about 20 nm.

For ionic Si⁺、SiO⁺、B⁺And Al⁺First, an increase in concentration in the region near the surface can be observed. As the depth increases, the concentration decreases and enters a plateau value, which simultaneously represents the minimum.

Fig. 7 shows a glass tube 10 made of a glass element comprising at least one alkali metal and/or alkali metal oxide. The glass tube 10 has a length 16 and includes a wall 14 having a wall thickness 15. The glass tube 10 and/or the glass wall 14 have an outer surface 11 and an inner surface 12, wherein the concentration of at least one alkali metal and/or alkali metal oxide increases from one or both surfaces in a direction towards the interior of the glass element, in particular such that the maximum concentration of said alkali metal and/or alkali metal oxide in the glass element is present at a distance of at most 60 nanometers measured perpendicularly from one or both surfaces.

Fig. 8 shows a reed switch 20 comprising a closing glass tube 10, said closing glass tube 10 forming the glass body of the reed switch 20. The reed switch 20 further comprises two leads 21 extending through the wall of the glass tube 10. On the inside of the glass tube, two lead wires 21 form a switch contact 22 or are connected to the switch contact 22. Fig. 9 shows a transponder 30 comprising a closing glass tube 10, said closing glass tube 10 forming the glass body of the transponder 30. In the inner volume of the closed glass tube 10, the transponder 30 further comprises a transponder element 31, for example an RFID element.