DE2505270A1 - PROCESS FOR HYDRATING SILICATE GLASSES - Google Patents

Description

Applicant: Corning Glass Works
Corning, NY, π SA

Process for hydrating silicate glasses

The invention relates to a method for hydrating Silicate glasses made from finely divided batches such as powder, grains, flakes, fibers, thin sheets and the like, which are thermoplastically formed into bodies or applied to a substrate and in situ into colors, coatings, etc. can be hydrated.

It is already known from US Pat. No. 3,498,803 that certain glasses can be hydrated with steam and then assume plastic or rubber-like properties. The glass glasses treated in this way essentially consist, in mol % on an oxide basis, of 6-40 % Na ₃ O and / or K ₂ O and 60-94% SiOp, which together make up at least 85 % of the glass. Compatible metal oxides such as PbO, BaO, MgO, BpO ^, AlpO ~ and ZnO can also be included. CaO and LipO are preferably absent. The glasses come with a gaseous

509835/0998

Atmosphere with at least 50 % (wt. %) Water vapor at 1 atm. Contains treated 200 ° lying temperature until at least a surface portion of the G-lases about 5-30% by weight of water - and a pressure usually between SO..

According to US Pat. No. 3,498,802, thermoplastic material and hydraulic cement are produced by hydration of alkali metal silicates in the form of glass powder containing, in Hol. %, on an oxide basis, 80-94 % SiO ₂ and _{6-20 Na 2} O and / or K ₂ O, which together make up at least 90 mol % of the total composition, and compatible metal oxides such as PbO, BaO, MgO, B ₂ O ₅ , Al ₂ O ₅ and ZnO, but are preferably free of CaO and Li ₂ O. The glass powder is in a gaseous atmosphere with at least 50 wt. % Steam at 1 atm. Pressure and about 100 -. 200 ° treated until at least a surface layer of the glass grains up to 30 wt% water. The hydrated powder becomes adhesive and cohesive when heated to 80-120 ° and can be pressed, rolled, extruded and injection-molded at these temperatures.

However, the chemical resistance and weathering resistance of the thermoplastic glasses produced according to the two aforementioned patents are so inadequate that they are none have achieved practical usefulness.

509835/0998

US-PS (Ser. No. 249,289) describes the hydration of certain alkali silicate glasses containing, in% by weight on an oxide basis, 10-30% Na ₂ O and / or K ₂ O and _{65-90% SiO 2} , which together at least 80 % of the total composition. If the surface is pierced, the glass spontaneously disintegrates under the influence of the atmosphere.

The concurrent application P 25 05 269.1 describes the Production of glasses with thermoplastic properties comparable to those of organic plastics through a two-step process Treatment in which the glass is first hydrated and. then becomes more or less dehydrated. this makes possible the precisely controlled production of glasses with the desired water content influencing the properties in comparatively short treatment time. In this way, in particular, larger shaped bodies can also be produced.

It is an object of the invention to reduce the risk of dehydration unless the temperature, pressure and relative humidity are regulated very precisely, the formation of To rule out cracks, cracks, deformation and foam formation, especially when treating finely divided glass in the form of pearls, grains, powder, Ribbons etc.

509835/0998

It has surprisingly been found that finely divided glass can also be treated in one stage only by hydration and can result in useful objects. Glass compositions suitable for this essentially consist, in mol % on an oxide basis, of 3 - 25 % Na ₂ O and / or KgO and 50 - 95 % SiO ₂ , the sum of these components should make up at least 55 mol% of the total composition. Favorable additives for the purpose of improving melting and shaping as well as influencing chemical and physical properties are metal oxides such as Al ₃ O ₅ , BaO, CdO, B ₃ O ₃ , CaO, MgO, PbO, ZrO ₃ , WO ₅ , MoO, TiO ₂ , SrO and ZnO, in particular PbO, CaO, ZnO and B ₂ O ₅ up to about 25 %, MgO up to about 35 %, BaO and Al ₂ O ₅ up to about 15 % _t in the remaining cases preferably below about 10%. CaO often produces translucent or opaque bodies instead of transparent ones and must therefore be left out if the object is to be transparent. Common coloring agents such as Fe ₂ O ₅ , FiO, Co ₂ O ₅ , CuO, CdS-Se can be added in known amounts of a few percent will. They can be added up to about 10 % if they are to fulfill a further function besides coloring at the same time. An addition of 2-3 % I * 2 ⁰ 5 ^{can result in} an opaque instead of transparent glass body after hydration. Well-known refining agents are also permitted.

509835/0998

The method of the invention comprises, depending on the composition, two embodiments. According to the first embodiment, which is independent of the composition, finely divided glass is exposed at a temperature of at least 100 ° to a gaseous H ₂ O-containing atmosphere with a relative humidity of 75 %, preferably less than 50 % . The second embodiment relates to compositions with a low alkali content, ie less than about 10 mol % Na ₂ O and / or K ₂ O, or also up to 17 mol % but more than a total of 15 mol % metal oxide (MLO.), wherein the metal has a valence of at least 2 and the sum of these components makes up at least 70% of the total composition. Here, the finely divided glass is treated _{at temperatures above 225 ° and an atmosphere containing H 2} O, a relative humidity of more than about 50 %. Examples of such metal oxides are BaO, PbO, GaO, CdO, MgO, Al ₂ O ₅ , SrO, TiO ₂ , ZrO ₂ , MoO ₅ , WO ₅ and ZnO.

The US-PS 3,498,802 and 3,498,803 remark explicitly on the use of a high water content at temperatures up to 200 °, that the quality of the rubber-like material obtained at temperatures above 200 ° is not significantly better than that at material obtained at a lower temperature, and in some cases even becomes unusable. In contrast, it is surprising that in the above-mentioned embodiment of the invention Temperatures above 200 are extremely good for promoting hydration

509835/0998

are favorable, Furthermore, compared to the very high temperatures and treatment times requiring treatment at low humidity close to that of humidity Saturation point preferred. The glasses with low alkali content are therefore particularly beneficial in cases where * treatment with high humidity is preferred. In These glasses can achieve the maximum HpO content even in the presence the saturation ratio can be precisely regulated. Thus, by selecting the composition, the Precisely adjust the maximum amount of water absorbed by hydration even at 100% relative humidity. This is true also possible with low humidity, but must. then the treatment time at the same temperature will be much longer.

The invention enables the hydration of finely divided glass material with precisely controlled water absorption. Up to 25 wt.% Water can be absorbed without generating cracks or foam formation, while the desired thermoplastic properties are achieved.

The amount of water absorbed can be precisely adjusted and kept so low that the hydrated material is good chemical resistance of the starting glass at least retains.

- 7 -

S09835 / 0998

The relative humidity "refers by definition to very high temperatures and a saturated vapor pressure. In pure water the so-called critical temperature (maximum liquefaction temperature of a gas) and the critical pressure (liquefaction temperature of a gas at the critical temperature) is about 374 ° and 3200 psi, respectively. above this critical temperature, HpO is neither a liquid nor a gaseous fluid. For details, reference is made to RA Laudisse and JW Nielsen, Solid State Physics, 12, pp. 149-222, in particular p. 180, Fig. 1, which shows the pressure temperature characteristics shows for HPO at constant volume. the straight lines denote different fill factors, the percentage filling volume of the autoclave or pressure vessel that is liquid HgO at ambient temperature. the Mindestfüllfaktor (minimum amount of liquid _H? 0, the saturated atmosphere of 100% humidity results) can can be calculated on the basis of the standard steam tables. At 374 ° this critical level is oil factor about 30%. At fill factors above 30 % , the liquid HpO expands to such an extent that the vessel is filled at temperatures below the critical point, 374 °, and is under hydrostatic pressure. (See Fig. 2 on page 181, loc. Cit.)

As can be seen from Fig. 1, the pressure-temperature characteristics are at a constant level beyond the coexistence curve (pressure and temperature limits where liquid and

- 8th -. 509835/0998

gaseous H ₀ O can exist together), essentially linear and probably extrapolated with certainty. Since, according to the invention, glass bodies are treated in gaseous EJ} ", the person skilled in the art can use FIG. 1 and the standard steam tables to determine the filling factor for saturated or unsaturated steam at temperatures below 374 ° and at a certain temperature at temperatures above 374 ° Calculate the desired pressure. Since the vapor-pressure-temperature characteristics are practically linear at a constant filling level beyond the coexistence curve, the behavior of the environmental conditions can be extrapolated based on an environment of a certain relative humidity below the critical temperature Steam Tables - Thermodynamic Properties of Water Including Vapor, Liquid, and Solid Phases (English Units), JH Keenan, FG Keyes, PG Hill, and JG Moore, John Wiley & Sons, New York, 1969 and Thermodynamic Properties of Steam, Including Data for the Liquid and Solid Phases, JH Keenan and FG Keyes.

Table I contains a number of those which can be used in accordance with the invention Glass compositions in mol-r% on an oxide basis. The batches can consist of the oxides or other compounds that result when they are melted. The approach components have been carefully, e.g. B. mixed in a ball mill and for 16 hours at 1450 - 1600 ° in open Platinum or silica crucibles melted. As is known, larger batches can be melted in melting tanks and the like will. Small glass particles can also be produced by passing a flow of fused glass through a hot flame, an air flow or made in water. Also can be a thin one

509835/0998

Tape that is hydrated or too hydrated as such Flakes being broken. Here, 15mm is usually a practical one Maximum thickness, while less than 5 m are preferred because of the higher rate of hydration ".

The hydration was because of the better regulation of steam pressure relative humidity and temperature carried out in an autoclave. The thin ribbon of glass was over the baseplate of the autoclave on fireproof material, Teflon or a non-sticking and non-converting material horizontally supported at points. Uniform autoclave operation was usually achieved. after half an hour, the higher the temperatures used, this took a little longer «

The time required to hydrate the entire glass or Ms to the desired depth is directly related to the composition of the glass, the HpO pressure and the temperature. Glasses with a high alkali content usually hydrate faster and Ms with a higher water concentration _s are, however, usually less chemically resistant. Higher temperatures and H ₉ Q bridges also result in faster hydration. The required oiling time is inversely proportional to the smallest glass cross-section. Although continuous hydration is preferred, articles having a hydrated furnace face layer can also be made.

509835/0398

In the following examples, an autoclave with a 1 Ft large chamber used «The vapor pressure has been through Heating - produced by distilled water in the bottom of the vessel. The pressure was adjusted via the temperature. The required Moisture was achieved by entering the amount of water corresponding to the given temperature. The autoclave can thus be set to any moisture content beforehand * but this will be more precise The setting is first dried before each treatment. When treating smaller amounts of glass, the amount absorbed has an effect The amount of water does not significantly affect the pressure. In len examples fill factors of 10% and less were mostly used. Usually used for plastic objects to facilitate molding devices used and to achieve complete hydration in a reasonable time have mostly become anger sizes used from 37 / µm to 4.76 mia. If the grain size is very fine, the treatment can be short, see B. 2 - 4 hours y during longer treatment times, see B. 24 - 72 hours or longer at larger grain sizes are required. After the treatment the autoclave is usually allowed to cool to 100 ° before the samples are taken. However, the removal is also at higher temperatures according to the available water possible. The amount of water absorbed by the glass is through Weighing of the item is determined before and after the treatment.

509835/0998

When sculpting into massive bodies, hydration becomes throughout preferred. Often the glass particles "flow together to form a solid body during hydration.

Table II provides a comparison of the on several glass samples of Table I! Having grain sizes of 1 mm in 16 hrs. At 300 °, and different moisture absorbed up to 100% water content in wt.% *

Table III contains a comparison of that of glasses from Table I by hydration of 1 mm particles in the autoclave for 16 hours at 350 ° and various humidity levels absorbed water content.

Table IV contains a comparison of the absorbed water content of glasses from Table I after treatment of 1 mm particles for 16 hours at 374 ° tmd of various Humidity.

Table V illustrates the effect of low alkali on hydration absorbed water. Examples 18-25 contain less than 10 mol % Ua ₂ O and / or K ₂ O. Particles 74 μm in size were treated in an autoclave for 16 hours at 250 ° and 100 % moisture.

509835/0 998

These compositions containing 10 or less mol % Na ₂ O and / or K _n O can illustrate the alternative embodiment of the invention. They are hydrated in a reasonable time at high temperature and approximately saturated steam atmosphere. Lower humidity is possible, but impractical because of the long treatment time required. Also, the maximum absorbed water content is not higher than about 25 wt.% And is usually determined by the composition of glass. This water content is sufficient for the development of thermoplastic properties and the hydrated product has good chemical resistance.

Table YI shows the influence of the absorbed water content on the chemical resistance. Conversely, it usually applies that the lower the amount of water absorbed, the lower the thermoplasticity of the object. Nevertheless, certain compositions, in particular, for example, glasses with a high proportion of PbO according to Examples 9-14, even with a low water content of, for example, 1 %, have sufficient plasticity for deformation at low temperatures. Accordingly, the preferred articles contain about 1-12 wt.% Water,

Table VI lists the results of the treatment of hydrated glass powder that was pressed into disks and carried out for 20 hours. at 70 ° with dist. Water has been treated. For most uses, weight loss means less than about

- 13 509835/0998

100 micrograms / qcm sufficient chemical resistance. The glass powder was classified to the specified sizes and placed in a 1 1/4 inch mold until it softened heated and then pressed into 1/8 - 1/4 inch disks with a ram at 5000-8000 psi load.

The minimum practical value found to be useful relative humidity is around 5%. However, hydration takes place the faster the higher the HpO pressure and the higher the temperature is. At very low relative humidity, e.g. 5-10%, very high temperatures are required for hydration in a reasonable time, about 300 and preferably above 350 °.

For glasses with a high Na ₂ O and / or HJ) Itsiialt the complete hydration requires! Temperature of at least 100 ° and preferably greater than 150 °, bite but are practically too high temperatures for glasses with low Alkaligeiialt _9, at least 225 ^ and preferably over 250 are treated.

The maximum hydration temperature depends on the Practice according to the equipment used, provided that the fine-grained material has no detrimental effect on the Intended use can be softened and / or melted «.

- 14 509835/0998

25.B, temperatures from 5OG - 600 ° are possible. Usually the hydration is below the softening temperature of the anhydrisohen Running glass.

Bulky bodies can be produced using the usual methods for molding organic plastics, e.g. Dry pressing, injection molding, extrusion, etc. The application of pressure is often sufficient at room temperature, but higher temperatures, e.g. about 100 - 400 "'are used when the material flows better. As a practical maximum temperature 500 ° was determined.

Since "may be lost in the formation of water absorbed, it is preferably in an autoclave or made other suitable pressure vessel. For suitable pressures different atmospheres may be suitable ₅ about the excessive volatilization sii prevent water *

Table VII compares the high and low water products. Particles with a grain size of 105 μm in the examples were hydrated for 4 hours at 270 °. The softened particles coalesced to form a cake, which was broken into pieces of different sizes. These were placed in a preferably preheated 11/4 inch mold and subjected to light pressure, about 10-50 psi, then heated, the glass beginning to soften at about 270-300 degrees.

- 15 509835/0998

The mold was then pressurized to 5000-8000 psi. After about 3 min. The heat source was removed and let the mold cool to below 60 °. The print was then defrosted and the 1/8 - 1/4 inch thick disk removed

The exercise observed in Examples 3, 6 and 9 (when treated at 38 % relative humidity) and the translucent nature of Example 9 when treated at 100 % relative humidity can be suppressed or eliminated by a more carefully controlled hydration treatment. Bodies with a high water content are often prone to ice formation if the drying is not done carefully.

The material produced can be used favorably as a paint or coating for something that does not react with it Substrates. Very hard, permanent coatings are turned into a fine powder by grinding the glass, e.g. the grain size 400 mesh and optionally mixing with a liquid carrier such as water or methanol until a thick layer is formed Obtain slurry. The dry powder or slurry is applied to a substrate, e.g. a steel or aluminum plate, a glass or a ceramic, and then treated in the autoclave. The hydration is the same as that described above for the vitreous and depends on the alkali oxide content of the coating material.

509835/0998

The batches of Examples 18 and 20 flowed in after 2 hours of treatment in 100 % moisture
clear, glassy coating.

treatment in 100 % humidity at 250 ° to a hard,

The batches of Examples 1, 3 and 13 flowed together after 16 hours at 250 ° in 49 % relative humidity to form a clear, hard, well-adhering glassy coating.

In addition to steam, the atmosphere in the examples consisted of air; instead, inert gases such as helium, Argon or nitrogen are introduced.

509835/0998

^ - CM OO

vD in Ε

co co

O VO

O CTi

cn tA ir- τ

OO C-

in · <φ C— T-

I 1 f

in

cm in

! I.

CO

(M CTi CT-

ιη | «« Ι ι ι f · »f

ΙΛ CO £ -

t- T-

■ Φ

CTi

CM

C-

OO O

O OO ι ·> * I i

00
C-

O in

i i i

(M • ^. • in OO in C— τ— I. d C- τ— • ^ (M ^. cn in in I. I. VD VO C-

I i

i I

(M O

O CM (M

• H Cd H

CQ! 25 <yy

O O O

ti ce .a cm N P5 9i «

509835/0998

CO

O E-

O in

I «.

VD

vo

ocT

VO

in

to

CM O

I - I I

ir *

cm c— to oo cn -c-

OJ in ο O O irv

E— v-

E - VO

in

O) H H

tO CM tO CO - ^ f-

co in Ln τ- cn

VO T-

CM

c—

E-

VO

CM O

1! If

CM

CO ν-

O E-C-

C- Ε

C- VO

Ι I

CM

m.

c-

cn vo cm vo

OO

I I I

CM Ε

cn

LTN

in

E-

oo *

Ι I I I

tn to

CM O O to

O CMO CMOO CMO

• HCÖ M rl P CMCQOJ

509835/0998

Table II - Relative Humidity and Vapor Pressure -

Example- 17.5% 21.3% 26.1% 32.1% 34.9% 39% 42.6% 43.4% 48.6% 100%

No. (218 psi) (265 psi) (325 psi) (400 psi) (434 psi) (485 psi) (530 psi) (540 psi) (605 psi) (1246 psi)

O CD CO OO

1 2 3 4 5 6 7 8 9 10

2.5

4.9

6.5

3.1

2.8

8.8

12.0 13th - 11.0 10 , 5 10.5 , 6 9.0 - 7.0 - 6.0 - 8.0 6th 5.9 , 5

3.2

4.0

24 18 22 19 13 14 13 13 7

ο cn
N)

Table II (conclusion)

Example- 17.5% 21.3% 26.1% 32.1% 34.9% 39% 42.6% 43.4% 48.6% 100%

No. (218 psi) (265 psi) (325 psi) (400 psi) (434 psi) (485 psi) (530 psi) (540 psi) (605 psi) (1246 psi)

12 -.-

13 - - 5.6 - - 5.3

cn ο 14- - - - -

«15 - - - 8.0 -

^^ ^ Q - - <m ~ « Mt > u -

cd 17 - - - - 4.5 5.6

3.2 3.0 7th 3.2 3.7 6th - - 10 3.3 - 5.5 9.4 11.5 17th • Μ WM ^ 25
• 13

ro cn ο

cn ro

-ο

! Table III - Relative! Humidity! And Vapor Pressure

Example- 17.5 % 20.6 % 25.9 % 30.9 % 37.1 % No. (420 PSi) (495 psi) (622 pai) (740 psi) (890 p si)

2 _ 7.8 6.4 9.6 8.3 3 4.5 5.8 5.0 8.5 9.4 9 3.3 4.6 - - 6.1 10 - - - - 3.0 11 - - - 2.2 3.9 12th - - 3.6 2.2 2.4 13th 2.7 2.8 - - 4.4 15th - 2.2 mm - 6.9 17th 3.2 7.0

509835/0998

-to. ²⁵⁰⁵²⁷ °

Table IT - Relative Humidity

and steam pressure

Example-
No. 16.6 %
(530 psi) 19.7 %
(630 psi) 24.1 %
(770 psi) 27.5 %
(880 psi) 3 _ 5.9 _ _ 9 2.2 3.4 4.0 4.5 10 - 0.8 - 1.3 11 - 1.4 2.3 2.7 12th 1.0 1.4 1.4 2.8 13th 2.1 2.4 2.8 3.5 15th - - 9.0 - 17th 2.4 4.3 5.0.

509835/0998

Table Y

18th 19th 20th 21 22nd 23 24 25th SiO ₂ 88 80 72 87 81 71 95 93 Na ₂ O 7th 7th 7th 3 3 3 3 5 PbO 5 13th 21 -4 10 20th - K ₂ O - - - 6th 6th 6th - - Al ₂ O ₅ - - - - - - - 2 % HgO 9.8 9.2 9.0 11.0 9.6 9.3 9.4 8.1

509835/0998

Table VI

Example-
No. Grain size Autoclave treatment 16 Hours. 30.9% RH x) extract
Na ₂ O 9.4 (ug / qcm
K ₂ O PbO absorbed
water * 1 -18 + 32 mesh 35O ⁰ C, 16 Hours. 19.7% RH x) 11.168 21
27 _ 12.5% • 1 -32 + 80 374 ⁰ C, 16 Hours. 30.9% RH χ) 5.264 7.9 - - 9.6% 3 -32 + 80 35O ⁰ C, 16 Hours. 19.7% RH x) 84 8.4 - - 8.5 % cn η
CD ^ -32 + 80 374 ⁰ C, 16
16 Hours.
Hours. 30.9%
100% RH
rf x)
X) 8.0 8.9 0.8 3.4% CD
oo 9
CO
CJi 10 -32 + 80
-32 + 80 35O ⁰ C,
270 ⁰ C ₉ 16 Hours. 30.9% RH x) 7.9 34
28 0.2
0.84 7.0% / S ¹⁰ -80 + 140 35O ⁰ C, 16 Hours. 19.7% RH χ) 9.9 1.9 0.4 2
- · ro
cn S 10 -140 + 200 374 ⁰ G., 16 Hours. 30.9% r.h. χ) 8.5 1.2 0.03 0.8% O
cn 11 -80 + 140 35O ⁰ C, 16 Hour ₉ 19.7% RH χ) 10 3.0 0.3 2.2% -.J
O 11 -140 + 200 374 ⁰ C, 16 Hours. 19.7% Tl x) 2.8 <0.01 1.4% 12th -140 + 200 374 ⁰ G., 16 Hours. 19.7% RH x) 1.9 0.2 1.4% 13th -80 + 140 374 ⁰ G., 16 Hours. 19.7% RH x) 3.6 0.01 2.4% 17th -32 + 80 374 ⁰ C, relative humidity ity 9.3 0.3 - x) RH =

Table VII

example
No. cn 1 O 2 CO
OO to 3 cn
• ^. O
co 4th co 6th

% relative humidity weight and water appearance % relative humidity weight and water appearance

24 24 18

22 13

12th

clear, quick tearing clear, quick tearing clear, quick tearing

clear, tearing quickly, almost clear, tearing

translucent, tearing quickly 10 9 6

10 6

clear, not ripping clear, not ripping

slight cloudiness, not tearing

clear, not ripping

slight cloudiness, not tearing

slight cloudiness, not tearing

cn ο cn ro

Claims (14)

Claims 1. A process for the production of glass or glass bodies with thermoplastic properties, characterized in that an anhydrisch.es glass of the composition, in mol % based on oxide, 3 - 25 % Na ₂ O and / or E ₂ O, 50 - 95 % SiO ₂ , the sum of these components making up at least 55 % of the total composition, in the form of small dimensions, such as powder, grains, flakes, fibers, thin webs, leaves and the like, but an EUO-containing gaseous atmosphere with a relative humidity of at least 5 % is exposed to less than 75 % at a ^{temperature exceeding 100 0} G until an amount of water causing the thermoplastic properties is absorbed in at least one part of the surface. 2. The method according to claim 1, characterized in that the anhydrous glass composition is 3 - 10 % Na ₂ O and / or KgO and 50 - 95 % SiO ₂ , the sum of these components making up at least 55 % of the total composition, the temperature of the contact atmosphere 225 ⁰ C and its relative humidity exceeds 50%, and the duration of the treatment is tailored to these conditions so that thermoplastic properties arise, but the absorbed water content does not exceed 15 wt.%. 509835/0998 3. The method according to claim 2, characterized in that the anhydrite-low G-las contains 3-17 % Na ₃ O and / or K ₃ O, 50-80 96 SiO ₉ and at least 15% MO, c. X y wherein M Oy is a metal oxide, the metal of which has a valence of at least 2, and the sum of these components makes up at least 70% of the total composition. 4. The method according to claims 1, 2 or 3, characterized in that that the temperature range of the treatment goes up to the G-las softening point. 5. Process according to claims 1, 2 or 3, characterized in that the upper temperature limit of the treatment is 600 ⁰ O. 6. The method according to claims 1, 2 or 3, characterized in that the thickness of the small-scale fflastteile Does not exceed 15 mm. 7. The method according to claim 1, characterized in that the relative humidity of the contact atmosphere is 5-50 % . 8. The method according to claims 1, 2 or 3, characterized in that that the contact time is 2-72 hours. -19 509835/0998 9. The method according to claim 1, characterized in that the absorbed amount of water is 1-25 wt. % . 10. The method according to claims 2 or 3, characterized in that the amount of water absorbed is 1-12 % . 11. The method according to claim 3, characterized in that MO consists of one or more of the oxides BaO, PbO, CdO, MgO, CaO, Al ₂ O ₅ , SrO, TiO ₂ , ZrO ₂ , MoO ₅ , WO ₅ , ZnO. 12. Process for making hard, permanent glazes or coatings on a carrier underneath. Application of the method according to claims 1 or 2, characterized in that that glass powder of the appropriate composition is applied to a carrier and there the Contact atmosphere is exposed at least as long as until the powder flows and coats the carrier. 13. Thermoplastic glass bodies produced according to claims 1, 2 or 3 _f, characterized in that they are formed at a temperature lying ^{between room temperature and 500 ° C.} B09835 / 0998 14. Thermoplastic glass body according to claim 13, characterized in that they are formed at 100-400 ^° C. 509835/0998 Blank page