JPS62158139A - Manufacture of glass sheet with reduced transmittance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention relates to a preloaded soda-lime glass with reduced transmission in a predetermined spectral range.
In manufacturing a glass plate, especially a glass plate for awnings, a metal layer containing mainly a metal or an alloy of an element having an atomic number of 22-28 in the periodic law is used on at least one side of the glass substrate. and at least one metal oxide or metal oxide mixture is applied to the side of the metal layer opposite to the glass substrate side, and a thermal preloading step and/or a bending step is performed. in the air,
The process is carried out at a temperature of 580 DEG to 680 DEG C., preferably 600 DEG to 650 DEG C.

(Prior Art) Glass plates with a coating of a metal or alloy on the surface and a protective layer of a metal oxide or a mixture of metal oxides are used in the field of architecture and in the vitrification of vehicles, in which uncoated glass substrates are used. It is used to reduce the transmittance of materials in specific spectral ranges. This is done, for example, in order to obtain a light attenuation effect and/or a sunshade effect, and if a color-neutral glass plate is desired as the metal layer, it is advantageous to use elements with atomic numbers 22 to 28 of the periodic table. Metals or alloys are used. In many such applications, it is necessary to thermally preload the glass substrate.
This is done in order to avoid the risk of damage (e.g. zesprungen) and to reduce the risk of breakage when the glass plate breaks.

In order to produce a thermal preload, a glass plate made of soda-lime glass, which is used almost exclusively in the above-mentioned applications, is heated rapidly in air to a temperature above the glass transition temperature.
Continue to rapidly cool. In this case, the required temperature in the preloading step is 5
80-680°C, preferably 600-650°C. Similar temperatures are also required when flat glass sheets obtained from glass production are subjected to a bending process in order to obtain curved glass sheets for certain applications, for example in the automotive sector.

In methods of the type described in the first concept, conventionally the coating of the metal layer and also of course the coating of the metal oxide layer is carried out after a separate preloading or bending step of the glass plate and cooling, usually using a vacuum coating method. is used.

This process, in which a preloading or bending step is followed by a coating, has various disadvantages compared to a method in which a coating is first applied and then a preloading or bending step is carried out.

The former can only cover objects with fixed dimensions;
This is because, as is well known, preloaded glass sheets cannot be cut. On the other hand, it is much more advantageous in terms of coating technology to coat glass products of standard size in the float process, especially strip products. In the latter case, the problem of obtaining a uniform layer thickness in vacuum coating is solved much more easily and simply than in the case of coating fixed dimensions with corresponding gaps between each glass plate in the coating field. be able to. Furthermore, it is less expensive to transport standard sizes than to transport individual pieces of various sizes through the coating device.

Another disadvantage is that the high temperatures of the preloading or bending process often cause impurities on the glass surface to form very strong bonds with the glass, which can be removed by subsequent surface cleaning before the coating process is carried out. It cannot be removed to the extent required by the process. The impurities are baked into the glass surface. This may lead to an undesirable deterioration of the coating quality.

In the coating of curved glass sheets, of course, the problem of obtaining sufficient uniformity of the layer is extremely great, since the angle and distance to the coating source additionally vary due to the curvature of the glass sheet.

Furthermore, the cost of vacuum coating equipment for coating curved glass sheets is significantly greater than equipment for coating flat glass sheets, since the inlet and outlet gates as well as the distance between the various coating stations are significantly higher than those for coating flat glass sheets. This is because the dart must be designed to be significantly wider than when covering flat glass.

For the abovementioned reasons, the method of coating flat glass in the form of a particularly standard size and subsequently prestressing or bending the fixed size after production in particular by cutting has significant advantages. However, this method cannot be implemented with the method described in the general concept, i.e. with the metal layers used in the above-mentioned applications, since the required temperatures above 480° C. cause harmful layer changes (in particular This is because oxidation of the layer) occurs.

This can be seen, for example, in West German Patent Application No. 17712
This is clear from the specification of No. 23. The specification describes a method for forming an oxide layer, according to which the metal layer formed by vacuum evaporation is a suboxide layer of the metal, in particular from the following metal groups: cobalt, iron. , manganese, cadmium, bismuth, copper, gold, lead, nickel are subjected to a heat treatment step at a temperature of 315 to 677.56 C, thereby converting them into the oxide. By changing to an oxide, the transmittance of the layer is increased, especially near the infrared. The effect of the sunshade is therefore disadvantageously worse than that of the metal layer.

Besides the metal layer, combinations of this layer with transparent oxide layers have also been proposed. In other words, a transparent oxide layer is used as a protective layer on the side of the metal layer opposite to the glass substrate side to improve mechanical properties. Mirror reflective layer (gntspiegelnn)
gsschcht) can be arranged to increase selective transmittance. In another configuration of such a layer system, care is taken to embed both sides of the metal layer in a highly refractive mirror-reflecting layer made of a metal oxide (for example, as described in Japanese Patent Application Publication No. 54-058719). (see book)
. Furthermore, in order to increase the long-term stability of such a layer system, another thin metal layer is provided between the metal layer and the mirror reflection layer provided on the side of this metal layer opposite to the glass substrate side. It has already been proposed to establish a
035906 specification).

Tests have shown that in the layer configurations described above, in which the metal layer is protected by an oxide layer on the side opposite to the glass substrate, these layer configurations cannot withstand the temperature loads that occur during the preloading or bending process. It has become clear that sufficient stability cannot be obtained when exposed to

Such layer configurations, which can also be obtained with the method described in the generic concept, are known in principle, for example from US Pat. No. 3,846,152.

European Patent Application Publication No. 0108616 Specification: 6
According to 2, in order to produce a four-bent automotive glass sheet with a conductive metal oxide coating, the bending process is changed to a predetermined stoichiometry of the metal oxide layer in order to avoid crack formation. Carry out at less than theoretical quantities. German Patent No. 917 347 relates to a method for producing electrically conductive layers, in which a substoichiometric layer of tin oxide or inzoum oxide is applied to a glass substrate and subsequently heated in air. This results in complete conversion to the oxide.

U.S. Tokukenshita No. 3962488 and No. 4017
No. 661 likewise relates to the production of electrically conductive coatings with high optical transparency. However, in this method, the silver or gold layer is embedded in the titanium oxide layer on both sides, and the titanium oxide layer is applied in an oxygen-deficient state in order to avoid formation of agglomerates of the noble metal layer. Finally, West German Patent Application Publication No. 302725
No. 6 describes the use of a substoichiometric titanium oxide layer as a component of the cover layer for a metal HM that changes the transmission, and in this way, among other means, the metal The purpose is to improve the corrosion resistance of the layer. However, the substance combinations described in the last-mentioned publication, in particular in the method according to DE 30 27 256 A1, do not involve a method in the generic type mentioned above, but rather by modifying the previously known process implementation and using a glass base. It can be used in the form of coating the material before the preloading process:
Such a method ie unconditionally avoids any unfavorable changes in the metal layer (
This publication also cannot give any suggestion for avoiding the drawbacks of the method described in the opening generic section, since it results in the formation of agglomerates (whether by oxidation or agglomeration).

Problems to be Solved by the Invention It is an object of the invention to avoid the methodological drawbacks associated with the coating of the glass substrate after the preloading or bending step in a method of the type mentioned at the outset. and already preloaded and/or coated with the necessary coating means without fear of layer change of the metal layer.
This is an improvement that can be carried out before the bending process.

(Alternative Means for Solving the Problems) The method of the present invention for solving the above-mentioned problems is characterized in that both the metal layer and the protective layer are applied to a substantially flat glass substrate before the thermal preloading and/or bending process. and a protective layer having an oxygen deficiency ratio x (0.05≦x≦0.4) with respect to the metal atoms of the metal oxide or metal oxide mixture and a thickness l.
Qnm to 1100n, and in a composition that does not cause significant oxygen diffusion into the metal layer during the preloading process and/or bending process.

(Embodiment) According to an advantageous embodiment of the present invention, as the protective layer S
A layer consisting of at least one metal oxide or metal oxide mixture from the group of n, n, Ta, or containing mainly said metal oxide or metal oxide mixture is applied.

In that case, the oxidation deficiency rate may be in the range O1l≦x≦0.3.

Furthermore, according to the present invention, as a protective layer, a coating No. 01.5. An indium oxide layer having a composition of H is applied.

Alternatively, according to the present invention, 5nO may optionally be used as a protective layer.
2-X17) A tin oxide layer with Mi composition is applied.

According to the invention, a tantalum oxide layer having a composition of TaO2,5-x can also be applied as a protective layer.

According to another embodiment of the invention, it is proposed that the thickness of the protective layer is at least 13 nm.

In that case, the thickness of the protective layer may be approximately 20 nm to 70 nm.

According to a further embodiment, a cover layer of at least one metal oxide of approximately stoichiometric composition can be provided over the protective layer.

Furthermore, according to a particular embodiment of the invention, the cover layer has at least one metal oxide from the group of selected metal oxides or metal oxide mixtures as a protective layer.

In that case, the metal composition of the cover layer may be the same as that of the protective layer.

Finally, according to the invention, the glass substrate may optionally be provided with at least one underlayer consisting of a metal, alloy, metal oxide or metal oxides, before the metal layer(s) are applied.

For example, when a preloaded handrail plate or the like is to be manufactured, the present invention can of course reduce the light transmission of the glass plate to zero. It is surprising that the protective effect necessary for preloading or bending of the applied oxide layer is achieved if the composition of the oxide layer deviates from the composition of the stoichiometric amount of the oxide. It is based on the recognition of A state of oxygen deficiency is required and the maximum value of this deficiency rate must not be exceeded nor should it fall below a minimum value. Periodic law atomic number 22
In the case of metal layers containing mainly metals or alloys from the elements ~28, the protective layer consists of the preferred materials proposed by the invention; for example, German Patent Application No. 3027
The material combination known from No. 256 cannot be used at all, since the metal layer inevitably breaks when the glass panes described there are bent or heated to the preloading temperature. It is from.

This binding was unexpected. That is, it has been accepted that if a stoichiometric composition exists as the protective layer, the effect of oxygen on the metal layer during heating will be minimal. Diffusion through the layer thus takes place via defect points in the layer, as is well known. However, when there is a stoichiometric composition of oxide, the number of defect sites is minimal. In particular, the cause of the observed protective effect within a certain range of oxygen deficiency rates is unknown.

Furthermore, it is surprising that the oxygen deficiency rate of the protective layer must not exceed a predetermined value. Layers with higher oxygen deficiency rates are not suitable. When using such layers, again significant changes in the optical data of the metal layer to be protected occur, in particular speckle formation and turbidity phenomena after temperature treatment. It is assumed that this, especially in the significantly substoichiometric range, results in non-uniform oxidation of the protective layer, resulting in the formation of additional grain boundaries or crack formation with increased oxygen diffusion in the coating. . However, even in this case, it is only possible to speculate because of the complexity of the process.

Suitable materials for the metal layer include elements with atomic numbers 22 to 280 in the periodic law, particularly metals such as chromium, iron, nickel, titanium, vanadium, alloys of these metals, and compositions mainly containing these metals or alloys. be. For example, chromium-iron-aluminum alloys have proven superior.

A layer consisting of or containing a predominant proportion of at least one metal oxide or a mixture of metal oxides from the group Sn, ■n, Ta has proven suitable as a protective layer. As already mentioned, these oxide layers or oxide mixture layers must differ from the stoichiometric composition of the oxides and have a certain oxygen deficiency. This deficiency rate is approximately equal to the metal atoms of the corresponding oxide in each case. The required composition is engineering nO□, 5
-X, 5no2-X, corresponds to TaO2,5-X,
or 0.05≦x≦0.4.

The thickness of the oxygen-deficient oxide layer must not fall below a minimum value in order to ensure that there is a sufficient protective effect in relation to the temperature cycles of the preloading or bending process. This minimum value is approximately IQ nm, preferably 13 nm.

Thicker layers can be used as well. This is the case, for example, if it is desired to achieve additional optical effects, such as specular reflection effects or color effects, via interference effects on the metal layer. The oxide layer required for this purpose generally ranges from about 20 nm to 70 nm.

Despite the presence of oxygen deficiencies in the protective layer, the protective layer generally has the hardness and abrasion resistance necessary for preloading or pre-curving handling of the coated glass plate. Of course, the value is slightly lower than that which would be achieved with an oxide layer having a stoichiometric composition.

In order to further improve the hardness and abrasion resistance of the layer, it may be advantageous to first apply a protective layer with oxygen deficiency to the required minimum thickness and then apply another oxide layer thereon. Proven. The second oxide layer may be an oxide layer having the same metal stoichiometric composition as used in the protective layer. However, oxide layers of other metals may also be provided.

This method of providing a double layer is particularly advantageous if the layer thickness required for the desired optical effect exceeds the minimum value with respect to the protective effect, since in this case this aspect can be further explained. This is because it can be combined with improved layer thicknesses. Furthermore, which is important in the present invention, the surface of the metal layer opposite to the glass substrate side is provided with a protective layer having a composition and thickness according to the present invention in an amount ratio below the stoichiometric amount. Another layer between the glass substrate and the metal layer, e.g. It is of course entirely possible within the scope of the invention to arrange the radium or other layers according to the desired spectral or generally optical properties.

The production of the coating according to the invention is usually carried out by vacuum coating. The layer can also be applied by vapor deposition from a resistively heated vapor deposition apparatus or alternatively by electron beam vapor deposition. Furthermore, as direct current sputtering or low frequency sputtering, high frequency sputtering and cathode sputtering as magnetron sputtering are particularly suitable. Metal or alloy layers can be produced by direct vapor deposition or sintering in a neutral atmosphere.

Direct vapor deposition is suitable for producing the oxide layer, in particular also also reversible settling. In this case, the method of reactive magnetron sputtering, in which the metal or alloy target is sputtered in an oxygen-containing atmosphere, is particularly economical. In this way, the required oxygen deficiency rate of the layer can be well identified and determined.

In the context of the present invention, a metal layer containing a major amount of a metal or an alloy of elements with atomic numbers 22-28 of the periodic law further includes:
It is understood as a metallic layer whose properties are primarily determined by the above-mentioned elements. Usually this is a layer in which the total content of one or more of these elements is at least 50 atoms.

The same applies to the protective layer according to the invention, which contains a major amount of at least one metal oxide or metal oxide protective layer from the group Sn, In, Ta0, in which case these metal oxides For material protective layers, the properties of the layer may be determined by any of the metal oxides mentioned above. This is usually done by engineering n, Sn and/or T
This is the case in layers in which the content of a totals at least 50 atoms relative to the metal content of the oxide layer.

Further characteristics and advantages of the invention can be obtained from the following detailed description based on an exemplary embodiment and with reference to the drawings.

In the embodiment shown in FIG.
A metal layer 12 of nickel with a thickness of Q nm is provided, which is followed by a protective layer 14 with a thickness of 20 nm. The protective layer has a composition Sn0.7 before the preloading step.

In the embodiment shown in FIG. 2, the glass substrate 10 has a thickness of 6 nm.
a base layer 16 consisting of a coating of 203 (which acts as a layer to improve adhesion), a metal layer 12 consisting of cobalt with a thickness of 22 nm, a protective layer 14 with a thickness of 1 (5 nm) (which has a composition SnO 1 before the preloading step); .7) and thickness 20
It has a cover layer 18 made of SnO2.

Glass plates of the type shown in FIGS. 1 and 2 can be manufactured in suitable form according to the examples described below.

Example 1 A float glass plate of dimensions 10 cm x 10 crn was successively coated with the following layers in a vacuum coating apparatus equipped with a coating apparatus for magnetron cathode sputtering: first a thickness of 8 cm. S
nm nickel layer in an argon atmosphere at a pressure of 5.10 nm.
A layer of tin oxide is then deposited on this nickel layer by sputtering from the nickel tube at mbar at a pressure of 4.10 ζ libar in an argon-oxygen atmosphere with a proportion of 40% oxygen. Established by. The reactive sputtering coating layer was then selected such that the layer had a composition of 5nO1.83. This composition was determined through single-electron analysis of the entire coating after it was manufactured. Layer thickness is 28nm
Met.

The coated glass plate had a neutral appearance when viewed from the glass side upon inspection. The coated glass plate was subsequently heated to 600° C. in a preload oven and rapidly cooled. This preloading step did not substantially change the appearance of the board.

Figure 3 shows the wavelength range of 300~so before and after the preload process.
The onm spectral transmittance is shown as curve 1 and curve 2. As can be seen from FIG. 3, the change in transmittance is particularly small in the visible spectral range.

It is hypothesized that this minimal change is caused by further oxidation of the outer protective layer during the preloading step and, coupled with this oxidation, the removal of residual absorption present in the oxygen-deficient conditions. The temperature treatment adds to this the heat treatment effect that typically occurs in vapor deposited layers.

Example 2 The process was carried out in the same manner as in Example 1, except that the tin oxide layer had no measurable oxygen deficiency, that is, the coating parameters were chosen to have a stoichiometric composition of Sn○2.

The results of the spectral measurements before and after the preloading step at 600° C. are shown in FIG. 4 as curves 1 and 2. It can be seen that the preloading process significantly increases the transmittance, ie there is no longer any significant light attenuation or sunshading effect.

Example 3 When manufacturing a tin oxide layer, the coating/grammeter has a composition of SnO
Example 1 was carried out in the same manner as in Example 1, except that adjustments were made to obtain a suboxide layer of .

Structural transmittance of the coated plate before preloading step No. 5
It is shown as song @l in the figure. Significantly lower transmittance values than those of Examples 1 and 11 were obtained due to the high absorption capacity of the Sn0 layer. A significant increase in transmittance occurred after carrying out the preloading step (curve 2). Moreover, the coating has a spot-like appearance and is therefore unsuitable for the above-mentioned applications.

Example 4 Two successive layers were applied in the coating apparatus of Example 1 on a float glass plate of 10 sides x 10 crn at a composition of 0.250%, Ar
5 (20 nm thick S by stumbling of the tin tart in a 1% alco-oxygen atmosphere)
nO2 layer, a nickel layer with a thickness of 2 nm by sputtering with 9 nickel turfs using a pressure of 4.10 Klipar in an argon atmosphere, and a 3 nm thick nickel layer by sputtering with 3 silver turfs at a pressure of 3.10 ζ Libar in an argon atmosphere. silver layer, nickel tardat at a pressure of 4.10 klipal in an argon atmosphere. Nickel layer 3 nm thick by tuttering, pressure 4-10; composition 0235% in Rivar, Ar
A composition of 5 no. with a thickness of 3 Qnm was obtained by reactive sintering of a tin target in a 65% argon-oxygen atmosphere.
Tin oxide layer with a value of 1.70.

Upon inspection, the coated plate had a slight amber tint, and when observed from the glass side, the plate appeared almost neutral. Spectral measurements carried out (FIG. 6, curves) show that the board exhibits a high light transmission in the visible range and a low transmission near the infrared, ie the sun protection works very well.

After performing the preloading step, a transmittance curve designated as curve 2 was obtained. Curve 2 shows that the optical data for the entire solar ray range is approximately maintained. It simply has a slightly higher transmittance than before in the shortwave visible spectral range.

This increase in transmittance, which is assumed to be caused by the post-oxidation of the 5nO1,2o layer, reduces the initially present light banding and thus improves the transparency.

The features of the invention disclosed in the above description, the drawings and the claims are important both individually and in any combination for realizing the invention in various embodiments.

[Brief explanation of drawings]

Figure 1 shows one of the glass plates that can be manufactured by the method of the present invention.
FIG. 2 is a cross-sectional view similar to FIG. 1 of another embodiment, and FIG. 3 shows the preload of the Takarasu plate manufactured according to Example 1. Figure 4 shows the spectral transmittance before and after the preloading process of the glass plate according to Example 2. Figure 5 shows the spectral transmittance of the glass plate manufactured according to Example 3. FIG. 6 shows the corresponding results of the spectral measurements of the glass plate according to Example 4. 10... Glass base material, 12... Metal layer, 14... Protective layer, 16...
...Middle layer, 18...Cover layer. 1 person

Claims (12)

[Claims] (1) Glass substrates for the production of preloaded and/or curved glass plates, in particular sunshade plates, made of soda-lime glass with reduced transmittance in a given spectral range. at least one metal layer containing a major amount of a metal or alloy of an element with an atomic number of 22 to 28 in the periodic law on at least one side of the metal layer, and a metal oxide on the side of the metal layer opposite to the glass substrate side. or at least one metal oxide mixture and a thermal preloading step and/or bending step in air at a temperature of 580 to 580°C.
680° C.) In a process preferably carried out at 600-650° C., both the metal layer and the protective layer are applied to an approximately flat glass substrate before the thermal preloading and/or bending step, and the protective layer is The metal oxide or metal oxide mixture has an oxygen deficiency ratio x (0.05≦x≦0.4) with respect to the metal atoms, and the thickness is 10 nm to 100 nm, and the preloading process and/or bending process a preloaded material having a reduced transmittance, characterized in that it is applied in such a composition that no appreciable oxygen diffusion into the metal layer occurs;
and/or a method for manufacturing a curved glass sheet. (2) A patent claim in which a layer consisting of at least one metal oxide or metal oxide mixture from the group of Sn, In, and Ta or a layer mainly containing the metal oxide or metal oxide mixture is applied as a protective layer. The method described in item 1. (3) The method according to claim 1 or 2, wherein the underoxidation rate is within the range of 0.1≦x≦0.3. (4) InO_1_. as a protective layer. Claim 1, in which an indium oxide layer having a composition of _5_-_x is applied.
The method described in any one of paragraphs 3 to 3. (5) The method according to any one of claims 1 to 3, wherein a tin oxide layer having a composition of SnO_2_-_x is applied as a protective layer. (6) TaO_2_. as a protective layer. 4. A method according to claim 1, wherein a tantalum oxide layer having a composition of _5_-_X is applied. (7) A method according to any one of claims 1 to 6, wherein the protective layer has a thickness of at least 13 nm. (8) The method according to claim 7, wherein the protective layer has a thickness of about 20 nm to 70 nm. (9) The method according to any one of claims 1 to 8, wherein a cover layer comprising at least one metal oxide having a composition in a substantially stoichiometric amount is applied on the protective layer. . (10) The method according to claim 9, wherein the cover layer contains at least one metal oxide from the group selected from metal oxides or metal oxide mixtures as a protective layer. (11) The method according to claim 10, wherein the metal composition of the cover layer is the same as that of the protective layer. (12) Metal on the glass substrate before applying the metal layer(s),
Claims 1 to 10, wherein at least one underlayer consisting of an alloy, metal oxide or metal oxides is applied.
The method described in any one of the sections.