DE2327382B2 - SILICATE GLASS WINDOWS WITH MECHANICAL AND CHEMICALLY RESISTANT DECORATIVE STRIPES HIGH ADHESION ON THE GLASS SURFACE AND METHOD OF ITS MANUFACTURING - Google Patents

Description

ίο The invention relates to a window made of silicate glass, in particular for motor vehicles, with one arranged along the edge areas, consisting of a Metal coating existing decorative strip, which gives the impression of a metallic frame and the high adhesion to the glass surface as well as high mechanical and chemical resistance has as well as a method for its production.

A window of this kind is in the German Offenle-

jo reference 1948315 described. With this well-known Windows should be made of a decorative strip that gives the appearance of a metallic frame thin silver film or an otherwise metallized thin film, which is preferably on is applied to the inside of the glass pane. It is obviously intended to use such metal coverings use as they are used in the usual mirror production.

Are such metal coverings unprotected from the atmosphere? exposed, they usually do not and must not have adequate corrosion resistance must therefore be protected by a varnish coating. In this case, however, the trim can only be Apply on the inside if the metallic effect is to be retained from the outside. But if the Decorative strip is arranged on the inside, in reality the impression of a glass pane goes The surrounding frame, which the decorative strip is ultimately supposed to convey from the outside, is lost again.

₄ , Another disadvantage of such known silver or other metal films on glass is that their adhesion to the glass surface is often poor. In the event of greater mechanical stress, which cannot be ruled out especially with car windows, the inadequate adhesion can lead to the metal film becoming detached.

The invention is based on the object of a decorative strip in egg nem window of the type referred to above in its composition and its role

J ₀ bau in such a way that it has a high adhesion to the glass surface as well as a high mechanical and chemical resistance. In addition, the decorative strip should be constructed in such a way that it rests on the outer surface of the glass pane.

J ₅ can be brought and that from the outside it gives the optical impression of a solid metal wire

This object is achieved according to the invention in that the decorative strip in a manner known per se

S ₀ consists of a ceramic silver layer burnt into the glass surface at elevated temperatures as well as layers galvanically applied to this ceramic silver layer in the order copper, nickel and chromium, the copper layer

jj a 3 μm to 15 μm thick layer of bright copper, the nickel layer is a 3 μm to 15 μm thick layer .ms GlanznL'kcl and the chrome layer emc (Jl;. ν chromschidit before. is less than 1 μm.

^J 4

1 “further development of the invention, the shafts serve as a He.zle.ter. Such layers are unsuitable as decorative stripes, cup layer a thickness of 5 μm to 8 μm, de Nik, as they have a matt metal layer with a thickness of 7 μm to 1 _μm and the surface and In addition, the Kraft chrome layer has a thickness of less than 0.5 _ίίΓ η.

It is particularly advantageous if the decorative strips _{5 are} constantly

is led around the edge of the glass pane and on high-gloss metal layers, as they are in large

_S I over both disk surfaces,: rstretched. _{over extent on} metal parts! be applied.

Appropriate, as it hanuelt at de, Gl '- the requirement for sufficient disk around a hollow glass, u ^ dder trim is provided corrosion resistance mainly, which is primarily reasonable on that surface of the glass pane wirif _l0 achieved by the chromium layer. Usually arranged, which is not in the manufacture of the glass sheet, therefore, the chromium layer thus formed to geko.nmen mild flussigen metal bath m touch applying the corrosion resistance. But that's just is. the case when either the chrome layer itself very much

In a further embodiment of the invention, the metal- is thick and / or when the underlying nickel Metallic trim i on a surface of the glass ₅ and the copper layers are selected in accordance thick, arranged disc, while the trim counter Accordingly, the process is carried on in the Galvanotechüber the other surface of the glass pane a nik today when applying galvanic gloss from tinem synthetic resin paint or a burn-in layers consistently with a thickness of the copper enamel of existing color strips is applied. layer of about 30 ym, a thickness of the nickel layer

It is particularly advantageous if in the process ₁₀ likewise about 30 μm and a thickness of the chromium for the production of the invention device ^; Ißen window layer of about 2 μm. In the case of metallic substrates, the metal-ceramic silver coating after baking and also for substrates made of plastic, under these circumstances and before the galvanic copper deposition, there are no signs of detachment of the metal layers due to mechanical polishing and / or through chen: i-metal layers, because on the one hand the Hafschen attack is on the surface purified and its upper ₂₅ tung on the substrate very well and on the other hand reduced surface roughness. _also occurring tensions in the substrate itself

It is particularly advantageous if it is possible to dismantle during the process. However, this technique fails to produce the window according to the invention when it is applied to silicate glass,
The metal-ceramic silver layer on selected Es does not cause any problems at first.

Set herüberge- over the edge of the glass _pane? Apply ₀ high gloss coatings on silicate glass, lead and the contacting in the galvanic bath to but occurs when using conventional these befincHichen on the edge of the glass pane techniques regularly in all trim according to ei-points of the silver layer. After a certain time, the metal layers become detached

Appropriately takes place when carrying out from the ground. More detailed investigations hades method for manufacturing the hen erfindungsgemü- ₃₅ shown that it does not comes about that of the plated layer for cleavage within Lkn window for greater lengths of the trim, but that in all contacting in the galvanic bath in several places, typically the separation within the on The glass is woven into a layer of silver for every meter of decorative stripe,
It has been found that the detachments

In German Auslegeschrift 1,088,198, although ₄ "by stresses in the layers caused a method described, with the thin metal, which are during the galvanic chromium-plating layers on inorganic objects such as in the underlying layers generated. Windows or lenses are applied, but with subsequent thermal shock loads, the process described there is superimposed on the temperature stresses with a process for producing transparent, ₄₃ internal stresses in the metal layers and electrically conductive layers, the increased hardness and which then reaches tension values which should have the adhesive strength lithium permeability. Due to the fact that it can be exceeded on the subsurface and used, only a few molecules thick, i.e. peeling off, lead to the layers.

extremely thin metal layers there is absolutely no.

metallic effect. Furthermore, in the case of the method described there, such disadvantageous effects are obviously eliminated, the topmost layer made of chromium, due to the strong reduction in the previously used metal layer, does not yet represent a protective layer.
Reduction must be covered by a protective layer. The copper and nickel layers should be a maximum

so that no corrosion skulls occur on the metal only half and preferably less than a third tallschichten. _{55 of} the previously usual layer thicknesses, and also

Although it is known per se, metal-ceramic SiI- the chromium layer should be half or less that coating on glass surfaces can be reduced if the layer thickness is increased. With such Burning in temperatures and then applying them to electroplated thin layers are apparently only decelerated on the one hand Ways to reinforce (dcutsc'.ic patent speaking generates low tensions, on the other hand 1 480445). It is also known that in the case of such metal layers, however, such thin layers are evidently rather ir First, galvanically coat the glass with copper and then relieve the stresses through plastic deformation also to degrade nickel ions by galvanic means, without detachment of the dei to be deposited, whereby the nickel layer can come primarily layers.

serves as corrosion protection (German patent specification A further advantage of the fen

1807043). This known layer structure is used, but consists in that neither the (ilas pad itself but not / UT formation of decorative stripes with shimmering nor the ceramic silver burnt on it Surface, but like this !! a certain electrical layer can be attacked by oxygen. In this respect lies <«Rhen resistance, since the known ratios in the window according to the invention

which the (ialvann specialist was not previously familiar with). The thin electroplating layers used in electroplating due to the previous Krfalmmgcn even were not applied, but are sufficient under the given special conditions in terms of corrosion resistance.

In the production of the windows according to the invention, it has proven to be expedient to maintain the same the tried and tested arrangement of a ceramic silver layer burnt into the surface of the glass as a Base layer to deposit a layer structure of so-called bright metal baths known per se, which have the property, the relatively rough surface of the burned-in silver layer level and thereby the decorative strip itself the appearance of a massive, polished to a shine To give metal strip. This effect is achieved in particular when the copper layer is already present is deposited from a bright copper bath, in which a leveling effect is achieved through suitable additives Effect is achieved.

A certain leveling of the surface of the ceramic, burned-in silver layer can also occur mechanical way can be achieved by this silver layer of a mechanical or optionally is also subjected to chemical polishing treatment, whereby the surface roughness is reduced. If such a polishing treatment is carried out, the thickness of the bright copper layer can thereby be increased may be chosen somewhat lower.

Windows with decorative strips according to the invention not only have the same durability, mechanical ones and chemical resistance such as windows with frames made of solid, chrome-plated metal, but rather have the extraordinary advantage that the decorative strips provide an optimal and permanent connection with the glass surface.

The invention is intended below on the basis of the description of various exemplary embodiments as well as are explained in more detail by comparative examples. It shows

Fig.! a cross section of a window according to the invention, in which a frame-shaped decorative strip on sits on a surface of the glass pane,

Fig. 2 is a cross-section of a second embodiment, in which the glass sheet on both surfaces is provided with decorative stripes,

3 shows a further embodiment in which the decorative strip is drawn around the edge of the glass pane is,

Fig. 4 is a perspective view of a particularly useful embodiment of the invention Window, and

5 is a diagram showing the tensile stress in chrome layers depending on the layer thickness.

The window according to the invention can have any shape and as a side window, windbreak or Rear window for a motor vehicle, as a window or door in buildings, as glazing for furniture. Fridges, stoves, but also as mirrors, table tops. Ornamental glass, etc. find use.

The window consists of a silicate glass pane 1 and one fixed to the glass surface, circumferential in form of a frame trim A. Of course, it is not necessary in all cases that the trim A in the form of a closed frame is arranged: rather, it may in some I All of them are sufficient to arrange ile decorative strips only along one edge of the glass pane. This is for example the I all with retractable side windows where only the upper edge can have such a strip. In other places it may be sufficient and / or appropriate. To arrange such a frame on three of four sides, for example when the window is clamped into a frame on its fourth side. If necessary, it can also

ίο be sufficient, not even one along an edge to arrange continuous decorative strips, but on the arrangement of such decorative strips to restrict selected positions. The essential ehe feature of the invention is not in the external Shape of the frame, but in its structure and composition.

As can be seen from all the figures in the drawing. the decorative strips A, B, C and D have the same structure and the same layer sequence.

ao The bottom layer 2 consists of a baked-in metallization compound of known composition with about W "c finely divided metallic silver and about Ml '/ f of a low-melting glass composition. The metallization compound is applied to the glass surface as a dispersion in an organic carrier by screen printing and baked at a temperature of at least 500 "C." The thickness of the silver layer 2 is approximately 3 μm to 6 μm.

A bright copper layer 3 with an average thickness of 3 μm to 15 μm, preferably 5 μm to 8 μm, is arranged on the silver layer 2. The bright copper layer 3 is applied by electroplating in a bright copper bath, ie using an electrolyte that has the properties

has the ability to level the surface well. In order to achieve sufficient leveling, the copper layer must 3 have a thickness of at least 3 / m. On the copper layer 3 is a bright nickel layer 4 and arranged on this a bright chrome layer 5. The thickness of the bright nickel layer is 3 / im to 15 μm and preferably 7 μm to 10 / im. The bright chrome layer S should not exceed a thickness of 1 μm and preferably has a thickness from about 0.1 / im to 0.5 / im. Through the succession These layers in the specified thicknesses are excellent in addition to their good appearance Corrosion resistance and mechanical resistance guaranteed. Both the shiny nikke layer 4 as well as the bright chrome layer S are applied by electroplating. However, it is it is also conceivable to apply these layers using one of the known electroless methods bring, although such processes are much less effective because of the relatively slow metal deposition

More economical than electro-galvanic work Procedure.

In the embodiment shown in Fig. 2, two decorative strips B of the same width are on both surfaces of a pane of glass 10 along the edge:

arranged. In contrast, FIG. 3 shows an embodiment in which the decorative strip C is drawn all the way around the edge of a pane of glass 20. The width of the decorative strips is in the usual use cases to about 1 cm to 3 cm.

In the embodiment shown in Fig. 1 is the burned-in silver layer 2 is visible through the glass disc. In the rain today The float glass used shows this layer of this

2

■ »hurry up a brown color, which is due to the in the glass > above the level of diffused silver ions will. If this color should have a disturbing effect in special lullen, you can help your that on the other side of the glass pane I dom metal strips / 1 opposite a colored strip, for example from a synthetic resin lacquer or a burn-in enamel. In case of a Motor vehicle window is the surface provided with the lacquered tire towards the interior of the vehicle built in while the resistant metal layer facing the outside atmosphere.

While in the illustrated exemplary embodiments the metal strips are always arranged directly on the edge of the pane, it is of course also possible to parallel these metal strips at a more or less large distance from the pane edges to be arranged in relation to these, without going beyond the scope of the discovery.

Fig. 4 shows a particularly useful development of the invention, which consists in that the bottom layer of the Zierstreifeiis Z), namely the burnt-in silver layer, at the point provided for contacting in the electroplating baths locally over an edge 31 of a pane of glass 30 out
wide and at this point V. on the edge of the glass the patch rode is attached. This procedure has the advantage that the visible surface of the decorative strip is not impaired at any point by the placement of the contacts, because the contacting points are usually later recognized as dark points. The contacting style E drawn over the edge of the glass pane can be selected in this way. that it can no longer be seen after the window has been installed. If the decorative strip, as shown in the case of FIG. 4, extends only along three sides of a motor vehicle window, it is advisable to provide the contacting point approximately in the middle of the decorative strip.

If it is a relatively long metal strip, as it occurs with larger pane formats, so it is also advisable to make the contact in the electroplating baths at several points to undertake. As a result of the voltage drop within the metal strips, it decreases with increasing Distance from the contacting point the thickness of the metal coating. Satisfactory results are achieved when a contacting style is provided for approximately every meter of decorative strip length.

Comparative examples and test results

A window made of silicate glass is provided with a decorative strip in the manner described above, the individual layers of which have the following thicknesses:

Silver layer 5 / in

Copper layer 20 / in

Nickel layer 15 / in

Chromium layer 2 / in.

Within a short time, the beginning of a detachment can be seen on a corner of such a decorative strip, which runs around the entire decorative stripe when exposed to high temperature changes and leads to scaling of the glass.

In contrast, a window made of silicate glass with the decorative strip shown in FIG of the invention. if the layer thickness !! in the trim have the following values:

Silver layer 5 µm

Cropping layer IO / im

Niekelschicht 12 / in

C'hromschichl 0.2 / im.

Such a decorative strip shows no signs of exposure to thermal shock stresses that have been tackled. If a decorative strip with the last-mentioned layer thicknesses is subjected to corrosion tests, then / are quite useful results. For example, a trim with the last-mentioned layer thicknesses of four passes of a Corrod-Kote tests in accordance with DIN was subjected 504. ¹ SK without damage to the trim were recognizable. The fact that a decorative strip with the first-mentioned layer thickness !! of the comparative example comes off within a very short time, while a decorative strip with the last-mentioned layer thickness also withstands corrosion tests without difficulty and shows no peeling effect despite exposure to temperature changes, depends crucially on the

ao (. h tonic i l together.

Chromium has the property of generating very high internal tensile stresses at the beginning of the layer build-up, the / was refilled from a certain layer thickness by cracking, but then the

»5 pad already torn. As a result, it results a detachment of the entire metal packing when exposed to temperature fluctuations. the crack being made directly on the Karitc of a so-called silver frit. A previously applied copper or nickel bead creates a tensile stress peak reinforced, with the addition of the glass at this point due to the notched structure the frit is weakened.

In Fig. 5 is an example of a voltage waveform reproduced in the chrome layer as a function of the layer thickness of the chrome. Noticeable at This diagram shows the initially steep rise in voltage and the subsequent almost equally steep Drop in tension, apparently caused by cracking in the chromium layer. But with that If this crack occurs, tensions are required which the substrate cannot withstand. If the layer thickness is greater than 0.5 / in for If the chrome layer is used, this will certainly lead to the edge of the trim strip becoming detached.

In-depth research has shown that in the case of a window made of silicate glass provided with decorative strips according to the invention, the individual layers have the following tasks:

Silver: build-up of a conductive primer on glass;

Copper: preparation of the silver for the Vernikkcln with a view to better adhesion and at the same time Leveling the heavily profiled surface of the Sil

be rs:

Nickel: Corrosion protection layer for copper and silver, the protective effect by a double layer can be reinforced; Chromium: a closed chromium layer is not used as corrosion protection, but then simply prevents tarnishing of the Niekelschicht and maintains somi the decorative shine. Only a microscopic chrome layer mediated by its greatly enlarged Surface protection against oxidizing corrosion.

As far as the layer thicknesses are concerned, the Si top layer to ensure a sufficiently strong Anchoring in the glass surface a thickness of vo

609.509 / 31

? 640

5 to not fall below. To pursue the Hill For effect, the cropping layer only needed to be about 1 // inch thick, but the layer thicknesses are approximately 1 0 / 4in preferable for an effective Hin leveling of the heavily profiled surface of the silver he follows. In the case of the copper layer, however, a bulge should be used to avoid bulging at the edges Thickness of 15 / nii must not be exceeded, as such Bulges are responsible if there is a detachment in the finished visual arrangement comes. If the silver layer is leveled by polishing before copper plating, the layer thickness can be reduced of copper to about 5 / <m. Copper is electroplated in a tension-free manner and thus leads not to be replaced on their own initiative.

10

I.infaeh nickel layers have no anti-corrosion properties at thicknesses less than d μη \ , so that layer thicknesses of approximately 10 μιν are to be aimed for. Since nickel baths do not scatter very well, the edges of the decorative strip are provided with thick nickel bulges, which can lead to detachment at the edge if the nickel coatings are not tension-free. Thus, layer thicknesses of the nickel of over 13 / <m must already be described as critical

ίο be. However, a reduction of the layer Dieken of nickel of about 7 μ \ χ \ thick nickel-Doppclschicht can be achieved in that a double layer of nickel is used, the Schut / wii kung about the protective effect of an approximately l2 // m thick nickel fünfachschicht corresponds.

For this purpose 2 sheets of drawings

Claims (10)

Patent claims: 1. Window made of silicate glass, especially for motor vehicles, with a decorative strip arranged along the edge areas, consisting of a metal coating, which gives the impression of a metallic frame and has high adhesion to the glass surface and high mechanical and chemical resistance, characterized in that the Decorative strips (A; B; C) in a manner known per se consists of a ceramic silver layer (2) burned into the glass surface at elevated temperatures and layers galvanically applied to this ceramic silver layer in the order copper, nickel and chromium, the copper layer being a 3 μm to 15 μm thick layer of bright copper, the nickel layer is a 3 μm to 15 μm thick layer of bright nickel and the chrome layer is a bright chrome layer of less than 1 μm. 2. Window according to claim 1, characterized in that the copper layer 5 μιη to 8 μιη is thick. 3. Window according to claim 1 or 2, characterized in that that the nickel layer is 7 μm to 10 μm thick. 4. Window according to one or more of claims I to 3, characterized in that the Chromium layer is thinner than 0.5 μm. 5. Window according to one or more of claims 1 to 4, characterized in that the Decorative strip (C) is led around the edge of the glass pane (20) and extends over both pane surfaces extends. 6. Window according to one or more of claims 1 to 4, characterized in that the Glass pane (1) is a float glass pane, and that the decorative strip (-4) on that surface the glass pane (1) is arranged, which is not with the liquid during the manufacture of the glass ribbon Came into contact with the metal bath. 7. Window according to one or more of claims 1 to 6, characterized in that the metallic trim is arranged only on one surface of the glass, and that the Decorative strips opposite on the other surface of the glass pane made of a synthetic resin varnish or a stoved enamel of existing color strips is applied. H. A method for producing a window according to one or more of claims 1 to 7, characterized in that the metal-ceramic silver coating after baking and before the galvanic copper deposition by mechanical Polishing and / or surface cleaned by chemical attack and its surface roughness is reduced. y. Method according to claim 8, characterized in that that the metal-ceramic silver layer in selected places over the edge tier Glass pane is passed over and the contact in the Galvanohad to this on the edge The silver layer located on the pane of glass takes place. 10. The method according to claim 8 or 9, daduich marked, that the contacting in the galvanic bath occurs with larger lengths of the decorative stripes several points takes place, one contact point being provided approximately per meter of decorative strip length will.