DD216839A3 - HIGHLY CORROSION-RESISTANT REFLECTION LAYER SYSTEM ON SUBSTRATES - Google Patents

Abstract

The invention relates to highly corrosion-resistant reflection layer systems on substrates, in particular on glass or glass-like substrates. For example, the substrates provided with the reflective layer systems are used as mirrors in the furniture industry, in the household, in transportation, in scientific apparatus engineering or as partially transparent mirrors. The object of the invention is to provide a highly corrosion-resistant reflection layer system while maintaining the reflectance. According to the invention, the reflective layer system consists of a reflection layer of Al or Cu or Zn and Cu and Zn or Sn deposited by DC-Plasmatron sputtering in vacuum sequence and a thin metal layer of Ti.

Description

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Title of the invention

High corrosion resistant reflection scans syst em on substrates

Field of application of the invention

The invention relates to highly corrosion-resistant reflection layer sy stones on glass or glass-like substrates. The provided with the reflective layer systems substrates are z. B. as a mirror in the furniture industry, in the household, in transportation, in the 'scientific apparatus construction or as partially transmissive mirror applied.

Characteristic of the known technical solutions

It is known that metallic reflective layers with or without self-passivation properties by applying a. another thin metal layer and / or an organic polymer layer, which may also consist of several layers, are protected against corrosion, 'The effectiveness of this S _c hutzes u. a * depends on the thickness, the impermeability and the porosity of these layers as well as the adhesion of the thin metal layer to the reflective layer or the adhesion of the organic polymer layer to the thin metal layer. Because the

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The protective effect of the thin metal layer with respect to the reflection layer is primarily determined by the galvanic interaction between the two metal layers. • The thin metal layer almost always consists of a metal, which after its position in the electrochemical voltage series, is less noble than the Metal is the reflection chip _i . The mostly consisting of a pure metal thin metal layer is applied mainly by means of wet chemical method or vacuum deposition. The reflection layer is protected by the thin metal layer only until it is not yet anodically dissolved. Most of the protective effect is taken over by the organic polymer layer, since the time to anodic dissolution of the thin metal layer is much smaller than the time of penetration of the organic polymer layer with atmospheres (water, oxygen, etc.) particular qualitative requirements are placed on the organic polymer layer inter alia with regard to the degree of crosslinking., Usually, the organic, polymer layer must be dried in an energy-intensive process,

However, in spite of costly manufacturing processes, 'z. B, in the deposition ' ¹ with the aid of thermal or Elektronenstrahlevampfung. in vacuum or by plasma processes in air, the required service life due to the low resistance to chemical corrosion. Not achievable. In the case of wet chemical separation, the handling of more toxic. Electrolysis baths made increased demands on occupational safety and environmental protection. The production of a corrosion protection layer on the reflective layer by means of anodic oxidation, ζ. B. after the anodizing process in use

of aluminum as a reflection layer, is associated with both a considerable technological effort and with the formation of numerous and leading to the deterioration of the reflectance of leading holes in the reflective layer,

It is known that when metal is applied to metal by means of piasmic processes in air, a series of metals (eg Ag-Al, Cu-JFi) undergo> chemical interaction and the optical and adhesive properties are affected (Kudinov et al .: The Optics of Plasma Covers, Verlag Nauka, Moscow 1981). Such chemical interactions between metals are bound to specific metal combinations. These chemical interactions and associated property changes are not detected in the metal combinations Al-Ti 'and Cu-Ti, for example. «

Object of the invention

It should'hoch corrosion resistant reflective coating systems on glass or glass-like substrates are created, which are technologically simple and inexpensive to produce and no deterioration of the reflectance, preferably the degree of light reflectance, during manufacture and have later use.

Explanation of the essence of the invention . · ... '

The object of the invention is to provide highly corrosion-resistant reflection layer systems on glass or glass

similar substrates that do not cause deterioration

... tion of the reflectance, preferably the degree of light reflectance, during manufacture and have the subsequent use and require, to achieve a long-term corrosion protection no organic polymer layer.

It was surprisingly found that the problem is then solved ν, if from a reflective layer of aluminum. or copper or zinc or copper and zinc or copper and. Tin and a thin metal layer of titanium existing reflective layer systems used and these are applied by means of, DC Plasmatron sputtering in vacuum sequence on a glass or glass-like substrate.

The highly corrosion-resistant reflective layer systems according to the invention produced in this technologically simple and cost-effective manner have such a long-term corrosion protection while retaining the reflectance, preferably the degree of light reflection, that an organic polymer layer is no longer required from this point of view necessary-only-to fulfill the function of protection against a strong mechanical attack on the reflection / coating system.

The found, substantial increase in long-term corrosion protection can be explained by the formation of a specific transitional layer. The specific transition layer apparently causes a much stronger. Self-passivation capability as the pure metals and thus forms the basis for a highly corrosion-resistant reflection, coating system,

By alloying suitable metals, ζ. , »" Nickel, to the metal of the reflective layer can be produced while maintaining the long - term corrosion protection for decorative purposes, different color variants.

Embodiment .

Example 1 '

On a carefully cleaned 10 cm χ 10 cm float glass sample is placed under vacuum at a working pressure of,; .133,32 mPa (argon) using the DC-Plasmatronsputterns the reflection layer system aluminum / titanium with an ^aluminum: miniumschichtdicke of approximately 110 mn and applied einer'Titanschichtdicke of approximately 20 'nm in a process successively. For the purpose of comparison, two ₁ × ₁ cm × 10 cm float glass samples cleaned in the same way are successively applied to the process using the aluminum / titanium reflection layer system with the same layer thicknesses in vacuo at a working pressure of 2.6.7 × P s by means of thermal evaporation. One of these two samples is coated with an organic polymer layer, the commercial Spiegldecklack RpDA. All three samples are subjected to an electrochemical resistance test in which the. time course of the corrosion current, in contrast to an oxygen-purged platinum electrode in a 0.5 n-HNO ,, a .Maß for the durability and thus life of the applied reflective layer system is. '. ,,

FIG. 1 shows the courses of the corrosion currents of the three samples as a function of time. In the

Curve 1 is the thermally evaporated sample without organic polymer layer, while Curve 2 represents the thermally evaporated sample with organic polymer layer, curve 3 represents the sample prepared by means of the DC Plasmatron sputtering. After only about three hours, the thermally vapor-deposited sample without an organic polymer layer has first visually detectable defects (eg holes), -after approximately 20 "hours, the reflection coating system reaches the maximum of the curve Most pronounced in solution are the steep rise and fall of the corrosion current course with a high maximum (curve 1). , ,

The course of the corrosion current in the thermally vapor-deposited sample with organic polymer layer (curve 2) is compared with curve Ί, flatter with a lower maximum, - the organic polymer layer thus exerts a certain protective effect. Here are first defects after approx. 20 hours to recognize, after approx. 60 hours goes the reflection layer. system.in the maximum of the curve strongest in solution.,

In the case of the sample prepared by means of DC plasmatron sputtering (curve 3), first defects can be observed at the earliest after about 200 hours. The extremely low corrosion current as well as the nearly constant course over time, even after about 480 hours, prove that hardly any solution of the reflection layer sy st ems. · Takes place and there is thus a highly corrosion resistant refleion layer system.

Measurements of the light reflectance of the reflective layer on the o.gy three samples immediately after preparation give values of 86%. The measurements in the course of the electrical

Trochemical resistance tests give values of 9% after 20 hours of test time in the thermally vapor-deposited sample without organic polymer layer, 12% after 20 hours - the test time in the thermally evaporated sample with or-. Ganic polymer layer and 9 % after 60 hours of T # st time, 85 % after 200 and 480 hours of test time on the sample prepared by means of the DC plasmatron sputtering.

To clarify the found high corrosion resistance also the reflective layer systems are using. "" of secondary ion mass spectroscopy (SIMS). Fig. 2 shows the SIMS profile (number of pulses per unit of time intensity as a function of a measuring time) of the thermally evaporated and Fig. 3 shows the SIMS profile of the prepared using the DC Plasmatronsputtems reflection layer system.

While there is a clear separation between the aluminum and titanium layer in the thermally vapor-deposited reflection layer system (FIG. 2), in the reflection layer system produced with the aid of DC plasmatron sputtering, in addition to a strong thorough mixing of the aluminum and titanium layer, a marked change in both profile profiles occurs. , Fe determined in the form of Einsattelungen. Both the strong mixing and the dip are evidence of the existence of a specific transition layer,. apparently responsible for the high corrosion resistance.

Example 2

Analogously to Example 1, the reflection coating system copper / Ti is applied to a float glass sample in vacuo at a working pressure of 133.32 mPa (argon) with the aid of DC-Plasmatron sputtering.

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tan with a copper layer thickness of about 100 nm and a; Titanschichtdicke.von about 20 nm in a process applied sequentially. For comparison, the system Reflexionsschicht- • copper / titanium is with the same layer thicknesses in a vacuum at a pressure of 2.67 · ^r work mpa by thermal evaporation in a process successively on a float glass sample is applied. Both samples are subjected to an electrochemical resistance test according to Example 1, in'Pig. 1 shows the courses of the corrosion currents of both samples as a function of time.

After just one hour, the thermally evaporated sample (curve 4) shows the first visually detectable defects; after about 35 hours, the reflection layer system dissolves most strongly at the maximum of the curve. Also characteristic of this example is the steep rise and fall of the corrosion current course with a high maximum. ^:

In the case of the sample prepared by means of the DC-Plasmatron sputtering (curve 5), however, first defects can be observed at the earliest, after 150 hours. The extremely low corrosion current and the almost constant time course without maximum prove that a solution / the reflection layer system hardly happens, so there is a highly corrosion resistant reflective coating system. ..

Example 3

Analogously to Example 1 is applied to a Ploatglasprobe in vacuum at a working pressure of 133.32 mPa (argon) with the aid of DC Plasmatronsputterns the Reflektionsschichtsystem.Kupfer- · tin / titanium with a copper-tin layer thickness of about 90 nm and a titanium layer thickness of about 20 nm. Applied sequentially in a process. , , - _:

According to Example 1, the sample is subjected to an electrochemical resistance test, the corrosion current as a function of time is shown in FIG. 1 as curve 6.

The analog waveform to the reflection layer system aluminum / titanium and copper / titanium is also in this example, the presence of a gene hochkorrosionsbestaridi- reflection layer system.

Claims (2)

Invention claim,. '- _r,. Hoci corrosion-resistant reflection coating system on substrates, especially on glass or glass-like. Substrates, characterized in that the reflection layer sy st em from a through. DC Plasmatron sputtering in Vakuumfo.lge applied reflective layer of aluminum or copper or zinc, or copper and zinc or
Copper and tin and a thin metal layer of titanium. , .For this 2 sheets of drawings