DE1771370A1 - Process for producing thin, colored layers that are clear when viewed through - Google Patents

Description

LEYBOLD-HERAEUS GMBH S CO XG 1771370 Cologne

File 5106

Process for the production of transparent, colored thin layers

The invention relates to a method for producing colored thin layers that are clear when viewed through simultaneous, or successive high vacuum evaporation of at least one absorbent and one non-absorbent component on a transparent support, wherein the non-absorbent, vitreous component is made up of the evaporation of a mixture at least two components including an SiO, component and a B20 component are produced.

It is known to thin absorbent layers by simultaneous or intermittent evaporation of absorbent and non-absorbent To manufacture fabrics. Such assignments are used, for example, for sun protection glasses or filter glasses. Particular difficulties arise when reproducibility of the degree of absorption, the hue, the mechanical and / or chemical properties, as well as aging and Temperature resistance are prescribed. In the previously known manufacturing processes, diffusion processes resulted between the absorbent and non-absorbent component a change in the total absorption, and the applied thin Layer showed a mottled appearance. Such a change in absorption caused by aging is without the aid of aids visible in the observation and occurs either immediately after the end of the vapor deposition process or shorter time afterwards.

Experiments have shown that with simultaneous evaporation img of absorbing substances, e.g. metals, metal logs, Sulphides, selenides or organic substances and SiO in oxygen-containing Atmosphere as a non-absorbent component Layers are created that have their color tone at room temperature

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change and make a reproducible production of a certain degree of absorption and a certain color tone impossible. A known improvement of these unfavorable layer properties can be achieved by using SiO ₂ or a glass with a sufficiently high SiO ₂ content by evaporation from directly or indirectly heated evaporation sources as the non-absorbent substance. However, there are further disadvantages. _{If, for example, pure SiO 2} is used as the non-absorbent material, a layer is created which is also not stable in terms of the degree of absorption. The means known up to now have therefore not succeeded in permanently producing colored thin layers with a reproducible degree of absorption.

The invention is based on the task of improving the aging and temperature resistance of thin, colored layers without impairing the other layer properties and, moreover, of producing very homogeneous layers when viewed through. The basis of the invention is a process for the production of transparent, colored thin layers by simultaneous or successive Ilocbakuumadapampung of at least one absorbent and one non-absorbent component on a transparent support, the non-absorbent, glass-like component by the evaporation of a mixture of at least two Components including an SiO2 component and a B ^ component are produced. To solve the problem, it is proposed according to the invention that the mixture to be melted under vacuum is provided with a particle size below 50 / IiAeT and has a B ₂ ° 3 content between 5 and 30 percent by weight. It has been shown that such a high content of B ₂ O _{3 has} a stabilizing effect with regard to the diffusion processes occurring between the absorbent and the non-absorbent component. It has also been found that such borosilicate glasses appear to be advantageous for influencing the diffusion processes favorably, but possibly. need further improvement so that completely homogeneous layers can be produced.

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During the evaporation process of these borosilicate glasses, particles and sometimes even particles lying in visible dimension are thrown onto the surface to be steamed, and so areas free of absorption arise on the evaporation layer during the manufacturing process or during subsequent cleaning (holes) It is proposed in a further embodiment of the invention that an approximately glass-like component of Na — O is kept as small as possible below 5 percent by weight of the mixture to be evaporated Vapor deposition and the hurling out of coarse particles no longer occur to a considerable extent. However, the higher the requirements with regard to clarity and transparency, the lower the Na ₂ O proportion must be. In practically all cases, the Na — O proportion is as low as possible It arises in connection with mi t the high BO content a uniformly colored, age-resistant thin layer, and the degree of absorption can easily be reproduced at any time by appropriate process management. With regard to the B, O_ content, a proportion of 5% by weight appears to stabilize the harmful diffusion processes, which is sufficient in many cases for room temperature. If the objects have to be exposed to higher temperatures, e.g. B. above 100 ⁰ C, the E ₂ ° 3 ~ content must be increased after the operating temperature to which the layer is exposed in use, finally up to 30 tons.

It can be useful to vaporize the non-absorbent Component and the absorbent component in such a way that the evaporation rate · of the non-absorbent Component is kept constant during the manufacturing process. There is a change in the evaporation rate of the absorbent constituent from the beginning to the corresponding Operating value, and the increasing absorption of the thin layer is in the manufacturing process with the help of a known Measuring device monitored. As soon as the absorption of the expected layer is a few percent below the desired absorption value, will the rate of evaporation of the «absorbent component is continuous lowered, and they eventually reached the desired point

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SAD

Absorption is its zero value.

The number of vaporized molecules of the glassy, non-absorbent It must be a component if the reflection of the colored thin layer is not to be higher than that of the non-absorbent layer used Constituent, be at least as large as the number of vaporized molecules of this non-absorbent Substance. For safety reasons, a ratio of 2: 1 (number of molecules of the vitreous constituent / number of molecules of the absorbent component).

When carrying out the process it has been shown that the hardness and adhesive strength of the thin layer are also dependent on the angle of incidence of the non-absorbent molecules. Evaporation source and substrates should therefore expediently be arranged in such a way that the evaporated molecules at least approximately hit the substrate perpendicularly.

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Claims (3)

-s- 5106 PATENTAKSPROCHS 1) Method xur production tob clear, colored thin layers in the transparency by simultaneous successive high vacuum evaporation of at least one absorbent and one non-absorbent component on a transparent support, the non-absorbent, vitreous component by the evaporation of a mixture of at least two components with the inclusion of an SiO ₂ * component as well as a BjOj component arises »characterized in that the mixture, which melts under vacuum, is nergestelit with a small size below 50% and has a BgO ^ content between 5 and 50 percent by weight. 2) The method according to claim 1, characterized by the fact that a small amount of Na ₂ O * in the vitreous component, for example, is kept small enough, below τοη S by weight around the evaporating mixture. 3) The method of claim 1 or 2 characterized · draws "dal in the manufacturing method of the m i t absorbent component continuously at a constant Verdaapfuagsrate is evaporated, and ά * & the evaporation rate ά ·" absorbent component ve "Mullwert to do a maximum value increased and Finally, it is lowered in such a way that when the predetermined degree of absorption is reached, the evaporation rate i * 9 of the absorbent component again reaches the zero value. 209815/0390