CS215427B1 - Method for producing reflective layers - Google Patents

Abstract

Method of producing reflective layers on the surface of organic or inorganic glass, especially for rear-view mirrors of motor vehicles. This method of production consists in depositing an amorphous layer of cobalt and its phosphides with a thickness of 0.15 to 0.5 pm on the surface of the glass. The layer is formed on the surface of the glass, freshly mechanically polished, activated with a one to two percent solution of tin chloride and sensitized with a 0.1 to 1% solution of palladium chloride in an ammonia bath, containing in 1 liter of water: cobalt chloride - 0.1 mol sodium dihydrogenphosphonate - 0.2 mol sodium citrate - 0.1 mol ammonium chloride - 0.8 mol. The temperature of this bath is 85 to 95 °C and the time of layer formation is 15 to 120 s. The reflectivity of the reflective layer in the visible region of the spectrum reaches 40-50%.

Description

The invention relates to a method for producing reflective reflectors. organic or inorganic surface layers; glass, especially for motor vehicle rear-view mirrors.

Motor vehicle rear-view mirrors are one of the factors that significantly affect the passive safety of their drivers. In addition to the requirements imposed on the actual design of the rear-view mirrors, the requirements for the reflective mirror surface also come to the fore! especially in terms of reflectance and image quality. Currently produced rear-view mirrors have a reflectance of less than 40%, so that the reproduced image is relatively dark and, moreover, such reflectance does not meet the requirements of current regulations. Furthermore, there are reflective mirrors having a reflectance of more than 90%, but which are also not suitable for motor vehicles, since there is a risk of undesirable glare of the driver.

[0003] The methods known to date for the production of reflective layers on glass also involve vacuum vapor deposition or even cathodic sputtering of metal layers, such as e.g. Both of these methods make it possible to create reflective layers with a wide range of reflectance, but their disadvantage lies in particular in the lengthy and demanding production process and at the same time in the cost of the production equipment, especially if it is intended for large series. In addition to vacuum methods, chemical methods are also known, namely reduction silvering, which uses a reduction of the ammoniacal silver complex, which can produce reflective mirrors with a reflectance of 95% and higher. Its main drawback is the considerable consumption deficit; silver. Further, chemical excretion is known; of nickel from phosphomann baths, which is suitable from the point of view of mass production, however, the reflectance of the reflective surfaces formed in this way is less than 40%.

- ¹ 215427

The above-mentioned drawbacks of the known reflective layers of mirrors in relation to the method for their production obviates the object of the invention, which is the method of producing reflective layers on the surface of organic or inorganic glass, especially for rear-view mirrors ^. la motor vehicles. The principle of the invention is that an amorphous layer of cobalt and its phosphides with a thickness of 0.15 μιη to 0.5 µm is deposited on ^one surface of the glass.

The main advantage of said process is ^one in that the reflectivity of the reflective layer in the visible spectrum is 40 to 50%, which corresponds to the regulations in force. The layers thus formed are both thermally and electrically conductive, so that their condensation or icing can be removed by electric current. Production is relatively inexpensive and fast, since the reflective layer is deposited in the respective phosphorous reduction bath within 15 to 20 s.

Example:

On the surface of a mirror glass, freshly mechanically polished, activated with a 1 to 2% stannous chloride solution and sensitized with a 0,1 to 1% palladium chloride solution, in an ammonia bath containing in 1 liter of water: cobalt chloride CoCl ₂ .6H ₂ O - 0 1 mol j sodium dihydrogenphosphoman NaH ₂ PO ₂ . H ₂ O - 0.2 mol sodium citrate Na ₃ C ₆ H ₅ O ₇ .2 H ₂ O - 0.1 mol i ammonium chloride NH ₄ Cl - 0.8 mol. forms a reflective layer of cobalt and its phosphides at a temperature of 85 to 95 ° C for 15 to 120 sj. After removal of the reflective layer from the surface of one side of the glass by scaling, a mirror having a reflectance of 40 to 50% in the visible region of the spectrum is obtained.

Claims (1)

OBJECT OF THE INVENTION '! Process for producing reflective layers on the surface by eliminating on the glass surface an amorphous layer of organic or inorganic glass, especially for cobalt and its phosphides with a thickness of 0.15 to 0.5 µm. motor vehicle rear-view mirrors;