CS220175B1 - METHOD OF MANUFACTURING THE TRANSPARENT OF THE REMOVABLE LAYERS OF OXYGEN NUMBER: ON GLASS - Google Patents

Abstract

The invention solves the problem of achieving maximum infrared reflectivity of thin, transparent heat-reflecting layers on glass. The surface of the heated glass is brought into contact with a medium containing at least one decomposable organic or inorganic tin compound and at least one decomposable electrically active additive from the group including fluorine and antimony for a period of time sufficient to form tin oxide; the exact concentration of the additive being selected in the range of 0.5 to 5% by weight depending on the temperature of the glass heating.

Description

The invention relates to a process for the production of transparent thermally reflective layers of tin oxide on a glass substrate.

One of the ways to reduce energy consumption for heating buildings in winter is to reduce the heat leakage from the rooms through the windows to the outside environment by means of thermally reflective transparent thin layers on the glass. These layers reflect the long-wave heat radiation back into the room and thus improve the thermal insulation properties of the windows. Very advantageous and recently developed types of heat reflective layers are semiconductor layers based on tin oxides Sn or indium In, doped to increase reflectivity by suitable electrically active impurities, mostly fluorine F or antimony Sb.

There are a number of methods of applying these layers. The most preferred and also most commonly used are thermal decomposition of a suitable compound which is brought into contact with the surface of the heated glass either in liquid (aerosol spraying, dipping and soaking, pouring, etc.) or in the gas phase (scrubbing the surface with gas mixtures). The principle of this method has been known for a long time, according to U.S. Pat. Further improvements of this process, including improved methods of construction of the necessary equipment, are disclosed, for example, in German Patent No. 2,716,183, France No. 2,348,167, United Kingdom No. 1,506,668, Australia No. 482,853 and USSR No. 269,226 .

The most important requirement for the properties of the thermal reflective layers is to achieve the highest possible value of infrared reflectance with a reduced visible transmission. The known methods solve the problem of maximum reflectance in the infrared range by selecting the appropriate concentration of electrically active impurities, which is determined experimentally. It is known that the fluorine F or antimony Sb content must be kept within certain limits, lower or higher concentrations lead to a decrease in reflectance or a sharp decrease in visible transmission.

However, as has now been determined by a series of experimental tests, the optimum concentration of electrically active impurities is not a constant but depends on the deposition temperature. At different application temperatures, maximum infrared reflectivity and visible transmission are achieved for »different admixture concentration values. If the fluorine F or antimony Sb content is determined irrespective of the deposition temperature, as shown in the prior art methods, there is no guarantee that maximum infrared reflectivity and visible transmittance are achieved in all cases.

The disadvantages of the present invention are eliminated by the process for producing transparent thermal reflective layers of Sn tin oxide according to the invention, which comprises contacting a heated glass surface with a medium comprising at least one decomposable organic or inorganic tin Sn compound and at least one decomposable electrically active additive compound. fluorine F and antimony Sb, for a time sufficient to form a layer of tin oxide Sn, wherein the exact value of the dopant concentration is chosen in the range of 0.5 to 5% by weight depending on the glass heating temperature. The deposition temperature is not fixed in advance; in addition to the type of starting compounds, it is further controlled by the deposition technology, the composition of the base glass, its viscosity and other parameters. The combination of these effects will result in a certain temperature value at which the glass will be heated when the layers are applied. It is only on the basis of this temperature that the exact concentration of impurities - fluorine F or antimony Sb - is determined experimentally (by measuring the reflectivity of a number of samples with variable content of electrically active ingredient) so that the layers have the highest infrared reflectivity.

The glass provided with the thermal reflective layer according to the invention is suitable for use in the thermal insulating glazing of buildings, thereby reducing heat loss from the room to the environment in winter. Energy savings can be achieved in the case of double glazing units with reflective layers up to about 50 ° / o.

More detailed features of the invention are best elucidated by several examples of the preparation of a heat reflective sheet on a flat glass.

He did

Float glass with a thickness of 3 mmi is heated to a temperature of 640 ° C and for 10 seconds a solution is sprayed onto the surface with the aid of an air spray gun resulting from the mixing of 100 grams of tin (II) dichloride (100 ml of distilled water H2O and 3.9 g). ml of hydrofluoric acid HF The glass forms a ternary layer of tin dioxide »SnO2 with a mass content of 2,5 ° / o of fluorine F with a uniform light green color in reflection, with transmission in the visible part of the spectrum in the range of 70-87%. 5 - 12 in the range 70 - - 80 0/0.

Example 2

The 3 mm float glass is heated to 650 ° C and a solution formed by mixing 100 grams of stannous dimethyl chloride (CH3) 2SnCl2, 100 ml of distilled H2O and 5.2 ml is sprayed onto the surface for 8 seconds with an air spray gun. HF. A homogeneous layer of tin (II) SnO2 with a mass of 3,5% fluorine F with a uniform light green color in reflection, with a transmittance in the visible part of the spectrum ranging between 70 and 85% is formed on the glass and reflects220175 within 5-12 μΐη. - 80%.

Example 3

Float glass with a thickness of 5 mm is heated to a temperature of 580 ° C and a mixture of tin tetrachloride vapor and antimony trichloride is fed to the surface for 6 s.

SbCl 3 in a weight ratio of 1: 0.8. A homogeneous layer of tin (II) SnO2 with a content of about 1% antimony Sb with a uniform light green color in reflection, with a transmission in the visible part of the spectrum in the range of 70-80% and with a reflectance in the 5-12 µm range .

Claims (1)

A method for producing transparent thermally reflective layers of tin oxide on a glass comprising contacting a heated glass surface with a medium comprising at least one degradable organic or inorganic tin compound and at least one electrically degradable compound INVENTION active ingredients from the group consisting of fluorine and antimony, for a time sufficient to form a tin oxide layer, characterized in that the concentration of the electrically active ingredient (s) is in the range of 0.5 to 5% by weight, depending on the particular glass heating temperature