Glass panel exhibiting antisolar properties for glazing windows

The subject of the invention is glazing glazing with sunscreen properties. The glass according to the invention takes the form of a substrate, which is a carrier of a pyrolytic coating containing tin and antimony, produced by spraying.

Vehicle windows, which should protect passengers from solar radiation, are increasingly glazed with reflective, transparent solar control glazing. They are used as side windows in railway wagons and as side, rear and roof in road vehicles. And what's more, for cars the whole roof surface from this type of glass was proposed. This provides sun protection, through reflection and / or absorption, and by eliminating the dazzling effects of intense solar radiation and creating an effective shield against bright light, increases optical comfort and reduces eye fatigue.

The properties of coated substrates discussed in this description are based on the standard definitions of the International Commission on Illumination- Commission Internationale de PEclairage ("CIE").

The standard illuminates quoted here are CIE Illuminant C and Illuminant A. Ilumunant C (most often used to assess the optical properties of glass panes used to glass buildings),

179 768 stands for average daylight with a bar temperature of 6700 ° K. Illuminant A (which is synonymous with the light emitted by the headlights of the car and hence most commonly used to assess the optical properties of windscreens in motor vehicles), means the radiation of Planck radiator at a temperature of about 2856 ° K.

The "light transmission coefficient" (TL) is the luminous flux transmitted through the substrate, expressed as a percentage of the incident flux.

The "light reflection coefficient" (RL) is the luminous flux that is reflected from the ground, expressed as a percentage of the incident flux.

"Transmitted energy" (TE) is the total radiant energy passed directly through the ground, expressed as a percentage of incident radiant energy.

"Reflected energy" (RE) is the reflected radiant energy from the ground expressed as a percentage of the incident radiant energy.

"Solar factor" (FS) is the ratio of the sum of the total energy directly passed through the substrate (TE) and the energy that has been absorbed and re-radiated on the other side of the pane from the energy source (AE), expressed as part of the total energy incident on the substrate.

The "selectivity" of the substrate coating refers to the balance between the light transmittance factor and the transmitted energy. For glazing in buildings, selectivity is often defined as the ratio of light transmittance to solar factor (TL / FS), but for glass in vehicles usually refers to the ratio of light transmittance to transmitted energy (TL / TE).

"Dominant wavelength" (λ d) means the peak of the wavelength in the transmission or reflection range of the coated substrate.

The "purity" (p) of the substrate color refers to the excitation purity measured with Ilumunant C. It is specified on a linear scale on which a particular white light source has a purity of zero and a pure color has a purity of 100%. The purity of the coated substrate is measured on the opposite side of the coating.

"Emissivity" (e) means the ratio of the energy emitted by a given surface at a given temperature to that of the perfect emitter (black body with 1.0 emissivity) at the same temperature.

From a technical point of view, it is desirable that in solar conditions too much of the total solar radiation does not pass through the glazing, so that there is no overheating inside the vehicles or buildings. The transmittance of the total incident solar radiation can be expressed by the "solar factor" (defined above). For vehicles, the main energy factor taken into account is total directly transmitted energy (TE), because energy that is internally absorbed and re-radiated (AE) is dissipated by the movement of the vehicle.

In our earlier patent GB 2200139, a method for forming a pyrolytic tin oxide coating on a hot glass substrate by spraying with a solution containing a tin compound and additives in a coating like fluorine and materials such as antimony, arsenic, vanadium, cobalt, zinc, cadmium is described and claimed , tungsten, tellurium and manganese, so as to obtain a coating with low emissivity and low internal haze value. Although the obtained coating has many desirable properties, it lacks the combination of properties currently sought for car windscreens.

The object of the present invention is a glazing pane with a high level of sun protection in combination with other desirable light transmission properties and high selectivity.

We have found that this and other useful goals can be achieved on a glassy substrate by applying a thick, pyrolytically sprayed coating containing tin and antimony oxides in the correct ratio.

Thus, in accordance with the present invention, a glazing pane is obtained, which is a carrier of a spray-formed pyrolytic oxide layer tin / antimony coating, at least 400 nm thick and containing tin and antimony in a molar ratio of 4

179 768 Sb / Sn size of 0.05-0.5, the substrate coating having a light transmittance factor (TL) below 35% and a selectivity (TL / TE) of at least 1.3.

Many technologies are known for the production of coatings on a glass substrate, including pyrolysis and cathode nodules. Pyrolysis generally has the advantage of producing a hard coating that prevents the need for a protective layer. Coatings produced by pyrolysis have good anti-corrosive properties and good abrasion resistance. It is assumed that this is related in particular to the process of deposition of the material forming the coating on a hot substrate. In general, pyrolysis is cheaper than an alternative vacuum sputtering process, especially in terms of industrial investment.

Preferably, the substrate is in the form of a web or sheet of glassy material, such as glass or other rigid, transparent material. Considering that part of the incident solar radiation is ebstsrbokene through the glass, especially in an environment where the glass is exposed to strong and long-lasting solar radiation, which causes the glass to heat up, it may be required that it has previously been subjected to a toughening process . However, the durability of the coating allows the glass to be mounted with the coated side on the outside, thus reducing the heating effect.

Preferably, the substrate is formed of colored glass. The combination of internal tinting of the glass material and coating of the present invention has been found to facilitate the achievement of the required low permeability coefficient and high selectivity. The general preferred colors for roof, side or rear windows that are used in vehicles are gray and green.

Preferably, the tin / antimony oxide coating has a thickness of 400-800 nm, in particular 450700 nm. Such thickness allows achieving a low value of the total energy ratio (TE), while maintaining a sufficient level of light transmission. Thick tin / antimony oxide layers, especially layers containing a low Sb / Sn molar ratio, provide not only the glass required. low value of light transmittance coefficient and high selectivity, but also a favorable combination of low solar coefficient FS and low emissivity.

It may be useful to prevent the interaction between the glass substrate and the tin / entomon oxide coating layer. For example, it was found that in pyrolysis-forming tin oxide coating of tin chloride on soda-lime glass, sodium chloride, resulting from the reaction of glass with the initial coating material or its reaction products, has a tendency to penetrate the coating, which leads to fogging of the coating . Thus, if required, an intermediate, anti-fog layer can be placed between the substrate and the syne / entimone oxide coating layer. Such an intermediate layer is generally unnecessary for panels with a low light transmittance factor because haze is imperceptible to any significant extent. If used, it may consist of silicon oxide approximately 100 nm thick. The presence of a silicon oxide subcoat on soda-lime glass inhibits the migration of sodium ions from the glass, either by diffusion or otherwise into the tin / antimony oxide coating layer during the formation of the outer coating or during high temperature subsequent treatment.

The glazing of the present invention is particularly suitable for use in vehicle roofs, for example, tilting or sliding roofs, or even to form a complete roofing material. They can also be used as rear and rear side windows for vehicles.

Glazing with a light transmittance factor of less than 35% is preferred as a vehicle roof plate, and especially if the plate makes up most or all of the roofing material. While a low light transmittance factor is required according to the invention, at the same time it is desirable for the windscreen to partially pass through visible light to create natural lighting inside the vehicle.

The high level of coating selectivity combined with the low light transmittance factor allows for low solar energy transmission. The selectivity provided according to the present invention is generally at least 1.3 and preferably at least 1.5. It is a special advantage of konelezek that it allows to achieve in practice selectivity close to 2.

179 768

Thus, the energy transmission (TE) is preferably less than 15%, especially less than 10%. Such low energy transmission relieves the vehicle's air conditioning system.

In the case of full-glass panes, it may be advantageous to use panes with a light transmission coefficient of up to 10%, an energy transmission of 5%, giving a selectivity of 2. In the case of opening roof panes, a slightly higher energy transmission, e.g. 20%, energy transmission about 12%, giving a selectivity close to 2.

The Sb / Sn molar ratio in the coating, preferably, is from 0.07 to 0.20, in particular from 0.08 to 0.15. The preferred range results from the need to provide sufficient antimony to give low transmissibility properties, because insufficient quantity affects the optical quality.

Preferably, the coating consists of a single tin / antimony oxide layer. However, to obtain some of the desired optical properties, it is possible to provide one or more further layers of the coating, obtained either by pyrolysis or by other methods. It should be noted, however, that the tin / antimony oxide layer produced by pyrolysis has sufficient mechanical stability and chemical resistance to serve as an outwardly directed layer. Alternatively, said layer may be applied to the surface of the substrate facing the interior of the vehicle.

The glass according to the present invention has a low visible reflection coefficient, which is particularly advantageous in the case of car windows. Preferably, the visible reflection coefficient (RL) is lower than 12%, and typically can be between 5 and 12%.

Windows in accordance with the present invention may be installed as individual or in combination. The coating layers are produced on a hot substrate by spraying liquid reagents, for example with spray nozzles. Although spraying does not achieve the precision as in the alternative pyrolytic method of chemical vapor deposition (CVD), it is nevertheless convenient and inexpensive for depositing thick layers of coating as in the present case. Indeed, CVD is generally the wrong way to create thick coatings.

In a particularly preferred case of applying coatings to a colored substrate, any differences in the thickness or uniformity of the coating resulting from the use of the spraying method are barely noticeable. Preferably, the tin source is SnCh and the source of SbCl antimony₃which are mixed with water before the spraying operation - Organometallic compounds can also be dissolved.

If it is advisable to manufacture pyrolytically coated flat glass panes, it is preferable to make on freshly formed glass. This procedure is economically justified because it does not create the need to reheat the glass for the pyrolysis reaction and the quality of the coating is also advantageous then, since the glass surface is provided in its original condition. Thus, preferably, said precoating material is applied to the upper surface of a hot glass substrate which is a freshly prepared glass filter.

Thus, the glazing panes of the present invention can be made as below. The pyrolytic coating step can be carried out at a temperature of at least 400 ° C, ideally at 550 ° C - 750 ° C.

To form each coating, the substrate is contacted in a coating chamber with spray droplets containing antimony and tin reagents. Spraying is carried out by means of one or more nozzles arranged in a line so as to provide coating across the width of the web to be coated.

In the spray-pyrolytic method, the Sb / Sn molar ratio in the final coating is not directly proportional to the ratio in the reagent mixture, and often differs substantially from it. Antimony content in the coating is significantly influenced by parameters such as spraying speed, type of glass and temperature. Attempts to calculate the proportion in the coating relative to the proportion in the starting materials are uncertain, and most often it is necessary to perform preliminary tests to determine the initial proportions to obtain the required proportions for individual cases.

179 768

After deposition, the coating is preferably polished using any conventional polishing agent. The product coated in this way may also be hardened, if appropriate.

In the following, the invention will be described in detail in non-limiting examples.

In the examples below, the Sb / Sn molar ratio in the coating layers was determined by X-ray analysis, in which the corresponding elements were compared. This technique is not as precise as chemical determination, because the similarity of antimony and tin causes that they respond similarly to X-rays. The ratio of the measured number of observed signals of the respective elements thus gives approximately their molar ratio.

Examples I-XXI

In all examples, an aqueous Sb / Sn mixture is used for a moving 4mm thick hot glass substrate web. As shown in Table A below, many different types of glass were used. The symbols in the headings of this and other tables (ie TE etc.) have the meaning described above. The columns FSpl and FSp2 in Table C refer to the solar factor for the corresponding side of the glass facing the light source (item 1) and to the glass turned away from the light source (item 2). Unless otherwise indicated, the properties shown in the tables were measured with Illuminant C. Under these conditions, the difference in TL between Illuminant C and Illuminant A (typically used in the field of motor vehicles) was minimal, of the same order as most routine measurement errors.

In each case, the mixture was a precoating solution containing 1000 g (total) of SnCl2 and SbCb per liter of mixture and in the proportions shown in Table B below. The solution was applied to the substrate by means of reciprocating spray nozzles arranged linearly transversely in relation to the width of the web.

Table A.

<td>Type of glass</td><td></td><td>Green A.</td><td>Green C.</td><td>Gray</td><td>Medium gray 1</td><td>Medium gray 2</td>

<td>λ₀ transmission (nm) [Illuminant: C / A]</td><td></td><td> 505,4/508,5</td><td> 509,7/510,2</td><td> 470,1/493,9</td><td> 493,2/502,7</td><td> 494,6/502,8</td>

<td>Purity (%)</td><td></td><td> 2,9/3,4</td><td> 3,2/4,0</td><td> 1,5/0,8</td><td> 5,6/5,1</td><td> 9,9/9,3</td>

<td>TL (%) [Lluminant: C / A]</td><td> 89,0</td><td> 72,66/71,12</td><td> 67,36/65,69</td><td> 55,65/55,56</td><td> 36,8/35,8</td><td> 37,07/35,13</td>

<td>TE (%) (CIE)</td><td> 83,0</td><td> 44,0</td><td> 37,1</td><td> 56,9</td><td> 25,9</td><td> 20,9</td>

<td>TL / TE (CIE C)</td><td> 1,07</td><td> 1,65</td><td> 1,81</td><td> 0,98</td><td> 1,42</td><td> 1,77</td>

<td>FSpl (CIE) (%)</td><td> 86,0</td><td> 56,8</td><td> 51,7</td><td> 66,3</td><td> 43,4</td><td> 39,7</td>

<td>TL / FS</td><td> 1,03</td><td> 1,28</td><td> 1,30</td><td> 0,84</td><td> 0,85</td><td> 0,93</td>

The sprayed tin and antimony components react to form a pyrolytic coating of tin oxide on the glass. The parameters used and the results obtained are shown in Table B and C.

It should be noted that Examples IV and V do not meet the requirements claimed in this application regarding the thickness and selectivity of the coating, and in the case of Example V also the required light transmittance factor. These examples are provided for comparison to show how inferior results are obtained when operations outside the scope of the claims are carried out.

179 768

Table B

<td>Example</td><td>Type of glass</td><td>Sb / Sn reactants</td><td>Sb / Sn in the shell</td><td>Coating thickness (nm)</td><td>TL (%)</td><td>RL (%)</td>

<td>AND</td><td>colorless</td><td> 0,20</td><td> 0,11</td><td> 535</td><td> 23,0</td><td> 10,0</td>

<td>II</td><td>colorless</td><td> 0,20</td><td> 0,12</td><td> 470</td><td> 27,0</td><td> 10,0</td>

<td>III</td><td>colorless</td><td> 0,30</td><td> 0,14</td><td> 670</td><td> 13,0</td><td> 10,0</td>

<td>IV</td><td>colorless</td><td> 0,30</td><td> 0,16</td><td> 306</td><td> 27,0</td><td> 11,0</td>

<td>V</td><td>colorless</td><td> 0,30</td><td> 0,19</td><td> 119</td><td> 56,0</td><td> 10,0</td>

<td>VI</td><td>Green A.</td><td> 0,30</td><td> 0,17</td><td> 670</td><td> 10,4</td><td> 9,9</td>

<td>VII</td><td>Green C.</td><td> 0,30</td><td> 0,14</td><td> 670</td><td> 9,6</td><td> 9,9</td>

<td>VIII</td><td>Med. Grey2</td><td> 0,30</td><td> 0,14</td><td> 520</td><td> 6,4</td><td> 10,5</td>

<td>IX</td><td>Med. Grey2</td><td> 0,30</td><td> 0,14</td><td> 520</td><td> 6,5</td><td> 10,5</td>

<td>X</td><td>Green A.</td><td> 0,20</td><td> 0,11</td><td> 530</td><td> 15,7</td><td> 10,3</td>

<td>XI</td><td>Green C.</td><td> 0,20</td><td> 0,11</td><td> 530</td><td> 17,3</td><td> 10,3</td>

<td>XII</td><td>Med. Grey1</td><td> 0,20</td><td> 0,11</td><td> 530</td><td> 9,5</td><td> 10,2</td>

<td>XIII</td><td>Med. Grey2</td><td> 0,20</td><td> 0,11</td><td> 530</td><td> 9,6</td><td> 10,2</td>

<td>XIV</td><td>Gray</td><td> 0,175</td><td> 0,11</td><td> 643</td><td> 15,0</td><td> 10,0</td>

<td>XV</td><td>Gray</td><td> 0,175</td><td> 0,11</td><td> 530</td><td> 19,0</td><td> 10,0</td>

<td>XVI</td><td>Green A.</td><td> 0,175</td><td> 0,11</td><td> 640</td><td> 19,0</td><td> 10,0</td>

<td>XVII</td><td>Green A.</td><td> 0,175</td><td> 0,11</td><td> 530</td><td> 25,0</td><td> 10,0</td>

<td>XVIII</td><td>Green C.</td><td> 0,175</td><td> 0,11</td><td> 640</td><td> 17,8</td><td> 10,0</td>

<td>nineteenth</td><td>Green C.</td><td> 0,175</td><td> 0,11</td><td> 530</td><td> 23,0</td><td> 10,0</td>

<td>XX</td><td>Med. Grey1</td><td> 0,175</td><td> 0,11</td><td> 640</td><td> 10,0</td><td> 10,0</td>

<td>XXI</td><td>Med. Grey2</td><td> 0,175</td><td> 0,11</td><td> 530</td><td> 12,6</td><td> 10,0</td>

Table C

<td>Example</td><td>TE (%)</td><td>RE (%)</td><td>FSpl (%)</td><td>FS p2 (%)</td><td>Emissivity (N)</td><td>TL / TE</td><td>TL / FS</td>

<td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td><td> 6</td><td> 7</td><td> 8</td>

<td> 1</td><td> 17,0</td><td> 11,0</td><td> 35,0</td><td> 31,0</td><td></td><td> 1,35</td><td> 0,66</td>

<td>II</td><td> 21,0</td><td> 11,0</td><td> 38,0</td><td> 39,0</td><td></td><td> 1,29</td><td> 0,71</td>

<td>III</td><td> 10,0</td><td> 11,0</td><td> 30,0</td><td> 26,0</td><td></td><td> 1,30</td><td> 0,43</td>

<td>IV</td><td> 25,0</td><td> 13,0</td><td> 41,0</td><td> 42,0</td><td> 0,53</td><td> 1,08</td><td> 0,66</td>

<td>V</td><td> 51,0</td><td> 13,0</td><td> 60,0</td><td> 61,0</td><td> 0,76</td><td> 1,14</td><td> 0,97</td>

<td>VI</td><td> 5,8</td><td> 10,9</td><td> 26,8</td><td> 22,9</td><td> 0,35</td><td> 1,80</td><td> 0,39</td>

<td>VII</td><td> 5,1</td><td> 10,9</td><td> 26,3</td><td> 22,3</td><td> 0,35</td><td> 1,90</td><td> 0,36</td>

<td>VIII</td><td> 4,2</td><td> 10,9</td><td> 25,6</td><td> 22,0</td><td> 0,40</td><td> 1,52</td><td> 0,25</td>

179 768 continuation of Table C

<td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td><td> 6</td><td> 7</td><td> 8</td>

<td>IX</td><td> 3,5</td><td> 10,9</td><td> 25,1</td><td> 21,5</td><td> 0,40</td><td> 1,86</td><td> 0,26</td>

<td>X</td><td> 10,0</td><td> 11,1</td><td> 29,9</td><td> 25,8</td><td> 0,35</td><td> 1,87</td><td> 0,62</td>

<td>XI</td><td> 8,7</td><td> 11,1</td><td> 28,9</td><td> 24,8</td><td> 0,35</td><td> 1,99</td><td> 0,60</td>

<td>XII</td><td> 5,5</td><td> 11,0</td><td> 26,6</td><td> 22,3</td><td> 0,35</td><td> 1,73</td><td> 0,36</td>

<td>XIII</td><td> 4,8</td><td> 11,0</td><td> 26,0</td><td> 21,7</td><td> 0,35</td><td> 2,00</td><td> 0,37</td>

<td>XIV</td><td> 10,0</td><td> 11,0</td><td> 30,0</td><td></td><td></td><td> 1,50</td><td> 0,50</td>

<td>XV</td><td> 14,0</td><td> 11,0</td><td> 33,0</td><td></td><td></td><td> 1,36</td><td> 0,58</td>

<td>XVI</td><td> 9,8</td><td> 11,0</td><td> 29,8</td><td></td><td></td><td> 1,94</td><td> 0,64</td>

<td>XVII</td><td> 13,0</td><td> 11,0</td><td> 32,0</td><td></td><td></td><td> 1,92</td><td> 0,78</td>

<td>XVIII</td><td> 8,6</td><td> 11,0</td><td> 28,9</td><td></td><td></td><td> 2,07</td><td> 0,62</td>

<td>nineteenth</td><td> 11,0</td><td> 11,0</td><td> 31,0</td><td></td><td></td><td> 2,09</td><td> 0,74</td>

<td>XX</td><td> 5,4</td><td> 11,0</td><td> 26,5</td><td></td><td></td><td> 1,85</td><td> 0,38</td>

<td>XXI</td><td> 7,7</td><td> 11,0</td><td> 27,7</td><td></td><td></td><td> 1,77</td><td> 0,45</td>

As a result of the changes in Examples 14 and 20, coatings with a thickness of 730 nm and a Sb / Sn molar ratio of 0.10 were obtained. In both cases, the properties were essentially the same as in the original examples XIV and XX.

The coated product in all examples had a blue hue with a predominant wavelength (λο), between 470-490 nm and a haze value of 0.7-1.1.

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