Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/04—Glass compositions containing silica
  • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
  • C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
  • C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
  • C03C3/087—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal containing calcium oxide, e.g. common sheet or container glass

Definitions

• the field of the invention is that of high energy transmission glasses, used in particular in photovoltaic modules or solar mirrors.
• a transmission energy measured according to the ISO9050 standard between the wavelengths 300 and 2500 nm.
• the energy transmission is measured according to this standard and given for a thickness of 3.85 mm.
• a light transmission calculated between the wavelengths of 380 and 780 nm according to the ISO9050 standard, and measured with the illuminant D65 (TLD) as defined by the ISO / IEC 10526 standard by considering the CIE 1931 colorimetric reference observer as defined by ISO / IEC 10527.
• TLD illuminant D65
• the light transmission is measured according to this standard and given for a thickness of 3.85 mm at a solid observation angle of 2 °.
• ferric Fe 3+ ions gives the glass a slight absorption of visible light of short wavelength and a stronger absorption in the near ultraviolet (absorption band centered on 380 nm), whereas the presence of Ferrous Fe 2+ ions (sometimes expressed as FeO oxide) cause high absorption in the near infrared (absorption band centered at 1050 nm).
• Fe 3+ ferric ions give the glass a slight yellowing, while ferrous Fe 2+ ions give a pronounced blue-green color.
• increasing the total iron content increases the absorption in the visible and the infrared, to the detriment of light and energy transmission.
• a high concentration of Fe 2+ ferrous ions leads to a decrease in energy transmission.
• CeO 2 cerium oxide
• the object of the invention is in particular to overcome the drawbacks of the prior art, that is to say to provide a glass sheet with high energy transmission.
• an objective of the invention in at least one of its embodiments, is to provide a glass sheet with high energetic transmission (via in particular an oxidation of the glass) and which is kept significantly stable over time.
• Another object of the invention is to provide a solution to the disadvantages of the prior art which is simple and economical. 4. Presentation of the invention
• the invention relates to a glass sheet having a composition which comprises, in a content expressed as percentages by total weight of glass:
• the composition comprises a ratio of manganese / (total iron) of 1 to 8.5, the manganese content being expressed in the form of MnO in percentage by weight relative to the total weight of the glass.
• the invention is based on a completely new and inventive approach because it solves the disadvantages of the prior art and solve the technical problem.
• the inventors have in fact surprisingly demonstrated, for so-called "extra-clear" glasses, that it is possible to obtain the oxidizing effect of manganese while controlling the coloring that it can induce and by limiting the solarization phenomenon appearing with time.
• the inventors have thus discovered that a weight ratio of manganese / (total iron) ranging from 1 to 8.5, combined with the other glass composition criteria defined above, makes it possible to obtain a significant increase in the energetic transmission of the glass sheet.
• FIG. 1 represents the effect of the weight ratio manganese / ( total iron) on the energetic transmission of glass sheets according to the invention and according to the state of the art
• FIG. 2 represents the effect over time of UV exposure on the energetic transmission of glass sheets according to the invention and according to the state of the art.
• the composition comprises a total iron content (expressed as Fe 2 O 3 ) ranging from 0.002 to 0.03% by weight relative to the total weight of the glass.
• This maximum value of total iron content makes it possible to significantly increase the energy transmission of the glass sheet compared to a clear glass. The minimum value makes it possible not to penalize too much the cost of the glass because of such low values often require very pure raw materials expensive or a purification of these.
• the composition comprises a total iron content (expressed as Fe 2 O 3 ) ranging from 0.002 to 0.02% by weight relative to the total weight of the glass.
• a total iron content (expressed as Fe 2 O 3 ) less than or equal to 0.02% by weight makes it possible to further increase the energy transmission of the glass sheet.
• the composition comprises a total iron content (expressed as Fe 2 O 3 ) ranging from 0.005 to 0.02% by weight relative to the total weight of the glass.
• the composition of the invention comprises a manganese / (total iron) ratio of 2.5 to 6.5, the manganese content being expressed as MnO as a percentage by weight relative to the total weight of the glass.
• a range of weight ratio manganese / (total iron) makes it possible to further increase the energy transmission of the glass sheet.
• the composition comprises a manganese content (expressed as MnO) of 0.005 to 0.2% by weight relative to the total weight of the glass.
• the composition comprises a content of manganese (expressed as MnO) of 0.01 to 0.2% by weight relative to the total weight of the glass.
• the composition comprises a manganese content (expressed as MnO) of 0.01 to 0.15% by weight relative to the total weight of the glass.
• the composition comprises a manganese content (expressed as MnO) of 0.01 to 0.1% by weight relative to the total weight of the glass.
• the composition has a redox of 0.01 to 0.4. This range of redox makes it possible to obtain very satisfactory optical properties and in particular, in terms of energy transmission.
• the composition has a redox of 0.03 to 0.3.
• the composition has a redox of 0.05 to 0.25.
• the composition of the glass sheet may comprise, in addition to the impurities contained in particular in the raw materials, a small proportion of additives (such as agents which assist the melting or refining of the glass) or of elements from the dissolution of the refractories constituting the melting furnaces.
• additives such as agents which assist the melting or refining of the glass
• the composition of the glass sheet comprises a cerium content (expressed as CeO 2 ) ⁇ 0.02% by weight per relative to the total weight of the glass.
• the composition of the glass sheet comprises a cerium content (expressed as CeO 2 ) ⁇ 0.01% by weight relative to the total weight of the glass.
• the composition of the glass sheet comprises a cerium content (expressed as CeO 2 ) ⁇ 0.005% by weight relative to the total weight of the glass.
• the composition of the glass sheet comprises a vanadium content (expressed as V 2 O 5 ) ⁇ 0.01% by weight relative to the total weight of the glass.
• the composition of the glass sheet comprises a vanadium content (expressed as V 2 O 5 ) ⁇ 0.005% by weight relative to the total weight of the glass.
• the composition comprises a vanadium content (expressed as V 2 O 5 ) ⁇ 0.01% by weight relative to the total weight of the glass and a cerium content (expressed in the form of CeO 2 ) ⁇ 0.02% by weight relative to the total weight of the glass.
• the composition comprises a vanadium content (expressed as V 2 O 5 ) ⁇ 0.005% by weight relative to the total weight of the glass and a cerium content (expressed as CeO 2 ) ⁇ 0.01 % by weight relative to the total weight of the glass.
• the composition comprises a vanadium content (expressed as V 2 O 5 ) ⁇ 0.005% by weight relative to the total weight of the glass and a cerium content (expressed as CeO 2 ) ⁇ 0.005% by weight relative to the total weight of the glass.
• the composition of the glass sheet comprises an antimony content (expressed as Sb 2 O 3 ) ⁇ 0.2% by weight relative to the total weight of the glass. Higher levels of antimony, coupled with manganese, lead to the appearance of the phenomenon of solarization.
• the composition of the glass sheet comprises an antimony content (expressed as Sb 2 O 3 ) ⁇ 0.15% by weight relative to the total weight of the glass.
• the composition of the glass sheet comprises an arsenic content (expressed as As 2 O 3 ) ⁇ 0.01% by weight relative to the total weight of the glass.
• the composition of the glass sheet comprises a chromium content (expressed as Cr 2 O 3 ) ⁇ 0.01% by weight relative to the total weight of the glass.
• the glass sheet according to the invention preferably has an energy transmission (TE), measured for a thickness of 3.85 mm, of at least 89%.
• the glass sheet according to the invention has an energy transmission (TE), measured for a thickness of 3.85 mm, of at least 90%, and more preferably, of at least 91%.
• the glass sheet according to the invention preferably has a light transmission, measured with the illuminant D65 (TLD), according to the ISO9050 standard and for a thickness of 3.85 mm, of at least 90.5%.
• TLD illuminant D65
• the glass sheet according to the invention may be a glass sheet obtained by a float, rolling or any other known method for producing a glass sheet from a molten glass composition.
• the glass sheet is a float glass sheet.
• Float glass sheet means a glass sheet formed by the float process (or "float"), of pouring the molten glass on a bath of molten tin, under reducing conditions.
• a sheet of float glass comprises, in known manner, a face called “tin face", that is to say a tin-enriched side in the mass of the glass near the surface of the sheet.
• tin enrichment is meant an increase in the tin concentration relative to the composition of the core glass which may be substantially zero (tin free) or not.
• the glass sheet according to the invention preferably constitutes the protective substrate (or cover) of the photovoltaic cells.
• the glass sheet is coated with at least one thin transparent and electrically conductive layer. This embodiment is advantageous for photovoltaic applications.
• the transparent and conductive thin layer is disposed on the internal face, that is to say between the glass sheet and the solar cells.
• a transparent and conductive thin layer according to the invention may, for example, be a layer based on SnO 2 : F, SnO 2 : Sb or ITO (indium tin oxide), ZnO: Al or still ZnO: Ga.
• the glass sheet is coated with at least one antireflective (or anti-reflective) layer.
• This embodiment is advantageous in the case of photovoltaic applications in order to maximize the energy transmission of the glass sheet and, for example, to increase the efficiency of the solar module comprising this sheet as a substrate (or cover) covering photovoltaic cells.
• the antireflective layer is disposed on the outer face, that is to say on the sun side.
• An antireflective layer according to the invention may, for example, be a porous silica layer with a low refractive index or it may consist of several layers (stack), in particular a stack of layers of dielectric material alternating layers at low levels. and high indices of refraction and ending with a low refractive index layer.
• the glass sheet is coated with at least one transparent and electrically conductive thin layer on one side and at least one antireflective layer on the other side.
• the glass sheet is coated with at least one antireflective layer on each of its faces.
• the glass sheet is coated with at least one anti-fouling layer.
• an antifouling layer may be combined with a thin transparent and electrically conductive layer deposited on the opposite side.
• Such an antifouling layer may also be combined with an antireflective layer deposited on the same face, the antifouling layer being outside the stack and thus covering the antireflective layer.
• the glass sheet is coated with at least one mirror layer.
• a mirror layer is for example a silver-based layer. This embodiment is advantageous in the case of solar mirror applications (planes or parabolic).
• the glass sheet according to the invention can be integrated in a multiple glazing (in particular double or triple).
• Multiple glazing means a glazing that includes at least two sheets of soft glass a space filled with gas or under vacuum between each pair of sheets.
• the glass sheet according to the invention can also be laminated and / or tempered and / or hardened and / or curved.
• the invention also relates to a solar photovoltaic module or a mirror for the concentration of solar energy, comprising at least one glass sheet according to the invention.
• Manganese was incorporated in each case as MnO 2 .
• the contents of the components were kept fixed with the exception of the amount of manganese.
• the weight ratio manganese / (total iron) is therefore variable from one glass sample to another.
• Composition 1 Content [% by weight]
• Composition 2 Content [% by weight]
• the optical properties of each glass sample in sheet form were determined and in particular, the energy transmission (TE) was measured according to ISO9050 for a thickness of 3.85 mm.
• the TE values were determined to verify whether the energy transmission gain due to the oxidative effect of manganese is greater than the transmission loss due to staining caused by said manganese.
• FIG. 1 (a) represents, for each of compositions 1 and 2, the difference in energy transmission ( ⁇ ) between an extra-clear glass according to the state of the art (reference) in which the manganese has not been added intentionally and is therefore present in trace amounts only (manganese content in the form of MnO ⁇ 15 ppm by weight) and each of the leaves of glass with variable manganese / (total iron) weight ratios.
• Figure 1 (b) is an enlargement of Figure 1 (a).
• a positive ⁇ therefore corresponds to a gain in energetic transmission compared to a usual extra-clear glass (manganese / (total iron) ⁇ 0) and a negative ⁇ corresponds to a loss in energetic transmission.
• TE values for a thickness of 3.85 mm were also evaluated for these same glass sheets over a period of 196 hours of exposure under a UV lamp (Philips HP 125R) in order to verify the stability of the energy transmission in solarization condition. The results obtained are illustrated in FIG.
• the glass sheets according to the invention have a TE which is significantly stable over time under the effect of UV irradiation (absence of solarization observed), especially in comparison with a sheet of glass comprising cerium.
• the latter solarizes and shows a drastic decrease in TE in time under the effect of UV (loss of more than 2% in TE after 196 hours).
• This figure also shows that the invention makes it possible to maintain a stability in time under the UV comparable to the "extra-clear" glass sheet according to the state of the art not comprising manganese.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Glass Compositions (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=51356361

Family Applications (1)

Country Status (1)

• 2012
  • 2012-09-27 EP EP12762613.3A patent/EP2780293A1/de not_active Ceased

Non-Patent Citations (2)

Similar Documents

Legal Events