Method for forming a layer of coloured glass on a glass substrate by flame pyrolysis

Abstract

A process includes the formation of a colored glass layer on a glass substrate by flame pyrolysis of a solution including at least one precursor of a cobalt, iron, manganese, chromium, silver, copper, gold or selenium oxide, alone or as a mixture of several of them. Moreover, a glass substrate is coated with a layer of colored glass obtained by such a process.

Claims

1. A process comprising depositing a colored glass layer on a surface of a glass substrate by flame pyrolysis of a solution comprising at least one first precursor of a cobalt, iron, manganese, chromium, silver, copper, gold or selenium oxide, alone or as a mixture of several of them, said solution further comprising a second precursor of SiO.sub.2 and at least one third precursor selected from the group consisting of B.sub.2O.sub.3, Na.sub.2O, LiO, CaO and any combination thereof, wherein the depositing includes introducing said solution including the first, second and third precursors into a burner and then decomposing the first, second and third precursors in solution in the burner to form silicate glass nanoparticles including SiO.sub.2 and at least one material selected from the group consisting of B.sub.2O.sub.3, Na.sub.2O, LiO, CaO and any combination thereof and then depositing the silicate glass nanoparticles on said glass substrate at a temperature between ambient temperature and 500 C. to form the colored glass layer on the surface of the glass substrate, said colored glass layer consisting of said glass nanoparticles.

2. The process as claimed in claim 1, wherein said first precursors consist of organometallic compounds and/or salts.

3. The process as claimed in claim 1, wherein said first precursors are soluble in alcoholic solution.

4. The process as claimed in claim 1, wherein a distance from the burner to the glass substrate is at most equal to 10 mm.

5. A glass substrate coated with a layer of colored glass obtained by a process as claimed in claim 1, wherein a thickness of the layer of colored glass is between 50 and 10 000 nm.

6. The process as claimed in claim 1, wherein the solution including the first, second and third precursors introduced into the burner includes tetraethoxysilane (TEOS), aluminum tri(sec-butoxide), triethoxyborane, magnesium methoxyethoxide, calcium methoxyethoxide, potassium t-butoxide and cobalt acetyl acetonate.

7. The process as claimed in claim 1, wherein the solution including the first, second and third precursors introduced into the burner includes tetraethoxysilane (TEOS), triethoxyborane, sodium nitrate, lithium ethoxide and cobalt acetylacetonate.

8. The process as claimed in claim 1, wherein the solution including the first, second and third precursors introduced into the burner includes tetraethoxysilane (TEOS), triethoxyborane, sodium nitrate, lithium ethoxide, cobalt acetylacetonate and calcium methoxyethoxide.

Description

EXAMPLE 1

(1) A 1% by weight cobalt acetylacetonate solution is prepared which has the following composition (amounts shown in grams):

(2) TABLE-US-00001 Absolute ethanol 480 (g) Tetraethoxysilane (TEOS) 65 Aluminum tri(sec-butoxide) 10 Triethoxyborane 55 Magnesium methoxyethoxide 5 Calcium methoxyethoxide 8 Potassium t-butoxide 3 Cobalt acetylacetonate 1.5 Hydrochloric acid 2

(3) A layer of blue glass is formed by flame pyrolysis on a 10 cm10 cm sample of soda-lime glass. The above solution is sprayed onto the sample in the flame with the orifice of a burner in the form of a slit with a length of 20 cm.

(4) The flow rates employed in the burner are:

(5) 2 ml/min of the above solution,

(6) 160 l/min of air and

(7) 8 l/min of propane.

(8) The burner is moved above the glass sample at an unchanging distance of 5 mm and at a speed of 3 m/min.

(9) The glass sample is at a temperature of between 450 and 600 C.

(10) Thirty passes of the burner above the sample are carried out.

(11) The thickness of the layer deposited is between 200 and 600 nm.

(12) The coated sample is blue in transmission and in reflection.

EXAMPLE 2

(13) A 500 ml solution in ethanol of the following oxide precursors is prepared:

(14) Tetraethoxysilane

(15) Triethoxyborane

(16) Sodium nitrate

(17) Lithium ethoxide and

(18) Cobalt acetylacetonate.

(19) The amounts are such that the blue glass of the layer which is formed by flame pyrolysis comprises, as % by weight:

(20) TABLE-US-00002 SiO.sub.2 56 (%) B.sub.2O.sub.3 12 Na.sub.2O 28 LiO 2 CoO 2

(21) The conditions of example 1 are reproduced but with a flow rate of the solution of precursors of 1 ml/min.

(22) The distance from the burner to the glass sample is 4 mm.

(23) The sample is at a temperature of between 500 and 600 C.

(24) Twelve passes of the burner above the sample are carried out here.

(25) The thickness of the layer deposited is between 50 and 150 nm.

(26) The coated sample is blue in transmission and in reflection.

EXAMPLE 3

(27) Example 2 is reproduced, additionally using calcium methoxyethoxide as CaO precursor.

(28) The composition of the blue glass layer formed by flame pyrolysis is, as % by weight:

(29) TABLE-US-00003 SiO.sub.2 74 (%) Na.sub.2O 14 CaO 10.2 CoO 1.8

(30) The operating conditions and the observations with regard to the product obtained are the same as in example 2.

(31) In the three examples, the layer formed is dense, as may be observed with a scanning electron microscope.