Aqueous solutions for cleaning glass articles and methods of use thereof

Abstract

In accordance with an embodiment of the present disclosure, an aqueous solution for cleaning a glass article may include: water; hydrochloric acid, nitric acid, phosphoric acid, organic acid and combinations thereof; and at least one of a positively charged surfactant and a metal salt. The aqueous solution may include from 0.01 wt.% to 1 wt.% of the positively charged surfactant, based on the total weight of the aqueous solution. The concentration of the metal salt in the aqueous solution may be 0.1 M to 1 M. The aqueous solution may have a pH of 0 to 4.

Description

[0001] This application claims priority to U.S. Provisional Application No. 63 / 428,456, filed on November 29, 2022, the content of which is incorporated herein by reference in its entirety. Technical Field

[0002] This specification generally relates to aqueous solutions, and more particularly, to aqueous solutions that can be used to clean glass articles. Background Art

[0003] In glass manufacturing processes, glass cleaning accompanies many steps in glass finishing. By way of example, and without limitation, glass articles can be cleaned after cutting, and glass articles can be cleaned after polishing. Conventional cleaning solutions can include acids, and their pH values can be 1 - 3. However, some glass articles are not durable in such acid solutions. Using a conventional acid cleaning solution on such glass articles may cause the glass articles to be etched, and the etching may cause optical defects in the glass articles, such as color shift of the glass articles. For example, the etching can cause some glass articles to exhibit a blue tint.

[0004] Accordingly, there is a need for aqueous solutions for cleaning glass articles and methods of using such aqueous solutions to clean glass articles that reduce the rate of formation of optical defects (such as color shift) in the glass articles when cleaning the glass articles. The present disclosure addresses this need and other needs. Summary of the Invention

[0005] According to a first aspect of the present disclosure, an aqueous solution for cleaning a glass article comprises: water; at least one of hydrochloric acid, nitric acid, phosphoric acid, organic acids, and combinations thereof; and at least one of the following: a positively charged surfactant, wherein the aqueous solution comprises 0.01 wt.% to 1 wt.% of the positively charged surfactant based on the total weight of the aqueous solution; and a metal salt, wherein the concentration of the metal salt is 0.1 M to 1 M; wherein the pH of the aqueous solution is 0 to 4.

[0006] A second aspect of the present disclosure may include the first aspect, wherein the aqueous solution comprises the positively charged surfactant.

[0007] A third aspect of the present disclosure may include the second aspect, wherein the positively charged surfactant comprises a quaternary ammonium cation.

[0008] A fourth aspect of the present disclosure may include the second aspect or the third aspect, wherein the molecular weight of the positively charged surfactant is 10,000 Da to 400,000 Da.

[0009] The fifth aspect of the present disclosure may include any one of the second to fourth aspects, wherein the surfactant comprises an anion selected from Cl - and Br - and the like.

[0010] The sixth aspect of the present disclosure may include any one of the second to fifth aspects, wherein the positively charged surfactant comprises poly(diallyldimethylammonium chloride), cetyltrimethylammonium bromide, or a combination thereof.

[0011] The seventh aspect of the present disclosure may include any one of the first to sixth aspects, wherein the aqueous solution comprises the metal salt.

[0012] The eighth aspect of the present disclosure may include the seventh aspect, wherein the metal salt comprises a metal cation with a +1 charge.

[0013] The ninth aspect of the present disclosure may include the seventh aspect or the eighth aspect, wherein the metal salt comprises LiCl, NaCl, CsCl, KCl, KNO3, or a combination thereof.

[0014] The tenth aspect of the present disclosure may include any one of the first to ninth aspects, wherein the aqueous solution comprises an organic acid.

[0015] The eleventh aspect of the present disclosure may include the tenth aspect, wherein the organic acid comprises citric acid, acetic acid, oxalic acid, or a combination thereof.

[0016] The twelfth aspect of the present disclosure may include any one of the first to eleventh aspects, wherein the aqueous solution comprises 3 wt.% to 0.03 wt.% hydrochloric acid.

[0017] The thirteenth aspect of the present disclosure may include any one of the first to twelfth aspects, wherein the aqueous solution comprises 0.1 wt.% to 5 wt.% citric acid.

[0018] The fourteenth aspect of the present disclosure may include any one of the first to thirteenth aspects, wherein the concentration of H3O + in the aqueous solution is 0.0001 M to 1 M.

[0019] The fifteenth aspect of the present disclosure may include any one of the first to fourteenth aspects, wherein the pH of the aqueous solution is 1 to 4.

[0020] According to a sixteenth aspect of the present disclosure, a method for cleaning a glass article includes contacting the glass article with an aqueous solution to form a cleaned glass article, the aqueous solution comprising: water; at least one of hydrochloric acid, nitric acid, phosphoric acid, organic acids, and combinations thereof; and at least one of the following: a positively charged surfactant, wherein the aqueous solution comprises 0.01 wt.% to 1 wt.% of the positively charged surfactant based on the total weight of the aqueous solution; and a metal salt, wherein the concentration of the metal salt is 0.1 M to 1 M; wherein the pH of the aqueous solution is 0 to 4.

[0021] A seventeenth aspect of the present disclosure may include the sixteenth aspect, wherein the contacting of the glass article with the aqueous solution is carried out at a temperature of 20°C to 70°C.

[0022] An eighteenth aspect of the present disclosure may include the sixteenth aspect or the seventeenth aspect, wherein the time for which the glass article is contacted with the aqueous solution is 0.5 minutes to 30 minutes.

[0023] A nineteenth aspect of the present disclosure may include any one of the sixteenth to eighteenth aspects, wherein the glass article comprises 45 mol.% to 70 mol.% of SiO2, 15 mol.% to 25 mol.% of Al2O3, 0 mol.% to 6 mol.% of B2O3, 0 mol.% to 5 mol.% of P2O5, 0 mol.% to 10 mol.% of LiO2, 5 mol.% to 15 mol.% of Na2O, 0 mol.% to 1 mol.% of K2O, 0 mol.% to 5 mol.% of MgO, 0 mol.% to 1 mol.% of TiO2, and 0 mol.% to 1 mol.% of SnO2.

[0024] A twentieth aspect of the present disclosure may include any one of the sixteenth to nineteenth aspects, wherein the color shift of the cleaned glass article is less than or equal to 1.

[0025] A twenty - first aspect of the present disclosure may include any one of the sixteenth to twentieth aspects, wherein the haze of the cleaned glass article is less than or equal to 0.03%.

[0026] A twenty - second aspect of the present disclosure may include any one of the sixteenth to twenty - first aspects, wherein the method includes an initial step of contacting the glass article with CeO2 particles, wherein contacting the glass article with the CeO2 particles polishes at least a portion of the glass article.

[0027] A twenty - third aspect of the present disclosure may include the twenty - second aspect, wherein the particle size of the CeO2 particles is 0.6 μm to 3 μm.

[0028] The twenty-fourth aspect of the present disclosure may include the twenty-second aspect or the twenty-third aspect, wherein the surface of the cleaned glass article is substantially free of the CeO2 particles.

[0029] The twenty-fifth aspect of the present disclosure may include any one of the sixteenth to twenty-fourth aspects, wherein the method further comprises contacting the cleaned glass article with an alkaline solution having a pH of 10 to 14.

[0030] The twenty-sixth aspect of the present disclosure may include the twenty-fifth aspect, wherein the alkaline solution comprises KOH, NaOH, or a combination thereof.

[0031] The twenty-seventh aspect of the present disclosure may include the twenty-fifth aspect or the twenty-sixth aspect, wherein the cleaned glass article is contacted with the alkaline solution for a time of 2 minutes to 12 minutes.

[0032] Additional features and advantages will be set forth in the following detailed description, and will be partly apparent from the detailed description to those of ordinary skill in the art, or may be recognized by practicing the embodiments described herein, including the following detailed description, the claims, and the drawings.

[0033] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. The drawings are included to provide a further understanding of the various embodiments, and the drawings are incorporated in and constitute a part of this specification. The drawings illustrate the various embodiments described herein and, together with the detailed description, are used to explain the principles and operations of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Depicts the haze measured over time for a glass article treated with an aqueous solution according to an embodiment of Example 4;

[0035] Figure 2 Depicts the color shift measured for a polished glass article according to an embodiment of Example 5;

[0036] Figure 3A Depicts a scanning electron microscopy (SEM) image of the surface of a polished glass article according to an embodiment of Example 5;

[0037] Figure 3B Depicts a SEM image of the surface of a polished glass article according to an embodiment of Example 5;

[0038] Figure 3CDepicts a SEM image of the polished surface of a glass article according to an embodiment of Example 5;

[0039] Figure 3D Depicts a SEM image of the polished surface of a glass article according to an embodiment of Example 5;

[0040] Figure 4A Depicts a SEM image of the polished surface of a glass article according to an embodiment of Example 5;

[0041] Figure 4B Depicts a SEM image of the polished surface of a glass article according to an embodiment of Example 5;

[0042] Figure 4C Depicts a SEM image of the polished surface of a glass article according to an embodiment of Example 5;

[0043] Figure 4D Depicts a SEM image of the polished surface of a glass article according to an embodiment of Example 5;

[0044] Figure 5A Depicts a SEM image of the polished surface of a glass article according to an embodiment of Example 5;

[0045] Figure 5B Depicts the energy dispersive x-ray (EDX) spectrum of particles on the polished surface of a glass article according to an embodiment of Example 5;

[0046] Figure 5C Depicts the EDX spectrum of particles on the polished surface of a glass article according to an embodiment of Example 5; and

[0047] Figure 5D Depicts the EDX spectrum of particles on the polished surface of a glass article according to an embodiment of Example 5. Detailed Description

[0048] Now, various embodiments of the aqueous solution for cleaning glass articles and the method of cleaning glass articles using such an aqueous solution will be described in detail. Where possible, the same reference numerals will be used throughout the drawing sections to refer to the same or similar components. In an embodiment, the aqueous solution for cleaning glass articles may comprise: water; at least one of hydrochloric acid, nitric acid, phosphoric acid, organic acids, and combinations thereof; and at least one of a positively charged surfactant and a metal salt. The embodiments of the aqueous solution can be used in a method for cleaning glass articles, which method comprises contacting the glass article with the aqueous solution. Embodiments of the aqueous solution and its method of use will be described in further detail herein.

[0049] In this document, ranges can be expressed as from “about” a particular value and / or to “about” another particular value. When expressing such a range, another embodiment includes from a particular value and / or to another particular value. Similarly, when a value is expressed as an approximation by use of the antecedent “about”, it is to be understood that the particular value forms another embodiment. It is further to be understood that each of the endpoints of each range is significant both in relation to the other endpoint and independently of the other endpoint.

[0050] As used herein, unless the context clearly dictates otherwise, the singular forms “a”, “an” and “the” include plural referents. Thus, for example, unless the context clearly indicates otherwise, reference to “a” component includes aspects having two or more such components.

[0051] During the finishing process of glass articles, an aqueous solution containing an acid can be used to clean the glass articles. Conventional aqueous solutions may etch glass articles with poor acid resistance. Such etching may cause optical defects in the glass articles, such as color shift. Therefore, an aqueous solution that can be used to clean glass articles with poor durability in an acid solution is needed. Embodiments of the aqueous solutions described herein can be suitable for cleaning glass articles that may be etched in a conventional acidic cleaning solution. Without being bound by theory, including a positively charged surfactant, a metal salt, or both in the aqueous solution can reduce the dissolution rate of the glass in the aqueous solution. This, in turn, can reduce the formation of optical defects in the glass articles.

[0052] In an embodiment, the aqueous solution can contain water. By way of example, but not limitation, the water can include one or more of deionized water, tap water, distilled water, or fresh water. In an embodiment, one or more components in the aqueous solution can be dissolved in the water.

[0053] In an embodiment, the aqueous solution can contain at least one of hydrochloric acid, nitric acid, phosphoric acid, organic acids, and combinations thereof. In an embodiment, the organic acid can contain citric acid, acetic acid, oxalic acid, or combinations thereof. In an embodiment, the aqueous solution can contain more than one acid. By way of example, the aqueous solution can contain 2, 3, 4, 5, or more acids.

[0054] In an embodiment, the pH of the aqueous solution can be from 0 to 4. By way of example, but not limitation, the pH of the aqueous solution can be from 0 to 4, from 0.5 to 4, from 1 to 4, from 1.5 to 4, from 2 to 4, from 2.5 to 4, from 3 to 4, from 3.5 to 4, from 0 to 3.5, from 0 to 3, from 0 to 2.5, from 0 to 2, from 0 to 1.5, from 0 to 1, from 0 to 0.5, or any sub-range formed by any of these endpoints. In an embodiment, the concentration of hydronium ions (H3O + ) in the aqueous solution can be from 0.0001 molar concentration (M) to 1 M. By way of example, but not limitation, the H3O +The concentration can be from 0.0001 M to 1 M, from 0.001 M to 1 M, from 0.01 M to 1 M, from 0.1 M to 1 M, from 0.5 M to 1 M, from 0.0001 M to 0.5 M, from 0.0001 M to 0.1 M, from 0.0001 M to 0.01 M, from 0.0001 M to 0.001 M, or any sub-range formed by any of these endpoints.

[0055] In an embodiment, the aqueous solution may contain 0.03 wt.% to 3 wt.% hydrochloric acid. By way of example, but not limited thereto, the aqueous solution may contain hydrochloric acid in the range of 0.03 wt.% to 3 wt.%, 0.05 wt.% to 3 wt.%, 0.1 wt.% to 3 wt.%, 0.5 wt.% to 3 wt.%, 1 wt.% to 3 wt.%, 1.5 wt.% to 3 wt.%, 2 wt.% to 3 wt.%, 2.5 wt.% to 3 wt.%, 0.03 wt.% to 2.5 wt.%, 0.03 wt.% to 2 wt.%, 0.03 wt.% to 1.5 wt.%, 0.03 wt.% to 1 wt.%, 0.03 wt.% to 0.5 wt.%, 0.03 wt.% to 0.1 wt.%, 0.03 wt.% to 0.05 wt.%, or any sub-range formed by any of these endpoints.

[0056] In an embodiment, the aqueous solution may contain 0.1 wt.% to 5 wt.% citric acid. By way of example, but not limited thereto, the aqueous solution may contain citric acid in the range of 0.1 wt.% to 5 wt.%, 0.5 wt.% to 5 wt.%, 1 wt.% to 5 wt.%, 1.5 wt.% to 5 wt.%, 2 wt.% to 5 wt.%, 2.5 wt.% to 5 wt.%, 3 wt.% to 5 wt.%, 3.5 wt.% to 5 wt.%, 4 wt.% to 5 wt.%, 4.5 wt.% to 5 wt.%, 0.1 wt.% to 4.5 wt.%, 0.1 wt.% to 4 wt.%, 0.1 wt.% to 3.5 wt.%, 0.1 wt.% to 3 wt.%, 0.1 wt.% to 2.5 wt.%, 0.1 wt.% to 2 wt.%, 0.1 wt.% to 1.5 wt.%, 0.1 wt.% to 1 wt.%, 0.1 wt.% to 1.5 wt.%, or any sub-range formed by any of these endpoints.

[0057] Without being bound by theory, when the glassware is in contact with the aqueous solution, the acid content in the aqueous solution may be sufficient to clean the glassware. However, when the glassware is exposed to the aqueous solution, part of the glassware may dissolve in the aqueous solution. For example, when the glassware is exposed to an acid, metal ions in the glassware react with hydronium ions (H3O + ) or hydrogen ions (H +) Ion exchange, either or both, may generate stress in the Si-O bonds on the surface of the glass article. Water may erode the Si-O bonds in tension on the surface of the glass article, which may lead to partial dissolution of the glass article and form a porous structure on the surface of the glass article. Air may penetrate into the porous structure, which may reduce the surface refractive index of the glass article, resulting in color shift. As the pore size increases, the surface of the glass article may become rough and may scatter light, resulting in an increase in the haze of the glass article. Without being bound by theory, including a positively charged surfactant or a metal salt or both in an aqueous solution may reduce the dissolution rate of the glass in acid. In turn, this can reduce the color shift and haze generated by the glass article in contact with the aqueous solution.

[0058] In embodiments, the aqueous solution may comprise a positively charged surfactant. The positively charged surfactant may comprise a quaternary ammonium cation. In embodiments, the positively charged surfactant may comprise an anion selected from Cl - and Br - . By way of example, but not limitation, the positively charged surfactant may comprise poly(diallyldimethylammonium chloride), cetyltrimethylammonium bromide, or a combination thereof. In embodiments, the positively charged surfactant may consist of poly(diallyldimethylammonium chloride), cetyltrimethylammonium bromide, or a combination thereof.

[0059] In embodiments, the molecular weight of the positively charged surfactant may be from 10,000 Da to 400,000 Da. By way of example, but not limitation, the molecular weight of the positively charged surfactant may be from 10,000 Da to 400,000 Da, from 50,000 Da to 400,000 Da, from 100,000 Da to 400,000 Da, from 150,000 Da to 400,000 Da, from 200,000 Da to 400,000 Da, from 250,000 Da to 400,000 Da, from 300,000 Da to 400,000 Da, from 350,000 Da to 400,000 Da, from 10,000 Da to 350,000 Da, from 10,000 Da to 300,000 Da, from 10,000 Da to 250,000 Da, from 10,000 Da to 200,000 Da, from 10,000 Da to 150,000 Da, from 10,000 Da to 100,000 Da, from 10,000 Da to 50,000 Da, or any sub-range formed by any of these endpoints.

[0060] In an embodiment, based on the total weight of the aqueous solution, the aqueous solution may contain 0.01 wt.% to 1 wt.% of a positively charged surfactant. By way of example, but not limitation, the aqueous solution may contain the positively charged surfactant in the following amounts: 0.01 wt.% to 1 wt.%, 0.05 wt.% to 1 wt.%, 0.1 wt.% to 1 wt.%, 0.2 wt.% to 1 wt.%, 0.3 wt.% to 1 wt.%, 0.4 wt.% to 1 wt.%, 0.5 wt.% to 1 wt.%, 0.6 wt.% to 1 wt.%, 0.7 wt.% to 1 wt.%, 0.8 wt.% to 1 wt.%, 0.9 wt.% to 1 wt.%, 0.01 wt.% to 0.9 wt.%, 0.01 wt.% to 0.8 wt.%, 0.01 wt.% to 0.7 wt.%, 0.01 wt.% to 0.6 wt.%, 0.01 wt.% to 0.5 wt.%, 0.01 wt.% to 0.4 wt.%, 0.01 wt.% to 0.3 wt.%, 0.01 wt.% to 0.2 wt.%, 0.01 wt.% to 0.1 wt.%, 0.01 wt.% to 0.05 wt.%, or any subrange formed by any of these endpoints.

[0061] Without being bound by theory, including a positively charged surfactant in the aqueous solution may reduce the glass dissolution rate when the glass article is in contact with the aqueous solution. The positively charged surfactant may compete with H3O + and H + ions in the aqueous solution for ion exchange with mobile ions in the glass article. This can reduce the ion exchange rate and dissolution rate of the glass article. In addition, the positively charged surfactant can attach to the negatively charged surface of the glass article through electrostatic interactions. This can form a protective layer on the surface of the glass article. The protective layer can also reduce the dissolution of the glass article in the aqueous solution. As described above, reducing the dissolution rate of the glass article in the aqueous solution can reduce the color shift and haze generated by the glass article when it is in contact with the aqueous solution.

[0062] In an embodiment, the aqueous solution may contain a metal salt. The metal salt may contain a metal cation with a +1 charge. By way of example, but not limitation, the metal salt may contain Li + , Na + , K + , or Cs + cations. It should be understood that the cations of the metal salt are not necessarily limited to alkali metals. Upon consideration, any metal ion with a +1 charge can be a suitable cation for the metal salt. The anion of the metal salt is not necessarily limited. In an embodiment, the metal salt may contain any suitable anion. By way of example, but not limitation, the anion may contain Cl - , Br - , NO3- or any other suitable anion.

[0063] In embodiments, the metal salt can include LiCl, NaCl, CsCl, KCl, KNO3, or combinations thereof. In embodiments, the metal salt can consist of LiCl, or NaCl, or CsCl, or KCl, or KNO3, or combinations thereof.

[0064] In embodiments, the concentration of the metal salt in the aqueous solution can be from 0.1 M to 1 M. By way of example, but not limitation, the concentration of the metal salt in the aqueous solution can be from 0.1 M to 1 M, from 0.2 M to 1 M, from 0.3 M to 1 M, from 0.4 M to 1 M, from 0.5 M to 1 M, from 0.6 M to 1 M, from 0.7 M to 1 M, from 0.8 M to 1 M, from 0.9 M to 1 M, from 0.1 M to 0.9 M, from 0.1 M to 0.8 M, from 0.1 M to 0.7 M, from 0.1 M to 0.6 M, from 0.1 M to 0.5 M, from 0.1 M to 0.4 M, from 0.1 M to 0.3 M, from 0.1 M to 0.2 M, or any sub-range formed by any of these endpoints.

[0065] Without being bound by theory, including the metal salt in the aqueous solution can reduce the metal concentration gradient between the glass article and the aqueous solution. This may reduce the ion exchange rate between metal ions in the glass article and H3O + and H + ions in the aqueous solution, thereby potentially reducing the dissolution rate of the glass article. Reducing the dissolution rate of the glass article can reduce the formation of optical defects (such as color shift) in the glass article.

[0066] In embodiments, the aqueous solution can include a positively charged surfactant and a metal salt as described in the present disclosure. By way of example, but not limitation, the aqueous solution can include from 0.01 wt.% to 1 wt.% of a positively charged surfactant and a metal salt at a concentration of from 0.1 M to 1 M, as described in the present disclosure.

[0067] The aqueous solution can be used to clean glass articles. In embodiments, a method for cleaning a glass article can include contacting the glass article with the aqueous solution to form a cleaned glass article.

[0068] In an embodiment, the glass article may comprise from 45 mol.% to 70 mol.% of SiO2. By way of example, but not limitation, the glass article may comprise SiO2 in the following amounts: from 45 mol.% to 70 mol.%, from 50 mol.% to 70 mol.%, from 55 mol.% to 70 mol.%, from 60 mol.% to 70 mol.%, from 65 mol.% to 70 mol.%, from 45 mol.% to 65 mol.%, from 45 mol.% to 60 mol.%, from 45 mol.% to 55 mol.%, from 45 mol.% to 50 mol.%, or any sub-range formed by any of these endpoints. In an embodiment, the glass article may comprise from 15 mol.% to 25 mol.% of Al2O3. In an embodiment, the glass article may comprise from 0 mol.% to 6 mol.% of B2O3. In an embodiment, the glass article may comprise from 0 mol.% to 5 mol.% of P2O5. In an embodiment, the glass article may comprise from 0 mol.% to 10 mol.% of LiO2. In an embodiment, the glass article may comprise from 5 mol.% to 15 mol.% of Na2O. In an embodiment, the glass article may comprise from 0 mol.% to 1 mol.% of K2O. In an embodiment, the glass article may comprise from 0 mol.% to 5 mol.% of MgO. In an embodiment, the glass article may comprise from 0 mol.% to 1 mol.% of TiO2. In an embodiment, the glass article may comprise from 0 mol.% to 1 mol.% of SnO2. In an embodiment, suitable glass articles may include, for example but not limited to, glass manufactured and sold by Corning Incorporated under a glass brand.

[0069] In an embodiment, the contact of the glass article with the aqueous solution may be carried out at a temperature of from 20 °C to 70 °C (i.e., the temperature of the aqueous solution may be from 20 °C to 70 °C). By way of example, but not limitation, the contact of the glass article with the aqueous solution may be carried out at the following temperatures: from 20 °C to 70 °C, from 30 °C to 70 °C, from 40 °C to 70 °C, from 50 °C to 70 °C, from 60 °C to 70 °C, from 20 °C to 60 °C, from 20 °C to 50 °C, from 20 °C to 40 °C, from 20 °C to 30 °C, or any sub-range formed by any of these endpoints. Without being bound by theory, increasing the temperature of the contact of the glass article with the aqueous solution can increase the cleaning rate of the glass article. However, if the temperature of the contact of the glass article with the aqueous solution is increased too much, for example but not limited to reaching a temperature exceeding 70 °C, then the dissolution rate of the glass article may increase and optical defects may form in the glass article.

[0070] In an embodiment, the contact time of the glass article with the aqueous solution can be from 0.5 minutes to 30 minutes. By way of example, but not limitation, the contact time of the glass article with the aqueous solution can be from 0.5 minutes to 30 minutes, from 1 minute to 30 minutes, from 5 minutes to 30 minutes, from 10 minutes to 30 minutes, from 15 minutes to 30 minutes, from 20 minutes to 30 minutes, from 25 minutes to 30 minutes, from 0.5 minutes to 25 minutes, from 0.5 minutes to 20 minutes, from 0.5 minutes to 15 minutes, from 0.5 minutes to 10 minutes, from 0.5 minutes to 5 minutes, from 0.5 minutes to 1 minute, or any sub-range formed by any of these endpoints.

[0071] Contacting the glass article with the aqueous solution to form a cleaned glass article may cause a color shift in the cleaned glass article. In an embodiment, the color shift of the cleaned glass article can be less than or equal to 1. By way of example, the color shift of the cleaned glass article can be less than or equal to 1, less than or equal to 0.9, less than or equal to 0.8, less than or equal to 0.7, less than or equal to 0.6, less than or equal to 0.5, less than or equal to 0.4, less than or equal to 0.3, less than or equal to 0.2, or even less than or equal to 0.1. As described herein, the color shift can be measured using an X-Rite spectrophotometer. The color of the glass article can be measured before contacting the glass article with the aqueous solution, and the color of the cleaned glass article can be measured after contacting the glass article with the aqueous solution. The X-Rite spectrophotometer can represent color using the color coordinates a, b, and L*. The color shift can be calculated using the formula given in Equation 1:

[0072]

[0073] In Equation 1, a, b, and L* correspond to the color coordinates of the glass article before contacting the glass article with the aqueous solution, and a0, b0, and L*0 correspond to the color coordinates of the cleaned glass article after contacting the cleaned glass article with the aqueous solution.

[0074] In an embodiment, the haze of the cleaned glass article can be less than or equal to 0.03%. By way of example, but not limitation, the haze of the cleaned glass article can be less than or equal to 0.03%, less than or equal to 0.025%, less than or equal to 0.02%, less than or equal to 0.015%, less than or equal to 0.01%, or even less than or equal to 0.005%. As described herein, the haze can be measured using an X-Rite spectrophotometer set to the transmission haze mode. Without being bound by theory, a haze of 0.1% may be visible to the human eye, while the visibility of a haze of 0.03% may be significantly lower. Considering this, a cleaned glass article with a haze less than or equal to 0.03% may not have a haze visible to the human eye.

[0075] A method for cleaning glassware can be carried out on a polished glassware. The polished glassware can include contacting the glassware with cerium oxide (CeO2) particles. In an embodiment, the method for cleaning glassware described herein can include a preliminary step of contacting the glassware with CeO2 particles, wherein contacting the glassware with CeO2 particles can polish at least a portion of the glassware. In an embodiment, the glassware can be contacted with a slurry containing CeO2 particles as part of a chemical mechanical polishing process. In an embodiment, the chemical mechanical polishing process can include contacting the glassware with the slurry and a polishing pad. Without being bound by theory, the polishing pad can contact the glassware together with the particles in the slurry at various pressures and rotational speeds to mechanically polish the glassware. Additionally, the slurry can be alkaline and can slightly etch the surface of the glassware to chemically polish the surface of the glassware. It should be noted that any suitable chemical mechanical polishing process can be used to polish the glassware.

[0076] In an embodiment, the particle size of the CeO2 particles can be from 0.6 μm to 3 μm. By way of example, but not limitation, the particle size of the CeO2 particles can be from 0.6 μm to 3 μm, from 1 μm to 3 μm, from 1.5 μm to 3 μm, from 2 μm to 3 μm, from 2.5 μm to 3 μm, from 0.6 μm to 2.5 μm, from 0.6 μm to 2 μm, from 0.6 μm to 1.5 μm, from 0.6 μm to 1 μm, or any sub-range formed by any of these endpoints. Without being bound by theory, polishing the glassware by contacting the glassware with CeO2 particles may result in some CeO2 particles remaining on the surface of the glassware. These CeO2 particles can be removed by contacting the glassware with an acidic solution (such as the aforementioned aqueous solution). However, if the particle size of the CeO2 particles is too small, for example less than 0.6 μm, then it may be difficult to remove the CeO2 particles remaining on the surface of the glassware using the aqueous solution described herein.

[0077] In an embodiment, cleaning the surface of the glassware using the aqueous solution described herein can remove CeO2 particles from the surface of the glassware. In an embodiment, the surface of the cleaned glassware may be substantially free of CeO2 particles. In an embodiment, the CeO2 particles on the surface of the glassware can be detected by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. Without being bound by theory, CeO2 particles that are not removed from the surface of the glassware may affect the optical properties of the glassware and may cause color shift or haze in the glassware. Therefore, it may be advantageous to remove CeO2 particles from the surface of the glassware by contacting the glassware with the aqueous solution described herein.

[0078] In an embodiment, the method for cleaning a glass article may further comprise contacting the cleaned glass article with an alkaline solution. The alkaline solution may comprise water and any suitable base. By way of example, but not limitation, the alkaline solution may comprise KOH, NaOH, or a combination thereof. In an embodiment, the alkaline solution may comprise a commercially available alkaline solution such as, but not limited to, Semiclean KG cleaner.

[0079] In an embodiment, the pH of the alkaline solution may be from 10 to 14. By way of example, but not limitation, the pH of the alkaline solution may be from 10 to 14, from 10.5 to 14, from 11 to 14, from 11.5 to 14, from 12 to 14, from 12.5 to 14, from 13 to 14, from 13.5 to 14, from 10 to 13.5, from 10 to 13, from 10 to 12.5, from 10 to 12, from 10 to 11.5, from 10 to 11, from 10 to 10.5, or any subrange formed by any of these endpoints.

[0080] In an embodiment, the cleaned glass article may be contacted with the alkaline solution for a time period of from 2 minutes to 12 minutes. By way of example, but not limitation, the cleaned glass article may be contacted with the alkaline solution for the following times: from 2 minutes to 12 minutes, from 3 minutes to 12 minutes, from 4 minutes to 12 minutes, from 5 minutes to 12 minutes, from 6 minutes to 12 minutes, from 7 minutes to 12 minutes, from 8 minutes to 12 minutes, from 9 minutes to 12 minutes, from 10 minutes to 12 minutes, from 11 minutes to 12 minutes, from 2 minutes to 11 minutes, from 2 minutes to 10 minutes, from 2 minutes to 9 minutes, from 2 minutes to 8 minutes, from 2 minutes to 7 minutes, from 2 minutes to 6 minutes, from 2 minutes to 5 minutes, from 2 minutes to 4 minutes, from 2 minutes to 3 minutes, or any subrange formed by any of these endpoints.

[0081] In an embodiment, the cleaned glass article may be contacted with the alkaline solution at a temperature of from 20 °C to 70 °C (i.e., the temperature of the alkaline solution is from 20 °C to 70 °C). By way of example, but not limitation, the cleaned glass article may be contacted with the alkaline solution at the following temperatures: from 20 °C to 70 °C, from 30 °C to 70 °C, from 40 °C to 70 °C, from 50 °C to 70 °C, from 60 °C to 70 °C, from 20 °C to 60 °C, from 20 °C to 50 °C, from 20 °C to 40 °C, from 20 °C to 30 °C, or any subrange formed by any of these endpoints.

[0082] Without being bound by theory, after contacting the glass article with the aqueous solution, contacting the cleaned glass article with the alkaline solution can rinse any residual aqueous solution from the cleaned glass article and can neutralize any residual acid remaining on the surface of the cleaned glass article. This can prevent further dissolution of the glass article and can reduce the likelihood of optical defects in the glass article. In addition, contacting the cleaned glass article with the alkaline solution can remove materials that may have caused color shifts by the aqueous solution from the surface of the cleaned glass article. Thus, contacting the cleaned glass article with the alkaline solution can remove optical defects generated during the contact of the glass article with the aqueous solution.

[0083] Examples

[0084] The embodiments described herein will be further illustrated by the following examples.

[0085] Example 1 - Dissolution of Glass Articles in Aqueous Solutions

[0086] The mass loss of the glass article after contact with the aqueous cleaning solution was measured as described herein.

[0087] Measured using a 5 - digit balance The mass of the first sample of Glass 7. The first sample was contacted with a comparative aqueous solution containing 1.5 wt.% citric acid at a temperature of 60 °C for 5 minutes. The mass of the first sample was measured again using a 5 - digit balance, and the mass loss of the first sample was calculated. The mass change of the first sample was 4.5 mg.

[0088] Measured using a 5 - digit balance The mass of the second sample of Glass 7. The second sample was contacted with a first aqueous solution containing 1.5 wt.% citric acid and 0.1 wt.% PDADMAC at a temperature of 60 °C for 5 minutes. The mass of the second sample was measured again using a 5 - digit balance, and the mass loss of the second sample was calculated. The mass change of the second sample was 1.2 mg. The inclusion of 0.1 wt.% PDADMAC in the first aqueous solution reduced the mass change of the second glass sample by 74% relative to the first glass sample.

[0089] Measured using a 5 - digit balance The mass of the third sample of Glass 7. The third sample was contacted with a second aqueous solution containing 1.5 wt.% citric acid and 1 M KCl at a temperature of 60 °C for 5 minutes. The mass of the third sample was measured again using a 5 - digit balance, and the mass loss of the third sample was calculated. The mass change of the third sample was 0.5 mg. The inclusion of 1 M KCl in the second aqueous solution reduced the mass change of the third glass sample by 88% relative to the first glass sample.

[0090] Example 2 - Color Shift of Glassware

[0091] Measure the color shift of the glassware after contact with the aqueous cleaning solution as described herein.

[0092] Measure the color shifts of the first glass sample of Example 1, the second glass sample of Example 1, and the third glass sample of Example 1, respectively. Before and after contacting the samples with the aqueous solution, measure the colors of the first glass sample of Example 1, the second glass sample of Example 1, and the third glass sample of Example 1 using an X-Rite spectrophotometer. Then calculate the color shift of each sample using Equation 1 as described above. The color shifts of each of the first, second, and third glass samples of Example 1 are included in Table 1.

[0093] Contact The fourth sample of Glass 7 with the comparative aqueous solution of Example 1 at a temperature of 60 °C for 5 minutes. Then contact the fourth sample with a 4 wt.% Semiclean solution at a temperature of 60 °C under sonication for 10 minutes. Measure the color shift of the fourth glass sample, and the color shift is included in Table 1.

[0094] Contact The fifth sample of Glass 7 with the first aqueous solution of Example 1 at a temperature of 60 °C for 5 minutes. Then contact the fifth sample with a 4 wt.% Semiclean solution at a temperature of 60 °C under sonication for 10 minutes. Measure the color shift of the fifth glass sample, and the color shift is included in Table 1.

[0095] Contact The sixth sample of Glass 7 with the second aqueous solution of Example 1 at a temperature of 60 °C for 5 minutes. Then contact the sixth sample with a 4 wt.% Semiclean solution at a temperature of 60 °C under sonication for 10 minutes. Measure the color shift of the sixth glass sample, and the color shift is included in Table 1.

[0096] Table 1:

[0097]

[0098] As shown in Table 1, contacting the glassware with an aqueous solution comprising a positively charged surfactant or metal salt results in less color shift of the glassware. In addition, after contacting the glassware with the aqueous solution, contacting the glassware with the Semiclean solution further reduces the color shift of the glassware.

[0099] Example 3 - Variation of Color Shift of Glassware with Metal Salt Concentration

[0100] Measure the color shift of the glassware after contact with aqueous cleaning solutions containing different amounts of metal salts as described herein.

[0101] Contact Glass 7 samples with four aqueous solutions. Each aqueous solution includes 1.5 wt.% citric acid. The four aqueous solutions contain 1 M KCl, 0.5 M KCl, 0.1 M KCl, and 0.05 M KCl, respectively. Contact each sample with the aqueous solution at a temperature of 55 °C for a time of 2 minutes. Measure the color shift of the samples in contact with the aqueous solution as described above. The color shift information is included in Table 2.

[0102] Samples of Glass 7 that have been in contact with each of the four aqueous solutions are contacted with a 4 wt.% Semiclean solution at a temperature of 60 °C under sonication for 10 minutes. Measure the color shift of each sample that has been in contact with the aqueous solution and the Semiclean solution. The color shift information is included in Table 2.

[0103] Table 2:

[0104]

[0105]

[0106] As shown in Table 2, as the KCl concentration in the aqueous solution increases, the color shift of the glassware decreases. In addition, when the concentration of KCl is 1 M or 0.5 M, contacting the glassware with the Semiclean solution further reduces the color shift of the glassware.

[0107] Example 4 - Effectiveness of Aqueous Solutions Containing Metal Salts with Different Cation Charges.

[0108] Measure the effect of metal salts with cations of different charges in aqueous solutions as described herein.

[0109] Contact the glassware with the aqueous solution at 95 °C for 13 hours. The composition of the glassware is given in Table 3. Each aqueous solution includes 20 wt.% citric acid. The aqueous solutions include metal salts in which the metal cations carry a charge of +1, +2, or +3. The metal salts tested are AlCl3, CaCl2, CsCl, MgCl2, NaCl, LiCl, KCl, and FeCl3. The concentration of the metal salt in each aqueous solution is 1 M. In addition, a control aqueous solution without a metal salt is also tested. Measure the haze of the glass samples using an X-Rite spectrophotometer at times of 6 hours, 8 hours, and 13 hours. The haze data for each aqueous solution is included in Figure 1 this.

[0110] Table 3:

[0111] Component (wt%) <![CDATA[SiO2 (difference)]]> 52.71 <![CDATA[B2O3(ICP)]]> 4.39 <![CDATA[Al2O3]]> 27.22 <![CDATA[P2O5]]> 3.12 <![CDATA[LiO2(ICP)]]> 3.44 <![CDATA[Na2O]]> 8.08 <![CDATA[K2O]]> 0.1 MgO 0.72 <![CDATA[TiO2]]> 0.12 <![CDATA[SnO2]]> 0.1

[0112] As Figure 1 shown, the haze value of a glass article treated with an aqueous solution comprising a metal salt having a +3 charged metal cation is greater than the haze value of a glass article treated with a control aqueous solution not comprising a metal salt. Similarly, the haze value of a glass article treated with an aqueous solution comprising a metal salt having a +2 charged metal cation is greater than the haze value of a glass article treated with a control aqueous solution. At a measurement time of 13 hours, the haze value of a glass article treated with an aqueous solution comprising a metal salt having a +1 charged metal cation is less than the haze value of a glass article treated with a control aqueous solution.

[0113] Example 5 - Cleaning a Polished Glass Article with an Aqueous Solution

[0114] First Group Samples of Glass 7 were polished with a slurry comprising CeO2 particles having a particle size of 0.6 μm (Hastilite Fin from Universal Photonics, Inc.). Second Group Samples of Glass 7 were polished with a slurry comprising CeO2 particles having a particle size of 1.2 μm (Super Cerite 415 from Gerard Kluyskens Co., Inc.).

[0115] The polished samples were cleaned with one of three aqueous solutions. The first aqueous solution comprised 0.1 wt.% HCl. The second aqueous solution comprised 0.1 wt.% HCl and 0.1 wt.% PDADMAC, and the third aqueous solution comprised 0.1 wt.% HCL and 1 M KCl. The polished samples were contacted with the aqueous solution for a time of 2 minutes at 22°C. After the polished samples were contacted with one of the aqueous solutions, the polished samples were contacted with a 4 wt.% Semiclean solution at a temperature of 60°C under sonication for a time of 10 minutes. Some of the polished samples were not contacted with one of the three aqueous solutions. The optical properties of the cleaned samples were measured using an X-Rite spectrophotometer. The color shift of each of the cleaned samples is included in Figure 2 . It is considered that the color shift of the cleaned samples is mainly attributed to CeO2 residues that were not removed from the surface of the glass samples.

[0116] Scanning electron microscopy (SEM) images of the samples polished with 1.2 μm CeO2 particles are depicted in Figures 3A - 3D . Figure 3A Depicted is the surface of a polished sample that was not contacted with an aqueous solution or a Semiclean solution.Figure 3B Depicts a polished sample surface in contact with an aqueous solution containing 0.1 wt.% HCl. Figure 3C Depicts a polished sample surface in contact with an aqueous solution containing 0.1 wt.% HCl and 0.1 wt.% PDADMAC. Figure 3D Depicts a polished sample surface in contact with an aqueous solution containing 0.1 wt.% HCl and 1 M KCl.

[0117] SEM images of samples polished with 0.6 μm CeO2 particles are depicted in Figures 4A - 4D . Figure 4A Depicts a polished sample surface not in contact with an aqueous solution or a Semiclean solution. Figure 4B Depicts a polished sample surface in contact with an aqueous solution containing 0.1 wt.% HCl. Figure 4C Depicts a polished sample surface in contact with an aqueous solution containing 0.1 wt.% HCl and 0.1 wt.% PDADMAC. Figure 4D Depicts a polished sample surface in contact with an aqueous solution containing 0.1 wt.% HCl and 1 M KCl. As Figure 3A shown in -D and 4A-D, fewer particles were observed on the surface of the glassware polished with 1.2 μm CeO2 particles than on the surface of the glassware polished with 0.6 μm CeO2 particles.

[0118] As Figure 5A depicted in, particles were observed on the polished sample surface, which was polished with CeO2 of a particle size of 0.6 μm and contacted with an aqueous solution containing 0.1 wt.% HCl and 0.1 wt.% PDADMAC and a 4 wt.% semiclean solution, as described above. Analyzed by energy dispersive x-ray (EDX) spectrometry Figure 5A the particles 301, 302, and 303 depicted in. The EDX spectrum of particle 301 is depicted in Figure 5B , the EDX spectrum of particle 302 is depicted in Figure 5C , and the EDX spectrum of particle 303 is depicted in Figure 5D . As Figures 5B - 5D shown, each particle is a CeO2 particle.

[0119] The present disclosure relates to various embodiments of aqueous solutions for cleaning glass articles and methods of using such aqueous solutions. In an embodiment, an aqueous solution for cleaning a glass article may comprise water; at least one of hydrochloric acid, nitric acid, phosphoric acid, organic acids, and combinations thereof; and a positively charged surfactant and a metal salt. The aqueous solution may comprise 0.01 wt.% to 1 wt.% of the positively charged surfactant, based on the total weight of the aqueous solution. The concentration of the metal salt may be from 0.1 M to 1 M. Additionally, the pH of the aqueous solution may be from 0 to 4.

[0120] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Accordingly, this specification is intended to cover modifications and variations of the various embodiments described herein, provided that such modifications and variations fall within the scope of the appended claims and their equivalents.

Claims

1. An aqueous solution for cleaning glassware, the aqueous solution comprising: Water; At least one of hydrochloric acid, nitric acid, phosphoric acid, organic acids, and combinations thereof; and At least one of the following substances: A positively charged surfactant, wherein, based on the total weight of the aqueous solution, the aqueous solution comprises 0.01 wt.% to 1 wt.% of the positively charged surfactant; and A metal salt, wherein the concentration of the metal salt is 0.1 M to 1 M; Wherein the pH of the aqueous solution is 0 to 4.

2. The aqueous solution according to claim 1, wherein the aqueous solution comprises the positively charged surfactant.

3. The aqueous solution according to claim 2, wherein the positively charged surfactant comprises a quaternary ammonium cation.

4. The aqueous solution according to any one of claims 2 to 3, wherein the molecular weight of the positively charged surfactant is 10,000 Da to 400,000 Da.

5. The aqueous solution according to any one of claims 2 to 4, wherein the positively charged surfactant comprises a surfactant selected from Cl - and Br - anion.

6. The aqueous solution according to any one of claims 2 to 5, wherein the positively charged surfactant comprises poly(diallyldimethylammonium chloride), cetyltrimethylammonium bromide, or a combination thereof.

7. The aqueous solution according to any one of claims 1 to 6, wherein the aqueous solution comprises the metal salt.

8. The aqueous solution according to claim 7, wherein the metal salt comprises a metal cation with a +1 charge.

9. The aqueous solution according to any one of claims 7 to 8, wherein the metal salt comprises LiCl, NaCl, CsCL, KCl, KNO3, or a combination thereof.

10. The aqueous solution according to any one of claims 1 to 9, wherein the aqueous solution comprises an organic acid.

11. The aqueous solution according to claim 10, wherein the organic acid comprises citric acid, acetic acid, oxalic acid, or a combination thereof.

12. The aqueous solution according to any one of claims 1 to 11, wherein the aqueous solution comprises 3 wt.% to 0.03 wt.% of hydrochloric acid.

13. The aqueous solution according to any one of claims 1 to 12, wherein the aqueous solution comprises 0.1 wt.% to 5 wt.% of citric acid.

14. The aqueous solution according to any one of claims 1 to 13, wherein the concentration of H3O + in the aqueous solution is from 0.0001 M to 1 M.

15. The aqueous solution according to any one of claims 1 to 14, wherein the pH of the aqueous solution is 1 to 4.

16. A method for cleaning glassware, the method comprising: Contacting the glassware with an aqueous solution to form a cleaned glassware, the aqueous solution comprising: Water; At least one of hydrochloric acid, nitric acid, phosphoric acid, organic acids, and combinations thereof; and At least one of the following substances: A positively charged surfactant, wherein, based on the total weight of the aqueous solution, the aqueous solution comprises 0.01 wt.% to 1 wt.% of the positively charged surfactant; and a metal salt, wherein the concentration of the metal salt is 0.1 M to 1 M; Wherein the pH of the aqueous solution is 0 to 4.

17. The method according to claim 16, wherein the contacting of the glassware with the aqueous solution is carried out at a temperature of 20°C to 70°C.

18. The method according to any one of claims 16 to 17, wherein the glass article is in contact with the aqueous solution for 0.5 minutes to 30 minutes.

19. The method according to any one of claims 16 to 18, wherein the glass article comprises 45 mol.% to 70 mol.% of SiO2, 15 mol.% to 25 mol.% of Al2O3, 0 mol.% to 6 mol.% of B2O3, 0 mol.% to 5 mol.% of P2O5, 0 mol.% to 10 mol.% of LiO2, 5 mol.% to 15 mol.% of Na2O, 0 mol.% to 1 mol.% of K2O, 0 mol.% to 5 mol.% of MgO, 0 mol.% to 1 mol.% of TiO2, and 0 mol.% to 1 mol.% of SnO2.

20. The method according to any one of claims 16 to 19, wherein the color shift of the cleaned glass article is less than or equal to 1.

21. The method according to any one of claims 16 to 20, wherein the haze of the cleaned glass article is less than or equal to 0.03%.

22. The method according to any one of claims 16 to 21, wherein the method comprises an initial step of contacting the glass article with CeO2 particles, wherein contacting the glass article with the CeO2 particles polishes at least a portion of the glass article.

23. The method according to claim 22, wherein the particle size of the CeO2 particles is 0.6 μm to 3 μm.

24. The method according to any one of claims 22 to 23, wherein the surface of the cleaned glass article is substantially free of the CeO2 particles.

25. The method according to any one of claims 16 to 24, wherein the method further comprises contacting the cleaned glass article with an alkaline solution having a pH of 10 to 14.

26. The method according to claim 25, wherein the alkaline solution comprises KOH, NaOH, or a combination thereof.

27. The method according to any one of claims 25 to 26, wherein the cleaned glass article is in contact with the alkaline solution for 2 minutes to 12 minutes.

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