Protective coating for glass inner wall of container and preparation method of protective coating

Abstract

The invention discloses a protective coating for a glass inner wall of a container and a preparation method of the protective coating, and belongs to the technical field of coatings. The protective coating is of a composite film structure and comprises an inner layer composed of oxides of silicon, aluminum, zirconium and titanium and an outer layer composed of pure silicon oxide. And the inner layer comprises the following elements in percentage by mass: 80 to 100 percent of silicon element, 0 to 10 percent of aluminum element, 0 to 10 percent of zirconium element and 0 to 3 percent of titanium element based on the total mass of the silicon element, the aluminum element, the zirconium element and the titanium element being 100 percent. By adopting a specific double-layer composite structure, the gradient compact barrier with complementary functions is formed. The structure not only can synergistically block precipitation of various ions, but also has the advantages of firm combination and good thermal stability, so that the chemical stability and the service life of the glass container are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a protective coating for the inner wall of a container glass and its preparation method. Background Technology

[0002] Glass, due to its excellent thermal and chemical stability, is often used for transporting and storing liquid reagents, especially suitable for biopharmaceutical preparations and high-purity chemical reagents. However, because the reagent is in direct contact with the inner wall of the glass container, the migration of elemental ions at the interface is inevitable during long-term storage: some components in the glass dissolve in ionic form and enter the reagent, resulting in excessive levels of impurity ions, which in turn affects the quality of the reagent and, in severe cases, can even cause high-purity reagents to fail or pharmaceutical safety issues.

[0003] The main ions that dissolve into the reagent include alkali metal ions (such as sodium and potassium), alkaline earth metal ions (such as calcium, magnesium, and barium), and metal element ions such as aluminum, which are abundant in glass. Currently, inorganic silicon or organosilicon materials are often used to form single-layer, multi-layer, or even composite thin films on the inner wall of the glass to block the migration of these ions. However, the permeability of different element ions varies, and relying solely on silicon-based systems is insufficient to completely and effectively suppress the dissolution of all ions.

[0004] Therefore, in order to solve the above problems, the present invention provides a protective coating for the inner wall of a container glass and a method for preparing the same. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a protective coating for the inner wall of a container glass and a method for preparing the same.

[0006] The objective of this invention can be achieved through the following technical solutions: A protective coating for the inner wall of a container glass, the protective coating being a composite thin film structure comprising an inner layer composed of oxides of silicon, aluminum, zirconium, and titanium, and an outer layer composed of pure silicon oxide; the mass percentage of each element in the inner layer, based on the total mass of silicon, aluminum, zirconium, and titanium as 100%, is as follows: 80-100% silicon, 0-10% aluminum, 0-10% zirconium, and 0-3% titanium.

[0007] The method for preparing the above-mentioned protective coating includes the following steps: Step 1: Preparation of mixed sol: According to the mass ratio of the inner layer elements mentioned above, the corresponding silicon source, aluminum source, zirconium source and titanium source precursors are dissolved in organic solvent. At room temperature to 60°C, an acidic catalyst is added to adjust the pH value to 2-3. After reacting for 8-12 hours, the mixture is allowed to stand and age to obtain a mixed sol. Step 2: Coating and heat treatment: Immerse the clean glass container in the mixed sol for coating. The immersion time is 50-70 seconds, and the rate of lifting it out of the liquid surface is 0.5-1.5 mm / min. Then, pre-treat at 90-110℃ for 4-6 minutes, and then heat-treat at 450-520℃ for 8-12 minutes. Step 3: Secondary coating and heat treatment: Immerse the glass container treated in step 2 in pure silica sol for secondary coating for 50-70 seconds, followed by heat treatment at 450-520℃ for 8-12 minutes, finally forming the protective coating on the inner wall of the glass.

[0008] Ideally, the silicon source is tetraethyl orthosilicate.

[0009] Ideally, the aluminum source is aluminum nitrate.

[0010] Ideally, the zirconium source is one of zirconium oxynitrate, zirconium n-propoxide, or zirconium tert-butoxide.

[0011] Ideally, the titanium source is one of tetrabutyl titanate or titanium tetrachloride.

[0012] Ideally, the organic solvent is one of anhydrous ethanol, isopropanol, and n-butanol.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention overcomes the limitations of traditional single silicon-based coatings in terms of composition and function by adopting a multi-component composite system of silicon, aluminum, zirconium, and titanium oxides. This composite coating can simultaneously and effectively block the dissolution and migration of alkali metal ions, alkaline earth metal ions, and other metal ions in glass, achieving comprehensive and synergistic suppression of the precipitation of multiple ions, and significantly improving the universality and reliability of coating protection.

[0014] (2) Through the optimized sol-gel process and precisely controlled heat treatment regime, the preparation method of the coating sol is simple. The prepared coating is firmly bonded to the glass substrate and exhibits excellent thermal stability and mechanical durability. Even in acidic or alkaline environments, the coating can still maintain its structural integrity and is not easy to crack or peel off, ensuring the protective effect for long-term use.

[0015] (3) The present invention employs a specific double-layer composite structure to form a gradient barrier with complementary functions. This structure can not only achieve strong bonding and efficient barrier with the substrate through the inner layer, but also effectively block potential micro-defects in the inner layer through the outer layer, thereby constructing a denser and more perfect protective layer and greatly improving the overall barrier performance. Attached Figure Description

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a comparison chart of the Na ion precipitation concentrations in the examples and comparative examples; Figure 2 This is a comparison chart of the K ion precipitation concentrations in the examples and comparative examples; Figure 3 This is a comparison chart of the Ca ion precipitation concentrations in the examples and comparative examples; Figure 4 This is a comparison chart of the Mg ion precipitation concentrations in the examples and comparative examples; Figure 5 This is a comparison chart of the Al ion precipitation concentrations in the examples and comparative examples. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: The protective coating is a composite thin film structure, comprising an inner layer composed of silicon and aluminum oxides and an outer layer composed of pure silicon oxide; the mass percentage of each element in the inner layer is 95% silicon and 5% aluminum; the preparation method of the protective coating is as follows: Step 1: Preparation of mixed sol: Dissolve aluminum nitrate (aluminum source) in anhydrous ethanol and stir thoroughly until completely dissolved. Then add tetraethyl orthosilicate (silicon source), wherein the mass ratio of aluminum to silicon is 5:95. At 60°C, add dilute hydrochloric acid to adjust the pH to 2. After stirring continuously for 10 hours, let stand and age to obtain mixed sol. Step 2: First coating and heat treatment: Clean the 20ml sodium calcium silicate glass vial to be treated, invert it, immerse it in the above mixed sol, soak for 60s, lift it out of the liquid surface at a rate of 1mm / min, then pre-treat the container at 100℃ for 5min, and then heat treat it at 500℃ for 10min. Step 3: Secondary coating and heat treatment: The glass container treated in step 2 is immersed in pure silica sol for secondary coating for 60 seconds, followed by heat treatment at 500℃ for 10 minutes to finally form a protective coating.

[0020] Example 2: The protective coating is a composite thin film structure, comprising an inner layer composed of oxides of silicon, aluminum, and zirconium, and an outer layer composed of pure silicon oxide; the mass percentage of each element in the inner layer is: 94% silicon, 5% aluminum, and 1% zirconium; the preparation method of the protective coating is as follows: Step 1: Preparation of mixed sol: Dissolve aluminum nitrate (aluminum source) in anhydrous ethanol and stir thoroughly until completely dissolved. Then add tetraethyl orthosilicate (aluminum:silicon mass ratio of 5:94) to the mixed solution. At 60°C, add dilute hydrochloric acid to adjust the pH to 2 and continue stirring for 2 hours. Then slowly add zirconium oxynitrate at an aluminum:zirconium mass ratio of 5:1 and continue stirring at 60°C for 6 hours. After the reaction is complete, allow it to stand and age. Step 2: First coating and heat treatment: Clean the 20ml sodium calcium silicate glass vial to be treated, invert it, immerse it in the above mixed sol, soak for 60s, lift it out of the liquid surface at a rate of 1mm / min, then pre-treat the container at 100℃ for 5min, and then heat treat it at 500℃ for 10min. Step 3: Secondary coating and heat treatment: The glass container treated in step 2 is immersed in pure silica sol for secondary coating for 60 seconds, followed by heat treatment at 500℃ for 10 minutes to finally form a protective coating.

[0021] Example 3: The protective coating is a composite thin film structure, comprising an inner layer composed of silicon oxide and an outer layer composed of pure silicon oxide; the mass percentage of each element in the inner layer is 100% silicon; the preparation method of the protective coating is as follows: Step 1: Preparation of the mixed sol: Tetraethyl orthosilicate (silicon source) was dissolved in anhydrous ethanol. At 60°C, dilute hydrochloric acid was added to adjust the pH to 2-3. The mixture was stirred continuously for 8 hours and then allowed to stand for aging to obtain the mixed sol. Step 2: First coating and heat treatment: Clean the 20ml sodium calcium silicate glass vial to be treated, invert it, immerse it in the above mixed sol, soak for 60s, lift it out of the liquid surface at a rate of 1mm / min, then pre-treat the container at 100℃ for 5min, and then heat treat it at 500℃ for 10min. Step 3: Secondary coating and heat treatment: The glass container treated in Step 2 is immersed again in pure silica sol for coating for 60 seconds, followed by heat treatment at 500℃ for 10 minutes to finally form a protective coating.

[0022] Comparative Example 1: No treatment was applied to the sodium-calcium silicate glass vials.

[0023] Testing experiment: The vials prepared in the examples and comparative examples were filled with ultrapure water and heated to 121°C in an autoclave for a water resistance test. The concentration of ion precipitation and the membrane adhesion were measured. The data obtained are shown in Tables 1 and 2. Figure 1-5 As shown; Conclusion: This invention, through the adoption of a specific double-layer composite structure, forms a functionally complementary gradient dense barrier. This structure not only synergistically blocks the precipitation of multiple ions but also possesses advantages such as strong bonding and good thermal stability, thereby significantly improving the chemical stability and service life of glass containers. Experimental results show that this coating can significantly inhibit the dissolution of multiple ions (such as Na, K, Ca, Mg, and Al) in glass. Compared with the untreated glass container in the comparative example, the concentrations of various ions dissolved in Examples 1, 2, and 3 were significantly reduced, especially Example 2, which showed the best performance in blocking multiple ions, such as calcium, magnesium, and aluminum ions, with near-zero precipitation. Furthermore, the coatings in all examples remained intact after the water resistance test, indicating that they have good adhesion performance and structural stability.

[0024] In summary, this composite coating not only effectively improves the chemical stability and service life of glass containers, but also provides a reliable protective solution for the storage of high-purity reagents and biopharmaceuticals.

[0025] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A protective coating for the inner wall of a container glass, characterized in that, The protective coating is a composite film structure, comprising an inner layer composed of oxides of silicon, aluminum, zirconium, and titanium, and an outer layer composed of pure silicon oxide. The mass percentage of each element in the inner layer, with the total mass of silicon, aluminum, zirconium, and titanium being 100%, is as follows: 80-100% silicon, 0-10% aluminum, 0-10% zirconium, and 0-3% titanium.

2. A method for preparing a protective coating for the inner wall of a container glass, characterized in that, The preparation of the protective coating for the inner wall of a container glass as described in claim 1 comprises the following steps: Step 1: Preparation of mixed sol: According to the mass ratio of each element in the inner layer as described in claim 1, the corresponding types of silicon source, aluminum source, zirconium source and titanium source precursors are dissolved in an organic solvent. At room temperature to 60°C, an acidic catalyst is added to adjust the pH value to 2-3. After reacting for 8-12 hours, the mixture is allowed to stand and age to obtain a mixed sol. Step 2: Coating and heat treatment: Immerse the clean glass container in the mixed sol for coating. The immersion time is 50-70 seconds, and the rate of lifting it out of the liquid surface is 0.5-1.5 mm / min. Then, pre-treat at 90-110℃ for 4-6 minutes, and then heat-treat at 450-520℃ for 8-12 minutes. Step 3: Secondary coating and heat treatment: Immerse the glass container treated in step 2 in pure silica sol for secondary coating for 50-70 seconds, followed by heat treatment at 450-520℃ for 8-12 minutes, finally forming the protective coating on the inner wall of the glass.

3. The method for preparing a protective coating for the inner wall of a container glass according to claim 2, characterized in that, The silicon source is tetraethyl orthosilicate.

4. The method for preparing a protective coating for the inner wall of a container glass according to claim 2, characterized in that, The aluminum source is aluminum nitrate.

5. A method for preparing a protective coating for the inner wall of a container glass according to claim 2, characterized in that, The zirconium source is one of zirconium oxynitrate, zirconium n-propoxide, or zirconium tert-butoxide.

6. The method for preparing a protective coating for the inner wall of a container glass according to claim 2, characterized in that, The titanium source is one of tetrabutyl titanate or titanium tetrachloride.

7. A method for preparing a protective coating for the inner wall of a container glass according to claim 2, characterized in that, The organic solvent is one of anhydrous ethanol, isopropanol, and n-butanol.

Images