WO2022052847A1 - Antibacterial molten salt, and glass and preparation method therefor - Google Patents

Abstract

The present invention provides an antibacterial molten salt and antibacterial glass obtained by using the antibacterial molten salt to perform antibacterial metal ion exchange. The antibacterial metal ion in the antibacterial molten salt is a copper ion, and the antibacterial molten salt is a multi-component composite sulfate. In the present invention, Cu ions exist stably in the glass after ion exchange, and no black CuO or polluting waste gas is generated. The compositional design of the ternary sulfate molten salt enables the glass to be melted at a temperature of 430-500°C or 440-470°C, facilitating antibacterial ion exchange of mainstream glass in industry. The glass needs to be preheated before ion exchange is performed. The preheating temperature T1 and the ion exchange temperature T2 of the antibacterial molten salt need to be controlled such that T2 − T1 < 50°C, and the ion exchange time is 2-10 min. The copper content of the antibacterial glass is 0.01-0.8%. The change in the absolute values of each of L*, a*, and b* before and after antibacterial metal ion exchange are such that |△L*| is 0-0.25, |△a*| is 0-0.08, and |△b*| is 0-0.05. The antibacterial effect index R value is greater than 5. Furthermore, the technical solution has a simple and environmentally friendly process, requires a shorter time, and is suitable for industrialized production.

Description

A kind of antibacterial molten salt, glass and preparation method technical field

The invention relates to the technical field of antibacterial glass, in particular to an antibacterial molten salt, glass and a preparation method thereof.

Background technique

With the popularization of smart devices, people inevitably often come into contact with the touch screen. During use, the touch screen is easily adhered to the surface of the touch screen due to the presence of a large number of bacteria, fungi, etc. in the environment. During the contact process, due to the heat or sweat of the human body, it will provide a suitable environment for the growth and reproduction of bacteria on the surface of the touch screen. Especially the public smart devices used by non-fixed people, such as: ATM machines, automatic ticket machines, medical equipment, etc. In addition, devices that are frequently used by fixed people, such as smartphones and Ipads, also face the same situation. The proliferation of bacteria on the touch screen not only affects the optical performance and sensitivity of the touch screen, but also has a certain impact on the health of users. Similarly, the above-mentioned problems also exist in the daily kitchenware glassware (dishes, bowls, plates, cups, bottles) products, especially products in public places such as restaurants and hotels. Therefore, the antibacterial properties of glass products have become an urgent problem for manufacturers to solve.

At present, the mainstream antibacterial glass products on the market are silver ions. However, the price of silver ion raw materials is high, the production cost is high, and silver is easy to be colored, which has high requirements on the control of the production process. In order to reduce production costs, existing manufacturers use silver and copper mixed antibacterial, or pure copper antibacterial, as an alternative.

However, the introduction of copper ions as antibacterial molten salts is usually the mixture of CuSO4 and nitrate, such as the mixture of one or more of NaNO3 and KNO3, or the mixture of CuSO4 and nitrate, sulfate, carbonate and chloride. The salt can be liquid in the range of >380℃, which is convenient for the ion exchange of glass. For example: Chinese patent 201610721270.0, High-strength antibacterial glass and preparation method thereof, discloses an antibacterial molten salt, including copper ion compound and KNO3. Chinese patent 202010452471.1, an antibacterial and anti-fingerprint glass and a manufacturing method thereof, discloses a potassium nitrate molten salt containing copper ions and silver ions.

However, due to the existence of nitrate, it is easy to emit yellow nitrogen oxides, and the more Cu content, the more severe the emission, resulting in serious production risks and pollution. On the other hand, Cu ions easily generate black CuO in such molten salts, which affects the light transmittance of glass. Therefore, the content of CuSO ₄ in the existing mass-produced molten salt generally does not exceed 1%, and even some manufacturers do not exceed 0.1%. However, although too little Cu content reduces gas emissions, it seriously affects the efficiency of copper ion exchange. , and the copper ion content in the final antibacterial glass is low, which cannot play an effective antibacterial effect.

SUMMARY OF THE INVENTION

Therefore, in order to solve the above problems, it is necessary to find a new molten salt combination that can stably exist Cu ions, does not generate black CuO, does not generate polluting waste gas, and is molten at a suitable temperature for ion exchange. Antibacterial glass prepared by ion exchange.

In order to achieve the purpose of the first aspect of the present invention, the present invention provides an antibacterial molten salt, wherein the antibacterial metal ions in the antibacterial molten salt are copper ions, and the antibacterial molten salt is a multi-component composite sulfate.

The antibacterial metal ions in the antibacterial molten salt are copper ions, and the antibacterial molten salt does not contain silver ions and zinc ions, and the antibacterial metal ions are introduced by CuSO ₄ . Since the melting point of CuSO ₄ is 560°C, pure CuSO ₄ molten salt is not suitable for mainstream glass ion exchange, and other molten salts need to be introduced to form a eutectic to lower the melting point.

The antibacterial molten salt of the present invention adopts sulfuric acid composite salt, which does not contain nitrate, carbonate and chloride. Carbonate is easy to corrode glass, causing surface fogging or cracking, which affects glass performance; chloride has high vapor pressure and is easy to volatilize irritating gas, which is not suitable for industrial mass production. _Sulfate , due to its low price, low saturated _vapor pressure, and good thermal stability, does not have the above problems in the _molten state _. ℃), so there is currently no copper ion antibacterial molten salt of pure sulfate system in the industry.

Preferably, the antibacterial molten salt is a ternary composite sulfate, and the components include CuSO ₄ , Na ₂ SO ₄ and K ₂ SO ₄ .

On the basis of a large number of experiments, the present invention has developed a molten salt formulation based on CuSO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ ternary composite sulfate system through continuous research experiments and continuous adjustment of various sulfates , and by limiting the content of the above three sulfates, the ternary composite sulfate can be formed into a molten state in the temperature range suitable for ion exchange. CuSO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ ternary composite sulfate can be directly used as ion exchange molten salt. Of course, it can also be mixed with other molten salts (including but not limited to sulfates, nitrates, carbonates) and used.

Preferably, the melting point temperature T ₀ of the antibacterial molten salt is 430-500°C. In the temperature range of 430-500°C, CuSO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ ternary composite sulfate is in molten state, and the base glass can be ion-exchanged in the molten molten salt.

Preferably, the components and mass percentages of the antibacterial molten salt are: CuSO ₄ 40%-65%, Na ₂ SO ₄ 15%-50%, K ₂ SO ₄ 10%-25%.

The Cu ion content (≥40%) is much higher than that of conventional antibacterial Cu molten salts, so that the ion exchange rate in the preparation process of the antibacterial glass of the present invention is faster, the Cu ion implantation content is higher, and the antibacterial effect is better. Since the content of copper in the antibacterial glass is greater than 0.006%, there is a good antibacterial effect, so the content of Cu ions is less than or equal to 65% to avoid waste. The composition of CuSO ₄ 40%-65%, Na ₂ SO ₄ 15%-50%, K ₂ SO ₄ 10%-25% makes the ternary composite sulfate melt together into a molten state with a melting point temperature of 430-500 °C.

Preferably, the melting point temperature T0 of the antibacterial molten salt is 440-470°C. In the temperature range of 440-470 ℃, CuSO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ ternary composite sulfate is in molten state, and the base glass can be ion-exchanged in molten molten salt, and 440-470 ℃ can be applied to Most base glasses are ion exchanged.

Preferably, the components and mass percentages of the antibacterial molten salt are: CuSO ₄ 50%-60%, Na ₂ SO ₄ 18%-30%, K ₂ SO ₄ 15%-25%. The composition of the component content makes the melting point temperature of the ternary composite sulfate in the molten state to be 440-470 ° C, as shown in Figure 1, the ternary phase diagram of the composition distribution of the antibacterial molten salt.

The antibacterial molten salt provided by the present invention is suitable for various daily-use glasses, including but not limited to white jade glass, soda lime glass, and aluminosilicate glass.

In order to achieve the purpose of the second aspect of the present invention, the present invention provides an antibacterial glass, wherein the antibacterial ions in the antibacterial glass are copper ions, and the antibacterial molten salt of the first aspect of the present invention in the antibacterial glass performs antibacterial ion exchange.

Preferably, the content of the copper ions is 0.01%-0.8% based on the quality of the antibacterial glass.

Preferably, the antibacterial R value of the antibacterial glass is >5.

Preferably, the difference between the absolute value of the L* value of the antibacterial glass and the absolute value of the L* value of the base glass before ion exchange, |ΔL*| is 0-0.25; the absolute value of the a* value of the ion exchange glass The difference between the absolute value of the a* value of the base glass before ion exchange, |Δa*| is 0-0.0.8, the absolute value of the b* value of the ion exchange glass and the absolute value of the b* value of the base glass before ion exchange The difference, |Δb*| is 0-0.0.5.

CIE color channel L* value a* value and b* value are an optical parameter defined by the International Institute of Illumination (CIE) in the L*a*b* color space. The L*a*b* color space includes all sensible colors in the three-dimensional real space. The luminance L* is L*=0 for the darkest black, and L*=100 for the brightest white. The color channels a* and b* represent true neutral grey values with a*=0 and b*=0. The relative red/green color is represented along the a* axis in the range -128 to +128, with green being negative a* values and red being positive a* values. The relative yellow/blue color is represented along the b* axis in the range -128 to +128, with blue being negative b* values and yellow being positive b* values.

In order to achieve the purpose of the third aspect of the present invention, the present invention provides the preparation method of the antibacterial glass according to the second aspect of the present invention, comprising the following steps:

Melting: melting the antibacterial molten salt according to the first aspect of the present invention at T2 temperature, 430°C≤T0≤T2≤500°C,

Preheating: Preheat the base glass, the preheating temperature is T1, T2-T1<50℃;

Ion exchange: put the preheated base glass into a molten antibacterial molten salt at a temperature of T2 for ion exchange and cooling to obtain the antibacterial glass.

Due to the high density of antibacterial copper molten salt, and the ion exchange temperature (antibacterial molten salt melting temperature) T2 is generally slightly higher than the melting point T0, at least higher than 430 ° C, if the temperature difference of the base glass is too large, it will be easily broken and easily broken. The molten salt at the contact position is partially solidified, so the preheating temperature T1 and the ion exchange temperature T2 of the antibacterial molten salt should be controlled to T2-T1<50°C. The preheating time is generally controlled at 30-60min.

Preferably, the ion exchange time is 2-10 min.

Since the molten salt is a high content of copper molten salt, too long ion exchange time will lead to more copper ions implanted, resulting in glass coloring and causing defects. On the other hand, when the copper content of the antibacterial glass in the industry is greater than 0.006%, it has a good antibacterial effect. Considering the production cost, it is meaningless to implant too much copper ions. Therefore, the ion exchange time of the glass in the molten salt should be controlled to 2 -10min.

Different from the prior art, the above technical solution at least includes the following beneficial effects: by introducing a polybasic sulfate molten salt containing copper ions, and by designing the composition of the polybasic sulfate molten salt, it can be melted at a temperature of 430-500 ° C, or at a temperature of 430-500 °C. The temperature of 440-470 ℃ is melted, which is convenient for the antibacterial ion exchange of mainstream glass in the industry. After ion exchange, Cu ions in the glass exist stably, no black CuO is generated, and no polluting waste gas is generated. Its antibacterial glass products can achieve implanted copper content between 0.01%-0.8% within 2-10min of ion exchange time, and the absolute value change of L*a*b before and after antibacterial |△L*| is 0-0.25, |△ a*| is 0-0.08, |△b*| is 0-0.05; the antibacterial effect index R value is more than 5. At the same time, the technical solution is simple and environmentally friendly, takes less time, and is very suitable for industrial production.

Description of drawings

Fig. 1 is the ternary phase diagram of the composition distribution of antibacterial molten salt, the position of picture mark 1 is the composition of eutectic molten salt at 440-470°C, and the square black dots are the composition distribution of Examples 1-6 in the ternary phase diagram;

Fig. 2 is the DSC curve of embodiment 2 antibacterial molten salt, and its endothermic peak-to-peak point temperature is 447.47 ℃;

Fig. 3 is the DSC curve of the antibacterial molten salt of Example 5, and its endothermic peak-to-peak point temperature is 454.23°C.

detailed description

In order to describe in detail the technical content, structural features, achieved objectives and effects of the technical solution, the following detailed description is given in conjunction with specific embodiments and accompanying drawings.

The antibacterial molten salt described in this embodiment is suitable for the preparation of various antibacterial glass products, which can be classified according to composition as soda lime glass, aluminosilicate (medium/high alumina) glass used in touch screens, and glass for daily use. Soda-lime glass, white jade glass and other different components and types of glass in the product.

Embodiments 1 to 6 of the present invention are prepared by the following methods:

First, CuSO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ ternary copper sulfate molten salts were weighed according to the proportions shown in Table 1 and mixed evenly; the melting points T0 of different proportions of antibacterial molten salts are shown in Table 1;

Put the evenly mixed ternary copper sulfate antibacterial molten salt in an alumina ceramic boat, put it into a tempering furnace or a melting furnace, and melt it within the temperature range of 430℃≤T0≤T2≤500℃, and wait for it to be molten for backup. use;

The glass samples shown in Table 1 were placed in a preheating furnace for 30 minutes, and the preheating temperature T1 and T2 should be controlled to T2-T1 < 50 °C, and then the glass samples were placed in the molten antibacterial molten salt at T2 temperature for ion exchange. , the ion exchange time and ion exchange temperature T2 are shown in Table 1. After the ion exchange is completed, the glass is placed in a muffle furnace for rapid cooling to obtain antibacterial glass. The surface residue of the antibacterial glass was washed with hot water, and the performance test was carried out. The test items and results are shown in Table 1.

In each example, three different glass samples were used as the base glass, namely:

Soda lime glass, its composition content is: SiO ₂ 65.23%, Al ₂ O ₃ 5.04%, Na ₂ O 15.41%, K ₂ O 1.14%, MgO 5.34%, CaO 7.8%, SnO 2 0.04%;

High alumina glass, its composition content is: SiO ₂ 60.08%, Al ₂ O ₃ 20.77%, Na ₂ O 13.23%, B ₂ O ₃ 0.32%, P ₂ O ₅ 2.52%, Li ₂ O 2.73%, CaO 0.15% , SnO2 0.2%;

White jade glass, its composition content is: SiO ₂ 66.34%, Al ₂ O ₃ 9.18%, Na ₂ O 9.72%, K ₂ O 2.86%, BaO 4.31%, ZnO 0.8%, CaO 3.09%, CaF ₂ 3.5%, SnO2 0.2%.

The base glass is first tested for L* value a* value and b* value, and then the antibacterial glass after ion exchange is tested for L* value, a* value and b* value, and the absolute value change of L*a*b before and after antibacterial is calculated. The results are shown in Table 1.

Table 1 Composition, process and performance table of the antibacterial glass prepared in Examples 1-6

The definitions and explanations or test methods of the physical properties of the test items of embodiment 1-6 are as follows:

(1) Melting point T0: multi-component molten salt solid-liquid phase change melting temperature, using DSC test;

(2) molten salt temperature: use infrared thermometer to measure;

(3) Cu content: obtained by XRF test;

(4) L*a*b value: test with a spectrophotometer;

(5) R value of antibacterial effect index: using the method in the standard JIS Z 2081:2010, by inoculating the suspension containing bacteria on the surface, the antibacterial products and untreated products were inoculated with bacteria for 24 hours, and their viable cells were calculated. Logarithmic difference of numbers.

At the same time, from the ternary phase diagram of the composition distribution of the antibacterial molten salt in Figure 1, the position marked 1 in the picture is the composition of the antibacterial molten salt with a melting point of 440-470 °C, and the square black dots are the composition distribution of Examples 1-6 in the ternary phase diagram. ; It can be seen from Figure 1 that the melting point T0 of the ternary sulfate antibacterial molten salt with the composition range of CuSO ₄ 50%-60%, Na ₂ SO ₄ 18%-30%, K ₂ SO ₄ 15%-25% is 440 -470℃.

Fig. 2 The DSC curve of the antibacterial molten salt of Example 2, it can be seen from Fig. 2 that there is a sharp endothermic peak between 430-500 ° C, which is the solid-liquid phase transition peak of ternary sulfate, and the starting point is from 430 ° C to the peak The point is 447.47°C, and the peak point is taken as its melting point T0.

Figure 3 is the DSC curve of the antibacterial molten salt of Example 5. It can be seen from the figure that there is a sharp endothermic peak between 430 and 500 ° C, which is the solid-liquid phase transition peak of ternary sulfate, and the starting point is from 433 ° C to the peak. Point 454.23 ℃, take the peak point as its melting point TO.

It can be seen from Table 1 and Figures 1-3 that by designing the component content of the copper ion-containing sulfate molten salt, a ternary composite sulfate is formed, CuSO ₄ 50%-60%, Na ₂ SO ₄ 18%- 30%, K ₂ SO ₄ 15%-25%, the composition of the component content makes the melting point temperature of the ternary composite sulfate to form a molten state is 440-470 ° C, which is suitable for most of the basic glass, and the method provided by the present invention is adopted. The preparation method can effectively implant copper ions into the base glass to obtain copper ion antibacterial glass, the Cu ions in the glass are stably existing, no black CuO is generated, and no polluting waste gas is generated. The content of copper ions in the copper ion antibacterial glass of the present invention is 0.01%-0.8%, the antibacterial R value is more than 5; the absolute value change of L*a*b before and after antibacterial |△L*| is 0-0.25, |△a*| is 0-0.08, and |△b*| is 0-0.05.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion such that a process, method, article or terminal device that includes a list of elements includes not only those elements, but also a non-exclusive list of elements. other elements, or also include elements inherent to such a process, method, article or terminal equipment. Without further limitation, an element defined by the words "includes..." or "comprises..." does not preclude the presence of additional elements in the process, method, article, or terminal device that includes the element. In addition, in this document, "greater than", "less than", "exceeds", etc. are understood to exclude the number; "above", "below", "within" and the like are understood to include the number.

It should be noted that, although the above embodiments have been described herein, it does not limit the scope of the patent protection of the present invention. Therefore, based on the innovative concept of the present invention, changes and modifications to the embodiments described herein, or equivalent structures or equivalent process transformations made by using the contents of the description and drawings of the present invention, directly or indirectly apply the above technical solutions In other related technical fields, all are included within the scope of patent protection of the present invention.

Claims (12)

1. An antibacterial molten salt, characterized in that the antibacterial metal ions in the antibacterial molten salt are copper ions, and the antibacterial molten salt is a multi-component compound sulfate.
2. The antibacterial molten salt according to claim 1, wherein the antibacterial molten salt is a ternary composite sulfate, and the components are CuSO ₄ , Na ₂ SO ₄ and K ₂ SO ₄ .
3. The antibacterial molten salt according to claim 2, wherein the melting point temperature T0 of the antibacterial molten salt is 430-500°C.
4. The antibacterial molten salt according to claim 3, wherein the components and mass percentages of the antibacterial molten salt are: CuSO ₄ 40%-65%, Na ₂ SO ₄ 15%-50%, K ₂ SO 4 ₄ 10%-25%.
5. The antibacterial molten salt according to claim 2, wherein the melting point temperature T0 of the antibacterial molten salt is 440-470°C.
6. The antibacterial molten salt according to claim 5, wherein the components of the antibacterial molten salt and their mass percentages are: CuSO ₄ 50%-60%, Na ₂ SO ₄ 18%-30%, K ₂ SO ₄ 15%-25%.
7. An antibacterial glass, characterized in that the antibacterial ions in the antibacterial glass are copper ions, and the antibacterial glass adopts any one of the antibacterial molten salts of claims 1-6 for antibacterial ion exchange.
8. The antibacterial glass according to claim 7, characterized in that, taking the antibacterial glass as a quality standard, the content of copper ions in the antibacterial glass is 0.01%-0.8%.
9. The antibacterial glass according to claim 7, wherein the antibacterial R value of the antibacterial glass is >5.
10. The antibacterial glass according to claim 8, wherein the difference between the absolute value of the L* value of the antibacterial glass and the absolute value of the L* value of the base glass before ion exchange, |ΔL*| is 0-0.25; The difference between the absolute value of the a* value of the ion-exchanged glass and the absolute value of the a* value of the base glass before ion-exchange, |Δa*| is 0-0.0.8, and the absolute value of the b* value of the ion-exchanged glass is the same as The difference between the absolute values of the b* values of the base glass before ion exchange, |Δb*| is 0-0.0.5.
11. The preparation method of antibacterial glass according to claim 7, is characterized in that, comprises the following steps:

    Melting: the antibacterial molten salt is melted at T2 temperature, 430℃≤T0≤T2≤500℃,

    Preheating: Preheat the base glass, the preheating temperature is T1, T2-T1<50℃;

    Ion exchange: put the preheated base glass into a molten antibacterial molten salt at a temperature of T2 for ion exchange and cooling to obtain the antibacterial glass.
12. The preparation method according to claim 11, wherein, in the ion exchange step, the ion exchange time is 2-10min.

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