Silverware surface oxide reducing agent as well as preparation method and application thereof

Abstract

The invention discloses a silverware surface oxide reducing agent as well as a preparation method and application thereof. The silverware surface oxide reducing agent comprises the following components in parts by weight: 65-89 parts of deionized water, 1-5 parts of tea extract, 2-10 parts of roxburgh rose extract and 0.01-0.05 part of colloidal platinum. According to the reducing agent, dissolved hydrogen molecules, tea extract, roxburgh rose extract and other reducing components are utilized to perform in-situ reduction on potassium chloroplatinate to obtain colloidal platinum, and the defect of difficult dispersion of added nano platinum and other catalysts is avoided. Substances such as silver oxide in color spots on the surface of silverware are solid phases and are difficult to directly reduce by hydrogen, tea polyphenol and an ascorbic acid aqueous solution, and the reducing agent utilizes colloidal platinum as a redox catalyst to adsorb and catalyze reduction components such as hydrogen molecules, tea polyphenol in a tea extract and ascorbic acid in a roxburgh rose extract to oxidize, so that the color spots on the surface of the silverware are reduced. And meanwhile, the released electrons can reduce oxides such as silver oxide in color spots on the surface of the silverware into elemental silver, so that the oxides on the surface of the silverware are effectively reduced.

Description

Technical Field

[0001] This invention relates to a silver cleaning agent, and more particularly to a silver surface oxide reducing agent, its preparation method, and its application. Background Technology

[0002] Items made from silver, such as utensils, jewelry, and ornaments, have been beloved throughout history. Due to silver's natural properties, prolonged contact with air or human sweat can cause black or yellow spots to appear on the surface of silverware, affecting its luster. This is often mistakenly perceived as discoloration or tarnishing. These black or yellow spots are primarily composed of silver sulfide, with small amounts of silver chloride and silver oxide also present. In most cases, people wish to remove these spots and restore the silverware to its pristine white color.

[0003] Currently, these pigmentation spots can be removed using physical or chemical methods, as follows:

[0004] Physical methods involve applying physical mechanical force to the surface of silver, using physical means such as polishing to remove stains. Examples include silver polishing cloths and sticks suitable for home use, along with accompanying silver polishing pastes and creams, as well as electric polishing tools and abrasives like diatomaceous earth and pearl powder used in silver processing factories. The common principle is to physically abrade the silver surface through friction and polishing with other objects, thus removing the stains. The advantages are convenience, suitability for both factories and homes, and the ability to quickly remove stains, leaving silver shiny and new. The disadvantages are that it can cause significant damage to the silver surface, and the polished silver is more prone to yellowing and tarnishing. Furthermore, it is unsuitable for silver surfaces with intricate designs, as it can easily damage the delicate patterns. Polishing details is time-consuming and labor-intensive, requiring professional operation.

[0005] Chemical methods remove stains through chemical reactions, which can be further divided into acid washing and reduction methods.

[0006] Acid cleaning often uses acidic substances such as nitric acid to dissolve and remove silver sulfide and other substances from the surface of silverware. For example, some commercially available silver cleaning solutions involve immersing the silverware in the solution for a few seconds, then rinsing it with water, leaving the silverware sparkling clean. While this method is convenient and quick, silver cleaning solutions are generally acidic and corrosive liquids that can severely damage silver. In general household use, improper operation can easily lead to irreparable damage. This method should be performed by professionals, and the use of corrosive cleaning solutions also poses safety hazards.

[0007] The reduction method removes stains from silver objects by directly or indirectly reacting with reducing agents through a redox reaction, reducing substances like silver sulfide to silver. For example, silver objects can be immersed in an electrolyte solution of sodium chloride along with more reactive metals like aluminum or magnesium, or hydrogen gas can be directly passed through the electrolyte solution containing the silver objects and heated to boiling. The aluminum or magnesium is oxidized to form aluminum hydroxide or magnesium hydroxide, while the silver sulfide is reduced to elemental silver and hydrogen sulfide. The advantage of this method is that it does not result in any loss of silver. The disadvantages are that the reaction rate is uncontrollable, and the newly formed silver surface is prone to defects. Especially when using reactive metals like magnesium, magnesium oxidizes quickly, easily producing large amounts of hydrogen gas, leading to waste. Furthermore, this method requires the reactive metal to be as close to the silver surface as possible, making the process cumbersome; magnesium strips and powder are difficult to preserve and pose certain safety hazards, making it unsuitable for home use or for large silver objects.

[0008] There are also methods that combine physical and chemical approaches. For example, borax solution is applied to the silver, the oxide layer is burned off, and then it is boiled in alum water in a copper pot. After rinsing with clean water and cleaning with a copper brush, the silver will be as bright as new. However, these methods are also cumbersome, require professional personnel, and may damage the surface of the silver. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a safe and effective reducing agent for the surface oxides of silverware; the present invention also provides a method for preparing the reducing agent for the surface oxides of silverware; the present invention also provides an application of the reducing agent for the surface oxides of silverware.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention includes the following components in parts by weight: 65-89 parts of deionized water, 1-5 parts of tea extract, 2-10 parts of prickly pear extract, and 0.01-0.05 parts of colloidal platinum.

[0011] Furthermore, the colloidal platinum is produced by the reduction of potassium chloroplatinate.

[0012] To solve the above-mentioned technical problems, the technical solution adopted by the preparation method of the present invention includes the following steps: (1) dissolving tea extract, prickly pear extract and potassium chloroplatinate in deionized water according to the component ratio to obtain a mixed solution;

[0013] (2) The mixture is pressurized and hydrogen is introduced to achieve hydrogen saturation and dissolution, and then heated to reduce potassium chloroplatinate to platinum.

[0014] Furthermore, in step (2), the pressurization pressure is 0.1 to 0.6 MPa and the heating temperature is 50°C to 90°C.

[0015] Furthermore, the heating time is 0.1 to 1 hour.

[0016] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is to immerse the oxidized silver surface in the reducing agent.

[0017] Furthermore, the soaking time is 2 hours to 24 hours.

[0018] The beneficial effects of the above technical solution are as follows: This invention utilizes dissolved hydrogen molecules, tea extracts, and prickly pear extracts, among other reducing components, to reduce potassium chloroplatinate in situ to obtain colloidal platinum, avoiding the drawbacks of difficult dispersion caused by externally added nano-platinum catalysts. The silver oxide and other substances in the stains on the surface of silverware are solid phases, making direct reduction with hydrogen, tea polyphenols, and ascorbic acid aqueous solutions difficult. This invention uses colloidal platinum as a redox catalyst, oxidizing reducing components such as hydrogen molecules, tea polyphenols in tea extracts, and ascorbic acid in prickly pear extracts through adsorption and catalysis. Simultaneously, the released electrons can reduce the silver oxide and other oxides in the stains on the surface of silverware to elemental silver, thereby effectively reducing the oxides on the surface of silverware and restoring its original surface color.

[0019] In the preparation process of this invention, hydrogen gas is introduced to form a hydrogen protective atmosphere, which isolates the influence of oxygen in the air and avoids the loss and inactivation of tea polyphenols in tea extract and ascorbic acid in prickly pear extract.

[0020] The composition of this invention is non-corrosive and removes oxide stains from the surface of silverware without damaging the silverware substrate. It can effectively treat silver-plated or finely patterned silverware. It does not contain reactive metals or acidic corrosive substances, making it safe, convenient to operate, and environmentally friendly. Attached Figure Description

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] Figure 1 These are comparative photos of the silver restoration effect in Embodiment 1 of the present invention;

[0023] Figure 2 These are comparison photos of the silver restoration effect in Embodiment 2 of the present invention;

[0024] Figure 3 These are comparison photos of the silver restoration effect in Embodiment 3 of the present invention;

[0025] Figure 4 These are comparative photos of the silver restoration effect in Embodiment 4 of the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to specific embodiments.

[0027] The reducing agent for the surface oxides of this silverware comprises the following components in parts by weight: 65-89 parts deionized water, 1-5 parts tea extract, 2-10 parts prickly pear extract, and 0.01-0.05 parts colloidal platinum; wherein the colloidal platinum is reduced by potassium chloroplatinate, preferably by heating and reducing with saturated dissolved hydrogen under pressure.

[0028] The preparation method of the surface oxide reducing agent of this silverware includes the following steps: (1) According to the following component ratio: 65-89 parts of deionized water, 1-5 parts of tea extract, 2-10 parts of prickly pear extract and 0.01-0.05 parts of platinum, wherein the platinum is potassium chloroplatinate, which is added after conversion according to the weight fraction of platinum; dissolve the tea extract, prickly pear extract and potassium chloroplatinate in deionized water to obtain a mixture.

[0029] The tea extract is prepared by the following process: tea leaves are extracted with water or a mixture of water and ethanol as the extractant. The process is as follows: the material-to-liquid ratio (g / mL) is 1:10 to 1:30, the extraction temperature is 35℃ to 80℃, and the extraction time is 15 to 60 minutes. Finally, the extract is filtered and the solvent is recovered to obtain tea extract powder, which is then freeze-dried and stored.

[0030] The prickly pear extract is prepared by the following process: prickly pear is extracted with water or a mixture of water and ethanol as the extractant. The process is as follows: the material-to-liquid ratio (g / mL) is 1:10 to 1:30, the extraction temperature is 35℃ to 80℃, the extraction time is 15 to 60 min, the solvent is finally filtered and recovered to obtain prickly pear extract powder, which is then freeze-dried and stored.

[0031] (2) The mixture is pressurized and hydrogen is introduced to achieve hydrogen saturation and dissolution. The pressurization pressure is 0.1 to 0.6 MPa. Potassium chloroplatinate is reduced to platinum by heating. The heating temperature is 50℃ to 90℃ and the heating time is 0.1 to 1 hour. After the reaction is completed, the mixture is kept under pressure and cooled to room temperature. It is then poured into an aluminum can. The can must be filled and sealed quickly to reduce hydrogen leakage. During daily storage, the pressure inside the can can be maintained at ≥0.1 MPa.

[0032] Application method of this silver surface oxide reducing agent: Immerse the oxidized silver surface in this reducing agent, with the reducing agent level 0.5-1cm above the silver layer, at room temperature, open or sealed for 2-24 hours; then remove the silver and rinse it with clean water. Depending on the reduction of the silver surface, the silver can be immersed in this reducing agent 2-3 times.

[0033] Example 1: The specific details of the reducing agent for the surface oxides of silverware, its preparation method, and its application are as follows.

[0034] (1) Preparation of reducing agent: Take 89 parts of deionized water, 5 parts of tea extract, 10 parts of prickly pear extract and potassium chloroplatinate converted to 0.05 parts of platinum; dissolve the tea extract, prickly pear extract and potassium chloroplatinate in deionized water to obtain a mixture; pass hydrogen gas through the mixture at 0.3 MPa to achieve saturation dissolution, heat to 50°C and heat for 0.5 hours to reduce potassium chloroplatinate to platinum; after the reaction is completed, maintain pressure and cool to room temperature, fill into aluminum easy-open cans, fill and seal quickly to reduce hydrogen gas escape, and maintain the pressure inside the can ≥0.1 MPa during daily storage.

[0035] The tea extract was prepared using the following process: tea leaves were used as the extractant with water at a material-to-liquid ratio of 1:30, and the extraction was carried out at 50°C under hydrogen protection for 30 minutes. Finally, the extract was filtered, the solvent was recovered, and the extract was freeze-dried to obtain tea extract powder.

[0036] The prickly pear extract is prepared by the following process: prickly pear is extracted with water or a mixture of water and ethanol as the extractant, with a material-to-liquid ratio (g / mL) of 1:30, at 40°C under hydrogen protection for 30 min, and finally filtered, the solvent is recovered, and freeze-dried to obtain prickly pear extract powder.

[0037] (2) Application of the reducing agent: Immerse the oxidized silver surface in this reducing agent, with the reducing agent level 0.5 cm above the silver layer, at room temperature, open or sealed for 6 hours; then remove the silver and rinse it with clean water. Repeat the immersion in this reducing agent 3 times depending on the reduction of the silver surface. To verify the reduction effect, in this embodiment, a portion of the oxidized silver was immersed, while the other portion was not immersed as a comparison.

[0038] (3) Application effect: The comparison chart of the above-mentioned oxidized silver items after partial reduction using this reducing agent is shown below. Figure 1 As shown in the figure, this reducing agent effectively reduced the oxides on the surface of the silverware.

[0039] Example 2: The specific details of the reducing agent for the surface oxides of silverware, its preparation method, and its application are as follows.

[0040] (1) Preparation of reducing agent: Take 70 parts of deionized water, 3 parts of tea extract, 6 parts of prickly pear extract and potassium chloroplatinate converted to 0.03 parts of platinum; dissolve the tea extract, prickly pear extract and potassium chloroplatinate in deionized water to obtain a mixture; pass hydrogen gas through the mixture at 0.25 MPa to achieve saturation dissolution, heat to 60°C and heat for 0.3 hours to reduce potassium chloroplatinate to platinum; after the reaction is completed, maintain pressure and cool to room temperature, pour into aluminum easy-open cans, fill and seal quickly to reduce hydrogen gas escape, and maintain the pressure inside the can ≥0.1 MPa during daily storage.

[0041] The preparation processes for the tea extract and the prickly pear extract are the same as in Example 1.

[0042] (2) Application of the reducing agent: Immerse the oxidized silver surface in this reducing agent, with the reducing agent level 0.5 cm above the silver layer, at room temperature, open or sealed for 18 hours; then remove the silver and rinse it with clean water. Depending on the reduction of the silver surface, repeat the immersion in this reducing agent twice. To verify the reduction effect, in this embodiment, a portion of the oxidized silver was immersed, while the other portion was not immersed as a comparison.

[0043] (3) Application effect: The comparison chart of the above-mentioned oxidized silver items after partial reduction using this reducing agent is shown below. Figure 2 As shown in the figure, this reducing agent effectively reduced the oxides on the surface of the silverware.

[0044] Example 3: The specific details of the reducing agent for the surface oxides of silverware, its preparation method, and its application are as follows.

[0045] (1) Preparation of reducing agent: Take 65 parts of deionized water, 2 parts of tea extract, 2 parts of prickly pear extract and potassium chloroplatinate converted to 0.01 parts of platinum; dissolve the tea extract, prickly pear extract and potassium chloroplatinate in deionized water to obtain a mixture; pass hydrogen gas through the mixture at 0.1 MPa to achieve saturation dissolution, heat to 80°C and heat for 0.2 hours to reduce potassium chloroplatinate to platinum; after the reaction is completed, maintain pressure and cool to room temperature, pour into aluminum easy-open cans, fill and seal quickly to reduce hydrogen gas escape, and maintain the pressure inside the can ≥0.1 MPa during daily storage.

[0046] The tea extract is prepared by the following process: tea leaves are extracted with water or a mixture of water and ethanol as the extractant, with a material-to-liquid ratio (g / mL) of 1:20, at 60°C under hydrogen protection for 40 minutes, and finally filtered and the solvent is recovered to obtain tea extract powder.

[0047] The preparation process of the prickly pear extract is the same as in Example 1.

[0048] (2) Application of reducing agent: Immerse the oxidized silver surface in this reducing agent, with the reducing agent level 1 cm above the silver layer, at room temperature, open or sealed for 12 hours; then remove the silver and rinse it with clean water. Repeat the immersion in this reducing agent 3 times depending on the reduction of the silver surface. To verify the reduction effect, in this embodiment, a portion of the oxidized silver was immersed, while the other portion was not immersed as a comparison.

[0049] (3) Application effect: The comparison chart of the above-mentioned oxidized silver items after partial reduction using this reducing agent is shown below. Figure 3 As shown in the figure, this reducing agent effectively reduced the oxides on the surface of the silverware.

[0050] Example 4: The specific details of the reducing agent for the surface oxides of silverware, its preparation method, and its application are as follows.

[0051] (1) Preparation of reducing agent: Take 80 parts of deionized water, 1 part of tea extract, 10 parts of prickly pear extract and potassium chloroplatinate converted to 0.04 parts of platinum; dissolve the tea extract, prickly pear extract and potassium chloroplatinate in deionized water to obtain a mixture; pass hydrogen gas through the mixture at 0.6 MPa to achieve saturation and dissolution, heat to 90°C and heat for 1 hour to reduce potassium chloroplatinate to platinum; after the reaction is completed, maintain pressure and cool to room temperature, pour into aluminum easy-open cans, fill and seal quickly to reduce hydrogen gas escape, and maintain the pressure inside the can ≥0.1 MPa during daily storage.

[0052] The preparation process of the tea extract is the same as in Example 1.

[0053] The prickly pear extract is prepared by the following process: prickly pear is extracted with water or a mixture of water and ethanol as the extractant, with a material-to-liquid ratio (g / mL) of 1:20, at 70°C under hydrogen protection for 30 min, and finally filtered and the solvent is recovered to obtain prickly pear extract powder.

[0054] (2) Application of reducing agent: Immerse the oxidized silver surface in this reducing agent, with the reducing agent level 1 cm above the silver layer, at room temperature, open or sealed for 24 hours; then remove the silver and rinse it with clean water. Depending on the reduction of the silver surface, repeat the immersion in this reducing agent twice. To verify the reduction effect, in this embodiment, a portion of the oxidized silver was immersed, while the other portion was not immersed as a comparison.

[0055] (3) Application effect: The comparison chart of the above-mentioned oxidized silver items after partial reduction using this reducing agent is shown below. Figure 4 As shown in the figure, this reducing agent effectively reduced the oxides on the surface of the silverware.

Claims

1. A silver surface oxide reducing agent, characterized in that, It comprises the following components in parts by weight: 65-89 parts deionized water, 1-5 parts tea extract, 2-10 parts prickly pear extract, and 0.01-0.05 parts colloidal platinum.

2. The silver surface oxide reducing agent according to claim 1, characterized in that: The colloidal platinum is produced by the reduction of potassium chloroplatinate.

3. The method for preparing the silver surface oxide reducing agent according to claim 1 or 2, characterized in that, The steps include: (1) dissolving tea extract, prickly pear extract and potassium chloroplatinate in deionized water according to the proportions of the components to obtain a mixture; (2) The mixture is pressurized and hydrogen is introduced to achieve hydrogen saturation and dissolution, and then heated to reduce potassium chloroplatinate to platinum.

4. The method for preparing a silver surface oxide reducing agent according to claim 3, characterized in that: In step (2), the pressurization pressure is 0.1 to 0.6 MPa and the heating temperature is 50°C to 90°C.

5. The method for preparing a silver surface oxide reducing agent according to claim 4, characterized in that: The heating time is 0.1 to 1 hour.

6. The application of the silver surface oxide reducing agent according to claim 1 or 2, characterized in that: The oxidized silver surface is immersed in the reducing agent.

7. The application of the silver surface oxide reducing agent according to claim 6, characterized in that: Soaking time is 2 hours to 24 hours.

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