Surface treatment processing method for antique bronze

Abstract

The invention discloses an antique bronze surface treatment processing method, and belongs to the technical field of copper product processing treatment. Comprising the following steps that S1, copper billet pretreatment is conducted, specifically, the surface of a cast copper billet is polished, and obviously uneven parts are removed; cleaning the surface of the copper blank by adopting an organic acid strong reduction cleaning agent; s2, boiling black treatment, wherein the pretreated copper blank is immersed in a metal blackening solution to be boiled, and a black oxidation antique layer is formed on the surface of the copper blank; s3, old biting treatment is conducted, specifically, an old biting solution is dipped, and an oxide layer formed on the surface of the copper product is evenly brushed; repeating for 2-3 times; s4, after-antiquing coloring is conducted, specifically, antiquing oily color concentrate is selected to conduct point coating antiquing on the surface of the copper product subjected to antiquing treatment; and S5, generating an isolation layer: after the steps S1 to S4 are completed, isolating the antique finishing layer on the surface of the copper product by using a transparent adhesive agent.

Description

Technical Field

[0001] The invention belongs to the technical field of copper product processing, and in particular relates to a surface treatment method for antique bronze. Background Art

[0002] Copper is an ancient metal, and its history can be traced back thousands of years. In ancient times, copper was widely used to make various utensils and decorations. As time goes by, copper products will also experience the baptism of the years, producing a unique antique effect; today, antique copper products have become a popular choice for decoration.

[0003] There are three main types of copper aging techniques currently available: 1) Chemical oxidation: using chemical substances to oxidize copper to produce a thin oxide layer on its surface to achieve an antique effect; however, this oxide layer is relatively thin and easy to fall off; 2) Heat treatment: using high temperatures to burn the surface of copper products to also form a similar oxide layer to achieve an antique effect; however, under high temperature burning, copper products are prone to deformation, and the oxide layer formed by burning is also easy to peel off; 3) Paint: using antique paint to paint on the surface of copper products to create an antique effect, but this method has high requirements for painting skills, and the antique effect is not realistic. Summary of the invention

[0004] The present invention provides a surface treatment processing method for antique bronze, which comprises the steps of boiling the bronze surface with an oxidant solution to produce an oxidized aging layer that is stable in the air; then, a biting aging treatment is performed to form red rust and green rust with distinct layers on the surface, so that the aging effect is more realistic and natural; finally, a coloring post-treatment is performed to form mottled, rusty and other texture patterns on the surface of the aging copper product by a spot coating method; after all aging processes are completed, a transparent isolation layer is sprayed on the surface of the copper product to isolate the aging oxide layer on the surface from the air, so as to prevent the oxide layer from disappearing after being damp, resulting in the disappearance of the aging effect.

[0005] In order to achieve the above technical objectives, the present invention is implemented by the following technical solutions:

[0006] A method for surface treatment of antique bronze comprises the following steps:

[0007] S1: Copper billet pretreatment: The surface of the cast copper billet is polished to remove the obvious uneven parts;

[0008] The surface of the copper billet is cleaned by using an organic acid strong reducing cleaning agent;

[0009] S2: Blackening treatment: immerse the pretreated copper billet in a metal blackening solution and boil it to form a black oxidized aging layer on the surface of the copper billet;

[0010] S3: Bite treatment: Dip the bite solution and apply it evenly on the oxide layer formed on the surface of the copper product; repeat 2 to 3 times; oxidize to form an old rust layer;

[0011] S4: Post-aging coloring: Use an aging oily colorant to spot-paint the surface of the copper product after the aging treatment to create an aging effect; forming an aging mottled pattern;

[0012] S5: generating an isolation layer: after completing S1 to S4, a transparent adhesive is used to form an isolation layer covering the aging layer on the surface of the copper product.

[0013] Preferably, the surface of the copper blank needs to be polished with sandpaper to smooth the casting mouth and the inner and outer walls of the copperware; then the entire copperware is polished for a second time with copper carbon dipped in water until the surface is fine.

[0014] Preferably, in S1, oxalic acid is used to clean the copper billet to remove the thin oxide layer produced on the surface of the copper billet during the period of time when the copper billet is exposed to the air after casting, so as to avoid affecting the subsequent processing reaction;

[0015] After cleaning, the copper billet needs to be rinsed with clean water to remove the residual oxalic acid on the surface and then dried naturally.

[0016] Preferably, the weight ratio of the solute to water in the metal blackening solution in the S2 blackening treatment is set to 1 to 1.5:3;

[0017] The boiling time is controlled at 20 to 40 minutes, which is determined by the volume of the copperware and the complexity of the surface structure and texture;

[0018] After the black boiling treatment, take out the copperware, soak it in clean water, brush off the black residue on the surface of the copperware that is easy to fall off, and then wipe it repeatedly with a coarse cloth.

[0019] Preferably, the solute components of the metal blackening solution include: one of copper sulfate, sodium nitrite and sodium sulfide.

[0020] Preferably, the ingredients of the chewing solution include: copper sulfate solution and selenium dioxide solution; the copper sulfate solution and water are mixed into the chewing solution in a weight ratio of 1:3:100.

[0021] Preferably, in S3, each time the biting solution is applied, the next application needs to be done after the surface of the biting solution is dried;

[0022] After the last application of the rust-corrosion solution, when the rust-corrosion solution is half dry, rinse it off with clean water, then lightly brush it with a brush dipped in water to modify the details to create a layered rust effect.

[0023] Preferably, the oily color essence in S4 needs to be diluted with alcohol in a weight ratio of 1:100 before use.

[0024] Preferably, in said S4, at any position of the copper product, a prepared color concentrate solution is applied by using a brush to form a mottled pattern;

[0025] Repeat the application 4 to 5 times on the same spot. Before each application, wait until the color of the previous application is 80 to 90% dry.

[0026] Preferably, the transparent adhesive in S5 comprises: one of transparent wax paste and varnish;

[0027] Put the varnish or melted transparent wax paste into a pressure spray pot, keep the copperware rotating at a constant speed, and spray the varnish or transparent wax paste evenly on the surface of the copperware to form a transparent isolation layer;

[0028] When the first sprayed isolation layer is 80-90% dry, spray the second isolation layer; repeat this 2-3 times.

[0029] The beneficial effects of the present invention are:

[0030] The present invention provides a method for surface treatment of antique bronze. In addition to using an oxidizing solution and copperware to boil together to form a black aged oxide layer, the present invention also forms a rust layering sense formed by the surface oxide layer by brushing an aged solution to enhance the aged effect; and by selecting random areas of the aged layer for aged coloring to form mottled weathering and other patterns, the aged details are made more realistic, thereby improving the overall aged effect of the copperware.

[0031] After completing all the aging processes, spray varnish or wax paste on the surface of the aged layer of the copperware to form an isolation protective layer; avoid exposing the aged layer directly to the air and reacting with oxygen, carbon dioxide, moisture, etc. in the air to cause corrosion and peeling of the aged layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0033] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] A method for surface treatment of antique bronze comprises the following steps:

[0037] S1: Pretreatment of copper billet: The surface of the cast copper billet is polished. Sandpaper is used to polish the casting mouth and the inner and outer wall surfaces of the copperware to make them smooth and flat, completing the first polishing. Then copper carbon is dipped in water to perform the second polishing on the surface of the copper billet. If there are patterns on the surface of the copper billet, the patterns need to be polished finely.

[0038] The purpose of grinding is to make the old oxide layer adhere better to the surface of the copper billet. In addition, some hot molten slurry points may be attached to the surface during the casting process, forming uneven convex points after cooling. The existence of these convex points will affect the overall aging effect.

[0039] After polishing, the surface of the copper billet needs to be cleaned with oxalic acid to remove stains such as oil on the surface of the copper billet. In addition, after the copper billet is cast, it is directly exposed to the air and in contact with oxygen, a thin oxide layer will inevitably form on the surface. This oxide layer may affect the subsequent aging treatment. The full reaction between the copper billet and the aging solution; therefore, oxalic acid is needed to remove this oxide layer;

[0040] After the oxalic acid cleaning is completed, the oxalic acid solution remaining on the surface of the copper billet needs to be rinsed off with clean water, and then the moisture on the surface of the copper billet is allowed to dry naturally.

[0041] S2: Blackening treatment: Put the polished and cleaned copper billet into the metal blackening solution, make the metal blackening solution completely cover the copper billet, and boil the metal blackening solution; the metal blackening solution will react with the copper billet to form a black oxide layer on its surface, which is the base layer for aging;

[0042] The metal blackening solution used in this embodiment is a sodium sulfide solution. The solute sodium sulfide and the solvent water are prepared in a weight ratio of 1.2:3 to obtain a sodium sulfide solution. The copper billet is put into the sodium sulfide solution, and the sodium sulfide solution is completely covered by the copper billet. The sodium sulfide solution is boiled and kept boiling for 30 minutes. If the copperware is large in size or has a complex surface structure and pattern, the boiling time may need to be extended.

[0043] After the black boiling treatment has reached a certain time, the copper billet is taken out and soaked in clean water. The floating black parts on the surface of the copper billet that are easy to fall off are brushed off, and then the surface of the copper billet is repeatedly wiped with a coarse cloth to make the black oxide layer formed by the black boiling appear bright and uniform.

[0044] S3: Bruising treatment: Dip in the rubbing solution and apply it evenly on the black oxide layer formed by boiling the copper product; the rubbing solution will produce a rust-like texture on the copper surface;

[0045] The preparation method of the old-biting liquid in this embodiment is as follows: copper sulfate, selenium dioxide and water are prepared in a weight ratio of 1:3:100, and mixed evenly; the prepared old-biting liquid is evenly applied to the surface of the copperware, preferably the copperware is placed on a turntable, and the old-biting liquid is applied while the copperware is kept rotating at a relatively low speed; a soft brush can be used for application; in this embodiment, a spray pot is used to evenly spray the old-biting liquid on the surface of the copperware, so that each area can be evenly coated; the purpose of keeping the copperware rotating is to give the copperware a centrifugal force, so that the old-biting liquid applied to the surface of the copperware, which has not dried, can avoid the old-biting liquid from flowing down the side wall of the copperware under the action of gravity under the appropriate rotation centrifugal action;

[0046] The application of the biting liquid needs to be repeated three times. After each application of the biting liquid, you need to wait for the surface of the applied biting liquid to dry before applying the next time. After the last application of the biting liquid is completed, when the biting liquid is semi-dry, that is, dry to 60-70%, rinse the applied biting liquid with clean water. After rinsing, you can also use a brush dipped in water to lightly brush the surface of the biting liquid to create a rust texture, which further increases the old feel of the copperware on the basis of the boiled black base.

[0047] S4: Post-aging coloring: Use an aging oily color essence to apply aging treatment to random areas on the surface of the copper product after the aging treatment; the purpose is to simulate the mottled feeling of the copper surface through color dotting;

[0048] Choose an oil-based color concentrate for old colors, and dilute the oil-based color concentrate with alcohol in a weight ratio of 1:100 before use;

[0049] Dip the brush into the prepared color solution, select random areas on the surface of the bronze, and apply any contours to simulate a mottled, rusty pattern on the surface of old bronze. Repeat the application 4 to 5 times on the same location, depending on the desired effect and the degree of restoration. Before each application, wait for the previous color to dry to 80 to 90% before applying again.

[0050] S5: Generate an isolation layer: After the above aging treatment is completed, the aging layer on the surface of the copper product is isolated using a transparent adhesive;

[0051] The above-mentioned transparent adhesive can be a transparent wax paste or a varnish. In this embodiment, the varnish is used to form the transparent isolation layer.

[0052] Put the varnish into a pressure spray bottle, place the copperware on the turntable and keep it rotating at a constant speed; then use the pressure spray bottle to evenly spray the varnish on the surface of the copperware from top to bottom; spray in multiple times, after spraying one layer, wait until the first spray layer is 80-90% dry, then continue to spray the second layer; after repeating 2-3 times, an isolation layer is formed on the antique layer of the copperware; the purpose of the isolation layer is to prevent the antique layer from direct contact with the air, because when the air is humid, the antique layer will further react with oxygen, carbon dioxide, moisture, etc. in the air, which may cause the antique effect to disappear or the antique layer to peel off.

[0053] According to the process method of Example 1, an aged copper ware was obtained, and the aged effect was judged from the rust color and layering, and recorded in Table 1.

[0054] Comparative Example 1

[0055] In this comparative example, the biting liquid is replaced with a single component of copper sulfate; the remaining process steps and parameters are exactly the same as those in Example 1;

[0056] Copper sulfate solution and water are prepared in a weight ratio of 4:100 to obtain an aging liquid; the surface of the copperware is aged according to the process steps in Example 1; the aging effect is judged from the rust color and layering, and recorded in Table 1.

[0057] Comparative Example 2

[0058] In this comparative example, the biting liquid was replaced with a single component of selenium dioxide; the remaining process steps and parameters were exactly the same as those in Example 1;

[0059] Selenium dioxide solution and water are prepared in a weight ratio of 4:100 to obtain an aging liquid; the surface of the copperware is aged according to the process steps in Example 1; the aging effect is judged from the rust color and layering, and recorded in Table 1.

[0060] Table 1 Effect of the ingredients of the biting liquid on the aging effect

[0061]

[0062] Analysis of results: Judging from the aging performance in Table 1, the aging liquid formula of the copper sulfate and selenium dioxide mixture used in the example forms rust on the surface of the copper ware, which is significantly better than the single copper sulfate component in Comparative Example 1 and the single selenium dioxide component in Comparative Example 2 in terms of the naturalness of the rust color and the obviousness of the rust layering.

[0063] Comparative Example 3

[0064] In this comparative example, the aged layer on the surface of the copperware is not protected by an isolation layer; the remaining process steps, reagents and parameters are the same as those in the embodiment;

[0065] A method for surface treatment of antique bronze comprises the following steps:

[0066] S1: Pretreatment of copper billet: The surface of the cast copper billet is polished. Sandpaper is used to polish the casting mouth and the inner and outer wall surfaces of the copperware to make them smooth and flat, completing the first polishing. Then copper carbon is dipped in water to perform the second polishing on the surface of the copper billet. If there are patterns on the surface of the copper billet, the patterns need to be polished finely.

[0067] The purpose of grinding is to make the old oxide layer adhere better to the surface of the copper billet. In addition, some hot molten slurry points may be attached to the surface during the casting process, forming uneven convex points after cooling. The existence of these convex points will affect the overall aging effect.

[0068] After polishing, the surface of the copper billet needs to be cleaned with oxalic acid to remove stains such as oil on the surface of the copper billet. In addition, after the copper billet is cast, it is directly exposed to the air and in contact with oxygen, a thin oxide layer will inevitably form on the surface. This oxide layer may affect the subsequent aging treatment. The full reaction between the copper billet and the aging solution; therefore, oxalic acid is needed to remove this oxide layer;

[0069] After the oxalic acid cleaning is completed, the oxalic acid solution remaining on the surface of the copper billet needs to be rinsed off with clean water, and then the moisture on the surface of the copper billet is allowed to dry naturally.

[0070] S2: Blackening treatment: Put the polished and cleaned copper billet into the metal blackening solution, make the metal blackening solution completely cover the copper billet, and boil the metal blackening solution; the metal blackening solution will react with the copper billet to form a black oxide layer on its surface, which is the base layer for aging;

[0071] The metal blackening solution used in this embodiment is a sodium sulfide solution. The solute sodium sulfide and the solvent water are prepared in a weight ratio of 1.2:3 to obtain a sodium sulfide solution. The copper billet is put into the sodium sulfide solution, and the sodium sulfide solution is completely covered by the copper billet. The sodium sulfide solution is boiled and kept boiling for 30 minutes. If the copperware is large in size or has a complex surface structure and pattern, the boiling time may need to be extended.

[0072] After the black boiling treatment has reached a certain time, the copper billet is taken out and soaked in clean water. The floating black parts on the surface of the copper billet that are easy to fall off are brushed off, and then the surface of the copper billet is repeatedly wiped with a coarse cloth to make the black oxide layer formed by the black boiling appear bright and uniform.

[0073] S3: Bruising treatment: Dip in the rubbing solution and apply it evenly on the black oxide layer formed by boiling the copper product; the rubbing solution will produce a rust-like texture on the copper surface;

[0074] The preparation method of the old-biting liquid in this embodiment is as follows: copper sulfate, selenium dioxide and water are prepared in a weight ratio of 1:3:100, and mixed evenly; the prepared old-biting liquid is evenly applied to the surface of the copperware, preferably the copperware is placed on a turntable, and the old-biting liquid is applied while the copperware is kept rotating at a relatively low speed; a soft brush can be used for application; in this embodiment, a spray pot is used to evenly spray the old-biting liquid on the surface of the copperware, so that each area can be evenly coated; the purpose of keeping the copperware rotating is to give the copperware a centrifugal force, so that the old-biting liquid applied to the surface of the copperware, which has not dried, can avoid the old-biting liquid from flowing down the side wall of the copperware under the action of gravity under the appropriate rotation centrifugal action;

[0075] The application of the biting liquid needs to be repeated three times. After each application of the biting liquid, you need to wait for the surface of the applied biting liquid to dry before applying the next time. After the last application of the biting liquid is completed, when the biting liquid is semi-dry, that is, dry to 60-70%, rinse the applied biting liquid with clean water. After rinsing, you can also use a brush dipped in water to lightly brush the surface of the biting liquid to create a rust texture, which further increases the old feel of the copperware on the basis of the boiled black base.

[0076] S4: Post-aging coloring: Use an aging oily color essence to apply aging treatment to random areas on the surface of the copper product after the aging treatment; the purpose is to simulate the mottled feeling of the copper surface through color dotting;

[0077] Choose an oil-based color concentrate for old colors, and dilute the oil-based color concentrate with alcohol in a weight ratio of 1:100 before use;

[0078] Dip the brush into the prepared color solution, select random areas on the surface of the bronze, and apply any contours to simulate a mottled, rusty pattern on the surface of old bronze. Repeat the application 4 to 5 times on the same location, depending on the desired effect and the degree of restoration. Before each application, wait for the previous color to dry to 80 to 90% before applying again.

[0079] According to the process steps provided in Example 1 and Comparative Example 3, an aging layer is formed on the surface of the copperware; the difference between the two is that the aging layer of Example 1 is coated with a varnish isolation layer, while the aging layer of Comparative Example 3 has no isolation layer; Example 1 is set as 1# aging copperware, and Comparative Example 3 is set as 2# aging copperware; the corrosion resistance of the aging layers of the two in a humid environment is compared;

[0080] Put the copperware #1 and #2 into the same sealed box, introduce air from the outside into the box, and keep the humidity in the box at 60-70% through the atomizing device; continue the treatment for 10 days; observe the corrosion of the copperware #1 and #2, and record it in Table 2;

[0081] Table 2 Corrosion of copperware in Example 1 and Comparative Example 3

[0082] Example 1 1# Old copperware Comparative Example 3 2# Old Copperware Rust color changes The rust color of the old layer has almost no change Part of the red-green rust turns into black-brown Changes in layering The old layer has almost no change in layering The sense of hierarchy between rust colors disappears Is the old layer peeling off? The old layer did not peel off Some areas have peeling

[0083] Analysis of results: In Example 1, a varnish isolation layer was provided for the aged layer to protect it, and no obvious corrosion was caused to the aged layer on the copperware in a humid oxidizing environment.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0085] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and use the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for surface treatment of antique bronze, characterized in that: The following steps are involved: S1: Copper billet pretreatment: The surface of the cast copper billet is polished to remove the obvious uneven parts; The surface of the copper billet is cleaned by using an organic acid strong reducing cleaning agent; S2: Blackening treatment: immerse the pretreated copper billet in a metal blackening solution and boil it to form a black oxidized aging layer on the surface of the copper billet; S3: Bite treatment: Dip the bite solution and apply it evenly on the oxide layer formed on the surface of the copper product; repeat 2 to 3 times; oxidize to form an old rust layer; S4: Post-aging coloring: Use an aging oily colorant to spot-paint the surface of the copper product after the aging treatment to create an aging effect; forming an aging mottled pattern; S5: generating an isolation layer: after completing S1 to S4, a transparent adhesive is used to form an isolation layer covering the aging layer on the surface of the copper product.

2. The method for surface treatment of antique bronze according to claim 1, characterized in that: The copper blank surface needs to be polished with sandpaper to smooth the casting mouth and the inner and outer walls of the copperware; then the entire copperware is polished for a second time with copper carbon dipped in water until the surface is fine.

3. The method for surface treatment of antique bronze according to claim 1, characterized in that: In S1, oxalic acid is used to clean the copper billet to remove the thin oxide layer produced on the surface of the copper billet during the period of time when the copper billet is exposed to the air after casting; After cleaning, the copper billet needs to be rinsed with clean water to remove the residual oxalic acid on the surface and then dried naturally.

4. The method for surface treatment of antique bronze according to claim 1, characterized in that: The weight ratio of the solute to water in the metal blackening solution in the S2 blackening treatment is set to 1 to 1.5:3; The boiling time is controlled between 20 and 40 minutes; After the black boiling treatment, take out the copperware, soak it in clean water, brush off the black residue on the surface of the copperware that is easy to fall off, and then wipe it repeatedly with a coarse cloth.

5. The method for surface treatment of antique bronze according to claim 4, characterized in that: The solute components of the metal blackening solution include: one of copper sulfate, sodium nitrite and sodium sulfide.

6. The method for surface treatment of antique bronze according to claim 1, characterized in that: The components of the old-bite-removing solution include: copper sulfate solution and selenium dioxide solution; the copper sulfate solution and water are mixed into the old-bite-removing solution in a weight ratio of 1:3:

100.

7. The method for surface treatment of antique bronze according to claim 1, characterized in that: In S3, each time the biting solution is applied, the next application needs to be done after the surface of the biting solution is dried; After the last application of the rust-corrosion solution, when the rust-corrosion solution is half dry, rinse it off with clean water, then lightly brush it with a brush dipped in water to modify the details to create a layered rust effect.

8. The method for surface treatment of antique bronze according to claim 1, characterized in that: The oily color essence in S4 needs to be diluted with alcohol in a weight ratio of 1:100 before use.

9. The method for surface treatment of antique bronze according to claim 1, characterized in that: In S4, the prepared color concentrate solution is applied to any position of the copper product using a brush to form a mottled pattern; Repeat the application 4 to 5 times on the same spot. Before each application, wait until the color of the previous application is 80 to 90% dry.

10. The method for surface treatment of antique bronze according to claim 1, characterized in that: The transparent adhesive in S5 includes: one of transparent wax paste and varnish; Put the varnish or melted transparent wax paste into a pressure spray pot, keep the copperware rotating at a constant speed, and spray the varnish or transparent wax paste evenly on the surface of the copperware to form a transparent isolation layer; When the first sprayed isolation layer is 80-90% dry, spray the second isolation layer; repeat this 2-3 times.

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