A surface treatment method for stainless steel sheets

Abstract

The application discloses a stainless steel plate surface treatment method, which comprises the following steps: S01 silk printing operation: water-based ink is screen printed on the stainless steel plate after a pretreatment operation, and is used after a curing reaction; S02 interface modification operation: the stainless steel plate is immersed in an interface modification solution to perform an interface modification reaction; and S03 etching operation: the stainless steel plate is placed in an electrochemical corrosion device containing an etching solution to perform an etching reaction, so that a smooth transition stainless steel plate surface treatment pattern is formed. The stainless steel plate surface treatment method avoids the formation of relatively sharp and clear corners at the etching edge interface of the stainless steel plate, and avoids the residual of metal ions on the ink at the etching edge interface after etching, thereby avoiding the heavy metal pollution of wastewater in the subsequent glue removal operation. After the surface treatment, the etching surface of the stainless steel plate is naturally transitioned to the original surface texture of the stainless steel plate base material, the appearance quality is higher, and the user satisfaction is improved.

Description

A surface treatment method for stainless steel plates Technical Field

[0001] This invention relates to the technical field of stainless steel surface treatment, and in particular to a method for surface treatment of stainless steel plates based on etching process. Background Technology

[0002] Stainless steel is widely used due to its excellent corrosion resistance and beautiful appearance, with applications extending beyond industry to all aspects of daily life, including clothing, food, housing, and transportation. With technological advancements and people's increasing aspirations for a better quality of life, the demands for the refinement of surface patterns on stainless steel are also rising. Current methods for creating patterns, whether using mechanical stamping or chemical etching, still suffer from issues such as unnatural transitions and a need for further improvement in the aesthetic appeal of the stainless steel substrate. Furthermore, traditional etching processes not only leave behind metal ions in the etching residue that requires recycling, but also leave metal ions in the ink removal solution, significantly increasing the difficulty and cost of wastewater treatment. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention provides a surface treatment method for stainless steel plates to solve the problems of low quality of patterns and textures, low production efficiency and high wastewater treatment costs of existing stainless steel plate surface treatment methods.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A surface treatment method for stainless steel plates, the method comprising the following steps:

[0006] S01 Screen Printing Operation: Water-based ink is screen printed onto a pre-treated stainless steel plate, and then cured for later use.

[0007] S02 Interface Modification Operation: The stainless steel plate treated in step S01 is immersed in the interface modification solution to carry out the interface modification reaction.

[0008] S03 Etching Operation: The stainless steel plate treated in step S02 is placed in an electrochemical corrosion device containing etching solution to carry out the etching reaction and form a smooth transition surface treatment pattern on the stainless steel plate.

[0009] Preferably, the pretreatment operation steps are as follows: first, the stainless steel plate is polished with 60-1200 grit sandpaper, then immersed in a mixed solution of hydrogen peroxide and hydrochloric acid for surface degreasing and activation treatment, and finally cleaned and dried to complete the pretreatment operation.

[0010] Preferably, the water-based ink is composed of the following raw materials in parts by weight: 42-47 parts water-soluble acrylic resin, 0.5-1 part monoethanolamine, 0.5-1 part polyethylene wax, 0.2-0.8 parts POSS, 1-2 parts glycerin, 50-90 parts pigment, and 40-60 parts deionized water. The water-soluble acrylic resin has CAS number 25767-39-9; the pigment is at least one selected from carbon black, phthalocyanine blue, phthalocyanine green, Lithol red, permanent red, and titanium dioxide. The water-based ink of this invention uses water-soluble acrylic resin as the main resin component, compounded with monoethanolamine, polyethylene wax, POSS, glycerin, pigment, and deionized water. Screen printing with this water-based ink not only results in high-quality screen printing and facilitates subsequent etching operations, but is also environmentally friendly and pollution-free. Cage-type polysilsesquioxane (POSS), with CAS number 68554-70-1, has a unique porous cage-like structure, which helps in the uniform dispersion of pigments.

[0011] Preferably, the curing reaction temperature is 100–150°C and the curing time is 10–30 min.

[0012] Preferably, the interface modification solution is a mixture of adamantane monohydric alcohol and a low-boiling-point organic solvent.

[0013] Preferably, the adamantane monohydric alcohol is at least one selected from 3-ethyl-1-adamantanol, 3,5-dimethyl-1-adamantanol, 2-adamantanol, 3-methyl-1-adamantanol, 3,5-dimethyl-1-adamantanol, 1-adamantanol, and 1-adamantanol. This invention introduces an adamantane structure through a graft modification reaction between the adamantane monohydric alcohol and the ink near the etching edge interface. On the one hand, the steric hindrance of the adamantane structure slows down or prevents the reaction between etched metal ions and carboxyl functional groups in the water-based ink, thereby reducing the load on subsequent wastewater treatment and lowering the cost and difficulty of wastewater treatment. On the other hand, it avoids the corrosive damage of acidic etching solution to water-soluble acrylic resin, thus further preventing the formation of sharp and clear angles at the etching edge interface of the stainless steel plate and improving the quality of the pattern texture at the etching edge interface.

[0014] Preferably, the low-boiling-point organic solvent is at least one of dichloromethane, diethyl ether, and acetone.

[0015] Preferably, the etching solution is composed of ferric chloride, hydrochloric acid, cerium ammonium nitrate, nitric acid, and deionized water; the content of ferric chloride is 200-350 g / L, the content of hydrochloric acid is 0.4-1.1 mol / L, the content of cerium ammonium nitrate is 100-250 g / L, and the content of nitric acid is 0.2-0.6 mol / L.

[0016] Preferably, the electrochemical etching device uses a stainless steel plate as the positive electrode and a platinum electrode as the negative electrode, and is operated by a DC power supply with an operating voltage of 25V and an operating time of 90–180s. This invention improves etching efficiency and quality by combining the prepared etching solution with the auxiliary method of electrochemical etching, ensuring that the etched pattern has clear texture and no obvious sharp angles.

[0017] Preferably, the processing method further includes step S04, a de-adhesive removal operation; the de-adhesive removal operation is performed after step S03, an etching operation, and specifically involves immersing the stainless steel plate in an ultrasonic water bath containing a cleaning agent, heating it to 50-80°C, and ultrasonically cleaning it for 5-10 minutes to remove the ink from the stainless steel plate.

[0018] The beneficial effects of this invention are:

[0019] The stainless steel plate surface treatment method of this invention first involves screen printing ink and performing interface modification treatment, followed by electrochemical assisted etching. This not only avoids the formation of sharp, clear angles at the etched edges of the stainless steel plate, but also prevents metal ions from remaining on the ink at the etched edges, thus avoiding heavy metal pollution in the wastewater from subsequent descaling operations. The stainless steel plate surface treated according to this invention exhibits a natural transition between the etched surface and the original stainless steel substrate surface texture, resulting in higher appearance quality and improved user satisfaction. Detailed Implementation

[0020] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0021] Example 1

[0022] The stainless steel plate surface treatment method of this embodiment includes the following steps:

[0023] S01 Screen Printing Operation: Water-based ink is screen printed onto a pre-treated 316 stainless steel plate, and cured for later use. The curing temperature is 110℃, and the curing time is 30 minutes. The pre-treatment steps are as follows: The stainless steel plate is first polished with 60-grit, 200-grit, 500-grit, and 1200-grit sandpaper in sequence, then immersed in a mixed solution of hydrogen peroxide and hydrochloric acid with a volume ratio of 1:1 (75% hydrogen peroxide and 35% hydrochloric acid) for surface degreasing and activation treatment, and finally cleaned and dried to complete the pre-treatment operation.

[0024] S02 Interface Modification Operation: The stainless steel plate treated in step S01 is immersed in the interface modification solution and the interface modification reaction is carried out for 6 hours; the interface modification solution is a mixture of 3-ethyl-1-adamantanol and dichloromethane in a mass ratio of 3:10.

[0025] S03 Etching Operation: The stainless steel plate treated in step S02 is placed in an electrochemical etching device containing etching solution to perform an etching reaction, forming a smooth transition surface treatment pattern on the stainless steel plate. The etching solution consists of ferric chloride, hydrochloric acid, cerium ammonium nitrate, nitric acid, and deionized water; the content of ferric chloride is 200 g / L, the content of hydrochloric acid is 0.6 mol / L, the content of cerium ammonium nitrate is 100 g / L, and the content of nitric acid is 0.2 mol / L. The electrochemical etching device uses the stainless steel plate as the positive electrode and a platinum electrode as the negative electrode, and is operated by a DC power supply with an operating voltage of 25V and an operating time of 180s.

[0026] S04 Removal of Adhesive: This removal of adhesive is performed after the etching operation in step S03. Specifically, the removal of adhesive involves immersing the stainless steel plate in an ultrasonic water bath containing a cleaning agent, heating it to 60°C, and ultrasonically cleaning it for 10 minutes to remove the ink from the stainless steel plate. The cleaning agent is commercially available HDW-T100 cleaning agent with a concentration of 20 g / L.

[0027] The water-based ink is composed of the following raw materials in parts by weight: 42 parts water-soluble acrylic resin, 0.5 parts monoethanolamine, 0.5 parts polyethylene wax, 0.2 parts POSS, 1 part glycerin, 50 parts pigment, and 40 parts deionized water. The pigment is composed of carbon black, phthalocyanine blue, phthalocyanine green, Lithol red, permanent red, and titanium dioxide in a mass ratio of 10:9:9:8:7:10.

[0028] The results show that the etched pattern on the 316 stainless steel plate in this embodiment transitions naturally with the original surface texture of the stainless steel plate substrate, the texture is clear, the appearance quality is high, the texture edges are not obviously sharp, and the user satisfaction is high; in addition, no metal ions were detected in the wastewater after the degumming operation in step S04, which reduced the difficulty and cost of treating the wastewater from the surface treatment of stainless steel plates.

[0029] Example 2

[0030] The stainless steel plate surface treatment method of this embodiment includes the following steps:

[0031] S01 Screen Printing Operation: Water-based ink is screen printed onto a pre-treated 316 stainless steel plate, and cured for later use. The curing reaction temperature is 120℃, and the curing time is 20 minutes. The pre-treatment operation steps are as follows: The stainless steel plate is first polished with 60-grit, 200-grit, 500-grit, and 1200-grit sandpaper in sequence, then immersed in a mixed solution of hydrogen peroxide and hydrochloric acid with a volume ratio of 1:1 (75% by mass of hydrogen peroxide and 35% by mass of hydrochloric acid) for surface degreasing and activation treatment, and finally cleaned and dried to complete the pre-treatment operation.

[0032] S02 Interface Modification Operation: The stainless steel plate treated in step S01 is immersed in the interface modification solution and the interface modification reaction is carried out for 6 hours; the interface modification solution is a mixture of 2-adamantanol and dichloromethane in a mass ratio of 3:10.

[0033] S03 Etching Operation: The stainless steel plate treated in step S02 is placed in an electrochemical etching device containing etching solution to perform an etching reaction, forming a smooth transition surface treatment pattern on the stainless steel plate. The etching solution consists of ferric chloride, hydrochloric acid, cerium ammonium nitrate, nitric acid, and deionized water; the content of ferric chloride is 300 g / L, the content of hydrochloric acid is 0.8 mol / L, the content of cerium ammonium nitrate is 150 g / L, and the content of nitric acid is 0.4 mol / L. The electrochemical etching device uses the stainless steel plate as the positive electrode and a platinum electrode as the negative electrode, and is operated by a DC power supply with an operating voltage of 25V and an operating time of 120s.

[0034] S04 Removal of Adhesive: This removal of adhesive is performed after the etching operation in step S03. Specifically, the removal of adhesive involves immersing the stainless steel plate in an ultrasonic water bath containing a cleaning agent, heating it to 60°C, and ultrasonically cleaning it for 10 minutes to remove the ink from the stainless steel plate. The cleaning agent is commercially available HDW-T100 cleaning agent with a concentration of 20 g / L.

[0035] The water-based ink is composed of the following raw materials in parts by weight: 45 parts water-soluble acrylic resin, 0.7 parts monoethanolamine, 0.8 parts polyethylene wax, 0.5 parts POSS, 1.5 parts glycerin, 70 parts pigment, and 50 parts deionized water. The pigment is the same as in Example 1.

[0036] The results show that the etched pattern on the 316 stainless steel plate in this embodiment transitions naturally with the original surface texture of the stainless steel plate substrate, the texture is clear, the appearance quality is high, the texture edges are not obviously sharp, and the user satisfaction is high; in addition, no metal ions were detected in the wastewater after the degumming operation in step S04, which reduced the difficulty and cost of treating the wastewater from the surface treatment of stainless steel plates.

[0037] Example 3

[0038] The stainless steel plate surface treatment method of this embodiment includes the following steps:

[0039] S01 Screen Printing Operation: Water-based ink is screen printed onto a pre-treated 316 stainless steel plate, and cured for later use. The curing reaction temperature is 130℃, and the curing time is 15 minutes. The pre-treatment operation steps are as follows: The stainless steel plate is first polished with 60-grit, 200-grit, 500-grit, and 1200-grit sandpaper in sequence, then immersed in a mixed solution of hydrogen peroxide and hydrochloric acid with a volume ratio of 1:1 (75% by mass of hydrogen peroxide and 35% by mass of hydrochloric acid) for surface degreasing and activation treatment, and finally cleaned and dried to complete the pre-treatment operation.

[0040] S02 Interface Modification Operation: The stainless steel plate treated in step S01 is immersed in the interface modification solution and the interface modification reaction is carried out for 6 hours; the interface modification solution is a mixture of 3-methyl-1-adamantanol and dichloromethane in a mass ratio of 3:10.

[0041] S03 Etching Operation: The stainless steel plate treated in step S02 is placed in an electrochemical etching device containing etching solution to perform an etching reaction, forming a smooth transition surface treatment pattern on the stainless steel plate. The etching solution consists of ferric chloride, hydrochloric acid, cerium ammonium nitrate, nitric acid, and deionized water; the content of ferric chloride is 350 g / L, the content of hydrochloric acid is 1.1 mol / L, the content of cerium ammonium nitrate is 250 g / L, and the content of nitric acid is 0.6 mol / L. The electrochemical etching device uses the stainless steel plate as the positive electrode and a platinum electrode as the negative electrode, and is operated by a DC power supply with an operating voltage of 25V and an operating time of 90s.

[0042] S04 Removal of Adhesive: This removal of adhesive is performed after the etching operation in step S03. Specifically, the removal of adhesive involves immersing the stainless steel plate in an ultrasonic water bath containing a cleaning agent, heating it to 60°C, and ultrasonically cleaning it for 10 minutes to remove the ink from the stainless steel plate. The cleaning agent is commercially available HDW-T100 cleaning agent with a concentration of 20 g / L.

[0043] The water-based ink is composed of the following raw materials in parts by weight: 47 parts water-soluble acrylic resin, 1 part monoethanolamine, 1 part polyethylene wax, 0.8 parts POSS, 2 parts glycerin, 90 parts pigment, and 60 parts deionized water. The pigment is the same as in Example 1.

[0044] The results show that the etched pattern on the 316 stainless steel plate in this embodiment transitions naturally with the original surface texture of the stainless steel plate substrate, the texture is clear, the appearance quality is high, the texture edges are not obviously sharp, and the user satisfaction is high; in addition, no metal ions were detected in the wastewater after the degumming operation in step S04, which reduced the difficulty and cost of treating the wastewater from the surface treatment of stainless steel plates.

[0045] Comparative Example 1

[0046] The surface treatment method for stainless steel plates in this comparative example is basically the same as that in Example 1. The difference is that the treatment method in this comparative example does not include the interface modification operation in step S02.

[0047] The results showed that: in this comparative example, the edges of the etched pattern on the 316 stainless steel plate had a few sharp parts; in addition, iron ions, nickel ions and chromium ions were detected in the wastewater after the descaling operation in step S04.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for surface treatment of stainless steel plates, characterized in that, The processing method includes the following steps: S01 Screen printing: Water-based ink is screen printed onto a pre-treated stainless steel plate, and the plate is cured and set aside; S02 Interface modification: The stainless steel plate treated in step S01 is immersed in an interface modification solution to perform an interface modification reaction; S03 Etching: The stainless steel plate treated in step S02 is placed in an electrochemical etching device containing an etching solution to perform an etching reaction, forming a smooth transition surface treatment pattern on the stainless steel plate; The interface modification solution is a mixture of adamantane monohydric alcohol and a low-boiling-point organic solvent; The adamantane monohydric alcohol is at least one of 3-ethyl-1-adamantanol, 3,5-dimethyl-1-adamantanol, 2-adamantanol, 3-methyl-1-adamantanol, 3,5-dimethyl-1-adamantanol, 1-adamantanol, and 1-adamantanol; The low-boiling-point organic solvent is at least one of dichloromethane, diethyl ether, and acetone.

2. The stainless steel plate surface treatment method as described in claim 1, characterized in that, The pretreatment steps are as follows: first, the stainless steel plate is polished with 60-1200 grit sandpaper, then immersed in a mixed solution of hydrogen peroxide and hydrochloric acid for surface degreasing and activation treatment, and finally cleaned and dried to complete the pretreatment operation.

3. The stainless steel plate surface treatment method as described in claim 1, characterized in that, The water-based ink is composed of the following raw materials in parts by weight: 42-47 parts water-soluble acrylic resin, 0.5-1 part monoethanolamine, 0.5-1 part polyethylene wax, 0.2-0.8 parts POSS, 1-2 parts glycerin, 50-90 parts pigment and 40-60 parts deionized water.

4. The stainless steel plate surface treatment method as described in claim 1, characterized in that, The curing reaction is carried out at a temperature of 100–150°C for 10–30 minutes.

5. The stainless steel plate surface treatment method as described in claim 1, characterized in that, The etching solution is composed of ferric chloride, hydrochloric acid, cerium ammonium nitrate, nitric acid, and deionized water; the content of ferric chloride is 200-350 g / L, the content of hydrochloric acid is 0.4-1.1 mol / L, the content of cerium ammonium nitrate is 100-250 g / L, and the content of nitric acid is 0.2-0.6 mol / L.

6. The stainless steel plate surface treatment method as described in claim 1, characterized in that, The electrochemical corrosion device uses a stainless steel plate as the positive electrode and a platinum electrode as the negative electrode, and is operated by a DC power supply with an operating voltage of 25V and an operating time of 90–180s.

7. The stainless steel plate surface treatment method as described in claim 1, characterized in that, The processing method further includes step S04, the adhesive removal operation; the adhesive removal operation is performed after step S03, the etching operation, and the adhesive removal operation specifically involves immersing the stainless steel plate in an ultrasonic water bath containing a cleaning agent, heating it to 50-80°C, and ultrasonically cleaning it for 5-10 minutes to remove the ink from the stainless steel plate.