WO2019006612A1

WO2019006612A1 - Passivator, passivation process for metal-plated part and metal workpiece

Info

Publication number: WO2019006612A1
Application number: PCT/CN2017/091547
Authority: WO
Inventors: 刘国平
Original assignee: 深圳市宏昌发科技有限公司
Priority date: 2017-07-03
Filing date: 2017-07-03
Publication date: 2019-01-10

Abstract

A passivator and a passivation process for a metal-plated part. The passivator comprises, per 3000 parts by weight thereof, the following components in parts by weight: 1-10 parts of cobalt salt, 10-100 parts of phosphate salt, 0.5-6 parts of fluoride, 1-5 parts of sodium molybdate, 1-5 parts of silica sol, and the balance of distilled water. The product does not contain chromium and is safe to the environment and human body. The passivated tin-plated plate is formed with a transparent rigid protective film on a plated surface thereof, greatly increasing the capabilities of anti-corrosion, anti-oxidation and anti-sulfuration, and can be widely applied to a variety of metal-plated parts, and is particularly beneficial to passivation of a tin-plated layer.

Description

Description: Inventive name: passivation agent, metal plated part passivation treatment method and metal workpiece

[0001] The present invention relates to the field of surface treatment technology, and in particular, to a passivating agent, a metal plated member passivation treatment method, and a metal workpiece.

Background technique

[0002] In order to improve the surface properties or appearance of a product, the surface treatment technology of the workpiece is usually applied. For example, steel and its electroplated parts, copper and its surface treatment methods for electroplated parts go deep into all walks of life. Passivation is a common surface treatment method.

[0003] The conventional passivation methods include boiling water method, dichromate method, metal salt method, etc. Although the boiling water passivation method is non-polluting, it is prone to powder frost, affecting the quality appearance and the bonding force between the paint layer and the substrate. And energy consumption is large. The dichromate method has been polluted by the environment and has been eliminated by the existing market. The metal salt method has a variety of ions, and there are some impurity ions, and the impurity ions have a certain interference with the passivation treatment. Moreover, the protective layer produced by the conventional passivation treatment is not dense, is not resistant to temperature, and has poor corrosion resistance.

technical problem

[0004] In view of the above, a passivating agent having strong bonding strength, temperature resistance, corrosion resistance, a passivation treatment method for a metal plating member, and a metal workpiece are provided.

Problem solution

Technical solution

[0005] A passivating agent in an amount of 3000 parts by weight, the passivating agent comprising the following components in parts by weight: 1- 10 parts of cobalt salt, 10-100 parts of phosphate, 0.5-6 parts of fluoride, 1-5 parts of sodium molybdate, 1-5 parts of silica sol and the balance of distilled water.

[0006] A method for passivating a metal plated part, comprising the steps of: preparing a passivating agent as described above, treating the metal plated part with a passivating agent, and controlling the pH of the solution to be in the range of 3.0-5.5, After the predetermined time, a passivation protective film is formed on the surface of the metal plating.

[0007] And, a metal workpiece having a metal plating film on the surface thereof, wherein the metal plating film is formed with a passivation protective film according to the metal plating member passivation treatment method as described above. Advantageous effects of the invention

Beneficial effect

[0008] The protective film layer formed by the above passivating agent has strong passivation property to the metal and the plating layer, and has the properties of anti-oxidation, anti-sulfurization and blackening, and forms a colorless and transparent strong protective film on the surface of the plating layer after drying, and is resistant to corrosion. The properties of anti-oxidation, anti-vulcanization and blackening are greatly enhanced. It can be widely used in various metal plating parts, especially for tin-plating layer passivation. It is a better choice for anti-corrosion and anti-discoloration of coating surface. The process of the above treatment method is easy to operate, and both dip coating and spray coating are possible. The above passivating agent is a water-soluble antiseptic passivating substance. This product is non-toxic, non-combustible, non-polluting and easy to use. The protective film formed after the treatment is insoluble in water, has good resistance to vulcanization and moisture resistance, has good toughness of the film layer, and is bendable and deformable. After passivation treatment of the above passivating agent, the surface of the passivated metal plated part has improved gloss and hardness, and can be widely applied to various metal plated parts.

Embodiments of the invention

The present invention will be described in detail below with reference to specific embodiments.

[0010] An embodiment of the present invention provides a passivating agent comprising a passivating agent, wherein the passivating agent comprises the following components in a proportion by weight: 1-10 parts of cobalt salt, based on 3000 parts by weight, 10-100 parts of phosphate, 0.5-6 parts of fluoride, 1-5 parts of sodium molybdate, 1-5 parts of silica sol and the balance of distilled water.

[0011] Preferably, the cobalt salt is in an amount of from 3 to 8 parts by weight. The proportion by weight of the phosphate is preferably from 20 to 60 parts. The parts by weight of the fluoride are preferably 2-4 parts by weight. The parts by weight of sodium molybdate are preferably 2-4 parts by weight. The weight fraction of the silica sol is preferably 2-4 parts by weight.

[0012] The passivating agent is controlled in the range of 3.0-5.5 using 吋PH value. In the passivating agent, the cobalt salt, sodium molybdate, and phosphate are the main components of the passivation film, and the silica sol acts as a filling covering to prevent the air from coming into contact with the substrate. Fluoride and sodium molybdate promote the formation of passivation film.

[0013] An embodiment of the present invention further provides a method for passivating a metal plated part, comprising the steps of: preparing a passivating agent as described above, treating the metal plated part with a passivating agent solution, and controlling the pH value of the solution. In the range of 3.0-5.5, after the predetermined time is processed, a passivation protective film is formed on the surface of the metal plated part, and then dried or naturally dried.

[0014] wherein, the metal plating member is treated with a passivating agent solution, including a dipping method, a spraying method or a brushing method, preferably a dipping method. During the treatment of the passivating solution, the control temperature is preferably 40-60 ° C, and the treatment time is preferred. For 4 to 8 minutes.

[0015] In addition, the embodiment of the present invention further provides a metal workpiece having a metal plating film on the surface thereof, for example, forming a plating layer by metal plating electroless plating, and the metal plating film is preferably a tin-plated workpiece. On the metal plating film, a passivation protective film is formed in accordance with the metal plating member passivation treatment method as described above.

[0016] The processing object of the above metal plating member may be, but not limited to, a tin-plated member. After the surface treatment as described above, the surface of the metal workpiece has a good protective effect, and the formed protective film has strong passivation property to the metal and the plating layer. And anti-oxidation, anti-sulfurization and blackening properties, after drying, form a colorless and transparent solid protective film on the surface of the coating. Corrosion resistance, oxidation resistance, anti-sulfurization and blackening properties are greatly enhanced, and the surface of the coating is corrosion-resistant and resistant. The best choice for color change. The process of the above treatment method is simple and easy to operate, and the dip coating can be used. The above passivating agent is a water-soluble antiseptic passivating substance. This product is non-toxic, non-combustible, environmentally friendly and easy to use. The protective film formed after the treatment is insoluble in water, has good resistance to vulcanization and moisture resistance, has good toughness of the film layer, and can be bent and deformed. In addition to metal workpieces, passivation is also widely used in decorative coatings and corrosion-resistant coatings for hardware machinery, communication equipment, instruments, household appliances, lamps and other products.

[0017] Hereinafter, the composition range, the preparation method, and the use effect of the above-mentioned passivating agent are exemplified by a plurality of embodiments, and the metal workpieces of the following embodiments are all exemplified by tin-plated parts.

Embodiment 1

[0019] The ingredients are mixed in the following parts by weight (based on a total weight fraction of 3000). The passivating agent comprises the following components in parts by weight: 1 part of cobalt chloride,

10 parts of trisodium phosphate, 0.5 parts of ammonium hydrogen fluoride, 1 part of sodium molybdate, 1 part of silica sol and the balance of distilled water, stirring

, evenly mixed, formulated as a passivating agent.

[0020] Passivation treatment method: After the metal workpiece is coated, the metal plating member is immersed in the passivating agent solution, and the pH value of the passivating agent solution is controlled to be controlled by phosphoric acid or ammonia water at 3.5, the temperature is 66 ° C, and the treatment is performed for 12 minutes. After that, a passivation protective film was formed on the surface of the metal plated member, and taken out at a temperature of 80 ° C for 15 minutes to dry.

[0021] After treatment, the metal plated part has a bright surface and uniform color, and has no abnormal brightness such as tin removal, black spots, cracks and yellowing, and the neutral salt spray test is more than 24 hours.

Embodiment 2

[0023] The components are mixed according to the following parts by weight (based on a total weight fraction of 3000). The passivating agent comprises the following components in parts by weight: 3 parts of cobalt chloride, 30 parts of trisodium phosphate, 1.5 parts of ammonium hydrogen fluoride, 2 parts of sodium molybdate, 2 parts of silica sol and the balance of distilled water, stirring

, evenly mixed, formulated as a passivating agent.

[0024] Passivation treatment method: After the metal workpiece is coated, the metal plating member is immersed in the passivating agent solution, and the pH value of the passivating agent solution is controlled to be controlled by phosphoric acid or ammonia water at 4, the temperature is 60 ° C, and the treatment is performed for 8 minutes. After that, a passivation protective film is formed on the surface of the metal plated member, and taken out at a temperature of 70 ° C for 15 minutes to dry.

[0025] After treatment, the appearance of the metal plated part is bright, uniform in color, and has no abnormal brightness such as tin removal, black spots, cracks, yellowing, and neutral salt spray test for more than 48 hours.

Embodiment 3

[0027] The components are mixed according to the following parts by weight (based on a total weight fraction of 3000). The passivating agent comprises the following components in parts by weight: 5 parts of cobalt chloride, 50 parts of trisodium phosphate, 3 parts of ammonium hydrogen fluoride 3 parts of sodium molybdate, 3 parts of silica sol and the balance of distilled water, stirred, uniformly mixed, and formulated into a passivating agent.

[0028] Passivation treatment method: After the metal workpiece is coated, the metal plating member is immersed in the passivating agent solution, and the pH value of the passivating agent solution is controlled to be controlled by phosphoric acid or ammonia water at 4.5, the temperature is 60 ° C, and the treatment is performed for 10 minutes. After that, a passivation protective film is formed on the surface of the metal plated member, and taken out at a temperature of 75 ° C for 15 minutes to dry.

[0029] After treatment, the appearance of the metal plated part is bright, the color is uniform, and there is no abnormal brightness such as tin removal, black spots, cracks, yellowing, and the neutral salt spray test is more than 72 hours.

Embodiment 4

[0031] The components are mixed in the following parts by weight (based on a total weight fraction of 3000). The passivating agent comprises the following components in parts by weight: 7 parts of cobalt chloride,

70 parts of trisodium phosphate, 4.5 parts of ammonium hydrogen fluoride, 4 parts of sodium molybdate, 4 parts of silica sol and the balance of distilled water, stirring

, evenly mixed, formulated as a passivating agent.

[0032] Passivation treatment method: After the metal workpiece is coated, the metal plating member is immersed in the passivating agent solution, and the pH value of the passivating agent solution is controlled to be controlled by phosphoric acid or ammonia water at 5.0, the temperature is 65 ° C, and the treatment is performed for 10 minutes. After that, a passivation protective film was formed on the surface of the metal plated member, and taken out at a temperature of 80 ° C for 15 minutes to dry.

[0033] The treated metal plated part has a bright surface appearance, uniform color, no abnormal brightness such as tin removal, black spots, cracks, yellowing, and neutral salt spray test of 96 hours or more.

Example 5

[0035] The components are mixed according to the following parts by weight (based on a total weight fraction of 3000), the passivating agent is included in parts by weight The following components are ratio: 9 parts of cobalt chloride, 90 parts of trisodium phosphate, 6 parts of ammonium hydrogen fluoride, 5 parts of sodium molybdate, 5 parts of silica sol and the balance of distilled water, stirred, uniformly mixed, and formulated into passivating agent. .

[0036] Passivation treatment method: After the metal workpiece is coated, the metal plating member is immersed in the passivating agent solution, and the pH value of the passivating agent solution is controlled to be controlled by phosphoric acid or ammonia water at 5.5, the temperature is 65 ° C, and the treatment is performed for 10 minutes. After that, a passivation protective film was formed on the surface of the metal plated member, and taken out at a temperature of 80 ° C for 15 minutes to dry.

[0037] After treatment, the appearance of the metal plated part is bright, uniform in color, and has no abnormal brightness such as tin removal, black spots, cracks and yellowing, and the neutral salt spray test is more than 96 hours.

[0038] It should be noted that the present invention is not limited to the above embodiments, and other changes may be made by those skilled in the art according to the inventive spirit of the present invention, and the changes according to the inventive spirit of the present invention should be It is intended to be included within the scope of the invention as claimed.

Claims

Claim

[Claim 1] A passivating agent characterized in that the passivating agent comprises, by weight of parts by weight, of the following components: 1-10 parts of a cobalt salt,

10-100 parts of phosphate, 0.5-6 parts of fluoride, 1-5 parts of sodium molybdate, 1-5 parts of silica sol and the balance of distilled water.

[Claim 2] The passivating agent according to claim 1, wherein the cobalt salt is cobalt sulfate or cobalt chloride in a part by weight of 3-8 parts.

[Claim 3] The passivating agent according to claim 1, wherein the phosphate is trisodium phosphate or disodium hydrogen phosphate or sodium dihydrogen phosphate in a part by weight of 20 to 60 parts.

[Claim 4] The passivating agent according to claim 1, wherein the fluoride is sodium fluoride or ammonium hydrogen fluoride in a part by weight of 2 to 4 parts.

[Claim 5] The passivating agent according to claim 1, wherein the sodium molybdate is in parts by weight

-4 parts.

[Claim 6] The passivating agent according to claim 1, wherein the silica sol has a weight fraction of 2

-4 parts.

[Claim 7] The passivating agent according to claim 1, wherein the PH value is 3.0-5.5, and is adjusted with phosphoric acid or sodium hydroxide, and the passivating agent is used at a temperature of 20-80. C.

[Claim 8] A metal plated member passivation treatment method, comprising the steps of: formulating the passivating agent according to any one of claims 1 to 7; treating the metal plated member with a passivating agent The pH of the control solution is in the range of 3.0-5.5. After the predetermined treatment, the passivation protective film is formed on the surface of the metal plated part.

[Claim 9] The method for passivating a metal plating member according to claim 7, wherein the treating the metal plating member with the passivating agent solution comprises a dipping method, a spraying method or a brushing method, During the treatment of the chemical solution, the control temperature is 20-80 ° C, and the treatment time is 3-10 minutes.

[Claim 10] A metal workpiece having a metal plating film on the surface of the metal workpiece, wherein the metal plating film is formed with a passivation protective film according to the metal plating member passivation treatment method according to claim 8.