WO2019000452A1

WO2019000452A1 - Coating agent, metal piece and surface coating treatment method therefor

Info

Publication number: WO2019000452A1
Application number: PCT/CN2017/091318
Authority: WO
Inventors: 王饶玲
Original assignee: 深圳市恒兆智科技有限公司
Priority date: 2017-06-30
Filing date: 2017-06-30
Publication date: 2019-01-03

Abstract

A coating agent, a metal piece and a surface coating treatment method therefor. The coating agent is used for surface pretreatment of a metal part and comprises the following components in mass content: 1-10g/L of trivalent chromium salt, 0.2-6g/L of titanium salt, 0.2-2g/L of promoter and 0.05-0.2g/L of fluoride salt. A film formed by the coating agent has good corrosion resistance and a strong binding force to a coating, and may be used as a good substrate for subsequent treatment such as spraying. In addition, after a work piece is treated, the film on the surface of the work piece is mainly trivalent chromium, which is more environmentally friendly than hexavalent chromium, and the surface of the work piece is colorful and bright.

Description

Film agent, metal part and surface film treatment method thereof

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

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, the surface treatment of aluminum, iron, etc. and its alloys goes deep into all walks of life. Moreover, most of the work needs to be pretreated before surface treatment, for example, cleaning, decontamination and degreasing, and some metal parts need to be filmed.

[0003] The filming treatment generally uses a film agent to pretreat the metal member to form a film layer on the surface of the metal member for subsequent surface treatment, thereby increasing the bonding force and corrosion resistance of the subsequent film. Traditional film treatment. The conventional film is generally a golden aluminum film. The film has good corrosion resistance and adhesion, but the composition of the surface film of the workpiece is hexavalent chromium, which is harmful to the environment. At present, many products have environmental protection requirements. The composition of such hexavalent chromium is obviously not in compliance with the requirements of safety and environmental protection.

technical problem

[0004] In view of the above, a coating agent having good corrosion resistance and strong coating adhesion, a surface treatment method of a metal member, and a metal member obtained by a film treatment are provided.

Problem solution

Technical solution

[0005] A film agent for surface pretreatment of metal parts, which comprises the following components: a mass content of 10-10 g/L trivalent chromium salt, 0.2-6 g/L titanium salt, 0.2-2 g/L accelerator, 0.05 -0.2 g / L of fluoride salt.

[0006] A method for treating a surface of a metal member, comprising the steps of: formulating a film agent as described above; adjusting the pH of the film solution to 3.0-5.5 by spraying or dipping the metal member into the film solution. After the predetermined daytime treatment, the metal parts are washed and dried.

And a metal member having a surface having a film formed by a surface treatment method of a metal member as described above. Advantageous effects of the invention

Beneficial effect

[0008] The film formed by the above-mentioned film agent has good corrosion resistance and strong adhesion to the coating, and can be used as a good substrate for subsequent treatment such as spraying. After the workpiece is processed, the film on the surface of the workpiece is mainly trivalent chromium and titanium salt, and the performance can completely replace the hexavalent chromium product, but it is more environmentally friendly than the hexavalent, and the surface of the workpiece can be multi-colored, and the decoration is good.

Embodiments of the invention

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

[0010] Embodiments of the present invention provide a film agent for surface pretreatment of a metal part, which comprises the following components of mass content: l-10 g/L trivalent chromium salt, 0.2-6 g/L titanium salt, 0.2-2 g / L accelerator, 0.05-0.2 g / L fluoride salt.

[0011] Preferably, the trivalent chromium salt has a mass content of 3-8 g / L, the trivalent chromium salt is preferably chromium nitrate or chromium trichloride, and the titanium salt has a mass content of l-3 g / L, The titanium salt is preferably titanyl sulfate or potassium fluorotitanate, the accelerator has a mass content of 0.5-2 g/L, and the accelerator is preferably sodium nitrate or hydrogen peroxide, and the fluorine salt has a mass content of 0.05- 0.2 g/L, the fluorine salt is preferably ammonium hydrogen fluoride or sodium fluoride. Further, the coating agent was adjusted to have a pH of 3.0 to 5.5 by using ammonia.

[0012] In the above-mentioned coating agent, a preferable film formation effect is achieved by controlling the balance of the respective distribution ratios. For example, when the ratio of trivalent chromium salt to fluoride salt is too high, the film formation is too slow and too thin to form a film. On the other hand, if the reaction is too fast, the film formation is too fast, the newly formed film is dissolved, and the film is not strong enough. The passivating agent has a chromium salt and a titanium salt as main film components, and a promoter and a fluorine salt are auxiliary film forming components.

[0013] The embodiment of the present invention further provides a metal film surface filming treatment method, comprising the following steps: preparing a film agent as described above; immersing the metal member in the film agent solution, adjusting the pH value of the film agent solution to 3.0 - 5.5, After the scheduled daytime treatment, the metal parts are washed and dried.

[0014] Specifically, after the metal member is immersed in the coating agent solution, the pH of the coating agent solution is adjusted to 3.0-5.5. The treatment time for the metal member to be immersed in the coating agent solution is preferably 3 to 10 minutes, and the thickness of the film formed is about 0.1 to 2 μm.

[0015] Embodiments of the present invention also provide a metal member which is processed by a surface treatment method of a metal member as described above to form a film on the surface of the metal member. The film protects the metal parts. Film treatment The method can be spray or soak. A colorless to blue corrosion-resistant passivation layer is formed on the surface of aluminum, die-cast aluminum, magnesium and their alloys by spraying or immersing. Especially for die-casting aluminum, the product does not contain Cr 6+ ions. To provide a coating to the bottom layer, or as a final anti-corrosion treatment.

[0016] Hereinafter, the coating agent and the treatment method thereof according to the examples of the present invention will be described by way of specific examples, and the case of the die-cast aluminum is taken as an example.

[0017] Embodiment 1

[0018] The ingredients are mixed according to the following mass contents: lg/L chromium trichloride, 0.2 g/L titanyl sulfate, 0.2 g/L hydrogen peroxide

, 0.05g / L ammonium hydrogen fluoride, add appropriate amount of water, stir, mix evenly, formulated into a film agent.

[0019] Treatment method: preparing a film agent; immersing the metal member in the film agent solution, adjusting the P of the film agent solution

The H value was 4.0, and after washing for 10 minutes at normal temperature, the metal parts were washed and dried. The film drying temperature should not be too high and should be controlled at about 80 degrees.

[0020] After the treatment of the above-mentioned film agent solution, the surface of the workpiece was observed, and the surface of the die-cast aluminum profile was uniformly light blue, the film layer was firm, and the corrosion resistance of the neutral salt spray test was more than 24 hours, and the boiling test was performed after spraying. Adhesion, no dropout, test level 0.

Embodiment 2

[0022] The ingredients are mixed according to the following mass contents: 3 g/L chromium trichloride, 2 g/L titanium oxysulfate, 0.8 g/L hydrogen peroxide

, 0.1g / L ammonium hydrogen fluoride, add appropriate amount of water, stir, mix evenly, formulated into a film agent.

[0023] Treatment method: preparing a film agent; immersing the metal member in the film agent solution, adjusting the P of the film agent solution

[0024] After the treatment of the above-mentioned film agent solution, the surface of the workpiece was observed, and the surface of the die-cast aluminum profile was uniformly light blue, the film layer was firm, and the corrosion resistance of the neutral salt spray test was 72 hours or more, and the boiling test was performed after spraying. Adhesion, no dropout, test level 0.

Embodiment 3

[0026] The ingredients were mixed according to the following mass contents: 6 g/L chromium trichloride, 4 g/L titanium oxysulfate, 1.2 g/L hydrogen peroxide

, 0.12g / L ammonium hydrogen fluoride, add appropriate amount of water, stir, mix evenly, formulated into a film agent.

[0027] Treatment method: preparing a film agent; immersing the metal member in the film agent solution, adjusting the pH value of the film agent solution to 4.0, and washing the metal parts at room temperature after 10 minutes of treatment, and drying. Film drying temperature Should not be too high, should be controlled at about 80 degrees.

[0028] After the treatment of the above coating agent solution, the surface of the workpiece was observed, and the surface of the die-cast aluminum profile was uniformly light blue, the film layer was firm, and the corrosion resistance of the neutral salt spray test was more than 120 吋, and the boiling test was performed after spraying. Adhesion, no dropout, test level 0.

Embodiment 4

[0030] The ingredients are mixed according to the following mass contents: 8 g/L chromium trichloride, 5 g/L titanium oxysulfate, 1.6 g/L hydrogen peroxide

, 0.16g / L ammonium hydrogen fluoride, add appropriate amount of water, stir, mix evenly, formulated into a film agent.

[0031] Treatment method: preparing a film agent; immersing the metal member in the film agent solution, adjusting the P of the film solution

[0032] After the treatment of the above-mentioned film agent solution, the surface of the workpiece was observed, and the surface of the die-cast aluminum profile was uniformly light blue, the film layer was firm, and the corrosion resistance of the neutral salt spray test was more than 400 吋, and the boiling test was performed after spraying. Adhesion, no dropout, test level 0.

Example 5

[0034] The ingredients are mixed according to the following mass contents: 10 g / L of chromium trichloride, 6 g / L of titanyl sulfate, 2 g / L of hydrogen peroxide,

0.2 g / L ammonium hydrogen fluoride, add an appropriate amount of water, stir, mix well, and prepare a film agent.

[0035] Treatment method: preparing a film agent; immersing the metal member in the film agent solution, adjusting the P of the film agent solution

[0036] After the treatment of the above-mentioned film agent solution, the surface of the workpiece was observed, and the surface of the die-cast aluminum profile was uniformly light blue, the film layer was firm, and the corrosion resistance of the neutral salt spray test was over 480 吋, and the boiling test was performed after spraying. Adhesion, no dropout, test level 0.

[0037] 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 creative 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

A filming agent for surface pretreatment of metal parts, characterized by comprising the following mass components: l-10 g/L trivalent chromium salt, 0.2-6 g/L titanium salt, 0.2-2 g/L accelerator, 0.05-0. 2g / L fluoride salt.

The film coating agent according to claim 1, wherein the trivalent chromium salt is chromium nitrate or chromium trichloride, and has a mass content of 3-8 g/L.

The coating agent according to claim 1, wherein the titanium salt is titanyl sulfate or potassium fluorotitanate, and has a mass content of from 1 to 3 g/L.

The coating agent according to claim 1, wherein the accelerator is sodium nitrate or hydrogen peroxide and has a mass content of 0.5 to 2 g/L.

The coating agent according to claim 1, wherein the fluorine salt is ammonium hydrogen fluoride or sodium fluoride, and the mass content is 0.05 to 0.2 g/L.

The film agent according to claim 1, wherein the film agent adjusts the P H value to 3.0 to 5.5 by ammonia water.

A method for treating a surface of a metal member, comprising the steps of: formulating a film agent according to any one of claims 1 to 6; adjusting the pH of the film solution by spraying or dipping the metal member into the film solution The value is 3.0-5.5. After the predetermined daytime treatment, the metal parts are washed and dried.

A metal member characterized in that the surface of the metal member is formed with a film by the surface filming treatment method of the metal member according to claim 7.

The metal member according to claim 8, wherein after the film is formed, the surface of the metal member is further subjected to passivation, oxidation resistance or coating treatment or anticorrosive treatment, and the film thickness is 0.1-2 μm.