WO2019006626A1

WO2019006626A1 - Chromium-free passivator, aluminum workpiece and surface passivation process therefor

Info

Publication number: WO2019006626A1
Application number: PCT/CN2017/091561
Authority: WO
Inventors: 万华
Original assignee: 深圳市盈恒科技有限公司
Priority date: 2017-07-03
Filing date: 2017-07-03
Publication date: 2019-01-10

Abstract

A chromium-free passivator is used for surface pretreatment of an aluminum workpiece and comprises the following components in parts by weight per 1000 parts by weight of the chromium-free passivator: 5-30 parts of ceric ammonium nitrate, 2-10 parts of sulphosalicylic acid, 1-5 parts of ammonium hydrogen fluoride, 0.1-0.5 parts of antimonous oxide and the balance of water. Also disclosed are an aluminum product and a surface passivation process therefor.

Description

Chromium-free passivating agent, aluminum workpiece and surface passivation treatment method thereof

[0001] The present invention relates to the field of metal surface treatment technology, and in particular, to a chromium-free passivating agent, an aluminum workpiece, and a surface passivation 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 and their 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 applications of aluminum workpieces need to be passivated.

[0003] The passivation treatment generally uses a passivating agent to pretreat the aluminum workpiece to form a film layer on the surface of the aluminum workpiece for subsequent surface treatment, thereby increasing the bonding force and corrosion resistance of the subsequent film. Conventional passivation generally treats chromium ions with passivation, which does not meet environmental requirements and the process requirements of some businesses.

technical problem

[0004] In view of the above, a chromium-free passivating agent with good corrosion resistance and strong bonding force, and a surface passivation treatment method for an aluminum workpiece and an aluminum workpiece obtained by passivation treatment are provided, and the passivation agent is environmentally friendly. Non-toxic, easy to process, washed after passivation.

Problem solution

Technical solution

[0005] A chromium-free passivating agent for surface pretreatment of aluminum workpieces, comprising 1000 parts by weight, including the following parts by weight: 5-30 parts of cerium ammonium nitrate, 2-10 parts of sulfosateric water Acid, 1-5 parts ammonium hydrogen fluoride, 0.1-0.5 parts of antimony trioxide and the balance water.

[0006] A method for surface passivation treatment of an aluminum workpiece, comprising the steps of: formulating a chromium-free passivating agent as described above; formulating a chromium-free passivating agent into a passivation solution having a mass percentage of 4-20% Control the passivation solution to a pH of 3-5; pass the passivation solution onto the surface of the aluminum workpiece by dipping or spraying, washing with water, and drying.

And an aluminum workpiece having a surface having passivation formed by an aluminum workpiece surface passivation treatment method as described above. Advantageous effects of the invention

Beneficial effect

[0008] The film formed by the above-mentioned chromium-free passivating agent has good corrosion resistance, can be used as a coating treatment bottom layer, and is processed by an aluminum workpiece, directly rolled up, not washed with water, and is very convenient to use, and the passivating agent does not contain damage. The environment's chromium ions and other heavy metals are green products that comply with the EU ROHS Directive.

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 chromium-free passivating agent for surface pretreatment of an aluminum workpiece, comprising 1000 parts by weight, including the following parts by weight: 5-30 parts of cerium ammonium nitrate, 2-10 parts Sulfosalicylic acid, 1-5 parts ammonium hydrogen fluoride, 0.1-0.5 parts of antimony trioxide and the balance water.

[0011] Specifically, the parts by weight of the cerium ammonium nitrate are preferably 10 to 30 parts by weight. The sulfosalicylic acid is preferably from 4 to 8 parts by weight. The parts by weight of the ammonium hydrogen fluoride are preferably 2-4 parts by weight. The weight fraction of the antimony trioxide is preferably 0.2 to 0.4 parts. The passivating agent has a rhodium ratio of 4 to 20% by weight, a pH of preferably 3-5, and a weak acidity.

[0012] In the above chromium-free passivating agent, a preferable film forming effect is achieved by controlling the balance of the respective distribution ratios. For example, ammonium cerium nitrate is the main component of the membrane layer, sulfosalicylic acid is the pH regulator and auxiliary film-forming agent, ammonium hydrogen fluoride is the accelerator, and antimony trioxide is the auxiliary film-forming agent to make the film layer firm and uniform.

[0013] Embodiments of the present invention also provide a method for surface passivation treatment of an aluminum workpiece, comprising the steps of: formulating a chromium-free passivating agent as described above; formulating a chromium-free passivating agent into a mass percentage of 4- 20% of the passivation solution; control the passivation solution to a pH of 3-5; the passivation solution is applied by dipping or spraying onto the surface of the aluminum workpiece, washed with water, and dried.

[0014] Specifically, the mass percentage of the passivating agent in the passivating agent solution is preferably 5-15%, and the ruthenium is sprayed onto the surface of the aluminum workpiece, and the impregnation method may also be employed. The treatment temperature is normal temperature, such as 20-25 °C. In addition, after the passivation is formed, the surface of the aluminum workpiece is further subjected to passivation, oxidation resistance or coating treatment. The drying temperature is controlled at about 80 degrees, and should not be too high to prevent cracks in the film.

[0015] Embodiments of the present invention also provide an aluminum workpiece which is treated by a surface passivation treatment method of an aluminum workpiece as described above to form passivation on the surface of the aluminum workpiece. Passivation protects aluminum workpieces and can be used as a coating The bottom layer is convenient for subsequent painting and the like. In addition to aluminum profiles, the passivating agent of this embodiment can also be applied to other materials, such as surface treatment processes that can be widely applied to automotive, furniture, electronic equipment, household appliances, CPU radiators, sports equipment, and the like, of course. The aluminum article in these products can be treated with the passivating agent of this embodiment to form passivation.

[0016] The chromium-free passivating agent and its treatment method and the like of the embodiments of the present invention are described below by way of specific examples.

[0017] Embodiment 1

[0018] The components are mixed according to the following parts by weight: 5 parts by weight of cerium ammonium nitrate, 2 parts of sulfosalicylic acid, 1 part of ammonium hydrogen fluoride, 0.1 part of antimony trioxide and the balance water, 1000 parts by weight, stirred , evenly mixed, formulated as a passivating agent.

[0019] Treatment method: preparing a chromium-free passivating agent; formulating a chromium-free passivating agent into a passivation solution having a mass percentage of 20%; controlling the pH of the passivating agent solution to be 4; at normal temperature, The surface of the aluminum workpiece was immersed in a passivation solution, treated for 10 minutes, washed with water, and dried at 80 degrees.

[0020] After the above passivating agent solution treatment, it is found that the corrosion resistance of the workpiece is greatly improved, the neutral salt spray test is more than 24 hours, and the adhesion after painting is boiled in boiling water for 2 hours, without any drop off. , rating is 0

Embodiment 2

[0022] The components are mixed according to the following parts by weight: 10 parts by weight of cerium ammonium nitrate, 4 parts of sulfosalicylic acid, 2 parts of ammonium hydrogen fluoride, 0.2 parts of antimony trioxide and the balance water, 1000 parts by weight, stirred , evenly mixed, formulated as a passivating agent.

[0023] Processing method: preparing a chromium-free passivating agent; formulating a chromium-free passivating agent into a passivation solution having a mass percentage of 15%; controlling the pH of the passivating agent solution to be 4; at normal temperature, The surface of the aluminum workpiece was immersed in a passivation solution, treated for 10 minutes, washed with water, and dried at 80 degrees.

[0024] After the above passivating agent solution treatment, it is found that the corrosion resistance of the workpiece is greatly improved, the neutral salt spray test is more than 36 吋, and the adhesion after painting is boiled in boiling water for 2 hours, without any drop off. , rating is 0

Embodiment 3

[0026] The components are mixed according to the following parts by weight: 15 parts by weight of cerium ammonium nitrate, 6 parts of sulfosalicylic acid, 3 parts of ammonium hydrogen fluoride, 0.3 parts of antimony trioxide and the balance water, stirring , evenly mixed, formulated as blunt Chemical agent.

[0027] Processing method: preparing a chromium-free passivating agent; formulating a chromium-free passivating agent into a passivation solution having a mass percentage of 10%; controlling the pH of the passivating agent solution to be 3.5; at normal temperature, The surface of the aluminum workpiece was immersed in a passivation solution, treated for 10 minutes, washed with water, and dried at 80 degrees.

[0028] After the above passivation agent solution treatment, it is found that the corrosion resistance of the workpiece is greatly improved, the neutral salt spray test is more than 48 吋, and the adhesion after painting is boiled in boiling water for 2 hours, without any drop off. , rating is 0

Embodiment 4

[0030] The components are mixed according to the following parts by weight: 1000 parts by weight, 20 parts of cerium ammonium nitrate, 8 parts of sulfosalicylic acid, 4 parts of ammonium hydrogen fluoride, 0.4 parts of antimony trioxide and the balance of water, stirring , evenly mixed, formulated as a passivating agent.

[0031] Treatment method: preparing a chromium-free passivating agent; formulating a chromium-free passivating agent into a passivation solution having a mass percentage of 10%; controlling the pH of the passivating agent solution to be 3; at normal temperature, The surface of the aluminum workpiece was immersed in a passivation solution, treated for 8 minutes, washed with water, and dried at 80 degrees.

[0032] After the above passivation agent solution treatment, it is found that the corrosion resistance of the workpiece is greatly improved, the neutral salt spray test is more than 58 吋, and the adhesion after painting is boiled in boiling water for 2 hours, without any drop off. , rating is 0

Example 5

[0034] The components are mixed according to the following parts by weight: 1000 parts by weight, 30 parts of cerium ammonium nitrate, 10 parts of sulfosalicylic acid, 5 parts of ammonium hydrogen fluoride, 0.5 parts of antimony trioxide and the balance of water, stirring , evenly mixed, formulated as a passivating agent.

[0035] Treatment method: preparing a chromium-free passivating agent; formulating a chromium-free passivating agent into a passivation solution having a mass percentage of 6%; controlling the pH of the passivating agent solution to be 3; at normal temperature, The surface of the aluminum workpiece was immersed in a passivation solution, treated for 8 minutes, washed with water, and dried at 80 degrees.

[0036] After the above passivation agent solution treatment, it is found that the corrosion resistance of the workpiece is greatly improved, the neutral salt spray test is more than 50 吋, and the adhesion after the paint is applied is boiled in boiling water for 2 hours, without any drop off. , rating is 0

[0037] It should be noted that the present invention is not limited to the above embodiment, and according to the inventive spirit of the present invention, Other variations may be made by those skilled in the art, and variations made in accordance with the inventive spirit of the invention are intended to be included within the scope of the invention.

Claims

Claim

[Claim 1] A chromium-free passivating agent for surface pretreatment of an aluminum workpiece, characterized by comprising 1000 parts by weight of the following components by weight: 5-30 parts of cerium ammonium nitrate, 2-10 Parts of sulfosalicylic acid, 1-5 parts of ammonium hydrogen fluoride, 0.1-0.5 parts of antimony trioxide and the balance water.

[Claim 2] The chromium-free deactivator according to claim 1, wherein the cerium ammonium nitrate is used in an amount of 10 to 30 parts by weight.

[Claim 3] The chromium-free deactivator according to claim 1, wherein the sulfosalicylic acid is in an amount of 4 to 8 parts by weight.

[Claim 4] The chromium-free deactivator according to claim 1, wherein the ammonium hydrogen fluoride is in an amount of 2 to 4 parts by weight.

[Claim 5] The chromium-free deactivator according to claim 1, wherein the antimony trioxide has a weight fraction of 0.2 to 0.4 parts.

[Claim 6] The chromium-free passivating agent according to claim 1, wherein the passivating agent is used in a ratio of 4 to 20 wt < 3⁄4.

[Claim 7] The chromium-free passivation agent according to claim 1, wherein a PH value of the passivating agent is

3-5.

[Claim 8] A method for surface passivation treatment of an aluminum workpiece, comprising the steps of: formulating the chromium-free passivating agent according to any one of claims 1 to 7; formulating a chromium-free passivating agent into a mass percentage The passivation solution having a content of 4-2 0%; controlling the PH value of the passivating solution is 3-5; the passivation solution is dipped or sprayed on the surface of the aluminum workpiece, washed with water, and dried.

[Attach 9] An aluminum workpiece, characterized in that the aluminum workpiece surface is formed with passivation by the aluminum workpiece surface passivation treatment method according to claim 8.

[Claim 10] The aluminum workpiece according to claim 9, wherein after the passivation is formed, the surface of the aluminum workpiece is further subjected to passivation, oxidation resistance or coating treatment.