阅读说明：本技术 一种高耐候性铝合金无铬钝化剂及其制备方法 (High-weather-resistance aluminum alloy chromium-free passivator and preparation method thereof ) 是由 张广勋 沈勇 王超 王清芳 于 2020-08-01 设计创作，主要内容包括：本发明提供一种高耐候性铝合金无铬钝化剂及其制备方法,涉及金属表面处理化学品技术领域,其原料为：氟钛酸、硅酸钠、硝酸锌、钨酸钠、水性聚氨酯、成膜促进剂、稳定剂、pH调节剂、催化剂、氧化剂和水。本发明通过设计一种高耐候性铝合金无铬钝化剂及其制备方法,本发明制备的铝合金无铬钝化剂耐腐蚀性能与六价铬钝化剂性能接近,且该钝化剂对环境不造成污染；同时采用pH调节剂和催化剂、稳定剂的加入还可避免挥发性酸对工作人员造成伤害,钝化剂中无铬,安全无毒,且能迅速在合金表面形成钝化膜,膜层均匀致密,同时具有高耐候性,使用寿命长,能提供长时间的有效保护,具有良好的的经济效益和社会效益。(The invention provides a high-weatherability aluminum alloy chromium-free passivator and a preparation method thereof, relating to the technical field of metal surface treatment chemicals, and the high-weatherability aluminum alloy chromium-free passivator comprises the following raw materials: fluotitanic acid, sodium silicate, zinc nitrate, sodium tungstate, waterborne polyurethane, a film forming accelerant, a stabilizing agent, a pH regulator, a catalyst, an oxidant and water. By designing the high-weather-resistance aluminum alloy chromium-free passivator and the preparation method thereof, the corrosion resistance of the aluminum alloy chromium-free passivator prepared by the invention is close to that of a hexavalent chromium passivator, and the passivator does not cause pollution to the environment; meanwhile, the addition of the pH regulator, the catalyst and the stabilizer can avoid the harm of volatile acid to workers, the passivating agent is chromium-free, safe and nontoxic, can quickly form a passivation film on the surface of the alloy, and has uniform and compact film layer, high weather resistance, long service life, long-term effective protection and good economic and social benefits.)

1. A high weather resistance aluminum alloy chromium-free passivator and a preparation method thereof are characterized in that: the feed is prepared from the following raw materials in parts by weight:

10-20 parts of fluotitanic acid, 10-20 parts of sodium silicate, 5-10 parts of zinc nitrate, 5-10 parts of sodium tungstate, 2-8 parts of waterborne polyurethane, 20-40 parts of film forming accelerant, 2-8 parts of stabilizing agent, 4-8 parts of pH regulator, 4-8 parts of catalyst, 2-6 parts of oxidant and 30-60 parts of water.

2. The high-weatherability chromium-free passivator for aluminum alloy and preparation method thereof according to claim 1, wherein: the stabilizer is benzotriazole.

3. The high-weatherability chromium-free passivator for aluminum alloy and preparation method thereof according to claim 1, wherein: the pH regulator is citric acid or acetic acid or lactic acid.

4. The high-weatherability chromium-free passivator for aluminum alloy and preparation method thereof according to claim 1, wherein: the catalyst is hydrogen peroxide.

5. The high-weatherability chromium-free passivator for aluminum alloy and preparation method thereof according to claim 1, wherein: the oxidant is nitric acid or potassium permanganate.

6. The high-weatherability chromium-free passivator for aluminum alloy and preparation method thereof according to claim 1, wherein: the film forming accelerant is alcohol ester twelve.

7. The chromium-free passivator for aluminum alloy with high weather resistance and the preparation method thereof as claimed in any one of claims 1-6, wherein:

the coating is characterized by comprising 15 parts of fluotitanic acid, 15 parts of sodium silicate, 8 parts of zinc nitrate, 8 parts of sodium tungstate, 5 parts of waterborne polyurethane, 30 parts of film forming accelerant, 5 parts of stabilizing agent, 6 parts of pH regulator, 6 parts of catalyst, 4 parts of oxidant and 50 parts of water.

8. The high-weatherability chromium-free passivator for aluminum alloy and preparation method thereof according to claim 7, wherein: the method comprises the following steps:

(1) firstly, adding 15 parts of fluotitanic acid, 150 parts of sodium silicate and 8 parts of zinc nitrate into 25 parts of water, stirring from bottom to top, and fully stirring and dissolving to obtain a mixed solution A;

(2) adding 8 parts of sodium tungstate, 5 parts of waterborne polyurethane and 30 parts of film forming accelerant into 25 parts of water, stirring from bottom to top, heating while stirring to 60-70 ℃ until the materials are fully dissolved, and then cooling to room temperature to obtain a mixed solution B;

(3) and (3) adding the mixed solution B obtained in the step (2) into the mixed solution A obtained in the step (1), stirring, sequentially adding 5 parts of stabilizer, 6 parts of pH regulator, 6 parts of catalyst and 4 parts of oxidant in the stirring process, and continuously stirring and uniformly mixing to obtain the high-weather-resistance aluminum alloy chromium-free passivator.

9. The chromium-free passivator for aluminum alloy with high weather resistance and a preparation method thereof as claimed in claim 8, wherein: the stirring time in the step (1) is 30-50 min.

10. The chromium-free passivator for aluminum alloy with high weather resistance and a preparation method thereof as claimed in claim 8, wherein: the heating temperature in the step (2) is 65 ℃.

Technical Field

The invention relates to the technical field of metal surface treatment chemicals, in particular to a high-weather-resistance aluminum alloy chromium-free passivator and a preparation method thereof.

Background

Aluminum has advantages such as large storage capacity, high strength-to-mass ratio, good machining performance, excellent heat and electrical conductivity, and the like, and is widely applied to modern industry and daily life, and is an important material in the aviation industry and shipbuilding industry. Aluminum is an amphoteric metal that forms aluminum salts (e.g., aluminum sulfate) in acidic media and aluminates (e.g., sodium metaaluminate) in alkaline media. When aluminum comes into contact with other high potential metals, contact corrosion occurs again. In the atmosphere, the aluminum surface forms a very thin oxide film, preventing the aluminum from continuing to contact the surrounding environment, so that the aluminum is even slower in corrosion than brass.

Because of the physical properties of the aluminum alloy, the aluminum alloy is difficult to electroplate and chemically plate, because the aluminum has great affinity to oxygen and is easy to generate an oxide film; anodic oxidation is one of the most common surface treatment methods for aluminum alloy materials, an anodic oxide film has good mechanical properties, good corrosion resistance and friction resistance, and the anodic oxide film can provide good corrosion resistance for the aluminum alloy; the chemical conversion coating can provide qualified adhesive force and proper corrosion resistance, and meanwhile, the chemical conversion coating has good conductivity, and does not have obvious influence on the fatigue performance of a base material.

The simplest and most effective metal surface passivation technology is applied in the prior aluminum alloy corrosion protection treatment, the chromate passivation treatment can obviously improve the corrosion resistance of the surfaces of aluminum and aluminum alloy, and meanwhile, the passivation film has good adhesive force to a coating and low cost, so the passivation film is widely applied in the fields of automobiles, machinery, household appliances, building materials and the like. However, the chromate passivation solution contains hexavalent chromium which is extremely harmful to human body and environment, which not only causes pollution in the treatment process, but also causes secondary pollution to the environment when the treated product is used and discarded in the future. With the increasing awareness of environmental protection, the use of hexavalent chromium has become increasingly restricted. Therefore, a novel aluminum alloy passivator which is safe, non-toxic and pollution-free is urgently needed to be developed, and the invention provides a high-weather-resistance aluminum alloy chromium-free passivator and a preparation method thereof to solve the problems.

Disclosure of Invention

The invention aims to provide a high-weather-resistance aluminum alloy chromium-free passivator and a preparation method thereof, and aims to solve the technical problems.

In order to solve the technical problems, the invention adopts the following technical scheme:

a high weather resistance aluminum alloy chromium-free passivator and a preparation method thereof are characterized in that: the feed is prepared from the following raw materials in parts by weight:

10-20 parts of fluotitanic acid, 10-20 parts of sodium silicate, 5-10 parts of zinc nitrate, 5-10 parts of sodium tungstate, 2-8 parts of waterborne polyurethane, 20-40 parts of film forming accelerant, 2-8 parts of stabilizing agent, 4-8 parts of pH regulator, 4-8 parts of catalyst, 2-6 parts of oxidant and 30-60 parts of water.

Preferably, the stabilizer is benzotriazole.

Preferably, the pH regulator is citric acid or acetic acid or lactic acid.

Preferably, the catalyst is hydrogen peroxide.

Preferably, the oxidizing agent is nitric acid or potassium permanganate.

Preferably, the film forming promoter is alcohol ester twelve.

Preferably, the coating comprises 15 parts of fluotitanic acid, 150 parts of sodium silicate, 8 parts of zinc nitrate, 8 parts of sodium tungstate, 5 parts of waterborne polyurethane, 30 parts of film forming accelerant, 5 parts of stabilizing agent, 6 parts of pH regulator, 6 parts of catalyst, 4 parts of oxidant and 50 parts of water.

Preferably, the high-weather-resistance aluminum alloy chromium-free passivator and the preparation method thereof comprise the following steps:

(1) firstly, adding 15 parts of fluotitanic acid, 15 parts of sodium silicate and 8 parts of zinc nitrate into 25 parts of water, stirring from bottom to top, and fully stirring and dissolving to obtain a mixed solution A;

(2) adding 8 parts of sodium tungstate, 5 parts of waterborne polyurethane and 30 parts of film forming accelerant into 25 parts of water, stirring from bottom to top, heating while stirring to 60-70 ℃ until the materials are fully dissolved, and then cooling to room temperature to obtain a mixed solution B;

(3) and (3) adding the mixed solution B obtained in the step (2) into the mixed solution A obtained in the step (1), stirring, sequentially adding 5 parts of stabilizer, 6 parts of pH regulator, 6 parts of catalyst and 4 parts of oxidant in the stirring process, and continuously stirring and uniformly mixing to obtain the high-weather-resistance aluminum alloy chromium-free passivator.

Preferably, the stirring time in the step (1) is 30-50 min.

Preferably, the heating temperature in the step (2) is 65 ℃.

The invention has the beneficial effects that:

according to the invention, by designing the high-weatherability aluminum alloy chromium-free passivator and the preparation method thereof, firstly, the corrosion resistance of the aluminum alloy chromium-free passivator prepared by the invention is close to that of a hexavalent chromium passivator, and the passivator does not cause pollution to the environment; meanwhile, the addition of the pH regulator, the catalyst and the stabilizer can avoid the harm of volatile acid to workers, the passivating agent is chromium-free, safe and nontoxic, can quickly form a passivation film on the surface of the alloy, and has uniform and compact film layer, high weather resistance, long service life, long-term effective protection and good economic and social benefits.

Detailed Description

The present invention will be further described with reference to specific embodiments for the purpose of facilitating an understanding of technical means, characteristics of creation, objectives and functions realized by the present invention, but the following embodiments are only preferred embodiments of the present invention, and are not intended to be exhaustive. Based on the embodiments in the implementation, other embodiments obtained by those skilled in the art without any creative efforts belong to the protection scope of the present invention. The experimental methods in the following examples are conventional methods unless otherwise specified, and materials, reagents and the like used in the following examples are commercially available unless otherwise specified.