CN115354379A

CN115354379A - High-temperature nickel-free hole sealing agent and hole sealing process

Info

Publication number: CN115354379A
Application number: CN202210977841.2A
Authority: CN
Inventors: 李海生; 叶献远; 洪永扣
Original assignee: Anhui Hanlu Environmental Protection New Material Co ltd
Current assignee: Anhui Hanlu Environmental Protection New Material Co ltd
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2022-11-18

Abstract

The invention relates to a high-temperature nickel-free hole sealing agent and a hole sealing process, wherein the high-temperature nickel-free hole sealing agent comprises a first component and a second component, the first component comprises 20-50g/L of silicate, 10-30g/L of surfactant and 0.1-2g/L of polystyrene sodium sulfonate, the second component comprises 20-50g/L of silicate, 10-30g/L of surfactant and 5-60g/L of aminobenzenesulfonate, and the first component and the second component are aqueous solutions and the pH value of the first component and the second component is adjusted to 5.5-6.0 through acetic acid or ammonia water. The invention can have good hole sealing effect on the thick anodic oxide film.

Description

High-temperature nickel-free hole sealing agent and hole sealing process

Technical Field

The invention relates to a high-temperature nickel-free hole sealing agent and a hole sealing process.

Background

The application range of the aluminum alloy product is very wide, but the aluminum product is easy to corrode, in order to avoid the corrosion of the aluminum alloy product, an anodic oxidation technology is generally applied in actual industrial production, and the aluminum alloy material after anodic oxidation treatment has the advantages of bright color, high hardness and corrosion resistance.

The high-temperature hole sealing is also called boiling water hole sealing, a boehmite body is generated through the hydration reaction of an oxide film on the surface of an aluminum product, the boehmite body has good corrosion resistance, and the micropores of the oxide film are sealed through the expansion of the molecular volume of the oxide film during the hydration reaction. The method has simple process and high hole sealing quality. In order to achieve a better color effect, the anodic oxide film usually needs a certain thickness, but the thick anodic oxide film is more difficult to seal holes due to the expansion of the molecular volume of the oxide film and the residual chemical substances, and the sealing effect is poor.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides a high-temperature nickel-free sealant which comprises a first component and a second component, wherein the first component consists of 20-50g/L silicate, 10-30g/L surfactant and 0.1-2g/L sodium polystyrene sulfonate, the second component consists of 20-50g/L silicate, 10-30g/L surfactant and 5-60g/L aminobenzenesulfonate, and the first component and the second component are aqueous solutions and the pH value of the first component and the second component is adjusted to 5.5-6.0 through acetic acid or ammonia water.

The weight average molecular weight of the polystyrene sodium sulfonate is 5000-80000.

The silicate is selected from one or two of sodium silicate and potassium silicate.

The aminobenzene sulfonate is selected from one or more of 4- (methylamino) benzene sodium sulfonate, 4- (ethylamino) benzene sodium sulfonate and 3- (ethylamino) -4-methyl benzene sodium sulfonate.

The surfactant is selected from one or more of polyoxyethylene alkyl ether sulfate, linear alkylbenzene sulfonate, alkyl sulfate, alcohol sulfate, secondary alkane sulfonate, alpha-olefin sulfonate, alpha-sulfo fatty acid ester salt, fatty acid polyoxyethylene ether sulfate and polyoxyethylene alkyl ether carboxylate.

A high-temperature nickel-free hole sealing process comprises the following steps:

hole sealing is carried out on the metal base material with the anodic oxide film by adopting a first component to obtain a pretreated base material, and hole sealing parameters are as follows: 1-10 minutes at 90-98 ℃;

and (3) carrying out high-temperature hole sealing on the pretreated base material by adopting a second component, wherein the hole sealing parameters are as follows: 10-60 minutes at 90-98 ℃;

the first component comprises 20-50g/L of silicate, 10-30g/L of surfactant and 0.1-2g/L of sodium polystyrene sulfonate, the second component comprises 20-50g/L of silicate, 10-30g/L of surfactant and 5-60g/L of aminobenzenesulfonate, and the first component and the second component are aqueous solutions, and the pH value of the first component and the second component is adjusted to 5.5-6.0 through acetic acid or ammonia water.

The invention can have good hole sealing effect on the thick anodic oxide film.

The above-described and other features, aspects, and advantages of the present application will become more apparent with reference to the following detailed description.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It should be apparent that the described embodiments are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the description and claims of the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one.

The high-temperature nickel-free hole sealing agent comprises a first component and a second component, wherein the first component comprises 20-50g/L of silicate, 10-30g/L of surfactant and 0.1-2g/L of sodium polystyrene sulfonate, the second component comprises 20-50g/L of silicate, 10-30g/L of surfactant and 5-60g/L of aminobenzenesulfonate, and the pH of the first component and the pH of the second component are aqueous solutions and are adjusted to 5.5-6.0 through acetic acid or ammonia water.

The metal surface treatment process comprises the following steps:

chemical polishing

The metal material subjected to degreasing and dewaxing is immersed in a solution consisting of phosphoric acid with the concentration of 650 g/l and sulfuric acid with the concentration of 200 g/l for chemical polishing for 3 seconds, then immediately immersed in water to clean the residual acid on the surface of the substrate, and then immersed in a sodium hydroxide solution with the concentration of 10 g/l for 8 minutes, and immediately immersed in water to clean the residual alkali on the surface of the substrate.

Anodic oxidation

Immersing the treated substrate in an electrolytic bath containing an aqueous solution of sulfuric acid having a concentration of 180 g/l and aluminum sulfate having a concentration of 8 g/l, and using the substrate as an anode at a voltage of 20V and a current density of 2A/dm ² And anodizing at 20 ℃ for 60 minutes, taking out after anodizing is finished, and cleaning to obtain the metal base material (32-40 microns) with the thick anodic oxide film.

Dyeing process

Organic dye: 6g/L and 1g/L of sodium acetate. The temperature is 55-60 ℃, and the treatment time is 10 minutes.

Hole sealing

A plurality of pieces of a metal substrate of a thick anodic oxide film were randomly selected 5 pieces, and immersed in the first component and the second component of the following examples and the sealant of the comparative example, the first component being at 90 to 98 ℃ for 5 minutes, and the second component being at 90 to 98 ℃ for 30 minutes.

The hole sealing effect is tested by a hole sealing weightlessness experiment, as specified in the standard GB/T5237.2-2000, frost spots on the surface of a sample are wiped off by a dry cloth, the sample is degreased by a proper organic solvent at room temperature, and is weighed after being dried, and then the sample is soaked in a (38 +/-1) DEG C obtained phosphorus chromic acid solution for 15min. And then taking out the sample, cleaning and drying the sample, weighing the sample again, and calculating the weight loss of the sample, wherein the weight loss is qualified below 20mg/dm < 2 >.

Example 1

A first component: 40g/L sodium silicate, 20g/L fatty acid polyoxyethylene ether sulfate surfactant and 0.5g/L sodium polystyrene sulfonate (molecular weight 70000); a second component: 40g/L of silicate, 20g/L of fatty acid polyoxyethylene ether sulfate surfactant and 20g/L of 4- (methylamino) sodium benzenesulfonate. The weight loss obtained by the experiment was 8.13%.

Example 2

A first component: 40g/L sodium silicate, 20g/L fatty acid polyoxyethylene ether sulfate surfactant and 0.7g/L sodium polystyrene sulfonate (molecular weight 70000); a second component: 40g/L of silicate, 20g/L of fatty acid polyoxyethylene ether sulfate surfactant and 30g/L of 4- (methylamino) sodium benzenesulfonate. The weight loss obtained by the experiment was 7.29%.

Comparative example 1

Only one component was used: 40g/L of silicate, 20g/L of fatty acid polyoxyethylene ether sulfate surfactant and 20g/L of 4- (methylamino) sodium benzenesulfonate. The weight loss obtained by the experiment was 16.23%.

Comparative example 2

The sodium 4- (methylamino) benzenesulfonate was replaced with sodium hexadecyldiphenyloxide disulfonate as in example 1. The weight loss obtained by the experiment was 19.05%.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and the description is given here only for clarity, and those skilled in the art should integrate the description, and the embodiments may be combined appropriately to form other embodiments understood by those skilled in the art.

Claims

1. The high-temperature nickel-free hole sealing agent is characterized by comprising a first component and a second component, wherein the first component is composed of 20-50g/L of silicate, 10-30g/L of surfactant and 0.1-2g/L of sodium polystyrene sulfonate, the second component is composed of 20-50g/L of silicate, 10-30g/L of surfactant and 5-60g/L of aminobenzenesulfonate, and the first component and the second component are aqueous solutions and the pH value of the first component and the second component is adjusted to 5.5-6.0 through acetic acid or ammonia water.

2. The high-temperature nickel-free sealant according to claim 1, wherein the weight average molecular weight of the sodium polystyrene sulfonate is 5000-80000.

3. The high temperature nickel-free sealant according to claim 1, wherein the silicate is selected from one or two of sodium silicate and potassium silicate.

4. The high-temperature nickel-free sealant according to claim 1, wherein the aminobenzenesulfonate is selected from one or more of sodium 4- (methylamino) benzenesulfonate, sodium 4- (ethylamino) benzenesulfonate, and sodium 3- (ethylamino) -4-methylbenzenesulfonate.

5. The high temperature nickel-free sealant according to claim 1, wherein the surfactant is selected from one or more of polyoxyethylene alkyl ether sulfate, linear alkylbenzene sulfonate, alkyl sulfate, alcohol sulfate, secondary alkane sulfonate, alpha-olefin sulfonate, alpha-sulfo fatty acid ester salt, fatty acid polyoxyethylene ether sulfate, and polyoxyethylene alkyl ether carboxylate.

6. A high-temperature nickel-free hole sealing process is characterized by comprising the following steps:

the method comprises the following steps of sealing holes of a metal base material with an anodic oxide film by adopting a first component to obtain a pretreated base material, wherein the hole sealing parameters are as follows: 1-10 minutes at 90-98 ℃;

7. The high-temperature nickel-free hole sealing process according to claim 6, wherein the weight average molecular weight of the sodium polystyrene sulfonate is 5000-80000.

8. The high-temperature nickel-free hole sealing process according to claim 6, wherein the aminobenzenesulfonate is one or more selected from sodium 4- (methylamino) benzenesulfonate, sodium 4- (ethylamino) benzenesulfonate and sodium 3- (ethylamino) -4-methylbenzenesulfonate.