CN111893497A

CN111893497A - Phosphorus-free and fluorine-free cleaning agent for aluminum alloy, concentrated solution of phosphorus-free and fluorine-free cleaning agent and preparation method of concentrated solution

Info

Publication number: CN111893497A
Application number: CN202010704723.5A
Authority: CN
Inventors: 张德忠; 张琪; 赵涛
Original assignee: Wuhan Research Institute of Materials Protection
Current assignee: Wuhan Research Institute of Materials Protection
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2020-11-06

Abstract

The invention discloses a phosphorus-free and fluorine-free cleaning agent for aluminum alloy, a concentrated solution thereof and a preparation method thereof. The concentrated solution of the cleaning agent comprises a solution A and a solution B which are independently subpackaged. The solution A comprises the following components in percentage by mass: 5 to 45 percent of alkali, 0.1 to 10 percent of chelating agent, 0.01 to 2 percent of corrosion inhibitor and the balance of deionized water. Solution B: 1 to 60 percent of composite surfactant, 0.01 to 5 percent of defoaming agent and the balance of deionized water. The solution A and the solution B with proper proportion are selected according to the aluminum alloy material and the surface pollution condition so as to obtain the best oil removing effect and the lowest aluminum loss. The raw materials used in the invention are green and environment-friendly, the corrosivity is low, the cleaning agent with high cleaning rate and low mass loss can be obtained through reasonable proportioning, and the cleaning process is simple. Meanwhile, the cleaning agent provided by the invention is simple in component, free of phosphorus, nitrogen and fluorine ions, green and environment-friendly, convenient to produce and low in cost.

Description

Phosphorus-free and fluorine-free cleaning agent for aluminum alloy, concentrated solution of phosphorus-free and fluorine-free cleaning agent and preparation method of concentrated solution

Technical Field

The invention belongs to the technical field of aluminum alloy cleaning, and particularly relates to a phosphorus-free and fluorine-free cleaning agent for aluminum alloy, a concentrate of the phosphorus-free and fluorine-free cleaning agent and a preparation method of the phosphorus-free and fluorine-free cleaning agent.

Background

In industrial application, aluminum alloy is used as a non-ferrous metal material, is most widely applied, and is mainly applied to the fields of aviation, aerospace, automobiles, mechanical manufacturing, ships, chemical engineering and the like at present. In order to improve the corrosion resistance and decorativeness of aluminum alloys, the aluminum alloys are usually subjected to anodic oxidation, chemical conversion or chemical conversion + organic coating, etcAnd (6) surface treatment. Before the surface treatment of the aluminum alloy, the surface oil stain is required to be cleaned. The traditional cleaning and oil removing mode is as follows: firstly, soaking the fabric in sulfuric acid to primarily remove oil stains on the surface; secondly, performing alkali corrosion to further remove oil stains, and removing natural oxides on the surface of the aluminum through a dissolution reaction, thereby facilitating subsequent treatment; and thirdly, soaking in nitric acid, removing black ash generated in the alkali corrosion process, and neutralizing residual alkali liquor. In the process, the aluminum alloy matrix is etched by the alkali corrosion, and the loss of unit area mass is 50-150 mg/dm²And the process is complicated. In order to simplify the process and reduce the quality loss, the traditional cleaning is replaced by acid cleaning. However, the acidic cleaning contains a large amount of fluoride ions, and the fluoride ions have strong corrosivity under acidic conditions, so that the corrosion to equipment is serious, and the fluoride ions harm the environment and the wastewater treatment is difficult. Thus, the use of the fluorine-containing acid cleaning process is limited. In view of the above, there is an urgent need to develop a cleaning technique that is simple in process, environmentally friendly, non-corrosive to metal equipment, and slightly etched in aluminum alloy.

Disclosure of Invention

In order to solve the technical problems, the invention provides a phosphorus-free and fluorine-free cleaning agent for aluminum alloy, a concentrated solution thereof and a preparation method thereof.

The cleaning agent concentrated solution is obtained by independently subpackaging two solutions, so that the cleaning agent concentrated solution is favorable for selecting and mixing proper proportion according to the aluminum alloy material and the surface pollution type and degree, the stability and the reliability of the cleaning agent are improved, and the optimal oil removing effect and the lowest aluminum loss are achieved.

Solution A of the present invention mainly contains alkali, chelating agent and corrosion inhibitor. Alkali can react with animal and vegetable oil (main component is stearic acid) in oil to generate sodium stearate (soap), and the sodium stearate is dissolved into alkaline solution, namely saponification reaction, so as to remove the oil; the alkali can also react with the aluminum to release hydrogen, form a large number of bubbles, and scour the oil stains, thereby driving the oil stains away from the aluminum surface through physical action. The chelating agent can chelate metal ions such as iron, calcium, magnesium and the like in water and also can chelate aluminum ions produced by the reaction of alkali and aluminum alloy, so that the aluminum ions are dissolved in the water, water-insoluble substances are prevented from being formed, and the oil removal effect is reduced. The corrosion inhibitor mainly slows down the excessive corrosion of alkali to the aluminum alloy and reduces the aluminum quality loss.

The solution B is mainly organic matter and comprises a composite surfactant and a defoaming agent. The composite surfactant is compounded by two or more than two nonionic or amphoteric surfactants and has a synergistic effect, so that the capability of emulsifying oil stains, particularly mineral oil, is improved, the surface tension is reduced, the oil stains are separated from the surface of the aluminum alloy, become very small oil drops, and are further dispersed in a solution. The surfactant has great foamability in solution, under the impact of bubbles, the foam accumulation causes the reduction of the cleaning effect and the obstruction of the operation, and the addition of the defoaming agent can quickly reduce the bubbles until the bubbles are broken.

The composite surfactant of the present invention contains C₁₂～C₁₅The alkyl alcohol ether carboxylate and the alkyl glycoside, and alkyl amine oxide and C can be optionally added₁₂-C₁₄The fatty alcohol of (1). The selected surfactant has the advantages of compound performance, degradability and environmental protection.

The alkyl Alcohol Ether Carboxylate (AEC) has an ether linkage structure and a terminal carboxyl group (R (OCH)₂CH2)_nOCH₂COONa) which is structurally similar to soap and dissociates in water into anions, but the embedded EO chains give it the characteristics of a non-ionic surfactant. The alkyl glycoside (APG) is prepared by taking carbohydrate and natural fatty alcohol as raw materials, and is a novel nonionic surfactant with relatively comprehensive performance. Tests show that the compatibility of the two is excellent, when the two are compounded and used according to a certain proportion, the surface tension, the wettability, the foaming performance and the like of the two are all superior to the service performance of a single component, and the synergistic effect is obvious. The main reason for this is that after the alkyl alcohol ether carboxylate is dissolved in water, it becomes an alkyl alcohol ether carboxylate anion, which exhibits electronegativity. And the alkyl glycoside is hydrogen bonded to H₂O and H₃O⁺The alkyl glycoside molecules are bound so as to have a certain electropositivity. When the two are miscible, an electrical interaction similar to that between the isoelectride surfactants is produced. This action causes the two to form a weak complex, which has excellent emulsifiability, dispersibility and foamability to the oil and fat.

Alkyl groups for use in the inventionThe Alcohol Ether Carboxylate (AEC) is preferably C₁₂～C₁₅Alkyl alcohol ether carboxylate, and its dosage is 0.5% -20%.

The alkyl glycoside used according to the invention is preferably dodecyl glucoside or amyloglycoside, in an amount of 0.5 to 15%.

The alkyl amine oxide is easy to dissolve in water, is a weak cationic amphoteric surfactant, is cationic in an aqueous solution under an acidic condition, is nonionic in an alkaline condition, has good thickening, antistatic, softening, foam increasing, foam stabilizing and decontamination properties, and also has the sterilization and calcium soap dispersing capabilities and good biodegradability. The alkylamine oxide used in the present invention is preferably dodecyldimethylamine oxide or tetradecyldimethylamine oxide. The dosage of it is 0-15%.

The fatty alcohol structure contains hydroxyl, and has good hydrophilicity, wherein C₁₂-C₁₄The fatty alcohol has the best decontamination performance and is suitable for water-based cleaning agents. C used in the invention₁₂-C₁₄The amount of the fatty alcohol is 0-10%.

The organosilicon can be used for defoaming rapidly, is safe and nontoxic, but is insoluble in water, resistant to high temperature and poor in strong alkali resistance. The invention is preferably polyether modified organic silicon defoamer. The polyether chain is introduced into the polysiloxane chain, so that the silicone defoaming agent has the advantages of both polyether and organic silicon defoaming agent, and has the advantages of low surface tension, quick defoaming, long foam inhibition time, good dispersibility in aqueous solution and acid and alkali resistance. The dosage of the composition is 0.01 to 5 percent.

The cleaning agent disclosed by the invention greatly improves the oil removing capability through the synergistic effect of saponification, emulsification and physical impact of bubbles. In the using process, if the oil stain is mainly animal and vegetable oil, the content of the component A can be properly improved, and the saponification effect is improved; if the oil stain is mainly mineral oil, such as lubricating oil, engine oil and the like, the content of the component B can be properly increased to enhance the emulsification. When the silicon content in the aluminum alloy is higher, the low content A is selected, so that the reaction of alkali and the aluminum alloy can be reduced, and the surface is prevented from generating black ash.

The technical scheme provided by the invention is as follows:

one of the purposes of the invention is to provide a preparation method of a phosphorus-free and fluorine-free cleaning agent concentrated solution for aluminum alloy, the concentrated solution comprises a solution A and a solution B which are independently subpackaged,

the preparation method of the solution A comprises the following steps: firstly, dissolving alkali in water to obtain alkali liquor, and then adding a chelating agent and a corrosion inhibitor into the alkali liquor to obtain a solution A;

the preparation method of solution B is as follows: and dissolving the composite surfactant in water, adding the defoaming agent, and uniformly mixing to obtain a solution B.

Further, the additive is selected from two or more of potassium hydroxide, potassium carbonate, sodium hydroxide and sodium carbonate.

Further, the chelating agent is selected from one or more of sodium lactate, sodium citrate, sodium gluconate, sodium tartrate and disodium EDTA.

Furthermore, the corrosion inhibitor is one or two of thiourea or benzotriazole.

Further, the solution A comprises the following components in percentage by mass:

5 to 45 percent of alkali, 0.1 to 10 percent of chelating agent, 0.01 to 1 percent of corrosion inhibitor and the balance of deionized water.

Further, the composite surfactant is selected from C₁₂～C₁₅Alkyl alcohol ether carboxylates, alkyl glycosides, alkyl amine oxides, C₁₂-C₁₄Two or more of the fatty alcohols of (1).

Further, the composite surfactant comprises the following components in percentage by mass: c₁₂～C₁₅0.5 to 20 percent of alkyl alcohol ether carboxylate, 0.5 to 15 percent of alkyl glucoside, 0 to 15 percent of alkyl amine oxide and C₁₂-C₁₄0-10% of fatty alcohol.

Further, the defoaming agent is a modified organic silicon defoaming agent.

Further, the solution B comprises the following components in percentage by mass:

1 to 60 percent of composite surfactant, 0.01 to 5 percent of defoaming agent and the balance of ionized water.

The invention also aims to provide the phosphorus-free and fluorine-free cleaning agent concentrated solution for the aluminum alloy prepared by the method.

The invention also aims to provide a preparation method of the phosphorus-free and fluorine-free cleaning agent for the aluminum alloy, which comprises the following steps: mixing the solution A and the solution B, and adding water for dilution to obtain the compound;

the mass fraction of the solution A in the cleaning agent is 0.5-50%, the mass fraction of the solution B is 0.2-20%, and the balance is water.

The fourth purpose of the invention is to provide the alkaline cleaning agent for the aluminum alloy prepared by the method, wherein the pH value is 10.0-13.5. The preferred pH is 11.0-12.0; the use temperature is 20-65 ℃, and the normal temperature is preferred.

The invention has the beneficial effects that:

1) the cleaning solution is alkaline and has no corrosion to carbon steel, stainless steel, PVC and other equipment;

2) the etching to the aluminum alloy substrate is slight, the aluminum mass loss in the treatment process is small, and the mass loss per unit area is less than 15mg/dm²Greatly reducing the loss of aluminum in cleaning;

3) the method does not contain phosphorus, nitrogen and fluorine ions, has simple wastewater treatment, meets the requirement of cleaning production, and is green and environment-friendly;

4) the surface of the aluminum alloy is bright and has no black ash in the cleaning process, the traditional oil removal, alkali etching and nitric acid treatment procedures can be replaced, and the process flow is simplified;

5) the oil can be used at normal temperature without heating, has excellent oil removing effect and saves energy;

6) the formula provided by the invention is scientific in proportioning, cheap and easily available in raw materials, simple in process, green and environment-friendly, and beneficial to industrial production.

Detailed Description

The technical solution of the present invention is further explained below, but the scope of the present invention is not limited thereto.

A preparation method of a phosphorus-free and fluorine-free cleaning agent concentrated solution for aluminum alloy comprises a solution A and a solution B which are independent,

the concentrated solution comprises a solution A and a solution B which are independently packaged,

Further, the composite surfactant is selected from C₁₂～C₁5 alkyl alcohol ether carboxylates, alkyl glycosides, alkyl amine oxides, C₁₂-C₁₄Two or more of the fatty alcohols of (1).

Further, the defoaming agent is a modified organic silicon defoaming agent. Polyether modified silicone defoamers are preferred.

Example 1

The preparation method of the phosphorus-free and fluorine-free cleaning agent concentrate for the aluminum alloy is as follows, and the components are as follows:

components	Fraction A/%)	Fraction of B/%)
			Potassium hydroxide	25
Sodium hydroxide	10
			Sodium gluconate	4
Thiourea	1
			C₁₂～C₁₅Alkyl alcohol ether carboxylates		10
Dodecyl glucoside		12
			Polyether modified organic silicon defoaming agent		0.1
Deionized water	60	77.9

The preparation steps of the cleaning agent are as follows: the solution A accounts for 5.0 percent by mass, the solution B accounts for 0.2 percent by mass, and the balance is tap water.

Example 2

components	Fraction A/%)	Fraction of B/%)
			Potassium hydroxide	15
Sodium hydroxide	10
			Sodium carbonate	10
EDTA disodium salt	8
			Thiourea	0.5
C₁₂～C₁₅Alkyl alcohol ether carboxylates		5
			Dodecyl glucoside		7
Tetradecyldimethylamine oxide		5
			Polyether modified organic silicon defoaming agent		0.3
Deionized water	56.5	82.7

The preparation steps of the cleaning agent are as follows: the mass fraction of the solution A is 2.0 percent, the mass fraction of the solution B is 0.3 percent, and the balance is tap water.

Example 3

components	Fraction A/%)	Fraction of B/%)
			Potassium hydroxide	20
Sodium hydroxide	10
			Trisodium citrate	2.5
Benzotriazole	1.2
			C₁₂～C₁₅Alkyl alcohol ether carboxylates		10
Dodecyl glucoside		8
			C₁₂-C₁₄Fatty alcohol of (2)		8
Polyether modified organic silicon defoaming agent		2
			Deionized water	66.3	72

The preparation steps of the cleaning agent are as follows: the solution A accounts for 1.0 percent by mass, the solution B accounts for 0.5 percent by mass, and the balance is tap water.

Example 4

the preparation steps of the cleaning agent are as follows: the solution A accounts for 10 percent by mass, the solution B accounts for 0.5 percent by mass, and the balance is tap water.

Example 5

components	Fraction A/%)	Fraction of B/%)
			Potassium hydroxide	17
Sodium hydroxide	13
			Sodium gluconate	3
Thiourea	1
			C₁₂～C₁₅Alkyl alcohol ether carboxylates		5
Dodecyl glucoside		5
			Dodecyl dimethyl amine oxide		2
C₁₂-C₁₄Fatty alcohol of (2)		3
			Polyether modified organic silicon defoaming agent		0.05
Deionized water	66	84.95

The preparation steps of the cleaning agent are as follows: the solution A accounts for 0.5 percent by mass, the solution B accounts for 0.3 percent by mass, and the balance is tap water.

Example 6

Cleaning effectiveness test

The test method comprises the following steps: the cleaning effect of the alkaline cleaner in the formula is measured by the cleaning rate. The clean aluminum alloy panels were wiped with ethanol and weighed (0.1 mg) on an analytical balance for the measurements. And uniformly coating industrial oil on one surface of the sample plate, putting the sample plate into a drying oven for drying, and accurately weighing the sample plate. And (3) placing the sample plate in a cleaning agent for cleaning for a certain time, cleaning for 2 times by using clear water, and drying the sample plate by using an air gun. Then the mixture is dried in a drying oven at 60 ℃ for 10 minutes, taken out and weighed. And taking an average value for several times.

Wherein W₁Initial sample weight, W₂Weight of steel plate sample piece after coating industrial oil on the position, W₃And cleaning and drying the sample plate.

The mass loss per unit area of the alkaline cleaner was evaluated according to GB/T8753.2-2005.

And wiping the surface of the aluminum plate subjected to alkali washing by using clean white cellophane paper to judge whether black ash exists after the alkali washing.

The results of the cleaning effect and the mass loss per unit area of the products of examples 1 to 5 are shown in the following table:

item	Cleaning rate/%)	Black ash	Mass loss per unit area/(mg/dm)²)
				Example 1	73.5	Small amount of	7.1
Example 2	89.7	Is free of	3.5
				Example 3	98.4	Is free of	11.8
Example 4	97.7	Is free of	1.2
				Example 5	90.2	Is free of	1.0

The results show that the alkaline cleaning agent provided by the invention not only has higher cleaning rate, but also has small corrosion to metal and low loss, and has higher practicability compared with the commercial degreasing products.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any modification, equivalent replacement, and improvement made by those skilled in the art within the technical scope of the present invention should be included in the scope of the present invention.

Claims

1. A preparation method of a phosphorus-free and fluorine-free cleaning agent concentrated solution for aluminum alloy is characterized in that the concentrated solution comprises a solution A and a solution B which are independently subpackaged,

2. The method for preparing the phosphorus-and fluorine-free cleaning agent concentrate for aluminum alloy as claimed in claim 1, wherein the alkali is two or more selected from potassium hydroxide, sodium hydroxide, potassium carbonate and sodium carbonate.

3. The method for preparing the phosphorus-free and fluorine-free detergent concentrate for aluminum alloy according to claim 1, wherein the chelating agent is one or more selected from sodium lactate, sodium citrate, sodium gluconate, sodium tartrate and disodium EDTA.

4. The method for preparing the phosphorus-free and fluorine-free cleaning agent concentrated solution for the aluminum alloy according to claim 1, wherein the corrosion inhibitor is one or two of thiourea and benzotriazole.

5. The preparation method of the phosphorus-free and fluorine-free cleaning agent concentrated solution for the aluminum alloy as claimed in claim 1, wherein the solution A comprises the following components in percentage by mass:

5 to 45 percent of alkali, 0.1 to 10 percent of chelating agent, 0.01 to 2 percent of corrosion inhibitor and the balance of deionized water.

6. The preparation method of the phosphorus-free and fluorine-free cleaning agent concentrated solution for the aluminum alloy as claimed in claim 1, wherein the composite surfactant comprises the following components in percentage by mass: c₁₂～C₁₅0.5 to 20 percent of alkyl alcohol ether carboxylate, 0.5 to 15 percent of alkyl glucoside, 0 to 15 percent of alkyl amine oxide and C₁₂-C₁₄0-10% of fatty alcohol.

7. The phosphorus-free and fluorine-free cleaning agent concentrate for aluminum alloy as claimed in claim 1, wherein the defoaming agent in solution B is a modified silicone defoaming agent.

8. The preparation method of the phosphorus-free and fluorine-free cleaning agent concentrated solution for the aluminum alloy as claimed in claim 1, wherein the solution B comprises the following components in percentage by mass:

9. A preparation method of a phosphorus-free and fluorine-free cleaning agent for aluminum alloy is characterized by comprising the following steps: mixing the solution A and the solution B according to the claims 1-8, and adding water for dilution;

the mass fraction of the solution A in the cleaning agent is 0.1-80%, the mass fraction of the solution B is 0.05-50%, and the balance is water.

10. A phosphorus-free and fluorine-free cleaning agent for aluminum alloy is characterized in that: prepared by the process of claim 9, having a pH of 10.0-13.5 and a use temperature of 20-65 ℃.