Normal-temperature degreasing agent for cold-rolled strip steel and preparation method of normal-temperature degreasing agent

Abstract

The invention discloses a normal-temperature degreasing agent for cold-rolled strip steel and a preparation method of the normal-temperature degreasing agent. The normal-temperature degreasing agent comprises the following components in percentage by mass: 15-20% of sodium hydroxide, 3-5% of sodium carbonate, 1-3% of a chelating agent, 1.8-2.4% of a compound anionic surfactant, 0.6-1.0% of a compound nonionic surfactant, 0.3-0.5% of a defoaming agent, 0.5-0.8% of ethylene glycol and the balance of water. Compared with a conventional alkaline degreasing agent, the normal-temperature degreasing agent has the advantages that steam and other heat energy consumed by high-temperature saponification are avoided, and the applicable temperature is 30-40 DEG C, so that the cleaning energy consumption is greatly reduced, and the cleaning cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of metal degreasing agents, and in particular to a room-temperature degreasing agent for cold-rolled strip steel and a preparation method thereof. Background Art

[0002] Before annealing the cold-rolled strip, the surface condition and cleanliness are the prerequisites to ensure continuous decoating. During the rolling process, various impurities will inevitably remain on the surface of the strip, such as rolling oil and slag in the rolling oil, iron powder generated during cold rolling, accumulated dust, welding slag generated during head welding, etc. Therefore, it must be cleaned before annealing to completely remove the oil stains on the surface of the strip (referred to as "degreasing"), otherwise the various oils remaining on the surface will form carbon stains during the annealing process, pollute the atmosphere in the furnace, affect the decarburization efficiency, and even cause carbon increase.

[0003] The process of removing oil stains from the surface of the strip is achieved by a degreaser, so technical personnel in the industry have conducted a lot of research on degreasers. Most of the degreasers on the market are currently compounded with alkaline additives, inorganic salts and surfactants. The degreasing principle mainly relies on the saponification of inorganic alkalis and the emulsification, dispersion, wetting and solubilization of surfactants. At the same time, the degreaser often needs to control the temperature at 60-85°C during use, which undoubtedly increases production energy consumption and increases the production cost of the enterprise. The present invention still uses alkaline additives, inorganic salts and surfactants as the main raw materials, and obtains a liquid degreaser that can be used at room temperature through compounding. During use, it only needs to heat the temperature of the cleaning liquid to 30-40°C, and the use process does not need to be compounded with other components. The operation is simple and it is expected to be used on a large scale in enterprises. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects existing in the prior art and provide a room temperature degreasing agent for cold rolled strip and a preparation method. Compared with conventional alkaline degreasing agents, the room temperature degreasing agent of the present invention avoids the consumption of steam and other heat energy by high temperature saponification, and its applicable temperature is 30-40°C, thereby greatly reducing the cleaning energy consumption and saving cleaning costs.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is to provide a room temperature degreasing agent, comprising the following components in mass percentage: 15-20% sodium hydroxide, 3-5% sodium carbonate, 1-3% chelating agent, 1.8-2.4% compound anionic surfactant, 0.6-1.0% compound nonionic surfactant, 0.3-0.5% defoaming agent, 0.5-0.8% ethylene glycol, and the balance is water.

[0006] The preferred technical solution is: the compound anionic surfactant is a mixture of sodium polyacrylate 445N and potassium phosphate H66, the compound nonionic surfactant is a mixture of fatty alcohol polyoxyethylene ether AEO-9 and isooctyl alcohol polyoxyethylene ether OE-35, the defoaming agent is AFE-1410, and the chelating agent is tetrasodium ethylenediaminetetraacetic acid.

[0007] A further preferred technical solution is: the mass percentage of the sodium polyacrylate 445N is 1-1.3%, the mass percentage of the potassium phosphate H66 is 0.8-1.1%, the mass percentage of the fatty alcohol polyoxyethylene ether AEO-9 is 0.5-0.8%, and the mass percentage of the isooctyl alcohol polyoxyethylene ether OE-35 is 0.1-0.2%.

[0008] A further preferred technical solution is: the water is pure water.

[0009] In order to ensure the smooth preparation and application of the above-mentioned room temperature degreasing agent, a preparation method of the room temperature degreasing agent is proposed, comprising the following steps:

[0010] S1: According to the mass percentages described in claim 1, weigh ethylene glycol, fatty alcohol polyoxyethylene ether AEO-9, isooctyl alcohol polyoxyethylene ether OE-35, potassium phosphate H66, sodium polyacrylate, and defoaming agent into container 1, and stir evenly at room temperature to obtain component A solution.

[0011] S2: According to the mass percentage of claim 1, water is first added to container 2 under stirring at room temperature, and then sodium hydroxide, sodium carbonate and a chelating agent are sequentially added to the water in container 2 to obtain a component B solution.

[0012] S3: When the component B solution is cooled to below 40°C, the component A solution in container 1 is added to container 2 to obtain a mixed solution of components A and B, and the mixed solution is stirred evenly at room temperature to obtain a room temperature degreasing agent.

[0013] Further preferred technical solutions include: in step S1, the stirring time after all six materials are added to the container 1 is 15 to 30 minutes; in step S2, the stirring time after the three materials are added to the water is 40 to 60 minutes; in step S3, the stirring time after the A component solution and the B component solution are mixed is 10 to 30 minutes.

[0014] The advantages and beneficial effects of the present invention are as follows: (1) Compared with conventional alkaline degreasing agents, the room temperature degreasing agent of the present invention avoids the consumption of heat energy such as steam for high temperature saponification, and its applicable temperature is 30-40°C, thereby greatly reducing the cleaning energy consumption and saving the cleaning cost. (2) When the room temperature degreasing agent of the present invention is used for cleaning cold-rolled steel sheets and other products in a coil continuous annealing production line, it does not need to be mixed with other components, and the cleaning operation steps are simple. DETAILED DESCRIPTION

[0015] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0016] (1) Embodiment 1

[0017] A room temperature degreasing agent (see Table 1), comprising the following components in mass percentage:

[0018] Table 1 Example 1 Formula

[0019]

[0020]

[0021] The preparation method of the room temperature degreasing agent in Example 1 comprises the following steps:

[0022] S1: According to the mass percentage of Example 1, ethylene glycol, fatty alcohol polyoxyethylene ether AEO-9, isooctyl alcohol polyoxyethylene ether OE-35, potassium phosphate H66, sodium polyacrylate, and defoamer are weighed in sequence in a small reactor with a stirrer, and stirred at room temperature for 20 minutes to mix the ingredients evenly. After mixing evenly, discharge the materials and place them in a small bucket for standby use. The A component solution is prepared.

[0023] S2: According to the mass percentage of Example 1, deionized water is first added to a large reactor equipped with a stirrer and a thermometer, and circulating cooling water is filled into the jacket of the reactor. Then weighed sodium hydroxide, sodium carbonate, and tetrasodium ethylenediaminetetraacetate are added in sequence, and stirred at room temperature for 50 minutes to fully dissolve the solid matter to obtain a component B solution.

[0024] S3: When the B component solution is cooled to below 40°C, add the A component solution into the large reaction kettle to obtain a mixed solution of A and B components, and stir for 20 minutes to make the solution uniform, thereby obtaining a room temperature degreasing agent.

[0025] (2) Embodiment 2

[0026] A room temperature degreasing agent (see Table 2), comprising the following components in mass percentage:

[0027] Table 2 Example 2 Formulation

[0028] Sodium hydroxide 20％ Sodium carbonate 3％ Tetrasodium EDTA 3％ Sodium polyacrylate 1.0％ Potassium phosphate 1.1％ Fatty alcohol polyoxyethylene ether 0.8％ 2-Ethylene Oxylate 0.1％ Defoaming agent 0.5％ Ethylene glycol 0.5％ Deionized water margin

[0029] The preparation method of the room temperature degreasing agent in Example 2 is the same as the preparation method of the room temperature degreasing agent in Example 1, and the stirring time can be adjusted within the scope of claim 3.

[0030] (3) Embodiment 3

[0031] A room temperature degreasing agent (see Table 3), comprising the following components in mass percentage:

[0032] Table 3 Example 3 Formulation

[0033] Sodium hydroxide 18％ Sodium carbonate 4％ Tetrasodium EDTA 2％ Sodium polyacrylate 1.2％ Potassium phosphate 0.9％ Fatty alcohol polyoxyethylene ether 0.6％ 2-Ethylene Oxylate 0.15％ Defoaming agent 0.4％ Ethylene glycol 0.6％ Deionized water margin

[0034] The preparation method of the room temperature degreasing agent in Example 3 is the same as the preparation method of the room temperature degreasing agent in Example 1, and the stirring time can be adjusted within the scope of Claim 3.

[0035] (4) Embodiment 4

[0036] A commercially available degreasing agent (liquid alkaline room temperature degreasing agent, a company in Dongguan) was used as a comparative example, and the room temperature degreasing agent prepared in Examples 1 to 3 of the present invention was used in the degreasing agent cleaning section of continuous annealing of cold-rolled strip. The surface cleaning parameters of the cold-rolled strip after cleaning are shown in Table 4.

[0037] Table 4 Surface parameters of cold rolled strip after cleaning

[0038]

[0039]

[0040] By comparing Example 1 with the comparative example, at the same temperature, the cleaning effect of the degreasing agent of the present invention is better than that of the commercial degreasing agent in terms of both surface reflectivity and the total amount of residual oil and iron per unit area of ​​the steel plate. By comparing Example 2 with the comparative example, even at a relatively low temperature, the cleaning effect of the degreasing agent of the present invention is better than that of the commercial degreasing agent, indicating that the degreasing agent of the present invention can further reduce the cleaning temperature during cleaning, thereby reducing the cleaning energy consumption.

[0041] The above examples are only preferred embodiments and are not intended to limit the invention. Although the present invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions described in the above embodiments or replace some of its technical features with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the invention shall be included in the protection scope of the present invention.

Claims

1. A room temperature degreasing agent for cold rolled steel strip, characterized in that: The invention comprises the following components in percentage by weight: 15-20% sodium hydroxide, 3-5% sodium carbonate, 1-3% chelating agent, 1.8-2.4% compound anionic surfactant, 0.6-1.0% compound nonionic surfactant, 0.3-0.5% defoaming agent, 0.5-0.8% ethylene glycol, and the balance is water; The compound anionic surfactant is a mixture of sodium polyacrylate 445N and potassium phosphate H66, the mass percentage of the sodium polyacrylate 445N is 1-1.3%, and the mass percentage of the potassium phosphate H66 is 0.8-1.1%; the compound nonionic surfactant is a mixture of fatty alcohol polyoxyethylene ether AEO-9 and isooctyl alcohol polyoxyethylene ether OE-35, the mass percentage of the fatty alcohol polyoxyethylene ether AEO-9 is 0.5-0.8%, and the mass percentage of the isooctyl alcohol polyoxyethylene ether OE-35 is 0.1-0.2%.

2. The room temperature degreasing agent for cold rolled steel strip according to claim 1, characterized in that: The model of the defoamer is AFE-1410.

3. The room temperature degreasing agent for cold rolled steel strip according to claim 1, characterized in that: The chelating agent is tetrasodium ethylenediaminetetraacetate.

4. A method for preparing a room temperature degreasing agent as claimed in claim 1, characterized in that: The steps include: S1: According to the mass percentages described in claim 1, weigh ethylene glycol, fatty alcohol polyoxyethylene ether AEO-9, isooctyl alcohol polyoxyethylene ether OE-35, potassium phosphate H66, sodium polyacrylate, and defoaming agent into container 1, and stir evenly at room temperature to obtain a component A solution; S2: According to the mass percentage of claim 1, water is first added to container 2 under stirring at room temperature, and then sodium hydroxide, sodium carbonate, and a chelating agent are sequentially added to the water in container 2 to obtain a component B solution; S3: When the component B solution is cooled to below 40°C, the component A solution in container 1 is added to container 2 to obtain a mixed solution of components A and B, and the mixed solution is stirred evenly at room temperature to obtain a room temperature degreasing agent.

5. The method for preparing a normal temperature degreasing agent according to claim 4, characterized in that: In step S1, the stirring time after adding all six materials into container 1 is 15 to 30 minutes; in step S2, the stirring time after adding three materials into water is 40 to 60 minutes; in step S3, the stirring time after mixing component A solution and component B solution is 10 to 30 minutes.

Images