Rapidly biodegradable rolling liquid composition as well as preparation method and application thereof

Abstract

The invention provides a rapidly biodegradable rolling liquid composition as well as a preparation method and application thereof. The rolling liquid composition comprises the following components in parts by weight: 82.0-94.0 parts of a boundary lubricant; 3.0-9.0 parts by weight of an anti-wear reagent at extreme pressure; 2.0 to 5.0 parts by weight of a surfactant; 1.0 to 4.0 parts by weight of an antioxidant preservative; wherein the boundary lubricant comprises a main boundary lubricant and an auxiliary boundary lubricant, the main boundary lubricant is selected from one or more of oxidized vegetable oil, coconut oil and palm oil, and the auxiliary boundary lubricant is selected from one or more of isooctyl palmitate, trimethylolpropane fatty acid ester and pentaerythritol fatty acid ester. And the weight ratio of the main boundary lubricant to the auxiliary boundary lubricant is (8-1): 1. The biodegradable rolling liquid composition has good biodegradability, and can be used for processing stainless steel, plain carbon steel and other multi-material metals.

Description

Technical Field

[0001] The present invention belongs to the technical field of rolling fluids, and particularly relates to a rapidly biodegradable rolling fluid composition, its preparation method and uses. Background Art

[0003] In the process of cold-rolled steel sheet processing and production, rolling fluid is an essential lubricating medium as a process lubricant, playing roles of lubrication, cooling, cleaning and rust prevention in cold rolling. After being used for a period of time, the performance of the rolling fluid deteriorates and the indicators become worse, and it needs to be replaced. The waste liquid generated has poor biodegradability in the environment, and direct discharge deteriorates the human environment. Using the traditional incineration method will generate a large amount of greenhouse gases such as carbon dioxide and methane. At present, there is a need to provide a rolling fluid with rapid biodegradability.

[0004] In recent years, patent applications regarding biodegradable rolling emulsifying oils have been successively disclosed. For example, Chinese Patent Application CN 105602674 A discloses a biodegradable rolling emulsifying oil composition and its uses for the process lubrication in the cold rolling process of stainless steel strip; Chinese Patent Application CN 105238525 A discloses the application of a biodegradable rolling emulsifying oil composition in the hot rolling process of aluminum alloy strip; Chinese Patent Application CN 114058427 A discloses a biodegradable aluminum hot rolling fluid and its preparation method; Chinese Patent CN 116144416 A discloses a biodegradable anionic-nonionic mixed aluminum hot rolling fluid and its preparation method. Although these patent documents all mention the biodegradable performance of rolling emulsions, they do not give specific data on the biodegradation rate, and the biodegradability rate and degradation speed cannot be judged. In addition, the products involved in these patent documents are all used for the single processing of a single metal and do not have adaptability to multiple metal materials.

[0005] Therefore, there is still a need to develop a biodegradable rolling fluid product that meets the technical requirements of current high-efficiency rolling mills and has rapid biodegradability. Summary of the Invention

[0006] In order to solve the above problems in the prior art, the present invention provides a rapidly biodegradable rolling fluid composition, its preparation method and uses. The biodegradable rolling fluid composition of the present invention has good biodegradability and can be used for processing multiple metal materials such as stainless steel and plain carbon steel.

[0007] The object of the present invention is achieved by the following technical solutions.

[0008] In a first aspect, the present invention provides a rapidly biodegradable rolling fluid composition, and the rolling fluid composition includes:

[0009]

[0010] Among them, the boundary lubricant includes a main boundary lubricant and an auxiliary boundary lubricant. The main boundary lubricant is selected from one or more of oxidized vegetable oil, coconut oil, and palm oil. The auxiliary boundary lubricant is selected from one or more of isooctyl palmitate, trimethylolpropane fatty acid ester, and pentaerythritol fatty acid ester. And the weight ratio of the main boundary lubricant to the auxiliary boundary lubricant is 8 to 1:1.

[0011] According to the rolling fluid composition provided by the present invention, among them, the weight ratio of the main boundary lubricant to the auxiliary boundary lubricant can be 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1.5:1, 1:1 or the range composed of them.

[0012] According to the rolling fluid composition provided by the present invention, among them, the main boundary lubricant is palm oil, and the auxiliary boundary lubricant is pentaerythritol fatty acid ester.

[0013] According to the rolling fluid composition provided by the present invention, among them, the boundary lubricant further includes 0 to 10 parts by weight of Group IV base oil. For example, the Group IV base oil can be PAO base oil.

[0014] According to the rolling fluid composition provided by the present invention, among them, the extreme pressure and anti-wear agent is selected from one or more of acidic phosphate esters, phosphite esters, alcohol ether phosphate esters, ammonium phosphate ester salts, sulfurized olefins, sulfurized fatty acid esters, sulfurized fatty oils, and nitrogen-containing borate esters.

[0015] In some embodiments, the extreme pressure and anti-wear agent is selected from at least two of acidic phosphate esters, phosphite esters, ammonium phosphate ester salts, sulfurized fatty acid esters, or nitrogen-containing borate esters, for example, 3 to 4 kinds.

[0016] In some preferred embodiments, the extreme pressure and anti-wear agent includes a main extreme pressure and anti-wear agent and an auxiliary extreme pressure and anti-wear agent. The main extreme pressure and anti-wear agent is selected from acidic phosphate esters, phosphite esters, and ammonium phosphate ester salts. The auxiliary extreme pressure and anti-wear agent is selected from sulfurized fatty acid esters and nitrogen-containing borate esters. The weight ratio of the main extreme pressure and anti-wear agent to the auxiliary extreme pressure and anti-wear agent is 1:(0.4 to 5), preferably 1:(1.5 to 3.5).

[0017] ]>In some specific embodiments, the main extreme pressure and anti-wear agent includes 1 to 2 parts by weight of acidic phosphate ester, 0 to 0.5 parts by weight of phosphite ester, and 0.5 to 1 part by weight of ammonium phosphate ester salt. The auxiliary extreme pressure and anti-wear agent includes 5 to 6 parts by weight of sulfurized fatty acid ester.

[0018] According to the rolling fluid composition provided by the present invention, wherein the surfactant is selected from at least two of low HLB value alkylphenol polyoxyethylene ethers, high HLB value alkylphenol polyoxyethylene ethers, low HLB value alkoxylated fatty alcohols, high HLB value alkoxylated fatty alcohols, alcohol ester type surfactants, high molecular weight surfactants, fatty alcohol ether carboxylic acids, quaternary ammonium salt type surfactants, low HLB value tallow amine polyoxyethylene ethers and high HLB value tallow amine polyoxyethylene ethers, preferably selected from at least two of low HLB value alkylphenol polyoxyethylene ethers, high HLB value alkylphenol polyoxyethylene ethers, alcohol ester type surfactants, high molecular weight surfactants, low HLB value tallow amine polyoxyethylene ethers and high HLB value tallow amine polyoxyethylene ethers.

[0019] In the present invention, the term "low HLB value" means HLB value ≤ 7; the term "high HLB value" means HLB value > 7.

[0020] Examples of the alcohol ester type surfactant suitable for the present invention include the alcohol ester type surfactant with the trade name S-8; and / or, examples of the high molecular weight surfactant suitable for the present invention include the high molecular weight surfactant with the trade name A07.

[0021] In some embodiments, the surfactant includes a main surfactant and an auxiliary surfactant; the main surfactant is selected from low HLB value alkylphenol polyoxyethylene ethers, high HLB value alkylphenol polyoxyethylene ethers, low HLB value tallow amine polyoxyethylene ethers, high HLB value tallow amine polyoxyethylene ether acid phosphates, and the auxiliary surfactant is selected from alcohol ester type surfactants and high molecular weight surfactants, and the mass ratio of the main surfactant to the auxiliary surfactant is 1:(0.05 - 1), preferably 1:(0.06 - 0.5).

[0022] In some specific embodiments, the main surfactant includes 0.5 - 1 part by weight of low HLB value alkylphenol polyoxyethylene ether and 2 - 3 parts by weight of high HLB value alkylphenol polyoxyethylene ether; the auxiliary surfactant includes 0.2 - 0.5 part by weight of high molecular weight surfactant and 0 - 1 part by weight of alcohol ester type surfactant.

[0023] According to the rolling fluid composition provided by the present invention, wherein the antioxidant preservative is selected from at least two of shielded phenolic antioxidants, amine antioxidants, sodium petroleum sulfonate, barium dinonylnaphthalene sulfonate, benzotriazole and its derivatives, thiadiazole derivatives, long-chain dibasic acids or organic tribasic acids. Preferably, the antioxidant preservative is selected from at least two of shielded phenolic antioxidants, sodium sulfonate, barium dinonylnaphthalene sulfonate, benzotriazole and its derivatives, long-chain dibasic acids and amine antioxidants.

[0024] In some embodiments, the antioxidant preservative includes a primary antioxidant preservative and a secondary antioxidant preservative; the primary antioxidant preservative is selected from sodium sulfonate, barium dinonylnaphthalene sulfonate, and benzotriazole and its derivatives, and the secondary antioxidant preservative is selected from hindered phenolic antioxidants, long-chain dibasic acids, and amine antioxidants. The weight ratio of the primary antioxidant preservative to the secondary antioxidant preservative is 1:(0.1 - 1.5), preferably 1:(0.5 - 1.5), and more preferably 1:(0.5 - 1).

[0025] According to the rolling fluid composition provided by the present invention, the rolling fluid composition does not contain organosiloxane.

[0026] In some embodiments, the rolling fluid composition is composed of a boundary lubricant, an extreme pressure anti-wear agent, a surfactant, and an antioxidant preservative.

[0027] In a second aspect, the present invention provides a method for preparing the fast biodegradable rolling fluid composition of the first aspect, wherein the preparation method includes the following steps:

[0028] S1: Heat and stir the extreme pressure anti-wear agent and the boundary lubricant to obtain a mixture;

[0029] S2: Add the surfactant and the antioxidant preservative to the mixture obtained in step S1, heat and stir, and cool to room temperature to obtain a cold rolling fluid composition.

[0030] According to the preparation method provided by the present invention, the conditions for heating and stirring in step S1 and step S2 independently include: the temperature is 45 - 55°C; and / or, the stirring rate is 300 - 500 rmp; and / or, the stirring time is 0.5 - 2 h.

[0031] In a third aspect, the present invention provides the application of the fast biodegradable rolling fluid composition of the first aspect or the rolling fluid composition prepared by the preparation method of the second aspect in the field of lubrication for cold rolling of plain carbon steel and stainless steel.

[0032] According to the application provided by the present invention, the fast biodegradable rolling fluid composition is applied in the form of an emulsion. Preferably, the emulsion is prepared by diluting the fast biodegradable rolling fluid composition with demineralized water; preferably, the concentration of the fast biodegradable rolling fluid composition in the emulsion is 0.5 - 8% by weight.

[0033] The above raw materials in the present invention can be self-made or obtained commercially, and the present invention does not make special limitations in this regard.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] (1) The cold rolling rolling fluid composition of the present invention has good biodegradability, meeting the requirements of rapid biodegradation and being more in line with the current environmental, safety, health, and low-carbon requirements; in the cold rolling rolling fluid composition of the present invention, through the compounding of various components and their synergistic cooperation, it has excellent performance, especially good extreme pressure lubrication performance and antioxidant and anti-corrosion performance, and can meet the cold rolling processes of stainless steel and plain carbon steel. For example, according to the test of carbon dioxide production for rapid biodegradability of chemicals in GB / T 21856-2008, it meets the requirements of the rapid biodegradation rate.

[0036] (2) The comprehensive performance of the rapid biodegradable rolling fluid composition provided by the present invention can meet the requirements of the rolling process development for rolling fluids, and can be used in the industrial applications of lubricating the cold rolling processes of single-stand cold rolling mills and continuous rolling mill trains for stainless steel or plain carbon steel, especially in single-stand reversible rolling mills and continuous rolling mill trains, and good technical effects have been achieved. Detailed implementation mode

[0037] The present invention will be further described below in conjunction with specific embodiments, but it does not constitute any limitation to the present invention.

[0038] Example 1

[0039] This example provides a rapid biodegradable rolling fluid composition, its preparation method and application. Prepare raw materials according to the component weight parts in Table 1, and the specific details are as follows:

[0040] S1: Add the boundary lubricant and extreme pressure anti-wear agent into a reaction kettle with stirring, heat and stir at a temperature of 50 ± 5 °C for 1 h to obtain a mixture, where the stirring rate is 400 rmp;

[0041] S2: Sequentially add the surfactant and antioxidant and anti-corrosion agent to the mixture obtained in step S1, stir at a temperature of 50 ± 5 °C until all the additives are dissolved (1 h), and cool to room temperature to obtain the cold rolling fluid composition, where the stirring rate is 400 rmp.

[0042] The cold rolling rolling fluid composition prepared in Example 1 was diluted with deionized water to an emulsion with a weight percentage concentration of 2.5% and used for the process lubrication of rolling stainless steel on a 1780 mm eighteen-high five-stand continuous rolling mill, and good application effects were obtained; among them, the maximum rolling pressure of the rolling mill is 1800 tons, and the maximum rolling speed is 300 m / min.

[0043] Example 2

[0044] This example provides a rapid biodegradable rolling fluid composition, its preparation method and application. Prepare raw materials according to the component weight parts in Table 1, and the specific details are as follows:

[0045] S1: Add boundary lubricant and extreme pressure anti-wear agent into a reactor with stirring, heat and stir at a temperature of 50±5°C for 1 h to obtain a mixture, where the stirring rate is 400 rmp;

[0046] S2: Sequentially add surfactant and antioxidant preservative into the mixture obtained in step S1, stir at a temperature of 50±5°C until all the additives are dissolved (1 h), and cool to room temperature to obtain a cold rolling fluid composition, where the stirring rate is 400 rmp.

[0047] Dilute the cold rolling fluid composition prepared in Example 2 with deionized water to an emulsion with a weight percentage concentration of 3.0%, and use it for the process lubrication of rolling plain carbon steel on a 1500 mm six-high reversing mill, achieving good application effects; among them, the maximum rolling pressure of the mill is 1500 tons, and the maximum rolling speed is 1200 m / min.

[0048] Examples 3 - 6

[0049] Prepare a fast biodegradable rolling fluid composition according to the formula in Table 1 using the same method as in Example 1.

[0050] Table 1 Formulas of the compositions in Examples 1 - 6 (parts by weight)

[0051]

[0052]

[0053] Comparative Example 1

[0054] Prepare a rolling fluid composition according to the formula disclosed in Example 1 of Document CN 105602674 A, and the specific formula is shown in Table 2.

[0055] Table 2 Formulas of the rolling fluid composition in Comparative Example 1

[0056] Raw material name Grade Content Palm oil - 44.45 parts by weight Trimethylolpropane oleate - 30 parts by weight Oleic acid - 5 parts by weight Sulfurized fatty acid ester S11 8 parts by weight Phosphate ester CN3 2 parts by weight Alkylphenol polyoxyethylene ether NP7 5 parts by weight Dodecanedioic acid - 2 parts by weight Octyldiphenylamine - 0.5 parts by weight 2,6-Di-tert-butyl-p-cresol - 1 part by weight Organosiloxane M5 0.05 parts by weight Chloromethylisothiazolinone - 2 parts by weight

[0057] Comparative Example 2

[0058] Select a commercially available cold rolling fluid composition with the brand QH EVEROLL S purchased from Quaker Houghton as a control.

[0059] Comparative Example 3

[0060] The formula and preparation method are basically the same as those in Example 1, except that: the dosage of palm oil is adjusted to 48.3 parts by weight, and the dosage of acidic phosphate ester is adjusted to 11 parts by weight.

[0061] Comparative Example 4

[0062] The formulation and preparation method are basically the same as those of Example 1, except that: the dosage of pentaerythritol tetraoleate is adjusted to 58.3 parts by weight, and the dosage of palm oil is adjusted to 30 parts by weight.

[0063] Comparative Example 5

[0064] The formulation and preparation method are basically the same as those of Example 1, except that: the dosage of acidic phosphate ester is adjusted to 5 parts by weight, and the dosage of sulfurized fatty acid ester is adjusted to 1 part by weight.

[0065] Performance Test

[0066] The performance of the rolling fluid compositions of each example and comparative example was measured according to the following method, and the results are shown in Table 3.

[0067] 1. Extreme Pressure Lubrication Performance

[0068] The extreme pressure lubrication performance represents the load-bearing capacity of the lubricating film formed by the lubricant. The maximum non-seizure load PB value of the oil sample to be tested was measured according to the test standard GB / T3142-2019. The larger the PB value, the greater the strength of the lubricating film, the stronger the load-bearing capacity, and the better the lubrication performance. In the detection method, the PB value is divided into grades. There are 57 grades from 98N (10kg) - 7845 (800kg). The PB value grades involved in the present invention belong to the following intervals: 1020N (104kg), 1069N (109kg), 1118N (114kg), 1167N (119kg), 1236N (126kg), 1294N (132kg), 1363N (139kg).

[0069] 2. Biodegradability

[0070] The biodegradation rate represents the biodegradability of the lubricant when it comes into contact with the inoculum within a limited time. The 28-day biodegradation rate of the chemical was tested according to GB / T 21856-2008 "Test for the Production of Carbon Dioxide for the Rapid Biodegradability of Chemicals". The larger the value, the higher the biodegradation rate. Among them, according to the provisions of GB / T 27850-2011 "General Rules for the Rapid Biodegradability of Chemicals", during the 28-day test period, reaching a passing level of 60% in a 10-day observation period belongs to rapid biodegradability.

[0071] Table 3 Performance of the Cold Rolling Fluid Compositions of Examples 1-6 and Comparative Examples 1-2

[0072]

[0073] As can be seen from Table 3, in the biodegradation rate experiment of the cold rolling rolling fluid compositions in Examples 1 to 6, they are superior to Comparative Examples 1 to 5, and the schemes of Examples 1 and 2 are the best; in addition, Examples 1 to 6 all reached a passing level of 60% during a 10-day observation period, having rapid biodegradability and being superior to Comparative Examples 1 to 5. The maximum non-seizure load PB of the cold rolling rolling fluid compositions in Examples 1 to 6 is between 1167 and 1294 N, all of which are superior to the comparative examples and have better extreme pressure lubrication effects.

[0074] It is believed that through the compounding and synergistic cooperation of each component, the present invention has excellent performance. For example, in the present invention, a specific boundary lubricant is used, which has good biodegradation ability. By compounding different types of extreme pressure and anti-wear agents, especially the synergistic effect of ammonium phosphate and other sulfurized extreme pressure agents, the PB value can be effectively increased, and more excellent extreme pressure performance can be obtained at a lower addition amount (moreover, the amount of the boundary lubricant can be increased); at the same time, the reasonable use of antioxidant and preservatives enables the rolling fluid composition of the present invention to have better rust and corrosion prevention ability, can meet the processing requirements of various materials such as plain carbon steel and stainless steel, and has better applicability.

[0075] In summary, the cold rolling rolling fluid composition of the present invention has good biodegradability, meets the requirements of rapid biodegradation, and is more in line with the current environmental, safety, health, and low-carbon requirements; in the present invention, through the compounding and synergistic cooperation of each component, the cold rolling rolling fluid composition of the present invention has excellent performance, especially has good extreme pressure lubrication performance and antioxidant and corrosion prevention performance, and can meet the cold rolling processes of stainless steel and plain carbon steel. The comprehensive performance of this composition can meet the requirements of the development of rolling processes for rolling fluids and can be used in industrial applications of lubricating the cold rolling processes of single-stand cold rolling mills and continuous rolling mill units for stainless steel or plain carbon steel.

[0076] For any numerical value mentioned in the present invention, if there is only a two-unit interval between any lowest value and any highest value, it includes all values increasing by one unit each from the lowest value to the highest value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, time, etc. is stated as 50 - 90, it means in this specification that the specific values 51 - 89, 52 - 88... as well as 69 - 71 and 70 - 71, etc. are specifically listed. For non-integer values, units of 0.1, 0.01, 0.001, or 0.0001 can be appropriately considered as one unit. These are only some specifically indicated examples. In this application, in a similar manner, all possible combinations of numerical values between the listed lowest value and highest value are considered to have been disclosed.

[0077] It should be noted that the above-described embodiments are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described by referring to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words rather than limiting words. Modifications can be made to the present invention within the scope of the claims of the present invention as stipulated, and the present invention can be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A rapidly biodegradable rolling fluid composition, the rolling fluid composition comprising: 82.0 to 94.0 parts by weight of a boundary lubricant; 3.0 to 9.0 parts by weight of an extreme pressure and anti-wear agent; 2.0 to 5.0 parts by weight of a surfactant; 1.0 to 4.0 parts by weight of an antioxidant and preservative; Wherein, the boundary lubricant includes a main boundary lubricant and an auxiliary boundary lubricant, the main boundary lubricant is selected from one or more of oxidized rapeseed oil, coconut oil and palm oil, the auxiliary boundary lubricant is selected from one or more of isooctyl palmitate, trimethylolpropane fatty acid ester and pentaerythritol fatty acid ester, and the weight ratio of the main boundary lubricant to the auxiliary boundary lubricant is 8 to 1:

1.

2. The rolling fluid composition according to claim 1, characterized in that, The main boundary lubricant is palm oil and the auxiliary boundary lubricant is pentaerythritol fatty acid ester.

3. The rolling fluid composition according to claim 1 or 2, characterized in that, The extreme pressure and anti-wear agent is selected from one or more of acidic phosphates, phosphites, alcohol ether phosphates, amine salts of phosphates, sulfurized olefins, sulfurized fatty acid esters, sulfurized fatty oils and nitrogen-containing borates; Preferably, the extreme pressure and anti-wear agent is selected from at least two of acidic phosphates, phosphites, ammonium salts of phosphates, sulfurized fatty acid esters or nitrogen-containing borates, such as 3 to 4 kinds.

4. The rolling fluid composition according to claim 3, wherein The extreme pressure and anti-wear agent includes a main extreme pressure and anti-wear agent and an auxiliary extreme pressure and anti-wear agent, the main extreme pressure and anti-wear agent is selected from acidic phosphates, phosphites and ammonium salts of phosphates, the auxiliary extreme pressure and anti-wear agent is selected from sulfurized fatty acid esters and nitrogen-containing borates, and the weight ratio of the main extreme pressure and anti-wear agent to the auxiliary extreme pressure and anti-wear agent is 1:(0.4 to 5), preferably 1:(1.5 to 3.5); Preferably, the main extreme pressure and anti-wear agent includes 1 to 2 parts by weight of acidic phosphate, 0 to 0.5 parts by weight of phosphite and 0.5 to 1 part by weight of ammonium salt of phosphate, and the auxiliary extreme pressure and anti-wear agent includes 5 to 6 parts by weight of sulfurized fatty acid ester.

5. The rolling fluid composition according to any one of claims 1-4, characterized in that, The surfactant is selected from at least two of low HLB value alkylphenol polyoxyethylene ethers, high HLB value alkylphenol polyoxyethylene ethers, low HLB value alkoxylated fatty alcohols, high HLB value alkoxylated fatty alcohols, alcohol ester type surfactants, high molecular weight surfactants, fatty alcohol ether carboxylic acids, quaternary ammonium salt type surfactants, low HLB value tallow amine polyoxyethylene ethers and high HLB value tallow amine polyoxyethylene ethers, preferably selected from at least two of low HLB value alkylphenol polyoxyethylene ethers, high HLB value alkylphenol polyoxyethylene ethers, alcohol ester type surfactants, high molecular weight surfactants, low HLB value tallow amine polyoxyethylene ethers and high HLB value tallow amine polyoxyethylene ethers.

6. The rolling fluid composition according to claim 5, characterized in that, The surfactant includes a main surfactant and an auxiliary surfactant; the main surfactant is selected from low HLB value alkylphenol polyoxyethylene ethers, high HLB value alkylphenol polyoxyethylene ethers, low HLB value tallow amine polyoxyethylene ethers, high HLB value tallow amine polyoxyethylene ether phosphoric acid esters, and the auxiliary surfactant is selected from alcohol ester type surfactants and high molecular weight surfactants, and the mass ratio of the main surfactant to the auxiliary surfactant is 1:(0.05 to 1), preferably 1:(0.06 to 0.5); Preferably, the main surfactant comprises 0.5 to 1 part by weight of an alkylphenol polyoxyethylene ether with a low HLB value and 2 to 3 parts by weight of an alkylphenol polyoxyethylene ether with a high HLB value; the auxiliary surfactant comprises 0.2 to 0.5 part by weight of a high molecular surfactant and 0 to 1 part by weight of an alcohol ester surfactant.

7. The rolling fluid composition according to any one of claims 1-6, characterized in that, The antioxidant preservative is selected from at least two of phenolic antioxidants, amine antioxidants, sodium petroleum sulfonate, barium dinonylnaphthalene sulfonate, benzotriazole and its derivatives, thiadiazole derivatives, long-chain dibasic acids or organic tribasic acids; Preferably, the antioxidant preservative is selected from at least two of phenolic antioxidants, sodium sulfonate, barium dinonylnaphthalene sulfonate, benzotriazole and its derivatives, long-chain dibasic acids and amine antioxidants.

8. The rolling fluid composition according to claim 7, characterized in that, The antioxidant preservative comprises a main antioxidant preservative and an auxiliary antioxidant preservative; the main antioxidant preservative is selected from sodium sulfonate, barium dinonylnaphthalene sulfonate and benzotriazole and its derivatives, the auxiliary antioxidant preservative is selected from phenolic antioxidants, long-chain dibasic acids and amine antioxidants, and the weight ratio of the main antioxidant preservative to the auxiliary antioxidant preservative is 1:(0.1 to 1.5), preferably 1:(0.5 to 1.5), more preferably 1:(0.5 to 1).

9. A method for preparing the rolling fluid composition according to any one of claims 1-8, wherein, The preparation method comprises the following steps: S1: Heating and stirring an extreme pressure antiwear agent and a boundary lubricant to obtain a mixture; S2: Adding a surfactant and an antioxidant preservative to the mixture obtained in step S1, heating and stirring, and cooling to room temperature to obtain a cold rolling fluid composition; Preferably, the heating and stirring conditions in step S1 and step S2 independently include: the temperature is 45 to 55 °C; and / or, the stirring rate is 300 - 500 rmp; and / or, the stirring time is 0.5 - 2 h.

10. Application of the rolling fluid composition according to any one of claims 1 - 8 in the field of lubrication for cold rolling of plain carbon steel and stainless steel.

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