Water-soluble mineral oil defoaming agent and preparation method thereof

Abstract

The invention provides a mineral oil defoaming agent capable of keeping water solubility for a long time and good compatibility in a water-based foaming system and a preparation method thereof. The preparation method comprises the following steps: firstly, introducing an anionic dispersant in a mixing and dispersing process of part of mineral oil carrier, defoaming active matter hydrophobic white carbon black, fatty acid metal soap and defoaming auxiliary agent fatty acid; the dispersing performance of the defoaming substance in the carrier oil is improved; the rest of the carrier mineral oil is mixed with the acrylate polymer, and the acrylate polymer has good compatibility with the mineral oil while improving the foam elimination and inhibition performance, so that the stability and compatibility of the defoaming agent are improved; finally, in the emulsification process, a compound emulsifier with the HLB value of 11-14, which is formed by compounding an oleophylic emulsifier (the HLB value is 2-8) and a hydrophilic emulsifier (the HLB value is 14-18), is introduced to emulsify the defoaming agent, so that the dispersing performance of the defoaming agent and the water solubility of the defoaming agent are further improved; in the preparation process, rapid mixing impact and rapid cooling methods are introduced to prepare the product, so that the stability and compatibility of the product are improved.

Description

Technical Field

[0001] The present invention relates to an antifoaming agent, and particularly to a water-soluble mineral oil antifoaming agent and a preparation method thereof. Background Art

[0002] An antifoaming agent is a fine chemical additive, and its main functions include defoaming and foam inhibition. A good antifoaming agent not only needs to have excellent defoaming and foam inhibition performance itself, but also requires good compatibility with other additives, without affecting the stability of the antifoaming agent itself and its foaming system. Compared with silicone antifoaming agents, mineral oil antifoaming agents have good compatibility and have been maturely applied in water-based coatings. Mineral oil antifoaming agents generally consist of mineral oil, hydrophobic particles, thickeners, and emulsifiers. They have good dispersibility in water-based coatings, and have good compatibility and defoaming and foam inhibition performance.

[0003] CN104771939A discloses a mineral oil antifoaming agent for papermaking black liquor. By introducing two different types of end-capped polyethers step by step, it avoids the problem that the viscosity of the antifoaming agent is too high and is not conducive to dispersion, and at the same time improves the defoaming and foam inhibition performance and storage stability; CN102489049A discloses that in a mineral oil antifoaming agent, after mixing metal soap substances with a solvent, they are added to a pre-mixed mineral oil / silica white system at a temperature of 40-90°C and stirred evenly, which can reduce the gelation of the fatty acid metal soap / hydrocarbon system, reduce the viscosity of the mineral oil antifoaming agent, and improve its dispersion performance; CN106390530A discloses a hyperbranched polyether modified silicone antifoaming agent containing mineral oil. By adding trifluoropropionic acid, its dispersibility is improved, and the performance of the antifoaming agent can be further improved; CN114949938A discloses a water-based mineral oil antifoaming agent and a preparation method thereof. The system is emulsified by polyether ester to overall improve the dispersibility of the mineral oil antifoaming agent.

[0004] The above patents all adjust the viscosity of the mineral oil antifoaming agent itself, reduce the viscosity, improve the dispersibility, and at the same time ensure the product stability; or improve the rapid dispersion performance of the mineral oil antifoaming agent when used in the application system. However, in the current industry, most of the mineral oil antifoaming agents are added as internal additive components to water-based coatings. It is not only necessary to consider the rapid dispersion performance and compatibility of the antifoaming agent, but also more necessary to consider the dispersion performance and compatibility of the antifoaming agent as an internal additive in the water-based application system for a long time, to avoid the mineral oil antifoaming agent floating or precipitating due to sticking to the wall after long-term mixing. In the current prior art, there is little research on such problems. Summary of the Invention

[0005] The present invention aims to provide a mineral oil defoamer that can maintain good water solubility and compatibility for a long time in an aqueous foaming system and a preparation method thereof. Firstly, an anionic dispersant is introduced during the mixing and dispersion process of a part of the mineral oil carrier, defoaming active substance hydrophobic silica, fatty acid metal soap, and defoaming aid fatty acid to improve the dispersion performance of the defoaming substances in the carrier oil; the remaining part of the carrier mineral oil is mixed with an acrylate polymer. While the acrylate polymer improves the defoaming and foam-suppressing performance, it has good compatibility with the mineral oil, enhancing the stability and compatibility of the defoamer; finally, a composite emulsifier with an HLB value of 11 - 14 formed by compounding a lipophilic emulsifier (HLB value of 2 - 8) and a hydrophilic emulsifier (HLB value of 14 - 18) is introduced during the emulsification process to emulsify the defoamer, further improving the dispersion performance of the defoamer and its water solubility; during the preparation process, methods of rapid mixing impact and rapid cooling are introduced to prepare the product, enhancing the stability and compatibility of the product.

[0006] The components of the mineral oil defoamer of the present invention are as follows: A. Mineral oil The mineral oil is selected from one or more of kerosene, diesel oil, soybean oil, white oil, machine oil, naphthenic oil, and alkylbenzene; the mineral oil is divided into two parts A1 and A2 for use, and the dosage of A1 accounts for 35 - 50% of the total mass of the mineral oil; the dosage of the mineral oil accounts for 70 - 90% of the total mass of the mineral oil defoamer; B. Hydrophobic silica The specific surface area of the hydrophobic silica is 20 - 500 m 2 / g, and the dosage accounts for 2 - 8% of the total mass of the mineral oil defoamer; C. Fatty acid The fatty acid is a fatty acid with 12 - 22 carbon atoms, and the dosage accounts for 1 - 5% of the total mass of the mineral oil defoamer; D. Fatty acid metal soap The fatty acid metal soap includes one or more of magnesium salt, aluminum salt, calcium salt, and zinc salt of fatty acid; preferably aluminum fatty acid, which can be one or two of monoaluminum fatty acid and dialuminum fatty acid mixed in any proportion; the dosage accounts for 1 - 5% of the total mass of the mineral oil defoamer; E. Anionic surfactant The anionic surfactant is selected from petroleum sulfonate, octadecylbenzene sulfonate, octadecyl sulfonate, and octadecyl phosphate ester salt, and the dosage accounts for 1 - 3% of the total mass of the mineral oil defoamer; F. Acrylate polymer The acrylate polymer is obtained by polymerization reaction of monomer F1, monomer F2, and monomer F3 under the action of initiator F4; the dosage of the acrylate polymer accounts for 1 - 5% of the total mass of the mineral oil defoamer; The monomer F1 is selected from alkyl acrylates and alkyl methacrylates; the monomer F2 is selected from one or more of hydroxyalkyl acrylates and hydroxyalkyl methacrylates; the monomer F3 is a linear α-olefin; the initiator F3 is selected from one of 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), and benzoyl peroxide; 48 - 75% of the monomer F1, 20 - 48% of the monomer F2, and 2 - 6% of the monomer F3 are mixed evenly, and 0.5 - 2% of the initiator is added dropwise, and the reaction is carried out at 60 - 100 °C for 2 - 8 h to obtain an acrylate polymer G, compound emulsifier The dosage of the compound emulsifier accounts for 2 - 10% of the total mass of the mineral oil defoamer; The compound emulsifier is obtained by compounding emulsifier G1 and emulsifier G2, and the HLB value of the compound emulsifier is 11 - 14; The emulsifier G1 is selected from Span 40, Span 60, Span 65, Span 80, fatty alcohol fatty acid esters; the HLB value of the emulsifier G1 is 2 - 8; The emulsifier G2 is selected from Tween 20, Tween 40, Tween 60, Tween 80, polyethylene glycol fatty acid esters, fatty alcohol polyoxyethylene ethers; the HLB value of the emulsifier G2 is 14 - 18; A preparation method of a water-soluble mineral oil defoamer is as follows:

[0007] (1) Mineral oil A1 and hydrophobic silica are dispersed at a high speed of 2500 - 3000 rpm, and the dispersion is uniform to obtain a mixture M; (2) The dispersed mixture M, fatty acid metal soap, fatty acid, and anionic dispersant are put into a container, stirred and heated to 130 - 150 °C, and kept warm for 60 - 90 min to obtain a mixture N; (3) Mineral oil A2 and the acrylate polymer are put into a container and stirred evenly, cooled to below 20 °C to obtain a mixture X; the mixture N after the end of heat preservation is used to quickly impact the mixture X, and the stirring speed is controlled at 300 - 400 rpm until the temperature is reduced to 50 - 60 °C to obtain a mixture Y; (4) The compound emulsifier is continuously added to the mixture Y, and kept warm at 50 - 60 °C for 30 - 60 min to obtain a mixture Z; After the heat preservation is completed, the mixture Z is quickly cooled to below 25 °C with chilled water, passed through a colloid mill, and degassed to obtain the mineral oil defoamer of the present invention. Specific embodiments

[0008] Examples of the acrylate polymer F are as follows:

[0009]

[0010] Examples of the composite emulsifier G are as follows:

[0011] Examples of mineral oil defoamers Example 1

[0012] (1) 28 g of white oil and 8 g of hydrophobic silica with a specific surface area of 20 m 2 / g were dispersed at a high speed with a rotation speed of 2500 rpm until evenly dispersed to obtain mixture M1; (2) The well-dispersed mixture M1, 3 g of aluminum monostearate, 5 g of C12 fatty acid, and 1 g of petroleum sulfonate were put into a container, stirred and heated to between 150 °C, and kept warm for 70 min to obtain mixture N1; (3) 42 g of soybean oil and 5 g of acrylate polymer F-1 were put into a container and stirred evenly, and the temperature was lowered below 20 °C to obtain mixture X1; the mixture N1 after the heat preservation was used to quickly impact mixture X1, and the stirring speed was controlled at 300 rpm until the temperature was lowered to 50 °C to obtain mixture Y1; (4) 8 g of composite emulsifier G-1 was continuously added to mixture Y1, and it was kept warm at 50 °C for 30 min to obtain mixture Z1; (5) After the heat preservation was completed, mixture Z1 was quickly cooled to below 25 °C with chilled water and passed through a colloid mill, and degassed to obtain the mineral oil defoamer of the present invention. Example 2

[0013] (1) 29.75 g of kerosene and 6 g of hydrophobic silica with a specific surface area of 50 m 2 / g were dispersed at a high speed with a rotation speed of 2600 rpm until evenly dispersed to obtain mixture M2; (2) The well-dispersed mixture M2, 5 g of a mixture of aluminum monostearate and aluminum distearate, 3 g of C14 fatty acid, and 3 g of octadecylbenzene sulfonate were put into a container, stirred and heated to between 140 °C, and kept warm for 80 min to obtain mixture N2; (3) 50.25 g of diesel oil and 1 g of acrylate polymer F-2 were put into a container and stirred evenly, and the temperature was lowered below 20 °C to obtain mixture X2; the mixture N2 after the heat preservation was used to quickly impact mixture X2, and the stirring speed was controlled at 320 rpm until the temperature was lowered to 55 °C to obtain mixture Y2; (4) 2 g of composite emulsifier G-2 was continuously added to mixture Y2, and it was kept warm at 60 °C for 60 min to obtain mixture Z2; (5) After the heat preservation was completed, mixture Z2 was quickly cooled to below 25 °C with chilled water and passed through a colloid mill, and degassed to obtain the mineral oil defoamer of the present invention. Example 3

[0014] (1) 45 g of mechanical oil and 2 g of hydrophobic silica with a specific surface area of 80 m 2 / g were dispersed at a high speed with a rotation speed of 2700 rpm until evenly dispersed to obtain mixture M3; (2) The well-dispersed mixture M3, 1 g of magnesium stearate, 1 g of C16 fatty acid, and 1 g of octadecyl sulfonate were put into a container, stirred and heated to 150 °C, and kept warm for 70 min to obtain mixture N3; (3) 45 g of naphthenic oil and 1 g of acrylate polymer F-3 were put into a container and stirred evenly, then cooled to below 20 °C to obtain mixture X3; The mixture N3 after the heat preservation was used to quickly impact mixture X3, and the stirring speed was controlled at 350 rpm until the temperature dropped to 55 °C to obtain mixture Y3; (4) 4 g of compound emulsifier G-3 was continuously added to mixture Y3, and kept warm at 50 °C for 40 min to obtain mixture Z3; (5) After the heat preservation was completed, mixture Z3 was quickly cooled to below 25 °C with chilled water, passed through a colloid mill, and degassed to obtain the mineral oil defoamer of the present invention. Example 4

[0015] (1) 30 g of alkylbenzene and 4 g of hydrophobic silica with a specific surface area of 120 m 2 / g were dispersed at a high speed with a rotation speed of 2800 rpm until evenly dispersed to obtain mixture M4; (2) The well-dispersed mixture M4, 2 g of calcium stearate, 2 g of C18 fatty acid, and 2 g of octadecyl phosphate were put into a container, stirred and heated to 130 °C, and kept warm for 80 min to obtain mixture N4; (3) 37 g of naphthenic oil and 3 g of acrylate polymer F-4 were put into a container and stirred evenly, then cooled to below 20 °C to obtain mixture X4; The mixture N4 after the heat preservation was used to quickly impact mixture X4, and the stirring speed was controlled at 400 rpm until the temperature dropped to 60 °C to obtain mixture Y4; (4) 10 g of compound emulsifier G-4 was continuously added to mixture Y4, and kept warm at 55 °C for 50 min to obtain mixture Z4; (5) After the heat preservation was completed, mixture Z4 was quickly cooled to below 25 °C with chilled water, passed through a colloid mill, and degassed to obtain the mineral oil defoamer of the present invention. Example 5

[0016] (1) 36 g of white oil and 5 g of hydrophobic silica with a specific surface area of 150 m 2 / g were dispersed at a high speed with a rotation speed of 2900 rpm until evenly dispersed to obtain mixture M5; (2) Put the well-dispersed mixture M5, 4 g of zinc fatty acid, 5 g of C20 fatty acid, and 2 g of octadecyl sulfonate into a container, stir and heat up to 140 °C, keep warm for 70 min to obtain mixture N5; (3) Put 40 g of white oil and 2 g of acrylate polymer F-5 into a container, stir evenly, cool down below 20 °C to obtain mixture X5; Use the mixture N5 after the heat preservation to quickly impact mixture X5, and control the stirring speed at 350 rpm until the temperature drops to 50 °C to obtain mixture Y5; (4) Continue to add 6 g of compound emulsifier G-5 to mixture Y5, keep warm at 50 °C for 60 min to obtain mixture Z5; (5) After the heat preservation is completed, quickly cool the mixture Z5 to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention. Example 6

[0017] (1) High-speed disperse 30 g of diesel oil and 3 g of hydrophobic silica with a specific surface area of 250 m 2 / g at a rotation speed of 3000 rpm until evenly dispersed to obtain mixture M6; (2) Put the well-dispersed mixture M6, a mixture of 2 g of zinc fatty acid and calcium fatty acid, 4 g of C22 fatty acid, and 1 g of octadecyl benzene sulfonate into a container, stir and heat up to 150 °C, keep warm for 60 min to obtain mixture N6; (3) Put 55 g of machine oil and 1 g of acrylate polymer F-6 into a container, stir evenly, cool down below 20 °C to obtain mixture X6; Use the mixture N6 after the heat preservation to quickly impact mixture X6, and control the stirring speed at 380 rpm until the temperature drops to 58 °C to obtain mixture Y6; (4) Continue to add 4 g of compound emulsifier G-6 to mixture Y6, keep warm at 60 °C for 30 min to obtain mixture Z6; (5) After the heat preservation is completed, quickly cool the mixture Z6 to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention. Example 7

[0018] (1) High-speed disperse 32 g of soybean oil and 7 g of hydrophobic silica with a specific surface area of 350 m 2 / g at a rotation speed of 2500 rpm until evenly dispersed to obtain mixture M7; (2) Put the well-dispersed mixture M7, 3 g of calcium fatty acid, 4 g of C15 fatty acid, and 2 g of petroleum sulfonate into a container, stir and heat up to 140 °C, keep warm for 80 min to obtain mixture N7; (3) Put 40 g of soybean oil and 2 g of acrylate polymer F-7 into a container, stir evenly, and cool down to below 20 °C to obtain mixture X7; use the mixture N7 after the heat preservation to quickly impact mixture X7, and control the stirring speed at 320 rpm until the temperature drops to 60 °C to obtain mixture Y7; (4) Continue to add 10 g of composite emulsifier G-7 to mixture Y7, and keep it at 55 °C for 40 min to obtain mixture Z7; (5) After the heat preservation is completed, quickly cool mixture Z7 to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention. Example 8

[0019] (1) Disperse 32 g of naphthenic oil and 2 g of hydrophobic silica with a specific surface area of 500 m 2 / g at a high speed of 2700 rpm, and disperse evenly to obtain mixture M8; (2) Put the well-dispersed mixture M8, 1 g of aluminum monostearate, 1 g of C22 fatty acid, and 1 g of octadecyl phosphate into a container, stir and heat up to between 130 °C, and keep it warm for 90 min to obtain mixture N8; (3) Put 58 g of kerosene and 1 g of acrylate polymer F-8 into a container, stir evenly, and cool down to below 20 °C to obtain mixture X8; use the mixture N8 after the heat preservation to quickly impact mixture X8, and control the stirring speed at 400 rpm until the temperature drops to 50 °C to obtain mixture Y8; (4) Continue to add 6 g of composite emulsifier G-8 to mixture Y8, and keep it at 50 °C for 60 min to obtain mixture Z8; (5) After the heat preservation is completed, quickly cool mixture Z8 to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention. Comparative Example 1

[0020] (1) Disperse 28 g of white oil and 8 g of hydrophobic silica with a specific surface area of 20 m 2 / g at a high speed of 2500 rpm, and disperse evenly to obtain mixture M1; (2) Put the well-dispersed mixture M1, 3 g of aluminum monostearate, and 6 g of C12 fatty acid into a container, stir and heat up to between 150 °C, and keep it warm for 70 min to obtain mixture N9; (3) Put 42 g of soybean oil and 5 g of acrylate polymer F-1 into a container, stir evenly, and cool down to below 20 °C to obtain mixture X1; use the mixture N9 after the heat preservation to quickly impact mixture X1, and control the stirring speed at 300 rpm until the temperature drops to 50 °C to obtain mixture Y9; (4) Continuously add 8 g of composite emulsifier G-1 to the mixture Y9, and keep it at 50 °C for 30 min to obtain the mixture Z9; (5) After the heat preservation is completed, quickly cool the mixture Z9 to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention. Comparative Example 2

[0021] (1) High-speed disperse 29.75 g of kerosene and 6 g of hydrophobic silica with a specific surface area of 50 m 2 / g at a rotation speed of 2600 rpm until evenly dispersed to obtain the mixture M2; (2) Put the well-dispersed mixture M2, 5 g of a mixture of aluminum monostearate and aluminum distearate, 3 g of C14 fatty acid, and 3 g of octadecyl benzene sulfonate into a container, stir and heat up to 140 °C, and keep it for 80 min to obtain the mixture N2; (3) Put 51.25 g of diesel into a container and stir evenly, cool it to below 20 °C to obtain the mixture X9; quickly impact the mixture X9 with the mixture N2 after the heat preservation ends, and control the stirring speed at 320 rpm until the temperature drops to 55 °C to obtain the mixture Y10; (4) Continuously add 2 g of composite emulsifier G-2 to the mixture Y10, and keep it at 60 °C for 60 min to obtain the mixture Z10; (5) After the heat preservation is completed, quickly cool the mixture Z10 to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention. Comparative Example 3

[0022] (1) High-speed disperse 45 g of machine oil and 2 g of hydrophobic silica with a specific surface area of 80 m 2 / g at a rotation speed of 2700 rpm until evenly dispersed to obtain the mixture M3; (2) Put the well-dispersed mixture M3, 1 g of magnesium fatty acid, 1 g of C16 fatty acid, and 1 g of octadecyl sulfonate into a container, stir and heat up to 150 °C, and keep it for 70 min to obtain the mixture N3; (3) Put 45 g of naphthenic oil and 1 g of acrylate polymer F-3 into a container and stir evenly, cool it to below 20 °C to obtain the mixture X3; quickly impact the mixture X3 with the mixture N3 after the heat preservation ends, and control the stirring speed at 350 rpm until the temperature drops to 55 °C to obtain the mixture Y3; (4) Continuously add 4 g of emulsifier Tween 40 to the mixture Y3, and keep it at 50 °C for 40 min to obtain the mixture Z11; (5) After the heat preservation is completed, quickly cool the mixture Z11 to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention. Comparative Example 4

[0023] (1) 45 g of machine oil and 2 g of hydrophobic silica with a specific surface area of 80 m 2 / g were dispersed at a high speed at 2700 rpm until evenly dispersed to obtain mixture M3; (2) The well-dispersed mixture M3, 1 g of magnesium stearate, 1 g of C16 fatty acid, and 1 g of octadecyl sulfonate were placed in a container, stirred and heated to 150 °C, and kept warm for 70 min to obtain mixture N3; (3) 45 g of naphthenic oil and 1 g of acrylate polymer F-3 were placed in a container and stirred evenly, then cooled below 20 °C to obtain mixture X3; The mixture N3 after the heat preservation was quickly impacted on the mixture X3, and the stirring speed was controlled at 350 rpm until the temperature dropped to 55 °C to obtain mixture Y3; (4) 4 g of emulsifier Span 80 was continuously added to mixture Y3, and kept warm at 50 °C for 40 min to obtain mixture Z12; (5) After the heat preservation was completed, the mixture Z12 was quickly cooled to below 25 °C with chilled water, passed through a colloid mill, and degassed to obtain the mineral oil defoamer of the present invention. Comparative Example 5

[0024] (1) 30 g of alkylbenzene and 4 g of hydrophobic silica with a specific surface area of 120 m 2 / g were dispersed at a high speed at 2800 rpm until evenly dispersed to obtain mixture M4; (2) The well-dispersed mixture M4, 2 g of calcium stearate, 2 g of C18 fatty acid, and 2 g of octadecyl phosphate were placed in a container, stirred and heated to 130 °C, and kept warm for 80 min to obtain mixture N4; (3) 37 g of naphthenic oil and 3 g of acrylate polymer F-4 were placed in a container and stirred evenly, then cooled below 20 °C to obtain mixture X4; The mixture N4 after the heat preservation was slowly added to the mixture X4, and the stirring speed was controlled at 400 rpm until the temperature dropped to 60 °C to obtain mixture Y11; (4) 10 g of compound emulsifier G-4 was continuously added to mixture Y11, and kept warm at 55 °C for 50 min to obtain mixture Z13; (5) After the heat preservation was completed, the mixture Z13 was quickly cooled to below 25 °C with chilled water, passed through a colloid mill, and degassed to obtain the mineral oil defoamer of the present invention. Comparative Example 6

[0025] (1) 36 g of white oil and 5 g of hydrophobic silica with a specific surface area of 150 m 2 / g were dispersed at a high speed at 2900 rpm until evenly dispersed to obtain mixture M5; (2) Put the well-dispersed mixture M5, 4 g of zinc fatty acid, 5 g of C20 fatty acid, and 2 g of octadecyl sulfonate into a container, stir and heat up to 140 °C, keep warm for 70 min to obtain mixture N5; (3) Put 40 g of white oil and 2 g of acrylate polymer F-5 into a container and stir evenly, cool down below 20 °C to obtain mixture X5; Use the mixture N5 after the heat preservation to quickly impact the mixture X5, and control the stirring speed at 350 rpm until the temperature drops to 50 °C to obtain mixture Y5; (4) Continue to add 6 g of compound emulsifier G-5 to the mixture Y5, keep warm at 50 °C for 60 min to obtain mixture Z5; (5) After the heat preservation is completed, let the mixture Z5 cool down to below 25 °C at room temperature, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention.

[0026] Performance Test (1) Defoaming and anti-foaming performance test

[0027] Test method: In a 500 Ml stainless steel cup, add 135 g of the prepared coating, then add 15 g of styrene-acrylic emulsion, use a high-speed disperser to stir at a speed of 600 rpm for 1 min to make the coating and styrene-acrylic emulsion evenly mixed, then add 1% thickener and 0.2% 2-amino-2-methyl-1-propanol, continue to stir at 600 rpm for 1 min, and finally add 0.3% defoamer, stir at a stirring speed of 600 rpm for 6 min. Immediately pour it into a 100 Ml graduated cylinder after stopping stirring, record the mass m and volume V, and calculate the specific gravity = m / V. The larger the value, the better the defoamer performance. (2) Compatibility test

[0028] Test method: After the above-mentioned high-speed dispersed coating is placed for 10 min, take out a little and let it stand on a glass plate. Use a 75um wet film former to scrape the coating evenly, observe the state of the coating film, and represent it with a grade. The higher the grade, the better the compatibility.

[0029]

[0030] Table 1 Defoaming and anti-foaming performance and compatibility test results

[0031] (3) Stability test Use the Formulaction / Turbiscan Tower / multiple light scattering stability analyzer to test the stability of the sample. The test temperature is 40 °C and the sample dosage is 20 g. In the test results, the smaller the TSI index, the better the sample stability.

[0032] Table 2 Stability test results

[0033]

[0034] (4)Dispersion stability test in water Test method: Prepare the mineral oil defoamers prepared in Examples 1-9 and Comparative Examples 1-6 into an aqueous dispersion with a mass dispersion of 1%, place it in a 250 ml beaker, stir evenly, let it stand for 24 h, observe the aqueous dispersion state, stir again and then observe the aqueous dispersion state for the second time. The less precipitation on the cup wall and the less floating matter on the liquid surface, the better the aqueous dispersion stability state.

[0035] Table 3 Test results of dispersion stability in water

Claims

1. A water-soluble mineral oil defoamer, which is composed of the following components: (1) Mineral oil: The mineral oil is selected from one or more of kerosene, diesel oil, soybean oil, white oil, machine oil, naphthenic oil, and alkylbenzene; the mineral oil is used in two parts A1 and A2, and the dosage of the mineral oil accounts for 70-90% of the total mass of the mineral oil defoamer; (2) Hydrophobic silica: The dosage accounts for 2-8% of the total mass of the mineral oil defoamer; (3) Fatty acid: The fatty acid is a fatty acid with 12-22 carbon atoms, and the dosage accounts for 1-5% of the total mass of the mineral oil defoamer; (4) Fatty acid metal soap includes one or more of magnesium salt, aluminum salt, calcium salt, and zinc salt of fatty acid, and the dosage accounts for 1-5% of the total mass of the mineral oil defoamer; (5) Anionic surfactant: The anionic surfactant is selected from petroleum sulfonate, octadecylbenzene sulfonate, octadecyl sulfonate, and octadecyl phosphate ester salt, and the dosage accounts for 1-3% of the total mass of the mineral oil defoamer; (6) Acrylate polymer: The acrylate polymer is obtained by polymerization reaction of monomer F1, monomer F2, and monomer F3 under the action of initiator F4; the dosage of the acrylate polymer accounts for 1-5% of the total mass of the mineral oil defoamer; monomer F1 is selected from alkyl acrylate and alkyl methacrylate; monomer F2 is selected from one or more of hydroxyalkyl acrylate and hydroxyalkyl methacrylate; monomer F3 is a straight-chain α-olefin; initiator F3 is selected from one of 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), and benzoyl peroxide; (7) Composite emulsifier: The composite emulsifier is obtained by compounding emulsifier G1 and emulsifier G2. The HLB value of emulsifier G1 is 2-8; the HLB value of emulsifier G2 is 14-18; the HLB value of the composite emulsifier is 11-14.

2. The water-soluble mineral oil defoamer according to claim 1, wherein, The dosage of the mineral oil A1 accounts for 35-50% of the total mass of the mineral oil.

3. A water-soluble mineral oil defoamer according to claim 1, characterized in that, The specific surface area of the hydrophobic silica is 20-500 m2 / g.

4. A water-soluble mineral oil defoamer according to claim 1, characterized in that, The fatty acid metal soap is aluminum fatty acid, which can be one or two of monoaluminum fatty acid and dialuminum fatty acid mixed in any proportion.

5. A water-soluble mineral oil defoamer according to claim 1, characterized in that, The preparation method of the acrylate polymer is to mix 48-75% of monomer F1, 20-48% of monomer F2, and 2-6% of monomer F3 evenly, dropwise add 0.5-2% of the initiator, and react at 60-100 °C for 2-8 h to obtain the acrylate polymer.

6. The water-soluble mineral oil defoamer according to claim 1, characterized in that, In the composite emulsifier, emulsifier G1 is selected from Span 40, Span 60, Span 65, Span 80, and fatty alcohol fatty acid ester.

7. A water-soluble mineral oil defoamer according to claim 1, characterized in that, In the composite emulsifier, emulsifier G2 is selected from Tween 20, Tween 40, Tween 60, Tween 80, polyethylene glycol fatty acid ester, and fatty alcohol polyoxyethylene ether.

8. The preparation method of the water-soluble mineral oil according to any one of claims 1-7 is as follows: (1) High-speed disperse the mineral oil A1 and the hydrophobic silica at a rotation speed of 2500-3000 rpm to obtain a uniform dispersion mixture M; (2) Put the well-dispersed mixture M, fatty acid metal soap, fatty acid, and anionic dispersant into a container, stir and heat up to 130 - 150 °C, and keep warm for 60 - 90 min to obtain mixture N; (3) Put mineral oil A2 and acrylate polymer into a container and stir evenly, cool down below 20 °C to obtain mixture X; Use the mixture N after the heat preservation to quickly impact mixture X, and control the stirring speed at 300 - 400 rpm until the temperature drops to 50 - 60 °C to obtain mixture Y; (4) Continue to add a compound emulsifier to mixture Y, and keep warm at 50 - 60 °C for 30 - 60 min to obtain mixture Z; (5) After the heat preservation is completed, quickly cool mixture Z to below 25 °C with chilled water, pass it through a colloid mill, and degas to obtain the mineral oil defoamer of the present invention.

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