Preparation method of solid defoaming agent

Abstract

The invention provides the preparation method of the solid defoaming agent, the prepared solid defoaming agent adopts a microwave drying mode, the product drying time, temperature and product tiling thickness are controlled, the product physical and chemical index moisture standard is reached, and compared with other drying modes, the microwave drying efficiency is high, and the product quality is high. The structure and distribution of the active matter in the carrier are not damaged, and the obtained solid defoaming agent has better defoaming and foam inhibition performance, is aging-resistant, and does not attenuate after being stored for a long time; meanwhile, due to the biological effect of microwave drying and the heat effect principle on bacteria, the microwave drying also has certain sterilization and mildew removal effects, and the storage period of the product is prolonged.

Description

Technical Field

[0001] The present invention relates to a preparation method of a solid defoamer. Since defoamers belong to fine chemical preparations, the present invention belongs to the technical field of fine chemical preparations. Background Art

[0002] In many industries such as daily chemicals, papermaking, textile printing and dyeing, water treatment, food processing, petrochemical industry, etc., excessive foam is inevitably generated, seriously affecting industrial production, such as reducing production capacity, affecting product quality, and affecting the normal progress of production, etc.

[0003] Defoamers can be divided into two types: solid and liquid according to their forms. Liquid defoamers have a wide range of application fields, but in some application fields, solid defoamers have an irreplaceable position compared with liquid defoamers.

[0004] Patent CN112473191A discloses an organosilicon solid defoamer particle and its preparation method. An active monomer and a synergist are used to prepare the active main body of the defoaming rod. After mixing a curing agent, an emulsifier and the active main body of the defoaming rod, they are injected into a paraffin or silica gel mold frame for curing to obtain the formed organosilicon solid defoaming particles. Patent CN109692505A discloses a solid particle mineral oil defoamer. An alkyl-modified silicone oil and hydrophobic fumed silica are mixed and reacted to form a silicone paste. A mixture of mineral oil, silicone paste, polyether and emulsifier is prepared, and the solid particle mineral oil defoamer is obtained by high-speed dispersion with a homogenizer; Patent CN118454290A discloses a solid defoaming composition and its preparation method. A defoaming active substance, an emulsifier and an inorganic carrier are mixed to prepare an intermediate, and then a water retaining agent and water are mixed to form a mixture. The mixture is mixed with the intermediate and prepared by high-speed dispersion to obtain a solid defoaming agent composition; Patent CN116351110A discloses a solid defoamer suitable for ceramic glazing. First, an active substance is prepared, and the active substance is uniformly mixed with a carrier and fumed silica, and a preservative is added and dried to obtain a solid defoamer; Patent CN115557728A discloses a solid defoamer for gypsum-based self-leveling and its preparation method. First, polyether ester and silicone paste are respectively prepared, and then an emulsifier and a carrier are added and dispersed at high speed, and then granulated and dried to obtain a solid defoamer. Summary of the Invention

[0005] Compared with the granulation drying and oven drying used in traditional solid defoamers, the solid defoamer provided by the present invention adopts microwave drying. By controlling the product drying time and the product laying thickness, the standard of the physical and chemical index moisture of the product is achieved. Compared with other drying methods, microwave drying has high efficiency, the structure and distribution of the active substance in the carrier are not damaged, the defoaming and foam-inhibiting performance of the obtained solid defoamer is better, and it is resistant to aging and does not decay after long-term storage. At the same time, due to the biological effect of microwave drying and the principle of thermal effect on bacteria, microwave drying also has a certain bactericidal and mildew-proof effect, extending the product storage period.

[0006] The solid defoamer of the present invention is characterized by comprising the following components:

[0007] A. Carrier

[0008] The carrier is divided into starch and inorganic salts. The starch is mainly selected from wheat starch, corn starch, tapioca starch, potato starch; the inorganic salts are specifically selected from sulfates, carbonates, silicates, phosphates, nitrates, etc., specifically selected from sodium sulfate, calcium sulfate, magnesium sulfate, potassium sulfate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, zeolite, magnesium silicate, calcium silicate, mica, bentonite, diatomite, sepiolite, natural clay, modified clay, talc, sodium tripolyphosphate, sodium citrate, potassium citrate, sodium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate.

[0009] The starch and inorganic salts of the present invention can be used alone or in combination, and the dosage is 5-20% of the total mass of the defoamer.

[0010] B. Silicone grease composition

[0011] The silicone grease composition is prepared by a well-known technology in the technical field, that is, polydimethylsiloxane with a viscosity of 100-10,000 mPa·s, MQ resin (M:Q = 0.4-1.2:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed, heated to 80-200 °C to react, and then hydrophobic silica with a specific surface area of 50-200 m 2 / g is added, the temperature of the reaction system is controlled at 80-150 °C, and the temperature is kept for 3-5 h. Finally, the reaction is carried out at a vacuum degree of -0.01 to -0.08 MPa for 1-2 h, and finally cooled to room temperature to obtain a silicone grease composition with a viscosity of 1,000-50,000 mPa·s. The dosage of the silicone grease composition is 60-85% of the total mass of the defoamer.

[0012] C. Emulsifier

[0013] The emulsifier is a non-ionic surfactant, selected from sorbitan fatty acid esters, fatty alcohol polyoxyethylene ethers, oleic acid polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, castor oil polyoxyethylene ethers, used alone or in combination, and the dosage is 1-10% of the total mass of the defoamer.

[0014] D. Structurant

[0015] The structurant is selected from acrylate polymers, specifically non-crosslinked polymers such as polymethyl(meth)acrylate, polyethyl(meth)acrylate, (meth)acrylate methyl ester-(meth)acrylate ethyl ester copolymer, (meth)acrylate methyl ester-(meth)acrylate butyl ester copolymer, (meth)acrylate methyl ester-styrene copolymer; crosslinked polymers such as (meth)acrylate methyl ester-ethylene glycol di(meth)acrylate copolymer, (meth)acrylate methyl ester-triethylene glycol di(meth)acrylate copolymer, copolymer of (meth)acrylate methyl ester and butadiene monomers. The dosage of the structurant is 2-15% of the total mass of the defoamer.

[0016] A solid defoamer according to the present invention has the following preparation method:

[0017] (1) Add the silicone grease composition, emulsifier, and structurant into a reaction vessel, mix and stir well to obtain a mixture M;

[0018] (2) Add the carrier to the mixture M, mix and stir well at 50-100 °C to obtain a preliminary product N;

[0019] (3) Microwave drying: Spread the preliminary product N evenly on the conveyor belt through a vibrating hopper, with a stacking thickness less than 10 cm, and perform microwave drying. First, keep the temperature constant at 80-130 °C for 10-30 min, and then keep the temperature constant at 30-60 °C for 5-20 min, controlling the final moisture content at 5-9%. Pay attention to dehumidifying during the drying process to keep the inside of the box dry, and monitor the temperature. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size. Specific embodiments

[0020] Component B silicone grease composition examples:

[0021] Example Polydimethylsiloxane MQ resin Catalyst Hydrophobic fumed silica Silicone grease composition Example 1 Viscosity 10000 mPa·s M:Q = 0.66:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 80m 2 / g]]> D1, viscosity 50,000 mPa·s Example 2 Viscosity 5000 mPa·s M:Q = 0.75:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 150 m 2 / g]]> D2, viscosity 30,000 mPa·s Example 3 Viscosity 100 mPa·s M:Q = 1.2:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 200 m 2 / g]]> D3, viscosity 1000 mPa·s Example 4 Viscosity 200 mPa·s M:Q = 0.66:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 80m 2 / g]]> D4, viscosity 5000 mPa·s Example 5 Viscosity 8000 mPa·s M:Q = 0.55:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 50m 2 / g]]> D5, viscosity 40000 mPa·s Example 6 Viscosity 800 mPa·s M:Q = 0.60:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 60m 2 / g]]> D6, viscosity 10,000 mPa·s Example 7 Viscosity 500 mPa·s M:Q = 0.40:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 150 m 2 / g]]> D7, viscosity 8000 mPa·s Example 8 Viscosity 300 mPa·s M:Q = 0.80:1.0 Prepared by mixing KOH and methyl silicone oil <![CDATA[Specific surface area 1200m 2 / g]]> D8, viscosity 4000 mPa·s

[0022] Example 1

[0023] (1) Add 80 parts of silicone grease composition D1, 1 part of fatty alcohol polyoxyethylene ether, and 7 parts of polymethyl(meth)acrylate into a reaction vessel, mix and stir well to obtain a mixture M1;

[0024] (2) Add 12 parts of wheat starch to the mixture M1, mix and stir evenly at 60 °C, and then perform microwave drying for 5 min to obtain the primary product N1;

[0025] (3) Microwave drying: Spread the primary product N1 evenly on the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep it at a constant temperature of 80 °C for 15 min, and then keep it at a constant temperature of 30 °C for 20 min, controlling the final moisture content at 7%. Pay attention to dehumidification during the drying process to keep the inside of the box dry, and monitor the temperature. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0026] Example 2

[0027] (1) Add 85 parts of silicone grease composition D2, 5 parts of polyoxyethylene oleate, and 5 parts of (meth)acrylate-ethylene glycol di(meth)acrylate copolymer to a reaction vessel, mix and stir well to obtain the mixture M2;

[0028] (2) Add 5 parts of magnesium silicate to the mixture M2, mix and stir evenly at 50 °C, and then perform microwave drying for 3 min to obtain the primary product N2;

[0029] (3) Microwave drying: Spread the primary product N2 evenly on the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep it at a constant temperature of 100 °C for 20 min, and then keep it at a constant temperature of 60 °C for 10 min, controlling the final moisture content at 6%. Pay attention to dehumidification during the drying process to keep the inside of the box dry, and monitor the temperature. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0030] Example 3

[0031] (1) Add 60 parts of silicone grease composition D3, 10 parts of polyoxyethylene oleate, and 10 parts of polyethyl (meth)acrylate to a reaction vessel, mix and stir well to obtain the mixture M3;

[0032] (2) Add 20 parts of potato starch to the mixture M3, mix and stir evenly at 80 °C, and then perform microwave drying for 5 min to obtain the primary product N3;

[0033] (3) Microwave drying: Spread the primary product N3 evenly on the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep it at a constant temperature of 90 °C for 10 min, and then keep it at a constant temperature of 50 °C for 20 min, controlling the final moisture content at 9%. Pay attention to dehumidification during the drying process to keep the inside of the box dry, and monitor the temperature. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0034] Example 4

[0035] (1) Add 70 parts of silicone grease composition D4, 3 parts of castor oil polyoxyethylene ether, and 9 parts of the copolymer of methyl (meth)acrylate and butadiene monomers into a reaction vessel, mix and stir well to obtain mixture M4;

[0036] (2) Add 18 parts of corn starch into mixture M4, mix and stir well at 90 °C, and then perform microwave drying for 5 min to obtain the preliminary product N4;

[0037] (3) Microwave drying: Spread the preliminary product N4 evenly on the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep the temperature constant at 130 °C for 30 min, and then keep the temperature constant at 30 °C for 5 min, controlling the final moisture content at 9%. Pay attention to dehumidification during the drying process to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with uniform particle size.

[0038] Example 5

[0039] (1) Add 75 parts of silicone grease composition D5, 2 parts of sorbitan fatty acid ester, and 12 parts of the copolymer of methyl (meth)acrylate - ethyl (meth)acrylate into a reaction vessel, mix and stir well to obtain mixture M5;

[0040] (2) Add 11 parts of sodium citrate into mixture M5, mix and stir well at 100 °C, and then perform microwave drying for 10 min to obtain the preliminary product N5;

[0041] (3) Microwave drying: Spread the preliminary product N5 evenly on the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep the temperature constant at 115 °C for 25 min, and then keep the temperature constant at 45 °C for 13 min, controlling the final moisture content at 8%. Pay attention to dehumidification during the drying process to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with uniform particle size.

[0042] Example 6

[0043] (1) Add 65 parts of silicone grease composition D6, 8 parts of castor oil polyoxyethylene ether, and 15 parts of the copolymer of methyl (meth)acrylate - styrene into a reaction vessel, mix and stir well to obtain mixture M6;

[0044] (2) Add a mixture of 12 parts of corn starch and magnesium nitrate into mixture M6, mix and stir well at 85 °C, and then perform microwave drying for 8 min to obtain the preliminary product N6;

[0045] (3) Microwave drying: The initial product N6 is evenly spread onto the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and then undergoes microwave drying. First, it is kept at a constant temperature of 95 °C for 22 min, and then at a constant temperature of 55 °C for 15 min, controlling the final moisture content to be 5%. During the drying process, pay attention to dehumidifying to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0046] Example 7

[0047] (1) Add 77 parts of silicone grease composition D7, 10 parts of a mixture of polyoxyethylene oleate and sorbitan fatty acid ester, and 8 parts of (meth)acrylate-(meth)acrylate butyl ester copolymer to a reaction vessel, and mix and stir well to obtain mixture M7;

[0048] (2) Add 5 parts of a mixture of wheat starch and sodium bicarbonate to mixture M7, mix and stir well under the condition of 95 °C, and then perform microwave drying for 2 min to obtain the initial product N7;

[0049] (3) Microwave drying: The initial product N7 is evenly spread onto the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and then undergoes microwave drying. First, it is kept at a constant temperature of 105 °C for 25 min, and then at a constant temperature of 45 °C for 12 min, controlling the final moisture content to be 6%. During the drying process, pay attention to dehumidifying to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0050] Example 8

[0051] (1) Add 80 parts of silicone grease composition D8, 2 parts of a mixture of alkylphenol polyoxyethylene ether and polyoxyethylene oleate, and 2 parts of (meth)acrylate-triglycol di(meth)acrylate copolymer to a reaction vessel, and mix and stir well to obtain mixture M8;

[0052] (2) Add 16 parts of a mixture of calcium silicate and bentonite to mixture M8, mix and stir well under the condition of 80 °C, and then perform microwave drying for 15 min to obtain the initial product N8;

[0053] (3) Microwave drying: The initial product N8 is evenly spread onto the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and then undergoes microwave drying. First, it is kept at a constant temperature of 110 °C for 10 min, and then at a constant temperature of 60 °C for 20 min, controlling the final moisture content to be 8%. During the drying process, pay attention to dehumidifying to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0054] Comparative Example 1

[0055] (1) Add 80 parts of silicone grease composition D1, 1 part of fatty alcohol polyoxyethylene ether, and 7 parts of sodium citrate into a reaction vessel, mix and stir well to obtain mixture M9;

[0056] (2) Add 12 parts of wheat starch into mixture M9, mix and stir well at 60 °C, and then perform microwave drying for 5 min to obtain preliminary product N9;

[0057] (3) Microwave drying: Spread the preliminary product N9 evenly on the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep it at a constant temperature of 80 °C for 15 min, and then keep it at a constant temperature of 30 °C for 20 min, controlling the final moisture content at 7%. Pay attention to dehumidification during the drying process to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0058] Comparative Example 2

[0059] (1) Add 85 parts of silicone grease composition D2, 5 parts of oleic acid polyoxyethylene ether, and 5 parts of (meth)acrylate-ethylene glycol di(meth)acrylate copolymer into a reaction vessel, mix and stir well to obtain mixture M10;

[0060] (2) Add 5 parts of magnesium silicate into mixture M10, mix and stir well at 50 °C, and then perform spray drying to obtain preliminary product N10;

[0061] (3) Microwave drying: Spread the preliminary product N10 evenly on the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep it at a constant temperature of 100 °C for 20 min, and then keep it at a constant temperature of 60 °C for 10 min, controlling the final moisture content at 6%. Pay attention to dehumidification during the drying process to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0062] Comparative Example 3

[0063] (1) Add 60 parts of silicone grease composition D3, 10 parts of oleic acid polyoxyethylene ether, and 10 parts of polyethyl (meth)acrylate into a reaction vessel, mix and stir well to obtain mixture M11;

[0064] (2) Add 20 parts of potato starch into mixture M11, mix and stir well at 80 °C, and then perform oven drying to obtain preliminary product N11;

[0065] (3) Microwave drying: The initial product N11 is evenly spread onto the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and then undergoes microwave drying. First, it is kept at a constant temperature of 90 °C for 10 min, and then at a constant temperature of 50 °C for 20 min, controlling the final moisture content at 9%. During the drying process, pay attention to dehumidifying to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0066] Comparative Example 4

[0067] (1) Add 70 parts of silicone grease composition D4, 3 parts of castor oil polyoxyethylene ether, and 9 parts of the copolymer of (meth)acrylic acid methyl ester and butadiene monomer into a reaction vessel, mix and stir well to obtain mixture M12;

[0068] (2) Add 18 parts of corn starch into mixture M12, mix and stir well at 90 °C, and then perform microwave drying for 5 min to obtain the initial product N12;

[0069] (3) Microwave drying: The initial product N12 is evenly spread onto the conveyor belt through a vibrating hopper, with a stacking thickness of 15 cm,

[0070] Perform microwave drying. First, keep it at a constant temperature of 130 °C for 30 min, and then at a constant temperature of 30 °C for 5 min, controlling the final moisture content at 9%. During the drying process, pay attention to dehumidifying to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0071] Comparative Example 5

[0072] (1) Add 75 parts of silicone grease composition D5, 2 parts of sorbitan fatty acid ester, and 12 parts of (meth)acrylic acid methyl ester-(meth)acrylic acid ethyl ester copolymer into a reaction vessel, mix and stir well to obtain mixture M13;

[0073] (2) Add 11 parts of sodium citrate into mixture M13, mix and stir well at 100 °C, and then perform microwave drying for 10 min to obtain the initial product N13;

[0074] (3) Microwave drying: The initial product N13 is evenly spread onto the conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and perform microwave drying. First, keep it at a constant temperature of 70 °C for 90 min, controlling the final moisture content at 5%. During the drying process, pay attention to dehumidifying to keep the inside of the box dry, and monitor the temperature well. After drying, perform crushing and screening to obtain a solid defoamer with a uniform particle size.

[0075] Performance test of solid defoamer

[0076] (1) Test of defoaming and foam suppression performance:

[0077] Add 50 g of commercially available washing powder and 0.3 g of solid antifoaming agent into a drum washing machine with a capacity of 7 kg. The test program is the standard wash. There are 11 measurement marks on the door of the washing machine, which are sequentially recorded as 0, 10, 20... 100, where 0 is the starting point, indicating no foam; 100 indicates full foam. Each 5 minutes is a washing cycle, and the foam height is recorded every 5 minutes, and the data is recorded when the machine stops. The larger the value, the higher the foam height in the washing machine, and the worse the foam suppression effect; the lower the foam height within the same time, the better the foam suppression performance of the product.

[0078] The present invention conducts machine washing tests on the product just prepared and after 3 months of storage and aging. The test results are as follows:

[0079]

[0080]

[0081] (2) Flowability test

[0082] Test the flowability of the powder antifoaming agent according to GB / T 21060-2007 of the national standard, and calculate it in seconds.

[0083] The flowability is divided into four grades, namely 1, 2, 3, and 4.

[0084] 1. Flow rapidly;

[0085] 2. Flow at a uniform speed;

[0086] 3. Flow intermittently;

[0087] 4. Do not flow.

[0088] The present invention conducts flowability tests on the product just prepared and after 3 months of storage and aging. The test results are as follows:

[0089]

Claims

1. A method for preparing a solid defoamer, characterized in that: The steps include: (1) Adding the silicone grease composition, emulsifier and structuring agent into a reaction container, mixing and stirring them thoroughly to obtain a mixture M; (2) adding the carrier to the mixture M, mixing and stirring at 50-100° C. to obtain the initial product N; (3) Microwave drying: The initial product N is evenly spread onto a conveyor belt through a vibrating hopper, with a stacking thickness of less than 10 cm, and then microwave dried. First, the temperature is kept constant at 80-130°C for 10-30 min, and then at 30-60°C for 5-20 min, with the final moisture content controlled at 5-9%. During the drying process, attention should be paid to dehumidifying to keep the inside of the box dry, and temperature monitoring should be done well. After drying, the product is crushed and screened to obtain a solid defoaming agent with uniform particle size.

2. The method for preparing a solid defoamer according to claim 1, characterized in that: The silicone grease composition in step (1) is prepared by a technique known in the art, namely, polysiloxane with a viscosity of 100 to 10,000 mPa·s, MQ resin (M:Q=0.4 to 1.2:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed, heated to 80 to 200°C for reaction, and then hydrophobic white carbon black with a specific surface area of ​​50 to 200 m2 / g is added, the temperature of the reaction system is controlled at 80 to 150°C, and the temperature is kept for 3 to 5 hours, and finally the reaction is carried out at a vacuum degree of -0.01 to -0.08 MPa for 1 to 2 hours, and finally the reaction is cooled to room temperature to obtain a silicone grease composition with a viscosity of 1,000 to 50,000 mPa·s; the amount of the silicone grease composition used is 60 to 85% of the total mass of the defoaming agent.

3. The method for preparing a solid defoamer according to claim 1, characterized in that: In the step (1), the emulsifier is a nonionic surfactant selected from sorbitan fatty acid esters, fatty alcohol polyoxyethylene ethers, oleic acid polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, and castor oil polyoxyethylene ethers, and is used alone or in combination, with an amount of 1 to 10% of the total mass of the defoamer.

4. The method for preparing a solid defoamer according to claim 1, characterized in that: In the step (1), the structuring agent is selected from acrylate polymers, specifically selected from non-crosslinking polymers such as polymethyl (meth)acrylate, polyethyl (meth)acrylate, methyl (meth)acrylate-ethyl (meth)acrylate copolymer, methyl (meth)acrylate-butyl (meth)acrylate copolymer, methyl (meth)acrylate-styrene copolymer, etc.; crosslinking polymers such as methyl (meth)acrylate-ethylene glycol di(meth)acrylate copolymer, methyl (meth)acrylate-triethylene glycol di(meth)acrylate copolymer, copolymer of methyl (meth)acrylate and butadiene monomer, etc.; the amount of the structuring agent is 2-15% of the total mass of the defoaming agent.

5. The method for preparing a solid defoamer according to claim 1, characterized in that: In step (2), the carriers are starch and inorganic salts, which can be used alone or in combination, and the amount used is 5-20% of the total mass of the defoamer.

6. The method for preparing a solid defoamer according to claim 1, characterized in that: In the step (2), the carrier is divided into starch and inorganic salt, and the starch is mainly selected from wheat starch, corn starch, cassava starch and potato starch.

7. The method for preparing a solid defoamer according to claim 1, characterized in that: In the step (2), the carrier is divided into starch and inorganic salt, and the inorganic salt is specifically selected from sulfates, carbonates, silicates, phosphates, nitrates, etc., and is specifically selected from sodium sulfate, calcium sulfate, magnesium sulfate, potassium sulfate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, zeolite, magnesium silicate, calcium silicate, mica, bentonite, diatomaceous earth, sepiolite, natural clay, modified clay, talc, sodium tripolyphosphate, sodium citrate, potassium citrate, sodium nitrate, potassium nitrate, magnesium nitrate, and calcium nitrate.

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