A high-concentration powdered solid defoamer and its preparation method

Abstract

The present invention provides a high-concentration powdered solid defoamer and a preparation method thereof. By compounding special molding agents and molding aids, the curing and molding effect of the defoamer is improved. Meanwhile, the molding aid acrylate polymer is introduced to enhance the defoaming and foam-inhibiting performance of the defoamer. Then a rewetting adhesive is introduced to further improve the curing effect of the product and prevent it from being wetted by air moisture. Finally, the high-concentration powdered solid defoamer is obtained by spray drying. It has the advantages of long-lasting defoaming and foam-inhibiting performance, being not easily hygroscopic and caking, high active substance content, and convenient for customers to use, thus greatly reducing the transportation and storage costs and minimizing the side effects of the defoamer on the application system.

Description

Technical Field

[0001] The present invention relates to a highly concentrated powdered solid defoamer and a preparation method thereof. Specifically, it is a solid defoamer applied to non-ionic surfactants. 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, which seriously affects industrial production, such as reducing production capacity, affecting product quality, and affecting the normal progress of production. Therefore, in these aqueous systems, it is necessary to control or prevent the generation of foam, and defoamers have become an essential additive.

[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] There are many known technical literature materials on the preparation methods of solid defoamers: Patent CN101721843A introduces a preparation method of a solid particle antifoaming agent. After mixing the main defoaming substance and the emulsifier, then mixing with an organic carrier, adding a structurant and water, stirring evenly, granulating, and drying. Patent CN101991976B introduces a preparation method of a solid defoamer. First, mix the defoaming active substance, the emulsifier and the structurant, then add the organic carrier and deionized water in sequence, and dry after granulation. CN102302869B introduces a preparation method of a solid particle antifoaming agent. First, mix the main defoaming substance and the emulsifier, then adsorb them on the carrier, and then add the structurant, granulate, and dry. CN102407033B introduces a preparation method of a granular defoamer. Use silicone emulsion to replace silicone grease, and stepwise agglomerate the silicone emulsion on the carrier to form two "layers" of silicone grease. Finally, granulate and dry the mixture. CN111821722A provides a nano solid defoamer for foam drainage gas production in gas wells. Heat and melt the curing agent and mix it with the emulsifier, and then stir and mix it with dimethyl silicone oil and modified silica nanoparticles. The active substance content of the solid defoamers prepared by the above patents does not exceed 30%. Although they have certain defoaming and antifoaming properties, their addition amount in the system is relatively high, which is uneconomical and may have side effects on the application system.

[0005] CN111389057A introduces a preparation method of an organosilicon defoamer with a high active substance content. By adding sodium carboxymethylcellulose, the emulsifying effect of the emulsifying aid is improved. In addition, a curing agent is added in the forming process of the preparation of the defoamer, which can not only extend the service life of the defoamer, but also increase the active substance content of the solid defoamer to 60%. However, the curing effect of the product needs to be further improved. The product will absorb moisture and caking after being placed for a long time, thus affecting the use of the product. Summary of the Invention

[0006] The present invention provides a high-concentration powder solid defoamer and a preparation method thereof. By compounding special forming agents and forming aids, the curing and forming effect of the defoamer is improved. At the same time, an acrylic ester polymer as a forming aid is introduced to improve the defoaming and foam-inhibiting performance of the defoamer. A rewetting adhesive is further introduced to further improve the curing effect of the product and prevent it from being wetted by air moisture. Finally, a high-concentration powder solid defoamer is obtained by spray drying. It has the advantages of long-lasting defoaming and foam-inhibiting performance, not easy to absorb moisture and cake, high active substance content, and convenient for customers to use, thus greatly reducing the transportation and storage costs and reducing the side effects of the defoamer on the application system.

[0007] The high-concentration solid defoamer described above is composed of the following components:

[0008] A. Carrier

[0009] The carrier is starch, selected from wheat starch, corn starch, tapioca starch, potato starch, used alone or in combination, and the dosage is 5-20% of the total mass of the defoamer.

[0010] B. Forming agent

[0011] The forming agent is polyvinyl alcohol, polyacrylamide, phenolic resin, acrylic resin, used alone or in combination, and the dosage is 2-10% of the total mass of the defoamer.

[0012] C. Forming aid

[0013] The molding aid is an acrylate polymer, which is prepared by solution polymerization from alkyl methacrylate / methacrylic acid, hydroxyalkyl methacrylate / methacrylic acid, organic solvent, and initiator; wherein the alkyl group of the alkyl methacrylate / methacrylic acid has 12-18 carbon atoms, and is selected from dodecyl acrylate, octadecyl acrylate, dodecyl methacrylate, octadecyl methacrylate, and its dosage accounts for 30-50% of the total mass of the molding aid; the hydroxyalkyl methacrylate / methacrylic acid is selected from hydroxyalkyl acrylate / methacrylic acid, specifically but not limited to hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and its dosage accounts for 5-20% of the total mass of the molding aid; the organic solvent is selected from polyethylene glycol, polypropylene glycol, polybutylene glycol, fatty alcohol polyoxyethylene ether, polyether ester, and its dosage accounts for 35-55% of the total mass of the molding aid; the initiator is benzoyl peroxide, and its dosage accounts for 0.4-0.8% of the total mass of the molding aid.

[0014] Preparation method: Mix the alkyl methacrylate / methacrylic acid, hydroxyalkyl methacrylate / methacrylic acid, and half of the initiator dosage evenly by ordinary stirring to obtain mixture I; mix the organic solvent and the remaining half of the initiator dosage evenly, heat up to 60-100 °C, and dropwise add mixture I under stirring, controlling the dropping time to be 3-8 h. During the dropping period, ensure the temperature is controlled at 60-100 °C by circulating water method or ice bath method; after the dropping is completed, continue to keep warm for 0.5-2 h to obtain the acrylate polymer molding aid.

[0015] The dosage of the molding aid is 2-10% of the total mass of the defoamer.

[0016] D. Silicone grease composition

[0017] 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 catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed, heated to 80-200 °C to react, and then hydrophobic fumed 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, kept warm for 3-5 h, and finally reacted under a vacuum 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.

[0018] E. Emulsifier

[0019] The emulsifier is a non-ionic surfactant, selected from sorbitan fatty acid esters, fatty alcohol polyoxyethylene ethers, oleic acid polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, and castor oil polyoxyethylene ethers, used alone or in combination, and the dosage is 1-10% of the total mass of the defoamer.

[0020] F. Aqueous solution of rewetting adhesive

[0021] The adhesive is selected from sodium alginate, gum arabic, and dextrin, used alone or in combination, and is used after being formulated into an aqueous solution with a mass fraction of 1-3%. The dosage of the rewetting adhesive aqueous solution is 1-10% of the total mass of the defoamer.

[0022] The preparation method of the powdered solid defoamer is as follows:

[0023] (1) Mix and stir the silicone grease composition and the emulsifier to form a mixture M;

[0024] (2) Mix and stir the rewetting adhesive aqueous solution, the molding agent, the molding aid, and the carrier at 50-100 °C to form a mixture N;

[0025] (3) Add the mixture M to the mixture N, mix and stir evenly at 50-100 °C, and then obtain the powdered defoamer P after spray drying. Specific embodiments

[0026] Examples of silicone grease compositions

[0027] Polydimethylsiloxane with a viscosity of 10000 mPa·s, MQ resin (M:Q = 0.66:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed, heated to 120 °C for reaction, and then hydrophobic fumed silica with a specific surface area of 80 m 2 / g is added, the temperature of the reaction system is controlled at 100 °C, and the mixture is kept warm for 3 h, then reacted at a vacuum degree of -0.02 MPa for 2 h, and finally cooled to room temperature to obtain a silicone grease composition D1 with a viscosity of 50,000 mPa·s.

[0028] Polydimethylsiloxane with a viscosity of 5000 mPa·s, MQ resin (M:Q = 0.75:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed, heated to 180 °C for reaction, and then hydrophobic fumed silica with a specific surface area of 150 m 2 / g is added, the temperature of the reaction system is controlled at 120 °C, and the mixture is kept warm for 5 h, then reacted at a vacuum degree of -0.06 MPa for 1.5 h, and finally cooled to room temperature to obtain a silicone grease composition D2 with a viscosity of 30,000 mPa·s.

[0029] Polydimethylsiloxane with a viscosity of 100 mPa·s, MQ resin (M:Q = 1.2:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed and heated to 80 °C for reaction. Then, hydrophobic fumed silica with a specific surface area of 200 m 2 / g is added, the temperature of the reaction system is controlled at 150 °C, and the mixture is kept warm for 4 h. Then, the reaction is carried out at a vacuum degree of -0.04 MPa for 1 h. Finally, it is cooled to room temperature to obtain silicone grease composition D3 with a viscosity of 1000 mPa·s.

[0030] Polydimethylsiloxane with a viscosity of 200 mPa·s, MQ resin (M:Q = 0.66:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed and heated to 100 °C for reaction. Then, hydrophobic fumed silica with a specific surface area of 80 m 2 / g is added, the temperature of the reaction system is controlled at 80 °C, and the mixture is kept warm for 3 h. Then, the reaction is carried out at a vacuum degree of -0.01 MPa for 1.5 h. Finally, it is cooled to room temperature to obtain silicone grease composition D4 with a viscosity of 5000 mPa·s.

[0031] Polydimethylsiloxane with a viscosity of 8000 mPa·s, MQ resin (M:Q = 0.55:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed and heated to 200 °C for reaction. Then, hydrophobic fumed silica with a specific surface area of 50 m 2 / g is added, the temperature of the reaction system is controlled at 90 °C, and the mixture is kept warm for 3 h. Then, the reaction is carried out at a vacuum degree of -0.08 MPa for 2 h. Finally, it is cooled to room temperature to obtain silicone grease composition D5 with a viscosity of 40000 mPa·s.

[0032] Polydimethylsiloxane with a viscosity of 800 mPa·s, MQ resin (M:Q = 0.60:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed and heated to 150 °C for reaction. Then, hydrophobic fumed silica with a specific surface area of 60 m 2 / g is added, the temperature of the reaction system is controlled at 110 °C, and the mixture is kept warm for 4 h. Then, the reaction is carried out at a vacuum degree of -0.05 MPa for 1 h. Finally, it is cooled to room temperature to obtain silicone grease composition D6 with a viscosity of 10,000 mPa·s.

[0033] Polydimethylsiloxane with a viscosity of 500 mPa·s, MQ resin (M:Q = 0.40:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed and heated to 120 °C for reaction. Then, hydrophobic fumed silica with a specific surface area of 150 m 2 / g is added, the temperature of the reaction system is controlled at 120 °C, and the mixture is kept warm for 5 h. Then, the reaction is carried out at a vacuum degree of -0.07 MPa for 2 h. Finally, it is cooled to room temperature to obtain silicone grease composition D7 with a viscosity of 8000 mPa·s.

[0034] Polydimethylsiloxane with a viscosity of 300 mPa·s, MQ resin (M:Q = 0.80:1.0), and a catalyst (prepared by mixing KOH and methyl silicone oil) are first mixed and heated to 150 °C for reaction. Then, hydrophobic fumed silica with a specific surface area of 1200 m 2 / g is added, and the temperature of the reaction system is controlled at 130 °C and kept for 3 h. Then, the reaction is carried out at a vacuum degree of -0.06 MPa for 1.5 h. Finally, it is cooled to room temperature to obtain silicone grease composition D8 with a viscosity of 4000 mPa·s.

[0035] Examples of molding aid acrylate polymer

[0036] 50 parts of dodecyl acrylate, 14.4 parts of 2-hydroxyethyl acrylate, and 0.4 part of benzoyl peroxide are mixed evenly by ordinary stirring method to obtain mixture I1; 35 parts of polyethylene glycol and 0.2 part of benzoyl peroxide are mixed evenly, heated to 80 °C, and mixture I1 is added dropwise under stirring state, controlling the dropping time to be 5 h. During the dropping period, the temperature is controlled at 80 °C by circulating water method or ice bath method; after the dropping is completed, it is kept warm for 2 h to obtain molding aid acrylate polymer C1.

[0037] 35 parts of dodecyl methacrylate, 20 parts of 2-hydroxyethyl methacrylate, and 0.4 part of benzoyl peroxide are mixed evenly by ordinary stirring method to obtain mixture I2; 44.3 parts of fatty alcohol polyoxyethylene ether and 0.3 part of benzoyl peroxide are mixed evenly, heated to 60 °C, and mixture I2 is added dropwise under stirring state, controlling the dropping time to be 4 h. During the dropping period, the temperature is controlled at 60 °C by circulating water method or ice bath method; after the dropping is completed, it is kept warm for 0.5 h to obtain molding aid acrylate polymer C2.

[0038] 45 parts of octadecyl methacrylate, 5 parts of hydroxybutyl acrylate, and 0.4 part of benzoyl peroxide are mixed evenly by ordinary stirring method to obtain mixture I3; 49.2 parts of polyether ester and 0.4 part of benzoyl peroxide are mixed evenly, heated to 100 °C, and mixture I3 is added dropwise under stirring state, controlling the dropping time to be 8 h. During the dropping period, the temperature is controlled at 100 °C by circulating water method or ice bath method; after the dropping is completed, it is kept warm for 1.5 h to obtain molding aid acrylate polymer C3.

[0039] Mix 30 parts of octadecyl acrylate, 15 parts of hydroxypropyl methacrylate, and 0.2 parts of benzoyl peroxide evenly by ordinary stirring method to obtain mixture Ⅰ4; mix 54.6 parts of polypropylene glycol and 0.2 parts of benzoyl peroxide evenly, heat up to 70 °C, and dropwise add mixture Ⅰ4 under stirring state, control the dropping time to be 6 h, and ensure the temperature is controlled at 70 °C by circulating water method or ice bath method during the dropping; after the dropping is completed, keep the temperature for 1 h to obtain the molding aid acrylic polymer C4.

[0040] Mix 30 parts of octadecyl acrylate, 14.1 parts of hydroxypropyl acrylate, and 0.3 parts of benzoyl peroxide evenly by ordinary stirring method to obtain mixture Ⅰ4; mix 55.4 parts of polybutylene glycol and 0.2 parts of benzoyl peroxide evenly, heat up to 90 °C, and dropwise add mixture Ⅰ4 under stirring state, control the dropping time to be 3 h, and ensure the temperature is controlled at 90 °C by circulating water method or ice bath method during the dropping; after the dropping is completed, keep the temperature for 1 h to obtain the molding aid acrylic polymer C5.

[0041] Examples of solid defoamers

[0042] Example 1

[0043] (1) Take 64 parts of silicone grease composition D1 and 9 parts of sorbitan fatty acid ester and mix and stir to form mixture M1;

[0044] (2) Take 5 parts of 1% sodium alginate and gum arabic aqueous solution, 10 parts of phenolic resin, 2 parts of molding aid C2, and 10 parts of wheat starch, and mix and stir at 90 °C to form mixture N1;

[0045] (3) Add mixture M1 to mixture N1, mix and stir evenly at 90 °C, and then spray dry to obtain powder defoamer P1.

[0046] Example 2

[0047] (1) Take 80 parts of silicone grease composition D2 and 1 part of castor oil polyoxyethylene ether and mix and stir to form mixture M2;

[0048] (2) Take 1 part of 1% gum arabic aqueous solution, 8 parts of acrylic resin, 4 parts of molding aid C3, and 6 parts of tapioca starch, and mix and stir at 80 °C to form mixture N2;

[0049] (3) Add mixture M2 to mixture N2, mix and stir evenly at 80 °C, and then spray dry to obtain powder defoamer P2.

[0050] Example 3

[0051] (1) Take 78 parts of silicone grease composition D3 and 6 parts of fatty alcohol polyoxyethylene ether, mix and stir to form mixture M3;

[0052] (2) Take 2 parts of an aqueous sodium alginate solution with a mass fraction of 2%, 5 parts of a mixture of acrylic resin and polyethylene glycol, 4 parts of molding aid C1, and 5 parts of tapioca starch, and mix and stir at 100 °C to form mixture N3;

[0053] (3) Add mixture M3 to mixture N3, mix and stir evenly at 100 °C, and then spray dry to obtain powder defoamer P3.

[0054] Example 4

[0055] (1) Take 80 parts of silicone grease composition D4 and 10 parts of polyoxyethylene oleate, mix and stir to form mixture M4;

[0056] (2) Take 1 part of an aqueous solution of sodium alginate and dextrin with a mass fraction of 3%, 2 parts of polyethylene glycol, 2 parts of molding aid C4, and 5 parts of corn starch, and mix and stir at 70 °C to form mixture N4;

[0057] (3) Add mixture M4 to mixture N4, mix and stir evenly at 70 °C, and then spray dry to obtain powder defoamer P4.

[0058] Example 5

[0059] (1) Take 85 parts of silicone grease composition D5, 4 parts of a mixture of polyoxyethylene castor oil and fatty alcohol polyoxyethylene ether, mix and stir to form mixture M5;

[0060] (2) Take 1 part of an aqueous gum arabic solution with a mass fraction of 3%, 2 parts of a mixture of polyethylene glycol and acrylic resin, 3 parts of molding aid C5, and 5 parts of potato starch, and mix and stir at 50 °C to form mixture N5;

[0061] (3) Add mixture M5 to mixture N5, mix and stir evenly at 50 °C, and then spray dry to obtain powder defoamer P5.

[0062] Example 6

[0063] (1) Take 70 parts of silicone grease composition D6 and 2 parts of alkylphenol polyoxyethylene ether, mix and stir to form mixture M6;

[0064] (2) Take 8 parts of an aqueous solution of gum arabic and dextrin with a mass fraction of 2%, 4 parts of phenolic resin, 6 parts of molding aid C4, and 10 parts of a mixture of wheat starch and corn starch, and mix and stir at 60 °C to form mixture N6;

[0065] (3) Mixture M6 was added to mixture N6. After mixing and stirring evenly at 60 °C, it was spray-dried to obtain the powder defoamer P6.

[0066] Example 7

[0067] (1) 65 parts of silicone grease composition D7, 1 part of the mixture of fatty alcohol polyoxyethylene ether and sorbitan fatty acid ester were taken and mixed and stirred to form mixture M7;

[0068] (2) 10 parts of an aqueous sodium alginate solution with a mass fraction of 2%, 2 parts of polyacrylamide, 7 parts of molding aid C1, 15 parts of the mixture of potato starch and cassava starch were taken and mixed and stirred at 50 °C to form mixture N7;

[0069] (3) Mixture M7 was added to mixture N7. After mixing and stirring evenly at 70 °C, it was spray-dried to obtain the powder defoamer P7.

[0070] Example 8

[0071] (1) 60 parts of silicone grease composition D8, 3 parts of the mixture of alkylphenol polyoxyethylene ether and oleic acid polyoxyethylene ether were taken and mixed and stirred to form mixture M8;

[0072] (2) 2 parts of an aqueous dextrin solution with a mass fraction of 2%, 5 parts of the mixture of polyvinyl alcohol and phenolic resin, 10 parts of molding aid C2, 20 parts of the mixture of wheat starch and potato starch were taken and mixed and stirred at 70 °C to form mixture N8;

[0073] (3) Mixture M8 was added to mixture N8. After mixing and stirring evenly at 80 °C, it was spray-dried to obtain the powder defoamer P8.

[0074] Comparative Example 1

[0075] The solid defoamer P9 was prepared according to Example 1 in the invention patent CN201010017656.6.

[0076] Comparative Example 2

[0077] The solid defoamer P10 was prepared according to Example 2 in the invention patent CN201010017656.6.

[0078] Comparing with Example 1 in Comparative Example 3, the molding agent was removed

[0079] (1) 64 parts of silicone grease composition D1 and 9 parts of sorbitan fatty acid ester were taken and mixed and stirred to form mixture M1;

[0080] (2) Take 5 parts of sodium alginate and arabic gum aqueous solution with a mass fraction of 1%, 12 parts of molding aid C2, and 10 parts of wheat starch, and mix and stir them at 90 °C to form mixture N9;

[0081] (3) Add mixture M1 to mixture N9, mix and stir evenly at 90 °C, and then obtain powder defoamer P11 after spray drying.

[0082] Compare with Comparative Example 4 - Example 2, and remove the molding aid

[0083] (1) Take 80 parts of silicone grease composition D2 and 1 part of castor oil polyoxyethylene ether and mix and stir to form mixture M2;

[0084] (2) Take 1 part of arabic gum aqueous solution with a mass fraction of 1%, 12 parts of acrylic resin, and 6 parts of cassava starch, and mix and stir them at 80 °C to form mixture N10;

[0085] (3) Add mixture M2 to mixture N10, mix and stir evenly at 80 °C, and then obtain powder defoamer P12 after spray drying.

[0086] Compare with Comparative Example 5 - Example 3, remove the binder, and only retain water

[0087] (1) Take 78 parts of silicone grease composition D3 and 6 parts of fatty alcohol polyoxyethylene ether and mix and stir to form mixture M3;

[0088] (2) Take 2 parts of water, 5 parts of acrylic resin and polyethanol mixture, 4 parts of molding aid C1, and 5 parts of cassava starch, and mix and stir them at 100 °C to form mixture N11;

[0089] (3) Add mixture M3 to mixture N11, mix and stir evenly at 100 °C, and then obtain powder defoamer P13 after spray drying.

[0090] Performance test of solid defoamer

[0091] Defoaming and foam suppression performance test

[0092] Washing machine test

[0093] Test method: 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, and the test program is standard washing. There are 11 measurement indicators marked on the door of the washing machine, which are recorded as 0, 10, 20, …… 100 in sequence, 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. The test results are as follows:

[0094] Table 1 Washing machine test results

[0095]

[0096] Unrestricted Compression Test (UCT)

[0097] Test method: Compress the antifoaming agent powder into a compacted object, and measure the force required to break the compacted object. Fill the powder into the barrel and level the surface. Place a 50 g plastic disc on top of the powder, slowly place a 10 kg weighted plunger on top of the disc, and keep it in place for 2 minutes. Then remove the weights and the plunger, and remove the powder from the barrel, leaving a 50 g plastic disc placed on top of the first disc, and keep it for about ten seconds. Then if the compacted object still does not break, add a 100 g disc to the plastic disc and keep it for ten seconds. Then, at ten-second intervals, increase the load in 250 g increments until the compacted object collapses. Record the total weight (w) required to cause the collapse.

[0098] The cohesiveness of the antifoaming agent powder is classified by weight (w) as follows:

[0099] 1. Good flow

[0100] 2. Moderate flow

[0101] 3. Cohesive

[0102] 4. Very cohesive

[0103] Table 2 UCT results measured at 35 °C

[0104]

Claims

1. A high-concentration powdered solid defoamer, characterized in that, It comprises the following components: A. Carrier The carrier is starch, selected from wheat starch, corn starch, tapioca starch, potato starch, used alone or in combination, and the dosage is 5-20% of the total mass of the defoamer; B. Molding agent The molding agent is polyvinyl alcohol, polyacrylamide, phenolic resin, acrylic resin, used alone or in combination, and the dosage is 2-10% of the total mass of the defoamer; C. Molding aid The molding aid is an acrylate polymer, which is prepared by solution polymerization from methyl / methacrylic acid alkyl ester, methyl / methacrylic acid hydroxyalkyl ester, organic solvent, and initiator; wherein the number of carbon atoms in the alkyl group of methyl / methacrylic acid alkyl ester is 12-18, selected from dodecyl acrylate, octadecyl acrylate, dodecyl methacrylate, octadecyl methacrylate, and the dosage accounts for 30-50% of the total mass of the molding aid; methyl / methacrylic acid hydroxyalkyl ester is selected from acrylic acid hydroxyalkyl ester, methacrylic acid hydroxyalkyl ester, specifically but not limited to hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and the dosage accounts for 5-20% of the total mass of the molding aid; the organic solvent is selected from polyethylene glycol, polypropylene glycol, polybutylene glycol, fatty alcohol polyoxyethylene ether, polyether ester, and the dosage accounts for 35-55% of the total mass of the molding aid; the initiator is benzoyl peroxide, and the dosage accounts for 0.4-0.8% of the total mass of the molding aid; The dosage of the molding aid is 2-10% of the total mass of the defoamer; D. Silicone grease composition The silicone grease composition is prepared by a well-known technology in the technical field, that is, a polyorganosiloxane with a viscosity of 100-10,000 mPa·s, an MQ resin with a molar ratio of M chain segment to Q chain segment of 0.4-1.2:1.0, a catalyst prepared by mixing KOH and methyl silicone oil are first mixed, heated to 80-200 °C for reaction, and then hydrophobic fumed silica with a specific surface area of 50-200 m2 / g is added, controlling the reaction system temperature at 80-150 °C, holding for 3-5 h, and finally reacting at a vacuum degree of -0.01 to -0.08 MPa for 1-2 h, and finally cooling 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; E. Emulsifier 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; F. Aqueous solution of rewetting adhesive The adhesive is selected from sodium alginate, gum arabic, dextrin, used alone or in combination, and is used after being formulated into an aqueous solution with a mass fraction of 1-3%, and the dosage of the aqueous solution of rewetting adhesive is 1-10% of the total mass of the defoamer.

2. A high-concentration powdered solid defoamer according to claim 1, characterized in that, Preparation method of the shaping aid: Mix alkyl methacrylate / methacrylic acid, hydroxyalkyl methacrylate / methacrylic acid, and half of the initiator dosage evenly by ordinary stirring method to obtain mixture I; Mix the organic solvent and the remaining half of the initiator dosage evenly, heat up to 60-100°C, and dropwise add mixture I under stirring state, control the dropping time to be 3-8h, and ensure that the temperature is controlled at 60-100°C by circulating water method or ice bath method during the dropping process; After the dropping is completed, continue to keep the temperature for 0.5-2h to obtain the shaping aid acrylate polymer.

3. The preparation method of a high-concentration powdered solid defoamer according to claim 1 is as follows: (1) Mix and stir the silicone grease composition and the emulsifier to form a mixture M; (2) Mix and stir the rewetting binder aqueous solution, the molding agent, the molding aid, and the carrier at 50-100 °C to form a mixture N; (3) Add the mixture M to the mixture N, mix and stir evenly at 50-100 °C, and then obtain the powdered defoamer by spray drying.

Images