Storage-stable organic silicon defoaming agent and preparation method thereof

Abstract

The invention discloses a storage-stable organic silicon defoaming agent and a preparation method thereof, and belongs to the technical field of organic silicon defoaming agents. Comprising the following raw materials in parts by weight: 20-60 parts of an organic silicon emulsion, 10-30 parts of silicon paste, 1-2 parts of an emulsion stabilizer, 1-6 parts of a defoaming agent main agent, 0.1-0.8 part of a thickening agent, 0.4-0.8 part of a stabilizer, 0.01-0.1 part of potassium hydroxide, 0.01-0.04 part of an anti-freezing agent and 20-40 parts of deionized water, the four-neck flask is heated, stirring reaction is carried out for 1.6-2 h when the temperature in the four-neck flask rises to 120 DEG C, and the needed defoaming agent main agent is prepared. Polyether modified silicone oil has the high emulsifying performance on dimethyl silicone oil, so that the prepared organic silicon defoaming agent is small in emulsion particle size, meanwhile, the emulsion particle size is in a spherical shape, and the defoaming agent main agent is prepared. The prepared organic silicon emulsion is used as the emulsion for preparing the organic silicon defoaming agent, and the prepared organic silicon defoaming agent is stable in storage at the temperature of 66 DEG C.

Description

Technical Field

[0001] The invention belongs to the technical field of organosilicon defoamers, and in particular relates to a storage-stable organosilicon defoamer and a preparation method thereof. Background Art

[0002] Silicone defoamer is composed of organosilicon compounds and surfactants. The main ingredients are siloxane monomers and other additives. It is made through polymerization reaction and modification process. It usually appears as a white viscous emulsion and has excellent defoaming performance.

[0003] The prior art discloses some invention patents in the technical field of organosilicon defoamers, among which the invention patent with publication number CN117643746B discloses a modified organosilicon defoamer and a preparation method thereof. The raw materials for preparing the modified organosilicon defoamer include, by weight, 10 to 40 parts of modified polysiloxane, 5 to 10 parts of emulsifier, 0.1 to 10 parts of other auxiliary agents and 50 to 80 parts of solvent. The modified polysiloxane is synthesized in two steps. First, polysiloxane and unimodal polypropylene are hydrolyzed and polymerized at 80 to 100° C. with 1 to 2% hydrochloric acid and concentrated sulfuric acid to obtain an intermediate product. Then, the intermediate product is polymerized with bimodal polypropylene and octamethylcyclotetrasiloxane at 100 to 120° C. with potassium hydroxide catalysis to obtain the modified polysiloxane. This defoamer has good water solubility, excellent heat resistance, rapid defoaming and long-lasting foam suppression. It has excellent defoaming and foam suppression effects in textile printing and dyeing, high-temperature rinsing, industrial cleaning, metal processing and other industries. However, this technical solution still has some shortcomings in the process of application. The emulsification process of this type of product is complicated, and the stability and foam suppression ability are poor. It is easy to have defects such as demulsification and oil bleaching at high temperature, which limits its application field.

[0004] Based on this, the present invention designs a storage-stable organosilicon defoamer and a preparation method thereof to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problems that the existing products have complex emulsification process, poor stability and antifoaming ability, easy to cause demulsification and oil bleaching at high temperature, which limits their application fields, and propose a storage-stable organosilicon defoamer and a preparation method thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A storage-stable organosilicon defoamer comprises the following raw materials in parts by weight: 20-60 parts of organosilicon emulsion, 10-30 parts of silicone paste, 1-2 parts of emulsion stabilizer, 1-6 parts of defoamer main agent, 0.1-0.8 parts of thickener, 0.4-0.8 parts of stabilizer, 0.01-0.1 parts of potassium hydroxide, 0.01-0.04 parts of antifreeze agent and 20-40 parts of deionized water;

[0008] The defoamer main agent is prepared by mixing silicone paste, polyether modified silicone oil and auxiliary emulsifier in a four-necked flask in a certain proportion, heating the four-necked flask until the temperature inside the four-necked flask rises to 120° C., stirring and reacting for 1.6-2 hours to obtain the desired defoamer main agent.

[0009] As a further description of the above technical solution:

[0010] The preparation of the organosilicon emulsion comprises the following steps:

[0011] Add hydrophobic fumed silica and hydrogenated silicone oil in a correct proportion into a three-necked flask, heat the three-necked flask, and stir and react at 170-200° C. for 2.8 hours to obtain silicone oil paste;

[0012] Add an appropriate amount of polyether-modified silicone oil into a three-necked flask, mix well, and drop distilled water during high-speed stirring to cause phase inversion emulsification;

[0013] In the process of adding distilled water dropwise, a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to prepare an organosilicon emulsion.

[0014] As a further description of the above technical solution:

[0015] The preparation of the polyether-modified silicone oil comprises the following steps:

[0016] Add measured hydrogen-containing silicone oil and allyl polyoxyethylene polyoxypropylene ether into a three-necked flask, the feed ratio of hydrogen-containing silicone oil to allyl polyoxyethylene polyoxypropylene ether being 1:1.2;

[0017] At the same time, add chloroplatinic acid of relative system mass into the three-necked flask and react at 100℃ for 8h under nitrogen protection;

[0018] After the reaction is completed, a small amount of the product is taken for the first high-temperature rotary evaporation to remove the unreacted silicon-hydrogen bonds therein;

[0019] The remaining product was subjected to a second rotary evaporation treatment to remove isopropanol and a small amount of low-boiling substances, thereby obtaining a yellow transparent viscous liquid polyether-modified silicone oil.

[0020] As a further description of the above technical solution:

[0021] In the first rotary evaporation treatment, the reaction temperature was 240° C. and the pressure was 0.01 MPa. The vinyl conversion rate was 86.76% as measured by iodine titration.

[0022] As a further description of the above technical solution:

[0023] In the second rotary evaporation treatment, the reaction temperature is 60° C. and the pressure is 0.01 MPa.

[0024] As a further description of the above technical solution:

[0025] The preparation of the silicone paste comprises the following steps:

[0026] A certain amount of dimethyl silicone oil is added into a three-necked flask, and after the dimethyl silicone oil is added, the three-necked flask is heated to 148° C. and stirred during the heating process;

[0027] After the temperature inside the three-necked flask rises to 148°C, hydrophobic fumed silica and a water dispenser are added, and the three-necked flask continues to be heated until the temperature inside the three-necked flask rises to 166°C and is kept warm for 5.8 hours;

[0028] After the insulation was completed, the internal temperature of the three-necked flask was lowered to 100°C, and then 204 water-soluble silicone oil and a modifier were added and stirred for 1 hour to obtain a silicone paste.

[0029] As a further description of the above technical solution:

[0030] The emulsion stabilizer is prepared by adding a certain amount of sodium carboxymethyl cellulose into a three-necked flask containing distilled water, heating it in a water bath to 66-74° C., and stirring it for 2 hours to obtain the emulsion stabilizer.

[0031] As a further description of the above technical solution:

[0032] The thickener consists of sodium carboxymethyl cellulose and carrageenan in a weight ratio of 1:(1-1.5), and the stabilizer consists of bentonite and attapulgite in a weight ratio of 1:(1-3).

[0033] A method for preparing a storage-stable organosilicon defoamer, the preparation method comprising the following steps:

[0034] Take the organosilicon emulsion, silicone paste, emulsion stabilizer, defoaming agent, thickener, stabilizer, potassium hydroxide, antifreeze agent and deionized water according to weight parts and set aside;

[0035] Mixing the silicone emulsion and silicone paste evenly to obtain a mixture;

[0036] Adding the defoaming agent main agent to the mixture, stirring, to obtain an emulsion;

[0037] The emulsion stabilizer, thickener, stabilizer, potassium hydroxide and antifreeze agent are added to the emulsion and stirred to obtain the organosilicon defoaming agent.

[0038] As a further description of the above technical solution:

[0039] During the preparation of the emulsion, the emulsion is stirred at a high speed, water is added dropwise to make it phase invert and emulsify, and a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to enhance its stability.

[0040] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0041] 1. In the present invention, the polyether-modified silicone oil has a strong emulsifying property for dimethyl silicone oil, so that the latex particle size of the prepared silicone defoamer is small and the distribution range is narrow, and the latex particle size is spherical. The prepared silicone emulsion is used as an emulsion for preparing the silicone defoamer. The prepared silicone defoamer is stable in storage at 66°C, will not be stratified under high temperature and pH value of 2-12, and will not float oil. At the same time, it can maintain a good defoaming speed and maintain a strong antifoaming activity.

[0042] 2. In the present invention, adding a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate helps to enhance the stability of the silicone emulsion, and adopts a high-speed shearing process to prepare a uniform emulsion-type silicone defoamer, thereby solving the problems of particle precipitation, demulsification, oil floating and mildew occurring during the application of the existing emulsion-type silicone defoamers. DETAILED DESCRIPTION

[0043] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Embodiment 1

[0045] A storage-stable organosilicon defoamer comprises the following raw materials in parts by weight: 20 parts of organosilicon emulsion, 10 parts of silicone paste, 1 part of emulsion stabilizer, 1 part of defoamer main agent, 0.1 part of thickener, 0.4 part of stabilizer, 0.01 part of potassium hydroxide, 0.01 part of antifreeze agent and 20 parts of deionized water;

[0046] The defoamer main agent is prepared by mixing silicone paste, polyether modified silicone oil and auxiliary emulsifier in a four-necked flask in a certain proportion, heating the four-necked flask until the temperature inside the four-necked flask rises to 120° C., stirring and reacting for 1.6-2 hours to obtain the desired defoamer main agent.

[0047] Specifically, the preparation of the organosilicon emulsion includes the following steps:

[0048] Add hydrophobic fumed silica and hydrogenated silicone oil in a correct proportion into a three-necked flask, heat the three-necked flask, and stir and react at 170-200° C. for 2.8 hours to obtain silicone oil paste;

[0049] Add an appropriate amount of polyether-modified silicone oil into a three-necked flask, mix well, and drop distilled water during high-speed stirring to cause phase inversion emulsification;

[0050] In the process of adding distilled water dropwise, a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to prepare an organosilicon emulsion.

[0051] Specifically, the preparation of the polyether-modified silicone oil comprises the following steps:

[0052] Add measured hydrogen-containing silicone oil and allyl polyoxyethylene polyoxypropylene ether into a three-necked flask, the feed ratio of hydrogen-containing silicone oil to allyl polyoxyethylene polyoxypropylene ether being 1:1.2;

[0053] At the same time, add chloroplatinic acid of relative system mass into the three-necked flask and react at 100℃ for 8h under nitrogen protection;

[0054] After the reaction is completed, a small amount of the product is taken for the first high-temperature rotary evaporation to remove the unreacted silicon-hydrogen bonds therein;

[0055] The remaining product was subjected to a second rotary evaporation treatment to remove isopropanol and a small amount of low-boiling substances, thereby obtaining a yellow transparent viscous liquid polyether-modified silicone oil.

[0056] Specifically, in the first rotary evaporation treatment, the reaction temperature was 240° C. and the pressure was 0.01 MPa. The vinyl conversion rate was 86.76% as measured by iodine titration.

[0057] Specifically, in the second rotary evaporation treatment, the reaction temperature is 60° C. and the pressure is 0.01 MPa.

[0058] Specifically, the preparation of the silicone paste includes the following steps:

[0059] A certain amount of dimethyl silicone oil is added into a three-necked flask, and after the dimethyl silicone oil is added, the three-necked flask is heated to 148° C. and stirred during the heating process;

[0060] After the temperature inside the three-necked flask rises to 148°C, hydrophobic fumed silica and a water dispenser are added, and the three-necked flask continues to be heated until the temperature inside the three-necked flask rises to 166°C and is kept warm for 5.8 hours;

[0061] After the insulation was completed, the internal temperature of the three-necked flask was lowered to 100°C, and then 204 water-soluble silicone oil and a modifier were added and stirred for 1 hour to obtain a silicone paste.

[0062] Specifically, the emulsion stabilizer is prepared by adding a certain amount of sodium carboxymethyl cellulose into a three-necked flask containing distilled water, heating it in a water bath to 66-74° C. and stirring it for 2 hours to obtain the emulsion stabilizer.

[0063] Specifically, the thickener is composed of sodium carboxymethyl cellulose and carrageenan in a weight ratio of 1: (1-1.5), and the stabilizer is composed of bentonite and attapulgite in a weight ratio of 1: (1-3).

[0064] A method for preparing a storage-stable organosilicon defoamer, the preparation method comprising the following steps:

[0065] Take the organosilicon emulsion, silicone paste, emulsion stabilizer, defoaming agent, thickener, stabilizer, potassium hydroxide, antifreeze agent and deionized water according to weight parts and set aside;

[0066] Mixing the silicone emulsion and silicone paste evenly to obtain a mixture;

[0067] Adding the defoaming agent main agent to the mixture, stirring, to obtain an emulsion;

[0068] The emulsion stabilizer, thickener, stabilizer, potassium hydroxide and antifreeze agent are added to the emulsion and stirred to obtain the organosilicon defoaming agent.

[0069] Specifically, during the preparation of the emulsion, high-speed stirring is performed, water is added dropwise to cause phase inversion emulsification, and a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to enhance its stability.

[0070] Embodiment 2

[0071] A storage-stable organosilicon defoamer comprises the following raw materials in parts by weight: 60 parts of organosilicon emulsion, 30 parts of silicone paste, 2 parts of emulsion stabilizer, 6 parts of defoamer main agent, 0.8 parts of thickener, 0.8 parts of stabilizer, 0.1 parts of potassium hydroxide, 0.04 parts of antifreeze agent and 40 parts of deionized water;

[0072] The defoamer main agent is prepared by mixing silicone paste, polyether modified silicone oil and auxiliary emulsifier in a four-necked flask in a certain proportion, heating the four-necked flask until the temperature inside the four-necked flask rises to 120° C., stirring and reacting for 1.6-2 hours to obtain the desired defoamer main agent.

[0073] As a further description of the above technical solution:

[0074] The preparation of the organosilicon emulsion comprises the following steps:

[0075] Add hydrophobic fumed silica and hydrogenated silicone oil in a correct proportion into a three-necked flask, heat the three-necked flask, and stir and react at 170-200° C. for 2.8 hours to obtain silicone oil paste;

[0076] Add an appropriate amount of polyether-modified silicone oil into a three-necked flask, mix well, and drop distilled water during high-speed stirring to cause phase inversion emulsification;

[0077] In the process of adding distilled water dropwise, a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to prepare an organosilicon emulsion.

[0078] As a further description of the above technical solution:

[0079] The preparation of the polyether-modified silicone oil comprises the following steps:

[0080] Add measured hydrogen-containing silicone oil and allyl polyoxyethylene polyoxypropylene ether into a three-necked flask, the feed ratio of hydrogen-containing silicone oil to allyl polyoxyethylene polyoxypropylene ether being 1:1.2;

[0081] At the same time, add chloroplatinic acid of relative system mass into the three-necked flask and react at 100℃ for 8h under nitrogen protection;

[0082] After the reaction is completed, a small amount of the product is taken for the first high-temperature rotary evaporation to remove the unreacted silicon-hydrogen bonds therein;

[0083] The remaining product was subjected to a second rotary evaporation treatment to remove isopropanol and a small amount of low-boiling substances, thereby obtaining a yellow transparent viscous liquid polyether-modified silicone oil.

[0084] As a further description of the above technical solution:

[0085] In the first rotary evaporation treatment, the reaction temperature was 240° C. and the pressure was 0.01 MPa. The vinyl conversion rate was 86.76% as measured by iodine titration.

[0086] As a further description of the above technical solution:

[0087] In the second rotary evaporation treatment, the reaction temperature is 60° C. and the pressure is 0.01 MPa.

[0088] As a further description of the above technical solution:

[0089] The preparation of the silicone paste comprises the following steps:

[0090] A certain amount of dimethyl silicone oil is added into a three-necked flask, and after the dimethyl silicone oil is added, the three-necked flask is heated to 148° C. and stirred during the heating process;

[0091] After the temperature inside the three-necked flask rises to 148°C, hydrophobic fumed silica and a water dispenser are added, and the three-necked flask continues to be heated until the temperature inside the three-necked flask rises to 166°C and is kept warm for 5.8 hours;

[0092] After the insulation was completed, the internal temperature of the three-necked flask was lowered to 100°C, and then 204 water-soluble silicone oil and a modifier were added and stirred for 1 hour to obtain a silicone paste.

[0093] As a further description of the above technical solution:

[0094] The emulsion stabilizer is prepared by adding a certain amount of sodium carboxymethyl cellulose into a three-necked flask containing distilled water, heating it in a water bath to 66-74° C., and stirring it for 2 hours to obtain the emulsion stabilizer.

[0095] As a further description of the above technical solution:

[0096] The thickener consists of sodium carboxymethyl cellulose and carrageenan in a weight ratio of 1:(1-1.5), and the stabilizer consists of bentonite and attapulgite in a weight ratio of 1:(1-3).

[0097] A method for preparing a storage-stable organosilicon defoamer, the preparation method comprising the following steps:

[0098] Take the organosilicon emulsion, silicone paste, emulsion stabilizer, defoaming agent, thickener, stabilizer, potassium hydroxide, antifreeze agent and deionized water according to weight parts and set aside;

[0099] Mixing the silicone emulsion and silicone paste evenly to obtain a mixture;

[0100] Adding the defoaming agent main agent to the mixture, stirring, to obtain an emulsion;

[0101] The emulsion stabilizer, thickener, stabilizer, potassium hydroxide and antifreeze agent are added to the emulsion and stirred to obtain the organosilicon defoaming agent.

[0102] As a further description of the above technical solution:

[0103] During the preparation of the emulsion, the emulsion is stirred at a high speed, water is added dropwise to make it phase invert and emulsify, and a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to enhance its stability.

[0104] Embodiment 3

[0105] A storage-stable organosilicon defoamer comprises the following raw materials in parts by weight: 40 parts of organosilicon emulsion, 20 parts of silicone paste, 1.5 parts of emulsion stabilizer, 3.5 parts of defoamer main agent, 0.45 parts of thickener, 0.6 parts of stabilizer, 0.06 parts of potassium hydroxide, 0.025 parts of antifreeze agent and 30 parts of deionized water;

[0106] The defoamer main agent is prepared by mixing silicone paste, polyether modified silicone oil and auxiliary emulsifier in a four-necked flask in a certain proportion, heating the four-necked flask until the temperature inside the four-necked flask rises to 120° C., stirring and reacting for 1.6-2 hours to obtain the desired defoamer main agent.

[0107] As a further description of the above technical solution:

[0108] The preparation of the organosilicon emulsion comprises the following steps:

[0109] Add hydrophobic fumed silica and hydrogenated silicone oil in a correct proportion into a three-necked flask, heat the three-necked flask, and stir and react at 170-200° C. for 2.8 hours to obtain silicone oil paste;

[0110] Add an appropriate amount of polyether-modified silicone oil into a three-necked flask, mix well, and drop distilled water during high-speed stirring to cause phase inversion emulsification;

[0111] In the process of adding distilled water dropwise, a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to prepare an organosilicon emulsion.

[0112] As a further description of the above technical solution:

[0113] The preparation of the polyether-modified silicone oil comprises the following steps:

[0114] Add measured hydrogen-containing silicone oil and allyl polyoxyethylene polyoxypropylene ether into a three-necked flask, the feed ratio of hydrogen-containing silicone oil to allyl polyoxyethylene polyoxypropylene ether being 1:1.2;

[0115] At the same time, add chloroplatinic acid of relative system mass into the three-necked flask and react at 100℃ for 8h under nitrogen protection;

[0116] After the reaction is completed, a small amount of the product is taken for the first high-temperature rotary evaporation to remove the unreacted silicon-hydrogen bonds therein;

[0117] The remaining product was subjected to a second rotary evaporation treatment to remove isopropanol and a small amount of low-boiling substances, thereby obtaining a yellow transparent viscous liquid polyether-modified silicone oil.

[0118] As a further description of the above technical solution:

[0119] In the first rotary evaporation treatment, the reaction temperature was 240° C. and the pressure was 0.01 MPa. The vinyl conversion rate was 86.76% as measured by iodine titration.

[0120] As a further description of the above technical solution:

[0121] In the second rotary evaporation treatment, the reaction temperature is 60° C. and the pressure is 0.01 MPa.

[0122] As a further description of the above technical solution:

[0123] The preparation of the silicone paste comprises the following steps:

[0124] A certain amount of dimethyl silicone oil is added into a three-necked flask, and after the dimethyl silicone oil is added, the three-necked flask is heated to 148° C. and stirred during the heating process;

[0125] After the temperature inside the three-necked flask rises to 148°C, hydrophobic fumed silica and a water dispenser are added, and the three-necked flask continues to be heated until the temperature inside the three-necked flask rises to 166°C and is kept warm for 5.8 hours;

[0126] After the insulation was completed, the internal temperature of the three-necked flask was lowered to 100°C, and then 204 water-soluble silicone oil and a modifier were added and stirred for 1 hour to obtain a silicone paste.

[0127] As a further description of the above technical solution:

[0128] The emulsion stabilizer is prepared by adding a certain amount of sodium carboxymethyl cellulose into a three-necked flask containing distilled water, heating it in a water bath to 66-74° C., and stirring it for 2 hours to obtain the emulsion stabilizer.

[0129] As a further description of the above technical solution:

[0130] The thickener consists of sodium carboxymethyl cellulose and carrageenan in a weight ratio of 1:(1-1.5), and the stabilizer consists of bentonite and attapulgite in a weight ratio of 1:(1-3).

[0131] A method for preparing a storage-stable organosilicon defoamer, the preparation method comprising the following steps:

[0132] Take the organosilicon emulsion, silicone paste, emulsion stabilizer, defoaming agent, thickener, stabilizer, potassium hydroxide, antifreeze agent and deionized water according to weight parts and set aside;

[0133] Mixing the silicone emulsion and silicone paste evenly to obtain a mixture;

[0134] Adding the defoaming agent main agent to the mixture, stirring, to obtain an emulsion;

[0135] The emulsion stabilizer, thickener, stabilizer, potassium hydroxide and antifreeze agent are added to the emulsion and stirred to obtain the organosilicon defoaming agent.

[0136] As a further description of the above technical solution:

[0137] During the preparation of the emulsion, the emulsion is stirred at a high speed, water is added dropwise to make it phase invert and emulsify, and a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to enhance its stability.

[0138] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A storage-stable organosilicon defoamer, characterized in that: The invention comprises the following raw materials in parts by weight: 20-60 parts of organic silicon emulsion, 10-30 parts of silicone paste, 1-2 parts of emulsion stabilizer, 1-6 parts of defoaming agent main agent, 0.1-0.8 parts of thickener, 0.4-0.8 parts of stabilizer, 0.01-0.1 parts of potassium hydroxide, 0.01-0.04 parts of antifreeze agent and 20-40 parts of deionized water; The defoamer main agent is prepared by mixing silicone paste, polyether modified silicone oil and auxiliary emulsifier in a four-necked flask in a certain proportion, heating the four-necked flask until the temperature inside the four-necked flask rises to 120° C., stirring and reacting for 1.6-2 hours to obtain the desired defoamer main agent.

2. A storage-stable organosilicon defoamer according to claim 1, characterized in that: The preparation of the organosilicon emulsion comprises the following steps: Add hydrophobic fumed silica and hydrogenated silicone oil in a correct proportion into a three-necked flask, heat the three-necked flask, and stir and react at 170-200° C. for 2.8 hours to obtain silicone oil paste; Add an appropriate amount of polyether-modified silicone oil into a three-necked flask, mix well, and drop distilled water during high-speed stirring to cause phase inversion emulsification; In the process of adding distilled water dropwise, a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to prepare an organosilicon emulsion.

3. The storage-stable organosilicon defoamer according to claim 1, characterized in that: The preparation of the polyether-modified silicone oil comprises the following steps: Add measured hydrogen-containing silicone oil and allyl polyoxyethylene polyoxypropylene ether into a three-necked flask, the feed ratio of hydrogen-containing silicone oil to allyl polyoxyethylene polyoxypropylene ether being 1:1.2; At the same time, add chloroplatinic acid of relative system mass into the three-necked flask and react at 100℃ for 8h under nitrogen protection; After the reaction is completed, a small amount of the product is taken for the first high-temperature rotary evaporation to remove the unreacted silicon-hydrogen bonds therein; The remaining product was subjected to a second rotary evaporation treatment to remove isopropanol and a small amount of low-boiling substances, thereby obtaining a yellow transparent viscous liquid polyether-modified silicone oil.

4. A storage-stable organosilicon defoamer according to claim 3, characterized in that: In the first rotary evaporation treatment, the reaction temperature was 240° C. and the pressure was 0.01 MPa. The vinyl conversion rate was 86.76% as measured by iodine titration.

5. The storage-stable organosilicon defoamer according to claim 4, characterized in that: In the second rotary evaporation treatment, the reaction temperature is 60° C. and the pressure is 0.01 MPa.

6. The storage-stable organosilicon defoamer according to claim 1, characterized in that: The preparation of the silicone paste comprises the following steps: A certain amount of dimethyl silicone oil is added into a three-necked flask, and after the dimethyl silicone oil is added, the three-necked flask is heated to 148° C. and stirred during the heating process; After the temperature inside the three-necked flask rises to 148°C, hydrophobic fumed silica and a water dispenser are added, and the three-necked flask continues to be heated until the temperature inside the three-necked flask rises to 166°C and is kept warm for 5.8 hours; After the insulation was completed, the internal temperature of the three-necked flask was lowered to 100°C, and then 204 water-soluble silicone oil and a modifier were added and stirred for 1 hour to obtain a silicone paste.

7. The storage-stable organosilicon defoamer according to claim 1, characterized in that: The emulsion stabilizer is prepared by adding a certain amount of sodium carboxymethyl cellulose into a three-necked flask containing distilled water, heating it in a water bath to 66-74° C., and stirring it for 2 hours to obtain the emulsion stabilizer.

8. The storage-stable organosilicon defoamer according to claim 1, characterized in that: The thickener consists of sodium carboxymethyl cellulose and carrageenan in a weight ratio of 1:(1-1.5), and the stabilizer consists of bentonite and attapulgite in a weight ratio of 1:(1-3).

9. A method for preparing a storage-stable organosilicon defoamer, characterized in that: Using a storage-stable organosilicon defoamer as described in claims 1-8, the preparation method comprises the following steps: Take the organosilicon emulsion, silicone paste, emulsion stabilizer, defoaming agent, thickener, stabilizer, potassium hydroxide, antifreeze agent and deionized water according to weight parts and set aside; Mixing the silicone emulsion and silicone paste evenly to obtain a mixture; Adding the defoaming agent main agent to the mixture, stirring, to obtain an emulsion; The emulsion stabilizer, thickener, stabilizer, potassium hydroxide and antifreeze agent are added to the emulsion and stirred to obtain the organosilicon defoaming agent.

10. The method for preparing a storage-stable organosilicon defoamer according to claim 9, characterized in that: During the preparation of the emulsion, the emulsion is stirred at a high speed, water is added dropwise to make it phase invert and emulsify, and a small amount of sorbitan monostearate and polyoxyethylene sorbitan monostearate are added to enhance its stability.