A fluorine-containing silicone paste defoamer and its preparation method and application

Abstract

The invention discloses a fluorine-containing silicone paste defoamer and its preparation method and application. The preparation method of the present invention includes: placing hydrogen-containing fluorosilicone oil and fluorine-containing vinyl silicone oil in a reactor, protecting with nitrogen, stirring and heating to 65-90°C, adding chloroplatinic acid, and performing an addition reaction for 0.5-2h to obtain a fluorine-containing silicone oil modifier; then adding hydroxyfluorosilicone oil, hydrophobic SiO2 and silicone resin to the reactor, stirring evenly and adding KOH, heating to 120-140°C, base-catalyzed reaction for 2-4h, cooling and discharging to obtain a fluorine-containing silicone paste; mixing fluorine-containing silicone paste, polyether-modified silicone oil A, polyether-modified silicone oil B and an emulsifier, stirring and heating to 55-65°C, adding deionized water for phase inversion emulsification, cooling, adding deionized water, and adding a thickener to obtain a fluorine-containing silicone paste defoamer. Compared with traditional fluorine-free silicone paste, the defoaming agent prepared by the invention has the advantages of fast black liquor defoaming speed, good foam suppression, good black liquor compatibility, good pulp washing and water filterability, and is non-toxic, harmless and simple in process.

Description

Technical Field

[0001] The invention belongs to the technical field of defoamers, in particular to a fluorine-containing silicone paste defoamer and a preparation method and application thereof. Background Art

[0002] In industrial production, foam problems are ubiquitous, such as in the fields of textiles, papermaking, coatings, food, fermentation, and petroleum refining. Foam often has a negative impact on the system, and the use of defoaming agents minimizes the harm caused by foam. The problem faced by scientific researchers is how to further improve the defoaming properties, foam suppression, stability, compatibility, and shear resistance of defoaming agents in their application areas, so as to achieve the best defoaming effect with the lowest dosage. Among them, silicone defoaming agents have a very wide range of applications because they can be well dispersed in water after emulsification due to their low surface tension. In order to improve certain properties of silicone, scientific researchers have developed a series of modified silicones, including polyether-modified silicones, silicone pastes, and organofluorine-modified silicones. Organofluorine-modified silicones have lower surface tension than conventional silicone oils and have better water spreadability.

[0003] For example, CN1180706A discloses a method for preparing a novel fluorinated alkoxypropyl methyl silicone oil prepared from fluorinated alcohol and allyl chloride as initial raw materials, which is subjected to cyclization and isomerization to obtain a novel polyfluorosilicone oil having fluorinated alkoxypropyl substituted groups. CN1017803585A discloses a fluorinated silicone oil and a method for preparing the same, wherein acrylic acid and a fluorinated fatty alcohol undergo an esterification reaction in the presence of a catalyst to obtain a fluorinated fatty alcohol acrylate, which is then subjected to a hydrosilylation reaction with methyldichlorosilane to obtain a fluorinated dichlorosilane, which is then subjected to a dechlorination cyclization reaction with dimethyldichlorosilane in the presence of a metal oxide, and finally, under the action of a capping agent, hexamethyldisiloxane, undergoes a ring-opening polymerization reaction to obtain a fluorinated silicone oil. The fluorinated silicone oil has the characteristics of low surface tension and excellent defoaming properties. CN202211588477A discloses a method for preparing a fluorinated polyether organosilicon defoamer, which is prepared by emulsifying a fluorinated organosilicon defoamer emulsion, a fluorinated polyether, and a fluorinated surfactant. However, the preparation process of the aforementioned fluorinated modified organosilicon is relatively complex, and the resulting fluorinated modified organosilicon defoamer has limited defoaming performance.

[0004] During pulp washing in papermaking, the presence of large amounts of fatty acids, resin acids, and neutral components in the wood raw material leads to excessive foaming in the black liquor, reducing washing efficiency. Conventional silicone defoamers can defoam in pulping, but their defoaming and foam suppression performance is poor, resulting in poor filterability of the black liquor. Furthermore, in the black liquor tank after washing, the defoamer precipitates, resulting in large amounts of floating silicone oil in the black liquor. This precipitated silicone oil can also be carried along with the pulp to the subsequent papermaking stage, impacting papermaking. Summary of the Invention

[0005] In order to solve the defects existing in the above-mentioned prior art, the present invention provides a high-temperature and strong alkali resistant fluorine-containing silicone paste defoaming agent and a preparation method, and applies the defoaming agent to papermaking pulping and washing to solve the problems of slow defoaming, weak foam suppression, and poor black liquor filterability in the pulping process, resulting in low pulp washing efficiency.

[0006] To this end, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a fluorine-containing silicone paste defoamer, comprising:

[0008] 1) Hydrogen-containing fluorosilicone oil and fluorine-containing vinyl silicone oil are placed in a reactor, protected by nitrogen, stirred and heated to 65-90°C, chloroplatinic acid is added, and addition reaction is carried out for 0.5-2h to obtain a fluorine-containing silicone oil modified product; hydroxyl fluorosilicone oil, hydrophobic SiO2 and silicone resin are then added to the reactor, stirred evenly, and KOH is added, the temperature is raised to 120-140°C, and a base-catalyzed reaction is carried out for 2-4h, and the temperature is lowered and the material is discharged to obtain a fluorine-containing silicone paste;

[0009] 2) mixing the fluorine-containing silicone paste, polyether-modified silicone oil A, polyether-modified silicone oil B and emulsifier, stirring and heating to 55-65° C., adding deionized water for phase inversion and emulsification, cooling, adding deionized water, and adding a thickener to obtain a fluorine-containing silicone paste defoamer;

[0010] The polyether-modified silicone oil A is an addition reaction product of hydrogen-containing silicone oil and allyl polyoxypropylene ether, and the polyether-modified silicone oil B is an addition reaction product of hydrogen-containing silicone oil and allyl polyoxyethylene polyoxypropylene ether.

[0011] Fluorine-containing silicone paste defoamer is prepared using a two-step process, first preparing the fluorine-containing silicone paste, then emulsifying the fluorine-containing silicone paste to obtain the fluorine-containing silicone paste defoamer. Fluorine-containing silicone paste is also prepared using a two-step process, first catalytic addition, then using base-catalyzed cross-linking to obtain a fluorine-containing silicone paste with a spatial network structure: first, hydrogen-containing fluorosilicone oil and fluorine-containing vinyl silicone oil are subjected to an addition reaction catalyzed by chloroplatinic acid to obtain a fluorine-containing silicone oil modifier. Then, based on silicone resin and hydrophobic SiO2, the hydroxyl groups in the hydroxyl fluorosilicone oil and the hydroxyl groups on the silicone resin and SiO2 surfaces are dehydrated through base catalysis to form ether bonds, which are then spatially entangled with the fluorine-containing silicone oil modifier from the first step to form a macromolecular three-dimensional network structure of the fluorine-containing silicone paste.

[0012] Among them, the modified fluorinated silicone oil and hydroxy fluorinated silicone oil are the main defoaming components, which have a lower surface tension than conventional silicone oil (about 23mN / m), up to 16-18mN / m, reducing the surface tension of the system and having faster spreading performance in the water system.

[0013] Hydrophobic SiO2 and silicone resin form the base of a spatial network structure. A network of fluorosilicone pastes is obtained by spatially entangled linear fluorosilicone oil modifications and hydroxyfluorosilicone oil. Compared to conventional fluorine-free silicone pastes, this fluorosilicone paste combines low-surface-tension linear bodies such as hydrogen-containing fluorosilicone oil, fluorinated vinyl silicone oil, and hydroxyfluorosilicone oil as the main spatial crosslinking agents. Combined with MQ silicone resin containing a high content of tetrafunctional Si-O units at the crosslinking base and hydrophobic SiO2 with a high specific surface area, a highly crosslinked fluorosilicone paste is obtained through a first addition followed by base catalysis. This silicone paste not only has low surface tension, but also has a more thorough spatial network crosslinking, making it less susceptible to bond breakage and loss of defoaming activity due to strong acids, strong bases, and high temperatures.

[0014] Preferably, the hydrogen-containing fluorosilicone oil has a fluorine content of 0.15-1.62wt%, a hydrogen content of 0.05-0.2wt%, and hydrogen-containing mode is end-side hydrogenation; the fluorine-containing vinyl silicone oil has a fluorine content of 0.075-1.62wt%, and a vinyl content of 0.15-0.45wt%; the hydroxyl fluorosilicone oil has a fluorine content of 0.038-0.16wt%, and a hydroxyl content of 0.048-0.068wt%.

[0015] Preferably, the specific surface area of ​​the hydrophobic SiO2 is 150-280m 2 / g.

[0016] Preferably, the silicone resin is an MQ type silicone resin with an M / Q value of 0.48-0.88.

[0017] Preferably, the hydrogen-containing silicone oil is a terminal hydrogen-containing silicone oil with a hydrogen content of 0.1-0.2 wt%; the molecular weight of the allyl polyoxypropylene ether is 400-1000; the molecular weight of the allyl polyoxyethylene polyoxypropylene ether is 800-1500, and the EO:PO ratio is 1:1-5.

[0018] Preferably, the emulsifier is one or a mixture of Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60 and Tween 80.

[0019] Preferably, the raw materials of the fluorine-containing silicone paste are in the following weight ratios: 20-45 parts of hydrogen-containing fluorosilicone oil, 20-40 parts of fluorine-containing vinyl silicone oil, 20-35 parts of hydroxyl fluorosilicone oil, 5-10 parts of hydrophobic SiO2 and 5-10 parts of silicone resin.

[0020] Preferably, the emulsified composition ratio by weight is: 5-15 parts of fluorine-containing silicone paste, 4-8 parts of polyether-modified silicone oil A, 1-4 parts of polyether-modified silicone oil B, 2-4 parts of emulsifier, 65-75 parts of water and 1-3 parts of thickener.

[0021] Preferably, the usage amount of chloroplatinic acid is 10-30 ppm; the usage amount of KOH is 20-50 ppm.

[0022] In a second aspect, the present invention provides a fluorine-containing silicone paste defoamer, which is prepared using the above-mentioned preparation method.

[0023] In a third aspect, the present invention provides the use of the defoaming agent prepared by the above preparation method, which is used in papermaking and pulping.

[0024] The present invention has the following beneficial effects:

[0025] The surface tension of the hydrogen-containing fluorosilicone oil, fluorovinyl silicone oil, fluorohydroxy silicone oil and the like of the present invention is lower than that of fluorosilicone oil without fluorosilicone oil, and they spread faster in water, showing a faster defoaming effect. MQ silicone resin with a high content of tetrafunctional Si-O units and hydrophobic SiO2 with a high specific surface area are reacted to obtain a highly cross-linked fluorosilicone paste, which has a more thorough spatial network cross-linking and is less likely to be deactivated by bond breaking under strong acid, strong alkali and high temperature environments. Combining the respective advantages of fast diffusion of fluorine and high cross-linking degree, the present invention solves the problems of defoaming, foam suppression, dispersion, black liquor compatibility and enhanced water filterability of the defoamer in pulping black liquor.

[0026] Compared with traditional fluorine-free silicone paste, the defoaming agent prepared by the invention has the advantages of fast black liquor defoaming speed, good foam suppression, good black liquor compatibility, good pulp washing and water filterability, and is non-toxic, harmless and simple in process.

[0027] The defoamer prepared by the invention has low surface tension, good spreading performance, good chemical stability, and resistance to strong acid, strong alkali and high temperature systems. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the examples, but they are not intended to limit the present invention in any way.

[0029] The following Examples 1-3 are methods for preparing the fluorine-containing silicone paste defoamer of the present invention.

[0030] Comparative Example

[0031] 40 parts of hydrogen silicone oil, 30 parts of vinyl silicone oil, 20 parts of hydroxy silicone oil, 5 parts of hydrophobic SiO2 and 5 parts of silicone resin are reacted by base catalysis to obtain silicone paste. 10 parts of silicone paste, 10 parts of silicone polyether and 5 parts of emulsifier are mixed and heated to 60°C. 25 parts of water are added for phase inversion and emulsification. The temperature is lowered, 55 parts of water are added and a thickener is added to obtain a conventional silicone paste type defoamer.

[0032] Example 1

[0033] 20 parts of hydrogen-containing fluorosilicone oil (fluorine content 0.15%, hydrogen content 0.05%) and 40 parts of fluorine-containing vinyl silicone oil (fluorine content 1.62%, vinyl content 0.15%) were placed in a reactor, heated to 65°C, 10 ppm of chloroplatinic acid was added, and the reaction was carried out for 2 hours to obtain a fluorine-containing silicone oil modified product; 25 parts of hydroxyl fluorosilicone oil (fluorine content 0.038%, hydroxyl content 0.048%), 5 parts of hydrophobic SiO2 (specific surface area 150m 2 / g), 10 parts of silicone resin (M / Q value is 0.48), add 20 ppm KOH, stir and heat to 120 ° C, react for 4 hours to obtain fluorine-containing silicone paste;

[0034] Mix 5 parts of fluorine-containing silicone paste, 4 parts of polyether-modified silicone oil A (hydrogen-containing silicone oil with a hydrogen content of 0.1% and a molecular weight of allyl polyoxypropylene ether of 1000), 1 part of polyether-modified silicone oil B (hydrogen-containing silicone oil with a hydrogen content of 0.1%, a molecular weight of allyl polyoxyethylene polyoxypropylene ether of 800, EO:PO=1:1), and 2 parts of emulsifier (1 part of Span 20 and 1 part of Tween 20), stir and heat to 60°C, add 25 parts of deionized water for phase inversion and emulsification, cool, add 55 parts of deionized water, and add 2 parts of thickener to obtain a fluorine-containing silicone paste defoamer.

[0035] Test method:

[0036] Defoaming test: take 100ml of pulping black liquor into a 250ml stoppered measuring cylinder, add 1ml of defoamer, shake 30 times, and observe the time it takes for the foam to disappear as the defoaming time. Continue shaking 100 times and observe the time it takes for the foam to disappear as the antifoaming time.

[0037] Black liquor compatibility test: Take 20g of defoamer in 400g of black liquor, heat to 90℃, stir for 6h, filter and weigh the precipitate.

[0038] Example 2

[0039] 45 parts of hydrogen-containing fluorosilicone oil (fluorine content 1.62%, hydrogen content 0.2%) and 20 parts of fluorine-containing vinyl silicone oil (fluorine content 0.075%, vinyl content 0.45%) were placed in a reactor, protected by nitrogen, heated to 90°C, and 10 ppm of chloroplatinic acid was added. The reaction was continued for 0.5 h to obtain a fluorine-containing silicone oil modified product. 20 parts of hydroxyl fluorosilicone oil (fluorine content 0.16%, hydroxyl content 0.068%) and 10 parts of hydrophobic SiO2 (specific surface area 280 m 2 / g), 5 parts of silicone resin (M / Q value is 0.88), add 20 ppm KOH, stir and heat to 140 ° C, react for 2 hours, cool and discharge to obtain fluorine-containing silicone paste;

[0040] Mix 15 parts of fluorine-containing silicone paste, 8 parts of polyether-modified silicone oil A (hydrogen-containing silicone oil with a hydrogen content of 0.2%, and a molecular weight of allyl polyoxypropylene ether of 400), 4 parts of polyether-modified silicone oil B (hydrogen-containing silicone oil with a hydrogen content of 0.2%, and a molecular weight of allyl polyoxyethylene polyoxypropylene ether of 1500, EO:PO=1:5), and 4 parts of emulsifier (including 2 parts of Span 40 and 2 parts of Tween 40), stir and heat to 60°C, add 25 parts of deionized water for phase inversion and emulsification, cool, add 55 parts of deionized water, and add 1 part of thickener to obtain a fluorine-containing silicone paste defoamer.

[0041] Test method:

[0042] Defoaming test: take 100ml of pulping black liquor into a 250ml stoppered measuring cylinder, add 1ml of defoamer, shake 30 times, and observe the time it takes for the foam to disappear as the defoaming time. Continue shaking 100 times and observe the time it takes for the foam to disappear as the antifoaming time.

[0043] Black liquor compatibility test: Take 20g of defoamer in 400g of black liquor, heat to 90℃, stir for 6h, filter and weigh the precipitate.

[0044] Example 3

[0045] 30 parts of hydrogen-containing fluorosilicone oil (fluorine content 0.56%, hydrogen content 0.1%) and 30 parts of fluorine-containing vinyl silicone oil (fluorine content 1.26%, vinyl content 0.25%) were placed in a reactor, protected by nitrogen, heated to 75°C, and 10 ppm of chloroplatinic acid was added. The reaction was continued for 1.5 hours to obtain a fluorine-containing silicone oil modified product. 30 parts of hydroxyl fluorosilicone oil (fluorine content 0.068%, hydroxyl content 0.055%) and 5 parts of hydrophobic SiO2 (specific surface area 180 m 2 / g), 5 parts of silicone resin (M / Q value is 0.58), add 20ppmKOH, stir and heat to 130℃, react for 1h to obtain fluorine-containing silicone paste;

[0046] Mix 8 parts of fluorine-containing silicone paste, 5.5 parts of polyether-modified silicone oil A (hydrogen-containing silicone oil with a hydrogen content of 0.12% and a molecular weight of allyl polyoxypropylene ether of 800), 2 parts of polyether-modified silicone oil B (hydrogen-containing silicone oil with a hydrogen content of 0.12% and a molecular weight of allyl polyoxyethylene polyoxypropylene ether of 1000, EO:PO=1:2), and 2 parts of emulsifier (1 part of Span 60 and 1 part of Tween 60), stir and heat to 60°C, add 25 parts of deionized water for phase inversion and emulsification, cool, add 55 parts of deionized water, and add 3 parts of thickener to obtain a fluorine-containing silicone paste defoamer.

[0047] Test method:

[0048] Defoaming test: take 100ml of pulping black liquor into a 250ml stoppered measuring cylinder, add 1ml of defoamer, shake 30 times, and observe the time it takes for the foam to disappear as the defoaming time. Continue shaking 100 times and observe the time it takes for the foam to disappear as the antifoaming time.

[0049] Black liquor compatibility test: Take 20g of defoamer in 400g of black liquor, heat to 90℃, stir for 6h, filter and weigh the precipitate.

[0050] Example 4

[0051] 25 parts of hydrogen-containing fluorosilicone oil (fluorine content 1.2%, hydrogen content 0.15%) and 25 parts of fluorine-containing vinyl silicone oil (fluorine content 0.86%, vinyl content 0.35%) were placed in a reactor, protected by nitrogen, heated to 85°C, and 10ppm of chloroplatinic acid was added. The reaction was continued for 45min to obtain a fluorine-containing silicone oil modified product. 35 parts of hydroxyl fluorosilicone oil (fluorine content 0.12%, hydroxyl content 0.06%), 8 parts of hydrophobic SiO2 (specific surface area 240m 2 / g), 7 parts of silicone resin (M / Q value is 0.68), add 20ppmKOH, stir and heat to 130℃, react for 1h to obtain fluorine-containing silicone paste;

[0052] Mix 12 parts of fluorine-containing silicone paste, 6.5 parts of polyether-modified silicone oil A (hydrogen-containing silicone oil with a hydrogen content of 0.16%, and a molecular weight of allyl polyoxypropylene ether of 600), 3 parts of polyether-modified silicone oil B (hydrogen-containing silicone oil with a hydrogen content of 0.16%, and a molecular weight of allyl polyoxyethylene polyoxypropylene ether of 1200, EO:PO=1:3), and 3 parts of emulsifier (1.5 parts of Span 80 and 1.5 parts of Tween 80), stir and heat to 60°C, add 25 parts of deionized water for phase inversion and emulsification, cool, add 55 parts of deionized water, and add 2 parts of thickener to obtain a fluorine-containing silicone paste defoamer.

[0053] Test method:

[0054] Defoaming test: take 100ml of pulping black liquor into a 250ml stoppered measuring cylinder, add 1ml of defoamer, shake 30 times, and observe the time it takes for the foam to disappear as the defoaming time. Continue shaking 100 times and observe the time it takes for the foam to disappear as the antifoaming time.

[0055] Black liquor compatibility test: Take 20g of defoamer in 400g of black liquor, heat to 90℃, stir for 6h, filter and weigh the precipitate.

[0056] Table 1 Comparison of defoaming properties, foam suppression properties and black liquor compatibility of different types of defoamers

[0057]

[0058] As can be seen from Table 1, in the pulping black liquor, the defoaming time and foam suppression time of the fluorine-containing silicone paste defoamer in the pulping black liquor are significantly shorter than those of the fluorine-free silicone paste defoamer and the non-silicone paste defoamer in the comparative example;

[0059] In terms of compatibility, the fluorine-containing silicone paste defoamer precipitates very little black liquor in the pulping black liquor, indicating that the defoamer has good dispersibility in the pulping black liquor.

[0060] Therefore, the test results further confirm that the fluorine-containing silicone paste defoamer has substantial improvement and obvious progress in defoaming, foam suppression and compatibility in pulping black liquor.

[0061] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some of the technical features therein according to the disclosed technical content without creative labor, and these substitutions and modifications are all within the protection scope of the present invention.

Claims

1. A method for preparing a fluorine-containing silicone paste defoamer, characterized in that: include: 1) Place hydrogen-containing fluorosilicone oil and fluorine-containing vinyl silicone oil in a reactor, protect with nitrogen, stir and heat to 65-90°C, add chloroplatinic acid, and react for 0.5-2h to obtain a fluorine-containing silicone oil modified product; then add hydroxyl fluorosilicone oil, hydrophobic SiO2 and silicone resin to the reactor, stir evenly, add KOH, heat to 120-140°C, and react with base catalysis for 2-4h, cool and discharge to obtain a fluorine-containing silicone paste; The hydrogen-containing fluorosilicone oil contains hydrogen at the end, with silicone resin and hydrophobic SiO2 as the base points. The hydroxyl groups in the hydroxyl fluorosilicone oil and the hydroxyl groups on the silicone resin and SiO2 surfaces are dehydrated by base catalysis to form ether bonds, which are then spatially entangled with the fluorosilicone oil modifier to form a macromolecular three-dimensional network structure of the fluorosilicone paste. 2) Mix the fluorine-containing silicone paste, polyether-modified silicone oil A, polyether-modified silicone oil B, and emulsifier, stir and heat to 55-65°C, add deionized water for phase inversion and emulsification, cool, add deionized water, and add thickener to obtain a fluorine-containing silicone paste defoamer; The polyether-modified silicone oil A is an addition reaction product of hydrogen-containing silicone oil and allyl polyoxypropylene ether, and the polyether-modified silicone oil B is an addition reaction product of hydrogen-containing silicone oil and allyl polyoxyethylene polyoxypropylene ether.

2. The method for preparing the fluorine-containing silicone paste defoamer according to claim 1, wherein: The hydrogen-containing fluorosilicone oil has a fluorine content of 0.15-1.62wt% and a hydrogen content of 0.05-0.2wt%; the fluorine-containing vinyl silicone oil has a fluorine content of 0.075-1.62wt% and a vinyl content of 0.15-0.45wt%; the fluorine content of the hydroxyl fluorosilicone oil is 0.038-0.16wt% and the hydroxyl content is 0.048-0.068wt%.

3. The method for preparing the fluorine-containing silicone paste defoamer according to claim 1, wherein: The specific surface area of ​​the hydrophobic SiO2 is 150-280m 2 / g.

4. The method for preparing the fluorine-containing silicone paste defoamer according to claim 1, wherein: The silicone resin is an MQ type silicone resin with an M / Q value of 0.48-0.

88.

5. The method for preparing the fluorine-containing silicone paste defoamer according to claim 1, wherein: The hydrogen-containing silicone oil is a terminal hydrogen-containing silicone oil with a hydrogen content of 0.1-0.2 wt%; the molecular weight of the allyl polyoxypropylene ether is 400-1000; the molecular weight of the allyl polyoxyethylene polyoxypropylene ether is 800-1500, and the EO:PO ratio is 1:1-5.

6. The method for preparing the fluorine-containing silicone paste defoamer according to claim 1, wherein: The emulsifier is one of Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60 and Tween 80, or a mixture of several of them.

7. The method for preparing the fluorine-containing silicone paste defoamer according to claim 1, wherein: The raw materials of the fluorine-containing silicone paste are mixed in the following weight ratios: 20-45 parts of hydrogen-containing fluorine silicone oil, 20-40 parts of fluorine-containing vinyl silicone oil, 20-35 parts of hydroxyl fluorine silicone oil, 5-10 parts of hydrophobic SiO2 and 5-10 parts of silicone resin.

8. The method for preparing the fluorine-containing silicone paste defoamer according to claim 1, wherein: The weight ratio of the emulsification is: 5-15 parts of fluorine-containing silicone paste, 4-8 parts of polyether modified silicone oil A, 1-4 parts of polyether modified silicone oil B, 2-4 parts of emulsifier, 65-75 parts of water and 1-3 parts of thickener.

9. A fluorine-containing silicone paste defoamer, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the defoaming agent prepared by the preparation method according to any one of claims 1 to 8, characterized in that: Used in papermaking and pulping.

Images