High-temperature durable organic silicon defoaming composition and preparation method thereof

Abstract

The invention provides a high-temperature durable organic silicon defoaming composition. The high-temperature durable organic silicon defoaming composition is prepared from alkyl polysiloxane, phenyl siloxane, fluorine-containing siloxane, hydrophobic modified silicon dioxide, an antioxidant and a dispersing agent, various groups, such as alkyl, benzene ring and fluorine-containing group, are introduced into the side chain of polysiloxane; according to the defoaming composition disclosed by the invention, due to the introduction of phenyl siloxane, the molecular structure is more stable, and relatively low volatility and excellent chemical stability can be kept under a high-temperature condition; the fluorine-containing group further enhances the thermal stability of polysiloxane on the molecular level, reduces the surface energy, and increases the adhesive ability of the defoaming agent on a gas-liquid interface. The optimized combination of the modified group, the dispersing agent and the antioxidant endows the defoaming agent with relatively strong oxidation resistance and chemical resistance, and the defoaming agent can stably work in a production environment with relatively strong oxygen-containing, acidic or alkaline properties.

Description

Technical Field

[0001] The present application belongs to the field of fine chemical technology, and in particular relates to a high-temperature durable organosilicon defoaming composition and a preparation method thereof. Background Art

[0002] In industrial fields such as petrochemicals, textile dyeing and finishing, metalworking fluids, distillation and purification, the production process is usually accompanied by the generation of foam, especially under high temperature and high pressure conditions. If these foams cannot be effectively controlled, they will not only reduce the efficiency of the equipment, but may also cause liquid overflow, damage equipment and products, and may even pose safety hazards. Taking petroleum refining and chemical production as an example, the production process often requires high temperature and high pressure conditions. If the foam is not eliminated in time, it will cause production line stagnation, flow obstruction or pipeline blockage, seriously affecting production progress and equipment safety.

[0003] Conventional defoamers on the market are mostly dimethylpolysiloxane type, mineral oil type, vegetable oil type or polyether type. Although they can effectively defoam under normal temperature conditions, they often face problems such as failure and decomposition under high temperature environments, resulting in the inability to continuously and effectively defoam. Polyether defoamers are prone to decomposition or oxidation reactions at high temperatures, and the defoaming effect is greatly reduced. Mineral oil defoamers have poor dispersibility and are difficult to stably adhere to the gas-liquid interface, while vegetable oil defoamers have reduced defoaming efficiency at high temperatures and short foam suppression time. Traditional silicone defoamers also have problems with molecular chain scission and defoaming structure destruction under high temperature conditions, making it difficult to meet long-term foam suppression requirements. Therefore, the development of a silicone defoamer that can work continuously under high temperature conditions has become an urgent need in actual production. Summary of the invention

[0004] The present application provides a high temperature durable organosilicon defoaming composition and a preparation method thereof and a defoaming preparation to solve the problems existing in the related art. The technical solution is as follows:

[0005] In a first aspect, the present invention provides a high temperature durable organosilicon defoaming composition, comprising the following components in parts by weight:

[0006] Alkyl polysiloxane: 50.0-60.0 parts;

[0007] Phenyl siloxane: 10.0-15.0 parts;

[0008] Fluorosilicone: 10.0-15.0 parts;

[0009] Hydrophobically modified silica: 2.0-5.0 parts;

[0010] Antioxidant: 0.1-1.0 parts;

[0011] Dispersant: 3.0-8.0 parts.

[0012] In one embodiment, the structure of the alkyl polysiloxane is as shown in Formula I:

[0013]

[0014] Wherein R1 is a C2-C8 alkyl group; m=60-500, and m is an integer.

[0015] In one embodiment, the phenylsiloxane is methylphenylpolysiloxane, and the structure is shown in Formula II:

[0016]

[0017] x=10-200, and x is an integer.

[0018] In one embodiment, the fluorinated polysiloxane structure is as shown in Formula III:

[0019]

[0020] Wherein n=3-10, and n is an integer; y=10-200, and y is an integer.

[0021] In one embodiment, the hydrophobically modified silica is fumed silica or precipitated silica modified by a modifier; the modifier is one or a combination of two or more of polydimethylsiloxane, polydimethylsilazane, long-chain alkyl silane, phenyl silane, or epoxy silane.

[0022] In one embodiment, the dispersant is polyether, alkane or polyether alkane co-modified polysiloxane.

[0023] In one embodiment, the dispersant structure is as shown in Formula IV:

[0024]

[0025] Wherein R2 is an ethoxylated and / or propoxylated polyether group having the structure -(CH2) g (OCH2CH2) e (OCH2CH2CH2) f OH, e=0-10, f=5-30, g=3-5, and e, f, g are integers; R3 is a C1-C8 alkyl group; p=0-100, q=0-100, and p, q are integers, and p and q are not 0 at the same time.

[0026] In one embodiment, the oxidant is a German BASF series antioxidant.

[0027] In one embodiment, the antioxidant is one of rganox 1010, 1098, 1035, 1135, 1425, 1076, 245, or a combination of two or more thereof.

[0028] In a second aspect, the present application provides a method for preparing a high-temperature durable organosilicon defoaming composition, comprising the following steps:

[0029] S1: mixing and stirring alkyl polysiloxane, phenyl siloxane and fluorine-containing siloxane, and heating to 50-100° C. to obtain a first mixture;

[0030] S2: adding hydrophobically modified silica and an antioxidant to the first mixture, stirring, mixing and dispersing at 50-100° C. to obtain a second mixture;

[0031] S3: adding a dispersant to the second mixture, stirring and dispersing, and obtaining a high-temperature durable organosilicon defoaming composition.

[0032] In one embodiment, in steps S1-S3, the stirring speed is 1000-2500 rpm;

[0033] In step S1, the stirring time is 0.5-2h; in step S2, the stirring time is 0.2-1h; in step S3, the stirring time is 0.2-1h.

[0034] The advantages or beneficial effects of the above technical solution include at least:

[0035] A high-temperature durable silicone defoaming composition of the present application comprises a combination of various modified polysiloxanes, and various groups such as alkyl, benzene ring and fluorine-containing groups are introduced into the side chains of polysiloxanes. Phenyl groups and fluorine-containing groups are not easy to decompose at high temperatures and have high resistance to chemical reactions, so that the defoaming agent is not easy to decompose or volatilize under high temperature conditions. Therefore, in the defoaming composition of the present application, the introduction of phenylsiloxane makes the molecular structure more stable, and can maintain low volatility and excellent chemical stability under high temperature conditions; the fluorine-containing group further enhances the thermal stability of polysiloxane at the molecular level, reduces the surface energy, and increases the adhesion ability of the defoaming agent at the gas-liquid interface. The optimized combination of modified groups, dispersants and antioxidants gives the defoaming agent strong antioxidant properties and chemical resistance, and can also work stably in production environments with strong oxygen, acidity or alkalinity.

[0036] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the following detailed description. DETAILED DESCRIPTION

[0037] Hereinafter, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the following description is considered to be exemplary and non-restrictive in nature.

[0038] In the existing petrochemical, textile dyeing and finishing, pulp and paper making, metal cleaning and other high-temperature production scenarios, when performing defoaming treatment, the defoamer must not only have a good defoaming effect, but also meet the requirements of the high-temperature environment. Although dimethylpolysiloxane-type, mineral oil-type, vegetable oil-type or polyether-type defoamers can effectively defoam under normal temperature conditions, they often face problems such as failure and decomposition under high temperature environments, resulting in the inability to continuously and effectively defoam. Therefore, the present application provides a high-temperature durable organosilicon defoaming composition and a preparation method thereof.

[0039] A high-temperature durable organosilicon defoaming composition comprises the following components in parts by weight:

[0040] Alkyl polysiloxane: 50.0-60.0 parts;

[0041] Phenyl siloxane: 10.0-15.0 parts;

[0042] Fluorosilicone: 10.0-15.0 parts;

[0043] Hydrophobically modified silica: 2.0-5.0 parts;

[0044] Antioxidant: 0.1-1.0 parts;

[0045] Dispersant: 3.0-8.0 parts.

[0046] Modified polysiloxane is used as the main material, and phenyl and fluorine-containing groups with high temperature resistance are introduced to improve its stability under high temperature conditions. At the same time, special modified fumed silica is added as a synergist and structural stabilizer, and high-performance antioxidants are added to further improve the thermal stability and durability of the defoamer. By reasonably controlling the ratio of modified polysiloxane, phenyl and fluorine-containing groups, modified fumed silica, and antioxidants, the defoamer can achieve the best defoaming effect and durability at higher temperatures. In addition, an appropriate amount of dispersant is added to the formula to ensure the dispersibility and adhesion of the defoamer in a high temperature environment, thereby achieving long-lasting defoaming and anti-foaming performance.

[0047] In one embodiment, the structure of the alkyl polysiloxane is as shown in Formula I:

[0048]

[0049] Wherein R1 is a C2-C8 alkyl group; m=60-500, and m is an integer.

[0050] In this embodiment, R1 is a C2-C8 alkyl group; as a preferred embodiment, R1 can be ethyl, n-propyl, isopropyl, butyl, hexyl, octyl. m=60-500, and m is an integer, and m can be any integer between 60-500.

[0051] In one embodiment, the phenylsiloxane is methylphenylpolysiloxane, and the structure is shown in Formula II:

[0052]

[0053] x=10-200, and x is an integer.

[0054] In this embodiment, the benzene ring is a strong carbon ring structure with good high temperature resistance, so a phenyl group is introduced into the side chain of polysiloxane to make the polysiloxane molecular structure more stable, and can maintain low volatility and excellent chemical stability under high temperature conditions, thereby improving the high temperature resistance of phenylsiloxane. In this embodiment, x can be any integer between 10 and 200. Compared with ordinary polydimethylsiloxane groups, the phenyl group is not easy to decompose at high temperatures and has a high resistance to chemical reactions, so it is suitable for use in high temperature industrial environments.

[0055] In one embodiment, the fluorinated polysiloxane structure is as shown in Formula III:

[0056]

[0057] Wherein n=3-10, and n is an integer; y=10-200, and y is an integer.

[0058] Fluorine-containing groups have extremely strong chemical inertness, can reduce surface energy, increase the spreading performance of defoamer, contribute to rapid distribution in liquid surface, and can tolerate oxidation and other chemical corrosion at the same time. Fluorine-containing groups further enhance the thermal stability of polysiloxanes at molecular level, reduce surface energy, and increase the adhesion ability of defoamer at gas-liquid interface. Compared with common polydimethylsiloxane groups, fluorine-containing groups are difficult to decompose at high temperatures, and have higher resistance to chemical reactions, and are therefore suitable for use in high temperature industrial environments. As a linking group, -CH2- length is not easy to be too short, so n is selected as an arbitrary integer of 3-10. In the present embodiment, y can be an integer arbitrarily between 10-200.

[0059] In one embodiment, the hydrophobically modified silica is fumed silica or precipitated silica modified by a modifier; the modifier is one or more of polydimethylsiloxane, polydimethylsilazane, long-chain alkyl silane, phenyl silane, or epoxy silane. Preferably, the modifier is one or more of hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, hexamethyldisilazane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octamethyltrimethoxysilane, octamethyltriethoxysilane, phenyltrimethoxysilane, or phenyltriethoxysilane. Preferably, the hydrophobic fumed silica is at least one of Evonik R974, Evonik R972, Evonik R816, Evonik R812S, Evonik R812, EvonikR202, Evonik R106, Evonik R104, CabotTS 610, CabotTS 530, Japan Tokuyama DM 30, Japan Tokuyama DM20S, Germany Wacker H20 or Germany Wacker H30).

[0060] Hydrophobically modified silica is used as a structural additive to improve the dispersibility and adhesion of defoamers. The special silica particles are hydrophobically treated to make them stable at high temperatures, improve the adhesion of defoamers, and thus enhance the defoaming performance.

[0061] In this embodiment, the method of modifying silica is:

[0062] The silica can be hydrophobically modified by heating the fumed silica or precipitated silica with a modifier in the presence of a catalyst. The catalyst is a silane coupling agent, such as KH-602, APMDS, etc. The reaction is carried out at 50-80°C for 2-12 hours.

[0063] In one embodiment, the dispersant is polyether, alkane or polyether alkane co-modified polysiloxane. The dispersant is added to the formula to ensure that the defoamer can be evenly distributed at the gas-liquid interface and will not evaporate or condense quickly at high temperatures.

[0064] In one embodiment, the dispersant structure is as shown in Formula IV:

[0065]

[0066] Wherein R2 is an ethoxylated and / or propoxylated polyether group having the structure -(CH2) g (OCH2CH2) e (OCH2CH2CH2) fOH, e=0-10, f=5-30, g=3-5, and e, f, g are integers; R3 is a C1-C8 alkyl group; p=0-100, q=0-100, and p, q are integers, and p and q are not 0 at the same time.

[0067] In one embodiment, the oxidant is a German BASF series antioxidant. Adding a high-performance antioxidant further improves the stability of the active components of the defoamer in a high temperature environment, reduces and delays the oxidation and chain breaking process of the active ingredient molecules, and greatly improves the durability and effectiveness of the defoaming performance in a high temperature environment.

[0068] In one embodiment, the antioxidant is one of rganox 1010, 1098, 1035, 1135, 1425, 1076, 245, or a combination of two or more thereof.

[0069] The present application also provides a method for preparing a high-temperature durable organosilicon defoaming composition, comprising the following steps:

[0070] S1: mixing and stirring alkyl polysiloxane, phenyl siloxane and fluorine-containing siloxane, and heating to 50-100° C. to obtain a first mixture;

[0071] S2: adding hydrophobically modified silica and an antioxidant to the first mixture, stirring, mixing and dispersing at 50-100° C. to obtain a second mixture;

[0072] S3: adding a dispersant to the second mixture, stirring and dispersing, and obtaining a high-temperature durable organosilicon defoaming composition.

[0073] In one embodiment, in steps S1-S3, the stirring speed is 1000-2500 rpm;

[0074] In step S1, the stirring time is 0.5-2h; in step S2, the stirring time is 0.2-1h; in step S3, the stirring time is 0.2-1h.

[0075] The following is a further description with reference to specific embodiments.

[0076] Example 1

[0077] A high-temperature durable organosilicon defoaming composition comprises the following components in parts by weight:

[0078] 55 parts of alkyl polysiloxane; 13 parts of phenyl siloxane; 13 parts of fluorine-containing siloxane; 3.5 parts of hydrophobically modified silica; 0.5 parts of antioxidant; 5 parts of dispersant;

[0079] The alkyl polysiloxane is shown in formula I, wherein R1 is n-butyl; m is 80;

[0080] Phenyl siloxane is shown in formula II, wherein x is 50;

[0081] The fluorinated siloxane is represented by formula III, wherein n is 3 and y is 50;

[0082] The hydrophobically modified silica is prepared by reacting fumed silica and decamethyltetrasiloxane in the presence of silane coupling agent KH-602 at a mass ratio of 10:3:2 at 70°C for 10 hours.

[0083] The dispersant is shown in Formula IV, wherein R2 is an ethoxylated and / or propoxylated polyether group having a structure of -(CH2) g (OCH2CH2) e (OCH2CH2CH2) f OH, e=5, f=10, g=4; R3 is ethyl; p=20, q=30.

[0084] The antioxidant is a composition of rganox 1010 and 1135 in a mass ratio of 1:1;

[0085] Prepared by the following method:

[0086] S1: Alkyl polysiloxane, phenyl siloxane and fluorine-containing siloxane are mixed and stirred at a speed of 2000 rpm, heated to 75° C., and stirred for 1 hour to obtain a first mixture;

[0087] S2: adding hydrophobically modified silica and an antioxidant to the first mixture, stirring and dispersing at 75° C. and 2000 rpm for 0.5 h to obtain a second mixture;

[0088] S3: Add a dispersant to the second mixture, and stir at 2000 rpm for 1 hour to disperse the mixture, thereby obtaining a high-temperature durable organosilicon defoaming composition.

[0089] Example 2

[0090] A high-temperature durable organosilicon defoaming composition comprises the following components in parts by weight:

[0091] 50 parts of alkyl polysiloxane; 15 parts of phenyl siloxane; 10 parts of fluorine-containing siloxane; 5 parts of hydrophobically modified silica; 0.1 parts of antioxidant; 8 parts of dispersant;

[0092] The alkyl polysiloxane is shown in formula I, wherein R1 is ethyl; m is 200;

[0093] Phenyl siloxane is shown in formula II, wherein x is 10;

[0094] The fluorinated siloxane is represented by formula III, wherein n is 5 and y is 100;

[0095] The hydrophobically modified silica was prepared by reacting fumed silica and hexadecyltrimethoxysilane in the presence of a silane coupling agent APMDS at a mass ratio of 10:4:1.5 at 50°C for 12 hours.

[0096] The dispersant is shown in Formula IV, wherein R2 is an ethoxylated and / or propoxylated polyether group having a structure of -(CH2) g (OCH2CH2) e (OCH2CH2CH2) f OH, e=10, f=20, g=3; p=50, q=0.

[0097] The antioxidant is rganox1076;

[0098] Prepared by the following method:

[0099] S1: mixing alkyl polysiloxane, phenyl siloxane and fluorine-containing siloxane and stirring at a speed of 1500 rpm, heating to 50° C., and stirring for 2 h to obtain a first mixture;

[0100] S2: adding hydrophobically modified silica and an antioxidant to the first mixture, stirring and dispersing at 50° C. and 1500 rpm for 1 h to obtain a second mixture;

[0101] S3: Add a dispersant to the second mixture, and stir at 1500 rpm for 0.2 h to obtain a high-temperature durable organosilicon defoaming composition.

[0102] Example 3

[0103] A high-temperature durable organosilicon defoaming composition comprises the following components in parts by weight:

[0104] 60 parts of alkyl polysiloxane; 10 parts of phenyl siloxane; 15 parts of fluorine-containing siloxane; 2 parts of hydrophobically modified silica; 1 part of antioxidant; 3 parts of dispersant;

[0105] The alkyl polysiloxane is shown in formula I, wherein R1 is n-octyl; m is 60;

[0106] Phenyl siloxane is shown in formula II, wherein x is 10;

[0107] The fluorinated siloxane is represented by formula III, wherein n is 10 and y is 100;

[0108] The hydrophobically modified silica is prepared by reacting fumed silica and phenyltrimethoxysilane in the presence of silane coupling agent KH-602 at a mass ratio of 10:2:1 at 80°C for 2h.

[0109] The dispersant is shown in Formula IV, wherein R2 is an ethoxylated and / or propoxylated polyether group having a structure of -(CH2) g (OCH2CH2) e (OCH2CH2CH2) f OH, e=10, f=0, g=5; R3 is n-hexyl; p=10, q=50.

[0110] The antioxidant was rganox 1010;

[0111] Prepared by the following method:

[0112] S1: mixing alkyl polysiloxane, phenyl siloxane and fluorine-containing siloxane and stirring at a speed of 1000 rpm, heating to 85° C., and stirring for 1 hour to obtain a first mixture;

[0113] S2: adding hydrophobically modified silica and an antioxidant to the first mixture, stirring and dispersing at 85° C. and 1000 rpm for 0.5 h to obtain a second mixture;

[0114] S3: adding a dispersant to the second mixture, stirring at 1000 rpm for 0.5 h to disperse, thereby obtaining a high-temperature durable organosilicon defoaming composition.

[0115] Comparative Example 1 (does not contain phenylsilane, heat resistance decreases)

[0116] The difference between Comparative Example 1 and Example 1 is that a defoaming composition comprises the following components in parts by weight:

[0117] 68 parts of alkyl polysiloxane; 13 parts of fluorine-containing siloxane; 3.5 parts of hydrophobically modified silica; 0.5 parts of antioxidant; 5 parts of dispersant; other material compositions and preparation methods are the same as those in Example 1.

[0118] Comparative Example 2 (without fluorinated silane, defoaming performance decreased)

[0119] The difference between Comparative Example 2 and Example 1 is that a defoaming composition comprises the following components in parts by weight:

[0120] 68 parts of alkyl polysiloxane; 13 parts of phenyl siloxane; 3.5 parts of hydrophobically modified silica; 0.5 parts of antioxidant; 5 parts of dispersant; other material compositions and preparation methods are the same as those in Example 1.

[0121] Comparative Example 3 (Silica is not modified, defoaming performance decreases)

[0122] The difference between Comparative Example 3 and Example 1 is that a defoaming composition comprises the following components in parts by weight:

[0123] 55 parts of alkyl polysiloxane; 13 parts of phenyl siloxane; 13 parts of fluorine-containing siloxane; 3.5 parts of fumed silica; 0.5 parts of antioxidant; 5 parts of dispersant; other material compositions and preparation methods are the same as those in Example 1.

[0124] Comparative Example 4 (without dispersant, defoaming performance decreased)

[0125] The difference between Comparative Example 4 and Example 1 is that a defoaming composition comprises the following components in parts by weight:

[0126] 55 parts of alkyl polysiloxane; 13 parts of phenyl siloxane; 13 parts of fluorine-containing siloxane; 3.5 parts of hydrophobically modified silica; 0.5 parts of antioxidant; other material compositions and preparation methods are the same as those in Example 1.

[0127] Comparative Example 5 (without fluorine-containing silane and phenyl silane, defoaming performance decreased)

[0128] The difference between Comparative Example 5 and Example 1 is that a high-temperature durable organosilicon defoaming composition comprises the following components in parts by weight:

[0129] 81 parts of alkyl polysiloxane; 3.5 parts of hydrophobically modified silica; 0.5 parts of antioxidant; 5 parts of dispersant; other material compositions and preparation methods are the same as those in Example 1.

[0130] Comparative Example 6 (without antioxidant, defoaming performance decreased)

[0131] The difference between Comparative Example 6 and Example 1 is that a defoaming composition comprises the following components in parts by weight:

[0132] 55 parts of alkyl polysiloxane; 13 parts of phenyl siloxane; 13 parts of fluorine-containing siloxane; 3.5 parts of hydrophobically modified silica; 5 parts of dispersant; other material compositions and preparation methods are the same as those in Example 1.

[0133] Comparative Example 7 (High Alkyl Polysiloxane Content)

[0134] The difference between Comparative Example 7 and Example 1 is that a defoaming composition comprises the following components in parts by weight:

[0135] 90 parts of alkyl polysiloxane; 13 parts of phenyl siloxane; 13 parts of fluorine-containing siloxane; 3.5 parts of hydrophobically modified silica; 0.5 parts of antioxidant; 5 parts of dispersant; other material compositions and preparation methods are the same as those in Example 1.

[0136] Test example:

[0137] Test method:

[0138] (1) The compositions of Example 1 and Comparative Examples 1-7 were placed in an oven at 200° C. for 1 hour, and the changes in properties before and after were compared. The results are shown in Table 1.

[0139] Table 1

[0140]

[0141] From the results in Table 1, it can be seen that the defoamer of Example 1 of the present application has a certain high temperature resistance, while the defoamers of Comparative Examples 1-7 show a certain degree of deterioration in properties at a high temperature of 200°C; the defoamers of Comparative Examples 1-7 have a significant change in viscosity after high temperature treatment, indicating poor thermal stability. However, the viscosity of the defoaming composition of Example 1 of the present application remains basically unchanged, showing good thermal stability.

[0142] (2) Using the reaction liquid in the petrochemical refining process as the test medium, the test sample foam is prepared to the same height by aeration; adding a defoaming agent, and recording the time for the foam to reach different volumes. The longer the time required, the worse the anti-foaming performance of the sample.

[0143] Test conditions: test temperature 200°C; amount of reaction liquid used in petrochemical refining process: 300ml; sample addition amount of Examples 1-3 and Comparative Examples 1-7: 30μL; test flow rate: 5L / min. The results are shown in Table 2;

[0144] (3) The test temperature was changed to 100°C, and the time it took for the foam to decrease from the preparation height to less than 50 ml was measured. The results are shown in Table 3.

[0145] Table 2 Test results

[0146] Foam volume / ml 850 700 550 400 250 Less than 100 Example 1 50″ 1′36″ 2′16″ 3′00″ 3′48″ 4′50″ Example 2 53″ 1′40″ 2′22″ 3′09″ 3′58″ 5′05″ Example 3 52″ 1′37″ 2′21″ 3′12″ 4′02″ 5′11″ Comparative Example 1 1′07″ 2′18″ 3′28″ 4′56″ 6′42″ 8′33″ Comparative Example 2 1′03″ 2′14″ 3′45″ 5′27″ 7′22″ 9′56″ Comparative Example 3 57″ 1′55″ 3′02″ 4′13″ 5′25″ 6′44″ Comparative Example 4 60″ 2′02″ 3′11″ 4′27″ 5′50″ 7′29″ Comparative Example 5 1′22″ 2′51″ 4′25″ 6′03″ 7′52″ 10′05″ Comparative Example 6 53″ 1′42″ 2′25″ 3′17″ 4′10″ 5′27″ Comparative Example 7 55″ 1′45″ 2′32″ 3′31″ 4′34″ 5′55″

[0147] Table 3 Test results

[0148]

[0149] As can be seen from Examples 1-3 in Table 2, at 200°C, the defoamers of Examples 1-3 can eliminate the foam generated by the reaction liquid in the petrochemical refining process from 1000ml to less than 100ml in about 5min, while Comparative Examples 1-7 take a long time to achieve the same effect, and the foam reaches less than 100ml, and the time used is longer than that of the examples, indicating that the defoaming and washing performance of the defoamer is not as good as that of the examples. Comparative Examples 1 and 2 do not contain phenyl siloxane and fluorine-containing siloxane respectively, and Comparative Example 5 does not contain the above two siloxanes at the same time. The time required for defoaming is greatly extended, from 5min to more than 8 and a half minutes. In particular, as the defoaming proceeds, the time used for each 150ml reduction in the foam volume is also extended. This is because at a high temperature of 200°C, the defoaming performance is not greatly affected by the high temperature when the defoamer is just added. As the time increases under the high temperature state, the defoamer decreases due to the high temperature activity, and thus the defoaming performance decreases significantly.

[0150] Comparative Example 3 illustrates that the hydrophobic modification of silica, as a structural additive, can improve the dispersibility and adhesion of the defoamer; and enable it to exist stably at high temperatures, improve the adhesion of the defoamer, and thus enhance the defoaming performance. Comparative Example 4 illustrates that the dispersant ensures that the defoamer can be evenly distributed at the gas-liquid interface and will not evaporate or condense quickly at high temperatures, which also helps the defoamer to play a defoaming role. Comparative Example 6 illustrates that the oxidant helps to ensure stability in a high temperature environment, reduce and delay the oxidation and chain breaking process of the active ingredient molecules, and greatly improve the durability and effectiveness of the defoaming performance in a high temperature environment. Comparative Example 7 illustrates that under the defoamer ratio of the present application, it is possible to ensure the stability of the defoamer in a high temperature environment.

[0151] As can be seen from Table 3, the defoaming time of the defoamer of Example 1 at 200°C and 100°C does not change much, showing an excellent high-temperature defoaming effect; while the defoaming time of the defoamers of Comparative Examples 1-7 at 100°C is significantly better than the defoaming effect at 200°C, which shows that at high temperatures, the stability of the defoamer decreases, resulting in a decrease in defoaming performance. The increase in temperature causes the defoaming performance of the defoamers of Comparative Examples 1-7 to decrease. This indirectly shows that the thermal stability of the defoamers of Comparative Examples 1-7 is not as good as that of the defoamers of the examples.

[0152] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0153] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0154] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A high temperature durable organosilicon defoaming composition, characterized in that: It includes the following components in parts by weight:

2. A high temperature durable organosilicon defoaming composition according to claim 1, characterized in that: The structure of the alkyl polysiloxane is shown in Formula I: Wherein R1 is a C2-C8 alkyl group; m=60-500, and m is an integer.

3. The high temperature durable organosilicon defoaming composition according to claim 1, characterized in that: The phenyl siloxane is methyl phenyl polysiloxane, and its structure is shown in Formula II: x=10-200, and x is an integer.

4. The high temperature durable organosilicon defoaming composition according to claim 1, characterized in that: The structure of the fluorinated polysiloxane is shown in Formula III: Wherein n=3-10, and n is an integer; y=10-200, and y is an integer.

5. The high temperature durable organosilicon defoaming composition according to claim 1, characterized in that: The hydrophobically modified silica is fumed silica or precipitated silica modified by a modifier; the modifier is one or a combination of two or more of polydimethylsiloxane, polydimethylsilazane, long-chain alkyl silane, phenyl silane, or epoxy silane.

6. The high temperature durable organosilicon defoaming composition according to claim 1, characterized in that: The dispersant is polyether, alkane or polyether alkane co-modified polysiloxane.

7. The high temperature durable organosilicon defoaming composition according to claim 6, characterized in that: The dispersant structure is shown in Formula IV: Wherein R2 is an ethoxylated and / or propoxylated polyether group having the structure -(CH2) g (OCH2CH2) e (OCH2CH2CH2) f OH, e=0-10, f=5-30, g=3-5, and e, f, g are integers; R3 is a C1-C8 alkyl group; p=0-100, q=0-100, and p, q are integers, and p and q are not 0 at the same time.

8. The high temperature durable organosilicon defoaming composition according to claim 1, characterized in that: The oxidant is a German BASF series antioxidant; preferably, the antioxidant is one of rganox 1010, 1098, 1035, 1135, 1425, 1076, 245 or a combination of two or more thereof.

9. A method for preparing a high-temperature durable organosilicon defoaming composition, characterized in that: The following steps are involved: S1: mixing and stirring alkyl polysiloxane, phenyl siloxane and fluorine-containing siloxane, and heating to 50-100° C. to obtain a first mixture; S2: adding hydrophobically modified silica and an antioxidant to the first mixture, stirring, mixing and dispersing at 50-100° C. to obtain a second mixture; S3: adding a dispersant to the second mixture, stirring and dispersing, and obtaining a high-temperature durable organosilicon defoaming composition.

10. The method for preparing a defoamer composition according to claim 9, characterized in that: In steps S1-S3, the stirring speed is 1000-2500 rpm; In step S1, the stirring time is 0.5-2h; in step S2, the stirring time is 0.2-1h; in step S3, the stirring time is 0.2-1h.

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