Preparation method of solvent-free defoaming agent with good stability

Abstract

The application provides a preparation method of a solvent-free defoaming agent with good stability, which comprises the following steps: (1) under a nitrogen atmosphere, 60-70 parts by mass of an end-allyl polyether, 8-10 parts by mass of an antioxidant and 0.2-0.6 parts by mass of a platinum catalyst are mixed, heated to 55-58 DEG C and uniformly stirred to obtain a mixture A; (2) 30-40 parts by mass of a hydrogen-containing silicone oil and 4-9 parts by mass of 4A molecular sieve are added into the mixture A, the temperature is kept at 80-100 DEG C, and constant-temperature stirring is carried out for 2-3 hours to obtain a mixture B; and (3) 10-14 parts by mass of a modified filler is added into the mixture B, and stirring is carried out for 30-50 min to obtain the solvent-free defoaming agent. The defoaming performance of the defoaming agent is improved by using specific raw materials and a specific ratio; and the defoaming agent can be better dispersed in a water-based or oil-based system by adding the modified filler, so that the use efficiency of the defoaming agent is improved.

Description

Technical Field

[0001] This invention belongs to the field of defoamer technology, specifically relating to a method for preparing a solvent-free defoamer with good stability. Background Technology

[0002] Defoamers are chemicals primarily used to eliminate foam generated during industrial production processes. In many industrial processes, such as fermentation, paint manufacturing, petrochemicals, papermaking, and wastewater treatment, large amounts of unwanted foam are often produced due to various chemical reactions, mechanical agitation, and gas release. This foam not only occupies extra container space and affects production efficiency, but can also lead to overflows, compromised product quality, and increased production costs.

[0003] Polyether-modified polysiloxane defoamers, as high-performance defoamers, combine the advantages of polyether and silicone, exhibiting excellent defoaming and foam-suppressing properties, as well as stability over a wide range of pH and temperature. Nevertheless, some technical problems may still arise when using such defoamers: (1) Turbidity: Polyether-modified polysiloxane defoamers may cause turbidity in certain systems, especially after the silicone oil in the defoamer is completely consumed. This may be related to the proportion, type, and dispersion state of the components in the defoamer. (2) Oil floating: Due to the insolubility of the defoamer itself, uneven dispersion may cause some silicone oil to accumulate on the surface, forming an oil film, known as "oil floating." This not only affects the appearance of the product but may also reduce the defoaming effect. (3) Foam suppression time: Ensuring that the defoamer has an appropriate foam suppression time is a major challenge. The properties and content of silicone oil directly affect the durability of the defoamer; too little will result in incomplete defoaming, while too much may reduce the defoaming efficiency. In addition, the size of the defoamer particles must be appropriate to avoid affecting their stability in the system. (4) Stability issues: including acid and alkali stability and high temperature stability. In strong acid and alkali environments, the silicone oil in the defoamer may decompose, affecting its performance. Similarly, in high temperature environments, the structure of the defoamer may change, reducing its defoaming efficiency. (5) Solubility and compatibility: Although polyether modification improves the water solubility of organosilicon, in specific systems, there may still be problems with poor compatibility, which may lead to a reduction in the defoaming effect or affect the quality of the final product.

[0004] Therefore, there is an urgent need for a solvent-free defoamer with good defoaming and foam-suppressing effects. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a solvent-free defoamer with good stability.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a solvent-free defoamer with good stability includes the following steps: (1) Under a nitrogen atmosphere, 60-70 parts by weight of terminal allyl polyether, 8-10 parts by weight of antioxidant, and 0.2-0.6 parts by weight of platinum catalyst are mixed and heated to 55-58°C and stirred evenly to obtain mixture A; the terminal allyl polyether is a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.2-1.5:0.6-0.8. (2) Add 30-40 parts by weight of hydrogen-containing silicone oil and 4-9 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 80-100℃, and stir for 2-3 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to neutral pH, react at 90-93℃ for 1-2 hours; reduce temperature by 40-50℃, add 10-14 parts by weight of modified filler, stir for 30-50 min, remove unreacted impurities by rotary evaporation, and obtain solvent-free defoamer.

[0007] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0008] Furthermore, the hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1.3-1.6:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0009] Furthermore, the antioxidant is selected from one or more of antioxidant T501, antioxidant T502, and antioxidant T502A.

[0010] Furthermore, the concentration of the hydrochloric acid is 0.01-0.012 mol / L.

[0011] Furthermore, the platinum catalyst is IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0012] Furthermore, the preparation method of the modified filler is as follows: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.2-0.3 parts by mass of the silane coupling agent KH560 and 70-80 parts by mass of the ethanol aqueous solution, and react at 45-50℃ for 1-2 hours to obtain the silane modified mixture; (3) Add 0.3-0.6 parts by weight of modifier to the silane modified mixture, stir at 30-35℃ for 1-2 hours, filter and dry to obtain modified filler.

[0013] Furthermore, the modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.3-0.6.

[0014] Furthermore, the mass fraction of ethanol in the aqueous ethanol solution is 60-70%.

[0015] Furthermore, the mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.4-1.6:0.3-0.5.

[0016] Furthermore, the particle size of silicon dioxide is 180-200 nm; the particle size of titanium dioxide is 20-60 nm; and the particle size of calcium carbonate is 100-120 nm.

[0017] The present invention also provides a solvent-free defoamer prepared by the aforementioned preparation method.

[0018] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: The present invention improves the defoaming performance of the defoamer by using specific raw material composition and ratio; by adding modified fillers, the physical and chemical stability of the defoamer can be enhanced, and it can be used as a dispersing aid to help the defoamer disperse better in aqueous or oily systems, thereby improving its efficiency. At the same time, it can improve the compatibility of the defoamer with other components of the system and avoid separation or precipitation. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 This embodiment provides a solvent-free defoamer with good stability, and its preparation method includes the following steps: (1) Under a nitrogen atmosphere, 64 parts by mass of terminal allyl polyether, 9 parts by mass of antioxidant and 0.4 parts by mass of platinum catalyst were mixed and heated to 57°C and stirred evenly to obtain mixture A; the terminal allyl polyether was a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.4:0.7. (2) Add 33 parts by mass of hydrogen-containing silicone oil and 6 parts by mass of 4A molecular sieve to mixture A, maintain the temperature at 90°C, and stir at a constant temperature for 2.5 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral and react at 92°C for 1.4 hours; reduce the temperature by 45°C, add 12 parts by mass of modified filler, stir for 40 minutes, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0021] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0022] The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1.4:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0023] The antioxidant is antioxidant T501.

[0024] The concentration of the hydrochloric acid is 0.011 mol / L.

[0025] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0026] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.24 parts by mass of the silane coupling agent KH560 and 75 parts by mass of the ethanol aqueous solution, and react at 48°C for 1.5 h to obtain the silane-modified mixture; (3) Add 0.5 parts by mass of modifier to the silane modified mixture, stir at 32°C for 1.6 h, filter and dry to obtain modified filler.

[0027] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.5.

[0028] The mass fraction of ethanol in the aqueous ethanol solution is 65%.

[0029] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.5:0.4.

[0030] The particle size of silica is 180-200nm; the particle size of titanium dioxide is 20-60nm and the particle size of calcium carbonate is 100-120nm.

[0031] Example 2 This embodiment provides a solvent-free defoamer with good stability, and its preparation method includes the following steps: (1) Under a nitrogen atmosphere, 60 parts by mass of terminal allyl polyether, 8 parts by mass of antioxidant and 0.2 parts by mass of platinum catalyst are mixed and heated to 55°C and stirred evenly to obtain mixture A; the terminal allyl polyether is a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.2:0.6. (2) Add 30 parts by mass of hydrogen-containing silicone oil and 4 parts by mass of 4A molecular sieve to mixture A, keep the temperature at 80℃, stir for 2 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral, react at 90°C for 1 hour; reduce temperature by 40°C, add 10 parts by mass of modified filler, stir for 30 min, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0032] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0033] The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1.3:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0034] The antioxidant is antioxidant T502.

[0035] The concentration of the hydrochloric acid is 0.01 mol / L.

[0036] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0037] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.2 parts by mass of the silane coupling agent KH560 and 70 parts by mass of the ethanol aqueous solution, and react at 45°C for 1 h to obtain the silane modified mixture. (3) Add 0.3 parts by mass of modifier to the silane modified mixture, stir at 30°C for 1-2 hours, filter and dry to obtain the modified filler.

[0038] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.3.

[0039] The mass fraction of ethanol in the aqueous ethanol solution is 60%.

[0040] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.4:0.3.

[0041] The particle size of silica is 180-200 nm; the particle size of titanium dioxide is 20-60 nm and the particle size of calcium carbonate is 100-120 nm.

[0042] Example 3 This embodiment provides a solvent-free defoamer with good stability, and its preparation method includes the following steps: (1) Under a nitrogen atmosphere, 70 parts by mass of terminal allyl polyether, 10 parts by mass of antioxidant and 0.6 parts by mass of platinum catalyst are mixed and heated to 58°C and stirred evenly to obtain mixture A; the terminal allyl polyether is a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.5:0.8. (2) Add 40 parts by mass of hydrogen-containing silicone oil and 9 parts by mass of 4A molecular sieve to mixture A, keep the temperature at 100℃ and stir for 3 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral, react at 93°C for 2 hours; reduce temperature by 50°C, add 14 parts by mass of modified filler, stir for 50 min, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0043] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0044] The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1.6:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0045] The antioxidant is antioxidant T502A.

[0046] The concentration of the hydrochloric acid is 0.012 mol / L.

[0047] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0048] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.3 parts by mass of the silane coupling agent KH560 and 80 parts by mass of the ethanol aqueous solution, and react at 50°C for 2 hours to obtain the silane-modified mixture. (3) Add 0.6 parts by mass of modifier to the silane modified mixture, stir at 35°C for 1-2 hours, filter and dry to obtain modified filler.

[0049] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.6.

[0050] The mass fraction of ethanol in the aqueous ethanol solution is 70%.

[0051] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.6:0.5.

[0052] The particle size of silica is 180-200nm; the particle size of titanium dioxide is 20-60nm and the particle size of calcium carbonate is 100-120nm.

[0053] Comparative Example 1 The difference between this comparative example and Example 1 is that the terminal allyl polyether is a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1:1.

[0054] A solvent-free defoamer with good stability is prepared by the following steps: (1) Under a nitrogen atmosphere, 64 parts by mass of terminal allyl polyether, 9 parts by mass of antioxidant and 0.4 parts by mass of platinum catalyst are mixed and heated to 57°C and stirred evenly to obtain mixture A; the terminal allyl polyether is a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1:1. (2) Add 33 parts by mass of hydrogen-containing silicone oil and 6 parts by mass of 4A molecular sieve to mixture A, maintain the temperature at 90°C, and stir at a constant temperature for 2.5 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral and react at 92°C for 1.4 hours; reduce the temperature by 45°C, add 12 parts by mass of modified filler, stir for 40 minutes, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0055] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0056] The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1.4:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0057] The antioxidant is antioxidant T501.

[0058] The concentration of the hydrochloric acid is 0.011 mol / L.

[0059] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0060] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.24 parts by mass of the silane coupling agent KH560 and 75 parts by mass of the ethanol aqueous solution, and react at 48°C for 1.5 h to obtain the silane-modified mixture; (3) Add 0.5 parts by mass of modifier to the silane modified mixture, stir at 32°C for 1.6 h, filter and dry to obtain modified filler.

[0061] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.5.

[0062] The mass fraction of ethanol in the aqueous ethanol solution is 65%.

[0063] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.5:0.4.

[0064] The particle size of silica is 180-200nm; the particle size of titanium dioxide is 20-60nm and the particle size of calcium carbonate is 100-120nm.

[0065] Comparative Example 2 The difference between this comparative example and Example 1 is that the hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0066] A solvent-free defoamer with good stability is prepared by the following steps: (1) Under a nitrogen atmosphere, 64 parts by mass of terminal allyl polyether, 9 parts by mass of antioxidant and 0.4 parts by mass of platinum catalyst were mixed and heated to 57°C and stirred evenly to obtain mixture A; the terminal allyl polyether was a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.4:0.7. (2) Add 33 parts by mass of hydrogen-containing silicone oil and 6 parts by mass of 4A molecular sieve to mixture A, maintain the temperature at 90°C, and stir at a constant temperature for 2.5 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral and react at 92°C for 1.4 hours; reduce the temperature by 45°C, add 12 parts by mass of modified filler, stir for 40 minutes, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0067] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0068] The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0069] The antioxidant is antioxidant T501.

[0070] The concentration of the hydrochloric acid is 0.011 mol / L.

[0071] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0072] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.24 parts by mass of the silane coupling agent KH560 and 75 parts by mass of the ethanol aqueous solution, and react at 48°C for 1.5 h to obtain the silane-modified mixture; (3) Add 0.5 parts by mass of modifier to the silane modified mixture, stir at 32°C for 1.6 h, filter and dry to obtain modified filler.

[0073] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.5.

[0074] The mass fraction of ethanol in the aqueous ethanol solution is 65%.

[0075] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.5:0.4.

[0076] The particle size of silica is 180-200nm; the particle size of titanium dioxide is 20-60nm and the particle size of calcium carbonate is 100-120nm.

[0077] Comparative Example 3 The difference between this comparative example and Example 1 is that the hydrogen-containing silicone oil used is a hydrogen-containing silicone oil with a hydrogen content of 1.2~1.6wt%, purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0078] A solvent-free defoamer with good stability is prepared by the following steps: (1) Under a nitrogen atmosphere, 64 parts by mass of terminal allyl polyether, 9 parts by mass of antioxidant and 0.4 parts by mass of platinum catalyst were mixed and heated to 57°C and stirred evenly to obtain mixture A; the terminal allyl polyether was a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.4:0.7. (2) Add 33 parts by mass of hydrogen-containing silicone oil and 6 parts by mass of 4A molecular sieve to mixture A, maintain the temperature at 90°C, and stir at a constant temperature for 2.5 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral and react at 92°C for 1.4 hours; reduce the temperature by 45°C, add 12 parts by mass of modified filler, stir for 40 minutes, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0079] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0080] The hydrogen-containing silicone oil is a hydrogen-containing silicone oil with a hydrogen content of 1.2~1.6wt%. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0081] The antioxidant is antioxidant T501.

[0082] The concentration of the hydrochloric acid is 0.011 mol / L.

[0083] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0084] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.24 parts by mass of the silane coupling agent KH560 and 75 parts by mass of the ethanol aqueous solution, and react at 48°C for 1.5 h to obtain the silane-modified mixture; (3) Add 0.5 parts by mass of modifier to the silane modified mixture, stir at 32°C for 1.6 h, filter and dry to obtain modified filler.

[0085] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.5.

[0086] The mass fraction of ethanol in the aqueous ethanol solution is 65%.

[0087] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.5:0.4.

[0088] The particle size of silica is 180-200nm; the particle size of titanium dioxide is 20-60nm and the particle size of calcium carbonate is 100-120nm.

[0089] Comparative Example 4 The difference between this comparative example and Example 1 is that the mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1:1.

[0090] A solvent-free defoamer with good stability is prepared by the following steps: (1) Under a nitrogen atmosphere, 64 parts by mass of terminal allyl polyether, 9 parts by mass of antioxidant and 0.4 parts by mass of platinum catalyst were mixed and heated to 57°C and stirred evenly to obtain mixture A; the terminal allyl polyether was a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.4:0.7. (2) Add 33 parts by mass of hydrogen-containing silicone oil and 6 parts by mass of 4A molecular sieve to mixture A, maintain the temperature at 90°C, and stir at a constant temperature for 2.5 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral and react at 92°C for 1.4 hours; reduce the temperature by 45°C, add 12 parts by mass of modified filler, stir for 40 minutes, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0091] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0092] The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1.4:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0093] The antioxidant is antioxidant T501.

[0094] The concentration of the hydrochloric acid is 0.011 mol / L.

[0095] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0096] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.24 parts by mass of the silane coupling agent KH560 and 75 parts by mass of the ethanol aqueous solution, and react at 48°C for 1.5 h to obtain the silane-modified mixture; (3) Add 0.5 parts by mass of modifier to the silane modified mixture, stir at 32°C for 1.6 h, filter and dry to obtain modified filler.

[0097] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.5.

[0098] The mass fraction of ethanol in the aqueous ethanol solution is 65%.

[0099] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1:1.

[0100] The particle size of silica is 180-200nm; the particle size of titanium dioxide is 20-60nm and the particle size of calcium carbonate is 100-120nm.

[0101] Comparative Example 5 The difference between this comparative example and Example 1 is that the particle size of silicon dioxide is 10-50 nm; the particle size of titanium dioxide is 300-400 nm; and the particle size of calcium carbonate is 100-200 nm.

[0102] A solvent-free defoamer with good stability is prepared by the following steps: (1) Under a nitrogen atmosphere, 64 parts by mass of terminal allyl polyether, 9 parts by mass of antioxidant and 0.4 parts by mass of platinum catalyst were mixed and heated to 57°C and stirred evenly to obtain mixture A; the terminal allyl polyether was a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.4:0.7. (2) Add 33 parts by mass of hydrogen-containing silicone oil and 6 parts by mass of 4A molecular sieve to mixture A, maintain the temperature at 90°C, and stir at a constant temperature for 2.5 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral and react at 92°C for 1.4 hours; reduce the temperature by 45°C, add 12 parts by mass of modified filler, stir for 40 minutes, and remove unreacted impurities by rotary evaporation to obtain solvent-free defoamer.

[0103] Allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B were all purchased from Liaoning Kelong Fine Chemical Co., Ltd.

[0104] The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1~0.4wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7~0.9wt% in a mass ratio of 1.4:1. It was purchased from Zhejiang Chuangji Organosilicon Materials Co., Ltd.

[0105] The antioxidant is antioxidant T501.

[0106] The concentration of the hydrochloric acid is 0.011 mol / L.

[0107] The platinum catalyst was IOTA-8300 chloroplatinic acid, purchased from Anhui Aiyota Silicon Oil Co., Ltd.

[0108] The modified filler is prepared by: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.24 parts by mass of the silane coupling agent KH560 and 75 parts by mass of the ethanol aqueous solution, and react at 48°C for 1.5 h to obtain the silane-modified mixture; (3) Add 0.5 parts by mass of modifier to the silane modified mixture, stir at 32°C for 1.6 h, filter and dry to obtain modified filler.

[0109] The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.5.

[0110] The mass fraction of ethanol in the aqueous ethanol solution is 65%.

[0111] The mass ratio of silicon dioxide, titanium dioxide, and calcium carbonate is 1:1.5:0.4.

[0112] The particle size of silicon dioxide is 10-50 nm; the particle size of titanium dioxide is 300-400 nm and the particle size of calcium carbonate is 100-200 nm.

[0113] Performance testing The performance of the solvent-free defoamers of Examples 1-3 and Comparative Examples 1-5 was tested.

[0114] Weigh 3.00g of sodium dodecylbenzenesulfonate into a beaker, dissolve it thoroughly with deionized water, and bring the volume to 1L. Shake well to obtain a 0.3% sodium dodecylbenzenesulfonate aqueous solution, which will be used as the foaming solution.

[0115] Foam suppression: Add 200 mL of foaming solution to a 1 L graduated cylinder, then add 0.20 g of the defoamer from the examples and comparative examples, and shake well. Bubble the mixture using an oxygen pump at a flow rate of 1200 mL / min, and record the time required for the foam height to reach the top (1 L mark). This is the foam suppression time. The longer the foam suppression time, the better the foam suppression performance of the defoamer.

[0116] Defoaming: Add 200mL of foaming solution to a 1L graduated cylinder, maintain a constant temperature, and aerate the solution using an oxygen pump at a flow rate of 1200mL / min. When the foam reaches the 1L mark, add 0.1% defoamer and record the time it takes for the foam to completely disappear. This is the defoaming time. The shorter the defoaming time, the better the defoaming performance of the defoamer.

[0117] Table 1 Performance Test Results

[0118] As can be seen from the above performance test results, the defoamers of Examples 1-3 have excellent overall performance.

[0119] The comparative example, however, did not employ the necessary technical solutions, resulting in significantly inferior performance compared to the embodiment in the corresponding tests. The above experimental results further demonstrate the importance of the technical solutions defined in this invention for its technical effects.

[0120] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a solvent-free defoamer with good stability, characterized in that, Includes the following steps: (1) Under a nitrogen atmosphere, 60-70 parts by weight of terminal allyl polyether, 8-10 parts by weight of antioxidant, and 0.2-0.6 parts by weight of platinum catalyst are mixed and heated to 55-58°C and stirred evenly to obtain mixture A; the terminal allyl polyether is a mixture of allyl epoxy-terminated polyether KL-11, allyl epoxy-terminated polyether KL-11B, and allyl epoxy-terminated polyether KL-91B in a mass ratio of 1:1.2-1.5:0.6-0.

8. (2) Add 30-40 parts by weight of hydrogen-containing silicone oil and 4-9 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 80-100℃, and stir for 2-3 hours to obtain mixture B; (3) Neutralize mixture B with hydrochloric acid to pH neutral, react at 90-93℃ for 1-2 hours; reduce temperature by 40-50℃, add 10-14 parts by weight of modified filler, stir for 30-50 min, remove unreacted impurities by rotary evaporation, and obtain solvent-free defoamer. The hydrogen-containing silicone oil is a mixture of hydrogen-containing silicone oil with a hydrogen content of 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% in a mass ratio of 1.3-1.6:

1. The antioxidant is selected from one or more of antioxidant T501, antioxidant T502, and antioxidant T502A; The preparation method of the modified filler is as follows: (1) Mix silica, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) Mix 10 parts by mass of the mixed filler, 0.2-0.3 parts by mass of the silane coupling agent KH560 and 70-80 parts by mass of the ethanol aqueous solution, and react at 45-50℃ for 1-2 hours to obtain the silane modified mixture; (3) Add 0.3-0.6 parts by weight of modifier to the silane modified mixture, stir at 30-35℃ for 1-2 hours, filter and dry to obtain modified filler; the modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.3-0.6; the mass ratio of silicon dioxide, titanium dioxide and calcium carbonate is 1:1.4-1.6:0.3-0.5; the particle size of silicon dioxide is 180-200nm; the particle size of titanium dioxide is 20-60nm and the particle size of calcium carbonate is 100-120nm.

2. The method for preparing the solvent-free defoamer according to claim 1, characterized in that, The concentration of the hydrochloric acid is 0.01-0.012 mol / L.

3. The method for preparing the solvent-free defoamer according to claim 1, characterized in that, The platinum catalyst is IOTA-8300 chloroplatinic acid.

4. The method for preparing the solvent-free defoamer according to claim 1, characterized in that, The mass fraction of ethanol in an aqueous ethanol solution is 60-70%.

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