Preparation method of solvent-free defoaming agent with good stability

Abstract

The invention provides a preparation method of a solvent-free defoaming agent with good stability, which comprises the following steps: (1) in a nitrogen atmosphere, mixing 60-70 parts by mass of allyl-terminated polyether, 8-10 parts by mass of antioxidant and 0.2-0.6 part by mass of platinum catalyst, heating to 55-58 DEG C, and uniformly stirring to obtain a mixture A; (2) adding 30-40 parts by mass of hydrogen-containing silicone oil and 4-9 parts by mass of a 4A molecular sieve into the mixture A, keeping the temperature at 80-100 DEG C, and stirring at a constant temperature for 2-3 hours to obtain a mixture B; and (3) adding 10-14 parts by mass of modified filler into the mixture B, and stirring for 30-50 minutes to obtain the solvent-free defoaming agent. The defoaming performance of the defoaming agent is improved by using specific raw material composition and proportion; by adding the modified filler, the defoaming agent can be better dispersed in a water-based or oil-based system, so that the use efficiency of the defoaming agent is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of defoamers, and in particular relates to a method for preparing a solvent-free defoamer with good stability. Background Art

[0002] Defoamers are chemicals that are mainly used to eliminate foam generated during industrial production. In many industrial processes, such as fermentation, paint manufacturing, petrochemicals, papermaking, wastewater treatment, etc., a large amount of unwanted foam is often generated due to various chemical reactions, mechanical stirring, gas release and other factors. These foams not only take up additional container space and affect production efficiency, but may also cause overflow, affect product quality, and increase production costs.

[0003] As a high-performance defoamer, polyether-modified polysiloxane defoamer combines the advantages of polyether and silicone, has good defoaming and antifoaming properties, and is stable over a wide pH and temperature range. Nevertheless, some technical problems may still be encountered when using such defoamers: (1) Turbidity problem: polyether-modified polysiloxane defoamers may appear turbid in some systems, especially when the silicone oil in the defoamer is completely consumed. This may be related to the proportion and type of each component in the defoamer and its dispersion state in the system. (2) Floating oil problem: Due to the insolubility of the defoamer itself, if it is not evenly dispersed, it may cause part of the silicone oil to gather on the surface to form an oil film, which is the so-called "floating oil" phenomenon. This not only affects the appearance of the product, but may also reduce the defoaming effect. (3) Antifoaming time problem: How to ensure that the defoamer has an appropriate antifoaming time is a major challenge. The nature and content of silicone oil directly affect the durability of the defoamer. Too little silicone oil will not completely defoam, and too much silicone oil may reduce the defoaming efficiency. In addition, the size of the defoamer particles must also be appropriate so as not to affect its stability in the system. (4) Stability issues: including acid-base stability and high-temperature stability. In a strong acid or alkali environment, the silicone oil in the defoamer may decompose, affecting its performance. Similarly, in a high-temperature environment, the structure of the defoamer may change, reducing its defoaming efficiency. (5) Solubility and compatibility: Although polyether modification increases the water solubility of silicone, in a specific system, there may still be poor compatibility issues, resulting in a reduced defoaming effect or affecting the quality of the final product.

[0004] Therefore, there is an urgent need for a solvent-free defoaming agent with good defoaming and anti-foaming effects. Summary of the invention

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

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A method for preparing a solvent-free defoamer with good stability comprises 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, heated to 55-58° C. and stirred evenly to obtain a 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 hydrogenated silicone oil and 4-9 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 80-100° C., and stir at the constant temperature for 2-3 hours to obtain mixture B; (3) Neutralize the mixture B with hydrochloric acid until the pH is neutral, and react at 90-93°C for 1-2 hours; reduce the temperature by 40-50°C, add 10-14 parts by weight of the modified filler, stir for 30-50 minutes, and remove unreacted impurities by rotary evaporation to obtain a solvent-free defoaming agent.

[0007] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% at a mass ratio of 1.3-1.6:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 chloroplatinic acid IOTA-8300, which is purchased from Anhui IOTA Silicone Oil Co., Ltd.

[0012] Furthermore, the preparation method of the modified filler is: (1) mixing silicon dioxide, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) 10 parts by weight of mixed filler, 0.2-0.3 parts by weight of silane coupling agent KH560 and 70-80 parts by weight of ethanol aqueous solution were mixed and reacted at 45-50° C. for 1-2 hours to obtain a silane-modified mixed solution; (3) Add 0.3-0.6 parts by weight of a modifier to the silane-modified mixed solution, stir at 30-35° C. for 1-2 hours, filter, and dry to obtain a 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 ethanol aqueous 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] Further, 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 invention also provides a solvent-free defoamer prepared by the 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 defoaming agent by using a specific raw material composition and ratio; the physical stability and chemical stability of the defoaming agent can be enhanced by adding a modified filler, and the defoaming agent can be used as a dispersing aid to help the defoaming agent to be better dispersed in an aqueous or oily system, thereby improving its use efficiency, and at the same time can improve the compatibility of the defoaming agent with other components of the system to avoid separation or precipitation. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1 This embodiment provides a solvent-free defoamer with good stability, and the preparation method thereof comprises 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, heated to 57° C. and stirred to obtain a 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 weight of hydrogenated silicone oil and 6 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 90° C., and stir at the constant temperature for 2.5 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 92°C for 1.4 hours. The temperature was lowered by 45°C, 12 parts by weight of modified filler was added, and the mixture was stirred for 40 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0021] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% at a mass ratio of 1.4:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

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

[0031] Example 2 This embodiment provides a solvent-free defoamer with good stability, and the preparation method thereof comprises the following steps: (1) Under a nitrogen atmosphere, 60 parts by weight of terminal allyl polyether, 8 parts by weight of antioxidant, and 0.2 parts by weight of platinum catalyst were mixed, heated to 55° C. and stirred to obtain a 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 1:1.2:0.6; (2) Add 30 parts by weight of hydrogenated silicone oil and 4 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 80° C., and stir at the constant temperature for 2 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 90°C for 1 hour. The temperature was lowered by 40°C, 10 parts by weight of modified filler was added, and the mixture was stirred for 30 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0032] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% at a mass ratio of 1.3:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

[0037] The preparation method of the modified filler is: (1) mixing silicon dioxide, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) 10 parts by weight of the mixed filler, 0.2 parts by weight of the silane coupling agent KH560 and 70 parts by weight of an ethanol aqueous solution were mixed and reacted at 45° C. for 1 hour to obtain a silane-modified mixed solution; (3) Add 0.3 parts by mass of a modifier to the silane-modified mixed solution, stir at 30° C. for 1-2 hours, filter, and dry to obtain a 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 ethanol aqueous 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 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.

[0042] Example 3 This embodiment provides a solvent-free defoamer with good stability, and the preparation method thereof comprises the following steps: (1) Under a nitrogen atmosphere, 70 parts by weight of terminal allyl polyether, 10 parts by weight of antioxidant, and 0.6 parts by weight of platinum catalyst were mixed, heated to 58° C. and stirred to obtain a 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 1:1.5:0.8; (2) Add 40 parts by weight of hydrogenated silicone oil and 9 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 100° C., and stir at the constant temperature for 3 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 93°C for 2 hours. The temperature was lowered by 50°C, 14 parts by weight of modified filler was added, and the mixture was stirred for 50 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0043] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% at a mass ratio of 1.6:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

[0048] The preparation method of the modified filler is: (1) mixing silicon dioxide, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) 10 parts by weight of the mixed filler, 0.3 parts by weight of the silane coupling agent KH560 and 80 parts by weight of an ethanol aqueous solution were mixed and reacted at 50° C. for 2 h to obtain a silane-modified mixed solution; (3) Add 0.6 parts by mass of a modifier to the silane-modified mixed solution, stir at 35° C. for 1-2 hours, filter, and dry to obtain a 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 ethanol aqueous 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 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.

[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, the preparation method of which comprises the following steps: (1) Under a nitrogen atmosphere, 64 parts by weight of terminal allyl polyether, 9 parts by weight of antioxidant, and 0.4 parts by weight of platinum catalyst were mixed, heated to 57° C. and stirred to obtain a 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 1:1:1; (2) Add 33 parts by weight of hydrogenated silicone oil and 6 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 90° C., and stir at the constant temperature for 2.5 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 92°C for 1.4 hours. The temperature was lowered by 45°C, 12 parts by weight of modified filler was added, and the mixture was stirred for 40 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0055] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% at a mass ratio of 1.4:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

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

[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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% in a mass ratio of 1:1, purchased from Zhejiang Chuangji Organic Silicone Materials Co., Ltd.

[0066] A solvent-free defoamer with good stability, the preparation method of which comprises 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, heated to 57° C. and stirred to obtain a 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 weight of hydrogenated silicone oil and 6 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 90° C., and stir at the constant temperature for 2.5 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 92°C for 1.4 hours. The temperature was lowered by 45°C, 12 parts by weight of modified filler was added, and the mixture was stirred for 40 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0067] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% in a mass ratio of 1:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

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

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

[0078] A solvent-free defoamer with good stability, the preparation method of which comprises 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, heated to 57° C. and stirred to obtain a 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 weight of hydrogenated silicone oil and 6 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 90° C., and stir at the constant temperature for 2.5 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 92°C for 1.4 hours. The temperature was lowered by 45°C, 12 parts by weight of modified filler was added, and the mixture was stirred for 40 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0079] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 1.2-1.6 wt %, purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

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

[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, the preparation method of which comprises 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, heated to 57° C. and stirred to obtain a 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 weight of hydrogenated silicone oil and 6 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 90° C., and stir at the constant temperature for 2.5 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 92°C for 1.4 hours. The temperature was lowered by 45°C, 12 parts by weight of modified filler was added, and the mixture was stirred for 40 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0091] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% at a mass ratio of 1.4:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

[0096] The preparation method of the modified filler is: (1) mixing silicon dioxide, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) 10 parts by weight of the mixed filler, 0.24 parts by weight of the silane coupling agent KH560 and 75 parts by weight of an ethanol aqueous solution were mixed and reacted at 48° C. for 1.5 hours to obtain a silane-modified mixed solution; (3) Add 0.5 parts by mass of a modifier to the silane-modified mixed solution, stir at 32° C. for 1.6 h, filter, and dry to obtain a 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 ethanol aqueous solution is 65%.

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

[0100] 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.

[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, the preparation method of which comprises 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, heated to 57° C. and stirred to obtain a 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 weight of hydrogenated silicone oil and 6 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 90° C., and stir at the constant temperature for 2.5 hours to obtain mixture B; (3) Mixture B was neutralized with hydrochloric acid to a neutral pH, and the mixture was reacted at 92°C for 1.4 hours. The temperature was lowered by 45°C, 12 parts by weight of modified filler was added, and the mixture was stirred for 40 minutes. Unreacted impurities were removed by rotary evaporation to obtain a solvent-free defoaming agent.

[0103] Allyl epoxy terminated polyether KL-11, allyl epoxy terminated polyether KL-11B, and allyl epoxy terminated polyether KL-91B were 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 0.1-0.4 wt% and hydrogen-containing silicone oil with a hydrogen content of 0.7-0.9 wt% at a mass ratio of 1.4:1, and is purchased from Zhejiang Chuangji Organic Silicone 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 is chloroplatinic acid IOTA-8300, which was purchased from Anhui IOTA Silicone Oil Co., Ltd.

[0108] The preparation method of the modified filler is: (1) mixing silicon dioxide, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) 10 parts by weight of the mixed filler, 0.24 parts by weight of the silane coupling agent KH560 and 75 parts by weight of an ethanol aqueous solution were mixed and reacted at 48° C. for 1.5 hours to obtain a silane-modified mixed solution; (3) Add 0.5 parts by mass of a modifier to the silane-modified mixed solution, stir at 32° C. for 1.6 h, filter, and dry to obtain a 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 ethanol aqueous 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 tests were performed on the solvent-free defoamers of Examples 1-3 and Comparative Examples 1-5.

[0114] Weigh 3.00 g of sodium dodecylbenzene sulfonate into a beaker, fully dissolve it with deionized water, and make the volume up to 1 L. Shake well to obtain a 0.3% sodium dodecylbenzene sulfonate aqueous solution as a foaming liquid.

[0115] Foam suppression: add 200 mL of foaming liquid to a 1 L graduated cylinder, then add 0.20 g of the defoaming agent of the embodiment and the comparative example, and shake well. The mixed solution is bubbled by an aeration pump, and the gas flow rate of the aeration pump is 1200 mL / min. The time required for the foam height to reach the top (1 L scale line) is recorded, which is the foam suppression time. The longer the foam suppression time, the better the foam suppression performance of the defoaming agent.

[0116] Defoaming: Add 200mL of foaming liquid to a 1L measuring cylinder, keep constant temperature and bubble the foaming liquid through an aeration pump, the gas flow rate of the aeration pump is 1200mL / min, when the upper end of the foam reaches the 1L scale line, add a defoamer with an effective content of 0.1%, and record the time when all the foam disappears, which is the defoaming time. The shorter the defoaming time, the better the defoaming performance of the defoamer.

[0117] Table 1 Performance test results

[0118] It can be seen from the above performance test results that the defoamers of Examples 1-3 have excellent comprehensive performance.

[0119] However, the comparative example does not adopt the necessary technical solution, resulting in its performance being significantly worse than that of the embodiment in the corresponding performance test. The above experimental results further prove the importance of the technical solution defined in the present invention to its technical effect.

[0120] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a solvent-free defoamer with good stability, characterized in that: The following steps are involved: (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, heated to 55-58° C. and stirred evenly to obtain a 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 hydrogenated silicone oil and 4-9 parts by weight of 4A molecular sieve to mixture A, maintain the temperature at 80-100° C., and stir at the constant temperature for 2-3 hours to obtain mixture B; (3) neutralizing the mixture B with hydrochloric acid until the pH is neutral, and reacting at 90-93°C for 1-2 hours; lowering the temperature by 40-50°C, adding 10-14 parts by weight of the modified filler, stirring for 30-50 minutes, and removing unreacted impurities by rotary evaporation to obtain a 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% at 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.

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

4. The method for preparing a solvent-free defoamer according to claim 1, characterized in that: The preparation method of the modified filler is: (1) mixing silicon dioxide, titanium dioxide and calcium carbonate to obtain a mixed filler; (2) 10 parts by weight of mixed filler, 0.2-0.3 parts by weight of silane coupling agent KH560 and 70-80 parts by weight of ethanol aqueous solution were mixed and reacted at 45-50° C. for 1-2 hours to obtain a silane-modified mixed solution; (3) Add 0.3-0.6 parts by weight of a modifier to the silane-modified mixed solution, stir at 30-35° C. for 1-2 hours, filter, and dry to obtain a modified filler.

5. The method for preparing a solvent-free defoamer according to claim 4, characterized in that: The modifier is a mixture of hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.3-0.

6.

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

7. The method for preparing a solvent-free defoamer according to claim 4, characterized in that: The mass ratio of silicon dioxide, titanium dioxide and calcium carbonate is 1:1.4-1.6:0.3-0.

5.

8. The method for preparing a solvent-free defoamer according to claim 7, characterized in that: 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.

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