CN105498303B - A kind of organic silicon defoamer and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of defoamers and their preparation, and relates to a composite silicone defoamer and a preparation method thereof. The weight percentage of each component in the silicone defoamer is: distilled water 48%-54%, silicon dioxide 1.1%-2.48%, simethicone 38%-48.5%, emulsifier 1%-3%, co-emulsifier 1%-6%, stabilizer 0.5%-1%, the total weight percentage is 100%; when preparing , first prepare the main defoamer with silicon dioxide and simethicone oil, then add distilled water, co-emulsifier, emulsifier and stabilizer to the reaction device in proportion to complete dissolution, and then add the main defoamer for emulsification, that is The organosilicon defoamer is obtained; the preparation process is simple, the raw materials are easy to obtain, and the cost is low. The prepared organosilicon defoamer has the characteristics of high efficiency, stability, alkali resistance and heat resistance while maintaining good defoaming and antifoaming performance.

Description

A kind of organosilicon defoamer and preparation method thereof

Technical field:

The invention belongs to the technical field of defoamers and their preparation, and relates to a compound type silicone defoamer and a preparation method thereof.

Background technique:

Since Quincke, a German experimental physicist, first proposed to use chemical methods to defoam, it has undergone four updates so far. The first generation of defoamers are organic substances such as mineral oil, fatty acids and fatty acid esters, fatty amides, and lower alcohols. The ability is poor; the second-generation defoamer is a polyether defoamer, mainly including linear polyether and polyether or end-group esterified polyether derivatives with alcohol and ammonia as initiators. Strong, it is the leading defoamer used in the fermentation industry at present, but the foam breaking rate is low, and a certain amount of defoamer needs to be added. In order to meet the defoaming requirements and changing operating conditions, a silicone defoamer has been developed That is, the third-generation defoamer. The silicone defoamer is generally polydimethylsiloxane, and dimethyl silicone oil belongs to the MDnM type linear polymethylsiloxane, and the molecule is easy to bend. "Zigzag chain, this kind of defoamer has a high defoaming efficiency, but the foam suppression effect is sometimes unsatisfactory. Therefore, silicone can be compounded with fatty acid amide, polyether and other surfactants with defoaming and antifoaming activity to form a composite defoamer, which can not only improve the antifoaming ability of the silicone defoamer, but also reduce the product the cost of. The fourth-generation defoamer is a polyether-modified polysiloxane defoamer, which is introduced into a polyether segment through modification on the polysiloxane segment. This kind of defoamer is resistant to high temperature and strong alkali, and can be quickly dissolved in water. It can be used alone or in combination with other treatment agents. It has good stability, no demulsification and oil drift, and no sediment. Also effective for non-aqueous systems. Chinese patent CN103074784 proposes a composite silicone defoamer with starch as a stabilizer, which increases the stability of the product and can prevent the occurrence of coagulation and demulsification, but due to the large amount of stabilizer, the defoaming Performance deterioration; Chinese patent CN104225965 proposes an emulsion-type silicone defoamer using high-boiling silicone oil as one of the raw materials, which reduces production costs and provides a reasonable treatment channel for the by-product high-boiler treatment of organic silicon monomers; Polyvinyl alcohol (PVA) is a thickener, but it will produce foam in the process of dissolving in water, which will reduce the production capacity and affect the quality and use of products; Chinese patent CN103603215 proposes to make siloxane Particles are not easily broken in a strong acid-base system, and the product can be used under harsh conditions, but the production cost is high and the preparation process is relatively complicated; CN103830938 proposes to use nonionic surfactants as emulsifiers, which can be Tween-60, At least any one of Span-40 or polyether silicone oil has high emulsifying ability, but the product has poor alkali resistance and high cost.

Contents of the invention

The object of the present invention is to overcome the shortcoming that prior art exists, seek design and provide a kind of organic silicon antifoaming agent and preparation method thereof, the prepared organic silicon antifoaming agent has strong defoaming and strong antifoaming ability, also has Good stability, good anti-dilution ability and wide range of pH and temperature.

In order to achieve the above object, the organosilicon defoamer of the present invention includes distilled water, simethicone, silicon dioxide, emulsifier, co-emulsifier and stabilizer; its weight percentage of each component is: distilled water 48%-54% , silicon dioxide 1.1%-2.48%, simethicone 38%-48.5%, emulsifier 1%-3%, co-emulsifier 1%-6%, stabilizer 0.5%-1%, the total weight percentage is 100 %.

The emulsifier of the present invention is an anionic surfactant, which is sodium dodecylsulfonate or sodium dodecylbenzenesulfonate.

The co-emulsifier in the present invention is one or two of AEO-9 and tributyl phosphate, and its hydrophilic-lipophilic balance (HLB) is 7-9.

The stabilizer of the present invention is carboxymethylcellulose sodium salt 800-1200.

The specific preparation steps of organosilicon defoamer of the present invention are:

(1) Preparation of the main defoamer: In the existing reaction device with heating and stirring functions, add 3-5 parts by mass of silicon dioxide solid powder, and slowly add 100 parts by mass of dimethyl Silicone oil, react at 180°C for 3 hours to obtain a good performance main defoamer (silicone paste), cool the main defoamer to 80°C for later use;

(2) Compound emulsification: Add distilled water accounting for 48%-54% of the total product to the existing reaction device with heating and stirring functions, and heat it to 80°C, and then add 1%-6% co-emulsifier in turn , 1%-3% emulsifier and 0.5%-1% stabilizer, after completely dissolving to obtain a mixed solution, slowly add the main defoamer which is cooled to 80°C and accounts for 40%-48% of the total product weight After emulsifying for 0.5-1h, stop heating, homogenize and cool to room temperature naturally to obtain a silicone defoamer in the form of a white viscous emulsion.

Compared with the prior art, the present invention uses dimethyl silicone oil as a raw material and adds silicon dioxide as an auxiliary agent, and the hydroxyl groups on the surface of the silicon dioxide are beneficial to the dispersion of silicone oil, which can improve the defoaming performance of silicone oil; The surface tension of water, the addition of anionic surfactants for wetting, penetration and emulsification make the emulsifier less foaming force and better emulsifying ability. At the same time through the compounding of various emulsifiers, there are AEO-9, sodium dodecylsulfonate or sodium dodecylbenzenesulfonate, sodium carboxymethylcellulose 800-1200 (CMC) and tributyl phosphate , enhance the balance and stability of the hydrophilic and lipophilic system, and improve the overall performance of the emulsion, such as alkali resistance and heat resistance. In addition, adding a thickener carboxymethylcellulose sodium salt 800-1200 (CMC) increases the viscosity of the dispersion medium and further increases the stability of the emulsion; the preparation process is simple, the raw materials are easy to obtain, and the cost is low. The prepared silicone While maintaining good defoaming and antifoaming properties, the defoamer has the characteristics of high efficiency, stability, alkali resistance and heat resistance.

detailed description:

Below by embodiment the present invention will be further described.

Example 1:

The process of preparing the organosilicon defoamer in this embodiment is:

(1). Preparation of the main defoamer: In the existing reaction device with heating and stirring functions, add 3 parts of silicon dioxide solid powder by mass, and slowly add 100 parts of mass simethicone under stirring, React at a temperature of about 180°C for 3 hours to obtain a main defoamer (silicone paste) with good performance, and cool the main defoamer to about 80°C for later use;

(2). Preparation of defoamer: add distilled water accounting for 49% of the total mass of the final product into the existing reaction device with heating and stirring functions and heat it to 80°C, then add 2% dodecylsulfonic acid in turn Sodium, 2.5% tributyl phosphate, 0.8% carboxymethyl cellulose sodium salt 800-1200 (CMC) and 2.2% AEO-9, add 43.5% main defoamer after complete dissolution, keep warm and Stir at about 2000r/min to fully emulsify for 50 minutes, then stop stirring and cool to room temperature to obtain a silicone defoamer in the form of a white viscous emulsion.

The process of preparing the organosilicon defoamer in this embodiment is:

(1). Preparation of the main defoamer: In the existing reaction device with heating and stirring functions, add 5 parts of silicon dioxide solid powder by mass, and slowly add 100 parts by mass of simethicone under stirring, React at a temperature of about 180°C for 3 hours to obtain a main defoamer (silicone paste) with good performance, and cool the main defoamer to about 80°C for later use;

(2).Preparation of defoamer: Add distilled water accounting for 54% of the total mass of the final product into the existing reaction device with heating and stirring functions and heat it to 80°C, then add 2.2% dodecylsulfonic acid in turn Sodium, 2.5% tributyl phosphate, 0.6% carboxymethylcellulose sodium salt 800-1200 (CMC) and 0.7% AEO-9, add 40% main defoamer after complete dissolution, keep warm and Stir at about 2000r/min to fully emulsify for 60 minutes, then stop stirring and cool to room temperature to obtain a silicone defoamer in the form of a white viscous emulsion.

Example 3:

The process of preparing the organosilicon defoamer in this embodiment is:

(1). Preparation of the main defoamer: In the existing reaction device with heating and stirring functions, add 3 parts of silicon dioxide solid powder by mass, and slowly add 100 parts of mass simethicone under stirring, React at a temperature of about 180°C for 3 hours to obtain a main defoamer (silicone paste) with good performance, and cool the main defoamer to about 80°C for later use;

(2).Preparation of defoamer: Add distilled water accounting for 50% of the total mass of the final product into the existing reaction device with heating and stirring functions and heat it to 80°C, then add 1% dodecylbenzenesulfonate in sequence sodium phosphate, 3% tributyl phosphate and 0.8% carboxymethyl cellulose sodium salt 800~1200 (CMC), add 45.2% main defoamer after complete dissolution, keep warm and stir at about 2000r/min After fully emulsifying for 30 minutes, stop stirring and cool to room temperature to obtain a silicone defoamer in the form of a white viscous emulsion.

Example 4:

The process of preparing the organosilicon defoamer in this embodiment is:

(1). Preparation of the main defoamer: In the existing reaction device with heating and stirring functions, add 4 parts of silicon dioxide solid powder by mass, and slowly add 100 parts of mass simethicone under stirring, React at a temperature of about 180°C for 3 hours to obtain a main defoamer (silicone paste) with good performance, and cool the main defoamer to about 80°C for later use;

(2).Preparation of defoamer: add distilled water accounting for 52% of the total mass of the final product into the existing reaction device with heating and stirring functions and heat it to 80°C, then add 3% dodecylbenzenesulfonate in sequence sodium phosphate, 1% tributyl phosphate, 0.5% carboxymethylcellulose sodium salt 800-1200 (CMC) and 3% AEO-9, add 40.5% main defoamer after complete dissolution, after heat preservation Stir at about 2000r/min to fully emulsify for 40 minutes, then stop stirring and cool to room temperature to obtain a silicone defoamer in the form of a white viscous emulsion.

Example 5:

The process of preparing the organosilicon defoamer in this embodiment is:

(1). Preparation of the main defoamer: In the existing reaction device with heating and stirring functions, add 3 parts of silicon dioxide solid powder by mass, and slowly add 100 parts of mass simethicone under stirring, React at a temperature of about 180°C for 3 hours to obtain a main defoamer (silicone paste) with good performance, and cool the main defoamer to about 80°C for later use;

(2). Preparation of defoamer: add distilled water accounting for 49.5% of the total mass of the final product into the existing reaction device with heating and stirring functions and heat it to 80°C, then add 2.2% dodecylbenzenesulfonate in sequence Sodium phosphate, 2.5% tributyl phosphate, 0.6% sodium carboxymethyl cellulose 800-1200 (CMC) and 2.2% AEO-9, add 40.5% main defoamer after complete dissolution, after heat preservation Stir at about 2000r/min to fully emulsify for 30 minutes, then stop stirring and cool to room temperature to obtain a silicone defoamer in the form of a white viscous emulsion.

The optimal conditions for the preparation of the silicone defoamer in this example: the HLB is between 7 and 9, the stirring temperature is about 80° C., and the stirring speed is about 2000 r/min.

In this example, the prepared silicone defoamer was tested for its stability, alkali resistance, ATSC (acetone thiosemicarbazone) resistance, defoaming speed, heat resistance and defoaming performance under alkaline conditions, specifically:

(1) Centrifugal stability test: Centrifuge the product and sample at 3000r/min, and the test time is 20min without delamination;

(2) Alkali resistance test: 80 mL of the prepared defoamer emulsion and a mixed aqueous solution with a mass fraction of sodium hydroxide of 5% were placed in a 100 mL beaker, stirred with a magnetic stirrer under high shear force for ten minutes, and then left to stand. Observe the properties of the solution after 24 hours, no wax formation;

(3) Resistance to ATSC (acetone thiosemicarbazone) test: 80 mL of a mixed aqueous solution of 5% by weight of silicone defoamer, sodium hydroxide and ATSC is placed in a 100 mL beaker, under high shear force Stir with a magnetic stirrer for ten minutes and then stand still, observe the properties of the solution after 24 hours, no stratification, no wax formation;

(4) Defoaming speed test: Prepare the prepared defoamer and water to make a diluent containing 1% defoamer for later use, put the bubbler sand core into a 500mL graduated cylinder, add a surfactant containing 1% by mass When the foaming solution reaches the 200mL mark, start the air pump to bubble, stop bubbling when the foam height reaches 500mL, inject 25mL of the prepared 1% defoamer solution diluent into the measuring cylinder and time it at the same time, until the foam disappears Time is the defoaming time, repeated 3 times to get the average value;

(5) Heat resistance test: Take the prepared silicone defoamer in a test tube and place it in an oven. When the temperature rises to 110°C, start timing, cool down to room temperature after 2 hours, and take out the sample to observe the high temperature resistance;

(6) Defoaming test under alkaline conditions: Add 50mL of foaming solution containing 1% surfactant with pH=14 in a 100mL graduated cylinder and shake for 30 times, then add 0.2mL of defoaming agent Make a dilution containing 1% of the antifoaming agent silicone antifoaming agent to measure the remaining foam volume.

Claims (1)

1. a preparation method of organosilicon defoamer, is characterized in that concrete preparation steps are: (1). Preparation of the main defoamer: In the existing reaction device with heating and stirring functions, add 3 parts of silicon dioxide solid powder by mass, and slowly add 100 parts of mass simethicone under stirring, React at a temperature of about 180°C for 3 hours to obtain a main defoamer with good performance, and cool the main defoamer to 80°C for later use; (2). Preparation of defoamer: add distilled water accounting for 49% of the total mass of the final product into the existing reaction device with heating and stirring functions and heat it to 80°C, then add 2% dodecylsulfonic acid in turn Sodium, 2.5% tributyl phosphate, 0.8% carboxymethylcellulose sodium salt 800-1200 and 2.2% AEO-9, add 43.5% main defoamer after complete dissolution, keep warm and heat at 2000r/ Min stirring to make it fully emulsified for 50 minutes, then stop stirring and cool to room temperature to obtain a silicone defoamer in the form of a white viscous emulsion.