Preparation method of compound siloxane modified defoaming agent

Abstract

The invention relates to the technical field of auxiliary chemicals, in particular to a preparation method of a compound siloxane modified defoaming agent, which is prepared from the following raw materials: paraffin oil, modified silicon resin polyether microemulsion, octamethylcyclotetrasiloxane, polyether polyol, polyether amine D-400, a silane coupling agent KH-560, an emulsifier AEO-9, hydrophilic silicon dioxide and hydrophobic silicon dioxide. The modified defoaming agent with excellent defoaming performance is prepared by stirring, mixing and reacting. According to the defoaming agent, foam is effectively controlled and eliminated under the combined action of various mechanisms such as foam surface tension reduction, permeation and diffusion, foam structure damage, interfacial film strength enhancement and particle effect enhancement. The defoaming agent has the advantages of being excellent in defoaming effect and stability, suitable for multiple industries such as chemical engineering, spinning, papermaking and food, environmentally friendly in component and capable of meeting the requirement of the modern industry for environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of chemical additives, and in particular to a method for preparing a highly efficient, stable and non-stratified composite defoaming siloxane modified defoaming agent. The defoaming agent is particularly suitable for various industrial fields such as rubber emulsions, coatings, adhesives, etc., so as to solve the problems of poor compatibility, easy stratification and insufficient defoaming performance of existing defoaming agents. Background Art

[0002] Mineral oil defoamers are mixtures, and their basic ingredients include mineral oil, hydrophobic particles, synergists and emulsifiers. Among them, hydrophobic particles include white carbon black, fatty acid soaps, and fatty acid amides. Synergists are basically achieved by modifying the components of silicone to improve the defoaming and anti-foaming functions, but while improving the foam control ability, it will bring problems such as shrinkage holes, fish eyes, and shrinkage edges. Another defect of mineral oil products is that they are easy to stratify, and hydrophobic particles will settle. In severe cases, a "cake" phenomenon will appear at the bottom of the packaging barrel, which will greatly affect the application effect. Therefore, the existing technology has not yet solved the common problems of compatibility and defoaming performance balance in defoamers and the stratification problem of defoamers. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, one of the purposes of the present invention is to provide a method for preparing a composite siloxane-modified defoamer, which has good antifoaming performance, good compatibility, is not easy to stratify, has a simple preparation process, is easy to operate, and the obtained defoamer has good dispersibility, good compatibility and spreadability.

[0004] The technical solution of the present invention is as follows: A method for preparing a composite siloxane-modified defoamer, characterized in that: The raw material quality formula is: Paraffin oil 60-80 parts Modified silicone resin polyether microemulsion (FM-550) 15-20 parts 4-6 parts of octamethylcyclotetrasiloxane Polyether polyol 8-12 parts Polyetheramine D-400 10-15 parts Silane coupling agent KH-560 1-2 parts Emulsifier AEO-9 3-5 parts 1-1.5 parts of hydrophilic silica 1-1.5 parts hydrophobic silica The preparation method comprises the following steps: S1: Add octamethylcyclotetrasiloxane and emulsifier AEO-9 to paraffin oil, stir at 60-80°C until dispersed, and react at 80-90°C for 3-4 hours to obtain siloxane-modified paraffin oil; S2: Add polyether polyol to the silicone-modified paraffin oil, and stir and mix evenly at 80-90°C; S3: Add polyetheramine D-400, modified silicone resin polyether microemulsion (FM-550), and silane coupling agent KH-560 to the mixture in step S2, stir and react at 80-90°C for 1-1.5 hours, add hydrophilic silica and hydrophobic silica, continue stirring and reacting for 2-3 hours, and obtain the product.

[0005] A method for preparing a composite siloxane-modified defoamer, characterized in that: The raw material quality formula is: 60 parts paraffin oil Modified silicone resin polyether microemulsion (FM-550) 15 parts 4 parts of octamethylcyclotetrasiloxane 8 parts of polyether polyol Polyetheramine D-400 10 parts Silane coupling agent KH-560 1 part Emulsifier AEO-9 3 parts 1 part hydrophilic silica 1 part of hydrophobic silica.

[0006] The method for preparing a composite siloxane-modified defoamer is characterized in that: The raw material quality formula is: 80 parts paraffin oil Modified silicone resin polyether microemulsion (FM-550) 20 parts 6 parts of octamethylcyclotetrasiloxane 12 parts of polyether polyol Polyetheramine D-400 15 parts Silane coupling agent KH-560 2 parts Emulsifier AEO-9 5 parts 1.5 parts of hydrophilic silicon dioxide 1.5 parts of hydrophobic silica.

[0007] The method for preparing a composite siloxane-modified defoamer is characterized in that: The raw material quality formula is: 70 parts paraffin oil Modified silicone resin polyether microemulsion (FM-550) 18 parts 5 parts of octamethylcyclotetrasiloxane 10 parts of polyether polyol Polyetheramine D-400 12 parts Silane coupling agent KH-560 1.5 parts Emulsifier AEO-9 4 parts 1.2 parts of hydrophilic silica 1.2 parts of hydrophobic silica.

[0008] A method for preparing a composite siloxane-modified defoamer, characterized in that the preparation method comprises the following steps: S1: Add octamethylcyclotetrasiloxane and emulsifier AEO-9 to paraffin oil, stir at 70-80°C until dispersed, and react at 85-90°C for 3 hours to obtain siloxane-modified paraffin oil; S2: Add polyether polyol to the silicone-modified paraffin oil, and stir and mix evenly at 85-90°C; S3: Add polyetheramine D-400, modified silicone resin polyether microemulsion (FM-550), and silane coupling agent KH-560 to the mixture in step S2, stir and react at 85-90°C for 1.5 hours, add hydrophilic silica and hydrophobic silica, continue stirring and reacting for 2-3 hours, and obtain the product.

[0009] The defoaming mechanism of the composite siloxane-modified defoamer of the present invention is mainly based on the following aspects: Surface tension reduction: The paraffin oil, modified silicone resin polyether microemulsion (FM-550) and octamethylcyclotetrasiloxane in the defoamer have low surface tension. When these ingredients are covered on the foam surface, they can significantly reduce the surface tension of the foam, making the foam unstable and easy to break.

[0010] Permeation and Diffusion: The addition of emulsifier AEO-9 helps the defoamer component to be evenly dispersed and penetrated in the foam system. As an emulsifier, AEO-9 can improve the compatibility between the components, making it easier for the defoamer to penetrate into the foam and destroy the stability of the foam.

[0011] Destroy the foam structure: Polyether compounds such as polyether polyols and polyetheramine D-400 have long molecular chains and a certain hydrophile-lipophile balance (HLB value). They can penetrate into the liquid film of the foam and destroy the liquid film structure of the foam through intermolecular interactions such as hydrogen bonds and van der Waals forces, causing the foam to lose stability.

[0012] Enhanced interfacial film strength: The addition of silane coupling agent KH-560 can enhance the interfacial film strength between the defoamer and the foam system to a certain extent. Although this sounds contrary to defoaming, in fact, an appropriate amount of interfacial film strength enhancement can prevent the defoamer from being quickly discharged by the foam, thereby extending the action time of the defoamer and improving the defoaming efficiency.

[0013] Particle Effects: The addition of hydrophilic silica and hydrophobic silica provides a particle effect for the defoamer. These silica particles can be adsorbed on the foam surface or liquid film to form a solid film, further reducing the stability of the foam. At the same time, the presence of particles can also increase the rate of foam drainage and accelerate the bursting of the foam.

[0014] In summary, the compound siloxane modified defoamer of this formula achieves effective control and elimination of foam through multiple mechanisms such as reducing foam surface tension, penetration and diffusion, destroying foam structure, enhancing interfacial film strength and particle effect.

[0015] The various components in the present invention act together on the foam system, which can quickly reduce the surface tension of the foam and destroy the stability of the foam, thereby achieving an excellent defoaming effect.

[0016] The ingredients such as polyether polyol and polyether amine D-400 in the formula of the present invention, as well as the addition of emulsifier AEO-9, help to improve the stability of the defoamer and prevent the delamination, precipitation and the like during storage and use.

[0017] The invention has excellent defoaming performance and stability, and can therefore be widely used in various occasions requiring defoaming, such as chemical, textile, papermaking, food and other industries.

[0018] Most of the components of the invention are environmentally friendly materials and will not cause harm to the environment and human body. At the same time, the defoamer will not produce harmful substances during use, which meets the requirements of modern industry for environmental protection. DETAILED DESCRIPTION

[0019] A method for preparing a composite siloxane-modified defoamer comprises weighing the following raw materials: 600g paraffin oil Modified silicone resin polyether microemulsion (FM-550) 180g Octamethylcyclotetrasiloxane 60g Polyether polyol 100g Polyetheramine D-400 120g Silane coupling agent KH-560 2g Emulsifier AEO-9 5g Hydrophilic silica 1.5 g Hydrophobic silica 1.5 g The preparation method comprises the following steps: S1: Add octamethylcyclotetrasiloxane and emulsifier AEO-9 to paraffin oil, stir until dispersed at 60-80°C, and react at 80-90°C for 3-4 hours to obtain modified paraffin oil; D4 is a low-viscosity siloxane with good fluidity and lubricity. D4 molecules interact with paraffin oil molecules to change the viscosity and fluidity of paraffin oil.

[0020] S2: Add polyether polyol to the modified paraffin oil, and stir and mix evenly at 80-90°C; S3: Add modified silicone resin polyether microemulsion (FM-550), polyetheramine D-400, and silane coupling agent KH-560 to the mixture of step S2, stir and react at 80-90°C for 1-1.5 hours, add hydrophilic silica and hydrophobic silica, continue stirring and reacting for 2-3 hours, and the defoaming agent of the present invention is obtained.

[0021] FM-550 may be a polymer containing silicon-oxygen bonds and ether bonds, which plays a role in compatibilization, dispersion and stabilization in the system. NH 2) and ether bonds (− O −), reacts with the epoxy or silane groups in the silane coupling agent KH-560 to undergo an amination reaction. The surface properties of the silica products are regulated. The hydrophilic silica surface is rich in hydroxyl groups and is easy to interact with water or other polar solvents; while the hydrophobic silica is surface treated to reduce the number of hydroxyl groups and increase compatibility with organic matter. The silica particles may be combined with other components in the system through the bridging effect of the silane coupling agent KH-560, which is conducive to the formation of a stable complex.

[0022] The samples produced by the present invention were tested: A certain amount of the defoamer of the present invention is weighed and put into styrene-butadiene latex, wherein the amount of the defoamer added is 0.2 to 0.6 of the styrene-butadiene latex, and after being kept at a constant temperature of 60-80° C. for ten minutes, the defoamer is quickly shaken up and down for 20-30 times using a defoamer test stand, and the defoaming is observed and the defoaming time is recorded.

[0023] result: The average defoaming time is 15s, which is faster and more water-soluble than the common defoamers on the market.

[0024] The following table shows the defoaming performance test of the samples of the present invention. .

Claims

1. A method for preparing a composite siloxane-modified defoamer, characterized in that: The raw material quality formula is: Paraffin oil 60-80 parts Modified silicone resin polyether microemulsion (FM-550) 15-20 parts 4-6 parts of octamethylcyclotetrasiloxane Polyether polyol 8-12 parts Polyetheramine D-400 10-15 parts Silane coupling agent KH-560 1-2 parts Emulsifier AEO-9 3-5 parts 1-1.5 parts of hydrophilic silica 1-1.5 parts hydrophobic silica The preparation method comprises the following steps: S1: Add octamethylcyclotetrasiloxane and emulsifier AEO-9 to paraffin oil, stir at 60-80°C until dispersed, and react at 80-90°C for 3-4 hours to obtain siloxane-modified paraffin oil; S2: Add polyether polyol to the silicone-modified paraffin oil, and stir and mix evenly at 80-90°C; S3: Add polyetheramine D-400, modified silicone resin polyether microemulsion (FM-550), and silane coupling agent KH-560 to the mixture in step S2, stir and react at 80-90°C for 1-1.5 hours, add hydrophilic silica and hydrophobic silica, continue stirring and reacting for 2-3 hours, and obtain the product.

2. The method for preparing a composite siloxane-modified defoamer according to claim 1, characterized in that: The raw material quality formula is: 60 parts paraffin oil Modified silicone resin polyether microemulsion (FM-550) 15 parts 4 parts of octamethylcyclotetrasiloxane 8 parts of polyether polyol Polyetheramine D-400 10 parts Silane coupling agent KH-560 1 part Emulsifier AEO-9 3 parts 1 part hydrophilic silica 1 part of hydrophobic silica.

3. The method for preparing a composite siloxane-modified defoamer according to claim 1, characterized in that: The raw material quality formula is: 80 parts paraffin oil Modified silicone resin polyether microemulsion (FM-550) 20 parts 6 parts of octamethylcyclotetrasiloxane 12 parts of polyether polyol Polyetheramine D-400 15 parts Silane coupling agent KH-560 2 parts Emulsifier AEO-9 5 parts 1.5 parts of hydrophilic silica 1.5 parts of hydrophobic silica.

4. The method for preparing a composite siloxane-modified defoamer according to claim 1, characterized in that: The raw material quality formula is: 70 parts paraffin oil Modified silicone resin polyether microemulsion (FM-550) 18 parts 5 parts of octamethylcyclotetrasiloxane 10 parts of polyether polyol Polyetheramine D-400 12 parts Silane coupling agent KH-560 1.5 parts Emulsifier AEO-9 4 parts 1.2 parts of hydrophilic silica 1.2 parts of hydrophobic silica.

5. The method for preparing a composite siloxane-modified defoamer according to claim 1, characterized in that: The preparation method comprises the following steps: S1: Add octamethylcyclotetrasiloxane and emulsifier AEO-9 to paraffin oil, stir at 70-80°C until dispersed, and react at 85-90°C for 3 hours to obtain siloxane-modified paraffin oil; S2: Add polyether polyol to the silicone-modified paraffin oil, and stir and mix evenly at 85-90°C; S3: Add polyetheramine D-400, modified silicone resin polyether microemulsion (FM-550), and silane coupling agent KH-560 to the mixture in step S2, stir and react at 85-90°C for 1.5 hours, add hydrophilic silica and hydrophobic silica, continue stirring and reacting for 2-3 hours, and obtain the product.