Preparation method of organic silicon emulsion defoaming agent for metal cleaning agent

Abstract

The invention relates to the technical field of chemical engineering, in particular to a preparation method of an organic silicon emulsion defoaming agent for a metal cleaning agent, and the defoaming agent is prepared from water-based silicon emulsion XWC-3627, methyl organic silicon body emulsion XWC-T950, large-viscosity organic methyl sulfide resin XWC-2067 and the like. The dispersing performance is good, the dispersing performance is good in water and cleaning agents with different pH values, and precipitation and separation are avoided; the defoaming speed is high, and rapid descending of foam can be obviously observed when the defoaming agent is added into a system with higher foam height; the foam inhibition effect is good, foam in a system can still be well eliminated after multiple times of oscillation by using an oscillation method, and the height of the foam can be maintained at a certain scale for a long time in the later period of testing by using a spraying method. The product has a good foam inhibition effect on foam generated in an industrial cleaning process, the foam in a system can still be well eliminated after multiple times of oscillation by using an oscillation method, and the height of the foam can be maintained at a certain scale for a long time in the later period of testing by using a spraying method.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, in particular to an organosilicon emulsion defoamer for metal cleaning agents and a preparation method thereof. The defoamer can efficiently and quickly eliminate foam generated by the metal cleaning agent during use, thereby improving cleaning efficiency and quality. Background Art

[0002] At present, when eliminating the foam generated in the metal cleaning industry and general industrial cleaning processes, the most commonly used defoaming agents are polyether-modified silicone and organosilicon defoaming agents provided by Dow Chemical. This defoaming agent achieves the defoaming effect by significantly reducing the local surface tension of the foam, causing the local foam to be strongly pulled and extended to the surroundings and finally burst.

[0003] Although the defoamers for cleaning agents currently provided by Dow Chemical are resistant to strong alkalis and have strong defoaming properties, experiments have found that they still have defects such as poor dispersibility and poor anti-foaming performance in neutral and alkaline cleaning agents. When the amount of defoamer added to the alkaline cleaning agent is 0.2% to 0.6%, the defoaming speed of the Dow cleaning agent is faster, but there are more white floating substances precipitated in the system, and after multiple shock tests, the Dow defoamer cannot completely defoam. In addition, as the pH of the cleaning agent system gradually decreases to neutral, the defoaming effect of the Dow defoamer in the system will gradually deteriorate. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing a silicone emulsion defoamer for metal cleaning agents to solve the following four problems: 1. Good dispersibility is required in the cleaning agent system with a pH of 7 to 14. When the defoamer addition amount is 0.2% to 0.6%, there is no obvious white precipitation or white flocculent floating in the system; 2. There needs to be an obvious defoaming effect. When using the oscillation method or spray method to test, it can be clearly observed that the foam height in the system decreases or remains at a low level; 3. It needs to have a good anti-foaming effect, and still have a good defoaming effect on the system after multiple or long-term tests; 4. It is commonly used in various cleaning agent systems, such as industrial cleaning agents, metal cleaning agents, surfactant cleaning agents, etc. When the system changes, the defoaming effect needs to be maintained at a relatively stable level.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A method for preparing an organosilicon emulsion defoamer for metal cleaning agents, characterized in that: The raw material quality formula is: Water-based silicone emulsion XWC-3627: 20%~25% Methyl silicone bulk emulsion XWC-T950: 75%~80% High viscosity organic methyl sulfide resin XWC-2067: Add 8% to 12% on the basis of the mass of water-based silicone emulsion XWC-3627 and methyl silicone bulk emulsion XWC-T950; Its preparation method is: S1: Heat the water-based silicone emulsion XWC-3627 and the methyl silicone bulk emulsion XWC-T950 to 80-95°C respectively, then mix and stir evenly to obtain a mixed solution A; S2: Add high viscosity organic methyl sulfide resin XWC-2067 to mixed solution A, stirring while adding to mix evenly; S3: Heat to 100-120°C and stir until a milky white semi-viscous emulsion is obtained.

[0006] Preferably, the raw material quality formula is: Water-based silicone emulsion XWC-3627: 25% Methyl silicone bulk emulsion XWC-T950: 75% High viscosity organic methyl sulfide resin XWC-2067: Add 12% additionally to the mass and basis of water-based silicone emulsion XWC-3627 and methyl silicone bulk emulsion XWC-T950.

[0007] Preferably, R29 thickener equivalent to 3-5% by weight is added to the semi-viscous emulsion obtained in step S3, and stirred evenly.

[0008] Furthermore, methanol or polyethanol or a mixture of the two is added to the mixed solution to which the R29 thickener is added to adjust the content of the effective ingredients of the emulsion.

[0009] Methyl silicone bulk emulsion XWC-T950: It has a foam breaking effect, and its small molecular structure ensures good dispersibility and defoaming effect.

[0010] Water-based silicone emulsion XWC-3627: It has the advantages of both silicone and polyether, has good temperature and alkali resistance, can show excellent anti-foaming effect in both water and oil phases, and enhances the dispersion stability of the system.

[0011] High viscosity organic methyl sulfide resin XWC-2067: Through its extremely small surface tension and high viscosity characteristics, it effectively suppresses foam generation and improves the foam suppression effect.

[0012] Advantages of the present invention: 1. Good dispersibility, it can be well dispersed in water and cleaning agents of different pH values ​​without precipitation or separation; 2. Fast defoaming. When added into the system with high foam height, the rapid decrease of foam can be clearly observed; 3. The foam suppression effect is good. After multiple shocks using the shock method, the foam in the system can still be eliminated well. In the later stage of the spray method test, the foam height can be maintained at a certain scale for a long time.

[0013] The product of the present invention has a good foam suppression effect on the foam generated in the industrial cleaning process. After multiple vibrations using the vibration method, the foam in the system can still be eliminated well. In the later stage of the spray method test, the foam height can be maintained at a certain scale for a long time. DETAILED DESCRIPTION

[0014] A method for preparing an organosilicon emulsion defoamer for metal cleaning agents, wherein the raw materials are weighed according to the following raw material quality formula: Water-based silicone emulsion XWC-3627: 25% Methyl silicone bulk emulsion XWC-T950: 75% High viscosity organic methyl sulfide resin XWC-2067: Add 12% additionally to the mass and basis of water-based silicone emulsion XWC-3627 and methyl silicone bulk emulsion XWC-T950; Preparation method: S1: Heat the water-based silicone emulsion XWC-3627 and the methyl silicone bulk emulsion XWC-T950 to 80-95°C respectively, then mix and stir evenly for 30-40 minutes to obtain a mixed solution A; S2: Add high viscosity organic methyl sulfide resin XWC-2067 to mixed solution A, stirring for 20-30 minutes while adding to mix evenly; S3: Heat to 100-120°C and stir for 40-60 minutes until a milky white semi-viscous emulsion is obtained.

[0015] More preferably, R29 thickener equivalent to 3% by weight and appropriate amount of methanol / ethanol are added to the compounded milky white semi-viscous emulsion to adjust the content of the effective ingredient of the emulsion to obtain a sample.

[0016] When the defoamer is added to a metal cleaning agent containing foam, its low surface tension silicone component will quickly spread on the foam surface to form a thin film. This film will destroy the liquid film structure of the foam, causing the foam to lose stability and burst quickly.

[0017] At the same time, the addition of high-viscosity methyl sulfide resin increases the viscosity and cohesion of the defoamer, which helps the durability and stability of the defoamer in the foam system and prevents foam regeneration.

[0018] The stirring and heating process helps the components to fully react and merge to form a uniform emulsion, thereby improving the overall performance and effect of the defoamer.

[0019] In summary, the preparation method of the organosilicon emulsion defoamer achieves effective control of the foam in the metal cleaning agent by means of reasonable selection and proportioning of raw materials, heating and mixing, and adding thickeners.

[0020] Sample test: 1. Take 10-20 g of cleaning agent as the base, add 0.2%-0.6% of defoaming agent, shake until completely dispersed, transfer to a shake bottle and dilute 10-20 times with water. Shake the shake bottle at room temperature for 5-20 seconds respectively, and observe the foam height and foam falling speed in the shake bottle.

[0021] Take 10-20 g of cleaning agent as the base, add 0.2%-0.6% defoaming agent, shake until completely dispersed, dilute 10-20 times and transfer to the spray device, record the initial liquid level height, and record the time taken for the foam liquid level to reach each scale after starting spraying.

[0022] Spray test data (foam height-time): Spraying method: Place the diluted liquid under the same conditions in the spraying device, record the initial liquid level height, and record the time it takes for the foam liquid level to reach each scale after starting to spray.

[0023] Dow defoamer for cleaning machine: 275mL-6s; 300mL-8s; 325mL-10s; 350mL-12s; 375mL-14s; 400mL-17s; 425mL-21s; 450mL-27s; 460mL-3min; 470mL-5min The present invention prepares defoamer: 275mL-8s; 300mL-9s; 325mL-12s; 350mL-13s; 375mL-15s; 400mL-17s; 425mL-20s; 450mL-26s; 455mL-3min; 460mL-5min.

Claims

1. A method for preparing a silicone emulsion defoamer for metal cleaning agents, characterized in that: The raw material quality formula is: Water-based silicone emulsion XWC-3627: 20%~25% Methyl silicone bulk emulsion XWC-T950: 75%~80% High viscosity organic methyl sulfide resin XWC-2067: Add 8% to 12% on the basis of the mass of water-based silicone emulsion XWC-3627 and methyl silicone bulk emulsion XWC-T950; Its preparation method is: S1: Heat the water-based silicone emulsion XWC-3627 and the silicone emulsion XWC-T950 to 80-95°C respectively, then mix and stir evenly to obtain a mixed solution A; S2: Add high viscosity methyl sulfide resin XWC-2067 to mixed solution A, stirring while adding to mix evenly; S3: Heat to 100-120°C and stir until a milky white semi-viscous emulsion is obtained.

2. The method for preparing a silicone emulsion defoamer for metal cleaning agents according to claim 1, characterized in that: The raw material quality formula is: Water-based silicone emulsion XWC-3627: 25% Methyl silicone bulk emulsion XWC-T950: 75% High viscosity organic methyl sulfide resin XWC-2067: Add 12% additionally to the mass and basis of water-based silicone emulsion XWC-3627 and methyl silicone bulk emulsion XWC-T950.

3. The method for preparing a silicone emulsion defoamer for metal cleaning agents according to claim 1, characterized in that: Add 3-5% of the mass of R29 thickener to the semi-viscous emulsion obtained in step S3, and stir evenly.

4. The method for preparing a silicone emulsion defoamer for metal cleaning agents according to claim 3, characterized in that: Methanol or ethanol or a mixture of the two is added to the mixed solution to which R29 thickener is added to adjust the content of the effective ingredients of the emulsion.

5. The method for preparing a silicone emulsion defoamer for metal cleaning agents according to claim 3, characterized in that A method for preparing a silicone emulsion defoamer for metal cleaning agents, characterized in that: The raw material quality formula is: Water-based silicone emulsion XWC-3627: 20%% Methyl silicone bulk emulsion XWC-T950: 80% High viscosity organic methyl sulfide resin XWC-2067: Add 12% additionally to the mass and basis of water-based silicone emulsion XWC-3627 and methyl silicone bulk emulsion XWC-T950.