A kind of silicone defoamer for PVC and preparation method thereof

Abstract

The invention discloses an organosilicon defoamer for PVC and a preparation method thereof, and relates to an industrial defoamer. The organosilicon defoamer of the present invention comprises the following components by mass percentage: 10-20% of the main defoamer; 5-10% of the auxiliary defoamer; 1-2% of suspended and stable water; 70-80% of deionized water ; Acid-base regulator 1 to 3%. The preparation method is as follows: first, add the stabilized jelly mother liquid into the ion-free water, stir for 15-20 minutes, add an acid-base regulator, slowly adjust the pH of the stabilized water to 6-7, and the solution becomes transparent when the pH of the stabilized water is stable , and then add the main defoamer modified silicon and the auxiliary defoamer water-soluble ether, stir for 25 to 30 minutes, and finally prepare the silicone defoamer through shearing treatment. The organosilicon antifoaming agent for PVC of the present invention can make the antifoaming agent have a good antifoaming effect under high temperature conditions, and the production process is simple and the storage is stable.

Description

technical field

[0001] The invention belongs to the technical field of defoamers for industrial use, and more specifically relates to a silicone defoamer for PVC and a preparation method thereof. Background technique

[0002] In the process of producing PVC resin by the suspension method, a large amount of dispersant is added to the polymerization kettle. Under the action of high temperature stirring, a large amount of foam will be generated in the polymerization kettle, and vinyl chloride monomer is entrained in the foam, which occurs on the top of the kettle and the surface of the condenser. The polymerization reaction produces a large amount of sticky wall matter and blocks the header leading to the reflux condenser from the top of the kettle, seriously affecting the normal progress of the polymerization reaction in the kettle. In addition, if the foam cannot be quickly eliminated, it will lead to the occurrence of foam overflow in the polymerization tank, and during the ...

Examples

Embodiment 1

[0034] The preparation method of a silicone defoamer for PVC in this embodiment comprises the following steps: adding 1% polyacrylic acid mother liquor into 75% deionized water, stirring for 20 minutes, and then adding 1% acid-base adjustment Slowly adjust the pH of the stable water to 6. When the pH of the stable water is stable, the solution is transparent. Stir for 10 minutes. Add 15% of the main defoamer polyether silicone oil and 8% of the auxiliary defoamer. Water-soluble ether, stirred for 30 minutes, then sheared for 10 minutes.

[0035] Sample performance test:

[0036] 1. Thermal stability:

[0037] After the sample was placed in an oven at a temperature of 100 degrees for 1 hour, it was observed that there was no layered precipitation in the sample aqueous solution.

[0038] 2. Normal temperature stability test

[0039] Place the sample at room temperature for 3 months, the sample has no delamination phenomenon, and the state is good and the fluidity is good.

...

Embodiment 2

[0043] The preparation method of a silicone defoamer for PVC in this embodiment comprises the following steps: adding 1.5% polyacrylic acid mother liquor into 75% deionized water, stirring for 20 minutes, adding 1.5% acid-base regulator hydrogen Sodium oxide solution, adjust the pH of the stable water to be 6, when the pH of the stable water is stable, the solution is transparent, add 13% of the main defoamer modified silicon (polyether silicone oil), 9% of the auxiliary defoamer water-soluble ether , stirred for 30 minutes, then sheared for 10 minutes. The stability and the defoaming and anti-foaming effect of the defoamer obtained in this embodiment are closer to those in Example 1.

Embodiment 3

[0045] A preparation method of a silicone defoamer for PVC in this embodiment comprises the following steps: adding 2% polyacrylic acid mother liquor into 79% deionized water, stirring for 15 minutes, adding 2% hydrogen as an acid-base regulator Sodium oxide solution, adjust the pH of the stable water to be 7, when the pH of the stable water is stable, the solution is transparent, add 10% of the main defoamer modified silicon (polyether silicone oil), 7% of the auxiliary defoamer water-soluble ether , stirred for 25 minutes, then sheared for 5 minutes. The stability and the defoaming and anti-foaming effect of the defoamer obtained in this embodiment are closer to those in Example 1.

technical field

[0001] The invention belongs to the technical field of defoamers for industrial use, and more specifically relates to a silicone defoamer for PVC and a preparation method thereof. Background technique

[0002] In the process of producing PVC resin by the suspension method, a large amount of dispersant is added to the polymerization kettle. Under the action of high temperature stirring, a large amount of foam will be generated in the polymerization kettle, and vinyl chloride monomer is entrained in the foam, which occurs on the top of the kettle and the surface of the condenser. The polymerization reaction produces a large amount of sticky wall matter and blocks the header leading to the reflux condenser from the top of the kettle, seriously affecting the normal progress of the polymerization reaction in the kettle. In addition, if the foam cannot be quickly eliminated, it will lead to the occurrence of foam overflow in the polymerization tank, and during the ...

Examples

Embodiment 1

[0034] The preparation method of a silicone defoamer for PVC in this embodiment comprises the following steps: adding 1% polyacrylic acid mother liquor into 75% deionized water, stirring for 20 minutes, and then adding 1% acid-base adjustment Slowly adjust the pH of the stable water to 6. When the pH of the stable water is stable, the solution is transparent. Stir for 10 minutes. Add 15% of the main defoamer polyether silicone oil and 8% of the auxiliary defoamer. Water-soluble ether, stirred for 30 minutes, then sheared for 10 minutes.

[0035] Sample performance test:

[0036] 1. Thermal stability:

[0037] After the sample was placed in an oven at a temperature of 100 degrees for 1 hour, it was observed that there was no layered precipitation in the sample aqueous solution.

[0038] 2. Normal temperature stability test

[0039] Place the sample at room temperature for 3 months, the sample has no delamination phenomenon, and the state is good and the fluidity is good.

...

Embodiment 2

[0043] The preparation method of a silicone defoamer for PVC in this embodiment comprises the following steps: adding 1.5% polyacrylic acid mother liquor into 75% deionized water, stirring for 20 minutes, adding 1.5% acid-base regulator hydrogen Sodium oxide solution, adjust the pH of the stable water to be 6, when the pH of the stable water is stable, the solution is transparent, add 13% of the main defoamer modified silicon (polyether silicone oil), 9% of the auxiliary defoamer water-soluble ether , stirred for 30 minutes, then sheared for 10 minutes. The stability and the defoaming and anti-foaming effect of the defoamer obtained in this embodiment are closer to those in Example 1.

Embodiment 3

[0045] A preparation method of a silicone defoamer for PVC in this embodiment comprises the following steps: adding 2% polyacrylic acid mother liquor into 79% deionized water, stirring for 15 minutes, adding 2% hydrogen as an acid-base regulator Sodium oxide solution, adjust the pH of the stable water to be 7, when the pH of the stable water is stable, the solution is transparent, add 10% of the main defoamer modified silicon (polyether silicone oil), 7% of the auxiliary defoamer water-soluble ether , stirred for 25 minutes, then sheared for 5 minutes. The stability and the defoaming and anti-foaming effect of the defoamer obtained in this embodiment are closer to those in Example 1.

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