CN111484630A - A kind of polymer emulsion type defoamer and preparation method thereof - Google Patents

Abstract

The invention provides a polymer emulsion type defoamer and a preparation method thereof. The components include an active substance, filler particles, water and a thickener, wherein the active substance is composed of acrylate, allyl polyether and catalyst. The introduction of allyl polyether containing hydrophilic functional groups in the acrylate polymer segment, the introduction of allyl polyether in the synthesis process solves the environmental protection problems caused by the use of harmful solvents such as toluene in the traditional acrylate synthesis process; The bond addition reaction forms a polymer polymer with self-emulsifying function, which can be emulsified in water to form emulsions with different particle size ranges; the polymer emulsion can self-emulsify itself to form an emulsion, which solves the problem of traditional silicone emulsion type elimination. The foaming agent uses some emulsifiers to cause a series of problems such as oil drift, precipitation, and demulsification.

Description

A kind of polymer emulsion type defoamer and preparation method thereof

technical field

The invention relates to a polymer emulsion type defoamer and a preparation method. The polymer emulsion is an important fine chemical additive, and therefore, the invention belongs to the technical field of fine chemical preparations.

Background technique

Papermaking is a key industry in national economic production. In the paper industry, various surfactants, such as defoamers, are often used. Most of the foam in industrial production will bring great harm, such as reducing the working efficiency of the machine, delaying the working time, affecting the quality of the final product, etc. The method of eliminating harmful foam generally adopts the method of adding defoamer. Depending on the defoaming composition, defoaming agents are divided into several main types, such as non-silicon type and silicone type. Compared with other defoamers, silicone-based defoamers have stable chemical properties, stable chemical resistance, less side effects, and at the same time, they have good instantaneous defoaming ability under the condition of very low dosage, so they are very popular. The non-silicon defoamer uses mineral oil, polyether, amide or fatty alcohol, acrylate as the active substance. When used in a large amount, the active substance amide will gradually aggregate, coagulate, and leave spots on the paper; and mineral oil is in the Under prolonged high temperature conditions, tetrachlorodibenzo-p-dioxin (TCDD) harmful substances will be produced, endangering personal safety and environmental safety. Silicone defoamers use polysiloxane, fillers, etc. as active substances. Long-term use will lead to the agglomeration of hydrophobic particles, which will then adhere to the paper and form silicon spots, resulting in a decrease in paper quality.

Patent US5152925A introduces a defoamer with a polyacrylate as the main defoaming active substance, wherein the acrylate polymer is mainly a hydroxyl-containing acrylate monomer in the solvent diisodecyl phthalate (DIDP) Acrylate polymers prepared in solvents such as DIOP or DIOP are used as the main active substances, and are used in papermaking black liquor washing and other papermaking processes. Patent CN102428142B also mentions using acrylate polymer as active material to prepare bulk defoamer, wherein acrylate polymer is composed of monomers such as isooctyl acrylate, hydroxy acrylate and acrylic acid in polybutene or polyether solvent, etc. Preparation, the prepared acrylate polymer is used as the main active component of the defoamer, and is compounded with defoaming aids such as white carbon black and alkyl silicone oil, which are used in oil exploration, water treatment, coating industry and ink, food and Beverage processing, drilling, textile, paper and other industries. The emergence of this type of defoamer can solve the problem of silicon precipitation and residual of traditional silicone defoamer, but the defoaming and antifoaming performance of the defoamer prepared by the current technology still has a lot of room for improvement. Therefore, it is of great significance to improve the defoaming performance of acrylate polymer defoamer.

SUMMARY OF THE INVENTION

The present invention solves the above-mentioned problems, and proposes an emulsion-type defoamer based on a polymer as an active substance. Advantages of the present invention:

(1) By introducing an allyl polyether containing a hydrophilic functional group into the acrylate polymer segment, a self-emulsifying polymer polymer is formed through a double bond addition reaction, which is adjusted by the content of the catalyst and the reaction time. The size of the molecular weight makes it have a certain range of viscosity, and can be emulsified in water to form emulsions with different particle size ranges.

(2) The allyl polyether introduced into the polymer can adjust the hydrophilic and hydrophobic balance (HLB) of the molecular structure by using (OCH ₂ CH ₂ ) _a and (OCH ₂ CHCH ₃ ) _b in its structure, The increase of (OCH ₂ CH ₂ ) _a can significantly improve the hydrophilic properties, and (OCH ₂ CHCH ₃ ) _b can adjust the hydrophobic properties, thereby realizing the self-emulsification of molecular structures to form emulsions.

(3) In the synthesis process, the viscosity of allyl polyether is small, which not only acts as a reaction monomer, but also functions as a reaction solvent, which solves the environmental protection problems caused by the use of harmful solvents such as toluene in the traditional acrylate synthesis process.

(4) Since the polymer emulsion can self-emulsify to form an emulsion, it solves a series of problems such as oil drift, precipitation and demulsification caused by the use of some emulsifiers in traditional silicone emulsion defoamer.

In order to achieve the above-mentioned effects, the technical scheme of a polymer emulsion type defoamer and preparation method of the present invention is as follows:

A polymer emulsion type defoamer is composed of the following components: active matter accounts for 10-35% of the total mass of the defoamer, filler particles account for 3-8% of the total mass of the defoamer, and water accounts for the total mass of the defoamer 60-85% of the total mass of the defoamer, and the thickener accounts for 0.5-3% of the total mass of the defoamer;

A polymer emulsion type defoamer and a preparation method thereof, wherein the active material is composed of acrylate, allyl polyether, and a catalyst, wherein the acrylate accounts for 29-70% of the total mass of the active material, and the allyl polyether It accounts for 29-70% of the total mass of the active substance, and the catalyst accounts for 0.5-2% of the total mass of the active substance;

A polymer emulsion type defoamer and preparation method, the acrylate is selected from hydroxyethyl acrylate, methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, octadecyl acrylate, isooctyl acrylate One or two or more are mixed in any proportion;

A polymer emulsion type defoamer and a preparation method, wherein the filler particles are selected from hydrophobic silica, titanium dioxide, magnesium oxide, aluminum oxide, ethylenediamine bis-stearic acid amide (EBS), and aluminum stearate. one or more;

In a polymer emulsion type defoamer and a preparation method, the filler particles have a specific surface area of 150-500 m ² /g;

A polymer emulsion type defoamer and its preparation method, the thickener is polyacrylamide, carbomer, xanthan gum, polyacrylate, methyl cellulose, carboxymethyl cellulose, hydroxyethyl One or more of cellulose and ethyl cellulose;

A polymer emulsion type defoamer and preparation method, the general structural formula of the allyl polyether is as follows:

_{CH2 = CHCH2} ( _OCH2CH2 ) _{a ( OCH2CHCH3} ) _b wherein a is an integer of 1-10 and b is an integer of 10-100.

A polymer emulsion type defoamer and a preparation method, the catalyst is selected from 2,2'-azobis(2-methylpropionitrile), 2-ethylhexyl peroxide tert-butyl ester, tertiary peroxide Butyl, one of 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), and benzoyl peroxide;

A method for preparing a polymer emulsion type defoamer, comprising the following steps:

(1) Preparation of active substances: add acrylate and catalyst into the flask, stir for 30-90min, drop the above mixture into the reactor containing allyl polyether, the reaction temperature is 60-100℃, and the reaction time is added dropwise. 2-8h;

(2) Put the active substance, filler particles, and thickener in a high-speed agitator, the stirring speed is 1500-2500rpm, slowly drop in water, and after the stirring time is 30-120min, the polymer emulsion defoamer is obtained.

Detailed ways

Embodiment 1.

(1) Preparation of active substances: 10 g of hydroxyethyl acrylate, 19 g of isooctyl acrylate, 1 g of catalyst 2,2'-azobis(2-methylpropionitrile) were added to the flask, and the mixture was stirred for 30 min. It was dropped into a reactor containing 70g of allyl polyether CH ₂ =CHCH ₂ (OCH ₂ CH ₂ )(OCH ₂ CHCH ₃ ) ₁₀₀ , the reaction temperature was 60°C, and the dropwise reaction time was 8h;

(2) Put 10g of active substance, 8g of hydrophobic silica (specific surface area of 150m ² /g), 1g of polyacrylamide, and 2g of polyacrylate in a high-speed stirrer, the stirring speed is 1500rpm, and slowly drop 79g of water. , and after stirring for 120 min, a polymer emulsion defoamer was obtained, which was denoted as A.

Embodiment two,

(1) Preparation of active substances: 70g of ethyl acrylate and 1g of catalyst tert-butyl 2-ethylhexyl peroxide were added to the flask, and the stirring time was 90min, and the above mixture was dropped into the mixture containing 29g of allyl polyether CH ₂ = In the reactor of CHCH ₂ (OCH ₂ CH ₂ ) ₁₀ (OCH ₂ CHCH ₃ ) ₁₀ , the reaction temperature is 100°C, and the dropwise addition reaction time is 2h;

(2) Put 35g of active material, 3g of titanium dioxide (specific surface area of 300m ² /g), and 0.5g of polyacrylamide in a high-speed stirrer, the stirring speed is 2500rpm, slowly drop 61.5g of water, and after stirring for 30min, obtain Polymer emulsion defoamer, denoted as B.

Embodiment three,

(1) Preparation of active substances: add 10 g of lauryl acrylate, 35 g of butyl acrylate, and 0.5 g of catalyst benzoyl peroxide into the flask, stir for 60 min, and drop the above mixture into the flask containing 54.5 g of allyl polyether CH ₂ In the reactor of =CHCH ₂ (OCH ₂ CH ₂ ) ₅ (OCH ₂ CHCH ₃ ) ₅₀ , the reaction temperature was 80°C, and the dropwise addition reaction time was 5h;

(2) Place 34g of active substance, 2g of ethylenediamine bis-stearic acid amide (specific surface area of 200 m ² /g), 3g of aluminum stearate (specific surface area of 300 m ² /g), and 1g of xanthan gum. In the high-speed stirrer, the stirring speed is 2000 rpm, and 60 g of water is slowly added dropwise. After the stirring time is 80 min, the polymer emulsion defoamer is obtained, which is denoted as C.

Embodiment four,

(1) Preparation of active substance: add 60g methyl acrylate, 5g octadecyl acrylate, 2g catalyst 2,2'-azobis(2-methylbutyronitrile) into the flask, stir for 50min, add dropwise the above mixture into a reactor containing 33g of allyl polyether CH ₂ =CHCH ₂ (OCH ₂ CH ₂ ) ₈ (OCH ₂ CHCH ₃ ) ₆₅ , the reaction temperature was 70°C, and the dropwise addition reaction time was 4h;

(2) Put 10.5g active material, 1.5g carbomer, 1.5g magnesium oxide (specific surface area of 250 m ² /g), and 1.5g alumina (specific surface area of 300 m ² /g) in a high-speed mixer , the stirring speed is 2300rpm, and 85g of water is slowly dripped into it. After the stirring time is 100min, the polymer emulsion defoamer is obtained, which is denoted as D.

Embodiment five,

(1) Preparation of active substances: add 10 g of hydroxyethyl acrylate, 10 g of isooctyl acrylate, 10 g of butyl acrylate, and 1.5 g of tert-butyl peroxide into the flask, stir for 40 min, and drop the above mixture into the flask containing 48.5 g of alkene. In the reactor of propyl polyether CH ₂ =CHCH ₂ (OCH ₂ CH ₂ ) ₃ (OCH ₂ CHCH ₃ ) ₃₂ , the reaction temperature is 70°C, and the dropwise addition reaction time is 7h;

(2) Put 22g of active material, 6g of aluminum stearate (specific surface area of 350 m ² /g), and 2g of carboxymethyl cellulose in a high-speed mixer, the stirring speed is 1600rpm, slowly drop 70g of water, and stir. After 50 minutes, a polymer emulsion defoamer is obtained, which is denoted as E.

Comparative Example 1

(1) Preparation of active substances: add 40 g of hydroxyethyl acrylate, 58 g of isooctyl acrylate, and 2 g of catalyst 2,2'-azobis(2-methylpropionitrile) into the flask, stir evenly, and heat up to the reaction temperature 60℃, the reaction time is 8h;

(2) Put 10g of active substance, 8g of hydrophobic silica (specific surface area of 150m ² /g), 1g of polyacrylamide, and 2g of polyacrylate in a high-speed stirrer, the stirring speed is 1500rpm, and slowly drop 79g of water. , and after stirring for 120 min, a polymer defoamer was obtained, denoted as F.

Comparative Example 2

(1) Preparation of active substances: 70g of ethyl acrylate and 1g of catalyst tert-butyl 2-ethylhexyl peroxide were added to the flask, and the stirring time was 90min, and the above mixture was dropped into the mixture containing 29g of allyl polyether CH ₂ = In the reactor of CHCH ₂ (OCH ₂ CH ₂ ) ₁₀₀ (OCH ₂ CHCH ₃ ) ₂₀₀ , the reaction temperature is 100°C, and the dropwise addition reaction time is 2h;

(2) Put 35g of active material, 3g of titanium dioxide (specific surface area of 300m ² /g), and 0.5g of polyacrylamide in a high-speed stirrer, the stirring speed is 2500rpm, slowly drop 61.5g of water, and after stirring for 30min, obtain Polymer defoamer, denoted as G.

Comparative Example 3

(1) Preparation of active substances: add 10 g of lauryl acrylate, 35 g of butyl acrylate, and 0.5 g of catalyst benzoyl peroxide into the flask, stir for 60 min, and drop the above mixture into the flask containing 54.5 g of allyl polyether CH ₂ In the reactor of =CHCH ₂ (OCH ₂ CH ₂ ) ₅ (OCH ₂ CHCH ₃ ) ₃ , the reaction temperature is 80°C, and the dropwise addition reaction time is 5h;

(2) Place 34g of active substance, 2g of ethylenediamine bis-stearic acid amide (specific surface area of 200 m ² /g), 3g of aluminum stearate (specific surface area of 300 m ² /g), and 1g of xanthan gum. In the high-speed stirrer, the stirring speed was 2000 rpm, and 60 g of water was slowly added dropwise. After the stirring time was 80 min, a polymer defoamer was obtained, which was denoted as H.

Comparative Example 4

Prepared according to Example 1 in patent CN109929120A, denoted as I.

Anti-foaming performance test:

The performance comparison test method of defoamer is as follows

Using self-prepared cork liquor, the defoaming and anti-foaming properties of sample A-sample I were tested in a circulating bubbler. Inject 600mL of cork liquor into a rigid glass cylinder with an inner diameter of 5cm in the circulating bubbler, raise the temperature and maintain it at 80°C, turn on the liquid circulation switch, and control the flow to 6L/min. When the foam height in the glass cylinder rises to 300mL, Inject 0.4mL of defoamer and start timing, while recording the foam height, until the foam height rises to 300mL again, stop the liquid circulation. After adding the defoamer, the faster the foam drops to 250mL, and the lower the minimum foam height, the better the defoaming performance; the longer the time required for the foam to rise to 300mL again, the better the defoamer composition. . The test results are shown in Table 1.

Table 1. Comparison of defoamer properties

In data table 1, it can be seen that the polymer emulsion type defoamer sample A-sample E has excellent defoaming and foam-suppressing effect in the papermaking black liquor test. The defoaming speed of sample I is slow in the early stage, and the foam recovery speed is fast in the later stage.

Claims (7)

1. The polymer emulsion type defoaming agent is characterized by comprising the following components in parts by weight: the active matter accounts for 10-35% of the total mass of the defoaming agent, the filler particles accounts for 3-8% of the total mass of the defoaming agent, the water accounts for 60-85% of the total mass of the defoaming agent, and the thickening agent accounts for 0.5-3% of the total mass of the defoaming agent;

the polymer emulsion type defoaming agent comprises an active matter, allyl polyether and a catalyst, wherein the active matter comprises 29-70% of acrylate, 29-70% of allyl polyether and 0.5-2% of catalyst, wherein the acrylate accounts for the total mass of the active matter;

a polymer emulsion type defoaming agent and a preparation method thereof comprise the following preparation steps:

(1) preparation of active matter: adding acrylate and a catalyst into a flask, stirring for 30-90min, dripping the mixture into a reactor containing allyl polyether, wherein the reaction temperature is 60-100 ℃, and the dripping reaction time is 2-8 h;

(2) and (3) placing the active substance, the filler particles and the thickening agent into a high-speed stirrer at the stirring speed of 1500-2500rpm, slowly dripping water, and stirring for 30-120min to obtain the polymer emulsion defoaming agent.

2. A polymer emulsion defoaming agent as claimed in claim 1 wherein said acrylate is selected from the group consisting of hydroxyethyl acrylate, methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, stearyl acrylate and isooctyl acrylate, and is mixed in any proportion.

3. The polymer emulsion defoaming agent according to claim 1 and its preparation method, wherein said filler particles are selected from one or more of hydrophobic white carbon black, titanium dioxide, magnesium oxide, aluminum oxide, Ethylenediamine Bisstearamide (EBS), and aluminum stearate.

4. The polymer emulsion-type defoaming agent according to claim 3 wherein the specific surface area of the filler particles is 150 to 500m 2/g.

5. The polymeric emulsion defoaming agent according to claim 1, wherein said thickener is one or more selected from the group consisting of polyacrylamide, carbomer, xanthan gum, polyacrylate, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and ethyl cellulose.

6. The polymeric emulsion defoamer as claimed in claim 1, wherein said allyl polyether has the following general structural formula: CH2= CHCH2(OCH2CH2) a (OCH2CHCH3) b wherein a is an integer from 1 to 10 and b is an integer from 10 to 100.

7. A polymer emulsion defoaming agent and a preparation method thereof as claimed in claim 1 wherein said catalyst is selected from one of 2,2 ' -azobis (2-methylpropanenitrile), tert-butyl peroxy-2-ethylhexyl, tert-butyl peroxide, 2,2 ' -azobis (2, 4-dimethylvaleronitrile), 2,2 ' -azobis (2-methylbutyronitrile) and benzoyl peroxide.