阅读说明：本技术 消泡剂及其制备方法和应用 (Defoaming agent and preparation method and application thereof ) 是由 杨磊 查汪敏 刘潇潇 李华杰 谢青宇 梁福根 李德品 其他发明人请求不公开姓名 于 2021-09-14 设计创作，主要内容包括：本发明涉及一种消泡剂及其制备方法和应用,所述消泡剂的制备方法包括如下步骤：将含氢硅油、烯丙基硅油和蓖麻醇混合,于第一温度下进行除杂质处理,得到混合物；将所述混合物与催化剂混合,于第二温度下进行反应,得到消泡剂活性物；以及将所述消泡剂活性物与溶剂、乳化剂混合,得到消泡剂。本发明所述消泡剂的制备工艺简单、无毒无害,并且制备得到的消泡剂活性物具有空间立体结构和良好配伍性,使得消泡剂的消泡能力强、在碱液体系中的相容性稳定,可用于聚丙烯酸酯乳液胶粘剂生产中的消泡。(The invention relates to a defoaming agent and a preparation method and application thereof, wherein the preparation method of the defoaming agent comprises the following steps: mixing hydrogen-containing silicone oil, allyl silicone oil and ricinol, and performing impurity removal treatment at a first temperature to obtain a mixture; mixing the mixture with a catalyst, and reacting at a second temperature to obtain an active matter of the defoaming agent; and mixing the defoaming agent active substance with a solvent and an emulsifier to obtain the defoaming agent. The preparation process of the defoaming agent is simple, nontoxic and harmless, and the prepared defoaming agent active substance has a spatial three-dimensional structure and good compatibility, so that the defoaming agent has strong defoaming capability and stable compatibility in an alkali liquor system, and can be used for defoaming in the production of polyacrylate emulsion adhesive.)

1. The preparation method of the defoaming agent is characterized by comprising the following steps:

mixing hydrogen-containing silicone oil, allyl silicone oil and ricinol, and performing impurity removal treatment at a first temperature to obtain a mixture;

mixing the mixture with a catalyst, and reacting at a second temperature to obtain an active matter of the defoaming agent; and

and mixing the defoaming agent active substance with a solvent and an emulsifier to obtain the defoaming agent.

2. The method for producing an antifoaming agent according to claim 1, wherein the molar ratio of the hydrogen-containing silicone oil to the allyl silicone oil is 1:0.3 to 1:0.8, and the molar ratio of the hydrogen-containing silicone oil to the ricinol is 1:0.5 to 1: 1.5.

3. The method for preparing the defoaming agent according to claim 1, wherein the hydrogen-containing silicone oil comprises at least one of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil, and the hydrogen content of the hydrogen-containing silicone oil is 0.05% -0.36%.

4. The method for preparing an antifoaming agent according to claim 1, wherein the allyl silicone oil includes at least one of a single-terminal allyl silicone oil, a double-terminal allyl silicone oil, and a side allyl silicone oil.

5. The method for preparing the defoaming agent according to claim 1, wherein the first temperature is 85 ℃ to 95 ℃, the impurity removal treatment is performed under a vacuum pressure condition of-0.09 MPa or less, and the time of the impurity removal treatment is 30min to 50 min; the second temperature is 90-125 ℃, the reaction is carried out in a protective gas environment, and the reaction time is 2-6 h.

6. The method for preparing the antifoaming agent according to claim 1, wherein the catalyst is selected from chloroplatinic acid, and the mass of the catalyst is 0.1% to 0.5% of the mass of the mixture.

7. An antifoaming agent obtained by the production method described in any one of claims 1 to 6.

8. The defoamer of claim 7, wherein the defoamer active is present in the defoamer in an amount of 20% to 50% by mass, the solvent is present in the defoamer in an amount of 40% to 75% by mass, and the emulsifier is present in the defoamer in an amount of 5% to 10% by mass.

9. Use of an antifoaming agent as claimed in any of claims 7 to 8 in the production of polyacrylate emulsion adhesives.

Technical Field

The invention relates to the technical research and development field of fine chemicals, in particular to a defoaming agent, a preparation method and application.

Background

Currently, in the spinning field, the spinning adhesive is usually a polyacrylate emulsion adhesive. In the preparation process of the polyacrylate emulsion adhesive, surfactants such as a dispersing agent, an emulsifying agent and the like are required to be added to enhance the stability of the emulsion. However, the addition of surfactants causes a large amount of large foam during the polymerization, discharge and downstream use of polyacrylate emulsion adhesives, which is not favorable for production control. The conventional solutions include reduction of stirring speed and discharge speed, standing, etc., but this affects production efficiency. Therefore, the most effective approach in the production of polyacrylate emulsion adhesives is to add a silicone defoamer.

However, the volatile organic solvent added in the production process of the polyacrylate emulsion adhesive can resolve part of active ingredients wrapping the organic silicon defoamer, so that the compatibility of the organic silicon defoamer is poor, the organic silicon defoamer is demulsified, and the production of the adhesive is influenced.

Disclosure of Invention

Based on the above, there is a need to provide a defoaming agent, a preparation method and application thereof; the defoaming agent active substance obtained by the preparation method has a spatial three-dimensional structure and good compatibility, so that the defoaming agent has strong compatibility and defoaming capability in an alkali liquor system, and can be used for defoaming in the production of polyacrylate emulsion adhesive.

A preparation method of the defoaming agent comprises the following steps:

mixing hydrogen-containing silicone oil, allyl silicone oil and ricinol, and performing impurity removal treatment at a first temperature to obtain a mixture;

mixing the mixture with a catalyst, and reacting at a second temperature to obtain an active matter of the defoaming agent; and

and mixing the defoaming agent active substance with a solvent and an emulsifier to obtain the defoaming agent.

In one embodiment, the molar ratio of the hydrogen-containing silicone oil to the allyl silicone oil is 1:0.3-1:0.8, and the molar ratio of the hydrogen-containing silicone oil to the ricinol is 1:0.5-1: 1.5.

In one embodiment, the hydrogen-containing silicone oil comprises at least one of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil, and the hydrogen content of the hydrogen-containing silicone oil is 0.05% -0.36%.

In one embodiment, the allyl silicone oil comprises at least one of a single-ended allyl silicone oil, a double-ended allyl silicone oil, and a lateral allyl silicone oil.

In one embodiment, the first temperature is 85-95 ℃, the impurity removal treatment is carried out under the vacuum pressure condition of-0.09 MPa or below, and the time of the impurity removal treatment is 30-50 min; the second temperature is 90-125 ℃, the reaction is carried out in a protective gas environment, and the reaction time is 2-6 h.

In one embodiment, the catalyst is selected from chloroplatinic acid, and the mass of the catalyst is 0.1-0.5% of the mass of the mixture.

The preparation method of the defoaming agent is ternary polymerization, under the action of a catalyst, double bonds in a molecular structure are opened by allyl silicone oil and ricinol in a ternary component, and are linked with hydrogen bonds in a hydrogen-containing silicone oil molecular structure, so that the defoaming agent active substance with a spatial three-dimensional structure is obtained. Compared with the defoaming agent active substance with a planar structure, the defoaming agent active substance with a spatial three-dimensional structure can reduce the surface tension and improve the chemical stability, so that the prepared defoaming agent has excellent compatibility and strong defoaming capability in an alkali liquor system. In addition, the ricinol monomer in the structure of the defoaming agent active substance has hydrophilic hydroxyl and carboxyl, so that the affinity of the defoaming agent active substance is stable, and the further emulsification and compounding of the defoaming agent active substance are facilitated.

An antifoaming agent obtainable by the above-described preparation method.

In one embodiment, the defoamer active is present in the defoamer in an amount of 20% to 50% by mass, the solvent is present in the defoamer in an amount of 40% to 75% by mass, and the emulsifier is present in the defoamer in an amount of 5% to 10% by mass.

The defoaming agent has good compatibility, the process that a volatile organic solvent permeates small liquid drops of the defoaming agent dispersed in a liquid phase and dissolves the internal defoaming agent active substances is slowed down, the solubility of the volatile organic solvent to the defoaming agent active substances in the small liquid drops of the defoaming agent dispersed in the liquid phase is reduced, the problems of demulsification and silicone oil precipitation of an organic silicon defoaming agent caused by the volatile organic solvent are effectively avoided, and the compatibility and defoaming capability of the defoaming agent in an alkali liquor system are remarkably improved by the defoaming agent active substances with a spatial three-dimensional structure in the defoaming agent.

The application of the defoaming agent in the production of the polyacrylate emulsion adhesive.

The defoaming agent is suitable for defoaming in the production and use processes of the polyacrylate emulsion adhesive, and can effectively solve the problem of demulsification of the defoaming agent caused by the fact that an organic solvent permeates small liquid drops of the defoaming agent dispersed in a liquid phase and dissolves active substances of the internal defoaming agent.

Detailed Description

The defoaming agent provided by the present invention, its preparation method and application will be further described below.

The preparation method of the defoaming agent provided by the invention comprises the following steps:

s1, mixing hydrogen-containing silicone oil, allyl silicone oil and ricinol, and removing impurities at a first temperature to obtain a mixture;

s2, mixing the mixture with a catalyst, and reacting at a second temperature to obtain an active matter of the defoaming agent; and

and S3, mixing the defoaming agent active substance with a solvent and an emulsifier to obtain the defoaming agent.

In step S1, in order to ensure the formation of a steric structure in the terpolymerization reaction, the molar ratio of the hydrogen-containing silicone oil to the allyl silicone oil is 1:0.3 to 1: 0.8; the molar ratio of the hydrogen-containing silicone oil to the ricinol is 1:0.5-1: 1.5.

Wherein the hydrogen-containing silicone oil comprises at least one of terminal hydrogen-containing silicone oil and side hydrogen-containing silicone oil. The content of hydroxyl groups in the hydrogen-containing silicone oil is further limited, the molecular weight of hydrogen is 1, the hydrogen content of the hydrogen-containing silicone oil is taken as a mass ratio and a molar ratio, and the hydrogen content of the hydrogen-containing silicone oil is 0.05-0.36%. The allyl silicone oil comprises at least one of single-end allyl silicone oil, double-end allyl silicone oil and side allyl silicone oil.

On the other hand, since the terpolymerization reaction requires a certain reaction temperature, the presence of low-boiling impurities in the mixed solution of the hydrogen-containing silicone oil, the allyl silicone oil, and the ricinol affects the terpolymerization reaction, and the purity of the product is reduced. Therefore, the mixed liquid of the hydrogen-containing silicone oil, the allyl silicone oil and the ricinol needs to be subjected to impurity removal treatment, wherein the first temperature is 85-95 ℃; the vacuum pressure condition of impurity removal treatment is below-0.09 MPa; the time for impurity removal treatment is 30min-50 min.

In step S2, the mixture of hydrogen-containing silicone oil, allyl silicone oil, and ricinol is subjected to a ternary polymerization reaction with the aid of a catalyst to synthesize the defoaming agent active compound.

Specifically, under the action of a catalyst, a C ═ C double bond contained in the molecular structure of the ricinol is opened, and is linked with a Si-H group in the molecular structure of the hydrogen-containing silicone oil to form a Si-C group. Similarly, the C ═ C double bond contained in the molecular structure of the allyl silicone oil is also opened by the action of the catalyst, and links with other Si — H groups in the molecular structure of the hydrogen-containing silicone oil to form Si — C groups. Therefore, the hydrogen-containing silicone oil, the allyl silicone oil and the ricinol are subjected to ternary polymerization to form the defoaming agent active substance with a spatial three-dimensional structure.

To further illustrate the ternary polymerization reaction process of the hydrogen-containing silicone oil, the allyl silicone oil and the ricinol, taking the hydrogen-containing silicone oil, the pendant allyl silicone oil and the ricinol containing both pendant hydrogen groups and terminal hydrogen groups as examples, the reaction equation of step S2 is shown in the following formula (1):

due to the fact that the positions of Si-H groups in the molecular structure of the hydrogen-containing silicone oil and C ═ C double bonds in the molecular structure of the allyl silicone oil are different, the defoaming agent active substances obtained after ternary polymerization reaction include, but are not limited to, any one of the following substances:

compared with the defoaming agent active substance with a planar structure, the defoaming agent active substance with a spatial three-dimensional structure can reduce the surface tension and improve the chemical stability, so that the prepared defoaming agent has excellent compatibility and strong defoaming capability in an alkali liquor system.

In addition, the ricinol monomer in the structure of the defoaming agent active substance has hydrophilic hydroxyl and carboxyl, so that the affinity of the defoaming agent active substance is stable, and the further emulsification and compounding of the defoaming agent active substance are facilitated.

In some embodiments, the catalyst is selected from chloroplatinic acid, the mass of the catalyst being 0.1% to 0.5% of the mass of the mixture.

In some embodiments, the second temperature is 90 ℃ to 125 ℃; the reaction of step S2 is performed under a protective gas environment, and the protective gas includes at least one of nitrogen and an inert gas, wherein the inert gas includes at least one of argon and helium, and the protective gas is further preferably nitrogen; the reaction time of the step S2 is 2-6 h.

In step S3, the solvent includes at least one of an alcohol organic solvent and deionized water, and in order to better achieve emulsification, the solvent includes an alcohol organic solvent and deionized water, and the mass ratio of the alcohol organic solvent to the deionized water is 1:0.5-1:2, preferably 1:1, wherein the alcohol organic solvent includes at least one of ethanol, propanol, butanol, pentanol, octanol, and further preferably at least one of ethanol and propanol.

By adding the emulsifier, the interfacial free energy can be reduced, and further the interfacial tension is reduced, so that two liquids which cannot be mixed together originally can be mixed together, wherein one phase of liquid is dispersed into a plurality of small liquid drops which are dispersed in the other phase of liquid to form an emulsion. Therefore, the emulsifier is an indispensable component for preparing the modified silicone oil defoaming agent and has an important effect on the stability of the defoaming agent. In order to enable the defoamer active matter to form a uniform and stable defoamer, the defoamer active matter and a solvent are emulsified and compounded by adopting an emulsifier to form an oil-in-water defoamer with an inner phase of oil and an outer phase of water, so that the defoamer can be uniformly dispersed in a defoamed solvent system to fully exert the defoaming effect.

Thus, in some embodiments, the emulsifier comprises at least one of fatty acid polyoxyethylene esters, fatty alcohol and ethylene oxide condensates comprising at least one of a103, a105, a115, nonylphenol polyoxyethylene ethers comprising at least one of MOA-3, MOA-15, fatty alcohol polyoxyethylene ethers comprising at least one of TX-10, TX-20, fatty alcohol polyoxyethylene ethers comprising at least one of O-10, O-20, fatty alcohol polyoxyethylene ethers. In order to realize the emulsification of the active matter of the defoaming agent and reduce the interfacial tension between water and oil phases, the formed defoaming agent is kept stable.

The invention also provides the defoaming agent prepared by the preparation method.

As some industrial preparations need to add volatile organic solvents in the production and use processes, the effect of quickly volatilizing residual monomers and organic components in the products is achieved. The addition of the volatile organic solvent is disadvantageous to the silicone defoamer, because the volatile organic solvent can permeate the outer surface of the small liquid drops of the silicone defoamer dispersed in the liquid phase, enter the small liquid drops of the defoamer dispersed in the liquid phase, dissolve the defoamer active matter in the small liquid drops of the defoamer dispersed in the liquid phase, and bring the silicone oil generated after dissolution out of the small liquid drops of the defoamer dispersed in the liquid phase, so that the demulsification phenomenon occurs; after the organic solvent is volatilized, the silicone oil which is carried out by the organic solvent and is dispersed outside the small liquid drops of the defoaming agent in the liquid phase can be mutually adsorbed and aggregated, finally, insoluble oily substances are generated in a defoaming solvent system, and silicon spots appear in the subsequent production and use processes, so that the whole industrial production process is influenced.

The defoaming agent disclosed by the invention contains a defoaming agent active component, so that the defoaming agent has good compatibility, the process that a volatile organic solvent permeates small droplets of the defoaming agent dispersed in a liquid phase and dissolves the internal defoaming agent active component is slowed down, the solubility of the volatile organic solvent to the defoaming agent active component in the small droplets of the defoaming agent dispersed in the liquid phase is reduced, the problems of demulsification and silicon oil precipitation of an organic silicon defoaming agent due to the volatile organic solvent are effectively avoided, and the compatibility and defoaming capability of the defoaming agent in an alkali liquor system are remarkably improved due to the defoaming agent active component with a spatial three-dimensional structure in the defoaming agent.

In some embodiments, the defoamer active is present in the defoamer in an amount of 20% to 50% by mass, the solvent is present in the defoamer in an amount of 40% to 75% by mass, and the emulsifier is present in the defoamer in an amount of 5% to 10% by mass.

The invention also provides an application of the defoaming agent in the production of the polyacrylate emulsion adhesive.

The defoaming agent is suitable for defoaming in the production and use processes of the polyacrylate emulsion adhesive, and can effectively solve the problem of demulsification of the defoaming agent caused by the fact that an organic solvent permeates small liquid drops of the defoaming agent dispersed in a liquid phase and dissolves active substances of the defoaming agent in the interior, so that the defoaming agent has higher defoaming speed and stronger defoaming capability, can reduce the using amount of the defoaming agent, is non-toxic and harmless when in use, and has little negative influence on the downstream spinning and spraying stages of the polyacrylate emulsion adhesive.

Hereinafter, the defoaming agent, the preparation method thereof and the application thereof will be further described by the following specific examples.

Example 1

Taking terminal hydrogen-containing silicone oil with hydrogen content of 0.1% as a preparation raw material, placing the terminal hydrogen-containing silicone oil, the terminal allyl silicone oil and the ricinol in a molar ratio of 1:0.3:1.5 into a reaction kettle, starting stirring, keeping at a constant temperature of 85 ℃ for 50min under a vacuum pressure condition of-0.09 MPa, and carrying out water removal and low-boiling-point impurity removal treatment. Then, the vacuum is turned off, chloroplatinic acid catalyst which accounts for 0.5 percent of the total mass of the system materials is added into the reaction kettle, the temperature is raised to 90 ℃ under the nitrogen protection environment, the constant temperature is kept for 2 hours, and the defoaming agent active substance is prepared after the reaction is finished. 20g of defoaming agent active matter, 75g of water-ethanol mixed solvent with the mass ratio of 1:1 and 5g of emulsifier are fully mixed for emulsification and compounding, and finally the defoaming agent is obtained.

Putting 100g of polyacrylate emulsion adhesive into a 250mL beaker, adding 2g of defoaming agent, stirring uniformly, heating to 80 ℃, keeping at a constant temperature for 2h, cooling, storing for 48h, observing the state of the polyacrylate emulsion adhesive in the beaker, and recording the compatibility of the defoaming agent in the polyacrylate emulsion adhesive, wherein the results are shown in Table 1.

50mL of the polyacrylate emulsion adhesive was placed in a 100mL measuring cylinder with a stopper, 0.05g of the defoamer was added and the flask was shaken, and the defoaming time was recorded, the results are shown in Table 1.

Taking a 2% NaOH aqueous solution, adding a 2% defoaming agent, uniformly stirring, standing for 24h, observing the state of the mixed solution, and recording the alkali liquor compatibility of the defoaming agent, wherein the results are shown in Table 1.

Example 2

Taking side hydrogen-containing silicone oil with hydrogen content of 0.36% as a preparation raw material, placing the side hydrogen-containing silicone oil, double-end allyl silicone oil and ricinol in a molar ratio of 1:0.5:1 into a reaction kettle, starting stirring, keeping at a constant temperature of 90 ℃ for 40min under a vacuum pressure condition of-0.09 MPa, and carrying out water removal and low-boiling-point impurity removal treatment. Then, the vacuum is turned off, chloroplatinic acid catalyst which accounts for 0.3 percent of the total mass of the system materials is added into the reaction kettle, the temperature is raised to 100 ℃ under the nitrogen protection environment, the temperature is kept for 4 hours at constant temperature, and the defoaming agent active substance is prepared after the reaction is finished. 30g of defoaming agent active matter, 62g of water-propanol mixed solvent with the mass ratio of 1:1 and 8g of emulsifier are fully mixed for emulsification and compounding, and finally the defoaming agent is obtained.

Putting 100g of polyacrylate emulsion adhesive into a 250mL beaker, adding 2g of defoaming agent, stirring uniformly, heating to 80 ℃, keeping at a constant temperature for 2h, cooling, storing for 48h, observing the state of the polyacrylate emulsion adhesive in the beaker, and recording the compatibility of the defoaming agent in the polyacrylate emulsion adhesive, wherein the results are shown in Table 1.

50mL of the polyacrylate emulsion adhesive was placed in a 100mL measuring cylinder with a stopper, 0.05g of the defoamer was added and the flask was shaken, and the defoaming time was recorded, the results are shown in Table 1.

Taking a 2% NaOH aqueous solution, adding a 2% defoaming agent, uniformly stirring, standing for 24h, observing the state of the mixed solution, and recording the alkali liquor compatibility of the defoaming agent, wherein the results are shown in Table 1.

Example 3

Taking side hydrogen-containing silicone oil with the hydrogen content of 0.15 percent as a preparation raw material, putting the side hydrogen-containing silicone oil, the double-end allyl silicone oil and the ricinol with the molar ratio of 1:0.8:0.5 into a reaction kettle, starting stirring, keeping the reaction kettle at the constant temperature of 95 ℃ for 30min under the vacuum pressure condition of-0.09 MPa, and carrying out water removal and low-boiling-point impurity removal treatment. Then, the vacuum is turned off, chloroplatinic acid catalyst which accounts for 0.1 percent of the total mass of the system materials is added into the reaction kettle, the temperature is raised to 125 ℃ under the nitrogen protection environment, the constant temperature is kept for 6 hours, and the defoaming agent active substance is prepared after the reaction is finished. And (3) removing the active matter of the defoaming agent by 50g, water by 40g and an emulsifier by 10g, fully mixing, emulsifying and compounding to finally obtain the defoaming agent.

Putting 100g of polyacrylate emulsion adhesive into a 250mL beaker, adding 2g of defoaming agent, stirring uniformly, heating to 80 ℃, keeping at a constant temperature for 2h, cooling, storing for 48h, observing the state of the polyacrylate emulsion adhesive in the beaker, and recording the compatibility of the defoaming agent in the polyacrylate emulsion adhesive, wherein the results are shown in Table 1.

50mL of the polyacrylate emulsion adhesive was placed in a 100mL measuring cylinder with a stopper, 0.05g of the defoamer was added and the flask was shaken, and the defoaming time was recorded, the results are shown in Table 1.

Taking a 2% NaOH aqueous solution, adding a 2% defoaming agent, uniformly stirring, standing for 24h, observing the state of the mixed solution, and recording the alkali liquor compatibility of the defoaming agent, wherein the results are shown in Table 1.

Comparative example 1

Taking 20g of conventional allyl polyether modified silicone oil, 75g of water-ethanol mixed solvent with the mass ratio of 1:1 and 5g of emulsifier, fully mixing, emulsifying and compounding to finally obtain the allyl polyether modified organic silicon defoamer.

Putting 100g of polyacrylate emulsion adhesive into a 250mL beaker, adding 2g of defoaming agent, stirring uniformly, heating to 80 ℃, keeping at a constant temperature for 2h, cooling, storing for 48h, observing the state of the polyacrylate emulsion adhesive in the beaker, and recording the compatibility of the defoaming agent in the polyacrylate emulsion adhesive, wherein the results are shown in Table 1.

50mL of the polyacrylate emulsion adhesive was placed in a 100mL measuring cylinder with a stopper, 0.05g of the defoamer was added and the flask was shaken, and the defoaming time was recorded, the results are shown in Table 1.

Taking a 2% NaOH aqueous solution, adding a 2% defoaming agent, uniformly stirring, standing for 24h, observing the state of the mixed solution, and recording the alkali liquor compatibility of the defoaming agent, wherein the results are shown in Table 1.

Comparative example 2

Taking terminal hydrogen-containing silicone oil with the hydrogen content of 0.1 percent as a preparation raw material, putting the terminal hydrogen-containing silicone oil, the terminal allyl silicone oil and the allyl polyether in a molar ratio of 1:0.5:1 into a reaction kettle, starting stirring, keeping at a constant temperature of 90 ℃ for 40min under the vacuum pressure condition of-0.09 MPa, and carrying out dewatering and low-boiling-point impurity removal treatment. Then, the vacuum is turned off, chloroplatinic acid catalyst which accounts for 0.3 percent of the total mass of the system materials is added into the reaction kettle, the temperature is raised to 100 ℃ under the nitrogen protection environment, the constant temperature is kept for 4 hours, and after the reaction is finished, the allyl polyether modified organic silicon defoamer active matter is prepared. Taking 30g of allyl polyether modified organic silicon defoamer active matter, 62g of water-propanol mixed solvent and 8g of emulsifier in a mass ratio of 1:1, fully mixing, emulsifying and compounding to finally obtain the defoamer.

Putting 100g of polyacrylate emulsion adhesive into a 250mL beaker, adding 2g of defoaming agent, stirring uniformly, heating to 80 ℃, keeping at a constant temperature for 2h, cooling, storing for 48h, observing the state of the polyacrylate emulsion adhesive in the beaker, and recording the compatibility of the defoaming agent in the polyacrylate emulsion adhesive, wherein the results are shown in Table 1.

50mL of the polyacrylate emulsion adhesive was placed in a 100mL measuring cylinder with a stopper, 0.05g of the defoamer was added and the flask was shaken, and the defoaming time was recorded, the results are shown in Table 1.

Taking a 2% NaOH aqueous solution, adding a 2% defoaming agent, uniformly stirring, standing for 24h, observing the state of the mixed solution, and recording the alkali liquor compatibility of the defoaming agent, wherein the results are shown in Table 1.

TABLE 1

As is clear from Table 1, first, since comparative example 1 is a conventional allyl polyether-modified silicone oil and does not have a steric defoaming agent active substance as in the defoaming agent of the present invention, its defoaming ability, compatibility and compatibility in alkaline solution are inferior to those of examples 1 to 3.

Second, comparative example 2 uses allyl polyether to replace ricinol as one of the raw materials of ternary polymerization reaction, and reacts with hydrogen-containing silicone oil and allyl silicone oil to prepare the allyl polyether modified organic silicon defoamer active substance, however, since allyl polyether is nonionic surfactant, has cloud point and water solubility is inversely proportional to temperature, as the temperature of polyacrylate emulsion adhesive system rises, the allyl polyether modified organic silicon defoamer active substance is changed from complete dissolution to partial dissolution, and the turbidity phenomenon occurs, and the compatibility is not good. In addition, the compatibility of the comparative example 2 in the alkali liquor in table 1 is combined, so that the compatibility of the defoaming agent in the comparative example 2 and the compatibility of the defoaming agent in the alkali liquor are poor, and the application in the production of the polyacrylate emulsion adhesive cannot be met.

Third, the example has a shorter defoaming time and a better defoaming capability than the blank and the comparative example. Moreover, in a polyacrylate emulsion adhesive system and an alkali liquor system, no floating and turbid phenomena appear in the examples, which shows that the three groups of examples have excellent and stable compatibility and defoaming property in the polyacrylate emulsion adhesive system.

Therefore, the defoaming agent prepared by the preparation method disclosed by the invention is high in defoaming speed and strong in defoaming capability, has excellent compatibility in a polyacrylic acid emulsion adhesive system, is stable in compatibility in an alkali liquor system, and can be used for defoaming in the production of polyacrylate emulsion adhesives.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.