KR20140103877A - Thickener by inverse emulsion synthetic and production method thereof - Google Patents

Abstract

Provided are a thickener by an inverse emulsion polymerization method and a production method thereof for the substitution of an alkaline swelling thickener or a cellulose-based thickener used to control flowability and physical properties of a common industrial product. The production method includes (a) preparing an aqueous phase having an unsaturated double bond; (b) preparing an organic solvent phase used as a dispersing medium; (c) preparing an emulsion of an initial emulsion state by adding the aqueous phase prepared in step (a) to the organic solvent phase prepared in step (b) and stirring the mixture at high speed; (d) performing a polymerization process by adding an initiator to the emulsion prepared in step (c) and increasing the temperature; and (e) aging for minimizing the remaining amount of unreacted monomers during the polymerization process in step (d) and for improving the stability. The viscosity, the flowability, and the workability during industrial mixing may be controlled.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thickener for inverse emulsion polymerization,

The present invention relates to a thickening agent by an inverse emulsion synthetic method and a method of preparing the same, and more particularly to a thickening agent by an inverse emulsion synthetic method and an alkaline swelling type thickening agent for controlling the flow of a product and a cellulose system And a method for producing the thickener by an inverse emulsion polymerization method.

The alkali-swelling thickener and the cellulose-based thickener used for industrial purposes are commonly used as thickeners for aqueous acrylic resins. However, due to consideration of pH dependency and dispersion stability, workability is difficult, stability after viscosity retention And there is a disadvantage that it is difficult to satisfy the user's rheological (rheological) requirements.

In order to compensate for this, the above-mentioned two types of thickening agents are mixed and used, but this is not a fundamental solution. A related solution is to provide a polymer dispersed in a non-aqueous medium. The method for this is to prepare a reversed-phase emulsion polymer by the reverse emulsion polymerization method and directly increase the viscosity by directly inputting in the thickening operation of the aqueous system.

Examples of such techniques are described in documents 1 and 2 below.

For example, the following Patent Document 1 discloses that a hydrophilic monomer having an unsaturated double bond such as acrylic acid, acrylamide and methacrylic acid, a hydrophobic monomer having an unsaturated double bond such as stearyl methacrylate, a reaction rate such as methylene bisacrylamide A rapid internal crosslinking agent and a slow external crosslinking agent such as glycidyl methacrylate are subjected to reversed phase emulsion polymerization, and the above reaction is divided into five steps, in which a part of the redox initiator is added in the initial stage and a part of the redox initiator , Part of the redox initiator in step 2, reverse phase emulsion polymerization of all of the azo initiator in step 3 and the remainder of the redox initiator in the last step to produce an acrylic water swellable thickener.

In Patent Document 2, 35 to 45% by weight of ion-exchanged water, 35 to 40% by weight of acrylic acid as main monomer, and 25 to 30% by weight of acrylamide are mixed and injected into a reactor, followed by stirring to prepare 100% 70 to 90% by weight of an ester-based oil Dysol 240 (Dsol-240), 5 to 15% by weight of a surfactant obtained by mixing two kinds of sorbitan fatty acid esters in a ratio of 1: 1 to 1: 5, Mixing 5 to 15% by weight of stearyl acrylate to prepare a 100% by weight oily phase; continuously injecting the aqueous phase at a ratio of 1: 1 on the oil phase; A method for producing a thickener for textile printing comprising the steps of: preparing a uniform emulsion monomer having a particle diameter of 10 nm or less by using a homogenizer; and aging the solid emulsion monomer for 10 to 60 minutes by constantly adding nitrogen thereto ≪ / RTI >

Korean Registered Patent No. 10-0431628 (Registered May 4, 2004) Korean Patent Registration No. 10-0540872 (registered on December 28, 2005)

Problems that have been generally encountered when using the conventional alkali swelling thickener or cellulose based thickener as described above are as follows.

1) Low viscosity: When the thickening agent is used in excess, the overall property deterioration, adhesion performance and dispersibility deteriorate.

2) Lack of stability after thickening (after viscosity increase): Changes in viscosity during storage after product blending, increase or decrease in viscosity during storage, lack of workability during construction.

3) Handling complexity: Additional ingredients and process are required to increase the viscosity and fluidity, and additional addition and dissolution processes such as alkali have occurred.

The object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a process for producing a water-soluble polymer which is hydrophobic and has an unsaturated double bond, (Water) addition type thickener is prepared by dispersing in a strong dispersion medium and then synthesized using an oil-soluble catalyst, and to provide a method for producing the same by an inverse emulsion polymerization method.

Another object of the present invention is to provide a process for producing a water-in-oil emulsion which is capable of improving the viscosity-enhancing ability when applied to various industrial aqueous products, And to provide a thickening agent by an emulsion polymerization method and a method for producing the same.

In order to accomplish the above object, the present invention provides a method for preparing a water-based thickener by an inverse emulsion polymerization method comprising the steps of: (a) preparing an aqueous phase having an unsaturated double bond; (b) (C) adding an organic solvent phase prepared in the step (b) to the aqueous phase prepared in the step (a) and stirring the mixture at a high speed to prepare an emulsion in an initial emulsified form (d) adding an initiator to the emulsion prepared in the step (c) and raising the temperature to carry out a polymerization process; (e) minimizing the amount of unreacted monomers polymerized in the step (d) And aging to improve the stability.

In the method for producing a thickener according to the present invention, the step (a) is an acrylic monomer having a high hydrophilicity and an acrylic monomer having a strong acidic functional group such as acrylic acid and methacrylic acid and having a carboxyl group, These acids are neutralized in the form of salts with a pH of 6-8 by the appropriate alkali. As the alkali, ammonia water (NH ₄ OH), caustic soda (NaOH), caustic soda (KOH) and the like can be used. Examples of the water-soluble monomer having a high hydrophilicity include amides such as acrylamide and methyl methacrylamide, and substituents thereof. In addition, a hydrophobic monomer may be added to the oil phase (organic solvent phase). As such a hydrophobic monomer, a (meth) acrylic monomer of about C4 to C15 may be used, and butyl acrylate, 2-ethylhexyl acrylate Tert-butyl methacrylate, stearyl acrylate, and the like can be used.

The composition ratio of these monomers is 30 to 80 wt% of acrylic acid alone or two kinds of acrylic acid and methacrylic acid, 10 to 60 wt% of acrylamide, 0 to 10 wt% of tertiary butyl methacrylate as hydrophobic monomer, And a control unit.

In the synthesis of the thickener, a crosslinking agent may be used. Examples of the crosslinking agent include amide-based substituents such as methylenebisacrylamide and diacetoneacrylamide, and allylmethacrylate, butane-diol-di- Phthalate and the like can be used. Such a crosslinking agent has a double bond showing a reactive and crosslinking ability in the molecular structure, thereby improving the reaction conversion rate during the synthesis and forming a proper crosslinking density, thereby influencing the depressurization force. And the amount thereof is 0.1 to 2.0 wt% based on the whole monomers.

In the method for producing a thickener according to the present invention, the organic solvent phase in the step (b) may be mineral oil composed of saturated hydrocarbons, normal paraffin oil or isoparaffin oil. Among them, low-odor, low aromatic, Considering BP (boiling point) of parazoles, 180 ° C to 300 ° C is used in consideration of the form having characteristic, the form having C10 to C17 carbon, and the form having good stability at high temperature. 10 to 30 wt% of the total weight is used.

In the method for producing a thickener according to the present invention, a surfactant is added in the step (b), and a surfactant is a substance that causes emulsification of a water-soluble medium and an organic solvent, and a hydrophilic- Value, the product of this type can increase the affinity of the water-soluble medium and the organic solvent to lead to the formation of emulsion.

The surfactant used is a combination of a sorbitan ester such as sorbitan monostearate, sorbitan monooleate, sorbitan monolaurate, and ethoxylated polyethoxylated sorbitan esters, The amount to be used is 4 to 12 wt% based on the total monomers.

Also, in the method of manufacturing a thickener according to the present invention, the initiator in the step (d) is used for proceeding radical chain polymerization, and benzoyl peroxide or AIBN (2,2'-azo bis isobutyronitrile) And the amount thereof to be used is 0.1 to 1.0 wt% based on the total monomers.

In the method for producing a thickening agent according to the present invention, the polymerization method in the step (d) is carried out by a batch polymerization method. In the case of the batch polymerization method, since the polymerization is temporarily carried out after the introduction of the raw material as compared with the polymerization method by the continuous process, the reaction time can be shortened and the reproducibility of the polymerization process and the reproducibility of the physical properties of the product can be improved.

As described above, according to the thickener and the method for producing the same according to the present invention, the water-soluble phase containing the water-soluble acrylic monomer, the hydrophobic monomer and the surfactant It is a product obtained by emulsification of two phase of solvent and emulsified by a radical polymerizing mechanism in which the reaction is initiated by an initiator. It is capable of maintaining an excellent storability in comparison with existing thickeners and an improved long-term viscosity stability in storage Is obtained.

Further, according to the thickener and the method for producing the same by the reverse emulsion polymerization method according to the present invention, it is possible to control viscosity, flowability, and workability in an industrial formulation in which an aqueous emulsion type product such as a building, .

1 is a process diagram for explaining a process for producing a thickener by the reverse emulsion polymerization method according to the present invention.

These and other objects and novel features of the present invention will become more apparent from the description of the present specification and the accompanying drawings.

A specific synthesis method of the present invention using the above-described raw materials will be described with reference to FIG.

1 is a process diagram for explaining a process for producing a thickener by the reverse emulsion polymerization method according to the present invention.

First, a water-soluble phase is prepared (S10).

That is, water-soluble acrylic monomers such as acrylic acid and methacrylic acid and acrylamide are mixed with water to prepare an aqueous phase.

At this time, while stirring the aqueous phase, alkali such as ammonia water and caustic soda is added dropwise to adjust the pH to 6 to 8.

In addition, adjust the pH and ensure that the temperature does not exceed 40 ° C by proper cooling. As described above, the crosslinking agent is added to the pH-regulated aqueous phase to complete the aqueous phase preparation.

Next, an organic solvent phase (Oil phase) is prepared separately from the step S10 (S20).

That is, the organic solvent phase is prepared by dispersing the surfactant having a large derivation value with the selected monomer in the oil.

Next, as described above, the organic solvent phase prepared in step S20 is added to the water-soluble phase prepared in step S10 (S30), dissolved oxygen is removed using high purity nitrogen, and strongly stirred at a high speed to form an initial emulsified form (S40).

In this case, the mixing ratio of the organic solvent phase to the water-soluble phase is 1: 2 to 1: 6 in the total percentage of 100wt%. When the mixing ratio is lowered or increased, the formation of the initial emulsion is deteriorated or the synthesis is inhibited Lt; / RTI >

In addition, in order to maintain and stabilize the emulsified state during the synthesis process along with the formation of the emulsion, the emulsion must be strongly agitated in the step S40 to form an initial emulsion.

Next, an initiator is added to the emulsion produced by stirring in step S40 (S50), and the temperature is raised to proceed the polymerization process (S60).

At this time, the polymerization process was carried out by batch polymerization in various synthesis methods.

In the polymerization process, the reaction initiation temperature starts to be synthesized at around 70 ° C, and always maintains around 90 ° C. At the beginning of the reaction, there may be a difference between the reaction initiation temperature and the maximum temperature depending on the degree of emulsification and the amount of dissolved oxygen in the emulsion produced by stirring in step S40. The reaction initiation temperature ranges from 70 ° C to 90 ° C and the maximum temperature ranges from 100 ° C to 110 ° C.

After completion of the polymerization process, the reaction is completed after a certain period of aging (S70). The remaining amount of unreacted monomers can be minimized and the stability of the product can be improved through the aging process.

Next, as described above, an example of a concrete manufacturing process of the thickener by the reverse emulsion polymerization method according to the present invention will be described with reference to the following examples.

[Example 1]

178 g of distilled water, 158 g of acrylic acid and 7 g of methacrylic acid are put into a reactor equipped with a thermometer, a condenser and a stirrer, and stirred well.

131 g of 25% ammonia water was added dropwise to the mixture to neutralize the mixture for 1.5 hrs.

After neutralization, pH should be maintained between 7.0 and 7.5.

135 g of distilled water, 67.5 g of acrylamide and 2.5 g of methylene bisacrylamide were added to another beaker and stirred to completely dissolve.

In another beaker, 230 g of parazole oil, 14 g of sorbitan monooleate and 5 g of PEG-20 sorbitan monooleate are mixed and stirred.

The aqueous phase and the organic solvent phase prepared above are added to the reactor, and then the mixture is stirred at a high speed for 10-15 minutes to obtain an initial emulsion. At this time, high purity nitrogen is flowed in to remove dissolved oxygen.

The initiator 2,2'-azo bis isobutyronitrile is added to the obtained initial emulsion and the temperature is raised by heating.

Once the reaction is initiated, moderate rapid heating through proper cooling and maintain the temperature at about 65 ° C to 95 ° C.

After completion of the reaction, the reaction mixture is aged at 65 ° C to 95 ° C for 1 hour, and the synthesis is terminated.

The resulting thickener had a solid content (NV) of 34%, a pH of 7.3, and a viscosity of 1,300 cps.

[Example 2]

230 g of distilled water, 158 g of acrylic acid and 7 g of methacrylic acid are put into a reactor equipped with a thermometer, a condenser and a stirrer and stirred well.

100 g of 25% ammonia water was added dropwise to the mixture to neutralize the mixture for 1.5 hrs.

After neutralization, maintain pH between 5 and 6.

135 g of distilled water, 67.5 g of acrylamide and 2.5 g of methylene bisacrylamide were added to another beaker and stirred to completely dissolve.

In another beaker, 178 g of paraffin oil, 14 g of sorbitan monooleate and 5 g of PEG-20 sorbitan monooleate are mixed and stirred.

The aqueous phase and the organic solvent phase prepared above are added to the reactor, and then the mixture is stirred at a high speed for 10-15 minutes to obtain an initial emulsion. At this time, high purity nitrogen is flowed in to remove dissolved oxygen.

The initiator 2,2'-azo bis isobutyronitrile is added to the obtained initial emulsion, and the temperature is raised by heating.

Once the reaction is initiated, moderate rapid heating through proper cooling and maintain the temperature at about 65 ° C to 95 ° C.

After completion of the reaction, aging at 65 ° C to 95 ° C for 1 hour, the synthesis is terminated.

The viscosity of the resulting thickener was 33.5% NV, pH 5.8, and viscosity of 3,400 cps.

[Example 3]

230 g of distilled water, 158 g of acrylic acid and 7 g of methacrylic acid are put into a reactor equipped with a thermometer, a condenser and a stirrer and stirred well.

131 g of 25% ammonia water was added dropwise to the mixture to neutralize the mixture for 1.5 hrs.

135 g of distilled water, 67.5 g of acrylamide and 2.5 g of methylene bisacrylamide were added to another beaker and stirred to completely dissolve.

In another beaker, 178 g of paraffin oil, 14 g of sorbitan monooleate and 5 g of PEG-20 sorbitan monooleate are mixed and stirred.

The aqueous phase and the organic solvent phase prepared above are added to the reactor, and then the mixture is stirred at a high speed for 10-15 minutes to obtain an initial emulsion. At this time, high purity nitrogen is flowed in to remove dissolved oxygen.

The initiator 2,2'-azo bis isobutyronitrile is added to the obtained initial emulsion and the temperature is raised by external heating.

Once the reaction is initiated, moderate rapid heating through proper cooling and maintain the temperature at about 65 ° C to 95 ° C.

After completion of the reaction, the mixture is aged at 65 ° C to 95 ° C for 1 hour, and the synthesis is terminated.

The viscosity of the resulting thickener was 34.2% NV, pH 7.5, and viscosity of 3,800 cps.

[Example 4]

A thermometer, a condenser and a stirrer were installed in the reactor, and then 165 g of acrylic acid was added to 230 g of distilled water and stirred well.

141 g of 25% ammonia water was added dropwise to the mixture to neutralize the mixture for 1.5 hrs.

135 g of distilled water, 67.5 g of acrylamide and 2.5 g of methylene bisacrylamide were added to another beaker and stirred to completely dissolve.

In another beaker, 178 g of paraffin oil, 14 g of sorbitan monooleate and 5 g of PEG-20 sorbitan monooleate are mixed and stirred.

The aqueous phase and the organic solvent phase prepared above are added to the reactor, and then the mixture is stirred at a high speed for 10-15 minutes to obtain an initial emulsion. At this time, high purity nitrogen is flowed in to remove dissolved oxygen.

The initiator 2,2'-azo bis isobutyronitrile is added to the obtained initial emulsion and the temperature is raised by external heating.

Once the reaction is initiated, moderate rapid heating through proper cooling and maintain the temperature at about 65 ° C to 95 ° C.

After completion of the reaction, the mixture is aged at 65 ° C to 95 ° C for 1 hour, and the synthesis is terminated.

The viscosity of the obtained thickener was 33.9% NV, pH 7.1, and viscosity of 4,300 cps.

The product test and evaluation according to the present invention are as follows.

In order to evaluate the physical properties of the thickener synthesized in the above examples, the physical properties of the alkaline-added thickener manufactured by Daeheung Chemical Co., Ltd. and the water-containing thickener obtained in the present invention were compared and evaluated.

The comparison of physical properties was evaluated for the potency and viscosity stability after thickening.

In order to measure the thickening ability, a thickening agent was added to a waterborne emulsion product for architectural use which is currently used for bonding, and then the viscosity of the thickener was measured.

In order to improve the smoothness and dispersibility of the thickened state, it was diluted with water and then thickened.

Considering the general usage form of the construction products, the viscosity is set to be about 1 million to 3 million cps (paste).

The mixing ratio for thickening is as follows.

Aqueous adhesive: H ₂ O: thickener = 100: 100: 22

Water-based adhesive: VE-2002 => manufactured by Daeheung Chemical Industry Co., Ltd. Water-based emulsion adhesive thickener: TH-A => manufactured by Daeheung Specialty Chemicals,

The test articles A, B and C correspond to Examples 2, 3 and 4 of the water-added type thickener synthesized in the present invention.

The viscosity was measured according to the blending ratio, and then the viscosity was measured using a Brookfield RVT viscometer. The measurement results are shown in Table 1.

* Spindle No. / rpm = Helipath spindle T-F / 2.5

* Viscosity measuring range: 0 to 4 million cps

* Temp. : at 25 ° C

* Unit: 10,000 cps

TH-A Experiment -A Experiment -B Experiment -C 1st 90 180 202 204 2nd 88 182 200 204 3rd 90 180 200 200 Ave. 89 181 200 200

The evaluation of the viscosity stability according to the present invention is shown in Table 2.

Each thickened paste-like composition was stored under constant temperature conditions and viscosity changes were measured over time.

As can be seen from the above Tables 1 and 2, the thickener according to the present invention exhibited an enhancement ability of 100% or more as compared with the existing alkali-added thickener in terms of its thickening ability, And it was confirmed that the phenomenon is remarkably stable.

Although the present invention has been described in detail with reference to the above embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

By using the thickener by the reverse emulsion polymerization method according to the present invention and the manufacturing method thereof, it is possible to maintain an excellent storability in comparison with existing thickeners and an improved long term viscosity stability in storage.

Claims (10)

A method for producing a water-added type thickener by an inverse emulsion polymerization method,
(a) preparing an aqueous phase having an unsaturated double bond,
(b) preparing an organic solvent phase used as a dispersion medium,
(c) adding an organic solvent phase prepared in the step (b) to the aqueous phase prepared in the step (a) and stirring the mixture at a high speed to produce an emulsion in an initial emulsified form,
(d) adding an initiator to the emulsion produced in the step (c), raising the temperature to carry out a polymerization process,
(e) aging the polymerized in the step (d) so as to minimize the residual amount of the unreacted monomers and to improve the stability. The method according to claim 1,
Wherein the step (a) is an acrylic monomer having a high hydrophilicity and an acrylic monomer having an acrylic acid, a methacrylic acid or a carboxyl group is mixed with water to prepare an aqueous phase. The method according to claim 1,
The monomer of the step (a) may be selected from the group consisting of 30 to 80 wt% of acrylic acid alone or two kinds of acrylic acid and methacrylic acid, 10 to 60 wt% of acrylamide, 10 wt% of tertiary butyl methacrylate as a hydrophobic monomer By weight to 10% by weight. The method according to claim 1,
Wherein the organic solvent phase in the step (b) is a normal paraffin oil composed of saturated hydrocarbons and has a form of C10 to C17 carbon and BP (boiling point) of 180 to 300 deg. 5. The method of claim 4,
In the step (b), a surfactant is added,
The surfactant is characterized by using a combination of a sorbitan ester such as sorbitan monostearate, sorbitan monooleate, sorbitan monolaurate and ethoxylated polyethoxylated sorbitan esters By weight. The method according to claim 1,
Wherein the initiator in step (d) is used to promote radical chain polymerization and is benzoyl peroxide or AIBN (2,2'-azo bis isobutyronitrile). The method according to claim 6,
Wherein the polymerization in step (d) is carried out by a batch polymerization method. The method according to claim 1,
Wherein the step (a) is carried out by dropping an alkali of ammonia water or caustic soda to adjust the pH to be between 6.0 and 8.0, and a crosslinking agent is added. 9. The method of claim 8,
Wherein the crosslinking agent is any one of methylene bisacrylamide, diacetone acrylamide, allyl methacrylate, butane-diol-di-acrylate, and di-allyl phthalate. A thickener produced by the process for producing a thickener according to any one of claims 1 to 9.

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