JPH10120713A - Method for producing polymer latex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for stably producing a high-concentration polymer latex excellent in water resistance and solvent resistance. SOLUTION: In the production of a polymer latex in which a monomer is reacted in the presence of an emulsifier and a modifier, the emulsifier is a compound represented by the general formula (1), and the modifier is a compound represented by the general formula (2): A method for producing a polymer latex, which is a compound represented by the formula: Embedded image Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an emulsifier and a modifier for producing a polymer latex.

[0002]

2. Description of the Related Art Polymer latex is used for paints, adhesives,
It is widely used in many fields such as paper and textile processing, and new applications are being developed every year. In particular, water-based emulsion paints, polymer latexes, and the like have been attracting attention as alternatives to organic solvent-based paints and adhesives, which have recently been restricted by regulations on air pollution and working environments.

However, since water is used during production, poor water resistance and poor solvent resistance have been pointed out mainly due to the influence of surfactants. As a means for this improvement, it has been found that these disadvantages can be improved by forming ultrafine particles of the polymer latex having a particle diameter of 0.1 μm or less and forming partial three-dimensional crosslinks in the particles.

[0004] Conventionally, as a method for synthesizing a microgel, many methods for polymerizing or copolymerizing a crosslinkable monomer having two or more functionalities such as divinylbenzene and diallyl phthalate have been reported. When these crosslinkable monomers are used, a characteristic is that a three-dimensional network structure can be introduced into the polymer latex particles, and the water resistance and solvent resistance of the polymer latex can be improved.

Further, this crosslinkable monomer not only forms a three-dimensional structure, but also a part of double bonds remains on the particle surface,
The double bond has a feature that it can be used for various reactions, and it is possible to modify the polymer latex by a chemical reaction, which is an interesting research subject.

However, due to the presence of reactive double bonds, the formed polymer latex particles tend to agglomerate with each other, and even when an anionic surfactant such as sodium dodecyl sulfate is used at a high concentration of 10% or more. , Solids concentration is 1
Because of aggregation at about 6%, it was very difficult to produce a polymer latex having a high concentration of 40% or more, which is practically necessary.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for stably producing a polymer latex having excellent water resistance and solvent resistance.

[0008]

That is, the gist of the present invention is to provide a polymer latex in which a monomer is reacted in the presence of an emulsifier and a modifier, wherein the emulsifier is a compound represented by the general formula (1): (Hereinafter, referred to as an emulsifier) and the modifier is a compound represented by the general formula (2) (hereinafter, referred to as a modifier).

[0009]

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[0010]

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[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, important matters will be described based on an embodiment of the present invention.

(1) Monomer The monomer to which the emulsifier or modifier of the present invention is applied is an acrylic monomer, an aromatic monomer, or another vinyl monomer.

The acrylic monomers include (meth) acrylates such as sodium acrylate and sodium methacrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, N-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methoxypolyethylene glycol methacrylate, polyethylene glycol methacrylate mono Ester, propylene glycol monoester methacrylate, dimethylaminoethyl methacrylate, methacrylic acid 2 (Meth) acrylic acid esters such as sulfoethyl ester Na salt.

As the aromatic monomer, styrene, α-
Styrene-based monomers such as methylstyrene and ethylvinylbenzene are exemplified.

Other vinyl monomers include diethyl maleate, dibutyl maleate,
Maleic esters such as maleic di-2-ethylhexyl ester; vinyl monomers such as vinyl methyl ether, vinyl ethyl ether, vinyl isopropyl ether, phenyl vinyl ether, phenyl vinyl ketone, N-vinyl pyrrolidone, 4-vinyl pyridine, and vinyl acetate -, Butadiene, ethylene, acrylonitrile and the like.

In the present invention, these monomers may be used alone or in combination of two or more.

(2) Emulsifier The emulsifier of the present invention includes, for example, the following compounds A to E alone or as a mixture of two or more.

[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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(3) Modifier The modifier of the present invention includes, for example, the following compounds I to D alone or a mixture of two or more.

[0024]

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[0025]

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[0026]

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[0027]

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(4) Polymerization Initiator The polymerization initiator used in the reaction of the present invention is, for example, one kind of potassium persulfate, ammonium persulfate, azobisisobutyronitrile, azobisvaleronitrile, benzoyl peroxide and the like. The above is mentioned. In addition, the usage amount is appropriately selected arbitrarily.

(5) Production of Polymer Latex The method for producing the polymer latex of the present invention includes the following method. That is, the emulsifier is dissolved in water, and then the temperature is raised to a predetermined temperature. Next, a predetermined amount of a monomer and a polymerization initiator are added to perform pre-polymerization, and then a predetermined amount of a mixed solution of a modifier and a monomer is dropped to further perform polymerization. Next, after aging for 1 hour at that temperature, the mixture is cooled, and the resulting emulsion is taken out to obtain a polymer latex.

The amount of the emulsifier used is 0.1 to 20% by weight, preferably 0.2 to 20% by weight, based on the total amount of the monomers used.
5% by weight, and the amount of the modifier used is from 0.1 to 50% by weight, preferably from 0.5 to 1%, based on the total amount of the monomers used.
0% by weight. Exceeding these ranges may result in inferior physical properties of the resulting polymer latex, while lower amounts may result in poor dispersion stability and agglomeration.

[0031]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Embodiments 1 to 7 A predetermined amount of the emulsifier was dissolved in 295 g of water, and the temperature was raised to 70 ° C. Next, 20 g of monomer
And 0.5 g of ammonium persulfate were added and pre-polymerized,
Three hours after 10 minutes from the start of the polymerization, a mixture of a predetermined amount of the modifier and 180 g of the monomer was added dropwise to carry out the polymerization.

Next, after aging at that temperature for 1 hour, the mixture was cooled, and the obtained emulsion was taken out to obtain a test sample. Further, this test sample was applied to a glass plate and dried at room temperature for 24 hours to prepare a polymer film.

Comparative Examples 1 to 5 It carried out like Example.

Table 1 shows the emulsion stability (polymerization stability and mechanical stability) and the water resistance and solvent resistance of the polymer films obtained in the examples and comparative examples. The polymerization stability, mechanical stability, and water resistance and solvent resistance of the polymer film were evaluated as follows.

[Polymerization Stability] After the completion of the polymerization, the emulsion was filtered through a 150 mesh stainless steel net, and the coagulate remaining on the net was thoroughly washed with water, and the weight was measured. The weight was evaluated by percentage based on the amount of monomer used. 0.5% or less: ◎ 0.5 to 2%: ○ 2 to 5%: △ 5% or more: ×

[Mechanical Stability] Using a Marlon-type mechanical stability tester under the conditions of 10 kg / cm 2 and 1000 rpm,
After treating the emulsion for minutes, the coagulated product was filtered through an 80 mesh stainless steel net, the coagulated product remaining on the net was sufficiently washed with water, and its weight was measured. The weight was evaluated by percentage based on the amount of monomer used. 0.5% or less: ◎ 0.5 to 2%: ○ 2 to 5%: △ 5% or more: ×

[Water Resistance of Polymer Film] A polymer film prepared on a glass plate was immersed in water to evaluate the whitening of the film. After 1 hour, no whitening: ◎ After 1 hour, slightly whitening: ○ Whitening in 10 to 30 minutes: △ Immediate whitening: ×

[Solvent Resistance of Polymer Film to Water] 5 mL of glacial acetic acid was placed on a polymer film formed on a glass plate.
Alternatively, ethanol is poured, and the dish is covered with the bottom of the dish up, and left for 12 hours. Then, wipe off with water, dry, and examine the surface condition. No change: ◎ Only swelling and no holes: ○ Deteriorated coating: △ Dissolved coating: ×

[0040]

[Table 1]

[0041]

According to the production method of the present invention, the modifier reacts with the monomer to be emulsion-polymerized, the acidic phosphate portion in the modifier structure coordinates to the surface of the polymer particles, and the chemical structure A similar type of emulsifier adheres to the surface of the polymer particles to obtain a polymer latex having excellent dispersion stability of the polymer particles. Furthermore, the obtained polymer latex can be adjusted to a high concentration necessary for practical use, and has excellent stability, excellent water resistance, and excellent solvent resistance. Wood, metal, paper,
It can be used for fabrics and other concrete.

Claims (1)

[Claims] 1. In the production of a polymer latex in which a monomer is reacted in the presence of an emulsifier and a modifier, the emulsifier is a compound represented by the general formula (1), and the modifier is a compound represented by the general formula (1): A method for producing a polymer latex, which is the compound represented by 2). Embedded image Embedded image