JPH0616708A - Method for producing polymer latex - Google Patents

Abstract

(57) [Summary] [Structure] In a method for producing a polymer latex obtained by emulsion-polymerizing a polymerizable monomer, polymerization is performed using the following polymerization tank. The stirring shaft 1 rotatable from the outside of the tank is provided at the center of the polymerization tank, and the tip end of the shaft 1 arranged at the bottom of the tank is arranged so that the lower end of the shaft 1 is close to the bottom wall surface of the stirring tank. A bottom paddle 2 having a receding angle α of 0 ° is attached, and the bottom paddle 2 and the bottom paddle 2 are provided at a position of 40 to 100 ° above the bottom paddle 2 of the stirring shaft 1.
A flat paddle 3 having a crossing angle β of 3 and a plate-like fin 4 extending downward is attached, and a plurality of baffle plates 5 along the axial direction from the lower part to the upper part are attached to the side wall surface of the stirring tank. Polymerization tanks arranged at intervals. [Effect] The amount of fine coagulated substances generated during polymerization can be drastically reduced even in a polymerization formulation with a small amount of an emulsifier or in a large-sized polymerization tank, and adhesion to the stirring blade and inside the polymerization tank can be reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polymer latex. More specifically, the present invention relates to a method for producing a polymer latex having excellent polymerization stability by suppressing the generation of fine coagulation products during polymerization by using a reaction tank having a specific stirring blade.

[0002]

2. Description of the Related Art Diene polymer latexes such as polybutadiene latex, styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, carboxylic acid- or vinylpyridine-modified styrene-butadiene polymer latex, etc. Is widely used as a binder for paper coating, fiber treatment or tire cord treatment, and as a rubber component of a rubber-reinforced resin. When producing these polymer latexes, the type of the monomer, the polymerization method,
The polymerization formulation is determined by the viscosity and the like during the polymerization, but the generation of fine coagulation during the polymerization poses a problem. This fine coagulated product not only lowers the productivity but also adversely affects the quality of the obtained polymer latex, and various studies have been made to reduce the generation of the microcoagulated product. For example, it is possible to reduce the generation of fine coagulated substances to some extent by increasing the proportion of polymerized water with respect to the monomer, or by increasing the emulsifier for stabilizing the latex particles, but the proportion of polymerized water On the contrary, increasing the ratio decreases the proportion of the polymer produced, resulting in a decrease in productivity. As a means for improving productivity, the reaction tank is being increased in size, but it is difficult to obtain a polymer latex having the same performance or structure by simply increasing the capacity of the reaction tank. In addition, the increase in the amount of emulsifier causes various adverse effects due to the emulsifier in the final product, and the present situation is that it has not been a fundamental solution.

[0003]

[Means for Solving the Problems] As a result of intensive studies on the above problems, the present inventors have paid attention to a stirring blade attached to a polymerization tank, and as a result, found that a certain stirring blade was attached. The above problems can be solved by using a polymerization tank consisting of
^The present invention has been completed by finding a method for obtaining a polymer latex having excellent polymerization stability, which suppresses the generation of fine coagulated substances during polymerization even with a large size of ³ or more.

That is, the present invention provides a method for producing a polymer latex, which is obtained by emulsion-polymerizing a polymerizable monomer, characterized by polymerizing using a polymerization tank described below. It is a thing. A stirring shaft 1 rotatable from the outside of the polymerization tank is provided in the center of the polymerization tank, and the shaft 1 has a lower end portion close to the bottom wall surface of the stirring tank and a tip portion arranged at the bottom portion of the stirring tank 30 to 60. A bottom paddle 2 having a receding angle α of 0 ° is attached, and the bottom paddle 2 and the bottom paddle 2 are provided at a position of 40 to 100 ° above the bottom paddle 2 of the stirring shaft 1.
A flat paddle 3 having a crossing angle β of 3 and a plate-like fin 4 extending downward is attached, and a plurality of baffle plates 5 along the axial direction from the lower part to the upper part are attached to the side wall surface of the stirring tank. Polymerization tanks arranged at intervals.

The present invention will be described in detail below. The polymerizable monomer used in the present invention, for example, a conjugated diene monomer, an ethylenically unsaturated carboxylic acid monomer,
Aromatic vinyl monomers, vinyl cyanide monomers, unsaturated carboxylic acid alkyl ester monomers, hydroxyalkyl group-containing unsaturated monomers, unsaturated carboxylic acid amide monomers, maleimide simple monomers Examples thereof include a polymer.

As the conjugated diene-based monomer, 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-
Dimethyl-1,3 butadiene, 2-chloro-1,3-butadiene, substituted linear conjugated pentadienes, substituted and side chain conjugated hexadienes, and the like can be mentioned, and one or more can be used. Particularly, 1,3-butadiene is preferable.

Aromatic vinyl monomers include styrene, α-methylstyrene, methyl α-methylstyrene,
Vinyltoluene and divinylbenzene and the like,
One kind or two or more kinds can be used. Particularly preferred is styrene.

Examples of vinyl cyanide-based monomers include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile and the like, and one or more of them can be used. Acrylonitrile is particularly preferable.

Examples of the ethylenically unsaturated carboxylic acid monomer include mono- or dicarboxylic acids (anhydrides) such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid. Two or more types can be used. Particularly, mono- or dicarboxylic acid is preferable.

Examples of the unsaturated carboxylic acid alkyl ester monomer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, glycidyl methacrylate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl malate, dimethyl. Itaconate, monomethyl fumarate, monoethyl fumarate, 2-ethylhexyl acrylate and the like can be mentioned, and one kind or two or more kinds can be used. Methyl methacrylate is particularly preferable.

Examples of unsaturated monomers containing a hydroxyalkyl group include β-hydroxyethyl acrylate and β-hydroxyethyl acrylate.
-Hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate,
Hydroxybutyl acrylate, hydroxybutyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, di- (ethylene glycol) maleate,
Di- (ethylene glycol) itaconate, 2-hydroxyethyl maleate, bis (2-hydroxyethyl)
Maleate, 2-hydroxyethylmethyl fumarate, etc. are mentioned, and 1 type (s) or 2 or more types can be used. Particularly, β-hydroxyethyl acrylate is preferable.

As the unsaturated carboxylic acid amide monomer,
Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N,
N-dimethylacrylamide and the like can be mentioned, and one kind or two or more kinds can be used. Particularly preferred is acrylamide.

The maleimide type monomers include maleimide, N-phenylmaleimide, N-methylmaleimide,
N-cyclohexylmaleimide and the like can be mentioned, and one or more kinds can be used. N-phenylmaleimide is particularly preferable.

In addition to the above monomers, any of the monomers used in ordinary emulsion polymerization such as ethylene, propylene, vinyl acetate, vinyl propionate, vinyl pyridine, vinyl chloride and vinylidene chloride can be used. Is.

Of the above-mentioned polymerizable monomers, it is preferable to use a conjugated diene monomer alone or a monomer copolymerizable therewith, and particularly, a conjugated diene monomer 10 to 80.
% By weight, 0.5 to 1 ethylenically unsaturated carboxylic acid monomer
0% by weight and a monomer copolymerizable therewith (most preferably, aromatic vinyl-based monomer, vinyl cyanide-based monomer, unsaturated carboxylic acid alkyl ester monomer, and hydroxyalkyl group) One or more monomers selected from the group of unsaturated monomers, unsaturated carboxylic acid amide monomers, maleimide-based monomers) 10 to 89.5% by weight
It is preferable to use a monomer consisting of

The average particle size of the obtained polymer latex is not particularly limited, but preferably 70 to 300 n.
m. Further, the gel content of the polymer latex is not particularly limited, but is preferably 20 to 90% by weight, and particularly when the latex is used as a binder for paper coating for offset printing paper, etc. The content is preferably 20 to 60% by weight.

The present invention also includes a mode in which the above-mentioned polymerizable monomer is emulsion polymerized in the presence of a rubbery polymer latex. As the rubbery polymer latex, for example, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer,
Any latex of a rubber-like polymer such as an ethylene-propylene copolymer or an acrylic ester copolymer can be used.

As the polymerizable monomer which is polymerized in the presence of the rubbery polymer latex, the above-exemplified monomers can be used, but particularly aromatic vinyl-based monomers and cyan. Use one or more monomers selected from the group of vinyl chloride-based monomers, ethylenically unsaturated carboxylic acid monomers, unsaturated carboxylic acid alkyl ester monomers and maleimide-based monomers. Is preferred.

The polymerization tank used for producing the polymer latex of the present invention is shown below. That is, a stirring shaft 1 rotatable from the outside of the polymerization tank is arranged at the center of the polymerization tank.
In addition, a bottom paddle 2 having a receding angle α of 30 to 60 ° is attached to the tip end portion of which the lower end portion is arranged close to the bottom wall surface of the stirring tank and is arranged on the bottom portion of the tank. A flat paddle 3 having a crossing angle β of 40 to 100 °, preferably 40 to 70 ° and a plate-like fin 4 extending downward at the tip end is attached to the portion and the stirring pad of the stirring tank is attached. It is a polymerization tank in which a plurality of baffles 5 along the axial direction from the lower portion to the upper portion are arranged at intervals on the side wall surface. It should be noted that the baffle plate 5 described above can also be made to pass cooling water to impart a cooling capacity.

Further, by using the specific polymerization tank specified in the present invention, the fine coagulated substance at the time of polymerization is reduced as compared with the case where the emulsion polymerization is carried out using the conventional polymerization tank, and the polymerization is performed. Although a latex having excellent stability can be obtained, in the present invention, the effect is particularly remarkable when a polymerization tank having an inner volume of 30 m ³ , preferably 40 m ³ or more is used. . This is 1 to 20 which is the conventional industrial production scale as well as the laboratory level.
It is a remarkably large scale in terms of m ³ , and is very useful in industrial production.

Various components (monomer or /
The addition method of the rubbery polymer latex) and the rubbery polymer latex) is not particularly limited, and any one of a batch addition method, a divided addition method, and a continuous addition method can be adopted. Further, in the present invention, any one-step polymerization, two-step polymerization or multi-step polymerization can be adopted.

In emulsion-polymerizing the polymer latex of the present invention, usual emulsifiers, polymerization initiators, electrolytes, chain transfer agents, polymerization accelerators, chelating agents and the like can be used.

As the emulsifier, a sulfuric acid ester salt of a higher alcohol, an alkylbenzene sulfonate, an alkyl diphenyl ether sulfonate, an aliphatic sulfonate, an aliphatic carboxylate, an anionic surfactant such as a sulfuric acid ester salt of a nonionic surfactant is used. Surfactants or nonionic surfactants such as alkyl ester type of polyethylene glycol, alkyl phenyl ether type, alkyl ether type and the like are used in one kind or in two or more kinds. The above-mentioned emulsifier causes various harmful effects due to this in the final product, and should be kept as small as possible, but conversely, if the used amount is reduced, the polymerization stability is lowered. In the present invention, 1.
Sufficient polymerization stability can be obtained even when the amount used is 0 part by weight or less, particularly 0.7 part by weight or less.

As the initiator, a water-soluble initiator such as potassium persulfate, ammonium persulfate or sodium persulfate, a redox initiator or an oil-soluble initiator such as benzoyl peroxide can be used.

Examples of the chain transfer agent include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-stearyl mercaptan, dimethylxanthogen disulfide, diisopropylxanthogen. Xanthogen compounds such as disulfide, α-methylstyrene dimer, terpinolene, and thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, and tetramethylthiuram monosulfide, 2,6-di-
Phenolic compounds such as t-butyl-4-methylphenol and styrenated phenol, allyl compounds such as allyl alcohol, halogenated hydrocarbon compounds such as dichloromethane, dibromomethane, carbon tetrachloride and carbon tetrabromide, α-
Benzyloxystyrene, α-benzyloxyacrylonitrile, vinyl ethers such as α-benzyloxyacrylamide, triphenylethane, pentaphenylethane, acrolein, methacrolein, thioglycolic acid, thiomalic acid, 2-ethylhexylthioglycolate, and the like, One kind or two or more kinds can be used.

In the emulsion polymerization, for example, cyclopentene, cyclohexene, cycloheptene, 4
The polymerization may be carried out in the presence of a cyclic unsaturated hydrocarbon having one unsaturated bond in the ring such as -methylcyclohexene or 1-methylcyclohexene or a hydrocarbon such as benzene, toluene, hexane or cyclohexane. At this time, the amount of the hydrocarbon used is 0.1 to 30 parts by weight based on 100 parts by weight of the monomer.

The above-mentioned polymer latex containing the conjugated diene monomer as an essential component is, for example, an adhesive for paper coating, an adhesive for carpet backing such as tufted carpet, needle punched carpet, a cushion for automobiles. As an adhesive for rock fiber bases used for materials, mats for civil engineering, industrial filters, adhesives for wood used for plywood, decorative materials, etc., and as raw rubber latex used for the production of ABS resin Can be used. Further, the polymer latex obtained by using the rubbery polymer latex is appropriately salted out and dried, and then recovered as a powder or pellet, which is widely used as various materials for automobile interior / exterior parts, weak electric field and the like. Can be used.

[Examples] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples unless the gist thereof is changed. In the examples, parts and percentages are based on weight. When the 45 m ³ reaction vessel was used, the total amount of the charged components including water was 43 m ³ . Further, the measurement of various physical properties in Examples and Comparative Examples was based on the following methods.

○ Average particle size Each particle size of 500 particles is measured by an electron micrograph,
The number average particle diameter was determined.

○ Gel Content The latex is dried at room temperature to prepare a latex film. Then latex film about 0.2-0.3
Accurately weigh g. After being immersed in 200 cc of toluene for 48 hours, the mixture was filtered through a 300-mesh wire net, the dry weight of the residue (toluene insoluble matter) on the wire net was determined, and the percentage relative to the weight before dipping in toluene was taken as the gel content.

Polymerization stability Measurement of coagulated product generation amount (latex is filtered through a 300 mesh wire net. The metal net is vacuum dried and the coagulated product on the wire net is weighed.
Calculate the weight of coagulated product per 100 g (solid content) of latex. ) And the state of adhesion to the stirring blade in the reaction tank, and comprehensively judged the polymerization stability.

Example 1 Polymerization of Copolymer Latex In a polymerization tank having an internal volume of 45 m ³ shown in FIG. 1, 100 parts of water and sodium dodecylbenzenesulfonate (0.1 part) were added.
3 parts, sodium hydrogen carbonate 0.3 part, potassium persulfate 1.0 part and 1,3-butadiene 25 parts, styrene 6
A monomer mixture consisting of 1 part and 4 parts of acrylic acid and 0.5 part of t-dodecyl mercaptan as a chain transfer agent were charged and polymerized at 70 ° C., and the polymerization was completed at a conversion of 97%. The obtained copolymer latex was adjusted to pH 5 with sodium hydroxide, and then unreacted monomers were removed by steam distillation to obtain a polymer latex A. The agglomerate of the polymer latex A was 0.1 g or less, the adhesion to the stirring blade in the tank was small, and the polymerization stability was very excellent. In addition,
The average particle size was 180 nm and the gel content was 55%.

[Example 2] Polymerization of copolymer latex Polymerization was carried out in the same manner as in Example 1 except that 0.5 part of t-dodecyl mercaptan was changed to 1.0 part of α-methylstyrene dimer. . The coagulated product of the polymer latex B was 0.2 g or less (0.1 to 0.2 g), the adhesion to the stirring blade in the tank was small, and the polymerization stability was very excellent. The average particle size was 165 nm and the gel content was 65.
%Met.

[Example 3] Polymerization of copolymer latex Polymerization was carried out in the same manner as in Example 1 except that 0.5 part of t-dodecyl mercaptan was changed to 1.0 part of terpinolene. The agglomerate of the polymer latex C is 0.2
When the amount was not more than g (0.1 to 0.2 g), there was little adhesion to the inside of the tank and the stirring blade, and the polymerization stability was very excellent. The average particle size was 160 nm and the gel content was 70%.

[Example 4] Polymerization was carried out in the same manner as in Example 1 except that 10 parts of toluene was added at the initial stage of polymerization per 100 parts of the monomer mixture. The agglomerate of the polymer latex D is 0.1 g or less, and the adhesion to the stirring blade in the tank is small,
The polymerization stability was very excellent. The average particle size is 1
70 nm, the gel content was 50%.

[Example 5] Polymerization was carried out in the same manner as in Example 1 except that 7 parts of cyclohexane was added at the initial stage of polymerization per 100 parts of the monomer mixture. The agglomerate of the polymer latex E was 0.1 g or less, the adhesion to the stirring blade in the tank was small, and the polymerization stability was very excellent. The average particle size was 180 nm and the gel content was 48%.

[Comparative Example 1] Polymer latex a was polymerized in the same manner as in Example 1 except that a polymerization tank having an internal volume of 45 m ³ equipped with the three-stage turbine blade shown in FIG. 2 was used.
Got Aggregates of the above-mentioned polymer latex a were remarkably 1.7 g, and adhesion to the stirring blades in the tank was large. The average particle size was 190 nm and the gel content was 50%.

[Comparative Example 2] Polymer latex b was obtained in the same manner as in Example 1 except that a polymerization tank having an internal volume of 45 m ³ equipped with a three-stage paddle blade shown in FIG. 3 was used. It was The aggregate of the polymer latex b was remarkably 3.2 g, and the adhesion to the stirring blade in the tank was also remarkable. The average particle size was 185 nm and the gel content was 55%.

Example 6 In the same polymerization tank as in Example 1,
Water 100 parts, polybutadiene latex (solid content) 60
Part, 0.3 parts of potassium persulfate were charged, and after nitrogen substitution,
The temperature was raised to ° C, and from that point, a monomer mixture consisting of 28 parts of styrene and 12 parts of acrylonitrile, 0.3 part of t-dodecyl mercaptan, and an aqueous emulsifier solution consisting of 0.4 part of sodium oleate and 20 parts of water were added. Polymerization was carried out by continuously adding and completing the polymerization at a polymerization conversion rate of 98% to obtain a polymer latex F. The agglomerate of the polymer latex F was 0.1 g or less, the adhesion to the stirring blade in the tank was small, and the polymerization stability was very excellent.

[Comparative Example 3] Polymer latex c was polymerized in the same manner as in Example 2 except that a polymerization tank having an internal volume of 45 m ³ equipped with the three-stage turbine blade shown in FIG. 2 was used.
Got The agglomerate of the polymer latex c was as large as 0.9 g, and the adhesion to the stirring blade and the inside of the tank was remarkable. The average particle size was 170 nm and the gel content was 60%.

[Comparative Example 4] Polymer latex d was obtained in the same manner as in Example 2 except that a polymerization tank having an internal volume of 45 m ³ equipped with a three-stage paddle blade shown in FIG. 3 was used. It was The agglomerate of the polymer latex d was as large as 1.5 g, and the adhesion to the stirring blade in the tank was remarkable. The average particle size was 175 nm and the gel content was 60%.

Example 7 In the same polymerization tank as in Example 1,
Water 150 parts, sodium dodecylbenzenesulfonate 0.5 parts, sodium hydrogen carbonate 0.3 parts, potassium persulfate 1.0 parts and 1,3-butadiene 45 parts, styrene 30 parts, methyl methacrylate 10 parts, acrylonitrile 10 parts And a monomer mixture consisting of 2 parts of itaconic acid,
1.2 parts of t-dodecyl mercaptan was charged as a chain transfer agent, polymerization was carried out at 70 ° C., and the polymerization was completed at a conversion of 97%. The obtained copolymer latex was adjusted to pH 5 with sodium hydroxide, and then unreacted monomers were removed by steam distillation to obtain a polymer latex G. Aggregates of the polymer latex G are 0.3 g or less (0.2 to 0.3
In g), there was little adhesion to the inside of the tank and the stirring blade, and the polymerization stability was very excellent. The average particle size was 105 nm and the gel content was 20%.

Example 8 In the same polymerization tank as in Example 1,
90 parts of water, sodium dodecylbenzene sulfonate 0.
2 parts, sodium hydrogen carbonate 0.6 part, potassium persulfate 1.0 part and 1,3-butadiene 60 parts, styrene 2
5 parts, 5 parts of methyl methacrylate, 3 parts of β-hydroxyethyl acrylate and 7 parts of methacrylic acid, and 0.3 part of t-dodecyl mercaptan as a chain transfer agent were charged and polymerization was carried out at 65 ° C. to carry out polymerization conversion. Rate 9
Polymerization was completed at 7%. The obtained copolymer latex was adjusted to pH 5 with sodium hydroxide, and then unreacted monomers were removed by steam distillation to obtain a polymer latex H. The aggregate of the polymer latex H was 0.2 g or less (0.1 to 0.2 g), the adhesion to the stirring blade in the tank was small, and the polymerization stability was very excellent. The average particle size was 250 nm and the gel content was 55%.

[0044]

EFFECTS OF THE INVENTION By using the polymerization tank having the specific stirring blade specified in the present invention, the amount of fine coagulated substance can be drastically reduced as compared with the conventional manufacturing method, and the inside of the polymerization tank can be changed to the stirring blade. Can be reduced. Further, it can be produced in a large polymerization tank of 40 m ³ or more, which is industrially very useful.

[Brief description of drawings]

FIG. 1 is a perspective view in which a polymerization tank equipped with a specific stirring blade used in Examples 1 to 8 of the present invention is cut away.

FIG. 2 is a perspective view in which a polymerization tank equipped with a three-stage turbine blade used in Comparative Examples 1 and 3 is cut away.

FIG. 3 is a perspective view in which a polymerization tank equipped with a three-stage paddle blade used in Comparative Examples 2 and 4 is cut away.

[Explanation of symbols]

1 ... Stirring shaft, 2 ... Bottom paddle, 3 ... Flat paddle, 4 ... Plate fins, 5 ... Baffle plate, α
・ ・ ・ Receding angle of bottom paddle 2, β ・ ・ ・ Crossing angle of bottom paddle 2 and flat paddle 3.

Claims (8)

[Claims] 1. A method for producing a polymer latex, which comprises emulsion-polymerizing a polymerizable monomer, wherein the polymerization is carried out using the following polymerization tank. A stirring shaft 1 rotatable from the outside of the polymerization tank is provided in the center of the polymerization tank, and the shaft 1 has a lower end portion close to the bottom wall surface of the stirring tank and a tip portion arranged at the bottom portion of the stirring tank 30 to 60. A bottom paddle 2 having a receding angle α of 0 ° is attached, and the bottom paddle 2 and the bottom paddle 2 are provided at a position of 40 to 100 ° above the bottom paddle 2 of the stirring shaft 1.
A flat paddle 3 having a crossing angle β of 3 and a plate-like fin 4 extending downward is attached, and a plurality of baffle plates 5 along the axial direction from the lower part to the upper part are attached to the side wall surface of the stirring tank. Polymerization tanks arranged at intervals. 2. The method for producing a polymer latex according to claim 1, wherein the polymerizable monomer comprises a conjugated diene monomer alone or a monomer copolymerizable therewith. 3. The method for producing a polymer latex according to claim 1, wherein the polymerizable monomer is emulsion polymerized in the presence of a rubbery polymer latex. 4. A conjugated diene monomer of 10 to 80% by weight,
Ethylenically unsaturated carboxylic acid monomer 0.5 to 10% by weight
The method for producing a polymer latex according to claim 1, which is obtained by emulsion-polymerizing a monomer consisting of 10 to 89.5% by weight of a monomer copolymerizable therewith. 5. The method for producing a polymer latex according to claim 4, wherein the gel content is 20 to 90% by weight. 6. The method for producing a polymer latex according to claim 4, wherein 1.0 part by weight or less of an emulsifier is used with respect to 100 parts by weight of the monomer. 7. The heavy polymer according to claim 1, which is obtained by emulsion polymerization in the presence of a cyclic unsaturated hydrocarbon having one unsaturated bond in the ring or a hydrocarbon such as benzene, toluene, hexane or cyclohexane. Method for producing united latex. 8. The method for producing a polymer latex according to claim 1, wherein a polymerization tank having a capacity of 40 m ³ or more is used.