JPH0625310A - Method for polymerizing vinyl chloride compounds - Google Patents

Abstract

PURPOSE:To provide the emulsion polymerization method of a vinyl chloride compound enabling the automatic charge of an antioxidant and giving vinyl chloride resins improved in their thermal stability. CONSTITUTION:When a vinyl chloride compound is polymerized, a powdery antioxidant is added as an emulsion in which the antioxidant is dispersed in water with an emulsifier and/or a suspending agent in a fine powdery state, thereby permitting to homogeneously disperse the antioxidant in the produced vinyl chloride resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improved method for polymerizing vinyl chloride by emulsion polymerization in an aqueous medium.

[0002]

2. Description of the Related Art Vinyl chloride resins are easily oxidized by oxygen in the air and deteriorate, so that they are often put on the market with an antioxidant added.

Usually, the antioxidant is added during the production of the compounded powder, but since it is difficult to mix it uniformly, it is added during the production of the vinyl chloride resin before, during or after the polymerization. Things have also been tried. In particular, it is desirable to add it when the vinyl chloride resin is in a molten state or an emulsified state because the antioxidant is uniformly dispersed.

By the way, as antioxidants, there are phenol-based antioxidants, amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, etc., but these are usually powders, and therefore a predetermined amount is automatically adjusted. It is difficult to charge it. In particular, when the vinyl chloride resin is in a molten state or an emulsified state, the system is under pressure, and it is more difficult to quantitatively press-in the powdered antioxidant.

[0005]

The above-mentioned problems caused by the fact that these antioxidants are powders can be solved by dissolving the antioxidants in an appropriate organic solvent and using them. When a solvent is contained or it is necessary to collect the solvent, and when it is added to the reaction system,
When recovering unreacted monomer or polymerization solvent, there is a problem of mixing with the recovered monomer or polymerization solvent. Further, in the case of suspension polymerization or emulsion polymerization in an aqueous medium such as vinyl chloride, the solvent used to dissolve the antioxidant is discharged into the waste water, which causes a problem of increasing COD in the waste water. is there.

When emulsion polymerization is carried out in an aqueous medium, an alkaline water-soluble antioxidant such as bisphenol A may be used by dissolving or suspending it in caustic soda solution or caustic solution. Alkaline water-soluble antioxidants are extremely limited and cannot be applied to water-repellent antioxidants. Further, when the antioxidant is brought into contact with alkaline water, there is a drawback that a vinyl chloride resin, particularly a phenolic one, has a quinone structure and is colored, and the resulting vinyl chloride resin is colored.

[0007]

Means for Solving the Problems As a result of intensive investigations under such circumstances, the present inventors have surprisingly crushed an antioxidant into fine powders and used an emulsifier and / or a suspending agent to prepare water. It has been found that, if dispersed as a fine powder, it can be easily added to the polymerization tank by a pump during the emulsion polymerization of vinyl chloride, and further research was conducted to complete the present invention.

It is an object of the present invention to provide an emulsion polymerization method for vinyl chlorides, which enables automatic charging of an antioxidant and obtains a vinyl chloride resin having improved thermal stability.

That is, the present invention is a method for polymerizing vinyl chlorides by an emulsion polymerization method in an aqueous medium, wherein a powdered antioxidant is finely dispersed in water by an emulsifier and / or a suspending agent during the polymerization of vinyl chlorides. The method for polymerizing vinyl chlorides is characterized in that an emulsion dispersed as a fine powder is added to uniformly disperse the antioxidant in the vinyl chloride resin produced.

In the present invention, vinyl chlorides include not only vinyl chloride alone but also a mixture of vinyl chloride and a monomer copolymerizable with vinyl chloride.

Examples of the monomer copolymerizable with vinyl chloride include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-, and the like.
Octene, 1-nonene, 1-decene, 1-undecene,
C2-C30 α-olefins such as 1-dodecene, 1-tridecene, 1-tetradecene, acrylic acid and its esters, methacrylic acid and its esters, maleic acid and its esters, vinyl acetate and vinyl propionate. , Vinyl compounds such as alkyl vinyl ether, and mixtures thereof.

In the aqueous emulsion polymerization method of vinyl chlorides, the ratio of vinyl chlorides to water is generally 80 to 300 parts by weight of water to 100 parts by weight of vinyl chlorides, and the polymerization temperature is usually 35 to 70 ° C. is there.

The polymerization initiator that can be used is, for example,
Diisopropyl peroxydicarbonate, dioctyl peroxydicarbonate, dilauryl peroxydicarbonate, dicetyl peroxydicarbonate, ditertiary butyl peroxydicarbonate, di (2-
Ethoxyethyl) peroxydicarbonate, di (2-
Peroxydicarbonate such as methoxypropyl) peroxydicarbonate, dibenzylperoxydicarbonate, dicyclohexylperoxydicarbonate, ditertiarybutylcyclohexylperoxydicarbonate, 2.2′-azobis-2,4-dimethylvaleronitrile 2.2'-azobis-4-methoxy-2.
Azo compounds such as 4-dimethylvaleronitrile, tert-butyl peroxyneodecanate, α-cumylperoxyneodecanate, tertiary octylperoxyneodecanate, tert-butylperoxypivalate, α-cumylperoxy Peroxides such as pivalate, amyl peroxypivalate, ditertiary butyl oxalate, isobutyryl peroxide, etc., water-soluble peroxides such as hydrogen peroxide, potassium persulfate, sodium persulfate, ammonium persulfate, sodium perborate, etc. These may be used in combination in order to make the polymerization reaction rate uniform.

As the emulsifier used in the emulsion polymerization method,
It can be used without problems as long as it is usually used for polymerization of paste resin, for example, alkyl sulfonate,
Examples thereof include anionic surfactants such as alkylallyl sulfonate, alkyl alcohol sulfate ester salt, fatty acid salt and dialkyl sulfosuccinate. These emulsifiers are usually used in the proportion of one kind or two or more kinds. Alkali metals are generally used as these salts.

In the emulsion polymerization method, an emulsification aid is used in addition to the above-mentioned anionic surfactant, and glycerin ester, glycol ester or sorbitan ester of higher fatty acid, higher alcohol condensate, higher fatty acid condensate, polypropylene condensation. It is also possible to use nonionic surfactants such as compounds, higher alcohols such as cetyl alcohol and lauryl alcohol, higher fatty acids such as lauric acid, palmitic acid and stearic acid or esters thereof together with anionic surfactants. .

In the emulsion polymerization method, aromatic hydrocarbons,
PH of higher aliphatic hydrocarbons, halogenated hydrocarbons such as chlorinated paraffin, sodium bicarbonate, ammonia, etc.
A usual polymerization aid such as a regulator and a chain transfer agent may be used in combination.

In the emulsion polymerization method, an emulsifier, a polymerization initiator,
Water, vinyl chlorides and, if necessary, other polymerization aids are premixed prior to the polymerization reaction and then subjected to high shear to homogenize. This homogenization is performed by a known homogenization method, for example, a method using a one-stage or two-stage pressurizing high-pressure pump, a colloid mill, a homomixer, a high-pressure jet from a nozzle or an orifice, and ultrasonic waves.

In the present invention, it is necessary to add a milk suspension in which a fine powdery antioxidant is dispersed in water as a fine powder during emulsion polymerization of vinyl chlorides. By dispersing the inhibitor as a fine powder in water using an emulsifier and / or a suspending agent, it can be stably and automatically charged into a polymerization tank under pressure by a pump or the like.

The antioxidant used here is usually a solid, fine powder that can be dispersed in water as a fine powder by an emulsifying agent and / or a suspending agent. As such, for example, 2.6-di-t-butyl-p-cresol (BH
T), 3-t-butyl-4-hydroxy-anisole (3-BHA), 2-t-butyl-4hydroxy-anisole (2-BHA), 2.2'-methylenebis (4-).
Methyl-6-t-butylphenol) (MBMBP),
2.2'-methylenebis (4-ethyl-6-t-butylphenol) (MBEBT), 4.4'-butylidenebis (3-methyl-6-1-butylphenol) (BBM
BP), 4.4'-thiobis (3-methyl-6-t-butylphenol) (SBMBP), styrenated-p-cresol, 1.1.3-tris (2-methyl-4-hydroxy-5-t). -Butylphenyl) butane, tetrakis [methylene-3- (3'.5'-di-t-butyl-4 '
-Hydroxyphenyl) propionate] methane, n-
Octadecyl-3- (4'-hydroxy-3 ', 5'-
Di-t-butylphenyl) propionate, 1.3.5
-Trimethyl-2.4.6-tris (3.5-di-t-
Butyl-4-hydroxybenzyl) benzene, 2.2 '
-Dihydroxy-3.3-t-di (α-methylcyclohexyl) -5.5'-dimethyl-diphenylmethane,
4.4'-methylenebis (2.6-di-t-butylphenol), tris (3.5-di-t-butyl-4-hydroxyphenyl) isocyanurate, 1.3.5-tris (3 '. 5'-di-t-butyl-4-hydroxy-benzoyl) isocyanurate, bis [2-methyl-4-
{3-n-Alkylthiopropionyloxy} -5-t
-Butylphenyl] sulfide, 1-oxy-3-methyl-isopropylbenzene, 2.5-di-t-butylhydroquinone, alkylated bisphenol, 2.5-di-t-amylhydroquinone, polybutylated bisphenol A, bisphenol A , 2.6-bis (2'-hydroxy-3-t-butyl-5'-methyl-benzyl)-
4-methylphenol, 1.3.5-tris (4-t-
Butyl-3-hydroxy-2.6-dimethylbenzyl)
Isocyanurate, terephthaloyl-di (2.6-dimethyl-4-t-butyl-3-hydroxybenzylsulfide), 2.6-di-t-butyl-α-dimethylamino-p-cresol, 2 .2'-methylene-bis (4-methyl-6-cyclohexylphenol), hexamethylene glycol bis (3.5-di-t-butyl-4-hydroxyphenyl) propionate, 6- (4-hydroxy- 3.5-di-t-butylanilino) -2,4-bis (octylthio) -1.3.5-triazine, 2.2-
Thio- [diethyl-bis-3- (3.5-di-t-butyl-4-hydroxyphenyl) propionate], N.I.
N'-hexamethylenebis (3.5-di-t-butyl-
4-hydroxy-hydrocinamide), 3.5-di-t-
Butyl-4-hydroxy-benzyl-phosphoric acid diethyl ester, 2.4-dimethyl-6-t-butylphenol, 4.4-methylenebis (2.6-di-t-butylphenol), 4.4'-thiobis (2 -Methyl-6-t
-Butylphenol), tris [β- (3.5-di-t
-Butyl-4-hydroxyphenyl) propionyl-oxyethyl] isocyanurate, 2.4.6-tributylphenol, bis- [3.3-bis (4'-hydroxy-3'-t-butylphenyl) -butyric acid ] Glycol ester, 4-hydroxymethyl-2.
6-di-t-butylphenol, bis (3-methyl-4)
-Hydroxy-5-t-butylbenzyl) sulfite and other phenolic antioxidants, N-phenyl-N'-isopropyl-p-phenylenediamine, N-phenyl-
N '-(1.3-dimethylbutyl) -p-phenylenediamine, N.V. N′-diphenyl-p-phenylenediamine, 2.2.4-trimethyl-1.2-dihydroquinoline polymer, amine antioxidant such as diaryl-p-phenylenediamine, dilauryl thiodipropionate, distearyl Examples thereof include sulfur antioxidants such as thiodipropionate and 2-mercaptobenzimidazole, and phosphorus antioxidants such as distearyl pentaerythritol diphosphite, but are not limited thereto. These antioxidants are used alone or in combination of two or more.

These antioxidants can be dispersed in water by using an emulsifier alone, a suspending agent alone or a combination of an emulsifying agent and a suspending agent. When the emulsifying agent is dispersed alone, the particle size is preferably 10 μm or less. 99 less than 5 μm
% Or more, the particle size of 50 μm or less is 99% or more when the suspension agent is used together, or the particle size is 5% when the emulsifier and the suspension agent are used in combination.
It is desirable that the particle size of 0 μm or less is 99% or more.
If more than these particle sizes are used, the antioxidant will often precipitate or float and cause phase separation,
In many cases, it is necessary to disperse it again before use.

In the present invention, the particle size distribution of the antioxidant dispersed in water was measured by a centrifugal automatic particle size distribution measuring device.

Usually, the concentration of the antioxidant in the emulsion is preferably 70 to 1% by weight, and when it exceeds 70% by weight, the fluidity of the emulsion is deteriorated, which is not preferable and less than 1% by weight. However, since a predetermined amount of antioxidant is added, it is necessary to add a large amount of emulsion, which is not preferable. More preferably, it is 65 to 10% by weight. The amount of the emulsifier used in this case is preferably 10 to 0.1% by weight in the emulsion, and the amount of the suspending agent used when dispersing the suspension alone is 10 to 0.5 in the emulsion. % Is preferable, and when the emulsifier and the suspending agent are used in combination, the amount of the emulsifier is 10 to 0.
It is preferable to add 1% by weight and the amount of the suspending agent so as to be 10 to 0.5% by weight in the emulsion.

The emulsifier used to disperse the antioxidant may be anionic, amphoteric, cationic or nonionic.

As the anionic emulsifier, lauric acid,
Fatty acids such as palmitic acid and stearic acid, sulfuric acid esters of acidic alkyl alcohols, paraffin sulfonic acids, alkylaryl sulfonic acids (eg dodecylbenzene sulfonic acid or dibutylnaphthalene sulfonic acid), alkali metals such as sulfo-succinic acid dialkyl esters, alkaline earths A salt with a metal or ammonium, and an epoxy group-containing fatty acid such as epoxystearic acid, a peracid (eg peracetic acid) and an unsaturated fatty acid (eg oleic acid or linoleic acid) or an unsaturated oxyfatty acid (eg ritinoleic acid) Examples thereof include salts with alkali metals or ammonium such as reaction products of. Examples of the amphoteric or cationic emulsifiers include alkylbetaines such as dodecylbetaine, alkylpyridinium salts such as laurylpyridinium-hydrochloride, and alkylammonium salts such as oxyethyl-dodecyl-ammonium chloride.

As the nonionic emulsifier, glycerin-
Mention may be made of fatty acid partial esters of polyhydric alcohols such as monostearate, sorbit-monolaurate and -oleate, polyoxyethyl esters of fatty acids or aromatic hydroxy compounds, polypropylene oxide-polyethylene oxide-condensation products and the like. These emulsifiers may be used alone or in combination of two or more as required. Among them, a nonionic emulsifier is preferably used.

The ratio of the emulsifier in the emulsion is preferably 10 to 0.1% by weight, more preferably 5 to 0.5% by weight. 1
If it exceeds 0% by weight, the cost becomes high, which is not preferable. Further, if it is less than 0.1% by weight, the storage stability of the emulsion is deteriorated, which is not preferable.

Examples of the suspending agent used to disperse the antioxidant include polyvinyl alcohol, cellulose derivatives, maleic anhydride-styrene copolymers, maleic anhydride-methyl vinyl ether copolymers, gelatin and the like.

The proportion of the suspending agent in the emulsion is preferably 10 to 0.5% by weight, more preferably 5 to 1% by weight. If it exceeds 10% by weight, the cost becomes high, which is not preferable.
If it is less than 5% by weight, the storage stability is deteriorated, which is not preferable.

The water used is not particularly limited, but deionized water and distilled water are preferably used. The method of adding the antioxidant dispersed in water may be before polymerization, during polymerization, or after polymerization, but before polymerization, it is manually charged from the manhole of the polymerization machine or automatically charged by a pump, or the polymerization reaction is stopped. Occasionally, a pot is used for manual charging or automatic pumping, but in either case, automatic pumping is preferable from the viewpoint of workability.

The proportion of the antioxidant emulsion added is 0.0.
01 to 1.0% by weight is preferable, 0.002 to 2% by weight
Is more preferable. If it is less than 0.001% by weight, the deterioration of the vinyl chloride resin cannot be prevented, and if it is more than 1.0% by weight, it is necessary to increase the amount of emulsion added.
This results in an increase in OD, which is not preferable.

[0031]

EXAMPLES The present invention will be described in more detail with reference to examples and comparative examples.

Throughout the examples and comparative examples, the thermal stability of Congo red of vinyl chloride resin was determined by adding 60 parts of dioctyl phthalate and 2 parts of T-72 (organotin) to 100 parts of the polymer to make a sol and heating it to 170 ° C. Was treated for 10 minutes to prepare a film, and the film was measured according to JIS K6723.

Example 1 50 parts of powdery 4.4'-butylidene bis (3-methyl-6-tert-butylphenol) having a particle size of 10 μm or less and 99.1% by weight, deionized water 48 parts, and sorbit mono 2 parts of laurate was placed in a stirring tank and homogenized with a homogenizer. The obtained emulsion had good fluidity. This emulsion was used for the polymerization of vinyl chloride monomer.

450 kg of water in a polymerization machine having an internal volume of 1000 L,
Sodium lauryl sulfate 3 kg, lauryl alcohol 6 kg, α-cumylperoxyneodecanate 0.1
2 kg, dioctyl peroxydicarbonate 0.06 kg
Was charged and the space was replaced with nitrogen, and then the pressure inside the container was reduced to 300 kg of vinyl chloride. The temperature inside the container is 30 ℃
And kept stirring for 30 minutes. Next, after homogenizing the liquid in the pre-stirrer with a pressure homogenizer, it was charged into a glass lining polymerization reactor with a volume of 1000 L under a reduced pressure of 35 mmHg abs by a vacuum pump and reacted at 50 ° C. When a pressure of 5 kg / cm ² G was reached, 1.5 kg of the above emulsion was pressed into the polymerization machine using a mill flow pump and stirred, and then unreacted monomers were recovered and the polymer latex was spray dried. After drying, it was crushed and obtained as a product.

The product obtained had a Congo red thermal stability of 80 minutes, and the same amount as in Example 1 was applied to a vinyl chloride resin obtained by emulsion polymerization without adding the above-mentioned antioxidant emulsion. It was better than the Congo red thermal stability (30 minutes) when 4.4'-butylidene bis (3-methyl-6-tert-butylphenol) was added.

Comparative Example 1 50 parts of powdery 4.4'-butylidene bis (3-methyl-6-tert-butylphenol) having a particle size of 10 μm or less and 99.1% by weight and 50 parts of deionized water were placed in a stirring tank. It was taken and stirred with a homogenizer, but it was not homogeneous, and the antioxidant floated on the water when the stirring was stopped. It was tried to press this product into the polymerization machine using a mill flow pump in the same manner as in Example 1, but only the separated water was pressed in,
The antioxidant could not be pressed.

Example 2 Fine powder of bisphenol A40 having an average particle size of 50 μm
Parts, deionized water 57 parts, and sorbit monolaurate 3 parts were put into a ball mill and pulverized and dispersed until the particle diameter of particles having a particle diameter of 5 μm or less became 99% by weight. The obtained emulsion had good fluidity.

1.5 kg of the above emulsion in the same manner as in Example 1.
Was pressed in, dried with a spray dryer and then pulverized to obtain a product. The resulting product has a Congo red thermal stability of 50 minutes, and is 30 when the same amount of bisphenol A is added to the emulsion polymer obtained by emulsion polymerization without adding the emulsion of the above-mentioned antioxidant. It was better than the minutes.

Comparative Example 2 10 parts of bisphenol A and 90 parts of methanol were placed in a stirring tank and stirred to dissolve.

An emulsion polymerization reaction of vinyl chloride was carried out in the same manner as in Example 2 except that 6.0 kg of this methanol solution was press-fitted in place of the emulsion of Example 2.

The heat stability of Congo red of the obtained product was 48 minutes, and the exhaust gas discharged from the dryer contained a large amount of methanol, and it was necessary to treat the exhaust gas.

Example 3 In Example 2, emulsion polymerization was carried out using sodium lauryl sulfate instead of sorbit monolaurate to obtain a product.

The heat stability of Congo red of the obtained product was 48 minutes, and when the same amount of bisphenol A was added to the polymer powder obtained by carrying out the polymerization without adding water suspension of the above-mentioned antioxidant. It was excellent in comparison.

However, the volume resistivity of the obtained product was 0.43 × 10 ¹³ Ωcm, which was slightly inferior to that of Example 2.

Example 4 Powdered bisphenol A35 having an average particle size of 50 μm
Parts, deionized water 61 parts, glycerin monostearate 2 parts, partially saponified polyvinyl alcohol 2 parts with a saponification degree of 80 mol% and an average degree of polymerization of 2000 are placed in a stirring tank and homogenized with a homogenizer to obtain a particle size of 99.
It was pulverized and dispersed until it became 5% by weight. The obtained emulsion had good fluidity. This emulsion was used for the polymerization of vinyl chloride monomer.

This emulsion 1.7 was prepared in the same manner as in Example 1.
After press-fitting kg, dehydration and drying, a vinyl chloride resin was obtained as a product.

The heat stability of Congo red of the obtained product was 55 minutes, which was higher than that of the polymer powder obtained by the polymerization without adding the water suspension of the above-mentioned antioxidant, to which bisphenol A was similarly added. Was excellent.

Example 5 Powdered bisphenol A35 having an average particle size of 50 μm
Part, deionized water 62 parts, partially saponified polyvinyl alcohol having a degree of saponification of 80 mol% and an average degree of polymerization of 2,000 are placed in a stirring tank and homogenized by a homogenizer to give a particle size of 50.
The particles were pulverized and dispersed until the content of μm or less became 99.5% by weight.
The obtained emulsion had good fluidity. This emulsion was used for the polymerization of vinyl chloride monomer.

This emulsion 1.7 was prepared in the same manner as in Example 1.
After press-fitting kg, dehydration and drying, a vinyl chloride resin was obtained as a product.

The congo red thermal stability of the obtained product was 45 minutes, and when bisphenol A was similarly added to the emulsion polymer obtained by emulsion polymerization without adding water suspension of the above-mentioned antioxidant. It was excellent in comparison.

Example 6 The emulsion of Example 1 was used in the emulsion polymerization of vinyl chloride monomer.

450 kg of water in a polymerization machine having an internal volume of 1000 L,
Sodium lauryl sulfate 3 kg, lauryl alcohol 6 kg, α-cumylperoxyneodecanate 0.1
2 kg, dioctyl peroxydicarbonate 0.06 kg
Was charged, and after the space was replaced with nitrogen, the pressure inside the container was reduced and 300 kg of vinyl chloride was charged. Then, 1.5 kg of the emulsion of Example 1 was pressed into the polymerization machine using a mill flow pump, After stirring, keep the temperature inside the container at 30 ° C and
Stir and mix for minutes. Next, homogenize the liquid in the preliminary stirrer with a pressure homogenizer, and then use a vacuum pump to produce 35 mmHg abs.
Into a glass-lined polymerization reactor having a volume of 1000 L under reduced pressure, reacted at 50 ° C., and when the internal pressure reached 5 kg / cm ² G pressure, the emulsion 1.
After 5 kg was pressed into the polymerization machine using a mill flow pump and stirred, the unreacted monomer was recovered, and the polymer latex was dried by a spray dryer and pulverized to obtain a product.

The heat stability of Congo red of the obtained product was 80 minutes, and the same amount as in Example 1 was applied to the vinyl chloride resin obtained by emulsion polymerization without adding the emulsion of the above-mentioned antioxidant. It was better than the Congo red thermal stability (30 minutes) when 4.4'-butylidene bis (3-methyl-6-tert-butylphenol) was added.

[0054]

INDUSTRIAL APPLICABILITY According to the present invention, there is a great industrial value that a vinyl chloride resin which can be charged automatically with an antioxidant and has improved thermal stability is obtained.

Claims (4)

[Claims] 1. A method of polymerizing vinyl chlorides by an emulsion polymerization method in an aqueous medium, wherein an antioxidant in powder form is dispersed in water in a fine powder form by an emulsifier and / or a suspending agent during polymerization of vinyl chlorides. A method for polymerizing vinyl chlorides, which comprises adding the emulsion as described above, and uniformly dispersing an antioxidant in the resulting vinyl chloride resin. 2. The particle size of the antioxidant dispersed in water as a fine powder is 10 μm or less, and the composition of the emulsion is 1 to 70% by weight of the antioxidant, 0.1 to 10% by weight of the emulsifier, and The method for polymerizing vinyl chlorides according to claim 1, wherein the content of water is 98.9 to 20% by weight. 3. The particle size of the antioxidant dispersed in water in the form of fine powder is 50 μm or less, and the composition of the emulsion is 1 to 70% by weight of the antioxidant, 0.1 to 10% by weight of the emulsifier, The method for polymerizing vinyl chlorides according to claim 1, wherein the suspension agent is 0.5 to 10% by weight and the water is 98.4 to 10% by weight. 4. The method for polymerizing vinyl chlorides according to any one of claims 1 to 3, wherein the emulsifier is a nonionic emulsifier.