JPH06107708A - Production of vinyl chloride polymer - Google Patents

Abstract

PURPOSE:To prevent the adhesion of scales and produce vinyl chloride polymer reduced in fish eyes by coating a thermal condensation product of a specific compound on the inner wall of a polymerizer and subsequently polymerizing vinyl chloride monomer in an aqueous medium. CONSTITUTION:The method for polymerizing vinyl chloride monomer or the mixture of vinyl chloride monomer with a copolymerizable monomer in an aqueous medium comprises preliminarily coating a thermal condensation product on the inner wall and monomer-contacting parts of a polymerizer and subsequently polymerizing the vinyl chloride monomer. The thermal condensation product is produced by reacting (A) a sulfur-containing phenolic compound, e.g. a sulfur- containing bisphenolic compound, (B) a polyhydric phenol having only a benzene skeleton, and (C) an aromatic diamine, A being 20-85mol.%, preferable 30-75mol.%, based on the total amount of A-C, the molar ratio of C to B being 0.5-10 times, preferable 1-5 times, in the presence of an acidic catalyst at 100-400 deg.C, preferably 150-300 deg.C. A, B and C are simultaneously reacted, or A is reacted with B or C and subsequently with the remaining component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vinyl chloride polymer, and more particularly, to prevent scale from adhering to the inner wall of a polymerization vessel and other portions where the monomer contacts during the polymerization reaction. The present invention relates to a method for producing an improved vinyl chloride polymer to be obtained.

[0002]

2. Description of the Related Art Conventionally, when a vinyl chloride polymer is polymerized in an aqueous medium, various methods have been proposed in which a chemical is applied to the inner surface of the polymerization vessel in order to prevent the scale from adhering to the inner wall of the polymerization vessel. Has been done. As the coating agent, for example, a method of applying a sulfoxide compound and / or a sulfone compound (JP-A-51-151788), a method of applying an initial condensation product of phenol and aldehyde and a cocondensation product of a nitrogen-containing compound ( Japanese Patent Publication 61-84
3), a method of applying a reaction product of thiodiphenol and a bleaching agent (Japanese Patent Publication No. 56-500417). Even if these coating agents are used and combined with high pressure water washing of the inner wall surface after reaction,
When 70 batches of polymerization are repeatedly carried out, the scale gradually adheres to the inner wall of the polymerization vessel, the heat removal capacity of the polymerization vessel is reduced, and the scale peeled off during the polymerization is mixed in the product. There is a problem that the quality of the product is deteriorated by causing fish eyes of the molded product. Further, the method of applying the initial condensate of phenol and aldehyde and the cocondensate of the nitrogen-containing compound is such that a slight amount of about several ppm remains with respect to the monomer such as vinyl chloride in the polymerization system. However, there is a drawback that it causes the delay of the polymerization, and the method of applying the sulfoxide compound and / or the sulfone compound is sufficient because the adhesive force to the inner wall of the polymerization container, the baffle plate, the stirring blade, etc. is small. There was a problem that it was not possible to obtain a large scale prevention effect. On the other hand, in recent years, the production method of vinyl chloride polymer using a large-scale polymerizer or reflux condenser has been adopted on an industrial scale, so that a coating agent excellent in scale prevention effect and its sustainability. Is coveted. That is, since the cooling area of the jacket for removing the reaction heat is relatively small with respect to the internal volume of the large-scale polymerization reactor, in order to improve the productivity of polymerization, the scale is prevented from adhering and the jacket heat removal is performed. Maintaining capacity is extremely important. Also, like the inner wall of the polymerization reactor, the reflux condenser, which contacts the monomers during the polymerization reaction, has a complicated structure such as internal heat transfer tubes, so once the scale adheres, it takes a lot of time to remove it. It takes labor. Therefore, it is an extremely important technical subject to develop a coating agent which is excellent in scale prevention effect and its durability and which does not deteriorate the quality.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to apply a coating agent which does not cause deterioration of quality such as coarsening of polymer particles and increase of fish eyes and which is excellent in scale prevention durability. Accordingly, it is an object of the present invention to provide a method for producing a vinyl chloride polymer having an improved scale adhesion preventing property on the inner wall of a polymerization vessel, a reflux condenser, and the like.

[0004]

Means for Solving the Problems That is, the present invention provides a method for polymerizing a vinyl chloride monomer or a mixture of a vinyl chloride monomer and a vinyl chloride monomer-copolymerizable monomer in an aqueous medium. A method for producing a vinyl chloride polymer in which a thermal condensation product of a sulfur phenol compound, a polyhydric phenol and an aromatic amine is applied in advance to the inner wall of the polymerization vessel and a portion where other monomers come into contact, particularly, in the production method, heat treatment is performed. The molar ratio of the components constituting the condensate is 20 to 85 mol% with respect to the total number of mols of all the constituent components of the sulfur-containing phenolic compound, and the molar ratio of the aromatic compound to the polyhydric alcohol is 0.5. It is intended to provide a method for producing a vinyl chloride-based polymer which is 10 times as much. Such an object of the present invention is to provide a sulfur-containing phenolic compound and a polyhydric phenol when polymerizing a vinyl chloride monomer or a mixture of a vinyl chloride monomer copolymerizable with vinyl chloride and a vinyl chloride monomer in an aqueous medium. And the aromatic amine thermal condensate is applied by previously coating the inner wall of the polymerization vessel and the portion where other monomers come into contact with each other. The sulfur-containing phenol compound used in the present invention is selected from, for example, bisphenol compounds. As typical examples thereof, pentafluorophenyl sulfide, 4-fluoro-3-nitrophenyl sulfone, 4-chlorophenyl sulfoxide, 4-chlorophenyl sulfone, 4-fluorophenyl sulfone,
4-nitrophenyl sulfone, 4-chlorophenyl sulfone, 4-amino-4′-nitrodiphenyl sulfone, phenyl sulfoxide, phenyl sulfone,
Examples include, but are not limited to, 4,4'-thiodiphenol, 4,4'-sulfonyldiphenol, resorcinol sulfoxide, phenyl sulfide, 3-aminophenyl sulfone and 4-aminophenyl sulfone. is not.

The polyhydric phenol used in the present invention has only one benzene ring skeleton and does not contain bisphenols. Typical examples thereof include phenol, catechol, resorcinol, pyrogallol, hydroquinone, hydroxyhydroquinone, phloroglicinol,
(O, m, p-) hydroxybenzaldehyde, salicylic acid, 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, (o, m, p-) nitrophenol, 4,4 ′
-Dihydroxyphenylmethane, (o, m, p-) chlorophenol, (o, m, p-) bromophenol,
Examples thereof include (o, m, p-) cresol, pt-butylphenol, pt-butylcatechol, etc., but are not limited to these. The aromatic amines used in the present invention include aminophenol, aminoanisole, aminophenetol, N-methylaminophenol, N-dimethylaminophenol, aminocresol, aminocatechol, aminoguaiacol, aminoresorcin, aminohydroquinone, diamino. Phenol,
Diaminoanisole, diaminoresorcin, aniline,
Phenylenediamine, N-methylaniline, N, N-dimethylaniline, toluidine, N-methylanthranilic acid, diaminobenzoic acid, aminobenzenesulfonic acid,
Examples thereof include, but are not limited to, methylaniline sulfonic acid, dimethylaniline sulfonic acid, aniline disulphonic acid, aminotoluene sulfonic acid, and phenylenediamine sulfonic acid. In the present invention, the sulfur-containing phenol compound used as a coating agent, as a method for producing a thermal condensate by the reaction of a polyhydric phenol and an aromatic amine, in the presence of an acidic catalyst, a sulfur-containing phenol compound, a polyhydric phenol and Each component of the aromatic amine is reacted at the same time, or the sulfur-containing phenol compound is reacted with one component of the polyhydric phenol or the aromatic amine, and then the other component is added and reacted. The reaction is 100-400 ° C, preferably 150-300 ° C
A typical method is to react at a temperature of 1 to 10 hours. As the acidic catalyst used here, hydrochloric acid, sulfuric acid, mineral acids such as phosphoric acid, paratoluene sulfonic acid, methane sulfonic acid, oxalic acid, organic acids such as formic acid and aluminum chloride, ferric chloride, stannous chloride, Lewis acids such as boron trifluoride and boron tribromide can be used. Further, the amount of the acidic catalyst varies depending on the reaction temperature, the charging ratio of each component constituting the thermal condensate or the charging sequence and the desired reaction time, but usually 0.001 to 1 per mol of all the constituents charged. A molar range can be employed.

In the present invention, a reaction product particularly useful as a coating agent for preventing scale adhesion is a sulfur-containing phenol compound, a polyhydric phenol or an aromatic amine as a raw material, and a sulfur-containing phenol compound, a polyhydric phenol or an aromatic compound. The molar ratio of the sulfur-containing phenol compound to the total number of moles of the group amine is 20 to 85 mol%, preferably 30 to 75.
Mol%, and the molar ratio of aromatic amine to polyhydric phenol is 0.5 to 10 times, preferably 1 to 5 times.
It is desirable to prepare the reaction so that the amount of reaction is doubled and to react. The above-mentioned sulfur-containing phenol compound is charged in a molar ratio of 20.
If it is less than mol%, the polymerization inhibiting effect is slightly lowered, and therefore the effect of preventing scale growth tends to be slightly lowered.
On the other hand, when the molar ratio of the sulfur-containing phenol compound to the polyhydric phenol exceeds 85 mol%, a strong polymerization inhibiting effect is exerted, so that depending on the polymerization mode, adverse effects such as slowing of the polymerization rate and deterioration of the quality of polymer particles may occur. Therefore, the molar ratio is preferably 20 to 85 mol%. When the molar ratio of the aromatic amine to the polyhydric phenol is less than 0.5 times, it is presumed that the adhesion to the metal surface due to the unshared electron pair of the aromatic amine decreases. The tendency of the water resistance of the polymer to appear decreases, and the coating agent may elute from the inner wall surface of the polymerization vessel into the aqueous medium during polymerization for a long time, which may reduce the persistence of the scale prevention effect. When the molar ratio of the amine to the polyhydric phenol exceeds 10, the hydrophilic effect is reduced, the solubility of the reaction product in alkaline water when preparing a coating solution is poor, and the coating amount is reduced or workability is difficult, and thus the scale prevention effect is obtained. May decrease, and the molar ratio may be 0.5 to 1
It is desirable to make it 0 times. That is, a coating agent comprising a reaction product obtained by reacting a sulfur-containing phenol compound, a polyhydric phenol and an aromatic amine in a specific ratio is a strong polymerization inhibiting effect by the sulfur-containing phenol compound, a coating film by the polyhydric phenol. It has the hydrophilic effect of 1) and the adhesion of the compound to the coating film by the aromatic amine in a harmonious manner, and exhibits the scale preventing effect and its excellent sustaining effect without deteriorating the quality of the product.

According to the method for producing a reaction product according to the present invention, the molecular weight and the softening point of the reaction product obtained are as follows:
Varies with catalyst amount, usually molecular weight (by GPC)
Is about 500 to 3,000, and the softening point is in the range of 70 to 250 ° C. The reaction product thus obtained may be used by dissolving it in a polar organic solvent such as alcohol, but it is usually used by dissolving it in an aqueous solution of an alkali metal hydroxide such as sodium hydroxide. As for the coating method, a known method such as spraying or brush coating is used to form a coating film on the inner wall of the polymerization vessel, agitator, baffle, reflux condenser, etc. where the monomer contacts during the polymerization reaction. be able to. In this way, it is possible to prepare with an aqueous solution of an alkali metal hydroxide such as sodium hydroxide,
It is very useful from the viewpoint of the COD problem of waste water that occurs when an organic solvent is used, the working environment in the polymerization vessel, and the explosion-proof safety. The coating amount may at the same level as when using a conventional coating agent, generally 0.001 to 20 g / m ² in solids is preferably 0.1 to 10 g / m ^2. If necessary, the surface after coating can be dried by heating, or can be simply washed with water. In this manner, the vinyl chloride polymer is produced using the polymerization vessel having the coating film of the coating agent formed on the inner surface thereof. It can be applied to suspension polymerization, emulsion polymerization, and fine suspension polymerization. The present invention is. It can be based on a homopolymerization reaction of vinyl chloride and a copolymerization reaction with a monomer which is copolymerizable with a vinyl chloride monomer. The monomer copolymerizable with the vinyl chloride monomer in the present invention is not particularly limited as long as it is a copolymer with vinyl chloride, any monomer may be used,
For example, an alkyl vinyl ester such as vinyl acetate, an alkyl vinyl ether such as cetyl vinyl ether, an α-monoolefin such as ethylene or propylene, an acrylic acid alkyl ester such as methyl acrylate and methyl methacrylate can be used.

The suspending agent, emulsifying agent and polymerization initiator used in the present invention are those usually used in suspension polymerization or emulsion polymerization of vinyl chloride. Examples of the suspending agent include polyvinyl alcohol, partially saponified polyvinyl acetate, cellulose derivatives such as methyl cellulose and hydroxypropylmethyl cellulose, and synthetic polymer substances such as maleic anhydride-vinyl acetate copolymer. Examples of emulsifiers include sorbitan esters or glycerin esters of higher fatty acids, and nonionic surfactants such as polyoxyethylene adducts thereof, anionic surfactants such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate. To be done. Examples of the polymerization initiator include di-2-ethylhexyl peroxydicarbonate, diethoxyethyl peroxydicarbonate, α-cumylperoxyneodecanate, t-butylperoxypivalate, 3,5,5-trimethylhexanoyl. Organic peroxides such as peroxides and acetylcyclohexylsulfonyl peroxide, and one of azo compounds such as α, α'-azobisisobutyronitrile and α, α'-azobis-2,4-dimethylvaleronitrile or Examples include a mixture of two or more kinds. In emulsion polymerization, a water-soluble catalyst such as potassium persulfate or ammonium persulfate is used as necessary with a reducing agent such as L-ascorbic acid. Further, if desired, a mercaptoalkanol, a chain transfer agent such as thioglycolic acid alkyl ester, an oil-soluble suspension aid such as polyvinyl alcohol having a saponification degree of 20 to 55 mol%, a pH adjusting agent and a polymerization inhibitor may be added. It can also be used. The polymerization is usually carried out at a temperature of 35 to 80 ° C. under stirring, and the charging amount and the number of parts of each component may be the conventional conditions conventionally used in vinyl chloride polymerization, and are not particularly limited. .

[0009]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Parts and% in the examples and comparative examples are based on weight unless otherwise specified. The physical properties of the vinyl chloride polymer shown in each example were measured by the following methods. (1) Fish eye 100 g of vinyl chloride polymer and dioctyl phthalate 4
5 g, cadmium stearate 2 g, barium stearate 1 g, and green toner 1 g were added and mixed, and then kneaded with a 6-inch roll at 145 ° C. for 6 minutes and drawn out to a sheet having a thickness of 0.4 mm.
It is shown by the number of transparent particles observed in m ² .

Comparative Example 1 A stainless steel polymerization vessel having an internal volume of 950 liters was degassed,
Deionized water 350 kg, vinyl chloride monomer 250 kg, partially saponified polyvinyl alcohol 140 g, di-2-ethylhexyl peroxydicarbonate 30 g and t-butyl peroxypivalate 50 g were charged and polymerization of vinyl chloride at 62 ° C. for 5 hours. I went. After the polymerization, the results of measurement of the weight of scale deposited on the inner wall of the polymerization vessel, scale 15 g / m ² in the liquid phase portion was 10 g / m ² in the gas phase portion.

Comparative Example 2 4,4'-Sulfonyldiphenol was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then the coating solution had an internal volume of 950 liters. Was coated on the inner wall of the stainless steel polymerization vessel of 2 g / m ^{2 so as to have} a coating amount of ² g / m ² (equivalent to pure content, the same hereinafter), and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the polymerization was completed, the thickness of the scale attached to the inner wall of the polymerization vessel was measured.
g / m ^2, it was 7g / m ² in the gas phase portion.

Comparative Example 3 4,4'-sulfonyldiphenol 10 was added to a four-necked flask.
0.3 g and 21.7 g of m-phenylenediamine were respectively weighed, 9.8 g of phosphoric acid was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. After the reaction is complete, cool to 200 ° C,
The reaction product was put into cold water and cooled. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a reddish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / A coating amount of m ² (converted to pure content, the same applies hereinafter) was applied and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured. As a result, the scale was 5 g / m ^{2 in the} liquid phase part and 5 g / m ^{2 in} the gas phase part.
It was m ² .

Comparative Example 4 4,4'-sulfonyldiphenol 10 was added to a four-necked flask.
0.3 g and resorcin 22.1 g were respectively weighed, phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. After completion of the reaction, the reaction product was cooled to 200 ° C., and the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a brown resinous reaction product was obtained. 0.5% of this reaction product
Dissolved in an aqueous solution of sodium hydroxide at a concentration of 1.0%
The coating solution was prepared, and then the coating solution was applied on the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters so as to have a coating amount of ² g / m ² , and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1.
After the polymerization, the results of measuring the scale thickness was adhered to the inner wall of the polymerization vessel, scale 9 g / m ² in the liquid phase portion was 11g / m ² in the gas phase portion.

Comparative Example 5 In a four-necked flask, 21.7 g of m-phenylenediamine and 22.1 g of resorcinol were weighed, and phosphoric acid as a catalyst 9.
8 g was added and the reaction was carried out at 270 ° C. for 1 hour. After completion of the reaction, the reaction product was cooled to 200 ° C., and the reaction product was put into cold water for cooling. After washing with water and dehydration, 1 at 50 ° C in a nitrogen atmosphere
It was dried for 2 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then Comparative Example 1
Polymerization of vinyl chloride was carried out in the same manner as in. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured. As a result, the scale was 9 g / m ^{2 in the} liquid phase part and 11 g in the gas phase part.
/ M ² .

Example 1 4,4'-Sulfonyldiphenol 10 was added to a four-necked flask.
0.3 g, resorcin 22.1 g, and m-phenylenediamine 21.7 g were weighed, phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 2 after the reaction
After cooling to 00 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured, and as a result, the scale had no liquid phase part and no gas phase part.

Example 2 82.9 g of phenyl sulfide and pt in a four-necked flask.
-Butylcatechol 37.0 g, aminophenol 24.
Weigh 3 g each and use aluminum chloride as a catalyst 9.
8 g was added and the reaction was carried out at 270 ° C. for 1 hour. After completion of the reaction, the reaction product was cooled to 200 ° C., and the reaction product was put into cold water for cooling. After washing with water and dehydration, 1 at 50 ° C in a nitrogen atmosphere
It was dried for 2 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then Comparative Example 1
Polymerization of vinyl chloride was carried out in the same manner as in. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured. As a result, the scale was 1 g / m ^{2 in the} liquid phase part and 3 g / m ^{2 in} the gas phase part.
It was m ² .

Example 3 91.7 g of 4,4'-thiodiphenol was added to a four-necked flask.
Pyrogallol (26.5 g) and aminoanisole (25.9 g) were weighed, paratoluenesulfonic acid (9.8 g) was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. After completion of the reaction, the reaction product was cooled to 200 ° C., and the reaction product was put into cold water for cooling. After washing and dehydration, under a nitrogen atmosphere at 50 ℃
And dried for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured, and as a result, the scale was found to have 2 g / m ^{2 in the} liquid phase part and none in the gas phase part.

Example 4 4,4'-Sulfonyldiphenol 15 was added to a four-necked flask.
00 g, resorcin 600 g, and m-phenylenediamine 900 g were weighed, 180 g of phosphoric acid was added as a catalyst, and the reaction was carried out at 250 ° C. for 1 hour. 20 after reaction
After cooling to 0 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%.
This coating solution was applied to the inner wall of a stainless steel polymerization vessel having an internal volume of 35 cm ³ so that the coating amount was 2 g / m ² , the coated surface was washed with water for 3 minutes, and then the polymerization vessel was deaerated and deionized water 16
Ton, followed by vinyl chloride monomer 13.5 tons, partially saponified polyvinyl alcohol 7.5 kg, di-2
3.5 kg of ethylhexyl peroxydicarbonate were simultaneously charged, and vinyl chloride was polymerized at a temperature of 57.5 ° C. for 8 hours. After the polymerization was completed and the contents were discharged, the inside of the polymerization vessel was washed with 250 kg / cm ² high-pressure water for 15 minutes. After washing with high-pressure water, the thickness of the scale attached to the inner wall of the polymerization vessel was measured. The scale had no liquid phase part or gas phase part.

Example 5 4,4'-Sulfonyldiphenol 6 was added to a four-necked flask.
2.5 g, resorcin 41.2 g, and m-phenylenediamine 40.5 g were weighed, phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 2 after the reaction
After cooling to 00 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the polymerization, the results of measuring the scale thickness was adhered to the inner wall of the polymerization vessel, scale 2 g / m ² in the liquid phase portion was 2 g / m ² in the gas phase portion.

Example 6 4,4'-sulfonyldiphenol 3 was added to a four-necked flask.
4.7 g, resorcin 10.4 g, and m-phenylenediamine 24.3 g were weighed, phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 2 after the reaction
After cooling to 00 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured, and as a result, the scale had no liquid phase part and no gas phase part.

Example 7 4,4'-Sulfonyldiphenol 3 was added to a four-necked flask.
4.7 g, resorcin 20.8 g and m-phenylenediamine 13.9 g were weighed and phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 2 after the reaction
After cooling to 00 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured. As a result, the scale had no liquid phase part and the gas phase part had 2 g / m ² .

Example 8 4,4'-Sulfonyldiphenol 8 was added to a four-necked flask.
3.3 g, resorcin 11.2 g and m-phenylenediamine 5.5 g were weighed and phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 20 after reaction
After cooling to 0 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the completion of the polymerization, the thickness of the scale attached to the inner wall of the polymerization vessel was measured. As a result, the scale was found to be 1 g / m ^{2 in the} liquid phase part and none in the gas phase part.

Example 9 4,4'-Sulfonyldiphenol 13 was added to a four-necked flask.
7.6 g, resorcin 3.3 g, and m-phenylenediamine 3.3 g were weighed, phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 200 after completion of reaction
After cooling to 0 ° C, the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / Apply so that the coating amount is m ² , and
It was dried at 0 ° C for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the polymerization, the results of the thickness of scale deposited on the inner wall of the polymerization vessel was measured, scale 4g / m ² in the liquid phase portion was 3 g / m ² in the gas phase portion.

Example 10 4,4'-Sulfonyldiphenol 7 was added to a four-necked flask.
2.1 g, resorcin 61.1 g and m-phenylenediamine 11.0 g were weighed and phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 2 after the reaction
After cooling to 00 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. This reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, and then this coating solution was applied to the inner wall of a stainless steel polymerization vessel having an inner volume of 950 liters at 2 g / The coating amount was set to m ² and dried at 80 ° C. for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the polymerization, the results of measuring the scale thickness was adhered to the inner wall of the polymerization vessel, scale 3 g / m ² in the liquid phase portion was 7 g / m ² in the gas phase portion.

Example 11 4,4'-Sulfonyldiphenol 7 was added to a four-necked flask.
2.1 g, resorcin 6.0 g, and m-phenylenediamine 66.1 g were weighed, phosphoric acid 9.8 g was added as a catalyst, and the reaction was carried out at 270 ° C. for 1 hour. 20 after reaction
After cooling to 0 ° C., the reaction product was put into cold water for cooling. After washing with water and dehydration, the product was dried in a nitrogen atmosphere at 50 ° C. for 12 hours. As a result, a blackish brown resinous reaction product was obtained. The reaction product was dissolved in a 0.5% aqueous sodium hydroxide solution to prepare a coating solution having a pure content of 1.0%, but in this case, the solution was not completely dissolved. Coat the inner wall of a 950 liter stainless steel polymerization vessel to a coating amount of ² g / m ² at 80 ° C.
And dried for 10 minutes. Then, vinyl chloride was polymerized in the same manner as in Comparative Example 1. After the polymerization, the results of the thickness of scale deposited on the inner wall of the polymerization vessel was measured, scale 4g / m ² in the liquid phase portion was 4g / m ² in the gas phase portion. From the above results, according to the method of the present invention, a polymerization reaction in which scale hardly adheres can be performed. Therefore, the heat removal ability of the polymerization vessel jacket can be maintained for a long period of time even if repeated polymerization is performed, and fish eyes do not increase, so that a product with high efficiency and high quality can be manufactured.

[0026]

According to the present invention, as compared with the prior art,
It is excellent in that it can effectively prevent scale adherence and that the effect can be maintained for a long period of time. Not only can the time required for scale removal work be greatly reduced, but the heat removal capacity of the polymerization reactor is also reduced due to scale adherence. Since this can be prevented, the advantage of improving the productivity of the vinyl chloride polymer production can be obtained. In addition, it is possible to reduce the fish eyes generated by the inclusion of scale in the product,
There is an advantage that scale adhesion can be prevented without deteriorating product quality such as particle size and porosity. Furthermore, since the scale inhibitor of the present invention can be applied as an alkaline aqueous solution,
There is also an advantage that drainage problems, working environment and safety problems do not occur in the coating process.

Claims (4)

[Claims] 1. When a vinyl chloride monomer or a mixture of a vinyl chloride monomer and a vinyl chloride monomer copolymerizable with the vinyl chloride monomer is polymerized in an aqueous medium, a sulfur-containing phenol compound, a polyhydric phenol and an aroma are used. A method for producing a vinyl chloride-based polymer, which comprises applying a thermal condensation product of a group amine to the inner wall of a polymerization vessel in advance. 2. The molar ratio of the components constituting the thermal condensate is 20 to 85 mol% of the sulfur-containing phenolic compound based on the total number of moles of all the constituent components, and the aromatic compound is based on the polyhydric alcohol. The method for producing a vinyl chloride polymer according to claim 1, wherein the molar ratio is 0.5 to 10 times. 3. The method according to claim 1 or 2, wherein the sulfur-containing phenolic compound comprises a bisphenolic compound. 4. The method according to claim 1, 2 or 3, wherein the polyhydric phenol has only one benzene ring skeleton.