JPH11130802A - Production of vinyl chloride-based polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject polymer capable of effectively preventing polymer scales from depositing and having high productivity by polymerizing a vinyl chloride monomer or the like in the presence of a specific condensed phosphoric acid-based compound in an aqueous medium using a polymerization initiator. SOLUTION: Vinyl chloride monomer or a vinylic monomer mixture consisting essentially of the vinyl chloride monomer is (co)polymerized in the presence of a condensed phosphoric acid-based compound having >=600 weight-average molecular weight (e.g. a linear condensate or a cyclic condensate) in an amount of preferably 25-200 ppm based on the monomer in aqueous medium in a polymerizing vessel having preferably >=80 m<3> internal volume by using a polymerization initiator (e.g. diisopropyl peroxydicarbonate or potassium persulfate) in an amount of 0.01-0.2 pt.wt. based on 100 pts.wt. monomer. Thereby, the objective polymer is produced. A coating film composed of a polymer scale deposition inhibitor is preferably formed on the inner wall surface of the polymerizing vessel and a part brought into contact with the monomer during the polymerization.

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 by controlling the formation of a polymer scale.

[0002]

2. Description of the Related Art In a method of suspension polymerization or emulsion polymerization of a vinyl chloride monomer or a mixture of a vinyl chloride monomer and another vinyl monomer in an aqueous medium in the presence of a polymerization catalyst. However, there is a problem that the polymer adheres as a scale to the inner wall surface of the polymerization vessel or a part of the equipment attached to the polymerization vessel in the polymerization process, such as the surface of the stirrer, which contacts the monomer, that is, the inner surface of the polymerization vessel. When the polymer scale adheres to the inner surface of the polymerization vessel in this manner, the heat transfer efficiency of the polymerization vessel wall, the polymer yield, etc. decrease, and the adhered scale peels off from the polymerization vessel and enters the product, so-called fish eye. The product quality is deteriorated. In addition, a great deal of labor and time is required to remove this scale, which leads to many undesirable disadvantages such as a decrease in the operation rate of the polymerization vessel.

In particular, in the case of suspension polymerization, the scale adhered to the polymerization vessel has a lower porosity (porosity) than that of a normal polymer produced at the same time. When mixed with the polymer, the affinity between the polymer and processing additives such as plasticizers added during molding processing deteriorates, and particles that do not partially dissolve in the final product (so-called fish eyes) may be generated. become. further,
If the polymerization is repeated without removing the scale from the polymerization vessel, the shape inside the polymerization vessel will change due to the accumulation of scale, and especially when the scale accumulation in the stirrer increases, the entire suspension system becomes large. Affected,
The shape, particle size distribution, yield and the like of the obtained polymer particles may be affected.

For such reasons, it is essential to periodically remove scale from the inner surface of the polymerization vessel. This requires shutting down or shutting down the operation of the polymerization vessel, and adds to the cost not directly related to the production of the polymer. The removal of the scale is generally performed by mechanically peeling off the inner surface, applying a high-speed jet water stream to the scale, or dissolving the scale with an organic solvent. In some of such operations, it is necessary for an operator to enter the vessel to perform the operation, but this involves the possibility of contact with a vinyl chloride monomer suspected of being carcinogenic, which is extremely undesirable. Also, mechanical removal of scale from the polymerization vessel is likely to damage the inner surface, which will promote scale formation in the next polymerization. In addition, the method of removing scale by using a solvent requires extra solvent recovery equipment and its operation cost and cost.

Therefore, as a method for preventing the adhesion of the polymer scale, a method of forming a coating film of a scale adhesion inhibitor on the inner wall of a polymerization vessel or the like is known, and various scale adhesion inhibitors have been proposed. ing. As the scale adhesion inhibitor, for example, dyes or pigments (JP-B-45-30835)
Polar organic compounds (JP-B-45-30343); polyaromatic amine compounds (JP-A-53-23381); condensates of phenol compounds with formalin or benzaldehyde (JP-A-54-36389). I have.

[0006] The formation of a coating film of these scale adhesion inhibitors is carried out as follows. After the polymerization is completed, the produced polymer slurry is withdrawn from the polymerization vessel, and the inside of the polymerization vessel is washed with water. (1) The polymer scale adhesion inhibitor coating solution is sprayed from a spray nozzle provided above the gas phase in the polymerization vessel. During polymerization of the inner wall surface and the like, spray coating is applied to a portion where the vinyl monomer comes into contact (coating step). (2) The coated surface after spray coating is dried to obtain a dried coating film (drying step). And (3) washing the dried coating film with water (water washing step).

After a coating film of a scale inhibitor is formed in this way, a vinyl chloride monomer and other raw materials are charged into a polymerization vessel and polymerization is carried out to produce a vinyl chloride polymer. Formation of polymer scale adhesion prevention coating film → raw material charging process → polymerization reaction process → recovery of unreacted monomer and extraction of polymer slurry → water washing process in polymerization vessel Shortening of recycling time is desired. As a part of this, it is required to reduce the time required for forming a coating film.

At the same time, recently, for the purpose of improving productivity, a polymerization method which uses a large polymerization vessel having a capacity of 40 m ³ or more and can shorten the polymerization reaction has been adopted. As described above, in the polymerization method capable of shortening the polymerization time, a method of increasing the amount of a polymerization initiator is employed. When the amount of the polymerization initiator is increased, the calorific value per unit time is large, so that it is necessary to improve the heat removal efficiency. As a heat removing means, a cooling jacket and a reflux condenser are typical. When the volume of the polymerization vessel is increased to 40 m ³ or more, the heat removal by the jacket is insufficient, so that it is necessary to increase the rate of heat removal by the reflux condenser. However, when the heat removal load of the reflux condenser is increased, the foaming of the slurry in the polymerization vessel increases, and the slurry overflows into the reflux condenser.As a result, the heat removal capability of the reflux condenser is reduced or the inside of the condenser is reduced. Adhesion of polymer scale occurs. In some cases, spilled polymer particles can clog the tubing, making it impossible to operate the condenser. Further, when the condenser is used from the beginning of polymerization, there are problems that the obtained polymer particles have a coarse particle size and that a foamy polymer is generated.

Therefore, when employing a polymerization method for shortening the polymerization reaction time by using a large polymerization vessel, the jacket and the reflux condenser alone have to have insufficient heat removal capacity, and the insufficient heat removal capacity is required. The capacity had to be compensated by other cooling methods. As such other cooling means,
An internal cooling device such as a cooling coil, a draft tube, and a cylindrical baffle for cooling is provided in the polymerization vessel.

[0010] When forming a coating film of the polymer scale adhesion inhibitor, conventionally, an efficient spray coating method has been used as described above. However, in this spray coating method, sufficient coating is not performed on a portion of the polymerization container that is shaded when viewed from the spray nozzle portion, for example, a surface of the baffle provided in the polymerization container facing the inner wall surface of the polymerization container, Application unevenness is likely to occur. In particular, as described above, when the structure inside the polymerization vessel is complicated by the internal cooling device, the places where coating is insufficient are increased. Therefore, as the number of repeated polymerization batches increases, the polymer scale adheres to portions where a sufficient coating film is not formed. As a countermeasure, it has been practiced to apply a sufficient amount of spray coating so as not to cause coating unevenness, that is, to apply a large amount of a polymer scale adhesion inhibitor coating solution over a long time in the coating process. However, as a result, it is often necessary to lengthen the drying time required in the drying step in accordance with the increase in the coating liquid, and in the water washing step, there is a large amount of the remaining polymer scale anti-adhesive coating liquid. Therefore, it is necessary to lengthen the washing time.

The prolongation of the time required for the formation of the coating film is inconvenient in that it goes against the above-mentioned demand for shortening the polymerization time. Furthermore, the use of a large amount of the polymer scale anti-adhesive agent coating solution reduces the initial coloring property of the vinyl chloride polymer product obtained by polymerization, and increases the colored foreign matter derived from the scale inhibitor in the product. Has a negative effect.

[0012]

The object of the present invention is, first, to make it difficult to apply an inhibitor by the surface of a polymerization vessel, especially by conventional spray coating, without applying a polymer scale adhesion inhibitor. Accordingly, it is an object of the present invention to provide a method for producing a high-productivity vinyl chloride-based polymer, which can effectively prevent the adhesion of the polymer scale even in a portion where the adhesion of the scale is likely to occur.

A second object of the present invention is to provide a highly productive chloride capable of obtaining a desired good scale prevention effect by a relatively short coating film forming operation even when the application of a polymer scale adhesion inhibitor is desired. An object of the present invention is to provide a method for producing a vinyl polymer.

[0014]

The present invention solves the above-mentioned problems by providing a vinyl chloride monomer or a vinyl monomer mixture mainly composed of a vinyl chloride monomer in an aqueous medium in a polymerization vessel. During the polymerization with a polymerization initiator, when producing a vinyl chloride-based polymer, the polymerization has a weight average molecular weight of 600 in an aqueous polymerization system containing the monomer or monomer mixture.
There is provided a method for producing a vinyl chloride polymer, which is carried out in the presence of the condensed phosphoric acid compound described above. In the method of the present invention, it is preferable that a coating film composed of a polymer scale adhesion inhibitor is further formed on the inner wall surface of the polymerization vessel and other portions where the monomer comes into contact during polymerization.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. MonomerAs the vinyl monomer polymerized by the method for producing a vinyl chloride polymer of the present invention, other than vinyl chloride alone, mainly vinyl chloride, and other monomers copolymerizable therewith. (Usually 50% by weight or more of vinyl chloride) can be used, and as a monomer copolymerized with this vinyl chloride,
Vinyl esters such as vinyl acetate and vinyl propionate,
Examples include acrylates or methacrylates such as methyl acrylate and ethyl acrylate, olefins such as ethylene and propylene, maleic anhydride, acrylonitrile, styrene, vinylidene chloride, and other monomers copolymerizable with vinyl chloride. .

Condensed phosphoric acid compound The condensed phosphoric acid compound has a weight average molecular weight of 60
0 or more, preferably 800 or more, more preferably 1600
That is all. Examples of the condensed phosphoric acid-based compound include those having various structures such as a linear condensate, a cyclic condensate, a graft-like (branched) condensate, and a network condensate. The acid-based compound is not particularly limited, and may be a single substance thereof or a mixture of two or more kinds.

Examples of the condensed phosphoric acid compound include an acid and a salt thereof. Examples of the salt include alkali metal salts such as sodium and potassium, alkaline earth metal salts such as calcium and magnesium, and ammonium salts. These include normal salts, acidic salts (hydrogen salts), single salts, and double salts. Any form may be used, and there is no limitation. The weight average molecular weight of this condensed phosphoric acid compound is a weight average molecular weight in terms of polyethylene glycol measured by gel permeation chromatography (GPC). Condensed phosphoric acid compound, a method is added and dissolved phosphorus pentoxide (P ₂ O ₅₎ while heating the phosphoric acid, the phosphate heated and dehydrated, 700 to 900 ° C.
And a method of melt polymerization.

In the present invention, the condensed phosphoric acid compound is added to the polymerization system in an amount of preferably from 10 to 1000 ppm, more preferably from 20 to 500 ppm, based on the weight of the monomers to be charged.
Particularly preferably, 25 to 200 ppm is added. If the amount of the condensed phosphoric acid compound is too small, a sufficient effect of preventing the adhesion of scale cannot be obtained, and if the amount is too large, there is a problem that the obtained vinyl chloride polymer may have a broad particle size distribution. The condensed phosphoric acid compound is usually added to the charged raw materials before the start of polymerization.

The production method and other polymerization conditions may be the same as those conventionally used for producing a vinyl chloride polymer by polymerization in an aqueous medium, as will be described at one end. As the polymerization initiator, an oil-soluble polymerization initiator and / or a water-soluble polymerization initiator are used. Examples of the oil-soluble polymerization initiator include diisopropyl peroxydicarbonate and di-2.
-Percarbonate compounds such as ethylhexyl peroxydicarbonate and diethoxyethyl peroxydicarbonate; t-butyl peroxyneodecanate, α-
Perester compounds such as cumylperoxyneodecanate and t-butylperoxyneodecanate; peroxides such as acetylcyclohexylsulfonyl peroxide and 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate; azobis- Examples include azo compounds such as 2,4-dimethylvaleronitrile and azobis- (4-methoxy-2,4-dimethylvaleronitrile). Examples of the water-soluble polymerization initiator include potassium persulfate, ammonium persulfate, and hydrogen peroxide. These exemplified polymerization initiators can be used alone or in combination of two or more.

The polymerization initiator is used during the charging of water or the monomer,
Alternatively, it may be added after the completion of charging, and may be uniformly mixed in advance with the monomer and charged together with the monomer, or may be charged together with the aqueous medium as an aqueous emulsion. These polymerization initiators are used for the monomer 100 to be charged.
It is preferred to use from 0.01 to 0.2 parts by weight per part by weight.

As the dispersion stabilizer, those conventionally used in the polymerization of vinyl chloride monomers can be used. Specifically, water-soluble starch ethers; acrylic acid polymers such as polyacrylic acid; Water-soluble polymers such as gelatin, partially saponified polyvinyl alcohol, and cellulose ether;
Oil-soluble partially saponified polyvinyl alcohol; oil-soluble emulsifiers such as sorbitan monolaurate, sorbitan triolate, sorbitan monostearate, glycerin tristearate, ethylene oxide / propylene oxide block copolymer; polyoxyethylene sorbitan monolaurate, polyoxy Ethylene glycerin oleate,
Water-soluble emulsifiers such as sodium laurate; calcium carbonate, calcium phosphate, sodium dodecylbenzenesulfonate, etc., which are used alone or in combination of two or more. The total amount of these dispersion stabilizers is usually from 0.02 to 1 per 100 parts by weight of the charged monomers.
What is necessary is just to adjust suitably in the range of a weight part. If necessary, it is also possible to add a polymerization regulator, a chain transfer agent, a pH regulator, a gelling improver, an antistatic agent and the like appropriately used for the polymerization of the vinyl chloride monomer.

The amount of the aqueous medium used for dispersing the monomer may be in a weight ratio to the monomer (water / monomer) of about 1.0 to 1.5, as in the conventional method. Water can be added during the polymerization. Further, the polymerization temperature may be set to about 40 to 70 ° C. similarly to the conventional method. Further, the method for charging the aqueous medium, the vinyl chloride monomer, other comonomer used in some cases, the dispersing aid, the polymerization initiator, and the like to the polymerization vessel may be performed in the same manner as the conventional method. May also be the same. In the present invention, examples of the polymerization method in an aqueous medium include suspension polymerization and emulsion polymerization, and it is preferable to use suspension polymerization.

The method of the present invention is effective when using a polymerization vessel having an internal volume of 40 m ³ or more, preferably 80 m ³ or more, provided with a stirrer and a jacket. Further, two or more cooling baffles are provided in the polymerization vessel,
It is particularly effective especially when a polymerization vessel having four or more polymerization vessels is used. Further, in the production method of the present invention, it is preferable that a coating film composed of a polymer scale adhesion inhibitor is formed on the inner wall surface of the polymerization vessel used and other portions where the monomer contacts during polymerization. . Less than,
The polymer scale adhesion inhibitor used for forming the coating film, the method for preparing the coating solution, and the method for forming the coating film will be described.

The polymer scale antiadhesive used in the coating solution for the polymer scale contains, as an active ingredient, an organic compound having 10 or more conjugated π bonds (hereinafter referred to as a conjugated π bond compound), and The molecular weight of the organic compound is 1000 or more, preferably 1500 or more. The molecular weight of the organic compound is preferably 50,000 or less, more preferably 20,000 or less. The molecular weight of the conjugated π-bonded compound is measured by gel permeation chromatography (GPC). Preferred examples of such a conjugated π-bonded compound are shown below.

Aldehyde compound / aromatic hydroxy system
The compound aldehyde compound / aromatic hydroxy compound condensation product is a condensation product of an aldehyde compound and an aromatic hydroxy compound. The use of such an aldehyde compound / aromatic hydroxy compound condensation product as a polymer scale adhesion inhibitor is described, for example, in JP-A-57-1.
92413, JP-B-06-62709, JP-A-57-1
64107.

Examples of the aldehyde compound include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, acrolein, crotonaldehyde, benzaldehyde, furfural, phenylacetaldehyde, 3-phenylpropionaldehyde,
-Phenylpropionaldehyde, etc., and formaldehyde and acetaldehyde are industrially and economically advantageous. Examples of the aromatic hydroxy compound include a dihydroxybiphenyl compound, a naphthol compound, a phenol compound, a tannin, and a dimer compound of 2,3-dihydroxynaphthalene.

Examples of dihydroxybiphenyl compounds include 2,2'-dihydroxybiphenyl and 2,2'-
Dihydroxy-5,5'-dimethylbiphenyl, 2,
2'-dihydroxy-4,4 ', 5,5'-tetramethylbiphenyl, 2,2'-dihydroxy-5,5'-dichlorobiphenyl, 2,2'-dihydroxy-5,5'
-Dicyclohexylbiphenyl, 2,2'-dihydroxy-5,5'-di-tert-butylbiphenyl and the like. Among them, 2,2'-dihydroxybiphenyl is particularly suitable industrially.

Examples of the naphthol compound include 1-naphthol, 1,3-dihydroxy-naphthalene, and 1,1-naphthol.
5-dihydroxy-naphthalene and 1,7-dihydroxy-naphthalene and the like. Examples of the phenolic compound include phenol, cresol, pyrogallol, hydroxyhydroquinone, resorcin, catechol, hydroquinone, bisphenol A, hydroxybenzoic acid, and salicylic acid. Examples of the tannins include tannic acid, quintuple tannin, gallic tannin, smack tannin, quebracho tannin, and persimmon tannin. As the dimer compound of 2,3-dihydroxynaphthalene, for example, 2,3,2 ', 3'-tetrahydroxyvionotyl and the like can be mentioned.

The condensation product of the aldehyde compound and the aromatic hydroxy compound is obtained by mixing these reaction components in a suitable medium in the presence of a catalyst, usually at room temperature to 200 ° C. for 2 to 100 hours, preferably 30 to 150 ° C. For 3 to 30 hours. As the medium for performing the above condensation reaction, for example, water, alcohols, ketones, organic solvents such as esters, for example, methanol, ethanol, alcohols such as propanol, acetone, ketones such as methyl ethyl ketone and the like. Esters such as methyl acetate and ethyl acetate are exemplified. The pH of the medium for performing the above condensation reaction is usually in the range of 1 to 13, and the pH adjuster can be used without any particular limitation. The condensation reaction catalyst as for example sulfuric acid used, hydrochloric acid, perchloric acid, P- toluenesulfonic acid, methanesulfonic acid, an acidic catalyst such as trifluoromethanesulfonic acid; NaOH, KOH, NH ₄ OH or the like of a basic catalyst Are used.

The ratio of the aldehyde to the aromatic hydroxy compound at the time of performing the condensation reaction is affected by the type of the aldehyde compound, aromatic hydroxy compound, solvent and catalyst used, the reaction time, the reaction temperature and the like. Usually, the aldehyde compound is preferably used in an amount of 0.1 to 10 mol per 1 mol of the aromatic hydroxy compound.

Pyrogallol / acetone condensation product Pyrogallol / acetone condensation product is a condensation product of pyrogallol and acetone.
The molar ratio of acetone is in the range of 1 / 0.1 to 1/10 and usually has a melting point of 100 to 500 ° C. The higher the molecular weight, the higher the melting point.For example, a melting point of 160-170 ° C. means a molecular weight of 1450-1650.
In addition, a melting point of 200-220 ° C. corresponds to a molecular weight of 2600-4000.
The use of such a pyrogallol / acetone condensation product as a polymer scale adhesion inhibitor is described, for example, in JP-A-4-328104. Pyrogallol / acetone condensation products are produced by dissolving pyrogallol in acetone and condensing in the presence of a condensation catalyst. At this time, pyrogallol is usually used in an amount of 1 to 100 parts by weight per 100 parts by weight of acetone, and, for example, oxyencarin or the like is used as a condensation catalyst. The reaction may be performed at room temperature to 100 ° C.

Polyhydric phenol self-condensation product and polyhydric phenol
The polyhydric phenols of the phthalol self-condensation product include , for example, catechol, resorcinol, chlororesorcinol , hydroquinone, phloroglucinol, pyrogallol, etc .; dihydroxytoluene and xylene; trihydroxytoluene and xylene;
Such as ethyl, propyl, butyl and ventilzye and trihydroxybenzene, and polyvalent naphthol is 1,
Examples include naphthol derivatives such as 3-, 1,4-, 1,5- or 1,7-dihydroxynaphthalene. The use of such a polyhydric phenol self-condensation product or a polyhydric naphthol self-condensation product as a polymer scale adhesion inhibitor is described, for example, in JP-A-54-7487.

The polyhydric phenol self-condensation product or polyhydric naphthol self-condensation product is prepared by reacting a polyhydric phenol or a polyhydric naphthol with an inert atmosphere such as nitrogen or argon.
It is manufactured by heating in a temperature range of 0 to 350 ° C. for 4 to 100 hours. Various catalysts such as zinc chloride, aluminum chloride and sodium hydroxide can be used for this reaction.

Examples of the aromatic amine compound condensation product aromatic amine compound condensation products, for example, self-condensation products of an aromatic amine compound, aromatic amine compound condensation product of a phenolic compound, A condensation product of an aromatic amine compound and an aromatic nitro compound; and a condensation product of an aromatic amine compound and an aromatic nitro compound based on an alkali metal salt or an ammonium compound. Use of such an aromatic amine compound condensation product as a polymer scale adhesion inhibitor is described, for example, in JP-B-59-16561 and JP-B-60-3068.
1 etc.

As the aromatic amine compound, aniline,
Ortho, meta or paraphenylenediamine, ortho, meta or paraaminophenol, ortho, meta or parachloroaniline, paraaminoazobenzene, 2,4-diaminoazobenzene, para-aminoacetanilide, ortho, meta or paramethylaniline, 4-aminodiphenylamine , 2-aminodiphenylamine, 4,4-diaminodiphenylamine, N, N-dimethyl-para-phenylenediamine, 4-amino-3'-methoxydiphenylamine, 4-amino-4'-hydroxydiphenylamine, 4-chloro-ortho- Phenylenediamine, 4-
Methoxy-ortho-phenylenediamine, 2-amino-
4-chlorophenol, 2,3-diaminotoluene,
Examples include diphenylamines such as 2,4-diaminophenol, 4-aminodiphenylamine, 2-aminodiphenylamine, 4,4'-diaminodiphenylamine, 4-amino-3'-methoxydiphenylamine, and 4-amino-4'-hydroxydiphenylamine. Is done.

The phenolic compounds include, specifically, phenol, hydroquinone, resorcinol, catechol,
Hydroxyhydroquinone, pyrogallol, ortho, meta or para-chlorophenol, ortho, meta or para-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3, 4-dihydroxybenzoic acid,
Phenol derivatives such as 3,5-dihydroxybenzoic acid, 2,5-, 2,6- or 3,5-dihydroxytoluene are exemplified.

Examples of the aromatic nitro compound include nitrobenzene, ortho, meta or paraoxynitrobenzene, ortho, meta or paranitroanisole, ortho, meta or paranitrophenetol, ortho, meta or parachloronitrobenzene, ortho, meta or paraaminonitrobenzene. Ortho, meta or para nitrobenzoic acid, ortho, meta or para nitrobenzene sulfonic acid, ortho,
Meta or para nitroaniline, 2-nitro-para-phenylenediamine, 2-amino-4-nitrophenol,
2-amino-5-nitrophenol, 4-amino-2-
Examples thereof include nitrophenol.

In order to carry out the self-condensation reaction of the aromatic amine compound alone, the condensation reaction of the aromatic amine compound with the phenol compound, and the condensation reaction of the aromatic amine compound with the aromatic nitro compound. , A mineral acid and a condensation catalyst are used. Examples of the mineral acid include hydrochloric acid, nitric acid, hydrobromic acid, phosphoric acid and sulfuric acid.

Suitable condensation catalysts include permanganic acid and salts thereof such as permanganic acid and potassium permanganate; chromic acid-related compounds such as chromium trioxide, potassium dichromate and sodium chromate; silver nitrate,
Metal nitrates such as lead nitrate, halogens such as iodine and bromine, hydrogen peroxide, sodium peroxide, benzoyl peroxide, potassium persulfate, ammonium persulfate, peracetic acid, cumene hydroperoxide, perbenzoic acid,
peroxides such as p-menthane hydroperoxide, oxygen acids or oxyacids such as iodic acid, potassium iodate, sodium chlorate, ferrous chloride, ferric chloride, copper sulfate, cuprous chloride And metal salts such as cupric chloride and lead acetate, and oxides such as ozone and copper oxide, mercury oxide, cerium oxide, manganese dioxide and osmic acid. It is also effective to use hydrogen peroxide in combination with ferrous chloride. The self-condensation reaction of the aromatic amine compound alone, the condensation reaction of the aromatic amine compound with the phenol compound, and the condensation reaction of the aromatic amine compound with the aromatic nitro compound are performed in the presence of a condensation catalyst. Performed at ~ 350 ° C for 2-100 hours.

In the condensation reaction between an aromatic amine compound and a phenol compound, and in the condensation reaction between an aromatic amine compound and an aromatic nitro compound, an aromatic amine compound, a phenol compound or an aromatic nitro compound is used. The ratio depends on the type of the aromatic amine compound, phenol compound, aromatic nitro compound and catalyst used, the reaction time, the reaction temperature, etc., but usually the aromatic amine compound 1
It is preferred that the phenolic compound or the aromatic nitro compound is used in an amount of 0.1 to 10 mol per mol.

To base the condensation product of an aromatic amine compound and an aromatic nitro compound with an alkali metal salt or an ammonium compound, for example, 100% by weight of the condensation product of an aromatic amine compound and an aromatic nitro compound Parts were dispersed in water, and NaOH, KOH, Na ₂ CO ₃ , NH ₄
10 to 20 parts by weight of an alkali or ammonium compound such as OH and (NH ₄ ) ₂ CO ₃ are added, and the mixture is heated at 90 to 140 ° C. The alkali or ammonium compound may be in an amount sufficient to neutralize the mineral acid used during the condensation reaction.

[0042] As the quinone compound condensation products quinone compound condensation products, for example, (A) a quinone compound self-condensation products, and (B) a quinone compound, an aromatic hydroxyl compound and an aromatic amine Examples include condensation products with one or more compounds selected from the compounds. The use of such a quinone-based compound condensation product or a polyvalent naphthol self-condensation product as a polymer scale adhesion inhibitor is described in, for example, JP-A-5-11.
2603 and 6-56911.

The quinone compounds include, for example, ortho, meta or para-benzoquinone, tol-para-
Quinone, ortho-xylo-para-quinone, thymoquinone,
Benzoquinones such as 2-methoxybenzoquinone, gentisylquinone, polypollic acid and ubiquinone n and derivatives thereof; 6-methyl-1,4-naphthoquinone, 2-methyl-1,4 naphthoquinone, α-naphthoquinone, juglone;
Lawson, bulbagin, alkannin, echinochrome A, vitamin K ₁ , vitamin K ₂ , shikonin, β, β '
-Naphthoquinones such as dimethyl acrylic shikonin, β-hydroxyisowarel shikonin, teracrylic shikonin and derivatives thereof; tectoquinone, 3-hydroxy-2
-Anthraquinones such as methylanthraquinone, anthraquinone, 2-hydroxyanthraquinone, alizarin, xanthobulbulin, rubiazine, mundistin, chrysophenic acid, carminic acid, kermesic acid, raccaic acid A and derivatives thereof; phenanthrenequinones such as phenanthrenequinone Is mentioned.

As the aromatic amine compound, specifically, aniline, ortho, meta or para-phenylenediamine, ortho, meta or para-chloroallylinine, ortho, meta or para-methylaniline, N,
N-dimethylparaphenylenediamine, 4-chloro-orthophenylenediamine, 4-methoxyorthophenylenediamine, 2-amino-4-chlorophenol, 2,
3-diaminotoluene, 4-amino-2-aminophenol; o-, m- or p-aminophenol, o
-, M- or p-aminobenzoic acid, 2,3-, 2,
4-, 2,5-, 2,6-, 3,4-, 3,5- or 4,6-diaminobenzoic acid, 3- or 4-aminophthalic acid, 2-, 4- or 5-aminoisophthalic acid , 4,6-diaminoisophthalic acid, 2,5- or 2,6-diaminoterephthalic acid, 3-, 4- or 5
-Aminosalicylic acid, 4-oxyanthranilic acid, o
-, M- or p-aminobenzenesulfonic acid, 2,
3-, 2,4-, 2,5-, 2,6-, 3,4- or 3,5-diaminobenzenesulfonic acid, 2-amino-
1-phenol-4-sulfonic acid, 6-amino-4-chloro-1-phenol-2-sulfonic acid, etc .; α-naphthylamine, β-naphthylamine, 1,5-diaminonaphthalene, 1-amino-5-hydroxynaphthalene , 1,
8-diaminonaphthalene, 2,3-diaminonaphthalene and the like; 4-amino-1-naphthol, 1-amino-5-naphthol, 1,2-naphthylenediamine-7-carboxylic acid, 1,5-naphthylenediamine- 2-carboxylic acid,
1,5-naphthylenediamine-4-carboxylic acid, 1,6
-Naphthylenediamine-4-carboxylic acid, 1,8-naphthylenediamine-4-carboxylic acid, 1,2-naphthylenediamine-3-sulfonic acid, 1,2-naphthylenediamine-4-sulfonic acid, , 2-Naphthylenediamine-5
-Sulfonic acid, 1,2-naphthylenediamine-6-sulfonic acid, 1,2-naphthylenediamine-7-sulfonic acid, 1,3-naphthylenediamine-5-sulfonic acid,
1,3-naphthylenediamine-6-sulfonic acid, 1,4
-Naphthylenediamine-2-sulfonic acid, 1,4-naphthylenediamine-7-sulfonic acid, 1,5-naphthylenediamine-2-sulfonic acid, 1,5-naphthylenediamine-4-sulfonic acid, , 5-Naphthylenediamine-7
-Sulfonic acid, 1,6-naphthylenediamine-2-sulfonic acid, 1,6-naphthylenediamine-4-sulfonic acid, 1,6-naphthylenediamine-7-sulfonic acid,
1,8-naphthylenediamine-4-sulfonic acid, 1,8
-Naphthylenediamine-3,6-disulfonic acid, 1,8
-Naphthylenediamine-4,5-disulfonic acid, α-amino-β-naphthalenepropionic acid, α-amino-β-
Naphthalenecarboxylic acid, 2-naphthylamine-1-sulfonic acid, 8-naphthylamine-1-sulfonic acid, 5-naphthylamine-1-sulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-8- Naphthol-6-sulfonic acid (γ-acid), 2-amino-5-naphthol-7-sulfonic acid (J-acid), 1-amino-8-naphthol-3,6-disulfonic acid (H-acid), etc .; Aminodiphenylamine, 2-aminodiphenylamine, 4,
4'-diaminodiphenylamine, 4-amino-3'-
Methoxydiphenylamine, 4-amino-4'-hydroxydiphenylamine, specifically, 4-hydroxydiphenylamine, 4-amino-4'-hydroxydiphenylamine, 4-carboxydiphenylamine, 4-amino-4'-carboxydiphenylamine, 4- Examples include diphenylamines such as sulfodiphenylamine and 4-amino-4'-sulfodiphenylamine.

Examples of the aromatic hydroxy compound include:
Phenol, hydroquinone, resorcinol, catechol, hydroxyhydroquinone, pyrogallol, ortho,
Meta or para-chlorophenol, ortho, meta or para-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-
Dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,5-, 2,6
Or phenols and phenol derivatives such as 3,5-dihydroxytoluene. Further, α-naphthol, β-naphthol, 1,3-, 1,4-, 1,5
Examples thereof include naphthol derivatives such as-, 2,3-, 2,6- or 2,7-dihydroxynaphthalene, 1-hydroxy-2-naphthoic acid, and 3-hydroxy-2-naphthoic acid.

The self-condensation of the quinone compound and the condensation of the quinone compound with the aromatic hydroxy compound and / or the aromatic amine compound are carried out in an organic solvent medium, if necessary, in the presence of a condensation catalyst. Will be The pH of the organic solvent-based medium is in the range of 1 to 13.5, preferably, pH 9 to 13.
It is. The pH adjuster can be used without any particular limitation.Examples of the acidic compound include phosphoric acid, sulfuric acid, phytic acid, and acetic acid, and examples of the alkaline compound include LiOH, KOH, and NaOH. Na ₂ CO ₃ , Na ₂ S
Alkali metal compounds such as iO ₃ , Na ₂ HPO ₄ and NH ₄ OH or ammonium compounds, organic amine compounds such as ethylenediamine, monoethanolamine and triethanolamine are used.

The medium for the condensation reaction is preferably an organic solvent such as alcohols, ketones and esters; a mixed solvent of water and a driving organic solvent miscible with water. Examples of the medium miscible with water include alcohols such as methanol, ethanol, and propanol; ketones such as acetone and methyl ethyl ketone; and esters such as methyl acetate and ethyl acetate.

If necessary, a condensation catalyst is used. Examples of the condensation catalyst include α, α′-azobisisobutyronitrile and α, α′-azobis-2,4-dimethylvaleronitrile. Azo catalyst, elemental or molecular elemental halogen such as iodine, bromine, chlorine, hydrogen peroxide, sodium peroxide, benzoyl peroxide, potassium persulfate,
Peroxides such as ammonium persulfate, peracetic acid, cumene hydroperoxide, perbenzoic acid, p-menthane hydroperoxide, oxygen acids such as iodic acid, periodate, potassium periodate, sodium perchlorate or oxygen acids Salts are exemplified. Since the quinone compound acts as a condensation catalyst, the condensation reaction is performed without using a condensation catalyst.

The condensation reaction is usually carried out at room temperature to 200 ° C. for 0.5 to
All you need to do for 100 hours. When the quinone compound (a) and the aromatic hydroxy compound and / or the aromatic amine compound (b) are condensed, the ratio of both reaction components is as follows: the aromatic amine compound, the quinone compound, and the aromatic hydroxy compound. In the present invention, the component (b) is used in an amount of 0.01 to 10.0 per mole of the component (a), although the type is affected by the type, reaction temperature, and reaction time.
It is preferred to be molar. The polymer scale inhibitors exemplified above can be used alone or in combination of two or more.

Preparation of Coating Solution for Polymer Scale Prevention Agent In order to form a coating film comprising a polymer scale prevention agent on the inner surface of a polymerization vessel, a coating solution is prepared using an appropriate solvent,
This is applied. Examples of the solvent used for preparing the coating solution for the polymer scale adhesion inhibitor include water; methanol,
Ethanol, propanol, butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-
Alcohol solvents such as propanol, 3-methyl-1-butanol, 2-methyl-2-butanol and 2-pentanol; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methyl formate, ethyl formate, methyl acetate; Ester solvents such as ethyl acetate and methyl acetoacetate; ether solvents such as 4-methyldioxolane and ethylene glycol diethyl ether; furans; aprotic solvents such as dimethylformamide, dimethylsulfoxide and acetonitrile. These are used singly or as a mixture of two or more solvents.

Preferred among the above solvents are water and a mixed solvent of water and an organic solvent miscible with water.
Among the above organic solvents, examples of the organic solvent having miscibility with water include alcohol solvents such as methanol, ethanol, and propanol; ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl acetate and ethyl acetate. Can be Particularly, it is preferable to use an alcohol solvent. When using a mixed solvent of water and an organic solvent that is miscible with water, the content of the organic solvent should be such that there is no danger of ignition, volatilization, etc., and there is no safety problem such as toxicity. More specifically, the content of the organic solvent is preferably 50% by weight or less, and more preferably 30% by weight or less. The coating solution has a pH of 7.5 to 13.5,
Further, it is preferable to use those in the range of 8.0 to 13.0. When it is in this range, the effect of preventing adhesion of the polymer scale is further improved. Examples of the alkaline compound used for pH adjustment include LiOH, NaOH, KOH, and Na ₂
Alkali metal compounds such as CO ₃ , Na ₂ HPO ₄ , and NH ₄ OH, or ammonia compounds, organic amine compounds such as ethylenediamine, monoethanolamine, diethanolamine, and triethanolamine can be used. The concentration of the conjugated π-bonding compound in the coating solution when applying the scale adhesion inhibitor is preferably in the range of 0.01 to 10% by weight, more preferably 0.05 to 3.0% by weight.

The above-mentioned polymer scale adhesion inhibitor preferably contains at least one member selected from the group consisting of inorganic colloids and alkali metal silicates in order to further improve the effect of preventing the adhesion of scale. The additive is
Possibly interacts with the conjugated π-bonding compound to increase the hydrophilicity of the surface of the resulting coating film of the anti-adhesion agent and to increase the adhesion of the anti-adhesion agent to the inner wall of the polymerization vessel. It is estimated to be.

As the inorganic colloid, for example, aluminum, thorium, titanium, zirconium, antimony,
Colloids of oxides and hydroxides of metals selected from tin, iron and the like, colloids of tungstic acid, vanadium pentoxide, gold and silver, colloids of silver iodide sol, selenium, sulfur, silica and the like can be mentioned. Preferred among these are colloids of oxides and hydroxides of metals selected from aluminum, titanium, zirconium, tin and iron, and colloidal silica. The inorganic colloid may be obtained by any production method, and the production method is not particularly limited. For example, a dispersion method using water as a dispersion medium,
A particle colloid produced by an aggregation method may be used. The size of the colloid particles is preferably from 1 to 500 mμ.

Examples of the alkali metal silicate include alkali metal metasilicates (M ₂ SiO ₃ ) such as lithium, sodium and potassium, and orthosilicate (M ₄ Si).
O ₄ ), disilicate (M ₂ Si ₂ O ₃ ), trisilicate (M ₃ Si
₃ O ₇ ), sesquisilicic acid (M ₄ Si ₃ O ₁₀ ) and the like (where M represents an alkali metal such as lithium, sodium and potassium), and water glass. The inorganic colloid and the alkali metal silicate can be used alone or in combination of two or more. Further, the amount of the component selected from the inorganic colloid and the alkali metal silicate,
Usually 0.01 to 10 parts by weight per 1 part by weight of the conjugated π bond compound.
Parts by weight, preferably 0.05 to 5 parts by weight. In addition, the above-mentioned polymer scale adhesion inhibitor preferably contains a water-soluble polymer compound in order to further improve the effect of preventing polymer scale adhesion. This is probably also the conjugate π
This is presumed to be due to the effect of increasing the hydrophilicity of the coating film surface by interacting with the binding compound.

Examples of the water-soluble polymer compound include amphoteric polymer compounds such as gelatin and casein; for example, anionic polymer compounds such as polyacrylic acid, polystyrenesulfonic acid, carboxymethylcellulose, and alginic acid; Cationic nitrogen-containing polymer compounds such as polyacrylamide; and hydroxyl group-containing polymer compounds such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, and pectin.

Formation of Coating Film In order to form a coating film on the inner wall surface of the polymerization vessel using the coating solution prepared as described above, first, the coating solution is applied to the inner wall surface of the polymerization container and the like. After being sufficiently dried in a temperature range from room temperature to 100 ° C., it is further washed with water if necessary. Further, the coating liquid is applied not only to the inner wall surface of the polymerization vessel but also to other portions where the monomer comes into contact during the polymerization. For example, a stirring blade, a stirring shaft, a baffle, a condenser, a header, a search coil, a bolt, a nut and the like can be mentioned. More preferably, even if the coating liquid is other than the part where the monomer comes into contact during polymerization, there is a possibility that the polymer scale may adhere thereto, for example, the inner surface of equipment and piping of a recovery system for unreacted monomer. For example, it is better to form the coating film. Specifically, the inner surfaces of a monomer distillation column, a condenser, a monomer storage tank, a valve and the like can be mentioned.

As described above, when a coating film is formed on a portion where the monomer comes into contact during the polymerization and on a portion where the polymer scale may adhere, the adhesion of the polymer scale to those portions is prevented. Is prevented. The method for applying the coating solution to the inner wall surface of the polymerization vessel is not particularly limited. Examples thereof include brush coating, spray coating, and a method in which the polymerization vessel is filled with the coating solution and then withdrawn.
57-61001, 55-36288, JP-B-56-501116, 56
No. -501117, spraying with N ₂ gas pressure described in JP-A-59-11303, etc., spray a monomer gas pressure, it is possible to use a method of coating spraying etc. by the low-pressure steam. Any of the coating methods may cause coating unevenness, but even in such a case, according to the method of the present invention, the adhesion of scale can be more effectively prevented than before. The jacket temperature of the polymerization vessel when applying is usually 10 to 95
° C, preferably 40-80 ° C. Drying after coating, jacket temperature 30 ~ 95 ℃, preferably 40 ~ 80 ℃
The inside of the container is dried under reduced pressure without opening the inside of the container.

[0058]

Examples 1 to 5: Comparative Examples 1 to 3 In each of the examples, a flat plate baffle, a stirrer, a jacket outside the polymerization vessel, a reflux condenser at the head of the polymerization vessel, and an upper portion of the gas phase portion of the polymerization vessel were used. 900 kg of deionized water is placed in a stainless steel polymerization vessel having an internal volume of 2.1 m ³ in which a spray nozzle for coating a polymer scale antiadhesive agent coating solution is laid, and the condensed phosphoric acid compounds described in Table 1 are shown in the same table. Then, 360 g of a water-soluble partially saponified polyvinyl alcohol and 60 g of an oil-soluble partially saponified polyvinyl alcohol were charged, and after evacuation of the inside of the polymerization vessel, 600 kg of a vinyl chloride monomer was charged. Next, 420 g of t-butyl peroxyneodecane
The polymerization was started by heating the contents by passing hot water through a jacket while stirring the contents in the polymerization vessel with stirring blades, and the temperature of the contents was adjusted to 57 ° C. After a lapse of 60 minutes from the start of heating, the reflux condenser was activated to start removing heat from the contents (heat removal amount: 150Mcal
/time). The pressure in the polymerization vessel is 6.5 kg / cm ² G (740 Kpa)
Then, the reaction was stopped (polymerization time was 4.3 hours).

After completion of the polymerization, unreacted monomers are recovered from the polymerization vessel, the obtained polymer is drawn out of the vessel in the form of a slurry, and the polymerization vessel is washed with water to remove the residual resin in the polymerization vessel. Was removed. Thereafter, the operations from charging of the raw materials, through polymerization, and washing with water were performed as one batch, and the same operation was repeated for the number of batches shown in Table 1. After the end of the final batch, the polymer scale on the inner wall surface of the polymerization vessel existing in the liquid phase during the polymerization and the surface of the flat plate baffle facing the inner wall surface of the polymerization vessel (the surface that becomes negative as viewed from the spray nozzle) The state of adhesion was observed. The results of the observation are shown in Table 2. After the final batch was completed, the polymer slurry obtained by extracting from the polymerization vessel was dehydrated and dried to obtain a vinyl chloride polymer. Table 2 shows the initial colorability test and the results of the obtained vinyl chloride polymer by the following method.

<Method of Measuring Initial Colorability> Vinyl Chloride Polymer
100 parts by weight of tin laurate 1.0 part, cadmium-based stabilizer 0.
5 parts and 50 parts of a plasticizer DOP were blended and kneaded at 160 ° C. for 5 minutes using a 6-inch roll to form a 0.8 mm thick sheet. Next, cut and overlap this sheet, 4cm x 4cm x
Put in a 1.5cm formwork and heat at 150 ℃, 65 ~ 70kgf / cm2,
A measurement sample was prepared by pressure molding. Using a photoelectric colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd.), the JIS Z-
L value, a value, b in the color difference formula of Hunter described in 8730
The values were measured and evaluated. At the same time, evaluation was made by visual observation.

Comparative Example 4 The polymerization vessel used in Example 1 was used, and (A) CI Direct Blue 1
(Brand name: Aldrich dye) (B) CI Direct Blue 12 (Brand name: Aldrich dye) and (C)
Phytic acid is polymerized from an aqueous solution having a weight ratio of (A) / (B) / (C) = 5/1/9 and a total concentration of {(A) + (B) + (C)} of 5% by weight. Spray coating was applied to the entire inside of the polymerization vessel from a spray nozzle installed above the gas phase part of the vessel. Spray application is liquid volume
This was performed at a rate of 100 g / min for 2 minutes. Next, it took 10 minutes at 50 ° C. to dry-form the coating film in the drying step. Next, it took 2 minutes to remove the remaining coating solution in the washing step. Therefore, the time required for forming the coating film composed of the polymer scale adhesion inhibitor (the time from the start of the application of the polymer scale adhesion inhibitor coating solution to the end of the water washing step) was 14 minutes.

Polymerization of vinyl chloride was carried out under the same conditions as in Comparative Example 3 except that a polymerization vessel having a coating film of the polymer scale adhesion inhibitor formed on the inner wall surface of the polymerization vessel was used. After completion of the polymerization, unreacted monomers were recovered from the polymerization vessel, and the obtained polymer was drawn out of the vessel in the form of slurry, and then the polymerization vessel was washed with water to remove the residual resin in the polymerization vessel. Thereafter, the operations from the formation of the coating film of the polymer scale adhesion inhibitor, the preparation of the raw materials, and the operations from polymerization to water washing were defined as one batch, and the same operation was repeated for the number of batches shown in Table 2. After the end of the final batch, the state of adhesion of the polymer scale on the inner wall surface of the polymerization vessel existing in the liquid phase during the polymerization and the surface of the flat plate baffle facing the inner wall surface of the polymerization vessel was observed. The results of the observation are shown in Table 2. Table 2 shows the results of the initial coloring test.

Comparative Example 5 A coating operation was performed in the same manner as in Comparative Example 4, except that spray coating was performed at a liquid amount of 100 g / min for 5 minutes. As a result, at 50 ° C., 10
It took a minute. In the washing step, it took 2 minutes to remove the remaining coating solution. Therefore, it took a total of 17 minutes to form a coating film composed of the polymer scale adhesion inhibitor. Polymerization was carried out in the same manner as in Comparative Example 3 except that the polymerization vessel on which the coating film was formed was used. Similarly, the number of batches shown in Table 2 was repeated. After completion of the final batch, the state of polymer scale adhesion on the liquid layer in the polymerization vessel, the polymerization vessel wall surface, and the flat plate baffle surface facing the polymerization vessel wall surface was observed. The results of the observation are shown in Table 2. Table 2 shows the results of the initial coloring test.

[0064]

[Table 1] **) Measurement of molecular weight of condensed phosphoric acid compound The weight average molecular weight in terms of polyethylene glycol was measured by gel permeation chromatography (GPC) under the following measurement conditions.

Column: Shodex OHpak KB-800KB + 802.
5 × 2 (SHOKO Co., Ltd.) Mobile phase: 0.1M-Nacl Flow rate: 0.7 ml / min Temperature: 40 ° C. Detector: RI (Shodex SE-61, SHOKO Co., Ltd.)

[0066]

[Table 2]

In the following examples, polymer scale adhesion inhibitors containing various condensation products as active ingredients were used. Production examples of these condensation products are shown below. Production of Condensation Product In the following Production Examples, the molecular weight of the obtained condensation product was measured as follows.

By [0068] the Molecular weight measured gel permeation chromatography (GPC), in the following measuring conditions, to measure the weight average molecular weight in terms of polystyrene. Column: Guard column Product name slim-pack GPC-800DP, Analytical column manufactured by Shimadzu Corporation Product name slim-pack GPC-803D, 802D, manufactured by Shimadzu Corporation Mobile phase: 10 mM LiBr / DMF Flow rate: 1.0 ml / min Detector: RI temperature: 60 ℃

Production Example 1 Production of condensation product No. 1: methanol 30,000 in a pressure-resistant reactor
Mol (960 kg), 1,8-diaminonaphthalene 100 mol (1
5.8 kg), 50 mol (5.4 kg) of parabenzoquinone, and 250 mol (31.5 kg) of pyrogallol, and the mixture was heated to 80 ° C. with stirring. After reaction at 80 ° C. for 5 hours, the mixture was cooled to obtain a methanol solution of a condensation product. Thus, the condensation product N
A solution of o.1 was obtained. The weight average molecular weight of condensation product No. 1 is
2,000.

Production Example 2 Production of condensation product No. 2: With reference to Production Example 3 of JP-B-6-62709, a scale adhesion inhibitor was produced. A pressure-resistant reactor is charged with 30 mol of 2,2'-dihydroxybiphenyl (5.59 kg), 22.5 mol (0.711 kg) of paraformaldehyde having a purity of 95%, 0.19 kg of paratoluenesulfonic acid and 10 L of ethylene glycol dimethyl ether. The temperature rose. After reacting at 130 ° C. for 17 hours, it was cooled to 50 ° C., and the reaction mixture was poured into 50 L of water. Filtration of resin precipitated by pouring into water, washing with water and drying, 5.1 kg
2,2'-dihydroxybiphenyl-formalin condensation resin (condensation product No. 2) was obtained. The weight average molecular weight of the condensation product No. 2 was 4,300.

Production Example 3 Production of condensation product No. 3: A scale adhesion inhibitor was produced with reference to Production Example 1 of JP-A-57-164107. 250 mol of 1-naphthol (36.0kg) and 1N NaOH aqueous solution
180 L (containing 180 mol of NaOH and 7.2 kg) was charged, and the temperature was raised to 70 ° C. while stirring. Next, formaldehyde (19.75 L of a 38 w / v% aqueous solution, 250 mol) was added dropwise to the reaction mixture over 1.5 hours. During this time, the internal temperature of the reactor was kept from exceeding 80 ° C. The reaction mixture is then stirred for 3 hours.
Cooled to 60 ° C. over time. Next, the reaction mixture was heated to 98 ° C. and reacted at 98 ° C. for 0.5 hour. Thereafter, the reaction mixture was cooled to obtain an alkaline solution of a condensation product (condensation product No. 3). The weight average molecular weight of the condensation product No. 3 was 1500.

Production Example 4 Production of Condensation Product No. 4: A scale adhesion inhibitor was produced with reference to Synthesis 2 of Coating Compound of JP-A-57-192413. 100 mol of pyrogallol (12.6 kg) and 100 L of water in a pressure-resistant reactor
And pyrogallol was dissolved in water. Next, 200 mol (21.2 kg) of benzaldehyde and 300 mol (29.4 kg) of phosphoric acid were added to the obtained solution, and the mixture was reacted at 100 ° C. for 6 hours. As a result, a red-brown product insoluble in water was obtained. Obtained. After washing the water-insoluble product with ether, a methanol-soluble component is extracted from the water-insoluble product with methanol, and then methanol is removed from the extract by drying, and the condensation product No. 4 (pyrogallol- Benzaldehyde condensate). The weight average molecular weight was 4000.

Production Example 5 Production of condensation product No. 5: With reference to Production Example 1 of JP-B-59-16561, a scale adhesion inhibitor was produced. 100 mol (10.8 kg) of m-phenylenediamine, 200 mol (22.0 kg) of resorcinol and 1.04 kg of 35% hydrochloric acid (HC
(10 mol as l)), and the temperature was raised to 305 ° C. As soon as the mixture in the reaction vessel reached 305 ° C, it was cooled. Water vapor generated during the heating and reaction processes is removed, and the internal pressure is 150k
It was kept below Pa. After cooling, the obtained m-phenylenediamine-resorcinol condensate was pulverized to obtain a condensation product No. 5
I got The weight average molecular weight was 3,000.

Production Example 6 Production of condensation product No. 6: With reference to Production Example VI of JP-B-59-16561, a scale adhesion inhibitor was produced. In a pressure-resistant reactor, 100 mol (10.9 kg) of p-aminophenol and 0.3% of 30% hydrochloric acid were added.
99 kg (9.5 mol as HCl) were charged and the temperature was raised to 169 ° C. When the temperature reached 169 ° C., 18 L of xylene was gradually added. The purpose of the addition of xylene is to remove water generated during the condensation reaction as an azeotrope. Next, the reaction mixture was heated to 222 ° C. and reacted at 222 ° C. for 3 hours. Remove the mixed vapor of xylene and water generated during the reaction,
It was kept below 150 kPa. After 3 hours of reaction, the reaction mixture was cooled. The obtained reaction product was solid. Next, the reaction product was pulverized into fine particles, washed with water, filtered and dried to obtain a condensation product No. 6. The weight average molecular weight was 2500.

Production Example 7 Production of condensation product No. 7: With reference to Example 1 of JP-A-54-7487, a scale adhesion inhibitor was produced. The reactor was charged with 200 mol (22.0 kg) of resorcinol and heated under a nitrogen atmosphere. Resorcinol was heated to 300 ° C., reacted at 300 ° C. for 8 hours, and cooled. The obtained solid self-condensation resorcinol was pulverized to obtain a condensation product No. 7.
The weight average molecular weight was 1700.

Production Example 8 Production of condensation product No. 8 Internal volume equipped with a reflux condenser
A mixed solvent of 450 g of methanol and 450 g of water was added to a 2-liter reactor, followed by 100 g of α-naphthoquinone and 10 g of sodium hydroxide. Next, the inside of the reactor
The temperature was raised to 5 ° C., and the mixture in the reactor was reacted at 65 ° C. for 10 hours, and then cooled to room temperature. Thus, a solution of condensation product No. 8 was obtained. The weight average molecular weight of the condensation product No. 8 was 3,000.

Preparation Example 9 Preparation of Condensation Product No. 9 A 3 L flask equipped with a reflux condenser was charged with 1 L of pure water, and then 5 g of sodium hydroxide and 50 g of 2,3,2 ', 3'-tetrahydroxybinaphthyl.
Was charged. Then, after the temperature was raised to 70 ° C., a solution obtained by dissolving 12.75 g of a 37% aqueous formaldehyde solution in 237.3 g of distilled water was added dropwise over 30 minutes. After the completion of the dropwise addition, the reaction was carried out at the same temperature for 5 hours, and then the temperature was raised to 95 ° C., and the reaction was continued for another 2 hours to obtain a solution of condensation product No. 9. This reaction was all performed in an N ₂ atmosphere. The weight average molecular weight of the condensation product No. 9 was 9,000.

Preparation of coating solution: condensation product N obtained above
o.1 to 9 and a solvent and a pH adjuster shown in Table 3 were used to prepare a coating solution under the conditions shown below.

[0079]

[Table 3]

Example 6 The polymerization apparatus shown in FIGS. 1 to 3 was used. FIG. 1 schematically shows a longitudinal section of a polymerization vessel 1 of the polymerization apparatus, and FIG. 2 shows A at a position of a coating apparatus 6 provided at an upper portion of the polymerization vessel.
-A is a horizontal sectional view, and FIG. 3 is a BB horizontal sectional view. This polymerization vessel 1 has a substantially cylindrical side wall 1a, a substantially hemispherical ceiling 1b and a bottom 1c, an internal volume of 2 m ³ , and a horizontal cross-sectional area of the cylindrical portion space of 0.865 m ² . The paddle blade 2 provided on the stirring shaft 3 disposed at the center of the polymerization vessel 1 has a blade diameter of 517 mm. Although not shown as a cooling means, a reflux condenser is provided at the top of the polymerization vessel, and a jacket is provided outside. Further, a polymerization coating device 6 having a total of 12 upward spray coating nozzles 13 and 12 downward spray coating nozzles 14 is attached to the upper part in the polymerization container. A pipe 7 is connected to the coating device 6, and the pipe 7 branches into a coating liquid piping line 18 and a washing water piping line 19.

The cooling baffle 4 has an outer diameter of 60.5 mm,
Four cooling baffles composed of austenitic stainless steel cylindrical pipes having an inner diameter of 52.7 mm (cooling water flows as streamline 5) at a position not obstructing the rotation of the paddle blade (455 mm from the center of the polymerization vessel) ) Are provided at equal intervals and point-symmetrically. The sum of the horizontal cross-sectional areas of these four baffles is 0.01149 m ² . A pipe 20 is connected to the bottom of the polymerization vessel 1 and a polymer slurry take-out pipe line 10 is connected.
And the drainage discharge pipe 12 are branched.

Step of Forming Coating Film for Polymer Scale Adhesion Prevention Agent: Warm water at 50 ° C. was passed through the attached jacket. The valves 16 and 9 were closed. Valve 17, valve
15, Valve 8 and Valve 11 were opened. The polymer scale anti-adhesive coating solution was sent to the polymer scale anti-adhesive coating device 6 through a pipe line 18 of the polymer scale anti-adhesive coating solution, and spray-coated from the spray nozzles 13 and 14 attached thereto. Spray coating was performed at a flow rate of 1200 g / min for 2 minutes. During the spray coating, the polymer scale adhesion preventing coating solution remaining at the bottom of the polymerization vessel was recovered from the drainage pipe line 12. After the spray application was completed, valves 15 and 17 were closed. It took 10 minutes at 50 ° C. to dry form the coating. Thereafter, the flow of warm water through the attached jacket was stopped. Next, the valves 16 and 15 are opened in the water washing step. The washing water was sent to the coating device 6 through the washing water pipe line 19, and sprayed from the attached spray coating nozzles 13 and 14 to remove the polymer scale adhesion preventing coating solution remaining in the polymerization vessel. During the water washing, the washing liquid remaining at the bottom of the polymerization vessel was drained and collected from the piping line 12. It took 2 minutes to remove the remaining polymer scale adhesion preventing coating solution in the washing step. Therefore, the time required for forming the coating film composed of the polymer scale adhesion inhibitor was 14 minutes. Next, after the horizontal process is completed, the valves 16, 15, 8, and 11 are closed.

Polymerization step: 900 kg of deionized water, the amount of the condensed phosphoric acid compound shown in Table 4 in the polymerization vessel of the above polymerization apparatus, in the amount shown in the same table, water-soluble partially saponified polyvinyl alcohol
After charging 360 g of oil-soluble partially saponified polyvinyl alcohol 60 g and evacuating the polymerization vessel, vinyl chloride monomer
600kg was charged. Next, 420 g of t-butyl peroxyneodecane was charged, and while the contents in the polymerization vessel were stirred with stirring blades, hot water was passed through the jacket to raise the temperature of the contents, thereby starting polymerization. After a lapse of minutes (the temperature of the contents: 57 ° C.), the reflux condenser was operated to start removing heat from the contents. (Heat removal: 150Mcal
/time). After the pressure in the polymerization vessel was reduced to 6.5 kg / cm ² G (740 kPa), the reaction was stopped (polymerization time was 4.3 hours).

After completion of the polymerization, unreacted monomers are recovered from a polymerization vessel through a recovery line (not shown), and the obtained polymer is slurried, valves 8 and 9 are opened, and a polymer slurry removal pipe After extracting from the line 10, the inside of the polymerization vessel was washed with water to remove the residual resin in the polymerization vessel.
Thereafter, the operations from the step of forming the coating film of the polymer scale adhesion inhibitor to the polymerization step (from the preparation of the raw materials through the polymerization and washing with water) were regarded as one batch, and the same operation was repeated in the number of batches shown in Table 6. After the final batch, the state of adhesion of the polymer scale on the inner wall surface of the polymerization vessel and the surface of the cooling baffle facing the inner wall surface of the polymerization vessel was observed. Table of the observation results
It is noted in 5.

After the final batch was completed, the polymer slurry obtained by extracting from the polymerization vessel was dehydrated and dried to obtain a vinyl chloride polymer. The obtained vinyl chloride polymer was subjected to an initial colorability test, a foreign matter fisheye test and a foreign matter evaluation test by the following methods. The results are shown in Table 5.

<Fish-Eye Measurement Method> 100 parts of the obtained vinyl chloride polymer, 50 parts of DOP, and 0.2 part of barium stearate.
1 part, cadmium stearate 0.1 part, cetanol 0.8
Parts, tin-based stabilizer, 2.0 parts 0.5 parts of titanium dioxide and 0.1 parts of carbon black, and 5 minutes mixing and kneading at a 6 inch roll of 140 ° C., aliquoted as sheet thickness 0.3 mm, in the sheet 100 cm ² It was indicated by the number of white transparent particles (fish eyes). (Here, “parts” means “parts by weight”.) <Test Method for Foreign Material Evaluation> Place 50 g of the obtained vinyl chloride polymer on white paper, add 5 ml of ethanol, mix well, and visually check for chloride. Pick up foreign substances other than vinyl polymer powder with a spoon. The number of foreign substances is represented by (number of picked up pieces) × 2 = (number of foreign substances in 100 g of vinyl chloride polymer).

Examples 7 to 10 and Comparative Examples 6 to 8 Vinyl chloride was added in the same manner as in Example 6 except that the condensed phosphoric acid compounds shown in Table 4 were added in the amounts shown in the same table, or were not added at all. A polymer was produced. The polymerization was repeated for the number of batches shown in Table 5, and the test was performed in the same manner as in Example 6 after the final batch. Table 5 shows the results. Comparative Example 9 A vinyl chloride polymer was produced in the same manner as in Example 6 except that a coating solution of a polymer adhesion inhibitor was applied at a flow rate of 1200 g / min for 5 minutes, and no condensed phosphoric acid compound was added. In this case, the time required for forming the coating film composed of the polymer scale adhesion inhibitor was 17 minutes in total. The polymerization was repeated for the number of batches shown in Table 5, and the test was performed in the same manner as in Example 6 after the final batch. Table 5 shows the results. Comparative Example 10 Production of vinyl chloride polymer in the same manner as in Example 6 except that the condensed phosphoric acid-based compound shown in Table 4 was added in the amount shown in the same table, and the polymer scale adhesion inhibitor coating solution was not applied. Was done. The polymerization was repeated for the number of batches shown in Table 5, and the test was performed in the same manner as in Example 6 after the final batch. Table 5 shows the results.

[0088]

[Table 4]

[0089]

[Table 5]

Examples 11 to 18 In each example, the production of the vinyl chloride polymer was carried out in the same manner as in Example 6 except that the coating solution was changed to the one shown in Table 6 and the number of batches shown in Table 7 was repeated. went. Table 7 shows the results.

[0091]

[Table 6]

[0092]

[Table 7]

Example 19 The structure was the same as that shown in FIGS. 1 to 3, but a large polymerization apparatus was used. This polymerization vessel 1 has an internal volume of 80 m ³ ,
The horizontal cross-sectional area of the cylindrical straight body is 10.2 m ² . The paddle blade 2 provided on the stirring shaft 3 disposed at the center of the polymerization vessel 1 has a blade diameter of 1775 mm. Although not shown as a cooling means, a reflux condenser is provided at the top,
A jacket is provided on the side. Further, a coating device 6 provided with a total of 12 spray coating nozzles 13 and 14 is provided in the upper part of the polymerization vessel. Cooling baffle 4
Four baffles consisting of austenitic stainless steel cylindrical pipes with an outer diameter of 190 mm and an inner diameter of 178 mm
It is provided at equal intervals and symmetrically with respect to the axis 3 at a position where the rotation of the paddle blade is not hindered (at a position 1565 mm from the center of the polymerization vessel).

Step of Forming Coating Film Made of Polymer Scale Adhesion Prevention Agent: The attached jacket was passed hot water at 50 ° C. The valves 16 and 9 are closed. Valve 17, valve
15. Open the valve 8 and the valve 11. The polymer scale anti-adhesive agent coating solution is spray-coated from the spray application nozzles 13 and 14 provided to the polymer scale anti-adhesive agent application device 6 through a pipe line 18 of the polymer scale anti-adhesive agent application solution. Spray coating was performed at a flow rate of 150 kg / min for 1 minute. During the spray coating, the polymer scale adhesion preventing coating solution remaining at the bottom of the polymerization vessel was drained and collected from the piping line 10. After the spray application step, the valves 15 and 17 are closed. It took 15 minutes at 50 ° C. to dry form the coating. Thereafter, the flow of warm water through the attached jacket was stopped. Next, the valves 16 and 15 are opened in the water washing step. The cleaning water is sent to the polymer scale anti-adhesion coating device 6 through the cleaning water pipe line 19, and sprayed from the spray coating nozzles 13 and 14 attached thereto, and the polymer scale anti-adhesion agent remaining in the polymerization vessel. The coating solution was removed. During washing,
The washing liquid remaining at the bottom of the polymerization vessel was drained and collected from the piping line 12. It took 8 minutes to remove the remaining polymer scale adhesion preventing coating solution in the washing step. After the washing step, the valves 16, 15, 8, and 11 were also closed.

Polymerization step: In this polymerization vessel, the condensed phosphoric acid compound shown in Table 8 was added in the amount shown in the same table and deionized water 3
8.2t, water-soluble partially saponified polyvinyl alcohol 14kg,
Oil-soluble partially saponified polyvinyl alcohol 8 kg, di-2-
After charging 18.2 kg of ethylhexyl peroxydicarbonate and evacuation of the polymerization vessel to 50 mmHg, 28 t of vinyl chloride monomer was charged, and hot water was passed through the jacket while stirring, and the internal temperature was reduced to 57 ° C. The temperature was raised to initiate polymerization.
When the internal temperature reached 57 ° C., cooling water was passed through the baffle and the jacket to maintain the internal temperature at 57 ° C., and the polymerization reaction was continued.
When the degree of polymerization reached 5%, the operation of the reflux condenser was started to continue the polymerization reaction. The pressure inside the polymerization vessel
After reducing the pressure to 6.5 kg / cm ² G (740 kPa), the reaction was stopped (the polymerization time was 4.1 hours).

After completion of the polymerization, unreacted monomers are recovered from the polymerization vessel through a recovery line (not shown), and the obtained polymer is slurried, and valves 8 and 9 are opened to take out polymer slurry. After extracting from the line 10, the inside of the polymerization vessel was washed with water to remove the residual resin in the polymerization vessel. Thereafter, the operations from the step of forming the coating film of the polymer scale adhesion preventing agent to the step of polymerization (from the preparation of the raw materials through the polymerization and washing with water) were regarded as one batch, and the same operation was repeated in the number of batches shown in Table 10. After the final batch, the state of adhesion of the polymer scale on the inner wall surface of the polymerization vessel and the surface of the cooling baffle facing the inner wall surface of the polymerization vessel was observed. The results of the observation are shown in Table 9.

After the final batch was completed, the polymer slurry obtained by extracting from the polymerization vessel was dehydrated and dried to obtain a vinyl chloride polymer. An initial coloring test, a foreign matter fisheye test and a foreign matter evaluation test were conducted on the obtained vinyl chloride polymer by the above-mentioned methods. The results are shown in Table 9.

Comparative Example 11 Example 19 was repeated without adding a condensed phosphoric acid compound to the polymerization system.
A vinyl chloride polymer was produced in the same manner as described above. Comparative Example 12 The procedure of Example 1 was repeated except that the coating method of the polymer scale inhibitor coating solution 1 was as shown below, and the condensed phosphoric acid-based compound was not added to the polymerization system, and the number of batches shown in Table 9 was repeated. A vinyl chloride polymer was produced in the same manner as in Example 19. Spray application is performed at a flow rate of 150 l / min for 2 minutes, and drying is performed.
Performed at 50 ° C. for 17 minutes. Further, it took 10 minutes for the washing step.

[0099]

[Table 8]

[0100]

[Table 9]

[0101]

According to the production method of the present invention, even if the coating film of the polymer scale adhesion preventing agent is not formed, the inside of the polymerization vessel, of course, the cooling coil, the draft tube, the cooling cylindrical baffle, etc. Because the cooling device is provided and the structure is complicated, the sprayed scale adhesion preventive agent has not been able to reach the conventional level, and effectively prevents scale adhesion even in parts where scale adhesion is likely to occur partially. Can be. Even if it is desirable to form a coating consisting of a polymer scale anti-adhesion agent on the inner surface of the polymerization vessel in order to obtain the required scale adhesion prevention effect, the time required for the required coating formation is longer than before. Be shortened. As described above, the application of the polymer scale adhesion inhibitor can be omitted or the time required for application can be reduced, so that high productivity can be obtained. Furthermore, the vinyl chloride-based polymer obtained by this method has good quality such as little fisheye and initial coloring when molded, and little colored foreign matter derived from the polymer scale adhesion inhibitor.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a longitudinal section of a polymerization apparatus used in Examples.

FIG. 2 is a schematic horizontal cross-sectional view of the polymerization apparatus of FIG. 1 taken along line AA.

FIG. 3 is a schematic horizontal cross-sectional view of the polymerization apparatus of FIG. 1 taken along line BB.

[Explanation of symbols]

 1: polymerization vessel 2: paddle blade 3: stirring shaft 4: cooling baffle 6: coating device 10: polymer slurry take-out piping line 12: drainage take-out piping line 13: upward spray application nozzle 14: downward spray application nozzle 18: Polymer scale adhesion inhibitor coating liquid piping line 19: Cleaning water piping line

Claims (2)

[Claims] In a polymerization vessel, a vinyl chloride monomer or a vinyl monomer mixture mainly composed of a vinyl chloride monomer is polymerized in an aqueous medium with a polymerization initiator in a polymerization vessel. In producing a coalescence, the polymerization is carried out in an aqueous polymerization system containing the monomer or monomer mixture, the weight average molecular weight is
A process for producing a vinyl chloride polymer, which is carried out in the presence of a condensed phosphoric acid compound having a molecular weight of 600 or more. 2. The coating film according to claim 1, wherein a coating film made of a polymer scale adhesion inhibitor is formed on the inner wall surface of the polymerization vessel and a portion where the monomer contacts during polymerization. A method for producing a vinyl chloride polymer.