JPH0559104A - Agent for preventing deposition of polymer scale, polymerizer and preventing method - Google Patents

Abstract

PURPOSE:To provide the subject preventing agent containing a condensation product of an aromatic amine compound, an aromatic nitro compound and an aromatic hydroxy compound and capable of effectively preventing the deposition of the scale of a polymer of a monomer having ethylenic double bond. CONSTITUTION:The objective agent for preventing the deposition of polymer scale contains a condensation product produced by heating (A) an aromatic amine compound such as aniline and o-, m- or p-phenylenediamine, (B) an aromatic nitro compound such as nitrobenzene and o-, m- or p-oxynitrobenzene and (C) an aromatic hydroxy compound such as phenol and hydroquinone in the presence of a mineral acid and a condensation catalyst under heating. The coating film of the deposition preventing agent is applied to the inner surface of a polymerizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scale adhesion preventive agent for polymerization of a monomer having an ethylenic double bond and a polymer scale adhesion prevention method.

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method of polymerizing a monomer having an ethylenic double bond, and particularly to the type of the monomer and the polymerization formulation (type of polymerization catalyst, stabilizer, etc.). The present invention provides a method capable of effectively preventing scale adhesion without being affected by the above). Conventionally, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, a gas phase polymerization method, or a bulk polymerization method is known as a polymerization method for vinyl monomers. In this case, there was a problem that polymer scale adhered to the inner wall of the polymerization vessel and other stirrer parts.

That is, when the vinyl monomer is polymerized by these methods, polymer scale is attached to the inner wall of the polymerization vessel and a portion where the monomer is in contact, such as a stirrer section. In addition to lowering the cooling capacity, this scale has the disadvantage that it peels and mixes into the product, degrading the quality of the product.On the other hand, in order to remove this adhered scale, excessive labor and time are required. Not only is it required, but since unreacted monomers are adsorbed in this scale, there is a danger of human injury due to monomers (such as vinyl chloride), which has become a very serious problem in recent years. There is a disadvantage.

As for the prevention of adhesion of the polymer (scale) to the inner wall of the polymerization vessel, polar organic compounds such as amine compounds, quinone compounds and aldehyde compounds have been heretofore used, for example, in some cases in suspension polymerization of vinyl chloride. Is known, or a method of adding these compounds to an aqueous medium is known. However, although these methods have a scale-preventing effect for repeated polymerization up to about 5 to 6 batches, they have a disadvantage that the preventive effect is lost when the number of polymerization batches is more than that (inferior in sustainability). I was not satisfied with it.

In order to overcome this disadvantage, Japanese Examined Patent Publication No. 60-30681
In the publication, a condensation product of an aromatic amine compound and an aromatic nitro compound is proposed. The condensation product of the aromatic amine compound and the aromatic nitro compound is applied to the wall surface of the polymerization vessel and the portion in contact with the monomer, and dried by heating,
Then, polymerization was performed. The scale does not adhere to the liquid phase in the polymerization vessel even if the polymerization after the coating is repeated. However, there is a drawback that scale adheres near the interface between the gas phase portion and the liquid phase portion located in the upper layer portion in the polymerization vessel.

[0006]

Generally, scale is likely to adhere to the vicinity of the interface between the gas phase portion and the liquid phase portion located in the upper layer portion in the polymerization vessel. Even if you form a coating film consisting of polymer scale adhesion inhibitor,
Scale adheres.

Once the scale adheres to the vicinity of the interface between the gas phase portion and the liquid phase portion, the adhered scale gradually grows as the polymerization is repeated, and finally the quality of the product is improved. However, it causes an increase in fisheyes of molded products, which is one of the most important physical properties. That is, as the polymer scale attached near the interface between the gas phase portion and the liquid phase portion grows, it may peel off and be mixed into the product polymer. When the scale thus peeled off is mixed in the product polymer, when the product polymer is processed into a molded product such as a sheet, many fish eyes are generated in the molded product, and the quality of the molded product is significantly deteriorated. Will be done.

Further, when the polymer adhesion preventing method of applying the condensation product of the aromatic amine compound and the aromatic nitro compound to the inside of the polymerization vessel is used, the condensation product formed into a coating film inside the polymerization vessel is used. When the product polymer is mixed in the product polymer and the product polymer is molded into a transparent sheet or the like, the initial colorability of the molded product is impaired and the quality of the molded product is deteriorated.

[0009]

The object of the present invention is to prevent the polymer scale from adhering to the polymer particles regardless of the kinds of the monomers used and the like. Polymer scale anti-adhesion agent and polymer scale adhesion preventive agent, which has a high quality of coalescence, can suppress the fish eye of the molded product after processing to an extremely low level, and can also suppress the deterioration of the initial coloring property to an extremely low level. To provide a method. That is, the present invention provides an ethylenic double bond, which comprises the condensation product of (A) an aromatic amine compound, (B) an aromatic nitro compound, and (C) an aromatic hydroxy compound. There is provided a scale adhesion preventive agent for polymerizing a monomer having:

Further, the present invention is a method for preventing the adhesion of polymer scale in the polymerization of a monomer having an ethylenic double bond in a polymerization vessel, wherein the above-mentioned (A The present invention provides a method for preventing adhesion of a polymer scale, which comprises the step of carrying out the above-mentioned polymerization in a polymerization vessel in which a coating film comprising the component), the component (B) and the condensation product of the component (C) is formed. In the method of the present invention, the so-called scale inhibitor applied to the inner wall of the polymerization vessel contains (A) an aromatic amine compound, (B) an aromatic nitro compound, and (C) a condensation product of an aromatic hydroxy compound. To do.

(A) Aromatic Amine Compound The aromatic amine compound (A) is, for example, a compound represented by the following general formulas (1) to (3).

[Chemical 1]

[Wherein R ¹ is --H, --NH ₂ , --Cl,-
_{OH, -NO 2, -CoCH 3,} - OCH 3, represents a -N (CH _{3) 2} or an alkyl group having 1 to 3 carbon atoms, R ² is, -H, -N
_{H 2, -OH, -CH 3,} -COOH, represents a -SO ₃ H. ]

Specifically, aniline, (ortho, meta,
(Para) phenylenediamine, (ortho, meta, para) aminophenol, (ortho, meta, para) chloroaniline, (ortho, meta, para) nitroaniline, (ortho, meta, para) methylaniline, N, N-dimethyl Paraphenylenediamine, 4-chloro-orthophenylenediamine, 4-methoxyorthophenylenediamine, 2-
Amino-4-chlorophenol, 2,3-diaminotoluene, 5-nitro-2-aminophenol, 2-nitro-
4-aminophenol, 4-amino-2-aminophenol, (ortho, meta, para) aminosalicylic acid and the like are exemplified.

[Chemical 2]

[Here, the two R ¹ may be the same or different and are as described above, and the two R ² may be the same or different and are as described above. ]

Specifically, diphenylamines such as 4-aminodiphenylamine, 2-aminodiphenylamine, 4,4'-diaminodiphenylamine, 4-amino-3'-methoxydiphenylamine and 4-amino-4'-hydroxydiphenylamine are available. It is illustrated.

[Chemical 3]

R ² is --H, --NH ₂ , --OH, --CH ₃ ,-.
COOH, representing the -SO ₃ H. [Here, two R ¹ may be the same or different and is as described above, and R ² is also as described above. ]

Specific examples include α-naphthylamine, β-naphthylamine, 1,5-diaminonaphthalene, 1-amino-5-hydroxynaphthalene, 1,8-diaminonaphthalene and 2,3-diaminonaphthalene. ..

(B) Aromatic Nitro Compound The aromatic nitro compound (B) is, for example, a compound represented by the following general formula (4).

[Chemical 4]

[Here, R ³ is --H, --OH, --OCH ₃ ,
-OC ₂ H _5, -Cl, -COOH or represents -SO ₃ H. ]

Specifically, nitrobenzene, (ortho,
(Meta or para) oxynitrobenzene, (ortho, meta or para) nitroanisole, (ortho, meta or para) chloronitrobenzene, (ortho, meta or para) nitrobenzoic acid, (ortho, meta or para) Examples include nitrobenzene sulfonic acid.

(C) Aromatic Hydroxy Compound Further, the aromatic hydroxy compound (C), which is the component (C) used in the condensation product of the present invention, has, for example, the general formula (5):
It is a compound represented by (6).

[Chemical 5]

[Here, R ⁴ is --H, --Cl, --OH,-
COCH ₃ , -OCH ₃ , -COOH, -SO ₃ H or C 1-3
Represents an alkyl group, and R ⁵ is —H, —Cl, —OH, —O.
CH _3, represents a -OC ₂ H ₅ or -COOH. ]

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,
Examples include phenol derivatives such as 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, and (2,5-, 2,6-, 3,5-) dihydroxytoluene.

[Chemical 6]

[Here, R ⁴ and R ⁵ are as described above. ] Specifically, α-naphthol, (1,3-, 1,4
-, 1,5-, 2,3-, 2,6-, 2,7-) dihydroquinnaphthalene, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid and other naphthol derivatives are exemplified. It

Condensation Product A mineral acid and a condensation catalyst are used for the condensation reaction of the aromatic amine compound, the aromatic nitro compound, and the aromatic hydroxy compound. The mineral acids include hydrochloric acid and nitric acid. , Oxalic acid, phosphoric acid and the like.

Further, as a suitable condensation catalyst,
Azo catalysts such as 2,2′-azobis, isobutyronitrile and 2,4-dimethylvaleronitrile, silver nitrate, nitrates such as lead nitrate, halogens such as iodine, bromine, chlorine and fluorine, hydrogen peroxide, Sodium peroxide, benzoyl peroxide, potassium persulfate, ammonium persulfate,
Peracetic acid, chimene hydroperoxide, perbenzoic acid,
peroxides such as p-menthane hydroperoxide, iodic acid, potassium iodate, sodium chlorate,
Oxygen acids or oxyacid salts such as periodate, potassium periodate, sodium perchlorate, ferrous chloride, ferric chloride, copper sulfate, cuprous chloride, cupric chloride, lead acetate, etc. Examples thereof include various metal salts, ozone, oxygen such as oxygen, copper oxide, cerium oxide, oxides such as manganese dioxide, and the like.

At least one or more of the aromatic amine compound (A), at least one or more of the aromatic nitro compound (B), and at least one or more of the aromatic hydroxy compound (C) are added to the above-mentioned mineral acid. And in the presence of a condensation catalyst, 50 ° C ~ 3
A condensation product is obtained by heating at 00 ° C. for 5 to 30 hours.

The condensation product is affected by the kind, composition ratio and reaction temperature, reaction time of aromatic amine compound, aromatic nitro compound, aromatic hydroxy compound, condensation catalyst and mineral acid. The aromatic nitro compound (B) is preferably 0.05 to 0.70 mol per 1 mol of the group amine compound (A), and when the amount is less than the lower limit of this range, the scale-inhibiting effect is obtained in a polymerization system using an oil-soluble polymerization catalyst. When it exceeds the upper limit, the aromatic nitro compound remains in the product, and the scale prevention effect is reduced. In addition, per 1 mol of aromatic amine compound (A), aromatic hydroxy compound
(C) is preferably 0.1 to 5.00 mol, even if the condensation product is less than the lower limit of this range as a scale anti-sticking agent, the initial colorability of the polymer obtained by polymerization is poor, the upper limit If it exceeds, the scale prevention effect decreases.
Further, the amount of the condensation catalyst is preferably 0.03 to 0.50 mol and the amount of the mineral acid is 0.02 to 5.0 mol per 1 mol of the aromatic amine compound (A).

A condensation product obtained by first subjecting an aromatic amine compound (A) and an aromatic nitro compound (B) to a condensation reaction, and then subjecting this to an aromatic hydroxy compound (C). May be.

Preferred condensation products are those of the general formula
(1) an aromatic amine compound and an aromatic hydroxy compound of the general formula (6) as reaction components; an aromatic amine compound of the general formula (2) and an aromatic compound of the general formula (5) and / or (6) And a condensation product containing an aromatic amine compound of the general formula (3) and an aromatic hydroxy compound of the general formula (5) as reaction components. Among these, more preferred are those of the general formula
(2) and / or (3) the aromatic amine compound and the general formula (5)
Is a condensation product containing as a reaction component the aromatic hydroxy compound of.

In a preferred embodiment of the scale inhibitor of the present invention, the condensation product may be used by adding an alkali metal salt or ammonium salt of a sulfonated product obtained by sulfonation of the condensation product. The scale prevention effect is improved. The addition amount is 10 to 1000 parts by weight, particularly 50 to 500 parts by weight, of the sulfonate salt per 100 parts by weight of the condensation product.
Parts by weight are preferred.

Next, the reaction product obtained by condensing the aromatic amine compound, the aromatic nitro compound and the aromatic hydroxy compound is dried to remove the solvent and obtain a condensation product. The condensation product is sulfonated, and the sulfonation may be performed according to a conventionally known method,
For example, by using sulfuric acid, fuming sulfuric acid, chlorosulfonic acid or the like as a sulfonating agent, and reacting at room temperature to 95 ° C. at a concentration of the sulfonating agent of 2 to 15 times (weight) of the reaction product, the sulfonated product Can be obtained.

By reacting this sulfonate with an alkali metal compound or an ammonium compound,
Although the desired sulfonate salt can be obtained, as the reaction method, for example, the sulfonate is dispersed in water, and an alkali metal compound such as NaOH, KOH, Na ₂ CO ₃ or the like under heating, or By adding a predetermined amount of an ammonium compound such as NH ₄ OH or (NH ₄ ) ₂ CO ₃ and reacting, the desired alkali metal salt or ammonium salt of the sulfonated product can be obtained.

Since this product is water-soluble, it can be obtained in a form dissolved in an aqueous medium. However, this product may be left as it is, or once evaporated to dryness, crushed and stored or transported. It may be in a convenient powder form.

The solvent used to prepare the coating solution for the scale inhibitor of the condensation products of the above components (A), (B) and (C) is, for example, water; methanol, ethanol, propanol. , Butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-propanol, 3-methyl-1-butanol, 2-methyl-
Alcohol solvents such as 2-butanol and 2-pentanol; Ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Ester solvents such as methyl formate, ethyl formate, methyl acetate and methyl acetoacetate; 4-
Examples include ether solvents such as methyldioxolane and ethylene glycol diethyl ether; furans; aprotic solvents such as dimethylformaside, dimethylsulfoxide, and acetonitrile. These are appropriately used alone or as a mixed solvent of two or more kinds.

The concentration of the condensation products of the components (A), (B) and (C) in the coating solution is not particularly limited as long as the total coating amount described below can be obtained, but is usually 0.001 to 15% by weight. degree,
It is preferably 0.01 to 1% by weight. The coating solution may be, for example, a surfactant (cationic, nonionic, and anionic); a pH adjuster (phosphoric acid, perchloric acid, sulfuric acid, hydrochloric acid, nitric acid, phytic acid) as long as it does not impair the scale preventing effect. , Acetic acid, paratoluenesulfonic acid, tannic acid) and the like can be added.

The water-soluble polymer shown below can be added to this coating solution. Examples of the water-soluble polymer include a hydroxyl group-containing polymer compound, a cationic polymer compound, an anionic polymer compound and an amphoteric polymer compound. For example, a hydroxyl group-containing polymer compound, a cationic polymer compound, Examples thereof include amphoteric polymer compounds and anionic polymer compounds.

Examples of the hydroxyl group-containing polymer compound include starches such as amylose, amylopectin, dextrin, oxidized starch, acetyl starch, nitrostarch, methyl starch, carboxymethyl starch and derivatives thereof; pectic acid, protopectin, Hydroxyl group-containing vegetative substances such as pectinic acid, alginic acid, laminarin, fucoidin, agar, and carrageenin; animal slime substances containing hydroxyl groups such as hyaluronic acid, chondroitin sulfate, hevalin, keratosulfate, chitin, chitosan, caronin sulphate and limacoitin sulphate Nucleic acids such as ribonucleic acid and deoxyribonucleic acid;
Methyl cellulose, ethyl cellulose, carboxymethyl cellulose, glycol cellulose, benzyl cellulose, cyanoethyl cellulose, methylene ether of cellulose, triphenylmethyl cellulose, formyl cellulose, cellulose acetate, cellulose propionate,
Cellulose butyrate, cellulose acetate propionate, sulfonic acid cellulose ester, carbamic acid cellulose ester, nitrocellulose, cellulose phosphate, cellulose derivatives such as cellulose xanthate; hemicelluloses such as xylan, mannan, alabogalactan, galactan, and araban; Alcohol lignin, dioxane lignin, phenol lignin, hydrotropic lignin, mercapto lignin, thioglycolic acid lignin, lignin sulfonic acid, alkaline lignin,
Lignins such as thioalkali lignin, acid lignin, copper oxide-ammonia lignin, periodate lignin;
Phenol-formaldehyde resin, partially saponified polyvinyl alcohol, polyvinyl alcohol and the like can be mentioned.

Examples of the cationic polymer compound include polyvinylamine, polyethyleneamine, polyethyleneimine, polyacrylamide, N-vinyl-2-pyrrolidone-acrylamide copolymer, dimethyl diamyl ammonium chloride cyclized polymer, and dimethyl. Cyclization polymer of diethylammonium bromide, cyclization polymer of diallylamine hydrochloride, cyclization copolymer of dimethyldiallylammonium chloride and sulfur dioxide, polyvinylpyridine, polyvinylpyrrolidone, polyvinylcarbazole, polyvinylimidazoline, polydimethylaminoethyl acrylate , Having a nitrogen atom in the side chain such as polydimethylaminoethyl methacrylate, polydiethylaminoethyl acrylate, polydiethylaminoethyl methacrylate, Nitrogen atom of a cationic polyelectrolyte bearing a charged positively, and the like.

Examples of the amphoteric polymer compound include amphoteric polymer compounds such as glue, gelatin, casein, and alpmine. Examples of the anionic polymer compound include sulfomethylated polyacrylamide; polyacrylic acid; alginic acid, acrylamide-vinyl sulfonic acid copolymer, polymethacrylic acid, polystyrene sulfonic acid, and the like, or an alkali metal salt or ammonium salt thereof; Examples thereof include anionic polymer compounds having a carboxyl group or a sulfonic acid group on the side chain such as carboxymethyl cellulose.

Further, an inorganic compound may be appropriately added to the coating liquid, if necessary, as long as it does not impair the scale preventing action. Examples of inorganic compounds that can be added include orthosilicic acid, metasilicic acid, mesodisilicate, mesotrisilicic acid, mesotetrasilicic acid, sodium metasilicate, sodium orthosilicate, sodium disilicate, sodium tetrasilicate, and water glass. Silicic acids or silicates; oxyacid salts of metals selected from alkaline earth metals such as magnesium, calcium and barium, zinc group metals such as zinc, aluminum group metals such as aluminum, and platinum group metals such as platinum, acetic acid Examples thereof include metal salts such as salts, nitrates, hydroxides and halides; inorganic colloids such as ferric hydroxide colloid, silicic acid colloid, barium sulfate colloid and aluminum hydroxide colloid. The above-mentioned inorganic colloid may be prepared by, for example, mechanical grinding, irradiation with ultrasonic waves, electrical dispersion and chemical method.

Formation of Coating Film 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 vessel, and then, for example, at room temperature. After thoroughly drying in the temperature range from 1 to 100 ° C, further wash with water if necessary. By doing so, a coating film is formed on the inner wall surface of the polymerization vessel, so that adhesion of the polymer scale to the inner wall surface of the polymerization vessel is prevented.

The coating solution is preferably applied not only to the inner wall surface of the polymerization vessel, but also to other portions with which the monomer contacts during the polymerization, thereby forming a coating film. .. For example, it is preferable to form a coating film on the stirring blade, stirring shaft, baffle, condenser, header, search coil, bolt, nut, etc. by applying the coating liquid.
In particular, the stirring blade, the stirring shaft, and the baffle should normally be coated with the coating liquid to form a coating film. In order to form a coating film by applying the coating liquid to these portions, it may be carried out in the same manner as in the case of forming the coating film on the inner wall of the polymerization vessel.

More preferably, the coating solution is a site other than the site where the monomer comes into contact during the polymerization, but a site where the polymer scale may adhere, for example, a device for recovering unreacted monomers and The coating liquid is preferably applied to the inner surface of the pipe to form a coating film. As such a part,
More specifically, the inner surface of a monomer distillation column, a condenser, a monomer storage tank, a valve and the like can be mentioned. The coating film may be formed at these portions as in the case of forming the coating film on the inner wall of the polymerization vessel.

In this way, when a coating film is formed on the site where the monomer contacts during the polymerization and the site where other polymer scales may adhere, the adhesion of the polymer scale to those sites. Is prevented. The method of applying the coating liquid to the inner wall surface of the polymerization vessel is not particularly limited, and examples thereof include brush coating, spray coating, and a method of withdrawing after filling the polymerization vessel with the coating solution.
No. 1, No. 55-36288, No. 56-501116, No. 56-50
The automatic coating method described in 1117, JP-A-59-11303, etc. can also be used.

There is no limitation on the method for drying the wet surface due to the application of the coating solution, and the following method can be used, for example.
That is, after applying the coating solution, a method of applying an appropriately heated hot air to the coating surface, or heating the inner wall surface of the polymerization vessel and the other surface to which the coating solution is applied in advance to, for example, 30 to 80 ° C. The method of directly applying the coating solution to the heated surface can be used. After drying the coated surface, the coated surface is washed with water as needed.

The coating film thus obtained has a total coating amount after drying of usually 0.001 g / m ² or more, particularly 0.05 to ²
It is preferably g / m ² . The above coating work is 1
It may be carried out for every 10 to several batches of polymerization. The formed coating film has high durability and the action of preventing the polymer scale from adhering is maintained, so that it is not always necessary to perform it for each batch of polymerization. Therefore, the productivity of the product polymer is improved.

Polymerization As described above, a coating process is applied to the inner wall of the polymerization vessel, and preferably to other portions where the monomer comes into contact during the polymerization to form a coating film, which is then subjected to a conventional method in the polymerization vessel. Polymerize. That is, in addition to a monomer having an ethylenic double bond and a polymerization initiator (catalyst), if necessary, a polymerization medium such as water, and a suspending agent, a solid dispersant, a nonionic or anionic emulsifier, etc. A dispersant and the like are charged, and then polymerization is performed by a conventional method.

Examples of the monomer having an ethylenic double bond which is polymerized by applying the method of the present invention include vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid. , Methacrylic acid, and their esters or salts; maleic acid, fumaric acid, and their esters or anhydrides; diene monomers such as butadiene, chloroprene, isoprene; styrene, acrylonitrile, vinylidene halide, vinyl ether, etc. Be done.

The type of polymerization to which the method of the present invention is applied is not particularly limited, and suspension polymerization, emulsion polymerization, solution polymerization,
It is effective in both bulk polymerization and vapor phase polymerization, and is particularly suitable for polymerization in an aqueous medium such as suspension polymerization and emulsion polymerization.

The general polymerization method will be specifically described below by taking the cases of suspension polymerization and emulsion polymerization as examples. First,
Water and a dispersant are charged into a polymerization vessel, and then a polymerization initiator is charged. Next, after exhausting the inside of the polymerization vessel to reduce the pressure to 0.1 to 760 mmHg, the monomer was charged (at this time, the internal pressure of the polymerization vessel was
Usually 0.5 to 30 kgf / cm ² · G), then 30 to 1
Polymerize at reaction temperature of 50 ° C. During the polymerization, one or more of water, a dispersant, and a polymerization-facilitating agent are added as needed. The reaction temperature during polymerization depends on the type of monomer to be polymerized. Polymerize with. For polymerization, the internal pressure of the polymerization vessel is 0
When it falls to 7 kgf / cm ² · G, or when there is almost no difference between the inlet temperature and the outlet temperature of the cooling water that flows in and out of the jacket installed on the outer periphery of the polymerization vessel (that is, the heat generated by the polymerization reaction disappears). It is judged that it has been completed. Water, a dispersant, and a polymerization initiator charged during the polymerization are usually 20 to 5 parts of water per 100 parts by weight of the monomer.
00 parts by weight, dispersant 0.01 to 30 parts by weight, polymerization initiator 0.01 to 5
Parts by weight.

In the case of solution polymerization, an organic solvent such as toluene, xylene or pyridine is used as the polymerization medium instead of water. A dispersant is used as needed. Other polymerization conditions are generally the same as those for suspension polymerization and emulsion polymerization. In the case of bulk polymerization, the inside of the polymerization vessel is evacuated to a pressure of about 0.01 to 760 mmHg, then the monomer and the polymerization initiator are charged into the polymerization vessel, and the polymerization is carried out at a reaction temperature of -10 to 250 ° C. .. For example, it is carried out at 30 to 80 ° C. in the case of vinyl chloride polymerization and at 50 to 150 ° C. in the case of styrene polymerization.

When polymerization is carried out by applying the polymer scale adhesion preventing method of the present invention, adhesion of the polymer scale can be prevented regardless of the material of the inner wall surface of the polymerization vessel. The adhesion of polymer scale can be prevented even when the polymerization is carried out in a steel or other steel-made polymerization vessel, a glass-lined polymerization vessel, or the like.

What is added to the polymerization system can be used without any restrictions. That is, for example, t-butyl peroxy neodecanoate, bis (2-ethylhexyl) peroxydicarbonate, 3,5,5-trimethylhexanoyl peroxide, α-cumylperoxy neodecanoate, cumene hydroper Oxide, cyclohexanone peroxide, t-butyl peroxypivalate, bis (2-ethoxyethyl) peroxy dicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, α,
Polymerization initiators such as α'-azobisisobutyronitrile, α, α'-azobis-2,4-dimethylvaleronitrile, potassium peroxodisulfate, ammonium peroxodisulfate and p-menthane hydroperoxide; partially saponified polyvinyl Suspending agents for alcohols, polyacrylic acid, copolymers of vinyl acetate and maleic anhydride, cellulose derivatives such as hydroxypropylmethyl cellulose, natural or synthetic polymer compounds such as gelatin; solid dispersants such as calcium phosphate and hydroxyapatite; Nonionic emulsifiers such as sorbitan monolaurate, sorbitan trioleate, and polyoxyethylene alkyl ether; sodium alkylbenzene sulfonates such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate; sodium dioctylsulfosuccinate Anionic emulsifiers such as lithium; fillers such as calcium carbonate and titanium oxide; stabilizers such as tribasic lead sulfate, calcium stearate, dibutyltin dilaurate, dioctyltin mercaptide; lubricants such as rice wax, stearic acid and cetyl alcohol; D
OP: plasticizer such as DBP; mercaptans such as t-dodecyl mercaptan; chain transfer agent such as trichlorethylene; pH
Even in a polymerization system in which a regulator or the like is present, the method of the present invention can effectively prevent the adhesion of polymer scale.

The polymer scale adhesion preventive agent of the present invention may be used for forming a coating film on the inner wall surface of the polymerization vessel or the like, and may be further added directly to the polymerization system, whereby the scale prevention effect is improved. You can also let it. In that case, the addition amount of the polymer scale anti-adhesion agent is appropriately about 10 to 1000 ppm with respect to the total weight of the charged monomers. When adding, care should be taken not to affect the quality of the product polymer such as fisheye, bulk specific gravity and particle size distribution.

[0056]

EXAMPLES Production Example 1 Production of condensation product No. 1 1.00 mol of 1,8-diaminonaphthalene and 30% hydrochloric acid were placed in a reactor.
1.5 mol, nitrobenzene 0.2 mol, pyrogallol 1.0
Mol was charged and this was cooled to 10 ° C or lower. Next to this
30 mol% hydrogen peroxide (2.0 mol) was added dropwise, the temperature was raised to 60 ° C and heated at the same temperature for 6 hours, then the temperature was raised to 150 ° C and the by-product water was distilled off at the same temperature. And reacted for 20 hours. During this time, a part of 1,8-diaminonaphthalene was mixed in the distilled water, which was separated from the water and then returned to the reactor. The reaction mixture (melted product) obtained by the reaction in this manner was poured into dilute hydrochloric acid, heated at 60 ° C. for 3 hours, and filtered while hot to remove unreacted 1,8-diaminonaphthalene, nitrobenzene and Pyrogallol was removed. Further, in order to remove excess hydrochloric acid, it was washed with water three times and dried to obtain a condensation product.

Production of Condensation Products No. 2 to No. 21 Using the aromatic amine compound, aromatic nitro compound, aromatic hydroxy compound, condensation catalyst and mineral acid shown in Table 1, the condensation products No. The condensation reaction was carried out under the same reaction conditions and operation as in the case of 1, to obtain condensation products No. 2 to No. 21 (Japanese Examined Patent Publication No. 60-30681, condensation product No. 1).

[0058]

[Table 1]

Example 1 Polymerization was carried out in the following manner using a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 1000 liters. In each experiment, first, the condensation product was dissolved in a solvent so that the concentration was as shown in Table 1 to prepare a coating solution. These coating solutions were applied to the inner wall of the polymerization vessel, the stirring shaft, the stirring blades, and other parts where the monomers come into contact with each other during the polymerization, and were heated and dried at 40 ° C for 15 minutes to form a coating film, and then washed with water. However, Experiment No. 121 is
This is a comparative example in which a coating solution containing the condensation product No. 1 described in 60-30681 is applied.

Then, 400 kg of water, 200 kg of vinyl chloride, 250 g of partially saponified polyvinyl alcohol, 25 g of hydroxypropylmethylcellulose and 25 g of 3,5,5-trimethylhexahexyl were placed in the polymerization vessel where the coating film was formed by the coating treatment as described above. Charge 70 g of Noyl peroxide and stir 66 while stirring.
Polymerization was carried out at ℃ for 6 hours. After the polymerization was completed, the produced polymer and unreacted monomer were recovered, and the inside of the polymerization vessel was washed with water to remove the residual resin.

Then, the operation of coating and polymerizing the coating solution as described above was regarded as one batch, and thereafter, the same operation was repeated 20 batches, and the scale adhesion amount of the 20th batch was examined. The results are shown in Table 2. However, the scale adhesion amount in each experiment was measured separately for the liquid phase part in the polymerization vessel and the vicinity of the interface between the gas phase part and the liquid phase part. Further, the fish eye when the polymer obtained in each experiment was molded into a sheet was measured by the following method.

A mixture prepared in a mixing ratio of 100 parts by weight of polymer, 50 parts by weight of DOP, 1 part by weight of dibutyltin dilaurate, 1 part by weight of cetyl alcohol, 0.25 part by weight of titanium oxide and 0.05 part by weight of carbon black was used with a 6 inch roll. After kneading at 150 ° C. for 7 minutes, it was formed into a sheet having a thickness of 0.2 mm, and the number of fish eyes contained in 100 cm ^{2 of the} obtained sheet was examined by a light transmission method. The results are shown in Table 2. Further, the brightness index (L value) when the polymer obtained in each experiment was molded into a sheet was measured by the following method.

-Measurement of lightness index (L value) Next, the lightness index of the polymers obtained in each of the examples and comparative examples is measured to determine the presence or absence of coloration. The brightness index was measured by the following method. 100 parts by weight of vinyl chloride polymer, 1 part by weight of stabilizer (TS-101 manufactured by Akishima Chemical Co., Ltd.), 0.5 part by weight of stabilizer (C-100 J manufactured by Katsuta Kako Co., Ltd.) and 50 parts by weight of dioctyl phthalate as a plasticizer. Using a two-roll mill 1
After kneading at 60 ° C. for 5 minutes, a sheet having a thickness of 1 mm is formed. Next, the molded sheet is placed in a 4 × 4 × 1.5 cm frame and heated and pressure molded at 160 ° C. and 65 to 70 kgf / cm ² to prepare a measurement sample. For this sample, JIS Z 8730
Lightness index L in the Hunter color difference formula described in (1980)
Was evaluated, and the larger the L value, the higher the whiteness was evaluated.

The L value is obtained as follows. JIS Z 8722
The standard value C, photoelectric colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd., Z-1001DP colorimetric color difference meter) is used to obtain the stimulus value Y of the XYZ color system by the stimulus value direct reading method. As the geometric condition of illumination and light reception, condition d described in JIS Z 8722, section 4.3.1 was adopted. From the obtained stimulation value Y,
The L value is calculated by the formula: L = 10 Y ^1/2 described in JIS Z 8730 (1980). The results are shown in Table 2.

[0065]

[Table 2]

Production Example 2 Production of Sulfonated Condensation Product After 100 g of condensation product No. 1 and 200 g of concentrated sulfuric acid were mixed at 30 ° C. or lower, this was heated to 50 ° C. and stirred at this temperature for 5 hours. And sulfonated. This reaction solution was poured into 1000 ml of water, and the precipitated sulfonated product was filtered, washed with water and dispersed in 1000 ml of water. At 90 ° C, 11.3 g of 40 wt% NaOH aqueous solution was added and dissolved, and then evaporated to dryness and ground. As a result, 86.4 g of the sulfonated product of the condensation product No. 1 (sodium metal salt) was obtained.

The condensation products No. 5 to No. 10 in Table 1 are also shown.
In addition, the sulfonating agent of Table 3 was used to carry out the sulfonation reaction at the reaction temperature and reaction time of the same table, and then the alkaline compound shown in Table 2 was used to give the sulfonated product No. 1 of the condensation product. Under the same reaction conditions and reaction operations, condensation product sulfone compounds Nos. 1 to 7 (alkali metal salts) were obtained.

[0068]

[Table 3]

Example 2 In each experiment, the coating solution having the conditions shown in Table 4 was used. Table 4 shows the ratio (weight ratio) of condensation product / condensation product sulfonate; pH regulator, pH concentration and solvent. The obtained coating solution was applied in the polymerization vessel in the same manner as in Example 1,
Polymerization was carried out in the same manner as in Example 1 to obtain a polymer. After the polymerization was completed, the amount of scale attached was examined. The results are shown in Table 4.
Further, the fish eye and the lightness index (L value) of the polymer obtained in each experiment were measured. The results are shown in Table 4.

[0070]

[Table 4]

Example 3 In a stainless steel polymerization vessel with an internal volume of 20 liters equipped with a stirrer, the total concentration and weight ratio of the condensation product and the sulfonated product of the condensation product, the pH adjuster used, and the type of solvent are shown in Table 5. The coating process was performed in the same manner as in Example 1 except that the coating liquid as shown in 1 was used. However, Experiment No. 302
~ 304 are comparative examples in which the condensation product does not satisfy the conditions of the present invention.

Next, 9 kg of water and sodium dodecylbenzenesulfonate 2 were placed in the polymerization vessel thus coated.
25 g of t-dodecyl mercaptan and 13 g of potassium peroxodisulfate were charged, the atmosphere was replaced with nitrogen gas, 1.3 kg of styrene and 3.8 kg of butadiene were charged, and polymerization was carried out at 50 ° C. for 20 hours.

Thereafter, the same operation was repeated for 10 batches, and after 10 batches, the amount of scale adhered in the liquid phase part in the polymerization vessel and the amount of scale adhered near the interface between the gas phase part and the liquid phase part were measured. The results are shown in Table 5. Further, the brightness index (L value) when the polymer obtained in each experiment was molded into a sheet was measured by the following method. The results are shown in Table 5.

[0074]

[Table 5]

Measurement of lightness index (L value) Next, the lightness index of the polymers obtained in each of the examples and comparative examples is measured to determine the presence or absence of coloration. The brightness index was measured by the following method. 1 kg of a 2% magnesium sulfate solution was added to 1 kg of the obtained polymer latex, coagulation and precipitation were performed, and then the precipitate was filtered off. The precipitate separated by filtration was washed with hot water at 80 to 90 ° C for 2 to 3 times, and then dried at 40 ° C using a vacuum dryer at 25 ° C.
After drying for an hour, a resin was obtained. The resulting resin was 9 × 9cm, placed in a mold having a thickness of 0.1 cm, 195 ° C., and heated at 50 to 60 kgf / cm ^2, and pressure molding at a final pressure 80 kgf / cm ² to create a measurement sample .. The lightness index L of this sample was determined in the same manner as described above.

[0076]

EFFECTS OF THE INVENTION According to the present invention, the adhesion of polymer scale can be effectively prevented, and the coating film formed on the inner wall surface of the polymerization vessel according to the present invention may be peeled off during the polymerization or may be polymerized. Since it does not dissolve in the system, when the resulting product polymer has a significantly reduced number of fish eyes after molding, the deterioration of the initial colorability of the product polymer after molding is reduced.

Further, according to the present invention, the adhesion of the polymer scale is effective regardless of the various conditions of the polymerization such as the type of the monomer and the polymerization initiator used, the polymerization type, the material of the inner wall of the polymerization vessel and the like. Can be prevented. That is, for example, in emulsion polymerization where it is difficult to prevent the adhesion of polymer scale, even when using a stainless steel polymerization vessel where the polymer scale easily adheres, or polymerization of potassium peroxodisulfate having strong oxidizing power is started. Even when it is used as an agent, the adhesion of polymer scale can be effectively prevented.

Therefore, when polymerization is carried out by applying the present invention, it is not necessary to carry out the work of removing the polymer scale for each polymerization, whereby the productivity is improved and the fisheye in the molded product is It is possible to produce significantly less high quality product polymer.

Claims (4)

[Claims] 1. A monomer having an ethylenic double bond, which comprises a condensation product of (A) an aromatic amine compound, (B) an aromatic nitro compound, and (C) an aromatic hydroxy compound. Polymer scale anti-sticking agent for polymerization. 2. The polymer scale anti-adhesion agent according to claim 1, further comprising a sulfonate alkali obtained by sulfonation of the condensation products of (A), (B) and (C). An inhibitor containing a metal salt and / or an ammonium salt. 3. A polymerization vessel having a coating film formed on its inner wall containing a condensation product of (A) an aromatic amine compound, (B) an aromatic nitro compound, and (C) an aromatic hydroxy compound. 4. A method for preventing adhesion of a polymer scale in the polymerization of a monomer having an ethylenic double bond in a polymerization vessel, wherein (A) an aromatic amine compound is previously attached to the inner wall of the polymerization vessel. A method for preventing adhesion of a polymer scale, which comprises the step of performing the polymerization in a polymerization vessel in which a coating film containing a condensation product of (B) an aromatic nitro compound and (C) an aromatic hydroxy compound is formed.