JPH0710904A - Polymer scale inhibitor and production of polymer using the same - Google Patents

Abstract

PURPOSE:To improve production efficiency by effectively preventing a polymerizer from suffering polymer scale deposition not only on polymerizer's part in contact with the liquid phase but also on polymerizer's part around the interface between the gas and liquid phases and eliminating the necessity of scale removal after every polymerization operation. CONSTITUTION:This polymer scale inhibitor, which is for use in polymerizing an ethylenic monomer, comprises an alkaline solution containing a condensate of a heterocyclic compound having at least two amino groups with at least one member selected from benzoquinone compounds and naphthoquinone compounds. The inhibitor is applied to a polymerizer on its inner wall and dried to form a coating film. The polymerization is conducted using this polymerizer to prevent polymer scale deposition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer scale adhesion preventive agent for polymerizing a monomer having an ethylenically unsaturated double bond and a method for producing a polymer using the same.

[0002]

2. Description of the Related Art Conventionally, as a method for polymerizing a monomer having an ethylenically unsaturated double bond, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, a gas phase polymerization method, a bulk polymerization method and the like are known. ing. In any of these polymerization methods, adhesion of the polymer scale is likely to occur on the inner wall of the polymerization vessel, the agitator, and the like where the monomer comes into contact.

When the polymer scale adheres, the yield of the polymer, the cooling capacity of the polymerization vessel and the like decrease, and the polymer scale peels off and is mixed into the polymer, and is obtained by molding the polymer. The disadvantage is that the quality of the molded product is reduced. Moreover, not only excessive labor and time are required to remove the adhered polymer scale,
Since the unreacted monomer is contained in this polymer scale, there is a risk of human injury due to the monomer, which has become a very serious problem in recent years.

As for the prevention of adhesion of the polymer scale to the inner wall of the polymerization vessel, the polarities of amine compounds, quinone compounds, aldehyde compounds, etc. have been used, as has been carried out, for example, in suspension polymerization of vinyl chloride. A method of applying a polymer scale anti-adhesion agent composed of an organic compound to the inner wall of a polymerization vessel to form a coating film, or a method of adding these compounds to an aqueous medium is known (Japanese Patent Publication No. 45-30343).
issue).

However, although these methods show an effect of preventing polymer scale adhesion when repeating the polymerization up to about 5 to 6 batches, when the number of polymerization batches is larger than that, the preventive effect disappears (in terms of sustainability). Inferior). In this respect, the use of a water-soluble catalyst has a particularly great effect and is not industrially satisfactory.

In order to overcome this disadvantage, JP-A-53-13689 proposes to use a condensation product of an aromatic amine compound as a polymer scale anti-adhesion agent. When a coating film containing the condensation product of this aromatic amine compound is formed on the inner wall of the polymerization vessel where the monomer contacts, even if the polymerization is repeated about 100 to 200 batches, the liquid phase portion in the polymerization vessel No polymer scale deposition occurs. Also, when a water-soluble catalyst is used, polymer scale adhesion in the liquid phase part is also prevented.

[0007]

However, there is a drawback that polymer scale adheres 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. Once the polymer scale adheres to the vicinity of the interface between the gas phase part and the liquid phase part, the polymer scale that adheres gradually grows as the polymerization is repeated, and finally it peels off and enters the polymer. I have something to do. Thus, when the polymer scale is mixed in the polymer, when the polymer is processed into a molded article such as a sheet, many fish eyes are generated in the resulting molded article, and the quality of the molded article is significantly deteriorated. It will be.

When the polymer obtained by the polymerization is processed into a molded product such as a sheet, the molded product obtained is required to have high whiteness. That is, even if the polymer is molded into a sheet or the like without adding any coloring agent, the molded product obtained is somewhat colored. This coloring is called initial coloring, and it is desired that the coloring be as small as possible. However, since the coating film composed of the condensation product of the aromatic amine compound may be peeled off or dissolved and mixed into the polymer, the whiteness of the molded article is lowered, that is, the initial colorability is deteriorated.

Therefore, an object of the present invention is to polymerize a monomer having an ethylenically unsaturated double bond, not only in the liquid phase part in the polymerization vessel but also in the vicinity of the interface between the gas phase part and the liquid phase part. In addition, it is possible to effectively prevent the adhesion of the polymer scale, and when molded into a sheet or the like, a polymer is obtained in which a molded product having very few fish eyes and good initial colorability is obtained. An object of the present invention is to provide a polymer scale anti-adhesion agent and a method for producing a polymer.

[0010]

Means for Solving the Problems In order to achieve the above object, the present invention is selected from the group consisting of (A) a heterocyclic compound having at least two amino groups and (B) a benzoquinone compound and a naphthoquinone compound. There is provided a polymer scale anti-adhesion agent for the polymerization of a monomer having an ethylenically unsaturated double bond, which comprises an alkaline solution containing a condensation product with at least one of the above.

The present invention also provides a method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein at least two amino groups (A) are present on the inner wall surface. A polymerization vessel having a coating film formed by applying an alkaline solution containing a condensation product of the heterocyclic compound having (B) and at least one selected from the group consisting of benzoquinone compounds and naphthoquinone compounds and drying the solution. There is provided a manufacturing method which comprises the step of carrying out the above-mentioned polymerization inside, thereby preventing the adhesion of the polymer scale inside the polymerization vessel.

Component (A) The component (A) is a heterocyclic compound having at least two amino groups (—NH ₂ ). The heterocyclic compound having at least two amino groups is, for example, a compound represented by the following general formula:
It is a compound represented by (1).

(R ¹ ) _k X (NH ₂ ) ₂ (1) [wherein R ¹ is --OH, --COOH, --SO ₃ H, --NH ₂ , --C
_{l, -Br, -I, -NO 2} , -COCH 3, -OCH 3, -N (CH
₃ ) ₂ , —C ₆ H ₅ and a group selected from the group consisting of alkyl groups having 1 to 3 carbon atoms, and when a plurality of R ^1's are present, they may be the same or different. k is 0-9
And X is a (k + 2) -valent heterocyclic group. ]

Here, the heterocyclic group represented by X is 1
A group containing at least one heterocycle in the molecule. The heterocycle may be fused with a carbon homocycle and / or another heterocycle. Examples of such heterocyclic groups include pyrrole, indole, isoindole, carbazole, porphyrin, oxazole, thiazole, benzothiazole, imidazole, pyrazole, triazole, thiadiazole, pyridine, pyrimidine, quinoline, acridine, phenanthridine, phenanthroline, Heterocyclic compounds such as naphthyridine, furan, benzofuran, pyran, pyrone, benzopyrylium, coumarin, and xanthone convert the hydrogen atom bonded to the ring into (k +
2) Those removed are listed.

Specific examples of the heterocyclic compound having at least two amino groups include the following compounds. For example, pyrrole compounds such as 2,4-diaminopyrrole and 2,5-diaminopyrrole.

For example, indole compounds such as 2,5-diaminoindole and 3,5-diaminoindole.

For example, 1,3-diaminoisoindole, 4,
Isoindole compounds such as 7-diaminoisoindole.

For example, 2,6-diaminocarbazole, 3,6-
Carbazole compounds such as diaminocarbazole.

For example, oxazole compounds such as 2,4-diaminooxazole and 4-acetyl-2,5-diaminooxazole.

For example, 2,4-diaminothiazole, 2,4-diamino-5-methylthiazole, 2,4-diamino-5-phenylthiazole, 2,4-diaminothiazole-5-carboxylic acid, 2,4- Thiamino compounds such as diaminothiazole-5-sulfonic acid.

For example, 2,5-diaminobenzothiazole,
Benzothiazole compounds such as 2,4-diaminobenzothiazole-6-carboxylic acid and 2,4-diaminobenzothiazole-6-sulfonic acid.

For example, 2,4-diaminoimidazole, 2,5-
Imidazole compounds such as diaminoimidazole.

Pyrazole compounds such as 3,4-diaminopyrazole and 3,5-diaminopyrazole.

For example, thiadiazole compounds such as 2,5-diamino-1,3,4-thiadiazole.

For example, 2,3-, 2,5-, 2,6- and 3,4-diaminopyridine, 4-hydroxy-2,6-diaminopyridine, 4-chloro-2,6-diaminopyridine, etc. Pyridine compound.

For example, 2,4-, 2,6- and 4,6-diaminopyrimidine, 2,4-diamino-6-hydroxypyrimidine, 2,4-
Pyrimidine compounds such as diaminopyrimidine-5-carboxylic acid, 4,6-diaminopyrimidine-2-sulfonic acid, and 2,4,5-triaminopyrimidine.

For example, 3,4-, 4,6-, 4,8-, 5,6-, 5,7-, 5,8-,
6,8- and 7,8-diaminoquinoline, 5,8-diamino-6-methoxyquinoline, 5,8-diaminoquinoline-2-carboxylic acid,
5,8-diaminoquinoline-2-sulfonic acid, 5,8-diamino-6
-Quinoline compounds such as hydroxyquinoline.

For example, 1,6-, 1,7-, 1,9-, 2,4-, 2,5-, 2,6-,
2,7-, 2,9-, 3,5-, 3,6-, 3,8-, 3,9- and 4,9-diaminoacridine, 4,9-diamino-2-hydroxyacridine, 4, 9-
Acridine compounds such as diaminoacridine-2-carboxylic acid and 4,9-diaminoacridine-2-sulfonic acid.

For example, 3,6-diaminophenanthridine,
Phenanthridine compounds such as 6,9-diaminophenanthridine.

Phenanthroline compounds such as 2,4-diamino-1,10-phenanthroline and 2,9-diamino-1,10-phenanthroline.

For example, naphthyridine compounds such as 2,6-diamino-1,5-naphthyridine and 2,4-diamino-1,8-naphthyridine.

Furan compounds such as 2,4-diaminofuran and 2,5-diaminofuran.

For example, 3,6-diaminobenzofuran, 4,6-
Benzofuran compounds such as diaminobenzofuran.

For example, pyran compounds such as 2,6-diaminopyran and 3,6-diaminopyran.

For example, 3,6-diamino-α-pyrone, 2,6-
Pyrone compounds such as diamino-γ-pyrone.

Benzopyrylium compounds such as 2,7-diamino-4-benzopyrylium chloride and 4,7-diamino-2-benzopyrylium chloride.

For example, coumarin compounds such as 3,4-diaminocoumarin and 5,7-diaminocoumarin.

Xanthone compounds such as 1,6-diaminoxanthone and 2,7-diaminoxanthone.

Preferred among the above are 2,6-diaminopyridine, 3,6-diaminoacridine, 1,6-diaminoacridine, 3,9-diaminoacridine, 4,9-diamino-2-hydroxyacridine, 4,9-Diaminoacridine-2-sulfonic acid, 2,4-diamino-6-hydroxypyrimidine, 4,6-
Diaminopyrimidine, 2,4,5-triaminopyrimidine, 2,
4-diaminopyrimidine-5-carboxylic acid, 4,6-diaminopyrimidine-2-sulfonic acid, 2,4-diaminothiazole, 2,
4-diaminothiazole-5-carboxylic acid, 5,8-diaminoquinoline and 4,8-diaminoquinoline.

The above-mentioned component (A) can be used alone or in combination of two or more kinds.

Component (B) The component (B) is at least one selected from the group consisting of benzoquinone compounds and naphthoquinone compounds. Benzoquinone Compounds Benzoquinone compounds have the following general formula (2):
And a compound represented by (3).

[0042]

[Chemical 1]

[0043]

[Chemical 2]

(In each formula, a plurality of R ^{2 s} may be the same or different and may be —H, —NH ₂ , —Cl, —Br, —OH, —NO ₂ , —C.
_{OCH 3, -OCH 3, -N (} CH 3) 2, -COOH, a group selected from -SO ₃ H and the group consisting of alkyl group having 1 to 3 carbon atoms. )

Specifically, o-, m- and p-benzoquinone,
Examples thereof include hydroxy-p-benzoquinone, chloro-p-benzoquinone, bromo-p-benzoquinone, juroquinone and chloranil.

Naphthoquinone Compounds Naphthoquinone compounds are represented by the following general formula (4)
And a compound represented by (5).

[0047]

[Chemical 3]

[0048]

[Chemical 4]

(In each formula, a plurality of R ² may be the same or different and are as described above. Also, a plurality of R ³ may be the same or different, and --H, --Cl, --Br,-. OH, −COCH
_3, -OCH _3, -CH _3, a group selected from the group consisting of -COOH and -SO ₃ H. )

Specific examples thereof include 6-methyl-1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, lawson, juglone, plumbagin, α-naphthoquinone and β-naphthoquinone.

Among the above-mentioned component (B), preferred is o-
And p-benzoquinone, α-naphthoquinone, β-naphthoquinone and lawson.

The above quinone compound (B) may be used alone or in combination of 2
It is also possible to use a combination of two or more species.

Condensation Reaction It is an essential component of the polymer scale anti-adhesion agent of the present invention.
Condensation products of (A) component and (B) component are (A) component and
Component (B) in a suitable solvent, optionally in the presence of a catalyst, usually at room temperature to 200 ° C for 0.5 to 100 hours, preferably room temperature to
It is produced by reacting at 150 ° C. for 3 to 30 hours.

Since the component (B) also acts as a condensation catalyst, it is not usually necessary to add another condensation catalyst. However, as the condensation catalyst which can be used when other condensation catalyst is added, iodine or bromine can be used. Elemental or molecular elemental halogen such as chlorine, fluorine and fluorine; oxyacids and oxyacid salts of halogens such as iodic acid, periodate, potassium periodate and sodium perchlorate; Inorganic peroxides such as sodium oxide, potassium persulfate and ammonium persulfate; for example, peracetic acid, benzoyl peroxide,
Organic peroxides such as cumene hydroperoxide, perbenzoic acid and p-menthane hydroperoxide; selected from iron and copper such as ferrous chloride, ferric chloride, copper sulfate and cuprous chloride Metal chlorides and sulfates; eg, α, α'-azobisisobutyronitrile, α, α '
-Azo compounds such as azobis-2,4-dimethylvaleronitrile; for example, nitrobenzene, o-, m- and p-oxynitrobenzene, o-, m- and p-nitroanisole, o-, m- and p-chloro Examples thereof include aromatic nitro compounds such as nitrobenzene, o-, m- and p-nitrobenzoic acid, o-, m- and p-nitrobenzenesulfonic acid.

As the solvent for the condensation reaction, for example, organic solvents such as alcohols, ketones and esters are used.
Among them, it is preferable to use an organic solvent miscible with water. Examples of the water-miscible organic solvent 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. Of these, alcohols are particularly preferable. It is also possible to use a mixed solvent of water and an organic solvent miscible with water.

The pH of the medium for carrying out the condensation reaction is usually 1 to 13
Therefore, the pH adjuster can be used without particular limitation.

The ratio of the component (A) and the component (B) at the time of carrying out the condensation reaction depends on the types of the component (A), the component (B) and the solvent used,
Although it is affected by the reaction temperature, the reaction time, etc., it is generally preferable that the amount of the component (B) is 0.01 to 10 parts by weight, and further 0.1 to 5 parts by weight, per 1 part by weight of the component (A). preferable.
If the amount of the component (B) is too large or too small, the effect of preventing polymer scale adhesion of the condensation product obtained will decrease.

Containing a condensation product of the component (A) and the component (B)
Polymer scale anti-adhesive agent consisting of an alkaline solution The polymer scale anti-adhesive agent of the present invention, the above (A) component and
It consists of an alkaline solution containing a condensation product with the component (B). The polymer scale adhesion preventive agent is applied to the inner wall surface of the polymerization vessel and the like, and dried to form a coating film, whereby the adhesion of the polymer scale to the inner wall surface of the polymerization vessel can be prevented.

The polymer scale anti-adhesion agent is prepared, for example, by adding the following solvent to the liquid containing the condensation product which has been subjected to the above condensation reaction, if necessary, and adjusting the pH to be alkaline. Further, the polymer scale adhesion preventive agent is
After the condensation product-containing liquid was poured into cold water to precipitate the condensation product, the precipitate was filtered off, and the dried product was added with the following solvent to adjust the pH to alkaline. Good.

By making the polymer scale anti-adhesive agent of the present invention alkaline, the solubility of the condensation products of the components (A) and (B) in the solvent is improved. Therefore, since the polymer scale adhesion preventing agent becomes a uniform solution, the polymer scale adhesion preventing effect can be improved when applied on the inner wall surface of the polymerization vessel or the like. The polymer scale anti-adhesion agent of the present invention preferably has a pH of 7.5 to 13.5, and particularly preferably pH 8.0 to 13.5. As the alkaline compound used for pH adjustment, for example, LiOH,
Alkali metal compounds and ammonia compounds such as NaOH, KOH, Na ₂ CO ₃ , Na ₂ HPO ₄ , NH ₄ OH, and, for example,
Examples include organic amine compounds such as ethylenediamine, monoethanolamine, diethanolamine, and triethanolamine.

As the solvent used for preparing the polymer scale anti-adhesive agent, for example, water; for example, methanol, ethanol, propanol, butanol, 2-butanol,
Alcohol solvents such as 2-methyl-1-propanol, 2-methyl-2-propanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 2-pentanol; for example, acetone, methyl ethyl ketone, methyl isobutyl Ketone-based solvents such as ketones; for example, methyl formate, ethyl formate,
Ester solvents such as methyl acetate, ethyl acetate and methyl acetoacetate; for example, ether solvents such as 4-methyldioxolane and ethylene glycol diethyl ether; furans; aprotic solvents such as dimethylformamide, dimethylsulfoxide and acetonitrile. Etc. are illustrated. These solvents are appropriately used alone or as a mixed solvent of two or more kinds.

Among the above solvents, water and a mixed solvent of water and an organic solvent miscible with water are preferable.
Among the above-mentioned organic solvents, water-miscible organic solvents include, for example, alcohol solvents such as methanol, ethanol and propanol; ketone solvents such as acetone and methyl ethyl ketone; methyl acetate, ethyl acetate and the like. The ester-based solvent and the like are listed. When using a mixed solvent of water and an organic solvent miscible with water, the content of the organic solvent shall be such that there is no risk of ignition, explosion, etc., and there is no problem in handling safety such as toxicity. Is preferred,
Specifically, the organic solvent content is preferably 50% by weight or less, more preferably 30% by weight or less.

The concentration of the condensation product in the alkaline solution is not particularly limited as long as the total coating amount described later can be obtained, but is usually about 0.001 to 5% by weight, preferably 0.01 to 1%.
It is about% by weight.

In order to further improve the polymer scale adhesion preventing effect, the inhibitor is selected from the group consisting of (C) water-soluble polymer compound and / or (D) inorganic colloid and alkali metal silicate. It is preferable to add at least one of the above. More preferably, (C) and (D) are used together. These additives (C) and (D) probably interact with the condensation product to increase the hydrophilicity of the coated surface ((C) water-soluble polymer compound) or to prevent the polymer scale from sticking. It is presumed that it has an effect of increasing the adhesion to the inner wall of the polymerization vessel (at least one selected from the group consisting of (D) inorganic colloid and alkali metal silicate).

(C) Water-Soluble Polymer Compound As the water-soluble polymer compound (C), for example, gelatin,
Amphoteric polymer compounds such as casein; for example, anionic polymer compounds such as polyacrylic acid, polystyrene sulfonic acid, carboxymethyl cellulose, alginic acid; and cationic nitrogen-containing polymer compounds such as polyvinylpyrrolidone and polyacrylamide; for example, polyvinyl Examples thereof include hydroxyl group-containing polymer compounds such as alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose and pectin. Among the above water-soluble polymer compounds, gelatin, casein, polyacrylic acid, carboxymethyl cellulose, polyvinylpyrrolidone and pectin are preferable.

The above water-soluble polymer compound (C) can be used alone or in combination of two or more. Also,
The amount of the water-soluble polymer compound (C) added to the polymer scale anti-adhesion agent is the condensation product 1 of the component (A) and the component (B).
It is usually 0.01 to 10 parts by weight per part by weight, preferably
0.05 to 2 parts by weight.

(D) Inorganic colloid and alkali metal silica
The at least one inorganic colloid selected from the group consisting of acid salts is, for example, a dispersion method using water as a dispersion medium,
It is a particle colloid produced by the agglomeration method, and the size of the colloid particles is 1 to 500 mμ. As the inorganic colloid, specifically, aluminum, thorium, titanium,
Colloids of oxides and hydroxides of metals selected from zirconium, antimony, tin, iron, etc., tungstic acid, vanadium pentoxide, colloids of gold and silver, silver iodide sol, colloids of selenium, sulfur, silica, etc. Is exemplified. Preferred among these are colloids of oxides and hydroxides of metals selected from aluminum, titanium, zirconium, tin and iron, and colloidal silica.

As the alkali metal silicate,
For example, alkali metal metasilicate (M ₂ SiO ₃ ), orthosilicate (M ₄ SiO ₄ ), disilicate (M ₂ Si ₂ O ₃ ), trisilicate ( M ₃ Si ₃ O _7), Sesukikei acid (M ₄ Si ₃ O ₁₀₎
Etc. (here, M represents an alkali metal such as lithium, sodium, potassium, etc.), and water glass.

The above-mentioned component (D) can be used alone or in combination of two or more kinds. Further, the addition amount of the component (D) to the polymer scale anti-adhesion agent is the same as that of the component (A).
Usually, 0.01 to about 1 part by weight of a condensation product with the component (B) is used.
10 parts by weight, preferably 0.05 to 5 parts by weight.

When the above-mentioned component (C) and component (D) are used in combination, it is preferable to use a combination of a water-soluble polymer and an inorganic colloid, or a combination of a water-soluble polymer and an alkali metal silicate. When the water-soluble polymer compound and the inorganic colloid are used in combination, it is preferable to use 5 to 3000 parts by weight of the inorganic colloid, and further 50 to 1000 parts by weight, per 100 parts by weight of the water-soluble polymer compound. Is preferred.
When used in combination with a water-soluble polymer compound and an alkali metal silicate, it is preferable to use 5 to 3000 parts by weight of an alkali metal silicate per 100 parts by weight of the water-soluble polymer compound. It is preferable to use 50 to 1000 parts by weight.

Formation of coating film A polymer scale anti-adhesive agent comprising an alkaline solution containing a condensation product of the component (A) and the component (B) prepared as described above was used to coat the inner wall surface of the polymerization vessel. In order to form a coating film, first, the inhibitor is applied to the inner wall surface of the polymerization vessel, then sufficiently dried in a temperature range from room temperature to 100 ° C., and then washed with water as necessary.

Further, the polymer scale adhesion preventive agent is
It is preferable to apply not only to the inner wall surface of the polymerization vessel, but also to other portions where the monomer contacts during the polymerization. For example, a stirring blade,
Examples include stirring shafts, baffles, condensers, headers, search coils, bolts and nuts.

More preferably, the polymer scale anti-adhesion agent is used for recovering a site where polymer scale may be attached, for example, an unreacted monomer, even at a site other than the site where the monomer contacts during polymerization. On the inside of the system equipment and piping,
It is better to form the coating film. Specific examples include inner surfaces of a monomer distillation column, a condenser, a monomer storage tank, a valve, and the like.

The method for applying the polymer scale anti-adhesion agent to the inner wall surface of the polymerization vessel is not particularly limited, and for example, brush coating, spray coating, a method of withdrawing after filling the polymerization vessel with the polymer scale anti-adhesion agent, etc. In addition, JP-A-57-61001, JP-A-55-36288 and JP-A-56-
The automatic coating methods described in JP-A-501116, JP-A-56-501117 and JP-A-59-11303 can also be used.

The method of drying the wet surface by applying the polymer scale adhesion preventive agent is not limited, and the following method can be used, for example. That is, after the application of the polymer scale anti-adhesive agent, a method of applying an appropriately heated hot air to the application surface, or the inner wall surface of the polymerization vessel and the other surface to which the polymer scale anti-adhesion agent is applied are preliminarily set to, for example, 30 It is possible to use a method in which the polymer scale adhesion preventive agent is directly applied to the heated surface by heating to -80 ° C. 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 to 5 g / m ² , and in particular,
It is preferably 0.05 to ² g / m ² .

The above coating operation may be carried out every 1 to 10 or more batches of polymerization. Since the formed coating film has high durability and the action of preventing the polymer scale from adhering continues, it is not always necessary to perform it for each batch of polymerization, so that the productivity is improved.

Polymerization As described above, after applying a coating treatment to the inner wall of the polymerization vessel, and preferably to other portions where the monomers come into contact with each other during polymerization, a coating film is formed. Polymerize. That is, in addition to a monomer having an ethylenically unsaturated 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. Then, a dispersant and the like are charged, and then polymerization is performed by a conventional method.

Examples of the monomer having an ethylenically unsaturated 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 and salts; maleic acid, fumaric acid, and their esters and anhydrides; Examples include diene-based monomers such as butadiene, chloroprene, and isoprene; styrene; acrylonitrile; vinylidene halide; vinyl ether and the like. These are used alone or in combination of two or more.

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, the inside of the polymerization vessel was evacuated and the pressure was reduced to 0.1 to 760 mmHg, and then monomers were charged (at this time, the internal pressure of the polymerization vessel was
Usually 0.5 to 30 kgf / cm ² · G), then 30 to 150
Polymerize at reaction temperature of ° C. During the polymerization, if necessary,
One or more of water, a dispersant and a polymerization initiator are added. Further, the reaction temperature at the time of polymerization varies depending on the type of monomer to be polymerized, for example, in the case of vinyl chloride polymerization, the polymerization is performed at 30 to 80 ° C., and in the case of styrene polymerization, it is 50
Polymerize at ~ 150 ° C. For polymerization, the internal pressure of the polymerization vessel is 0 to 7 kg.
When it decreases to f / 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 mounted 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 polymerization are usually 20 to 500 parts by weight of water, 0.01 to 30 parts by weight of a dispersant, and 0.01 to 5 parts by weight of a polymerization initiator with respect to 100 parts by weight of a monomer. It is a department.

In the case of solution polymerization, an organic solvent such as toluene, xylene or pyridine is used instead of water as a polymerization medium. 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, about 0.01-
After evacuating to a pressure of 760 mmHg, a monomer and a polymerization initiator are charged in the polymerization vessel and polymerization is carried out at a reaction temperature of -10 to 250 ° C. For example, in the case of vinyl chloride polymerization, 30-80 ℃
In the case of styrene polymerization, it is carried out at 50 to 150 ° C.

When the polymer scale adhesion preventing method of the present invention is applied to carry out polymerization, the polymer scale adhesion 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.

The substances 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 hydroperoxide,
Cyclohexanone peroxide, t-butyl peroxypivalate, bis (2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate,
Polymerization initiators such as α, α′-azobisisobutyronitrile, α, α′-azobis-2,4-dimethylvaleronitrile, potassium peroxodisulfate, ammonium peroxodisulfate, and p-menthane hydroperoxide; Suspending agents such as partially saponified polyvinyl alcohol, polyacrylic acid, copolymers of vinyl acetate and maleic anhydride, cellulose derivatives such as hydroxypropylmethyl cellulose, natural and synthetic polymer compounds such as gelatin; for example, calcium phosphate, hydroxyapatite Solid dispersants such as; nonionic emulsifiers such as sorbitan monolaurate, sorbitan trioleate, polyoxyethylene alkyl ethers; sodium alkylbenzene sulfonates such as sodium lauryl sulfate, sodium dodecylbenzene sulfonate Anionic emulsifiers such as sodium, dioctyl sodium sulfosuccinate; fillers such as calcium carbonate, titanium oxide; stabilizers such as tribasic lead sulfate, calcium stearate, dibutyltin dilaurate, dioctyltin mercaptide; rice, for example Lubricants such as wax, stearic acid and cetyl alcohol; plasticizers such as DDP and DBP; mercaptans such as t-dodecyl mercaptan; chain transfer agents such as trichloroethylene; and pH controlling agents, etc. The method of the present invention can effectively prevent the adhesion of polymer scale.

The polymer scale anti-adhesion 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 to improve the scale prevention effect. You can also let it. In this case, the amount of the polymer scale anti-adhesion agent added 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 polymer such as fish eye, bulk specific gravity and particle size distribution.

[0087]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. In the tables below, the test numbers marked with * are comparative examples, and the other test numbers are examples of the present invention.

Production Example 1 Production of condensation product No. 1 In a reactor having an internal volume of 2 liter equipped with a reflux condenser, 900 g of methanol and 2,6-diaminopyridine 4 as component (A) 4
0 g was charged and stirred at room temperature to dissolve 2,6-diaminopyridine in methanol. To the thus obtained methanol solution, 60 g of α-naphthoquinone was added as the component (B), the temperature was raised to 65 ° C., the mixture was reacted at 65 ° C. for 10 hours, and then cooled. In this way, a methanol solution of the condensation product No. 1 was obtained.

Production of Condensation Products Nos. 2 to 26 In each production, component (A) (heterocyclic compound having at least two amino groups) and component (B) (benzoquinone compound and naphthoquinone compound) shown in Table 1 are used. A condensation product was produced in the same manner as the condensation product No. 1 using at least one selected from the group consisting of 1) and the solvents shown in Table 2. Table 2 shows (A) + (B) total concentration, (A) :( B)
The weight ratio, reaction temperature and reaction time are shown.

[0090]

[Table 1]

[0091]

[Table 2]

Example 1 (Experiment Nos. 101 to 126) In each experiment, a polymerization vessel made of stainless steel and equipped with a stirrer with an internal volume of 1000 liters was used as a polymerization vessel. In each experiment,
Conditions shown in Tables 3 and 4 (solvent composition, condensation product (E) + (C) +
(D) total concentration, (E) :( C) :( D) weight ratio and pH) so that the condensation products (E), the water-soluble polymer compound (C), shown in Tables 3 to 4, A polymer scale anti-adhesive agent was prepared using at least one kind (D) selected from the group consisting of inorganic colloids and alkali metal silicates, an alkaline compound and a solvent. Table 6 shows the inorganic colloid of component (D) (a to g in Tables 3 to 4 and Tables 7 to 8) used in this example and Example 2 described below.

In each experiment, the polymer scale anti-adhesion agent prepared as described above was applied to the inner wall of the polymerization vessel, the stirring shaft, the stirring blade and other portions where the monomer comes into contact during the polymerization.
After heating and drying at 15 ° C for 15 minutes to form a coating film, the inside of the polymerization vessel was washed with water.

Then, in each experiment, polymerization was carried out as follows. Water 400 kg, vinyl chloride 200 kg, partially saponified polyvinyl alcohol 250 g, hydroxypropyl methylcellulose 25 g and 3,5,5-trimethylhexanoyl peroxide 70 g were placed in the polymerization vessel where the coating film was formed by the above coating treatment. Was charged and polymerized at 66 ° C. for 6 hours with stirring. 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.

Thereafter, the coating operation was not carried out, and the above-mentioned polymerization and washing in the polymerization vessel were regarded as one batch, and the same operation was repeated for the number of batches shown in Table 5, and after the end of the final batch, the liquid phase portion in the polymerization vessel was repeated. The amount of polymer scale attached and the amount of polymer scale attached in the vicinity of the interface between the gas phase portion and the liquid phase portion were measured by the following methods for each experiment. The results are shown in Table 5.

Measurement of polymer scale The scale adhering to a 10 × 10 cm area at a predetermined location on the inner wall of the polymerization vessel was scraped off with a spatula and weighed with a balance. Weighing value 1
It was multiplied by 00 to determine the amount of scale deposit per 1 m ² .

Further, the number of fish eyes 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.・Fish eye measurement 100 parts by weight of the obtained polymer, dioctyl phthalate (DO
P) 50 parts by weight, dibutyltin dilaurate 1 part by weight, cetyl alcohol 1 part by weight, titanium oxide 0.25 parts by weight, carbon black 0.05 parts by weight A mixture prepared at a mixing ratio is kneaded at 150 ° C. for 7 minutes using a 6 inch roll. After that, the sheet 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.

Further, the lightness index (L value) was measured by the following method in order to evaluate the initial colorability when the polymer obtained in each experiment was molded into a sheet. The results are shown in Table 5. -Measurement of lightness index (L value) 100 parts by weight of the obtained polymer, 1 part by weight of tin laurate-based stabilizer (TS-101 manufactured by Akishima Chemical Co., Ltd.), cadmium-based stabilizer (manufactured by Katsuta Kako Co., Ltd., C- 100 J) 0.5 part by weight and 50 parts by weight of dioctyl phthalate as a plasticizer are kneaded in a two-roll mill at 160 ° C. for 5 minutes, and then a sheet having a thickness of 1 mm is formed. Next, the molded sheet is put in a 4 × 4 × 1.5 cm frame and heated and pressure molded at 160 ° C. and 65 to 70 kgf / cm ² for 0.2 hours to prepare a measurement sample. JIS for this sample
The lightness index L in the Hunter color difference formula described in Z 8730 (1980) was determined, and the larger the L value, the higher the whiteness, that is, the better the initial colorability. The L value is obtained as follows.

According to the description of JIS Z 8722, using standard light C, photoelectric colorimeter (Nippon Denshoku Industries Co., Ltd., Z-1001DP type colorimetric color difference meter), stimulus value direct reading method, stimulating XYZ color system Calculate the value Y. 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 according to the formula: L = 10Y ^1/2 described in JIS Z 8730 (1980).

[0100]

[Table 3]

[0101]

[Table 4]

[0102]

[Table 5]

[0103]

[Table 6]

Example 2 (Experiment Nos. 201 to 226) In each experiment, a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 20 liters was used as the polymerization vessel. In each experiment,
Conditions shown in Tables 7 to 8 (solvent composition, condensation product (E) + (C) +
(D) total concentration, (E) :( C) :( D) weight ratio and pH) so that the condensation products (E), water-soluble polymer compounds (C) shown in Tables 7 to 8 A polymer scale anti-adhesive agent was prepared using at least one type (D) selected from the group consisting of colloidal silica and silicates of alkali metals, an alkaline compound and a solvent. These polymer scale anti-adhesion agents are applied to the inner wall of the polymerization vessel and the stirring shaft, stirring blades and other parts where the monomers come into contact during the polymerization, heated at 40 ° C for 15 minutes and dried to form a coating film, and then polymerized. The inside of the vessel was washed with water.

Next, in each experiment, polymerization was carried out as follows. Into the polymerization vessel where the coating film was formed by applying the coating as described above, 9 kg of water, 225 g of sodium dodecylbenzenesulfonate, 12 g of t-dodecyl mercaptan and 13 g of potassium peroxodisulfate were charged, and the inside of the polymerization vessel was replaced with nitrogen gas. After that, 1.3 kg of styrene and 3.8 kg of butadiene
Was charged and polymerized at 50 ° C. for 20 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.

Thereafter, the coating operation was not carried out, and the above-mentioned polymerization and washing in the polymerization vessel were regarded as one batch, and the same operation was repeated for the number of batches shown in Table 9. The amount of polymer scale attached and the amount of polymer scale attached near the interface between the gas phase part and the liquid phase part were determined in the same manner as in Example 1 for each experiment. The results are shown in Table 9
Shown in. Further, in order to evaluate the initial colorability when the polymer obtained in each experiment is formed into a sheet, the lightness index (L
The value) was measured by the following method. The results are shown in Table 9.

Measurement of lightness index (L value) 1 kg of a 2% magnesium sulfate solution was added to 1 kg of the obtained polymer latex to perform coagulation precipitation, and then the precipitate was separated by filtration. 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. for 25 hours using a vacuum dryer to obtain a resin. The obtained resin is put into a 9 × 9 cm, 0.1 cm thick mold, heated at 195 ° C. and 50-60 kgf / cm ² for 0.2 hours, and pressure molded at a final pressure of 80 kgf / cm ² to obtain a measurement sample. It was made.
The lightness index L of this sample was determined in the same manner as in Example 1.

[0108]

[Table 7]

[0109]

[Table 8]

[0110]

[Table 9]

Example 3 (Experiment Nos. 301 to 305) In each experiment, a stainless steel polymerization vessel with an internal volume of 20 liter and equipped with a stirrer was used as the polymerization vessel. In each experiment, the polymer scale anti-adhesion agent (the one used in Experiment No. shown in Table 10) was applied to the inner wall of the polymerization vessel, the stirring shaft, the stirring blade, and other parts where the monomer contacts during the polymerization. After heating for 15 minutes at ℃ and drying to form a coating film, it was washed with water.

Then, in each experiment, polymerization was carried out as follows. 4.0 kg of water and 6 g of sodium dodecylbenzenesulfonate were charged into the polymerization vessel in which the coating film was formed by the coating treatment as described above, and the temperature was raised to 60 ° C. with stirring. Next, after replacing the gas phase in the polymerization vessel with nitrogen gas, n-butyl acrylate (94 g), methyl methacrylate (220 g), acrylic acid (5 g) and methacrylic acid (5 g) were charged, and then ammonium persulfate (1 g) and sodium hydrosulfite (1 g) were charged.
Stirred for 20 minutes at ° C. Furthermore, mixed monomer (n-butyl acrylate 2.1 kg, methyl methacrylate 4.8 k) was added to the polymerization vessel.
g, a mixture of acrylic acid 100 g and methacrylic acid 100 g) 1% by weight ammonium persulfate aqueous solution 500 g, 1% by weight sodium hydrosulfite aqueous solution 500 g and 25% by weight polyoxyethylene nonylphenyl ether aqueous solution 2.0 kg respectively over 3 hours. A fixed amount was added. After the addition was completed, the temperature of the polymerization vessel was raised to 70 ° C. and polymerization was carried out for 2 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.

Thereafter, the operation from the formation of the above-mentioned coating film to the washing of the inside of the polymerization vessel through the polymerization is regarded as one batch.
The same procedure as in Example 1 was repeated for each experiment with 50 batch repetitions and the amount of polymer scale deposited in the liquid phase portion in the polymerization vessel at the 50th batch and the amount of polymer scale deposited near the interface between the gas phase portion and the liquid phase portion. I asked for. The results are shown in Table 10.

[0114]

[Table 10]

Example 4 (Experiment No. 401 to 405) In each experiment, a polymerization vessel made of stainless steel with an internal volume of 100 liter and equipped with a stirrer was used. In each experiment,
Apply the polymer scale anti-adhesive agent (used in Experiment No. shown in Table 11) to the inner wall of the polymerization vessel, the stirring shaft, the stirring blade and other parts where the monomer contacts during the polymerization, and then at 50 ° C for 15 minutes. After heating and drying to form a coating film, it was washed with water.

Then, in each experiment, polymerization was carried out as follows. Water 40 kg, disproportionated potassium rosinate in the polymerization vessel where the coating film was formed by coating as described above 500
g, polybutadiene latex (solid content 45%) 13 kg, styrene monomer 9 kg, acrylonitrile monomer 5 kg, t-dodecyl mercaptan 40 g, and cumene hydroperoxide 140 g were charged. Next, increase the temperature in the polymerization vessel to 47
While maintaining the temperature at 0 ° C, 200 g of glucose, 2 g of ferrous sulfate and 100 g of sodium pyrophosphate were charged into the polymerization vessel.
Then, the mixture in the polymerization vessel was stirred at 65 ° C. for 4 hours.
Polymerized for 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.

Thereafter, the operations from the formation of the coating film as described above to the washing of the inside of the polymerization vessel through the polymerization are regarded as one batch.
The same procedure as in Example 1 was repeated for each experiment by repeating 80 batches, and determining the polymer scale deposition amount in the liquid phase part in the polymerization vessel of the 80th batch and the polymer scale deposition amount in the vicinity of the interface between the gas phase part and the liquid phase part. I asked for. The results are shown in Table 11.

[0118]

[Table 11]

[0119]

According to the present invention, it is possible to effectively prevent the adhesion of polymer scale not only in the liquid phase portion in the polymerization vessel but also in the vicinity of the interface between the gas phase portion and the liquid phase portion. Therefore, when the present invention is applied to carry out the polymerization, it is not necessary to carry out the work of removing the polymer scale for each polymerization, thereby improving the productivity. When a polymer obtained by applying the present invention for polymerization is molded into a sheet or the like, a molded product having extremely few fish eyes can be obtained. Furthermore, the molded product has good initial colorability. Specifically, the lightness index (L value) in the Hunter color difference formula described in JIS Z 8730 (1980) is, for example, 70 or more for vinyl chloride polymers and 80 or more for SBR.

Claims (3)

[Claims] 1. An alkaline solution comprising a condensation product of (A) a heterocyclic compound having at least two amino groups and (B) at least one selected from the group consisting of benzoquinone compounds and naphthoquinone compounds. , A polymer scale anti-adhesion agent for polymerization of a monomer having an ethylenically unsaturated double bond. 2. The polymer scale anti-adhesion agent according to claim 1, further comprising (C) a water-soluble polymer compound, and / or (D) an inorganic colloid and an alkali metal silicate. Containing at least one of 3. A method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein the inner wall surface has (A) a heterocyclic group having at least two amino groups. Polymerization in a polymerization vessel having a coating film formed by coating an alkaline solution containing a condensation product of a compound and (B) at least one selected from the group consisting of a benzoquinone compound and a naphthoquinone compound, and drying. And a step of carrying out the step, whereby the adhesion of polymer scale in the polymerization vessel is prevented.