JP2727402B2 - Polymer scale adhesion inhibitor and method for producing polymer using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer scale inhibitor 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 polymerization method of 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 easily occurs on the inner wall of the polymerization vessel, a stirrer, or the like at a site where the monomer comes into contact.

When the polymer scale adheres, the yield of the polymer, the cooling capacity of the polymerization vessel, etc. decrease, and the polymer scale peels off and is mixed into the polymer to obtain the polymer. The disadvantage is that the quality of the moldings is reduced. In addition, removing the attached polymer scale requires not only excessive labor and time, but also
Since unreacted monomers are contained in this polymer scale, there is a risk of human injury due to monomers, which has become a very serious problem in recent years.

Conventionally, in order to prevent the adhesion of polymer scale to the inner wall of such a polymerization vessel, for example, as is practiced in the suspension polymerization of vinyl chloride, the polarity of amine compounds, quinone compounds, aldehyde compounds, etc. A method of applying a polymer scale adhesion inhibitor comprising an organic compound to the inner wall of a polymerization vessel to form a coating film, or a method of adding those compounds to an aqueous medium is known (Japanese Patent Publication No. 45-30343).
issue).

[0005] However, these methods show an effect of preventing the adhesion of polymer scale when the polymerization is repeated up to about 5 to 6 batches. Inferior). This point is particularly significant when a water-soluble catalyst is used, 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 adhesion inhibitor. If a coating film containing the condensation product of the aromatic amine compound is formed on the inner wall of the polymerization vessel or the like where the monomer comes in contact, even if the polymerization is repeated for about 100 to 200 batches, the polymerization proceeds to the liquid phase inside the polymerization vessel. Does not occur on the polymer scale. In addition, even when a water-soluble catalyst is used, the adhesion of the polymer scale in the liquid phase is similarly prevented.

[0007]

However, there is a disadvantage that the polymer scale adheres near the interface between the gas phase and the liquid phase located in the upper part of the polymerization vessel. Once the polymer scale adheres to the vicinity of the interface between the gas phase and the liquid phase, the polymer scale attached grows gradually as the polymerization is repeated, and eventually separates and mixes with the polymer. May be. When the polymer scale is mixed into the polymer as described above, when the polymer is processed into a molded product such as a sheet, many fish eyes are generated in the obtained molded product, and the quality of the molded product is significantly reduced. Will be.

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

Accordingly, an object of the present invention is to provide a method for polymerizing a monomer having an ethylenically unsaturated double bond, not only in the liquid phase in the polymerization vessel but also in the vicinity of the interface between the gas phase and the liquid phase. In addition, it is possible to effectively prevent the adhesion of the polymer scale and, when molded into a sheet or the like, produce a polymer from which a molded product having extremely low fish eyes and good initial coloring properties is obtained. It is an object of the present invention to provide a polymer scale adhesion inhibitor and a method for producing a polymer.

[0010]

Means for Solving the Problems According to the present invention, there is provided a compound 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. A polymer scale adhesion inhibitor for polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing a condensation product with at least one condensation product.

The present invention also relates to a method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein at least two (A) amino groups are formed on the inner wall surface. A polymerization vessel having a coating film formed by applying an alkaline solution containing a condensation product of a heterocyclic compound having the same and (B) at least one selected from the group consisting of a benzoquinone compound and a naphthoquinone compound, followed by drying. The present invention provides a production method comprising the step of performing the polymerization in the polymerization vessel, whereby the adhesion of the polymer scale in the polymerization vessel is prevented.

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,} a group selected from the group consisting of alkyl groups of -C ₆ H ₅ and 1 to 3 carbon atoms, they may be the same or different if R ¹ is more present. k is 0-9
And X is a (k + 2) -valent heterocyclic group. ]

Here, the heterocyclic group represented by X is 1
Refers to a group containing at least one heterocycle in the molecule. Further, the heterocyclic ring may be condensed with a homocarbon ring and / or another heterocyclic ring. Such heterocyclic groups include, for example, pyrrole, indole, isoindole, carbazole, porphyrin, oxazole, thiazole, benzothiazole, imidazole, pyrazole, triazole, thiadiazole, pyridine, pyrimidine, quinoline, acridine, phenanthridine, phenanthroline, A hydrogen atom bonded to a ring from a heterocyclic compound such as naphthyridine, furan, benzofuran, pyran, pyrone, benzopyrylium, coumarin, xanthone is converted to (k +
2) ones removed.

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- Thiazole 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;

For example, 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 and the like Pyridine compounds.

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.

For example, 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.

For example, 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.

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

Coumarin compounds such as 3,4-diaminocoumarin and 5,7-diaminocoumarin.

For example, 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 component (A) can be used alone or in combination of two or more.

Component (B) The component (B) is at least one selected from the group consisting of benzoquinone compounds and naphthoquinone compounds. Benzoquinone compound The benzoquinone compound has, for example, the following general formula (2)
And compounds represented by (3).

[0042]

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[0043]

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(In each formula, a plurality of R ^{2 s} may be the same or different, and —H, —NH ₂ , —Cl, —Br, —OH, —NO ₂ , —C
It is a group selected from the group consisting of OCH ₃ , —OCH ₃ , —N (CH ₃ ) ₂ , —COOH, —SO ₃ H, and an 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, duloquinone, and chloranil.

Naphthoquinone Compound The naphthoquinone compound has, for example, the following general formula (4)
And compounds represented by (5).

[0047]

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[0048]

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[0049] (wherein, the plurality of R ² may be the same or different, are as defined above In addition, the plurality of R ³ may be the same or different, -H, -Cl, -Br,. - OH, −COCH
₃ , —OCH ₃ , —CH ₃ , —COOH, and —SO ₃ H. )

Specific examples include 6-methyl-1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, Lawson, juglone, plumbagin, α-naphthoquinone, β-naphthoquinone and the like.

Among the above components (B), preferred are o-
And p-benzoquinone, α-naphthoquinone, β-naphthoquinone and Lawson.

The quinone compound (B) may be used alone or
A combination of more than one species can be used.

Condensation reaction is an essential component of the polymer scale adhesion inhibitor of the present invention.
The condensation product of component (A) and component (B) is component (A) and component (A).
Component (B) is placed 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 at room temperature to 200 ° C.
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 usually unnecessary to add another condensation catalyst. However, when the other condensation catalyst is added, examples of the condensation catalyst that can be used include iodine and bromine. , Chlorine, fluorine and other elemental or elemental halogens; for example, oxyacids and oxyacids of halogens such as iodic acid, periodate, potassium periodate, 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; for example, selected from iron and copper such as ferrous chloride, ferric chloride, copper sulfate and cuprous chloride Metal chlorides and sulfates; for example, 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, and o-, m- and p-nitrobenzenesulfonic acid.

As a 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 having miscibility with water. Examples of the organic solvent having miscibility with water include alcohols such as methanol, ethanol and propanol; ketones such as acetone and methyl ethyl ketone; and esters such as methyl acetate and ethyl acetate. Among them, 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 from 1 to 13
And the pH adjuster can be used without any particular limitation.

The ratio of the component (A) to the component (B) when the condensation reaction is carried out 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 usually preferred that the component (B) be 0.01 to 10 parts by weight, more preferably 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 the obtained condensation product on the prevention of polymer scale adhesion is reduced.

Contains a condensation product of component (A) and component (B)
The polymer scale anti-adhesive agent of the present invention comprises an alkaline solution comprising the above-mentioned component (A)
(B) It consists of an alkaline solution containing a condensation product with the component. The polymer scale adhesion inhibitor is applied to the inner wall surface of the polymerization vessel 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 adhesion inhibitor is prepared, for example, by adding the following solvent to the solution containing the condensation product obtained by the above condensation reaction, if necessary, and adjusting the pH to alkaline. In addition, the polymer scale adhesion inhibitor,
After the condensation product-containing liquid was poured into cold water to precipitate the condensation product, the precipitate was separated by filtration, the following solvent was added to the dried product, and the pH was adjusted to alkaline to prepare the solution. Is also good.

By making the polymer scale adhesion inhibitor of the present invention alkaline, the solubility of the condensation product of the components (A) and (B) in the solvent is improved. Accordingly, since the polymer scale adhesion inhibitor becomes a uniform solution, the polymer scale adhesion prevention effect can be improved when applied to the inner wall surface of the polymerization vessel or the like. The polymer scale adhesion inhibitor of the present invention further preferably has a pH of 7.5 to 13.5, and particularly preferably has a pH of 8.0 to 13.5. Examples of the alkaline compound used for pH adjustment include LiOH,
_{NaOH, KOH, Na 2 CO 3} , Na 2 HPO 4, NH 4 OH alkali metal compounds and ammonia compounds such as well, for example,
Examples thereof include organic amine compounds such as ethylenediamine, monoethanolamine, diethanolamine, and triethanolamine.

The solvent used for preparing the polymer scale adhesion inhibitor includes, 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 and 2-pentanol; for example, acetone, methyl ethyl ketone, methyl isobutyl Ketone solvents such as ketones; for example, methyl formate, ethyl formate,
Ester solvents such as methyl acetate, ethyl acetate, methyl acetoacetate; ether solvents such as 4-methyldioxolane, ethylene glycol diethyl ether; furans; aprotic solvents such as dimethylformamide, dimethyl sulfoxide, acetonitrile Etc. are exemplified. These solvents are appropriately used alone or as a mixed solvent of two or more kinds.

Among the above solvents, preferred are water and a mixed solvent of water and an organic solvent miscible with water.
Among the organic solvents described above, examples of the organic solvent having miscibility with water include alcohol solvents such as methanol, ethanol, and propanol; ketone solvents such as acetone and methyl ethyl ketone; and methyl acetate and ethyl acetate. And the like. When using a mixed solvent of water and an organic solvent that is miscible with water, the content of the organic solvent should be such that there is no danger of ignition, explosion, etc., and there is no problem in handling safety such as toxicity. Is preferred,
Specifically, the content of the organic solvent is preferably 50% by weight or less, and 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 below is obtained, but is usually about 0.001 to 5% by weight, preferably 0.01 to 1% by weight.
% By weight.

In order to further improve the effect of preventing the adhesion of polymer scale, the above-mentioned inhibitor is selected from the group consisting of (C) a water-soluble polymer compound and / or (D) an inorganic colloid and a silicate of an alkali metal. It is preferable to add at least one of these. More preferably, (C) and (D) are used in combination. These additives (C) and (D) probably interact with the condensation products to increase the hydrophilicity of the coated surface ((C) water-soluble polymeric compounds) or to reduce the polymer scale adhesion inhibitor. It is presumed to have the effect of increasing adhesion to the inner wall of the polymerization vessel ((D) at least one selected from the group consisting of inorganic colloids and alkali metal silicates).

(C) Water-Soluble Polymer Compound Examples of the water-soluble polymer compound (C) include gelatin,
Amphoteric polymer compounds such as casein; for example, anionic polymer compounds such as polyacrylic acid, polystyrenesulfonic acid, carboxymethylcellulose, and alginic acid; cationic nitrogen-containing polymer compounds such as polyvinylpyrrolidone and polyacrylamide; Examples thereof include hydroxyl group-containing polymer compounds such as alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, and pectin. Preferred among the above water-soluble polymer compounds are gelatin, casein, polyacrylic acid, carboxymethylcellulose, polyvinylpyrrolidone and pectin.

The 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 adhesion inhibitor is the amount of the condensation product of the component (A) and the component (B).
Per part by weight, usually 0.01 to 10 parts by weight, preferably
It is 0.05 to 2 parts by weight.

(D) Inorganic colloid and alkali metal silicon
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 particle 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., colloids of tungstic acid, vanadium pentoxide, gold and silver, colloids of silver iodide sol, 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.

Further, examples of the alkali metal silicate include:
For example, metasilicates (M ₂ SiO ₃ ), orthosilicates (M ₄ SiO ₄ ), disilicates (M ₂ Si ₂ O ₃ ), and trisilicates of alkali metals such as lithium, sodium, and potassium M ₃ Si ₃ O ₇ ), sesquisilicic acid (M ₄ Si ₃ O ₁₀ )
(Where M represents an alkali metal such as lithium, sodium, potassium, etc.), and water glass.

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

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

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

Further, the above-mentioned polymer scale adhesion inhibitor comprises:
It is preferable to apply the coating not only on the inner wall surface of the polymerization vessel but also on other parts where the monomer comes into contact during the polymerization. For example, stirring blades,
Examples include a stirring shaft, a baffle, a condenser, a header, a search coil, a bolt, a nut, and the like.

More preferably, the polymer scale adhesion preventive agent may be a site other than the site where the monomer comes into contact during polymerization, but may be a site where the polymer scale may adhere, for example, the recovery of unreacted monomer. On the inner surface of the system equipment and piping,
It is better to form the coating film. Specifically, the inner surfaces of a monomer distillation column, a condenser, a monomer storage tank, a valve and the like can be mentioned.

The method of applying the polymer scale adhesion inhibitor to the inner wall surface of the polymerization vessel is not particularly limited. For example, brush coating, spray coating, a method of filling the polymerization vessel with the polymer scale adhesion inhibitor, and then extracting the polymer scale. And Japanese Patent Application Laid-Open Nos. 57-61001 and 55-36288, and
The automatic coating method described in JP-A Nos. 501116, 56-501117, and JP-A-59-11303 can also be used.

The method of drying the wet surface by applying the polymer scale adhesion inhibitor is not limited, and for example, the following method can be used. That is, after applying the polymer scale anti-adhesion agent, a method of applying an appropriately heated warm air to the application surface, or the inner wall surface of the polymerization vessel to which the polymer scale anti-adhesive agent is to be applied and other surfaces in advance, for example, 30 It is possible to use a method in which the composition is heated to about 80 ° C., and the polymer scale adhesion inhibitor is directly applied to the heated surface. After the application surface is dried, the application surface is washed with water as needed.

The coating thus obtained has a total coating weight after drying of usually 0.001 to 5 g / m ² .
It is preferably 0.05 to ² g / m ² .

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

Polymerization As described above, a coating film is formed by applying a coating treatment to the inner wall of the polymerization vessel, and preferably to a portion where the monomer comes into contact during the polymerization, and the like, followed by a conventional method in the polymerization vessel. Perform polymerization. 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, anionic emulsifier And then polymerization is carried out by a conventional method.

The monomer having an ethylenically unsaturated double bond to be polymerized by applying the method of the present invention includes, for example,
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; Diene monomers such as butadiene, chloroprene and isoprene; styrene; acrylonitrile; vinylidene halide; and vinyl ether. 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 any polymerization mode of bulk polymerization and gas phase polymerization, and is particularly suitable for polymerization in an aqueous medium such as suspension polymerization and emulsion polymerization.

Hereinafter, a general polymerization method will be described in detail by taking 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 to reduce the pressure to 0.1 to 760 mmHg, and then the monomer was charged (at this time, the internal pressure of the polymerization vessel was
Usually 0.5 ~ 30kgf / cm ²・ G), then 30 ~ 150
Polymerizes at a reaction temperature of ° C. During the polymerization, if necessary,
One or more of water, a dispersant and a polymerization initiator are added. The reaction temperature during the polymerization varies depending on the type of the 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, the polymerization temperature is 50.
The polymerization is carried out at ~ 150 ° C. For polymerization, the internal pressure of the polymerization vessel is 0 to 7 kg
f / cm ² · G, or when the difference between the inlet and outlet temperatures of the cooling water flowing into and out of the jacket provided around the polymerization vessel has almost disappeared (ie, the heat generated by the polymerization reaction has been eliminated). ) Is determined to be completed. Water, dispersant, and polymerization initiator charged during the polymerization are usually 20 to 500 parts by weight of water, 0.01 to 30 parts by weight of a dispersant, 0.01 to 5 parts by weight of a polymerization initiator based on 100 parts by weight of a monomer. Department.

In the case of solution polymerization, an organic solvent such as toluene, xylene and pyridine is used as a polymerization medium instead of water. A dispersant is used as needed.
Other polymerization conditions are generally the same as the polymerization conditions for suspension polymerization and emulsion polymerization.

In the case of bulk polymerization, about 0.01 to
After evacuating to a pressure of 760 mmHg, a monomer and a polymerization initiator are charged into the polymerization vessel, and polymerization is performed at a reaction temperature of -10 to 250 ° C. For example, in the case of vinyl chloride polymerization, 30 to 80 ° C
In the case of styrene polymerization, the reaction is carried out at 50 to 150 ° C.

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

Further, those added to the polymerization system can be used without any restrictions. That is, for example, t-
Butyl peroxy neodecanoate, bis (2-ethylhexyl) peroxy dicarbonate, 3,5,5-trimethylhexanoyl peroxide, α-cumyl peroxy neodecanoate, cumene hydroperoxide,
Cyclohexanone peroxide, t-butylperoxypivalate, bis (2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropylperoxydicarbonate,
polymerization initiators such as α, α′-azobisisobutyronitrile, α, α′-azobis-2,4-dimethylvaleronitrile, potassium belloxodisulfate, ammonium belloxodisulfate, 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 hydroxypropylmethylcellulose, natural and synthetic high molecular compounds such as gelatin; for example, calcium phosphate, hydroxyapatite Nonionic emulsifiers such as sorbitan monolaurate, sorbitan triolate, and polyoxyethylene alkyl ether; and sodium alkyl benzene sulfonate such as sodium lauryl sulfate and sodium dodecylbenzene sulfonate Anionic emulsifiers such as sodium and sodium dioctyl sulfosuccinate; fillers such as calcium carbonate and titanium oxide; stabilizers such as tribasic lead sulfate, calcium stearate, dibutyltin dilaurate, dioctyltin mercaptide; 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; The method of the present invention can effectively prevent the adhesion of the polymer scale.

The polymer scale adhesion inhibitor of the present invention may be used for forming a coating film on the inner wall surface of the polymerization vessel and then added directly to the polymerization system, thereby improving the scale prevention effect. It can also be done. In this case, the amount of the polymer scale adhesion inhibitor is suitably about 10 to 1000 ppm based on the total weight of the monomers to be charged. At the time of addition, care is taken so as not to affect the quality of the polymer such as fish eye, bulk specific gravity, particle size distribution and the like.

[0087]

The present invention will be described below in detail with reference to examples and comparative examples. In each of the following tables, an experiment number marked with * is a comparative example, and other experiment numbers are examples of the present invention.

Production Example 1 Production of condensation product No. 1 900 g of methanol and 2,6-diaminopyridine 4 as the component (A) were placed in a 2 liter reactor equipped with a reflux condenser.
After charging 0 g, the mixture was stirred at room temperature to dissolve 2,6-diaminopyridine in methanol. To the methanol solution thus obtained, 60 g of α-naphthoquinone was added as the component (B), the temperature was raised to 65 ° C., the reaction was carried out at 65 ° C. for 10 hours, and the mixture was cooled. Thus, 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 And a solvent shown in Table 2 to produce a condensation product in the same manner as in the production of condensation product No. 1. Table 2 shows the total concentration of (A) + (B), (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 a stainless steel with a stirrer and having a capacity 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), the condensation products (E) shown in Tables 3 and 4, the water-soluble polymer compound (C), A polymer scale adhesion inhibitor was prepared using at least one kind (D) selected from the group consisting of an inorganic colloid and an alkali metal silicate, an alkaline compound and a solvent. In addition, the inorganic colloids (a to g in Tables 3 to 4 and Tables 7 to 8) of the component (D) used in this example and Example 2 shown below are as shown in Table 6.

In each experiment, the polymer scale adhesion inhibitor prepared as described above was applied to the inner wall of the polymerization vessel, a stirring shaft, a stirring blade, and other portions where the monomer was in contact with 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.

Thereafter, in each experiment, polymerization was carried out as follows. 400 kg of water, 200 kg of vinyl chloride, 250 g of partially saponified polyvinyl alcohol, 25 g of hydroxypropylmethylcellulose, and 70 g of 3,5,5-trimethylhexanoyl peroxide were placed in a polymerization vessel in which a coating film was formed by the coating treatment as described above. And polymerized at 66 ° C. for 6 hours with stirring. After completion of the polymerization, 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 performed, and the above-mentioned polymerization and washing with water in the polymerization vessel were regarded as one batch, and the same procedure was repeated for the number of batches shown in Table 5. Of polymer scale and the amount of polymer scale attached near the interface between the gas phase part and the liquid phase part were measured by the following methods for each experiment. Table 5 shows the results.

Measurement of polymer scale The scale adhered to a predetermined area of 10 × 10 cm on the inner wall of the polymerization vessel was scraped off with a spatula and weighed with a balance. Weigh 1
By multiplying by 00, the scale adhesion amount per 1 m ² was determined.

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

According to the description of JIS Z 8722, a standard light C, a stimulus of XYZ color system was obtained by a stimulus value direct reading method using a photoelectric colorimeter (Z-1001DP type colorimeter, manufactured by Nippon Denshoku Industries Co., Ltd.). Find the value Y. As the geometrical conditions for illumination and light reception, condition d described in JIS Z 8722, section 4.3.1 was employed.
From the obtained stimulus value Y, the L value is calculated by the equation: 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 a capacity of 20 liters was used as a polymerization vessel. In each experiment,
Conditions shown in Tables 7 and 8 (solvent composition, condensation product (E) + (C) +
(D) total concentration, (E): (C): (D) weight ratio and pH), the condensation products (E) shown in Tables 7 to 8, the water-soluble polymer compound (C), A polymer scale adhesion inhibitor was prepared using at least one kind (D) selected from the group consisting of colloidal silica and a silicate of an alkali metal, an alkaline compound and a solvent. The polymer scale adhesion inhibitor is applied to the inner wall of the polymerization vessel, the stirring shaft, the stirring blade, and other parts where the monomer comes into contact during polymerization, and heated and dried at 40 ° C. for 15 minutes to form a coating film. The vessel was washed with water.

Next, in each experiment, polymerization was carried out as follows. 9 kg of water, 225 g of sodium dodecylbenzenesulfonate, 12 g of t-dodecylmercaptan and 13 g of potassium peroxodisulfate were charged into a polymerization vessel having a coating film formed by the above-mentioned coating treatment, and the inside of the polymerization vessel was purged with nitrogen gas. 1.3 kg of styrene and 3.8 kg of butadiene
And polymerized at 50 ° C. for 20 hours. After completion of the polymerization, 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 performed, and the above-mentioned polymerization and washing in the polymerization vessel were performed as one batch, and the same procedure was repeated for the number of batches shown in Table 9. And the amount of polymer scale deposited near the interface between the gas phase and the liquid phase were determined in the same manner as in Example 1 for each experiment. Table 9 shows the results.
Shown in Further, in order to evaluate the initial coloring property when the polymer obtained in each experiment was formed into a sheet, a lightness index (L) was used.
Value) was measured by the following method. Table 9 shows the results.

Measurement of lightness index (L value) To 1 kg of the obtained polymer latex, 1 kg of a 2% magnesium sulfate solution was added, coagulated and precipitated, and the precipitate was separated by filtration. The precipitate separated by filtration was washed with hot water at 80 to 90 ° C. two to three times, and then dried at 40 ° C. for 25 hours using a vacuum dryer to obtain a resin. The obtained resin was placed in a mold having a size of 9 × 9 cm and a thickness of 0.1 cm, 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 sample for measurement. Produced.
The brightness 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 (Experiments Nos. 301 to 305) In each experiment, a stainless steel polymerization vessel with an internal volume of 20 liters and having a stirrer was used as a polymerization vessel. In each experiment, the polymer scale adhesion inhibitor (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 was in contact with the polymerization. After heating and drying at 15 ° C. for 15 minutes to form a coating film, the film was washed with water.

Thereafter, in each experiment, polymerization was carried out as follows. 4.0 kg of water and 6 g of sodium dodecylbenzenesulfonate were charged into a polymerization vessel in which a coating film was formed 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, 94 g of n-butyl acrylate, 220 g of methyl methacrylate, 5 g of acrylic acid and 5 g of methacrylic acid were charged, and then 1 g of ammonium persulfate and 1 g of sodium hydrosulfite were charged.
Stirred at C for 20 minutes. Further, the mixed monomer (n-butyl acrylate 2.1 kg, methyl methacrylate 4.8 k
g, 100 g of acrylic acid and 100 g of methacrylic acid), 500 g of a 1% by weight aqueous solution of ammonium persulfate, 500 g of a 1% by weight aqueous solution of sodium hydrosulfite, and 2.0 kg of a 25% by weight aqueous solution of polyoxyethylene nonylphenyl ether over 3 hours. Aliquots were added in portions. After the addition was completed, the temperature of the polymerization vessel was raised to 70 ° C., and polymerization was performed for 2 hours. After completion of the polymerization, 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, through the polymerization to the washing in the polymerization vessel, are defined as one batch.
The same procedure as in Example 1 was used for each experiment to determine the amount of polymer scale attached to the liquid phase in the polymerization vessel and the amount of polymer scale attached near the interface between the gas phase and the liquid phase in the 50th batch. I asked for it. Table 10 shows the results.

[0114]

[Table 10]

Example 4 (Experiments Nos. 401 to 405) In each experiment, a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 100 liters was used as the polymerization vessel. In each experiment,
A polymer scale adhesion inhibitor (used in Experiment No. shown in Table 11) was applied to the inner wall of the polymerization vessel, the stirring shaft, the stirring blades, and other parts where the monomer was in contact with the polymerization. After heating and drying to form a coating film, the film was washed with water.

Thereafter, in each experiment, polymerization was carried out as follows. 40 kg of water and 500 disproportionated potassium rosinate were placed in the polymerization vessel in which the coating was formed as described above.
g, 13 kg of polybutadiene latex (solid content: 45%), 9 kg of styrene monomer, 5 kg of acrylonitrile monomer, 40 g of t-dodecylmercaptan, and 140 g of cumene hydroperoxide. Next, the temperature in the polymerization vessel was set to 47
While maintaining the temperature at 200 ° C., 200 g of glucose, 2 g of ferrous sulfate and 100 g of sodium pyrophosphate were further charged into the polymerization vessel.
Subsequently, the mixture in the polymerization vessel was stirred at 65 ° C for 4 hours.
Polymerized for hours. After completion of the polymerization, 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, through the polymerization to the washing in the polymerization vessel, are defined as one batch.
80 batches were repeated, and the 80th batch was measured for the amount of polymer scale attached to the liquid phase in the polymerization vessel and the amount of polymer scale attached near the interface between the gas phase and the liquid phase in the same manner as in Example 1 for each experiment. I asked for it. Table 11 shows the results.

[0118]

[Table 11]

[0119]

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

Claims (3)

(57) [Claims] 1. An alkaline solution containing 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 a benzoquinone compound and a naphthoquinone compound. And a polymer scale adhesion inhibitor for the polymerization of a monomer having an ethylenically unsaturated double bond. 2. The polymer scale adhesion inhibitor according to claim 1, further comprising: (C) a water-soluble polymer compound, and / or (D) an inorganic colloid and a silicate of an alkali metal. Containing at least one of the above. 3. A method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, comprising: (A) a heterocyclic compound having at least two amino groups on its inner wall surface. A compound and an alkaline solution containing a condensation product of at least one compound selected from the group consisting of a benzoquinone compound and a naphthoquinone compound are coated and dried in a polymerization vessel having a coating film formed by drying. And thereby preventing the polymer scale from adhering in the polymerization vessel.