JPH06263805A - Polymer scale deposition inhibitor and production of polymer using the same - Google Patents

Abstract

PURPOSE:To effectively prevent a polymerizer from suffering polymer scale deposition not only in the part which is in contact with the liquid phase but also in the part around the interface between the gas and liquid phases, and to produce a polymer which, when molded into a sheet, etc., has diminished fish eyes and good initial colorability. CONSTITUTION:This inhibitor, which is for use in the polymerization of an ethylenic monomer (a), comprises an alkaline solution containing a condensation product of an aromatic compound having at least two amino groups with an aromatic tetracarboxylic anhydride and further containing at least either of a water-soluble polymer and an inorganic colloid. The monomer (a) is polymerized in a polymerizer having, on its inner wall, a coating film formed by applying and drying this inhibitor. Thus, polymer scale deposition is prevented.

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 inhibitor.

[Prior art]

Conventionally, as a method for polymerizing a monomer having an ethylenically unsaturated double bond, a suspension polymerization method, an emulsion polymerization method,
Solution polymerization method, gas phase polymerization method, bulk polymerization method and the like are known. In any of these polymerization methods, the polymer scale is likely to adhere to the inner wall of the polymerization vessel, the agitator, and the like where the monomer contacts.

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. As a result, the polymer is molded. This has the disadvantage of reducing the quality of the resulting molding. Further, in order to remove the adhered polymer scale, not only excessive labor and time are required, but also unreacted monomer is contained in this polymer scale, which is a very serious problem in recent years. There is a risk of human injury due to the monomer.

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, and a method of adding these compounds to an aqueous medium in which suspension polymerization is carried out are known (Japanese Patent Publication No. 45). -30343).

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). This point is not particularly industrially satisfactory because the effect is remarkable when a water-soluble catalyst is used in the polymerization.

[0006]

In order to overcome this disadvantage, for example, a condensation product of an aromatic amine compound and an aromatic nitro compound (Japanese Patent Publication No. 60-30681), a phenolic compound and an aromatic aldehyde Reaction product of
-192414), reaction products of polyhydric phenols and aliphatic aldehydes (Japanese Patent Publication No. 57-502169), reaction products of 1-naphthol and formaldehyde (Japanese Patent Publication No. 01-3).
Japanese Patent No. 1523) has been proposed to apply a polymer scale adhesion preventive agent containing, for example, an active ingredient to the inner wall of the polymerization vessel. When each of these polymer scale anti-adhesion agents is applied to a portion of the inner wall of the polymerization vessel where the monomer comes into contact to form a coating film, even if the polymerization is repeated about 100 to 200 batches,
Polymer scale does not adhere to the liquid phase in the polymerization vessel. Also, when the water-soluble catalyst is used, the polymer scale adhesion in the liquid phase part is similarly prevented.

However, even when a coating film of a polymer scale anti-adhesion agent containing the condensation product of the aromatic amine compound and the aromatic nitro compound as an active ingredient is formed, it is located in the upper layer of the polymerization vessel. There is a drawback that polymer scale adheres near the interface between the vapor phase and the liquid phase. Once the polymer scale adheres to the vicinity of the interface between the gas phase and the liquid phase, the polymer scale that adheres gradually grows as the polymerization is repeated, and finally peels off and mixes into the polymer. Sometimes. When the polymer scale is mixed with the polymer in this way, when the polymer is processed into a molded product such as a sheet, many fish eyes are generated in the molded product, and the quality of the molded product is significantly deteriorated. become.

When the polymer obtained by polymerization is molded into a sheet or the like, the molded product obtained is required to have a high whiteness. That is, even if the polymer is molded into a sheet or the like without adding any coloring agent, the obtained molded product is colored to some extent, but this coloring is called initial coloring, and it is desired that the coloring is as small as possible. However, when a coating film of a polymer scale anti-adhesive agent containing the condensation product of an aromatic amine compound and an aromatic nitro compound as an active ingredient is formed, the coating film peels or dissolves to form a polymer. Since it may be mixed, the whiteness of the molded product is lowered, that is, the initial colorability is deteriorated.

The object of the present invention is effective not only in the case of polymerizing a monomer having an ethylenically unsaturated double bond, but also in the vicinity of the interface between the gas phase and the liquid phase as well as the liquid phase portion in the polymerization vessel. In addition to being able to prevent the adhesion of polymer scale to, when formed into a sheet etc., the fish eyes are extremely small,
Another object of the present invention is to provide a polymer scale anti-adhesion agent capable of producing a polymer capable of obtaining a molded article having good initial colorability, a polymerization vessel using the inhibitor, and a method for producing a polymer.

[0010]

Means for Solving the Problems In order to achieve the above object, the present invention provides an aromatic compound (A-1) having at least two amino groups and an aromatic tetracarboxylic acid anhydride (A-
2) Condensation product with (A) and water-soluble polymer compound (B-1)
And polymer scale adhesion prevention for polymerization of a monomer having an ethylenically unsaturated double bond, which comprises an alkaline solution containing at least one kind (B) selected from the group consisting of and an inorganic colloid (B-2) Provide the agent.

Furthermore, the present invention is a method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein an aromatic compound having at least two amino groups on its inner wall surface. Group consisting of condensation product (A) of compound (A-1) and aromatic tetracarboxylic acid anhydride (A-2), water-soluble polymer compound (B-1) and inorganic colloid (B-2) The method comprises the steps of applying an alkaline solution containing at least one (B) selected from the group consisting of (B) and performing the above-mentioned polymerization in a polymerization vessel having a coating film formed by drying. Provided is a manufacturing method that is prevented.

Component (A) The polymer scale adhesion preventive agent of the present invention comprises, as the component (A), an aromatic compound (A-
It contains a condensation product of 1) with an aromatic tetracarboxylic acid anhydride (A-2). (A-1) aromatic compound an amino group (-NH ₂₎ an aromatic compound containing at least two having at least two amino groups (A-1), for example, the general formula (1) as follows - (11)
Is a compound represented by.

[0013]

[Chemical 1] (In the formula, plural R ^{1 s} may be the same or different and each is —H, —NH ₂ , —Cl, —OH, —NO ₂ , —COCH ₃ , —OC.
_{H 3, -N (CH 3)} 2, -COOH, a -SO ₃ H or an alkyl group having 1 to 3 carbon atoms. )

[0014]

[Chemical 2] (In the formula, a plurality of R ¹ may be the same or different and is as described above. A plurality of R ² may be the same or different,
It is an alkyl group having 1 to 10 carbon atoms having an amino group. )

[0015]

[Chemical 3] (In the formula, plural R ^{1 s} may be the same or different and are as described above, and n is an integer of 1 or 2.)

[0016]

[Chemical 4] [Wherein, plural R ^{1 s} may be the same or different, and as described above, n is also as described above, X is an alkylene group having 1 to 5 carbon atoms, -CH = CH-, -N = N-, -NH-,-
N (CH ₃ )-, -CONH-, -P (= O) H-, -SO _2- , -O-, -S-,
—Si (R) ₂ — (wherein R is an alkyl group having 1 to 10 carbon atoms), or a formula:

[0017]

[Chemical 5] Is a group represented by. ]

[0018]

[Chemical 6] (In the formula, plural R ^{1 s} may be the same or different and are as described above, and n is also as described above.)

[0019]

[Chemical 7] (In each formula, a plurality of R ¹ may be the same or different and is as described above, and n is also as described above.)

[0020]

[Chemical 8] (In each formula, a plurality of R ¹ may be the same or different and is as described above, and n is also as described above.)

[0021]

[Chemical 9] (In the formula, plural R ^{1 s} may be the same or different and are as described above.)

[0022]

[Chemical 10] (In each formula, a plurality of R ¹ may be the same or different and is as described above, and n is also as described above.)

[0023]

[Chemical 11] (In the formula, plural R ^{1 s} may be the same or different and are as described above, and n is also as described above.)

[0024]

[Chemical 12] (In each formula, a plurality of R ¹ may be the same or different and is as described above, and n is also as described above.)

Specific examples of the compound represented by the above general formula (1) include o-, m- and p-diaminobenzene and 3,4-
And 3,5-diaminobenzoic acid, 2,5-diaminobenzenesulfonic acid, 3,4-diaminochlorobenzene, 3,4-diaminophenol, 1,2-diamino-4-nitrobenzene, 2,4-diamino-1- Nitrobenzene, 2,4-, 2,5- and 2,6-diaminotoluene, 2,5- and 2,6-diamino-m-xylene, 2,5- and 2,6-diamino-p-xylene, etc. It is illustrated.

Specific examples of the compound represented by the above general formula (2) include 2,4-bis (β-amino-t-butyl) toluene and p-bis (2-methyl-4-aminopentyl). ) Benzene, p-bis (1,1-dimethyl-5-aminopentyl) benzene and the like are exemplified.

Specific examples of the compound represented by the above general formula (3) include 4,4'-diamino-3,3'-biphenyldiol and 3,3'-dimethyl-4,4'-diamino. Biphenyl, 3,3 '
-Dimethoxy-4,4'-diaminobiphenyl, 4,4'-diaminobiphenyl and the like are exemplified.

Specific examples of the compound represented by the above general formula (4) include 2,4-diaminoazobenzene, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylamine, 4,4'- Diaminodiphenylmethane, 3,3'- and
4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzanilide, 4,4'-diaminostilbene, 4,4'-diaminostilbene-2,2'-disulfonic acid, 9,10-bis (4- Aminophenyl) anthracene, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane,
Examples include bis (4-aminophenyl) diethylsilane, bis (4-aminophenyl) phosphine oxide, and bis (4-aminophenyl) -N-methylamine.

Specific examples of the compound represented by the above general formula (5) include 1,5- and 1,8-diaminonaphthalene.

Specific examples of the compounds represented by the above general formulas (6-1) to (6-2) include 1,4- and 1,5-diaminoanthracene.

Specific examples of the compounds represented by the above general formulas (7-1) to (7-3) include 1,6-, 1,8-, 3,5- and 5,10-diamino. Pyrene and the like are exemplified.

Specific examples of the compound represented by the above general formula (8) include 2,3-, 3,4- and 2,6-diaminopyridine.

Specific examples of the compounds represented by the above general formulas (9-1) to (9-2) include 3,6-diaminoacridine.

Specific examples of the compound represented by the above general formula (10) include 1,2-, 1,4- and 2,6-diaminoanthraquinone.

Specific examples of the compounds represented by the above general formulas (11-1) to (11-2) include 2,3- and 2,7-diaminofluorene.

Among the compounds exemplified above, preferred are 3,5-diaminobenzoic acid, 2,5-diaminobenzenesulfonic acid, 4,4'-diamino-3,3'-biphenyldiol, 4,
4'-diaminophenyl ether, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenylmethane, 3,3'-
And 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzanisodo, 4,4'-diaminostilbene-2,2'-disulfonic acid, 4,4'-diaminodiphenylpropane, 2,6-
Diaminopyridine and 2,7-diaminofluorene.

The aromatic compounds (A-1) having at least two amino groups are used alone or in combination of two or more.

(A-2) Aromatic tetracarboxylic acid anhydride Examples of the aromatic tetracarboxylic acid anhydride (A-2) include, for example, pyromellitic acid anhydride and 2,2-bis (3,4-dicarboxylate). Phenyl) propanoic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 3,3 ', 4,4'- Biphenyltetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) Ether dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 2,3,4,5- Examples thereof include thiophenone tetracarboxylic acid dianhydride and 2,2 ′, 6,6′-biphenyltetracarboxylic acid dianhydride.

Among the compounds exemplified above, preferred are pyromellitic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride and 2,3,6,7-naphthalenetetracarboxylic dianhydride. Anhydrous and 2,2 ', 6,6'-biphenyltetracarboxylic dianhydride. The aromatic tetracarboxylic acid anhydride (A-2) is used alone or in combination of two or more.

Condensation reaction Aromatic compound having at least two amino groups as described above
The condensation of (A-1) with the aromatic tetracarboxylic acid anhydride (A-2) is carried out in a suitable organic solvent medium, usually at room temperature to 100 ° C.
The reaction is carried out for 0.5 to 300 hours, preferably room temperature to 50 ° C for 1 to 100 hours.

As the medium of the condensation reaction, for example, methanol, ethanol, propanol, butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 3-methyl-1-butanol, 2
-Alcohol solvents such as methyl-2-butanol, 2-pentanol; ketone solvents such as acetone, dioxane, methyl ethyl ketone, methyl isobutyl ketone, etc .; such as methyl formate, ethyl formate, methyl acetate, methyl acetoacetate, etc. Ester solvents; for example, ether solvents such as 4-methyldioxolane, diethyl ether, ethylene glycol diethyl ether; for example, chloride solvents such as methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene; for example,
Hydrocarbon-based solvents such as n-heptane and n-hexane; furans such as tetrahydrofuran; aprotic solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, dimethylsulfone, acetonitrile, N-methylpyrrolidone; m An organic solvent such as cresol is exemplified. These can be used alone or as a mixed solvent of two or more kinds.

The ratio of the aromatic compound (A-1) having at least two amino groups and the aromatic tetracarboxylic acid anhydride (A-2) used for the production of the condensation product (A) is the same as the ratio (A -1)
The amount of the component (A-2) is 0.01 to 5 parts by weight per 1 part by weight of the component (A-1), though it is affected by the types of the component (A-2) and the solvent, the reaction temperature, the reaction time, and the like. It is preferable that 0.1 to
It is preferably 3 parts by weight. If the amount of the aromatic tetracarboxylic acid anhydride (A-2) is too large or too small, the polymer scale adhesion-preventing effect when used as a polymer scale adhesion-preventing agent is lowered.

For the preparation of the polymer scale anti-adhesion agent described below, the condensation reaction liquid containing the condensation product (A) after the completion of the condensation reaction may be used as it is. Further, the condensation product (A) may be separated from the reaction solution and used. In order to separate the condensation product (A) from the reaction solution, if the condensation product (A) formed is precipitated, the condensation product may be filtered off as it is. When the product is in the form of a solution dissolved in a solvent, for example, the solution may be dropped into a poor solvent such as water to precipitate the condensation product, and the condensation product thus deposited may be filtered off. .

Component (B) In addition to the condensation product (A) described above, the polymer scale anti-adhesive agent of the present invention includes a water-soluble polymer compound as a component (B).
At least one selected from the group consisting of (B-1) and inorganic colloid (B-2) is included. These have a function of improving the polymer scale adhesion preventing effect. Preferably,
Use (B-1) and (B-2) together. These (B-1) components and (B-
2) The component probably interacts with the condensation product to enhance the hydrophilicity of the coating surface (component (B-1)) and enhances the adhesion of the polymer scale adhesion inhibitor to the inner wall surface of the polymerization vessel. Tari ((B-
2) Ingredient)

(B-1) Water-Soluble Polymer Compound Examples of the water-soluble polymer compound (B-1) include nonionic polymer compounds such as gelatin and casein; for example, polyacrylic acid, polystyrenesulfonic acid, carboxy. Anionic polymer compounds such as methyl cellulose and alginic acid; for example, cationic nitrogen-containing polymer compounds such as polyvinylpyrrolidone and polyacrylamide; for example, hydroxyl group-containing polymer compounds such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose and pectin. Is exemplified.

Among the above water-soluble polymer compounds (B-1), preferred are gelatin, casein, polyacrylic acid, carboxymethylcellulose, polyvinylpyrrolidone and pectin.

The amount of the component (B-1) added is such that the condensation product (A) 1
It is usually 1 to 1000 parts by weight, preferably 5 to 200 parts by weight, per 00 parts by weight. The above water-soluble polymer compound (B-1) can be used alone or in combination of two or more.

(B-2) Inorganic Colloid Inorganic colloid (B-2) is a particle colloid produced by a dispersion method using water as a dispersion medium or a condensation method, and the size of the colloid particles is 1 to 500 mμ. Is. Specific examples of the inorganic colloid include colloids of oxides and hydroxides of metals selected from the group consisting of aluminum, thorium, titanium, zirconium, antimony, tin and iron; tungstic acid, vanadium pentoxide, gold and Examples thereof include silver colloids; silver iodide sols; colloids of selenium, sulfur, silica and the like. Preferred among these are colloids of oxides and hydroxides of metals selected from the group consisting of aluminum, titanium, zirconium, tin and iron,
And colloidal silica.

The amount of the component (B-2) added is the condensation product (A) 1
It is usually 1-1000 parts by weight, preferably 5-500 parts by weight, per 00 parts by weight. The above inorganic colloid (B-
2) can be used alone or in combination of two or more.

As described above, as the component (B), it is preferable to use the water-soluble polymer compound (B-1) and the inorganic colloid (B-2) in combination. In that case, the water-soluble polymer compound is used. (B-1)
It is preferable to use the inorganic colloid (B-2) in an amount of 5 to 3000 parts by weight, and more preferably 50 to 1000 parts by weight, based on 100 parts by weight.

Preparation of Polymer Scale Anti-Adhesive Agent The polymer scale anti-adhesive agent of the present invention comprises an alkaline solution containing the above-mentioned component (A) and component (B). The polymer scale adhesion preventive agent is applied to the inner wall surface of the polymerization vessel or the like, and dried to form a coating film, whereby the polymer scale adhesion to the inner wall of the polymerization vessel or the like can be prevented. The polymer scale anti-adhesion agent is prepared, for example, by adding the following solvent to the component (A) and the component (B) and mixing them, and then adjusting the pH of the resulting mixed solution to be alkaline.

Since the polymer scale adhesion preventive agent of the present invention is alkaline, the solubility of the condensation product in a solvent is improved. Therefore, the polymer scale deposition inhibitor is obtained as a uniform solution. As a result, it is presumed that the polymer scale adhesion preventive effect is improved because the polymer scale adhesion preventive agent of the present invention can be applied uniformly 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 12.5. Alkaline compounds used to adjust pH include, for example, LiOH, NaOH, KOH, Na ₂ CO ₃ , Na ₂ HP.
Examples thereof include alkali metal compounds such as O ₄ ; ammonium compounds such as NH ₄ OH; and organic amine compounds such as ethylenediamine, monoethanolamine and triethanolamine.

The solvent for preparing the polymer scale anti-adhesive is water; for example, methanol, ethanol, propanol, butanol, 2-butanol, 2-methyl-.
1-propanol, 2-methyl-2-propanol, 3
Alcoholic solvents such as -methyl-1-butanol, 2-methyl-2-butanol, 2-pentanol;
Ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based solvents such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, and methyl acetoacetate; ethers such as 4-methyldioxolane and ethylene glycol diethyl ether. System solvent;
Furans; for example, aprotic solvents such as dimethylformamide, dimethylsulfoxide, acetonitrile and the like. These are appropriately used alone or as a mixed solvent of two or more kinds.

Among the solvents, preferred are water and a mixed solvent of water and an organic solvent miscible with water. Examples of the organic solvent miscible with water include alcohol solvents such as methanol, ethanol and propanol;
Examples thereof include ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl acetate and ethyl acetate. The content of the organic solvent when using a mixed solvent of water and an organic solvent miscible with water is flammable,
It is preferable that the amount is such that there is little danger of explosion, etc. and there is no problem in handling safety such as toxicity. Specifically, it is preferable that the organic solvent is 50% by weight or less, and further 30% by weight.
The following is preferable.

Condensation products in polymer scale inhibitors
The concentration of (A) is not particularly limited as long as the total coating amount described below is obtained, but it is usually about 0.001 to 5% by weight, preferably about 0.01 to 1% by weight. Coating film formation

In order to form a coating film on the inner wall surface of the polymerization vessel using the polymer scale adhesion preventing agent prepared as described above, first, the polymer scale adhesion prevention agent is applied to the inner wall surface of the polymerization vessel, Then, for example, after being sufficiently dried in a temperature range from room temperature to 100 ° C., it is further washed with water if necessary.
Further, it is preferable to form the coating film not only on the inner wall surface of the polymerization vessel, but also on other portions where the monomer contacts during the polymerization.
Specifically, the stirring blade, stirring shaft, baffle, condenser,
Examples include headers, search coils, bolts and nuts.

More preferably, even at a site other than the site where the monomer comes into contact during the polymerization, a site where the polymer scale may adhere, for example, the inner surface of the equipment and piping of the recovery system for the unreacted monomer For this, 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, JP-A-56-501116, JP-A-56-501117 and JP-A-59
It is also possible to use the automatic coating method described in, for example, JP-11303.

There is no limitation on the method for drying the wet surface due to the application of the polymer scale adhesion preventive agent, 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 .
Particularly, it is preferably in the range of 0.05 to ² g / m ² . The above coating work has a high durability of the formed coating film,
Since the polymer scale adhesion preventing action continues, it is not always necessary to carry out each batch of polymerization. Therefore, 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 the other portions where the monomers come into contact with each other during the polymerization. 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, a suspending agent, a solid dispersant, a nonionic or anionic emulsifier, etc. The 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; 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. Hereinafter, the general polymerization method will be specifically described by taking the cases of suspension polymerization and emulsion polymerization as examples.

First, water and a dispersant are charged into a polymerization vessel. Next, after exhausting the inside of the polymerization vessel and reducing the pressure to 0.1 to 760 mmHg,
Charge the monomer. At this time, the internal pressure of the polymerization vessel is usually 0.5 to
It will be 30kgf / cm ² · G. Further, the polymerization initiator is charged before and / or after charging the monomer. Then 30-15
Polymerize at reaction temperature of 0 ° C. During the polymerization, one or more kinds of water, a dispersant and a polymerization initiator are added, if necessary. The reaction temperature during polymerization depends on the type of monomer to be polymerized.For example, in the case of vinyl chloride polymerization, the polymerization is carried out at 30-80 ° C, and in the case of styrene polymerization 50-150 ° C. Polymerize with. For polymerization, the internal pressure of the polymerization vessel is 0
When it falls to 7 kgf / cm ² · G, or when there is almost no difference between the inlet temperature and the outlet temperature of the cooling water that flows in and out of the jacket installed on the outer circumference of the polymerization vessel (that is, the heat generated by the polymerization reaction disappears). It is judged that it has been completed. Water, a dispersant, and a polymerization initiator charged during the polymerization are usually 20 to 500 parts by weight of water per 100 parts by weight of the monomer.
Parts by weight, 0.01 to 30 parts by weight of dispersant, and 0.01 to 5 parts by weight of polymerization initiator.

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

When polymerization is carried out by applying the method of the present invention, adhesion of polymer scale can be prevented regardless of the material such as the inner wall surface of the polymerization vessel. For example, a glass-lined polymerization vessel is Of course, the adhesion of the polymer scale can be prevented even when the polymerization is carried out in a polymerization vessel made of stainless steel or other steel.

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, and natural or synthetic polymer compounds such as pyrogallol-acetone resin; for example, calcium phosphate. , A solid dispersant such as hydroxyapatite; for example, a nonionic emulsifier such as sorbitan monolaurate, sorbitan trioleate, polyoxyethylene alkyl ether;
Anionic emulsifiers such as sodium alkylbenzene sulfonates such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate, anionic emulsifiers such as sodium dioctylsulfosuccinate; fillers such as calcium carbonate, titanium oxide; tribasic lead sulfate, calcium stearate, dibutyl Stabilizers such as tin dilaurate and dioctyl tin mercaptide; lubricants such as rice wax, stearic acid and cetyl alcohol; eg DOP, D
Even in a polymerization system in which a plasticizer such as BP; for example, a mercaptan such as t-dodecyl mercaptan, a chain transfer agent such as trichlorethylene; a pH adjuster, etc., the method of the present invention effectively adheres the polymer scale. Can be prevented.

The polymer scale adhesion preventive agent of the present invention can also be added to the polymerization medium. In that case, for example, a polymer scale adhesion inhibitor may be used to form a coating film on the inner wall surface of the polymerization vessel, and then the inhibitor may be added in a small amount to the polymerization medium. In this case, the polymer scale adhesion preventing effect is improved as compared with the case where only the coating process is performed. When the polymer scale anti-adhesion agent is added to the polymerization medium, the addition amount of the anti-scale agent is preferably 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.

[0069]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. In addition, in each of the following tables, the experiment numbers marked with * are comparative examples, and the other experiment numbers are examples of the present invention. Production of Condensation Product No. 1 Acetone was added to 0.3 mol of 4,4′-diaminodiphenylmethane and stirred at room temperature to obtain an acetone solution of 4,4′-diaminodiphenylmethane. Acetone solution of pyromellitic dianhydride was obtained by adding acetone to 0.15 mol of pyromellitic dianhydride and stirring at room temperature. These acetone solutions were charged into a 3-liter pressure resistant reactor, mixed, and reacted at room temperature for 10 hours. Next, the precipitated condensation product was separated by filtration and dried under reduced pressure at room temperature. Thus, condensation product No. 1 was obtained.

Production of Condensation Products Nos. 2 to 10 Condensation products Nos. 2 to 10 are prepared from aromatic compounds (A-1) and aromatic tetracarboxylic acids each having at least two amino groups shown in Table 1, respectively. It was produced in the same manner as in the condensation product No. 1 using the acid anhydride (A-2) and the solvent. In Table 1, (A-1) + (A-2) total moles in each production, (A-1) :( A-2) mole ratio,
The reaction temperature and reaction time are shown.

[0071]

[Table 1]

Example 1 (Experiment Nos. 101 to 110) In each experiment, polymerization was carried out as follows using a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 1000 liters as a polymerization vessel. In each experiment, the conditions ((A) + (B
-1) + (B-2) total concentration, (A) :( B-1) :( B-2) weight ratio, solvent composition and pH) so that the condensation products (A )
, Water-soluble polymer compound (B-1), inorganic colloid (B-2),
A polymer scale anti-adhesion agent was prepared using a solvent and an alkaline compound. The inorganic colloids used in Example 1 and Example 2 below (a to a in Tables 2 and 5) were used.
g) is as shown in Table 4. These polymer scale adhesion inhibitors are applied to the inner wall of the polymerization vessel and the stirring shaft, stirring blades and other portions where the monomers come into contact during the polymerization, heated at 40 ° C for 15 minutes, and dried 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. 400 kg of water, 200 kg of vinyl chloride, 250 g of partially saponified polyvinyl alcohol, 25 g of hydroxypropylmethyl cellulose and 70 g of 3,5,5-trimethylhexanoyl peroxide are placed in the polymerization vessel where the coating film is formed by applying the coating as described above. The mixture was charged and polymerized at 66 ° C. for 6 hours while 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 performed, 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 3. For each experiment,
After the end of the final batch, 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 were measured by the following methods. The results are shown in Table 3.

Measurement of amount of adhered polymer scale : The scale attached to a predetermined area of 10 × 10 cm on the inner wall of the polymerization vessel was completely scraped off with a spatula made of stainless steel as far as possible with the naked eye, and the scale was put on a balance. Weighed. The measured value was multiplied by 100 to obtain the scale adhesion amount 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 3.・Fish eye measurement 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 in 100 cm ^{2 of the} obtained sheet was examined by a light transmission method.

Further, in order to evaluate the initial colorability when the polymer obtained in each experiment was molded into a sheet, a lightness index was used.
(L value) was measured by the following method. The results are shown in Table 3. -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 (C-Katsuda Kako Co., Ltd. 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. JIS Z 8722
The standard value C, photoelectric colorimeter (Nippon Denshoku Industries Co., Ltd., Z-1001DP type colorimetric color difference meter) is used to obtain the stimulus value Y of the XYZ color system by the stimulus value direct reading method. As the geometric condition of illumination and light reception, condition d described in JIS Z 8722, Section 4.3.1 was adopted. From the obtained stimulus value Y,
According to the formula described in JIS Z 8730 (1980): L = 10Y ^1/2 , L
The value is calculated.

[0079]

[Table 2]

[0080]

[Table 3]

[Table 4]

Example 2 (Experiment Nos. 201 to 210) In each experiment, a stainless steel polymerization vessel with an internal volume of 20 liters equipped with a stirrer was used as the polymerization vessel. In each experiment,
Conditions shown in Table 5 ((A) + (B-1) + (B-2) total concentration, (A) :( B
-1) :( B-2) weight ratio, solvent composition and pH) so that the condensation product (A) and water-soluble polymer compound (B-1) shown in Table 5
A polymer scale anti-adhesion agent was prepared using the inorganic colloid (B-2), the solvent and the alkaline compound. These polymer scale anti-adhesion agents are added to the inner wall of the polymerization vessel and the stirring shaft,
Apply to the stirring blade and other parts where the monomer contacts during polymerization,
After heating at 40 ° C. for 15 minutes and drying to form a coating film, the inside of the polymerization 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. After that, without performing the coating operation, the above-mentioned polymerization and washing with water in the polymerization vessel were regarded as one batch,
The same operation was repeated for the number of batches shown in Table 6. For each experiment, the amount of polymer scale attached to the liquid phase portion in the polymerization vessel and the amount of polymer scale attached near the interface between the gas phase and the liquid phase were determined by the same method as in Example 1 after the end of the final batch. The results are shown in Table 6.

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 6.

Measurement of lightness index (L value) To 1 kg of the obtained polymer latex, 1 kg of a 2% magnesium sulfate solution was added to carry out 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 in a mold of 9 × 9 cm, depth of 0.1 cm, heated at 195 ° C. at 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.

[0085]

[Table 5]

[0086]

[Table 6]

Example 3 As a polymerization vessel, a stainless steel polymerization vessel with an internal volume of 100 liter and equipped with a stirrer was used. The polymer scale anti-adhesion agent used in Experiment No. 201 of Example 2 was added to the inner wall of the polymerization vessel and the stirring shaft.
Apply to the stirring blade and other parts where the monomer contacts during polymerization,
After heating and drying at 50 ° C. for 15 minutes to form a coating film, the inside of the polymerization vessel was washed with water.

Then, 40 kg of water and disproportionated potassium rosinate were placed in the polymerization vessel on which the coating film was formed by the coating treatment as described above.
500g, polybutadiene latex (solid content 45%) 13k
g, styrene monomer 9kg, acrylonitrile monomer 5k
40 g of g, t-dodecyl mercaptan, and 140 g of cumene hydroperoxide were charged. Next, while maintaining the internal temperature of the polymerization vessel at 47 ° C., further add 200 g of glucose,
2 g of ferrous sulfate and 100 g of sodium pyrophosphate were charged. Then, the internal temperature of the polymerization vessel was raised to 65 ° C., and the reaction mixture in the polymerization vessel was polymerized for 4 hours while 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 operation from the formation of the coating film as described above to the washing of the inside of the polymerization vessel through the polymerization is regarded as one batch.
After repeating 80 batches, the amount of polymer scale attached to the liquid phase portion in the polymerization vessel of the 80th batch and the amount of polymer scale attached near the interface between the gas phase and the liquid phase were measured in the same manner as in Example 1.
As a result, the amount of polymer scale attached to the liquid phase portion was 0 g / m ²
The amount of polymer scale attached near the interface between the gas phase and the liquid phase was 25 g / m ² .

Example 4 As a polymerization vessel, a stainless steel polymerization vessel having an internal volume of 20 liter and equipped with a stirrer was used. The coating solution used in Experiment No. 204 of Example 2 was applied to the inner wall of the polymerization vessel, the stirring shaft, the stirring blade, and other portions where the monomer contacts during the polymerization, and heated at 50 ° C. for 15 minutes and dried to form a coating film. After forming, the inside of the polymerization vessel was washed with water.

Thereafter, 4.0 kg of water and 6 g of sodium dodecylbenzenesulfonate were charged into the polymerization vessel having the coating film 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, 94 g of n-butyl acrylate and 220 g of methyl methacrylate were used.
g, 5 g of acrylic acid and 5 g of methacrylic acid were charged, subsequently 1 g of ammonium persulfate and 1 g of sodium hydrosulfite were charged, and the mixture was stirred at 60 ° C. for 20 minutes.

Further, mixed monomers (mixed with 2.1 kg of n-butyl acrylate, 4.8 kg of methyl methacrylate, 100 g of acrylic acid and 100 g of methacrylic acid) were added to the polymerization vessel.
1 wt% ammonium persulfate aqueous solution 500 g, 1 wt% sodium hydrosulfite aqueous solution 500 g and 25 wt% polyoxyethylene nonylphenyl ether aqueous solution 2.0 kg
Was added in a constant amount over 3 hours. After the addition was completed, the temperature of the polymerization vessel was raised to 70 ° C. and polymerization was performed 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 coating film as described above to the washing of the inside of the polymerization vessel through the polymerization is regarded as one batch.
After repeating 80 batches, the amount of polymer scale attached to the liquid phase portion in the polymerization vessel of the 80th batch and the amount of polymer scale attached near the interface between the gas phase and the liquid phase were measured in the same manner as in Example 1.
As a result, the amount of polymer scale attached to the liquid phase portion was 0 g / m ²
And the amount of polymer scale attached near the interface between the gas phase and the liquid phase was 40 g / m ² .

[0094]

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 and the liquid phase. Therefore,
When polymerization is carried out by applying the present invention, it is not necessary to carry out a polymer scale removing operation for each polymerization, and thereby productivity is improved. 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. Moreover, since the coating film formed on the inner wall surface of the polymerization vessel according to the present invention does not peel off during the polymerization or dissolve in the polymerization system, 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. Furthermore, the polymer scale anti-adhesion agent of the present invention can also contain water as the main component, so there is little risk of ignition, explosion, etc. of the organic solvent, and it should be used within the range where toxicity does not pose a problem. You can also

Claims (2)

[Claims] 1. A condensation product (A) of an aromatic compound (A-1) having at least two amino groups and an aromatic tetracarboxylic acid anhydride (A-2), and a water-soluble polymer compound (B -1) and at least one kind (B) selected from the group consisting of inorganic colloid (B-2), and a polymer for polymerization of a monomer having an ethylenically unsaturated double bond, which is composed of an alkaline solution. Anti-scale agent. 2. A method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein an aromatic compound having at least two amino groups (A -1) and the condensation product of aromatic tetracarboxylic acid anhydride (A-2)
It is formed by applying an alkaline solution containing (A) and at least one kind (B) selected from the group consisting of a water-soluble polymer compound (B-1) and an inorganic colloid (B-2) and drying it. A production method comprising the step of carrying out the above-mentioned polymerization in a polymerization vessel having a coated film, whereby adhesion of polymer scale is prevented.