JPH0641205A - Preventive of polymer scale deposition and method for producing polymer using same - Google Patents

Abstract

PURPOSE:To provide the preventive which effectively prevents the polymer scale deposition not only in the liq. phase in a polymn. reactor but also near the interface of the liq. phase and the vapor phase. CONSTITUTION:The preventive which is used in the polymn. of an ethylenically unsaid. monomer is an alkaline soln. of a condensate of an arom. amine having at least two amino groups with an arom. tetracarboxylic anhydride. The preventive is applied to the inner wall of a polymn. reactor and dried to form a coating film, which prevents the polymer scale deposition during the polymn.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polymer scale anti-adhesion agent for polymerizing a monomer having an ethylenically unsaturated double bond, a polymerization vessel effective for preventing the adhesion of polymer scale, and the use thereof. The present invention relates to a method for producing a polymer.

[0002]

2. Description of the Related Art Conventionally, as a method for polymerizing a monomer having an ethylenically unsaturated double bond, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, a gas phase polymerization method, a bulk polymerization method and the like are known. ing. In any of these polymerization methods, 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, and is obtained by molding the polymer. The disadvantage is that the quality of the molded product is reduced. Moreover, not only excessive labor and time are required to remove the adhered polymer scale,
Since the unreacted monomer is contained in this polymer scale, there is a risk of human injury due to the monomer, which has become a very serious problem in recent years.

As for the prevention of adhesion of the polymer scale to the inner wall of the polymerization vessel, the polarities of amine compounds, quinone compounds, aldehyde compounds, etc. have been used, as has been carried out, for example, in suspension polymerization of vinyl chloride. A method of applying a polymer scale anti-adhesion agent composed of an organic compound to the inner wall of a polymerization vessel and the like, and a method of adding these compounds to an aqueous medium 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). In this respect, the use of a water-soluble catalyst has a particularly great effect and is not industrially satisfactory.

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

[0007]

However, there is a drawback that polymer scale adheres to the vicinity of the interface between the gas phase portion and the liquid phase portion located in the upper layer portion in the polymerization vessel.

Once the polymer scale adheres to the vicinity of the interface between the gas phase portion and the liquid phase portion, the adhered polymer scale gradually grows as the polymerization is repeated, and finally, the polymer scale adheres to the surface and peels off. May be mixed during coalescence. When the polymer scale is mixed in 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 resulting molded product, and the quality of the molded product is significantly deteriorated. Will end up.

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

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

[0011]

DISCLOSURE OF THE INVENTION The present invention relates to an alkaline solution containing a condensation product of (A) an aromatic amine compound having at least two amino groups and (B) an aromatic tetracarboxylic acid anhydride. The present invention provides a polymer scale anti-adhesion agent for polymerization of a monomer having an ethylenically unsaturated double bond.

The present invention is also a method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein at least 2 amino groups (A) are present on the inner wall surface. An aromatic amine compound having a unit, and (B) an alkaline solution containing a condensation product of an aromatic tetracarboxylic acid anhydride is applied, and the polymerization is carried out in a polymerization vessel having a coating film formed by drying. The present invention provides a method for producing a polymer scale, the method including the steps of:

The condensation product, which is an essential component of the polymer scale adhesion preventive agent of the present invention, comprises (A) an aromatic amine compound having at least two amino groups and (B) an aromatic tetracarboxylic acid anhydride. Is a compound obtained by condensing. The raw materials and the synthesis will be described below.

(A) Fragrance having at least two amino groups
The group amine compound (A) component is an aromatic amine compound having at least two amino groups, and for example, the following general formula (1) to
It is a compound represented by (13).

[0015]

[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 group selected from -SO ₃ H and the group consisting of alkyl group having 1 to 3 carbon atoms. )

Specifically, o-, m- and p-diaminobenzene, 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-
Examples include diaminotoluene, 2,5- and 2,6-diamino-m-xylene, 2,5- and 2,6-diamino-p-xylene and the like.

[0017]

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

Specifically, 2,4-bis (β-amino-t-butyl) toluene, p-bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-dimethyl-5) -Aminopentyl) benzene and the like are exemplified.

[0019]

[Chemical 3] (In the formula, a plurality of R ¹ may be the same or different and is as described above, and n is an integer of 1 to 2.)

Specifically, 4,4'-diamino-3,3'-biphenyldiol, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'- Diaminobiphenyl, 4,4 '
Examples include diaminobiphenyl and the like.

[0021]

[Chemical 4] [Wherein, a plurality of R ^1's may be the same or different and are as described above, n is also as described above, X is a divalent alkylene group having 1 to 5 carbon atoms, -CH = CH- , -N = N-, -N
H-, -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), and a formula:

[Chemical 5] Is a group selected from the group consisting of groups represented by. ]

Specifically, 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, bis (4-amino Phenyl) diethylsilane, bis (4-aminophenyl) phosphine oxide, bis (4-
Aminophenyl) -N-methylamine and the like are exemplified.

[0023]

[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.)

Specific examples include 1,5- and 1,8-diaminonaphthalene.

[0025]

[Chemical 7] (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.)

Specific examples include 1,4- and 1,5-diaminoanthracene.

[0027]

[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.)

Specific examples include 1,6-, 1,8-, 3,5- and 5,10-diaminopyrene.

[0029]

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

Specific examples include 2,3-, 3,4- and 2,6-diaminopyridine.

[0031]

[Chemical 10] (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.)

Specific examples include 3,6-diaminoacridine and the like.

[0033]

[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.)

Specific examples include 1,2-, 1,4- and 2,6-diaminoanthraquinone.

[0035]

[Chemical 12] (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.)

Specific examples include 2,3- and 2,7-diaminofluorene.

Among the above aromatic amine compounds having at least two amino groups, preferred are 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 4, 4'-diaminobenzanilide, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane, p-diaminobenzene, 3,3'-dimethyl-4,4'-diaminobiphenyl,
4,4'-diaminodiphenylamine, 4,4'-diamino-3,
3'-biphenyldiol, 3,5-diaminobenzoic acid, 2,5-
These are diaminobenzenesulfonic acid and 4,4′-diaminostilbene-2,2′-disulfonic acid. Particularly preferred is 4,
4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 4,
4'-diaminobenzanilide, 4,4'-diaminodiphenyl sulfide, 3,5-diaminobenzoic acid, 2,5-diaminobenzenesulfonic acid and 4,4'-diaminostilbene-2,
It is 2'-disulfonic acid.

The above aromatic amine compounds having at least two amino groups can be used alone or in combination of two or more kinds.

(B) Aromatic tetracarboxylic acid anhydride As the aromatic tetracarboxylic acid anhydride (B), for example,
Pyromellitic anhydride, 2,2'-bis (3,4-dicarboxyphenyl) propanoic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, bis (3,4-di Carboxyphenyl) sulfone dianhydride, 3,4,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 1,2,5,6 -Naphthalenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 2,3,2 ', 3'-biphenyltetracarboxylic dianhydride, 3,4,3', 4'-benzophenone tetracarboxylic dianhydride, 2,3,4,5-thiophenone tetracarboxylic dianhydride, 2,6,2 ', 6'-biphenyltetracarboxylic dianhydride and the like. Preferred among these are pyromellitic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,4, 3 ', 4'-biphenyltetracarboxylic dianhydride,
And 2,6,2 ′, 6′-biphenyltetracarboxylic dianhydride.

The above-mentioned aromatic tetracarboxylic acid anhydride is
They can be used alone or in combination of two or more.

Condensation Product The condensation product of the aromatic amine compound (A) having at least two amino groups and the aromatic tetracarboxylic acid anhydride (B), which is an active ingredient of the polymer scale of the present invention, is ,
The component (A) and the component (B) are usually produced by reacting in a suitable organic solvent medium at room temperature to 100 ° C for 0.5 to 300 hours, preferably at room temperature to 50 ° C for 1 to 100 hours. You can

An organic solvent is generally used as a medium for the condensation reaction. Examples of the organic solvent include methanol, ethanol, propanol, butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 3-methyl-1-butanol, 2-methyl-2-. Alcohol solvents such as butanol and 2-pentanol;
Ketone-based solvents such as acetone, dioxane, methyl ethyl ketone, and methyl isobutyl ketone; ester-based solvents such as methyl formate, ethyl formate, methyl acetate, methyl acetoacetate; such as 4-methyldioxolane, diethyl ether, ethylene glycol diethyl ether, etc. Ether solvents; for example, chlorinated solvents such as methylene chloride, chloroform, carbon tetrachloride, trichlorethylene, perchloroethylene; hydrocarbon solvents such as n-heptane, n-hexane; furan such as tetrahydrofuran Examples include solvents such as dimethylformamide; dimethylacetamide; dimethylsulfoxide; dimethylsulfone; acetonitrile; pyridine; N-methylpyrrolidone; m-cresol. These are appropriately used alone or as a mixed solvent of two or more kinds.

The ratio of the aromatic amine compound (A) having at least two amino groups and the aromatic tetracarboxylic acid anhydride (B) in the condensation reaction is such that the aromatic amine having at least two amino groups used is used. It is usually affected by the types of the compound, the aromatic tetracarboxylic acid anhydride and the solvent, the reaction temperature, the reaction time, etc., but usually, the aromatic tetra compound is used per 1 part by weight of the aromatic amine compound (A) having at least two amino groups. The amount of the carboxylic acid anhydride (B) is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight. If the amount of the aromatic tetracarboxylic acid anhydride (B) is too large or too small, the polymer scale adhesion-preventing effect of the obtained condensation product decreases.

After the completion of the condensation reaction, when the formed condensation product is precipitated, the condensation product may be filtered off as it is. When the produced condensation product is dissolved, for example, the condensation product may be dropped into a poor solvent such as water to precipitate the condensation product, and the condensation product may be filtered off.

Containing a condensation product of the component (A) and the component (B)
Polymer scale anti-adhesive agent consisting of an alkaline solution The polymer scale anti-adhesive agent of the present invention, the above (A) component and
It consists of an alkaline solution containing a condensation product with the component (B). It is possible to prevent the adhesion of the polymer scale to the inner wall surface of the polymerization vessel by applying the polymer scale anti-adhesion agent to the inner wall surface of the polymerization vessel or the like and drying it to form a coating film.

The polymer scale anti-adhesive agent of the present invention is prepared, for example, by mixing and dispersing the condensation product of the above-mentioned component (A) and component (B) in a suitable aqueous solvent, and then adding the resulting mixture to an alkaline solution. To prepare a uniform solution.

Since the polymer scale anti-adhesion agent of the present invention is alkaline, the solubility of the condensation product of the component (A) and the component (B) in the aqueous medium is improved, and the polymer scale as a uniform solution is obtained. An anti-sticking agent is obtained. Therefore, when the polymer scale anti-adhesion agent of the present invention is applied to the inner wall of the polymerization vessel or the like, it can be uniformly applied, and it is presumed that the polymer scale anti-adhesion effect is improved.

Examples of the aqueous solvent used for preparing the polymer scale anti-adhesion agent include water and a mixed solvent of water and an organic solvent miscible with water. As the organic solvent miscible with water, for example, methanol, ethanol,
Alcohols such as propanol; ketones such as acetone and methyl ethyl ketone; methyl acetate,
Esters such as ethyl acetate are exemplified. When using a mixed solvent of water and an organic solvent miscible with water, the content of the organic solvent should be such that there is little risk of ignition, explosion, etc. and there is no problem in handling safety such as toxicity. Is preferred,
Specifically, the organic solvent content is preferably 50% by weight or less, more preferably 30% by weight or less.

The pH of the polymer scale anti-adhesion agent is alkaline, preferably 7.5 to 13.5, and more preferably 9.5 to 12.5. Of polymer scale anti-sticking agent
As the alkaline compound for adjusting the pH, for example, LiO
H, NaOH, KOH, Na ₂ CO ₃ , Na ₂ SiO ₃ , Na ₂ HPO ₄ , N
Examples thereof include alkali metal compounds and ammonium compounds such as H ₄ OH, and organic amine compounds such as ethylenediamine, propylenediamine, monoethanolamine and triethanolamine.

Component (A) in the polymer scale anti-adhesion agent
The concentration of the condensation product with the component (B) is not particularly limited as long as the total coating amount described below can be obtained, but is usually 0.005 to 10% by weight.
And preferably 0.01 to 5% by weight.

The polymer scale adhesion preventive agent of the present invention may contain a cationic, nonionic or anionic surface active agent, as long as the polymer scale adhesion preventive effect is not impaired. Furthermore, if necessary, a water-soluble polymer compound such as a cationic polymer compound, an anionic polymer compound or an amphoteric polymer compound can be added.

Examples of the cationic polymer compound include polyvinylamine, polyethyleneamine, polyethyleneimine, polyacrylamide, N-vinyl-2-pyrrolidone-acrylamide copolymer, dimethyl diamyl ammonium chloride cyclized polymer, and dimethyl. Cyclic polymer of diethylammonium bromide, Cyclic polymer of diallylamine hydrochloride, Cyclic copolymer of dimethyldiallylammonium chloride and sulfur dioxide, Polyvinylpyridine, Polyvinylpyrrolidone, Polyvinylcarbazole, Polyvinylimidazoline, Polydimethylaminoethyl acrylate , Polydimethylaminoethylmethacrylate, polydiethylaminoethylacrylate, polydiethylaminoethylmethacrylate, etc. have a nitrogen atom in the side chain and Atoms cationic polyelectrolyte bearing a charged positively, and the like.

Examples of the anionic polymer compound include sulfomethylated polyacrylamide; polyacrylic acid; alginic acid, acrylamide-vinyl sulfonic acid copolymer, polymethacrylic acid, polystyrene sulfonic acid, and their alkali metal salts and Ammonium salt: Anionic polymer compounds having a carboxyl group or a sulfonic acid group in the side chain such as carboxymethyl cellulose can be mentioned.

Examples of the amphoteric polymer compound include amphoteric polymer compounds such as glue, gelatin, casein and albumin.

Further, to the polymer scale adhesion preventive agent of the present invention, an inorganic compound may be appropriately added, if necessary, as long as the polymer scale adhesion preventing action is not impaired. Examples of the inorganic compound that can be added include orthosilicic acid, metasilicic acid, mesodisilicate, mesotrisilicic acid, mesotetrasilicic acid, sodium metasilicate, sodium orthosilicate, sodium disilicate, sodium tetrasilicate, and water glass. And silicic acids and silicates such as; oxygen of a metal selected from alkaline earth metals such as magnesium, calcium and barium, zinc group metals such as zinc, aluminum group metals such as aluminum, and platinum group metals such as platinum Examples thereof include metal salts such as acid salts, acetates, nitrates, hydroxides and halides; for example, inorganic colloids such as ferric hydroxide colloid, silicic acid colloid, barium sulfate colloid and aluminum hydroxide colloid. The above-mentioned inorganic colloid may be prepared by, for example, mechanical grinding, irradiation with ultrasonic waves, electrical dispersion and chemical method.

Formation of Coating Film To form a coating film on the inner wall surface of the polymerization vessel using the polymer scale adhesion preventing agent prepared as described above, first, the polymer scale adhesion preventing agent is added to the inner wall surface of the polymerization vessel. Then, after being sufficiently dried in a temperature range from room temperature to 100 ° C., it is further washed with water if necessary.

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

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

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

There is no limitation on the method of drying the wet surface due to the application of the polymer scale anti-adhesion 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-adhesive agent is to be applied are previously set to, for example, 30 It is possible to use a method in which the polymer scale adhesion preventive agent is directly applied to the heated surface by heating to -80 ° C. After drying the coated surface, the coated surface is washed with water as needed.

The coating film thus obtained has a total coating amount after drying of usually 0.001 to 5 g / m ² , and particularly
It is preferably from 05 to ² g / m ² .

The above coating operation may be carried out for every one to several tens of batches of polymerization. The formed coating film has high durability and the action of preventing the polymer scale from adhering is maintained, so that it is not always necessary to perform it for each batch of polymerization. Therefore, the productivity of the product polymer is improved.

Polymerization As described above, a coating film is formed by applying a coating treatment to the inner wall of the polymerization vessel, and preferably to other portions where the monomer contacts during the polymerization, and then a coating film is formed in the polymerization vessel by a conventional method. Polymerize. That is, in addition to a monomer having an ethylenically unsaturated double bond and a polymerization initiator (catalyst), if necessary, a polymerization medium such as water, and a suspending agent, a solid dispersant, a nonionic or anionic emulsifier. Then, a dispersant and the like are charged, and then polymerization is performed by a conventional method.

Examples of the monomer having an ethylenically unsaturated double bond which is polymerized by applying the method of the present invention include:
Vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid, methacrylic acid, and their esters and salts; maleic acid, fumaric acid, and their esters and anhydrides; Examples include diene-based monomers such as butadiene, chloroprene, and isoprene; styrene; acrylonitrile; vinylidene halide; vinyl ether and the like. These are used alone or in combination of two or more.

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

The general polymerization method will be specifically described below by taking the cases of suspension polymerization and emulsion polymerization as examples. First,
Water and a dispersant are charged into a polymerization vessel, and then a polymerization initiator is charged. Next, the inside of the polymerization vessel was evacuated and the pressure was reduced to 0.1 to 760 mmHg, and then monomers were charged (at this time, the internal pressure of the polymerization vessel
Usually 0.5 to 30 kgf / cm ² · G), then 30 to 150
Polymerize at reaction temperature of ° C. During the polymerization, if necessary,
One or more of water, a dispersant and a polymerization initiator are added. Further, the reaction temperature at the time of polymerization varies depending on the type of monomer to be polymerized, for example, in the case of vinyl chloride polymerization, the polymerization is performed at 30 to 80 ° C., and in the case of styrene polymerization, it is 50
Polymerize at ~ 150 ° C. For polymerization, the internal pressure of the polymerization vessel is 0 to 7 kg.
When it decreases to f / cm ² · G or when there is almost no difference between the inlet temperature and the outlet temperature of the cooling water that flows in and out of the jacket installed on the outer periphery of the polymerization vessel (that is, the heat generated by the polymerization reaction disappears). It is judged that it has been completed. Water, a dispersant, and a polymerization initiator charged during polymerization are usually 20 to 500 parts by weight of water, 0.01 to 30 parts by weight of a dispersant, and 0.01 to 5 parts by weight of a polymerization initiator with respect to 100 parts by weight of a monomer. It is a department.

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

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

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

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 for partially saponified polyvinyl alcohol, polyacrylic acid, copolymers of vinyl acetate and maleic anhydride, cellulose derivatives such as hydroxypropylmethyl cellulose, natural and synthetic polymer compounds such as gelatin; for example, calcium phosphate, hydroxyapatite Solid dispersants such as; nonionic emulsifiers such as sorbitan monolaurate, sorbitan trioleate, polyoxyethylene alkyl ethers; sodium lauryl sulfate, sodium dodecylbenzenesulfonate, etc. Arm, anionic emulsifiers such as sodium dioctylsulfosuccinate; for example, calcium carbonate, filler such as titanium oxide; for example, tribasic lead sulfate, calcium stearate, dibutyltin dilaurate, stabilizers such as dioctyl tin mercaptide; for example,
Lubricants such as rice wax, stearic acid and cetyl alcohol; plasticizers such as DDP and DBP;
Even in a polymerization system in which a mercaptan such as dodecyl mercaptan, a chain transfer agent such as trichloroethylene, a pH adjusting agent and the like are present, the method of the present invention can effectively prevent the adhesion of polymer scale.

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

[0072]

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

Production Example 1 Production of Condensation Product No. 1 Acetone was added to 0.3 mol of 4,4′-diaminodiphenylmethane and stirred at room temperature to dissolve. Acetone was added to 0.3 mol of pyromellitic dianhydride, and dissolved by stirring at room temperature. The acetone solution of 4,4′-diaminodiphenylmethane and the acetone solution of pyromellitic dianhydride thus obtained were charged into a 3 liter pressure resistant reactor and mixed.
The resulting mixed liquid was reacted at room temperature (20 to 30 ° C) for 10 hours. After the reaction was completed, the precipitated condensation product was filtered off and dried under reduced pressure at room temperature. The condensation product thus obtained was designated as condensation product No. 1.

Production of Condensation Products Nos. 2 to 14 In each production, at least 2 amino groups shown in Table 1 were used.
A condensation product was produced in the same manner as the condensation product No. 1 using the aromatic amine compound (A) and aromatic tetracarboxylic acid anhydride (B) each having the same and the solvent shown in Table 2. Table 2 shows the total number of moles of (A) + (B) in each production, (A) :( B)
The ratio, reaction temperature and reaction time are shown.

[0075]

[Table 1]

[0076]

[Table 2]

Example 1 (Experiment Nos. 101 to 115) Polymerization was carried out as follows using a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 1000 liters.

In each experiment, the polymer scale adhesion prevention was carried out by using the condensation product, the solvent and the alkaline compound shown in Table 3 so that the conditions (solvent composition, concentration of the condensation product and pH) shown in Table 3 were obtained. The agent was prepared. In each experiment,
The polymer scale anti-adhesion agent prepared as described above is 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, heated at 40 ° C for 15 minutes, and dried to apply. After forming the film, the inside of the polymerization vessel was washed with water.

Then, in each experiment, 400 kg of water, 200 kg of vinyl chloride, and 250 parts of partially saponified polyvinyl alcohol were placed in a polymerization vessel in which a coating film was formed by coating as described above.
g, hydroxypropyl methylcellulose 25 g and 3,
70 g of 5,5-trimethylhexanoyl peroxide 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 of the inner wall of the polymerization vessel were made into one batch, and the same operation was repeated for the number of batches shown in Table 4, and after the end of the final batch, the liquid phase part in the polymerization vessel was repeated. The amount of polymer scale adherence and the amount of scale adherence near the interface between the gas phase part and the liquid phase part were measured by the following methods for each experiment. The results are shown in Table 4.

Measurement of polymer scale The scale adhering to a 10 × 10 cm area at a predetermined location on the inner wall of the polymerization vessel was scraped off with a spatula and weighed with a balance. Weighing value 1
It was multiplied by 00 to 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 4.

Measurement of fish eye 100 parts by weight of the obtained polymer, dioctyl phthalate (DO
P) 50 parts by weight, dibutyltin dilaurate 1 part by weight, cetyl alcohol 1 part by weight, titanium oxide 0.25 parts by weight, and carbon black 0.05 parts by weight.
After kneading with an inch roll for 7 minutes at 150 ℃, thickness
The sheet was molded into a 0.2 mm sheet, and the number of fish eyes contained in 100 cm ^{2 of the} obtained sheet was examined by a light transmission method.

Further, the lightness index (L value) was measured by the following method in order to evaluate the initial colorability when the polymer obtained in each experiment was molded into a sheet. The results are shown in Table 4.

Measurement of lightness index (L value) 100 parts by weight of the obtained polymer, stabilizer (TS manufactured by Akishima Chemical Co., Ltd., TS
-101) 1 part by weight, stabilizer (C-100J, manufactured by Katsuta Kako Co., Ltd.) 0.5
After kneading 5 parts by weight and 50 parts by weight of dioctyl phthalate as a plasticizer with a two-roll mill at 160 ° C. for 5 minutes,
Form a sheet with a thickness of 1 mm. Next, the formed sheet is 4
Put in a mold of × 4 × 1.5cm, 160 ℃, 65 ~ 70kgf / cm ²
Heat and pressure mold for 0.2 hours to prepare a sample for measurement. For this sample, the lightness index L in the Hunter color difference formula described in JIS 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.

[0087]

[Table 3]

[0088]

[Table 4]

Example 2 (Experiment Nos. 201 to 210) Polymerization was carried out as follows using a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 20 liters.

In each experiment, the polymer scale adhesion prevention was performed by using the condensation product, the solvent and the alkaline compound shown in Table 5 so that the conditions (solvent composition, concentration of the condensation product and pH) shown in Table 5 were obtained. The agent was prepared. In each experiment,
The polymer scale anti-adhesion agent prepared as described above is 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, heated at 40 ° C for 15 minutes, and dried to apply. After forming the film, the inside of the polymerization vessel was washed with water.

Next, in each experiment, 9 kg of water, 225 g of sodium dodecylbenzene sulfonate, 12 g of t-dodecyl mercaptan and 13 g of potassium peroxodisulfate were placed in the polymerization vessel in which the coating film was formed by the coating treatment as described above. Was charged, and the inside of the polymerization vessel was replaced with nitrogen gas.
kg and 3.8 kg of butadiene were charged and polymerized at 50 ° C. for 20 hours. After the polymerization was completed, the produced polymer and unreacted monomer were recovered, and the inside of the polymerization vessel was washed with water to remove the residual resin.

Thereafter, the coating operation was not performed, and the above-mentioned polymerization and washing of the inner wall of the polymerization vessel were regarded as one batch, and the same operation was repeated for the number of batches shown in Table 6. The amount of polymer scale attached and the amount of polymer scale attached near the interface between the gas phase part and the liquid phase part were determined in the same manner as in Example 1 for each experiment. The results are shown in Table 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 perform coagulation precipitation, and then the precipitate was filtered off. The precipitate separated by filtration was washed with hot water at 80 to 90 ° C. for 2 to 3 times and then dried at 40 ° C. for 25 hours using a vacuum dryer to obtain a resin. The obtained resin is put into a 9 × 9 cm, 0.1 cm thick mold, heated at 195 ° C. and 50-60 kgf / cm ² for 0.2 hours, and pressure molded at a final pressure of 80 kgf / cm ² to obtain a measurement sample. It was made.
The lightness index L of this sample was determined in the same manner as in Example 1.

[0095]

[Table 5]

[0096]

[Table 6]

[0097]

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

Claims (2)

[Claims] 1. An ethylenically unsaturated double composition comprising an alkaline solution containing a condensation product of (A) an aromatic amine compound having at least two amino groups and (B) an aromatic tetracarboxylic acid anhydride. A polymer scale anti-adhesion agent for the polymerization of a monomer having a bond. 2. A method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein (A) an aromatic amine having at least two amino groups on its inner wall surface. Compound, (B) coating an alkaline solution containing a condensation product of an aromatic tetracarboxylic acid anhydride, in a polymerization vessel having a coating film formed by drying, a step of performing the polymerization , A manufacturing method whereby polymer scale adhesion is prevented.