JP2727393B2 - Polymer scale adhesion inhibitor and method for producing polymer using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer scale inhibitor for polymerizing a monomer having an ethylenically unsaturated double bond, a polymerizer effective for preventing polymer scale from sticking, and the use of the same. The present invention relates to a method for producing a polymer.

[0002]

2. Description of the Related Art Conventionally, as a polymerization method of a monomer having an ethylenically unsaturated double bond, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, a gas phase polymerization method, a bulk polymerization method and the like are known. ing. In any of these polymerization methods, the adhesion of the polymer scale easily occurs on the inner wall of the polymerization vessel, a portion such as a stirrer, etc. where the monomer comes into contact.

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

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

[0005] However, these methods show an effect of preventing the adhesion of polymer scale when the polymerization is repeated up to about 5 to 6 batches. Inferior). This point is particularly significant when a water-soluble catalyst is used, and is not industrially satisfactory.

To overcome this disadvantage, Japanese Patent Application Laid-Open No. Sho 53-13689
In Japanese Patent Application Laid-Open No. H11-163, it is proposed to use a condensation product of an aromatic amine compound as a polymer scale adhesion inhibitor. If a coating film containing the condensation product of the aromatic amine compound is formed on the inner wall of the polymerization vessel or the like where the monomer comes in contact, even if the polymerization is repeated for about 100 to 200 batches, the polymerization proceeds to the liquid phase inside the polymerization vessel. Does not occur on the polymer scale. Even when a water-soluble catalyst is used, adhesion of the polymer scale in the liquid phase is similarly prevented.

[0007]

However, there is a disadvantage that the polymer scale adheres near the interface between the gas phase and the liquid phase located in the upper part of the polymerization vessel.

[0008] Once the polymer scale adheres to the vicinity of the interface between the gas phase and the liquid phase, the adhered polymer scale grows gradually as the polymerization is repeated, and finally peels off, and the polymer scale adheres. May be mixed during coalescence. When the polymer scale is mixed into the polymer as described above, when the polymer is processed into a molded product such as a sheet, many fish eyes are generated in the obtained molded product, and the quality of the molded product is significantly reduced. Will be lost.

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

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

[0011]

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

The present invention also relates to a method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein at least two amino groups (A) are provided on the inner wall surface. In a polymerization vessel having a coating film formed by applying an alkaline solution containing a condensation product of (B) an aromatic tetracarboxylic acid anhydride and an aromatic amine compound having (B) an aromatic tetracarboxylic acid anhydride, the polymerization is carried out. A production method comprising the steps of: carrying out a step of preventing adhesion of a polymer scale.

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

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

[0015]

Embedded image (Wherein, a plurality of R ^{1 s} may be the same or different, and are each -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, 4-diaminophenol, 1,2-diamino-4-nitrobenzene,
2,4-diamino-1-nitrobenzene, 2,4-, 2,5- and 2,6-
Examples thereof include diaminotoluene, 2,5- and 2,6-diamino-m-xylene, 2,5- and 2,6-diamino-p-xylene, and the like.

[0017]

Embedded image (Wherein, a plurality of R ¹ may be the same or different and are as described above, and a plurality of R ² may be the same or different;
It is 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.

[0019]

Embedded image (In the formula, a plurality of R ^{1 s} may be the same or different and are 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 '
-Diaminobiphenyl and the like.

[0021]

Embedded image [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- (where R is an alkyl group having 1 to 10 carbon atoms), and a formula:

Embedded image And 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'-diaminodiphenylsulfone, 4,4'-diaminobenzanilide, 4,4'-diaminostilbene, 4,
4'-diaminostilbene-2,2'-disulfonic acid, 9,10-bis (4-aminophenyl) anthracene, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylpropane, bis (4-amino Phenyl) diethylsilane, bis (4-aminophenyl) phosphine oxide, bis (4-
Aminophenyl) -N-methylamine and the like.

[0023]

Embedded image (In the formula, a plurality of 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]

Embedded image (In the formula, a plurality of 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]

Embedded image (In each formula, a plurality of R ^{1 s} may be the same or different, and are as described above, and n is also as described above.)

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

[0029]

Embedded image (In the formula, a plurality of 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]

Embedded image (In the formula, a plurality of R ^{1 s} may be the same or different, and are as described above, and n is also as described above.)

Specifically, 3,6-diaminoacridine and the like are exemplified.

[0033]

Embedded image (In the formula, a plurality of 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]

Embedded image (In the formula, a plurality of 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-mentioned aromatic amine compounds having at least two amino groups, preferred are 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 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-
Diaminobenzenesulfonic acid and 4,4'-diaminostilbene-2,2'-disulfonic acid. Particularly preferred are 4,
4'-diaminodiphenylmethane, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 4,
4'-diaminobenzanilide, 4,4'-diaminodiphenyl sulfide, 3,5-diaminobenzoic acid, 2,5-diaminobenzenesulfonic acid and 4,4'-diaminostilbene-2,
2'-disulfonic acid.

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

(B) Aromatic tetracarboxylic anhydride The aromatic tetracarboxylic anhydride (B) includes, for example,
Pyromellitic anhydride, 2,2'-bis (3,4-dicarboxyphenyl) propanoic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, bis (3,4-di Carboxyphenyl) sulfonic 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'-benzophenonetetracarboxylic dianhydride, 2,3,4,5-thiophenonetetracarboxylic dianhydride, 2,6,2 ', 6'-biphenyltetracarboxylic dianhydride and the like can be mentioned. Among these, pyromellitic anhydride, 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 aromatic tetracarboxylic 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 anhydride (B), which is an active ingredient of the polymer scale of the present invention, is ,
The component (A) and the component (B) are produced by reacting in a suitable organic solvent medium, usually at room temperature to 100 ° C for 0.5 to 300 hours, preferably at room temperature to 50 ° C for 1 to 100 hours. Can be.

As a medium for the condensation reaction, an organic solvent is generally used. As the organic solvent, for example, methanol, ethanol, propanol, butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 3-methyl-1-butanol, 2-methyl-2- Alcoholic solvents such as butanol and 2-pentanol; for example,
Ketone solvents such as acetone, dioxane, methyl ethyl ketone and methyl isobutyl ketone; for example, ester solvents such as methyl formate, ethyl formate, methyl acetate, methyl acetoacetate; for example, 4-methyl dioxolane, diethyl ether, ethylene glycol diethyl ether and the like Ether-based solvents; for example, chlorinated solvents such as methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, and perchloroethylene; hydrocarbon-based solvents such as n-heptane and n-hexane; and furans such as tetrahydrofuran Dimethylformamide; dimethylacetamide; dimethylsulfoxide; dimethylsulfone; acetonitrile; pyridine; N-methylpyrrolidone; These may be used singly or as a mixture of two or more solvents.

The ratio of the aromatic amine compound (A) having at least two amino groups to the aromatic tetracarboxylic anhydride (B) at the time of performing the condensation reaction depends on the aromatic amine having at least two amino groups to be used. Depending on the type of the compound, the aromatic tetracarboxylic anhydride and the solvent, the reaction temperature, the reaction time, and the like, usually, the aromatic tetraamine compound having at least two amino groups (A) per part by weight of the aromatic The carboxylic anhydride (B) is preferably used in an amount of 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 effect of the obtained condensation product on the prevention of polymer scale adhesion is reduced.

After the completion of the condensation reaction, if the formed condensation product is precipitated, the condensation product may be filtered off as it is. When the formed condensation product is dissolved, for example, the condensation product may be precipitated by dropping into a poor solvent such as water, and the condensation product may be filtered off.

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

The polymer scale adhesion inhibitor of the present invention can be prepared, for example, by mixing and dispersing the above-mentioned condensation product of the components (A) and (B) in a suitable aqueous solvent, and then subjecting the resulting mixture to an alkaline solution. To make a homogeneous solution.

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

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

The pH of the polymer scale adhesion inhibitor is alkaline, preferably from 7.5 to 13.5, and more preferably from 9.5 to 12.5. Polymer scale adhesion inhibitor
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 such as H ₄ OH and ammonium compounds, and organic amine compounds such as ethylenediamine, propylenediamine, monoethanolamine and triethanolamine.

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

The polymer scale adhesion inhibitor of the present invention may contain a cationic, nonionic or anionic surfactant or the like as long as the effect of preventing polymer scale adhesion is not impaired. Further, if necessary, a water-soluble polymer compound such as a cationic polymer compound, an anionic polymer compound and an amphoteric polymer compound can be added.

Examples of the cationic polymer compound include polyvinylamine, polyethyleneamine, polyethyleneimine, polyacrylamide, N-vinyl-2-pyrrolidone-acrylamide copolymer, cyclized polymer of dimethyldiamylammonium chloride, dimethyl Cyclized polymer of diethylammonium bromide, cyclic polymer of diallylamine hydrochloride, cyclic copolymer of dimethyldiallylammonium chloride and sulfur dioxide, polyvinylpyridine, polyvinylpyrrolidone, polyvinylcarbazole, polyvinylimidazoline, polydimethylaminoethyl acrylate , Polydimethylaminoethyl methacrylate, polydiethylaminoethyl acrylate, polydiethylaminoethyl methacrylate and the like having a nitrogen atom in the side chain, 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 the like; Ammonium salt; anionic polymer compounds having a carboxyl group or a sulfonic acid group in a side chain such as carboxymethyl cellulose.

Examples of the amphoteric polymer compound include glue, gelatin, casein, albumin and the like.

Further, an inorganic compound can be appropriately added to the polymer scale adhesion inhibitor of the present invention, if necessary, as long as the action of preventing the polymer scale adhesion is not impaired. Examples of the inorganic compound that can be added include orthosilicic acid, metasilicic acid, mesodisilicic acid, mesotrisilicic acid, mesotetrasilicic acid, sodium metasilicate, sodium orthosilicate, sodium disilicate, sodium tetrasilicate, and water glass. For example, alkaline earth metals such as magnesium, calcium and barium; zinc group metals such as zinc; aluminum group metals such as aluminum; and oxygen of metals selected from platinum group metals such as platinum. Metal salts such as acid salts, acetate salts, nitrate salts, hydroxides and halides; examples thereof include inorganic colloids such as ferric hydroxide colloid, silicate colloid, barium sulfate colloid, and aluminum hydroxide colloid. The above-mentioned inorganic colloid may be prepared by, for example, mechanical pulverization, irradiation of ultrasonic waves, electric dispersion and chemical methods.

Formation of Coating Film In order to form a coating film on the inner wall of a polymerization vessel using the polymer scale adhesion inhibitor prepared as described above, first, the polymer scale adhesion inhibitor is added to the inner wall surface of the polymerization vessel. And then dried sufficiently in a temperature range of, for example, room temperature to 100 ° C., and further washed with water as needed.

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

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

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

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

The coating thus obtained has a total coating weight after drying of usually from 0.001 to 5 g / m ² , especially from 0.1 to 5 g / m ² .
It is preferably from 05 to ² g / m ² .

The above coating operation may be carried out for every one to ten or more batches of polymerization. Since the formed coating film has high durability and maintains the action of preventing the adhesion of the polymer scale, it is not always necessary to perform the coating for each batch of polymerization. For this reason, 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 a portion where the monomer comes into contact during the polymerization, and the like. Perform polymerization. That is, in addition to a monomer having an ethylenically unsaturated double bond and a polymerization initiator (catalyst), if necessary, a polymerization medium such as water, and a suspending agent, a solid dispersant, a nonionic, anionic emulsifier And then polymerization is carried out by a conventional method.

The monomer having an ethylenically unsaturated double bond to be polymerized by applying the method of the present invention includes, for example,
Vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid, methacrylic acid, and their esters and salts; maleic acid, fumaric acid, and their esters and anhydrides; Diene monomers such as butadiene, chloroprene and isoprene; styrene; acrylonitrile; vinylidene halide; and vinyl ether. These are used alone or in combination of two or more.

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

Hereinafter, a general polymerization method will be specifically described by taking suspension polymerization and emulsion polymerization as examples. First,
Water and a dispersant are charged into a polymerization vessel, and then a polymerization initiator is charged. Next, the inside of the polymerization vessel was evacuated to reduce the pressure to 0.1 to 760 mmHg, and then the monomer was charged (at this time, the internal pressure of the polymerization vessel was
Usually 0.5 ~ 30kgf / cm ²・ G), then 30 ~ 150
Polymerizes at a reaction temperature of ° C. During the polymerization, if necessary,
One or more of water, a dispersant and a polymerization initiator are added. The reaction temperature during the polymerization varies depending on the type of the monomer to be polymerized.For example, in the case of vinyl chloride polymerization, the polymerization is performed at 30 to 80 ° C., and in the case of styrene polymerization, the polymerization temperature is 50.
The polymerization is carried out at ~ 150 ° C. For polymerization, the internal pressure of the polymerization vessel is 0 to 7 kg
f / cm ² · G, or when the difference between the inlet and outlet temperatures of the cooling water flowing into and out of the jacket provided around the polymerization vessel has almost disappeared (ie, the heat generated by the polymerization reaction has been eliminated). ) Is determined to be completed. Water, dispersant, and polymerization initiator charged during the polymerization are usually 20 to 500 parts by weight of water, 0.01 to 30 parts by weight of a dispersant, 0.01 to 5 parts by weight of a polymerization initiator based on 100 parts by weight of a monomer. Department.

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

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

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

Those added to the polymerization system can be used without any restrictions. That is, for example, t-
Butyl peroxy neodecanoate, bis (2-ethylhexyl) peroxy dicarbonate, 3,5,5-trimethylhexanoyl peroxide, α-cumyl peroxy neodecanoate, cumene hydroperoxide,
Cyclohexanone peroxide, t-butylperoxypivalate, bis (2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropylperoxydicarbonate,
polymerization initiators such as α, α′-azobisisobutyronitrile, α, α′-azobis-2,4-dimethylvaleronitrile, potassium belloxodisulfate, ammonium belloxodisulfate, and p-menthane hydroperoxide; Partially saponified polyvinyl alcohol, polyacrylic acid, copolymers of vinyl acetate and maleic anhydride, cellulose derivatives such as hydroxypropylmethylcellulose, suspending agents such as natural and synthetic polymer compounds such as gelatin; calcium phosphate, hydroxyapatite Nonionic emulsifiers such as sorbitan monolaurate, sorbitan triolate, polyoxyethylene alkyl ether; sodium alkyl benzene sulfonate such as sodium lauryl sulfate and sodium dodecylbenzene sulfonate; 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;
-In a polymerization system in which mercaptans such as dodecyl mercaptan, a chain transfer agent such as trichloroethylene, and a pH regulator are present, the method of the present invention can effectively prevent adhesion of polymer scale.

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

[0072]

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

Production Example 1 Production of condensation product No. 1 Acetone was added to 0.3 mol of 4,4'-diaminodiphenylmethane and dissolved by stirring at room temperature. Acetone was added to 0.3 mol of pyromellitic anhydride and dissolved by stirring at room temperature. The resulting acetone solution of 4,4′-diaminodiphenylmethane and the pyromellitic anhydride were charged into a 3 liter pressure-resistant reactor and mixed.
The obtained mixture was reacted at room temperature (20 to 30 ° C.) for 10 hours. After the reaction was completed, the precipitated condensation product was separated by filtration and dried at room temperature under reduced pressure. 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 two amino groups shown in Table 1 were used.
Using the aromatic amine compound (A) and the aromatic tetracarboxylic anhydride (B) each having one and the solvent shown in Table 2, a condensation product was produced in the same manner as in the condensation product No. 1. 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 (Experiments Nos. 101 to 115) Polymerization was carried out as follows using a stainless steel polymerization vessel having an internal volume of 1000 liters and equipped with a stirrer.

In each experiment, the condensation product, solvent and alkaline compound shown in Table 3 were used to prevent polymer scale adhesion so that the conditions (solvent composition, condensation product concentration and pH) shown in Table 3 were obtained. An agent was prepared. In each experiment,
The polymer scale anti-adhesive agent prepared as described above is applied to the inner wall of the polymerization vessel, a stirring shaft, a stirring blade, and other portions where the monomers come into contact during polymerization, and heated at 40 ° C. for 15 minutes, dried and coated. After forming the film, the inside of the polymerization vessel was washed with water.

Thereafter, in each experiment, 400 kg of water, 200 kg of vinyl chloride, 250 kg of partially saponified polyvinyl alcohol were placed in a polymerization vessel in which a coating film was formed by the coating treatment 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 with stirring. After completion of the polymerization, the produced polymer and unreacted monomer were recovered, and the inside of the polymerization vessel was washed with water to remove the residual resin.

Thereafter, the above-mentioned operation of polymerization and washing of the inner wall of the polymerization vessel was regarded as one batch without performing the coating operation, and the same procedure was repeated for the number of batches shown in Table 4. Of the polymer scale and the amount of scale attached near the interface between the gas phase part and the liquid phase part were measured by the following methods for each experiment. Table 4 shows the results.

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

The number of fish eyes when the polymer obtained in each experiment was formed into a sheet was measured by the following method. Table 4 shows the results.

Measurement of Fish Eye 100 parts by weight of the obtained polymer, dioctyl phthalate (DO
P) A mixture prepared by mixing 50 parts by weight, 1 part by weight of dibutyltin dilaurate, 1 part by weight of cetyl alcohol, 0.25 part by weight of titanium oxide and 0.05 part by weight of carbon black
After kneading at 150 ° C for 7 minutes using an inch roll,
The sheet was formed into a 0.2 mm sheet, and the number of fish eyes contained per 100 cm ^{2 of the} obtained sheet was examined by a light transmission method.

Further, the lightness index (L value) was measured by the following method in order to evaluate the initial coloring property when the polymer obtained in each experiment was formed into a sheet. Table 4 shows the results.

Measurement of lightness index (L value) 100 parts by weight of the obtained polymer, stabilizer (TSI, manufactured by Akishima Chemical Co., Ltd.)
-101) 1 part by weight, stabilizer (C-100J, manufactured by Katsuta Kako Co., Ltd.) 0.5
After kneading 50 parts by weight of dioctyl phthalate and 50 parts by weight of dioctyl phthalate as a plasticizer using a two-roll mill at 160 ° C. for 5 minutes,
A 1 mm thick sheet is formed. Next, the molded sheet is
× 4 × 1.5cm formwork, 160 ℃, 65 ~ 70kgf / cm ²
Heat and pressure mold for 0.2 hours to prepare a measurement sample. For this sample, the lightness index L in the color difference formula of Hunter described in JIS Z 8730 (1980) was determined, and the larger the L value, the higher the whiteness, that is, the better the initial coloring property.

The L value is obtained as follows. JIS Z 8722
According to the description of the above, the stimulus value Y of the XYZ colorimetric system is obtained by a stimulus value direct reading method using a standard light C and a photoelectric colorimeter (Z-1001DP colorimeter, manufactured by Nippon Denshoku Industries Co., Ltd.). As the geometrical conditions for illumination and light reception, condition d described in JIS Z 8722, section 4.3.1 was employed. From the obtained stimulus value Y,
According to the equation described in JIS Z 8730 (1980): L = 10Y1 ^{/ 2}
A value is calculated.

[0087]

[Table 3]

[0088]

[Table 4]

Example 2 (Experiments Nos. 201 to 210) Polymerization was carried out as follows using a 20-liter stainless steel polymerization vessel equipped with a stirrer.

In each experiment, the condensation product, the solvent and the alkaline compound shown in Table 5 were used to prevent the polymer scale from adhering to the conditions (solvent composition, condensation product concentration and pH) shown in Table 5. An agent was prepared. In each experiment,
The polymer scale anti-adhesive agent prepared as described above is applied to the inner wall of the polymerization vessel, a stirring shaft, a stirring blade, and other portions where the monomers come into contact during polymerization, and heated at 40 ° C. for 15 minutes, dried and coated. 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 dodecylbenzenesulfonate, 12 g of t-dodecylmercaptan and 13 g of potassium peroxodisulfate were placed in a polymerization vessel in which a coating film was formed as described above. After replacing the inside of the polymerization vessel with nitrogen gas, styrene 1.3
kg and 3.8 kg of butadiene were charged and polymerized at 50 ° C. for 20 hours. After completion of the polymerization, the produced polymer and unreacted monomer were recovered, and the inside of the polymerization vessel was washed with water to remove the residual resin.

Thereafter, the coating operation was not performed, and the above-mentioned operation of polymerization and washing of the inner wall of the polymerization vessel was regarded as one batch, and the same procedure was repeated for the number of batches shown in Table 6. And the amount of polymer scale deposited near the interface between the gas phase and the liquid phase were determined in the same manner as in Example 1 for each experiment. Table 6 shows the results.

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 formed into a sheet. Table 6 shows the results.

Measurement of lightness index (L value) To 1 kg of the obtained polymer latex, 1 kg of a 2% magnesium sulfate solution was added, coagulated and precipitated, and the precipitate was filtered off. The precipitate separated by filtration was washed with hot water at 80 to 90 ° C. two to three times, and then dried at 40 ° C. for 25 hours using a vacuum dryer to obtain a resin. The obtained resin was placed in a mold having a size of 9 × 9 cm and a thickness of 0.1 cm, heated at 195 ° C. and 50-60 kgf / cm ² for 0.2 hours, and pressure-molded at a final pressure of 80 kgf / cm ² to obtain a sample for measurement. Produced.
The brightness index L of this sample was determined in the same manner as in Example 1.

[0095]

[Table 5]

[0096]

[Table 6]

[0097]

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

Claims (2)

(57) [Claims] 1. An ethylenically unsaturated double compound 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 anhydride. Polymer scale adhesion inhibitor for 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, comprising: (A) an aromatic amine having at least two amino groups on its inner wall surface. A step of applying the compound and an alkaline solution containing a condensation product of (B) an aromatic tetracarboxylic anhydride and performing the polymerization in a polymerization vessel having a coating film formed by drying. A production method whereby the adhesion of the polymer scale is prevented.