JP2764653B2 - Polymer scale adhesion inhibitor and method for preventing adhesion of polymer scale - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polymer scale adhesion inhibitor for polymerization of a monomer having an ethylenic double bond and a method for preventing adhesion of a polymer scale.

[Conventional technology]

In a method of producing a polymer by polymerizing a monomer in a polymerization vessel, there is a known problem that the polymer adheres as a scale to an inner wall surface of the polymerization vessel.

When the polymer scale adheres to the inner wall of the polymerization vessel, the yield of the polymer decreases, the cooling capacity of the polymerization vessel decreases, and the quality of the product polymer decreases due to the detachment of the attached polymer scale and mixing into the product. And the like, and further, a great deal of labor and time are required for removing the polymer scale. In addition, because the polymer scale contains unreacted monomers, workers may be exposed to it and cause physical disability.

Conventionally, in the polymerization of a monomer having an ethylenic double bond, as a method of preventing the adhesion of polymer scale to the inner wall surface of the polymerization vessel, a suitable substance is used as a polymer scale adhesion inhibitor as an inner wall surface of the polymerization vessel. There is known a method of applying the composition to a surface.

Suitable substances as the polymer scale adhesion inhibitor include, for example, specific polar compounds (JP-B-45-30343).
No.), dyes or pigments (JP-B Nos. 45-30835 and 52-294)
No. 53), aromatic amine compounds (JP-A-51-50887),
A reaction product of a phenolic compound and an aromatic aldehyde is disclosed (JP-A-55-54317).

[Problems to be solved by the invention]

By the way, as a vinyl chloride polymer obtained by polymerization, a polymer having high whiteness is required.
8730 (1980), the value of the lightness index L in the Hunter's color difference formula is required to be 70 or more.

A conventional polymer scale adhesion inhibitor is disclosed in JP-B-45-3083.
No. 5 and JP-B No. 52-24953 dyes or pigments,
As represented by aromatic amine compounds described in JP-A-51-50887, and reaction products of phenolic compounds and aromatic aldehydes described in JP-A-55-54317, colored compounds are Many. Presumably, when a suspension polymerization of vinyl chloride or the like is performed in a polymerization vessel in which a coating film composed of these scale inhibitors is formed, a colored polymer is obtained. That is, for example, when the lightness index L is measured, a value of 65 or less is obtained, and coloring is confirmed. It is considered that this coloring occurs as a result of the components of the coating film being mixed into the polymerization system due to dissolution or peeling of the coating film. Improvements are also required to improve the quality of polymers.

Also, the conventional polymer scale adhesion preventive is
-Aminic substances such as aniline, nitrobenzene and formaldehyde exemplified as polar compounds described in No. 30343,
Many of them are toxic, as exemplified by pigments containing heavy metals such as chromium and lead, which are exemplified as pigments described in JP-B-45-30835. Some of the dyes described in JP-B-45-30835 and JP-B-52-24953 are concerned about carcinogenicity. For this reason, when these substances are used, there is a safety problem for workers.

[Means for solving the problem]

An object of the present invention is to effectively prevent adhesion of a polymer scale, and to obtain a polymer having a high whiteness because the polymer is not colored, and furthermore, there is no toxicity and the like for safety and health. It is an object of the present invention to provide a polymer scale anti-adhesion agent having no concept and a method for preventing adhesion of a polymer scale.

That is, the present invention provides a polymer scale for polymerizing a monomer having an ethylenic double bond, comprising (A) a hydroxyanthraquinone and (B) a vinylpyrrolidone-based polymer. Provide an anti-adhesion agent.

The present invention also relates to a method for preventing adhesion of a polymer scale in the polymerization of a monomer having an ethylenic double bond in a polymerization vessel, wherein (A) hydroxyanthraquinones And (B) a method for preventing adhesion of a polymer scale, comprising the step of performing the polymerization in a polymerization vessel in which a coating film containing a vinylpyrrolidone-based polymer is formed.

According to the polymer scale adhesion preventive agent and the method for preventing polymer scale adhesion of the present invention, it is possible to produce a high whiteness product polymer having an L value of 70 or more. Moreover, the polymer scale adhesion inhibitor used has no toxicity or the like and is highly safe, so that there is no problem in terms of safety and health of workers.

(A) Hydroxyanthraquinone The hydroxyanthraquinone, which is the component (A) of the polymer scale adhesion inhibitor of the present invention, is a natural or synthetic hydroxyanthraquinone having at least one hydroxyl group or a derivative thereof, and is preferably a polyvalent. Hydroxyanthraquinone or a derivative thereof.

As the hydroxyanthraquinones, for example,
Alizarin, Purproxanthin, Purproxanthin carboxylic acid, Purpurin, Pseudopurpurin, Rubiazine, Morindadiol, Chrysophonic acid, Morindone, Emodin, Laccaic acid, Kermesic acid, Carminic acid, Quinizarin, Antralphine, Clizazine, Anthraflavin Acids, quinalizarin, 1-hydroxyanthraquinone and the like. These can be used alone or in combination of two or more.

Of these, particularly preferred are alizarin, purpurin, quinalizarin, anthraflavic acid, laccaic acid, and carminic acid.

(B) Vinylpyrrolidone-based polymer The vinylpyrrolidone-based polymer which is the component (B) of the polymer scale adhesion inhibitor of the present invention includes polyvinylpyrrolidone which is a homopolymer of vinylpyrrolidone, and vinylpyrrolidone and other comonomers. And a copolymer of Examples of the comonomer that can be copolymerized with vinylpyrrolidone include acrylic acid, methyl acrylate, methyl methacrylate, and vinyl acetate. These can be used alone or in combination of two or more. The content of these comonomers in the polymer is usually 1 to 50% by weight, preferably 5 to 30% by weight.

These vinylpyrrolidone polymers can be used alone or in combination of two or more. Among them, those having a high molecular weight of 10,000 or more, particularly, polyvinylpyrrolidone, vinylpyrrolidone-acrylic acid copolymer and vinylpyrrolidone-vinyl acetate copolymer having a molecular weight of 40,000 or more are preferable.

The polymer scale adhesion inhibitor of the present invention contains a hydroxyanthraquinone as the component (A) and a vinylpyrrolidone-based polymer as the component (B).
The polymer scale adhesion preventing agent is used, for example, to be formed as a coating film on the inner wall surface of a polymerization vessel to prevent scale adhesion on the inner wall surface of the polymerization vessel.

In the polymer scale adhesion preventive agent of the present invention, by using (A) hydroxyanthraquinones and (B) vinylpyrrolidone-based polymer in combination, a remarkable scale prevention effect can be obtained even when the concentration of (A) hydroxyanthraquinones is low. can get. The mechanism of action of such a vinylpyrrolidone polymer is not clear, but it is presumed that the vinylpyrrolidone polymer acts on hydroxyanthraquinones to increase hydrophilicity.

The content ratio of the component (B) to the component (A) in the polymer scale adhesion inhibitor of the present invention is usually 0.1 to 1000 parts by weight, preferably 1 to 600 parts by weight, per 100 parts by weight of the component (A). . When the content ratio of the component (B) to the component (A) is out of the above-mentioned normal range, it is difficult to obtain a good scale prevention effect by the combined use.

The polymer scale adhesion inhibitor of the present invention is, for example, formed as a coating film on the inner wall surface of a polymerization vessel to prevent scale adhesion on the inner wall surface of the polymerization vessel. Usually, when the coating film is formed on the inner wall surface of a polymerization vessel, it is used in a solution state, that is, as a coating solution.

Preparation of Coating Solution The coating solution as described above is prepared by adding the components (A) and (B) to an appropriate solvent.

Examples of the solvent used for preparing such a coating solution include water; methanol, ethanol, propanol, butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, and 3-methyl- 1
Alcohol solvents such as butanol, 2-methyl-2-butanol and 2-pentanol; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone;
Ester solvents such as methyl formate, ethyl formate, methyl acetate, methyl acetoacetate; ether solvents such as 4-methyldioxolane, ethylene glycol diethyl ether; furans; aprotic solvents such as dimethylformamide, dimethyl sulfoxide, acetonitrile, etc. Is mentioned. These are used singly or as a mixture of two or more solvents.

When dissolving (A) hydroxyanthraquinones in these solvents, if necessary, the solvent can be made alkaline (pH 8 to 11) by adding an alkaline substance to facilitate dissolution. . Examples of the alkaline substance to be added include sodium hydroxide, sodium carbonate, ethylenediamine, ethanolamine, and triethanolamine.

The total concentration of the components (A) and (B) in the coating solution is not particularly limited as long as the total coating amount described below is obtained, but is usually about 0.001 to 15% by weight, preferably 0.01 to 1% by weight.
It is. Further, the content ratio of the component (B) to the component (A) in the coating solution is the same as the content ratio in the polymer scale adhesion inhibitor. When the content ratio of the component (B) to the component (A) in the coating liquid is too large or too small,
The improvement of the scale prevention effect by the combined use is reduced.

In addition, a surfactant (cationic, inionic, anionic) or the like can be added to the coating solution as long as the scale preventing action is not impaired.

Further, the coating liquid has a non-coloring property which is the object of the present invention,
Inorganic compounds can also be added as needed, as long as they do not impair nontoxicity and do not impair the scale-inhibiting action. As inorganic compounds that can be added, orthosilicic acid, metasilicic acid, mesodisilicic acid, mesotrisilicic acid,
Mesotetrasilicate, sodium metasilicate, sodium orthosilicate, sodium disilicate, sodium tetrasilicate,
Silicic acids or silicates such as water glass; 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, acetates, nitrates, hydroxides or halides; and inorganic colloids such as ferric hydroxide colloid, silicate colloid, barium sulfate colloid and aluminum hydroxide colloid. The above inorganic colloid,
For example, it may be prepared by mechanical pulverization, ultrasonic irradiation, electric dispersion, and chemical method.

To form a coating film on the inner wall of the polymerization vessel using the coating solution prepared as described above, first, apply the coating solution to the inner wall surface of the polymerization vessel, and then, for example, from room temperature to 100 ° C. After sufficiently drying in the temperature range up to, and further washing with water as needed. In this case, since a coating film is formed on the inner wall surface of the polymerization vessel, adhesion of the polymer scale to the inner wall surface of the polymerization vessel is prevented.

Further, the coating liquid is preferably applied not only to the inner wall surface of the polymerization vessel but also to other parts where the monomer comes into contact during the polymerization, and it is preferable to form a coating film thereby. For example, stirring blades, stirring shafts, baffles, condensers,
It is better to form a coating film on the header, search coil, bolt, nut and the like by applying the coating liquid. In particular, a coating film should usually be formed on the stirring blade, stirring shaft, and baffle by applying the coating solution. The application of the coating solution to these sites to form a coating film may be performed in the same manner as when forming a coating film on the inner wall of the polymerization vessel.

More preferably, the coating liquid is a part other than the part where the monomer comes into contact during the polymerization, a part where the polymer scale may adhere, for example, an unreacted monomer recovery system device and piping. It is preferable that the coating liquid is applied to an inner surface to form a coating film. More specifically, such portions include inner surfaces of a monomer distillation column, a condenser, a monomer storage tank, a valve, and the like. The formation of the coating film at these sites may be performed in the same manner as the case of forming the coating film on the inner wall of the polymerization vessel.

In this way, when a coating film is formed at a site where the monomer comes into contact during polymerization and at a site where other polymer scale may be attached, adhesion of the polymer scale to those sites is prevented. You.

The method for applying the coating solution to the inner wall surface of the polymerization vessel is not particularly limited. Examples thereof include brush coating, spray coating, and a method in which the polymerization vessel is filled with the coating solution and then withdrawn. Automatic coating methods described in 61001, 55-36288, JP-B-56-501116, JP-B-56-501117, JP-A-59-11303 and the like can also be used.

Further, the method of drying the surface that is wet by the application of the coating liquid is not limited, and for example, the following method can be used. That is, after the application of the coating solution, a method of applying an appropriately heated warm air to the application surface,
Alternatively, a method in which the inner wall surface of the polymerization vessel to be coated with the coating solution and other surfaces are previously heated to, for example, 30 to 80 ° C., and the coating solution is directly applied to the heated surface can be used. After the application surface is dried, the application surface is washed with water as needed.

The coating film obtained in this manner has a total coating weight after drying, typically, 0.001 g / m ² or more, and particularly preferably 0.05 to 2 g / m ^2.

The above-described coating operation may be performed for each polymerization of 1 to 10 or more batches. 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 polymerization, and then the polymerization is carried out in the polymerization vessel by a conventional method. Do. That is, in addition to a monomer having an ethylenic double bond and a polymerization initiator (catalyst), if necessary, a collecting medium such as water, and a suspending agent, a solid dispersant, a nonionic, an anionic emulsifier, etc. A dispersant or the like is charged, and then polymerization is performed by a conventional method.

Examples of the monomer having an ethylenic double bond to be polymerized by applying the method of the present invention include vinyl halide such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid and methacrylic acid And their esters or salts; maleic acid, fumaric acid, and their esters or anhydrides; diene monomers such as butadiene, chloroprene, and isoprene;
Acrylonitrile, vinylidene halide, vinyl ether and the like can be mentioned.

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

Hereinafter, taking the case of suspension polymerization and emulsion polymerization as examples,
A general polymerization method will be specifically described.

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 0.1 to 760
After reducing the pressure to mmHg, the monomer was charged (at this time, the internal pressure of the polymerization vessel was usually 0.5 to 30 kgf / cm ² · G).
Polymerizes at a reaction temperature of ~ 150 ° C. During polymerization, one or more of water, a dispersant, and a polymerization initiator are added as necessary. 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, 50 to 150 ° C. To carry out polymerization. In polymerization, when the internal pressure of the polymerization reactor drops to 0 to 7 kgf / cm ² · G, or in the jacket provided around the polymerization reactor, the difference between the inlet temperature and the outlet temperature of the cooling water almost disappears. Is completed (that is, when the heat generated by the polymerization reaction has been eliminated), it is determined to be completed. Water, dispersant and polymerization initiator charged during the polymerization are usually 20 to 500 parts by weight of water, 0.01 to 30 parts by weight of a dispersant, 0.01 to 5 parts by weight of a polymerization initiator based on 100 parts by weight of a monomer. Department.

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

In the case of bulk polymerization, the inside of the polymerization vessel is about 0.01 to 760 m
After exhausting to a pressure of mHg, a monomer and a polymerization initiator are charged into the polymerization vessel, and polymerization is performed at a reaction temperature of -10 to 250C. For example, in the case of vinyl chloride polymerization at 30-80 ° 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 a polymer scale of the present invention, adhesion of the polymer scale can be prevented regardless of the material such as the inner wall surface of the polymerization vessel. Even when polymerization is performed in a steel polymerization vessel, a glass-lined polymerization vessel, or the like, adhesion of the polymer scale can be prevented.

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 hydroper Oxide, cyclohexanone peroxide, t-butyl peroxypivalate, bis (2-ethoxyethyl) peroxydicarbonate,
Benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, α, α′-azobisisobutyronitrile, α, α′-azobis-2,4-dimethylvaleronitrile , Potassium peroxodisulfate, ammonium peroxodisulfate, polymerization initiators such as p-menthane hydroperoxide; partially saponified polyvinyl alcohol, polyacrylic acid, copolymers of vinyl acetate and maleic anhydride, and cellulose derivatives such as hydroxypropylmethyl cellulose Suspending agents such as natural or synthetic high molecular compounds such as gelatin and gelatin; solid dispersing agents such as calcium phosphate and hydroxyapatite; non-dispersing agents such as sorbitan monolaurate, sorbitan triolate and polyoxyethylene alkyl ether Emulsifiers; anionic emulsifiers such as sodium alkylbenzenesulfonate such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate; sodium dioctylsulfosuccinate; fillers such as calcium carbonate and titanium oxide; tribasic lead sulfate, calcium stearate, dibutyl Stabilizers such as tin dilaurate and dioctyltin mercaptide; lubricants such as rice wax, stearic acid and cetyl alcohol; DO
P, a plasticizer such as DBP; mercaptans such as t-dodecyl mercaptan, a chain transfer agent such as trichloroethylene; even in a polymerization system in which a pH regulator and the like are present, the method of the present invention effectively adheres polymer scale. Can be prevented.

In addition, 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 the like, and further added directly to the polymerization system, thereby improving the scale prevention effect. it can. In that case, the amount of the polymer scale adhesion inhibitor added is about
About 10 to 1000 ppm is appropriate. 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.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. In each of the tables below, the experiment N marked with *
o is a comparative example, and other experiment numbers are examples of the present invention.

Example 1 Polymerization was carried out as follows using a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 1000.

In each experiment, first, the component (A) (polyvalent hydroxyanthraquinone) and the component (B) (polyvinylpyrrolidone; a reagent manufactured by Aldrich chemical Co.) were mixed with a solvent so that the total concentration was as shown in Table 1. To prepare a coating solution. These coating solutions were applied to the inner wall of a polymerization vessel, a stirring shaft, a stirring blade, and other portions where the monomers contact during polymerization, heated and dried at 40 ° C. for 15 minutes to form a coating, and then washed with water.

However, Experiment No. 101 is a comparative example in which no coating liquid was applied, Experiment No. 102 was a comparative example in which a coating liquid containing only the component (B) was applied, and Experiment Nos. 103 and 107 were only the component (A). It is a comparative example in which a coating solution contained was applied. Experiment N
o.104 uses 1,8-diaminonaphthalene instead of polyvalent hydroxyanthraquinones as the component (A),
Experiment Nos. 105 and 106 used 1,8-diaminonaphthalene instead of polyvalent hydroxyanthraquinones as component (A). It is a comparative example in which a coating solution containing components was applied.

(A) The kind of polyvalent hydroxyanthraquinone in the coating solution used in each experiment, (B) the average molecular weight of the vinylpyrrolidone polymer used, (A) +
Table 1 shows the total concentration and weight ratio (A) / (B) of (B), and the type of solvent used.

Thereafter, 400 kg of water, 200 kg of hinyl chloride, 250 g of partially saponified polyvinyl alcohol, 25 g of hydroxypropylmethylcellulose, 25 g of hydroxypropylmethylcellulose and 75 g of diisopropylperoxydicarbonate were charged and stirred in the polymerization vessel in which the coating treatment was formed in this manner. The polymerization was carried out at 57 ° C. for 6 hours.

After the polymerization was completed, the amount of polymer scale adhered to the inner wall of the polymerization vessel (the amount of polymer scale adhered) was measured. In addition, each experiment
The whiteness of the polymer obtained in No. was measured by the following method.

100 parts by weight of polymer, stabilizer TS-101 (Akishima Chemical Co., Ltd.) 1
Parts by weight, 0.5 parts by weight of C-100J (manufactured by Katsuta Kako Co., Ltd.) and 50 parts by weight of a plasticizer DOP were kneaded at 160 ° C. for 5 minutes using a two-roll mill, and then formed into a sheet having a thickness of 1 mm. Next, this sheet was placed in a mold having a size of 4 cm × 4 cm × 1.5 cm (thickness), and heated and pressed at 160 ° C. at 65 to 70 kgf / cm ² to prepare a measurement sample. About this measurement 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.

 The L value was determined as follows.

According to the description of JIS Z 8722, a standard light C, a photoelectric colorimeter (Z-1001DP type colorimeter manufactured by Nippon Denshoku Industries Co., Ltd.) is used, and the stimulus value Y of the XYZ color system is obtained by a stimulus value direct reading method. I asked. The geometric conditions of illumination and light reception include:
The condition d described in section 4.3.1 of JIS Z 8722 was adopted.

Next, L was determined from the equation: L = 10Y1 ^{/ 2} described in JIS Z 8730 (1980).

 The results are shown in Table 1.

Example 2 (A) Types of polyvalent hydroxyanthraquinones used in a stainless steel polymerization vessel equipped with a stirrer having an internal volume of 20,
(B) average molecular weight of vinylpyrrolidone-based polymer, (A)
Coating treatment was carried out in the same manner as in Example 1, except that the total concentration of + (B), the weight ratio (A) / (B), and the type of the solvent used were as shown in Table 2. Was done. However, Experiment No. 201 is a comparative example in which no coating liquid was applied, Experiment No. 202 was a comparative example in which a coating liquid containing only the component (B) was applied, and Experiment No. 203 was a comparative example in which only the component (A) was applied. It is a comparative example in which a coating solution contained was applied. Experiment No. 204
Is a comparative example in which 3,6-diaminoacridine was used as the component (A) instead of the polyvalent hydroxyanthraquinone, and a coating solution containing no component (B) was applied. A) using 3,6-diaminoacridine instead of polyvalent hydroxyanthraquinones as a component,
7 is a comparative row in which a coating solution containing the component (B) is applied.

Next, 9k of water was placed in the polymerization vessel thus coated.
g, sodium dodecylbenzenesulfonate 225 g, t-
After charging 12 g of dodecyl mercaptan and 13 g of potassium peroxodisulfate and purging with nitrogen gas, styrene 1.3 k
g and 3.8 kg of butadiene were charged and polymerized at 50 ° C. for 20 hours.

After the polymerization was completed, the amount of polymer scale adhered on the inner wall surface of the polymerization vessel was measured. The results are shown in Table 2.

[Effects of the Invention] According to the present invention, it is possible to effectively prevent the adhesion of the polymer scale, and it is possible to produce a high-white product polymer having the above-mentioned L value of 70 or more. In addition, since the scale inhibitor used has low toxicity and high safety, there is no problem in terms of safety and health of workers.

Furthermore, according to the present invention, regardless of the type of the monomer and the polymerization initiator used, the type of polymerization, and the conditions of polymerization such as the material of the inner wall of the polymerization vessel, the adhesion of the polymer scale is effectively prevented. can do. That is, for example, even in emulsion polymerization where it is difficult to prevent adhesion of the polymer scale, even when a stainless steel polymerization vessel to which the polymer scale is easily attached is used, or polymerization of potassium peroxodisulfate having strong oxidizing power is started. When used as an agent, the adhesion of the polymer scale can be effectively prevented.

Therefore, when the polymerization is carried out by applying the present invention, it is not necessary to carry out the work of removing the polymer scale for each polymerization, whereby the productivity is improved and the high quality product polymer without coloring is obtained. Can be manufactured.

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Claims (2)

(57) [Claims] A polymer scale adhesion inhibitor for polymerizing a monomer having an ethylenic double bond, comprising (A) a hydroxyanthraquinone and (B) a vinylpyrrolidone polymer. 2. A method for preventing adhesion of a polymer scale in polymerization of a monomer having an ethylenic double bond in a polymerization vessel, wherein (A) hydroxyanthraquinone and (B) A method for preventing adhesion of a polymer scale, comprising a step of performing the polymerization in a polymerization vessel in which a coating film containing a vinylpyrrolidone-based polymer is formed.