JPH0450201A - Polymer scale adhesion inhibitor and polymer scale adhesion prevention method - Google Patents

Abstract

PURPOSE:To obtain the title preventing agent for polymerization of ethylenic double bond-containing monomer consisting of proteins and polysaccharide, free from toxicity, having high safety and capable of preventing deposition of a polymer scale even when a polymerization vessel made of stainless steel is used and even when a polymerization initiator having strong oxidizing force is used. CONSTITUTION:When a monomer [e.g. vinyl chloride, vinyl acetate, (meth)acrylic acid, styrene, etc.] having an ethylenic double bond is polymerized, a polymer scale deposition-preventing agent consisting of (A) proteins (preferably gelatin, casein, gluten, egg white albumin or collagen) and (B) polysaccharide (e.g. pectin, hyaluronic acid, amylose or methyl cellulose) is previously applied to the inner wall face of a polymerization vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polymer scale adhesion inhibitor for polymerization of monomers having ethylenic double bonds and a method for preventing polymer scale adhesion.

[Conventional technology]

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

When polymer scale adheres to the inner wall surface 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 adhered polymer scale peeling off and contaminating the product. In addition, there are disadvantages such as a great deal of effort and time required to remove the polymer scale. Moreover, the polymer scale contains unreacted monomers, which can expose workers and cause physical injury.

Conventionally, in the polymerization of monomers having ethylenic double bonds, the method of preventing polymer scale from adhering to the inner wall surface of the polymerization vessel, etc. is to use a suitable substance as a polymer scale adhesion inhibitor. There is a known method of applying it to

Substances suitable as polymer scale adhesion inhibitors include:
For example, certain polar compounds (Japanese Patent Publication No. 4530343)
, dye or pigment (Japanese Patent Publication No. 45-30835, 52
-24953), aromatic amine compounds (JP-A-51-
50887) and a reaction product of a phenolic compound and an aromatic aldehyde (Japanese Patent Application Laid-Open No. 55-54317).

[Problem to be solved by the invention]

By the way, the vinyl chloride polymer obtained by polymerization is required to have a high degree of whiteness, and for example, according to JIS
It is required that the value of the brightness index in Hunter's color difference formula described in Z 8730 (1980) be 70 or more.

Conventional polymer scale adhesion inhibitors were developed by Japanese Patent Publication No. 45-30
dyes or pigments described in JP-A No. 835 and JP-B No. 52-24953, aromatic amine compounds described in JP-A-51-50887, and phenolic compounds and aromatic aldehydes described in JP-A-55-54317. Many of them are colored, as typified by the reaction products of This may be because of this, when suspension polymerization of vinyl chloride or the like is carried out in a polymerization vessel in which a coating film made of these scale inhibitors is formed, a colored polymer is obtained. That is, for example, when the above-mentioned brightness index is measured, a value of 65 or less is obtained, and coloration is confirmed. This coloring is thought to occur as a result of components of the coating being mixed into the polymerization system due to dissolution or peeling of the coating. Improvements are also required to improve the quality of polymers.

In addition, conventional polymer scale adhesion prevention agents are
Representative examples include deleterious substances such as aniline, nitrobenzene, and formaldehyde, which are exemplified as polar compounds described in Japanese Patent Publication No. 30343, and heavy metals such as chromium and lead, which are exemplified as pigments described in Japanese Patent Publication No. 30835-1983. As you can see, many of them are poisonous. In addition, the special public
Some of the dyes described in Japanese Patent Publication No. 30835 and Japanese Patent Publication No. 52-24953 may be carcinogenic. Therefore, when these substances are used, there are safety problems for workers.

[Means to solve the problem]

The purpose of the present invention is to effectively prevent the adhesion of polymer scale, to obtain a polymer with high whiteness because it does not color the polymer, and to have no toxicity and improve safety and health. It is an object of the present invention to provide a polymer scale adhesion preventing agent and a polymer scale adhesion prevention method that are free from concerns.

That is, the present invention achieves the above object by providing a polymer scale adhesion inhibitor for the polymerization of monomers having ethylenic double bonds, which is composed of (A) proteins and (B) multi-Ii species. provide.

The present invention also provides a method for preventing the adhesion of polymer scale during polymerization of monomers having ethylenic double bonds in a polymerization vessel, in which (A) proteins and (B) Provided is a method for preventing the adhesion of polymer scale, which comprises the step of carrying out the polymerization in a polymerization vessel in which a coating film made of Polymer II is formed.

According to the polymer scale adhesion prevention agent and polymer scale adhesion prevention method of the present invention, it is possible to produce a product polymer with a high degree of whiteness and the above-mentioned threshold value of 70 or more. Furthermore, the polymer scale adhesion inhibitor used is non-toxic and highly safe, so there is no problem in terms of safety and health for workers.

1 plate of jellyfish The proteins that are component (A) of the polymer scale adhesion prevention side of the present invention are non-toxic and suitable for the purpose of the present invention.

Such (A) proteins include simple proteins,
Compound protein awards, derived protein awards, and alkali metal salts or ammonium salts thereof, such as sodium salts, potassium salts, etc., are included.

Simple proteins include albumins such as ovalbumin, milk albumin, globin, and leucosine; globulins such as serum globulin, fibrinogen, and glycinin; glutelins such as oryzenin, glutenin, and hordenin; prolamins such as gliadin, zein, and hordein; Examples include hard proteins such as collagen, elastin, keratin, and fibroin; histones such as thymic histone; and protamines such as salmin and crupein.

Examples of complex proteins include nuclear proteins such as nucleohistones and nucleoprotamines in which nucleic acids and simple proteins are combined; glycoproteins in which carbohydrates and simple proteins are combined such as mucins and mucoids; casein, ovovitelin, etc. Phosphoproteins, which are a combination of a phosphorus-containing substance and a simple protein, such as; lipids, such as residobrotiin and tissue fibrinogen;
Examples include combinations of simple proteins and botanicals.

Examples of the induced protein include gelatin and glue.

These (A) proteins can be used alone or in combination of two or more.

Among the above proteins (A), preferred are gelatin, casein, alkali metal salts and ammonium salts of casein, gluten, ovalbumin, and collagen.

(2) L and Plate The polysaccharide which is the component (B) of the polymer scale adhesion prevention agent of the present invention is non-toxic and suitable for the purpose of the present invention, like the above-mentioned (A) proteins.

Such polysaccharides (B) include neutral polysaccharides and acidic polysaccharides, such as pectin, pectic acid, vectinic acid, fucocudin, carrageenin, laminarin, guar gum, locust bean gum, alginic acid, and propylene glycol alginate. Vegetable mucilage polysaccharides such as hyaluronic acid, chondroitin sulfate, heparin, ketora sulfate, caronine sulfate, limacoitin sulfate; animal mucilage polysaccharides such as amylose, amylopectin, dextrin,
Starches and their derivatives such as oxidized starch, acetyl starch, nitro starch, methyl starch, carboxymethyl starch; methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, glycol cellulose, benzyl cellulose, cyanoethyl cellulose, triphenyl methyl cellulose, formyl cellulose , cellulose derivatives such as cellulose propionate, cellulose butyrate, cellulose acetate, cellulose acetate propionate, cellulose sulfonate ester, cellulose carbamate ester, nitrocellulose, carboxymethyl cellulose, cellulose sulfate, cellulose phosphate, cellulose xanthate; and these Examples include alkali metal salts or ammonium salts such as sodium salts, potassium salts, and the like. These can be used alone or in combination of two or more.

The polymer scale adhesion prevention agent of the present invention containing these components (A) and (B) can be formed as a coating film on the inner wall surface of a polymerization vessel, for example, to prevent scale adhesion on the inner wall surface of the polymerization vessel. This is to prevent

In addition to the above-mentioned components (A) and (B) which are effective in preventing scale adhesion, this polymer scale adhesion inhibitor also contains a solvent, a cationic surfactant, and a nonionic surfactant, if necessary. , anionic surfactant, etc. can be added.

In addition to the above, substances that can be added include orthosilicic acid, metasilicic acid, mesosilicic acid, mesotrisilicic acid, mesotetrasilicic acid,
Silicates or silicates such as sodium metasilicate, sodium orthosilicate, sodium disilicate, sodium tetrasilicate, water glass; alkaline earth metal elements such as magnesium, calcium, barium, zinc group elements such as zinc, aluminum Oxygen salts, acetates, nitrates, hydroxides or Metal salts such as halides; gold colloid, silver colloid, ferric hydroxide colloid, stannic acid colloid, silicic acid colloid, barium sulfate colloid, aluminum hydroxide colloid, etc. The above-mentioned colloids include inorganic colloids prepared by mechanical grinding, ultrasonic irradiation, electrical dispersion, and chemical methods, and the like. Usually, when forming the coating film on the inner wall surface of a polymerization vessel, it is in a solution state, that is,
Used as a coating liquid.

Eharu standing dish type The coating liquid as described above contains the above-mentioned (A) component and (B)
Prepared by adding the ingredients to the appropriate solvent.

Examples of the solvent used for preparing such a coating solution include water; methanol, ethanol, propatool, butanol, 2-butanol, 2-methyl-1-propatool, 2-methyl-2-propatool, 3 -Methyl-1-
Alcohol-based N agents such as butanol, 2-methyl-2-butanol, and 2-pentanol; Ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; Ester-based agents such as methyl formate, ethyl formate, methyl acetate, and methyl acetoacetate. Solvents; ether solvents such as 4-methyldioxolane and ethylene glycol diethyl ether; furans; aprotic solvents such as dimethylformamide, dimethyl sulfoxide, and acetonitrile. These solvents may be used alone or as a mixed solvent of two or more.

The total concentration of components (A) and (B) in the coating solution is not particularly limited as long as the preferred coating amount described below, that is, the total weight of components (8) and (B) per unit area is obtained. , usually about 0.005 to 10% by weight, preferably about 0.01 to 5% by weight. In addition, (A
) component and (B) component is usually (A) component 1.
0.1 to 1000 parts by weight of component (B) per 00 parts by weight,
Preferably it is 1 to 600 parts by weight. (B) The component is (A
) If the amount is too large or too small compared to component (A) and component (B), the effect of using the components (A) and (B) together may not be obtained.

Moreover, the pH of the coating liquid is not particularly limited. If necessary, a suitable acid or alkali may be selected and used as the pH adjuster.

! In order to form a coating film on the inner wall surface of the polymerization vessel using the coating liquid prepared as described above, first, the coating liquid is applied to the inner wall surface of the polymerization vessel, and then, for example, the coating liquid is heated at 100° from room temperature. After sufficiently drying at a temperature range of up to C, the film is further washed with water if necessary. In this way, since a coating film is formed on the inner wall surface of the polymerization vessel, adhesion of polymer scale to the inner wall surface of the polymerization vessel is prevented.

Further, it is preferable that the coating liquid is applied not only to the inner wall surface of the polymerization vessel but also to other parts that come into contact with the monomer during polymerization, thereby forming a coating film.

For example, it is preferable to form a coating film on stirring blades, stirring shafts, condensers, headers, search coils, bolts, nuts, etc. by applying the coating liquid. In particular, a coating film should usually be formed on the stirring blade, stirring shaft, and panfur by applying the coating liquid. To form a coating film by applying a coating liquid to these parts, it is possible to perform the same procedure as in the case of forming a coating film on the inner wall of the polymerization vessel.

More preferably, the coating liquid is applied to areas where polymer scale may adhere even to areas other than those that come into contact with monomers during polymerization, such as equipment and piping of an unreacted monomer recovery system. It is preferable to apply the coating liquid to the inner surface to form a coating film.

More specifically, such sites include the inner surfaces of monomer distillation columns, condensers, 7-mer storage tanks, valves, and the like. The coating film may be formed at these locations in the same manner as in the case of forming the coating film on the inner wall of the polymerization vessel.

In this way, by forming a coating film on areas that come into contact with monomers during polymerization and other areas where polymer scale may adhere, the adhesion of polymer scale to those areas is prevented. Ru.

The method of applying the coating liquid to the inner wall surface of the polymerization vessel is not particularly limited, and includes, for example, brush coating, spray coating, and a method of filling the polymerization vessel with the coating liquid and then drawing it out.
Others: JP-A-57-61001, JP-A No. 55-3628
No. 8, Special Publication No. 56-501116, No. 56-5011
17, JP-A-59-11303, and the like can also be used.

Further, the method of drying the surface that is wet due to the application of the coating liquid is not limited, and for example, the following method can be used.

That is, after applying the coating liquid, a method in which appropriately heated hot air is applied to the coating surface, or a method in which the inner wall surface of the polymerization vessel and other surfaces to which the coating liquid is to be applied are heated to, for example, 30 to 80°C in advance. , a method of directly applying a coating liquid to the heated surface, etc. can be used. After the coated surface is dried, the coated surface is washed with water if necessary.

The coating film thus obtained has a coating amount per unit area, that is, a total weight of components (A) and (B) per unit area, which is usually 0.001 g/rrr or more, particularly 0.001 g/rrr or more. It is preferable that it is 05-2 g/ryf.

The above coating operation may be performed every time one to ten bunches are polymerized. Since the formed coating film has high durability and the effect of preventing the adhesion of polymer scale continues, it is not necessary to carry out this process every time one batch of polymerization is carried out. Therefore, the productivity of the product polymer is improved.

Moreover, the polymer scale adhesion inhibitor of the present invention can also be added to the polymerization medium. In that case, for example, after using the coating liquid for the coating treatment, a small amount of a polymer scale adhesion inhibitor in a solution state similar to that of the coating liquid may be added to the polymerization medium. In this case, the scale prevention effect is improved compared to when only the coating treatment is performed. In addition, when such a polymer scale adhesion inhibitor in a solution state is added to the polymerization medium, the amount added is about 10 to 100% based on the total weight of monomers having ethylenic double bonds.
It may be within the range of 11,000 pp.

! - Hill After forming a coating film by coating the inner wall of the polymerization vessel and preferably other areas that come into contact with the monomer during polymerization as described above, polymerization is carried out in the polymerization vessel by a conventional method. Let's do it. That is, in addition to a monomer having an ethylenic double bond and a polymerization initiator (catalyst), if necessary, a polymerization medium such as water, a suspending agent, a solid dispersant, a nonionic emulsifier, an anionic emulsifier, etc. Prepare dispersant etc., then
Polymerization is carried out by conventional methods.

Monomers having ethylenic double bonds that can be polymerized by applying the method of the present invention include, for example, vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid and methacrylic acid. , and esters or salts thereof; maleic acid, fumaric acid, and esters or anhydrides thereof; butadiene, chloroprene.

Diene monomers such as isoprene; examples include styrene, acrylonitrile, vinylidene halides, and vinyl ether.

In addition, the method of polymerization to which the method of the present invention is applied is not particularly limited, and is effective in any polymerization format such as suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization, and gas phase polymerization.
In particular, it is more suitable for polymerization in an aqueous medium such as suspension polymerization and emulsion polymerization.

Below, examples of suspension polymerization and emulsion polymerization are given.
A practical polymerization method will be explained in detail.

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 0.1 to 7
After reducing the pressure to 60 Kgf, charge the monomer (at this time, the internal pressure of the polymerization vessel is usually 0.5 to 30) cgf/all-G
), followed by polymerization at a reaction temperature of 30-150°C. During polymerization, one or more of water, a dispersant, and a polymerization initiator are added as necessary. The reaction temperature during polymerization varies depending on the type of monomer to be polymerized; for example, in the case of vinyl chloride polymerization, polymerization is carried out at 30 to 80 °C, and in the case of styrene polymerization, it is 50 to 150 °C.
Polymerization is carried out at °C. During polymerization, the internal pressure of the polymerization vessel is O~7k.
gf/cd-G, or when the difference between the inlet and outlet temperatures of the cooling water flowing into and out of the jacket installed around the polymerization reactor has almost disappeared (i.e., the heat generated by the polymerization reaction has disappeared). It is determined that the process is complete. The water, dispersant, and polymerization initiator charged during polymerization are usually 20 parts by weight of water per 100 parts by weight of monomer.
~500 parts by weight, 0.01 to 30 parts by weight of the dispersant, and 0.01 to 5 parts by weight of the polymerization initiator.

In addition, in the case of solution polymerization, an organic solvent such as toluene, xylene, pyridine, etc. is used instead of water as the polymerization medium. A dispersant is used as necessary. Other polymerization conditions are generally similar to those for suspension and emulsion polymerizations.

In addition, in the case of bulk polymerization, the inside of the polymerization vessel should be approximately 0.01 to 7
After evacuating to a pressure of 60 mHg, monomers and polymerization initiators were charged into the polymerization vessel, and the temperature was set at -10°C to 250°C.
Polymerizes at a reaction temperature of Note that specific polymerization methods using bulk polymerization include, for example, a liquid bulk polymerization method and a gas phase polymerization method in the polymerization of vinyl chloride monomers.

When polymerization is carried out by applying the polymer scale adhesion prevention method of the present invention, it is possible to prevent polymer scale adhesion regardless of the material of the inner wall surface of the polymerization vessel. Adhesion of polymer scale can also be prevented when polymerization is carried out in a steel polymerization vessel, a glass-lined polymerization vessel, or the like.

Those added to the polymerization system can be used without any restrictions. That is, for example, t-butylperoxyneodecanoate, bis(2-ethylhexyl)peroxydicarbonate, 3,5°5-trimethylhexanoyl peroxide, α-cumylperoxyneodecanoate, cumene hydroper oxide, cyclohexanone peroxide, t-butyl peroxypihalate,
Bis(2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, α, α′-azobisisobutyronitrile, α, α′-azobis-2,4
-Polymerization initiators such as dimethylvaleronitrile, potassium peroxodisulfate, ammonium peroxodisulfate, p-menthane hydroperoxide; partially saponified polyvinyl alcohol, polyacrylic acid, copolymer of hinyl acetate and maleic anhydride, hydroxypropyl methyl cellulose, etc. Suspending agents such as natural or synthetic polymer compounds such as cellulose derivatives and gelatin; Solid dispersing agents such as calcium phosphate and hydroxyapatite; Nonionic emulsifying agents such as sorbitan monolaurate, sorbitan triolate, and polyoxyethylene alkyl ether; Lauryl sulfate Anionic emulsifiers such as sodium, sodium alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate, and sodium dioctylsulfosuccinate; Fillers such as calcium carbonate and titanium oxide; Tribasic lead sulfate, calcium stearate, diptyltin dilaurate, and dioctyltin mercaptan. stabilizers such as; lubricants such as rice wax, stearic acid, cetyl alcohol;
Even in polymerization systems in which plasticizers such as DOP and DBP; mercaptans such as t-dodecyl mercaptan; chain transfer agents such as trichlorethylene; and pH adjusters, etc., the method of the present invention effectively prevents the deposition of polymer scale. It can be prevented.

〔Example〕

Hereinafter, the present invention will be explained in detail by giving Examples and Comparative Examples. In each table below, the experiments marked with * are comparative examples, and the other experiments are examples of the present invention.

Polymerization was carried out in the following manner using a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 1000 ffi.

In each experiment, first, component (A) and component (B) were
A coating solution was prepared by dissolving it in a solvent to give the total concentration shown in Table 1. These coating solutions were applied to the inner wall of the polymerization vessel, stirring shaft, stirring blade, and other parts that come into contact with the monomer during polymerization, heated at 60°C for 15 minutes, dried to form a coating film, and then washed with water.

However, Experiments Nos. 101 to 103 are comparative examples in which no coating liquid was applied or a coating liquid containing only either the component (A) or the component (B) was applied.

Types of (A) proteins and (B) polysaccharides in the coating solution used in each experiment, (A) + (B) in the coating solution
Table 1 shows the total concentration and weight ratio (A)/(B), the type of solvent used, and the pH of the coating solution.

Thereafter, 400 kg of water (polymerization medium), 200 kg of vinyl chloride (monomer), and partially saponified polyvinyl alcohol (
250 g (suspending agent), 25 g hydroxypropyl methylcellulose (suspending agent) and bis(2-ethylhexyl)
75 g of peroxydicarbonate (polymerization initiator) was charged. Next, polymerization was carried out at 57°C for 6 hours without stirring.

After the polymerization was completed, the amount of polymer scale adhering to the inner wall of the polymerization vessel (polymer scale adhesion amount) was measured. In addition, the whiteness of the polymer obtained in each experiment was measured by the following method.

100 parts by weight of polymer, 1 part by weight of stabilizer TS-101 (manufactured by Akishima Kagaku Co., Ltd.) and 0 parts by weight of C-100J (manufactured by Katsuta Kako Co., Ltd.)
．． After kneading 5 parts by weight and 50 parts by weight of the plasticizer DOP at 160° C. for 5 minutes using a two-roll mill, the mixture was formed into a sheet having a thickness of 11111. Next, this sheet was put into a mold of 4 CIIX 4 cmXl, 5 C1l (thickness), and heated and pressure-molded at 160°C and 165 to 70 kgf/cd to prepare a measurement sample. For this measurement sample, the brightness index was determined according to Hunter's color difference formula described in JIS Z 8730 (1980), and it was evaluated that the larger the L value, the higher the whiteness.

The L value was determined as follows.

■ In accordance with the description of JIS Z 8722, a standard light C1 photoelectric colorimeter (Z-1001 manufactured by Nippon Denshoku Kogyo Co., Ltd.) was used.
X
The stimulus value Y in the yz color system was determined. Condition d described in section 4.3.1 of JIS Z 8722 was adopted as the geometric conditions for illumination and light reception.

(2) Next, calculate L using the formula described in JIS Z 8730 (1980) (2): L=10Y"".

The results are shown in Table 1.

Real] L Zui λ Internal volume 20! Types of (A) proteins and (B) polysaccharides used in a stainless steel polymerization vessel with a stirrer, (
Total concentration and weight ratio of A) + (B) (A) / (
B) The coating process was carried out in the same manner as in Example 1, except that the type of solvent used and the pH of the coating liquid were as shown in Table 2. However, experiment Nα2
01 to 203 do not apply coating liquid or (A
This is a comparative example using a coating liquid containing only either component () or component (B).

Next, 9 kg of water (polymerization medium), 225 g of sodium dodecylbenzenesulfonate (anionic emulsifier), 12 g of t-dodecylmercaptan (chain transfer agent), and potassium beroxonisulfate (polymerization initiator) were placed in the polymerization vessel coated in this manner. After charging 13 g of agent) and purging with nitrogen gas, 1.3 kg of styrene (monomer) and 3.8 kg of butadiene (monomer) were charged and polymerized at 50°C for 20 hours.

After the polymerization was completed, the amount of polymer scale deposited on the inner wall 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 polymer scale, and also to produce a product polymer having a high degree of whiteness and having the above-mentioned L value of 70 or more. Furthermore, the polymer scale adhesion inhibitor of the present invention is non-toxic and highly safe, so there is no problem in terms of safety and health for workers.

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

Agent: Patent attorney Shushi Iwamiya

Claims (2)

[Claims] (1) A polymer scale adhesion inhibitor for polymerization of a monomer having an ethylenic double bond, consisting of (A) proteins and (B) polysaccharides. (2) A method for preventing the adhesion of polymer scale during polymerization of monomers having ethylenic double bonds in a polymerization vessel, the method comprising: (A) proteins and (B) being preliminarily applied to the inner wall surface of the polymerization vessel; A method for preventing adhesion of polymer scale, comprising the step of carrying out the polymerization in a polymerization vessel in which a coating film made of polysaccharide is formed.