JPH0977805A - Polymer scale anti-adhesion agent and method for producing polymer using the same - Google Patents

Abstract

(57) Abstract: Polymerization containing a monomer such as styrene, α-methylstyrene, acrylic acid, acrylate ester, acrylonitrile, etc., which has a remarkably high solubility in a coating film composed of a conventional polymer scale adhesion preventive agent Provided is a polymer scale adhesion preventive agent capable of reliably preventing adhesion of polymer scale even in a system. A polymer scale anti-adhesive agent containing a condensation product of an aminonaphthalene compound and pyrogallol-acetone resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to adhesion of a polymer scale to an inner wall surface of a polymerization vessel or the like when producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in the polymerization vessel. And a method for producing a polymer using the same.

[0002]

2. Description of the Related Art It is known that when a monomer having an ethylenically unsaturated double bond such as vinyl chloride is polymerized in a polymerization vessel, the polymer adheres to the inner wall surface of the polymerization vessel as a scale. ing. This polymer scale deposition is
As the number of batches increases, the problem becomes remarkable, and there is a problem that the cooling capacity of the polymerization vessel is reduced and the yield of the polymer is reduced. Further, there is a problem that the polymer scale separated from the inner wall is mixed with the obtained polymer and the quality of the product is deteriorated. Then, it takes a lot of labor and time to remove the polymer scale. Since the polymer scale also contains unreacted monomers, there is a problem that if left untreated, it will affect the body of the worker.

Conventionally, in order to prevent adhesion of polymer scale when polymerizing a monomer having an ethylenically unsaturated double bond, a polymer scale adhesion preventive agent is applied to the inner wall surface of the polymerization vessel or the like. Methods of forming a film are known. Examples of the polymer scale adhesion preventive agent include specific polar compounds (Japanese Patent Publication No. 45-30343), dyes or pigments (Japanese Patent Publication No. 45-30835, 52-24953).
JP-A-51-5088.
7), a reaction product of a phenolic compound and an aromatic aldehyde (JP-A-55-54317), and the like.

[0004]

A method for preventing polymer scale adhesion using these substances is such that when the monomer having an ethylenically unsaturated double bond to be polymerized is a vinyl chloride monomer. Is valid. However, when the monomer is styrene, α-methylstyrene, acrylic acid ester, acrylonitrile, vinyl acetate, etc., these monomers have a large effect on the coating film of the above-mentioned polymer scale anti-adhesion agent. Due to its solubility, it is difficult to effectively prevent the adhesion of polymer scale.

Therefore, the object of the present invention is to polymer scale in the polymerization of vinyl chloride and other monomers having an ethylenically unsaturated double bond having a large solubility such as α-methylstyrene. It is an object of the present invention to provide a novel polymer scale anti-adhesion agent capable of effectively preventing the adhesion of the polymer and a method for producing a polymer using the same.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object, and as a result, have found that a condensation product of an aminonaphthalene compound and a pyrogallol-acetone resin has excellent polymer scale adhesion. It has been found to have a preventive effect. That is, the present invention provides a polymer scale anti-adhesion agent for polymerization of a monomer having an ethylenically unsaturated double bond, which contains the condensation product as an active ingredient.

The present invention also provides a method for producing a polymer, which comprises a step of polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel having a polymer scale anti-adhesion coating film on an inner wall surface. And a method for producing a polymer, wherein the coating film comprises the polymer scale adhesion preventive agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

(Polymer scale anti-adhesion agent) The polymer scale anti-adhesion agent of the present invention comprises an aminonaphthalene compound and pyrogallol-
It contains a condensation product with acetone resin as an active ingredient.

Aminonaphthalene Compound Examples of the aminonaphthalene compound as a raw material for the condensation product include those represented by the general formula (1):

[0010]

Embedded image

(Here, R ¹ is a monovalent atom or group selected from the group consisting of hydrogen atom, carboxyl group, hydroxyl group and methyl group, and R ² is selected from the group consisting of hydrogen atom, amino group and carboxyl group. A monovalent atom or group selected, m is an integer of 1 to 2, and n is an integer of 1 to 4). Examples of the compound of the general formula (1) include β-naphthylamine, 3-amino-2-naphthoic acid, 3-amino-2-naphthol, 5-amino-1-naphthol, 1-amino-2-naphthol, 1 , 5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 4-amino-2-methyl-1-naphthol and the like,
Preferred are 1,5-diaminonaphthalene and 1,8-diaminonaphthalene. These aminonaphthalene compounds may be used alone or in combination of two or more.

Pyrogallol-acetone resin Another source of the condensation product, pyrogallol-acetone resin, is a condensation polymer of pyrogallol and acetone. The amount of the acetone component in the pyrogallol-acetone resin is usually 1 mol of the pyrogallol component.
It may be in the range of 0.1 to 10 mol. The melting point of pyrogallol-acetone resin is usually 100 to 500 ° C, and the higher the molecular weight is, the higher the melting point is. Equivalent to ~ 4000.

This condensation polymer is obtained by dissolving pyrogallol in acetone and condensing it in the presence of a condensation catalyst. The amount of pyrogallol / acetone to be blended may be appropriately determined depending on the molar ratio of pyrogallol and acetone in the desired condensation polymer, and usually 1 to 100 parts by weight of pyrogallol per 100 parts by weight of acetone. The reaction is carried out at room temperature to 100 ° C. Examples of the condensation catalyst include phosphorus oxychloride and the like. In addition, this condensation polymer is a commercially available product [for example, Pyrogallol-Acetone manufactured by Fuji Chemical Industry Co., Ltd.
Resin] may be obtained and used.

Aminonaphthalene compound and pyrogallol-
Condensation Product of Acetone Resin A condensation product of an aminonaphthalene compound and a pyrogallol-acetone resin is obtained by reacting an aminonaphthalene compound and a pyrogallol-acetone resin in the presence of an acidic catalyst.

As the acidic catalyst used in the above reaction,
Specifically, hydrochloric acid, phosphoric acid, nitric acid, sulfuric acid, anhydrous aluminum chloride and the like are exemplified, and among them, hydrochloric acid is preferable. The amount of the acidic catalyst was 0,0 per 1 mol of the aminonaphthalene compound.
The range of 005 to 0.25 mol is preferable, and the range of 0.005 to 0.1 mol is more preferable. The reaction is carried out at 180 to 350 ° C, preferably 180 to 250 ° C, and the reaction time is usually about 2 to 10 hours.

The molar ratio of the aminonaphthalene compound and the pyrogallol-acetone resin used in the reaction is preferably in the range of 1 to 5 mol, more preferably 1.5, in the unit structure of the pyrogallol-acetone resin per mol of the aminonaphthalene compound. The range is from ~ 3.5 mol. In the following description, when the amount of pyrogallol-acetone resin is represented by the number of moles of the structural unit, the number of moles is referred to as "unit mole". If the amount of the pyrogallol-acetone resin is too large with respect to the amount of the aminonaphthalene compound, the obtained condensate has a wide molecular weight distribution and the scale-inhibiting effect is reduced. On the other hand, if the amount is too small, the effect of preventing scale also deteriorates.

The molecular weight of the condensation product is preferably in the range of 3,000 to 30,000, more preferably 3,000 to 15,000. If the molecular weight is too low, the effect of preventing polymer scale adhesion decreases. On the other hand, if the molecular weight is too high, there is a risk of forming a precipitate in the coating liquid when the coating liquid described below is prepared, and as a result of the coating liquid being unstable, a good coating film is formed on the wall surface of the polymerization vessel and the like. Becomes difficult.

Inorganic Colloid An inorganic colloid is preferably added to the polymer scale adhesion preventive agent according to the present invention. By this addition, the effect of preventing polymer scale is further improved. Examples of the inorganic colloid include gold, silver, aluminum hydroxide, ferric hydroxide, stannic acid, silicic acid, barium sulfate, titanium oxide, antimony oxide, antimony sulfide, ferricyanide, iron ferrocyanide, and lithium. Examples include colloids such as silicates. A silicic acid colloid is preferable, and an aqueous silica sol, a methanol silica sol, an ethylene glycol silica sol, a DMF silica sol, and the like are most preferable.
The inorganic colloid is preferably such that the weight ratio of the condensation product / inorganic colloid is in the range of 100/1 to 1/100,
Further, an amount in the range of 10/1 to 1/10 is preferable.

(Method for Producing Polymer Using Polymer Scale Adhesion Preventing Agent) The method for producing a polymer according to the present invention is a polymerization vessel having a coating film comprising the polymer scale adhesion preventing agent on the inner wall of the polymerization vessel or the like. Is a method of polymerizing a monomer having an ethylenically unsaturated double bond to obtain a polymer.

Preparation of Coating Liquid The polymer scale anti-adhesion agent according to the present invention is mainly used for forming a coating film on the inner wall surface of a polymerization vessel or other portions where monomers come into contact with each other during polymerization. Therefore, it is used in the form of a coating liquid. The coating liquid is prepared by dissolving or dispersing the above-mentioned condensation product and, in some cases, an inorganic colloid in a solvent at an appropriate concentration and mixing them. The concentration of the condensation product in the coating liquid is not limited as long as the coating amount after drying described below can be obtained, and is usually 0.01% by weight or more, preferably 0.05 to 5% by weight. If the concentration of the condensation product is too low, it becomes difficult to obtain a desired coating amount on the inner wall surface of the polymerization vessel. On the other hand, although the upper limit of the concentration is not particularly limited, if the concentration is unnecessarily high, it is economically disadvantageous, and in extreme cases, it becomes difficult to form a uniform coating film. When adding an inorganic colloid, its concentration is preferably 0.01% by weight or more,
It is more preferably 0.1 to 5% by weight.

The solvent used for preparing the coating solution is
An organic solvent that is highly compatible with water, such as methyl alcohol,
Examples thereof include alcohols such as ethyl alcohol and allyl alcohol, cellosolve, dimethylformamide, dimethyl sulfoxide, and acetone. You may use these individually by 1 type or in mixture of 2 or more types. Preferred solvents are methyl alcohol, ethyl alcohol and dimethyl sulfoxide.

Further, it is desirable to add an additive to the above-mentioned coating liquid to improve the wettability with the surface to be coated. As this additive, a monohydric alcohol having 3 to 6 carbon atoms is suitable, and for example, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, sec-butyl alcohol, t-butyl alcohol. ， N-
Examples include amyl alcohol, t-amyl alcohol, iso-amyl alcohol, sec-amyl alcohol, and sec-hexyl alcohol. These may be used alone or in combination of two or more. The concentration of the monohydric alcohol in the obtained coating liquid is preferably 1 to 20% by weight, more preferably 1 to 10% by weight. As a result of the increased wettability of the surface to be coated with the coating liquid, a uniform coating film can be formed on the wall surface, and the scale adhesion preventing effect can be further improved.

Formation of coating film To form a coating film on the inner wall surface of the polymerization vessel using the coating solution prepared as described above, first, the coating solution is applied to the inner wall surface of the polymerization vessel, and then, for example, at room temperature. After thoroughly drying in the temperature range from 1 to 100 ° C, further wash with water if necessary.

Further, it is preferable that the coating solution is applied not only to the inner wall surface of the polymerization vessel, but also to other portions with which the monomer contacts during the polymerization. For example, stirring blade, stirring shaft, baffle,
Examples include capacitors, headers, search coils, bolts and nuts. More preferably, the coating solution is a site other than the site where the monomer contacts during the polymerization, but a site where the polymer scale may adhere, for example, the inner surface of the device and piping of the recovery system of the unreacted monomer. For this, it is better to form the coating film. Specifically, a monomer distillation column, a condenser,
Inner surfaces such as a monomer storage tank and a valve are included. In this way, when a coating film is formed on the site where the monomer contacts during the polymerization and the site where the other polymer scale may adhere, the adhesion of the polymer scale to those sites is prevented.

The method of applying the coating solution to the inner wall surface of the polymerization vessel is not particularly limited, and examples thereof include brush coating, spray coating, and the method of withdrawing after filling the polymerization vessel with the coating solution. No. 57-61001, No. 55-3628
No. 8, Special Publication Nos. 56-501116, 56-501117, JP
The automatic coating method described in 59-11303 or the like can also be used.

There is no limitation on the method of drying the wet surface due to the application of the coating liquid, and the following method can be used, for example. After applying the coating solution, a method of applying an appropriately heated warm air to the coating surface, or the inner wall surface of the polymerization vessel and the other surface to be coated with the coating solution are heated in advance to, for example, 30 to 80 ° C. A method of directly applying the coating solution to the heated surface can be used. After drying the coated surface, the coated surface is washed with water as needed. The coating amount of the coating film thus obtained after drying is usually preferably 0.001 to 3 g / m ² .

The above coating operation may be carried out every 1 to 10 or more batches of polymerization. The formed coating film has high durability, and the polymer scale adhesion preventing action continues. Therefore, it is not always necessary to carry out each batch of polymerization. Therefore, productivity is improved.

Polymerization The method of the present invention is applied to the polymerization of a monomer having an ethylenically unsaturated double bond, and examples of this monomer include vinyl halides such as vinyl chloride; vinyl acetate and vinyl propionate. Acrylic acid, methacrylic acid and their esters or salts; Maleic acid, fumaric acid and their esters or anhydrides; Diene-based monomers such as butadiene, chloroprene, isoprene; Styrene, acrylonitrile, vinylidene halide , Vinyl ether and the like. As an example in which the method of the present invention is particularly preferably carried out, vinyl halide such as vinyl chloride or vinylidene halide or a monomer mixture containing them as a main component by suspension polymerization or emulsion polymerization in an aqueous medium is used. There is manufacturing of coalescence. Further, the coating film formed by the method of the present invention has high durability against a monomer having a high solubility in conventional coating films such as α-methylstyrene, acrylic acid ester, acrylonitrile, and vinyl acetate. Therefore, polymer beads such as polystyrene, polymethacrylate and polyacrylonitrile, production of latex, production of synthetic rubber such as SBR, NBR, CR, IR and IIR (these synthetic rubbers are usually produced by emulsion polymerization). , ABS resin can also be suitably carried out.

In polymerizing one or more of these monomers, an emulsifier, a stabilizer, a lubricant, a suspension polymerization, an emulsion polymerization, a bulk polymerization, a solution polymerization, etc.
Even in the presence of any additive such as a plasticizer, a pH adjuster and a chain transfer agent, the purpose of scale prevention is effectively achieved. For example, in the case of suspension polymerization or emulsion polymerization of vinyl-based monomers, the additives added to the polymerization system are partially saponified polyvinyl alcohol, suspending agents such as methyl cellulose, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, dioctylsulfosuccinic acid. Anionic emulsifiers such as sodium, sorbitan monolaurate, nonionic emulsifiers such as polyoxyethylene alkyl ether, stabilizers such as tribasic lead sulfate, calcium stearate, dibutyltin dilaurate, dioctyltin mercaptide, life wax, stearic acid, etc. Even in a polymerization system in which a lubricant, a plasticizer such as DOP and DBP, a chain transfer agent such as trichloroethylene and mercaptans, and a pH adjuster are present, scale adhesion can be effectively prevented.

The characteristics of the present invention are not affected by the type of polymerization catalyst, and a remarkable polymer scale adhesion preventing effect is exhibited regardless of which catalyst is used. In particular,
t-butyl peroxy neodecanoate, bis (2-ethylhexyl) peroxydicarbonate, 3,5,5-trimethylhexanoyl peroxide, α-cumylperoxy neodecanoate, cumene hydroperoxide, cyclohexanone per Oxide, t-butylperoxypivalate, bis (2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, diisopropylbenzene hydroperoxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropylperoxydioxide Carbonate,
Examples include α, α′-azobisisobutyronitrile, α, α′-azobis-2,4-dimethylvaleronitrile, di-2-ethylhexyldiperoxyisophthalate, potassium persulfate and ammonium persulfate.

The general polymerization method will be specifically described below by taking the cases of suspension polymerization, emulsion polymerization and bulk polymerization as examples.

First, water and a dispersant are charged into a polymerization vessel, and then a polymerization initiator is charged. Next, exhaust the inside of the polymerization vessel.
After reducing the pressure to 0.1 to 760 mmHg (0.01 to 101 kPa), the monomer was charged (at this time, the internal pressure of the polymerization vessel is usually 0.1
5 to 30 kgf / cm ² · G (35 to 3040 kPa)], and then polymerize at a reaction temperature of 30 to 150 ° C. During the polymerization, if necessary, 1 of water, a dispersant and a polymerization initiator is added.
Seed or two or more types are added. The reaction temperature during polymerization depends on the type of monomer to be polymerized.For example, in the case of vinyl chloride polymerization, the reaction temperature is 30 to 80 ° C, and in the case of styrene polymerization, the polymerization temperature is 50 to 150 ° C. To do. For polymerization, the internal pressure of the polymerization vessel is 0 to 7 kgf / cm ² · G (100 to 790 kP
When the temperature falls to a), or when there is almost no difference between the inlet temperature and the outlet temperature of the cooling water that flows in and out of the jacket installed on the outer circumference of the polymerization vessel (that is, when the heat generated by the polymerization reaction disappears). , Judged to be completed.
Water, a dispersant and an initiator charged during the polymerization are usually
20 to 500 parts by weight of water to 100 parts by weight of monomer, dispersant
0.01 to 30 parts by weight and 0.01 to 5 parts by weight of polymerization initiator.

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

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

[0035]

The present invention will be described in more detail by way of examples. Note that the experiment No. Those marked with * are comparative examples that do not satisfy the conditions of the present invention, and other examples are examples.

[Preparation Example 1] (Preparation of condensation product) 15.8 g (0.1 mol) of 1,5-diaminonaphthalene, 58.4 g (0.35) of pyrogallol-acetone resin (molecular weight: about 1600)
(Unit mol) and 1.04 g (0.01 mol) of 35% hydrochloric acid were charged into the reactor, and the mixture was heated to 200 ° C. and stirred at the same temperature for 2 hours. After completion of the reaction, the obtained molten material was dissolved in 400 mL of dimethylformamide, and the obtained solution was poured into dilute hydrochloric acid to precipitate a condensation product. After the condensation product was filtered, it was washed with water three times to remove hydrochloric acid and unreacted components from the condensation product. Then, it dried and the condensation product was obtained.

When the obtained condensation product was analyzed by gel permeation chromatography (hereinafter referred to as GPC), the weight average molecular weight was 10,000. GPC
The measurement conditions were as follows. Column: GPC-802D, GPC-803D Shimadzu styrene-divinylbenzene copolymer spherical porous gel Carrier: LiBr / DMF = 10 mmol / L Flow rate: 1.0 mL / min Detector: UV absorption spectrum 290 nm

[Preparation Examples 2 to 6] (Preparation of Condensation Products) The aminonaphthalene compound (a) shown in Table 1 and pyrogallol-acetone resin (b) were reacted at the molar ratio and reaction temperature shown in Table 1. A condensation reaction was performed in the same manner as in Preparation Example 1 except that the condensation product was obtained. The weight average molecular weight of each condensation product was measured in the same manner as in Preparation Example 1. Table 1 shows the conditions and results of Preparation Examples 1 to 6.

[0039]

[Table 1]

[Example 1] (Polymerization Example of Vinyl Chloride) In each experiment, one of the condensation products prepared in Preparation Examples 1 to 6 (A) and the inorganic colloid (B) is in the proportion shown in Table 2. To a total concentration of 0.1% by weight with respect to the solvent (D) of the coating solution, and then add C ₃ -C ₆ monohydric alcohol (C) to (C) /
(D) A coating liquid was prepared by adding it so that the weight ratio was 5/95. However, in Experiment No. 104 *, which is a comparative example, a coating solution was prepared without using the condensation product. These coating solutions are applied to the inner wall of a stainless steel polymerization vessel equipped with a stirrer with an internal volume of 100 L, the stirrer and other parts where the monomer contacts, heated at the temperature shown in the same table, dried and washed with water to form a coating film. did. However, in Experiment No. 101 *, which is a comparative example, the coating film was not formed.

28 kg of vinyl chloride monomer, 52 kg of water, 8 g of partially saponified polyvinyl alcohol, and 8 g of α, α'-2,4-dimethylvaleronitrile were charged into the polymerization vessel having the coating film thus formed and stirred. While carrying out the polymerization at an internal temperature of 57 ° C for 10 hours. This polymerization operation was defined as 1 batch, and the above polymerization was repeated 3 batches without applying the coating liquid.
However, in Experiment No. 101 * and Experiment No. 104 *, which are comparative examples, only one batch was polymerized. After the polymerization was completed, the amount of polymer scale adhesion (g / m ² ) was measured by the following measuring method. Table 2 shows the results.

Polymer scale measurement method : As much as the scale adhering to an area of 10 cm square can be visually confirmed, after scraping off with a stainless spatula and weighing,
The measured value was multiplied by 100 to obtain the scale adhesion amount per 1 m ² .

[0043]

[Table 2]

[Example 2] (Example of polymerization of AS) In each experiment, one of the condensation products prepared in Preparation Examples 1 to 4 (A) and the inorganic colloid (B) were used in the proportions shown in Table 3. The coating solution was added to the solvent (D) to a total concentration of 0.5% by weight, and C _{3 to} C ₆ monohydric alcohol (C) was added in the weight ratio [(C) / (D)] shown in Table 3. Was added to prepare a coating solution. This coating solution is applied to the inner wall of a stainless steel polymerization vessel with a stirrer having an internal volume of 100 L, the stirrer and other portions where the monomer contacts, heated at the temperature shown in the same table, dried and washed with water to form a coating film. did. However, Experiment No. 201 *, which is a comparative example
No coating film forming treatment was performed.

35 kg of water, 675 g of hydroxyapatite, 13.5 g of sodium lauryl sulfate, 100 g of t-dodecyl mercaptan and 135 g of lauroyl peroxide were charged in the polymerization vessel having the coating film thus formed. next,
Separately, a mixture of 20 kg of styrene and 13.5 kg of acrylonitrile was prepared, and this mixture was charged in the polymerization vessel.
Then, after raising the temperature to 70 ° C., the mixture was stirred at the same temperature for 1 hour.
Further, the temperature was raised to 80 ° C. over 2 hours, and then polymerization was carried out at the same temperature for 5 hours. After the completion of polymerization, the amount of polymer scale adhesion (g / m ² ) was measured in the same manner as in Example 1. The results are shown in Table 3.

[0046]

[Table 3]

[Example 3] (Example of polymerization of ABS resin) In each experiment, one of the condensation products (A) and the inorganic colloid (B) prepared in Preparation Examples 1 to 5 is shown. In a proportion shown in Table 4, a total concentration of 1.0% by weight was added to the solvent (D) of the coating solution, and C _{3 to} C ₆ monohydric alcohol (C) was added in the weight ratio [(C) shown in Table 4]. / (D)],
A coating liquid was prepared. This coating solution was applied to the inner wall of a glass-lined polymerization vessel with a stirrer having an internal volume of 100 L, the stirrer and other parts in contact with the monomer, and dried by heating under the conditions shown in the same table, followed by washing with water, A coating film was formed. However, in Experiment No. 301 *, the coating film was not formed.

In the polymerization vessel thus formed with the coating film, 14.3 kg of polybutadiene latex (solid content concentration: 45% by weight), 44 kg of water, 550 g of sodium oleate, 9 kg of styrene, 5.5 kg of acrylonitrile, t-dodecyl were used. 45g mercaptan and 15 cumene hydroperoxide
After charging 4 g and raising the internal temperature to 65 ° C with stirring,
220 g of glucose, 2.2 g of ferrous sulfate and 110 g of sodium pyrophosphate were charged and reacted at 65 ° C. for 5 hours to produce a polymer. After the completion of polymerization, the amount of polymer scale adhesion (g / m ² )
Was measured in the same manner as in Example 1. The results are shown in Table 4.

[0049]

[Table 4]

[0050]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to effectively prevent the adhesion of the polymer scale on the inner wall of the polymerization vessel, the stirrer and the like where the monomer having an ethylenically unsaturated double bond contacts. . This effect is exhibited regardless of the type of monomer, the composition of the polymerization system, the type of polymerization catalyst, etc. in the polymerization system such as suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization and the like. It is possible to effectively prevent the scale from adhering even in the polymerization of a monomer having a large solubility such as α-methylstyrene, which has been difficult to prevent from adhering to the polymer scale.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiya Aragaki No. 1 Towada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture Shin-Etsu Chemical Co., Ltd.

Claims (3)

[Claims] 1. A polymer scale anti-adhesion agent for the polymerization of a monomer having an ethylenically unsaturated double bond, which comprises as an active ingredient a condensation product of an aminonaphthalene compound and pyrogallol-acetone resin. 2. The polymer scale anti-adhesion agent according to claim 1, which further contains an inorganic colloid. 3. A method for producing a polymer, which comprises a step of polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel having a polymer scale adhesion-preventing coating film on an inner wall surface thereof. A method for producing a polymer, wherein the film comprises the polymer scale adhesion preventing agent according to claim 1.