JPH06206909A - Preventing agent for deposition of polymer scale and production of polymer using the same - Google Patents

Abstract

PURPOSE:To obtain a preventing agent, composed of an alkaline solution containing a condensate of hydroxynaphthalene with an aldehyde and an inorganic colloid and capable of preventing polymer scales of a monomer having an ethylenically unsaturated double bond from depositing in a polymerizer and providing colorless moldings. CONSTITUTION:This preventing agent comprises an alkaline solution containing a condensate of a hydroxynaphthalene compound with an aldehyde compound and an inorganic colloid. Furthermore, a water-soluble polymeric compound is contained therein. The preventing agent is present as a film in a polymerizer for a monomer having an ethylenically unsaturated double bond to carry out the reaction. 1-Naphthol, 1,4-dihydroxynaphthalene, etc., and formaldehyde, etc., are converted into the condensate. Oxides, etc., of aluminum or titanium are used as the inorganic colloid. The pH of this preventing agent is 11-13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer scale adhesion preventive agent for polymerizing a monomer having an ethylenically unsaturated double bond and a method for producing a polymer using the same.

[0002]

2. Description of the Related Art Conventionally, as a method for polymerizing a monomer having an ethylenically unsaturated double bond, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, a gas phase polymerization method, a bulk polymerization method and the like are known. ing. In any of these polymerization methods, the polymer scale is likely to adhere to the inner wall of the polymerization vessel, the agitator, and the like where the monomer contacts.

When the polymer scale adheres, the yield of the polymer, the cooling capacity of the polymerization vessel and the like decrease, and the polymer scale peels off and is mixed into the polymer. As a result, the polymer is molded. This has the disadvantage of reducing the quality of the resulting molding. Further, in order to remove the adhered polymer scale, not only excessive labor and time are required, but also unreacted monomer is contained in this polymer scale, which is a very serious problem in recent years. There is a risk of human injury due to the monomer.

As for the prevention of adhesion of the polymer scale to the inner wall of the polymerization vessel, the polarities of amine compounds, quinone compounds, aldehyde compounds, etc. have been used, as has been carried out, for example, in suspension polymerization of vinyl chloride. A method of applying a polymer scale anti-adhesion agent composed of an organic compound to the inner wall of a polymerization vessel to form a coating film, and a method of adding these compounds to an aqueous medium in which suspension polymerization is carried out are known (Japanese Patent Publication No. 45). -30343). However, although these methods show a polymer scale adhesion preventing effect when repeating polymerization up to about 5 to 6 batches, when the number of polymerization batches is larger than that, the preventing effect is lost (inferior in sustainability). There is a disadvantage. This point is not particularly industrially satisfactory because the effect is remarkable when a water-soluble catalyst is used in the polymerization.

In order to overcome this disadvantage, for example, a condensation product of an aromatic amine compound and an aromatic nitro compound (Japanese Patent Publication No. 60-30681), a reaction product of a phenolic compound and an aromatic aldehyde (special (Kaisho 57-192414), reaction products of polyhydric phenols and aliphatic aldehydes (Japanese Patent Publication No. 57-502169), reaction products of 1-naphthol and formaldehyde (Japanese Patent Publication No. 01-31523). ) Or the like as an active ingredient, a polymer scale adhesion preventive agent is applied to the inner wall of the polymerization vessel. When these polymer scale anti-adhesion agents are applied to the portions of the inner wall of the polymerization vessel where the monomers come into contact with each other to form a coating film, the polymerization will be 100 to 20
0 Even if it is repeated about a batch, polymer scale does not adhere to the liquid phase part in the polymerization vessel. Also, when the water-soluble catalyst is used, the polymer scale adhesion in the liquid phase part is similarly prevented.

[0006]

However, even if a coating film of a polymer scale anti-adhesion agent containing the condensation product of the above-mentioned aromatic amine compound and aromatic nitro compound as an active ingredient is formed, the polymerization reactor There is a drawback that polymer scale adheres to the vicinity of the interface between the gas phase and the liquid phase located in the upper layer portion of the inside.
Once the polymer scale adheres near the interface between the gas phase and the liquid phase, the polymer scale that adheres gradually grows as the polymerization is repeated, and finally it peels off and mixes into the polymer. There is. When the polymer scale is mixed with the polymer in this way, when the polymer is processed into a molded product such as a sheet, many fish eyes are generated in the molded product, and the quality of the molded product is significantly deteriorated. become.

When the polymer obtained by polymerization is molded into a sheet or the like, the molded product obtained is required to have high whiteness. That is, even if the polymer is molded into a sheet or the like without adding any coloring agent, the obtained molded product is colored to some extent, but this coloring is called initial coloring, and it is desired that the coloring is as small as possible. However, when a coating film of a polymer scale anti-adhesive agent containing the condensation product of an aromatic amine compound and an aromatic nitro compound as an active ingredient is formed, the coating film peels or dissolves to form a polymer. Since it may be mixed, the whiteness of the molded product is lowered, that is, the initial colorability is deteriorated.

An object of the present invention is to effectively polymerize a monomer having an ethylenically unsaturated double bond not only in the liquid phase part in the polymerization vessel but also in the vicinity of the interface between the gas phase and the liquid phase. A polymer capable of preventing adhesion of polymer scale and, when formed into a sheet or the like, having a very small number of fish eyes, and capable of producing a polymer having a good initial colorability, capable of producing a polymer An object of the present invention is to provide a scale adhesion preventive agent and a method for producing a polymer using the preventive agent.

[0009]

The present invention provides an alkaline solution containing (A) a condensation product of (A-1) a hydroxynaphthalene compound and (A-2) an aldehyde compound, and (B) an inorganic colloid. Consists of,
Provided is a polymer scale anti-adhesion agent for polymerizing a monomer having an ethylenically unsaturated double bond.

The present invention also provides a method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein (A) (A-1) hydroxy A naphthalene compound and (A-2) a condensation product of an aldehyde compound, and (B) an alkaline solution containing an inorganic colloid is applied,
There is provided a production method having a step of performing the above-mentioned polymerization in a polymerization vessel having a coating film formed by drying, thereby preventing adhesion of a polymer scale in the polymerization vessel. Hereinafter, the present invention will be described in detail.

(A) Condensation Product (A-1) Hydroxynaphthalene Compound The hydroxynaphthalene compound (A-1) is, for example, a compound represented by the following general formula (1).

[0012]

[Chemical 1] (In the formula, R ¹ is a group selected from the group consisting of —H, —SO ₃ H and —COOH, and when plural R ^1's are present, they may be the same or different. I is 1 to 1 4 is an integer, and j is an integer of 0 to 4.)

Specific examples of the compound represented by the above general formula (1) include 1-naphthol, 2-naphthol, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene,
1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 3,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,2,3-trihydroxynaphthalene, 1,4,5,
8-tetrahydroxynaphthalene, 1-naphthol-2-sulfonic acid, 1-naphthol-4-sulfonic acid, 2-naphthol-6
Examples include sulfonic acid and 1-naphthol-4-carboxylic acid. Preferred among these are 1-naphthol, 1,
4-dihydroxynaphthalene, 1,2,3-trihydroxynaphthalene, 1,4,5,8-tetrahydroxynaphthalene and 1-naphthol-4-sulfonic acid. The above hydroxynaphthalene compound (A-1) can be used either alone or in combination of two or more.

(A-2) Aldehyde Compound The aldehyde compound (A-2) is an organic compound having at least one aldehyde group (—CHO group), preferably 1 to 2. The aldehyde compound is, for example, a compound represented by the following general formulas (2) to (4). R ² —CHO (2) (In the formula, R ² is a group selected from —H, —COOH, —CHO, and a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms.)

[0015]

[Chemical 2] (In the formula, R ³ is a group selected from the group consisting of —H and —OH, and when plural R ³ are present, they may be the same or different. M is an integer of 1 to 6. )

[0016]

[Chemical 3] (In the formula, R ⁴ is a group selected from the group consisting of —H and an alkyl group having 1 to 5 carbon atoms, and when a plurality of R ⁴ are present, they may be the same or different. N is 1 ~ 4
Is an integer. )

Specific examples of the compound represented by the above general formula (2) include formaldehyde, acetaldehyde, glyoxylic acid and glyoxal.
Specific examples of the compound represented by the general formula (3) include benzaldehyde, salicylaldehyde, and phthalaldehyde. The compound represented by the general formula (4), specifically, furfural, 5-methyl-2
-Furaldehyde and the like are exemplified. Preferred among these are formaldehyde, glyoxylic acid, benzaldehyde, salicylaldehyde and furfural. The above aldehyde compounds (A-2) may be used alone or in combination of 2
It is also possible to use a combination of two or more species.

Production of Condensation Product (A) The condensation product (A) is obtained by condensing the hydroxynaphthalene compound (A-1) and the aldehyde compound (A-2). The condensation of the hydroxynaphthalene compound (A-1) and the aldehyde compound (A-2) is usually carried out in water in the presence of a catalyst at 50
~ 150 ℃ 1 ~ 20 hours, preferably 60 ~ 90 ℃ 2 ~ 10
It is carried out by reacting for a time. Examples of the catalyst include acid catalysts such as phosphoric acid, sulfuric acid and hydrochloric acid, and NaO.
Base catalysts such as H, KOH, LiOH and NH ₃ can be mentioned.

The proportions of the hydroxynaphthalene compound (A-1) and the aldehyde compound (A-2) used in the production of the condensation product (A) are the same as those of the components (A-1), (A-2) and Although it is affected by the type of catalyst, reaction temperature, reaction time, etc., it is preferable that the amount of the component (A-2) is 0.1 to 10 mol, and more preferably 0.3 to 3 mol, per mol of the component (A-1). Preferably. (A-
2) If the amount of the component is too large or too small, the polymer scale adhesion-preventing effect when the obtained condensation product (A) is used as a polymer scale adhesion-preventing agent is lowered. The amount of the above catalyst used is not particularly limited, but is usually 0.1 to 10 mol, preferably 0.5 to 5 mol, per 1 mol of the hydroxynaphthalene compound (A-1).

(B) Inorganic Colloid Inorganic colloid (B) is a particle colloid produced by a dispersion method using water as a dispersion medium or a condensation method, and the size of the colloid particles is 1 to 500 mμ. Specific examples of the inorganic colloid include colloids of oxides and hydroxides of metals selected from the group consisting of aluminum, thorium, titanium, zirconium, antimony, tin, iron, etc .; tungstic acid, vanadium pentoxide, gold. And silver colloid; silver iodide sol; colloids of selenium, sulfur, silica and the like. Among these, preferred are colloids of oxides and hydroxides of metals selected from the group consisting of aluminum, titanium, zirconium, tin and iron, and colloidal silica. The above inorganic colloid (B) is 1
They can be used alone or in combination of two or more.

Preparation of Polymer Scale Anti-Adhesive Agent The polymer scale anti-adhesive agent of the present invention comprises an alkaline solution containing the condensation product (A) and the inorganic colloid (B) described above. The polymer scale adhesion preventive agent is applied to the inner wall surface of the polymerization vessel or the like, and dried to form a coating film, whereby the polymer scale adhesion to the inner wall of the polymerization vessel or the like can be prevented.

The polymer scale anti-adhesive is, for example, prepared by adding an aqueous medium to the condensation product (A) and the inorganic colloid (B) and mixing them, and then adjusting the pH of the resulting mixed solution to be alkaline. It is prepared by

When the condensation product (A) used for preparing the polymer scale anti-adhesion agent is produced by using a base catalyst, the condensation product (A) after completion of the condensation reaction is included. The condensation reaction liquid is alkaline. Therefore, the reaction solution can be used as it is for the preparation of the polymer scale deposition inhibitor. On the other hand, when the condensation product (A) is produced using an acid catalyst, the solvent of the obtained condensation reaction solution is removed, the condensation product (A) is washed, and the pressure is reduced at a low temperature. The dried product is used for preparing a polymer scale anti-adhesion agent.

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

The pH of the polymer scale adhesion preventive agent is alkaline, preferably 9 to 14, and more preferably 11 to 13. Further, as the alkaline compound used for adjusting the pH, for example, NaOH, KOH, Li
OH, NH _{3 and the} like can be mentioned.

The content ratio of the component (B) in the polymer scale adhesion preventive agent is usually 0.1 to 10 per 100 parts by weight of the component (A).
The amount is 00 parts by weight, preferably 1 to 600 parts by weight.
If the amount of the component (B) is too large or too small as compared with the amount of the component (A), the effect of preventing adhesion of polymer scale may not be obtained.

Further, in order to further improve the polymer scale adhesion preventing effect, it is preferable to add (C) a water-soluble polymer compound to the above inhibitor.

(C) Water-Soluble Polymer Compound As the water-soluble polymer compound (C), for example, gelatin,
Amphoteric polymer compounds such as casein; for example, anionic polymer compounds such as polyacrylic acid, polystyrene sulfonic acid, carboxymethyl cellulose, alginic acid; and cationic nitrogen-containing polymer compounds such as polyvinylpyrrolidone, chitosan, polyacrylamide; Examples thereof include hydroxyl group-containing polymer compounds such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, and pectin. Among the above water-soluble polymer compounds (C), preferred are gelatin, casein, polyacrylic acid, carboxymethylcellulose, polyvinylpyrrolidone and pectin. The above water-soluble polymer compound (C) can be used alone or in combination of two or more. The content ratio of the component (C) is usually 0.1 to 1000 parts by weight, preferably 1 to 300 parts by weight, per 100 parts by weight of the component (A).

The total concentration of the component (A) and the component (B) in the polymer scale anti-adhesion agent is not particularly limited as long as the total coating amount described below can be obtained, but it is usually about 0.005 to 10% by weight, and preferably Is about 0.03 to 2.0% by weight. Also,
(A) component, (B) component and (C) when (C) component is added
The total concentration of the components is preferably about 0.005 to 10% by weight, more preferably about 0.03 to 2.0% by weight.

Formation of Coating Film In order to form a coating film on the inner wall surface of the polymerization vessel by using the polymer scale adhesion preventing agent prepared as described above, first, the inhibitor is applied to the inner wall surface of the polymerization vessel. Then, after sufficiently drying in a temperature range from room temperature to 100 ° C., for example, further washing with water is carried out.

Further, the polymer scale adhesion preventive agent is
It is preferable to apply not only to the inner wall surface of the polymerization vessel, but also to other portions where the monomer contacts during the polymerization. For example, a stirring blade,
Examples include stirring shafts, baffles, condensers, headers, search coils, bolts and nuts. More preferably,
The polymer scale anti-adhesive agent is a site other than the site where the monomer contacts during the polymerization, but the site where the polymer scale may adhere, for example, the inner surface of the equipment and piping of the recovery system of the unreacted monomer. For example, it is better to form the coating film. Specific examples include inner surfaces of a monomer distillation column, a condenser, a monomer storage tank, a valve, and the like.

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

There is no limitation on the method for drying the wet surface due to the application of the polymer scale anti-adhesion agent. For example, the following method can be used. That is, after the application of the polymer scale anti-adhesive agent, a method of applying an appropriately heated hot air to the application surface, or the inner wall surface of the polymerization vessel and the other surface to which the polymer scale anti-adhesion agent is applied are preliminarily set to, for example, 30 It is possible to use a method in which the polymer scale adhesion preventive agent is directly applied to the heated surface by heating to -80 ° C. After drying the coated surface, the coated surface is washed with water as needed.

The coating film thus obtained has a total coating amount after drying of usually 0.001 to 5 g / m ² ,
The range of 0.05 to ² g / m ² is particularly preferable. The coating operation described above does not necessarily have to be performed for each batch of polymerization, because the formed coating film has high durability and the polymer scale adhesion preventing action continues. Therefore, productivity is improved.

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

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

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

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

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

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

When polymerization is carried out by applying the method of the present invention, the adhesion of polymer scale can be prevented regardless of the material of the inner wall surface of the polymerization vessel. For example, a glass lined polymerization vessel or the like can be used. Of course, the adhesion of the polymer scale can be prevented even when the polymerization is carried out in a stainless steel or other steel polymerization vessel.

The substances added to the polymerization system can be used without any restrictions. That is, for example, t-
Butyl peroxy neodecanoate, bis (2-ethylhexyl) peroxydicarbonate, 3,5,5-trimethylhexanoyl peroxide, α-cumylperoxy neodecanoate, cumene hydroperoxide,
Cyclohexanone peroxide, t-butyl peroxypivalate, bis (2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate,
Polymerization initiators such as α, α′-azobisisobutyronitrile, α, α′-azobis-2,4-dimethylvaleronitrile, potassium peroxodisulfate, ammonium peroxodisulfate and p-menthane hydroperoxide; Partially saponified polyvinyl alcohol, polyacrylic acid, copolymers of vinyl acetate and maleic anhydride, cellulose derivatives such as hydroxypropylmethyl cellulose, and suspending agents such as natural or synthetic polymer compounds such as pyrogallol-acetone resin; for example, calcium phosphate, Solid dispersants such as hydroxyapatite; for example, nonionic emulsifiers such as sorbitan monolaurate, sorbitan trioleate, polyoxyethylene alkyl ethers;
Anionic emulsifiers such as sodium alkylbenzene sulfonate such as sodium lauryl sulfate and sodium dodecylbenzene sulfonate, sodium dioctyl sulfosuccinate; fillers such as calcium carbonate, titanium oxide; tribasic lead sulfate, calcium stearate, dibutyl Stabilizers such as tin dilaurate, dioctyl tin mercaptide; lubricants such as rice wax, stearic acid, cetyl alcohol; DOP, DBP
Plasticizers such as; mercaptans such as t-dodecyl mercaptan; chain transfer agents such as trichlorethylene; pH
Even in a polymerization system in which a regulator or the like is present, the method of the present invention can effectively prevent the adhesion of polymer scale.

The polymer scale adhesion preventive agent of the present invention can also be added to the polymerization medium. In that case, for example, a polymer scale adhesion inhibitor may be used in the coating treatment, and then the inhibitor may be added in a small amount to the polymerization medium. In this case, the scale prevention effect is improved as compared with the case where only the coating process is performed. In addition, when such a polymer scale anti-adhesion agent in a solution state is added to the polymerization medium, the addition amount is 5 to 1000 ppm with respect to the total weight of the charged monomers having an ethylenically unsaturated double bond. The range should be

[0044]

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

Production of Condensation Product No. 1 In a 2-liter three-neck separable flask equipped with a reflux condenser, a thermometer, and a stirrer, water (1 liter) and hydroxynaphthalene compound (A-1) as 1, 4,5,8-Tetrahydroxynaphthalene (1 mol), formaldehyde (1.2 mol) as the aldehyde compound (A-2), and phosphoric acid (1 mol) as the catalyst were added. Subsequently, while the flask was heated to 85 ° C. in an oil bath, the reaction mixture in the flask was stirred under a nitrogen stream for 5 hours to carry out a reaction, and then cooled. Next, the solvent of the cooled reaction mixture was removed, the residue was washed, and dried under reduced pressure at 50 ° C. In this way, condensation product No. 1
was gotten.

Production of Condensation Products Nos. 2 to 10 Condensation products Nos. 2 to 10 are shown in Table 1 (A-1).
Condensation product using component (hydroxynaphthalene compound), (A-2) component (aldehyde compound), catalyst and solvent
It was manufactured by the same method as No.1. Table 1 shows the total concentration of (A-1) + (A-2) + catalyst, (A-1) :( A-2): catalyst molar ratio, reaction temperature and reaction time in each production. The condensation product No. 2
Is a condensation product described in JP-B-01-31523, Example 1.

[0047]

[Table 1]

Example 1 (Experiment Nos. 101 to 114) In each experiment, a stainless steel polymerization vessel equipped with a stirrer and having an internal volume of 2000 liters was used as the polymerization vessel. In each experiment, the conditions shown in Table 2 ((A) + (B) + (C) total concentration, (A):
(B) :( C) weight ratio, solvent composition and pH)
A polymer scale anti-adhesive agent was prepared using the condensation product (A), the inorganic colloid (B), the water-soluble polymer compound (C), the solvent and the alkaline compound shown in (1). The inorganic colloids (a to g in Tables 2 and 5) used in Example 1 and Example 2 below are as shown in Table 4. These polymer scale anti-adhesion agents are applied to the inner wall of the polymerization vessel and the stirring shaft, stirring blades and other portions where the monomers come into contact during the polymerization, heated at 50 ° C for 15 minutes and dried to form a coating film, and then the polymerization. The inside of the vessel was washed with water.

Then, in each experiment, polymerization was carried out as follows. 800 kg of water, 400 kg of vinyl chloride, 500 g of partially saponified polyvinyl alcohol, 50 g of hydroxypropylmethyl cellulose and 140 g of 3,5,5-trimethylhexanoyl peroxide are placed in the polymerization vessel in which the coating film has been formed by the above coating treatment. Charge and stir at 66 ° C for 6
Polymerized for hours. After the polymerization was completed, the produced polymer and unreacted monomer were recovered, and the inside of the polymerization vessel was washed with water to remove the residual resin.

The operation from the formation of the coating film through the polymerization to the washing of the inner wall of the polymerization vessel with water was defined as one batch, and the same operation was repeated for the number of batches shown in Table 3. For each experiment, the amount of polymer scale attached to the liquid phase in the polymerization vessel and the amount of polymer scale attached near the interface between the gas phase and the liquid phase were measured by the following methods after the end of the final batch. The results are shown in Table 3. -Measurement of the amount of polymer scale adhered The scale adhered to a 10 cm x 10 cm area at a predetermined location on the inner wall of the polymerization vessel was completely scraped off as much as possible with a spatula made of stainless steel with the naked eye, and weighed with a balance. . The measured value was multiplied by 100 to determine the amount of polymer scale attached per 1 m ² .

Further, the number of fish eyes when the polymer obtained in each experiment was molded into a sheet was measured by the following method. The results are shown in Table 3. Measurement of fish eye 100 parts by weight of polymer, 50 parts by weight of dioctyl phthalate (DOP), 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 were prepared. The mixture was kneaded with a 6-inch roll at 150 ° C. for 7 minutes, formed into a sheet having a thickness of 0.2 mm, and the number of fish eyes contained in 100 cm ^{2 of the} obtained sheet was examined by a light transmission method.

Further, in order to evaluate the initial colorability when the polymer obtained in each experiment was molded into a sheet, the lightness index was used.
(L value) was measured by the following method. The results are shown in Table 3. -Measurement of lightness index (L value) 100 parts by weight of the obtained polymer, 1 part by weight of tin laurate-based stabilizer (TS-101 manufactured by Akishima Chemical Co., Ltd.), cadmium-based stabilizer (C-Katsuda Kako Co., Ltd. 100 J) 0.5 part by weight and 50 parts by weight of dioctyl phthalate as a plasticizer are kneaded in a two-roll mill at 160 ° C. for 5 minutes, and then a sheet having a thickness of 1 mm is formed. Next, the molded sheet is put in a 4 × 4 × 1.5 cm frame and heated and pressure molded at 160 ° C. and 65 to 70 kgf / cm ² for 0.2 hours to prepare a measurement sample. JIS for this sample
The lightness index L in the Hunter color difference formula described in Z 8730 (1980) was determined, and the larger the L value, the higher the whiteness, that is, the better the initial colorability. The L value is obtained as follows. Standard light C, photoelectric colorimeter (Nippon Denshoku Industries Co., Ltd., Z-1001DP colorimetric color difference meter) according to JIS Z 8722
Using the stimulus value direct reading method, the stimulus value Y in the XYZ color system
Ask for. The geometric conditions for illumination and light reception are JIS
The condition d described in Section 4.3.1 of Z 8722 was adopted. From the obtained stimulation value Y, the formula described in JIS Z 8730 (1980): L = 10
The L value is calculated from Y ^1/2 .

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

Example 2 (Experiment Nos. 201 to 207) In each experiment, a stainless steel polymerization vessel with an internal volume of 20 liter and equipped with a stirrer was used as the polymerization vessel. In each experiment,
Conditions shown in Table 5 ((A) + (B) + (C) total concentration, (A) :( B):
(C) Weight, solvent composition ratio and pH) are adjusted by using the condensation product (A), inorganic colloid (B), water-soluble polymer compound (C), solvent and alkaline compound shown in Table 5. A polymer scale anti-sticking agent was prepared. These polymer scale anti-adhesion agents are applied to the inner wall of the polymerization vessel and the stirring shaft, stirring blades and other portions where the monomers come into contact during the polymerization, heated at 50 ° C for 15 minutes and dried to form a coating film, and then the polymerization. The inside of the vessel was washed with water.

Next, in each experiment, polymerization was carried out as follows. Into the polymerization vessel where the coating film was formed by applying the coating as described above, 9 kg of water, 225 g of sodium dodecylbenzenesulfonate, 12 g of t-dodecyl mercaptan and 13 g of potassium peroxodisulfate were charged, and the inside of the polymerization vessel was replaced with nitrogen gas. After that, 1.3 kg of styrene and 3.8 kg of butadiene
Was charged and polymerized at 50 ° C. for 20 hours. After the polymerization was completed, the produced polymer and unreacted monomer were recovered, and the inside of the polymerization vessel was washed with water to remove the residual resin. The operation from the formation of the coating film through the polymerization to the washing in the polymerization vessel as described above was defined as one batch, and the same operation was repeated for the number of batches shown in Table 6. For each experiment, the amount of polymer scale attached to the liquid phase portion in the polymerization vessel and the amount of polymer scale attached near the interface between the gas phase and the liquid phase were measured by the same method as in Example 1 after the end of the final batch. The results are shown in Table 6.

The lightness index (L value) was measured by the following method in order to evaluate the initial colorability when the polymer obtained in each experiment was molded into a sheet. The results are shown in Table 6. -Measurement of lightness index (L value) To 1 kg of the obtained polymer latex, 1 kg of a 2% magnesium sulfate solution was added to perform coagulation precipitation, and then the precipitate was filtered off. The precipitate separated by filtration was washed with hot water at 80 to 90 ° C. for 2 to 3 times and then dried at 40 ° C. for 25 hours using a vacuum dryer to obtain a resin. The obtained resin is put in a mold of 9 × 9 cm, depth of 0.1 cm, heated at 195 ° C. at 50-60 kgf / cm ² for 0.2 hours, and pressure-molded at a final pressure of 80 kgf / cm ² to obtain a measurement sample. It was made.
The lightness index L of this sample was determined in the same manner as in Example 1.

[0059]

[Table 5]

[0060]

[Table 6]

[0061]

According to the present invention, it is possible to effectively prevent the adhesion of polymer scale not only in the liquid phase portion in the polymerization vessel but also in the vicinity of the interface between the gas phase and the liquid phase. 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, thereby improving the productivity. When a polymer obtained by applying the present invention for polymerization is molded into a sheet or the like, a molded product having extremely few fish eyes can be obtained. Moreover, the molded product has good initial colorability. Specifically, the lightness index (L value) in the Hunter color difference formula described in JIS Z 8730 (1980) is, for example, 70 or more for vinyl chloride polymers and 80 or more for SBR. Further, the polymer scale anti-adhesion agent of the present invention can suppress the use of the organic solvent at the time of forming a coating film, so that the risk of ignition, explosion, etc. of the organic solvent is small, and the handling safety such as toxicity is also high. there is no problem.

Claims (3)

[Claims] 1. An alkaline solution containing (A) (A-1) a condensation product of a hydroxynaphthalene compound and (A-2) an aldehyde compound, and (B) an inorganic colloid.
A polymer scale anti-adhesion agent for polymerization of a monomer having an ethylenically unsaturated double bond. 2. The polymer scale adhesion preventive agent according to claim 1, further comprising (C) a water-soluble polymer compound. 3. A method for producing a polymer by polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel, wherein (A) (A-1) hydroxynaphthalene compound is provided on the inner wall surface. (A-2) a condensation product with an aldehyde compound, and (B) apply an alkaline solution containing an inorganic colloid,
A production method comprising a step of carrying out the above-mentioned polymerization in a polymerization vessel having a coating film formed by drying, whereby adhesion of polymer scale in the polymerization vessel is prevented.