JPH0987304A - Polymer scale deposition inhibitor and production of polymer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inhibitor excellent in the prevention of polymer scale deposition even in the polymerization of an ethylenic monomer having high solubility such as α-methylsytrene, by mixing a silica sol with a salt of a sulfonated condensate of an aminonaphthalene compound. SOLUTION: The deposition inhibitor comprises (I) a metal salt and/or an ammonium salt of a sulfonated aminonaphthalene compound condensate having an average mol.wt. of 3,000 or higher and (II) a silica sol in a weight ratio of desirably 100/1 to 1/100, preferably 10/1 to 1/10.

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
It becomes remarkable as the number of batches is increased, which causes a problem that the cooling capacity of the polymerization vessel is reduced and the yield of the polymer is reduced. Further, there is also a problem that the polymer scale peeled from the inner wall is mixed with the obtained polymer to deteriorate the quality of the product. Then, it takes a lot of labor and time to remove the polymer scale. Further, since the polymer scale also contains unreacted monomers, there is a problem that the body of a worker is affected if left unattended.

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 a condensate of an aromatic amine compound (JP-B-60-30681).

[0004]

These methods for preventing adhesion of polymer scale are effective when the monomer having an ethylenically unsaturated double bond to be polymerized is a vinyl chloride monomer. is there. However, in the case of styrene, α-methylstyrene, acrylic acid ester, acrylonitrile, vinyl acetate, etc., these monomers have a large solubility in the coating film of the above-mentioned polymer scale anti-adhesion agent, It becomes difficult to effectively prevent the adhesion of polymer scale.

Therefore, the object of the present invention is not only in the polymerization of vinyl chloride but also in the polymerization of other monomers having an ethylenically unsaturated double bond having a large dissolving ability 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 coalescence scale and a method for producing a polymer using the same.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that a specific composition has an excellent polymer scale adhesion preventing effect. That is, the present invention provides (I) a metal salt and / or ammonium salt of a sulfonate obtained by further sulfonating a condensate having an average molecular weight of 3,000 or more obtained by condensing an aminonaphthalene compound, and (II) a silica sol. The present invention provides a polymer scale anti-adhesion agent for polymerization of a monomer containing an ethylenically unsaturated double bond.

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.

BEST MODE FOR CARRYING OUT THE INVENTION

(Polymer Scale Adhesion Preventing Agent) Component (I) The polymer scale adhesion preventing agent of the present invention is a sulfone obtained by sulfonation of a condensate having an average molecular weight of 3,000 or more obtained by condensing an aminonaphthalene compound. It contains a metal salt and / or ammonium salt of a compound as an active ingredient.

Examples of the aminonaphthalene compound which is a raw material of the aminonaphthalene compound (I) include compounds represented by the following general formula (1):

[0010]

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[Wherein a plurality of R ^1's may be the same or different and each is a monovalent atom or group selected from the group consisting of a hydrogen atom, a carboxyl group, a hydroxyl group and a methyl group, and a plurality of R ^3's are the same. Or they may be different, a hydrogen atom, a methyl group,
A monovalent atom or group selected from the group consisting of a phenyl group, an α-naphthyl group and a β-naphthyl group, R ² is a hydrogen atom, a carboxyl group and -N (R ³ ) ₂ (R ³ is the same as the above. Is a monovalent atom or group selected from the group consisting of), when ^two or more R ² are present, they may be the same or different, m is an integer of 1 to 2, and n is 1 To an integer of 4].

Examples of the compound represented by the general formula (1) include α-naphthylamine, 1-amino-2-methylnaphthalene, 1-amino-3-methylnaphthalene, 3-amino-2-naphthol and 5-amino-2. -Naphthol, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, N-methyl-α-naphthylamine, N-
Phenyl-α-naphthylamine, N, N-dimethyl-α-naphthylamine, dinaphthylamine, N-methyl-β-naphthylamine, N-phenyl-β-naphthylamine, 3-amino-2-naphthoic acid and the like, and preferably α-naphthylamine, 1-amino-2-methylnaphthalene, N-phenyl-
α-naphthylamine, N, N-dimethyl-α-naphthylamine and N-phenyl-β-naphthylamine, more preferably α-naphthylamine and N-phenyl-α-naphthylamine. These aminonaphthalene compounds are 1
They may be used alone or in combination of two or more.

Preparation of Condensate of Aminonaphthalene Compound To obtain a condensate of aminonaphthalene compound, for example, a method of reacting an aminonaphthalene compound in an acidic aqueous medium in the presence of a catalyst can be mentioned. The average molecular weight of the condensate of aminonaphthalene compound is 3,000 or more, preferably
It is in the range of 3,500 to 10,000. If the average molecular weight is less than 3,000, the polymer scale adhesion preventing effect will be low.

Examples of the aqueous medium include water and a mixed solvent of water and an organic solvent. As an organic solvent, alcohols such as methanol, ethanol and 2-propanol,
N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone and the like polar solvents and the like, preferably methanol and
It is N, N-dimethylacetamide. These may be used alone or in combination of two or more. The concentration of the organic solvent in the mixed solvent is usually 1.0 to 80% by weight, preferably
The amount is 5.0 to 50% by weight, more preferably 10 to 20% by weight.

To make the aqueous medium acidic, hydrochloric acid, sulfuric acid,
Mineral acids such as perchloric acid and the like, organic acids such as acetic acid, formic acid, P-toluenesulfonic acid and the like can be used, preferably mineral acids, more preferably hydrochloric acid and perchloric acid. The concentration of the acid in the above aqueous medium may be usually 0.01 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 1.0.
~ 5.0% by weight.

Examples of the catalyst include iron (III) chloride, aluminum chloride, copper (II) chloride, potassium permanganate, and other metal salts; ammonium persulfate, potassium persulfate, sodium persulfate, and other persulfates; peroxidation. Examples thereof include inorganic peroxides such as hydrogen and oxidants such as organic peroxides such as benzoyl peroxide. Of these, iron (III) chloride, hydrogen peroxide and ammonium persulfate are preferred. The amount of the catalyst added is 0.1 to 5 per mol of the aminonaphthalene compound.
It may be mol, preferably 0.5 to 2 mol.

The condensation reaction of the aminonaphthalene compound is carried out at a temperature not higher than the boiling point of the solvent used, and is usually -5.0 to 80 ° C, preferably 0 to 25 ° C. The condensation reaction is often an exothermic reaction. At this time, in order to release the heat generated, it is preferable to keep the temperature of the solvent at 0 to 10 ° C. The reaction time may be about 1 to 12 hours depending on the conditions, and may be 1 to 6 hours in some cases, and the reaction is preferably carried out while dropping the catalyst. After the dropping, the reaction is completed for another 5 to 72 hours, preferably 12 to 24 hours.

After completion of the reaction, the obtained condensate is purified as follows. When a dispersion medium is used in the condensation reaction and when a condensation product is precipitated in the solvent by the condensation reaction, the reaction solution is filtered and dried. When the condensate is obtained in the form of a solution, the condensate is deposited by pouring the solution into a poor solvent having a weight ratio of 1 to 20 times that of the solution. The subsequent processing is the same as that of the dispersion medium. As the poor solvent, water, saline, ether, benzene, n-hexane,
Isopropanol and the like.

Sulfonates of condensates of aminonaphthalene compounds
A known method can be used for the method of sulfonation of the condensate of the fluorinated aminonaphthalene compound. For example, there are a method of using a sulfonating agent as a reaction solvent and a method of dissolving or dispersing a condensate in an organic solvent and using the sulfonating agent. When the condensate is difficult to dissolve in an organic solvent,
A method using a sulfonating agent as a reaction solvent is preferable.

Examples of the sulfonating agent include concentrated sulfuric acid, fuming sulfuric acid, sulfur trioxide, chlorosulfonic acid, sulfur trioxide-DMF complex, sulfur trioxide-pyridine complex and the like, preferably concentrated sulfuric acid and fuming sulfuric acid. is there. The amount of the sulfonating agent used depends on the type of condensate, the sulfonation method, the sulfonating agent, and other conditions, and may be determined accordingly. When concentrated sulfuric acid or fuming sulfuric acid is used as the reaction solvent, the amount of concentrated sulfuric acid or fuming sulfuric acid is usually 2 to 20 times, preferably 3 to 10 times the weight ratio of the condensate. The concentration of sulfur trioxide in fuming sulfuric acid may be 5 to 60% by weight, preferably 10 to 30% by weight. In the examples, the description of X% fuming sulfuric acid means fuming sulfuric acid containing X% by weight of sulfur trioxide.

The sulfonation procedure will be described for the case where concentrated sulfuric acid or fuming sulfuric acid is used as the reaction solvent. First,
The condensate is added in small portions to the reaction solvent while stirring the solvent. The resulting mixture is at room temperature to 200 ° C, preferably 30 to
The sulfonation is carried out at 80 ° C. for 1 to 72 hours, preferably 12 to 48 hours. Next, the obtained sulfonated product is put into 1 to 10 times by volume of water while stirring. Then, the mixture is further stirred for 1 to 3 hours to precipitate a cake-shaped sulfonated product, and filtration and washing with water are repeated 2 to 4 times to obtain a sulfonated cake.

Metal salt or ammonium salt of sulfonate
Preparation of the sulfonated cake obtained above in a volume ratio of 1-5
It is dispersed in double the amount of water, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or ammonium hydroxide is added to make the sulfonated compound a metal salt or ammonium salt.

The concentration of the alkali metal hydroxide or ammonium hydroxide in the aqueous solution to be added is usually 1 to 40% by weight, preferably 5 to 5% so that the pH of the sulfonated cake is adjusted to 8 to 9. 20% by weight. The amount of the solution used is an amount necessary for the sulfone group (SO ₃ H) of the sulfonate to become a metal salt or ammonium salt,
It may be an equivalent amount, preferably an equivalent amount to 1.2 times the equivalent amount.
The solution thus prepared is heated to 80 to 95 ° C. and stirred for 1 to 12 hours to obtain an aqueous solution of sulfonated metal salt or ammonium salt.

The aqueous solution of the obtained metal salt or ammonium salt may be directly added to the solvent for the coating solution for preparing the polymer scale anti-adhesive agent described below. In addition, a polymer scale inhibitor is prepared by drying, solidifying, or salting out or throwing it into the above-mentioned poor solvent (excluding water) to precipitate it, and then filtering and drying it to obtain a metal salt or ammonium salt solid. May be used for.

Component (II) The polymer scale inhibitor of the present invention further contains silica sol as an essential component. This component has a function of improving the polymer scale prevention effect together with the component (I).
Examples of the silica sol include aqueous silica sol, methanol silica sol, butanol silica sol, ethylene glycol silica sol, and DMF silica sol. Aqueous silica sols and methanol silica sols are preferable, and aqueous silica sols are particularly preferable.

The particle size of colloidal particles of silica sol is 1 to 10
A range of 0 nm (nanometer) is desirable, and more preferably 4 to 20 nm (nanometer).

The amount of the silica sol compounded is preferably 100/1 to 1/100 in terms of the weight ratio of the component (I) / silica sol,
More preferably, it is 10/1 to 1/10. If the amount of silica sol is too small or too large, the advantage of combined use may not be obtained.

(Method for Producing Polymer Using Polymer Scale Adhesion Preventing Agent) The method for producing a polymer according to the present invention is directed to the inside of a polymerization vessel having a coating film comprising the polymer scale adhesion preventing agent on the inner wall of the polymerization vessel. Is a production method of polymerizing a monomer having an ethylenically unsaturated double bond. This coating film can be obtained by applying a coating liquid containing the component (I) and the component (II) to the inner wall surface of the polymerization vessel or a portion where other monomers come into contact during the polymerization and drying.

Preparation of Coating Liquid The coating liquid can be obtained by dissolving or dispersing the component (I) and the component (II) in a solvent at appropriate concentrations and mixing them. The concentration of the component (I) in the coating solution is not limited as long as the coating amount after drying described below can be obtained, and is usually 0.
It is 001 to 10% by weight, preferably 0.01 to 2% by weight. When the concentration of the component (I) 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, if the concentration is higher than necessary, it is economically disadvantageous, and in extreme cases, it may not be possible to form a uniform coating film. Then, with the concentration of the coating liquid containing (II) silica sol,
The total amount of component (II) is preferably 0.01 to 5% by weight. As a method of adding the (II) silica sol to the (I) component, after dissolving or dispersing the (I) component in the coating solution solvent, water, coating solution solvent, silica sol is previously added to this solution or dispersion. A silica sol having a concentration of 1 to 10% by weight is mixed with the dispersion medium or the like.

The solvent of the coating liquid is water; methanol,
Alcohols such as isobutanol; aromatic hydrocarbon solvents such as benzene, toluene, xylene; halogenated hydrocarbons such as methylene chloride, dichloroethylene, 1,1,2-trichloroethane; acetone, methyl ethyl ketone,
Ketones such as methyl isobutyl ketone; esters such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, and methyl acetoacetate; ethers such as 1,4-dioxane and ethylene glycol monomethyl ether; and dimethylformamide, N, N -A polar solvent such as dimethylacetamide or N-methylpyrrolidone can be used. These solvents are used alone or as a mixed solvent of two or more kinds. Of these, water, methanol, isobutanol, acetone and dimethylformamide, and mixed solvents thereof are preferable.

Formation of Coating Film To form a coating film on the inner wall surface of the polymerization vessel using the above coating solution, first, the coating solution is applied to the inner wall surface of the polymerization vessel, and then, for example, at a temperature from room temperature to 100 ° C. After being sufficiently dried within the range, it is further washed with water if necessary.

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 portions with which the monomer comes in contact during the polymerization. Specific examples include stirring blades, stirring shafts, baffles, condensers, headers, search coils, bolts and nuts. More preferably, even at a site other than the site where the monomer contacts during the polymerization, the site where the polymer scale may be attached, for example, the inner surface of the device and the pipe of the recovery system of the unreacted monomer, etc. It is better to form a coating film. Specifically, the inner surfaces of a monomer distillation column, a condenser, a monomer storage tank, a valve and the like can be mentioned.

The method 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. 57-61001, 55-36
The automatic coating methods described in JP-A No. 288, JP-B-56-501116, JP-A-56-501117, JP-A-59-11303 and the like can also be used.

There is no limitation on the method of drying the wet surface after the coating liquid is applied, and the following method can be used, for example. After the application of the coating solution, a method of applying an appropriately heated hot air to the application surface, the inner wall surface of the polymerization vessel and the other surface to which the application solution is applied are preliminarily set to 30
It is a method in which the coating liquid is directly applied to the heated surface by heating to -80 ° C. Further, when the boiling point of the solvent or dispersion medium of the coating liquid exceeds 80 ° C., it may be dried under reduced pressure if necessary. After the coated surface is dried, the coated surface is washed with water as needed.

The coating amount of the obtained coating film after drying is usually 0.001 to 5 g / m ² , preferably 0.01 to 3 g / m ² .
The above coating operation may be carried out every 1 to 3 batches of polymerization. The formed coating film has high durability, and the polymer scale anti-adhesion action continues. Therefore, it is not always necessary to carry out the coating operation for 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 halide such as vinyl chloride; vinyl acetate and propionic acid. Vinyl esters such as vinyl; acrylic acid, methacrylic acid and their esters or salts; maleic acid, fumaric acid and their esters or anhydrides; diene monomers such as butadiene, chloroprene, isoprene; styrene, acrylonitrile, halogenated Examples thereof include vinylidene, vinyl ether and isobutene. As an example in which the method of the present invention is particularly preferably carried out, vinyl halides such as vinyl chloride or vinylidene halide or a polymer thereof obtained by suspension polymerization / emulsion polymerization of a monomer mainly containing them in an aqueous medium. Manufacturing. In addition, the coating film formed by the method of the present invention can be applied to a monomer having a large solubility in conventional coating films such as α-methylstyrene, acrylic ester, acrylonitrile, vinyl acetate and the like. Since it has high durability, it can produce polymer beads such as polystyrene, polymethacrylate, polyacrylonitrile, latex, and synthetic rubbers such as SBR, NBR, CR, IR, IIR. (These synthetic rubbers are usually produced by emulsion polymerization. ), And ABS resin can also be suitably manufactured.

In the polymerization of one or more of these monomers, regardless of the type of polymerization such as suspension polymerization, emulsion polymerization, bulk polymerization and solution polymerization, an emulsifier, a stabilizer, a lubricant,
The effect of preventing scale can be obtained even in the presence of any additive such as a plasticizer, a pH adjuster, and a chain transfer agent. For example, in the case of suspension polymerization or emulsion polymerization of vinyl monomers, the additives added to the polymerization system are partially saponified polyvinyl alcohol, polyacrylic acid, a copolymer of vinyl acetate and maleic anhydride, and hydroxypropyl methylcellulose. Suspending agents such as cellulose derivatives, natural or synthetic polymer compounds such as gelatin; solid dispersants such as calcium phosphate, hydroxyapatite; anionic emulsifiers such as sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium dioctylsulfosuccinate; sorbitan mono Nonionic emulsifiers such as laurate, sorbitan trioleate and polyoxyethylene alkyl ether; fillers such as calcium carbonate and titanium oxide; tribasic lead sulfate;
Calcium stearate, dibutyltin dilaurate,
Stabilizers such as dioctyltin mercaptide; Lubricants such as life wax, stearic acid, cetyl alcohol; DO
P, DBP and other plasticizers, trichlorethylene, mercaptans and other chain transfer agents; pH adjusters; Rongalit, iron sulfate and other reducing agents, etc. can effectively prevent polymer scale adhesion even in a polymerization system. .

The feature of the present invention is that, regardless of which catalyst is used, a remarkable polymer scale adhesion preventing effect can be obtained regardless of the type of the polymerization catalyst. Specifically, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyneodecanoate, bis (2-ethylhexyl) peroxydicarbonate, 3,5,5-trimethylhexanoyl peroxide, α-cumylperoxy neodecanoate, cyclohexanone peroxide, t-butylperoxypivalate, bis (2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoylper Oxide, diisopropyl peroxydicarbonate, α, α′-azobisisobutyronitrile, α, α ′
Examples of the polymerization initiator include -azobis-2,4-dimethylvaleronitrile, potassium persulfate, ammonium persulfate and p-menthane hydroperoxide.

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, the inside of the polymerization vessel was evacuated to 0.1 to 76
After reducing the pressure to 0 mmHg (0.01 to 101 kPa), the monomers were charged [at this time, the internal pressure of the polymerization vessel is usually 0.5 to 30 kgf /
cm ² · G (150 to 3040 kPa)], 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.
Perform at 30-80 ° C, 50-150 ° C for styrene polymerization
Polymerize with. For polymerization, the internal pressure of the polymerization vessel is 0 to 7 kgf / c
m ² · G (100 to 790 kPa), or when there is almost no difference between the inlet temperature and the outlet temperature of the cooling water that flows into and out of the jacket installed on the outer circumference of the polymerization vessel (
That is, it is judged to be completed when the heat generated by the polymerization reaction disappears). Water, a dispersant, and an initiator charged during the polymerization are usually 20 parts of water per 100 parts by weight of the monomer.
~ 500 parts by weight, dispersant 0.01 to 30 parts by weight, polymerization initiator 0.01
~ 5 parts by weight.

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 exhausting to a pressure of 760 mmHg (0.0001 to 101 kPa),
Charge the monomer and the polymerization initiator in the polymerization vessel, -10 ~
Polymerize at a reaction temperature of 250 ° C. For example, in the case of vinyl chloride polymerization, it is carried out at 30 to 80 ° C, and in the case of styrene polymerization, it is carried out at 50 to 150 ° C.

The polymer scale adhesion preventive agent of the present invention may be used for forming a coating film on the inner wall surface of a polymerization vessel or the like, and may be further added directly to the polymerization system, whereby the polymer scale prevention effect is improved. You can also let it. In that case, the addition amount of the polymer scale anti-adhesion agent is appropriately about 10 to 1000 ppm with respect to the total weight of the charged monomers. When adding, care should be taken not to affect the quality of the product polymer such as fish eye, bulk specific gravity and particle size distribution.

[0043]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the table, those marked with * in Nos. Of condensates of aminonaphthalene compounds, reaction products, and coating solutions do not satisfy the conditions of the present invention and are provided for comparative examples. Experiment No. Those marked with * are comparative examples that do not satisfy the conditions of the present invention, and other examples are examples.

(Preparation of Condensate of Aminonaphthalene Compound) [Preparation Example 1] 36 g of 35% hydrochloric acid and 180 g of ion-exchanged water were charged into a 500 mL three-necked flask, and stirring was started using a stirring blade. Next, 25 g of α-naphthylamine was dispersed in this aqueous hydrochloric acid solution, and the resulting α-naphthylamine dispersion was diluted to 0
Cool to ５5 ° C. Next, 59.6 g of ammonium persulfate was dissolved in 100 g of ion-exchanged water while stirring, and the obtained ammonium persulfate aqueous solution was added to the α-naphthylamine dispersion liquid using a dropping funnel. This addition was carried out for 3 hours, and the temperature of the α-naphthylamine dispersion was kept at 0 to 5 ° C during the addition. When this reaction solution was further kept at room temperature for 24 hours, a deep blue color was obtained after 1 hour. The reaction solution was filtered and washed with 500 g of warm water at 50 ° C. Furthermore, the same filtration and washing are performed once, and 50
It was dried at ° C for 12 hours to obtain a condensate (A) -1. This condensate
When (A) -1 was analyzed by high performance liquid chromatography, the average molecular weight was 3,650. The measurement conditions were as follows. Equipment: Shimadzu High Performance Liquid Chromatograph LC-10A
D GPC system column: Shimadzu GPC column Shim-pack GPC-80
2D / 803D (8.0 mmφ x 300 mm), column temperature 60 ° C Carrier: LiBr / DMF = 10 mmol / L, flow rate:
1.0 mL / min Detector: UV absorption spectrum 290 nm Determination of average molecular weight: Based on polystyrene calibration curve.

[Preparation Example 2] 35 in a 500 mL three-necked flask
% G hydrochloric acid, ion-exchanged water 250 g, and ferrous sulfate heptahydrate 3.3 g were charged, and stirring was started using a stirring blade. Next, 25 g of α-naphthylamine was dispersed in this aqueous hydrochloric acid solution, and the resulting α-naphthylamine dispersion was cooled to 0 to 5 ° C. Next, an aqueous hydrogen peroxide solution prepared by adding 30% hydrogen peroxide to 125 g of ion-exchanged water was added to the α-naphthylamine dispersion liquid using a dropping funnel. This addition was carried out for 3 hours, and the temperature of the α-naphthylamine dispersion was kept at 0 to 5 ° C during the addition. Furthermore, at room temperature
When it was kept for 24 hours, it became deep blue after 1 hour.
After the reaction solution was filtered, it was washed with 500 g of warm water at 50 ° C. Further, the same filtration and washing were performed once, and the product was dried at 50 ° C. for 12 hours to obtain a condensate (A) -2. The average molecular weight of this condensate was measured in the same manner as in [Preparation Example 1]. Table 1 shows the results.

[Preparation Example 3] 60 in a 500 mL three-necked flask
% G of perchloric acid and 200 g of ion-exchanged water were charged, and stirring was started using a stirring blade. Next, α-naphthylamine 25
After adding g to this aqueous solution of perchloric acid and raising the temperature to 30 ° C,
An α-naphthylamine solution can be obtained, then 0
Cool to ５5 ° C. Next, an ammonium persulfate aqueous solution in which 59.6 g of ammonium persulfate was dissolved in 150 g of ion-exchanged water was added to the above α-naphthylamine solution using a dropping funnel. In addition, this addition is performed over 3 hours,
The temperature of the solution was kept at 0-5 ° C during the addition. further,
When it was kept at room temperature for 24 hours, it turned black blue after 1 hour. The obtained reaction solution was filtered and washed with 500 g of warm water at 50 ° C. Furthermore, the same filtration and washing are performed once, and 50
It was dried at ° C for 12 hours to obtain a condensate (A) -3. The average molecular weight of this condensate was measured in the same manner as in [Preparation Example 1]. Table 1 shows the results.

[Preparation Example 4] 35 in a 500 mL three-necked flask
% Hydrochloric acid 94 g, ion-exchanged water 320 g, and sodium lauryl sulfate 2.0 g as a dispersant were charged, and stirring was started using a stirring blade. Next, N-phenyl-α-naphthylamine 10
0 g was dispersed in this aqueous hydrochloric acid solution and cooled to 0 to 5 ° C. Next, 156 g of ammonium persulfate was divided into small portions and gradually added to the above N-phenyl-α-naphthylamine dispersion over 1 hour. The temperature of the dispersion liquid was maintained at 0 to 5 ° C during the addition. Furthermore, 48 at 0-5 ° C
When it was kept for a time, it turned dark blue after 2 hours and turned gray green after 24 hours. The obtained reaction solution was filtered and then washed with 1000 g of water at room temperature. Furthermore, the same filtration and washing were carried out once, and washing and filtration were carried out with 500 g of ethanol. The obtained filtered product was dried at 50 ° C for 12 hours to obtain a condensate (A) -4. The average molecular weight of this condensate was measured in the same manner as in [Preparation Example 1]. Table 1 shows the results.

[Preparation Example 5] 35 in a 500 mL three-necked flask
% Hydrochloric acid 94 g, ion-exchanged water 230 g, ferrous sulfate heptahydrate
0.1 g and 2.0 g of sodium lauryl sulfate as a dispersant
Was charged, and stirring was started using a stirring blade. Next, this hydrochloric acid aqueous solution was cooled to 0 to 5 ° C., and 100 g of N-phenyl-α-naphthylamine was gradually added and dispersed. Then 30
% 7.5% hydrogen peroxide was added to the N-phenyl-α-naphthylamine dispersion. This addition was carried out for 1 hour, and the temperature of the N-phenyl-α-naphthylamine dispersion was kept at 0 to 5 ° C during the addition. In addition, at room temperature 48
When it was kept for a time, it became dark blue after 2 hours and turned black brown after 24 hours. The obtained reaction solution is filtered, washed and dried in the same manner as in [Preparation Example 4] to give the condensate (A) -5.
I got The average molecular weight of this condensate was measured in the same manner as in [Preparation Example 1]. Table 1 shows the results.

[Preparation Example 6] A condensate (in the same manner as in Preparation Example 1) except that the aqueous solution of ammonium persulfate was added dropwise in [Preparation Example 1] and then held for 3 hours instead of for 24 hours at room temperature ( A) -6 * got. This average molecular weight was measured in the same manner as in [Preparation Example 1]. Table 1 shows the results. In addition,
(A) -6 * was used as a comparative example.

[Preparation Example 7] The same operation as in [Preparation Example 4] was repeated except that after addition of ammonium persulfate in [Preparation Example 4], the mixture was held at 0 to 5 ° C for 3 hours instead of 48 hours. A condensate (A) -7 * was obtained. This average molecular weight was measured in the same manner as in [Preparation Example 1]. Table 1 shows the results. In addition,
(A) -7 * served as a comparative example.

(Preparation of condensate sulfonated product and salt thereof) [Preparation Example 8] Condensates (A) -1 to 5, (A) -6 * and (A) -7 *
Reaction products a to e, n * and o * each of which was sulfonated with concentrated sulfuric acid and further converted into sodium salt with sodium hydroxide were prepared by the following procedure. First, (A) -1 ~ 5,, (A) -6
20g of one of ** and (A) -7 * was collected and kept below 30 ℃ 98
% 100% concentrated sulfuric acid was added with stirring. 50 after addition
The temperature was raised to 0 ° C., and sulfonation was performed for 16 hours. The resulting sulfonated solution was added to 200 g of cold water with stirring and further stirred for 1 hour to form a sulfonated cake. The cake obtained was washed with 200 g of ion-exchanged water and filtered. Furthermore, the same washing and filtration are performed once,
150 g of deionized water with purified sulfonated cake
Dispersed. This dispersion was adjusted to pH 9.0 with a 10% aqueous sodium hydroxide solution, then heated to 90 ° C. and stirred at the same temperature for 3 hours to give a sodium salt. After completion of stirring, the mixture was cooled to room temperature and adjusted to pH 7.0 with 1% dilute sulfuric acid. The solid content of this aqueous solution was measured using the dry weight method.

[Preparation Example 9] In [Preparation Example 8], each of the condensates (A) -1 to 5 was subjected to sulfonation.
Other than using 20% fuming sulfuric acid instead of 98% concentrated sulfuric acid,
The same operations as in [Preparation Example 8] were performed to prepare reaction products f to j.

[Preparation Example 10] In [Preparation Example 8], the condensate (A)-
For 1 and (A) -4, the ammonium salt of the sulfonated condensate was prepared in the same manner as in [Preparation Example 8] except that a 25% aqueous ammonium solution was used instead of the 10% aqueous sodium hydroxide solution. Certain reaction products (hereinafter referred to as a'and d ', respectively) were prepared.

[Preparation Example 11] Two kinds of metal salts of sulfonates obtained by sulfonation of non-condensed aminonaphthalene compounds were prepared. One is sodium 1-amino-5-naphthalenesulfonate (hereinafter referred to as l *), the other is sulfonation of N-phenyl-α-naphthylamine by the method of [Preparation Example 8], and It is a sodium salt (hereinafter referred to as m *). These were used in Comparative Examples that did not satisfy the conditions of the present invention.

[0055]

[Table 1]

[Examples 101 to 107 and Comparative Examples 108 * to 114]
*] (When polymerizing only one batch) A coating solution of the polymer scale inhibitor used in each example was prepared as follows. The combination shown in Table 3 using the (I) reaction product shown in Table 1 and the (II) silica sol shown in Table 2
Coating liquids (Nos. 1 to 30) were prepared by adding and mixing to a solvent of the coating liquid so that the weight ratio (solid content conversion) and concentration [total concentration of (I) and (II)] were obtained.

[0057]

[Table 2]

[0058]

[Table 3]

In each example, the coating liquid of No. shown in Table 4 was brought into contact with the inner wall of the stainless steel polymerization vessel equipped with a stirrer (internal volume: 1000 L), stirring shaft, stirring blade, and other monomers during the polymerization. The coating was applied to the site, dried at 50 ° C. for 15 minutes, and then washed with water to form a coating film. However, in [Comparative Example 108 *], the coating liquid was not applied. Next, 400 kg of water, vinyl chloride
200 kg, partially saponified polyvinyl alcohol 250 g, hydroxypropylmethyl cellulose 25 g and diisopropyl peroxydicarbonate 75 g were charged into this polymerization vessel and polymerized at 57 ° C. for 6 hours while stirring. After completion of the polymerization, the amount of polymer scale adhesion (g / m ² ) per unit area of the inner wall surface of the polymerization vessel was measured as follows.

Polymer scale measurement method : The scale attached to an area of 10 cm square was scraped off with a stainless steel spatula as far as it could be visually confirmed. The polymer scale obtained was weighed and multiplied by 100 to determine the amount of polymer scale attached per 1 m ² . The results are shown in Table 4.

[0061]

[Table 4]

[Examples 201 to 209 and Comparative Examples 210 * to 214
*] (When polymerizing only one batch) In each example, the coating liquid with the No. shown in Table 5 and the internal volume were 20
A coating film was formed on the polymerization vessel in the same manner as in [Example 101] except that the L polymerization vessel was used. However, in [Comparative Example 210 *], the coating liquid was not applied. Next, 8 kg of water, 5.2 kg of styrene monomer, 2.8 kg of methacrylic acid monomer, 8 g of partially saponified polyacrylamide and 24 g of α, α'-azobisisobutyronitrile were charged into this polymerization vessel,
Polymerization was carried out at 90 ° C. for 5 hours with stirring. After polymerization, the amount of polymer scale attached was measured in the same manner as in [Example 101].
The results are shown in Table 5.

[0063]

[Table 5]

[Examples 301 to 307 and Comparative Examples 308 * to 311]
*] (When polymerized in only one batch) In each example, the coating liquid with the No.
A coating film was formed on the polymerization vessel in the same manner as in [Example 101] except that the L polymerization vessel was used. However, in [Comparative Example 308 *], the coating liquid was not applied. Next, 10 kg of water, 2.5 kg of styrene, 1.0 kg of acrylonitrile, 2.4 kg of SBR latex, 50 g of synthetic rubber emulsifier manufactured by Harima Kasei Kogyo Co., Ltd. (Bandis T-100P), sodium hydroxide
2.0 g, t-dodecyl mercaptan 30 g and ammonium persulfate 5.0 g were charged into this polymerization vessel, and polymerization was carried out at 70 ° C. for 2 hours while stirring. After the completion of polymerization, the amount of polymer scale attached was measured in the same manner as in [Example 101]. Table 6 shows the results.

[0065]

[Table 6]

[Examples 401 to 407 and Comparative Examples 408 * to 413
*] (When polymerized continuously for 15 batches) In each example, the coating liquid with the No. shown in Table 7 and the internal volume were 20
A coating film was formed on the polymerization vessel in the same manner as in [Example 101] except that the L polymerization vessel was used. However, in [Comparative Example 408 *], the coating liquid was not applied. Next, 9 kg of water, 225 g of sodium dodecylbenzene sulfonate, 12 g of t-dodecyl mercaptan and 13 g of potassium persulfate were charged into this polymerization vessel, which was replaced with nitrogen gas, and then styrene 1.3 k
g and 3.8 kg of butadiene were charged and polymerized at 50 ° C. for 20 hours. After the polymerization was completed, the polymer slurry was extracted, and then the inside of the polymerization vessel was washed with water. The operation of polymerization and washing with water was defined as one batch, and 15 batches of polymerization were carried out continuously, and then the polymer scale adhesion amount was measured in the same manner as in [Example 101]. However, the amount of polymer scale adhesion was measured not only in the liquid phase during polymerization but also in the vicinity of the gas-liquid interface. The results are shown in Table 7.

[0067]

[Table 7]

As shown in the above Examples, the polymer scale anti-adhesion agent containing a sol obtained by sulfonating a condensate of an aminonaphthalene compound and further forming a metal salt or an ammonium salt is a conventional aromatic compound. The reason why it is superior to that of a condensation product of an amine compound and an aromatic nitro compound (hereinafter referred to as a condensation product of aromatic amine) is as follows.
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The amino group (-NH ₂ group) in the compound is generally easily charged positively, and is easily ionically bonded to the negatively charged polymer particles. Therefore, the condensation product of the aminonaphthalene compound of the present invention and the conventional condensation product of aromatic amine, -N
Comparing the amounts of H ₂ groups, the condensate of aminonaphthalene compound is smaller. Therefore, it can be said that the adhesion of the polymer scale is small.

Further, when a condensate of an aminonaphthalene compound is sulfonated, a negatively charged sulfone group causes
The ionic bond with the polymer particles is prevented, and since the sulfone group is hydrophilic, it does not dissolve with the monomer.

However, by introducing a sulfone group, the condensate becomes water-soluble. Therefore, it becomes difficult to fix the polymer scale adhesion preventing agent. Therefore, in order to improve this adverse effect, silica sol is added. Silica sol
It is a porous fine particle and has a coating property in a dried gel state. A salt of a condensate of an aminonaphthalene compound having a sulfone group can be retained in the pores. Also,
Since this dry gel has a negative charge and is hydrophilic, it is difficult to dissolve in a monomer and water. Therefore, it is presumed that the durability of the polymer scale inhibitor can be improved when a condensate of an aminonaphthalene compound retained in a gel and having a sulfone group is used as the polymer scale inhibitor.

Furthermore, since the molecular weight of the condensate of the aminonaphthalene compound of the present invention is larger than that of the conventional condensate of aromatic amine, it is considered that the former is less soluble in the polymer.

[0073]

EFFECT OF THE INVENTION Monomers having an ethylenically unsaturated double bond, which have been difficult to prevent the adhesion of polymer scales, because the coating films formed from the conventional polymer scale adhesion preventive agents have a large solubility. In the above-mentioned polymerization or copolymerization, by using the polymer scale adhesion preventive agent according to the present invention, the adhesion of the polymer scale to the inner wall surface of the polymerization vessel or the like can be effectively prevented. In particular, even in a polymerization system containing a monomer such as styrene, α-methylstyrene, acrylic acid, acrylic acid ester, and acrylonitrile, which has a significantly high solubility in a coating film, the adhesion of polymer scale can be reliably prevented. . In addition, the formed coating film has high durability, and the polymer scale adhesion preventing action continues. Therefore, the polymerization vessel can be used repeatedly. Therefore, productivity is improved. Further, in the conventional polymer scale adhesion-preventing agent, the polymer scale was more likely to adhere to the polymerization vessel whose inner wall surface was glass-lined than the stainless steel polymerization vessel. Use of the polymer scale anti-adhesion agent of the present invention can effectively prevent the adhesion of polymer scale regardless of the material of the inner wall of the polymerization vessel.

Claims (3)

[Claims] 1. Containing (I) a metal salt and / or ammonium salt of a sulfonated product obtained by further sulfonation of a condensate having an average molecular weight of 3,000 or more obtained by condensing an aminonaphthalene compound, and (II) a silica sol. A polymer scale adhesion preventive agent for polymerizing a monomer having an ethylenically unsaturated double bond. 2. The component (I) is a metal salt of a sulfonated product obtained by further sulfonation of a condensate having an average molecular weight of 3,000 or more obtained by reacting an aminonaphthalene compound in an acidic aqueous medium, and / or Alternatively, the polymer scale anti-adhesion agent according to claim 1, which is an ammonium salt. 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.