JPS62236804A - Polymerization of vinyl monomer - Google Patents

Abstract

PURPOSE:To obtain a high-quality product in good productivity, excellent yield of product and excellent efficiency of a polymerizer by decreasing scale deposition on the film of excellent durability, by polymerizing a vinyl monomer in an aqueous medium in a polymerizer whose inside wall is coasted with a specified reaction product. CONSTITUTION:A reaction product is obtained by reacting a ketone resin of a softening point of 80-130 deg.C, which is a condensate of a ketone (e.g., cyclohexanone) with HCHO, with a phenolic compound (e.g., pyrogallol) and, optionally, an aldehyde compound at 50-250 deg.C for 5min-10hr in a nitrogen atmosphere in the presence of a Friedel-Crafts catalyst or an acid catalyst (e.g., p-toluenesulfonic acid). A scale deposition inhibitor comprising this reaction product is dissolved in, e.g., a polar hydrocarbon solvent so that the concentration of the resulting solution may be 1-10wt%, and this solution is applied to the inside surface of a polymerizer at a coating weight of 0.01-10g/m<2>. A vinyl monomer (e.g., vinyl chloride), a dispersant, a polymerization initiator, etc., together with an aqueous medium (e.g., water) are fed to the polymerizer and polymerized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improved method for polymerizing vinyl monomers, and more particularly, to a method for polymerizing vinyl monomers using an aqueous medium. The present invention relates to a method for preventing the deposition of polymer scale on the inner surface of a polymerization reactor during polymerization or emulsion polymerization.

[Prior Art] When a vinyl monomer is polymerized in the presence of a dispersant or emulsifier and a polymerization initiator, the inner surface of a polymerization reactor, that is, the inner wall thereof,
Solid polymers called scale often adhere to stirring blades, vacuum plates, condensers, etc.

This scale causes a decrease in heat transfer efficiency, a decrease in product yield, a decrease in quality due to the contamination of exfoliated scale into the product, a decrease in productivity due to the labor and time required for removing the scale, and This brings about many disadvantages, such as causing occupational safety and health problems.

In order to solve these problems, many methods have been proposed to prevent scale formation and its adhesion to the polymerization vessel.

For example, reaction products were obtained using dyes, pigments, other polar organic compounds, inorganic acids and their salts, polyvalent metal salts, etc., in the same manner except that deuterium hydroquinone was used.

(Synthesis Example 3) A reaction product was obtained in the same manner as in Synthesis Example 1 except that resorcinol was used instead of pyrogallol.

(Synthesis Example 4) Instead of the ketone resin used in Synthesis Example 1, a condensate of acetophenone formaldehyde with a softening point of 10
A reaction product was obtained in the same manner except that a ketone resin at 5 to 115°C was used.

(Synthesis Example 5) In the same manner as Synthesis Example 1, 100 parts of the ketone resin used in Synthesis Example 1, 100 parts of pyrogallol, and p-4 luenesulfonic acid were placed in a 4-tubular flask equipped with a stirrer, a thermometer, and a condenser. Charge 12g and heat at 190℃ under nitrogen atmosphere for 3 hours.
After reacting for an hour, the mixture was cooled, 50 parts of 35% formaldehyde was added, and the reaction was further carried out under reflux for 2 hours. The reaction temperature was controlled by refluxing the water in the system.

-11-1 Then, a reaction product was obtained in the same manner as in Synthesis Example 1.

(Synthesis Example 6) In the same manner as Synthesis Example 1, pyrogallol 100
1, 50 parts of 35% formaldehyde and 2000 parts of 50% phosphoric acid were reacted at 60° C. for 1 hour to obtain a reddish-purple precipitate.

100 parts of the precipitate obtained by dehydrating and drying this, 100 parts of the ketone resin used in Synthesis Example 1, and 12 parts of p-toluenesulfonic acid.
g in the same flask and heated at 190℃ under nitrogen atmosphere for 5 hours.
After carrying out the reaction for a period of time, a reaction product was obtained in the same manner as in Synthesis Example 1.

(Synthesis Example 7) In the same manner as Synthesis Example 1, 100 parts of the ketone resin used in Synthesis Example 1, 100 parts of pyrogallol, and 50 parts of 35% formaldehyde were placed in a 4-tube IA flask equipped with a stirrer, a thermometer, and a condenser. , 6 parts of oxalic acid dihydrate were charged, and the reaction was carried out under a nitrogen atmosphere for 5 hours. The reaction temperature was controlled by refluxing the water in the system. After the reaction was completed, a reaction product was obtained in the same manner as in Synthesis Example 1.

(Synthesis Example 8) In the same manner as in Synthesis Example 1, an aqueous solution containing 126 parts of pyrogallol and 85 parts of formaldehyde at a concentration of 35% was added to a 50% by weight aqueous solution of phosphoric acid in an Ik 4-tube flask equipped with a stirrer, a thermometer, and a condenser. 2000 copies plus 60°C
The mixture was reacted for 1 hour to obtain a water-insoluble solid.

(Comparative Example 1) Contents: 200 kg of vinyl chloride, 400 kg of pure water, 150 kg of partially saponified polyvinyl acetate, and 6 kg of azobisdimethylvaleronitrile in a 1ffl stainless steel polymerization vessel.
0g was added and polymerization was carried out at 57°C for 9 hours with stirring.

After the polymerization was completed, the amount of scale attached was measured, and the results shown in Table 1 were obtained.

(Comparative Example 2) The product obtained by the method of Synthesis Example 8 was made into a 3% acetone solution, sprayed onto the inner surface of the polymerization vessel used in Comparative Example 1, and dried. The amount of coating at this time was 0.4 g/I.

When a polymerization reaction was carried out in the same manner as in Comparative Example 1 using this polymerization vessel, the amount of scale deposited was as shown in Table 1.

(Examples 1 to 7) Each of the products obtained by the methods of Synthesis Examples 1 to 7 was made into a 3% acetone solution, sprayed onto the inner surface of the polymerization vessel used in Comparative Example 1, and dried.

The coating amount at this time was 0.4 g/r&.

Using this polymerization vessel, a polymerization reaction was carried out in the same manner as in Comparative Example 1, and the scale adhesion amounts were as shown in Table 1.

(Comparative Example 3) In the same polymerization vessel as used in Example 1, vinyl chloride 190
kg', 10 kg of vinyl acetate, 450 kg of pure water, 180 g of partially saponified polyvinyl acetate, and 60 g of azobisdimethylvaleronitrile were added, and polymerization was carried out at 60° C. for 10 hours with stirring.

After the polymerization was completed, the polymerization vessel was washed with water under a pressure of 5 atm, and the amount of scale attached was measured. Table 2 shows the results.

Acid, organic acids such as para-toluenesulfonic acid can be used.

The ketone resin and phenolic compound are 5 to 200 parts by weight of the ketone resin per 100 parts by weight of the phenolic compound,
Preferably 30 to 150 parts by weight are used.

Further, the aldehyde compound is used in an amount of 0 to 2 mol, preferably 0.5 to 1.5 mol, per 1 mol of the phenolic compound.

If the amount of ketone resin relative to the phenolic compound is less than the above range, the reaction rate of the phenolic compound will decrease, which is economically disadvantageous. On the other hand, if the amount is too large, the effect of preventing scale adhesion will be reduced. The use of an aldehyde compound increases the effect of preventing scale adhesion, but if the amount exceeds the above range, the solubility in a solvent or alkaline solution decreases.

The catalyst was 0% per 100 parts by weight of the Fe, noric compound.
．． 01 to 30 parts by weight, preferably 1 to 20 parts by weight. When the amount of the catalyst is less than the above range, the reactivity decreases, while when it increases, the solubility in a solvent or alkaline solution decreases.

The scale adhesion inhibitor obtained by the reaction in this manner is used after being dissolved in a hydrocarbon polar solvent or an alkaline solution. This solution is applied to the surface of the target polymerization vessel as a scale adhesion prevention agent at 0.01g/rIf to 1% per square meter.
It is applied by a method such as a spray method or a rinsing method at a ratio of 0 g/rrf'.

The appropriate concentration of the solution is 1 to 10% by weight; if it is thinner than 1% by weight, the effect of preventing scale adhesion cannot be obtained, so 10% by weight is recommended.
If the amount exceeds 50%, it becomes difficult to apply by spraying or rinsing.

Polymerization of the vinyl monomer used in the present invention includes suspension polymerization,
Emulsion polymerization is employed. The dispersant used in this polymerization,
There are no particular restrictions on the emulsifier, initiator, etc., and commonly used ones can be used.

Examples of dispersants and emulsifiers include partially saponified polyvinyl acetate, acrylic acid copolymers, cellulose derivatives,
Anionic interfaces such as protective colloidal compounds such as gelatin and starch, esters of higher fatty acids and polyhydric alcohols, anionic surfactants such as polyoxyethylene derivatives, metal salts of higher fatty acids, and metal salts of alkylbenzenesulfonic acids. An activator or the like is used.

Benzoyl peroxide is used as a polymerization initiator.

Organic peroxides such as lauroyl peroxide and dioctyl peroxydicarbonate, azo compounds such as azobisisodimethylvaleronitrile, and persulfates such as potassium persulfate and ammonium persulfate are used.

The vinyl monomers mentioned here are monomers having a vinyl group, such as olefins such as ethylene and propylene, vinyl halides such as vinyl chloride and vinylidene chloride, and vinyl esters such as vinyl acetate. , vinyl ethers such as ethyl vinyl ether, acrylic acid ethers such as methyl methacrylate, metal salts or esters such as maleic acid and fumaric acid, aromatic vinyls such as styrene, diene monomers such as butadiene, chloroprene, isoprene, etc. Examples include acrylonitrile, acrylonitrile, etc.

Although the present invention can also be used for the polymerization of the above-mentioned vinyl monomers alone or a mixture of two or more vinyl monomers, it is particularly effective in the polymerization of monomers mainly composed of vinyl chloride. .

[Examples] The present invention will be specifically explained below using Examples, but the scope of the present invention is not limited thereby. Note that parts and percentages described below are in weight units.

(Synthesis Example 1) Ketone resin 10, which is a condensation product of cyclohexane and formaldehyde and has a softening point of 85 to 105°C, was placed in a 4-hour IA flask equipped with a stirrer, a thermometer, and a condenser.
0 parts, 100 parts of pyrogallol, and 12 g of p-toluenesulfonic acid were charged, and the reaction was carried out at 190° C. for 5 hours under a nitrogen atmosphere. After the reaction was completed, the reaction product was washed with pure water cooled to about 0°C.

After washing, dehydration, and drying, a blackish brown reaction product soluble in methanol, acetone, and alkali was obtained.

(Synthesis Example 2) A reaction product was obtained in the same manner as in Synthesis Example 1 except that hydroxyhydroquinone was used instead of pyrogallol.

(Synthesis Example 3) A reaction product was obtained in the same manner as in Synthesis Example 1 except that resorcinol was used instead of pyrogallol.

(Synthesis Example 4) Instead of the ketone resin used in Synthesis Example 1, a condensate of acetophenone formaldehyde with a softening point of 10
A reaction product was obtained in the same manner except that a ketone resin at 5 to 115°C was used.

(Synthesis Example 5) In the same manner as Synthesis Example 1, 100 parts of the ketone resin used in Synthesis Example 1, 100 parts of pyrogallol, and 12 g of p-toluenesulfonic acid were placed in a 4-hour IA flask equipped with a stirrer, a thermometer, and a condenser. Preparation, 3 at 190℃ under nitrogen atmosphere
After reacting for an hour, the mixture was cooled, 50 parts of 35% formaldehyde was added, and the reaction was further carried out under reflux for 2 hours. The reaction temperature was controlled by refluxing the water in the system.

11 one Then, a reaction product was obtained in the same manner as in Synthesis Example 1.

(Synthesis Example 6) In the same manner as Synthesis Example 1, 100 parts of pyrogallol, 50 parts of 35% formaldehyde, and 2000 parts of 50% phosphoric acid were charged into a 4-tube IA flask equipped with a stirrer, a thermometer, and a condenser. The reaction was carried out at ℃ for 1 hour to obtain a reddish-purple precipitate.

100 parts of the precipitate obtained by dehydrating and drying this, 100 parts of the ketone resin used in Synthesis Example 1, and 12 parts of p-toluenesulfonic acid.
g in the same flask and heated at 190℃ under nitrogen atmosphere for 5 hours.
After carrying out the reaction for a period of time, a reaction product was obtained in the same manner as in Synthesis Example 1.

(Synthesis Example 7) In the same manner as Synthesis Example 1, 100 parts of the ketone resin used in Synthesis Example 1, 100 parts of pyrogallol, and 50 parts of formaldehyde at a concentration of 35% were placed in a 1J2 4-tube flask equipped with a stirrer, a thermometer, and a condenser. , 6 parts of oxalic acid dihydrate were charged, and the reaction was carried out under a nitrogen atmosphere for 5 hours. The reaction temperature was controlled by refluxing the water in the system. After the reaction was completed, a reaction product was obtained in the same manner as in Synthesis Example 1.

(Synthesis Example 8) In the same manner as in Synthesis Example 1, an aqueous solution containing 128 parts of pyrogallol and 85 parts of 35% formaldehyde was added to a 50% by weight aqueous solution of phosphoric acid in an IA 4-tube flask equipped with a stirrer, a thermometer, and a condenser. 2000 copies plus 60°C
The mixture was reacted for 1 hour to obtain a water-insoluble solid.

(Comparative Example 1) In a stainless steel polymerization vessel with a content of 1 ffl, 2 ml of vinyl chloride was added.
00 kg, pure water 400 kg, partially saponified polyvinyl acetate 150 kg, and azobisdimethylvaleronitrile 60 g were added, and polymerization was carried out at 57° C. for 9 hours with stirring.

After the polymerization was completed, the amount of scale attached was measured, and the results shown in Table 1 were obtained.

(Comparative Example 2) The product obtained by the method of Synthesis Example 8 was made into a 3% acetone solution, sprayed onto the inner surface of the polymerization vessel used in Comparative Example 1, and dried. The amount of coating at this time was 0.4 g/bath.

When a polymerization reaction was carried out in the same manner as in Comparative Example 1 using this polymerization vessel, the amount of scale deposited was as shown in Table 1.

(Examples 1 to 7) Each of the products obtained by the methods of Synthesis Examples 1 to 7 was made into a 3% acetone solution, sprayed onto the inner surface of the polymerization vessel used in Comparative Example 1, and dried.

The coating amounts at this time were 0 and 4 g/d, respectively.

Using this polymerization vessel, a polymerization reaction was carried out in the same manner as in Comparative Example 1, and the scale adhesion amounts were as shown in Table 1.

(Comparative Example 3) In the same polymerization vessel as used in Example 1, vinyl chloride 190
10 kg of vinyl acetate, 450 kg of pure water, 180 g of partially saponified polyvinyl acetate, and 60 g of azobisdimethylvaleronitrile were added, and polymerization was carried out at 80° C. for 10 hours with stirring.

After the polymerization was completed, the polymerization vessel was washed with water under a pressure of 5 atm, and the amount of scale attached was measured. Table 2 shows the results.

(Comparative Example 4) The product obtained by the method of Synthesis Example 8 was made into a 3% acetone solution, sprayed onto the inner surface of the polymerization vessel used in Comparative Example 3, and dried. The amount of coating at this time was 0.4 g/bath.

When a polymerization reaction was carried out in the same manner as in Comparative Example 3 using this polymerization vessel, the amount of scale deposited was as shown in Table 2.

(Examples 8 to 14) Each of the products obtained by the methods of Synthesis Examples 1 to 7 was made into a 3% acetone solution, sprayed onto the inner surface of the polymerization vessel used in Comparative Example 3, and dried.

The coating amounts at this time were 0 and 4 g/d, respectively.

Using this polymerization vessel, a polymerization reaction was carried out in the same manner as in Comparative Example 3, and the scale adhesion amounts were as shown in Table 2.

(Comparative Example 5) In the same polymerization vessel as used in Example 1, chloroprene 200
kg, polyoxyethylene tallow alkylpropylene diamine 8 kg, acetic acid 2 kg, alumina sol 1 shoe, sodium formaldehyde sulfoxylate) 0.04 kg
Then, 200 kg of pure water was added, and the polymerization was completed in 10 hours at 40° C. while adding 0.02 kg of t-butyl hydroperoxide.

After polymerization, the polymerization vessel was washed with water under a pressure of 5 atm, and the amount of scale attached was measured. Table 3 shows the results.

(Comparative Example 6) The product obtained by the method of Synthesis Example 8 was made into an 8% acetone solution, and the solution was sprayed onto the inner surface of the polymerization vessel used in Comparative Example 5, and dried. The amount of coating at this time was 0.4 g/bath.

When a polymerization reaction was carried out in the same manner as in Comparative Example 5 using this polymerization vessel, the amount of scale deposited was as shown in Table 3.

(Examples 15 to 21) The products obtained by the methods of Synthesis Examples 1 to 7 were each made into a 3% acetone solution, sprayed onto the inner surface of the polymerization vessel used in Comparative Example 5, and dried.

The coating amounts at this time were 0 and 4 g/rd, respectively.

Using this polymerization vessel, a polymerization reaction was carried out in the same manner as in Comparative Example 5, and the scale adhesion amounts were as shown in Table 3.

Table 1 Table 2 Table 3 *1: The effective number of batches in the table refers to the fact that the scale adhesion prevention effect is lost because the applied scale adhesion preventive agent is peeled off by slurry stirring due to polymerization, and the quality of foreign matter, color, etc. This means the number of batches that can be effectively used until it becomes impossible to continue polymerization without washing any longer due to the adverse effect on the washing.

[Effects of the Invention] As explained above, the present invention significantly reduces the amount of scale adhesion and improves the number of effective batches by improving the durability of the coating film.

Claims (1)

[Scope of Claims] 1) When polymerizing a vinyl monomer in an aqueous medium, a reaction product of a ketone resin, a phenolic compound, and optionally an aldehyde compound is applied to the inner surface of the polymerization vessel in advance. A method for polymerizing vinyl monomers characterized by: 2) The polymerization method according to claim 1, wherein the vinyl monomer is vinyl chloride alone or a mixture of vinyl chloride and a monomer copolymerizable therewith. 3) The polymerization method according to claim 1, wherein the phenolic compound is pyrogallol and/or hydroxyhydroquinone.