JPS6030682B2 - Method for polymerizing monomers having ethylenic double bonds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improved method for polymerizing monomers having ethylenic double bonds. The purpose of the present invention is to provide a method that can significantly prevent scale adhesion without being affected by the type (type, etc.).

Conventionally, known methods for polymerizing vinyl monomers include suspension polymerization, emulsion polymerization, solution polymerization, gas phase polymerization, and bulk polymerization. In either case, there was a problem of polymer scale adhesion on the inner walls of the polymerization vessel and other parts of the stirring device.

That is, when vinyl monomers are polymerized by these methods,
Polymer scale adheres to the inner wall of the polymerization vessel and the parts where the monomer comes in contact with the vessel, such as the stirring device, which reduces the polymer yield and cooling capacity of the polymerization vessel, and also causes the scale to peel off. This has the disadvantage of being mixed into the product and reducing the quality of the product.On the other hand, removing this adhered scale not only requires excessive effort and time, but also unreacted scale in this scale. monomers are adsorbed, so there is a disadvantage that there is a risk of injury to the human body due to the monomers (vinyl chloride, etc.), which has become a very serious problem in recent years.

Conventionally, in order to prevent polymer (scale) from adhering to the inner wall of a polymerization vessel, coating polar organic compounds such as amine compounds, quinone compounds, and aldehyde compounds has been used in some cases, for example, in the suspension polymerization of vinyl chloride. Methods or methods of adding these compounds into an aqueous medium are known.

However, these methods have the disadvantage that although they exhibit a scale adhesion prevention effect when polymerization is repeated up to 5 to 6 batches, the prevention effect disappears when the number of polymerization batches increases (poor sustainability). It was not completely satisfactory.

In addition, this method of applying a sacrificial organic compound exhibits a scale adhesion prevention effect in the case of suspension polymerization using an oil-soluble polymerization catalyst; There is a point at which it is difficult to prevent scale adhesion. In addition, for example, a stainless steel polymerization can is used to polymerize vinyl chloride, and in this polymerization can, styrene, styrene-butadiene,
When polymerizing acrylonitrile-butadiene-styrene, etc., there is a lot of scale adhesion, so in this case a glass-lined polymerization can is used. However, glass-lined polymerization cans have the drawbacks of low thermal coefficient and poor durability (-1), and are difficult to process, especially in the production of large-sized polymerization cans. The present inventors completed the present invention as a result of intensive research to solve such conventional problems. At the part where the polymer comes into contact, 'oi' is an alkali metal salt or ammonium salt of a sulfonated product obtained by sulfonating a condensate of an aromatic amine compound and an aromatic nitro compound, and 'oi is an alkali metal salt or an ammonium salt having 3 to 6 carbon atoms. p containing monohydric alcohol,
The present invention relates to a method for polymerizing a monomer having an ethylenic double bond, which comprises applying an aqueous solution of H7 or less and drying it.

When using the method of the present invention, it is possible to prevent the deposition of polymer scale on the inner wall of the polymerization vessel or on the parts such as a stirrer that come into contact with the monomer, regardless of whether the polymerization vessel is made of stainless steel or glass-lined. This effect can also be significantly prevented in suspension polymerization, emulsion polymerization,
In various types of polymerization such as bulk polymerization, this method has the advantage that it can be performed without being affected by the type of monomer or the composition of the polymerization system.

Therefore, the method of the present invention has the feature that it can be carried out using a stainless steel polymerization can even in fields that could not be practically carried out using a glass-lined polymerization can, and this method is also suitable for use as a coating solvent in terms of safety and hygiene. , has the advantage of using water that is non-toxic and harmless.

The mechanism by which the deposition of polymer scale is significantly prevented by the method of the present invention is that the coating agent made of the above-mentioned combination of Shitake and 'Rho ingredients is easy to apply and has good wettability to the surface to be coated. Also, the river component is soluble in water and shows alkalinity, but if this is adjusted to below 7 in advance, it will dry on the wall of the polymerization vessel and will no longer be soluble or soluble in water, and will be transferred to the wall. It is presumed that this is due to the strong adsorption of , which exerts a remarkable scale prevention effect.

In addition, the method of the present invention exhibits a remarkable scale prevention effect in any case with various polymerization methods and polymerization recipes, but this is probably because the surface charge of the coated surface is strongly anionic. amine compounds, quinone compounds,
This is thought to be because, unlike when an aldehyde compound or the like is applied, specific adsorption of all dissociated molecules and undissociated molecules present in the polymerization system is hindered.

The 'i' component constituting the so-called scale inhibitor in the present invention is an alkali metal salt or ammonium salt of a sulfonated product obtained by sulfonating a condensate of an aromatic amine compound and an aromatic nitro compound. The aromatic amine compound used for the production is a compound represented by the following general formula.

In the above formula, RI is one day, one NH2, one CI, one N=
N-C 6 days 5, 1OH, 1COCH3, 1OCH3, 1NH-C6 days 5, 1NH-C6 days 4-NH2, 1NH1C6 days 4-OCH3, 1N(CH3)2, 1NH1 C8
410H or an alkyl group having 1 to 3 carbon atoms,
R2 represents -day, one NQ, one OH, -C horse.

Such aromatic amine compounds include aniline, (
ortho, meta, para)phenylenediamine, (ortho,
Meta, para) aminophenol, (ortho, meta, para) chloroaniline, (ortho, meta, para) nitroaniline, (para) aminoazobenzene, 2,4-diaminoazobenzene, para-aminoacetanilide, (ortho, meta, para) ) Methylaniline, 4-aminodiphenylamine, 2-aminodiphenylamine, 4,4'-diami/diphenylamine, N,N-dimethyl-para-phenylenediamine, 4-amino-3'-methoxydiphenylamine, 4- Amino-i-hydroxydiphenylamine, 4-chloro-ortho-phenylenediamine, 4-methoxy-ortho-phenylenediamine, 2-nitro-para-phenylenediamine, 2-amino-4-chlorophenol, 2-amino-4-nitrophenol, 2-amino- Examples include 5-nitrophenol, 4-amino-2-nitrophenol, and 2-3-diaminotoluene.

Further, the aromatic nitro compound subjected to the condensation reaction with the aromatic amine compound is a compound represented by the following general formula.

In the above formula, R3 is 1OH, 1OCH3, -
OC2 days 5, 1 CI, 1 NH2, 1 COO days, 1 S03
represents the day.

Such aromatic nitro compounds include nitrobenzene, (ortho, meta, para)oxynitrobenzene, (
ortho, meta, para) nitroanisole, (ortho, meta, para) nitrophenethole, (ortho, meta, para) chloronitrobenzene, (ortho, meta, para) aminonitrobenzene, (ortho, meta, para) nit] Examples include benzoic acid and (ortho, meta, para) nitrobenzenesulfonic acid.

A key acid and a condensation catalyst are used to carry out the condensation reaction between the aromatic amine compound and the aromatic nitro compound described above, and examples of the hydrochloric acid include hydrochloric acid, nitric acid, hydrochloric acid, phosphoric acid, and sulfuric acid. Ru.

Suitable condensation catalysts include permanganic acid, permanganic acid and its salts such as potassium permanganate, chromic acid related compounds such as chromium trioxide, potassium dichromate, sodium chloride chromate, and silver nitrate. , nitric acid and its salts such as lead nitrate, halogens such as iodine, bromine, chlorine, fluorine, hydrogen peroxide, sodium peroxide,
Peroxides such as benzoyl peroxide, potassium persulfate, ammonium persulfate, peracetic acid, cumene hydroperoxide, benzoic acid, p-methane hydroperoxide, iodic acid, potassium iodate, chlorine Oxygen acids or salts such as sodium chloride, ferrous chloride, ferric chloride, steel sulfate, metal salts such as cuprous chloride, cupric chloride, lead acetate, ozone, oxygen such as oxygen kind,
Examples include oxidized steel, mercury oxide, cerium oxide, manganese dioxide, and acid oxides such as osmic acid. A condensate is obtained by aging at least one aromatic amine compound and at least one aromatic nitro compound at 150 to 250°C for 10 to 3 q hours in the presence of the above-mentioned stannic acid and condensation catalyst. It will be done. The produced condensate is influenced by the type, composition ratio, reaction temperature, and reaction time of the aromatic amine compound, aromatic nitro compound, condensation catalyst, and grandson acid, but in the present invention, the aromatic nitro compound is It is preferable that the amount of the compound be 0.15 to 0.50 mol. If it is below the lower limit of this range, the scale prevention effect will decrease in the bottle-soluble polymerization catalyst system, and if it is above the upper limit, aromatic nitro The compound remains and the scale prevention effect decreases. In addition, the condensation catalyst is 0.03 to 0.50 mol, and the hydrogenated acid is 0.02 mol per mol of the aromatic amine compound.
It is preferable to use it in a range of 0.50 mol to 0.50 mol. Note that it may be a condensate obtained by first subjecting an aromatic amine compound to a condensation reaction in the presence of a condensation catalyst and stannic acid, and then subjecting this to a condensation reaction with an aromatic nitro compound.

The condensate obtained by condensing an aromatic amine compound and an aromatic nitro compound in this way is then sulfonated, and this sulfonation itself can be carried out according to any conventionally known method. , e.g. sulfuric acid as a sulfonating agent,
Using fuming sulfuric acid, chlorosulfonic acid, etc., the reaction temperature is 3.
The sulfonated product can be obtained by reacting the condensate at a concentration of 5 to 9 pi and the concentration of the sulfonating agent is 2 to 1 volume (weight) of the condensate.

Next, the desired component can be obtained by reacting this sulfonated product with an alkali metal compound or an ammonium compound.This reaction method involves, for example, dispersing the sulfonated product in water and adding Na to it under heating.
The desired alkali metal salt or ammonium salt of the sulfonate can be obtained by adding a predetermined amount of an alkali metal compound such as OH, KOH, Na2C03 or an ammonium compound such as NH40 or (N is)2C03 and causing a reaction.

Since this product is water-soluble, it can be obtained dissolved in aqueous solution, but it may be mixed as is with a predetermined amount of the raw component described later, or it may be evaporated to dryness and pulverized. It may also be made into a powder form, which is convenient for storage and transportation. On the other hand, {low components include -hydric alcohols having 3 to 6 carbon atoms, such as bropyl alcohol, n-butyl alcohol, lso-butyl alcohol, sec-butyl alcohol, and
-Butyl alcohol, n-amyl alcohol, t-amyl alcohol, ISO-amyl alcohol, SeC-amyl alcohol, SeC-hexyl alcohol, etc. are used, and one or more of these are finally adjusted. By adding it to a concentration of approximately 1 to 2% by weight in an aqueous liquid as a coating liquid,
A scale-preventing coating solution that wets the inner wall of the polymerization vessel (made of stainless steel, etc.) well can be obtained.

In carrying out the method of the present invention, first of all, the above-mentioned 'a component and' are used.

}Adjust the aqueous liquid containing the ingredients by dissolving the ingredients in water at a concentration appropriate for the coating operation, but the concentration of the 'i ingredient should be approximately 0.01% by weight or more. If the concentration is lower than this, it will be difficult to form a water-soluble film with the desired thickness on the inner wall surface of the polymerization vessel, which is mainly composed of the component. On the other hand, there is no particular limit on the upper limit of this concentration, but if the concentration is higher than necessary, it will be economically disadvantageous, and in extreme cases, it will interfere with the coating work.
Generally it should be up to about 5% by weight. In addition, as described above, the 'o component may be blended in a concentration of approximately 1 to 2% by weight in the final aqueous liquid. In addition, when preparing the aqueous liquid, Organic solvents that are easily miscible with water, such as alcohols with 1 or 2 carbon atoms, ester solvents, ketone solvents, etc., may be used in combination with water. Drying after application to etc. becomes easier.
On the other hand, the aqueous liquid prepared in this way can obtain an excellent scale prevention effect by making it an aqueous liquid with a pH of 7.0 or less in advance, but it is used to make this pH 7.0 or less. Substances include sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, carbonic acid, perchloric acid, molybdic acid, tungstic acid, formic acid, acetic acid, oxalic acid, lactic acid, maleic acid, glycolic acid, thioglycolic acid, and phytic acid. are exemplified, and it is convenient to prepare these as an aqueous solution in advance.

In the method of the present invention, the above-mentioned aqueous liquid is applied in advance to the inner wall of the polymerization vessel and other parts that come into contact with the monomer, and then dried. Either method can be used, such as blowing air onto the surface to dry it, or preheating the inner wall of the polymerization vessel and other parts that come into contact with the monomer (to 40 to 10 degrees Fahrenheit), applying it directly to the heated surface, and drying it. However, if necessary, wash the coated surface with water after thoroughly drying it.

Since the film formed by drying is insoluble in water, it will not be eluted and removed by washing with water. The amount of the aqueous solution applied to the inner wall of the polymerization vessel, etc. after drying is 0.001 m/m or more to the inner wall of the polymerization vessel, the stirrer, etc. to fully exhibit the scale prevention effect. In addition,
When applying the above aqueous solution to the inner wall of the polymerization vessel, etc.
There is no problem in precoating the inner walls of the polymerization vessel with an organic solvent solution-type scale prevention coating solution containing a conventionally known organic dye or other organic polar compound as the main ingredient. The effect is that the formation of the scale prevention film on the inner wall of the polymerization vessel is more reliably and firmly performed.

After coating the inner walls of the polymerization vessel and other areas that come into contact with the monomer, add the aqueous medium, monomer, polymerization initiator, and other necessary ingredients to the polymerization vessel in the usual manner. Agents such as monomer dispersion aids are charged and polymerized.

The method of the present invention is applied to the polymerization of various monomers having ethylenic double bonds, and specific examples of these monomers include vinyl halides such as vinyl chloride, vinyl acetate, and propionic acid. Vinyl esters such as vinyl, acrylic acid, methacrylic acid or their esters or salts, maleic acid or fumaric acid and their esters or anhydrides, butadiene. , chlorobrene,
Gen-based monomers such as isoprene, as well as styrene,
Examples include acrylonitrile, halogenated pinylidene, and pinylether.

When polymerizing one or more of these monomers, the purpose of scale prevention can be effectively achieved regardless of the polymerization format or polymerization recipe. For example, suspension polymerization or emulsion polymerization of vinyl monomers The additives added to the polymerization system in the case of
Suspending agents such as partially saponified polypinyl alcohol and methylcellulose, anionic emulsifiers such as sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and sodium dioctyl sulfosuccinate, nonionic emulsifiers such as sorbitan monolaurate, and polyoxyethylene alkyl ether. , fillers such as calcium carbonate and titanium oxide, stabilizers such as tribasic lead sulfate, calcium stearate, dibutyltin dilaurate, and dioctyltin mercaptide, thickeners such as rice wax and stearic acid, and plasticizers such as DOP and DBP. agent, trichloroethylene,
Chain transfer agents such as mercaptans, pH adjusters, diisopropyl peroxydicarbonate, Q,Q'-azobis-2,4-day dimethylvaleronitrile, lauroyl peroxide, potassium persulfate, cumene hydro/gu oxide, p- Scale adhesion is effectively prevented in a polymerization system in which a polymerization catalyst such as menthane hydroperoxide is present.

The method of the present invention is particularly suitably carried out by suspension polymerization or emulsion polymerization of vinyl halides such as vinyl chloride or pinylidene halides, or monomers or mixtures containing these as main components. In addition, in the case of the production of polymers such as polystyrene, polymethyl methacrylate, and polyacrylonitrile, the production of polymer beads and latex, and the production of synthetic rubbers such as SBR, NBR, CR, IR, and 11R (these synthetic rubbers are usually emulsion polymerized). This is the case for the production of ABS resin (manufactured by ABS).

Next, specific examples will be given. However, as the water-soluble condensate (scale inhibitor), one manufactured as follows was used.

Mizuaya compound M, 1 chick: In the reactor, aniline 200.0
(2.1 mol), ortho-phenylenediamine 20
0.0 mol (1.9 mol), 120.0 mol (0.8 mol) of ortho-oxynitobenzene, and 1 liter of 35% hydrochloric acid.
AB8 (1.2 mol) was charged and cooled to below 1.0 mol.

Next, add 200% ammonium persulfate with a smoke weight of 4% to this.
0.0 mol (0.351 mol) was added dropwise and the temperature was raised to 60° C., and the mixture was allowed to ripen at the same temperature for 6 hours.Then, the temperature was raised to 185°C, and the water produced was removed at the same temperature. The reaction was carried out for one hour. During this time, some aniline will be mixed into the water used to remove the crabs, but
This was separated from water and then returned to the reactor. Furthermore, the internal temperature was raised to 21 psi, and the reaction was continued for 5 hours. The reaction mixture (molten material) obtained by the reaction was poured into dilute hydrochloric acid, heated at 60°C for 3 hours, and filtered while hot to remove unreacted aniline and orthophenylenediamine.

Furthermore, in order to remove excess hydrochloric acid, the mixture was washed with water six times and dried to obtain condensate 2352. After mixing 50 μm of the condensate obtained above and 300 μm of concentrated sulfuric acid at a temperature below 30°C, the mixture was heated to 4° C. At this temperature, the dilute N content was rapidly and completely dissolved in the OH. Stir until sulfonated.

This reaction solution was poured into 1,000 ml of water, and the sulfonated product was filtered and washed with water, then dispersed in 1,000 ml of water.
After adding and dissolving 11.3 ml of a 4% by weight aqueous NaOH solution at a temperature of 0.9° C., the mixture was evaporated to dryness and pulverized to obtain 52.0 ml of a water-dropping condensate (sodium metal salt of sulfonate). Water-soluble condensate M. Production of M.2-20: Using the aromatic amine compound, aromatic nitro compound, condensation catalyst and mineral acid shown in Table 1, the water-soluble condensate M. The condensation reaction was carried out under the same reaction conditions and reaction operations as in case 1, and a water-soluble condensate M.
I got 2-20.

Table 1 Example 1 As shown in Table 2, a water-soluble condensate was dissolved in water to make an aqueous solution with a concentration of 1% by weight, and this was adjusted to the pH shown in the table.
Add a regulator to adjust the pH and add to this aqueous solution.

'A coating solution was obtained by adding alcohol. However, the amount of alcohol added (parts by weight) is expressed as the amount per 10 parts by weight of the aqueous solution in which the component [A] is dissolved. This coating liquid was applied to the inner wall of a polymerization vessel with an internal volume of 1000 and equipped with a stirrer and the portion of the stirrer that would come into contact with the monomer, and dried under the heat drying conditions shown in Table 2.

Add 20% of pinyl chloride monomer to the polymerization vessel coated in this way.
0k9, water 400k9, partially saponified polyvinyl alcohol 250k, hydroxypropyl methylcellulose 25
Diisopropyl peroxydicarbonate 75
The mixture was prepared and polymerization was carried out for 1q hours at an internal temperature of 57° C. while stirring.

After the polymerization was completed, the amount of scale adhesion (T/R) was measured, and the results were as shown in Table 2.

In the same table, experimental yuzu to which alcohol other than the present invention was added. 20
has poor scale adhesion prevention effect. Also, the experimental site.
21 and lungs. The amount of scale deposited on pine is large because the molar ratio of aniline and nitrobenzene in the water-dropping condensate used as a coating agent is not within an appropriate range. Table 2 Example 2 In advance, a second
The coating agent shown in the table was applied, dried by heating, and thoroughly washed with water.

Next, 26 k9 of pinyl chloride monomer, 52 k9 of water, 26 k9 of partially saponified polyvinyl alcohol, and 8 moles of Q,Q'-2,4-dimethylvaleronitrile were charged into the polymerization vessel coated in this way, and stirred. Polymerization was carried out for 1q hours at an internal temperature of 570° C. After the polymerization was completed, the amount of scale was measured and the results were as shown in Table 3. Really dangerous place.
But I showed it.

However, the experimental shipboard in the same table. 35 is a water-soluble condensate M. 5
The water-soluble condensate produced under the same conditions except that nitrobenzene was removed was dissolved in water to make an aqueous solution with a concentration of 1% by weight.
This is a case where a coating solution was used in which 1% by weight of lso-butyl alcohol was added after adjusting the pH value to 2.5 with sulfuric acid, but this was determined experimentally. Compared to No. 26, the amount of scale adhesion is extremely large.

Table 3 Example 3 Contents 50 The coating solution shown in Table 4 was applied to the inner wall of a stainless steel polymerization vessel equipped with a stirrer and the portion in contact with the monomer of the stirrer, and then dried by heating and washed with water.

Next, 20k9 of water and 10k of styrene monomer were added to this polymerization vessel.
k9, calcium phosphate 100g, sodium dodicylbenzenesulfonate 10g and penzoyl peroxide 10g
After adding water, polymerization was carried out at 90° C. for 11 hours while stirring. After the polymerization was completed, the amount of scale was measured.
It was as shown in Table 4. The coating agent column in the same table is the experimental site of the coating agent already used in Example 1. But I showed it.

Table 4 Example 4 After applying the coating solution shown in Table 5 to the inner wall of the stainless steel polymerization vessel with an internal volume of 50 and the part of the stirrer that comes into contact with the monomer, the coating solution shown in Table 5 was dried by heating at 90q0 for 10 minutes and washed with water. did.

Next, using the polymerization vessel coated in this way, polymerization was carried out under the same preparation and conditions as in Example 2. After the polymerization is completed, the polymerization product is taken out, the inside of the polymerization vessel is washed with water, and the above preparation is performed again.The number of polymerizations that can be performed without the amount of scale adhesion exceeding 1 evening/day (number of times scale prevention)
The results were as shown in Table 5. The coating agent column in the same table is the one already used in Example 1 in Experiment M.
．． But I showed it.

Table 5

Claims (1)

[Claims] 1. When polymerizing a monomer having an ethylenic double bond, (a) an aromatic amine compound and an aromatic nitro compound are preliminarily added to the portion that contacts the inner wall of the polymerization vessel with other monomers. An aqueous solution with a pH of 7 or less containing an alkali metal salt or ammonium salt of a sulfonate obtained by sulfonating a condensate with (b) a monohydric alcohol having 3 to 6 carbon atoms is applied and dried. A method for polymerizing a monomer having a characteristic ethylenic double bond. 2. Claim 1, wherein the condensate is obtained by subjecting an aromatic amine compound and an aromatic nitro compound to a condensation reaction in the presence of a condensation catalyst in a temperature range of 100 to 250°C.
Polymerization method described in section.