JPH0323083B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinyl polymerization process. More specifically, the present invention relates to a vinyl polymerization method in which a hydrophilic vinyl monomer and a lipophilic vinyl monomer are copolymerized in a specific solvent. Conventionally, as a copolymerization method of a hydrophilic vinyl monomer and a lipophilic vinyl monomer, an aqueous solution polymerization method,
Emulsion polymerization methods, suspension polymerization methods, etc. are known, but these polymerization methods only yield copolymers with extremely low copolymerization ratios of hydrophilic vinyl monomers or extremely low amounts of lipophilic vinyl monomers. There were flaws. In order to improve these drawbacks, a method is known in which a hydrophilic vinyl monomer and a lipophilic vinyl monomer are copolymerized in a mixed solvent of dioxane, dimethylformamide, dimethyl sulfoxide, etc., and water. In the previously proposed method of polymerization in a mixed solvent of an organic solvent and water, the organic solvent used is highly toxic and flammable, and is also thermally unstable, making it inconvenient to handle. Ta. In addition, the method for recovering organic solvents from mixtures of organic solvents and water, or mixtures with solvents such as alcohol or acetone added as precipitants for polymers formed therein, may be complicated or difficult. There was also a drawback. The present inventors have discovered that in the copolymerization of such hydrophilic vinyl monomers and lipophilic vinyl monomers, the copolymerization ratio of these hydrophilic vinyl monomers and lipophilic vinyl monomers can be carried out at any ratio, and that the copolymerization can be carried out using conventional methods. As a result of researching methods that are easier to handle with organic solvents, we have developed a general formula for such polymerization.

They have found that the conventional drawbacks can be overcome by carrying out the process in a mixed solvent of alkylene carbonate and water represented by the formula: (wherein R is C ₂ H ₄ or C ₃ H ₆ ). Furthermore, according to the polymerization method of the present invention, the polymerization proceeds faster than the conventionally known polymerization method in a mixed solvent, and it is easy to form a copolymer of any ratio of hydrophilic vinyl monomer and lipophilic vinyl monomer. There is a characteristic that it can be obtained. Hydrophilic vinyl monomers to which the vinyl polymerization method of the present invention can be applied include monomers having hydrophilic functional groups such as amino groups, carboxyl groups, sulfonic acid groups, amide groups, hydroxyl groups, and quaternary ammonium bases. Examples of monomers having an amino group include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, diethylaminoethyl acrylate,
Examples include diethylaminoethyl methacrylate, diethylaminopropyl acrylate, diethylaminopropyl methacrylate, and the like. Examples of monomers having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and salts thereof, such as sodium salts, potassium salts, and ammonium salts. Examples of monomers having a sulfonic acid group include vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, vinylbenzylsulfonic acid, acryloyloxyethylsulfonic acid, acryloyloxypropylsulfonic acid, methacryloyloxyethylsulfonic acid, methacryloyloxypropylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid,
2-methacrylamido-2-methylpropanesulfonic acid and their sodium and potassium salts,
Examples include ammonium salts. Examples of monomers having an amide group include acrylamide, methacrylamide, hydroxyethylacrylamide, hydroxyethylmethacrylamide, hydroxypropylacrylamide,
Examples include hydroxypropyl methacrylamide. Examples of monomers having hydroxyl groups include 2-
Examples include hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate. Monomers having a quaternary ammonium base include, for example, acryloyloxyethyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, acrylamideethyltrimethylammonium chloride, methacrylamideethyltrimethylammonium chloride, acrylamidepropylmethylammonium chloride, methacrylamidepropyltrimethyl Examples include ammonium chloride. Other hydrophilic vinyl monomers include vinylpyridine, vinylpyrrolidone, N-acryloylpiperidine, and the like. Examples of lipophilic vinyl monomers to which the vinyl polymerization method of the present invention can be applied include acrylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and glycidyl acrylate. , methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, n-ethylhexyl methacrylate, lauryl methacrylate, glycidyl methacrylate, vinyl acetate, vinyl propionate, vinyl methoxy acetate, benbroic acid Examples include vinyl, vinyl esters such as vinyl salicylate, styrenes such as styrene, methylstyrene, and chlorostyrene, and olefins such as ethylene, butadiene, chloroprene, vinyl chloride, vinylidene chloride, acrylonitrile, and methacrylonitrile. The vinyl polymerization method of the present invention carries out the polymerization of the lipophilic vinyl monomer and the lipophilic vinyl monomer using the general formula

The polymerization is carried out by a conventional radical polymerization method in a mixed solvent of alkylene carbonate represented by the formula: (wherein R is C ₂ H ₄ or C ₃ H ₆ ) and water. The mixed solvent of the present invention uses a mixture of alkylene carbonate represented by the general formula and water, and the mixing ratio is selected depending on the ratio of hydrophilic vinyl monomer and lipophilic vinyl monomer used in polymerization. can. When the amount of hydrophilic vinyl monomer used is large, the ratio of water may be increased, and when the amount of lipophilic vinyl monomer used is large, the ratio of alkylene carbonate may be increased. To explain this further, the solvent composition of the present invention may be selected depending on the solubility of the mixture of hydrophilic vinyl monomer and lipophilic vinyl monomer in the solvent. The mixing ratio with alkylene carbonate is used in the range of 95 to 15 wt%.
Usually, the polymerization reaction is carried out by dissolving, emulsifying, or dispersing part or all of the target monomer in such a solvent, and then adding a radical polymerization initiator, but the vinyl monomer concentration in the solvent is 1. It is carried out within the range of ~20 wt%, preferably 3-15 wt%. If the monomer concentration is too high, the amount of precipitates during polymerization will increase, which is undesirable, and if the monomer concentration is too low, it is economically disadvantageous. Furthermore, the polymerization initiators used may be those known as conventional radical polymerization initiators, such as azobisisobutyronitrile, t-butyl hydroperoxide, kyumene hydroperoxide, benzoyl peroxide or potassium persulfate. Persulfates such as may also be used. Using such a radical polymerization initiator, polymerization is carried out at the polymerization temperature used in normal radical polymerization reactions, and the polymerization temperature is 10 to 100℃, usually 40 to 90℃.
You can do it with Thus, the present invention is useful as a method for copolymerizing a hydrophilic vinyl monomer and a lipophilic vinyl monomer, and the polymer obtained by the present invention can be prepared as a solution or suspension from the solvent of the present invention. It can be collected as a polymer using methods such as filtration, centrifugal sedimentation, or addition of a precipitant. Such polymers have the possibility of being widely used because hydrophilic groups are introduced at any ratio. For example, it can be used for ion exchange resins, ion exchange membranes or dialysis membranes, polyion complex membranes that can be used for ultrafiltration membranes, humidity sensors, etc., and can also be used as colored bodies for toner materials, etc., and for various resins. It can be used for various antistatic agents etc. by kneading or surface coating. EXAMPLES The present invention will be explained in more detail below with reference to Examples, but the scope of the present invention is not limited in any way by the description of these Examples. still,
In the Examples, the polymerization rate of the vinyl monomer was determined by quantifying unreacted vinyl groups using a bromine addition method. Example 1 Mixing commercially available ethylene carbonate and water
An 85 wt% ethylene carbonate aqueous solution was prepared and charged into a 180 g polymerization vessel. After charging 16.2 g of styrene and 4.4 g of spinomer (NaSS (sodium p-styrene sulfonate, purity 82.0 wt%, manufactured by Toyo Soda Kogyo, registered trademark. The same applies hereinafter) to a polymerization vessel and raising the temperature to 80°C, azobisisomer Butyronitrile 0.4
g was dissolved in 20 g of an 85 wt% ethylene carbonate aqueous solution, added to a polymerization vessel, and polymerized at 80°C. The polymerization reaction proceeded very smoothly, with a polymerization rate of 95 mol% after 3 hours and 98 mol% after 20 hours. The above polymerization reaction operation was carried out in a nitrogen gas atmosphere. The polymer was obtained in the form of a fine emulsion, which was dropped into a large amount of acetone to precipitate the polymer, which was then washed with water and dried under reduced pressure. When the polymer was subjected to elemental analysis, the results shown in Table 1 were obtained. Table-1 Measured value Calculated value (Note-1) C 84.2% 83.88% H 7.0% 6.98 S 2.7% 2.86 Note-1 Polymerization rate 100 from the amount of vinyl monomer charged
Calculated as %. Examples 2-4 Commercially available ethylene carbonate similar to Example 1
153 g and 27 g of water were mixed and an 85 wt% ethylene carbonate aqueous solution was charged into a polymerization vessel. Polymerization was carried out by the method shown in Example 1 using styrene and sodium p-styrene sulfonate having the composition shown in Table 2. The polymerization reaction proceeded very smoothly, and the polymerization rates after 3 hours and 20 hours were as shown in Table 2.

[Table] Examples 5 to 6 Polymerization was carried out in the same manner as in Example 2, except that the composition of the ethylene carbonate aqueous solution used was as shown in Table 3.

[Table] All polymers were obtained in a fine suspension state, which was poured into a large amount of acetone to precipitate the polymer, then washed with water and dried under reduced pressure. The monomer charge composition is 70 mol% styrene, p
- Sodium styrene sulfonate was 30 mol%, but by measuring the IR spectrum of the obtained polymer, the IR spectral characteristic absorption ratio of styrene homopolymer and sodium p-styrene sulfonate homopolymer (each 760 cm ^-1 The copolymerization composition of the polymer determined from the calibration curve obtained from , 840cm ^-1 ) is
It was calculated to be about 83 mol% styrene and about 17 mol% sodium p-styrene sulfonate. Example 7 153 g of commercially available ethylene carbonate and 27 g of water were mixed to prepare an 85 wt % ethylene carbonate aqueous solution and charged into a polymerization vessel. Metal methacrylate (purity 98.0wt%) 16.6g
and 4.6 g of spinomer NaSS were charged into a polymerization vessel and polymerized in the same manner as in Example 1. The polymerization reaction progressed very smoothly, and the polymerization rate of all monomers after 3 hours was 96 mol%, and after 7 hours it was 96 mol%.
Reached 99.5%. The solution after the polymerization was homogeneous and transparent. The polymer solution was dropped into a 3N hydrochloric acid aqueous solution to precipitate the polymer, which was then washed with water and dried under reduced pressure. When the composition ratio of each monomer was determined by elemental analysis of the polymer, the charging composition and polymer composition were as shown in Table 4.

[Table] Examples 8 to 11 Polymerization was carried out using methyl methacrylate and spinomer NaSS as monomers and the solvent and monomer compositions shown in Table 5. Polymerization temperature is 80℃,
Polymerization initiator is azobisisobutyronitrile 0.4g
The polymerization was conducted in the same manner as in Example 1, except that the polymerization initiator was dissolved in a solvent having the composition used in each example.

[Table] All polymerizations were very smooth, and the polymerization rate of all monomers after 3 hours was 99.5 mol% or more. Further, the polymer after completion of polymerization was obtained in the form of a fine emulsion or a dispersion of particles. The polymer dispersion was dropped into a 3N aqueous hydrochloric acid solution to precipitate a polymer, which was then washed with water and dried under reduced pressure. When we analyzed sulfur in the polymer, we found that
Each precipitated polymer was copolymerized with sodium p-styrene sulfonate. Example 12 153 g of commercially available ethylene carbonate and 27 g of water were charged into a polymerization vessel, and then 1 g of acrylonitrile was added.
After preparing 11.0 g of spinomer NaSS and raising the temperature to 60℃, 0.33 g of azobisisobutyronitrile was added.
It was dissolved in 20g of 85wt% ethylene carbonate aqueous solution and added, and polymerized at 60°C. Polymerization was carried out in a nitrogen atmosphere. After 5 hours of polymerization, the polymer solution was dropped into methanol to precipitate the polymer, which was then washed with water and dried under reduced pressure. The polymerization rate of all monomers was estimated to be 96 wt% or more based on the polymer yield. Example 13 85wt% using commercially available ethylene carbonate
An aqueous ethylene carbonate solution was prepared and 180 g was charged into a polymerization vessel. Styrene and 10.9g and methacrylate DMC (methacryloyloxyethyltrimethylammonium chloride, purity 80wt%, manufactured by Sanyo Chemical Industries) 11.5
g was charged into a polymerization vessel and the temperature was raised to 80℃, and then 0.4g of azobisisobutyronitrile was dissolved in 20g of an 85wt% ethylene carbonate aqueous solution and added to the polymerization vessel.
Polymerization was carried out at 80°C. The polymerization reaction proceeded smoothly, with a polymerization rate of 75 mol% after 3 hours and 92 mol% after 22 hours. The above polymerization reaction operation was performed in a nitrogen gas atmosphere. After 30 hours of polymerization, the polymer was obtained as a homogeneous transparent solution.

Claims (1)

[Scope of Claims] 1. A vinyl polymerization method characterized in that copolymerization of a hydrophilic vinyl monomer and a lipophilic vinyl monomer is carried out in a mixed solvent of an alkylene carbonate represented by the following general formula and water. general formula However, in the formula, R is C ₂ H ₄ or C ₃ H ₆ .