JP6512591B2 - Method for producing purified polyvinylamine - Google Patents

Description

The present invention relates to a method of producing purified polyvinylamine.

Polyvinylamine can potentially be used in various applications such as laminating anchors, adhesives, dye binders, antistatic agents, etc., but by-products are generated during the manufacturing process and can not be removed efficiently. It was difficult to use for these applications. About the method of producing | generating polyvinylamine, the method (patent document 1) of making it precipitate on alkaline conditions, and the method (patent document 2) of producing with an ultrafiltration membrane are examined. Among them, in the method of depositing under alkaline conditions, the polymer content in the deposit was as low as about 60%, which was insufficient. In the method of producing with an ultrafiltration membrane, there is a problem that, particularly when the molecular weight cut-off is reduced, the treatment speed is slowed and purification takes time. Therefore, there is a need for an efficient method of producing purified polyvinylamine free of impurities.

JP-A-7-118333 JP 2006-521433 gazette

An object of the present invention is to efficiently obtain a purified polyvinylamine containing few impurities by a simple operation.

As a result of examining in order to achieve the above-mentioned subject, impurities can be easily removed by washing with water by obtaining a crosslinked polyvinylamine cross-linked copolymer in advance, and then polyvinylamine which is easily purified by oxidative decomposition is obtained. Found out that

That is, according to the method for producing purified polyvinylamine in the present invention, polyvinylamine crosslinking is carried out by hydrolyzing the crosslinked copolymer after copolymerizing N-vinylcarboxylic acid amide and a polyvinyl compound to obtain a crosslinked copolymer. The present invention relates to a method for producing a polyvinylamine which is converted to a copolymer and washed and removed from residual compounds such as by-products by water washing, and then purified by oxidative decomposition.

According to the present invention, by-products and the like produced in the production process can be easily removed, and purified polyvinylamine can be produced conveniently and efficiently.

The present invention will be described in detail below.

There is no particular limitation on the method for obtaining the cross-linked copolymer of N-vinyl carboxylic acid amide and polyvinyl compound, but known solution polymerization method, suspension polymerization method, emulsion polymerization method, bulk polymerization method, etc. may be appropriately applied. Ru.

The method for producing a crosslinked copolymer by the reverse phase suspension polymerization method will be described. In the reverse phase suspension polymerization, an N-vinylcarboxylic acid amide, a polyvinyl compound, a polymerization initiator, and optionally water are mixed, and the dispersion stabilizer is contained in an organic solvent of an oil-like substance consisting of water and a non-miscible hydrocarbon. The reaction can be carried out by generating monomer droplets by stirring and using radical polymerization.

Examples of N-vinylcarboxylic acid amide monomers include N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylformamide, N-methyl-N-vinylacetamide, in particular N-vinylamide. It is preferred to use formamide.

As polyvinyl compounds, aromatic polyvinyl compounds such as divinylbenzene, trivinylbenzene, divinyltoluene, etc., ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerol di (meth) acrylate, trimethylolpropane tri (meth) It is also possible to use poly (meth) acrylates such as acrylate, methylene bis acrylamide and the like. However, it is preferable to use an aromatic divinyl compound because poly (meth) acrylate, methylene bis acrylamide and the like are easily hydrolyzed. Most preferred is divinylbenzene. The amount of the polyvinyl compound is preferably 0.01 to 10% by mass with respect to all the polymerizable monomers. Moreover, 0.1-5 mass% is still more preferable.

Examples of the polymerization initiator include azo-based and peroxide-based polymerization initiators such as 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobis (4-methoxy-2,4-dimethylvalero). Nitrile), 2,2'-azobis (2-methylpropionitrile), 2,2'-azobis-2-amidinopropane hydrochloride, 4, 4-azobis-4-cyanovaleric acid, 2,2'-azobis [ 2- (5-Methyl-imidazolin-2-yl) propane] hydrochloride, 2, 2'-azobis [2- (2-imidazolin-2-yl) propane] hydrochloride etc., ammonium or potassium peroxodisulfate, peroxide Hydrogen, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, succinic peroxide, t-butylperoxy-2- Chill hexanoate, and the like. The amount thereof used is usually 0.02 to 5% by mass, preferably 0.05 to 2% by mass, based on the monomer.

Examples of oil-like substances composed of hydrocarbons immiscible with water include paraffins or kerosene, light oil, mineral oil such as medium oil, or hydrocarbon-based synthesis having characteristics such as boiling point and viscosity substantially in the same range as these Oils or mixtures thereof are mentioned. The content is 50 to 100% by mass with respect to the total amount of the suspension medium.

  As a dispersion stabilizer, ethyl cellulose, sorbitan monooleate, etc. are used. The addition rate is usually 0.05 to 5% by mass, preferably 0.1 to 2% by mass, with respect to the organic solvent of the suspension medium.

The polymerization reaction is usually carried out at a temperature of 30 ° C. to 100 ° C. for 1 hour to 15 hours.

After completion of the polymerization, the organic solvent can be removed by azeotropic removal or washing with a solvent such as acetone. The dispersion stabilizer can be removed by washing with a solvent such as acetone.

As another method of obtaining the cross-linked copolymer of N-vinyl carboxylic acid amide and a polyvinyl compound, it can manufacture by the suspension polymerization method in salt solution.

Suspension polymerization in aqueous salt solution generates monomer droplets by suspending N-vinyl carboxylic acid amide, polyvinyl compound, polymerization initiator, and dispersion stabilizer in brine and stirring to generate radical polymerization. It can be done by The particle diameter of the monomer droplet is controlled by the dispersion stabilizer and the stirring strength, and is 0.01 mm to 10 mm, preferably 0.1 mm to 5 mm.

Examples of N-vinylcarboxylic acid amide monomers include N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylformamide, N-methyl-N-vinylacetamide, in particular N-vinylamide. It is preferred to use formamide.

As polyvinyl compounds, aromatic polyvinyl compounds such as divinylbenzene, trivinylbenzene, divinyltoluene, etc., ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerol di (meth) acrylate, trimethylolpropane tri (meth) It is also possible to use poly (meth) acrylates such as acrylate, methylene bis acrylamide and the like. However, it is preferable to use an aromatic divinyl compound because poly (meth) acrylate, methylene bis acrylamide and the like are easily hydrolyzed. Most preferred is divinylbenzene. The amount of the polyvinyl compound is preferably 0.01 to 10% by mass with respect to all the polymerizable monomers. Moreover, 0.1-5 mass% is still more preferable.

Examples of the polymerization initiator include azo-based and peroxide-based polymerization initiators such as 2,2′-azobis (2,4-dimethylvaleronitrile) and 2,2′-azobis (4-methoxy-2,4-dimethylvalero). Nitrile), 2,2'-azobis (2-methylpropionitrile), 2,2'-azobis-2-amidinopropane hydrochloride, 4, 4-azobis-4-cyanovaleric acid, 2,2'-azobis [ 2- (5-Methyl-imidazolin-2-yl) propane] hydrochloride, 2, 2'-azobis [2- (2-imidazolin-2-yl) propane] hydrochloride etc., ammonium or potassium peroxodisulfate, peroxide Hydrogen, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, succinic peroxide, t-butylperoxy-2- Chill hexanoate, and the like. The amount thereof used is usually 0.02 to 5% by mass, preferably 0.05 to 2% by mass, based on the monomer.

  Examples of the salt include ammonium sulfate, sodium sulfate, ammonium chloride, sodium chloride, calcium chloride and the like, and these may be used alone or in combination. The addition rate is in the range of 50 to 100% by mass with respect to water, and if less than 50% by mass, the N-vinylcarboxylic acid amide does not separate into two phases, and the effect by the salt is sufficient at 100% by mass.

As a dispersion stabilizer, a polymer dispersant is preferable. As the polymeric dispersant, either ionic or non-ionic can be used, but is preferably ionic. Examples of the ionic polymer include those obtained by polymerizing (meth) acryloyloxyethyltrimethylammonium chloride, dimethyldiallylammonium chloride and the like which are cationic monomers. Copolymers with mer can also be used. Examples of nonionic monomers include acrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, N, N-dimethylacrylamide, acrylonitrile, diacetoneacrylamide, 2-hydroxyethyl (meth) acrylate Etc. Examples of nonionic dispersants include polyvinyl alcohol and polyethylene glycol polyacrylamide. The addition rate is usually 0.05 to 5% by mass, preferably 0.1 to 2% by mass, with respect to the organic solvent of the suspension medium.

The polymerization reaction is usually carried out at a temperature of 30 ° C. to 100 ° C. for 1 hour to 15 hours.

After polymerization, the salt, dispersion stabilizer, unreacted monomer and the like can be removed by washing with water.

In addition, as a method of obtaining the cross-linked copolymer of N-vinyl carboxylic acid amide and a polyvinyl compound, bulk polymerization method etc. can also be used. In the case of bulk polymerization, after completion of the polymerization, it is pulverized and granulated, and if necessary, residual monomers can be removed by vacuum drying or the like to proceed to the next step.

The crosslinked copolymer particles are purified as described above and subjected to hydrolysis. The hydrolysis of the cross-linked copolymer particles polyvinylcarboxylic acid amide can be carried out under basic conditions, acidic conditions, but in order to obtain free polyvinylamine, it is preferable to hydrolyze under basic conditions .

The base suitable for the hydrolysis is not particularly limited as long as the pH can be in the range of 8 to 14 during the hydrolysis, and it is most preferable to use an aqueous solution of sodium hydroxide, potassium hydroxide or ammonia. The addition rate is preferably 0.05 to 2, more preferably 0.4 to 1.2 equivalents based on the formyl group of the polymer.

The acid suitable for the hydrolysis is not limited as long as the pH can be in the range of 0 to 5 during the hydrolysis, and inorganic acids such as hydrohalic acid, sulfuric acid, nitric acid and phosphoric acid, C 1 carbon number Examples of organic acids such as mono and dicarboxylic acids, sulfonic acids, benzenesulfonic acids and toluenesulfonic acids in the range of 1 to 5 can be exemplified, and it is particularly preferable to use a gas of hydrohalic acid and hydrogen halide, and use hydrohalic acid Is most preferred. The addition rate is preferably 0.05 to 2, more preferably 0.4 to 1.2 equivalents based on the formyl group of the polymer.

After hydrolysis, the by-product is washed with water or the like to obtain a purified polyvinylamine copolymer. In the case of base hydrolysis, free polyvinylamine copolymer particles are obtained, and in the case of acid hydrolysis, salt type polyvinylamine copolymer particles are obtained.

Next, the oxidative decomposition reaction process is described. By oxidatively decomposing the polyvinylamine copolymer particles with an oxidizing agent, the particles become liquid, and polyvinylamine can be obtained. For oxidative decomposition, hydrogen peroxide, persulfates such as ammonium persulfate and the like can be used, but in view of the residue, hydrogen peroxide is preferred. The amount of the oxidizing agent is 0.1 to 10 g / g, preferably 0.3 to 5 g / g based on the dry weight of the polyvinylamine copolymer particles. The temperature of the oxidation reaction depends on the reaction time, preferably 30 ° C. to 100 ° C.

  The composition of the resulting polyvinylamine, that is, the mole fraction of vinylamine units, is appropriately adjusted by the hydrolysis rate of the N-vinylcarboxylic acid amide polymer. The acid amide group is cationized by converting it to an amino group, but the degree of hydrolysis, that is, the degree of amination, is in the range of 10 to 100 mol% as applied to the present invention.

  The weight average molecular weight of the polyvinylamine obtained by the production method of the present invention is in the range of 1000 to 100000 as measured by gel permeation chromatography (GPC) in terms of polyethylene glycol.

  According to the present invention, highly purified free polyvinylamine or salt type polyvinylamine can be obtained by a simple and efficient method.

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1
(Polymerization reaction) In a 300 mL separable flask, 100 g of naphthenic hydrocarbon oil (Exhol D110, Exxon Mobil), 0.4 g of dispersion stabilizer sorbitan monooleate and 0.2 g of ethylcellulose are added, stirred, did. 49.9 g of N-vinylformamide, 0.2 g of divinylbenzene (55% by mass of pure content), 1 g of demineralized water, azo polymerization initiator 2, 2'-azobis [2- (2-imidazolin-2-yl) propane] 0.20 g of hydrochloride (VA-044, manufactured by Wako Pure Chemical Industries, Ltd.) was mixed to obtain a monomer solution. The monomer solution and the polymerization bath were mixed and stirred at 300 rpm while displacing the flask with nitrogen. After 30 minutes, polymerization was carried out at 50 ° C. for 4 hours and at 60 ° C. for 2 hours. After polymerization, the oil was removed by filtration, washed with acetone and vacuum dried to obtain 37.9 g of dried polyvinylformamide particles.

(Hydrolysis reaction) 10 g of dried polyvinylformamide particles were placed in a four-necked flask, and 100 g of demineralized water and 14.1 g of 48% by mass sodium hydroxide were added to obtain basic conditions. After holding at 80 ° C. for 4 hours, it was allowed to cool to room temperature. Thereafter, filtration and washing with water were repeated three times to remove by-products. After filtration, 123 g of purified water-containing polyvinylamine particles were obtained.

(Oxidative decomposition reaction) 10.0 g of 35 mass% hydrogen peroxide was added to 103.4 g of polyvinylamine particles in a water-containing state, and kept at 70 ° C. for 2 hours. After that, 1.0 g of 35 mass% hydrogen peroxide was further added and maintained for 6 hours. The polyvinylamine particles were oxidatively decomposed to obtain a transparent uniform solution. Hydrogen peroxide decomposes into oxygen and water, so no impurities are generated. The obtained free purified aqueous polyvinylamine solution was subjected to colloid titration under acidic conditions (pH 4) to determine the ion group density, which was 11.0 meq / g.

(Example 2)
(Polymerization reaction) 50.1 g of demineralized water, 32.0 g of ammonium sulfate, and 1.0 g of an aqueous solution of polyacryloyloxyethyl trimethyl ammonium chloride (polymer concentration 20 mass%, weight average molecular weight 800,000) are added to a 300 mL separable flask and homogenized. It was a solution. Here, 30.0 g of vinyl formamide, 0.15 g of divinylbenzene (55% by mass of pure content), azo polymerization initiator 2, 2′-azobis (4-methoxy-2, 4-dimethylvaleronitrile) (V-70) A monomer solution in which 0.09 g of Wako Pure Chemical Industries, Ltd. was made into a uniform solution was added, and nitrogen substitution was performed for 30 minutes while stirring at 300 rpm. Thereafter, polymerization was carried out at 40 ° C. for 1.5 hours and at 60 ° C. for 1.5 hours. After polymerization, washing with water and filtration were repeated to remove ammonium sulfate and polyacryloyloxyethyl trimethyl ammonium chloride. As a result, 33.7 g of polyvinyl formamide particles in a water-containing state in solid conversion of 23.7 g were obtained.

(Hydrolysis reaction) In a 300 ml separable flask, 154 g of polyvinyl formamide particles in a wet state (10 g in terms of solid content) and 17.6 g of a 48% by mass aqueous solution of sodium hydroxide are charged, and kept at 80 ° C. for 5 hours under basic conditions. did. After cooling to room temperature, filtration and washing with water were repeated three times to remove by-products. After filtration, 233 g of purified water-containing polyvinylamine particles were obtained.

(Oxidative decomposition reaction) 5.0 g of 35 mass% hydrogen peroxide was added to 102.6 g of polyvinylamine particles in a water-containing state, and kept at 60 ° C. for 8 hours. The polyvinylamine particles were oxidatively decomposed to obtain a transparent uniform solution. Hydrogen peroxide decomposes into oxygen and water, so no impurities are generated. The obtained free purified aqueous polyvinylamine solution was subjected to colloid titration under acidic conditions (pH 4) to determine the ion group density, which was 16.7 meq / g.

(Example 3)
(Polymerization reaction) 50.0 g of demineralized water, 32.1 g of ammonium sulfate, and 1.1 g of a polyacryloyloxyethyl trimethyl ammonium chloride aqueous solution (polymer concentration 20 mass%, weight average molecular weight 800,000) are added to a 300 mL separable flask and homogenized. It was a solution. Here, 29.7 g of vinyl formamide, 0.29 g of divinyl benzene (55 mass% of pure part), azo polymerization initiator 2, 2'-azobis (4-methoxy-2, 4-dimethyl valeronitrile) (V-70) A monomer solution in which 0.09 g of Wako Pure Chemical Industries, Ltd. was made into a uniform solution was added, and nitrogen substitution was performed for 30 minutes while stirring at 300 rpm. Thereafter, polymerization was carried out at 45 ° C. for 3 hours and at 60 ° C. for 2 hours. After polymerization, washing with water and filtration were repeated to remove ammonium sulfate and polyacryloyloxyethyl trimethyl ammonium chloride. As a result, 322 g of polyvinyl formamide particles in a water-containing state in solid conversion of 29.7 g were obtained.

(Hydrolysis reaction) In a 300 mL separable flask, 107.4 g (10 g solid equivalent) of water-containing polyvinylformamide particles and 19.0 g of a 48 mass% aqueous solution of sodium hydroxide are added, and the basic conditions are I kept it for a while. After cooling to room temperature, filtration and washing with water were repeated three times to remove by-products. After filtration, 115.2 g of purified water-containing polyvinylamine particles were obtained.

(Oxidative decomposition reaction) 5.0 g of 35 mass% hydrogen peroxide was added to 50.5 g of polyvinylamine particles in a water-containing state, and kept at 70 ° C. for 11 hours. The polyvinylamine particles were oxidatively decomposed to obtain a transparent uniform solution. Hydrogen peroxide decomposes into oxygen and water, so no impurities are generated. The obtained free polyvinylamine aqueous solution was subjected to colloid titration under acidic conditions (pH 4) to determine the ion group density, which was 14.2 meq / g.

(Example 4)
(Polymerization reaction) 50.0 g of desalted water, 32.2 g of ammonium sulfate, and 1.2 g of an aqueous solution of polyacryloyloxyethyl trimethyl ammonium chloride (polymer concentration 20 mass%, weight average molecular weight 800,000) are added to a 300 mL separable flask It was a solution. Here, 29.4 g of vinyl formamide, 0.6 g of divinylbenzene (55 mass% of pure content), azo polymerization initiator 2, 2'-azobis (4-methoxy-2, 4-dimethyl valeronitrile) (V-70) A monomer solution in which 0.09 g of Wako Pure Chemical Industries, Ltd. was made into a uniform solution was added, and nitrogen substitution was performed for 30 minutes while stirring at 300 rpm. Thereafter, polymerization was carried out at 45 ° C. for 3 hours and at 60 ° C. for 2 hours. After polymerization, washing with water and filtration were repeated to remove ammonium sulfate and polyacryloyloxyethyl trimethyl ammonium chloride. As a result, 219 g of polyvinyl formamide particles in a water-containing state in solid content conversion of 27.9 g were obtained.

(Hydrolysis reaction) In a 300 mL separable flask, 78.5 g (10 g solid content conversion) of water-containing polyvinylformamide particles and 18.4 g of a 48 mass% aqueous sodium hydroxide solution are added to make basic conditions at 80 ° C. Hold for 5 hours. After cooling to room temperature, filtration and washing with water were repeated three times to remove by-products. After filtration, 84.6 g of purified water-containing polyvinylamine particles were obtained.

(Oxidative decomposition reaction) 8.0 g of 35% by mass hydrogen peroxide was added to 50.1 g of water-containing polyvinylamine particles, and maintained at 70 ° C. for 10 hours. The polyvinylamine particles were oxidatively degraded, and after filtering a small amount of insoluble matter, a clear homogeneous solution was obtained. Hydrogen peroxide decomposes into oxygen and water, so no impurities are generated. The obtained free polyvinylamine aqueous solution was subjected to colloid titration under acidic conditions (pH 4) to determine the ion group density, which was 10.9 meq / g.

(Comparative example 1)
(Polymerization reaction) 50.1 g of demineralized water, 32.0 g of ammonium sulfate, and 1.0 g of an aqueous solution of polyacryloyloxyethyl trimethyl ammonium chloride (polymer concentration 20 mass%, weight average molecular weight 800,000) are added to a 300 mL separable flask It was a solution. Here, 30.0 g of vinyl formamide, azo polymerization initiator 2, 2'-azobis (4-methoxy-2, 4-dimethyl valeronitrile) (V-70, manufactured by Wako Pure Chemical Industries, Ltd.) 0.09 g The monomer solution was added to a homogeneous solution, and the system was purged with nitrogen for 30 minutes while stirring at 300 rpm. Thereafter, polymerization was carried out at 40 ° C. for 1.5 hours and at 60 ° C. for 1.5 hours. After polymerization, when washed with water, the obtained polymer was dissolved and could not be filtered.

Claims (5)

After copolymerizing N-vinyl carboxylic acid amide and a polyvinyl compound to obtain crosslinked copolymer particles , the crosslinked copolymer particles are hydrolyzed to form polyvinylamine crosslinked copolymer particles, and after washing, the polyvinyl alcohol The manufacturing method of the polyvinylamine obtained by oxidatively decomposing with 0.1-10 g / g of oxidizing agents with respect to amine crosslinked copolymer particle dry mass . The method for producing polyvinylamine according to claim 1, wherein the hydrolysis is performed under basic conditions. The method for producing polyvinyl amine according to claim 1 or 2, wherein the oxidative decomposition is performed by hydrogen peroxide. The method for producing polyvinyl amine according to any one of claims 1 to 3, wherein the crosslinked copolymer is obtained by reverse phase suspension polymerization. The method for producing a polyvinylamine according to any one of claims 1 to 3, wherein the crosslinked copolymer is obtained by suspension polymerization in a salt solution.