JPS6234774B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aqueous dispersion of a water-soluble polymer composite having excellent stability and fluidity, and more specifically, the present invention relates to an aqueous dispersion of a water-soluble polymer composite having excellent stability and fluidity. The present invention relates to an aqueous dispersion of a water-soluble polymer composite obtained by polymerizing a water-soluble polymer compound and a water-soluble ethylenically unsaturated monomer in a weight ratio within a specific range. Water-soluble vinyl addition polymers produced from water-soluble ethylenically unsaturated monomers are becoming important in many fields, such as polymer flocculants, soil conditioners, adhesives, food additives, and pharmaceuticals. , cosmetics, dispersants, detergents, and many other uses, and demand for it has increased significantly in recent years. Conventionally, the most common method for producing water-soluble vinyl addition polymers has been an aqueous solution polymerization method using water as a solvent. However, the aqueous solution polymerization method has advantages such as simply making the monomer water-soluble in the presence of a polymerization initiator and making it easy to obtain a high polymer, but on the other hand,
(1) It is extremely difficult to remove the reaction heat during the polymerization process, (2) There is a limit to the monomer concentration during polymerization (5 to
(20% concentration), which poses a problem in improving productivity; and (3) as the reaction progresses, the viscosity increases significantly, making stirring difficult, and at high concentrations, a so-called agar-like formation occurs. Because it becomes a gel, it is not only extremely inconvenient to transport, store, etc. when used as is, but also requires complicated processing steps such as collection, drying, and powdering when powdered. It has the following disadvantages. In order to improve these drawbacks, precipitation polymerization methods are used in which polymerization is carried out in an organic solvent in which monomers are dissolved but polymers are not, and the resulting polymer is separated as a precipitate.
A reverse-phase suspension polymerization method, in which a mixture of a monomer and water is dispersed using a surfactant in an organic solvent in which both the monomer and the polymer are poorly soluble, is widely known. However, these methods use organic solvents, making it difficult to obtain high molecular weight polymers;
Large-scale equipment is required from the viewpoint of recovery and safety of organic solvents, and in many cases, they are provided as powder or granules, which makes it difficult to dissolve them uniformly in water for use. It is easy to form gel-like lumps. Once a gel-like mass is formed, it is difficult for water to penetrate into the gel-like mass, so it has disadvantages such as requiring a considerable amount of time for dissolution. Furthermore, after producing a water-in-oil emulsion by polymerizing a water-soluble ethylenically unsaturated monomer in a hydrophobic liquid organic dispersion medium containing a water-in-oil emulsifier,
A method has been proposed in which this is converted into an oil-in-water emulsion in the presence of water without separating the produced polymer. However, this method uses a large amount of organic solvent that is insoluble in water, so secondary contamination by the organic solvent is a problem, other surfactants are required for phase transformation, and dispersion It has the disadvantage of poor stability and condensation during storage and transportation. As a result of various studies aimed at improving the drawbacks of the conventional methods, the present inventors found that a specific combination of water concentration, water-soluble polymer compound concentration, and water-soluble ethylenically unsaturated monomer concentration was determined. An aqueous dispersion of a water-soluble polymer composite obtained by polymerization within a range of
This product improves the shortcomings of conventional water-soluble polymer production methods, and also has excellent stability and fluidity, making it possible to use the polymer as it is without having to separate and recover it from water. They discovered this and arrived at the present invention. That is, the present invention comprises (A) 100 parts by weight of water and (B) a water-soluble polymeric compound having an ether group and/or a hydroxyl group in the polymeric constituent unit, or at least 10% by weight of the polymeric compound. In the presence of an aqueous solution consisting essentially of 1 to 150 parts by weight of a mixture with another water-soluble polymer compound, (C) [In the formula, R represents a hydrogen atom, a methyl group, or a halogen atom, and X represents a hydrogen atom, an alkali metal, or a _-NH4 group. ] or a mixture with other water-soluble ethylenically unsaturated monomers containing more than 50% by weight of the water-soluble ethylenically unsaturated monomer, and The present invention relates to an aqueous dispersion of a water-soluble polymer composite having excellent stability and fluidity obtained by polymerization in a weight ratio of (B) to (C) in the range of 10:1 to 1:10. The aqueous dispersion of the water-soluble polymer composite of the present invention has an extremely low viscosity while containing a polymer obtained from a water-soluble ethylenically unsaturated monomer at a high concentration, so it is easy to handle and requires sufficient water. It can be easily converted to a homogeneous aqueous solution by dilution.
Furthermore, in the present invention, a high molecular weight polymer can be easily obtained because dangerous and expensive organic solvents are not used when producing an aqueous dispersion of a water-soluble polymer composite. These problems include the difficulty in handling conventional water-soluble polymers, the difficulty in uniformly dissolving them in water, the high viscosity of highly concentrated solutions, and the complicated operations required to recover organic solvents. This method solves the problems all at once, and has great industrial significance. The water-soluble polymer compound used in the present invention is one having an ether group and/or a hydroxyl group in the polymer constituent unit, and specifically includes agar, gum arabic, dextran, starch, starch derivatives, and cellulose derivatives. , polyethylene glycol, polypropylene glycol,
Typical examples include copolymers of ethylene glycol and propylene glycol, polyvinyl alcohol, and the like. These water-soluble polymer compounds may be used alone or in combination of two or more. Also,
These water-soluble polymer compounds contain functional groups other than ether groups or hydroxyl groups, such as sulfone groups, amino groups, imino groups, tertiary amino groups, quaternary ammonium bases, and hydrazino groups. It may be used in combination with at least one other water-soluble polymer compound having a functional group in the polymer structural unit, such as polyvinylpyrrolidone, polyvinylpyridine, and polyethyleneimine. At that time, the proportion of the water-soluble polymer compound having an ether group and/or hydroxyl group in the constituent units in the mixture is at least 10
% by weight, and if it is less than 10% by weight, it is difficult to obtain the remarkable effects of the present invention. The amount of these water-soluble polymer compounds or mixtures of these compounds and other water-soluble polymer compounds with water is 1 to 150 parts by weight, preferably 5 to 125 parts by weight, per 100 parts by weight of water. More preferably 10-100
Parts by weight. If the amount is less than 1 part by weight, the effect of lowering the viscosity will be small and an aqueous dispersion with excellent stability and fluidity will not be obtained. On the other hand, the blending amount is 150
If the amount exceeds 1 part by weight, it is not only difficult to dissolve in water, but also the water-soluble polymer compound itself has a high viscosity, so the viscosity of the aqueous dispersion becomes too high, and water with excellent stability and fluidity becomes difficult to dissolve. A dispersion cannot be obtained. Examples of the water-soluble ethylenically unsaturated monomers represented by the general formula used in the present invention include acrylic acid, methacrylic acid, sodium acrylate, potassium acrylate, sodium methacrylate, potassium methacrylate, ammonium acrylate, Examples include ammonium methacrylate, α-chloroacrylic acid, α-bromoacrylic acid, α-fluoroacrylic acid, and the like. These water-soluble ethylenically unsaturated monomers may be used alone or in combination of two or more. Further, these water-soluble ethylenically unsaturated monomers may be used in combination with other water-soluble ethylenically unsaturated monomers that can be copolymerized with the monomer. Examples of other water-soluble ethylenically unsaturated monomers copolymerizable with the water-soluble ethylenically unsaturated monomer include acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N,N-dimethyl Acrylamide, NN'-dimethylmethacrylamide, N,
N'-diethylacrylamide, N,N'-diethylmethacrylamide, N-methyl-N-ethylacrylamide, N-methyl-N-ethylmethacrylamide, acrylonitrile, sodium styrene sulfonate, N-vinylpyrrolidone, vinylpyridine, acetic acid Examples include vinyl. These other water-soluble ethylenically unsaturated monomers may be one or two types.
You may use a mixture of more than one species. When water-soluble ethylenically unsaturated monomers and other water-soluble ethylenically unsaturated monomers are mixed and used, the proportion of water-soluble ethylenically unsaturated monomers in the total monomers is 50 It is desirable that the amount is greater than % by weight. The amount of these water-soluble ethylenically unsaturated monomers or the mixture of these monomers and other water-soluble ethylenically unsaturated monomers is 1 to 1 to 100 parts by weight of water.
150 parts by weight, preferably 10 to 100 parts by weight, and the ratio between the water-soluble polymer compound and the water-soluble ethylenically unsaturated monomer, or between this monomer and another water-soluble ethylenically unsaturated monomer. The weight ratio of mixed monomers is 10:1 ~
The ratio is 1:10, preferably 5:1 to 1:5, more preferably 2.5:1 to 1:2.5. water 100
water-soluble ethylenically unsaturated monomer, based on parts by weight;
Alternatively, if the amount of the mixture of this monomer and other water-soluble ethylenically unsaturated monomer is 1 part by weight or less, a high polymer cannot be obtained due to the low concentration. On the other hand, if the blending amount is 150 parts by weight or more, it is difficult to reduce the viscosity of the aqueous dispersion, and an aqueous dispersion with excellent stability and fluidity cannot be obtained. In addition, if the weight ratio of the water-soluble polymer compound to the water-soluble ethylene monomer is outside the range of 10:1 to 1:10, the water-soluble ethylene monomer, or the monomer and other water-soluble ethylene When a mixture with a system unsaturated monomer is polymerized, it becomes a rich aqueous solution of a water-soluble polymer compound or a rich aqueous solution of a polymer obtained from a water-soluble ethylene monomer, and Since the viscosity is controlled by the viscosity of each solution, an aqueous dispersion with excellent stability and fluidity cannot be obtained. The aqueous dispersion of the water-soluble polymer composite of the present invention can be obtained by polymerizing the water-soluble ethylenically unsaturated monomer represented by the general formula above in the presence of water and a water-soluble polymer compound. It will be done. The polymerization reaction can be carried out by simply applying heat, but
Preferably, radical initiators, ultraviolet light or radiation are used. In practicing the present invention, water-soluble radical initiators such as hydrogen peroxide, potassium persulfate, ammonium persulfate, etc.
Alternatively, it is preferable to polymerize in the presence of a so-called redox initiator, which is a combination of these and a reducing agent such as an amine or sodium sulfite. The amount of initiator used is 0.005 to 10% by weight based on the weight of the water-soluble ethylenically unsaturated monomer, and the addition method is as follows:
The entire amount may be added at the beginning of the polymerization, or a portion may be added and the remaining amount may be added as the polymerization progresses. The reaction temperature is between 10 and 100°C, especially between 40 and 70°C. Moreover, the polymerization time is within the range of 3 to 10 hours. The polymerization reaction can be carried out either batchwise or continuously. When producing the aqueous dispersion of the present invention, nonionic surfactants such as polyethylene glycol and higher alcohols; aliphatic salts;
Anionic surfactants such as higher alcohol sulfate ester salts, liquid fatty oil sulfate esters, aliphatic amines, aliphatic amide sulfates and aliphatic alcohol phosphate esters, aliphatic amine salts,
Cationic surfactants such as quaternary ammonium salts and alkylpyridinium salts may be added, and in particular, nonionic surfactants such as copolymers of propylene glycol and ethylene glycol are preferably added. These surfactants may be used alone or in combination of two or more, and the amount used is 0.05 to 50 parts by weight per 100 parts by weight of water.
When the blending amount is 0.05 parts by weight or less, there is no noticeable difference in the effect compared to the case where no additive is added. On the other hand, if the blending amount is 50 parts by weight or more, not only the improvement effect by addition is no longer observed, but also stability may be impaired in some cases, which is not preferable. The surfactant may be added in its entirety at the beginning of the polymerization, or a portion may be added during the polymerization and the remainder may be added appropriately as the polymerization progresses. Further, these surfactants may be added at the end of polymerization. Furthermore, when producing the aqueous dispersion of the present invention, inorganic salts having a solubility in water of at least 1% by weight may be added as necessary. Inorganic salts include chlorides, nitrates, sulfates, and phosphates of alkali metals, alkaline earth metals, and ammonia, and typical examples include sodium chloride, calcium chloride, calcium nitrate, sodium nitrate, ammonium nitrate, and sulfuric acid. Examples include potassium and calcium phosphate. These inorganic salts may be used alone or in a mixture of two or more, and the amount added is at least 0.5 parts by weight per 100 parts by weight of water. It should be kept within the range that dissolves in the water. The inorganic salts may be added all at once during polymerization, or may be added intermittently during any period from the start of polymerization to the end of polymerization. Further, these inorganic salts may be added at the end of polymerization. Furthermore, an organic solvent having a solubility in water of at least 2% by weight may be added to the aqueous dispersion of the present invention, if necessary. Examples of organic solvents include alcohol solvents such as methyl alcohol, ethyl alcohol, propyl alcohol, ethylene glycol, and glycerin, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as tetrahydrofuran and dioxane, and amides such as dimethylformamide and dimethylacetamide. Examples include solvents. These organic solvents may be used alone or in a mixture of two or more, and can be added in any amount within the range of dissolution in water, but preferably 1 to 50 parts by weight per 100 parts by weight of water. %.
The organic solvent is preferably added at the end of the reaction in order to prevent a decrease in the degree of polymerization due to chain transfer to the solvent during polymerization. The aqueous dispersion of the present invention may contain stabilizers, colorants, pigments, dyes, fragrances and other additives. The aqueous dispersion of the present invention can be used not only in fields such as polymer flocculants, paints, adhesives, soil conditioners, food additives, pharmaceuticals, and cosmetics, but also for various products by taking advantage of the characteristics of the aqueous dispersion of the present invention. It is also useful as a sticky agent and dispersant. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 Equipped with a stirrer, reflux condenser and nitrogen inlet tube
Add 100 g of water and 20 g of polyethylene glycol (molecular weight 20.000) to a 500 ml flask, mix and dissolve, then add 30 g of acrylic acid and 16.65 g of sodium hydroxide.
g, and further added a 10% aqueous solution of sodium hydroxide to adjust the pH to 12. Next, while replacing the air in the flask with nitrogen gas, 1.2 ml of a 0.84% aqueous solution of ammonium persulfate, which is a polymerization initiator, and 3 ml of a 2% aqueous solution of triethanolamine were added to the flask, and polymerization was carried out with stirring at a temperature of 45°C. I did this. As the polymerization progressed, the reaction solution became a viscous emulsion, but stirring could be easily continued until the end of the polymerization. 5
After a period of time, the polymerization was stopped, and the residual acrylic acid in the reaction solution was quantified by liquid chromatography. The residual acrylic acid was 0.022%, and the polymerization rate was 99% or more. The viscosity of the obtained aqueous dispersion was 780 poise when measured using a rotational viscometer. This aqueous dispersion remained stable even after one month. Next, pure water was added to this aqueous dispersion (concentration of sodium polyacrylate was 0.5%) and stirred.
After 1 hour, a homogeneous solution was obtained, and the viscosity measured by a rotational viscometer was 5 poise. In addition, when the viscosity of a 0.5% aqueous solution of commercially available high molecular weight sodium polyacrylate ([η]7) was measured using a rotational viscometer, the viscosity was 5.5 poise. It was found that sodium polyacrylate was produced. Comparative Example 1 In Example 1, polymerization was carried out in the same manner as in Example 1 except that polyethylene glycol was not used, but the viscosity of the system increased 2 to 3 minutes after adding the polymerization initiator, and stirring became difficult. became impossible. Example 2 Into a flask similar to Example 1, 100 g of water, 20 g of polyethylene glycol (molecular weight 20.000) and 5 g of soluble starch were added and mixed and dissolved, then 8 g of acrylic acid, 2 g of acrylamide, and 4.44 g of sodium hydroxide were added. sodium hydroxide
The pH was adjusted to 12 by adding 10% aqueous solution. Hereinafter, polymerization was carried out in the same manner as in Example 1,
An aqueous dispersion with a viscosity of 450 boas was obtained. When 20 times the amount of pure water was added to this aqueous dispersion and stirred, it became a homogeneous solution in about 1 hour, and its viscosity was 5 poise. Example 3 In a flask similar to Example 1, 100 g of water, 5 g of polyvinyl alcohol, and 20 g of polyvinylpyrrolidone were added.
g and mixed and dissolved, 25 g of methacrylic acid was added, and further 6.98 g of sodium hydroxide was added for neutralization. Hereinafter, polymerization was carried out in the same manner as in Example 1,
An aqueous dispersion with a viscosity of 420 poise was obtained. This aqueous dispersion remained stable even after one month. Next, pure water was added to this aqueous dispersion (concentration of polysodium methacrylate was 1%) and stirred. After about 1 hour, it became a homogeneous solution with a viscosity of 6 poise. Comparative Example 2 After adding 100 g of water and 2 g of polyvinyl alcohol to a flask similar to Example 1 and mixing and dissolving them,
25 g of methacrylic acid was added and further 6.98 g of sodium hydroxide was added for neutralization. Hereinafter, when polymerization was carried out in the same manner as in Example 1, the viscosity of the system increased rapidly 2 to 3 minutes after the start of polymerization, and after 5 minutes, it became agar-like and stirring became impossible. Summer. Example 4 Into a flask similar to Example 1, 100 g of water and polyethylene glycol (molecular weight 20.000) were mixed and dissolved, and then 60 g of acrylic acid was added. Further, 4 g of a surfactant (Emulgen PP150, nonionic type) was added to this. Thereafter, polymerization was carried out in the same manner as in Example 1 to obtain an aqueous dispersion with a viscosity of 400 poise. This aqueous dispersion was stable and no aggregation occurred even after two months. When this dispersion was diluted 60 times with pure water and stirred, it became a homogeneous solution in about 45 minutes, and its viscosity was 6 poise. Example 5 In a flask similar to Example 1, 100 g of water, 15 g of polyethylene glycol (molecular weight 6.000), 5 g of polypropylene glycol (molecular weight 1.000), and 5 g of polyethyleneimine were added and mixed and dissolved.
20g of acrylic acid and 20g of methacrylic acid were dissolved.
After neutralizing this by adding sodium hydroxide, 2g of surfactant (Emulgen PP230, nonionic)
and surfactant (Emulgen 903, nonionic) 1
In addition, 3 ml of a 2% aqueous solution of sodium bisulfite was added as a polymerization initiator. Hereinafter, as a result of polymerization in the same manner as in Example 1,
An aqueous dispersion with a viscosity of 470 poise was obtained. This aqueous dispersion remained stable for more than two months. next,
When this dispersion was diluted 50 times with pure water and stirred, it became a homogeneous solution in about 45 minutes, and its viscosity was 5.5 poise. Examples 6 to 8 After adding 100 g of water, 15 g of polyethylene glycol (molecular weight 20.000), and 10 g of polyvinyl alcohol to the same flask as in Example 1 and mixing and dissolving them,
Example 1 was prepared by dissolving 30 g of acrylic acid and adding sodium chloride in the proportions listed in Table 1.
Polymerization was carried out under the same conditions. The result is the first
Shown in the table.

[Table] Examples 9 to 11 In a flask similar to Example 1, 100 g of water, 5 g of polyvinyl alcohol, and 10 g of polyvinylpyrrolidone were added.
After adding and mixing and dissolving 10 g of acrylic acid and 10 g of methacrylic acid, polymerization was carried out under the same conditions as in Example 1 without neutralization. After the polymerization was completed, methyl alcohol was added in the proportions shown in Table 2. The results are shown in Table 2.

[Table] Example 12 100 g of water, 50 g of polyethylene glycol (molecular weight 6.000), and 50 g of polyvinylpyrrolidone were added to the same flask as in Example 1, mixed and dissolved, and then
100 g of α-chloroacrylic acid was dissolved. next,
To this was added 6 ml of a 2% aqueous solution of potassium hydroxide. Hereinafter, as a result of polymerization in the same manner as in Example 1,
An aqueous dispersion with a viscosity of 890 poise was obtained. This dispersion was prepared at a concentration of 0.5% potassium polyα-chloroacrylate.
When I diluted it with pure water and stirred it so that it was approx.
It became a homogeneous solution in 60 minutes, and its viscosity was 7 poise.

Claims (1)

[Scope of Claims] 1 (A) 100 parts by weight of water and (B) a water-soluble polymeric compound having an ether group and/or hydroxyl group in the polymeric constituent unit, or at least 10% by weight of the polymeric compound. (C) general formula [In the formula, R represents a hydrogen atom, a methyl group, or a halogen atom, and X represents a hydrogen atom, an alkali metal, or a _-NH4 group. ] or a mixture with other water-soluble ethylenically unsaturated monomers containing more than 50% by weight of the water-soluble ethylenically unsaturated monomer, and An aqueous dispersion of a water-soluble polymer complex obtained by polymerizing the weight ratio of (B) to (C) within the range of 10:1 to 1:10.