JPH037687B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a water-insoluble polymer, and more specifically, a method for producing a water-insoluble polymer having a desired shape. Regarding the method.

[Prior Art] Conventionally, a water-insoluble polymer having a desired shape with uniform size and shape has been produced from a water-soluble radically polymerizable vinyl monomer and a crosslinkable monomer having two or more radically polymerizable vinyl groups. There are problems with the production, such as moldability, wide shape distribution, and controllability of the polymerization reaction, and its industrial use has been extremely difficult.

Suspension polymerization has been used as a method for producing particularly particulate water-insoluble polymers using these monomers.

In this suspension polymerization method, an aqueous monomer solution and a surfactant are added to a medium in which water and monomers do not dissolve at all or hardly dissolve, and are thoroughly stirred, so that the aqueous monomer solution becomes a suspension of fine particles. By adding a readily soluble polymerization initiator to the monomer, polymerization is carried out in suspension droplets, which are an aqueous monomer solution, to produce particulate water-insoluble polymers. The particle size of the particulate water-insoluble polymer obtained by this conventional method varies depending on the medium used, the type of monomer and surfactant, the shape of the polymerization tank, the shape of the stirring blade, and the stirring speed. However, it is usually suitable for producing particulate water-insoluble polymers with a small particle size of 0.1 mm or less, and the particle size distribution range of the obtained particles is wide, and particulate polymers of a specific particle size can be produced. If it is necessary to use coalescence, the resulting particles must be sieved and used, and particulate polymers with a particle size other than the desired size are discarded, which makes economical production difficult. It could not be said that it was a law.

Furthermore, it is extremely difficult to produce granular polymers with large particle diameters of several millimeters or more, and if you try to produce large particle diameter polymers, large lumpy polymers will be produced, causing fouling on the walls of the polymerization tank. Therefore, a situation may easily occur in which it becomes difficult to continue the polymerization. Furthermore, there is a drawback that water-insoluble polymers in shapes other than granules cannot be produced by this suspension polymerization method.

The inventors have finally arrived at the present invention as a result of intensive research into a method for stably producing a water-insoluble polymer having a desired shape and a narrow shape distribution.

[Means to solve the problem]

This invention provides (a) a water-soluble alginate, (b) a phosphoric ester represented by the following formula, (In the formula, R ₁ , R ₂ and R ₃ each represent hydrogen or a methyl group.), and (c) a crosslinkable vinyl monomer having two or more radically polymerizable vinyl groups, optionally (d) Dissolving or partially suspending a water-soluble radically polymerizable vinyl monomer in water and contacting this aqueous solution or suspension with a solution capable of gelling the water-soluble alginate. to form a water-insoluble gel with a desired uniform shape, and then radical polymerization of this gel to produce a water-insoluble polymer with a desired uniform shape. .

In the method of this invention, when a water-insoluble polymer with a desired shape and a uniform shape is produced, a crosslinkable vinyl monomer, and if necessary, a radically polymerizable monomer in an aqueous solution and a radical initiator,
In advance, the alginate is dissolved or partially suspended in water together with the water-soluble alginate, and this liquid is brought into contact with a liquid having the ability to gel the alginate to first gel it. , a water-soluble alginate used for the gelation of a solution of the radically polymerizable monomer, which is polymerized into a water-insoluble polymer after being formed into a gel of the desired shape. Examples include sodium alginate, potassium alginate, or ammonium alginate.

Alginic acid is a copolymer of mannuronic acid and guluronic acid obtained from seaweed, and its composition varies depending on the place of production and time of collection.
Water-soluble alginates that can be gelled by a gelling agent can be used in the method of the present invention regardless of their composition. Furthermore, the molecular weight of alginic acid used is within the range of 1,000 to 1,000,000. The alginate concentration of the water-soluble alginate aqueous solution for the production of alginate gel is usually
It is within the range of 0.1 to 20 wt.%, preferably 0.5 to 10 wt.%.

If the concentration of alginate is low, the strength of the resulting alginate gel will be low, making it difficult to form a gel into the desired shape, and the radically polymerizable monomer will easily flow out from the gel. If the concentration is too high, the strength of the resulting alginate gel will increase, but the viscosity of the alginate solution will increase, making it difficult to handle and molding into a gel of a desired shape, and in addition, it will be uneconomical.

Dissolved oxygen is preferably removed from the water-soluble alginate aqueous solution containing these radically polymerizable monomers for the purpose of smooth progress of the subsequent polymerization reaction. An inert gas such as nitrogen may be introduced for this purpose.

Examples of the solution capable of gelling the aqueous solution of water-soluble alginate used in the method of this invention include, for example:
There are acidic aqueous solutions with a pH of 7 or less, and aqueous solutions containing polyvalent metal ions other than magnesium and mercury. Examples of acidic aqueous solutions with a pH of 7 or less include hydrochloric acid, sulfuric acid,
There are aqueous solutions of inorganic acids such as nitric acid, aqueous solutions of organic acids such as formic acid and acetic acid, and polyvalent metal ions such as Ca, Fe, Co, Ni, Zn, Cd, Sr, Cu, Pb,
There are solutions containing metal ions such as

In addition, when including the below-mentioned live microorganism cells, it is preferable to use an acidic aqueous solution with a pH of 4 to 7.

The method of producing an alginate gel containing a radically polymerizable monomer and, if necessary, a radical initiator in the method of this invention is an alginate aqueous solution or suspension containing a radically polymerizable monomer and, if necessary, a radical initiator. This can be done by contacting the alginate with a gelling agent solution. The shape of the resulting alginate gel can be greatly varied depending on the contact method.

For example, by dropping an alginate aqueous solution containing a radically polymerizable monomer into an alginate gelling agent solution, a spherical alginate gel with high sphericity and an extremely narrow particle size distribution range can be formed. The particle size of the spherical gel varies depending on the viscosity of the alginate aqueous solution, the shape of the alginate aqueous solution dropping nozzle, and other factors.

Further, when an alginate aqueous solution containing a polymerizable monomer is injected into an alginate gelling agent solution, the shape of the alginate gel is changed depending on the shape of the injection port. Furthermore, after an alginate aqueous solution is injected into the mold in advance, the mold is partially opened and immersed in the gelling agent solution, so that the gelling agent solution flows into the inside of the mold from the opening. The alginate gel penetrates into the mold, gels the surface upon contact with the alginate aqueous solution, penetrates into the interior, and finally gels the entire alginate aqueous solution inside the mold, making it extremely easy to form an alginate gel into the desired shape. It is also possible to form

In addition, an aqueous alginate solution is injected and expanded into a shallow dish-shaped container, and an alginate gelling agent solution is gently poured from above to gel it into a thin plate shape, and then this gel is punched and formed. is also possible.

Alternatively, the aqueous alginate solution and the alginate gelling agent solution can be blended at high speed and then immediately poured into a mold to form a gel in a desired shape. During this gelation operation, an alkali phosphate, an alkali chelate, or the like may be added as a gelation retarder.

Furthermore, once the gel has been molded, it may be subjected to processing such as cutting or cutting in order to obtain a desired shape. The preparation of these alginate gels must be carried out at a temperature below the temperature at which the radical initiator begins to decompose and polymerization begins.
Usually, it is preferable to carry out within the range of 0 to 100°C. Further, the preparation of the alginate gel is preferably carried out under an atmosphere of an inert gas, such as nitrogen gas, for smooth progress of the subsequent polymerization reaction.

The radically polymerizable monomer-containing alginic acid gel thus obtained is then subjected to a polymerization reaction.

The polymerization reaction is preferably carried out under conditions in which the alginate gel is placed in a solvent that does not interfere with radical polymerization, such as water, alcohol, or hydrocarbon, and oxygen is removed. Of course, the polymerization reaction may also be carried out without using a solvent and in the presence of an inert gas stream from which oxygen has been removed.

The polymerization temperature varies depending on the type of radical initiator used, but it may be carried out at a temperature equal to or higher than the decomposition temperature of the radical initiator. If the polymerization reaction is preferably carried out at low temperatures, a substance that accelerates the decomposition of the radical initiator, or a liquid containing this substance, may be brought into contact with the gel in order to lower the decomposition temperature of the radical initiator. It will be done.

For example, for hydrogen peroxide, tetramethylethylenediamine, for potassium persulfate,
These include ferrous ions.

When the radically polymerizable monomer-containing alginic acid gel does not contain a radical initiator, the alginic acid gel can also be radically polymerized by radiation irradiation.

In the method of the present invention, the steps of gelling the alginate aqueous solution or suspension and polymerizing the resulting gel may be performed separately or simultaneously.

That is, when a gelling agent solution capable of gelling alginate is maintained at a temperature higher than the decomposition temperature of the radical initiator, and an aqueous alginate solution containing a radically polymerizable monomer is brought into contact with this solution, Polymerization can be initiated simultaneously with the formation of the alginate gel to synthesize a water-insoluble polymer in the desired form.

The water-insoluble polymer thus obtained contains a portion of the previously used and gelled alginate. Depending on the intended use, the alginate in the water-insoluble polymer gel can be removed if it is unnecessary or has a detrimental effect.

Substances that can remove alginate include those that can chelate polyvalent metal ions into water-soluble metal ions, such as sodium ethylenediaminetetraacetate, potassium salts, aqueous solutions of alkali metal phosphates, or alkali metal hydroxides. , carbonate aqueous solutions, etc., and these aqueous solutions contain 0 to 100% of the water-insoluble polymer after radical polymerization.
It may be immersed or washed with these aqueous solutions at a temperature in the range of 100°C.

Although the water-insoluble polymer obtained by the method of the present invention does not dissolve in water, it is sufficiently hydrophilic and the water-insoluble polymer obtained after polymerization is also swollen with water. Depending on the purpose of use, the polymer may be swollen with water and used as is after polymerization, or the water-insoluble polymer may be used after being sufficiently washed with water.
Furthermore, it may be used after being dried to remove water.

In the method of this invention, representative examples of the phosphoric acid ester (b) include acid phosphooxyethyl acrylate (R ₁ , R ₂ and R ₃ in the above formula are all H), acid phosphooxyethyl methacrylate (R ₁
and R ₂ is H, R ₃ is a methyl group), acid phosphooxypropyl acrylate (either R ₁ or R ₂ is H, the other is a methyl group, and R ₃ is H), acid phosphooxypropyl methacrylate (R ₁ , R ₂ is H, the other is a methyl group, and R ₃ is a methyl group), and one type or a mixture of two or more of these can be used.

Typical examples of crosslinkable vinyl monomers having two or more radically polymerizable vinyl groups used in the method of this invention include N,N'-methylenebisacrylamide, N,N'-propylenebisacrylamide, N-Acroylacrylamide, diacrylamide dimethyl ether,
1,2-diacrylamide ethylene glycol,
Ethylene urea bisacrylamide, polyethylene glycol, or esters of acrylic acid or methacrylic acid of ethylene oxide and propylene oxide copolymers having hydroxyl groups at both ends and 1,3,5-triacrylhexahydro-s-
These include triazines.

The ratio of phosphoric acid ester and crosslinkable vinyl monomer used in the production of the water-soluble polymer in this invention is usually 100:
0.05~100:20, preferably 100:0.1~100:15
It is appropriate to use it within the range of .

Typical examples of the water-soluble radically polymerizable vinyl monomer used in the method of the present invention include unsaturated carboxylic acid salts such as alkali metal salts such as sodium and potassium of acrylic acid or methacrylic acid, hydroxyethyl acrylate, Hydroxypropyl acrylate, aminoethyl acrylate, N-methylaminoethyl acrylate,
N,N-dimethylaminoethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, aminoethyl methacrylate, N-methylaminoethyl methacrylate,
Acrylic acid, methacrylic acid esters such as N,N-dimethylaminoethyl methacrylate, acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, N,N-diethyl acrylamide, acrylamide derivatives such as 2-acrylamidoethanesulfonic acid or alkali metal or magnesium salts of 2-acrylamidoethanesulfonic acid, methyl vinyl ketone, o-, m-, and p-aminostyrene;
These monomers include alkali metal salts of vinyl sulfonic acid or allyl sulfonic acid, alkali metal salts or magnesium salts of styrene sulfonic acid, and N-vinylpyrrolidone.
Alternatively, two or more types can be used.

The amount of the radically polymerizable vinyl monomer to the phosphoric acid ester is usually 1:0.01 to 1:10, preferably 1:0.1 to 1:10 by weight.
It is within the range of 5.

When adding a water-soluble radically polymerizable vinyl monomer to a phosphoric acid ester, the ratio of the crosslinkable vinyl monomer to the total weight of these monomers is usually 100:0.05 to 100:20, preferably 100:0.1 to It is appropriate to use a ratio of 100:15.

When the proportion of the crosslinkable vinyl monomer is small, the resulting water-insoluble polymer is easily swollen by water, and when swollen by water, in the state of a so-called hydrogel, it exhibits elasticity and has low tensile strength. On the other hand, if the ratio of crosslinkable vinyl monomer increases, the resulting water-insoluble polymer becomes difficult to swell with water, and the water-containing gel swollen with water tends to have a high tensile strength, but is brittle. become

Before polymerization, these radically polymerizable monomers are dissolved together with water-soluble alginic acid to form an alginic acid aqueous solution. may be done.

The concentration of radically polymerizable monomers in the alginate aqueous solution is expressed as the total value of acid phosphooxyethyl acrylates and crosslinkable vinyl monomers, and is usually within the range of 0.1 to 50 wt.%.
The content is preferably 1 to 20 wt.%, and can be 20 to 45 wt.% in order to obtain a harder polymer.

Even when a radically polymerizable monomer and a water-soluble radically polymerizable vinyl monomer are added, the concentration of all radically polymerizable monomers in the alginate aqueous solution is usually 0.1 to 50 wt.%, preferably 1 to 50% by weight.
20 wt.%, and can be 20-45 wt.% to obtain harder polymers.

In the method of this invention, a water-insoluble gel containing a radically polymerizable monomer by gelation of alginate, hereinafter abbreviated as alginate gel,
This is then subjected to a polymerization reaction,
It is usually preferable to use a radical initiator in this polymerization reaction. Examples of radical initiators used include common water-soluble radical initiators such as hydrogen peroxide, sodium persulfate, potassium persulfate, and ammonium persulfate. These can usually be added to the alginate aqueous solution before preparing the alginate gel. Of course, a radical initiator that is sparingly soluble or insoluble in water can also be used after being dispersed in the aqueous alginate solution.

That is, these radical initiators can be contained in the alginate gel in the same way as the polymerizable monomers.

Of course, before the subsequent radical polymerization reaction,
It is preferable that the decomposition of the radical initiator is suppressed by taking into consideration the following: keeping it at a low temperature or using a radical initiator that is difficult to decompose at low temperatures. Note that, as described above, when the polymerization reaction is carried out by radiation or the like, it is also possible not to contain a radical initiator in the alginic acid gel.

The free radical initiator dosage is usually in the range 0.01 to 10%, preferably 0.1 to 5%, based on the free radically polymerizable vinyl monomer, including the crosslinkable vinyl monomer. Furthermore, there is no problem in adding anything other than these radical initiators that does not interfere with the alginate gel production reaction and polymerization reaction.

〔Effect of the invention〕

When the well-shaped water-insoluble polymer obtained by the method of the present invention is used as a carrier for an enzyme-active substance, the advantage of its well-shaped shape is utilized.

In particular, if target microorganisms are added at a stage before the alginate gel is prepared, it is possible to encapsulate the microorganisms and form a well-shaped water-insoluble polymer. It becomes possible to use it effectively for the enzyme reaction to be utilized.

In addition, the dried water-insoluble polymer obtained by the method of the present invention has extremely high water absorbency and can be used as a water-absorbing polymer for use in soil conditioners, disposable diapers, and sanitary napkins. Its characteristics as a well-shaped water-insoluble polymer can also be used as a sanitary material such as.

The alginate contained in the water-insoluble polymer obtained by this invention can be removed by contacting it with a reagent capable of dissolving alginate gel, if necessary, so that it does not contain alginic acid and has a uniform shape. Water-insoluble polymers can be produced.

In addition, not only can a polymer with a desired shape be produced, but also the heat of polymerization accompanying polymerization can be easily removed, the polymerization reaction can be controlled, and the polymerization tank is hardly contaminated. There are also advantages.

〔Example〕

Examples are given below to explain the method of the present invention in more detail, but the method of the present invention is not limited to these Examples.

Example 1 Acid phosphooxyethyl acrylate 15
g, N, N'-methylenebis(acrylamide)
An aqueous solution was prepared by dissolving 1 g of sodium alginate and 2 g of sodium alginate (“Datsuk Algin NSPM” manufactured by Kamogawa Kasei) in water to make a total of 100 g, and adding 1 ml of hydrogen peroxide solution with a concentration of 1 wt.%. Bubbled by gas. Ferrous sulfate 1
The above aqueous solution was added dropwise to a solution of 6 g of calcium chloride and 6 g of calcium chloride dissolved in 300 ml of water under a nitrogen stream while the temperature of the solution was maintained at 20°C. The solution containing the generated spherical particulate gel was kept at 50°C under a nitrogen stream and the polymerization reaction was continued for 1 hour, resulting in spherical water-insoluble copolymer particles with a uniform particle size of 3 mm. was generated. 20g of these copolymer particles were placed in container 1, 500ml of 2N aqueous sodium hydroxide solution was added, and the mixture was stirred at 20°C for 5 hours to reduce the particle size to 4mm, which does not substantially contain alginic acid. A uniform, spherical, water-insoluble copolymer was produced.

Example 2 Acid phosphooxyethyl methacrylate 10
g, N, N'-methylenebis(acrylamide)
An aqueous solution was prepared by dissolving 1 g of sodium alginate (Datsuk Algin NSPM, manufactured by Kamogawa Kasei) in water to make a total of 100 g, and adding 1 ml of 5 wt.% potassium persulfate, followed by bubbling nitrogen gas. received.

Into a solution of 1 g of tetramethylethylenediamine and 6 g of calcium chloride dissolved in 300 g of water,
The above aqueous solution was added dropwise under a nitrogen stream while maintaining the liquid temperature at 20°C. The aqueous solution containing the generated spherical particulate gel was kept at 50°C under a nitrogen stream and the polymerization reaction was allowed to continue for 1 hour, resulting in a spherical water-insoluble copolymer with a uniform particle size of 2 mm. generated.

Example 3 Acid phosphooxyethyl methacrylate 10
g, acrylamide 5g, 1g N,N'-methylenebis(acrylamide) 1g, sodium alginate (Kamogawa Kasei "Datsuku Algin")
NSPM”) 2g is dissolved in water, totaling 100g
An aqueous solution was prepared by adding 1 ml of ammonium persulfate aqueous solution having a concentration of 5 wt.%, and was bubbled with nitrogen gas. 1g of tetramethylethylenediamine and 6g of calcium chloride is 300
The above aqueous solution is added to the solution dissolved in ml of water at a temperature of 20
It was added dropwise under a nitrogen stream while being maintained at ℃.

The aqueous solution containing the generated spherical particulate gel was kept at 50°C under a nitrogen stream and the polymerization reaction was allowed to continue for 1 hour, resulting in a spherical water-insoluble copolymer with a uniform particle size of 2 mm. was generated.

Claims (1)

[Scope of Claims] 1 (a) a water-soluble alginate, (b) a phosphoric ester represented by the following formula, (In the formula, R ₁ , R ₂ and R ₃ each represent hydrogen or a methyl group.) and (c) a crosslinkable vinyl monomer having two or more radically polymerizable vinyl groups is added to water. The aqueous solution or suspension is brought into contact with an aqueous solution that gelates the water-soluble alginate to form a well-shaped non-aqueous gel. 1. A method for producing a water-insoluble polymer with a uniform shape, the method comprising producing a water-insoluble polymer by radical polymerizing.