JP2007145998A - Method for producing hydroxy group-containing polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily producing in high yield a hydroxy group-containing copolymer of a hydrophilic hydroxy group-containing monomer and a hydrophobic monomer by suspension polymerization in an aqueous medium in a desired copolymerization ratio while suppressing mutual particles coagulation. <P>SOLUTION: The method for producing the hydroxy group-containing copolymer comprises the process of dispersing, in the aqueous medium dissolved with a salt and added with a dispersion stabilizer, a mixture comprising ethylenically unsaturated monomers comprising the hydrophilic hydroxy group-containing monomer and the hydrophobic monomer, an organic solvent and a polymerization initiator followed by conducting a suspension polymerization. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a hydroxyl group-containing polymer, and more particularly, particularly as a diagnostic agent and a pharmaceutical carrier, a chromatography carrier, a viscosity modifier, a resin molding material, a paint additive, a crosslinking / curing agent, and a cosmetic additive. The present invention relates to a method for producing a hydroxyl group-containing polymer which can be suitably used for applications.

  Conventionally, when a polymer is produced by polymerizing a monomer mixture containing a hydrophilic monomer having a hydroxyl group or the like, since the monomer is water-soluble, a solution polymerization method in an aqueous solution, The emulsion polymerization method, the suspension polymerization method in water, the reverse phase suspension polymerization method, and the like have been used.

  For example, a production method is disclosed in which a monomer mixture containing a carboxyl group-containing monomer and a monomer having a polyethylene glycol chain is solution-polymerized in a mixed solvent of a water-soluble organic solvent and water (for example, Patent Document 1). However, when a hydrophobic monomer such as styrene is mixed, it is difficult to obtain a copolymer because phase separation occurs.

  Moreover, the technique which emulsion-polymerizes the monomer mixture containing a carboxyl group-containing monomer and the monomer which has a polyethyleneglycol chain in water, and obtains a polymer is disclosed (for example, refer patent documents 2-4). . However, since the particle size of particles obtained by emulsion polymerization is 1 μm or less, it is difficult to wash particles for removing impurities such as residual monomers and surfactants, and impurities such as diagnostic agents, pharmaceutical carriers, and chromatography carriers It is not suitable for uses that dislike it.

  On the other hand, as one of the methods for polymerizing water-soluble ethylenically unsaturated monomers, a so-called reverse phase suspension polymerization method is known in which an aqueous monomer solution is suspended and dispersed in a hydrophobic solvent. Yes, for example, a method using a nonionic surfactant of HLB 3-6 (see, for example, Patent Document 5), a copolymer of an α-olefin and an α, β-unsaturated polyvalent carboxylic acid anhydride or a derivative thereof There is known a method using the method (for example, see Patent Document 6). However, the reverse phase suspension polymerization method can be applied mainly when a water-soluble monomer is used, and copolymerization with a hydrophobic monomer is difficult.

  On the other hand, a method of copolymerizing a hydrophobic monomer is disclosed (for example, see Patent Document 7), but the content of the copolymerizable hydrophobic monomer is equal to the amount of the water-soluble monomer. On the other hand, the upper limit is 5% by mass. Thus, in the reverse layer suspension polymerization method, it is difficult to copolymerize using a large amount of a hydrophobic monomer.

Also disclosed is a method of obtaining a polymer by suspension polymerization in water of a monomer mixture containing hydroxyethyl methacrylate, a hydrophobic monomer such as diethylene glycol dimethacrylate, glycidyl methacrylate, and toluene and a solvent. (For example, refer to Patent Document 8). However, since hydroxyethyl methacrylate is water-soluble, suspension polymerization in water causes polymerization in water, and has a drawback that particles tend to aggregate during polymerization. In addition, since the water-soluble monomer is distributed in oil droplets and water, it is difficult to produce a polymer with a desired copolymerization ratio.
JP-A-3-239709 JP 60-122770 A JP-A-1-111769 Japanese Patent Laid-Open No. 7-10943 JP 61-157513 A JP 62-95308 A JP 2003-147005 A JP 2001-318086 A

The object of the present invention is to solve the above-mentioned problems of the prior art.
That is, the present invention provides a copolymer of a monomer having a hydrophilic hydroxyl group and a hydrophobic monomer by suspension polymerization in an aqueous medium, while suppressing aggregation of particles, and a desired copolymer. An object of the present invention is to provide a method for producing a hydroxyl group-containing polymer which can be easily obtained at a polymerization ratio and in a good yield.

The above-described problems are achieved by the present invention described below. That is, the method for producing the polymer of the present invention comprises:
<1> A mixture containing an ethylenically unsaturated monomer containing a hydrophilic monomer having a hydroxyl group and a hydrophobic monomer, an organic solvent, and a polymerization initiator, dissolving a salt and dispersing stabilizer It is a manufacturing method of the hydroxyl-containing polymer including the process of disperse | distributing in the aqueous medium which added and carrying out suspension polymerization.

<2> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the content of the hydrophobic monomer is in the range of 20.0 to 99.9% by mass in all monomer components.

<3> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the content of the hydrophobic monomer is in the range of 50.0 to 90.0% by mass in all monomer components.

<4> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the hydrophilic monomer having a hydroxyl group is at least one selected from 2-hydroxyethyl (meth) acrylate and polyethylene glycol (meth) acrylate. It is.

<5> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the organic solvent is at least one selected from diethylbenzene, lauryl alcohol, and isoamyl alcohol.

<6> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the ethylenically unsaturated monomer includes a crosslinking agent.

<7> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the salt is an inorganic salt.

<8> The method for producing a hydroxyl group-containing polymer according to <7>, wherein the salt concentration in the aqueous medium is 5% by mass or more.

<9> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the aqueous medium is water.

<10> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the dispersion stabilizer is an inorganic powder.

<11> The method for producing a hydroxyl group-containing polymer according to <1>, wherein the content of the dispersion stabilizer is in the range of 1 to 20 parts by mass with respect to 100 parts by mass of all monomer components.

  According to the present invention, copolymerization of a polymer of a monomer containing a hydroxyl group at a desired copolymerization ratio and a hydrophobic monomer is suppressed by suspension polymerization in an aqueous medium and having a desired copolymerization ratio. It is possible to provide a method for producing a hydroxyl group-containing polymer, in which a coalescence can be easily obtained with a good yield.

Hereinafter, the present invention will be described in detail.
The method for producing a hydroxyl group-containing polymer of the present invention is a mixture in which an ethylenically unsaturated monomer containing a hydrophilic monomer having a hydroxyl group and a hydrophobic monomer, an organic solvent, and a polymerization initiator are mixed. Comprising a step of suspension polymerization by dispersing in an aqueous medium in which a salt is dissolved and a dispersion stabilizer is added.

  As described above, when a hydrophobic monomer and a hydrophilic monomer having a hydroxyl group are mixed and subjected to suspension polymerization in water, the particles tend to aggregate during the polymerization, and a desired copolymerization ratio can be obtained. There was a problem that it was difficult to obtain the polymer. The reason is that, since the hydrophilic monomer is water-soluble, the hydrophilic monomer diffuses into the water from the oil droplets dispersed as a monomer mixture in water, and polymerizes in water other than the oil droplets. It was to do.

  The present inventors addressed the above problems by (1) allowing the monomer mixture to exist as stable and uniform suspended particles in the aqueous medium, and (2) preventing these particles from agglomerating during the polymerization. I tried to improve from two viewpoints.

  First, for (1) above, an organic solvent is added to a mixture of a hydrophilic monomer and a hydrophobic monomer so that the hydrophilic monomer and the hydrophobic monomer having different polarities It was found that the compatibility is good and stable suspended particles can be formed in the aqueous medium. Further, even in the above case, in order to prevent the diffusion of the hydrophilic monomer from the suspended particles into the aqueous medium, the monomer is dissolved in the aqueous medium and contains the hydrophilic monomer due to the salting-out effect. The mixture could be preferentially placed in the oil layer of the suspension polymerization system.

  On the other hand, with respect to (2), it can be said that the dissolution of the salt in the aqueous medium suppresses the occurrence of emulsion polymerization that occurs during suspension polymerization, and at the same time, it is effective for the aggregation of particles. Furthermore, it has been found that the addition of a dispersion stabilizer in the aqueous medium can suppress the aggregation of particles.

  That is, in the present invention, the above (1) and (2) are not satisfied until the three conditions of addition of the organic solvent into the monomer mixture, dissolution of the salt in the aqueous medium and addition of the dispersion stabilizer are satisfied. The action was exhibited, and a stable polymerization reaction in suspension particles containing a hydrophilic monomer and a hydrophobic monomer became possible. By doing so, a copolymer of a hydrophobic monomer and a hydrophilic monomer, which has conventionally been difficult to control the polymerization ratio, can be easily produced at a desired copolymerization ratio. Realized.

  Hereafter, the manufacturing method of the hydroxyl-containing polymer of this invention is demonstrated in detail. In addition, the ethylenically unsaturated monomer in this invention means the monomer which has ethylenically unsaturated groups, such as a vinyl group. The following hydrophilic monomer and hydrophobic monomer are both included in the ethylenically unsaturated monomer in the present invention.

<Process for mixing monomers>
(Hydrophilic monomer having a hydroxyl group)
Examples of the hydrophilic monomer having a hydroxyl group used in the present invention include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and glycerin di (meth) acrylate. 1,6-bis (3-acryloxy-2-hydroxypropyl) -hexyl ether, pentaerythritol tri (meth) acrylate, tris- (2-hydroxyethyl) isocyanuric acid ester (meth) acrylate, polyethylene glycol (meth) acrylate And so on.
Here, the (meth) acrylate is an expression representing acrylate or methacrylate, and the same applies to the following.

  Among these, it is possible to use at least one selected from 2-hydroxyethyl (meth) acrylate and polyethylene glycol (meth) acrylate, to control the copolymerization ratio with the hydrophobic monomer described later, and to control the polymerization reaction From the viewpoint of properties and the like.

(Hydrophobic monomer)
Examples of the hydrophobic monomer include aromatic vinyl monomers such as styrene and α-methylstyrene; an alkyl group having 1 to 18 carbon atoms (more preferably 2 to 16) or an aralkyl group (meth). Acrylic acid alkyl ester (for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate , Benzyl (meth) acrylate, etc.); (meth) acrylic acid alkoxyalkyl esters having an alkylene group having 1 to 12 (more preferably 2 to 10) carbon atoms (for example, methoxymethyl (meth) acrylate, methoxyethyl (meth) ) Acrylate, Echitosimethyl (Meth) acrylate, ethoxyethyl (meth) acrylate, ethoxybutyl (meth) acrylate, n-butoxymethyl (meth) acrylate, n-butoxyethyl (meth) acrylate, etc.); amino group-containing (meth) acrylic acid ester (for example, , Diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, etc.); acrylonitrile, ethylene, vinyl chloride, vinyl acetate and the like.

  Among these, styrene, methyl (meth) acrylate, butyl (meth) acrylate 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, ethoxybutyl (meth) acrylate, benzyl (meth) acrylate, and diethylaminoethyl (meth) acrylate Further, styrene, methyl (meth) acrylate, and butyl (meth) acrylate are particularly preferable.

The content of the hydrophobic monomer copolymerizable with the hydrophilic monomer is preferably in the range of 20.0 to 99.9% by mass in all monomer components, and is preferably 50.0 to The range of 90.0% by mass is more preferable.
If the content is less than 20.0% by mass, the amount of hydroxyl groups in the polymer becomes too large, and uniform polymerization may not be possible even by the method of the present invention. If the content exceeds 99.9% by mass, The hydrophilic effect due to the hydroxyl group may not be obtained.

(Other monomers)
If necessary, a crosslinking agent can be mixed in the reactive mixture (containing the ethylenically unsaturated monomer and the like) dispersed in the aqueous medium described later. By adding a crosslinking agent into the monomer mixture, granular hydroxyl group-containing crosslinked polymer particles can be obtained.

As a crosslinking agent to be used, a known crosslinking agent can be appropriately selected and used. Preferred examples thereof include divinylbenzene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, methylene bis (meth) acrylamide, Examples thereof include glycidyl (meth) acrylate and 2-([1′-methylpropylideneamino] carboxyamino) ethyl methacrylate. Among these, divinylbenzene, ethylene glycol di (meth) acrylate, and diethylene glycol di (meth) acrylate are more preferable, and divinylbenzene is particularly preferable.
As addition amount of a crosslinking agent, it is preferable that it is 0.1-80 mass parts with respect to 100 mass parts of all the monomer components, and it is more preferable that it is 0.5-50 mass parts.

  Other ethylenically unsaturated monomers include, for example, acrylamides, glycidyl (meth) acrylates, and the like, which are added to the hydrophilic monomer and the hydrophobic monomer as necessary. Can be used.

(Organic solvent)
As the organic solvent used in the present invention, all organic solvents can be used in principle as long as they are hardly soluble in water and have a boiling point higher than the reaction temperature during polymerization and do not inhibit the polymerization. Examples include hydrocarbons, alcohols, ketones, ethers and the like, but are not limited thereto.
Examples of the hydrocarbons include aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons include hexane, heptane, octane, dodecane, cyclohexane, decahydronaphthalene, petroleum hydrocarbons, naphthenic hydrocarbons, etc., and aromatic hydrocarbons include toluene, xylene, diethylbenzene, And dodecylbenzene.

  As said alcohol, C8-C24 (preferably 12-22) aliphatic alcohol etc. can be used, Any of acyclic aliphatic alcohol and alicyclic alcohol may be sufficient. Further, any of natural alcohol and synthetic alcohol (Ziegler alcohol, oxo alcohol, etc.) may be used. Further, the alkyl group portion may be linear or branched.

  As the acyclic aliphatic alcohol, a saturated aliphatic alcohol and an unsaturated aliphatic alcohol are used. Examples of the acyclic saturated aliphatic alcohol include isoamyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol (lauryl alcohol), tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol , Nonadecyl alcohol, tetracocenyl alcohol and the like. Examples of the acyclic unsaturated aliphatic alcohol include octenyl alcohol, decenyl alcohol, dodecenyl alcohol, tridecenyl alcohol, pentadecenyl alcohol, oleyl alcohol, tetracocenyl alcohol, Examples thereof include gadreyl alcohol and linoleyl alcohol.

  As the alicyclic alcohol, monocyclic aliphatic alcohols and polycyclic aliphatic alcohols are used. Examples of monocyclic aliphatic alcohols include ethyl cyclohexyl alcohol, propyl cyclohexyl alcohol, octyl cyclohexyl alcohol, nonyl cyclohexyl alcohol, and stearyl cyclohexyl alcohol. Examples of the polycyclic aliphatic alcohol include adamantyl alcohol and dicyclohexyl alcohol.

  As said ketones, a C6-C22 (preferably 7-12) aliphatic ketone, an aromatic ketone, etc. can be used, and any of an acyclic aliphatic ketone and an alicyclic ketone may be sufficient as an aliphatic ketone. . Further, the alkyl group portion may be linear or branched. For example, dipropyl ketone, methyl amyl ketone, methyl hexyl ketone, diisobutyl ketone and the like can be mentioned.

As the ethers, aliphatic ethers and aromatic ethers having 6 to 22 (preferably 7 to 12) carbon atoms can be used, and aliphatic ethers may be either acyclic aliphatic ethers or alicyclic ethers. . Further, the alkyl group portion may be linear or branched. Examples thereof include ethylene glycol dibutyl ether, methyl phenyl ether, butyl phenyl ether, diethylene glycol dibutyl ether and the like. These solvents can be used alone or in combination of several kinds.
These solvents can be used alone or in combination of several kinds.

  The organic solvent used in the present invention is desirably one having affinity for both the hydrophilic monomer and the hydrophobic monomer for the reasons described above. As a specific method for selecting an organic solvent, it is preferable to select a solvent that is higher than the boiling point of the ethylenically unsaturated monomer to be used, hardly soluble in water, does not inhibit polymerization, and has high compatibility. Depending on the combination of the organic solvent and the monomer, the yield of the finally obtained polymer may vary. The solvent may be a solvent that dissolves the monomer and also dissolves the polymer, or a solvent that dissolves the monomer but does not dissolve the polymer.

From such a viewpoint, it is preferable to use at least one selected from diethylbenzene, lauryl alcohol, and isoamyl alcohol as the organic solvent.
Moreover, as an organic solvent, it is desirable to adjust solubility (solubility parameter) and surface tension according to the ethylenically unsaturated monomer to be used, and as a method, two or more organic solvents are mixed and used. Is also preferable.

  In the present invention, the content of the organic solvent in the mixture is preferably in the range of 5 to 80% by mass, and more preferably in the range of 10 to 60% by mass.

(Polymerization initiator)
Preferred examples of the polymerization initiator used in the present invention include azo polymerization initiators and peroxide initiators. Among them, oil-soluble initiators are preferable.
Examples of oil-soluble azo initiators include azobisisobutyronitrile (AIBN), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl Examples include 2,2′-azobis (2-methylpropionate), 1,1′-azobiscyclohexane-1-carbonitrile and the like. Examples of the oil-soluble peroxide-based initiator include benzoyl peroxide, acetyl peroxide, decanoyl peroxide, lauroyl peroxide, o-methoxybenzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, Diisopropyl peroxide, di-2-ethylhexyl peroxide, acetylcyclohexylsulfonyl peroxide, t-butyl perisobutyrate, t-butyl perbivalate, t-butyl per-2-ethylhexanoate, t-butyl peroxide , T-butyl cumyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl hydroperoxide and the like.

  Although the said polymerization initiator can be used in arbitrary quantity, it is preferable that it is the range of 0.05-10 mass parts with respect to 100 mass parts of all the monomer components, Furthermore, 0.1-5 masses Part.

(Other additives)
The hydroxyl group-containing polymer of the present invention can further contain dyes, pigments, carbon black, and other magnetic powders for the purpose of coloring the polymer. Each additive can be included.

  The mixture containing the monomer and the like is prepared by mixing the ethylenically unsaturated monomer, the organic solvent, the polymerization initiator, and other necessary components. The mixing method is not particularly limited, but an organic solvent is added to an ethylenically unsaturated monomer containing a hydrophilic monomer and a hydrophobic monomer to increase the compatibility of the two monomers. It is preferable to stir for about minutes.

<Step of suspending the mixture in an aqueous medium>
(Aqueous medium)
As the aqueous medium in the present invention, water or a solution obtained by adding a water-soluble organic solvent such as methanol or ethanol to water is preferably used, and water alone is particularly preferable among them. The amount of water-soluble organic solvent to be added depends on the properties of the monomer to be suspended, but is preferably 30% by mass or less, particularly preferably 10% by mass or less, based on the total solvent. When the addition amount is 30% by mass or less, the dispersion stability may be kept good in some cases.

(salt)
In the present invention, it is an essential requirement to dissolve a salt in the aqueous medium. The reaction of emulsion polymerization is suppressed by the salting out effect, the dispersion stability of the suspended particles is obtained, and a good yield can be realized.

  As the salt to be dissolved, water-soluble inorganic or organic salts can be used. In particular, inorganic salts are preferable because the salting-out effect can be effectively exhibited. Examples of the inorganic salts include sodium chloride, potassium chloride, potassium carbonate, calcium chloride, ammonium chloride, sodium sulfate, sodium acetate, ammonium sulfate, magnesium chloride, magnesium sulfate and the like. Among these, sodium chloride, potassium chloride Potassium carbonate and calcium chloride are more preferable, and sodium chloride is particularly preferable.

The addition amount of the salt is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 15% by mass or more with respect to the aqueous medium from the viewpoint of dispersion stability.
If the dissolution amount is less than 5% by mass, the salting-out effect may not be sufficiently obtained, and emulsion polymerization may easily occur.

(Dispersion stabilizer)
In the present invention, it is further essential that a dispersion stabilizer is present in the aqueous medium. As the dispersion stabilizer, known dispersion stabilizers can be used, but using an inorganic powder such as calcium carbonate and calcium phosphate is effective in enhancing the dispersibility of the suspended particles in the present invention, and the particles are This is preferable because aggregation of the resin can be suppressed. In addition, it is preferable that the surface of the inorganic powder is coated with a surface modifier in terms of dispersion stability of suspended particles and dispersion stability of the inorganic powder in an aqueous medium. Furthermore, it is also preferable to use a surfactant such as an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier in addition to the inorganic powder.

  Although the said dispersion stabilizer can be used in arbitrary quantity, it is preferable that it is the range of 1-30 mass parts with respect to 100 mass parts of the mixture of all the monomer components and an organic-solvent component, and 5-20 More preferably, it is in the range of parts by mass. By being 1 part by mass or more, a good dispersion state can be obtained, while by being 30 parts by mass or less, derivation of fine particles can be suppressed and the particle size distribution of suspended particles can be sharpened. There is an advantage.

The mixture containing the monomer and the like can be suspended in an aqueous medium containing the salt and the like (hereinafter sometimes referred to as “dispersion medium”) as follows.
That is, a mixture in which a hydrophilic monomer, a hydrophobic monomer, a polymerization initiator, a crosslinking agent, etc. are added to an aqueous medium in which the salt is dissolved and a dispersion stabilizer is present is added and suspended. . As a suspension method, a known suspension method can be used. For example, like a mixer, a special stirring blade is rotated at a high speed to suspend monomers and the like in an aqueous medium, a method of suspending with a rotor-stator shear force known as a homogenizer, and suspension by ultrasonic waves. And mechanical suspension methods such as

In addition, it is also possible to prepare a liquid to which the above-described monomer or the like is added and suspend it using an emulsification method known as a membrane emulsification method in which the liquid is extruded from a porous membrane into an aqueous medium.
The mixing mass ratio of the mixture to be suspended and the dispersion medium (mixture / dispersion medium) is preferably in the range of 1/10 to 3/1, and the number average particle diameter of the suspended particles is A range of 1 to 200 μm is preferable.

<Process for polymerizing suspended particles>
In the present invention, a polymer is obtained by suspension polymerization of particles such as the suspended monomer. The polymerization reaction can be carried out not only in the air but also under pressure, but these other reaction conditions are applied as required and are not particularly limited.

  As the reaction conditions, for example, it is possible to carry out the reaction at a reaction temperature of 40 to 100 ° C. for 1 to 24 hours while stirring the suspension in which the suspended particles are dispersed under atmospheric pressure, in a high yield. From the viewpoint of obtaining

  The polymer thus obtained is diluted and dispersed in a solvent such as methanol, filtered, further washed with water and / or solvent, and then isolated as a powder by ordinary means such as spray drying, reduced pressure drying, freeze drying and the like. can do.

<Physical properties of hydroxyl group-containing polymer>
(Hydroxyl content)
The amount of hydroxyl groups in the hydroxyl group-containing polymer obtained in each step can be determined by a general titration method. For example, a certain amount of a reagent such as pyridine solution of acetic anhydride is added to the above polymer, heated, hydrolyzed by adding water, separated into particles and supernatant by a centrifuge, and the supernatant is used as an indicator such as phenolphthalein. The amount of hydroxyl groups can be determined by titrating with an ethanolic potassium hydroxide solution or the like.

  The amount of hydroxyl group of the hydroxyl group-containing polymer in the present invention is preferably in the range of 0.01 to 7 mmol / g, more preferably in the range of 0.1 to 5 mmol / g, although it varies depending on the application.

(Molecular weight)
Moreover, although the molecular weight (number average molecular weight) of the hydroxyl group-containing polymer in the present invention varies depending on the application, in the case where no crosslinking agent is added in the polymerization step, a range of 5,000 to 1,000,000 is preferable. A range is more preferred.

  The number average molecular weight was measured using gel permeation chromatography (GPC). GPC uses HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation), and column uses two TSKgel and SuperHM-H (manufactured by Tosoh Corporation, 6.0 mm ID × 15 cm). As THF (tetrahydrofuran).

(Number average particle size)
Furthermore, the number average particle size of the hydroxyl group-containing polymer in the present invention is preferably in the range of 0.5 to 150 μm, and more preferably in the range of 1 to 80 μm. The above number average particle diameter is obtained by taking a photograph of dry particles with an optical microscope or an electron microscope, measuring the particle diameters of 100 to 200 particles randomly selected from them, and summing them. The value divided by the number. In this measurement, it is preferable that there are no aggregated particles (one in which a plurality of particles are aggregated, or one in which fine particles are attached to one particle and become deformed).

(Other characteristics)
The particles of the hydroxyl group-containing polymer obtained by the present invention may become porous particles having fine pores by removing the organic solvent from the particles after polymerization. The fine pores are present on the particle surface and in the particles. For example, when the particle surface is observed with a scanning electron microscope, the presence of pores having an average diameter in the range of 50 to 500 nm can be confirmed. On the other hand, depending on conditions, the particle surface may not be porous.

  As mentioned above, although the manufacturing method of the hydroxyl-containing polymer of this invention was demonstrated in detail, the hydroxyl-containing polymer obtained by the manufacturing method of this invention is a diagnostic agent, a pharmaceutical carrier, a chromatography carrier, a viscosity regulator, and a resin molding material. , Coating additives, crosslinking / curing agents and cosmetic additives. In particular, the hydroxyl group-containing polymer has excellent uniformity as particles, and the surface adsorption / desorption characteristics can be easily controlled by controlling the composition of the hydrophilic monomer and the hydrophobic monomer. Can be suitably used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. In the examples, “parts” and “%” represent “parts by mass” and “% by mass”, respectively.

<Example 1>
(Production of hydroxyl group-containing polymer)
11 parts of hydroxyethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 35 parts of styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.) and 7 parts of divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.) are mixed. 25 parts of diethylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.) and 50 parts of isoamyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) as an organic solvent, and azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator 2.5 parts was added to prepare a monomer mixture (mixture).

  To an aqueous solution in which 29 parts of sodium chloride was dissolved in 120 parts of ion-exchanged water, 10 parts of calcium carbonate (manufactured by Maruo Calcium Co., Ltd., trade name: Luminous) was added as a dispersion stabilizer and dispersed in a ball mill for 24 hours to obtain a dispersion medium. The monomer mixture was added to this dispersion medium and emulsified at 8000 rpm for 3 minutes with an emulsifying apparatus (manufactured by SMT Co., Ltd., HIGH-FLEX HOMOGENIZER) to obtain a suspension. The number average particle diameter of the suspended particles at this time was about 68 μm.

  On the other hand, nitrogen was introduced into the separable flask equipped with a stirrer, a thermometer, a cooling pipe, and a nitrogen introduction pipe from the nitrogen introduction pipe, and the inside of the flask was made a nitrogen atmosphere. The above suspension was placed therein, reacted at 65 ° C. for 3 hours, further heated at 70 ° C. for 10 hours and cooled. The reaction solution was a good dispersion, and no agglomerates could be confirmed during polymerization. A 10% aqueous hydrochloric acid solution was added to the reaction solution to decompose calcium carbonate, and solid-liquid separation was performed by centrifugation. The obtained particles were washed with 1 L of ion-exchanged water, and then washed with 500 ml of ethanol for 30 minutes over 30 minutes to obtain polymer particles A. The polymer particles A were oven-dried at 60 ° C., and the yield of the polymer was measured to be 50 parts and the yield was 94%.

(Characteristic evaluation of hydroxyl group-containing polymer)
-Hydroxyl amount-
A polymer is weighed and placed in a capped test tube, and a predetermined amount of a pre-prepared acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) pyridine (manufactured by Wako Pure Chemical Industries, Ltd.) solution is added, and the temperature is 95 ° C. Heated for 24 hours.
Further, distilled water was added to hydrolyze acetic anhydride in the test tube, and then centrifuged at 3000 rpm for 5 minutes to separate into particles and supernatant. The polymer was further washed with ethanol (manufactured by Wako Pure Chemical Industries, Ltd.) by repeated ultrasonic dispersion and centrifugation, and the supernatant and the washing solution were collected in a conical beaker, and phenolphthalein (manufactured by Wako Pure Chemical Industries, Ltd.) was used as an indicator. The solution was titrated with a 0.1M ethanolic potassium hydroxide solution (Wako Pure Chemical Industries, Ltd.).

A blank experiment without using a polymer was also performed, and the amount of hydroxyl group (mmol / g) was calculated from the difference according to the following formula (1).
Hydroxyl group amount = ((BC) × 0.1 × f) / w Formula (1)
In the above formula (1), B is the dripping amount (ml) in the blank experiment, C is the dripping amount (ml) of the sample, f is the factor of the potassium hydroxide solution, and w is the weight (g) of the particles.
As a result, the amount of hydroxyl groups in the polymer particles A was 1.21 mmol / g.

-Number average particle size and particle shape-
As described above, the number average particle diameter of the polymer particles was determined from a photograph of the dried particles observed with an electron microscope and found to be 52 μm. In the photograph, no agglomerated particles were observed.

<Example 2>
(Production of hydroxyl group-containing polymer)
19 parts of hydroxyethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 28 parts of styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.) and 7 parts of divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.) are mixed. 25 parts of diethylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.) and 50 parts of isoamyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) as organic solvents and azobisisobutyronitrile (manufactured by Wako Pure Chemicals, trade name) as polymerization initiators V-60) 2.5 parts was added to prepare a monomer mixture.

  To an aqueous solution in which 29 parts of sodium chloride was dissolved in 120 parts of ion-exchanged water, 10 parts of calcium carbonate (manufactured by Maruo Calcium Co., Ltd., trade name: Luminous) was added as a dispersion stabilizer and dispersed in a ball mill for 24 hours to obtain a dispersion medium. The monomer mixture was added to this dispersion medium and emulsified at 8000 rpm for 3 minutes with an emulsifying apparatus (manufactured by SMT Co., Ltd., HIGH-FLEX HOMOGENIZER) to obtain a suspension. The number average particle size of the suspended particles at this time was about 71 μm.

  On the other hand, nitrogen was introduced into the separable flask equipped with a stirrer, a thermometer, a cooling pipe, and a nitrogen introduction pipe from the nitrogen introduction pipe, and the inside of the flask was made a nitrogen atmosphere. The above suspension was placed therein, reacted at 65 ° C. for 3 hours, further heated at 70 ° C. for 10 hours and cooled. The reaction solution was a good dispersion, and no agglomerates could be confirmed during polymerization. A 10% aqueous hydrochloric acid solution was added to the reaction solution to decompose calcium carbonate, and solid-liquid separation was performed by centrifugation. The obtained particles were washed with 1 L of ion-exchanged water, and then washed with 500 ml of ethanol for 30 minutes over 30 minutes to obtain polymer particles B. After the polymer particles B were oven-dried at 60 ° C., the yield of the polymer was measured and found to be 49 parts and the yield was 91%.

(Characteristic evaluation of hydroxyl group-containing polymer)
When the hydroxyl group content of the polymer particles B was measured by the same method as in Example 1, the hydroxyl group content of the particles was 1.95 mmol / g.
Similarly, the number average particle diameter was determined to be 51 μm, and no agglomerated particles were found.

<Example 3>
21 parts of hydroxyethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 26 parts of styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.) and 7 parts of divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.) were mixed. 25 parts of diethylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.) as an organic solvent, 50 parts of isoamyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) and azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator 2.5 parts was added to prepare a monomer mixture.

  To an aqueous solution in which 29 parts of sodium chloride was dissolved in 120 parts of ion-exchanged water, 10 parts of calcium carbonate (manufactured by Maruo Calcium Co., Ltd., trade name: Luminous) was added as a dispersion stabilizer and dispersed in a ball mill for 24 hours to obtain a dispersion medium. The monomer mixture was added to this dispersion medium and emulsified at 8000 rpm for 3 minutes with an emulsifying apparatus (manufactured by SMT Co., Ltd., HIGH-FLEX HOMOGENIZER) to obtain a suspension. The number average particle size of the suspended particles at this time was about 72 μm.

  On the other hand, nitrogen was introduced into the separable flask equipped with a stirrer, a thermometer, a cooling pipe, and a nitrogen introduction pipe from the nitrogen introduction pipe, and the inside of the flask was made a nitrogen atmosphere. The above suspension was placed therein, reacted at 65 ° C. for 3 hours, further heated at 70 ° C. for 10 hours and cooled. The reaction solution was a good dispersion, and no agglomerates could be confirmed during polymerization. A 10% aqueous hydrochloric acid solution was added to the reaction solution to decompose calcium carbonate, and solid-liquid separation was performed by centrifugation. The obtained particles were washed with 1 L of ion-exchanged water, and then washed with 500 ml of ethanol for 30 minutes over 30 minutes to obtain polymer particles C. The polymer particles C were oven dried at 60 ° C., and the yield of the polymer was measured. As a result, it was 48 parts and the yield was 89%.

(Characteristic evaluation of hydroxyl group-containing polymer)
When the hydroxyl group content of the polymer particles C was measured by the same method as in Example 1, the hydroxyl group content of the particles was 2.67 mmol / g.
Similarly, the number average particle diameter was determined to be 50 μm, and no agglomerated particles were found.

<Example 4>
15 parts of polyethylene glycol methacrylate (number average molecular weight Mn: 360, manufactured by Aldrich), 32 parts of styrene monomer (manufactured by Wako Pure Chemical Industries, Ltd.) and 7 parts of divinylbenzene (manufactured by Wako Pure Chemical Industries, Ltd.) are mixed, To this was added 50 parts of lauryl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.) as an organic solvent and 2.5 parts of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator. A mixed solution was prepared.

  To an aqueous solution in which 29 parts of sodium chloride was dissolved in 120 parts of ion-exchanged water, 10 parts of calcium carbonate (manufactured by Maruo Calcium Co., Ltd., trade name: Luminous) was added as a dispersion stabilizer and dispersed in a ball mill for 24 hours to obtain a dispersion medium. The monomer mixture was added to this dispersion medium and emulsified at 8000 rpm for 3 minutes with an emulsifying apparatus (manufactured by SMT Co., Ltd., HIGH-FLEX HOMOGENIZER) to obtain a suspension. The number average particle size of the suspended particles at this time was about 71 μm.

  On the other hand, nitrogen was introduced into the separable flask equipped with a stirrer, a thermometer, a cooling pipe, and a nitrogen introduction pipe from the nitrogen introduction pipe, and the inside of the flask was made a nitrogen atmosphere. The above suspension was placed therein, reacted at 65 ° C. for 3 hours, further heated at 70 ° C. for 10 hours and cooled. The reaction solution was a good dispersion, and no agglomerates could be confirmed during polymerization. A 10% aqueous hydrochloric acid solution was added to the reaction solution to decompose calcium carbonate, and solid-liquid separation was performed by centrifugation. The obtained particles were washed with 1 L of ion-exchanged water, and then washed with 500 ml of ethanol for 30 minutes over 30 minutes, and polymer particles D were obtained. The polymer particles D were oven-dried at 60 ° C., and the yield of the polymer was measured. As a result, it was 47 parts and the yield was 91%.

(Characteristic evaluation of hydroxyl group-containing polymer)
When the hydroxyl group content of the polymer particles D was measured by the same method as in Example 1, the hydroxyl group content of the particles was 0.70 mmol / g.
Similarly, the number average particle diameter was determined to be 56 μm, and no agglomerated particles were found.

<Comparative Example 1>
In Example 3, suspension polymerization was performed in the same manner except that diethylbenzene and isoamyl alcohol, which are organic solvents, were not used. In this case, agglomerates were seen during the polymerization. When the yield of the obtained polymer was measured, it was 33 parts, and the yield decreased to 61%.

When the amount of hydroxyl groups of the obtained polymer particles was measured by the same method as in Example 1, the amount of hydroxyl groups of the polymer particles was as low as 0.06 mmol / g.
Further, when these polymer particles were observed with a microscope, the variation in the particle diameters was large, but the number average particle diameter was 39 μm. A considerable number of aggregated particles were observed.

<Comparative example 2>
In Example 1, except that sodium chloride was not added at the time of preparation of the dispersion medium, the same procedure as in Example 1 was performed to suspend and polymerize the monomer mixture. It was confirmed that the emulsion polymerization was derived in the dispersion medium when white fine particles passing through ADVANTEC No. 5C (retained particle diameter 1 μm) were observed. When the yield of the obtained polymer was measured, it was 43 parts, and the yield dropped to 79%.

When the amount of hydroxyl groups in the obtained polymer particles was measured by the same method as in Example 1, the amount of hydroxyl groups in the polymer particles was as low as 0.03 mmol / g.
Further, when these polymer particles were observed with a microscope, there was a large variation in particle diameter, but the number average particle diameter was 45 μm. A considerable number of aggregated particles were observed.

<Comparative Example 3>
In Example 3, suspension polymerization was performed with the same formulation except that calcium carbonate as a dispersion stabilizer was not used. In this case, the suspended particles were not stably dispersed and became aggregates during the polymerization, and the intended particle shape was not achieved.

  As described above, according to the method for producing a hydroxyl group-containing polymer of the present invention in Examples, the suspended particles at the time of polymerization are stable, so that aggregation does not occur and the composition is in accordance with the charged composition. It can be obtained as polymer particles having a uniform particle size. On the other hand, in the comparative example in which even one of the production conditions in the present invention is insufficient, some problem occurred in yield, particle state, and the like.

Claims (6)

  A mixture containing an ethylenically unsaturated monomer containing a hydrophilic monomer having a hydroxyl group and a hydrophobic monomer, an organic solvent, and a polymerization initiator was dissolved in a salt and a dispersion stabilizer was added. A method for producing a hydroxyl group-containing polymer, comprising a step of suspension polymerization in an aqueous medium.   2. The method for producing a hydroxyl group-containing polymer according to claim 1, wherein the content of the hydrophobic monomer is in a range of 20.0 to 99.9 mass% in all monomer components.   2. The method for producing a hydroxyl group-containing polymer according to claim 1, wherein the content of the hydrophobic monomer is in the range of 50.0 to 90.0 mass% in all monomer components.   2. The hydroxyl group-containing polymer according to claim 1, wherein the hydrophilic monomer having a hydroxyl group is at least one selected from 2-hydroxyethyl (meth) acrylate and polyethylene glycol (meth) acrylate. Production method.   The method for producing a hydroxyl group-containing polymer according to claim 1, wherein the organic solvent is at least one selected from diethylbenzene, lauryl alcohol, and isoamyl alcohol.   The method for producing a hydroxyl group-containing polymer according to claim 1, wherein the dispersion stabilizer is an inorganic powder.