JP2002201211A - Method for preparing hydrophilic polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preparing a hydrophilic polymer which removes a hydrophobic solvent in a short period of time and does not cause problems such as the fusing of the hydrophilic polymers with each other and their coloration. SOLUTION: The method for preparing a hydrophilic polymer comprises a polymerization reaction of the reversed phase system using a hydrophobic solvent, distilling the hydrophobic solvent out after the polymerization reaction, adding a hydrophilic solvent, and then redistilling the hydrophobic solvent out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a useful method for producing a hydrophilic polymer in a reversed-phase system using a hydrophobic solvent.

[0002]

2. Description of the Related Art
Various hydrophilic polymers are manufactured in various industrial fields. Among them, production methods such as reverse phase suspension polymerization and dispersion polymerization are used. For example, in a reversed-phase suspension polymerization method or a dispersion polymerization method, a hydrophobic solvent in which a monomer component, a crosslinking agent, and a polymerization initiator are uniformly dissolved, and water or the like is added as necessary, and the dispersant is uniformly dissolved or dispersed. And a polymerization reaction is carried out.

[0003] The reaction product obtained by the reversed-phase suspension polymerization method or the dispersion polymerization method is a slurry containing the hydrophobic solvent used in the reaction, and is dehydrated as necessary for the purpose of facilitating removal. A method is used in which a hydrophobic solvent is removed under heating, followed by drying to obtain a powder. However, it is not easy to remove the hydrophobic solvent used for the reaction from the reaction product, which not only causes a cost increase, but also causes a case where the hydrophilic polymer is fused when dried under heating for a long time,
There were problems such as coloring.

[0004] An object of the present invention is to provide a method for producing a hydrophilic polymer, which removes a hydrophobic solvent in a short time and does not cause problems such as fusion and coloring of the hydrophilic polymers.

[0005]

Means for Solving the Problems The present invention relates to a reversed-phase polymerization reaction using a hydrophobic solvent, wherein after the polymerization reaction, the hydrophobic solvent is distilled off, the hydrophilic solvent is added, and then the hydrophobic solvent is added. The present invention provides a method for producing a hydrophilic polymer, in which is distilled off again.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Hydrophilic polymer] The hydrophilic polymer of the present invention includes (a) a vinyl monomer containing a cationic group such as an amino group, an ammonium group, a pyridyl group, an imino group, a betaine structure and / or A salt (hereinafter referred to as a cationic monomer), (b) a vinyl monomer containing a hydrophilic nonionic group such as a hydroxy group, an amide group, an ester group or an ether group (hereinafter referred to as a nonionic monomer); And a polymer obtained from one or more monomers selected from vinyl monomers containing an anionic group such as a sulfonic acid group and a phosphoric acid group and / or a salt thereof (hereinafter, referred to as an anionic monomer). A polymer obtained from the above cationic monomer and one or more nonionic monomers.

Further, the hydrophilic polymer of the present invention preferably has a cross-linked structure by a cross-linkable vinyl monomer having at least two reactive unsaturated groups in a molecule (hereinafter, referred to as a cross-linkable monomer). . The above (a) ~
Other vinyl monomers copolymerizable with the monomer (c) can also be copolymerized.

<(A) Cationic monomer> As the cationic monomer of (a), dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, diisopropylaminoethyl (meth) Acrylate, dibutylaminoethyl (meth) acrylate, diisobutylaminoethyl (meth) acrylate, di-t-butylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, dipropylaminopropyl (meth) ) Acrylamide, diisopropylaminopropyl (meth) acrylamide, dibutylaminopropyl (meth) acrylamide, diisobutylaminopropyl (meth) acryl (Meth) acrylic acid esters or (meth) acrylamides having a dialkylamino group having 2 to 44 carbon atoms, such as amide and di-t-butylaminopropyl (meth) acrylamide; total number of carbon atoms such as dimethylaminostyrene and dimethylaminomethylstyrene Styrene having a 2-44 dialkylamino group; vinylpyridine such as 2- or 4-vinylpyridine; N-vinyl heterocyclic compounds such as N-vinylimidazole; vinyl ethers such as aminoethyl vinyl ether and dimethylaminoethyl vinyl; An acid neutralized product of a monomer having an amino group or an alkyl halide (having 1 to 2 carbon atoms)
2), benzyl halide, alkyl (1 to 1 carbon atoms)
8) or quaternized with aryl (C6-24) sulfonic acid or dialkyl sulfate (total carbon number 2-8); diallyl-type quaternary ammonium salts such as dimethyldiallylammonium chloride and diethyldiallylammonium chloride; N- (3-sulfopropyl) -N
-(Meth) acryloyloxyethyl-N, N-dimethylammonium betaine, N- (3-sulfopropyl)
-N- (meth) acryloylamidopropyl-N, N-
Dimethylammonium betaine, N- (3-carboxymethyl) -N- (meth) acryloylamidopropyl-
N, N-dimethylammonium betaine, N-carboxymethyl-N- (meth) acryloyloxyethyl-
Examples include monomers such as vinyl monomers having a betaine structure such as N, N-dimethylammonium betaine.
Among these cationic groups, amino group- and ammonium group-containing monomers are preferable, and are represented by the general formula (I) or (I
At least one selected from the compounds represented by I) is more preferable.

[0009]

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[In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ are the same or different and represent an alkyl group or alkenyl group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom or a carbon atom. Y represents -O-, -NH,
- or _{-O-CH 2 CH (OH)} - represents a group, Z is a linear or branched alkylene group having 1 to 4 carbon atoms, conjugate base of X is an acid, a halogen atom or carbon atoms from 1 to 4 Represents an alkyl sulfate group. ]

[0011]

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Wherein R ⁵ and R ⁶ are the same or different and represent a hydrogen atom or a methyl group; R ⁷ and R ⁸ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;
Has the above-mentioned meaning. As specific examples of the compound represented by the general formula (I), a (meth) acrylic ester or a (meth) acrylate having a dialkylamino group exemplified above.
Examples thereof include an acid-neutralized product obtained by neutralizing acrylamide with an acid and a quaternary ammonium salt obtained by quaternizing with a quaternizing agent. Specific examples of the compound represented by the general formula (II) are exemplified above. Diallyl-type quaternary ammonium salts.

Preferred acids for obtaining the above acid-neutralized products include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, formic acid, maleic acid, fumaric acid, citric acid, tartaric acid, adipic acid, sulfamic acid, and toluenesulfone. Acids, lactic acid, pyrrolidone-2-carboxylic acid, succinic acid, propionic acid, glycolic acid, and other organic acids having a total of 1 to 22 carbon atoms, and the like, and preferred quaternizing agents for obtaining the above quaternary ammonium salts Examples thereof include general alkylating agents such as alkyl halides having 1 to 8 carbon atoms such as methyl chloride, ethyl chloride, methyl bromide and methyl iodide, dimethyl sulfate, diethyl sulfate and di-n-propyl sulfate. .

Among the compounds represented by formula (I) or (II), particularly preferred are dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, Diethylaminopropyl (meth)
A quaternary ammonium salt obtained by quaternizing acrylamide with the above-described quaternizing agent, or dimethyldiallylammonium chloride can be used. Here, the acid-neutralized monomer has a disadvantage that the stability of the viscosity is low because the neutralized acid is dissociated due to the pH of the system and the polymer structure is changed. From this viewpoint, a quaternary ammonium salt type monomer is more preferable.

<(Ii) Nonionic monomer> As the nonionic monomer (ii), vinyl alcohol; N-hydroxypropyl (meth) acrylamide, N-hydroxyethyl (meth) acrylate, N-hydroxypropyl (meth) (Meth) acrylic acid esters or (meth) acrylamides having a hydroxyalkyl (1-8 carbon atoms) group such as acrylamide; and polyhydric alcohols such as polyethylene glycol (meth) acrylate (the degree of polymerization of ethylene glycol is 1 to 30). (Meth) acrylic acid ester; (meth) acrylamide; N-methyl (meth)
Acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-
Alkyl (C1-8) such as t-butyl (meth) acrylamide and N-isobutyl (meth) acrylamide
(Meth) acrylamide; dialkyl (total carbon number of 2 to 8) such as N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide
(Meth) acrylamide; diacetone (meth) acrylamide; N-vinyl cyclic amide such as N-vinylpyrrolidone; alkyl such as methyl (meth) acrylate, ethyl (meth) acrylate, and n-butyl (meth) acrylate 8) (Meth) acrylic acid ester having a group; (meth) acrylamide having a cyclic amide group such as N- (meth) acryloylmorpholine is exemplified. Preferably, a (meth) acrylamide-based monomer represented by the general formula (III) or (IV), the above-mentioned (meth) acrylic ester (V) having a hydroxyalkyl (C1-8) group, or the above-mentioned polyvalent (Meth) acrylic acid esters of alcohols (VI).

[0016]

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[In the formula, R ¹ has the same meaning as above, and R ⁹ and R ¹⁰ are the same or different and each have a hydrogen atom or a linear or branched hydroxy group having 1 to 8 carbon atoms. Represents an alkyl group or an alkenyl group. ]

[0018]

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[Wherein R¹Represents the above-mentioned meaning, and A¹as well as
A^TwoAre the same or different and have the formula-(CH_Two) _n− (N is 2 to 6
Wherein B is -O- or-
CH_Two-Represents a group. As the monomer represented by the general formula (III), (meth)
Acrylamide, N-methyl (meth) acrylamide,
N, N-dimethyl (meth) acrylamide, N, N-di
Ethyl (meth) acrylamide, Nn-propyl (meth
TA) acrylamide, N-isopropyl (meth) acryl
Luamide, Nt-butyl (meth) acrylamide, N
-Isobutyl (meth) acrylamide, N-hydroxy
Propyl (meth) acrylamide and the like;
As the monomer represented by (IV), N- (meth)
Loylmorpholine and the like.

<(C) Anionic monomer> As the anionic monomer of (c), a carboxylic acid monomer having a polymerizable unsaturated group such as (meth) acrylic acid, maleic acid, itaconic acid and / or an acid anhydride thereof Product (when one monomer has two or more carboxyl groups); polymerizable unsaturated groups such as styrenesulfonic acid and 2- (meth) acrylamido-2-alkyl (C1-4) propanesulfonic acid A sulfonic acid monomer having: vinylphosphonic acid, (meth) acryloyloxyalkyl (having 1 to 1 carbon atoms)
4) Phosphoric acid monomers having a polymerizable unsaturated group such as phosphoric acid are exemplified. The anionic group may be neutralized to an arbitrary degree of neutralization by a basic substance. In this case, all or some of the anionic groups in the polymer form a salt.

Here, ammonium ion, trialkylammonium ion having 3 to 54 carbon atoms (for example, trimethylammonium ion, triethylammonium ion), hydroxyalkylammonium ion having 2 to 4 carbon atoms, and total Number 4 ~
8, a dihydroxyalkylammonium ion, a trihydroxyalkylammonium ion having 6 to 12 carbon atoms in total, an alkali metal ion, an alkaline earth metal ion and the like. In the neutralization, the monomer may be neutralized, or the polymer may be neutralized first.

Among them, the above-mentioned carboxylic acid monomer having a polymerizable unsaturated group and / or an acid anhydride thereof (provided that one monomer has two or more carboxyl groups) (VII) And the above-mentioned sulfonic acid monomer (VIII) having a polymerizable unsaturated group.

<Crosslinkable Monomer> Examples of the crosslinkable monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and dipropylene glycol di (meth) acrylate. A) acrylate, polypropylene glycol di (meth) acrylate, 1,2-butylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate (Meth) acrylic of polyhydric alcohol such as glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate Esters; N- methyl-allyl acrylamide, N- vinyl acrylamide, N,
Acrylamides such as N'-methylenebis (meth) acrylamide and bisacrylamideacetic acid; divinyl compounds such as divinylbenzene, divinyl ether and divinylethylene urea; diallyl phthalate, diallyl maleate,
Polyallyl compounds such as diallylamine, triallylamine, triallylammonium salt, allyl etherified pentaerythritol, allyl etherified sucrose having at least two allyl ether units in the molecule; vinyl (meth) acrylate, allyl (meth) ) Acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, 2-hydroxy-3-
(Meth) acrylic acid esters of unsaturated alcohols such as acryloyloxypropyl (meth) acrylate are used.

Among these crosslinking monomers, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, divinylbenzene,
Pentaerythritol triallyl ether and pentaerythritol tetraallyl ether are preferred.

<Other Monomers> Other vinyl monomers copolymerizable with the monomers (a) to (c) constituting the hydrophilic polymer of the present invention include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, neopentyl (meth) acrylate, Cyclopentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-
Ethylhexyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate,
Lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, phenyl (meth) acrylate, toluyl (meth) acrylate, xylyl (meth) acrylate, benzyl (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-butoxy (meth) acrylate, 2-phenoxy (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, and the like (Meth) acrylic acid derivatives and the like.

<Hydrophilic polymer> The hydrophilic polymer used in the present invention is preferably at least one monomer selected from the above (A) to (C), more preferably selected from the above (I) to (VIII). Although one or more kinds of the monomers are essential constituent monomers, other monomers copolymerizable with these monomers can be copolymerized. In all the monomers, the total amount of the monomers (a) to (c) is preferably 70 to 100% by weight, and more preferably 8 to 100% by weight.
5 to 100% by weight.

The hydrophilic polymer of the present invention preferably contains a crosslinkable monomer as a constituent monomer, and the amount of the crosslinkable monomer is preferably 0.005 to 5% by weight based on all monomers, and 0.01 to 5% by weight. ~ 1.0% by weight is more preferred.

Particularly preferred hydrophilic polymers are radically polymerized using at least one kind of the cationic monomer (a), at least one kind of the nonionic monomer (b), and a crosslinkable monomer as essential constituent monomers. The most preferred hydrophilic polymer is at least one cationic monomer selected from (I) to (II) and at least one nonionic monomer selected from (III) to (VI). It is obtained by radical polymerization using one kind and a crosslinkable monomer as essential constituent monomers.

[Production Method of Hydrophilic Polymer] The production method of the hydrophilic polymer of the present invention uses the above-mentioned monomers (A) to (C) and optionally a crosslinkable monomer, preferably a radical polymerization initiator ( For example, the following peroxides, or 2,
Polymerization is carried out in the presence of an azobis compound such as 2-azobisisobutyronitrile) by a reverse-phase polymerization method (for example, a suspension polymerization method, a dispersion polymerization method, an emulsion polymerization method, etc.) using a hydrophobic solvent. After the polymerization reaction, the hydrophobic solvent is distilled off, the hydrophilic solvent is added, and then the hydrophobic solvent is distilled off again.

Specifically, the monomer and the initiator are uniformly mixed in an aqueous solution, and then mixed with a hydrophobic solvent. If necessary, a dispersant is used. Next, the mixture is preliminarily dispersed or emulsified by a high-pressure homogenizer or a line mixer or the like, and then heated under an inert gas such as nitrogen to carry out polymerization.
The polymerization initiation temperature varies depending on the monomer, but is usually 40 to
It is about 90 ° C., and the reaction time is about 1 to 24 hours.

After the polymerization reaction, it is preferable to carry out dehydration in advance in order to facilitate the distillation of the hydrophobic solvent. Thereafter, the reaction vessel is kept preferably at 50 to 100 ° C., and the hydrophobic solvent is distilled off. The point at which distillation cannot be confirmed visually, that is, when the hydrophobic solvent is in the hydrophilic polymer, preferably 1,000 to 20,000 ppm, more preferably
At the time when the concentration becomes 1,000 to 10,000 ppm, a hydrophilic solvent is added, the mixture is uniformly mixed and stirred, and the distillation is further continued preferably for 2 to 40 hours, so that the amount of the hydrophobic solvent is extremely small. After confirming that no longer occurs, the hydrophilic polymer is dried.

The amount of the hydrophobic solvent in the hydrophilic polymer produced by the production method of the present invention is preferably less than 1000 ppm,
0-500 ppm is more preferred.

In the method for producing a hydrophilic polymer according to the present invention, after the polymerization reaction, dehydration and evaporation of the hydrophobic solvent, and then addition of the hydrophilic solvent, the polymer swells, and the hydrophobicity contained in the polymer is increased. It is considered that the ionic solvent can be eluted from the inside and distilled off.

In the production method of the present invention, the dried hydrophilic polymer preferably has a volume average particle diameter of 50 μm or less, more preferably 1 to 30 μm. These were measured with an optical microscope.

In the present invention, in addition to obtaining the hydrophilic polymer as a powder after drying, the hydrophilic polymer can be obtained in a liquid form such as a slurry or a paste for the purpose of improving productivity and handling properties. In this case, a method is also used in which the hydrophobic solvent used during the polymerization reaction is replaced with a component (hereinafter, referred to as a product component) blended in the final product, for example, a fragrance, a plasticizer, a surfactant, or the like. After the polymerization reaction, preferably after dehydration, this product component is added, and the hydrophobic solvent is distilled off to perform substitution. Along with the hydrophilic solvent,
It is more effective to add product components. The conditions for adding the hydrophilic solvent are the same as when the above-mentioned product components are not added.

<Hydrophobic solvent> The hydrophobic solvent used in the present invention has a solubility in 100 g of water at 25 ° C of 1% by weight or less. Specific examples of these hydrophobic solvents include hexane, cyclohexane, heptane, octane, benzene, toluene, xylene, hydrocarbon solvents such as ethylbenzene, carbon tetrachloride, halogenated hydrocarbon solvents such as dichloroethane, isobar and the like. Mineral oil or the like is used. Of these, hydrocarbon solvents are preferably used as the hydrophobic solvent, and hexane and cyclohexane are more preferable. The amount of the solvent is 1 to 1 based on the total amount of the monomers.
It is preferably 20 times by weight, more preferably 1 to 10 times by weight.

<Dispersant> The dispersant used in the method for producing the hydrophilic polymer of the present invention includes sorbitan monostearate, sorbitan monopalmitate, polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxycellulose, carboxymethylcellulose, carboxyethylcellulose, and the like. Sugar ester (trade name, manufactured by Mitsubishi Chemical Foods Corporation), polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene glycol, alkyl trimethyl ammonium chloride, dialkyl dimethyl ammonium chloride, alkyl sulfate, Polyoxyethylene alkyl ether sulfate or the like is used, and one or more of these dispersants may be used in combination. Among these, sorbitan monostearate and sugar ester are preferred from the viewpoint of dispersion stability. These dispersants are preferably used in an amount of 0.3 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of all monomers.

<Polymerization Initiator> As the polymerization initiator used in the production method of the present invention, a radical polymerization initiator is preferably used. For example, a peroxide, an organic or inorganic peracid or a peroxide which is uniformly dissolved in the monomer component is used. Redox compounds obtained by using salts or azobis compounds alone or in combination with a reducing agent are exemplified. Representative examples thereof include t-butyl peroxide, t-amyl peroxide, cumyl peroxide, acetyl peroxide, propionyl peroxide, benzoyl peroxide, benzoyl isobutyryl peroxide, lauryloyl peroxide, t-butyl hydroperoxide, cyclohexyl hydroperoxide, tetralin hydroperoxide, t-butyl peracetate, t-butyl perbenzoate, bis (2-ethylhexyl peroxydicarbonate), 2,2′-azobisiso Butyronitrile, phenylazotriphenylmethane, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (2- (5-methyl-2-
Imidazolin-2-yl) dihydrochloride, sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, a combination of a persulfate with a tertiary amine such as triethylamine, triethanolamine, diethylaniline and the like. . Of these, t-butyl peroxide, benzoyl peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis ( 2-
(5-methyl-2-imidazolin-2-yl) dihydrochloride, sodium persulfate, potassium persulfate, or ammonium persulfate alone, or a persulfate thereof and a third salt such as triethylamine, triethanolamine, or dimethylaniline; Combinations with secondary amines are preferred. The amount of polymerization initiator used increases the degree of polymerization of the main chain polymer chain,
From the viewpoint of reducing the proportion of polymer chains that are not cross-linked to make them less soluble in water or a hydrophobic solvent, increasing the reaction rate of the polymerization reaction, and reducing the amount of residual monomers, all monomers 100
Based on parts by weight, preferably 0.01 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, particularly preferably 0.1 to 5 parts by weight.
1 part by weight.

<Hydrophilic solvent> The hydrophilic solvent used in the production method of the present invention has a solubility parameter δ [(MPa)
^[1/2 ]] is 20 or more. Specifically, it is preferable to use at least one selected from the group consisting of water (47.9), polyhydric alcohol and lower alcohol.
Ethylene glycol (29.
9) dihydric alcohols such as diethylene glycol (24.8), triethylene glycol (21.9), tetraethylene glycol (20.3), polyethylene glycol and propylene glycol (25.8), and glycerin (33.8) And trihydric alcohols such as trimethylolpropane, tetrahydric or higher alcohols such as diglycerin, triglycerin, polyglycerin, pentaerythritol and sorbitol, aldoses such as glucose, and compounds having a sugar skeleton such as sucrose. Examples of lower alcohols include isopropanol (23.5) and butyl alcohol (23.3). These may be used alone or in combination. The values in parentheses indicate the δ value of the solubility parameter.

The molecular weight of the hydrophilic solvent is preferably 1800 or less, more preferably 1000 or less, particularly preferably 50 or less, from the viewpoint of swelling the polymer particles well.
0 or less, most preferably 300 or less.

Of these, water and / or polyhydric alcohol are preferred, water and / or dihydric alcohol are more preferred, and water is particularly preferred. The amount of the hydrophilic solvent to be added is preferably 0.1 to 20 parts by weight, more preferably 1 to 15 parts by weight, particularly preferably 1 to 15 parts by weight, based on 100 parts by weight of the hydrophilic polymer.
5 to 10 parts by weight are preferred.

[0042]

EXAMPLE 1 60 g of dimethylaminoethyl methacrylate diethyl sulfate quaternary product was placed in a 5 LSUS reaction tank as a monomer.
(Effective 90%), N, N-dimethylacrylamide 1
55 g, polyethylene glycol dimethacrylate (E
O14 mol adduct) as initiator, 0.045 g
2-azobis (2-amidinopropane) dihydrochloride
0 g, water 300 g, hexane 1800 as a hydrophobic solvent
g, using 2 g of sugar ester as a dispersant, pre-emulsifying with a line mixer or the like, and then under an inert gas such as nitrogen,
The temperature was raised to 70 ° C., and the polymerization reaction was performed for 3 hours. After the completion of the reaction, 290 g of water was dehydrated at 85 ° C.

Next, as a product component, polyoxyethylene alkyl ether (Emulgen 116; manufactured by Kao) 46
5 g was added, the jacket temperature was set to 80 ° C., and hexane was distilled off under reduced pressure (40 kPa). At the time when the distillation of hexane could not be visually confirmed (the residual hexane amount was 3500 ppm), 58.8 g of the above polyoxyethylene alkyl ether and 10.5 g of water as a hydrophilic solvent were used.
(5% by weight based on the weight of the hydrophilic polymer) was added.

Thereafter, hexane was distilled off again for 3 hours. The amount of residual hexane of the obtained paste-like composition was 4
It was 50 ppm. In addition, the residual hexane amount was extracted with methyl acetate, and measured by gas chromatography (internal standard method).

Example 2 A dimethylaminoethyl methacrylate diethyl sulfate quaternary 131 was added as a monomer to a 5 LSUS reaction tank.
g (effective content 90%), N, N-dimethylacrylamide 88 g, polyethylene glycol dimethacrylate (EO 14 mol adduct) 0.37 g, 2,2-azobis (2-amidinopropane) dihydrochloride 0.1 g as an initiator. Using 4 g, 290 g of water, 1800 g of cyclohexane as a hydrophobic solvent, and 2 g of sugar ester as a dispersant, pre-emulsify with a line mixer or the like, and then raise the temperature to 70 ° C. under an inert gas such as nitrogen and polymerize for 3 hours. The reaction was performed. After the completion of the reaction, 286 g of water was dehydrated at 85 ° C.

Next, the reaction product was heated at 100 ° C. in a fluidized bed drier.
And cyclohexane was distilled off under reduced pressure (40 kPa). When the distillation of cyclohexane cannot be visually confirmed (the amount of residual cyclohexane is 10,000 pp).
m), 15 g of water (7% by weight relative to the weight of the hydrophilic polymer) were added. After that, the temperature of the fluidized bed dryer is
, And the cyclohexane was removed under reduced pressure (40 kPa) for about 6 hours. The amount of residual cyclohexane in the obtained powdery composition was measured by gas chromatography, and as a result, it was 390 ppm.

Example 3 A dimethylaminoethyl methacrylate diethyl sulfate quaternary 100
g (effective content: 90%), N, N-dimethylacrylamide (115 g), polyethylene glycol dimethacrylate (EO 14 mol adduct) (1.0 g), sodium persulfate (0.5 g), water (290 g) as an initiator, and cyclohexane (1) as a hydrophobic solvent. After pre-emulsifying with a line mixer or the like using 800 g of the sugar ester and 2 g of the sugar ester as a dispersing agent, the temperature was raised to 70 ° C. under an inert gas such as nitrogen to carry out a polymerization reaction for 3 hours. After the reaction, 256 g at 85 ° C
Of water was dehydrated.

Next, as a product component, polyoxyethylene alkyl ether (Emulgen 116; manufactured by Kao) 40
8 g was added, the temperature of the jacket was set to 80 ° C., and cyclohexane was distilled off under reduced pressure (40 kPa). At the time when the distillation of cyclohexane could not be visually confirmed (the residual cyclohexane amount was 9,000 ppm), 15 g of triethylene glycol (7% by weight based on the weight of the hydrophilic polymer) was added to 80 g of the above polyoxyethylene alkyl ether as a hydrophilic solvent. Was dissolved and added. Thereafter, the cyclohexane was removed again for about 4 hours. The obtained paste-like composition was extracted, and the amount of residual cyclohexane measured by gas chromatography was 90 ppm.

Comparative Examples 1 to 3 Hydrophilic polymers were produced in the same manner as in Examples 1 to 3, except that no hydrophilic solvent was added. The results are shown in Table 1. If a hydrophilic solvent is not added, it is not preferable because the hydrophobic solvent used during the polymerization reaction is difficult to remove.

Table 1 summarizes the results of Examples 1 to 3 and Comparative Examples 1 to 3.

[0051]

[Table 1]

[0052]

According to the method of the present invention, the hydrophobic solvent can be removed in a short time, and the treatment in a short time not only leads to cost reduction but also fusion of hydrophilic polymers, or Problems such as coloring can be avoided.

Continued on the front page (72) Inventor Motoichi Nakamura 1334, Minato, Wakayama, Wakayama Prefecture Inside Kao Co., Ltd. (72) Inventor Zenhei Meiwa 1334, Minato, Wakayama City, Wakayama Prefecture, Kao Co., Ltd. 1334 Minato, Wakayama City, Wakayama Pref., Kao Corporation Research Institute (72) Inventor Kazutomo Osaki, 1334 Minato, Wakayama City, Wakayama Pref., Kao Corporation Research Center F-term (reference) AL09Q AL62R AL63R AL66R AL75R AM17Q AM19P AM19Q AM21P AM21Q AM23R AM24R AN13R AN14P AN14R AQ08Q AQ12P AQ15Q AQ19P BA02R BA03Q BA03R BA08Q BA08R BA14Q BA16P BA20P BA29P BA31P BA32P BA58P

Claims (4)

[Claims] In a reverse phase polymerization reaction using a hydrophobic solvent, a hydrophilic polymer is obtained by distilling off the hydrophobic solvent after the polymerization reaction, adding the hydrophilic solvent, and distilling off the hydrophobic solvent again. Manufacturing method. 2. The method according to claim 1, wherein the hydrophilic solvent is at least one selected from the group consisting of water, polyhydric alcohols and lower alcohols. 3. The method according to claim 1, wherein the amount of the hydrophilic solvent is 0.1 to 20 parts by weight based on 100 parts by weight of the hydrophilic polymer. 4. A hydrophilic polymer comprising at least one kind of a vinyl monomer containing a cationic group and / or a salt thereof, at least one kind of a vinyl monomer containing a hydrophilic nonionic group,
And a compound obtained by radical polymerization of a crosslinkable vinyl monomer having at least two reactive unsaturated groups in a molecule as an essential constituent monomer.
4. The production method according to any one of Items 3 to 3.