JPH02115201A - Dispersant for reversed phase suspension polymerization and production of hydrophilic resin therewith - Google Patents

Abstract

PURPOSE:To prepare a polymer useful as a dispersant in reversed phase suspension polymerization to produce a hydrophilic resin, by copolymerizing two specific vinyl monomers. CONSTITUTION:A polymer contg. structural units of formula I (wherein R<1> is H or methyl; X is 2-4C alkylene oxide residue wherein at least 50% is ethylene oxide residue; n is 3-300; and R<2> is H, 1-3C alkyl, etc.) and structural units of formula II (wherein R<3> is H or methyl; and R<4> is 2-4C alkyl, alkenyl, aryl, aralkyl, etc.) in a wt. ratio of said units of formula I to II of (5:95)-(35:65), the sum of said two units accounting for at least 70wt.% of the total polymer, and having a number-average MW of 1000-500,000 (e.g., polyethylene glycol monomethacrylate/dodecyl acrylate copolymer) is produced. The polymer is useful as a dispersant in reversed phase suspension polymerization to produce a hydrophilic resin.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to reverse phase suspension polymerization by adding a water-soluble ethylenically unsaturated monomer or an aqueous solution thereof to a polymerization inert and hydrophobic solvent. The present invention relates to a dispersant used in the process. More specifically, a dispersant for reverse phase suspension polymerization that provides spherical polymer particles with a large average particle size and a stable polymerization system with significantly less deposits on the side walls of a polymerization tank during polymerization, and a dispersant using the same. This invention relates to a method for producing a hydrophilic resin.

[Prior Art] One method of polymerizing a water-soluble ethylenically unsaturated monomer is to suspend and disperse the water-soluble ethylenically unsaturated monomer or its aqueous solution in a hydrophobic organic solvent and polymerize it. A reverse phase suspension polymerization method is known.

When carrying out the reversed-phase suspension polymerization method, a dispersant is usually used in order to stabilize the dispersion of monomers in an organic solvent and also to prevent or reduce aggregation and aggregation of the resulting polymer particles. Moreover, since the particle size of the resulting polymer particles and the stability of the system are greatly influenced by the dispersant, the selection of the dispersant is important.

Conventionally, dispersants used in reverse-phase suspension polymerization of water-soluble ethylenically unsaturated monomers include nonionic agents such as sorbitan fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, and sucrose fatty acid esters. Cellulose derivatives such as surfactants, cellulose ethers, and cellulose esters were known (Japanese Patent Publication No. 54-3).
No. 0710, JP-A-57-158209, etc.).

[Problems to be Solved by the Present Invention] However, when the above-mentioned nonionic surfactant is used, the average particle size of the obtained polymer is 10074 m or less and the particle size distribution is also quite wide. Dust countermeasures were necessary when handling polymers as powder. Additionally, there was a problem in that a large amount of it adhered to the wall surface of the reaction vessel during polymerization.

On the other hand, cellulose ether, cellulose ester, etc.
When Jil [ is used with a bare conductor, the average particle size of the polymer becomes large, approximately 100 to 200 μm, but the solubility of these dispersants in hydrophobic organic solvents is generally low;
Dispersants easily precipitate at room temperature, resulting in lumps of dispersant being mixed into the product, or lumps of dispersant melting during drying of the product, causing the products to fuse together.

The present inventors have conducted repeated research focusing on dispersants in order to solve the above problems, and as a result, they have arrived at the present invention.

Therefore, an object of the present invention is to provide a dispersant for reverse phase suspension polymerization that provides polymer particles with a large average particle size and provides a stable polymerization system with significantly less deposits on the side walls of a polymerization tank during polymerization. It's about getting.

Another object of the present invention is to provide a method for producing a hydrophilic resin in high yield by reverse-phase suspension polymerization, which is free from the problem of powder formation and is easy to handle as a powder.

[Means and Effects for Solving the Problems J The present invention has the general formula % % () (wherein, R1 is hydrogen or a methyl group, and X is 50% with respect to the total ff1ffi of all alkylene oxide residues C2-4 alkylene oxide residue containing ethylene oxide residue in weight% or more, n is 3-300
R2 represents hydrogen, an alkyl group having 1 to 3 carbon atoms, or an organic group having 2 to 5 carbon atoms and an unsaturated bond.

) and at least one structural unit (A) represented by the general formula % () (wherein, R3 is hydrogen or a methyl group, and R4
is an alkyl group, alkenyl group, aryl group, aralkyl group, cyclic alkyl group, cyclic alkenyl group having 4 to 60 carbon atoms or -GOOR5 (wherein R5 is an alkyl group having 4 to 60 carbon atoms)
represents an alkyl group, alkenyl group, aryl group, aralkyl group, cyclic alkyl group or cyclic alkenyl group. )
), the content of the structural unit (A) is 5 to 65% by weight, the content m of the structural unit (B) is 35 to 95% by weight, and the structural unit Reverse-phase suspension polymerization consisting of a polymer (C) in which the total content of (8) and structural unit (8) is in the range of 70% by weight or more, and the average molecular weight is in the range of 1,000 to 500,000. A hydrophilic resin is produced by dispersing a water-soluble ethylenically unsaturated monocypress material or its aqueous solution in a polymerization-inactive hydrophobic organic solvent, and performing reverse phase suspension polymerization with a water-soluble radical polymerization initiator. In this case, the above polymer (C) is used as a dispersant in an unsaturated tl
The present invention relates to a method for producing a hydrophilic resin, characterized in that it is used in a proportion of 0.1 to 10 parts by weight based on 100 parts by weight of the ffi compound.

In the general formula (I) representing the hydrophilic structural unit (8) constituting the polymer (C) in the present invention, + 50% or more of the total alkylene oxide residues are ethylene oxide residues. n, which indicates the total number of moles added of alkylene oxide, is 3 to 3.
300, preferably 3-100. R2 is a terminal group of a polyoxyalkylene chain, such as hydrogen, methyl group, ethyl group, n-propyl group, isopropyl group, vinyl group, methylvinyl group, allyl group, (meth)
Examples include acryloyl group, (iso)crotonoyl group, and dimethylacryloyl group.

Further, R4 in the general formula (II) representing the hydrophobic structural unit (B) is an alkyl group having 4 to 60 carbon atoms, an aryl group,
-COOR5 is an organic group, but -COO
Specific examples of groups other than the group represented by R5 include n
-butyl group, n-hexyl group, 2-ethylhexyl group,
Alkyl groups such as n-octyl group, n-nonyl group, 1,3.5-trimethylhexyl group, decyl group, dodecyl group, hexadecyl group, octadecyl group; M alkenyl group such as nibutenyl group, decenyl group, oleyl group; phenyl group ,
7-aryl groups such as methylphenyl group, octylphenyl group, nonylphenyl group, naphthyl group; 7ralkyl groups such as benzyl group, methylbenzyl group, phenethyl group; cyclic alkyl groups such as cyclohexyl group, dimethylcyclohexyl group, dichloropentenyl group Examples include cyclic alkenyl groups such as. In addition, in the group represented by 1000R5 in R4, as R5, the above R4
Groups similar to the groups other than 100OR5 can be mentioned.

In the present invention, the dispersant that can be used in reverse-phase suspension polymerization is preferably appropriately hydrophilic and soluble in a hydrophobic organic solvent. Therefore, the content of each structural unit constituting the polymer (C) is such that the structural unit (A) is 5 to 5.
65% limbs, preferably 10-40% by weight, structural units (
B) is 35-95% by weight, preferably 60-90% by weight
The structural unit (^) in the polymer (C) is within the range of
) and the structural unit (B) in a range of 70% or more. Polymers outside these ranges have too strong hydrophobicity or hydrophilicity, and the balance between polyoxyalkylene chains and hydrophobic chains cannot be maintained. Therefore, when reverse-phase suspension polymerization is performed using such a polymer,
Problems arise during polymerization, such as the formation of a large amount of aggregates and the formation of a large amount of deposits on the side walls of the polymerization tank.

The molecular darkness of polymer (C) is i, o o o~50
10,000, preferably 3. A range of OOO to 300,000 is desirable.

Polymer (C
) is not particularly limited, and can be produced by any method. For example, ■ a vinyl monomer that produces a structural unit (A) represented by general formula (I) and a vinyl monomer that produces a structural unit (B) represented by general formula (II) by polymerization; , A method of copolymerization in the coexistence of other monomers if necessary, ■ A polymer (C) having 8 structural units (A) and 8 structural units (B) by adding modification such as esterification reaction with alcohol. Examples include methods of modifying the raw material polymer for producing by esterification reaction with alcohol or alkyl halide, addition reaction with alkylene oxide, terminal modification reaction of polyoxyalkylene chains, etc.

In the method (2), the vinyl monomer that produces the hydrophilic structural unit (^) can be, for example, the following polyalkylene glycol derivatives or vinyl esters of alkylene oxide adducts; Contains 50% or more of ethylene oxide units based on the total weight of the oxyalkylene chain, and these terminal alkoxylated monomers are monomers alkoxylated with an alkyl group having 1 to 3 carbon atoms, and the terminal alkenoxylated monomers are monomers alkoxylated with an alkyl group having 1 to 3 carbon atoms. It is a monomer alkenoxylated with 2 to 5 alkenyl groups.

Specific examples of vinyl monomers that produce the structural unit (^) include polyalkylene glycol tacrylates such as polyethylene glycol mono(meth)acrylate, polyethylene glycol-polypropylene glycol 7-(meth)acrylate: methoxypolyethylene glycol (meth)acrylate, methoxypolyethylene glycol-polypropylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol-polybrobylene glycol (meth)acrylate, etc., which are alkoxylated with an alkyl group having 1 to 3 carbon atoms. alkoxypolyalkylene glycol (meth)acrylate; alkenoxypolyalkylene glycol (meth)acrylate alkenoxylated with an alkenyl group having 2 to 5 carbon atoms such as allyloxypolyethylene glycol (meth)acrylate; One or two of these
More than one species can be used.

In addition, in the method (2), examples of vinyl monomers that produce the hydrophobic structural unit (B) include 1-hexene, 1-
octene, isooctene, 1-nonene, 1-decene, 1
- Aliphatic vinyl compounds such as dodecene and vinylcyclohexane; aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, 3-phenyl-1-propene, and vinylnaphthalene; butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-
Octyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, phenyl (meth)acrylate, naphthyl (meth)acrylate, p-methylphenyl (meth)acrylate, octylphenyl (meth)acrylate, nonylphenyl (meth)acrylate, ) acrylate, dinonylphenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (
In addition to meth)acrylate-i-, examples include (meth)acrylates having an alkyl group, alkenyl group, aryl group, aralkyl group, cyclic alkyl group, or cyclic alkenyl group having 4 to 60 carbon atoms. One type or two or more types can be used.

As mentioned above, the ratio of monomers that can be used when producing the polymer (C) by the method (2) is as follows: 5-65
% by weight, preferably 10-40% by weight, structural unit (B)
is 35 to 95% by weight, preferably 60 to 90% by weight, and the total content of structural units (A) and structural units (B) is 70% by weight or more.

Therefore, the monomers that produce structural units other than the structural unit (A) and the structural center (B) after polymerization are limited to a range that does not impair the effects of the present invention, that is, the polymer of the structural units (
C) is used within a range where the content in the structural unit (A) is 30% by weight or less, and the structural unit (B) is used.
) is copolymerized with a monomer that produces a polymer (C
) can also be added with functions such as reactivity. Examples of polymers that produce structural units other than structural unit (A) and structural unit (B) include (meth)acrylic acid (salt), maleic acid (salt), fumar M (MA), and croton. Various unsaturated carboxylic acids (salts) such as acids (salts) and itaconic acid (salts); (meth)allylsulfonic acid (salts), 2-(
meth)acryloylethanesulfonic acid (salt), styrene sulfone 1lf (F), vinyl sulfone @ (salt), 2-
Acrylamide-2=methylpropanesulfonic acid (salt)
Various sulfonic acids (salts) such as (meth)acrylamide, N-methylol (meth)acrylamide, dimethylaminoethyl (meth)acrylamide, etc.
acrylamide dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate,
Various aminoalkyl (meth)acrylates such as dimethylaminopropyl (meth)acrylate or their quaternized products; carbon atoms having 1 to 3 carbon atoms such as methyl (meth)acrylate, ethyl (meth)acrylate, and n-propyl (meth)acrylate; (Meth)acrylic acid ester: An organic group with 3 or less carbon atoms such as ethylene, propylene, isobutyne, vinyl chloride, etc. is attached! ! Vinyl compounds having as a base; examples include acrylonitrile and glycidyl (meth)acrylate, and one or more of these can be used.

Further, in order to produce the polymer (C) by the method (2), the monomer components may be copolymerized by a known method using a polymerization initiator. Copolymerization can be carried out by methods such as polymerization in a solvent or bulk polymerization.

Polymerization in a solvent can be carried out either batchwise or continuously, and the solvents used include, for example, water: lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; benzene, toluene, xylene, cyclohexane, Aromatic, aliphatic or heterocyclic compounds such as n-hexane and dioxane: Ethyl acetate:
Examples include ketone compounds such as acetone and methyl ethyl ketone. Examples of polymerization initiators include persulfates such as ammonium persulfate and sodium persulfate, peroxides such as benzoyl peroxide and lauroyl peroxide, hydroperoxides such as cumene hydroperoxide, and aliphatic compounds such as azobisisobutyronitrile. Azo compounds and the like are used.

At this time, a promoter such as an amine compound can also be used in combination. The polymerization temperature is adjusted appropriately depending on the solvent and polymerization initiator used, but it is usually carried out within the range of 0 to 150°C.

Bulk polymerization uses peroxides such as benzoyl peroxide and lauroyl peroxide, hydroperoxides such as cumene hydroperoxide, and aliphatic azo compounds such as azobisisobutyronitrile as polymerization initiators.
It is carried out within a temperature range of 50-150°C.

In addition, the copolymer obtained by copolymerization in this manner can be used as it is as a dispersant for reverse-phase suspension polymerization of the present invention, but if necessary, the solvent used during polymerization may be separated and removed or other methods may be used. It can also be used in place of other solvents, water, etc.

Furthermore, monobasic substances such as alkali metal or alkaline earth metal hydroxides, oxides, carbonate salts, ammonia, and organic amines may be added as pH adjusters before use.

Next, when producing the polymer (C) by the method of
Using a (meth)acrylic acid polymer as a raw material, alcohol and structural unit (B
) Method by esterification reaction with alcohol or alkyl halide, etc. to produce) Structural unit (B)
Using a (meth)acrylic acid copolymer having as a raw material,
Method by esterification reaction with alcohol to produce structural unit (8). c) A method of introducing the structural unit (A) by adding alkylene oxide to a (meth)acrylic acid-based polymer having the structural unit (B). 2) Structural unit (A) after modification using (meth)acrylic acid ester polymer as raw material
and a method by transesterification with an alcohol to produce structural unit (8).

e) Among the polymers obtained by the method of ■ or the method of (a) to c) of Examples include modification methods such as etherification, (meth)acryloylation, and dimethyl acryloylation.

If the small coalescence fc) is to be reduced to 1q using each method (2), the following conditions must be satisfied. However, the modified polymer (the content of the structural unit (A) in C1 is 5 to 65%)
, preferably 10 to 40% by weight, the content of the structural unit (B) is 35 to 95% by weight, preferably 60 to 90% by weight, and the content of the structural unit (A) and The total content of structural units (B) must be 70% by weight or more, and when introducing structural units (^) by adding alkylene oxide, the ethylene oxide unit in the polyoxyalkylene chain after addition is The content needs to be 50% by weight or more.

To give a specific example of method (a), the (meth)acrylic acid polymer that can be used as a raw material is:
Examples include poly(meth)acrylic acid or copolymers of acrylic acid and methacrylic acid, and these polymers are combined with polyethylene glycol, methoxypolyethylene glycol, methoxypolyethylene glycol-polypropylene glycol, toxypolyethylene glycol, and allyloxy. One or more types of alcohols that can generate structural units (^) such as polyethylene glycol, and structural units (B) that can generate structural units such as butanol, octatool, dodecanol, oleyl alcohol, phenol, nonylphenol, benzyl alcohol, etc. Alcohol 1
Polymer (C) can be obtained by esterification using a weighing scale or for 2 seconds or more using a known method.

To give a specific example of the method described above, the raw material polymers include, for example, (meth)acrylate having an alkyl group having 4 to 60 carbon atoms, and alkylphenyl having an alkyl group having 1 to 10 carbon atoms as a substituent. meth)acrylate, styrene, α-methylstyrene, carbon number 4-6
One or more α-olefins having 0 and (
Examples include copolymers with meth)acrylic acid, and a method of esterifying these copolymers with an alcohol that generates the structural center (A) mentioned in method (a) above using a known method. It will be done.

The raw material polymers that can be used in method 3) include the same copolymers as those mentioned in method 3), and these copolymers are added with ethylene oxide and, if necessary, propylene oxide or butylene oxide. Polymer (C) can be obtained by adding an alkylene oxide such as by a known method.

Method 2) uses polymethyl acrylate and poly(meth)acrylate.
Poly(meth)acrylic acid lower alkyl esters such as meth)ethyl acrylate, or copolymers of methyl acrylate and methyl methacrylate are used as raw material polymers, and these polymers are combined with polyethylene glycol and methoxypolyethylene. One or more alcohols capable of producing structural unit (8) such as glycol, methoxypolyethylene glycol, polypropylene glycol, ■ toxypolyethylene glycol, allyloxypolyethylene glycol, and butanol, octatool, dodecanol, oleyl alcohol, nonylphenol, Polymer (C) is produced by transesterification by a known method using one or more alcohols capable of producing the structural unit (B) such as benzyl alcohol.
can be obtained.

The method (e) is a method in which a polymer having a polyoxyalkylene chain having a terminal group of 10H is used as a raw material, and the terminal is modified. As an example of etherification modification, for example, the raw material polymer is combined with an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms, such as methyl chloride, methyl bromide, ethyl chloride, propyl chloride, allyl chloride, etc. Examples include a method in which Williamson reaction is carried out by a known method using one or more selected from among halogenated hydrocarbons. To carry out modification such as (meth)acryloylation or (iso)crotonoylation, the raw material polymer is combined with one or more types selected from (meth)acrylic acid, (iso)crotonic acid, dimethylacrylic acid, etc. Esterification may be carried out by a known method.

The water-soluble ethylenically unsaturated monomer that can be subjected to reverse phase suspension polymerization using the reverse phase *mi Aigawa dispensing agent of the present invention has a certain degree of solubility in water and the polymer is hydrophilic. There is no particular restriction as long as it becomes a resin, such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid,
Anionic monomers such as 2-(meth)acryloylethanesulfonic acid, 2-(meth)acryloylpropanesulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, etc. j! i; Nonionic single seedlings such as (meth)acrylamide, N-substituted (meth)acrylamide, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate; dimethylaminoethyl (meth)acrylate, diethylamine propyl Examples include cationic monomers such as (meth)acrylate and dimethylaminopropyl (meth)acrylamide, and quaternized products thereof; vinylimidazole, vinylpyridine, vinylpyrrolidone, and the like. Among such water-soluble ethylenically unsaturated monohung bodies, acrylic acid, methacrylic acid, 2-(meth)acryloylethanesulfonic acid, 2-
(Meth)acrylamide-2-methylpropanesulfonic acid and salts thereof, dimethylaminoethyl (meth)acrylate and its quaternized product, and (meth)acrylamide is one or more selected from the group consisting of . In addition, hydrophobic unsaturated monomers such as (meth)acrylic acid alkyl esters, vinyl acetate, and styrene may be mixed to the extent that the water solubility of these water-soluble ethylenically unsaturated monohung bodies is not impaired. It may also be subjected to suspension polymerization.

When an aqueous solution of a water-soluble ethylenically unsaturated single solid is used in the present invention, the monomer concentration in the aqueous monomer solution can be arbitrarily selected over a wide range, but is preferably from 201 tai% or more to a saturated concentration.

Further, when preparing the monomer aqueous solution, a specific thickener may be mixed to adjust the viscosity of the monomer aqueous solution. Thickeners used in this case include, for example, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, carboxymethyl cellulose, polyethylene glycol, polyethylene oxide, polyacrylamide, polyvinyl alcohol, polyacrylic acid, (partially) neutralized polyacrylic acid, Examples include cross-linked polyacrylic acid, neutralized cross-linked polyacrylic acid, dextrin, and sodium alginate. The viscosity of the monomer aqueous solution at that time was measured with a Brookfield rotational viscometer (25°C, 6Qrpm), and was 15 to 5000c.
ps, particularly preferably in the range of 20 to 3000 cps.

By increasing the viscosity of the monomer aqueous solution in this way, the effect that the average particle size of the resin obtained by polymerization becomes larger than when no monomer is used can be obtained.

As the hydrophobic organic solvent that can be used in reverse-phase suspension polymerization in the present invention, those commonly used for reverse-phase suspension polymerization are used, such as n-pentane, n-hexane, n-hebutane, n- Aliphatic hydrocarbons such as octane; alicyclic hydrocarbons that may have a d substituent such as cyclohexane, cyclooctane, methylcyclohexane, and decalin; and n substituents such as benzene, ethylbenzene, toluene, and xylene. For example, aromatic hydrocarbons may be used, and one or a mixture of two or more of these may be used.

Among them, particularly preferred are n-hexane, n-hebutane, cyclohexane, methylcyclohexane, toluene,
It's xylene.

The ratio of the hydrophobic organic solvent to the water-soluble ethylenically unsaturated monomer or its aqueous solution is generally from 1 to 1 from the viewpoint of removing polymerization heat, controlling temperature during polymerization, and stable dispersibility.
A range of 4:1 is suitable.

The polymerization conditions for reverse-phase suspension polymerization using the dispersant for reverse-phase suspension polymerization of the present invention may be carried out in accordance with the usual conditions employed in conventional reverse-phase suspension polymerization. For example, the polymerization temperature can be appropriately selected in the range of usually 20 to 100°C depending on the type of water-soluble ethylenically unsaturated mono-omega substance used and the type of polymerization initiator.

Furthermore, as the water-soluble radical polymerization initiator for reverse-phase suspension polymerization, any one commonly used in the field can be used without restriction, such as potassium persulfate, sodium persulfate, ammonium persulfate, etc. Persulfates: Hydroperoxides such as hydrogen peroxide, t-butyl hydroperoxide, and cumene hydroperoxide; Examples include azo compounds such as 2.2' azobis-2-amidinobrovan dihydrochloride. The use of such a water-soluble radical polymerization initiator is generally preferably in the range of 0.001 to 5 mol % based on the water-soluble ethylenically unsaturated mono-omega substance.

In the present invention, the desired hydrophilic resin can be produced by reverse-phase suspension polymerization of the water-soluble ethylenically unsaturated monohung material using the polymer (C) as a dispersant. .

In the present invention, the amount of polymer (C) used during reverse phase suspension polymerization is preferably 0.1 to 10 parts by weight per 100 parts by weight of the water-soluble ethylenically unsaturated monomer to be subjected to polymerization. ranges from 1 to 5 parts by weight. When the amount of polymer (C) used is less than 0.1 parts by weight, aggregates are likely to be formed during reverse phase suspension polymerization and deposits are likely to be formed on the side walls of the polymerization tank. Furthermore, even if the amount of polymer (C) exceeds 10 folds between uses, it is not only uneconomical but also the particle size distribution of the hydrophilic resin finally obtained becomes wide. Further, a conventionally known dispersant for reverse phase suspension may be used in combination with the polymer (C) as long as the effects of the present invention are not impaired.

The polymerization method may be carried out according to the usual reverse phase suspension polymerization method, for example, a water-soluble ethylenically unsaturated polymer containing a water-soluble radical chassis initiator in a hydrophobic organic solvent containing the polymer (C) as a dispersant. The monomer or its aqueous solution may be added under stirring, dispersed and suspended, and the monomer may be polymerized at a predetermined temperature. The dispersant, polymerization initiator, or the monomer may be added to the polymerization system all at once or in portions.

If reverse phase suspension polymerization is carried out in this way, a suspension in which a hydrophilic resin or its hydrated substance is dispersed in a hydrophobic organic solvent can be obtained, but it is necessary to separate the hydrophilic resin or its hydrated substance from the organic solvent. By drying, the desired spherical hydrophilic resin can be prepared.

The obtained hydrophilic resin depends on the type and amount of polymer (C) used as a dispersant during reverse phase suspension polymerization, the type and amount of water-soluble ethylenically unsaturated monomer used in polymerization, and the amount of polymer (C) used during the polymerization. Although it varies depending on the polymerization conditions such as the concentration of single particles, the average particle size is generally
It is an easy-to-handle powder with a narrow particle size distribution of 00 to 600 μm, preferably 200 to 400 μm.

The hydrophilic resin obtained in the present invention is, for example, a water-soluble resin, a hygroscopic resin, a water-absorbing resin, etc., and is not particularly limited as long as it has an affinity for water.

Water-absorbing resins are cross-linked water-soluble resins that have the ability to absorb water and swell when they come into contact with water. Sometimes, a small amount of a crosslinking agent having two or more polymerizable unsaturated groups or reactive functional groups may be copolymerized. Examples of the crosslinking agent used to obtain the water-absorbing resin include N, N'-
Methylene bis(meth)acrylamide, hemethylol(meth)acrylamide, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, glycerin tri(meth)acrylate, glycerin di(meth)acrylate, ( Polyvalent metal salts of meth)acrylic acid, trimethylolpropane tri(meth)acrylate, triallyl cyanurate, triallylamine, triallyl phosphate, glycidyl (meth)acrylate, ethylene glycol diglycidyl ethyl, glycerin tri(di) Examples include glycidyl ether, polyethylene glycol diglycidyl ether, and the like. Further, two or more of these crosslinking agents may be used in combination.

These crosslinking agents are generally mixed with the water-soluble ethylenically unsaturated monomer in a proportion of about 0.001 to 1.0 mol %, or added to the water-soluble ethylenically unsaturated monomer during or after the polymerization. or may be added to the obtained hydrophilic resin.

[Effects of the Invention] The hydrophilic resin obtained by using the dispersant for reverse-phase suspension polymerization of the present invention is spherical particles with a large average particle size and a narrow particle size distribution that are easy to handle.

Furthermore, according to the present invention, there is significantly less adhesion of small polymer particles to the side walls of the polymerization tank, the stirrer, etc., which was conventionally observed during reverse phase suspension polymerization of water-soluble ethylenically unsaturated monomers ( Therefore, continuous production of hydrophilic resin becomes possible, and productivity can be improved.

[Examples] The present invention will be described in detail below with reference to Examples, but the scope of the present invention is not limited to these Examples.

In addition, unless otherwise specified in the examples, parts represent parts by weight.

Moreover, the average particle diameter of the obtained polymer was determined by the method described below.

That is, JIS standard sieves (20 mesh, 32 mesh, 48 mesh, 60 mesh, 100 mesh, 14 mesh
After the resin powder was sieved using 5 mesh, 200 mesh, and 350 mesh, the residual weight percentage R was plotted on logarithmic probability paper, and the particle size corresponding to R-50% was taken as the average particle size.

Reference Example 1 50 parts of toluene was charged into a flask equipped with a thermometer, a stirrer, two dropping funnels, a gas inlet tube, and a reflux condenser, and the inside of the flask was replaced with nitrogen while stirring, and the mixture was heated to 80 parts under a nitrogen stream.
heated to ℃. Thereafter, while maintaining the same temperature under a nitrogen stream, 30 parts of polyethylene glycol monomethacrylate (containing an average of 23 ethylene oxide units per molecule) as a monomer to produce the structural unit (A),
A monomer mixture solution consisting of 70 parts of dodecyl acrylate and 50 parts of toluene as monomers for forming the structural unit (B) was added dropwise over 120 minutes, and at the same time 0% of azobisisobutyronitrile was added from the other dropping funnel. A polymerization initiator solution consisting of .75 parts and 50 parts of toluene was added dropwise over 180 minutes. After the dropwise addition was completed, the same temperature was further maintained for 60 minutes to complete the polymerization. The polymerization rate of each monomer at this time is
Polyethylene glycol monomethacrylate was 98% as a result of GPC analysis, and dodecyl acrylate was 98% as a result of gas chromatography analysis (in the following reference examples, the monomer that produces the structural unit (A) was analyzed by GPC, and the other monomers were analyzed by GPC). (The polymerization rate was determined by gas chromatographic analysis.), and the average molecule R of the obtained polymer was 100,000 as a result of GPC analysis using polystyrene as a standard (1! The average molecular weight of the obtained polymer was determined by GPC analysis. Thereafter, the dispersant (1) was obtained by distilling off the solvent under reduced pressure.

Reference Example 2 Polymerization was carried out in the same manner as in Reference Example 1, except that the same amount of stearyl acrylate was used as a monomer to form the structural unit (B);
2) is 1!7. The polymerization rate was 98% for polyethylene glycol monomethacrylate and 97% for stearyl acrylate.

Reference Example 3 50 parts of toluene was charged into a reactor similar to Reference Example 1, and the inside of the flask was purged with nitrogen while stirring, and heated to 80° C. under a nitrogen stream. Thereafter, while maintaining the same temperature under a nitrogen stream, 20 parts of methoxypolyethylene glycol, acrylate (containing an average of 20 ethylene oxide units per molecule), M
60 parts of dodecyl acrylate as a monomer that produces the 4-structural unit (B), 1tiff that produces other structural units
20 parts of methyl acrylate and 5 parts of toluene as i-form
A monomer mixed solution consisting of 0 parts was added dropwise over 120 minutes,
Simultaneously, a polymerization initiator solution consisting of 1.0 part of azobisisobutyronitrile and 50 parts of toluene was added dropwise from the other dropping funnel over 180 minutes. After the dropwise addition was completed, the same temperature was further maintained for 60 minutes to complete the polymerization. The polymerization rate of each monomer at this time was 98% for methoxypolyethylene glycol acrylate and 99% for dodecyl acrylate.
, methyl acrylate was 99%, and the average molecule M of the small aggregate obtained was 40,000. Thereafter, the solvent was distilled off under reduced pressure to obtain a dispersant (3).

Reference Example 4 50 parts of toluene was charged into a reactor similar to Reference Example 1, and the inside of the flask was purged with nitrogen while stirring, and heated to 80° C. under a nitrogen stream. Thereafter, while maintaining the same temperature under a nitrogen stream, 30 parts of ethoxypolyethylene glycol methacrylate (containing an average of 4 ethylene oxide units per molecule) as a monomer for forming the structural unit (A), and the structural unit ( A monomer mixed solution consisting of 50 parts of dotecyl acrylate as a monomer for producing B), 20 parts of acrylamide and 50 parts of toluene as monomers for producing other structural units was added dropwise over 120 minutes, and at the same time From one dropping funnel, add 180 parts of a polymerization initiator solution consisting of 1.0 part of azobisisobutyronitrile and 50 parts of toluene.
It was dripped over several minutes.

After the dropwise addition was completed, the same temperature was further maintained for 60 minutes to complete the polymerization. The polymerization rate of each monomer at this time was 99% for ethoxypolyethylene glycol methacrylate, 98% for dodecyl acrylate, and 99% for acrylamide.
The average molecular weight of the polymer obtained was 50,000. Thereafter, the solvent was distilled off under reduced pressure to obtain a dispersant (4).

Reference Example 5 50 parts of toluene was charged into a reactor similar to Reference Example 1, and the inside of the flask was replaced with nitrogen while stirring, and heated to 80° C. under a nitrogen stream. 40 parts of methoxypolyethylene glycol methacrylate (containing an average of 9 ethylene oxide units per molecule) as a monomer to form the structural unit (A) while maintaining the same temperature under a nitrogen stream and the structural unit A monomer mixture consisting of 60 parts of nonylphenyl acrylate and 50 parts of toluene as a monomer to produce (B)) δ solution was added dropwise over 120 minutes, and at the same time, 7zobisisobutyronitrile was added from the other dropping funnel. A polymerization initiator solution consisting of 1.0 part and 50 parts of toluene was added to 180 parts of
It was dripped over several minutes. After the dropwise addition was completed, the same temperature was further maintained for 60 minutes to complete the polymerization. The polymerization rate of each single product at this time was 98% for methoxypolyethylene glycol methacrylate and 97% for nonyl phenyl acrylate.
The average molecular size of the 1q polymer was 70,000. Thereafter, the dispersant (5) was removed by distillation of the solvent under reduced pressure.
is.

Reference Example 6 50 parts of toluene was charged into a reactor similar to Reference Example 1, the inside of the flask was replaced with nitrogen while stirring, and the temperature was heated to 100°C under a nitrogen stream.
heated to. Thereafter, while maintaining the same temperature under a nitrogen stream, 40 parts of methoxypolyethylene glycol methacrylate (containing an average of 9 ethylene oxide units per molecule) as a monomer for forming the structural center (Δ), and the structural unit Monomer h1 consisting of 60 parts of nonylphenyl acrylate and 50 parts of toluene as a monomer for producing (8)
The mixed solution was added dropwise over 120 minutes, and at the same time from the other dropping funnel, azobisisobutyroni 1 to 1.0
A polymerization initiator solution consisting of 50 parts of toluene and 18 parts of
It was added dropwise over 0 minutes. After the dropwise addition was completed, the same temperature was further maintained for 60 minutes to complete the polymerization. The polymerization rate of each single product at this time was such that the average molecular weight of the methoxypolymer was 20,000. Thereafter, the solvent was distilled off under reduced pressure to remove the dispersant (
6) was obtained.

Reference Example 7 50 parts of toluene was charged into a flask equipped with a thermometer, a stirrer, three dropping funnels, a gas inlet tube, and a reflux condenser, and while stirring, 5 parts of nitrogen was exchanged in the flask, and 10 parts of nitrogen was exchanged under a nitrogen stream.
Heated to 0°C. Thereafter, while maintaining the same temperature under a nitrogen stream, 40 parts of an α-olefin having 30 to 60 carbon atoms as a monomer to form the structural unit (B), and 40 parts of an α-olefin to form other m units as a monomer to form the structural unit (B). An aqueous monomer solution consisting of 20 parts of anhydrous maleic R and 50 parts of toluene was added dropwise over 120 minutes, and at the same time the structural units (^) were added from two other dropping funnels.
) was added over 180 minutes to a monomer solution consisting of 40 parts of polyethylene glycol monomethacrylate (containing an average of 23 ethylene oxide units per molecule) and 50 parts of toluene. A polymerization initiator solution consisting of 3 parts of ronitrile and 50 parts of toluene was added dropwise over 240 minutes. After the dropwise addition was completed, the same temperature was further maintained for 120 minutes to complete the polymerization. At this time, the polymerization rate of each car m body was 98% for polyethylene glycol monomethacrylate and 9% for α-olefin.
0%, maleic anhydride was 92%, and the average molecular weight of the obtained polymer was 10,000. Thereafter, the solvent was distilled off under reduced pressure to obtain the dispersant (7).

Example 1 1.0 l of cyclohexane was placed in 21 four-separable flasks equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen gas inlet tube, and a dropping funnel, and 1.0 l of cyclohexane was added to the dispersant (1.0 l) obtained in Reference Example 1. ) was added and dissolved, and nitrogen gas was blown in to drive out the dissolved oxygen.

In another flask, 84.6 g of sodium acrylate and 21.6 q of acrylic M were dissolved in 248 g of ion-exchanged water to prepare an aqueous monomer solution having a monomer depth of 30% by weight.

After 0.15 g of potassium persulfate was added to and dissolved in this monomer aqueous solution, nitrogen gas was blown into the monomer aqueous solution to drive out oxygen dissolved in the aqueous solution.

Next, the aqueous monomer solution in this flask was added to the separable flask and dispersed by stirring at 23 Orpm. Thereafter, the bath temperature was raised to 60° C. to initiate the polymerization reaction, and then maintained at this temperature for 2 hours to complete the polymerization. Thereafter, the polymer was separated from the solvent by suction filtration, and dried under reduced pressure at 80° C. to obtain a granular polymer.

The average particle size of the obtained polymer was 300 μm, and the amount of deposits m on the stirrer and separable flask after polymerization was 0.
．． It was 3 ().

Example 2 Polymerization and drying were carried out under the same conditions as in Example 1 except that the dispersant (2) in Reference Example 2 was used as the dispersant.

The average particle size of the obtained polymer was 280 μm, and the amount of deposits on the stirrer and separable flask after polymerization was 0.
．． It was 2 a.

Example 3 Polymerization and drying were carried out under the same conditions as in Example 1 except that the dispersant (3) obtained in Reference Example 3 was used as the dispersant.

The average particle size of the obtained polymer was 350 μm, and there were no particles adhering to the stirrer or separable flask after the polymerization was completed.
．． It was 60.

Example 4 Cyclohexane 1 and Ol were placed in the same reaction vessel as in Example 1, and 2.5 g of the dispersant (4) obtained in Reference Example 4 was added and dissolved, and then nitrogen gas was blown in to remove dissolved oxygen. kicked out.

In a separate flask, dissolve 84.6 g of sodium acrylic liquor, 21.6 g of acrylic acid, and 0.02 g of methylene bisacrylamide in 196 el of ion-exchanged water to prepare a monomer aqueous solution with a monomer concentration of 35% by weight. After adding 0.150 g of potassium persulfate to this monomer aqueous solution and dissolving it, nitrogen gas was blown in to drive out oxygen dissolved in the aqueous solution.

Next, the aqueous monomer solution in this flask was added to the separable flask and dispersed by stirring at 23 Orpm. Thereafter, the bath temperature was raised to 60° C. to initiate the polymerization reaction, and then maintained at this temperature for 2 hours to complete the polymerization. Thereafter, the polymer was separated from the solvent by suction filtration, and dried under reduced pressure at 80° C. to obtain a granular polymer.

The average particle size of the 1q polymer obtained was 260 μm, and the amount of deposits on the stirrer and separable flask after completion of polymerization was 0.15 g.

Example 5 Polymerization and drying were carried out under the same conditions as in Example 4, except that the dispersant (5) used in Reference Example 5 was used as the dispersant.
.

The average particle size of the obtained polymer was 230 μm, and the amount of adhesion to the stirrer and separable flask after the polymerization was 0.1J.

Example 6 Cyclohexane 1 and Ol were placed in the same reaction vessel as in Example 1, and 2.5 g of the dispersant (6) obtained in Reference Example 6 was added and dissolved, and then nitrogen gas was blown in to remove dissolved oxygen. kicked out.

In a separate flask, 84.6 g of sodium acrylate, 21.6 g of acrylic acid (J, 0 methylenebisacrylamide)
．． 02 (+) and 0.5c+ of hydroxyethyl cellulose (Daicel Chemical Industries ■VEP~850) were dissolved in 196.6!J of ion-exchanged water to prepare a 35% by weight monomer aqueous solution for the monomer part. The viscosity of the aqueous solution is 40
It was cps. This monomer aqueous solution contains 0 potassium persulfate.
．． 1! After M was added and dissolved, nitrogen gas was blown into the aqueous solution to drive out oxygen dissolved in the aqueous solution.

Next, the monomer aqueous solution in this flask was added to the above-mentioned bulk flask, and dispersed by Iff ff at 23 Orpm. Thereafter, the bath temperature was raised to 6°C to initiate the polymerization reaction, and this temperature was then maintained for 2 hours to complete the polymerization. Thereafter, the polymer was separated from the solvent by suction filtration, and dried under reduced pressure at 80° C. to obtain a granular polymer.

The average particle diameter of the iq polymerized product was 480 μm, and the amount of deposits on the stirrer and separable flask after completion of polymerization was 0.2 a.

Example 7 1.0 l of cyclohexane was placed in the same reaction vessel as in Example 1, 2.5 g of the dispersant (4) prepared in Reference Example 4 was added and dissolved, and then nitrogen gas was blown in to dissolve it. '7 Oxygen was expelled.

In a separate flask, 125 g of acrylamide was dissolved in 232.14 ++ of ion-exchanged water to prepare an aqueous monomer solution having a monomer concentration of 35% by weight. This monomer aqueous solution contains 2.2'
-7zobis-2-amidinopropane hydrochloride 0.2 (
After adding and dissolving the aqueous solution, nitrogen gas was blown in to drive out the oxygen dissolved in the aqueous solution.

Next, the monomer aqueous solution in this flask was added to the above-mentioned bulk flask and dispersed by stirring at 23 Orpm. Thereafter, the bath temperature was raised to 60° C. to initiate the polymerization reaction, and then maintained at this temperature for 2 hours to complete the polymerization. Thereafter, the polymer was separated from the solvent by suction filtration, and dried under reduced pressure at 80° C. to obtain a granular polymer.

1! The average particle size of the polymer obtained was 200 μm, and the amount of deposits on the stirrer and the flexible flask after the polymerization was 0.32 μm.

Actual flow example 8 In a reaction vessel similar to Example 1, 1. The dispersant (2) prepared in Reference Example 2 was added in an amount of 3.59 g and dissolved therein, and then nitrogen gas was blown in to drive out the dissolved oxygen.

Dimethylaminoedyl methacrylate + in another flask
-87,9 () and acrylic Pt 37.7 (188.4 liters of ion-exchanged water!) to prepare a monomer aqueous solution with a monomer depth of 4% by weight. .2'-azobis-2-amidinopropane hydrochloride 0
．． After adding and dissolving 43!7, nitrogen gas was blown into the aqueous solution to drive out oxygen dissolved in the aqueous solution.

Next, the aqueous monomer solution in this flask was added to the separable flask and dispersed by stirring at 230 rpffi. Thereafter, the bath temperature was raised to 60° C. to initiate the polymerization reaction, and then maintained at this temperature for 2 hours to complete the polymerization. Thereafter, the polymer was separated from the solvent by suction filtration, and dried under reduced pressure at 80° C. to obtain a granular polymer.

The average particle size of the obtained polymer was 215 μm, and the amount of deposits on the stirrer and separable flask after polymerization was 0.
．． It was 29.

Example 9 1.01 g of cyclohexane was placed in the same reaction vessel as in Example 1, 3.5 g of the dispersant (7) obtained in Reference Example 7 was added and dissolved, and then nitrogen gas was blown in to remove dissolved oxygen. kicked out.

In a separate flask, sodium 2-methacryloylethanesulfonate 90.6Ω, sodium acrylate 12.6Ω
g, acrylic 13.3! IJ and 0.02a of N,N'-methylenebisacrylamide in 198g of ion-exchanged water
to prepare an aqueous monomer solution having a mono-ω-isomer concentration of 35% by weight. Add 2.2'-azobis-2- to this monomer aqueous solution.
After adding and dissolving 0.430 of amidinopropane hydrochloride, nitrogen gas was blown into the solution to drive out oxygen dissolved in the aqueous solution.

Next, the aqueous monomer solution in this flask was added to the separable flask and dispersed by stirring at 23 Orpm. Thereafter, the bath temperature was raised to 60° C. to initiate the polymerization reaction, and then maintained at this temperature for 2 hours to complete the polymerization. Thereafter, the polymer was separated from the solvent by suction filtration and dried under reduced pressure at 80°C to obtain a granular polymer.

The average particle size of the obtained polymer was 215 μm, and the amount of deposits on the stirrer and separable flask after polymerization was 0.
．． It was 2g.

Comparative Example 1 Polymerization and drying were carried out under the same conditions as in Example 1 except that 3.5 g of sorbitan monostearate was used as a dispersant.

The average particle size of the obtained polymer was 80 μm, and the amount of deposits on the stirrer and separable flask after polymerization was 2.
It was a lot at 2g.

Comparative Example 2 Example 1 except that ethylcellulose was used as a dispersant.
Polymerization and drying were carried out under the same conditions as above.

The average particle size of the obtained polymer was 220 μm, and the amount of deposits ω on the stirrer and separable flask after polymerization was 5.
．． The amount was as much as 5 g, and ethyl cellulose was found to be mixed into the polymer.

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (However, in the formula, R^1 is hydrogen or a methyl group, and
contains 50% by weight or more of ethylene oxide residues based on the total weight of all alkylene oxide residues and has 2 carbon atoms
~4 alkylene oxide residue, n is a number from 3 to 300, and R^2 represents hydrogen, an alkyl group having 1 to 3 carbon atoms, or an organic group having an unsaturated bond having 2 to 5 carbon atoms. ) with at least one structural unit (A) represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (II) {However, in the formula, R^3 is hydrogen or a methyl group, and R
^4 is an alkyl group having 4 to 60 carbon atoms, alkenyl group, aryl group, aralkyl group, cyclic alkyl group, cyclic alkenyl group, or -COOR^5 (however, R^5 is an alkyl group having 4 to 60 carbon atoms, alkenyl group, aryl group, aralkyl group,
Indicates a cyclic alkyl group or a cyclic alkenyl group. )} structural unit (
B), the content of the structural unit (A) is 5 to 65% by weight, and the content of the structural unit (B) is 35% by weight.
-95% by weight, a total content of structural units (A) and structural units (B) in the range of 70% by weight or more, and an average molecular weight in the range of 1,000 to 500,000 (C) A dispersant for reverse phase suspension polymerization. 2. When producing a hydrophilic resin by dispersing a water-soluble ethylenically unsaturated monomer or its aqueous solution in a polymerization-inactive hydrophobic organic solvent and performing reverse phase suspension polymerization with a water-soluble radical polymerization initiator, The polymer according to claim 1 (C
) in a proportion ranging from 0.1 to 10 parts by weight per 100 parts by weight of the unsaturated monomer. 3. The manufacturing method according to claim 2, wherein the hydrophilic resin is a water-absorbing resin obtained by polymerizing a water-soluble ethylenically unsaturated monomer or an aqueous solution thereof in the presence of a crosslinking agent.