JP2001018222A - Method for drying water absorptive macromolecular polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for drying water-containing water absorptive macromolecular polymer efficiently in a short time, wherein possibility of contamination with impurities such as metals or the like is eliminated. SOLUTION: After previously applying preliminary drying (in reduced pressure at 40-80 deg.C) in a non-vibration state or a weak vibration state of a degree not to give a certain kind of free motion to a water-containing water absorptive macromolecular polymer such as p-alkenylphenol polymer or the like having its repetitive unit represented by the formula: (in the formula, R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom and a C1-C6 alkyl group which may be substituted, R3 represents a C1-C6 alkyl group which may be substituted, and may be the same or different per each repetitive unit.), proper drying (under reduced pressure at 50-140 deg.C) is carried out while vibration for giving a certain kind of free motion is added. For drying, a vibration dryer is used. Further, the vibration dryer having an inner peripheral face of a cylindrical proper body of the vibration dryer coated with ceramics is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drying a water-containing water-absorbing polymer, and more particularly to a method for drying a water-containing water-absorbing polymer using a vibration dryer equipped with a vibration generator.

[0002]

2. Description of the Related Art Alkenylphenol-based polymers, which are one of the water-absorbing high-molecular polymers, are useful in the field of photosensitive materials. In particular, resists having a submicron resolution required for the production of VLSI. As a material, a high-purity alkenylphenol polymer having a structure having a phenolic hydroxyl group or a copolymer with various other monomers and having a small amount of impurities such as metals has been demanded.

As a method for producing an alkenylphenol polymer having a controlled structure or a copolymer with various monomers, for example, JP-A-59-199705, JP-A-4-53809, and JP-A-3-277608. Patent Publication No. JP-A-2003-133873, an anionic polymerization method using a p-alkenylphenol having a phenol hydroxyl group protected by a saturated aliphatic protecting group or a monomer copolymerizable with such a p-alkenylphenol with an organic alkali metal or the like. After polymerization using
A method for production by removing a protecting group is described.

In the above method, a polymer having a controlled structure can be obtained, but an acidic aqueous solution such as hydrochloric acid or sulfuric acid must be used for elimination of the saturated aliphatic protecting group. The acidic component causes a metal portion of the dryer to corrode in a drying step of the high-molecular polymer, and causes impurities such as a metal to be mixed into a product. Therefore, the polymer is crystallized in a large amount of water or the acidic component is removed by washing the crystal well with water, but the alkenylphenol polymer having a large amount of hydroxyl groups in the molecule absorbs water. There is a problem in the drying method because water cannot be sufficiently removed by an operation such as centrifugal separator or filtration, and thus acidic components cannot be completely removed.

On the other hand, as a powder drying apparatus, a stationary type,
Various types of drying apparatuses, such as a rotary type, a gas flow type, a stirring type, a spray type, and a fluidized bed type, are widely known, and have been appropriately used depending on the properties of the powder and the purpose of drying. Conventionally, when drying a water-containing water-absorbing polymer, a rotary type, a stirring type, a spray type, and the like have been used.

[0006]

However, when a rotary drier is used, it must be rotated from the beginning of the drying step and used, so that the surface of the crystal particles becomes firmly covered with the inside of the particles. There is a problem that it is difficult to completely remove the taken in moisture and the like. In addition, in order to completely dry, a step of pulverizing such particles is necessary, and the metal components of the pulverizer may be corroded by the acidic components left in water or the like, and metal impurities may be mixed in,
This has been a particularly serious problem in resist materials that dislike trace amounts of metal impurities.

[0007] Even in the case of a stirring dryer or a spray dryer, mixing of a trace amount of metal due to contact with a metal portion such as a stirring blade or a metal portion such as a nozzle becomes a problem, and a special material is used for such a portion. There is a problem that it needs to be used or a special coating, and is not suitable for industrial large-scale production.

An object of the present invention is to solve the above problems and to provide a method for drying a water-containing water-absorbing polymer which is efficient in a short time and has no risk of contamination of impurities such as metals. .

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies on various types of drying apparatuses. As a result, a powder processing apparatus having a vibration generating apparatus, a so-called vibration drying machine, has been disclosed. It has been found that it is suitable for drying high molecular weight polymers. That is, in the vibration dryer, there is no need to worry about mixing of metal due to contact with the vibration generator because the vibration generator is installed outside, and special coating technology is used because the shape of the drying device body is simple. It has been found that it is superior to other drying devices in that it is not required, and that it can efficiently remove water and the like because the powder mass gradually collapses due to vibration.

However, if a water-containing water-absorbing polymer is dried by applying vibrations from the beginning under heating, the polymer may be slurried once, and if the water is removed from the state, the whole will become large. It has been found that a considerable amount of time may be required until the material becomes a lump and finally collapses into a powder due to vibration.

Therefore, as a result of further study on the drying conditions, it was found that instead of heating and drying while applying vibration from the beginning, water or the like was removed in a state where vibration was stopped or in a state where vibration was weak, and then vibration was applied. The inventors have found that drying can be carried out efficiently by heating and drying, and furthermore, it has been found that by coating the inner surface of the dryer with ceramics, the contamination of impurities such as metals can be completely prevented, and the present invention has been completed.

That is, the present invention provides a method for drying a water-absorbent polymer, which comprises drying the water-absorbent polymer while applying vibration (claim 1). After pre-drying in advance in a non-vibration state or a weak vibration state that does not give a certain free motion,
A method for drying a water-absorbing polymer, wherein the main drying is carried out while applying a vibration giving a certain kind of free motion (claim 2);
The method for drying a water-absorbing polymer according to claim 1 or 2, wherein the water content of the water-absorbing polymer is 50 to 70%. The method for drying a water-absorbent polymer according to claim 3 (claim 4), and the preliminary drying is heating drying under reduced pressure in a temperature range of 40 to 80 ° C. Item 5. A method for drying a water-absorbing polymer according to any one of Items 2 to 4 (Claim 5), and removing water corresponding to a water content of 5 to 30% in predrying. The method for drying a water-absorbent polymer according to any one of claims 2 to 5 (claim 6), and the main drying is heat drying in a temperature range of 50 to 140 ° C under reduced pressure. Item 7 relates to a method for drying a water-absorbing polymer according to any one of Items 2 to 6 (Claim 7).

[0013] The present invention also provides a cylindrical body for drying, an elastic support mechanism for elastically supporting the body, and a vibration generator for causing the body to vibrate to cause a certain free movement of the powder. The method for drying a water-absorbing polymer according to any one of claims 1 to 7, wherein the drying is performed using a vibration dryer having: 9. A method for drying a water-absorbing polymer according to claim 8, wherein a cylindrical body having a ceramic coating applied to an inner peripheral surface thereof is used. 10. The method for drying a water-absorbing polymer according to claim 8 or 9, wherein a cylindrical main body having an uneven portion provided on a peripheral surface thereof is used. In a vertical cylindrical closed system with an inlet at the bottom and an outlet at the bottom Drying process for a water-absorbent high molecular polymer according to any one of claims 8-10, characterized by using a container about (claim 11).

Further, the present invention provides a water-absorbing high-molecular polymer,
The method for drying a water-absorbent polymer according to any one of claims 1 to 11, wherein the polymer is a polymer reprecipitated by mixing a reaction solution after the polymerization reaction with water.
2) or a water-absorbent polymer, wherein the repeating unit is represented by the following general formula (I) (wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, C1 to C6 Or an optionally substituted alkyl group of C1 to C6 and / or C6 to C15
Represents a silyl group substituted with an optionally substituted aryl group, and may be the same or different for each repeating unit, but at least one or more represents a hydrogen atom;
₃ represents a C1 to C6 optionally substituted alkyl group, which may be the same or different for each repeating unit. The present invention relates to a method for drying a water-absorbing polymer according to any one of claims 1 to 12, which is an alkenylphenol polymer represented by the formula (13).

Embedded image

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The water-absorbing polymer used in the present invention may be any polymer as long as it absorbs and swells when it comes into contact with water and has a water-retaining ability. , Alkenylphenols, crosslinked polyacrylates, polyvinyl alcohols, polyacrylamides,
Specific examples of polyoxyethylene-based, starch-based, and cellulose-based high-molecular polymers can be given, and their repeating units are represented by the general formula (I)

Embedded image (Wherein, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents
A hydrogen atom, a C1-C6 optionally substituted alkyl group,
Or a silyl group substituted with a C1 to C6 optionally substituted alkyl group and / or a C6 to C15 optionally substituted aryl group, which may be the same or different for each repeating unit. At least one or more represent a hydrogen atom, and R ₃ represents a C1 to C6 optionally substituted alkyl group, which may be the same or different for each repeating unit. The method is particularly suitable for a method for drying an alkenylphenol polymer represented by the formula (1), especially a p-alkenylphenol polymer.

In the general formula (I), R ₂ is specifically a hydrogen atom, an n-butyl group, a t-butyl group, a t-butyldimethylsilyl group, a triisopropylsilyl group, a phenyldimethylsilyl group, Examples thereof include a -butyldimethylsilylmethyl group and the like, and R ₂ may be the same or different for each repeating unit, but at least one or more represents a hydrogen atom. Specific examples of R ₃ include a methyl group, a butyl group, and an isopropyl group, and R ₃ may be the same or different for each repeating unit.

The alkenylphenol polymer containing a repeating unit represented by the general formula (I) is prepared by a method represented by the general formula (II)

Embedded image (Wherein, R ₄ represents a hydrogen atom or a methyl group, and R ₅ is
A C1-C6 optionally substituted alkyl group, or C1-C6
It represents a C6 of optionally substituted alkyl and / or silyl group substituted with optionally substituted aryl group C6～C15, alkyl R ₆ is optionally substituted in C1~C6 Represents a group. ), After homo- or copolymerizing at least one compound in which the hydroxyl group of the phenol residue is protected, or with one or more compounds in which the hydroxyl group of the phenol residue represented by the general formula (II) is protected, and a conjugated diene. And at least one of a vinyl aromatic compound and an acrylic acid derivative, and then a protective group is eliminated.

The conjugated diene to be copolymerized with the compound represented by the general formula (II) is generally a conjugated diene having 4 to 12 carbon atoms, such as 1,3-butadiene,
Isoprene, 2,3-dimethyl-1,3-butadiene,
1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diene-1,3
-Octadiene, 3-butyl-1,3-octadiene and the like, and these can be used alone or in a mixture of two or more.

The vinyl aromatic compound to be copolymerized with the compound represented by the general formula (II) includes styrene, o
-Methylstyrene, p-methylstyrene, α-methylstyrene, pt-butylstyrene, 1,3-butylstyrene, vinylnaphthalene, divinylbenzene, 1,1-
Examples thereof include diphenylethylene, and these can be used alone or in a mixture of two or more.

The acrylic acid derivative to be copolymerized with the compound represented by the general formula (II) includes methyl (meth) acrylate, ethyl (meth) acrylate, t-butyl (meth) acrylate, ) Adamantyl acrylate and the like can be mentioned, and these can be used alone or in a mixture of two or more.

The polymerization reaction includes ordinary radical polymerization,
Although any of reactions such as cationic polymerization and anionic polymerization can be used, radical polymerization and anionic polymerization are preferable in terms of post-treatment of the reaction and control of the physical properties of the resulting polymer. By these polymerization reactions, a weight average molecular weight of 100
A polymer in the range from 0 to 100,000 is obtained.

The radical polymerization can be carried out by a method such as a suspension polymerization method, a solution polymerization method, or an emulsion polymerization method, but the solution polymerization method is preferred in view of the easiness of the deprotection group reaction in the subsequent step. Examples of the solvent used in the solution polymerization method include, for example, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as dioxane and tetrahydrofuran, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate and butyl acetate. Isoesters, halogenated hydrocarbons such as chloroform, dichloroethane and the like can be exemplified, and these can be used as a single solvent or a mixed solvent of two or more. Known initiators for radical polymerization include, for example, peroxides such as benzoyl peroxide and t-butyl hydroperoxide, and azoisobutyronitrile. Although the temperature and time of the polymerization reaction are not particularly limited,
It is preferable to set the temperature to 0 ° C. for 1 to 72 hours.

In the anionic polymerization, an organic alkali metal compound such as n-butyllithium and sodium naphthalene, or an alkali metal such as sodium is used as a polymerization initiator, usually in an atmosphere of an inert gas such as nitrogen or argon in an organic solvent. At a temperature of -100 to 150C. Examples of the organic solvent include aliphatic hydrocarbons such as n-hexane and n-heptane, alicyclic hydrocarbons such as cyclohexane and cyclopentane, aromatic hydrocarbons such as benzene and toluene, diethyl ether, dioxane, and tetrahydrofuran. Organic solvents such as ethers and the like generally used in anionic polymerization can be exemplified, and these can be used as a single solvent or a mixed solvent of two or more.

A copolymer using the alkenylphenol represented by the general formula (II) and one or more of a conjugated diene, a vinyl aromatic compound, and an acrylic acid derivative is a random copolymer or a block copolymer. It represents coalescence, and the ratio of each monomer used is not particularly limited. Further, in the case of a block copolymer, the bonding form of each block is not particularly limited, and for example, AB type, AB-
A type, ABC type and the like can be exemplified.

In particular, after the completion of the anionic polymerization reaction, the reaction system may be further added with one or more other vinyl monomers, for example, vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine, or acrylonitrile. It is possible. Also, particularly in the anionic polymerization reaction,
When a functional group is introduced at the end of the polymerization chain, after the polymerization reaction is completed, the reaction solution is treated with carbon dioxide or a cyclic ether compound such as ethylene oxide, and further treated with water, hydrochloric acid, methanol, etc. And a hydroxyl group can be introduced.

After homopolymerizing the alkenylphenol represented by the general formula (II), or copolymerizing the alkenylphenol represented by the general formula (II) with at least one of a conjugated diene, a vinyl aromatic compound and an acrylic acid derivative. The step of removing the protecting group after polymerization is performed in the presence of a solvent exemplified in the polymerization reaction or a chlorinated solvent such as carbon tetrachloride, hydrochloric acid, hydrogen chloride gas, sulfuric acid, perchloric acid, phosphoric acid, trifluoroacetic acid. , P-toluenesulfonic acid, hydrobromic acid or the like, and the reaction can be carried out at a temperature from room temperature to 150 ° C, preferably from room temperature to 100 ° C. In this elimination step, any ratio among the protective groups contained in the polymer can be eliminated by appropriately adjusting the reagent used, the amount of the reagent, the reaction temperature, and the reaction time.

After completion of the elimination step, the reaction solvent is distilled off to solidify the water-absorbent polymer, and the resultant is washed with water to remove acidic components and dried. However, the reaction with water or a polymer-insoluble solvent is possible. It is preferable to charge the solution, precipitate the polymer, separate the solution by filtration or centrifugation, and then perform drying.

When water is used in the post-treatment step, the water content is 30 to 90% of the total weight after solid-liquid separation even in the state of solid-liquid separation. In the method of the present invention, the water content after solid-liquid separation is 30 to 90% of the total weight, preferably,
It is suitable for drying a 50-70% water-absorbing polymer. In the present invention, the water content is represented by% by weight of water based on the total weight of the wet water-absorbent high molecular weight polymer which has been solid-liquid separated after the completion of the polymerization reaction. And the organic solvent used in the polymerization reaction.

In the method for drying a water-absorbent polymer according to the present invention, the above-mentioned water-absorbent polymer is dried while applying vibration. Alternatively, pre-drying is performed in advance in a weak vibration state that does not give a certain free movement, and then main drying is performed while applying vibration giving a certain free movement.

For drying while applying vibration, a cylindrical main body, an elastic supporting mechanism for elastically supporting the main body, and a vibration for vibrating the main body to cause a certain free movement of the powder. A vibration dryer having a generator can be used, and more specifically, an exhaust port for discharging gas generated from the water-absorbent polymer powder and heating the powder. Alternatively, a cylindrical main body provided with a jacket for flowing a heat medium for cooling, an elastic support mechanism including four springs and the like for elastically supporting the main body, and the main body vibrated to be in the granular material. A vibration drier or the like including a vibration generator such as a vibration motor for giving a kind of free motion can be used. When a vertical vibration dryer ("VU type" manufactured by Chuo Kakoki Co., Ltd.) is used as such a vibration dryer,
Vibration is applied from the bottom of the main body, and the powder inside the main body moves up and down in the radial direction while rotating in the circumferential direction, and the powder is mixed simultaneously with drying.

The type of installation of the cylindrical main body is not particularly limited to either a horizontal type or a vertical type. As a cylindrical main body, a vertical cylindrical type having an inlet at the upper part and an outlet at the lower part is provided. It is suitable when a closed hollow container is used. In addition, SUS or the like is used as a material for forming the cylindrical main body in consideration of corrosion resistance. However, especially when a trace amount of impurities such as metal is disliked, the inner peripheral surface is coated with glass, fluororesin, or the like. Among them, a ceramic coating is particularly preferable in terms of abrasion resistance and corrosion resistance.

The shape of the inside of the cylindrical body is not particularly limited, but is usually preferably circular or U-shaped. In particular, when unevenness is provided on the inner peripheral surface of the cylindrical shape, the stirring efficiency is dramatically improved, which is preferable. The shape of the unevenness on the inner peripheral surface is not particularly limited, but in the case of a horizontal cylindrical main body, its cross section can be exemplified by a petal pattern or a star shape.

The cylindrical main body is provided with an exhaust port for discharging gas generated from the powder, and a filter for collecting or collecting fine powder entrained in the exhaust during the vibration treatment is attached. I have. Although the shape of this filter is not particularly limited, for example, the filter is configured to be integrally and detachably attached to the main body, and in particular, to removably cover the filter with a filter material on a helically wound support frame, Therefore, a structure that can vibrate the filter integrally with the main body to prevent clogging of the filter medium of the filter can be exemplified. The material used for the filter is not particularly limited, but SUS or the like is preferable in consideration of corrosion resistance.

In the present invention, a certain kind of free motion given by vibration means a free motion of a powder or the like, for example, a floating motion of the powder in the air or a general convection mixing by a simple circulation movement. Motion of a simple rotation trajectory. In particular, when an uneven surface is provided on the inner peripheral surface of the cylindrical main body, each particle uniformly flows to the heat transfer portion because the powder and granular material flows upward and downward in the radial direction while rotating in the circumferential direction in each uneven surface. Drying efficiency can be improved because the particles can come into contact with each other and the chance of contact between the particles increases.

In the present invention, as described above, before the final drying while applying a vibration that gives the water-containing water-absorbent polymer a certain kind of free movement, no vibration or a certain kind of free movement is given. It is preferable to carry out preliminary drying in advance in a state of slight vibration. When the two-stage drying process of the preliminary drying and the main drying is employed, the main drying is performed while applying vibration that gives a certain free motion to the water-absorbent polymer without performing the preliminary drying. On the other hand, among the water and the like confined in the polymer, water in a portion relatively close to the surface is released at a time, so that the polymer does not enter a slurry state. When water is removed from the slurry state, in some cases, water or the like is removed from the entire surface of the slurry, so that the water becomes a strong lump in a state in which water is confined again. It takes a long time to disintegrate by vibration. However, by performing predrying, it is possible to dry efficiently in a short time.

For example, a water-containing water-absorbing high-molecular polymer is charged into a processing device such as a vibration drier,
Alternatively, the vibration frequency of a vibration dryer or the like is suppressed to such a low frequency that the powder does not undergo any kind of free movement, and water is removed under reduced pressure at an internal temperature of the body of 40 to 80 ° C. By this operation, of the water taken in the polymer, a portion of the water which is relatively close to the polymer surface is removed, and the water-absorbing high-molecular polymer becomes a honeycomb-like mass with holes through which the water has escaped. The temperature at which water is removed is in the range of 40 to 80 ° C. in the main body, but it is preferable to remove at as low a temperature as possible. This operation is usually performed until the evaporation of water is no longer visually observed. Although the end point of this operation varies depending on the solid to be dried, the moisture content is 5 to 30%, preferably 5 to 1%.
This operation is preferably terminated when the water equivalent to 5% has been removed.

Further, in order to completely remove the water, the vibration frequency is raised to a frequency at which the powder can freely move in a certain kind, and the main drying is performed under reduced pressure at a temperature in the range of 50 to 140 ° C. in the main body. I do. Due to the vibration that gives a certain kind of free motion, the honeycomb-shaped mass gradually disintegrates into powder, and these powders are made finer by making a simple rotational trajectory, etc., in which overall convective mixing is performed. Even water that has been pulverized and trapped inside the polymer can be completely removed.

[0038]

The present invention will be described in more detail with reference to the following examples, but the technical scope of the present invention is not limited to the examples. Example 1 A reaction liquid of an acid-treated p-butoxystyrene polymer was poured into water to precipitate a polymer (high-molecular polymer), which was filtered by a centrifugal filter, and 560 kg of a p-hydroxystyrene polymer having a water content of 56%. I got The obtained water-containing polymer was washed with a vertical vibration dryer (Chuo Kakoki Co., Ltd. “VU1
60 ”), and the solvent was distilled off at 40 ° C. for 2 hours under reduced pressure without vibration.
The drying was performed at 80 ° C. for 15 hours under reduced pressure at a setting of 00 vibrations / minute. The resulting polymer was powdery and had a water content of 0.2% or less.

Example 2 400 kg of a p-hydroxystyrene polymer having a water content of 56% and obtained in the same manner as in Example 1 were subjected to a vibration under reduced pressure at a frequency of 1500 using the same vertical vibration drier as in Example 1. The drying was performed at 80 ° C. for 24 hours at a vibration / minute setting. The obtained polymer is in a powder form including a part of particles, and has a water content of 0.1.
It was less than 2%.

Example 3 A reaction solution of an acid-treated p-butoxystyrene polymer was poured into water to precipitate a polymer, which was filtered by a centrifugal filter to obtain 6 kg of a p-hydroxystyrene polymer having a water content of 70%. . The obtained water-containing polymer was charged into a vertical vibration dryer ("VU30", manufactured by Chuo Kakoki Co., Ltd., interior ceramic coating), and was not vibrated.
After distilling off the solvent under reduced pressure at 40 ° C. for 30 minutes, the vibration frequency was set to 1500 vibrations / minute, and the pressure was further reduced under reduced pressure at 80 ° C. to 3.7.
Drying was performed for hours. The resulting polymer was powdery, had a water content of 0.5% or less, and had metal impurities of 100 ppb or less.

Example 4 6 kg of a p-hydroxystyrene polymer having a water content of 68% obtained in the same manner as in Example 3 was subjected to a vibration under reduced pressure at a frequency of 1500 using the same vertical vibration drier as in Example 3. vibration/
The drying was performed at 80 ° C. for 5.3 hours. The obtained polymer was in the form of a powder containing some granules, and had a water content of 0.6.
% And metal impurities were 100 ppb or less.

COMPARATIVE EXAMPLE 1 A reaction solution of an acid-treated p-butoxystyrene polymer was poured into water to precipitate a polymer, which was filtered by a centrifugal filter to obtain 60 kg of a p-hydroxystyrene polymer having a water content of 70%. The obtained water-containing polymer was charged into a conical dryer (GL specification, manufactured by Yakko Sangyo Co., Ltd.), and was rotated at a rotation speed of 60 rotations / minute under reduced pressure at 130 ° C.
While drying for 15 hours. It was found that the obtained polymer was a powder containing a large amount of a ball-shaped polymer and could not be dried sufficiently.

[0043]

By using the drying method of the present invention,
Compared with the conventional method, the drying time can be shortened and the drying efficiency can be greatly improved, and it becomes possible to industrially supply polymers of excellent quality without impurities such as metals. .

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Inoshima 12-8 Goi-minamikaigan, Ichihara-shi, Chiba Japan Soda Co., Ltd. Chiba Plant Production Engineering Laboratory (72) Inventor Eiichiro Kobayashi 12- Goi-minamikaigan, Ichihara-shi, Chiba 8 Nippon Soda Co., Ltd. Chiba Plant Production Technology Laboratory F-term (reference) 4F070 AA17 BA10 BB05 BB08 4F201 AA37 AJ06 AJ09 AR06 AR15 AR20 BA04 BC01 BC12 BC15 BN01 BN21 BN23 BN27

Claims (13)

[Claims] 1. A method for drying a water-absorbent polymer, comprising drying the water-absorbent polymer while applying vibration. 2. After pre-drying the water-containing water-absorbent polymer in a non-vibration state or in a weak vibration state that does not give a certain kind of free movement, it is subjected to a vibration giving a certain kind of free movement. A method for drying a water-absorbing high molecular weight polymer, which is characterized by performing main drying. 3. The water-containing water-absorbent polymer has a water content of 30.
The method for drying a water-absorbing polymer according to claim 1 or 2, wherein the amount is from 90 to 90%. 4. A water-absorbing polymer having a water content of 50 to 7
The method for drying a water-absorbing polymer according to claim 3, wherein the amount is 0%. 5. The predrying is a heating drying under a reduced pressure in a temperature range of 40 to 80 ° C.
5. The method for drying a water-absorbing polymer according to any one of the above items 4. 6. The pre-drying, wherein the water content is 5 to 30%.
The water equivalent to is removed.
6. The method for drying a water-absorbing polymer according to any one of the above items 5. 7. The drying according to claim 2, wherein the main drying is heating drying in a temperature range of 50 to 140 ° C. under reduced pressure.
7. The method for drying a water-absorbing polymer according to any one of the above items 6. 8. A drying apparatus comprising: a cylindrical main body; an elastic support mechanism for elastically supporting the main body; and a vibration generator for causing the main body to vibrate to cause a certain free movement of the powder. The method for drying a water-absorbent polymer according to any one of claims 1 to 7, wherein the drying is performed using a vibration drier. 9. The method for drying a water-absorbing polymer according to claim 8, wherein the cylindrical main body is a cylindrical main body having an inner peripheral surface coated with a ceramic coating. 10. The method for drying a water-absorbent polymer according to claim 8, wherein a cylindrical main body having an uneven portion on an inner peripheral surface thereof is used as the cylindrical main body. 11. A vertical cylindrical closed container having an inlet at an upper portion and an outlet at a lower portion as a cylindrical main body. A method for drying a water-absorbing polymer according to the above. 12. The water-absorbing polymer according to claim 1, wherein the water-absorbing polymer is a polymer reprecipitated by mixing a reaction solution after the polymerization reaction with water. Method for drying conductive polymer. 13. A water-absorbent polymer having a repeating unit represented by the general formula (I): (Wherein, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents
A hydrogen atom, a C1-C6 optionally substituted alkyl group,
Or a silyl group substituted with a C1 to C6 optionally substituted alkyl group and / or a C6 to C15 optionally substituted aryl group, which may be the same or different for each repeating unit. At least one or more represent a hydrogen atom, and R ₃ represents a C1 to C6 optionally substituted alkyl group, which may be the same or different for each repeating unit. The method for drying a water-absorbing polymer according to any one of claims 1 to 12, which is an alkenylphenol polymer represented by the following formula: